Kuraray Co., Ltd.

Matsushita Electric Industrial Co., Ltd.

Matsushita Electric Co., Ltd.

Ichiro Matsuzaki

Yoshihiro Kumagai

Osamu Yoshimura

Masaki Ishii

Hiroshi Kuwada

Katsuaki Mitani

Kazuo Funazaki

Tokuo Ikari

Noboru Yasumatsuya

Toru Watanabe

Hidehiro Tango

Toshiyuki Yoshikawa

Katsuya Fujisawa

Masao Uetsuki

Ikuo Onishi

Nobuhiro Kawatsuki

Youji Ono

Yoshiki Mukoo

Makoto Toyohara

Etsuo Nakazato

Kazunori Hirose

Kazuo Baba

Masao Otaki

Ken Abe

Yoshihiro Oda

Shinichi Asano

Takao Kibushi

A design method for an optical sheet for solar concentration and an optical sheet for solar concentration obtained by means of the design method are disclosed. The design method is characterized in that, for a resin optical sheet for solar concentration containing an ultraviolet absorber in a base material thereof, an amount of the ultraviolet absorber to be contained in the base material is determined such that: in an accelerated degradation test by means of a metal-halide-lamp weathering test (device specification: JTM G 01:2000, Japan Testing Machinery Association), decrease in average transmittance in a wavelength range of 400 nm to 1850 nm after testing for an irradiation time Tsatisfies the following equation (1)&#x3c4;(0)+&#x3c4;()&#x3e;&#x3c4;(0)+&#x3c4;()&#x2003;&#x2003;(1)and that decrease in transmittance at each of wavelengths in the wavelength range from a corresponding initial value after testing for the irradiation time Tis not greater than 10%. Tis the accelerated test time required corresponding to the actual location of use. The optical sheet of the present invention is capable of efficiently concentrating light without decrease in transmittance while being used for a long time in an environment with a large amount of ultraviolet radiation.

Fresnel lens sheet for solar concentration and design method therefor

The present invention aims at providing a manufacturing method for an optical sheet capable of manufacturing a thin optical sheet of a uniform thickness distribution with a high thickness accuracy, and high shaping/transferring performances, and an optical sheet manufactured by using the manufacturing method. A manufacturing method for an optical sheet according to the present invention includes passing a resin discharged from a die between a touch roll and a shaping roll under pressure.

Method for producing optical sheet

A backlight device for a liquid crystal display comprising a light diffuser, a light source disposed behind the light diffuser, and a reflector for reflecting light from the light source, in which a liquid crystal panel is disposed in front of the light diffuser and irradiated, from the back side, with the direct light from the light source and the light reflected by the reflector and diffused by and passed through the light diffuser. The light source is of a type which radiates UV-rays and heat along with visible light. The warp and yellowing of the diffuser are suppressed even if the quantity of UV-rays is increased with an increase in the quantity of light from the light source. In a direct-under type backlight device for a liquid crystal display employing the light diffuser, the color difference (&#x394;E) defined in JIS K 7105 after exposed for 500 hours to artificial light employed for artificial light source test defined in JIS h7350-2 is 2.0 or less, and saturated water absorption rate of the light diffuser is 0.9% or less.

Backlight device for liquid crystal display

An object of the invention is to provide a rear projection screen that has a high contrast and produces high-quality images. The object is achieved by a rear projection screen and rear projection display apparatus having the same. This rear projection screen contains a vertical lenticular lens sheet on the viewer side, and the vertical lenticular lens sheet includes a lenticular lens capable of vertically refracting the incident light on its incident surface, black stripes in the vicinity of the focus of the lenticular lens in portions where the incident light does not pass through, and a flat surface on its viewer side.

Rear projection screen with shifted lens

A rear projection screen for use in a rear projection display apparatus contains a Fresnel lens sheet, a horizontal lenticular lens sheet capable of horizontally refracting the incident light, and a vertical lenticular lens sheet capable of vertically refracting the incident light, in this order from the incident side of the incident light, in which the lens center of the Fresnel lens sheet is arranged upward with respect to the mechanical center of the screen, and, in relation to this arrangement, black stripes of the vertical lenticular lens sheet are shifted with respect to the vertical lenticular lens.

Rear projection screen and rear projection display apparatus

To provide a rear-projection type screen in which, without the need for a tape-attachment operation on the outer circumferential part of the lens sheets, the top of the Fresnel lens can be prevented from being pared by the abrasion caused by the vibration during transportation. A rear-projection type screen according to the present invention is configured from two or more overlapping sheet-like members such as a Lenticular lens sheetand Fresnel lens sheet, in which a fixing protrusionis integrally formed in the sheet-like members in such way that neither of the two sheet-like members is displaced from the state in which the two sheet-like members overlap. A protrusion, used to attach the rear-projection type screen to the main body of a rear-projection-type image display apparatus or the screen frame, may be integrally formed in the sheet-like members from which the rear-projection type screen is configured. In addition, a protrusion, which produces a gap between the top of a lens in one of the sheet-like members and the other sheet-like member in a state in which the two sheet-like members overlap, may be integrally formed in the sheet-like members.

Method for manufacturing rear-projection type screen having sheets with protrusions integrally formed thereon

To provide a rear-projection type screen in which, without the need for a tape-attachment operation on the outer circumferential part of the lens sheets, the top of the Fresnel lens can be prevented from being pared by the abrasion caused by the vibration during transportation. A rear-projection type screen according to the present invention is configured from two or more overlapping sheet-like members such as a Lenticular lens sheet and Fresnel lens sheet , in which a fixing protrusion is integrally formed in the sheet-like members in such way that neither of the two sheet-like members is displaced from the state in which the two sheet-like members overlap. A protrusion, used to attach the rear-projection type screen to the main body of a rear-projection-type image display apparatus or the screen frame, may be integrally formed in the sheet-like members from which the rear-projection type screen is configured. In addition, a protrusion, which produces a gap between the top of a lens in one of the sheet-like members and the other sheet-like member in a state in which the two sheet-like members overlap, may be integrally formed in the sheet-like members.

Rear-projection type screen

Eliminating occurrence of non-uniform vertical line patterns observable in image display apparatus with its associative projector device having its pixel structure in the horizontal direction. To this end, rear projection image display apparatus includes a screen including a lenticular lens sheet having its light incidence surface on which lenticular lenses ( ) are periodically provided and a light exit surface having a substantially flat surface ( ) at or near the focal position of each lenticular lens ( ) on the light incidence surface. The lenticular lens sheet has a light absorption layer ( ) provided in a region different from the focal position. The apparatus also includes a projector device having a periodical pixel structure for projecting an optical image onto the screen, such as liquid crystal display panels or the like. Optionally, one or more micro-lenticular lenses may be provided on the substantially flat surface, which lenses have a periodical structure in the same direction as that of the lenticular lenses on the light incidence surface, wherein the pitch ranges from 0.03 to 0.1 mm whereas the lens height measures 0.003 to 0.03 mm.

Rear projection image display apparatus including light exit surface configured to reduce noise

Eliminating occurrence of non-uniform vertical line patterns observable in image display apparatus with its associative projector device having its pixel structure in the horizontal direction. To this end, rear projection image display apparatus includes a screen including a lenticular lens sheet having its light incidence surface on which lenticular lenses ( ) are periodically provided and a light exit surface having a substantially flat surface ( ) at or near the focal position of each lenticular lens ( ) on the light incidence surface. The lenticular lens sheet has a light absorption layer ( ) provided in a region different from the focal position. The apparatus also includes a projector device having a periodical pixel structure for projecting an optical image onto the screen, such as liquid crystal display panels or the like. Optionally, one or more micro-lenticular lenses may be provided on the substantially flat surface, which lenses have a periodical structure in the same direction as that of the lenticular lenses on the light incidence surface, wherein the pitch ranges from 0.03 to 0.1 mm where as the lens height measures 0.003 to 0.03 mm.

Provided is an optical device through which the angle of light passing and going out has little wavelength dependency and which is well applicable to Fresnel lenses with little coloration of light passing through it. The optical device has a diffraction grating formed on one surface and capable of diffracting rays of light incident thereon, and has a refracting member (e.g., a Fresnel lens) formed on the other surface opposite to the diffraction grating and capable of refracting the diffracted rays of light from the diffraction grating to make the refracted rays of light go out of it, in which the wavelength dependency of the diffractive angle of the main rays diffracted by the diffraction grating compensates for the wavelength dependency of the refractive angle thereof refracted by the refracting member, or that is, the former wavelength dependency is opposite to and cancels out the latter one.

Optical device and Fresnel lens sheet

A lenticular lens sheet capable of reducing the color shift and improving the overall light beam transmittance. The lenticular lens sheet has an incident side lenticular lens on its light beam incident side surface and further has an emergent side lenticular lens on its emergent side surface, with peak portions of the emergent side lenticular lens being formed at substantially convergent positions of the incident side lenticular lens. When an inter-lens distance at the sheet central portion is taken to be t.sub.0 and an inter-lens distance of an end portion of an viewable area of a rear-projection screen composed of this lenticular lens sheet is taken as t.sub.1, the rate of the inter-lens distances t.sub.0 and t.sub.1 is determined to satisfy 0.98.ltoreq.t.sub.1 /t.sub.0 .ltoreq.1.10.

Lenticular lens sheet capable of reducing color shift and improving

A projection type display device comprising a light source for irradiating a light valve, a light valve wherein pixels are arranged in delta matrix, each pixel containing color pixels for the three primary colors and a composite color of red (R), green (G) and blue (B) being displayed on each pixel, a projection lens for projecting the visual images formed on the light valve by receiving the light emitted from the light valve, and a screen including a lenticular lens which has a periodic structure in one direction and on which projected images are formed, which is characterized in that, given the pitch PL of the periodic structure of the lenticular lens and the pitch P of the projected image on the lenticular lens in the direction corresponding to the periodic structure, the pitches PL and P satisfy the equation (1) below when 0.41&lt;m1&lt;0.57,

Projection type display device

A rear-projection screen having at least a Fresnel lens and a light-diffusing member, and is characterized by having vertical-direction light diffusion properties greater at its upper and lower end portions than at its middle portion. For example, the light-diffusing member contains light-diffusing fine particles and has a vertical lenticular lens that diffuses light in the vertical direction, provided on the light-incident surface of the Fresnel lens. This decreases the rainbows caused by misdirected light and also improves the brightness at the border, without causing a lowering of peak gain.

Rear-projection screen

A double-faced lenticular lens sheet including at least one incident side lens formed on a first face of the double-faced lenticular lens sheet; and at least one corresponding emergent side lens formed on a second opposite face of the double-faced lenticular lens sheet; wherein light rays incident on the at least one incident side lens parallel to an optical axis thereof pass through the lenticular lens sheet and emerge from the at least one emergent side lens; an angle of refraction .theta.1 is formed by a straight line parallel to an optical axis of the at last one incident side lens and a light ray refracted by an incident plane passing through the lenticular lens sheet; an angle of refraction .theta.2 is formed by a straight line parallel to an optical axis of the at least one emergent side lens and the light ray refracted by and emitted from an emergent plane; .DELTA..theta.1 is an absolute value of the angle of refraction .theta.1 on the incident plane; .DELTA..theta.2 is an absolute value of an angle of refraction given by (.theta.2-.theta.1) on the emergent plane; a ratio between .DELTA..theta.1 and .DELTA..theta.2 given by (.DELTA..theta.2/.DELTA..theta.1) is 1.0 or more when a center of the lenticular lens sheet rests on the optical axis of the at least one incident side lens and a width of the lenticular lens sheet is 80% or less of the lens pitch of the at least one incident side lens.

Lenticular lens sheet

A lenticular lens sheet comprising lengthwise long lenticular lenses formed on the light incident-side surface and light emergent-side surface thereof, the lenticular lenses being constituted of cylindrical lenses each having a long dimension in the top and bottom direction of a screen when used, and satisfying

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Tokyo, Japan

Ichiro Matsuzaki