Abstract: A device for splitting an incident light on an image forming optical system by a relief type diffraction grating. The device is constructed of a transparent substrate and a transparent filling layer having substantially the same refractive index as that of the transparent substrate, and the relief type diffraction grating is formed on the interface between the substrate and the filling layer. With such an arrangement, the reflectively diffracted light is detected by the photodetector without any undue influence in the image-formation based on the transmissively diffracted light.

Abstract: A laser beam recording member capable of recording information by absorbing the radiation energy of a laser beam to cause a thermal melting deformation and/or evaporation removal at the portion exposed to the laser beam wherein the recording layer is composed of a non-metallic layer mainly composed of S, Se, Te or chalcogenide compounds thereof.

Abstract: A recording medium or video disk of this invention consists basically of a base, a plurality of layers formed on the base and made of a compound or compounds sensitive to radiation energy, and intermediate layers interposed between the adjacent radiation sensitive layers. Said radiation sensitive layers may have different sensitivities to radiation energy, and the intermediate layer should not chemically react with the photosensitive layers.

Abstract: A speed control device for a moving member which comprises a moving member, driving mechanism for the moving member, position coherent light containing a position information of the moving member, reference coherent light so formed as to not containing the position information of the moving member for required formation of the position coherent light and an interference light, interference light forming means utilizing the position coherent light and the reference coherent light, means for detecting interference light formed by the interference light forming means, and controlling means for the driving means to render the detected output obtained by the detection means to become a sinusoidal wave having a predetermined frequency.

Abstract: The present invention relates to a linear image forming apparatus. Said apparatus includes a beam generator for generating a light beam, a filter provided with a plurality of slits to irradiate the light beam from said beam generator to pass it therethrough in a rectangular form, whose width determines the length of the linear image formed by the beam which has passed through said slit, and a converging optical system for irradiating the beam passed through the plural slits of said filter and converge the irradiated beam for making one linear image.

Abstract: An optical device includes a recording medium for recording and reproducing information by light beam, a generator of writing and reproducing light beam, a floating member provided at least one floating shoe which produces high air pressure at that surface thereof which faces to the recording medium at an extremely small distance thereof, an optical lens mounted upon the floating member for focusing the light beam upon the surface of the recording medium, a detector of the floating height of the floating member above the recording medium, and optical system controller for controlling in response to the output from the floating height detector in such a way that the point at which the light beam is focused by the optical lens is within a predetermined range relative to the surface of the recording medium.

Abstract: A linear image composition device comprising a beam generator, a first rectangular beam producer for causing the beam generated by the beam generator to be a first parallel light beam with rectangular cross section, a second rectangular beam producer for causing the rectangular beam obtained by the first rectangular beam producer to be a second parallel light beam with rectangular cross section different from that of the first parallel light beam, and a beam condenser to which the parallel light beam with rectangular cross section produced in the record rectangular beam producer is applied.

Abstract: In an optical head moving device, there is provided a pair of parallel, spaced apart guide members having the axes thereof lying on a common plane. A movable member having engaging portions engaged with the pair of guide members and a connecting portion connecting together the engaging portions is provided on the guide members. An optical head for focusing a light beam introduced thereinto is securely mounted on the movable member in such a manner that the emergence-side principal point of the optical head lies on the plane containing the axes of the pair of guide members. Means is provided for introducing a light beam into the optical head. Mover means is provided for moving the movable means with the engaging portions thereof in engagement with the guide members, to thereby move the optical head.

Abstract: An optical device for producing a minute beam comprises beam forming means such as laser generator or the like, annular beam forming means such as lens or annular aperture mask for forming the beam from the beam forming means into a beam of annular cross section, and a condenser lens for condensing the annular beam from the annular beam forming means.