Abstract: A projection lens unit (15) of a projector (10) is disposed in a state in which an optical axis (CL) of the projection lens unit deviates from a center of an image forming panel (14); a first lens holder (43) of a lens barrel (40) includes holding pieces (55a, 55b) that are provided at intervals in a circumferential direction of a first lens group (L1) and are engaged with a first portion (A1) of the first lens group positioned on a side to which the image forming panel is shifted, and a holding piece (55c) that is engaged with a second portion (A2) of the first lens group positioned on a side opposite to the side to which the image forming panel is shifted; and the linear expansion coefficient of each of the holding pieces is lower than the linear expansion coefficient of the holding piece.

Abstract: A projection lens unit (15) of a projector (10) is disposed in a state in which an optical axis (CL) of the projection lens unit deviates from a center of an image forming panel (14); a first lens holder (43) of a lens barrel (40) includes holding pieces (55a, 55b) that are provided at intervals in a circumferential direction of a first lens group (L1) and are engaged with a first portion (A1) of the first lens group positioned on a side to which the image forming panel is shifted, and a holding piece (55c) that is engaged with a second portion (A2) of the first lens group positioned on a side opposite to the side to which the image forming panel is shifted; and the linear expansion coefficient of each of the holding pieces is lower than the linear expansion coefficient of the holding piece.

Abstract: A projection lens unit (15) of a projector (10) is disposed in a state in which an optical axis (CL) of the projection lens unit deviates from a center of an image forming panel (14); a first lens holder (43) of a lens barrel (40) includes holding pieces (55a, 55b) that are provided at intervals in a circumferential direction of a first lens group (L1) and are engaged with a first portion (A1) of the first lens group positioned on a side to which the image forming panel is shifted, and a holding piece (55c) that is engaged with a second portion (A2) of the first lens group positioned on a side opposite to the side to which the image forming panel is shifted; and the linear expansion coefficient of each of the holding pieces is lower than the linear expansion coefficient of the holding piece.

Abstract: A projection lens unit (15) of a projector (10) is disposed in a state in which an optical axis (CL) of the projection lens unit deviates from a center of an image forming panel (14); a first lens holder (43) of a lens barrel (40) includes holding pieces (55a, 55b) that are provided at intervals in a circumferential direction of a first lens group (L1) and are engaged with a first portion (A1) of the first lens group positioned on a side to which the image forming panel is shifted, and a holding piece (55c) that is engaged with a second portion (A2) of the first lens group positioned on a side opposite to the side to which the image forming panel is shifted; and the linear expansion coefficient of each of the holding pieces is lower than the linear expansion coefficient of the holding piece.

Abstract: An optical lens assembly containing a plural number of lens elements for an optical system to be incorporated into a tip end portion of an endoscopic insertion instrument. Of a plural number of lenses which constitute an optical system, a metal film layer is formed on confronting outer peripheral surface portions of at least two adjacently located lenses, outside respective effective lens areas, and the two adjacently located lenses are assembled and fixedly bonded together by applying solder to the outer peripheral surface portions with a metal film layer.

Abstract: An optical lens assembly containing a plural number of lens elements for an optical system to be incorporated into a tip end portion of an endoscopic insertion instrument. Of a plural number of lenses which constitute an optical system, a metal film layer is formed on confronting outer peripheral surface portions of at least two adjacently located lenses, outside respective effective lens areas, and the two adjacently located lenses are assembled and fixedly bonded together by applying solder to the outer peripheral surface portions with a metal film layer.

Abstract: A piston of an air and water supply valve in an endoscope comprises: a base cylinder; a water supply switching piston; and an air supply switching piston, which is inserted in the water supply switching piston. An air supply button functioning as a check valve is attached to the top end of the air supply switching piston, and air is supplied by slightly pressing the air supply button and water is supplied by deeply pressing the air supply button. If liquid flows back, the air supply button functions as the check valve to prevent the backflow from flowing into the base cylinder from the air supply switching piston.

Abstract: A diffusion plate includes a plurality of superimposed basic patterns, each having a large number of microstructures. The microstructures are located in two dimensional periodic arrangements, and lattice vectors, corresponding to the periodic arrangement of the microstructures, vary in accordance with the pattern. The invention also discloses a method for manufacturing a master die for such a diffusion plate, and a focusing screen using the diffusion plate.

Abstract: A diffusion plate includes a plurality of superimposed basic patterns, each having a large number of microstructures, wherein the microstructures are located in two dimensional periodic arrangements, and wherein lattice vectors, corresponding to the periodic arrangement of the microstructures, vary in accordance with the pattern. The invention also discloses a method for manufacturing a master die for such a diffusion plate, and a focusing screen using the diffusion plate.

Abstract: A diffusion plate includes a plurality of superimposed basic patterns, each having a large number of microstructures. The microstructures are located in two dimensional periodic arrangements, and lattice vectors, corresponding to the periodic arrangement of the microstructures, vary in accordance with the pattern. The invention also discloses a method for manufacturing a master die for such a diffusion plate, and a focusing screen using the diffusion plate.