Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Mistubishi Denki Kabushiki Kaisha

Shinsuke Shikama

Eiichi Toide

Hiroshi Kida

Shinji Okamori

Mitsushige Kondo

Kohei Teramoto

Akira Daijogo

Hiroshi Suzuki

Jiro Suzuki

Masahiro Usui

Takao Endo

Akihisa Miyata

Mitsushige Kondou

Shuso Wadaka

Hiroaki Sugiura

Jun Someya

Yoshihito Hirano

Kiyohide Sakai

Yasuharu Koyata

Teruo Fujita

Shigenori Shibue

Masao Imaki

Toshihide Kaneko

Yoshiteru Suzuki

Kouhei Teramoto

Hirokazu Taguchi

Kazuo Iwata

Keizo Kono

Daisuke Umeno

Takao Endou

Takashi Saito

Shuichi Kagawa

Kuniko Kojima

Toru Yoshihara

Kazuo Okada

Koji Minami

Toshitaka Tachibana

Manabu Koike

Shigeru Takeuchi

Takeshi Utakoji

Masayuki Kubota

Fusaaki Yamada

Kan Kawahara

Nobumasa Egashira

Eiichi Tiode

Shigekazu Tsuda

Each of a plurality of Fresnel prismsis formed so that a refractive surfacethereof includes a non-light incidence surfaceupon which any light ray emitted from a projectoris not directly incident because it is intercepted by another Fresnel prism, the non-light incidence surface having an angle &#x3c4;' with a reflective surfacewhich is different from the prism apex angle &#x3c4; of each of the plurality of Fresnel prisms. As a result, a light ray reflected by the refractive surfaceof each of the plurality of Fresnel prisms without passing through the refractive surface can be preventing from emerging, as unnecessary light, toward the viewer's line of sight.

Fresnel optical element and projection display apparatus

Provided are a speckle removing light source capable of removing speckle by using laser light whose wavelength is temporally changed and a lighting apparatus for producing an image from which the speckle is removed. Included are a light source for outputting laser light, and a light frequency modulator for temporally changing a wavelength of the laser light. The light frequency modulator has a predetermined period set for changing the wavelength of the laser light. Also, provided is a lighting apparatus, including a spatial light modulator illuminated with the laser light outputted from the speckle removing light source to produce an image. The spatial light modulator has a period set for producing the image, which is longer than the period for changing the wavelength of the laser light by the light frequency modulator.

Speckle removing light source and lighting apparatus

Provided is a lighting apparatus capable of uniformly and efficiently lighting a spatial light modulator. The lighting apparatus includes: a light source for outputting laser light; a multimode optical fiber in which the laser light outputted from the light source propagates through an internal core whose lateral cross section is a substantially polygonal outer diameter shape; and spatial light modulator for producing an image with illumination light from the multimode optical fiber. In the lighting apparatus, the laser light is outputted from the light source and is propagated to the multimode optical fiber in which an outer diameter shape of the lateral cross section of the core is a substantially polygonal shape, whereby the spatial light modulator can be uniformly and efficiently lighted.

Lighting apparatus

An image display device comprises an optical imaging arrangement for providing image information to illumination light and for transmitting the light as an optical image signal; a display for receiving the optical image signal and for displaying an image based on the image information; and a projecting optical arrangement including a reflecting part having a reflecting surface for reflecting the optical image signal, and a refracting optical part having a refracting surface for projecting the optical image signal onto the reflecting part. At least one of the reflecting surface and the refracting surface is aspherical.

Image display device and adjustment for alignment

Each of a plurality of Fresnel prismsis formed so that a refracting surfacethereof includes a non-light incidence surfaceupon which any ray of light emitted from a projectoris not directly incident because it is intercepted by another Fresnel prism, the non-light incidence surface having an angle &#x3c4;' with a reflecting surfacewhich is different from the prism apex angle &#x3c4; of each of the plurality of Fresnel prisms. As a result, a ray of light reflected by the refracting surfaceof each of the plurality of Fresnel prisms without passing through the refracting surface can be preventing from emerging, as unnecessary light, toward the viewer's line of sight.

Fresnel optical element and projection display device

An image display system includes a light valvefor providing image information to light converged by a converging lensand for emitting the light, a projective optical systemincluding a refractive optical lensfor projecting the light from the light valveand a convex mirrorfor reflecting the light from the refractive optical lensby using a reflecting surface thereof having negative power and for enlarging and projecting the reflected light, and a displayfor receiving the light from the projective optical systemby way of a receiving surfaceA, wherein the light valve is placed away from an optical axisof the projective optical systemand between a front surface of the displayand a rear surface of the projective optical system

Image display system

A transmission screen has a refraction total reflection Fresnel lens plate, a stray light eliminating plate, and an image display plate. The stray light eliminating plate has a condensing lens array and black stripes. The array has unit lenses arranged at an incident plane of the transparent substrate in a periodic structure in an up-and-down direction. The black stripes have transparent sections placed near condensing light points of the unit lens and opaque sections around the condensing light points of the unit lenses. The sections are alternately arranged at the outgoing plane of the transmission substrate in a periodic structure in an up-and-down direction. The image display plate has lenticular lenses in which unit lenses are arranged in a periodic structure in a horizontal direction at an incident plane of the transmission substrate of a scattering characteristic capable of scattering light fluxes.

Transmission screen and projection display

A transparent screen includes a refraction/total reflection plate in a form of a Fresnel lens, the refraction/total reflection plate having a sawtooth surface upon which light is incident and another surface via which the light exits, and an image formation/display plate for forming a projection image from the light that exits from the refraction/total reflection plate. Refraction slating surface portions each for refracting incident light towards the other surface of the refraction/total reflection plate, transmission slating surface portions each for making incident light pass therethrough, and total reflection slating surface portions each for reflecting incident light passing through one transmission slating surface portion towards the other surface of the refraction/total reflection plate being formed concentrically on the sawtooth surface of the refraction/total reflection plate.

Transparent screen and projection display apparatus

An image display device includes an optical imaging arrangement for providing image information to illumination light and for transmitting the image information as an optical image signal; a projecting optical arrangement for receiving the optical image signal and for projecting the optical image signal; a display for receiving the optical image signal through the projecting optical arrangement and for displaying an image based on the image information; and a plane mirror for reflecting the optical image signal output from the projecting optical arrangement on the display.

There is disclosed a display device using a color wheel having a color filter Cw, in addition to normal color filters corresponding to the three primary colors. The filter Cw has almost flat spectral transmission characteristics. Brightness information included in a color image signal is quantized with (n+m) bits. Information corresponding to the lower-order n bits is displayed by light transmitted through the filter Cw. Information corresponding to the upper-order n bits is displayed by light transmitted through the normal color filters. Only brightness information to which the human eye is visually sensitive is reproduced by the filter Cw having a lower transmissivity. This can eliminate a lack of the number of gray levels due to a constraint on the minimum switching speed of a light valve. Furthermore, the brightness little deteriorates.

Display device for displaying digital input image data using different filter segments for the lower and higher order bits

In an image display which reproduces a color image by using lights color-separated into four or more colors through color filters, the objects of the invention are to effectively utilize the energy of light from a light source and to reduce the effect that a slight shift of the spectral transmittance characteristics of the color filters exerts on the spectral distributions of the lights after color separated. In an image display having a light source and four or more kinds of color filters and for color-separating light emitted from the light source into four or more colors through the four or more kinds of color filters and reproducing a color image by using the color-separated lights, the spectral transmittance characteristics of the color filters are set so that the cutoff wavelengths of the four or more kinds of color filters exist in a wavelength region in which the spectral distributions obtained by multiplying the spectral emissivity characteristic of the light emitted from the light source by the color matching functions are smaller than the values obtained by multiplying the average values of the spectral distributions in the wavelength region from 380 to 780 nm by an integer.

Image display performing color reproduction using color filters

A refracting optical lens is provided to project light from transmitting means onto a convex mirror to correct for pincushion distortion of the convex mirror

Growing community of inventors

Tokyo, Japan

Shinsuke Shikama