Abstract: Provided are a light source device, a light emission control method, and a computer program for mitigating flickers. The light source device includes a plurality of light sources, and a controller configured to individually control the plurality of light sources to emit light. The controller controls one or more of the plurality of light sources to emit light at random in a time domain or controls such that light emission timings of the plurality of light sources do not overlap.

Abstract: Provided are a light source device, a light emission control method, and a computer program for mitigating flickers. The light source device includes a plurality of light sources, and a controller configured to individually control the plurality of light sources to emit light. The controller controls one or more of the plurality of light sources to emit light at random in a time domain or controls such that light emission timings of the plurality of light sources do not overlap.

Abstract: An image display apparatus including a first light source, a spherical lens configured to receive light output from the first light source, an aspherical lens configured to receive light output from the spherical lens, a first free curved mirror configured to receive light output from the aspherical lens is incident, a second free curved mirror configured to receive light output from the first free curved mirror, a third free curved mirror configured to receive light output from the second free curved mirror, and an image display panel configured to receive light output from the third free curved mirror and configured to display image information, wherein a light path of the light output from the first free curved mirror, a light path of the light output from the second free curved mirror, and a light path of the light output from the third free curved mirror intersect each other.

Abstract: An optical member, a polarization member, and a display device are provided. The optical member includes a substrate, and a functional layer provided on the substrate, the functional layer including a high refractive layer and a low refractive layer, wherein the high refractive layer has a higher refractive index than that of the substrate and a diffraction grating structure, and the low refractive layer has a lower refractive index than that of the high refractive layer, wherein an interface between the substrate and the high refractive layer and an interface between the high refractive layer and the low refractive layer are in states in which components of the respective layers with the respective interfaces therebetween are compatible with each other.

Abstract: An image display apparatus including a first light source, a spherical lens configured to receive light output from the first light source, an aspherical lens configured to receive light output from the spherical lens, a first free curved mirror configured to receive light output from the aspherical lens is incident, a second free curved mirror configured to receive light output from the first free curved mirror, a third free curved mirror configured to receive light output from the second free curved mirror, and an image display panel configured to receive light output from the third free curved mirror and configured to display image information, wherein a light path of the light output from the first free curved mirror, a light path of the light output from the second free curved mirror, and a light path of the light output from the third free curved mirror intersect each other.

Abstract: An optical member, a polarization member, and a display device are provided. The optical member includes a substrate, and a functional layer provided on the substrate, the functional layer including a high refractive layer and a low refractive layer, wherein the high refractive layer has a higher refractive index than that of the substrate and a diffraction grating structure, and the low refractive layer has a lower refractive index than that of the high refractive layer, wherein an interface between the substrate and the high refractive layer and an interface between the high refractive layer and the low refractive layer are in states in which components of the respective layers with the respective interfaces therebetween are compatible with each other.

Abstract: A light deflection diffusion sheet, a stacked light deflection diffusion sheet, and a stacked optical sheet that are used in a liquid crystal panel are disclosed. A liquid crystal display (LCD) device include a liquid crystal panel having a length direction and a width direction; a surface light emitting module; a base sheet disposed between the liquid crystal panel and the surface light emitting module; a light diffusion layer disposed on a surface of the base sheet facing the surface light emitting module and diffusing light incident from the surface light emitting module; and a light deflection layer disposed on a surface of the base sheet facing the liquid crystal panel and controlling a travel direction of the light.

Abstract: A light deflection diffusion sheet, a stacked light deflection diffusion sheet, and a stacked optical sheet that are used in a liquid crystal panel are disclosed. A liquid crystal display (LCD) device include a liquid crystal panel having a length direction and a width direction; a surface light emitting module; a base sheet disposed between the liquid crystal panel and the surface light emitting module; a light diffusion layer disposed on a surface of the base sheet facing the surface light emitting module and diffusing light incident from the surface light emitting module; and a light deflection layer disposed on a surface of the base sheet facing the liquid crystal panel and controlling a travel direction of the light.

Abstract: Provided is a projection optical system for an ultra-short focus image projection device. The disclosed projection optical system includes a first optical system for zooming an image formed by an image display device to form a first intermediate image, a second optical system for enlarging the first intermediate image to form a second intermediate image, and a reflection optical system for reflecting light which forms the second intermediate image. An optical axis of the first optical system translates parallel with respect to an optical axis of the second optical system in a direction perpendicular to the optical axis of the first optical system.

Abstract: An illumination optical system, an illumination unit, and an image projection apparatus employing the same are provided. The illumination optical system includes a light source irradiating a diverging light, a reflection optical system condensing the diverging light from the light source, and a lens optical system projecting the light condensed by the reflection optical system. The reflection optical system is comprised of an aspherical concave mirror. The lens optical system comprises a condensing lens having a positive refractive power in a central part and a refractive power of the condensing lens being decreased toward a circumferential part. Optical efficiency may be improved even when a light-emitting surface of the light source is relatively large and the light source cannot be regarded as a point light source.

Abstract: A projection optical system and a projection display device employing the projection optical system are provided. The projection optical system includes a display device displaying an image to be projected onto an image display region, and first and second optical systems sequentially disposed along an optical path from a screen to the display device. When the optical axis of the first optical system is taken as a reference axis, the image display region of the display device is disposed with parallel eccentricity to the reference axis, and the second optical system is disposed eccentrically to the reference axis. Thus, an image displayed on the image display region is enlarged and projected on a position that is eccentric with reference to the reference axis.

Abstract: An illumination optical system, an illumination unit, and an image projection apparatus employing the same are provided. The illumination optical system includes a light source irradiating a diverging light, a reflection optical system condensing the diverging light from the light source, and a lens optical system projecting the light condensed by the reflection optical system. The reflection optical system is comprised of an aspherical concave mirror. The lens optical system comprises a condensing lens having a positive refractive power in a central part and a refractive power of the condensing lens being decreased toward a circumferential part. Optical efficiency may be improved even when a light-emitting surface of the light source is relatively large and the light source cannot be regarded as a point light source.

Abstract: A display apparatus, which can be mounted on the head portion of a man, includes a two-dimensional display unit for displaying an image. A projection optical system projects the image displayed on the two-dimensional display unit onto the retina of the eyeball of a user. A shutter is arranged in front of the eyeball of the user. A detector detects at least a forward inclination of motions of the head portion of the user. A control unit controls the shutter in accordance with the output from the detector to switch the shutter between a light transmission state and a light shielding state. A housing incorporates and holds the two-dimensional display unit, the projection optical system, the shutter, and the detector to be mountable on the head portion of the user.

Abstract: An image display apparatus, for example, a head-mounted image display apparatus, which has a compact magnifying optical system designed so that the horizontal angle of view is as wide as 30.degree. or more, and yet the most off-axis distortion can be reduced to about 5%. The image display apparatus has a display device (D), an optical system (L+R) for projecting the content of information displayed by the display device (D) on an observer's eyeball as a enlarged virtual image without effecting image formation in the optical path, and an optical axis bending device (P) for bending the optical axis of the optical system. The optical axis bending device (P) is a beam splitter prism having a semitransparent surface. The beam splitter prism has an aspherical surface (r.sub.11) constituting a surface thereof which faces the display device (D). The aspherical surface (r.sub.

Abstract: An image display apparatus, e.g., a head-mounted display apparatus, which uses a half-mirror or a beam splitter prism and yet has an even more compact structure and provides a favorably flat image surface. A half-mirror (S) is obliquely disposed in front of an observer's eyeball (1), and an image display device (3), e.g., a liquid crystal display device, and a magnifying reflecting mirror (4) are disposed to face each other across the half-mirror (S) and to extend parallel to the observer's line of sight. To widen the field angle without increasing the size and weight of the optical system considerably, at least one surface (L) having positive refractive power is interposed between the eyeball (1) and the half-mirror (S). An even more compact arrangement is obtained by using a beam splitter prism in place of the half-mirror (S).

Abstract: A head-mounted display apparatus wherein an image displayed on an image display device is projected on an observer's eyeball, which is designed so that the displayed image can be observed at a desired angle of view and at a desired magnification by making the projection magnification changeable. The head-mounted image display apparatus includes an image display device (11) for displaying an image, and a projection optical system for projecting the image displayed on the image display device (11) onto an observer's eyeball. The projection optical system is composed of a first relay optical system (12), a second relay optical system (13), and an ocular optical system (14). The second relay optical system (13), which is an afocal optical system, is rotatable about an axis (16) perpendicular to the optical axis so that the projection magnification is changed in three steps by the rotation of the second relay optical system (13).