Hitachi, Ltd.

Toru Numata

Mikio Shiraishi

Yasuo Otsuka

Kenji Fuse

Yasuo Ohtsuka

Koji Hirata

Masahiko Yatsu

Naoyuki Ogura

Shigeru Mori

Kazunari Nakagawa

Shigeru Inaoka

Hiroshi Shimizu

Naoki Yamamoto

Tadashi Kuwabara

Yutaka Igarashi

Shinichiro Fukushima

Yukinobu Tada

Mayumi Ueyama

Maki Furui

Rituko Kanazawa

Katsuki Ikuta

Misuzu Mochizuki

A display apparatus includes a light source, and a partition wall which divides an inside of the display apparatus into an enclosing space which includes a plurality of optical elements and an outer space with respect to the enclosing space. The optical elements includes a color separator which receives a light from the light source and emits a plurality of separate color beams, at least one reflecting type light valve which forms an image by reflecting the plurality of color beams, and a projection lens which projects the image of an external screen. A first cooling fan is provided which causes an air flow in the outer space. A least one of the optical elements forms a part of the partition wall, and the air flow cools the at least one reflecting type light valve from the outer space.

Display device and display optical system unit

A display apparatus includes a light source, plural reflecting type light valves having a light incidence/reflection surface which reflects incident light from the light source, and a partition wall which partitions a space in the display apparatus into a cooling air side and a light incidence/reflection surface side. Plural cooling fans which cause air flow to respective ones of the light valves, and a discharge fan which discharges a cooling air inside of the display apparatus through an outlet port are provided. A respective one of the cooling fans flows air to a side which is opposite to the incidence/reflection surface of a respective one of the light valves and a path of the air flow is formed from at least one of the cooling fans to the outlet port in an order of the opposite side of the light valve, the light source and the discharge fan.

In order to prevent dust from sticking to the LCD panel, to prevent the LCD panel from being heated and to suitably adjust the position of the LCD panel, a duct is provided between cooling means for a light source and cooling means for a LCD panel to send cooling air from the LCD panel side to the light source side. Therefore, a light incidence/reflection plane of the LCD panel is disposed in an almost hermetically closed space and an optical path from an integrator lens to the LCD panel is formed in the almost hermetically closed space.

Image display mechanism and image display device

For changing services to readers who desires to obtain electronic books exactly or minutely, an electronic book management systemdistributes at least electronic purchase certificates relating to books which are stocked at a bookstores owing a bookstore terminal device, in advance, to that bookstore terminal device. When buying the book(s), a reader obtains in an IC cardowned by her/him a purchase certificate(s) of that book(s) which she/he bought, from the bookstore terminal. When ordering to obtain the electronic book(s), the reader transmits the purchase certificate(s) from a reader terminal deviceto the electronic book management systemthrough a communication network. The electronic book management systemchanges over it's service when supplying the electronic book(s) to that reader depending upon the existence of the purchase certificate(s).

Electronic book distributing system by use of purchase certificate and devices therefor

For obtaining both high brightness under condition of small-sized and simplified structure and suppression of increase in temperature of liquid crystal display elements and polarizing elements, in a liquid crystal display apparatus, comprising: a liquid crystal display element for converting light from a light source into display picture depending on a driving signal; an optical projection system containing a first optical element and for projecting said light signal toward an object of projection; exit side polarizing elements ; a holding member for holding them with the liquid crystal display element ; and cooling medium incident side polarizing elements , wherein, a space is defined by either one of the incident side polarizing elements and the liquid crystal display element , the first optical element , between the liquid crystal display element and the first optical element , and the holding member , and said space is filled up with the cooling medium

Liquid crystal display apparatus and optical device for use therein

A display apparatus includes a light source, a reflecting type light valve having a light incidence/reflection surface which reflects incident light from the light source, a first cooling fan which cools the reflecting type light valve, and a second cooling fan which cools the light source. A part of the display apparatus which is opposite to the light incidence/reflection surface of the reflecting type light valve is cooled by a cooling fluid generated by the first cooling fan.

A display apparatus having a reflecting type light valve which has a light incidence/reflection surface, a drive circuit which drives the reflecting type light valve by supplying an image signal, a cooling system which cools at least the reflecting type light valve with cooling fluid, and a partition wall which partitions a space in the display apparatus into a cooling fluid side and a light incidence/reflection side. The reflecting type light valve forms a part of the partition wall, and the light incidence/reflection surface faces the light incidence/reflection side and a part opposite to the light incidence/reflection surface of the reflecting type light valve is cooled by the cooling system.

For obtaining both high brightness under condition of small-sized and simplified structure and suppression of increase in temperature of liquid crystal display elements and polarizing elements, in a liquid crystal display apparatus, comprising: a liquid crystal display element for converting light from a light source into display picture depending on a driving signal; an optical projection system containing a first optical element and for projecting said light signal toward an object of projection; exit side polarizing elements ; a holding member for holding them with the liquid crystal display element ; and cooling medium ; incident side polarizing elements , wherein, a space is defined by either one of the incident side polarizing elements and the liquid crystal display element , the first optical element , between the liquid crystal display element and the first optical element , and the holding member , and said space is filled up with the cooling medium

Liquid crystal display apparatus having liquid crystal display element immersed in cooling medium

A display device, such as a reflecting type liquid crystal projector, in which dust is prevented from becoming attached to a reflecting type light valve, such as a liquid crystal panel, and an improvement in cooling effect are attained. The device has a structure having a partition wall for forming an enclosed space including at least an incidence/emission optical system of the reflecting type light valve. The reflecting type light valve is provided in the partition wall such that a light incidence/emission surface of the light valve faces into the side of the enclosed space. A part opposite to the light incidence/emission surface of the reflecting type light valve faces outside the enclosed space. In a structure where a cooling arrangement or a thermal conductive partition wall is connected to the part opposite to the light incidence emission surface, the cooling effect is further improved.

For obtaining both high brightness under condition of small size and simplified structure, and for achieving suppression of increase in temperature of liquid crystal display elements and polarizing elements in a liquid crystal display apparatus, a liquid crystal display element converts light from a light source into a display picture depending on a driving signal, and an optical projection system contains a first optical element and projects a light signal toward an object of projection. A space is defined by an incident side polarizing element or the liquid crystal display element, the first optical element and a holding member, and the space is filled up with a cooling medium.

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Yokohama, Japan

Toru Numata