Dai Nippon Printing Co., Ltd.

Nobuhiko Ichikawa

Tsuyoshi Hotta

Hiroshi Kishimoto

Keiko Sekine

Masaki Katsumata

Yoichi Higuchi

Tadatsugu Onuma

Kenji Ueda

Hiroshi Sekiguchi

Masachika Watanabe

Tsuyoshi Kashiwagi

Tetsuya Sadahiro

Hiroyuki Amemiya

Takeshi Ogawa

Jun Horikoshi

Akihide Sano

Provided is an optical sheet hardly causing a change in color depending on the observation angle of an image, the optical sheet including a plurality of layers, at least one of the layers being an optical functional sheet layer including prisms arranged in parallel along a surface of the optical sheet such that light is transmittable; and light-absorbing portions arranged in parallel between the prisms in a way to absorb light, at least another one of the layers being a light diffusing material-containing layer with optical diffusing particles dispersed in a base material, and the optical sheet satisfying a relation of Nd&#x3c;Ndand vd&#x3c;vd, wherein Ndis a refractive index of the base material of the light diffusing material-containing layer, vdis an Abbe number thereof, NdR is a refractive index of the optical diffusing particles and vdis an Abbe number thereof.

Optical sheet and display device

A reflecting screencomprises a base portion, light transmitting portionsprovided on the base portion, and light absorbing portions. Each of the light transmitting portionscomprises a unit prism shapewhich has a generally wedge-like shape with a larger width on the image source side than its width on the rear face side and is arranged along a screen face. A reflecting layeradapted to reflect the image light, which has been transmitted through the unit prism shapes, is provided on the rear face side of each unit prism shape. Each unit prism shapeextends linearly, and each light absorbing portionis arranged between each adjacent pair of the unit prism shapes

Reflecting screen, method of manufacturing the same, and reflection-type projection system

The invention provides a hologram plate which is used with the double-focus replication process, and which is integrated with a spacer to impart marring resistance thereto, and is integrated with a light absorbing layer to allow zero-order light and first-order light to have substantially the same intensity. This hologram platecomprises an array of collective element holograms for diffracting parallel light incident thereon at a specific wavelength and a specific incident angle in such a way that the light is converged onto a specific focal length position. The hologram plateis a multilayer structure made up of a first transparent substrate, a hologram layer, an adhesive layerand a second transparent substrate. The second transparent substratedefines a surface in contact with a hologram photosensitive materialduring hologram replication.

Hologram plate and its fabrication process

The present invention provides an electroluminescent display which can efficiently radiate light emitted from an electroluminescent layer to a viewer side and, at the same time, can reduce a deterioration in contrast of a displayed image caused by external light. The electroluminescent display includes a light transparent substrate and an electroluminescent layer provided on the light-transparent substrate. The electroluminescent layer includes at least a transparent electrode, an organic luminescent layer, and a cathode. Two or more regions with different refractive indexes are provided within said light-transparent substrate.

Electroluminescent display device with substrate having regions with different refractive indexes

The invention provides a hologram plate which is used with the double-focus replication process, and which is integrated with a spacer to impart marring resistance thereto, and is integrated with a light absorbing layer to allow zero-order light and first-order light to have substantially the same intensity. This hologram plate comprises an array of collective element holograms for diffracting parallel light incident thereon at a specific wavelength and a specific incident angle in such a way that the light is converged onto a specific focal length position. The hologram plate is a multilayer structure made up of a first transparent substrate a hologram layer an adhesive layer and a second transparent substrate The second transparent substrate defines a surface in contact with a hologram photosensitive material during hologram replication.

A liquid crystal display apparatus and liquid crystal projection display apparatus, which employ a hologram color filter, and which are designed so that the illuminating light utilization efficiency is improved to a considerable extent, and that a color image can be faithfully displayed with excellent color reproducibility without uneven color or other similar problem. A color liquid crystal display apparatus ( ) has a hologram ( ), which diffractively disperses incident light so as to emanate light rays in different wavelength regions at a predetermined spatial period, as a color filter, and a liquid crystal display device ( ). The display apparatus ( ) is illuminated by white parallel back light ( ) from an illuminator ( ). A displayed image which is modulated in the color liquid crystal display apparatus ( ) is passed through a field lens, which is disposed in the vicinity of the display apparatus ( ), and formed as an enlarged image on a screen ( ) for display through a projection lens ( ). A short-wavelength cut-off filter whose transmittance for a wavelength not longer than 430 nm is not higher than 5% is disposed at a position in an optical path extending from a lamp ( ) to the screen ( ), thereby preventing crosstalk of colors which might otherwise occur when light which should be incident on a pixel assigned to display blue undesirably enters a pixel which is adjacent to the pixel for blue, and thus making it possible to display a faithful color image.

Liquid crystal display apparatus and liquid crystal projection display apparatus which employ hologram color filter

The present invention provides a hologram color filter having a drastically decreased dependence of diffraction efficiency on wavelength and well corrected for a color balance among the three colors R, G and B comprising an array of converging element holograms 5&prime;, each of which enables white light incident at a given angle &thgr; with respect to a normal line of a hologram recorded surface thereof to be spectroscopically separated by wavelength dispersion in a direction substantially along the hologram recorded surface, wherein the converging element holograms 5&prime; have each a plurality of hologram pieces and superposed on each other or multi-recorded therein, which, with respect to the white light incident at the given angle &thgr;, have substantially identical spatial wavelength distributions of wavelength dispersion and different peak wavelengths of diffraction efficiency.

Hologram color filter, and its fabrication method

The invention relates to a process capable of fabricating a variety of transmission holograms having a simple structure, a wide visible range and a large area and comprising the first stage of recording the wavefront to be finally reconstructed in the form of the first hologram that is a reflection hologram with a wide visible range, the second stage of using the first hologram to record the second hologram that is a combined reflection and transmission hologram, and the third stage of recording in the third hologram photosensitive material only a transmission hologram for reconstructing only the wavefront recorded in the second hologram and desired to be reconstructed.

Transmission hologram fabrication process

A liquid crystal display apparatus and liquid crystal projection display apparatus, which employ a hologram color filter, and which are designed so that the illuminating light utilization efficiency is improved to a considerable extent, and that a color image can be faithfully displayed with excellent color reproducibility without uneven color or other similar problem. A color liquid crystal display apparatus (11) has a hologram (5), which diffractively disperses incident light so as to emanate light rays in different wavelength regions at a predetermined spatial period, as a color filter, and a liquid crystal display device (6). The display apparatus (11) is illuminated by white parallel back light (3) from an illuminator (14). A displayed image which is modulated in the color liquid crystal display apparatus (11) is passed through a field lens, which is disposed in the vicinity of the display apparatus (11), and formed as an enlarged image on a screen (19) for display through a projection lens (18). A short-wavelength cut-off filter whose transmittance for a wavelength not longer than 430 nm is not higher than 5% is disposed at a position in an optical path extending from a lamp (15) to the screen (19), thereby preventing crosstalk of colors which might otherwise occur when light which should be incident on a pixel assigned to display blue undesirably enters a pixel which is adjacent to the pixel for blue, and thus making it possible to display a faithful color image.

Liquid crystal display apparatus and liquid crystal projection display

The present invention has for its object to spectrally diffract white light by a hologram for the illumination of a given position, thereby achieving some considerable improvement in the efficiency of utilization of backlight for liquid crystal display, etc., and makes use of a difference in the angle of diffraction of a hologram 5 depending on wavelength to diffract the wavelength components of the colors displayed into liquid crystal cells R, G and B of a liquid crystal display element 10 located at the back side of the hologram 5, thereby achieving some considerable improvement in the efficiency of utilization of backlight. As the hologram 5, an array form of converging unit holograms with the efficiency of diffraction independent, or less dependent, on wavelength, or other equivalent hologram arrangement may be used.

Growing community of inventors

Tokyo, Japan

Nobuhiko Ichikawa