Abstract: For dissolving ununiformity in the brightness of a projection image within a display image apparatus, obtaining an enlarged projection image through an oblique projection of image lights onto a rear-surface projection type screen, wherein an image from an image generating source 1 is projected through a projection optical system, having a projection lens 2, curved surface reflection mirrors 4 and 5, a reflection mirror 6, from a rear surface of the rear-surface projection type screen 3, within a housing 7 being narrow in depth thereof; the rear-surface projection type screen includes a Fresnel lens sheet 8, wherein the prism surfaces of the Fresnel lens making up the Fresnel lens sheet are formed in an aspheric configuration, thereby letting the light beams from the screen to exit at an exit angle of about zero (0) degree, almost all over the entire surface thereof.

Abstract: In a projection type image display apparatus, for enlarging an image on a image display apparatus 1 by means of a projection lens 2, thereby projecting the enlarged image onto a screen 6, obliquely, being inclined thereto, between the projection lens 2 and a rear-surface mirror 5, there are disposed free shaped surface mirrors 3 and 4, each having a free shaped surface for compensating a trapezoidal distortion due to oblique projection of the enlarged image. The surface configuration of the free shaped surface mirror is so shaped as to satisfy a following equation: |L1?L2|>1.4·Dv if assuming that a distance for a light beam of an upper end of the enlarged image to reach the screen after being reflected upon a free shaped surface is “L1”, a distance for a light beam of a lower end of the enlarged image to reach the screen after being reflected upon the free shaped surface is “L2”, and a distance from an upper end of an image on the screen to a lower end thereof is “Dv”.

Abstract: Sensitivity of a velocity modulation device is increased and noise such as a leakage magnetic field and a leakage electric field from the device are reduced to thereby lower power consumed by the device. A cathode ray tube device and a television set each include a velocity modulation device on a cathode side of a deflection yoke. All or part of the circumference of a velocity modulation coil to modulate scan beam velocity is covered with material having an initial permeability of at least 10 at 2 MHz.

Abstract: Sensitivity of a velocity modulation device is increased and noise such as a leakage magnetic field and a leakage electric field from the device are reduced to thereby lower power consumed by the device. A cathode ray tube device and a television set each include a velocity modulation device on a cathode side of a deflection yoke. All or part of the circumference of a velocity modulation coil to modulate scan beam velocity is covered with material having an initial permeability of at least 10 at 2 MHz.

Abstract: Sensitivity of a velocity modulation device is increased and noise such as a leakage magnetic field and a leakage electric field from the device are reduced to thereby lower power consumed by the device. A cathode ray tube device and a television set each include a velocity modulation device on a cathode side of a deflection yoke. All or part of the circumference of a velocity modulation coil to modulate scan beam velocity is covered with material having an initial permeability of at least 10 at 2 MHz.

Abstract: A bulb (4) of lamp (1) has a reflection film (2) or reflection mirror (9) to make light components going outside a reflector (3) direct to the reflector (3) to reflect. If the lamp (1) is a spot light source, a light emission center is positioned at a center of spherical reflection mirror (9). If the lamp (1) is not a spot light source, the reflection mirror (9) is made ellipsoid and at its two focal points, ends of two light emitting electrodes are positioned. Also, the lamp (1) having the reflection mirror (9) is used in the illumination unit for a liquid crystal display apparatus to increase the brightness of the image projected onto the screen (26). Further, the liquid crystal display device (23) has within a liquid crystal display device (23) a microlens array for collecting the incoming light into an area of each picture element electrode (39) to increase the light utilization efficiency of the liquid crystal display device (23).

Abstract: A light scanning system employing a rotating mirror, spherical lens, and a toric-surfaced reflecting mirror. The toric-surfaced reflecting mirror is disposed in the optical path between the spherical lens and the image plane. The spherical lens sufficiently corrects field curvature and the toric-surfaced reflecting mirror corrects scan nonlinearity. And by the spherical lens and the toric-surfaced reflecting mirror together, the field curvature and the scan nonlinearity are satisfactorily corrected. The toric-surfaced reflecting mirror is surfaced to have a circular arc with a larger radius of curvature in the scan plane and to have a circular arc with a smaller radius of curvature in the cross-scan plane.

Abstract: An automatic focusing apparatus configured such that a projected light from a light emitting element is reflected on an object and the reflection light is passed through a flat plate so as to be received by a light receiving element. The position where the reflection light is received on the light receiving element varies depending on the distance between the apparatus and the object. This positional variation is corrected so as to receive the reflection light at the same position by changing an angle of inclination of the flat plate. A focusing lens is moved in cooperation with the adjustment of the inclination angle of the flat plate, thereby achieving the automatic focusing operation.

Abstract: An automatic focusing apparatus comprises a light emitting element emitting a beam of electromagnetic radiation directed toward a subject through a light projecting lens, a light receiving element receiving a beam spot reflected from the subject and passing through a light receiving lens, and a parallel-surface transparent plate disposed rotatably between the light receiving lens and the light receiving element. The parallel-surface transparent plate is rotated in interlocking relation with linear movement of an optical lens moving together with movement of a focus ring, thereby automatically attaining the focus by ceasing the movement of the lens optical system as soon as the output signal of the light receiving element attains a predetermined level.

Abstract: In a zoom lens system with plastic lenses, shifting of an image forming plane of the zoom lens caused by resultant deformation and optical characteristic changes due to temperature changes of plastic single lenses and of plastic lenses included in compound lenses in the zoom lens system is corrected by a compound lens of a plastic lens and a glass lens cemented together or by a compound lens of a plastic lens and a glass lens spaced apart from each other with a slight air gap between opposing surfaces thereof of substantially the same radius of curvature, the compound lens having a temperature change dependent shifting of image forming plane to correct that of other plastic lenses.

Abstract: An electron gun structure for a pickup tube comprises a cathode lens electrode assembly, a beam disc electrode and a main lens electrode assembly. The main lens electrode assembly includes first and second electrodes adapted to be supplied with different potentials so as to form a bipotential electron lens in the main lens electrode assembly. The beam disc electrode which has a beam limiting hole is adapted to be supplied with a potential not higher than about 2.5 times the lower one of the potentials to be supplied to the first and second electrodes in the main lens electrode assembly.