Canon Kabushiki Kaisha

Junko Shingaki

Hideaki Mitsutake

Kazumi Kimura

Shigeru Kawasaki

Katsumi Kurematsu

Shuzo Kaneko

Noritaka Mochizuki

Hidetoshi Suzuki

Sadahiko Tsuji

Nobuo Minoura

Kohtaro Yano

This specification discloses a plate-like polarizing element for converting light into polarized light having a plurality of units arranged along a common plane across the light, each of the units being provided with dividing means for dividing the light into reflected light and transmitted light whose planes of polarization are orthogonal to each other, varying means for varying the polarized state of at least one of the reflected light and the transmitted light to thereby make the planes of polarization of the two lights coincident with each other, and reflecting means for reflecting one of the reflected light and the transmitted light and directing it substantially in the same direction as the direction of travel of the other. The specification also discloses a polarizing conversion unit provided with such plate-like polarizing element, and a projector provided with such unit.

Plate-like polarizing element, a polarizing conversion unit provided with the element, and a projector provided with the unit

A projector comprising a light source having first and second high-luminance light emitting areas, an illuminating optical system for directing the light, from said light source, toward an object to be illuminated, wherein said first and second high-luminance light-emitting areas are positioned on the optical axis of said illuminating optical system, and a projection optical system for projecting the light emerging from said illuminated object, wherein said illuminating optical system is constructed in such a manner that a central area of said illuminated object is illuminated by most of the light beam from said first high-luminance light-emitting area, and a peripheral area of said illuminated object is illuminated by the remainder of the light beam from said first high-luminance light emitting area and most of the light from said second high-luminance light-emitting area.

Illuminating device and projector utilizing the same

The present invention relates to an optical modulation device that maintains good contrast despite changes in temperature and is capable of performing stable display. A polarizer, a first and second modulator and an analyzer are provided. Each modulator is a chiral smectic liquid crystal layer held between two opposite substrates which have different orientation determining abilities. The chiral smectic liquid crystal layers have at least two stable alignment states and substantially the same temperature dependency and tilt angle. The molecular axis of the first modulator at one of the two stable alignment states is substantially parallel to a transmitting modulation axis of said polarizer and is substantially perpendicular to a transmitting polarizing axis of said analyzer, and a molecular axis at one of the two stable alignment states of said second modulator is substantially parallel to a transmitting polarization axis of said analyzer.

Optical modulation device having different pretilts in the compensation

A liquid crystal device comprises: a) a liquid crystal cell including a plurality of pixels aligned on a plurality of lines and rows, each of the pixels composed of a pair of electrodes and liquid crystals provided between the pair of electrodes; and b) an optical unit including high-refractive portions positioned corresponding to the pixels, and low-refractive portions positioned next to the high-refractive portions on a plane, the high-refractive portions and low-refractive portions having the refractive indexes the ratio between which satisfies the condition for total reflection of incident light.

Liquid crystal device with optical means of high refractive index at

Plate-like polarizing element, a polarizing conversion unit provided

A liquid crystal device comprising a liquid crystal cell including a plurality of pixels aligned on a plurality of lines and rows, each of the pixels composed of a pair of electrodes and liquid crystals provided between the pair of electrodes; and an optical unit including high-refractive portions positioned corresponding to the pixels, and low-refractive portions positioned next to the high-refractive portions on a plane, the high-refractive portions and the low-refractive portions having the refractive indexes the ratio between which satisfies the condition for total reflection of incident light. Another embodiment is a liquid crystal device comprising two liquid crystal cells wherein each of the cells exhibit monostable orientation.

Liquid crystal device with two monostable liquid crystal cells

This specification discloses a polarization converting apparatus having means emitting non-polarized light, and polarizing means having a light incidence surface and a light emergence surface, the polarizing means receiving the non-polarized light by the light incidence surface and causing polarized light to emerge from the light emergence surface, the size and shape of the light incidence surface being similar to the size and cross-sectional shape of the non-polarized light. The specification also discloses an optical instrument having such apparatus.

Polarization converting apparatus and optical instrument having the same

A polarization conversion unit is disclosed. In the unit, a definitely polarized light emitted from a light source is divided into a pair of lights differing in polarized state and are caused to be incident on the optical components including the polarizing beam splitter. The plane of polarization of one of the paired polarized light is rotated to be coincident with the plane of polarization of the other light by the optical components, so that the paired lights with the same plane of polarization are caused to be separately emitted. The optical component has a plano-convex lens which has a positive power and which is arranged at an exit side where the paired lights are separately emitted. The lens has a focal point at a position further than the position of the surface to be illuminated.

Polarization conversion unit, polarization illumination apparatus

An optical modulating device comprises a polarizer, an analyzer and liquid crystals positioned between the polarizer and the analyzer. The device controls the birefringence of the liquid crystals by applying an electric field to the liquid crystals so as to change the polarization of light of the device. The device further comprises a rotatable halfwave plate which is positioned between the liquid crystals and the analyzer or between the liquid crystals and the polarizer in such a manner that the optical axis of the halfwave plate will be rotated around the optical axis of light coming into the optical modulating device. The device varies the rotational angle of the halfwave plate in accordance with the temperature of the liquid crystals or the environment thereof.

Growing community of inventors

Atsugi, Japan

Junko Shingaki