Minolta Company, Ltd.

Konica Minolta Opto, Inc.

Shigeru Sawamura

Katsuhiro Takamoto

Kohtaro Hayashi

Shunta Takimoto

Yasumasa Sawai

Nobuo Mushiake

Jun Nishikawa

Hideki Nagata

Kenji Konno

Tomokazu Masubuchi

Tsutomu Yoshikawa

Tomoko Nakagawa

Tokuji Matsuda

Katsunari Fujiki

A video projection device has one of a plurality of types of projection lenses replaceably loaded and projects a video on a screen at a fixed position. The video projection device includes: a converter lens which is composed of a plurality of lenses, which is afocal as a whole, and which is detachably provided in front of the projection lens to convert projection magnification; and a gap adjustment mechanism changing a predetermined gap in the converter lens to a setting in accordance with at least one of a projection distance to the screen and the type of the projection lens loaded.

Video projection device having a converter lens attachably and detachably provided

The invention provides an optical system for image projection, wherein when used in an image projection apparatus, a screen-continuing portion (e.g., screen-underlying portion) of the apparatus can be reduced to a small size, or can be removed, and thereby the apparatus can be so compacted, and provides an image projection apparatus mounting such optical system. An optical systemfor image projection including a lighting optical systemleading light from a light sourcefor lighting a display element(or'), and a projecting optical systemfor projecting projection light containing image information from the display element(or&#x2032;). The lighting optical systemis arranged such that a straight optical axis &#x3b1; from the light sourcein the lighting optical systemis positioned in an area deviated from a luminous flux &#x3b2; of the projection light incident into the projecting optical systemtoward an area where the projection light &#x3b3; from the projecting optical systempasses. The image projection apparatus A (or B or C) mounting such optical system

Optical system for image projection and image projection apparatus

A projection optical system includes from the enlargement side a first lens unit, a mirror which is an optical path bending member, a second lens unit, and a third lens unit. The projection optical system is designed so that a condition (1), 5.5&#x3c;T/FL&#x3c;12.0, is fulfilled. Here, Tis the air equivalent distance between the first lens unit and the second lens unit, and FL is the overall focal length of the projection optical system. By fulfilling the condition (1), it is unnecessary that the diameter of the first lens unit be extremely large. It is also unnecessary to change the lens shape to prevent interference between the first lens unit and the second lens units, so that an increase in the cost of the projection optical system can be suppressed.

Projection optical system and projecting apparatus provided with same

An illuminating apparatus has a light source emitting illumination light; and a prism having a plurality of reflecting surfaces and reflecting the illumination light from said light source by the reflecting surfaces to thereby bend an illumination optical path at an obtuse angle.

Illuminating apparatus, and projector using the illuminating apparatus

An optical system includes a first prism having a first surface and a second surface forming an acute angle therebetween, and a second prism having a third surface. The first prism and the second prism form an air gap between the second surface and the third surface. The air gap formed by the second surface and the third surface has a cross section perpendicular to the first surface and the second surface which is a wedge shape which is wide at a part thereof near the first surface and narrower at a part thereof more distant from the first surface.

Optical system and projection-type image display device

A projection system that is capable of providing a high-performance projection system and producing a high contrast projection image by using an optical modulation element, which can be positioned a predetermined distance away from an illumination optical system and a projection optical system. The optical modulation element is capable of modulating light received from the illumination optical system and projecting the modulated light to a projection optical system in the direction of a projection surface.

Projection system

An illumination optical system has a light source, an integrator for making the intensity distribution of the light from the light source even, and a relay optical system for imaging the light from the integrator on a plane conjugate with the exit surface of the integrator. The relay optical system includes a rear lens unit of which the refractive power is asymmetrical in one direction so that the plane on which the light is imaged is inclined relative to the optical axis of the relay optical system. This makes it possible to direct light to an inclined surface with an even intensity distribution and with minimum loss of the illumination light.

Illumination optical system and image projection apparatus

An illumination system has a light source for emitting illumination light, a color wheel, a first deflecting member, and a second deflecting member. The color wheel transmits or reflects the illumination light while rotating about a rotation axis in such a way that illumination light exiting from the color wheel has colors that are switched sequentially with time. The first deflecting member deflects the illumination light in such a way that the illumination light enters the color wheel. The second deflecting member deflects the illumination light having exited from the color wheel. The illumination light entering the first deflecting member and the illumination light exiting from the second deflecting member are both substantially perpendicular to the rotation axis of the color wheel.

Illumination system and projector

A scanning optical system is used to re-form an original image on a CCD line sensor. The optical system has an object side lens unit, a mirror and an image side lens unit. The object side lens unit condenses light from the object. The mirror is arranged between the object side lens to deflect the light having passed through the object side lens unit for scanning. An exit pupil of the object side lens unit coincide with an entrance pupil of the image side lens unit.

Scanning optical system

In a projector optical system provided with a DMD having minute mirror devices regularly arranged on one plane so as to correspond to the pixels of an image and selectively reflecting illuminating light in the direction of the optical axis of a projection optical system or in a direction different from the direction of the optical axis by bringing the mirror devices into an ON state or an OFF state according to the input video signals, and a prism disposed between the DMD and the projection optical system and having a first surface reflecting the illuminating light to be directed to the DMD and transmitting the light reflected at the DMD, the prism has a second surface transmitting, of the light transmitted by the first surface, light reflected at the mirror devices in the ON state and reflecting light reflected at the mirror devices in the OFF state.

Projection optical system comprising an optical function surface for reflecting or transmitting light from a spatial light modulator

Projection optical apparatus

An optical apparatus has a reflection-type spatial light modulator having a plurality of minute variable-reflection-angle mirrors that individually deflect the light incident thereon in one of two different directions, namely in a first direction or in a second direction, in accordance with a signal fed in, an optical system to which the light deflected in the first direction by the modulator is directed, a prism disposed between the modulator and the optical system so as to direct the light deflected in the first direction by the modulator to the optical system and direct the light deflected in the second direction by the modulator to a side face of the prism, and a light-absorbing member shaped like a plane-parallel plate and disposed with an entrance face thereof kept in close contact with the side face of the prism. The light-absorbing member is so designed that the light deflected in the second direction by the modulator enters the light-absorbing member through the entrance face thereof but does not exit from the light-absorbing member through the entrance face back into the prism.

Optical system for a projector

A display apparatus of the present invention includes: an illumination optical system for emitting illumination light; a reflective display panel divided into a plurality of pixels, illuminated by the illumination light from the illumination optical system, and selectively reflecting the incident illumination light pixel by pixel as projection light; a projection optical system for projecting image information the reflective display panel onto a projected surface by transmitting the projection light reflected at the reflective display panel; and a reflection angle converting optical system disposed ahead of the reflective display panel, changing the angle of incidence of the illumination light on the reflective display panel, and adjusting the sum of the angle of incidence of the illumination light on the reflective display panel and the angle of reflection of the projection light at the reflective display panel.

Display apparatus

An optical apparatus has a reflection-type spatial light modulator having a plurality of minute variable-reflection-angle mirrors that individually deflect the light incident thereon in one of two different directions, namely in a first direction or in a second direction, in accordance with a signal fed in, an optical system to which the light deflected in the first direction by the modulator is directed, a prism disposed between the modulator and the optical system so as to direct the light deflected in the first direction by the modulator to the optical system and direct the light deflected in the second direction by the modulator to a side face of the prism, and a light-expelling member having a polyhedral shape and disposed with an entrance face thereof kept in close contact with the side face of the prism. The light-expelling member is so designed that the light deflected in the second direction by the modulator enters the light-expelling member through the entrance face thereof and exits from the light-expelling member through a face thereof other than the entrance face.

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Sakai, Japan

Shigeru Sawamura