Hitachi, Ltd.

Hitachi Consumer Electronics Co., Ltd.

Hitachi Displays, Ltd.

Hitachi Maxell, Limited

Takanori Hisada

Koji Hirata

Masahiko Yatsu

Hiroki Yoshikawa

Tetsu Ohishi

Naoyuki Ogura

Takesuke Maruyama

Daisuke Imafuku

Takashi Azumi

Hidehiro Ikeda

Kenji Sano

Masayuki Ohki

Masaharu Deguchi

Hironobu Satoh

Yoshio Ariki

Kyohei Fukuda

Futoshi Yamasaki

Takashi Kakuda

Yoshihiko Noro

Souichi Sakurai

Sakae Watanabe

Shunichi Taguchi

Yoshifumi Honma

A projection display system includes a projection display unit and a member in a form of one of a windable screen, a white board and a notice board. The projection display unit projects an image light onto a projection plane of the member to display an image thereon. The projection display unit includes a light source, an image display element, a lighting optical system irradiating a beam of light from the light source on the image display element, and a projection optical system projecting the image light from the image display element toward the member. The projection optical system includes, in order toward the member from the image display element, a front lens group, and a reflecting mirror shaped to be axial-asymmetrical with respect to the optical axis.

Projection display system with two reflecting mirrors

A display apparatus includes a light source which is configured to emit a light, a first light modulation unit which is configured modulate the light emitted from said light source, a first drive unit which is configured to drive said first light modulation unit, a projection unit, which is configured to project the light from said first light modulation unit enlargedly, a second light modulation unit, which is configured to modulate the light emitted from said projection unit so as to be emitted to an observer side, a second drive unit which is configured to drive said second light modulation unit, and an optical direction conversion unit, which is configured to convert the light from said projection unit so that the light is incident upon an incident surface of said second light modulation unit in a direction approximately perpendicular thereto.

Display apparatus and projection type lighting apparatus therefor

In a projection type display apparatus for enabling to display an image, by projecting an image on an image display element(s), enlargedly, upon a nearly horizontal surface, such as, a table, a reflection mirror for reflecting a light from a light source is so disposed that an optical axis of the light source is nearly perpendicular to an optical axis of a lens group having a plural number of lens elements, which are disposed symmetric with respect to the optical axis.

Projection type display apparatus

A projection type image display apparatus includes a first lens group including a plural number of lenses being disposed in a direction of propagation light with respect to an image display element, a second lens group including a plural number of lenses being disposed in a direction of propagation light with respect to said first lens group and a reflection mirror, which is configured to reflect light emitted from at least one of said first and second lens groups, so as to project the light obliquely upon a screen. A ratio (Lo/Lp) of a diagonal size (Lo) of said screen and a distance (Lp) from a center of said reflection mirror to said screen is at least 2, and the second lens group includes a refractive lens having a negative power and a rotationally symmetric surface configuration.

Projection type image display apparatus

A projection display system comprising a projection display unit including a light source, an image display element, a lighting optical system irradiating a beam of light on the image display element, and a projection optical system projecting an image light from the image display element toward a screen. The projection optical system including a lens group composed of a plurality of lens elements arranged in order toward the screen from the image display element and symmetrically with respect to an optical axis, and a reflecting mirror shaped to be axial-asymmetrical with respect to the optical axis. The projection display system further comprises a screen. The projection display unit projects the image light onto a projection plane of the screen to display an image.

Projection display system including lens group and reflecting mirror

A projection type image display apparatus includes an image display element, a projection unit including a first lens group and a second lens group formed with a plural number of lenses, a reflection mirror configured to reflect light emitted from the second lens group thereon after the light passes through the first lens group so as to project the light on a screen obliquely, and a mechanism configured to enable movement of at least one lens of the second lens group in a direction of an optical axis. The first lens group is fixed with respect to a bottom portion of the mechanism and is configured to compensate for an aberration of an optical system thereof. The second lens group is configured to enable movement of at least one lens of the second lens group with respect to the first lens group and the bottom portion of the mechanism.

A projection image display device is disclosed in which a trapezoidal distortion and/or aberration are restrained when an image is enlarged and projected obliquely onto a screen. An image generator is connected to an optical system base in such a manner that at least an inclination thereof (on an axis parallel to X axis) with respect to a vertical line and a distance thereof in forward and backward direction (Z axis direction) can be adjusted by an adjusting mechanism. Further, a projecting lensas a first optical system and a free-form curved surface mirror as a second optical system are fixed to the optical system base. The free-form curved surface mirror is rotatable (on an rotary axis parallel to X axis) with respect to the vertical line at a substantial center of the free-form curved surface mirror.

Projecting optical unit and projecting type image display apparatus therewith

In a projection type image display apparatus, for enlarging an image on a image display apparatusby means of a projection lens, thereby projecting the enlarged image onto a screen, obliquely, being inclined thereto, between the projection lensand a rear-surface mirror, there are disposed free shaped surface mirrorsand, each having a free shaped surface for compensating a trapezoidal distortion due to oblique projection of the enlarged image. The surface configuration of the free shaped surface mirror is so shaped as to satisfy a following equation:|1&#x2212;2|&#x3e;1.4&#xb7;if assuming that a distance for a light beam of an upper end of the enlarged image to reach the screen after being reflected upon a free shaped surface is 'L1', a distance for a light beam of a lower end of the enlarged image to reach the screen after being reflected upon the free shaped surface is 'L2', and a distance from an upper end of an image on the screen to a lower end thereof is &#x201c;Dv&#x201d;.

Projection image display apparatus and projection optical unit to be used therein

A projection type image display apparatus includes an image display element, and a projection optical unit, which is configured to project an image displayed on the image display element, enlargedly, upon a screen. The projection optical unit includes a lens group, which is configured to compensate an distortion on an image surface on the screen, a mirror for compensating a trapezoidal distortion on the screen. The mirror reflects lights emitted from the lens group, so as to project upon the screen obliquely.

A projection type image display apparatus includes an image display element, a lens group disposed in a direction of propagation of light with respect to the image display element and being formed with a plural number of lenses, a s reflection mirror configured to reflect light emitted from the lens group thereon so as to project the light on a screen, obliquely, and a housing configured to receive the reflection mirror and the lens group therein. The lens group is fixed on a bottom portion of the housing, and a part of the lens group is configured to enable movement of lenses of the lens group.

A projection-type image display apparatus for projecting an image, enlargedly, onto a projection surface, comprises: an image display element; a lens group, being disposed behind the image display element, comprising therein, a front lens group made up with a plural number of lenses, including, at least, a refractive lens, and a rear lens group made up with a plural number of lenses, including, at least, a lens having a free curved surface configuration and being rotationally asymmetric, thereby emitting an image displayed on the image display element; a reflection mirror for reflecting the light from the lens group, thereby projection onto the projection surface, obliquely; and a movement member for moving the plural number of lenses of the rear lens group.

Projection-type image display apparatus

A projection type image display apparatus includes a lens group, being disposed adjacent to an image display element, which is configured to include a plural number of lenses, and a mirror, which is configured to reflect emission lights from the lens group, so as to project upon the screen obliquely. A ratio (Lo/Lp) between a distance (Lp) from a center of the mirror up to the screen and a diagonal size (Lo) of the screen is at least 2.

A display apparatus comprises a lighting unit for emitting a light, and a first light modulation unit for forming an image through modulation of the light from a light source unit, wherein the lighting unit includes a light source for emitting the light, a second light modulation unit for modulating the light from the light source, being smaller than the first light modulation unit for modulating the light from the light source, and a projection unit for projecting the light modulated through the second light modulation unit, enlargely, upon the first light modulation unit for use of display.

Growing community of inventors

Yokohama, Japan

Takanori Hisada