Snowmobiles are vehicles designed primarily to move or travel over snow covered terrain. Generally, snowmobiles are open air vehicles with a motorcycle style seat that can accommodate up to four people. Snowmobiles are usually powered by an internal combustion engine that drives a long continuous or endless track which is located in a rearward position of the snowmobile, and substantially below or underneath the seat. This continuous or endless track, powered by the snowmobile's motor, is configured to engage the snow covered terrain and propel the snowmobile over the snow. The track provides a similar function for the snowmobile as a tire does on a road vehicle.
Snowmobiles are typically further equipped with a pair of skis positioned in a forward position. The function of the skis is to provide a front ground contact for stabilization, as well as to facilitate guiding or steering of the snowmobile. A pair of handlebars, accessible by an occupant on the seat, can be pivoted in order to turn the skis and thus turn or steer the snowmobile.
The front skis on a snowmobile, however, have several disadvantages that affect snowmobile performance and operation. For example, since the skis are designed to slide over the snow, they provide very little traction to the snowmobile. Consequently, the rear track often partially overpowers the traction of the ski and continues to push the snowmobile forward instead of through a turn. This partial overpowering of the ski traction causes the vehicle to make a wider turn, thereby affecting the cornering ability and overall handling of the snowmobile. Sometimes the rear track completely overpowers the skis and moves the snowmobile in a forward direction regardless of the direction the skis are turned. This is particularly the case when trying to traverse across hard surfaces such as hard pack snow, asphalt, or the like. The problem is compounded as snow provides a poor traction surface, and in the case of unpacked snow, is easily pushed or displaced. As such, when turning or moving sideways along a hill, the rider must often lean dramatically on the snowmobile in order to weight the front end and get the skis to bite into the snow. To account for these problems, those skilled in the art have equipped snowmobile skis with rails that extend down from the underside or contact portion of the skis. Although the rails are designed to increase the traction of the snowmobile by digging into the snow, these rails result in only marginal improvements.
Another disadvantage of the front skis is that they provide no assistance to the snowmobile's ability to accelerate, slow down, or reverse. In other words, they are passive and provide no driving force. In fact, since all the skis do is slide on or across the snow, they actually decrease the efficiency of the snowmobile as they tend to produce drag and a resistance that the rear endless track must overcome. Moreover, since the rear endless track of typical snowmobiles can sometimes become bogged down by snow, ice, rocks, and other debris becoming lodged in the track tunnel between the track and the seat, the additional resistance of the skis can stop the snowmobile from moving at all.
Still another disadvantage of the front skis is that they tend to ride on the top or upper surface of the snow, whereas the rear track tends to dig into the snow due to its driving force as powered by the snowmobile's motor, thus actively displacing the snow. The result of this is that the snowmobile has a tendency to move or travel with its longitudinal axis oriented on an incline with respect to the ground level, with the front end higher than the back end. In this position, there is less weight being placed on the skis, and thus the snowmobile is more difficult to maneuver and turn. In addition, this can provide vision problems as the rider's line of sight to the ground surface is obstructed causing him/her to have to look a greater distance past the front of the snowmobile to see the ground surface. This problem is made worse at night time since it causes the headlight of the snowmobile to point uselessly toward the sky instead of on the ground in front of the moving machine.


Optical brighteners are a class of fluorescent materials that absorb light in the ultraviolet regions of the electromagnetic spectrum (e.g., less than 400 nm) and re-emit light in the violet and blue regions of the electromagnetic spectrum (e.g., greater than 400 nm). Optical brighteners are used in a variety of applications to enhance the color or appearance of materials, such as paper and fabrics. Generally, optical brighteners are used to increase the perceived whiteness of such materials by increasing the overall amount of blue light emanating from the material (i.e., reflected from the material and emitted by substances deposited on the material).
While optical brighteners have been used to treat a variety of materials, some commercially-available optical brighteners have proven difficult to effectively deposit on certain substrates. For example, some commercially-available optical brighteners do not effectively deposit onto polyester-based fabrics. When such optical brighteners are used in laundry care compositions, polyester-based fabrics treated with the compositions typically show no deposition of the optical brightener and, consequently, no improvement in their whiteness index.
Accordingly, a need still remains for optical brighteners that exhibit effective whitening on a variety of substrates and for compositions (e.g., laundry care compositions) comprising such optical brighteners. This application seeks to provide such optical brighteners.


This application is related to Japanese application No. 2000-222703 filed on Jul. 24, 2000, whose priority is claimed under 35 USC xc2xa7 119, the disclosure of which is incorporated by reference in its entirety.
1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor device. More particularly, the invention relates to processing of a barrier film at a contact hole etching step (etching step for forming a contact hole).
2. Description of the Related Art
In recent years, a semiconductor device has been made minute and multifunctional. With this, a phenomenon in which functions of various functional components formed in the semiconductor device are deteriorated by harmful elements, molecules, and the like, has become remarkable. As measures against this, there has been adopted a method for protecting the functional components against the harmful elements, molecules and the like by various protection films (barrier films). As constituent materials of the barrier films, Al2O3 (alumina), TiO2, TiN, TiON, Ta2O5, TaSiN, SiN and the like can be enumerated. One of these barrier films blocks the penetration of a harmful material by the dense film, and another takes a harmful material in the film to trap it. However, there is a problem that the barrier films prevent etching in a subsequent processing step or produce reactive secondary product materials (deposited materials) during the etching.
Hereinafter, an example of the prior art will be described with reference to FIGS. 3A to 3C.
First, a resist pattern 26 for contact hole formation is formed in a state where an NSG film 22, a BPSG film 23, an alumina film (barrier film) 24, and an NSG film 25 are deposited over a silicone (Si) substrate 21 on which various functional components (not shown) are formed (FIG. 3A). In this case, what is barriered by the alumina film 24 is not limited to a semiconductor component formed just on the Si substrate 21, but all functional components under the alumina film 24 are barriered.
Conventionally, in a subsequent contact hole etching, the alumina film and a Si oxide films (NSG film and BPSG film) are dry etched at the same time under normal conditions for etching the Si oxide films, for example, by a gas including a fluorine based gas in plasma etching such as RIE. As an example of existing techniques, although the alumina film is not used for a barrier, an example of Japanese Unexamined Patent Publication No. Hei. 8 (1996)-31932 discloses a similar step. In this case, etching is stopped in the alumina film, or a reactive secondary product material (deposited material) 27 produced from alumina is deposited on the bottom of a contact hole (FIG. 3B).
The deposited material prevents electrical contact between the Si substrate and a metal wiring of an upper layer, and must be removed before the wiring is formed in the contact hole. As a conventional method, the deposited material is removed by a treatment using chemicals (for example, EKC270 of EKC Technology Inc., etc.) capable of dissolving the deposited material, or by physically impacting inert molecules of Ar or the like, ions, radicals or the like to the deposited material to make scattering (called sputter etching, inverse sputtering, or the like).
However, the conventional methods have problems. That is, both the deposited material removal by the chemicals and the deposited material removal by the sputter etching have an etching rate with respect to the Si substrate of the bottom of the contact hole (see Table 1). Thus, there arise problems that a damage 28 is caused (FIG. 3C) at the bottom of the contact hole (surface of the Si substrate), and the contact resistance becomes unstable from fluctuation in the removable state of the deposited material.
As another example of the prior art, as in an embodiment of Japanese Unexamined Patent Publication No. Hei. 7 (1995)-273112, a method is also conceivable in which etching of the alumina film is carried out by changing a gas and by a gas containing chlorine. In the etching by the gas containing chlorine, the etching rate of the alumina film is fast, and an etching stop in the alumina film does not occur. However, the mechanism in which the deposited material is produced is not changed, and since a similar treatment for the deposited material becomes necessary, the superiority is not high.
Incidentally, in the foregoing description of the prior art and the problems, the same is the case with a barrier film (film made of TiO2, TiN, TiON, Ta2O5, TaSiN, or SiN) other than the alumina film.
As described above, in the etching of the contact hole containing the barrier film, it is necessary to obtain contact hole etching conditions under which the deposited material is not produced from the barrier film, or to conceive a method in which the deposited material is effectively and certainly removed without damage.
According to the present invention, there is provided a method of manufacturing a semiconductor device provided with a first insulating film and a barrier film on a conductive region and an opening portion in the first insulating film and the barrier film, the method comprising the steps of:
forming a first opening portion in the barrier film reaching the first insulating film;
forming a second insulating film at least on the first insulating film in the first opening portion; and
forming a second opening portion smaller than the first opening portion and reaching the conductive region by simultaneously boring a hole into the first insulating film and the second insulating film in the first opening portion.
One of the features of the present invention is that the barrier film is removed more extensively than the second opening portion in advance to suppress the production of a deposited material in the opening portion at the etching for forming the second opening portion (contact hole), so that the barrier film which causes deposit in the contact hole is not exposed at the etching of the second opening portion.
Further, according to the present invention, the step of forming the first opening portion in the barrier film reaching the first insulating film may comprise covering the barrier film with a third insulating film, forming a resist pattern by using a mask for forming the second opening portion, forming a pattern for forming the first opening portion on the third insulating film by using the resist pattern, and forming the first opening portion in the barrier film by using the pattern for forming the first opening portion.
According to the above method, since the formation of the first opening portion can be made by using the second opening portion formation mask, the number of masks to be used can be decreased.
These and other objects of the present application will become more readily apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.


In many environments, it is useful to have a surface which is level regardless of the orientation of the structure supporting the surface. For example, helicopters or other vehicles including fixed-wing Unmanned Aerial Vehicles (UAVs) and rotary-wing Vertical Take-off Unmanned Aerial Vehicles (VTUAVs) often need a level surface from which they can take off and land in a wide range of sea conditions. Providing such a surface is not a problem on land-based facilities or other structures that are secured to a solid surface such as oil drilling platforms that are anchored to a sea bed, etc. However, providing such a surface can be difficult when the object on which the aircraft is to land can move. For example, helicopters attempting to take off and land on ships are currently limited to a relatively narrow range of sea conditions in order to avoid injuring the aircraft and/or crew.
Given these problems, there is a need for a mechanism that can be operated to maintain a surface in a desired orientation regardless of the fact that the support for such a surface is not level and/or is moving.


A vertical field-effect transistor (FET) has a channel perpendicular to the substrate surface, as opposed to being situated along the plane of the surface of the substrate. By using this design, it is possible to increase packing density. That is, by having the channel perpendicular to the substrate surface, vertical FETs improve the scaling limit beyond planar finFETs.
However, vertical FETs are still severely challenged past the 7 nm node due to high aspect ratios, Vmax limits, and material thickness not scaling well. For example, insulator material and shared contacts formed between gate material of adjacent vertical FETs make it very difficult to scale the devices beyond the 7 nm node, basically due to material thicknesses, leakage concerns, breakdown voltage, decreased resistances and capacitance, etc. Accordingly, these constraints make it very difficult to decrease gate pitch in current vertical FET designs.


The present application claims priority under 35 U.S.C xc2xa7119 to Japanese Patent Application No.2000-073932 filed Mar. 13, 2000 entitled xe2x80x9cROLLING GUIDE DEVICE xe2x80x9d, No.2000-367605 filed Dec. 1, 2000 entitled xe2x80x9cROLLING GUIDE DEVICE AND DRIVE SYSTEM USING ROLLING GUIDE DEVICExe2x80x9d, and No.2001-037486 filed Feb. 14, 2001 entitled xe2x80x9cROLLING GUIDE DEVICE AND DRIVE SYSTEM USING ROLLING GUIDE DEVICExe2x80x9d. The contents of that application are incorporated herein by reference in their entirety.
1. Field of the Invention
The present invention relates to a rolling guide device in which a movable rail is made slidable with respect to a track rail and also relates to a drive system using such a rolling guide device.
2. Description of the Related Art
As a rolling guide device in which a movable rail is made slidable with respect to a track rail, there has been known a slide rail such as shown in FIG. 25 (see Japanese Utility Model Publication No. SHO 62-8765). Such slide rail comprises a track rail member 1 having an opened recess 1a (i.e. having substantially -shaped (box-shaped) cross section) formed by both inner side surfaces 1b, 1b and a bottom surface 1c and a movable rail member 2 which is supported between both the inner side surfaces 1b, 1b of the track rail member 1 to be movable in the longitudinal direction thereof. The movable rail member 2 also has an opened recess 2a (i.e. having substantially -shaped (box-shaped) cross section).
The track rail member 1 and the movable rail member 2 have substantially the same longitudinal length. The inner side surfaces 1b of the track rail member 1 are formed with ball rolling grooves, respectively, along which balls roll in the longitudinal direction thereof, and outer side surfaces 2b of the movable rail member 2 are also formed with loaded ball rolling grooves, respectively, so as to extend in the longitudinal direction thereof and to oppose the ball rolling grooves formed to the track rail member 1.
A number of balls 3 are arranged and housed between these ball rolling grooves and loaded ball rolling grooves, and these balls 3 are held by a cage 4 to be rotatable and slidable. When the movable rail member 2 slides with respect to the track rail member 1 in the longitudinal direction thereof, these balls 3 roll and, hence, the slide rail becomes smoothly expandable or contractive.
Further, though not shown, there is also known a cam-follower type drawer device of a structure that is movable and track rails are both provided with wheels so that the movable rail is drawn with respect to the track rail, as a rolling guide device in which a movable rail is slidable with respect to a track rail.
However, in the conventional slide rail such as mentioned above, a number of balls 3 disposed and arranged between the track rail member 1 and the movable rail member 2 do not completely perform the rolling motion and will roll with a slight sliding motion. In the conventional slide rail, because the balls 3 do not circulate and only reciprocally move along the loaded rolling passage between the ball rolling grooves and the loaded ball rolling grooves, if the balls 3 slide, the cage 4 supporting (bearing) the balls 3 would be displaced from the initial position. As a result, in spite of the fact that an effective stroke of the movable rail member 2 is not achieved, the cage 4 collides with a stopper 5 of the track rail member 1 and, hence, such effective stroke could not be obtained. In this case, when it is required to slide the movable rail member 2 with the cage 4 colliding with the stopper 5, the movable rail member 2 will slide with the balls 3 being slipped, and accordingly, a large force is required to move the movable rail member 2.
Furthermore, in the conventional structure of the slide rail, in order to obtain a large stroke of the movable rail member 2, it is necessary for the movable rail member 2 to once come off from a portion at which the balls 3 exist and then to be engaged with that portion at which the balls 3 exist. That is, in the case where the movable rail member 2 comes off from the portion at which the balls 3 exist, for example, the movable rail member 2 which has been loaded with ten (10) balls 3 is loaded with, for example, six (6) balls 3, and hence the ability for bearing moment load, radial load and thrust load is deteriorated.
Moreover, with the cam-follower type drawer device, because the wheels generally have backlash or looseness, the movable rail member 2 does not smoothly slide, and furthermore, because the wheel has a cylindrical structure, a direction along which a load is received is determined, and hence, the thrust load cannot be received.
An object of the present invention is to substantially eliminate defects or drawbacks encountered in the prior art mentioned above and to provide a rolling guide device capable of taking a large expansion/contraction stroke and sufficiently bearing moment load, radial load and thrust load at any expanded (contracted) attitude and also provide a drive system incorporated with such a rolling guide device.
This and other objects can be achieved according to the present invention by providing, in one aspect, a rolling guide device comprising:
a track rail formed with a rolling member rolling surface extending along a longitudinal direction thereof;
a movable rail formed with a loaded rolling member rolling surface extending along a longitudinal direction thereof so as to oppose the rolling member rolling surface of the track rail;
a track rail side rolling member circulation passage formed to the track rail so as to circulate the rolling members rolling between the track rail and the movable rail;
a movable rail side rolling member circulation passage formed to the movable rail so as to circulate the rolling members rolling between the track rail and the movable rail; and a number of rolling members disposed and arranged in the track rail side rolling member circulation passage and the movable rail side rolling member circulation passage.
According to this aspect, when the movable rail slides with respect to the track rail, the rolling members arranged between the track rail and the movable rail endlessly circulate in the track rail side rolling member circulation passage and the movable rail side rolling member circulation passage while rolling therealong. As mentioned, because the rolling members circulate in the endless manner, even if the rolling member slides during the rolling motion, there is no causing of a case that a cage is shifted from the initial position as in the conventional structure, and hence, a large expansion (contraction) stroke is obtainable. Furthermore, in an optional expanded (contracted) attitude, there remains a considerable distance between the track rail side rolling member circulation passage and the movable rail side rolling member circulation passage, so that a rolling guide device, which can bear even the moment load, can be realized.
Further, when the movable rail slides and its stroke is made large, the considerable distance corresponding to this stroke is made short and the capability of bearing the moment load is reduced. However, according to the present invention, the movable rail does not come off from the balls, so that the capability of bearing the moment load is not extremely reduced. Moreover, because the movable rail does not come off from the balls and the number of the rolling members supported at an optional expansion (contraction) attitude is not changed, in contrast to the conventional slide rail, there can be provided a rolling guide device bearing the constant radial load and thrust load.
In the above aspect, the following preferred embodiments or examples may be provided with advantageous functions and effects thereof.
The track rail side rolling member circulation passage is formed in one longitudinal end side of the track rail and the movable rail side rolling member circulation passage is formed in one longitudinal end side, opposing that one end side of the track rail, of the movable rail.
Accordingly, the distance between the track rail side rolling member circulation passage and the movable rail side rolling member circulation passage can be made large, so that a rolling guide device bearing the large moment load can be provided.
Furthermore, the track rail has an opened recess having a-shaped section and has inside surfaces to which the rolling member rolling surfaces are formed, the movable rail is fitted into the recess of the track rail, and the movable rail has outside surfaces to which the loaded rolling member rolling surfaces are formed so as to oppose the rolling member rolling surfaces formed to the track rail inside surfaces.
Thus, various kinds of loads including radial load, thrust load and moment load can be supported in a balanced condition.
The track rail side rolling member circulation passage is provided with a rolling member return passage substantially parallel to the rolling member rolling surface and a rolling direction changing passage communicating the rolling member rolling surface and the rolling member return passage, the movable rail side rolling member circulation passage is provided with a rolling member return passage substantially parallel to the loaded rolling member rolling surface and a rolling direction changing passage communicating the rolling member rolling surface and the rolling member return passage, the rolling direction changing passages of the track rail side rolling member circulation passage and the movable rail side rolling member circulation passage are formed to a deflector which is formed independently from a track rail body and a movable rail body, and the deflector is fitted to holes formed in the track rail body and movable rail body from the side portions thereof.
According to this embodiment, the rolling direction changing passages can be easily formed in the long track rail and movable rail.
The return passages are drilled in the track rail body and the movable rail body from the longitudinal end portions thereof.
According to this embodiment, the return passages can be easily formed in the long track rail and movable rail.
The deflector is composed of a plurality of sections splitting along the rolling direction changing passages.
Accordingly, the rolling direction changing passages having a complicated structure may be easily formed in the deflector.
The deflector is made of a synthetic resin.
Accordingly, the rolling direction changing passages having a complicated structure may be easily formed in the deflector, and moreover, noise which may be generated when the rolling members roll in the rolling direction changing passages will be suppressed.
The above mentioned object of the present invention can be also achieved by providing, in another aspect, a drive system comprising:
a track rail formed with a rolling member rolling surface extending along a longitudinal direction thereof;
a movable rail formed with a loaded rolling member rolling surface extending along a longitudinal direction thereof so as to oppose the rolling member rolling surface of the track rail;
a track rail side rolling member circulation passage formed on the track rail so as to circulate the rolling members rolling between the track rail and the movable rail;
a movable rail side rolling member circulation passage formed on the movable rail so as to circulate the rolling members rolling between the track rail and the movable rail;
a number of rolling members disposed and arranged in the track rail side rolling member circulation passage and the movable rail side rolling member circulation passage; and
a linear motor means having a primary side mounted to either one of the track rail and the movable rail and a secondary side mounted to another one of the track rail and the movable rail.
According this aspect, the expansion (contraction) stroke can be made large and the moment load, the radial load and the thrust load can be sufficiently supported at an optional attitude of the system. Furthermore, because the linear motors are incorporated between the track rail and the movable rail, the use of the ball screw or like can be eliminated, thus moving the movable rail at high speed with less noise. Moreover, because it is not necessary to provide a space for a rotary motor, the drive system can be made thin and compact.
According to preferred embodiments or examples of this aspect, the following advantageous functions and effects may be attained.
The track rail side rolling member circulation passage is formed in one longitudinal end side of the track rail and the movable rail side rolling member circulation passage is formed in one longitudinal end side, opposing that one end side of the track rail, of the movable rail, and the linear motor means comprises first and second linear motors, the first linear motor having a primary side mounted to a portion near the track rail side rolling member circulation passage of the track rail, the second linear motor having a secondary side mounted to the track rail along the longitudinal direction thereof so as to be continuous to the primary side of the first linear motor, and the second linear motor having a primary side mounted to a portion near the movable rail side rolling member circulation passage of the movable rail, the first linear motor having a secondary side mounted to the movable rail along the longitudinal direction thereof so as to be continuous to the primary side of the second linear motor.
According to this embodiment, because two sets of linear motors are incorporated in the drive system, the thrust force can be made two times (twice), and the excitation is averaged to thereby make smooth the movement of the movable rail. Furthermore, the first linear motor has a primary side mounted to a portion near the track rail side rolling member circulation passage of the track rail and the second linear motor has a primary side mounted to a portion near the movable rail side rolling member circulation passage of the movable rail, so that the thrust force can be generated at substantially the same positions of the movable side rolling member circulation passage and the track rail side rolling member circulation passage, regardless of the stroke of the movable rail. Therefore, even if a pitching or yawing moment is applied to the movable rail, the thrust force can be stably applied to the movable rail.
The first and second linear motors may be composed of linear induction motors or linear pulse motors such that the secondary sides thereof are opposed to each other.
For example, in a case where linear D.C. motors are used, two sets of linear motors are disposed in back-to-back arrangement and a distance between the secondary side magnets is short, an alternating magnetic field may be generated between the magnets. However, according to this embodiment of the present invention, because the linear induction motors or linear pulse motors are used without using the magnets, there is no fear of causing any alternating magnetic filed. However, a linear D.C. motor may be utilized as far as a relatively large distance between the secondary sides of the linear D.C. motors can be taken so as not to influence from each other.
The nature and further characteristic features of the present invention may be made clear from the following descriptions made with reference to the accompanying drawings.


Many modern vehicles (e.g., automobiles or aerial vehicles) or mobile computer devices, such as smartphones, tablet computers or other general or special purpose machines, include one or more components for determining information regarding positions, orientations, velocities or accelerations of such vehicles or devices, and for providing navigational advice or instructions based on such information. For example, some vehicles and computer devices include Global Positioning System (or “GPS”) transceivers for determining positions using data received from one or more orbiting satellites, or cellular telephone equipment configured to estimate (e.g., triangulate) a position using signals received from one or more cellular telephone network towers or other network sources.
A GPS-enabled vehicle, device or other system or component may determine its position by interpreting signals that are received from multiple GPS satellites. A distance between a GPS receiver and a GPS satellite may be determined by calculating a “time of flight” between the GPS satellite and the GPS receiver for each such signal, which is assumed to travel at approximately the speed of light. Where three or more such signals are interpreted, the GPS receiver may be determined to be located at a specific point on the planet to within a certain degree of accuracy or tolerance, commonly on the order of two to ten meters.
Occasionally, position information determined using GPS satellites and GPS-enabled equipment may be inaccurate, irrelevant or unavailable. For example, like any computer device, most GPS-enabled equipment requires an initialization period during which GPS position information obtained or determined by such equipment is unreliable. Furthermore, where an environment includes many natural or artificial obstructions, such as tree limbs, office towers, mountains, walls or ceilings, the receipt of GPS signals by a GPS-enabled device may be delayed or otherwise interpreted as having arrived in an untimely manner. Moreover, the use of GPS satellites and GPS-enabled equipment necessarily relies on the viability of the GPS system as a whole. Like any computer-based system or communications system, the GPS system is at risk, at least theoretically, of hacking, spoofing or jamming, and may be taken offline or rendered unavailable for one or more legitimate or illegitimate purposes from time to time.


The exemplary embodiment relates to color selection. It finds particular application in connection with a system and method for classification and selection of color palettes based on an achromatic taxonomy.
A color palette is a set of different colors, which may be displayed as an ordered or unordered sequence of swatches, one for each color in the set. The colors in the palette have typically been selected by a graphic designer, or other skilled artisan working with color, to harmonize with each other, when used in various combinations. The effect of different color palettes on the human perception of the objects to which the colors are applied, such as brochures, textiles, automobiles, and the like, is not fully understood. However, either through common usage or innate preferences, the selection of a color palette can influence a customer's perception of an object. For example a brochure advertising Mediterranean vacations which utilizes a set of muted hues may be less likely to draw the interest of a customer than one which uses the bright colors typically associated with the region. Accordingly, designers often wish to select a color palette which is associated, in human perception, with a certain achromatic entity, such as an emotion, geographical location, musical genre, seasons of the year, or the like. In the case of emotions, palettes which elicit an excited or enthusiastic emotion may be suitable for some applications, such as a flyer for a circus production, while for others, such as a food product, the designer may wish to elicit emotions of pleasantness, such as contented or warm-hearted emotions. The designer uses his or her acquired experience in selecting a suitable color palette for the particular application.
Increasingly, color palettes are used by those who do not have extensive experience in color selection and design. To ascertain the response of a wide variety of people to a particular color palette, the palette may be submitted for review. Users look at the palettes, e.g., displayed on a screen or printed on print media, and assign labels which are natural language expressions of the particular users' perceptions. Large collections of labelled data where millions of users create, annotate, and review color combinations are now accessible.
The present exemplary embodiment takes advantage of such labelled data in a system and method which enables selection and creation of palettes according to achromatic entities, such as emotions.


The literature is full of examples where processor and system faults or "bugs" were discovered long after the processors or systems were shipped to customers. It is well known that the later in the product cycle that a "bug" is discovered, the greater the expense to fix it. Compounding this problem is the trend towards shorter and shorter product cycles. Finally, the problem is compounded again by the trend towards tightly-coupled multiple processor computer systems. This compounding is because in such a tightly-coupled multiple processor system, it is not only necessary to discover and fix the faults in a single processor, it is also now necessary to discover and fix faults resulting from the interaction among the multiple processors.
One problem with implementing tightly coupled multiple processor computer systems are in exhaustively testing the interactions between and among multiple processors. For example, in a tightly coupled system, two or more processors may each have an individual high-speed level one (L1) cache, and share a slightly lower speed level two (L2) cache. This L2 cache is traditionally backed by an even larger main memory. The L1 and L2 caches are typically comprised of high speed Static Random Access Memory (SRAM), and the main memory is typically comprised of slower speed Dynamic Random Access Memory (DRAM).
It is necessary that the cache and memory be maintained for coherency. Thus, for example, at most only a single L1 cache of a single processor is allowed to contain a cache line corresponding to a given block of main memory. When multiple processors are reading and writing the same block in memory, a conflict arises among their cache controllers. This is conflict is typically resolved in a tightly coupled multiprocessor system with an interprocessor cache protocol communicated over an interprocessor bus. For example, a first processor may be required to reserve a cache copy of the contested block of memory. This is communicated to the other processors. However, if another (second) processor already has reserved the contested block of memory, the first processor must wait until the block is unlocked, and potentially written at least back to the L2 cache.
Debugging a cache protocol can be quite difficult. This stems from a number of interrelated factors. First, the multiple processors are each typically operating asynchronously from each other at extremely high frequencies or rates of speed. Secondly, the L1 caches, and their cache controllers are typically operating at essentially the same speed as the processors. Third, instruction cache misses for test instruction sequences can delay instruction execution by relatively long, somewhat variable, periods of time. There are a number of reasons for this later problem. One reason is it may be possible to retrieve a cache line of instructions from L1 cache or from L2 cache, or it may be necessary to load the cache line from slower main memory. The DRAM comprising the main memory typically operates quite a bit slower than the processor (and L1 cache). Another problem is that the time it takes to fetch a block of instructions from the main memory may vary slightly. There are a number of causes of this. First, accessing different addresses in the DRAM may take slightly different times. This is partly because of differing signal path lengths. Secondly, different memory banks may have slightly different timing. This is true, even when the specifications for the memories are equivalent. This is particularly true, when the memories are self-timed. This problem may be accentuated when multiple processors or multiple memories share a common memory access bus, where the actions of one processor or memory may lock out, and stall, another processor or memory. Note also that asynchronous Input/Output (I/O) operations to memory can have seemingly random effects on timing.
Despite the problems described above, in order to effectively test the interaction among multiple processors, it is preferable to exhaustively test each set of possible combinations. In the case of a cache protocol as described above, it is preferable to exhaustively test each possible set of cache states and cache state transitions. It is also preferable to be able to detect and record state changes at a lower level than that available to a user program.
In order to test the interactions among multiple processors, the various combinations of states and state transitions should be tested. This can be done by executing programs simultaneously on each of the processors. Varying the time when each processor executes its program can test the different combinations. Unfortunately, there is no mechanism in the prior art to accurately exhaustively vary the times when each processor executes its program. This is partly due to the processor instruction timing variations described above. The result is that timing windows often arise where particular state and state transition interactions are not tested.
One solution to this problem is to increase the number of tests run and the number of test cycles run. This increases the chances of uncovering faults, but does not guarantee exhaustive fault coverage.
Another set of prior art solutions is to try to control more closely the timing between executions of programs by the multiple processors. One such solution is to use NOP instructions to delay execution. The larger the number of NOP instructions executed, the longer the delay. However, NOP instructions are typically executed out of blocks of instructions held in cache lines. Each time execution crosses a cache line boundary, there is a potential for a cache miss, resulting in retrieving the cache line from slower memory. There is also a potential at that point that execution may be delayed for one or more cycles due to memory bus contention. Each of these potential delays introduces a potential window that did not get tested utilizing this set of solutions. Note also that virtual memory program activity must also be accounted for.
Another problem that arises is that it is often hard to distinguish states and state transitions from a programmer's view of a processor. This is partly because there is much that is not visible at this level. States and state transitions must therefore be assumed from visible programmer model level changes in the processor. This problem of distinguishing state and state transitions is a particular problem when the states and state transitions are cache states and state transitions during interaction testing among multiple processors.
One prior art solution to determining machine states and state transitions is through the use of SCAN. Using SCAN, a known pattern of states can be loaded into a processor. The processor then executes one or two instructions. The states of the various memory elements in the processor are then unloaded from the processor and compared with their expected values. This type of functional testing is becoming common for high-end microprocessors. Unfortunately, it does not lend itself to exhaustively testing the interactions among multiple processors. One reason for this is that a processor under the control of SCAN typically only executes for one or two instruction cycles, before the SCAN latches are unloaded, and another set of values loaded. The result of this is that SCAN is extremely slow, especially in comparison to the speed of modern processors. This significantly reduces the amount of testing that can be realistically done with SCAN. Secondly, there is no readily apparent mechanism available to test multiple processors at the same time, and more importantly to vary the start times of each of the multiple processors being tested together.
In the past, it has been sometimes been possible to run enough signals out of a processor that the states and state transitions being tested can be monitored by test equipment. One problem with this method of testing is that it is a manual and error prone process. Just as important, this method is fast becoming less and less possible as more and more functionality is embedded on single chips. Pin-count has become a major concern, and it has become increasingly unlikely that precious external pins can be dedicated for the sort of interprocessor state testing described above.
Testability, and thus reliability through earlier fault detection would be significantly increased in tightly coupled multiprocessor systems if the interactions among multiple processors could be accurately exhaustively tested, with the guarantee that no timing windows were inadvertently left untested. This testability would be further enhanced by a mechanism for recording states and state transitions over a series of clock cycles for each of the processors being tested.


A Fixed Wireless Loop (FWL) is a system that supports access of wireline telecommunications devices to the public wireline network via wireless communications. A radio transceiver transmits and receives communication signals to and from a remote transceiver located at a subscriber's home or office. Thus, a FWL eliminates the need for copper wire transmission between service providers and their respective subscribers.
A FWL is typically provided utilizing a FWL terminal at the subscriber's home or office. Mobility has been added to the FWL via a cradled handset. While the handset, or hand-held transceiver, is in the cradle, the combined unit functions as a FWL terminal providing telephone service over the subscriber's telephone wiring. When the hand-held transceiver is removed from the cradle, the hand-held transceiver acts as a mobile unit allowing the subscriber to roam throughout the house, or the FWL home sector. This type of FWL terminal serves the market of telecommunications users not needing mobile wireless services on a continuous basis, but would like to have easy access to such services when needed. Known FWL terminals as described above include the CelDock manufactured by Telular and the IntelliGo manufactured by GTE.
Such devices, however, render the wireline phones connected to the FWL terminal inoperative when the hand-held transceiver is removed from the cradle. Furthermore, the mobility of the hand-held transceiver is limited to the FWL sector surrounding the subscriber's home or office.
Thus, there exists a need for a FWL terminal that supports wireline telecommunications services when the hand-held transceiver is removed from the cradle. There also exists a need for providing hand-off capability between the FWL hand-held transceiver and the public wireless network.


1. Field of the Invention
This invention relates generally to a tensioner for tensioning a power transmission belt of a belt drive system. Particularly, it relates to a tensioner having a linear pulley movement. Specifically, this invention relates to a linear movement tensioner whose movement is mechanically damped and travel limited with included applicability to power transmission belt drive systems having a unitary device performing both the engine starting function and the electrical power generation function, such as a motor/generator sometimes referred to as a Gen-Star.
2. Description of the Prior Art
Internal combustion engines, or power plants, commonly use power transmission belt drive systems to tap power from the engine's crankshaft and deliver it to one or more various engine auxiliaries or accessories. In automotive applications, these accessories include power steering pumps, water pumps, air conditioning compressors, fuel pumps, and alternators. Historically, such engines have had the main power takeoff point at the crankshaft protruding from the rear of the engine to which is attached the drive train for driving the wheels to move the automobile. The accessories are driven from a pulley attached to the front of the crankshaft. Each accessory is equipped with a pulley. All of the pulleys are in mechanical communication via one or more power transmission belts trained about them. Some method of tensioning each power transmission belt is provided. The power transmission belt, the pulleys, and devices accomplishing belt tensioning form the accessory belt drive system.
Earlier systems included multiple v-belts. Commonly, each belt was tensioned by manual adjustment and fixing of the position of one accessory or idler per belt. These are referred to as locked-center belt drives, because there is no provision for automatic movement of any of the pulleys to accommodate varying condition of the belt or of the drive as a whole. If the belt should stretch or otherwise lengthen, the tension upon the belt would lessen. Further, for proper operation of the belt drive system, the tension of the belt must be set high enough to accommodate the worst case condition. Such worst case conditions can be the result of extremes of temperature, engine operation, or accessory operation.
There has been interest in making the volume, of the engine compartments of automobiles, smaller. To accommodate the smaller compartments, various aspects of the engines have become smaller, including the accessory belt drive systems. This has been accomplished, at least in part, by reducing the number of belts employed. As each belt is removed, and the number of layers extending from the front of the engine is thereby removed, the total distance the belt drive system extends from the front of the engine is reduced. Ultimately, this has resulted in the use of a single serpentine belt for many applications. A serpentine belt is so named because of the way it snakes around the various pulleys in a series of bends, both forward and backward. A v-ribbed or Micro-V (a registered trademark of The Gates Rubber Company) belt is most suited to serpentine applications.
The limitations of the locked-center approach to belt tensioning are exacerbated in serpentine applications. Accordingly, most modern serpentine belt drives include an automatic tensioner whereby the changing conditions of the belt drive system can be better accommodated. In basic form, an automatic tensioner has a framework or attachment point, which attaches directly to the cylinder block of the engine, or indirectly to some point on the vehicle that is stationary with respect to the engine of the vehicle, and a pulley, which presses upon the belt in the plane of rotation of the belt drive system. A moveable member or connective portion extends between the framework and the pulley to provide pressure upon the belt, via the pulley. The pressure acts to lengthen the distance about which the belt is trained and thereby causes the belt to be in tension. Various techniques and geometries have been employed to provide the biasing force. Commonly, a resilient member, such as a steel spring acts to force the moveable member in motion which results in the pulley tending to move in a direction toward a surface of the belt which, in turn, tends to increase tension upon the belt.
A tensioner with only these elements provides a somewhat constant force upon the surface of the belt when the system is in a resting state (i.e., the pulleys are not rotating). Dimensional instability, of the drive system caused by time, temperature, or manufacturing variation is accommodated fairly well through the action of the resilient member, at least to the limits of the resilient member and geometry of the tensioner. Thus, the tension upon the belt remains relatively constant, when the system is at rest, even though the belt may have stretched or the engine may be hot or cold. However, a tensioner with only these elements may not maintain appropriate tension upon the belt for all operating conditions of the system.
An operating power transmission belt drive system typically oscillates due to the influences of torsional vibration or other angular acceleration of the crankshaft or accessories, the influences of unbalanced conditions, or other influences. Torsional vibration of the crankshaft occurs, in part, as a result of the distinct impulses delivered to the crankshaft through the combustion cycles of each cylinder and piston combination. The oscillations lead to vibration of the belt. This, in turn, leads to vibration of the moveable portions of the tensioner. Momentum then builds in those moveable portions modifying the force the pulley exerts upon the belt surface and the tension upon the belt. The changing tension upon the belt can cause unacceptable performance for the belt drive system. In one instance, issues of short-term performance, such as where the belt of the belt drive system slips excessively limiting the system's efficiency or power transmission capability, or is excessively noisy due to slippage or otherwise, can arise. In another instance, the amount of tension necessarily applied to the belt, to have acceptable performance on the short-term, leads to long-term issues such as premature failure of one or more components of the system, including the belt, or one or more accessories.
To accommodate these issues and thus improve the performance of tensioners, damping devices have been included in tensioners. Early damped tensioners have included symmetrical damping where movement of the moveable portions of the tensioners are damped approximately equally whether the instantaneous movement is in the direction tending to increase tension upon the belt or in the direction tending to decrease tension upon the belt. Damping combines with the forces supplied by the resilient member to result in a modified biasing, at the pulley/belt interface.
Other tensioners have utilized asymmetrical damping. Commonly, such tensioners are damped such that the damping upon the moveable portion is minimal when the tensioner is moving in the belt tensioning direction and maximal when moving in the belt loosening direction. In one approach, a shoe is biased against a race at an angle different from normal to the surface of the race. As a result, the relative movement of the shoe and race in one direction tends to lift the shoe from the race. This reduces the pressure at their interface, reduces the friction that gives rise to the damping, and thereby reduces the damping. The other direction tends to wedge the shoe against the race and increase the damping. An example is described in U.S. Pat. No. 5,964,674, to Serkh et al. These have involved the use of tensioners having a single pulley biased against a surface of the belt, to supply tension. Further, the biasing against the belt has been solely relative to the engine block.
U.S. Pat. No. 4,416,647 to White, Jr. discloses the use of tensioners with two pulleys pressing upon the power transmission belt. The '647 patent states that the approach is useful for tensioning a system with a cyclic load such as an air conditioning compressor. One, of the pulleys, presses upon a span of the power transmission belt immediately upstream of the cyclic load. While, the other pulley presses upon the power transmission belt immediately downstream of the cyclic load. In one embodiment, the two pulleys are fixed relative to each other upon a angled member that can pivot about its apex. The assembly is pressed toward the power transmission belt to supply static tension in a locked-center fashion. The pivot is said to accommodate dynamic tension. Static tension is the result of the force applied to the power transmission belt by the tensioner in the belt tensioning direction with the effect of tending to lengthen the distance the power transmission belt is forced to travel about the pulleys of the system. If it were assumed that each of the pulleys of the system is allowed to rotate freely, tension on every span would be the same and at static tension. Dynamic tension is the tension over the length of the power transmission belt that is the result of static tension as altered by the influences of torque upon each of the pulleys and various imbalances of the system. As an additional result, each span tends to be under differing tension.
Power transmission belt tensioners used in conjunction with accessory belt drive systems for internal combustion engines are known with pulley movements that are both arcuate and linear. Those of the above discussion have all used arcuate movements. Certain applications benefit from linear movement tensioners (i.e., those where the idler pulley contacting the power transmission belt moves in a substantially straight path).
An example of a linear movement tensioner can be found in U.S. Pat. No. 4,634,408 to Foster. The '408 patent discloses the construction of a relatively complex tensioner that incorporates a plurality of springs about a hydraulic damping mechanism. The tension upon the belt is adjustable by bolts that define the level of compression applied to the springs. The carrier, upon which the tensioning pulley is mounted, engages the track, that defines the carriers two degrees of freedom of movement, with a ball and track bearing structure. All of this, has inherent limits of travel, as with all mechanical structures. However, there is no intentional travel limitation disclosed. Further, there is no disclosure of travel limitation structure or technique to accommodate a controlled deceleration if the tensioner reaches the limit of it travel. It is common in the art, of tensioners for belt drive systems, for tensioners to be designed to have adequate travel in their movements to never reach the limit of their travel in normal belt system operation. The '408 patent does not suggest that the disclosed tensioner is contemplated to be any different. The inclusion of hydraulics creates the concern of leaking hydraulic fluid. The hydraulic mechanism disclosed is apparently not compact. Thus, the tensioner appears to be relatively large. The relatively large number of parts adds to cost and complexity of construction. Further, there is no provision for compensating for the parasitic torque across the carrier that supports the idler pulley, which tends to twist that carrier, other than the effectiveness of the ball and track bearing structure.
Traditionally, an electric starter motor is provided to spin the crankshaft of the engine so that combustion may be initiated and the engine will begin to run. The starter motor is located near the rear of the engine and is adapted to intermittently engage the rear portion of the crankshaft through a gear train.
Currently, there is increasing pressure to reduce emissions and increase fuel economy by lowering the weight of the automobile and reducing the number of under-the-hood components. An approach taken toward these goals involves combining the function of the starter motor and the function of the alternator into a single device, a motor/generator or a Gen-Star. Also toward the goal of increasing fuel economy, the Gen-Star promotes the use of a feature called “stop-in-idle”. This feature is where the engine is allowed to die when it would ordinarily idle, then be restarted when the automobile is expected to resume motion. This feature substantially increases the demands placed upon accessory belt drives. In application, the motor/generator is placed in mechanical communication with the crankshaft via the accessory belt drive. The motor/generator and associated accessory belt drive system tends to be placed at the front of the engine. However, placing these systems at other locations, including the rear of the engine is envisioned.
The advent of Gen-Star systems causes the designer, of power transmission belt drive systems, to face substantial new challenges, above mere oscillatory loads. A significant challenge, among these, has been to develop a tensioning system that results in acceptable performance, by an accessory belt drive that includes this new device, which not only offers substantial load and rotational inertia, but also adds large driving torque into the accessory belt drive. Further, it provides this large driving torque on an intermittent basis.
It has been discovered that for various layouts of belt drive systems incorporating a linear movement tensioner and a motor/generator that the inclusion of damping, especially asymmetric damping, can positively affect both short-term and long-term performance of such a belt drive system. It has also been discovered that placing specific limits on the travel of the tensioner in the belt loosening direction can positively affect both short-term and long-term performance of such a belt drive system. This can be true even where a system does not include a motor/generator. However, deleterious side effects caused by such a travel limitation include undesirable belt and other system noise, when the limits are reached.
U.S. Pat. No. 4,758,208 to Bartos et al., discloses the use of two arms with arcuate movements, each carrying a pulley. The arms are mounted with pivot points that correspond with the shaft of a motor/generator. The two arms are biased toward each other by a spring. The tensioner also includes having the motor/generator mounted in a limited rotatable fashion such that the housing is allowed to rotate a few degrees in reaction to whether the motor/generator mode is of operating as a starter or an alternator. This reactive movement operates a pair of latches, which alternatingly lock one or the other of the two arms against movement, depending upon mode. In this manner, the arm associated with the power transmission belt span terminating at the motor/generator pulley with the greatest tension, as a result of the motor/generator mode, is locked in place. The free arm then supplies tension to the power transmission belt system. This tensioner is apparently complex, requires special mounting of the motor/generator having moving parts subject to wear, and is not flexible in its application. Further, the '208 patent does not disclose the contemplation of adding damping to the movement of either pulley to enhance system performance. Also, it does not disclose a travel limiting structure that is either resilient, cooperates with a damping mechanism, or suggests an attempt at overcoming the previously described deleterious side effects.
Installation of a linear tensioner having specific travel limits can also be enhanced by making those specific limits adjustable on a case-by-case basis and by providing a release mechanism that can be selectively released upon installation of the belt. Further, tension decay characteristics of the belt can be better accommodated where the adjusters providing the adjustable specific limits can be preset to provide an initial locked-center tensioner adjustment.
Accordingly, there is a continuing need for a linear movement tensioner that is travel limited while avoiding deleterious side effects in operation for those applications that can benefit therefrom. An accessory power transmission belt drive system having a motor/generator is one such application.
There is a continuing need for a linear tensioner having travel limits that are adjustable, or can provide an initial locked-center tension, or both. There is also a continuing need for a linear tensioner having a release mechanism.
Further, there remains the need for a tensioner and system, for use in conjunction with a motor/generator that provides, at once, adequate short-term performance, adequate long-term performance, optimizes the width of the belt that may be used for any given application, contains cost and complexity, is flexible according to the motor/generator systems to which it can be applied and offers a linear movement.