An optical head device adapted to be optically coupled to an optical disk includes a light-source laser and an objective lens optically coupled thereto. This lens receives an output light of the light source, and causes it to be projected onto the optical disk to form a focused spot thereon. Photodetectors which are arranged near the light-source laser are optically coupled to the lens in one optical path so that they are responsive to a light component which is reflected from the optical disk toward the photodetectors by way of the objective lens. A beam-shaping prism is located between the lens and a group of the light source and the photodetectors in the optical path. When the laser output light travels toward the lens, the prism reshapes the light into a predetermined isotropic beam profile. When the reflected light from the optical disk propagates reversely along the same optical path to enter the beam-shaping prism, this prism permits such an incident light to pass through itself toward the photodetectors.

Light beam shaping device to change an anisotropic beam to an isotropic beam for reducing the size of an optical head

A tilting member has a force bearing portion to which operating force is applied, and a supported surface A supporting member has a supporting projection with which the supported surface of the tilting member may come in contact When the operating force is applied to the tilting member, the tilting member tilts with respect to the supporting member The supporting member supports the tilting member at a supporting point where the supporting projection of the supporting member is in contact with the supported surface of the tilting member, about which supporting point the tilting member tilts The tilting of the tilting member, with respect to the supporting member, establishes a predetermined electrical contact

Selective multiple position switch with common pivoted operator

Accessory producing apparatus

A tilting member has a force bearing portion to which operating force is applied, and a supported surface. A supporting member has a supporting projection with which the supported surface of the tilting member may come in contact. When the operating force is applied to the tilting member, the tilting member tilts with respect to the supporting member. The supporting member supports the tilting member at a supporting point where the supporting projection of the supporting member is in contact with the supported surface of the tilting member, about which supporting point the tilting member tilts. The tilting of the tilting member, with respect to the supporting member, establishes a predetermined electrical contact.

Control-key mechanism having improved operation feeling

PURPOSE: To precisely reproduce data at the time of reproducing when a pit already recorded and an additional recording pit are detected by a data demodulation part by generating and outputting a recording timing signal at regular time intervals based on a time width signal corresponding to a time width which is related to the cycle of a signal which synchronizes with a pit detection signal CONSTITUTION: The data demodulation part B 1 generates a synchronizing signal synchronously with the input of the pit detection signal of the pit already recorded and a time width generation part B5 outputs the time width signal which is related to the cycle of the synchronizing signal A recording timing signal generation part B 6 generates and outputs the recording timing signal after the time corresponding to the time width signal given from the time width generation part B5 is delayed from the recording position of the pit already recorded Therefore, when a next pit is additionally recorded by the recording timing signal, the additional recording pit is recorded on a recording medium so that the positional deviation thereof is continued with respect to the pit already recorded Thus, both pits are precisely reproduced at the time of reproducing COPYRIGHT: (C)1990,JPO&Japio

Optical recording and reproducing device

PURPOSE:To form the spot of all directions on the disc efficiently and to enable to increase the range of automatic focus drawing, by increasing the numerical aperture of coupling lens and locating the prism at the post stage of the coupling lens. CONSTITUTION:To the semiconductor laser element 1 having non-isotropic spread angle, the coupling lens has greate automatic focussing drawing range to greater numberical aperture allowing to realize perfect automatic focussing to the up and down movement of the disc 4. Then, by using the coupling lens 2 having greater numerical aperture and inserting the prism 7 immediately after the coupling lens 2, the conversion of isotropic beam can be made. This light beam can obtain the isotropic spot 5 on the disc 4 by means of the objective lens 3, and since the numerical aperture of the coupling lens 2 is taken greater, the feedback of reflection light to the semiconductor laser 1 is greater, allowing to extend the range of automatic focus drawing.

Processor for optical information

PURPOSE:To form an isotropic spot by a simple optical system by providing a beam converting prism in an optical system leading a beam from a semiconductor laser element to an information recording medium. CONSTITUTION:A beam having an expansion angle, emitted from one end face of a semiconductor laser element 1 passes through a coupled lens 2, a prism 7 and an objective 3, and forms a spot 5 on a disk 4. When angles at e in the horizontal direction and the vertical direction of an emitted light distribution in a distant view field image of the beam from the laser element 1 are denoted thetaH and thetaV, and a hemihedral angle made by the laser 1 and the lens 2 is denoted as theta, a numerical aperture of the lens 2 is selected so as to satisfy theta<thetaH<=thetaV, the prism 7 is formed so as to satisfy a prescribed condition, and the horizontal direction of expansion of the beam is expanded and made to coincide with expansion in the vertical direction, by which an isotropic spot is obtained by a simple optical system.

Optical information processing device

PURPOSE:To improve the optical coupling efficiency of reproducing laser light and to ensure the stable reproduction of information, by setting both the light emitting end face of a semiconductor laser and the photodetecting surface of a photodetecting element in a container staring them so that they are put on a straight line to the light transmitting window of the container. CONSTITUTION:A light transmitting window 9, the light emitting end face of a semiconductor laser 1 and the photodetecting surface of a photodetecting element 2 are set in a container so that they are approximately put on a straight line along an axial line passing through the center of a support ring. The laser light radiated from a light transmitting part is irradiated on the surface 3 of an optical disk, and the information recorded on the surface 3 is reproduced by means of the reflected light given from the surface 3. Thus the reproducing laser light is extracted from the upper surface of the container with use of a single light emitting part. This extracted laser light is fitted to a cylinder which supports optical systems 4 and 4' that lead the laser light to the surface 3. This device facilitates coupling of laser light as well as position matching of optical axes. As a result, the optical coupling efficiency is improved for the reproducing laser light.

Information pickup device using semiconductor laser

PURPOSE:To facilitate, in compact manner, the coupling with an external optical system and the positioning and thus contrive to improve the photo coupling efficiency by a method wherein a photo transmitting part, a laser, and a photo detecting element are constituted by arrangement nearly on a straight line, and a laser light is radiated from the upper end part of a package, along the center axial line of the package. CONSTITUTION:One output of the photo detecting element is led outward by connecting a conductive film to a lead terminal by means of a bonding wire. The whole package is so formed as to be hermetically sealed with a photo transmitting window 9 and a supporting ring 10 therefor. The photo transmitting window, the light emitting end surface of the semidonductor laser, and the photo receiving surface of the photo detecting element are arranged nearly on a straight line along the direction of the axial line passing through the center of the annular supporting ring, and particularly the whole package is very small-sized. The photo detecting element is made electrically floating from a package base body 11, and lead terminals come out in three pieces altogether. The semiconductor laser whose reflectance is decreased by coating the disc side end surface of the laser with a reflection preventing film is used.

Masahiro Oshima

Papers

Processor for optical information

Optical information processing device

Information pickup device using semiconductor laser

Semiconductor laser device with photo detecting element built-in