Hitachi, Ltd.

Hitachi Device Engineering Co., Ltd.

Hitachi Displays, Ltd.

Osamu Itoh

Katsumi Kondo

Ikuo Hiyama

Yuka Utsumi

Kazuhiko Yanagawa

Keiichiro Ashizawa

Masahito Ohe

Naoki Kikuchi

Shinichi Komura

Masaya Adachi

Junichi Hirakata

Shoichi Hirota

Makoto Abe

Masaaki Kitajima

Tatsuhisa Fujii

Jun-ichi Hirakata

Hitomi Madokoro

Tohru Sasaki

Akira Arimoto

Makoto Tsumura

Yoshiharu Nagae

Tatsuya Sugita

Masahiko Ando

Kenkichi Suzuki

Hidetoshi Abe

Katsuyuki Funahata

Yoshihito Maeda

Yoshiaki Nakamura

A liquid crystal display apparatus includes a liquid crystal panel having polarizers, and a back light having a light source for illumination of the liquid crystal panel which has a characteristic of spectral transmittance required to satisfy the following equation, x&#x3e;y&#x3e;z, when a medium tone display voltage varies in a range between a minimum and maximum voltage for a Blue pixel, where 'x' is a value of the transmittance in the panel at a wavelength corresponding to a longest wavelength in a range of wavelengths designated for blue light, 'y' is a value of the transmittance in the panel at a wavelength corresponding to a maximum value of the intensity in a range of wavelengths designated for green light, and &#x201c;z&#x201d; is a value of the transmittance in the panel at a wavelength corresponding to a maximum value of the intensity in a range of wavelengths designated for red light.

Active matrix type liquid crystal display apparatus

A liquid crystal display apparatus includes a liquid crystal panel including a pair of polarizers, and a back light provided at a back side of said liquid crystal panel. The liquid crystal panel is an active matrix type liquid crystal panel enabling display and has a characteristic of spectral transmittance required to satisfy the following equation, &#xd7;&#x3e;y, when a drive voltage is applied thereto so as to vary from a dark state to a light state, in which 'x' is a value of the transmittance in the liquid crystal panel at a wavelength which corresponds to one of 490 nm and 500 nm, and 'y' is a value of the transmittance in the liquid crystal panel at a wavelength which corresponds to 545 nm.

A low cost transflective type liquid crystal display is provided which can display a bright image with high contrast under both indoor and outdoor illumination environments. The liquid crystal display performing transmission type display and reflection type display, includes: a plurality of pixels surrounded on a substrateby a plurality of gate electrodesand a plurality of source electrodesarranged perpendicularly to the gate electrodes; a switching elementarranged in each pixel and disposed neat at the intersection between each gate electrode and each source electrode; and a pixel electrodeconnected to the switching element, wherein the pixel electrode is constituted of a transparent conductive layer and a conductive memberhaving a light reflection function and electrically connected to the transparent conductive layer.

Translucent reflective type liquid crystal display

A liquid crystal display apparatus having a liquid crystal panel including a pair of substrates, a plurality of electrodes formed on at least one of the pair of substrates and a liquid crystal layer sandwiched between the pair of substrates, and a light source provided on one surface of the liquid crystal panel. An electric field in the liquid crystal layer produced by the plurality of electrodes is predominantly in parallel with surfaces of the pair of substrates. The light source has a luminous characteristic with a first chromaticity and the liquid crystal panel has a characteristic of spectral transmittance with a second chromaticity different from the first chromaticity so as to compensate for the color of the light source.

Active matrix type liquid crystal display apparatus including liquid crystal layer having different thicknesses at portions where different colors of light are transmitted

A liquid crystal display featuring excellent visibility with both good brightness and a high contrast ratio uses a projection optical system in which a polarizing plate, a first phase plate and a second phase plate in which the retardation of each of the phase plates and a gradient of wavelength dispersion of the retardation can be freely set, a liquid crystal layer, and a reflection plate are arranged in parallel and a transmitted light is reflected by the reflection plate. A gradient of one of the phase plates is set to an extremely steep gradient, a gradient of the other phase plate is set to an extremely flat gradient, and the wavelength dispersion of a retardation composite value obtained from the liquid crystal layer and the two phase plates is approximated to a retardation curve expressed by a relational expression of (0.25&plus;0.5n)&lgr;, where (n) is an integer and &lgr; is a wavelength (nm) of the transmitted light.

Liquid crystal display

A liquid crystal display apparatus includes a liquid crystal panel having a pair of substrates, a plurality of electrodes formed on at least one of the pair of substrates and a liquid crystal layer sandwiched between the pair of substrates, and a light source provided on the back surface of the liquid crystal panel. The light source has the luminous characteristic with the chromaticity of a warm color family, and the liquid crystal panel has a spectral transmission characteristic with the chromaticity of a cold color family, whereby the color of the light source can be compensated.

Active matrix type liquid crystal display apparatus with light source

A reflective liquid crystal display apparatus realizing a bright image display without using a backlight is provided. In this reflective liquid crystal display apparatus, a reflecting electrode having a scattering property and a directional property is manufactured using a small number of steps. A pattern of unevenness, such as a polygonal pattern, a cylindrical pattern, and the like, is formed on an insulating substrate utilizing a material layer formed for composing switching devices. By causing the unevenness of the pattern to influence the surface contour of the reflecting electrodes, it becomes possible to give both a scattering property and a directional property to the surface of the reflecting electrodes.

Reflective LCD with cylindrical pattern formed in reflecting electrode

In a polarizing beam converter, a uniaxial anisotropic transparent medium is inserted and supported between isotropic transparent media; and an optical axis of said uniaxial anisotropic transparent medium is arranged almost perpendicular to an incident light beam or an incident face of the incident light beam at an interface between the isotropic transparent medium and the uniaxial anisotropic transparent medium. A half wavelength plate is placed with an inclined angle of 45.degree. relative to a polarization axis for either of a reflected light component or a transmitted light component at the interface. The retractive index of the isotropic medium, n.sub.p, and a refraction index n.sub.e greater than n.sub.0, of the uniaxial anisotropic transparent medium are substantially equal to one another. Further, at the interface of the isotropic medium and the uniaxial anisotropic transparent medium, an incident angle satisfying sin(.theta.).gtoreq.n.sub.0 /n.sub.p for satisfying a total reflection angle.

Liquid crystal display polarizing beam splitter with specific incidence

A liquid crystal projector having a high contrast ratio has an optical system including, for each color, a liquid crystal display device, a drive device for driving the liquid crystal display device and a polarization device, and a light source. The liquid crystal display device has active devices connected to reflective electrodes. Driving voltages applied to pixels have different polarities in every row. The liquid crystal layer is aligned at an angle from 75.degree. to 105.degree. to the direction of an electric field between electrodes. An optical rotator is provided between the liquid crystal display device and the polarization device.

Liquid crystal projector

A reflective liquid crystal display device has a liquid crystal cell formed by laminating upper and lower orientation layers 11 and 21, upper and lower electrodes 14 and 24, upper and lower substrates 12 and 22, and upper and lower polarizers 13 and 23 arranged in order above and below a liquid crystal layer 10 so that they may face their counterparts respectively. The liquid crystal cell is provided with viewing angle dependence so that the light transmission ratio of the dark display section to the bright display section for the light incident at the required angle may be less than 2 at the required azimuth angle of the liquid crystal cell, and the direction of the required azimuth angle is aligned with the direction of the main light source incident into the liquid crystal cell.

Reflective liquid crystal display device

A color STN-LCD having preferable display quality and decreased manufacturing cost uses a liquid crystal display apparatus which includes a liquid crystal layer having a twist angle in a range from 200.degree. and less than 360.degree., a retardation of the liquid crystal layer in a range of 0.80 .mu.m.about.0.90 .mu.m, an azimuth of transmittance axis of the upper polarizer in a range of 30.degree..about.70.degree., an azimuth of the transmittance axis of the lower polarizer in a range of 60.degree..about.90.degree., an azimuth of the slow axis of the upper phase plate in a range of 150.degree..about.190.degree., an azimuth of the slow axis of the lower phase plate in a range of 30.degree..about.80.degree., a retardation of the upper phase plate at a wave length of 550 nm in a range of 200 nm.about.300 nm, and a retardation of the lower phase plate at a wave length of 550 nm in a range of 500 nm.about.620 nm.

Liquid crystal display apparatus

A reflective-type display device having a light modulating layer, including a host dispersed with light scatterers, which is held between two transparent electrodes; and a light absorbing layer disposed in back of the light modulating layer. The size of each light scatterer or the nearest distance between the adjacent light scatterers is nearly equivalent to the wavelength of incident light at least in two-dimensional directions. The refractive index ratio relative to incident light between the light scatterers and host is changed from 1 to 1.5 or more depending on the magnitude of a voltage applied across the electrodes.

Reflective-type display device having a refractive index ratio between

A reflective liquid crystal display apparatus has a liquid crystal display part composed of at least a liquid crystal layer and a pair of polarizers holding the liquid crystal layer therebetween, for display of bright and dark states in a mode of transmitting and shielding external light in a direction approximately normal to a display plane, and a reflecting part for reflecting the external light which has been transmitted through the liquid crystal display part. The liquid crystal display part has a property where it can transmit external light in a designated direction other than in a direction approximately normal to the display plane even in a mode of shielding the external light, and the reflecting part reflects the external light received in the designated direction so as to transmit the external light once again through the liquid crystal display part in a direction approximately normal to the display plane.

Reflective liquid crystal display apparatus which does not require a

A liquid crystal display device comprising: (a) a liquid crystal layer arranged between substrates each having an electrode; (b) a pair of polarizers arranged so as to sandwich the liquid crystal layer; (c) a birefringent medium arranged between the liquid crystal layer and at least one of the polarizers, when a voltage is applied so that liquid crystal molecules at boundary regions facing said substrates have different tilt angles from other molecules, retardation in said birefringent medium being equal or close to remaining retardation due to the liquid crystal molecules at boundary regions, and the slow axis of said birefringent medium being set for an angle to compensate for said remaining retardation; and (d) control means for changing transmission of said liquid crystal layer by applying voltages of two or more values between said electrodes.

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Hitachi, Japan

Osamu Itoh