Abstract: A double-wavelength light source unit capable of stable signal detection, is realized.

Abstract: An adhesive is coated on at least one surface of a thin film of organic material having birefringent properties and a phase-difference producing function, and a fixing substrate having transmitting or reflecting properties is bonded to the thin film of organic material by the adhesive, wherein materials satisfying relations of E1<E2 and E3<E2 where E1 is the linear expansion coefficient of the thin film of organic material, E2 is the linear expansion coefficient of the adhesive and E3 is the linear expansion coefficient of the fixing substrate, and the glass transition temperature of the thin film of organic material being 150° or more, are selected.

Abstract: An optical head device having an optical element capable of transmitting without diffracting light having a wavelength emitted from a two-wavelength semiconductor laser and capable of diffracting light having another wavelength, to provide high utilization efficiency of light in a stable manner.

Abstract: A diffraction element having concave/convex-like diffraction gratings in its two surfaces from which at least two separated light beams can be taken in the same direction without changing largely the propagating direction of diffracted light even if the temperature of the operating environment changes. A diffraction grating having a concave/convex shape in cross-section is formed in the incoming-side surface of the transparent substrate and two diffraction gratings of concave/convex shape in cross-section are formed in the outgoing-side surface wherein the grating pitch of the first one is made equal to the grating pitch of one of the second ones.

Abstract: A multi-layer diffraction type polarizer and a liquid crystal element capable of realizing a stable high extinction ratio is provided. Further, a liquid crystal element is obtained, which can rotate the polarization direction maintaining high linearity of output light when linearly polarized light is incident.

Abstract: An optical head device having an optical element capable of transmitting without diffracting light having a wavelength emitted from a two-wavelength semiconductor laser and capable of diffracting light having another wavelength, to provide high utilization efficiency of light in a stable manner.

Abstract: An adhesive is coated on at least one surface of a thin film of organic material having birefringent properties and a phase-difference producing function, and a fixing substrate having transmitting or reflecting properties is bonded to the thin film of organic material by the adhesive, wherein materials satisfying relations of E1<E2 and E3<E2 where E1 is the linear expansion coefficient of the thin film of organic material, E2 is the linear expansion coefficient of the adhesive and E3 is the linear expansion coefficient of the fixing substrate, and the glass transition temperature of the thin film of organic material being 150° or more, are selected.

Abstract: An adhesive is coated on at least one surface of a thin film of organic material having birefringent properties and a phase-difference producing function, and a fixing substrate having transmitting or reflecting properties is bonded to the thin film of organic material by the adhesive, wherein materials satisfying relations of E1<E2 and E3<E2 where E1 is the linear expansion coefficient of the thin film of organic material, E2 is the linear expansion coefficient of the adhesive and E3 is the linear expansion coefficient of the fixing substrate, and the glass transition temperature of the thin film of organic material being 150° or more, are selected.

Abstract: An adhesive is coated on at least one surface of a thin film of organic material having birefringent properties and a phase-difference producing function, and a fixing substrate having transmitting or reflecting properties is bonded to the thin film of organic material by the adhesive, wherein materials satisfying relations of E1<E2 and E3<E2 where E1 is the linear expansion coefficient of the thin film of organic material, E2 is the linear expansion coefficient of the adhesive and E3 is the linear expansion coefficient of the fixing substrate, and the glass transition temperature of the thin film of organic material being 150° or more, are selected.

Abstract: A projection type display apparatus comprising a light source apparatus which is provided with an elliptic mirror 12, a light source 11 disposed at the first focal point, a cone-like material disposed at the second focal point, a condenser lens 13, display elements 15R-15B, a color separating and synthesizing optical system, second condenser lenses 16R-16B and a projection lens 19. The cone-like material is one selected from the group of a convex cone lens, a concave cone lens 2, a convex cone-like reflector and a concave cone-like reflector 20. In the projection type display element, light emitted from the light source is introduced into the cone-like material and is emitted as divergent light through the conical surface of the cone-like material.

Abstract: The display device using a transparent-scattering type liquid crystal element has such a structure that the light quantity to an observer is controlled as possible when a black image is provided, and a high efficiency of light is maintained in comparison with the conventional technique when a white image is provided. A prism array 2 is disposed at the back surface of the transparent-scattering type display element so that a sawteeth-like surface of the prism array 2 faces the display element 1, and a light absorber 3 is disposed at the back surface of the prism array.

Abstract: A projection type display apparatus has a light source optical system, a first filter (1), a first aperture (17), a condenser lens (13), a liquid crystal element (15) having a color filter for each pixel, a second aperture (18), a second filter (2), a projection optical system which form a schlieren optical system wherein first and second filters each composed of a spectral element for controlling each color of R, G and B are provided.

Abstract: A light source optical system for projection 1, dichroic mirrors 21, 22 disposed to have a predetermined included angle .beta., a reflection type liquid crystal optical element blocks 31-33 each including a closely contacted converging lens and having a reflection surface and a projection optical system 4 are provided, wherein the normal line of a dichroic mirror surface and the optical axis of incident light form an included angle .alpha.; the normal line of the reflection surface and the optical axis of incident light form an included angle .gamma.; light emitted from a light source is color-separated so as to become color lights; the color lights are rendered to be parallel light beams, and are modulated and reflected by means of the reflection type liquid crystal optical elements; the reflected light beams are color-synthesized; and the color-synthesized light is projected through a projection lens.

Abstract: A projection type display apparatus comprising a light source apparatus which is provided with an elliptic mirror 12, a light source 11 disposed at the first focal point, a cone-like material disposed at the second focal point, a condenser lens 13, display elements 15R-15B, a color separating and synthesizing optical system, second condenser lenses 16R-16B and a projection lens 19. The cone-like material is one selected from the group of a convex cone lens, a concave cone lens 2, a convex cone-like reflector and a concave cone-like reflector 20. In the projection type display element, light emitted from the light source is introduced into the cone-like material and is emitted as divergent light through the conical surface of the cone-like material.

Abstract: A light source optical system for projection 1, dichroic mirrors 21, 22 disposed to have a predetermined included angle .beta., a reflection type liquid crystal optical element blocks 31-33 each including a closely contacted converging lens and having a reflection surface and a projection optical system 4 are provided, wherein the normal line of a dichroic mirror surface and the optical axis of incident light form an included angle .alpha.; the normal line of the reflection surface and the optical axis of incident light form an included angle .gamma.; light emitted from a light source is color-separated so as to become color lights; the color lights are rendered to be parallel light beams, and are modulated and reflected by means of the reflection type liquid crystal optical elements; the reflected light beams are color-synthesized; and the color-synthesized light is projected through a projection lens.

Abstract: An illumination device for a direct viewing type display element comprising a flat light guide; a light source set such that light is incident on a side portion of said flat light guide; a polarized light separating flat set on a first side of a light emitting side of the flat light guide for transmitting a p polarized light component and reflecting at least a portion of an s polarized light component with respect to a light ray substantially having a predetermined direction of incidence; and a light reflecting sheet disposed on a second side opposite to said light emitting side of the flat light guide in parallel with the light emitting site.

Abstract: A liquid crystal display element comprises a liquid crystal and solidified matrix composite, in which liquid crystal is dispersed and held in a solidified matrix, which is interposed between a pair of substrates with electrodes at least one of which is transparent, wherein at least one of the substrates with electrodes has a fine concave-convex electrode surface at the side for the liquid crystal and solidified matrix composite.

Abstract: A projection type display apparatus comprises a light source optical system having an anisotropic luminance distribution, a transparent-scattering type display element for controlling light emitted from the light source optical system and a projection optical system having an aperture which projects the transmitted light, wherein the aperture of the projection optical system is an aperture having a non-circular opening which is disposed in the vicinity of the focal point of the transmitted light of the transparent-scattering type display element.

Abstract: An illumination device for a direct viewing type display element comprising a flat light guide; a light source set such that light is incident on a side portion of said flat light guide; a polarized light separating flat set on a first side of a light emitting side of the flat light guide for transmitting a p polarized light component and reflecting at least a portion of an s polarized light component with respect to a light ray substantially having a predetermined direction of incidence; and a light reflecting sheet disposed on a second side opposite to said light emitting side of the flat light guide in parallel with the light emitting site.

Abstract: An illumination device for a direct viewing type display element comprising a flat light guide; a light source set such that light is incident on a side portion of said flat light guide; a polarized light separating flat set on a first side of a light emitting side of the flat light guide for transmitting a p polarized light component and reflecting at least a portion of an a polarized light component with respect to a light ray substantially having a predetermined direction of incidence; and a light reflecting sheet disposed on a second side opposite to said light emitting side of the flat light guide in parallel with the light emitting site.