Abstract: In a power module having at least one power device chip and circuits for driving and controlling the power device chip which are incorporated within one and the same package, a heat spreader which is constituted by a material having a heat dissipation property and supports the power device chip on its upper surface is inserted into an opening formed in a control substrate having an upper surface on which patterns for forming the chip driving and controlling circuits and a connection pattern for connection with the power device chip are printed, and the control substrate and the heat spreader inserted into the opening are fixedly supported on a base substrate. Thus, the power device chip and the control substrate can be disposed in plane and reduced in size.

Abstract: In order to effectively use light from a light source, the light from the light source is split into P-polarized light and S-polarized light by a splitter or the like. The split P-polarized light is directly incident on a liquid crystal display apparatus for displaying an image by using P-polarized light. The split S-polarized light is optically rotated by a wavelength plate or the like and converted into P-polarized light. This P-polarized light is also incident on the liquid crystal display apparatus. The liquid crystal display apparatus effectively utilizes the light from the light source and displays an image with high luminance.

Abstract: A back-surface projection screen for observing a light image, projected from the rear surface of a screen, on a major surface of the screen comprises a lenticular lens constructed of a greater number of lens units in a continuous array with a top surface section defined as a lens section and with a pair of total-reflection surfaces formed as side convex lenses relative to a central convex lens section formed at the lens section. A pair of linear surfaces are formed one at each of the total-reflection surfaces in an opposed relation with the central lens section located therebetween. The total-reflection surfaces are so curved as to allow light which is incident on the screen from behind to be condensed by reflection toward the linear surfaces. The lens section of each lens unit in the lenticular lens is recessed at the central section to define that center convex lens surface there with the pair of side total-reflection surfaces formed as a pair of convex lens.

Abstract: A projection display apparatus includes a light source unit for generating light for image formation, an electro-optical display device for displaying an optical image by utilizing the light emitted from the light source unit, and an enlarging/projection lens. The light source unit, the display device, and the projection lens are accommodated in a housing with vent openings. The housing also includes a fan for cooling the interior of the housing with cool air and a cooler for maintaining a display panel within a predetermined temperature range. The light source unit includes a lamp and a reflector and is designed not to cause image deformation and formation of a shadow of a discharge portion. In order to display a television image on the display device, all television image display circuit units excluding an antenna are accommodated in the housing. The enlarging/projection lens can control a magnification and a focal point of the image projected on the screen.

Abstract: A projection lens, for enlarging and projecting an image displayed on a liquid crystal display panel onto a transmission type screen provided at a display window of a projector case, is arranged so that its optical axis is perpendicular to the optical axis of projection toward the transmission type screen. At least one mirror, for reflecting an image projected through the projection lens toward the transmission type screen, is arranged between the projection lens and the transmission type screen. The liquid crystal display panel is arranged such that its optical axis is perpendicular to the optical axis of the projection lens. At least one mirror, for reflecting an image displayed on the liquid crystal display panel toward the projection lens, is arranged between the liquid crystal display panel and the projection lens.

Abstract: In a liquid crystal projector wherein a light source is arranged behind a transmission liquid crystal display panel having a rectangular display portion, an image displayed on the liquid crystal display panel is enlarged by a projection lens, and an enlarged image is projected on the screen located in front of the liquid crystal display panel, a linear Fresnel lens is arranged between the light source and the liquid crystal display panel to narrow illumination light beam from the light source along only the widthwise direction of the rectangular display portion. When the illumination light beam from the light source is narrowed along only the widthwise direction of panel, the amount of unused light beam emitted outside the long sides of the display portion can be reduced, and the light beam from the light source can be effectively utilized for image projection.