Abstract: An optical element according to an embodiment of the present invention includes: a reflective imaging element for reflecting light from an object an even number of times to cause an image of the object to be formed; a first polarizer disposed on a light-outgoing side of the reflective imaging element; and a first phase difference plate disposed between the reflective imaging element and the first polarizer.

Abstract: An optical system according to an embodiment of the present invention includes a reflective imaging element having a first principal face which is struck by light emitted from a display panel, a second principal face parallel to the first principal face, and two mutually-orthogonal specular elements being perpendicular to the first principal face, and causes an image displayed on a display surface of the display panel to form an image at a position of planar symmetry with respect to the reflective imaging element as a plane of symmetry. A transparent substrate which is disposed on at least either the first principal face side or the second principal face side of the reflective imaging element is further included, and first light striking the transparent substrate is linearly polarized light, with a large proportion of p-polarized light.

Abstract: Disclosed is a thin-film transistor (10) manufacturing method that includes a process for forming a nitrate film (12x) that includes residual nickel (22) on a surface thereof, by bringing a nitric acid solution into contact with a polysilicon layer (11x); and a process for removing the nitrate film (12x) that includes residual nickel (22) from the polysilicon layer (11x) surface. With this surface treatment process, a polysilicon layer (11) with reduced concentration of a surface residual nickel (22) is provided, and a thin-film transistor (10) having excellent surface smoothness is attained.

Abstract: A reflective imaging element includes: a plurality of holes penetrating through the plate-like substrate along a thickness direction thereof; two orthogonally-disposed specular elements on inner walls of the plurality of holes; a first principal face on which light from an object is received; a second principal face parallel to the first principal face; and two taper elements opposing the two specular elements. The two taper elements each have a first side parallel to the first principal face, a second side orthogonal to the first principal face and to the first side, and a hypotenuse meeting the first and second sides and constituting an angle ? with the second side. An angle constituted by a normal direction of the first principal face and an incident direction of light striking the first principal face defines an incident angle ?, such that, in a range of 0°<?<90°, the angle ? satisfies (90°??)/4??.

Abstract: An optical system includes: a reflective imaging element; and a liquid crystal display panel disposed on a light-incident side of the reflective imaging element, the liquid crystal display panel having a display surface which is inclined with an angle of no less than 45° and no more than 75° relative to a plane defined by the reflective imaging element, a viewing angle dependence of a contrast ratio of the liquid crystal display panel taking a central value in a direction inclined by 10° or more in a direction of tilt of the display surface from a normal of the display surface, and causes an image displayed on the display surface of the liquid crystal display panel to form an image at a position of planar symmetry with respect to the reflective imaging element as a plane of symmetry.

Abstract: A color filter frame, which covers a non-display surface of an optical display section, is provided with frame color filter picture elements using at least two of three colors used for color filter picture elements, which correspond to displaying pixels. An area ratio of the frame color filter picture elements corresponding to different colors is set so as to be different from that of the color filter picture elements, which correspond to the colors used in the frame color filter picture elements. With this arrangement, it is possible to omit the step of manufacturing a black mask so as to reduce the cost; consequently, a color filter for an optical display device can be provided with an excellent appearance on a display.