Abstract: A laser data recording method in which data is recorded on a heat mode recording material with high sensitivity and low laser power. A scanned laser beam is adjusted to have a substantially circular configuration on the recording material with a diameter defined at an intensity value of 1/e.sup.2 of approximately one scanning line pitch on the recording material. The laser beam is intensity modulated in such a manner that the ratio of the laser beam intensity in the "on" state to the laser beam intensity in the "off" state is in a range of 1:0.24 to 1:0.53, more preferably 1:0.25 to 1:0.50.

Abstract: A light beam scanning system in which the vibration of a rotating multi-face mirror and a high-speed motor which constitute the light beam scanning means of the system is prevented from being transmitted to other optical components of the system by mounting the rotating multi-face mirror and the high-speed motor on the optical component mounting board through the medium of vibration isolators.

Abstract: A light beam scanning system in which deviations perpendicular to the scanning direction of the scan line due to parallelism deviations of a rotary multi-surfaced mirror are eliminated. A first linear image pattern is formed on the reflecting surface of the mirror parallel to the scanning direction by a connex cylindrical lens. The image is reflected to a first convergent lens which forms a second linear image perpendicular to the scanning direction then passes through a concave cylindrical lens which diverges the light in a direction perpendicular to the scanning direction. A second convergent lens converges the beam to form a point image on the scanned surface.

Abstract: Synchronizing signals for a laser beam scanner are generated by applying first and second angularly spaced light beams 100,200 to the same reflecting surface 11 of a rotary, multi-surfaced mirror 10. When the first reflected light beam 110' is close to the start point 111 of the line 130, the second reflected light beam 210 is focused onto a photo-detector 30 whose output constitutes the synchronizing signal for the scan. Since both input beams 100, 200 are incident on the same mirror surface rather than impinging an edge thereof, jitter due to angle division errors, rotational speed fluctuations, and mechanical vibrations is eliminated.

Abstract: A light beam scanner employs two rotary multi-surfaced mirrors 510, 520 manufactured together and having the same parallelism error characteristics between paired reflecting surfaces, and a relay lens 610 disposed between the two mirrors. The synchronously rotated mirrors are disposed at the conjugate planes of the relay lens, whereby parallelism errors are eliminated by subtractive cancellation.

Abstract: A laser beam generated from a laser source is passed through a semi-cylindrical lens having a horizontal axis and vertically converged thereby to a horizontal line on a face of a rotating multi-face mirror. The vertically converging light beam is reflected by the face of the mirror and vertically diverges. The vertically diverging light beam impinges on a hologram and the first-order diffraction beam emerging from the hologram converges to a point. As the mirror rotates about the axis of rotation thereof, the point to which the first-order diffraction beam converges repeatedly moves along a line of predetermined length. The hologram has the effect of converging the first-order diffraction beam emerging therefrom when it receives a vertically diverging light beam so that any beam emerging from vertically the same level on the face of the mirror converges to the same point.

Abstract: A beam scanning device comprises a rotating multi-face mirror, a single optical element having major and minor axes of different focal length and an image forming optical system. A beam of collimated light is passed through or reflected by the single optical element a first time to form a line image on the rotating multi-face mirror. The reflected beam of light issuing from the line image is passed through or reflected by the single optical element a second time and the resulting collimated beam is passed through the image forming optical system to form a light spot on the image plane. As the rotating multi-face mirror is rotated, the light spot successively scans the image plane without any displacement of the scanning lines resulting from error in parallelism of the rotating multi-face mirror.

Abstract: A hologram which is made by use of a collimated light beam incident upon the hologram at an angle with respect to the line orthogonal thereto is used as an optical element to converge a laser beam in a process of making a hologram lens. Since the hologram made by use of the obliquely incident collimated light beam has a large effective area, a hologram lens having a large effective diameter can be produced.

Abstract: A white light source is employed for illuminating a color image hologram have no effect of diffusion. The primary or first order diffraction light is directed to and focused on a spectrum selecting spatial filter for selecting the spectra which contribute to form a multi-color image reconstructed by the hologram. The spatial filter is provided with a central slit of the width substantially equally to the band width of the spatial frequency peculiar to the object recorded and reconstructed. The spatial filter is further provided with a red filter and a blue filter on the opposite sides of the slit adjacent thereto. By providing the red and blue filters adjacent to the slit of the spatial filter, the brightness of the image reconstructed by the color halogram reconstructing system is markedly enhanced.

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.

Abstract: A plurality of holograms carrying equivalent information are arranged so that the undiffracted beam passing through the first hologram is used as a reconstructing beam to illuminate the second hologram, and the undiffracted beam of the second is used as a reconstructing beam for illuminating the third and so on to obtain a single bright image constituted by a plurality of perfectly overlapped images. Another embodiment of the invention employs a plurality of holograms carrying information corresponding to different parts of an object in which the undiffracted beam passing through the i-th hologram is used to illuminate the (i+ 1)-th hologram as a reconstructing beam.