Asahi Glass Company, Limited

Ag Technology Co., Ltd.

Ashai Glass Company, Limited

Tomoki Gunjima

Yoshinori Hirai

Satoshi Niiyama

Yoshiharu Ooi

Hiromasa Sato

Tatsuro Asawa

Hiroshi Kumai

Hiroki Hotaka

Yuzuru Tanabe

Masaya Kunigita

Yukio Yoshikawa

Eiji Shidoji

Hiroshi Ukihashi

Isamu Takeshita

Masanori Yuki

Haruhisa Miyake

Masao Ozeki

Yutaka Nakagawa

Kara Yoshida

Hiroshi Hasebe

Hiroaki Ito

Ryutaro Takei

Tetsuro Matsumoto

Nobuhiko Takeshita

Shoichi Tsuchiya

Mitsuru Kurosawa

Manabu Suhara

Masaaki Yamabe

Minoru Akatsuka

Toshio Ichiki

Tsuneji Ishii

Kouichi Murata

Kaoriko Masuda

Eriko Aoyama

Kara c/o Asahi Glass Company Limited Yoshida

N Asahi Glass Koriyama Elec Mat Takeshita

H Asahi Glass Koriyama Elec Mat Sato

H Asahi Glass Koriyama Elec Mat Hotaka

Yuzuru c/o Asahi Glass Company Limited Tanabe

An optical head device having a broadband phase plate of transforming at least three linearly polarized light beams having different wavelengths into circularly polarized light beams, is obtained. A broadband phase plate comprising two phase platesA andB laminated with e.g. an adhesive agent so that their optical axes are crossed, wherein provided that wavelengths of linearly polarized incident light beams are &#x3bb;, &#x3bb;and &#x3bb;(&#x3bb;&#x3c;&#x3bb;&#x3c;&#x3bb;), at least one or both of the two phase plates has such a phase difference characteristics that a ratioR(&#x3bb;)/R(&#x3bb;)and a ratioR(&#x3bb;)/R(&#x3bb;)between retardation values of the wavelengths are smaller than 1 andR(&#x3bb;)/R(&#x3bb;)is smaller thanR(&#x3bb;)/R(&#x3bb;), is integrated in the optical head device.

Optical head device

A polarizing diffraction element having a wavelength selectivity which functions as a polarizing diffraction element at a wavelength &#x3bb;, and which does not function as a diffraction grating not depending on incident polarization state and shows high transmittance at a wavelength &#x3bb;, and an optical head device employing the element, are provided. The polarizing diffraction element selectively diffracts or transmits incident light having two different wavelengths each containing a first circularly polarized light and a second circularly polarized light having a rotation opposite from the rotation of the first circularly polarized light, depending on wavelength and polarization state of the incident light. Then, a reflective wavelength region for at least the first circularly incident light, does not contain said two incident wavelengths.

Polarizing diffraction element and optical head device

To provide optical elements such as a phase plate suitably used in a broadband range and a polarizing diffraction element excellent in diffraction efficiency, a polymerizable liquid crystal composition to be used for them, and an optical head device using them. A polymerizable liquid crystal composition containing a polymerizable compound having a mesogen structure comprising the following condensed benzene ring group (A) and the following 6-membered cyclic group (B) bonded to at least one bond in the group (A) directly or via a connecting group &#x2014;OCO&#x2014; or &#x2014;COO&#x2014;, and a monovalent terminal group bonded to each of both terminals of the mesogen structure, at least one of the terminal groups being a monovalent organic group having a polymerizable moiety:

Polymerizable liquid crystal composition, optical anisotropic material, optical element and optical head device

Acrylic acid derivative compounds and polymeric liquid crystal obtained by polymerizing the same

As an optically anisotropic diffraction grating in an optical head for reading and/or writing of an optically recording medium, optically anisotropic diffraction grating which comprises an optically anisotropic polymer liquid crystal sandwiched between two transparent substrates are used. The optically anisotropic polymer liquid crystal can have an alignment direction periodically changed to form a grating of different refractive indices, obtaining a high-utilization efficiency by light ray and a high degree of reliability.

Optical head, method of manufacturing the same, and diffraction element suitable therefor

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.

LCD device including an illumination device having a polarized light separating sheet between a light guide and the display

Optical head device including an optically anisotropic diffraction grating and process for its production

High molecular liquid crystal obtained by photopolymerizing a liquid crystal composition which comprises CH,&boxH;CHCOO&mdash;X&mdash;OC,H,&mdash;C,H,CN (X is an alkylene group) and CH,&boxH;CHCOOC,H,&mdash;C,H,CN. An optical element which is a polarized hologram element made by using the high molecular liquid crystal and an optical head having the polarized hologram element as a beam splitter.

Liquid-crystal composition and polymeric liquid crystal obtained by polymerizing the same

A liquid crystal display element comprises a pair of substrates provided with electrodes and a liquid crystal and solidified matrix composite material, disposed between the pair of substrates, which includes a nematic liquid crystal dispersed and held in a solidified matrix, the nematic liquid crystal being such that the refractive index of the liquid crystal is changed depending on states of applying a voltage wherein in a state, the refractive index of the liquid crystal substantially coincides with that of the solidified matrix to thereby pass light, and in the other state, the former does not coincide with the latter to thereby cause the scattering of light, wherein the refractive index anisotropy .DELTA.n of the liquid crystal used is 0.18 or higher, and the dielectric anisotropy .DELTA..epsilon..sub.LC of the liquid crystal used satisfies the relation of 5&lt;.DELTA..epsilon..sub.LC &lt;13.

Liquid crystal display element and a projection type liquid crystal

Optical head device including an optically anisotropic diffraction

A composition for use in a liquid crystal optical element, such as a liquid crystal display or laser shutter device, comprised of a liquid crystal material and a solidified polymer material. The liquid crystal is such that its refractive index is changed depending on states of applying a voltage. In one state, the refractive index of the liquid crystal substantially coincides with the refractive index of the solidified matrix to thereby pass light. While in the other state, the refractive index of the liquid crystal does not coincide with the refractive index of the solidified matrix to thereby cause the scattering of light. Specifically, the liquid crystal material used in the composition has a refractive index anisotropy (.DELTA.n) is greater than 0.18 and the dielectric anisotropy (.DELTA..epsilon.) satisfies the relation of 5&lt;.DELTA..epsilon.&lt;11.6.

Liquid crystal/polymer composite with high optical anisotropy and low

LCD device including an illumination device having a polarized light

An active matrix liquid crystal display element and a projection type active matrix liquid crystal display device by which a display can be obtained which is good in color balance and high in brightness and also in contrast ratio. The display element includes a liquid crystal material held between an active matrix substrate and a counter electrode substrate. The liquid crystal material is formed from a liquid crystal polymer composite wherein nematic liquid crystal is contained dispersively in a polymer matrix having a refractive index which coincides with the ordinary refractive index of the liquid crystal used, and a silicon thin film transistor is used as an active element on the active matrix substrate. The display device includes such an active matrix liquid crystal display element, a light source for projection light, and an optical system of projection.

Active matrix liquid crystal display element and projection type active

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.

Projection type display apparatus having an aperture stop means

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Yokohama, Japan

Tomoki Gunjima