Minolta Company, Ltd.

Konica Minolta Opto, Inc.

Minolta Camera Kabushiki Kaisha

Minolta

Jun Ishihara

Kohtaro Hayashi

Masayuki Imaoka

Kenji Konno

Soh Ohzawa

Hiromu Mukai

Yasumasa Sawai

Ichiro Kasai

Tomokazu Masubuchi

Shigeto Ohmori

Yuichiro Ori

Ichiro Tsujimura

Hiroshi Ueda

Masataka Hamada

Katsuyuki Nanba

Reiji Seki

Yasuo Maeda

Hidehiko Fujii

Yasumasa Sugihara

Takashi Ohta

Taro Shibuya

Atsushi Matsuura

Tomiei Kuwa

Katsuto Tanaka

Mitsuaki Shimo

Kyoko Yamaguchi

Kotomi Murakami

A projection optical system () comprises a relay optical system (), a PBS prism (), and two projection lenses (). The image light beam from a DMD () enters the PBS prism () via the relay optical system (), is polarization-split there, and is directed to a screen by means of the two projection lenses (). Displaying an image by means of the DMD () is controlled while the polarized states of the light beams produced by the polarization split by means of the PBS prism () are controlled. Thereby, a three-dimensionally viewable image and a high-resolution image created by pixel-offset can be projected. Since the relay optical system () is provided, the lens backs of the projection lenses () can be shortened, and the projection lenses () and further the projection optical system () can be made compact.

Projection optical system and image projecting device

A rear projector for performing image projection includes: a screen and a projection optical system. The screen has a rotationally symmetric Fresnel lens. The projection optical system has at least one reflection surface formed of a rotationally asymmetric free curved surface. The projection optical system is nonaxisymmetric and makes a central principle ray incident obliquely on the screen in the image projection. The Fresnel lens has aberration that cancels out pupil aberration of the projection optical system so that principal rays of beams exiting from the Fresnel lens become substantially parallel to each other.

Rear projector

A projection optical system for projecting, while enlarging, an image formed on an image formation surface onto an image projection surface from an oblique direction relative thereto has at least three optically powered reflective surfaces and a refractive lens surface having a non-rotation-symmetric free-form curved surface and disposed between the first and second reflective surfaces as counted from the image formation surface side.

Projection optical system

An projection type image display apparatus includes a projection optical system having a plurality of concave mirrors and digital micromirror device (DMD). An optical path from the DMD to the concave mirror closest to the DMD is a sealed space which is surrounded by an image forming device holding plate holding the DMD, an optical component holding member holding the concave mirror and the image forming device holding plate, and a cover glass (transparent dust-proof cover) arranged on the optical path from the DMD to the concave mirror closest to the DMD.

Projection type image display apparatus

In a projection optical system for obliquely performing enlargement projection of an image formed on a display device surface onto a screen surface, a plurality of reflective surfaces are provided, at least one of which is a curved reflective surface having an optical power. Letting the curved reflective surface, out of said at least one curved reflective surface, having the largest effective optical region be the largest curved reflective surface, the reflective surface other than the largest curved reflective surface is slightly decentered with the largest curved reflective surface kept in a fixed state so as to perform pixel shift on the screen surface in a vertical direction, or a horizontal direction, or an oblique direction, or vertical and horizontal directions within the range of a pixel pitch.

An oblique projection optical system for leading rays of light from a display surface on which an image is displayed to a projection surface in such a way that the ray of light from the center of the display surface is obliquely incident on the projection surface in order to project a magnified image of the image displayed on the display surface onto the projection surface includes a plurality of reflecting surfaces having a power. At least two of the reflecting surfaces have a free-form curved surface, and, of all the reflecting surfaces, the one closest to the projection surface has a negative power and at least one of the other has a positive power. Alternatively, in a rear projection optical system having a projection optical system for projecting an image displayed on a panel display surface onto a screen surface, the projection optical system includes at least four curved-surface reflecting mirrors.

Image projection apparatus

An image-taking optical system for forming an optical image of an object on the light-receiving surface of an image sensor includes a plurality of optical blocks. The optical blocks each have a prism unit provided with a curved surface and an optical unit composed of a member different from a member composing the prism unit. The prism unit uses the curved surface as a total reflection surface and also as a transmission surface. The optical unit has near the curved surface a curved surface identically or substantially identically shaped therewith.

Image-taking optical system

A thin and light optical device satisfactorily separates light components having different properties. A blazed grating is formed on a surface of a flat-plate-shaped transparent substrate, and a separation coating that reflects or transmits incident light according to the properties of the incident light is provided on the blazed grating. The thus obtained optical device offers a function of separating light into reflected light and transmitted light, and also has a function of diffracting or refracting the thus separated light. As the separation coating, a polarization separation film, dichroic film, angle separation film, or chiral nematic liquid crystal layer is used to separate linearly polarized light components having different polarization planes, light components having different wavelengths, light components incident at different angles of incidence, or circularly polarized light components having different rotation directions.

Light separation device, blazed grating device, diffraction grating device, and illumination optical system

In a projection-type display apparatus that directs light from a light source through the illumination optical system to a display panel so that an image displayed on the display panel illuminated by the light directed thereto is projected through a projection optical system onto a screen, an illumination optical system is used that has a light intensity uniformizing device of which the entrance surface is located at a first conjugate position substantially conjugate with the light source and of which the exit surface has a shape geometrically similar to the panel surface of the display panel and a reflection optical system for forming an image of the exit surface of the light intensity uniformizing device on the panel surface of the display panel. In the reflection optical system, every surface having an optical power is a reflective surface.

Projection-type display apparatus

Rear projection optical system

An oblique projection optical system is compact as compared with the size of the image it presents, offers high imaging performance, produces satisfactorily small distortion, and has a small f-number. The oblique projection optical system is composed of a plurality of powered reflection surfaces, of which the one closest to the projection surface is positively powered and the one second closest thereto is negatively powered. At least one of these two reflection surfaces is a free-form surface, and the one closest to the projection surface has a size larger than half the size of the projection surface.

Oblique projection optical system and method for setting the same

A color liquid crystal display device which separates white light in to component colors. The separated colors are modulated by a reflective liquid crystal display. A lens group between the light separator and the reflective liquid crystal display condenses the entering light to each pixel of the liquid crystal display. High brightness and aperture efficiency are achieved by including in the lens group a birefringent material so that a different optical function is performed relative to the entering light fluxes and the modulated light fluxes.

Color liquid crystal display device

A viewfinder optical system directs a luminous flux emanating from an image plane to a pupil. The viewfinder optical system has an eyepiece optical system. The eyepiece optical system enlarges an image in order to be viewed by the pupil. The eyepiece optical system has a first lens unit, a second lens unit and a third lens unit. The first lens unit has at least one surface having a positive optical power. The second lens unit has at least one surface having a negative optical power. The third lens unit has a reflecting surface having a positive Optical power.

Growing community of inventors

Kobe, Japan

Jun Ishihara