Abstract: For recording an image on a photosensitive material with the employment of a liquid crystal device, the device used therein is conventionally constructed so as to modulate an amount of light rays transmitted therethrough or reflected thereby commonly by the control of an amount of electric voltage impressed to the liquid crystal device and/or impression timing or frequencies thereof. In this instance, although the light rays irradiated are considered normally as parallel, they are not intact strictly parallel light rays, and consequently unless the light rays transmitted from the device are converged by Selfoc lens arrays and the like, sufficient resolution can hardly be obtained on the photosensitive material on account of the light rays still having comparatively large diffusion coefficients.

Abstract: In a laser beam scanning system for recording information of characters and/or marks on a heat mode recording material, the pulses used for modulating the laser beam according to the information to be recorded are extended by 10% to 100%. By the extension, the dots or the minimum elements recorded on the recording material are expanded in the main scanning direction. Thus, the thickness of the lines constituting the character or the like are recorded in the constant thickness both in the vertical and horizontal directions. The pulses are delayed and the delayed pulses are added to the original pulses to obtain a logical sum thereof, thereby obtaining extended pulses. Alternatively, the fall of the pulses is detected and other pulses are generated upon detection of the fall, and the original pulses and the other generated pulses are added together to obtain extended pulses.

Abstract: An apparatus for detecting and measuring the area of defects in a sheet or rolled material comprises a defect detection section which rapidly scans the whole area of the material to locate the positions of defects and a defect size measuring section which is moved directly to each of the located positions to measure the area of the defect.

Abstract: A disk-recording plate is produced by successively forming an etching layer and a laser-sensitive layer on a substrate. The assembly is exposed to the irradiation of laser beams to selectively remove the laser-sensitive layer and is then subjected to a sputter-etching treatment in an atmosphere of a reactive gas to remove the etching layer at portions corresponding to the removed portions of the laser-sensitive layer. The method permits monitoring of recording, and thus ensures accurate recording with good resolution.

Abstract: In a light scanning recording or displaying system, a synchronizing light beam is separated from a signal light beam used for recording images or display utilizing the difference in wavelength of the two light beams. The synchronizing light beam and the signal light beam are produced by different light sources of different wavelength and made to advance in the same direction to be reflected and deflected by a light scanning means such as a rotating mirror together in the same direction. After both the light beams are deflected by the light scanning means, the two beams are divided by use of a prism, a holographic plate or a dichroic mirror.

Abstract: A rotary polygonal mirror is used to horizontally deflect a laser beam emitted by a laser source. A cylindrical lens is provided between the laser source and the rotary polygonal mirror for vertically converging the laser beam to form a horizontally extending light spot on the face of the rotary mirror. The beam reflected by the face of the mirror is vertically collimated and horizontally converged by a convergent lens to form a vertically extending light spot on an elemental hologram plate. By the hologram plate, the beam is vertically converged. Behind the hologram plate is located another cylindrical lens for horizontally converging the beam. By the vertical convergence effect of the elemental hologram plate and the horizontal convergence effect of the second cylindrical lens, the laser beam incident to the elemental hologram plate is converged to a minute light spot on a focusing plane. A microfilm is located on the focusing plane and the laser beam scans the microfilm to record information thereon.

Abstract: A method and apparatus for deflecting a light beam having high resolution, good linearity with time and high frequency response. For deflecting a light beam, after a monochromatic light beam is applied to a light deflection unit driven by a sinusoidal AC voltage so as to carry out light deflection, the deflected monochromatic light beam is scanned on a deflection angle correction plate which comprises elemental holograms formed by a multiple-beam hologram production technique. Thereafter, the light beam passing through the deflection angle correction plate is focused on a light receiving surface to perform a uniform scanning thereon.