Abstract: An optical member that will be incorporated in a surface light source unit and that is scarcely deformed while it is used as a component of the surface light source unit. The optical member comprises optical sheets layered on each other. The optical sheets at least includes: an outermost optical sheet on the light-entrance side, which is situated outermost on the light-entrance side; and a high-rigidity optical sheet situated on the light-exit side of the outermost optical sheet on the light-entrance side, a rigidity of the high-rigidity optical sheet being higher than a rigidity of the outermost optical sheet on the light-entrance side.

Abstract: The present invention provides a surface light source device and a transmission display device, which can exhibit smoother output light properties and higher front luminance, and avoid occurrence of moiré. A surface light source device 10A includes a light source portion 13A, a light controlling sheet 15 located on the output light side of the light source portion 13A, and a light diffusing sheet 16 located on the output light side of the light controlling sheet 15 and including micro-convex structures. The light diffusing sheet 16 includes a transparent base film 16a, and a light diffusing layer 16d coated on a surface of the transparent base film 16a. Micro-beads 16b incorporated in the light diffusion sheet 16 can exhibit a lens effect and provide a light condensing effect and a light diffusing effect. As such, the output light properties of the surface light source device 10A can be changed smoother, thereby providing higher front luminance and avoiding occurrence of moiré.

Abstract: The invention is concerned with a volume hologram medium obtained by multiple recording of holograms, which is improved in terms of just only security for forgery prevention but also aesthetics. A volume hologram medium 29? comprises a reflection hologram in which a stereoscopic image of a three-dimensional object and an image of a plane pattern of a mask plate are recorded by interference of the same reference light beams having the same angle of incidence and the same wavelength with object light beams having mutually different angles of incidence. The stereoscopic image of the three-dimensional object is reconstructed in the form of diffracted light 31 in a single color and in angle relations close to recording conditions, and the image of a plane pattern of the mask plate is reconstructed as diffracted light 32b, 32?b at various angles of incidence of white illumination light 30 and in different colors depending on those angles of incidence.

Abstract: The invention provides a computer-generated hologram which can be viewed in white at the desired viewing region and a reflective liquid crystal display using the same as a reflector. The computer-generated hologram H is designed to diffuse light having a given reference wavelength ?STD and incident thereon at a given angle of incidence ? in a specific angle range. In a range of wavelengths ?min to ?max including the reference wavelength ?STD wherein zero-order transmission light or zero-order reflection light of incident light on the computer-generated hologram at a given angle of incidence is seen in white by additive color mixing, the maximum diffraction angle ?2MIN of incident light of the minimum wavelength ?MIN in the wavelength range and incident at the angle of incidence ? is larger than the minimum diffraction angle ?1MAX of incident light of the maximum wavelength ?MAX in the wavelength range and incident at said angle of incidence ?.

Abstract: The invention provides a computer-generated hologram which can be viewed in white at the desired viewing region and a reflective liquid crystal display using the same as a reflector. The computer-generated hologram H is designed to diffuse light having a given reference wavelength ?STD and incident thereon at a given angle of incidence ? in a specific angle range. In a range of wavelengths ?min to ?max including the reference wavelength ?STD wherein zero-order transmission light or zero-order reflection light of incident light on the computer-generated hologram at a given angle of incidence is seen in white by additive color mixing, the maximum diffraction angle ?2MIN of incident light of the minimum wavelength ?MIN in the wavelength range and incident at the angle of incidence ? is larger than the minimum diffraction angle ?1MAX of incident light of the maximum wavelength ?MAX in the wavelength range and incident at said angle of incidence ?.

Abstract: The present invention is a light-controlling sheet for making light emitted from light sources uniform and/or converging the light. The light-controlling sheet includes a lens part having a large number of rod-like unit lenses arranged in parallel, with a lens surface of each unit lens facing to the light-exiting side. A cross section of the lens surface of each rod-like unit lens taken perpendicularly to the longitudinal direction of the unit lens is asymmetrical. The lens surface of each unit lens has a flat surface part in the shape of a flat surface, and a curved surface part in the shape of part of a cylindrical surface.

Abstract: A light controlling sheet 14 is provided in a surface light source device 10a including a light source portion 13a. The light controlling sheet 14 includes an outgoing light side lens portion 141a having multiple unit lenses 141 arranged to project toward the outgoing light side, and transparent portions 143 and reflecting portions 144 provided on the incident light side. The transparent portions 143 and the reflecting portions 144 are arranged alternately, and the transparent portions 143 comprise 40% to 60% of the total area of the light controlling sheet 14 when viewed form a direction orthogonal to the sheet surface 14S on the incident light side.

Abstract: The invention relates to a color hologram display an image of a three-dimensional object and a hologram image of a pattern of plane characters, images or the like are recorded in the same volume type hologram photosensitive material in a superposed or multiplexed fashion. A color hologram display 27? comprising a combined reflection and volume type of single layer, wherein a color pattern 29g of plane characters, images or the like and a color three-dimensional subject image O? are reconstructably recorded while spatially superposed one upon another.

Abstract: The invention provides a computer-generated hologram which can be viewed in white at the desired viewing region and a reflective liquid crystal display using the same as a reflector. The computer-generated hologram H is designed to diffuse light having a given reference wavelength ?STD and incident thereon at a given angle of incidence ? in a specific angle range. In a range of wavelengths ?min to ?max including the reference wavelength ?STD wherein zero-order transmission light or zero-order reflection light of incident light on the computer-generated hologram at a given angle of incidence is seen in white by additive color mixing, the maximum diffraction angle ?2MIN of incident light of the minimum wavelength ?MIN in the wavelength range and incident at the angle of incidence ? is larger than the minimum diffraction angle ?1MAX of incident light of the maximum wavelength ?MAX in the wavelength range and incident at said angle of incidence ?.

Abstract: The invention provides a computer-generated hologram which can be viewed in white at the desired viewing region and a reflective liquid crystal display using the same as a reflector. The computer-generated hologram H is designed to diffuse light having a given reference wavelength ?STD and incident thereon at a given angle of incidence ? in a specific angle range. In a range of wavelengths ?MIN to ?MAX including the reference wavelength ?STD wherein zero-order transmission light or zero-order reflection light of incident light on the computer-generated hologram at a given angle of incidence is seen in white by additive color mixing, the maximum diffraction angle ?2MIN of incident light of the minimum wavelength ?MIN in the wavelength range and incident at the angle of incidence ? is larger than the minimum diffraction angle ?1MAX of incident light of the maximum wavelength ?MAX in the wavelength range and incident at said angle of incidence ?.

Abstract: The invention relates to a color hologram display an image of a three-dimensional object and a hologram image of a pattern of plane characters, images or the like are recorded in the same volume type hologram photosensitive material in a superposed or multiplexed fashion. A color hologram display 27? comprising a combined reflection and volume type of single layer, wherein a color pattern 29g of plane characters, images or the like and a color three-dimensional subject image O? are reconstructably recorded while spatially superposed one upon another.

Abstract: The invention provides a computer-generated hologram which can be viewed in white at the desired viewing region and a reflective liquid crystal display using the same as a reflector. The computer-generated hologram H is designed to diffuse light having a given reference wavelength &lgr;STD and incident thereon at a given angle of incidence &thgr; in a specific angle range. In a range of wavelengths &lgr;MIN to &lgr;MAX including the reference wavelength &lgr;STD wherein zero-order transmission light or zero-order reflection light of incident light on the computer-generated hologram at a given angle of incidence is seen in white by additive color mixing, the maximum diffraction angle &bgr;2MIN of incident light of the minimum wavelength &lgr;MIN in the wavelength range and incident at the angle of incidence &thgr; is larger than the minimum diffraction angle &bgr;1MAX of incident light of the maximum wavelength &lgr;MAX in the wavelength range and incident at said angle of incidence &thgr;.

Abstract: The invention is concerned with a volume hologram medium obtained by multiple recording of holograms, which is improved in terms of just only security for forgery prevention but also aesthetics. A volume hologram medium 29′ comprises a reflection hologram in which a stereoscopic image of a three-dimensional object and an image of a plane pattern of a mask plate are recorded by interference of the same reference light beams having the same angle of incidence and the same wavelength with object light beams having mutually different angles of incidence. The stereoscopic image of the three-dimensional object is reconstructed in the form of diffracted light 31 in a single color and in angle relations close to recording conditions, and the image of a plane pattern of the mask plate is reconstructed as diffracted light 32b, 32′b at various angles of incidence of white illumination light 30 and in different colors depending on those angles of incidence.

Abstract: The invention provides a computer-generated hologram which can be viewed in white at the desired viewing region and a reflective liquid crystal display using the same as a reflector. The computer-generated hologram H is designed to diffuse light having a given reference wavelength &lgr;STD and incident thereon at a given angle of incidence &thgr; in a specific angle range. In a range of wavelengths &lgr;MIN to &lgr;MAX including the reference wavelength &lgr;STD wherein zero-order transmission light or zero-order reflection light of incident light on the computer-generated hologram at a given angle of incidence is seen in white by additive color mixing, the maximum diffraction angle &bgr;2MIN of incident light of the minimum wavelength &lgr;MIN in the wavelength range and incident at the angle of incidence &thgr; is larger than the minimum diffraction angle &bgr;1MAX of incident light of the maximum wavelength &lgr;MAX in the wavelength range and incident at said angle of incidence &thgr;.

Abstract: A hologram recording film has a hologram image of an object recorded in a volume hologram photosensitive material by holographic duplication and further has a hologram image of an additional information pattern, e.g. a character or an image, recorded superimposedly in the same volume hologram photosensitive material simultaneously with the holographic duplication so that the additional information pattern is reconstructable in a plane with a depth from the hologram plane. Reflection type additional information is recorded in the hologram recording film so as to be reconstructable simultaneously in superimposition with a reconstructed image from the volume hologram. In addition, transmission type additional information that is in mirror image relation to the reflection type additional information is recorded in the hologram recording film so as to be reconstructable simultaneously in superimposition with the reconstructed image from the volume hologram.

Abstract: A holographic display element for three-dimensionally displaying a three-dimensional model and a plane image, for example, in a superimposed manner, which is prevented from causing a change in color or a reduction in contrast of the foreground pattern at an overlap between the foreground pattern and the background pattern. The holographic display element is formed from a single reflection type volume hologram layer, wherein a foreground pattern and a background pattern are recorded so that the two patterns can be reconstructed away from each other in space and a portion of the background pattern that is shadowed by the foreground pattern as superimposed thereover is vacant.

Abstract: The invention relates to a viewing and an image pickup optical system for display devices, which can be used with high efficiency at a plurality of wavelengths and enables bright images to be viewed with satisfactory color reproducibility. The optical system comprises a first prism 3, a second prism 4 and a volume hologram element 6 disposed between them and cemented to them. The hologram element 6 comprises a first grating vector corresponding to at least a first wavelength and a second grating vector corresponding to a second wavelength shorter than the first wavelength.

Abstract: The invention relates to a viewing and an image pickup optical system for display devices, which can be used with high efficiency at a plurality of wavelengths and enables bright images to be viewed with satisfactory color reproducibility. The optical system comprises a first prism 3, a second prism 4 and a volume hologram element 6 disposed between them and cemented to them. The hologram element 6 comprises a first grating vector corresponding to at least a first wavelength and a second grating vector corresponding to a second wavelength shorter than the first wavelength.

Abstract: A color hologram recording medium 2 includes volume hologram recording mediums 14R, 14G and 14B for diffracting light of wavelengths different from each other. Reconstruction patterns 1R, 1G and 1B of the volume hologram recording mediums 14R, 14G and 14B are recorded so that the reconstruction patterns 1R, 1G and 1B are reconstructed at reconstruction positions different from each other. Thus, the color hologram recording medium 2 can have a wide variety of designs and artistic characters that the recorded color reconstruction patterns vary depending on watched directions.

Abstract: A hologram recording film has a hologram image of an object recorded in a volume hologram photosensitive material by holographic duplication and further has a hologram image of an additional information pattern, e.g. a character or an image, recorded superimposedly in the same volume hologram photosensitive material simultaneously with the holographic duplication so that the additional information pattern is reconstructable in a plane with a depth from the hologram plane. Reflection type additional information is recorded in the hologram recording film so as to be reconstructable simultaneously in superimposition with a reconstructed image from the volume hologram. In addition, transmission type additional information that is in mirror image relation to the reflection type additional information is recorded in the hologram recording film so as to be reconstructable simultaneously in superimposition with the reconstructed image from the volume hologram.