Abstract: In recent years, much attention has been paid to a projection type display apparatus using a plurality of light sources, as projection type video equipment capable of large screen display. However, in an optical system using a plurality of light sources, devices are designed so that uniform lighting can be provided assuming only the use of all the light sources. Thus, the uniformity of brightness within a display screen may be degraded if not all of the plurality of light sources are used. A light apparatus includes a plurality of lamp unit sections, a synthetic mirror section that reflects and synthesizes lights generated by all or some of the plurality of lamp unit sections and, and a synthetic mirror section adjusting mechanism that holds the synthetic mirror section so that its position can be changed so as to adjust the reflecting optical paths of the reflected lights.

Abstract: An illuminating optical system for focusing a radiant light of a light source (1) onto a reflecting light valve (6) and a projection lens (7) for magnifying and projecting a reflected light from the reflecting light valve (6) onto a screen are provided, a diaphragm (31) is disposed at a substantially conjugate position of an entrance pupil of the projection lens (7) on an optical path of the illuminating optical system, the diaphragm (31) has an opening whose area is changed by a light-shielding member, and a shape of a shielded portion of the diaphragm (31) shielded by the light-shielding member is rotationally asymmetric to an optical axis (12) of the illuminating optical system. Accordingly, shielding of necessary light can be better avoided compared with a diaphragm for changing the light-shielding area in a rotationally symmetric manner, for example, a diaphragm for narrowing the opening concentrically, making it possible to improve contrast performance while minimizing brightness reduction.

Abstract: An illuminating optical system for focusing a radiant light of a light source (1) onto a reflecting light valve (6) and a projection lens (7) for magnifying and projecting a reflected light from the reflecting light valve (6) onto a screen are provided, a diaphragm (31) is disposed at a substantially conjugate position of an entrance pupil of the projection lens (7) on an optical path of the illuminating optical system, the diaphragm (31) has an opening whose area is changed by a light-shielding member, and a shape of a shielded portion of the diaphragm (31) shielded by the light-shielding member is rotationally asymmetric to an optical axis (12) of the illuminating optical system. Accordingly, shielding of necessary light can be better avoided compared with a diaphragm for changing the light-shielding area in a rotationally symmetric manner, for example, a diaphragm for narrowing the opening concentrically, making it possible to improve contrast performance while minimizing brightness reduction.

Abstract: An illuminating optical system for focusing a radiant light of a light source (1) onto a reflecting light valve (6) and a projection lens (7) for magnifying and projecting a reflected light from the reflecting light valve (6) onto a screen are provided, a diaphragm (31) is disposed at a substantially conjugate position of an entrance pupil of the projection lens (7) on an optical path of the illuminating optical system, the diaphragm (31) has an opening whose area is changed by a light-shielding member, and a shape of a shielded portion of the diaphragm (31) shielded by the light-shielding member is rotationally asymmetric to an optical axis (12) of the illuminating optical system. Accordingly, shielding of necessary light can be better avoided compared with a diaphragm for changing the light-shielding area in a rotationally symmetric manner, for example, a diaphragm for narrowing the opening concentrically, making it possible to improve contrast performance while minimizing brightness reduction.

Abstract: An illuminating optical system for focusing a radiant light of a light source (1) onto a reflecting light valve (6) and a projection lens (7) for magnifying and projecting a reflected light from the reflecting light valve (6) onto a screen are provided, a diaphragm (31) is disposed at a substantially conjugate position of an entrance pupil of the projection lens (7) on an optical path of the illuminating optical system, the diaphragm (31) has an opening whose area is changed by a light-shielding member, and a shape of a shielded portion of the diaphragm (31) shielded by the light-shielding member is rotationally asymmetric to an optical axis (12) of the illuminating optical system. Accordingly, shielding of necessary light can be better avoided compared with a diaphragm for changing the light-shielding area in a rotationally symmetric manner, for example, a diaphragm for narrowing the opening concentrically, making it possible to improve contrast performance while minimizing brightness reduction.

Abstract: In recent years, much attention has been paid to a projection type display apparatus using a plurality of light sources, as projection type video equipment capable of large screen display. However, in an optical system using a plurality of light sources, devices are designed so that uniform lighting can be provided assuming only the use of all the light sources. Thus, the uniformity of brightness within a display screen may be degraded if not all of the plurality of light sources are used. A light apparatus includes a plurality of lamp unit sections, a synthetic mirror section that reflects and synthesizes lights generated by all or some of the plurality of lamp unit sections and, and a synthetic mirror section adjusting mechanism that holds the synthetic mirror section so that its position can be changed so as to adjust the reflecting optical paths of the reflected lights.

Abstract: An imaging apparatus including a projection section for projecting an image onto a screen, a cooling section for cooling the projection section by means of air, and an exterior cabinet for housing the projection section and the cooling section. The imaging apparatus further includes an exhaust section for exhausting the air used for the cooling of the projection section by the cooling section, from the exterior cabinet. The exhaust section has a function for attenuating a noise caused by the cooling section.

Abstract: A projection lens for projecting the visual image of the cathode ray tube apparatus (CRT) consists of plastic lens elements, at least one glass lens element which absorbs X-rays from the CRT, and a body tube made of plastic material containing X-ray shielding material such as PbO, Zn, BaSO.sub.4, Pb-Sn alloy or the like.