Victor Company of Japan, Limited

Tsutomu Matsumura

Shintaro Nakagaki

Tetsuji Suzuki

Ryusaku Takahashi

Ichiro Negishi

Fujiko Tatsumi

Hiroyuki Bonde

Toshio Konno

An optical system is disclosed which is for a display apparatus having a light source for emitting read light and a reflection type spatial light modulator for modulating the read light incoming thereto into in accordance with image written thereon. The modulated light is projected onto a screen by a projection lens to display the image. A field lens is provided between the modulator and screen at such a position that both the read and modulated light pass therethrough. The field lens focuses the modulated light on near an entrance pupil of the projection lens so that the intensity of the modulated light is increased.

Optical system for display apparatus

A clear color image having a high contrast ratio without particular coloration is displayed on a screen by improved display apparatus. Such display apparatus is comprised of a spatial light modulator including a photo-conductive layer, a photo-modulator layer and a dielectric mirror, a device for writing color images of different colors onto the spatial light modulator time-divisionally in a sequence of the different colors, a reading device for producing reading lights having different colors in synchronism with time-divisional writing of the color images, and for projecting the reading lights to the spatial light modulator, a driving device for supplying the spatial light modulator with different voltages and frequencies correspondingly with the reading light of different colors and in synchronism with time-divisional projections of the reading lights, and a device for projecting the color images read out from the spatial light modulator on the display device. The dielectric mirror may have a light absorbance characteristic controlled to be wavelength-selective to absorb a color of light to which the photo-conductive layer is most sensitive, so that lights having different colors leaked into the photo-conductive layer through the dielectric mirror are controlled to cause a uniform impedance of the photo-conductive layer.

Display device

A display device of projection type capable of projecting an image with well defined image frame is disclosed. The device comprises 3 spatial light modulators on which color image information is written in 3 primary colors respectively and is read out as a combined optical color image in a form of light beam, the light beam is then projected out of the display device through lens groups for forming a projected image on a screen, the device further comprises a mask disposed in a proximity of an imaginary image formation plane arranged to locate in a vicinity of one of the lens groups, the light beam is caused to form an optical image on the imaginary image formation plane. The mask has a variable light shielding configuration controlled either electronically or electro-mechanically for cutting off unnecessary light portions of the light beam carrying the optical image so that an image of high contrast and well defined clear fringe is projected on the screen.

Projection type display device having a mask for cutting off unnecessary

Growing community of inventors

Yokosuka, Japan

Tsutomu Matsumura