  This paper, first, presents introductory reviews of the Space Infrared
Telescope for Cosmology and Astrophysics (SPICA) mission and the SPICA
Coronagraph Instrument (SCI). SPICA will realize a 3m class telescope cooled to
6K in orbit. The launch of SPICA is planned to take place in FY2018. The SPICA
mission provides us with a unique opportunity to make high dynamic-range
observations because of its large telescope aperture, high stability, and the
capability for making infrared observations from deep space. The SCI is a high
dynamic-range instrument proposed for SPICA. The primary objectives for the SCI
are the direct coronagraphic detection and spectroscopy of Jovian exoplanets in
the infrared region, while the monitoring of transiting planets is another
important target owing to the non-coronagraphic mode of the SCI. Then, recent
technical progress and ideas in conceptual studies are presented, which can
potentially enhance the performance of the instrument: the designs of an
integral 1-dimensional binary-shaped pupil mask coronagraph with general
darkness constraints, a concentric ring mask considering the obscured pupil for
surveying a wide field, and a spectral disperser for simultaneous wide
wavelength coverage, and the first results of tests of the toughness of MEMS
deformable mirrors for the rocket launch are introduced, together with a
description of a passive wavefront correction mirror using no actuator.
