Seiko Epson Corporation

Kabushiki Kaisha Suwa Seikosha

Seiko Epson Kabushiki Kaisha

Mitsuo Nagata

Haruo Nakamura

Kenji Aoki

Teiji Miura

Tomo Ikebe

Takashi Takeda

Akira Komatsu

Masatoshi Yonekubo

Katsunori Yamazaki

Takeshi Seto

Kunihiko Takagi

Minoru Hosokawa

Koichi Oguchi

Satoru Yazawa

A light source device includes: a laser light source emitting a laser beam of a prescribed wavelength; a nonlinear optical element, disposed facing a light emergence surface of the laser light sources which converts an emission wavelength of the laser beam emitted from the laser light source and causes the laser beam to emerge; a volume phase grating, disposed facing an emergence surface of the laser beam of the converted wavelength converted by the nonlinear optical element, which has formed in an interior thereof a Bragg grating structure which selectively reflects a laser beam of an emission wavelength; and a first dielectric multilayer, provided on a light emergence surface of the volume phase gratings which transmits the laser beam of the converted wavelength and reflects the laser beam of the emission wavelength.

Light source device and projector including light source device

A light source apparatus including: a solid state light source that includes a pair of electrodes and emits light in response to power being supplied with from the electrodes; a liquid medium that removes heat that is generated in the solid state light source; and a mounting unit which is provided a flow path in an interior thereof in which the liquid medium flows, including: a base that defines the flow path; and a placement member which defines a remainder of the flow path and on which the solid state light source is mounted.

Light source apparatus and projection display apparatus

A light source apparatus includes a light emitting chip which generates light and heat when energized via a first electrode and a second electrode, wherein the first electrode is a base on which the light emitting chip is directly packaged.

Light source apparatus with light-emitting chip which generates light and heat

A mechanism for driving a matrix liquid crystal display which compensates for cross talk due to changes in temperature is provided. A matrix liquid crystal display has two substrates and a liquid crystal layer sandwiched between the two substrates. A group of common electrodes is formed on one substrate. A group of segment electrodes is formed on the other substrate. The common electrodes intersect with the segment electrode. A voltage is provided at the common electrodes and segment electrodes to produce a voltage waveform for driving the liquid crystal. A voltage waveform compensation circuit changes the voltages waveform in accordance with the pattern of drawings or characters to be displayed in the liquid crystal display device to produce the desired display and in accordance with at least one of an ambient temperature and a temperature of the liquid crystal display.

Circuit for driving a liquid crystal display device

A high-speed responsive liquid crystal optical device with improved light transmissivity is provided. The device includes a liquid crystal panel including an optically active liquid crystal material having dielectric anisotropy which becomes zero at a crossing frequency ('fc') of 100 KHz or below. The dielectric anisotropy of the liquid crystal is positive at frequencies lower than fc ('fl') and negative at frequencies higher than fc ('fh'). Crossed polarizers are disposed on each side of the liquid crystal panel. A liquid crystal driving circuit selectively applies a signal of a frequency fh to open the device and a signal of a frequency fl to close the device. The optical device is particularly well suited for use as a light valve in a printer device. Response time within 1 m sec. permits a printing speed of 10 prints of A4 size to be produced per minute with a resolving power of about 10 dots per 1 m/m. This amounts to a printing speed of approximately 500 lines in one second with each line being written into m sec. or less. The optically active nematic liquid crystal is a composition comprising an optically inactive nematic liquid crystal and an optically active liquid crystal material added thereto.

Dual frequency, optically active liquid crystal cell

A high-speed responsive liquid crystal optical device with improved light transmissivity is provided. The device includes a liquid crystal panel including an optically active liquid crystal material having dielectric anisotropy which becomes zero at a crossing frequency ('fc') of 100 KHz or below. The dielectric anisotropy of the liquid crystal is positive at frequencies lower than fc ('fl') and negative at frequencies higher than fc ('fh'). Crossed polarizers are disposed on each side of the liquid crystal panel. A liquid crystal driving circuit selectively applies a signal of a frequency fh to open the device and a signal of a frequency fl to close the device. The optical device is particularly well suited for use as a light valve in a printer device. Response time within 1 m sec. permits a printing speed of 10 prints of A4 size to be produced per minute with a resolving power of about 10 dots per 1 m/m. This amounts to a printing speed of approximately 500 lines in one second with each line being written into m sec. or less. The optically active nematic liquid crystal is a composition comprising a optically inactive nematic liquid crystal and an optically active liquid crystal material added thereto.

Liquid crystal cell with opaque mask for printing device

A liquid crystal display device wherein display elements are arranged in a matrix display on a substrate and the display is driven in response to external display signals is provided. The display device includes a thin film layer having a rugged diffusing surface and an opposed transparent electrode plate spaced apart from the thin film layer. A guest-host liquid crystal material including a pleochroic dye is utilized. The thin film layer may be a metal film such as, aluminum, an aluminum alloy, silver or a silver alloy having a rugged surface for providing a diffused white surface formed by vaccum evaporation, sputtering, heat-treatment, recrystallization or etching.

Liquid crystal display device having diffusely reflective picture

An electro-photographic printer utilizing a liquid crystal material which operates as a light valve. The liquid crystal material is sandwiched between two base plates which include electrodes which define a plurality of micro-shutters. A light source illuminates one side of the liquid crystal material. A driving circuit selectively applies driving signals to the electrodes for selectively opening and closing the micro-shutters to allow light from the light source to pass therethrough. A photo-sensitive drum on the other side of the liquid crystal receives the light transmitted through the liquid crystal to form characters. The characters are transmitted to a recording paper. The liquid crystal material, which has an inverted dielectric anisotropy on opposite sides of the critical frequency, is selectively driven by selectively applying two different frequency signals to the liquid crystal.

Electro-photographic printer

A liquid crystal display device suitable for a matrix display of a large number of lines of picture cells can nevertheless provide high contrast. The liquid crystal material used in the device is suitable for operating in the twisted nematic mode and has a dielectric anisotropy which is positive at low frequency and negative at high frequency. A timing signal is provided to the picture cell, the timing signal comprising a high frequency component and a low frequency component such that the dielectric anisotropies of the liquid crystal are at least nearly equal and opposite in sign. In addition a data signal is supplied, said data signal being equal in frequency to one or the other of the components in the timing signal. The signals are utilized in driving the display by suitable matrix-addressing.

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Suwa, Japan

Mitsuo Nagata