The current global framework, with growing oil price instability, limited oil and gas resources and the Kyoto Protocol environmental requirements, calls for continued improvements in the usage of renewable energy resources, including solar. During the last decades, interest in solar energy solutions has increased because the potential of solar energy has become apparent.
Even though solar radiation is a source of high temperature and energy at the origin, sun-earth geometrical constraints lead to a dramatic dilution of flux and to irradiance available for terrestrial of about 1 kW/m2 and consequently, to a supply of low temperature to the thermal fluid. It is therefore essential requisite for solar thermal power plants to make use of optical concentration devices that enable the thermal conversion of high solar flux and with relatively little heat loss. Typical concentration devices for solar radiation are: parabolic troughs, linear Fresnel reflectors, parabolic dishes, and power tower (or central receiver solar systems—CRS). Solar thermal power based on such concentrators is called Concentrated Solar thermal Power (CSP). The most common solar thermal power systems are parabolic trough and power tower.
A parabolic trough power plant is basically composed of three main elements: the solar system, the steam generator and the power block. The solar system comprises parabolic trough collectors' field and the oil (i.e. heat transfer fluid) circuit. At the solar field, solar radiation is collected and converted into thermal energy as the temperature of the oil circulating through the receivers, increases. Once heated at the solar field, the oil is pumped and conveyed to a steam generator, to produce high pressure/temperature steam. The steam is then used to produce power similarly to conventional steam power plants (e.g. Rankine cycle).
In power towers (or CRS), incident sunrays are reflected from large mirror collectors (heliostats), which track the apparent sun movement and concentrate the energy flux onto a solar receiver, where energy is transferred to thermal fluid. This fluid can also be direct steam. The thermal energy conversion into electricity is quite similar to fossil-fueled power plants.
Both parabolic trough and CRS are proven technology. However, their cost is not yet competitive with conventional alternatives unless subsidized. Therefore, it is yet desired to improve the existing plants cost effectiveness.
U.S. Pat. No. 5,444,972 describes a hybrid power plant driven by hydrocarbon fuels and solar energy. The solar system is CRS and the power block is condensing steam cycle (Rankine). Exhaust gas of a turbine and fuel added burner backup the solar field in generating the steam. Sensible heat storage and a receiver thermal shield are described in this publication as being optional features.
GB 2449181 discloses a combined gas/steam (or Brayton/Rankine) hybrid power plant. The heat input to the gas cycle partially depends on solar heating of air supplied to an initial combustion stage from a compressor of the gas turbine engine. Simplification and/or greater responsiveness of the gas turbine engine's fuel control system is achieved by providing the power plant with separate combustion stages being coupled to an associated turbine. Compensation for variations in insolation is achieved by controlling fuel flow to the initial combustion stage while compensation for variations in electrical load is achieved by controlling fuel flow to a subsequent combustion stage. The final turbine stage drives a generator, and the exhaust from the final turbine stage is passed through a heat recovery steam generator to raise further power in a steam turbine that also drives a generator. The second combustion stage, including a superheater, may be located in the steam cycle part of the combined cycle to further heat the steam before entry to the steam turbine. Concentrated solar energy may heat a heat transfer fluid, e.g. a molten salt, for intermediate heat transfer and heat storage.
U.S. Pat. No. 5,417,052 describes a hybrid, combined cycle power plant driven by CRS and natural gas. The combined cycle is Brayton/Rankine. The CRS heat transfer fluid (HTF) is molten salt. The molten salt preheats the air leaving the gas cycle compressor. The exhaust gases from the gas cycle drive a steam cycle for additional energy production.
US 2008127647 discloses a method for oversizing the Rankine power block with respect to the topping cycle block in combined cycles where the bottoming cycle is Rankine. The method describes the production of the additional steam in the Rankine plant by solar energy. The method is applicable in plants that are equipped with an oversized heat recovery steam generator (HRSG) and steam turbine system that is coordinated with duct burners or other means for additional steam generation.
US 20060260314 discloses an integration between a combined cycle power plant and a solar Rankine power plant. Relatively high temperature, low pressure reheat from the combined cycle power generation system can be used, through, for example, a superheater, to raise the temperature and pressure of a working fluid in a solar Rankine power generation system. The resulting integrated system has enhanced efficiencies as compared with stand-alone systems.
Most of the solar thermal power today is produced by parabolic trough technology. Typically, parabolic trough plants consist of large fields of parabolic trough collectors, a heat transfer fluid/steam generation system, a Rankine steam turbine/generator cycle, and optional thermal storage and/or fossil-fired backup system(s). The solar field is modular in nature and comprises many parallel rows of single-axis-tracking parabolic trough solar collectors, normally aligned on north-south horizontal axis. Each solar collector has a parabolic shaped reflector that focuses the sun's direct beam radiation on a linear receiver located at the parabola focal axis. The collectors track the sun from east to west during the day. A heat transfer fluid (hereinafter “HTF”) is heated up to about 400° C. while being circulated through the receiver and returns to a series of heat exchangers (hereinafter “HE”) in the power block where the solar heat absorbed by the HTF (typically synthetic oil) is extracted to generate high pressure superheated steam (e.g. 100 bar, 371° C.). The superheated steam is then fed to a conventional reheat steam turbine/generator (condensing turbine) to produce electricity. The expanded steam from the turbine is condensed in a saturated condenser and returned to the HE via feed-water pumps to be transformed back into steam. Wet cooling towers or sea water supply cold water to the condenser. After passing through the power block, the cooled HTF is re-circulated through the solar field.
The parabolic trough approach is currently the most proven and lowest cost large-scale solar power technology available today as described by H. Price et al. in “Advances in Parabolic Trough Solar Power Technology”, Journal of Solar Energy Engineering V. 124, Issue 2, pp. 109-125, May 2002. However, the cost of parabolic trough power is not yet competitive with conventional alternatives unless subsidized (typical installation cost for 50 MW plants is in the range of 4-6 $/W). One of the reasons is that the standard condensing steam power block described above has several drawbacks that highly limit the overall plant cost effectiveness and deployment. Some of these drawbacks are the following:
1) Water Cooled Condenser:
The condensers in steam power units are typically water cooled type where the water are typically cooled by a wet cooling tower (WCT). Air cooled condensers (dry cooling towers—DCT) are inferior because they increase the steam condensation temperature, and the steam condensing cycle efficiency is very sensitive to that temperature. In addition, DCT are more expensive than WCT. Consequently, solar thermal power plants are installed mostly in locations where water is available, rather than in desert and arid areas where solar radiation levels are typically the highest.
2) Condensing Turbine:
Condensing steam turbines for solar plants, typically designed to generate 50-80 MW, have a very unique design which creates low market availability (up to two years of manufacturing lead time). This might introduce a significant bottleneck to projects time tables because the other components lead times are substantially lower (typically less than one year). Another downside of the condensing turbine is the performance penalty when scaling down. For instance, the difference between 60 MW and 5 MW turbine shaft (isentropic) efficiencies is about 6%. The performance penalty increase both the specific required collection area (m2/W) and the electricity specific cost ($/W). This is critical because the small and medium size plants (5-20 MW) market is currently growing rapidly.
3) Operation Time (Capacity Factor):
During day time, the solar radiation intensity varies. In a clear sky day, the radiation level increases gradually during the morning and reaches maximal level around noon while from afternoon to sunset, the insolation declines. In a standard (condensing turbine) power block, steam is fed into the turbine only when reaching a certain desired temperature, typically around 370° C. and an initial flow rate. Operating the turbine with substantially lower steam temperatures is eluded because that would expose the turbine blades to high levels of moisture which is destructive. Therefore, the standard routine in such a solar plant would be to wait until the heat transfer fluid heats up to about 390° C. so the desired steam top temperature can be achieved. However, this oil temperature can be obtained only when reaching a minimum insolation level, say 400 W/m2. Thus, during early mornings and late afternoons' periods the solar plant cannot produce power. The result is shorter plant operation time (or lower capacity factor) and of course, higher electricity cost.
4) Working Fluid:
Steam condensation increases the power block complexity and cost due to the following two reasons:
a) The saturated steam specific volume is very high (for example, 12 m3/kg at 50° C.), requiring large size condensing unit.
b) The saturated pressure of steam at typical condensing temperatures is much below atmospheric (for instance, at 35° C. the pressure is 0.056 bar). Consequently, the condenser must always be maintained under deep vacuum and free of oxygen. Addressing these constrains, increases the plant O&M costs.
Other power cycles are also described in the literature.
For example, A. I. Kalina in “Combined-cycle system with novel bottoming cycle”, Journal of Engineering for Gas Turbines and Power v. 106, pp. 737-741 (1984) describe a thermodynamic cycle that is designed to replace the Rankine cycle as a bottoming cycle for a combined-cycle energy system as well as for generating electricity by using low-temperature heat sources.
P. A. Lobos and E. D. Rogdakis described in their publication “A Kalina power cycle driven by renewable energy sources”, Energy, Jan. 31, 2009, a Kalina cycle using low-temperature heat sources to produce power. The main heat source of the cycle is provided by flat solar collectors. In addition, an external heat source is connected to the cycle, providing 5% up to 10% of the total thermal energy used in the cycle. The cycle operates at low pressure levels (0.2-4.5 bar) and low maximum temperature (130° C.). For given conditions, an optimum range of vapor mass fractions and operating pressures can be identified that result in optimum cycle performance. Simple equations have been derived that link the operational parameters with the independent variables as well as with the cycle efficiency.
The present invention seeks to provide a solution that eliminates the major part of the above problems while increasing the solar plant efficiency.


In order to restore or assume the function of a damaged or lacking tissue or organ the transplantation of natural tissues or organs from another donor or, if possible, the concerned individual himself is an established practice that has long been known. Due to the constant lack of suitable donor tissues and donor organs and other disadvantages of natural tissue, e.g., rejection reactions and the risk of the transfer of diseases from the donor to the recipient, many efforts are being directed to the production of artificial tissues and organs as alternatives.
A customary procedure for this is the provision of a carrier or matrix structure from material compatible with the body that is colonized with differentiated cells of the target tissue, and the cultivation of the cells in vitro until a tissue-like cell structure has been produced. The differentiated cells are obtained either from cultures of explanted tissue samples or from stem cells that had been stimulated to differentiate. The use of stem cells permits a more rapid production of larger amounts of the desired cells in many instances. Traditionally, pure cell populations of a certain type are produced. Most of the in vitro organs or in vitro tissues known in the state of the art are disadvantageous in as far as that they do not have or do not develop the tissue structure that corresponds to the morphological constitution of the native tissue or organ even after implantation and a fairly long residence time in the body. This applies as a rule even when the carrier matrix had been colonized with several different populations of tissue-typical cells.
Another approach for treating degenerative diseases or damage to tissues and organs using stem cells consists in implanting the stem cells and/or differentiated cells derived from them directly into the damaged tissue/organ in order to proliferate there and result in a regeneration of the damaged tissue/organ. In this instance too the implantation or regeneration of a certain cell type traditionally is in the foreground. The problem is, however, that in very many degeneration phenomena or damages to various organs a plurality of cells is always involved so that, e.g., in the skin keratinocytes, epithelial cells and blood vessels are also affected in addition to fibroblasts. In the case of nerve damage even glia cells often have to be replaced too and muscle damage often means destruction of the accompanying nerves.


This application is based upon and claims the benefits of priority from the prior Japanese Patent Application No. 2001-100402 filed on Mar. 30, 2001; the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an infrared sensor and a manufacturing method thereof and, in particular, to a pixel construction of an uncooled infrared sensor and a manufacturing method thereof.
2. Related Art
Infrared image sensing is characterized in its ability to pick up images at night as well as during the daytime and its higher transmittance to smoke and fog than visible radiation. Being capable of acquiring temperature information of an object to be sensed, infrared image sensors are adaptable to a variety of applications, such as a monitor camera and a fire detection camera, besides the field of defense.
In recent years, extensive studies have been made on xe2x80x9cuncooled infrared solid-state imaging elementsxe2x80x9d which eliminate the need for the cooling mechanism to allow for a low-temperature operation, which is the most critical shortcoming of a quantum type infrared solid-state imaging element or a leading conventional type. In such an uncooled infrared solid-state imaging device, an incident infrared ray having a wavelength of 10 xcexcm or so is converted into heat by an absorber and then the temperature change caused by this small amount of heat at a heat sensing portion is converted into an electric signal by thermoelectric conversion means of any kind, before reading out the electric signal to obtain infrared image information.
There are three ways of improving the sensitivity of such an uncooled infrared sensor, generally classified as follows:
The first method is to improve the ratio of an infrared power incident to an infrared detection portion, dP, to a temperature change of an object, dTs, namely dP/dTs. This method achieves improvement mainly by optical systems, which corresponds to enlargement of an infrared lens aperture, application of an antireflective coating, use of a lens material of low optical absorption, increase of an infrared absorptivity at an infrared detection portion or increase of an infrared absorption area. In accordance with the recent multiplication of pixels for an uncooled infrared sensor, the size of a unit pixel has mainly come to as small as 40 xcexcmxc3x9740 xcexcm and, among the items mentioned above, the increase of an infrared absorption area at an infrared detection portion has remained a relatively critical problem to be solved. However, a report has been published that an infrared absorption area can be increased up to 90% of a pixel area by stacking an infrared absorption layer on top of the pixel (Tomohiro Ishikawa, et al., Proc. SPIE Vol. 3698, p. 556, 1999) and it is difficult to obtain a further considerable amount of improvement in sensitivity by any optical means.
The second method is to improve the ratio of a temperature change at an infrared detection portion, dTd, to an incident infrared power, dP, namely dTd/dP. Whereas the aforementioned method is an optical one, this can be said to be thermal. Generally speaking, in an uncooled infrared sensor to be packed in a vacuum package, transportation of heat from an infrared detection portion to a supporting substrate is predominantly accomplished by heat conduction by a supporting structure which supports the infrared detection portion in a cavity within the supporting substrate. Thus, attempts have been made to lay a leg-like supporting structure made of a material of low thermal conductivity as narrowly and longways as possible within the constraint of the design. See Tomohiro Ishikawa, et al., Proc. SPIE Vol. 3698, p. 556, 1999, for example. As shown in FIGS. 14(a) and 14B, a construction has been made such that a pair of narrow, spiral slits 201 is formed around a pixel 200 to form a cavity 204 at the bottom of the element. These spiral channels 202 are used as a supporting structure to support the pixel 200 afloat and wirings 203 are provided to connect to a peripheral circuit. When a pixel is being miniaturized to as small as 40 xcexcmxc3x9740 xcexcm or so, however, since fine processing has already been made at the silicon LSI processing level, a considerable degree of further improvement in sensitivity may hardly be realized through refinement of the layout of the supporting structure. Similarly, it is difficult to further reduce the thermal conductivity which is a material characteristic of the supporting structure. In particular, with regard to the wiring for outputting electric signals from the infrared detection portion, it is difficult to realize a considerable amount of improvement in sensitivity in terms of material since there is a requirement contradictory between the electric conduction and heat conduction whose mechanisms are similar.
The third method is to improve the ratio of an electric signal change caused by thermoelectric conversion means, dS, to a temperature change at an infrared detection portion, dTd, namely dS/dTd and is, therefore, electrical in nature. This method is, unlike the other two, is directed to sheer sensitization, that is, improvement of dS/dTd; however, it is quite important to reduce various electric noises generated. Thus, various kinds of thermoelectric conversion means have so far been investigated. Reported are, for example, a thermopile for converting a temperature change into a potential change by means of Seebeck effect (Toshio Kanno, et al., Proc. SPIE Vol. 2269, pp. 450-459, 1994), a bolometer for converting a temperature change into a resistance change by means of the temperature change of a resistor (A. Wood, Proc. IEDM, pp. 175-177, 1993), a pyroelectric element for converting a temperature change into an electric charge by pyroelectric effect (Charles Hanson, et al., Proc. SPIE Vol. 2020, pp. 330-339, 1993), a silicon pn junction for converting a temperature change into a voltage change by certain forward currents (Tomohiro Ishikawa, et al., Proc. SPIE Vol. 3698, p. 556, 1999), etc.
If a comparison is made among those methods, however, no one method is then decisively superior to the others in comprehensive view of their thermoelectric conversion characteristics, noise characteristics and manufacturing methods. For instance, the bolometer is superior in terms of temperature resolution while the silicon pn junction, which can be manufactured by the silicon LSI processing alone, is superior in terms of manufacturing method.
As described above, one of the methods for sensitizing an uncooled infrared sensor is a secondly mentioned thermal one, which improves the ratio of a temperature change at an infrared detection portion, dTd, to an incident infrared power, dP, namely dTd/dP. Generally speaking, transportation of heat from an infrared detection portion to a supporting substrate is predominantly accomplished by heat conduction through a supporting structure which supports the infrared detection portion in a cavity within the supporting substrate. Thus, attempts have been made to lay a leg-like supporting structure made of a material of low thermal conductivity as narrowly and longways as possible within the constraint of the design. When a pixel is being miniaturized to as small as 40 xcexcmxc3x9740 xcexcm or so, however, since fine processing has already been made at the silicon LSI processing level, a considerable degree of further improvement in sensitivity may hardly be realized through refinement of the layout of the supporting structure.
Furthermore, with a trend of miniaturizing pixels and supporting structures involved in the development of fine processing technology in silicon LSI processing, the influence of the heat transportation by emission from the bottom of a pixel and supporting structure will predictably be appreciable and the sensitization only through the reduction of heat conduction by the miniaturization of a supporting structure will predictably be restricted by a limit in sensitivity contributable to such emission.
In addition, in order to read signals out from an infrared detection portion, a supporting beam line to be formed within a supporting structure must be provided with a unique wiring layer made of a low thermal conductivity material. For example, a supporting beam line structure using titanium material is known to be effective.
Except for the case where titanium itself is used as a thermoelectric conversion material, however, in addition to the wiring process at an element peripheral circuit, another process will be required for forming a supporting beam line structure alone.
The present invention is directed to improve the above supporting structure and to provide a highly sensitized infrared sensor and a manufacturing method thereof.
According to one aspect of the present invention, provided is an infrared sensor device comprising:
a semiconductor substrate having a principal plane including a surface portion in which a hole is provided;
an infrared detection pixel disposed in the hole, comprising an infrared absorption portion configured to absorb an infrared ray and convert it into heat and a thermoelectric conversion portion configured to convert the heat into an electric signal;
a semiconductor peripheral circuit, disposed on the principal plane of the substrate, configured to read out the electric signal from the infrared detection pixel; and
a supporting beam line with U-shaped cross section, extending across the infrared detection pixel and the surface portion having the hole, configured to support the infrared detection pixel, afloat within the hole and to electrically connect the infrared detection pixel to the semiconductor peripheral circuit.
According to another aspect of the present invention, also provided is an infrared sensor device comprising: a semiconductor substrate having a principal plane including a plurality of surface portions in each of which a hole is provided;
a plurality of infrared detection pixels each disposed in the hole, each comprising an infrared absorption portion, configured to absorb an infrared ray and to convert it into heat and a thermoelectric conversion portion configured to convert the heat into an electric signal;
a semiconductor peripheral circuit, disposed on the principal plane of the substrate, configured to read out the electric signals from the infrared detection pixels, the semiconductor peripheral circuit including at least a MOS transistor having a gate comprising a first electric conductor with U-shaped cross section along the directions of the source and drain and a metal filled within the electric conductor; and
a plurality of supporting beam lines, each extending across the infrared detection pixel and the surface portion having the hole, configured to support the infrared detection pixel, afloat within the hole and configured to electrically connect the infrared detection pixels to the semiconductor peripheral circuit, each of the supporting beam lines including at least a second electric conductor with U-shaped cross section and being formed in the same layer as the first electric conductor with U-shaped cross section of the gate of the MOS transistor.
According to still another aspect of the present invention, further provided is an infrared sensor device comprising:
a semiconductor substrate having a semiconductor supporting substrate and a semiconductor layer and an insulating layer interposed therebetween, in which a plurality of holes are provided on the semiconductor substrate, the holes penetrating the semiconductor layer and the insulating layer to reach the semiconductor supporting substrate;
a plurality of infrared detection pixels each disposed in each of the holes, each comprising an infrared absorption portion configured to absorb an infrared ray and to convert it into heat and a thermoelectric conversion portion configured to convert the heat into an electric signal;
a semiconductor peripheral circuit, formed on the semiconductor layer, including at least a MOS transistor having a damascene metal gate formed for driving the infrared detection pixels to read out the electric signal; and
damascene metal supporting beam lines, extending across the infrared detection pixels and side surfaces of the holes of the semiconductor substrate respectively, configured to support the infrared detection pixel, afloat within the holes respectively and to electrically connect the infrared detection pixels to the semiconductor peripheral circuit respectively, the damascene metal supporting beam lines being disposed in the same layer as the damascene metal gate.
The U-shaped electric conductor may have a shape of a square having one side thereof open, a circle or oval having a segment thereof open or a parabola.
By forming the supporting beam line across the infrared detection pixel and the substrate on the same layer as the damascene metal gate of the MOS transistor of the peripheral circuit, the beam line with U-shaped cross section may be rigid and elaborate, thereby considerably reducing the cross section of the supporting beam line.
It is therefore possible to considerably reduce the heat conduction through the supporting beam line, which predominates the heat transportation between the infrared detection pixel and the substrate, consequently providing a highly sensitive uncooled infrared sensor device.
According to another aspect of the present invention, provided is a method of manufacturing an infrared sensor, comprising:
embedding a silicon oxide layer in a substrate comprising a single crystalline silicon supporting substrate, an silicon oxide film layer formed on the single crystalline silicon supporting substrate and a single crystalline silicon layer formed on the silicon oxide film layer, over a predetermined region of the single crystalline silicon layer;
forming a thermoelectric converter pn junction for an infrared detection pixel in the single crystalline silicon layer;
forming a supporting beam line including a U-shaped electric conductor on the silicon oxide layer while forming a gate electrode of a MOS transistor having an electric conductor with U-shaped cross section, the MOS transistor being included in a peripheral circuit on the single crystalline silicon layer;
forming an infrared absorption layer on the single crystalline silicon layer; and
forming a hole by etching for isolating the infrared detection pixel of the substrate from the substrate and suspending the infrared detection pixel within the hole by the supporting beam line.
By forming the supporting beam line with a minimum cross section through the step of etching the hole for isolating the periphery of the infrared detection pixel from the substrate, the length of the supporting beam line may considerably be lessened and the aperture ratio, defined as an infrared detection pixel area relative to a unit pixel area, may considerably be improved. In addition, lessening the length of the supporting beam line may increase the mechanical strength and stabilize the operation while enabling sensitization to an infrared ray. Furthermore, linearization of the supporting beam line may extremely stabilize the manufacturing method thereof and, in turn, improvement of the yield may lower the cost.
At the same time, according to the present invention, the chip area may be reduced by miniaturizing the peripheral circuit and, therefore, the cost may naturally be lowered.
As described above, according to the present invention, an inexpensive and highly sensitive uncooled infrared sensor may be obtained.


Geologic formations may contain reservoirs of sought-after hydrocarbons. Boreholes are typically drilled into the reservoirs where the hydrocarbons can be extracted through rock fractures in the formations. Logging tools may be conveyed through the boreholes in order to characterize the formations so that drilling and/or completion resources can be used efficiently. Hence, innovations that improve the accuracy of formation characterization would be well received in the drilling and production industries.


A superacid is a known class of acidic material that has an acid strength, measured by Hammett acidity function H.sub.0, greater than that of 100% H.sub.2 SO.sub.4, which has an H.sub.0 value of -12. A superacid, therefore, has an H.sub.0 value of less than -12 or an acid strength greater than -12. Superacids are useful for reactions that are generally catalyzed by strong acid, such as paraffin isomerization.
M. Hino and K. Arata describe the synthesis of a solid superacid having an acid strength of up to H.sub.0 .ltoreq.-16.04 by exposing hydroxides or oxides of Fe, Ti, Zr and Hf, prior to crystallization, to sulfate ions, followed by calcination in air at over 500.degree. C. in J. Chem. Soc., Chem. Commun., 1148 (1979). K. Arata and M. Hino also describe the synthesis of a solid superacid having an acid strength of H.sub.0 .ltoreq.-14.52 by impregnating Zr(OH).sub.4 or amorphous ZrO.sub.2 with aqueous ammonium metatungstate, followed by calcining in air at 800.degree. to 850.degree. C. in J. Chem. Soc., Chem. Commun., 1259 (1988) and in "Synthesis of Solid Superacid of Tungsten Oxide Supported on Zirconia and Its Catalytic Action", Proceedings 9th International Congress on Catalysis, Volume 4, pages 1727-1734 (1988).
The superacid described by K. Arata and M. Hino in "Synthesis of Solid Superacid of Tungsten Oxide Supported on Zirconia and Its Catalytic Action" is particularly useful as a catalyst in the isomerization of butane to isobutane and of pentane to isopentane. However, in order to obtain maximum catalytic activity, K. Arata and M. Hino report calcination temperatures of from 800.degree. to 850.degree. C. for the tungsten-modified zirconia catalyst.
Soled et al describe, in U.S. Pat. No. 5,113,034, a solid acid catalyst having an H.sub.0 value ranging from -14.5 to about -16.5, comprising a sulfate or tungstate-modified Group IVB oxide, which is useful to dimerize C.sub.3 or C.sub.4 containing feedstreams. A calcination temperature range for the tungstate-modified zirconia catalyst of 450.degree. to 800.degree. C. is given. Specifically, the Examples use an initial calcination temperature of 600.degree. C., followed by a calcination temperature of 800.degree. C. prior to charging.
U.S. Pat. No. 5,198,403 (Brand et al, herinafter Brand) discloses a catalyst for the selective reduction of nitrous oxide with ammonia which contains, in addition to titanium oxide as component A, at least one oxide of tungsten, silicon, boron, aluminum, phosphorus, zerconium, barium, yttrium, lanthanum, cerium as component B1 and at least one oxide of vanadium, niobium, molybdenum, iron and copper as B2, with an atomic ratio between the elements of components A and B from 1:0.001 up to 1. The catalyst of Brand requires the presence of titanium oxides, presumably because it is effective in the reduction of nitrous oxides. Reduction of nitrous oxides is the intended purpose of Brand. The catalysts of the instant invention do not contain titanium and are not drawn to nitrous oxide reduction.
U.S. Pat. No. 4,918,041 (Hollstein et al, hereinafter Hollstein) is directed to a sulfated calcined solid catalyst. The catalysts of the instant invention are not sulfated. Group VI B metals such as tungsten are employed in the superacid, rather than Group VI A metals such as sulfur. Group VI B metals are preferred in the instant invention due to their stability and ease in regeneration.
The generation of acid activity in solid oxide catalysts in general, and in the tungsten-modified zirconia catalyst specifically, requires calcination of the catalyst at temperatures of about 800.degree. C. This extreme temperature, however, causes significant loss of catalyst surface area. For example, K. Arata and M. Hino report surface areas of 35.3 and 29.5 m.sup.2 /g for catalysts calcined at 800.degree. and 900.degree. C. in "Synthesis of Solid Superacid of Tungsten Oxide Supported on Zirconia and Its Catalytic Action". By contrast, the surface areas for catalysts calcined at 600.degree. and 700.degree. C. are reported as 44.2 and 38.5 m.sup.2 /g. Hence, it is clear that as the calcination temperature is increased, the surface area of the catalyst is decreased. Further, the extreme calcination temperature required to generate acid activity results in a more difficult manufacturing process.


Materials, such as wall patching compound or wall board joint compound are available, generally, in large containers such as tubs or drums, and smaller containers, such as tubes. Particularly, wall patching compounds are available in the smaller, tube-type containers.
In use, these materials are squeezed or expelled from the tube in an appropriate amount for the required task. The material is then spread over the area to be covered using a separate trowel or spreading knife.
Typically, this operation requires the use of both hands to open the container, dispense or expel the material from the container, close the container, and spread the material on the surface which needs to be repaired. This operation can be particularly cumbersome when the user is standing, for example, on a ladder or an elevated surface.
Another drawback to known containers is that many such containers do not provide an air-tight seal to keep the material fresh and usable. The material which is exposed to air tends to harden and become unusable. This is particularly troublesome with tube-type containers which have small nozzle openings to discharge the material. If the material hardens in the nozzle, the tube is generally unusable, and the entire tube must be discarded.
Thus, there continues to be a need for a container for materials such as wall patching compound, which permits "one-handed" operation, and which container provides an air-tight seal to maintain the compound in a fresh, usable condition.


I. Field
The present disclosure relates generally to extension of battery life in wireless communication systems, and more particularly to extension of battery lifetime in Bluetooth equipped wireless communication devices.
II. Background
Battery lifetime is a chief concern in portable Bluetooth 802.11 computing devices, such as Ultra Mobile Personal Computers (UMPCs) and Personal Digital Assistants (PDAs). It is known that battery lifetime can be extended by keeping the host processor asleep whenever possible. It is useful for such computer devices to be aware when they enter 802.11 coverage, and wake-up the host processor, if needed, thereby eliminating the need for the user to manually check for coverage.
In this connection, wake-up conditions must be sophisticated, varying from the existence of a network to complex conditions such as the existence of an urgent e-mail, availability of a particular kind of service, etc.
However, traditional wake-up solutions require the existence of alternative interfaces other than 802.11 to initiate wake-up, the presence of full-blown additional processors, or host processor hierarchies for wake-up initiation. Further, some solutions restricted to 802.11-based wake-ups are extremely inflexible (such as WoWLAN and AMD Magic packet). Moreover, traditional host processor wake-up conditions are not variable from application to application, which often change according to complex user requirements, such as the need to be notified of urgent e-mails, existence of a particular service, existence of a particular network and so forth. Current 802.11-initiated wake-up methods are very rigid and limiting.
U.S. Pat. No. 7,398,408 disclose methods for accessing computing devices over wireless local area networks and more particularly to systems and methods for waking computing devices from a powered down or sleep state with signals sent over wireless local area networks. This is accomplished by:
broadcasting a signal containing a wake-up data sequence for at least one computing device over a wireless network, wherein broadcasting the signal comprises periodically broadcasting the signal over one or more wireless channels until either a first predetermined time period expires or a confirmation signal is received;                receiving the broadcast signal at the at least one computing device, while that device is in a reduced power mode; wherein receiving comprises first entering a wake-up data sequence detection mode;        scanning the received signal for a wake-up data sequence for that computing device, wherein scanning is performed until either the wake-up data sequence for that computer device is received or a second predetermined time period expires; and        restoring that computing device to a full power mode upon detection of a wake-up data sequence for that device and exiting the wake-up data sequence detection mode if the second predetermined time period expires.
There is a need for an infrastructure system where 802.11 ATs are only awake when interaction with the AP is needed and possible, and asleep (in standby) otherwise.
There is also a need to provide a flexible mechanism whereby the AT's 802.11 interface can detect when “interaction with the AP Is needed” as possible.


1. Field of the Invention
The present invention relates to the field of displaying technology, and in particular to a method for manufacturing a curved liquid crystal panel.
2. The Related Arts
A liquid crystal display (LCD) is composed of an enclosure, a liquid crystal panel arranged in the enclosure, and a backlight module mounted in the enclosure, in which the liquid crystal panel is composed of a color filter (CF) substrate, a thin-film transistor (TFT) array substrate, and a liquid crystal layer filled between the two substrates. The CF substrate and the array substrate have inside surfaces that face each other and comprise transparent electrodes formed thereon. The liquid crystal display applies an electric field to control the orientation of the liquid crystal molecules so as to change the polarization state of light and uses a polarizer to select transmission or blocking of a light path so as to achieve the purpose of displaying. With the progress of the displaying technology, people's demands of consumer electronics are no longer limited to functionality and also require satisfactory aspects in regard to design, aesthetics, and excellent visual experience. A curved liquid crystal display that has been created for such purposes is not only a novel design but also providing better visual effect and experience.
A curved liquid crystal panel is a key component of a curved liquid crystal display. A conventional way of manufacturing a curved liquid crystal panel is to first laminate prepared CF substrate and array substrate in a flat condition to form a flat panel like liquid crystal panel and to subject the flat panel like liquid crystal panel to the application of an external force so as to make the liquid crystal panel that is originally in the form of a flat panel curved, where a degree of curving (radius of curvature) is determined according to a design size and viewing distance of the liquid crystal panel.
In a liquid crystal panel of a main stream LCD, a black matrix (BM) is provided on the CF substrate side to prevent the occurrence of light leakage at the site of each of pixels. Further, photo spacers (PSs) are provided between the CF substrate and the array substrate to maintain the distance between the two substrates in order to prevent the occurrence of abnormality.
As shown in FIG. 1, in the conventional way of manufacturing a curved liquid crystal panel, when the liquid crystal panel is being curved, since the CF substrate 100 and the array substrate 200 are moved relative to each other, a relative displacement of the black matrix 110 with respect to TFT pixels occurs in a curving portion, resulting in change of aperture ratio and causing dark blocks occurring in eye vision during a displaying process. When the liquid crystal panel is further curved, the relative shift between the CF substrate and the array substrate 200 is further enlarged so that two adjacent color resist blocks may move to locations close to a data line 210. The electric field around the data line 210 would cause the liquid crystal molecules to rotate and eventually, light leakage results. Such a displaying defect is even more apparent in displaying a pure color image. Thus, the relative shift between the CF substrate 100 and the array substrate 200 would cause movement of color resist, leading to color shift of the mixed color and irregularity of displayed color.
As shown in FIG. 2, due to the curving of the liquid crystal panel, the photo spacers 400 that were originally distributed in a reasonable manner in a flat panel are caused to generate different pushing effects that are generally in proportion to the different degrees of curving from the center of the liquid crystal panel to the two opposite, left and right, edges. With the curving of the liquid crystal panel, the curvature at the locations marked B, C, D and B′, C′, D′ in FIG. 2 changes so that photo spacers 400 at different locations would be of different heights. This readily leads to a potential risk that the cell thickness of the liquid crystal layer 300 becomes inconsistent due to the photo spacers 400 at different locations having different heights.
In brief, for a liquid crystal panel of which a circumference is adhesively fixed by enclosure resin 600, to change from a flat panel form into a curved condition would cause the array substrate 200 and the CF substrate 100 to move relative to each other and thus changes of the aperture ratio and the cell thickness of the liquid crystal layers 300 at different locations of the liquid crystal panel, in the entirety thereof and consequently displaying defects associated therewith would result.


The use of Digital Subscriber Line (DSL) technology depends heavily on the length and quality of the copper wire between the modem of an end user and the DSL Access Multiplexer (DSLAM). Longer copper wiring reduces the line quality and thus the bandwidth usable on this line. Reducing the length of the copper wire by locating a DSLAM near the end user, typically within a few kilometers, and serving only a small amount of users, for instance 120, will improve the service to the end user significantly.
A DSLAM that is located near the end user is protected from weather conditions by some sort of enclosure, for instance an outdoor cabinet. The DSLAM requires a high bandwidth connection to the Central Office (CO) which could be an office of a telecom operator or internet service provider, and has multiple low bandwidth connections to end users generally used for xDSL access. Other technologies such as Integrated Services Digital Network (ISDN) or Plain Old Telephone Service (POTS) work similarly where a group of end users is connected to an Access Multiplexer (AM), which in turn provides access to the network of an operator.
A Remote Unit (RU) is an enclosure which may be provided with at least one Access Multiplexer, one or more high bandwidth media to a CO and one or more low bandwidth links to end users. Such a Remote Unit is usually located above ground in what is referred to as street cabinet or outdoor enclosure. Alternatively a remote unit can be located underground in what is typically referred to as a manhole.
A remote unit typically has several connections to the central office. Optical fiber provides a reliable high-speed medium which is ideal for carrying multiple information flows simultaneously. Putting fibers in the ground is however an expensive task with major disturbance for the public and traffic. Roads and sidewalks need to be opened before fiber can be placed underneath. Therefore spare fibers are made available in the remote unit for future expansion of the remote unit.
A brochure concerning the Alcatel 7300 ASAM (Advanced Services Access Manager) ETSI version, Release 4.3/4.4 describes the use and advantages of the Alcatel 7300 ASAM in xDSL technology. Particularly the section titled “Extending Network Coverage” on page 6 of the brochure describes how the Alcatel 7300 ASAM can be used as a remote unit to extend geographical coverage of an xDSL deployment. It further describes how such a 7300 ASAM can be connected to products such as a micro DSLAM or a remote Alcatel 7300 ASAM-o as outdoor cabinet. Both the 7300 ASAM and subsequent connected devices such as a micro DSLAM can be considered a remote unit for the current invention. This brochure can be retrieved from the Internet via:
http://www.alcatel.be/doctypes/opgproductbrochure/pdfa4/7300_etsi_bro.pdf.
The datasheet containing specifications of the Alcatel 7300 ASAM-c compact (ETSI version) release 4.3 discloses a DSLAM that can be included in an enclosure to form a remote unit. The Alcatel 7324 Remote Unit is yet another product offering DSLAM technology close to the end user premises. This datasheet can be retrieved from the Internet via:
http://www.alcatel.be/doctypes/opgdatasheet/pdfa4/7300c_etsi_R43_ds.pdf.
All of the above-described products can be included in outdoor cabinets in order to be located near a particular amount of users. These outdoor cabinets provide protection from weather conditions and prevent unwanted physical access to the equipment inside.
Several manufacturers provide enclosures for communication equipment. For instance ICEE Ltd. (Installers of Communication and Electrical Equipment) offers the design and installation of custom-made enclosures. Knürr AG provides a series of outdoor enclosures for various purposes in their Tecoras product line. The CS product line of Rittal is another example of outdoor enclosures that can be used to house communications equipment and be a part in the remote units described in this invention.
Content broadcasters, such as television stations have a need to provide coverage of particular events, for instance music festivals or major news events. This coverage involves acquiring video and audio content, editing this content to an item ready for broadcast and transmitting this item to a central location for broadcast, not necessarily in that order. Typical parts in this process are satellite trucks which provide a satellite uplink to a central location and which are used to transmit the audio and video content. These trucks may also provide an editing studio to prepare the items before they are transmitted. Satellite uplinks are not always reliable; they are prone to delays and interference of radiation in the atmosphere. A typical example of this is the loss of a link during a live interview or the delays that occur between asking a question and a person actually hearing that question.
It is an object of the present invention to provide flexible means for delivering content to a central location from a remote location using existing network infrastructure. It is another object of the present invention to provide encoding and decoding means for easy content delivery. It is a further object of the present invention to facilitate real time audio and video communication between two remote points. It is another objective of the present invention to provide these means for delivering content in a secure way, restricting access from unauthorized persons or devices.


1. Field of the Invention
The present invention relates to a drive circuit and a drive method of a semiconductor laser module that externally modulates carrier light output from a semiconductor laser using an electro-absorption type optical modulator to output the modulated light, in particular, to a drive control technique for compensating for temperature characteristics of the semiconductor laser and the electro-absorption type optical modulator.
2. Description of the Related Art
In various optical communication systems for transmitting optical signals over a long distance, there is sometimes used a semiconductor laser module in which a semiconductor laser and an external modulator of electro-absorption type are integrated with each other, since such a semiconductor laser module enables to increase a transmission distance compared with a semiconductor laser of direct modulation type. In the aforementioned semiconductor laser module, operation characteristics of the semiconductor laser and the electro-absorption type optical modulator (hereinafter referred to as EA modulator) each has dependence on temperature. Therefore, in order to hold optical output power in stable, it is necessary to stabilize a module temperature or to control a drive condition according to a temperature change.
In a conventional drive control of a semiconductor laser module having an EA modulator, such a method is typical in that, for example, by using an electronic cooling device such as a Peltier device and a temperature detection device such as a thermistor integrated with each other in a module, a current to be supplied to the Peltier device is controlled so that a resistance value of the thermistor is maintained to be constant, to hold the temperature of a semiconductor laser and the EA modulator to be constant. In this case, the EA modulator is driven by a constant modulated electric signal and at the same time, a constant drive current or a drive current to make a back power monitor current constant is supplied to the semiconductor laser, thereby achieving a stable optical output. The drive control method described above, however, has a disadvantage that since the Peltier device needs to be driven, the power consumption is increased and also a package size of the module is made to be large.
To cope with this problem, a semiconductor laser module using an EA modulator which is not provided with a Peltier device, has recently been under development. According to this semiconductor laser module, both the reduction of power consumption and the miniaturization can be achieved by eliminating the need of a Peltier device, although there is a need of stabilizing optical output power by controlling a bias voltage of the EA modulator or a drive current of the semiconductor laser according to a temperature change. Also, since this module is of an external modulation system using the EA modulator, it is possible to obtain an optical output having a small amount of chirping.
As a conventional drive control technique applicable to such a semiconductor laser module without the Peltier device as described above, a drive circuit for an EA modulator is disclosed in Japanese Unexamined Patent Publication No. 11-119176. In this drive circuit, an anode voltage of the EA modulator is detected and according to the detection result, a bias voltage of the EA modulator is controlled, so that an applied voltage to the EA modulator is maintained to be constant even if a temperature change or a change with age occurs.
However, in the case where the semiconductor laser module provided with EA modulator without the Peltier device is driven by applying the conventional control technique as described above, although the bias voltage of the EA modulator is controlled according to the temperature change and the like, since the EA modulator is driven by a constant modulated electric signal, an optical output waveform of the semiconductor laser module is considerably deteriorated.
FIG. 16 is a diagram showing temperature dependence of operating characteristics of a typical EA modulator. In FIG. 16, each characteristic curve represents a relation between power Pf of an optical signal output from the EA modulator and an applied voltage Vea to the EA modulator at each of temperatures 0° C., 25° C. and 75° C. In FIG. 16, if a modulated electric signal of a waveform as shown in the lower left part is applied to drive the EA modulator, since the optical output power Pf is changed along each characteristic curve, an optical waveform at 0° C. output from the EA modulator is considerably deteriorated as compared with an optical waveform at 75° C. as shown in the upper right part. Even if the bias voltage is controlled according to the temperature change as in the conventional technique so that the EA modulator operates in a region where the characteristic curve has the large inclination and is changed substantially linearly, since the inclination or the distortion of the characteristic curve in each operating region differs from each other depending on the temperature, an extinction ratio or a duty of the optical output waveform is changed depending on temperature when the EA modulator is driven by the modulated electric signal in which a modulated amplitude and a cross point are set to be constant.
Further, since a current generated by absorption of carrier light (hereinafter referred to as a photocurrent) flows through the EA modulator, there is caused a problem in that the applied voltage to the EA modulator deviates, if the photocurrent is changed when controlling a current source for drive controlling the EA modulator. Therefore, for the semiconductor laser module without the Peltier device, it is critically important to realize a drive control method that is not affected by a change in the photocurrent due to the electro-absorption effect, when the temperature change or the change with age is compensated by controlling the electrical drive signal of the EA modulator.


This patent document relates in general to on-chip waveguides with flattened dispersion, and in particular to on-chip generation of an ultra-broad optical spectrum, called a supercontinuum, based on the flattened dispersion of the waveguides.
Generating a supercontinuum from a narrowband pulse is of particular interest in both fundamental science and engineering research of modern optics. Although recent years have witnessed dramatic advances in supercontinuum generation using photonic crystal fibers, it is quite challenging to obtain an octave-spanning supercontinuum on a chip, partially because of strong chromatic dispersion in high-index-contrast nonlinear integrated waveguides.


Three-dimensional (3D) virtual worlds (for example, World Of Warcraft, Second Life, Runescape, etc.) allow users to enter and move about, as well as interact with other users and objects, within a three-dimensional virtual environment. Such 3D virtual worlds systems generally operate in the following manner:
1) They require a 3D rendering engine to be resident on the client's system in order to render a user's viewport into the 3D world.
2) The 3D rendering software further requires that the client machine have certain graphics processing capabilities which allow the 3D world to be rendered on the local machine. The more complex the world, the more powerful the client device's graphics capabilities must be.
3) In order for a user to view a scene on her local system, the 3D rendering engine must have access to the assets necessary to build the scene accurately. Such assets typically include geometry mesh data (vertices, index and attribute buffers), material and shader definitions (including procedural shaders), and texture maps. As scene complexity increases, the amount of data required to render a scene on a local client increases as well. Assets for such complex virtual worlds are often included in a download or DVD that the user must first install before the 3D rendering engine on the local client can begin rendering a scene. Therefore, the more complex and dense the virtual world, the more data the user must either have installed or download on their system. Instantaneous virtual world rendering systems that depend on streaming render assets for client-side rendering may introduce objectionable visual artifacts as a viewport is procedurally refreshed with new textures and meshes that replace placeholder versions.
4) Virtual world systems generally use a centralized server system to persistently maintain the state of the world. State data from these servers are continuously sent to each client when needed (including position, orientation, velocity and dynamics of objects within the world) in order for each viewport to remotely render the scene on the client's local machine. If all clients have the same assets, and the same hardware graphics capabilities, visual parity across each client viewport is possible.
However, the overhead of synchronizing states across each user's viewport when the client systems are not homogenous can become problematic in many cases, as the visual representation of the same viewport may vary across each client, based on the client's local graphics capabilities. For example, if a faceted 3D object is tessellated and smoothed in hardware on a client system which supports curved patch tessellation, the silhouette of the object may appear to be significantly different than the silhouette of the same object on a client that does not support tessellation. In the latter case, the client would be forced to render the 3D object with a faceted outline. These differences can create objectionable discontinuities among remotely rendered viewports in cases where collision detection is performed by the server on the aforementioned 3D object. If the server performs collision detection using the smooth tessellated version of the object, and then transmits this singular result to each client, the visual representation of the point of impact and bounce vector from the collision may not appear to correspond to a valid point and slope on the surface of the object from the point of view of a user displaying the scene without tessellation. This can become even more objectionable, when the tessellation is performed on a macroscopic object such as terrain, where control of vehicles or avatars depends heavily on an accurate representation of the ground surface. These types of discontinuities between the state of world on the server, and the visual representation on an arbitrary client, increases significantly as a 3D virtual world becomes more complex, and the range of client devices that need to be supported expands to mobile phones, TV set top boxes and other hardware that may have limited or no 3D graphics capabilities on the local machine.


1. Field of the Invention
The invention relates to the field of information security and privacy and, more specifically, to finding matching entries in sets from two or more parties without revealing all of any party's entries.
2. Discussion of the Prior Art
Modern research and technology have provided society with a wide variety of electronic devices. Some of these modern electronic devices are very powerful and useful to those who use them. For example, the global positioning system (GPS) was initially deployed for United States military purposes, but today can be a useful aid for almost anyone.
For back country travelers, boaters on open waters, or others who navigate off the beaten path, carrying a light weight, battery powered GPS receiver can provide them with their position within several hundred feet. For motorists, a dramatic improvement in convenience and safety can be provided by carrying a GPS receiver integrated with a trouble alert system (perhaps using mobile telephone technology) or a road map database.
GPS receivers can be configured to record the time and position of the trajectories along which they travel. Such information can be maintained within such GPS receiver/recorder device. Periodically, it can be off-loaded onto a personal computer (PC), a personal digital assistant (PDA), or a server, for example.
Such trajectory information can be gathered and recorded with little or no intrusion on the person carrying the GPS receiver/recorder. Thus, a person could record their daily locations and travel over a period of days, years or even indefinitely.
Nevertheless, mining or making use of such information is difficult, both because of the volume of information potentially involved, and because of the privacy and security implications of sharing such information. Few individuals would be willing to make available to anyone else a complete log of where they have been over a period of time of significant duration. Even if certain “private” time periods could be easily deleted or not recorded, many people would consider a voluminous log of their whereabouts to be no business of anyone else.
Additionally, the security implications are daunting. Someone interested in burglarizing even an ordinary residence or place of business would be given a tremendous advantage by knowing the trends or patterns of who comes and goes from the place at what time—let alone if the person carrying the GPS receiver/recorder were a high profile person such as a leading politician or famous entertainer.
On the other hand, many people would be willing or even eager to reveal a limited subset of such trajectory information. For example, it often happens that two individuals who are meeting each other socially or for business have a feeling that they might have met before, but are unable to recall where and when that may have happened.
More generally, two or more individuals or organizations may possess information that can be represented as collections, data points or sets. They may desire to find what entities, elements or individual data points are present in all of the sets, but only if they can do so without revealing to the other participants all of the elements in their set. One example of such a problem includes several diplomats attempting to select where and when they will meet. Another example is two individuals determining if they both belong to any of the same golf courses, fraternal clubs or other organizations, which can be represented as the longitude and latitude of the clubhouse or headquarters.
Yet another example is two individuals selecting the time, date and place for initially meeting on a blind date. Another example is a company whose trucks are equipped with GPS receiver/recorder devices demonstrating that none of their trucks were near the coordinates of an accident. Yet another example is a person demonstrating that they have never gone near a location or region that is forbidden by the conditions of their parole or probation.


Non-volatile semiconductor memories (NVSMs) are widely used in many electronic devices such as personal digital assistants (PDAs), laptop computers, mobile phones and digital cameras. Some of these memories have arrays of charge storage transistors, such as floating gate transistors.


The present invention relates to a mechanism in a plastic injection machine and the mechanism ensures the screw rod to be precisely moved together with the open and close of the molds.
A conventional plastic injection molding machine for manufacturing products having screw holes generally employs a gear system for controlling a screw rod moving into or removing from the cavity between two molds. The gear system is controlled by electric control system. The gear system including too many gears which is a load of maintenance. The gear system is difficult to precisely move the screw rod relative the molds so that the depth of the screw rod in the cavity cannot be obtained the same each time when the plastic material is injected into the cavity. The screw hole of the products could be damaged if the screw rod cannot be removed from the molds in stable. The gear system is activated after the movement of the molds is finished so that it prolongs the period of the complete process.
In accordance with one aspect of the present invention, there is provided a plastic injection molding machine which comprises a position block on the upper mold and a slide member on the lower mold. A pin is inserted in the position block and the movable member. A rod extends through the slide member so that the top end of the rod is inserted in the cavity when the pin is inserted in the slide member. Two side members each have threaded semi-circular recesses which are engaged with a threaded section on the rod so that when the rod is rotated by a motor, the rod is smoothly removed from the cavity.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.


This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 2000-117739, Apr. 19, 2000; No. 2000-117740, Apr. 19, 2000; No. 2001-055815, Feb. 28, 2001; and No. 2001-110469 Apr. 9, 2001, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a focus stabilizing apparatus for stabilizing a focused state of an optical apparatus, such as a microscope.
2. Description of the Background Art
Generally, a sample observation is carried out with the use of a microscope. This sample observation is made as follows. An observation sample is placed on a microscope stage and an objective lens is moved closer to the observation sample. By doing so, an observation spot of the observation sample is observed under a magnified state.
In this case, an objective lens has its focal depth decreased as the magnifying power becomes higher. It is, therefore, difficult to achieve a focus setting between the objective lens and the observation sample. Further, if the distance between the objective lens and the observation sample minutely varies, defocusing occurs between the focal point position of the objective lens and the observation sample due to a variation of the minute distance, so that the quality of the observation image is greatly degraded.
On the other hand, an apparent position between the objective lens and the observation sample is very closer to each other. By the way, there exists a mechanical coupling length between the objective lens and the observation sample. This mechanical coupling length is constituted by many mechanical component parts present between the objective lens and the observation sample. The mechanical coupling length is provided by the length over which, for example, a microscope frame, objective lens moving mechanism, objective lens mounting revolver are passed. Therefore, the length is very long because many mechanical components are interposed.
These mechanical component parts are liable to be varied in their dimensions due to a temperature variation involved.
Further, the greater the number of the mechanical component parts the greater the mechanical coupling length involved. The microscope is easily affected by a vibration and the vibration amplitude becomes greater.
If, therefore, the ambient temperature varies due to, for example, the turning ON/OFF of an illumination, internal power supply, etc., as well as the operation of an air conditioning equipment, then there arises a variation in the dimensions of mechanical component parts in the microscope. Even if, therefore, the focal setting of the objective is made relative to the observation sample, the distance between the objective lens and the observation sample greatly varies due to the above-mentioned dimensional variation and there occurs a defocusing.
Further, under a somewhat smaller external vibration, a greater vibration amplitude is involved and a distance between the objective lens and the sample varies, thus resulting in an out-of-focus state.
Heretofore, various kinds of autofocusing mechanisms have been considered to compensate such defocusing. These autofocusing mechanisms require a complex mechanical/electrical mechanism and control system. For this reason, the resultant apparatus becomes bulkier and expensive. Further, another microscope is known in which, like a fluorescent observation, the brightness is extremely darker at a time of observation. To such a microscope it is originally difficult to apply the above-mentioned autofocusing mechanism.
The following technique is disclosed in JPN PAT APPLN KOKAI Publication No. 9-120030. In this technique, a stage is provided through a rack and drive gears and it is driven in the optical axis direction of the objective lens. Between the gears and the stage, at least two rods are inserted. These rods are different in their thermal expansion coefficients and configured such that the direction of the thermal expansion coefficient of one rod acts in a direction opposite to that of the other rod. By doing so, defocusing is compensated.
In such a technique, the rods are arranged within the microscope body and a time is taken until the temperature is compensated under a variation of the ambient temperature. For this reason, there is a risk that, when the sample is observed, its operation, efficiency will be lowered. Further, since the rods are interposed, the mechanical coupling length becomes greater and its structure is liable to be affected from the external vibration. It is, therefore, necessary to remodel the microscope itself.
In the case where a living cell, etc., is observed as a target object, only a periphery side of the observation sample is sometimes warmed by a warmer. However, it is not possible to compensate a temperature drift involved.
It is accordingly the object of the present invention to provide a focus stabilizing apparatus which can make a focus setting of an objective lens relative to an observation sample under a stable way without being adversely influenced from a variation in the ambient temperature.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to a observation sample, and position adjusting means provided at an outer periphery of the objective lens and adapted to move the observation sample in an optical axis direction to set a focal point of the objective lens to the observation sample.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to the observation sample, a stage so provided as to be movable in a direction orthogonal to an optical axis of the objective lens, a sample base placed on the stage to retain the observation sample, position adjusting means provided at an outer periphery of the objective lens and adapted to move the observation sample in an optical axis direction through the sample base to set a focal point of the objective lens to the observation sample, and elastic means provided on the stage and so set through the sample base as to have a low rigidity in the optical axis direction of the objective lens and a high rigidity in a moving direction of the stage.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to an objection lens, a stage so provided as to be movable in a direction orthogonal to an optical axis of the objective lens, a sample base placed on the stage to retain the observation sample, and position adjusting means provided at an outer periphery of the objective lens and adapted to move the observation sample in an optical axis direction of the objective lens through the sample base to set a focal point of the objective lens to the observation sample, wherein the position adjusting means has a fixing base for fixing the objective lens, a sample retaining base for placing the observation sample thereon, and an operation ring threadably inserted over the fixing base and, by being rotated relative to the fixing base, moving in the optical axis direction of the objective lens and moving the sample retaining base in the optical axis direction of the objective lens to adjust a relative distance between the observation sample and the objective lens.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to an observation sample, a stage so provided as to be movable in a direction orthogonal to an optical axis of the objective lens, a sample base placed on the stage to retain the observation sample, position adjusting means provided at an outer periphery of the objective lens to move the observation sample in the optical axis direction of the objective lens through the sample base to set a focal point of the objective lens to the observation sample, and elastic means provided on the stage and so set relative to the sample base as to have a low rigidity in the optical axis direction of the objective lens and a high rigidity in a moving direction of the stage, wherein the position adjusting means has a fixing base for fixing the objective lens, a sample retaining base placing the observation sample thereon, and an operation ring threadably inserted over the fixing base and, by being rotated relative to the fixing base, moving in the moving axis direction of the objective lens and moving the sample retaining base in the optical axis direction of the objective lens to adjust a relative distance between the observation sample and the objective lens.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to an observation sample, a stage so provided as to be movable in a direction orthogonal to an optical axis of the objective lens, a sample base placed on a stage to retain the observation sample, and position adjusting means provided at an outer periphery of the objective lens and moving the observation sample in an optical axis direction of the objective lens through the sample base to set a focal point of the objective lens to the observation sample, wherein the position adjusting means has a fixing base for fixing the objective lens, and a sample retaining base placing the observation sample thereon and threadably inserted over the fixing base and, being rotated relative to the fixing base, moving in the optical axis direction of the objective lens.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to an observation sample, a stage so provided as to be movable in a direction orthogonal to an optical axis of the objective lens, a sample base placed on the stage to retain the observation sample, position adjusting means provided at an outer periphery of the objective lens and moving the observation sample in an optical axis direction of the objective lens through the sample base to set a focal point of the objective lens to the observation sample, and elastic means provided on the stage and so set relative to the sample base as to have a low rigidity in the optical axis direction of the objective lens and a high rigidity in a moving direction of the stage, wherein the position adjusting means has a fixing base for fixing the objective lens and a sample retaining base placing the observation sample thereon and threadably inserted over the fixing base and, by being rotated relative to the fixing base, moving in the optical axis direction of the objective lens.
In such focus stabilizing apparatus, the objective lens is fixed to the fixing base and threadably inserted directly into a revolver provided at a microscope body.
The position adjusting means has a rotation stop section arranged at the upper side of the sample retaining base, an intermediate seat arranged on the upper side of the rotation stop section and having the observation sample placed thereon, and a pin having one end mounted in the fixing base and the other end inserted through a hole in the rotation stop section and provided parallel to the optical axis direction of the objective lens.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to an observation sample, a stage so provided as to be movable in a direction orthogonal to an optical axis of the objective lens, a sample base placed on the stage to retain the observation sample, and position adjusting means provided at an outer periphery of the objective lens and moving the observation sample in an optical axis direction of the objective lens through the sample base to set a focal point of the objective lens to the observation sample, wherein the position adjusting means has a fixing base for fixing the objective lens, a sample retaining base placing the observation sample thereon, fitted over an outer periphery of the fixing base and so provided as to be movable in the optical axis direction of the objective lens, and a friction member situated between the fixing base and the sample retaining base and retaining the sample retaining base by a friction force relative to the fixing base.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to an observation sample, a stage so provided as to be movable in a direction orthogonal to an optical axis of the objective lens, a sample base placed on the stage to retain an observation sample, position adjusting means provided on an outer periphery of the objective lens and moving the observation sample in an optical axis direction of the objective lens through the sample base to set a focal point of the objective lens to the observation sample, and elastic means provided on the stage and so set relative to the sample base as to have a low rigidity in the optical axis direction of the objective lens and a high rigidity in a moving direction of the stage, wherein the position adjusting means has a fixing base for fixing the objective lens, a sample retaining base placing the observation sample thereon and fitted over an outer periphery of the fixing base and so provided as to be movable in the optical axis direction of the objective lens, and a friction member situated between the fixing base and the sample retaining base and retaining the sample retaining base by a friction force relative to the fixing base.
In the focus retaining apparatus, a sample retaining base grasping mechanism is provided for grasping and fixing the sample retaining base.
Further, a temperature sensor is provided on the fixing base to detect the ambient temperature and a temperature adjusting means is provided for adjusting the temperature of the fixing base and sample retaining base on the basis of a detection output of the temperature sensor to be made constant at all times.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to an observation sample, a stage so provided as to be movable in a direction orthogonal to an optical axis of the objective lens, a sample base placed on the stage to retain the observation sample, and position adjusting means provided at an outer periphery of the objective lens and moving the observation sample in an optical axis direction of the objective lens through the sample base to set a focal point of the objective lens to the observation sample, wherein the position adjusting means has a fixing base for fixing the objective lens, a sample retaining base fitted over an outer periphery of the fixing base and so provided as to be movable in the optical axis direction of the objective lens, a piezoelectric actuator provided on the upper side of the sample retaining base and performing its extending/contracting operation in the optical axis direction of the objective lens, a sample base provided on the upper side of the piezoelectric actuator and placing the observation sample thereon and an electrostatic sensor provided on the upper side of the sample retaining base to detect a moving amount of the sample base.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to an observation sample, a stage so provided as to be movable in a direction orthogonal to an optical axis of the objective lens, a sample base placed on the stage to retain the observation sample, position adjusting means provided at an outer periphery of the objective lens and moving the observation sample in an optical axis direction of the objective lens through the sample base to set a focal point of the objective lens to the observation sample, and elastic means provided on the stage and so set relative to the sample base as to have a low rigidity in the optical axis direction of the objective lens and a high rigidity in a moving direction of the stage, wherein the position adjusting means has a fixing base for fixing the objective lens, a sample retaining base fitted over an outer periphery of the fixing base and so provided as to be movable in the optical axis direction of the objective lens, a piezoelectric actuator provided on the upper side of the sample retaining base and performing its extending/contracting operation in the optical axis direction of the objective lens, a sample base provided on the upper side of the piezoelectric actuator and placing the observation sample thereon, and an electrostatic sensor provided on the upper side of the sample retaining base to detect a moving amount of the sample base.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to an observation sample, a stage so provided as to be movable in a direction orthogonal to an optical axis of the objective lens, a sample base placed on the stage to retain the observation sample, and position adjusting means provided at an outer periphery of the objective lens and moving the observation sample in an optical axis direction of the objective lens through the sample base to set a focal point of the objective lens to the observation sample, wherein the position adjusting means has a fixing base for fixing the objective lens and having a flange at its outer periphery and a sample retaining base fitted over an outer periphery of the fixing base and so provided as to be movable in the optical axis direction of the objective lens and having a flange at its outer periphery, and a feed screw section provided between the flange of the fixing base and the flange of the sample retaining base to feed the sample retaining base in the optical axis direction of the objective lens relative to the fixing base.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to an observation sample, a stage so provided as to be movable in a direction orthogonal to an optical axis of the objective lens, a sample base placed on the stage to retain the observation stage, position adjusting means provided at an outer periphery of the objective lens and moving the observation sample in an optical axis direction of the objective lens through the sample base to set a focal point of the objective lens to the observation sample, and elastic means provided on the stage and so set relative to the sample base as to have a low rigidity in the optical axis direction of the objective lens and a high rigidity in a moving direction of the stage, wherein the position adjusting means has a fixing base for fixing the objective lens and having a flange at its outer periphery, a sample retaining base fitted over the outer periphery of the fixing base and so provided as to be movable in the optical axis direction of the objective lens and having a flange at its outer periphery, and a feed screw section provided between the flange of the fixing base and the flange of the sample retaining base to feed the sample retaining base in the optical axis direction of the objective lens relative to the fixing base.
In the focus stabilizing apparatus, leaf springs are provided on the sample retaining base to fix the observation sample thereon.
Further, a mechanical coupling length between the objective lens and observation sample is set by the fixing base, sample retaining base and operation ring.
A mechanical coupling length between the objective lens and the observation sample is set by the fixing base and the sample retaining base.
In the focus stabilizing apparatus, the fixing base, operation ring and sample retaining base are made of at least two different kinds of materials and selectable in their dimensions.
The operation ring and sample retaining base are made of at least two different kinds of materials and selectable in their dimensions.
The operation ring and sample retaining base are formed of materials of different linear expansion coefficients.
An auxiliary member is located between the operation ring and the sample retaining base and made of a material different in liner expansion coefficient from the materials of the operation ring and sample retaining base.
The elastic means is comprised of leaf springs provided on the stage and arranged along the direction orthogonal to the optical axis of the objective lens and a magnet provided on the leaf spring to attract the sample base.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to an observation sample, position adjusting means provided at an outer periphery of the objective lens and moving the observation sample in an optical axis direction of the objective lens to set a focal point of the objective lens to the observation sample, a minute movement mechanism for minutely displacing the objective lens in the optical axis direction of the objective lens, displacement amount detecting means for detecting a displacement amount of the objective lens, and control means for operating the minute movement mechanism on the basis of a detection output of the displacement amount detecting means to control a relative distance between the objective lens and the observation sample to a predetermined distance.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to an observation sample, a stage so provided as to be movable in a direction orthogonal to an optical axis of the objective lens, a sample base placed on the stage to retain the observation sample, position adjusting means provided at an outer periphery of the objective lens and moving the observation sample in an optical axis direction of the objective lens through the sample base to set a focal point of the objective lens to the observation sample, a minute movement mechanism for minutely displacing the objective lens in the optical axis direction of the objective lens, displacement amount detecting means for detecting a displacement amount of the objective lens, control means for operating the minute movement mechanism on the basis of a detection output of the displacement amount detecting means to control a relative distance between the objective lens and the observation sample to a predetermined distance, and elastic means provided on the stage and so set relative to the sample base as to have a low rigidity in the optical axis direction of the objective lens and a high rigidity in a moving direction of the stage.
In the focus stabilizing apparatus, the position adjusting means has a fixing base for fixing the objective lens through the minute movement mechanism, a sample retaining base for placing the observation sample thereon, and an operation ring threadably inserted over the fixing base and, by being rotated relative to the fixing base, moving in the optical axis direction of the objective lens and moving the sample retaining base in the optical axis direction of the objective lens to adjust a relative distance between the observation sample and the objective lens.
A mechanical coupling length between the objective lens and the observation sample is set by the fixing base for fixing the objective lens through the minute movement mechanism, the sample retaining base for placing the observation sample thereon and the operation ring inserted over the fixing base and, by being rotated relative to the fixing base, moving in the optical axis direction of the objective lens and moving the sample retaining base in the optical axis direction of the objective lens to adjust a relative distance between the observation sample and the objective lens.
The minute movement mechanism has a moving stage relative to which the objective lens is provided, and an actuator for minutely moving the moving stage in the optical axis direction of the objective lens.
The minute movement mechanism has a moving stage relative to which the objective lens is provided, and piezoelectric actuators arranged in those positions symmetric relative to the optical axis of the objective lens to minutely move the moving stage in the optical axis direction of the objective lens.
The displacement amount detecting means is comprised of an electrostatic capacity sensor.
The control means has means for receiving, as inputs, an objective lens displacement amount detected by the displacement amount detecting means and an instruction value representing the position of the objective lens, means for finding a deviation between the displacement amount of the objective lens and the instruction value, and means for performing operation control of the minute movement mechanism in accordance with the deviation to move the objective lens to a position designated by the instruction value.
The elastic means is comprised of leaf springs mounted on the stage and arranged along the direction orthogonal to the optical axis of the objective lens and a magnet mounted on the leaf spring to attract the sample base.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to an observation sample, a minute movement mechanism for minutely displacing the objective lens in the optical axis direction of the objective lens, displacement amount detecting means for detecting a displacement amount of the objective lens, and control means for operating the minute movement mechanism on the basis of a detection output of the displacement amount detecting means to control a relative distance between the objective lens and the observation sample to a predetermined distance.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to an observation sample, a fixing base for fixing the objective lens, a minute movement table on which the objective lens is provided, parallel springs situated between the fixing base and the minute movement table to allow the minute movement table to be moved in an optical axis direction of the objective lens, an actuator provided between the fixing base and the minute movement table to minutely displace the minute movement table in the optical axis direction of the objective lens, a displacement sensor for detecting a displacement amount of the objective lens, and control means for allowing the actuator to perform its extending/contracting operation on the basis of a detection output of the displacement sensor to control the objective lens and bring it to a just-in-focus position relative to the observation sample.
In the focus stabilizing apparatus, the control means has a memory section for storing an output of the displacement sensor corresponding to a just-in-focus state between the observation sample and the objective lens, a comparing section for comparing an output of the displacement sensor and an output of the displacement sensor stored in the memory section, and a control section for outputting an electric signal for canceling a distance variation between the observation sample and the objective lens on the basis of a result of comparison by the comparing section to the actuator.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises an objective lens arranged opposite to an observation sample, position adjusting means provided at an outer periphery of the objective lens and moving the observation sample in an optical axis direction of the objective lens to set a focal point of the objective lens to the observation sample, a minute movement mechanism for minutely varying a distance between the observation sample and the objective lens in the optical axis direction, and control means for operating the minute movement mechanism to make a fine adjustment of the distance between the observation sample and the objective lens.
According to a main aspect of the present invention, a focus stabilizing apparatus is provided which comprises a fixing base having an objective lens mounting section, a sample base for supporting an observation sample, and position adjusting means provided on the fixing base to allow the sample base to be moved in an optical axis direction of the objective lens.
In the focus stabilizing apparatus, the position adjusting means has a fixing base for fixing the objective lens, an operation ring inserted over the fixing base and, by being rotated, moving in the optical axis direction of the objective lens, and a sample retaining base so provided as to be movable in the optical axis direction and, upon a rotation operation of the operating ring, adjusting a distance between the observation sample and the objective lens.
According to the present invention, the mechanical coupling length between the objective lens and the observation sample is determined by only the position adjusting means provided relative to the objective lens and can be set to be very short. By doing so, there is almost no variation in a positional relation between the objective lens and the observation sample even if the ambient temperature varies. The structure suffers no adverse effect from an external vibration and the sample can be observed at all times under a stable condition.
After the focal point of the objective lens has been set to the observation sample, the observation sample can be moved in a direction orthogonal to the optical axis of the objective lens simply by moving the stage and it is also possible to readily position the observation sample in a moving direction of the stage.
Further, as the position adjusting means use is made of at least two different kinds of materials and its component elements are selectable in their materials and dimensions. It is, therefore, possible to prevent an observation image from being degraded even if the ambient temperature varies.
Further, the mechanical coupling length between the objective lens and the observation sample is set to be short and the operation of the minute movement mechanism is controlled in accordance with a deviation between the displacement amount of the objective lens and the instruction value to allow the objective lens to be set to a position designated by the instruction value. Therefore, even if the ambient temperature varies, there is almost no variation in positional relation between the objective lens and the observation sample. The structure also suffers no adverse effect from external vibrations and the objective lens can be set to a desired position given by the instruction value and the observation sample can be observed, under a stable way, over an extended period of time.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.