Seiko Epson Corporation

Mutsuya Furuhata

Akitoshi Kuroda

Motoyuki Fujimori

Kiyoshi Miyashita

Takeshi Takizawa

Shinji Haba

Akitaka Yajima

Toshiaki Hashizume

Tomiyoshi Ushiyama

Keijiro Naito

Toshio Matsumiya

Terunaga Koide

Hiroshi Harima

Fumio Koyama

Hisashi Iechika

Jun Arai

Toshihiko Nakazawa

The invention provides a liquid crystal light valve that makes it possible to increase the life of a polarizer at a light-exiting-surface side of the liquid crystal light valve by reducing the burden thereon, and a projection display device that incorporates the liquid crystal light valve. In liquid crystal light valves that modulate incident light in accordance with image information, at least two corresponding polarizers are provided respectively at the light-exiting-surface sides of liquid crystal panels.

Liquid crystal light valve and projection display device including the same

A panel cooling system A has a pair of Sirocco fansA,B arranged at both sides of the radial direction of a projection lensa suction duct portionA and an exhaust duct portionB. The suction duct portionA communicates a suction port of the undersurface of an armored casewith a suction side of each of the Sirocco fanA,B, and the exhaust duct portionB communicates an exhaust side of each of the Sirocco fansA,B and color lights R, G, B of an optical part. Thereby, a cooling air is blown to the vicinity of each light incident position of the color lights R, G, B of the optical part for approximately the same air quantity, so that the cooling of the optical part is performed

Cooler for electro optic device and projector

In a projection display device which can be controlled by a remote controller, the remote controller includes a power supply switch button for turning on/off a power supply at a body of the projection display device, a zoom adjuster button for adjusting the zooming of a projection lens, and a focus adjuster button for adjusting the focusing of the projection lens. The projection display device body includes a restricting system which can restrict the adjusting functions of these buttons, so that inadvertent operation of any of these buttons does not affect the projection display device.

Projection display device and remote controller

A power supply unit is formed so as to be divided into first and second power supply blocks, which are disposed on both sides of a projecting lens. This allows the power supply blocks to be efficiently disposed in a projection display device, so that dead space is not easily formed in the projection display device, making it possible to reduce the size of the projection display device. First and second power supply block cooling paths are formed at first and second power supply blocks which are liable to generate heat, respectively. A light modulating system cooling path is formed at a light modulating system disposed at substantially the center of the projection display device. Therefore, even when these component parts are closely disposed in the projection display device of a compact size, proper cooling operations can be carried out, making it possible to cool the entire projection display device more efficiently.

Projector

In a projection display provided with an optical unit, a power source unit, an external case to store the optical unit and the power source unit, a suction opening ( ) is formed in one end part of the power source unit, a discharge opening ( ) is formed in the other end part, and the suction opening ( ) is arranged in the vicinity of an air inlet in the external case. Because the suction opening ( ) and the discharge opening ( ) are provided, the inside of the power source unit can be independently and efficiently cooled, and the optical unit and the power source unit can be arranged closely to each other.

A projector is provided which can project a high quality image unaffected by dust, or the like, scattered in the projector by preventing the temperature of light-modulating elements from rising. Light transmissive plates are adhered to the light emitting surface of a liquid crystal panel for red light and the light emitting surface of a liquid crystal panel for green light. The amount of heat transmitted from the polarizing plates, which generate the heat, to the liquid crystal panels is reduced by the light transmissive plates. In addition, dust, scattered in the projector, does not stick onto the light emitting surfaces of the liquid crystal panels. In contrast, a light transmissive plate is not provided at the light emitting surface of liquid crystal panel for blue light having a high energy value per unit quantity of light. Thus, the problem of a light transmissive plate preventing heat dissipation at the liquid crystal panel is eliminated, so that efficient cooling can be achieved. The relative luminosity factor of blue light B is low, so that dust is not noticeable on the screen even when it sticks onto the light emitting surface of the liquid crystal panel.

A projector prevents deterioration in optical characteristics of liquid crystal panels caused by heat generated by polarizers, and sticking of dirt onto the light-outgoing surface of the liquid crystal panels. Polarizers are disposed adjacent to the light-outgoing surfaces of liquid crystal panels, while other polarizers are disposed adjacent to the light-incoming surfaces of the liquid crystal panels. The liquid crystal panels and the two polarizers disposed adjacent to the light-incoming and light-outgoing surface of their corresponding liquid crystal panels, are supported by dust protection members. The area between the light-incoming surface of each liquid crystal panel and its associated polarizer disposed adjacent to the light-incoming surface, and the area between the light-outgoing surface of each liquid crystal panel and its associated polarizer disposed adjacent to the light-outgoing surface thereof are cut off from the outside by the dust protection member associated thereto. By virtue of this structure, it is possible to prevent deterioration in the optical characteristics of each liquid crystal panel, and to prevent dirt from sticking onto the light-outgoing surface of each light valve. Therefore, a high quality image with excellent contrast can be projected.

In a projection display device, a main board that is substantially perpendicular to a plane defined by optical axes of an optical unit is allowed to stand aside the optical unit. Therefore, if the main board is designed to have a small vertical size, the vertical size, i.e., the thickness of the projection display device, can be reduced. Therefore, unlike the conventional projection display device in which the main board is disposed above the optical unit, the entire device can be reliably reduced in thickness and size regardless of the thickness of the main board.

Projector, circuit board, and electronic device provided with said circuit board

Projection display device

A projection display device capable of improving cooling efficiency of the power unit includes a light source lamp unit, a projection lens unit, an exhaust fan provided near the light source lamp unit for ventilating an outer case, and a ventilating path provided inside the power unit. A suction fan is provided at the inlet of the ventilating path which is connected to the cooling air intake port through a duct cover to directly conduct fresh air into the ventilating path. Because the interior of the power unit is cooled by fresh air which is cooler than the air inside the outer case, cooling efficiency is enhanced.

Projection display apparatus

A projection-type display apparatus in which the entry of light rays to the back side of liquid crystal light valves from dichroic prism that composes optical system light synthesizer is prevented. To this end, a projection display according to the present invention preferably includes a color synthesizer for combining colored and modulated light beams, comprising: a square column dichroic prism composed of four triangle prisms having equal refractive index together whose cross sections are right isosceles triangles such that three light valves are located adjacent to three exterior peripheral surfaces of dichroic prism to receive colored and modulated light beams therefrom and; a filter for absorbing light with a specified wavelength range, leaked from surface of dichroic prism at the opposite side of incident light surface and directed to liquid crystal light valve, the filter being located between liquid crystal light valves and surface of dichroic prism. As for construction of the dichroic prism itself, specifically, of the four aforementioned triangular prisms, the first triangular prism and the aforementioned third triangular prism are mutually affixed in a condition in which there is a first step difference in the vertical direction. The first exposed side is formed on one edge of the affixed side of the first triangular prism. Similarly, the second triangular prism and the fourth triangular prism are attached to each other such that there is a second step difference on the same edge, and a second exposed side is formed on one edge of the affixed surface of the second triangular prism. Further, the first and the third triangular prisms and the second and the fourth triangular prisms are attached, with a step difference between them, in such a way that the aforementioned first exposed side and the aforementioned second exposed side are located on the edges facing the same direction; and a third exposed surface that is orthogonal to the aforementioned first and second exposed surfaces is formed between the aforementioned first triangular prism and the aforementioned second triangular prism.

Projection-type display apparatus

A projection display comprising: a square column dichroic prism composed of four triangle prisms having equal refractive index together whose cross sections are right isosceles triangles such that three light valves are located adjacent to three exterior peripheral surfaces of dichroic prism to receive colored and modulated light beams therefrom and; a filter for absorbing light with a specified wavelength range, leaked from surface of dichroic prism at the opposite side of incident light surface and directed to liquid crystal light valve, the filter being located between liquid crystal light valves and surface of dichroic prism. As for construction of the dichroic prism itself, specifically, of the four aforementioned triangular prisms, the first triangular prism and the aforementioned third triangular prism are mutually affixed in a condition in which there is a first step difference in the vertical direction. The first exposed side is formed on one edge of the affixed side of the first triangular prism. Similarly, the second triangular prism and the fourth triangular prism are attached to each other such that there is a second step difference on the same edge, and a second exposed side is formed on one edge of the affixed surface of the second triangular prism. Further, the first and the third triangular prisms and the second and the fourth triangular prisms are attached, with a step difference between them, in such a way that the aforementioned first exposed side and the aforementioned second exposed side are located on the edges facing the same direction; and a third exposed surface that is orthogonal to the aforementioned first and second exposed surfaces is formed between the aforementioned first triangular prism and the aforementioned second triangular prism.

Growing community of inventors

Hata-machi, Japan

Mutsuya Furuhata