Abstract: An optical system of an optical neural network model for parallel data processing is disclosed. Taking advantage of the fact that an auto-correlation matrix is symmetric with respect to a main diagonal and the weights for modulating the values of diagonals of the auto-correlation matrix are equal to each other, the configuration of an optical modulation unit is simplified by a one-dimensional modulation array on the one hand, and both positive and negative weights are capable of being computed at the same time on the other hand. In particular, the optical system makes up a second-order neural network exhibiting invariant characteristics against the translation and scale.

Abstract: A method of and apparatus for fabricating an article having an aspheric figure, wherein the three-dimensional positional relationship between a work and a grinding spindle as a processing tool is controlled in terms of a polar coordinate system. The grinding spindle extends in a plane which is perpendicular to the direction of rotation of said work and is made to swing along an arcuate path. The distance between the axis of rotation of the work and the axis of the swing of the grinding spindle is changed in relation to the rotational angular position of the work.

Abstract: An optical integrated circuit and an optical apparatus used in optical communication or an opto-electronics apparatus such as an optical disk recording apparatus, in which various kinds of aberration caused by wavelength variation of a light source when a semiconductor laser is used as the light source. An aberration correcting grating having such grating pitches as to nearly satisfy the Bragg condition preferably with respect to a certain wavelength of the semiconductor laser beam is used. As a result, lowering of incidence (entrance) and radiation (exit) coupling efficiencies of the grating coupler and aberration such as chromatic aberration can be prevented. Even if a multi-mode semiconductor laser is used as a light source, the characteristics of the optical integrated circuit and optical apparatus do not vary largely.

Abstract: A variable density scanning apparatus comprises a semiconductor laser which generates at least one laser beam, a first drive circuit which applies to said semiconductor laser a modulation drive signal having a predetermined modulation frequency in accordance with the density of dots constituting the pattern to be formed on the scanning surface, a dynamic diffraction grating which receives a laser beam from said semiconductor laser and diffracts said laser beam into a plurality of diffraction beams, a second drive circuit which applies to said dynamic diffraction grating a diffraction drive signal having a predetermined high frequency in accordance with the dot density, a polygonal mirror which receives a plurality of diffraction beams from said dynamic diffraction grating and scans said diffraction beam in the main scanning direction, a third drive circuit which applies to said polygonal mirror a rotation drive signal having a predetermined rotation frequency in accordance with the dot density, and a control

Abstract: An optical scanning apparatus has a scanning lens with a rotationally asymmetric aspheric surface having individual curvature radii in the main scanning direction and in the sub-scanning direction. The curvature radius in the sub-scanning direction is asymmetrically increased in the lateral direction with the distance from the optical axis. A field curvature aberration which may be generated in the sub-scanning direction on the scanning surface due to an oblique incident of optical beams on the rotating polygonal mirror or the movement of the reflective surface caused by rotation of the rotating polygonal mirror is compensated for by the scanning lens and the focusing properties of the system can be kept at a level of high resolving power.

Abstract: Prism optics for changing the shape of a light beam, including a composite prism consisting of at least two types of prisms made of materials having different variations in the refractive index due to variations of the refractive index due to wavelength variations and to temperature variations, which materials are so chosen that the angle of the light beam exitting from the prism optics remains almost constant, independent of variations in the wavelength of the light beam and temperature, and an optical information processing apparatus using these prism optics.

Abstract: An optical scanner and method in which light beams from a plurality of sources are directed onto a medium to form a composite spot. The relative positions of the beams are detected and changed to change the diameter of the composite spot so that lines formed by such spots appear unbroken. The modulating times, intensities and number of sources of the beams can also be varied to provide a linear relation between the dither matrix and the picture element density.

Abstract: A scanning apparatus for use in a laser beam printer or the like comprising a control means for varying the spacing between adjoining scanning beams of a plurality of laser beams, which further comprises a plurality of light sources, a means for changing intensity, including on/off states, of the beam from the light sources, and a rotating polygonal mirror for allowing the beams to scan the scanned plane in parallel, and is adapted, in accordance with the value of the pixel density of information to be recorded, such that, in the beam scanning direction, the area exposed to the beam is changed by changing the width of a beam intensity modulating pulse, and in the direction perpendicular to the beam scanning, the number of revolutions of the rotating polygonal mirror is changed.

Abstract: In an information device which has a laser light source and a non-linear optical crystal for converting the laser fundamental wave light irradiated from the laser light source into harmonic wave light and uses the laser light passing through the non-linear optical crystal, a prism or an optical grating is provided to separate an optical path of the fundamental wave light remaining in the laser light passing through the crystal from an optical path of the harmonic wave light with the purpose of eliminating the fundamental wave light. In another embodiment, a polarization filter is provided to eliminate the fundamental wave light.

Abstract: An optical pickup comprises at least a semiconductor laser, a waveguide optically coupled with the semiconductor laser for propagating therein a light from the semiconductor to guide it to a recording medium and a light deflector element provided on the waveguide for deflecting the light propagated in the waveguide by means of a surface acoustic wave. A multi-mode oscillation laser capable of stably operating in longitudinal modes the number of which is not larger than 5 is used as the semiconductor laser. The semiconductor laser is disposed in proximity to the waveguide at a distance not larger than 1 .mu.m, thereby inputting the light from the semiconductor laser into the waveguide with a high efficiency. A frequency applied to the light deflector element may be changed upon change between a read-out state and a write-in state so that a light spot on the recording medium is held at a predetermined position (track or address).

Abstract: Electric-photosensitive printing is accomplished with an LD providing a laser scanning beam that is modulated to affect printing, and the power output of the LED is maintained constant through negative feedback by a holding voltage provided by a capacitor having its charge determined only during a non-printing portion of the printing period wherein a plurality of sheets are printed. During the non-printing period, contact of the scanning laser beam with the electro-photosensitive material is disabled while the laser beam is maintained on so that its power may be measured and compared with a reference level to provide a feedback signal for controlling the output of the laser beam, particularly the feedback signal being provided to the holding capacitor only during the non-printing portion of the period, and the holding capacitor being isolated from the feedback signal during the printing portion of the period.

Abstract: In an optical scanning apparatus, a scanning lens is composed of three lens elements. The centrally located lens element of the scanning lens has a refractive power in the direction for correcting the surface tilt, that is, an inverted number of a focal length that is changed in accordance with the scanning view angle, whereby curvature of field is well corrected and RMS spot diameters on the scanning surface may be small. In addition, even if the view angle is increased, imaging characteristics may be kept at a high resolving power.

Abstract: An optical pickup comprising a semiconductor laser, a first waveguide for leading light emitted by the semiconductor laser to recording medium and coupling again light returning from the recording medium; splitting element for separating the light returning from the recording medium from the first waveguide path; and a second waveguide propagating light returning from the recording medium and separated by the splitting element; wherein light going towards the recording medium and light returning from the recording medium propagate separately in the first and the second waveguide so that the utilization efficiency of the light is increased.

Abstract: A beam deflector device in which two light beams from two light sources are simultaneously applied through movable reflectors to a beam deflector scanning a drum. The beams are also applied, through a beam splitter to two photodetectors used to control the position of the respective reflector. The two beams are separated before they are applied to the photodetectors by means of polarization plates, color filters, diffraction gratings or prisms.

Abstract: A semiconductor laser array device in which a single photodetector is provided near the exit ports on one side of the semiconductor laser array device that has a plurality of semiconductor lasers arranged close to each other, the light outputs from each of the laser light sources are detected in a time-sharing manner, and the corresponding lasers are controlled by feedback relying upon the detected signals, so that outputs of the lasers are stabilized.

Abstract: An optical printer using laser beams, wherein, when a plurality (n) of laser beams are used at once to carry out a scanning operation, the positions of spots of said laser beams in both the primary scanning direction and sub-scanning direction are set so as to have the relation l=(n-1)a+m.multidot.n.multidot.a, wherein m is a positive integer (m.gtoreq.1); a the distance between the adjacent scanning lines in the sub-scanning direction on the printing surface of the optical printer after a printing operation; and l the distance between the adjacent laser beams in the sub-scanning direction on the surface of a photosensitive drum, whereby a high-quality printing effecting no overlapping and omission of images can be obtained even if the distance between the adjacent laser beams is increased during a scanning operation using a plurality of laser beams at once.

Abstract: A method and equipment for fabricating two diffraction gratings having the same period but phases that are shifted by .lambda./4 on a work to be treated. A laser beam is divided into two light beams and one of the beams is delayed over a portion of the light beam. The divided light beams are then mixed together so that they interfere. Using the known photolithography technology, the interference patterns are formed into diffraction gratings.

Abstract: An optical system and a optical information processing equipment utilizing the same are disclosed. The optical system comprises a laser diode and a hologram lens has an interference fringe prepared by the interference of a beam having substantially the same intensity distribution and/or phase characteristic as that of a laser beam emitted from the laser diode with a beam having a desired characteristic. The laser beam from the laser diode is irradiated on the hologram lens so that its characteristic is converted into the desired characteristic.

Abstract: An optical system for converting the shape of a light beam by making use of refraction of prisms comprises a prism optic which includes a complex prism constituted by combination of at least two types of prisms made of materials differing from each other in respect to dispersion of refractivity. An optical information processing apparatus includes the optical system employing the prisms. Geometric optical properties of the optical system are insusceptible to being changed irrespective of changes in wavelength of the light beam brought about by dispersion in oscillation wavelength of a light source, change in the course of time lapse, change in ambient temperature and/or change in emitted light energy. With the optical system, information processing is realized which is insusceptible to the influence of the change in wavelength of the light beam.

Abstract: A recording optical system comprises: a laser light source; means for modulating an intensity of a laser beam emitted from the light source; means for shaping a cross sectional shape of the laser beam; means for controlling the modulating means and the shaping means; and deflecting and focusing means for focusing and scanning the shaped laser beam onto the scanning surface. The laser beam size in the direction (sub scanning direction) perpendicular to the scanning direction is varied on the scanning surface by the shaping means, during the recording operation.