Abstract: An optical pickup head apparatus comprises a yoke provided in an opposing relation to a magnet, a movable member having formed therethrough an aperture into which the yoke is inserted and around which a first coil is wound in an opposing relation to the magnet, an object lens supporting device having a pair of leaf springs for supporting the objective lens so that the objective lens can move in the direction parallel to the optical axis thereof and a plurality of second coils of substantially square shape for moving the objective lens in the direction parallel to the optical axis thereof and a tracking control device for rotating a mirror portion so that a beam spot focused on the optical disc by the objective lens follows a track on the optical disc, wherein the objective lens supporting device is secured to the movable member, the movable member is movably supported by the yoke and sides of the second coils which cross the optical axis of the objective lens and the first coil are located within a common mag

Abstract: An optical head comprises a laser beam source, a photo-detector device for receiving a laser beam emitted from the laser beam source and reflected at a data recording medium, an optical system for sending the laser beam from the data recording medium to the photo-detector device, and a base member for fixing the photo-detector device and the optical system. The photo-detector device has a photo-detector element, a mount member on which the photo-detector element is mounted, a block for fixing one end of the mount member, a spring member for applying elastic force to the mount member, a screw member for moving the photo-detector element along one direction against elastic force of the spring member and fixing the element to an arbitrary position, and a hinge portion formed in the fixing end of the mount member.

Abstract: In a tracking control apparatus, a tracking error signal having a level of a positional shift of a beam of light projected through an optical head onto a recording medium is detected based on a reflected light from the recording medium, and the optical head is controlled so that a beam of light scans on the track to be recorded or reproduced based on the tracking error signal. Offset values of the tracking error signal on adjustment tracks which are predetermined among a plurality of tracks of the recording medium are detected, and then coefficients of a predetermined approximate equation approximately representing an offset value characteristic on the track based on the detected offset values are calculated. Further, an offset value corresponding to the track to be recorded or reproduced is calculated based on the first approximate equation with the calculated coefficients, and an offset value of the tracking error signal is corrected based on the calculated offset value.

Abstract: An apparatus for recording/reproducing information on/from an optical card, in which a card identifying information data, which is recorded on the outside of a normal data recording portion of an optical card, can be reproduced by an optical head, a demodulating circuit and a focusing/tracking circuit, which are originally provided for recording/reproducing information on/from the normal data recording portion of the optical card. Therefore, in the apparatus according to the invention, it is unnecessary to specially provide the other apparatus for reproducing the card identifying information data, so that the apparatus as a whole can be made small and the cost therefor can be decreased.

Abstract: A signal sensing device is provided that includes an optical system having a first splitting function by which a beam reflected by a magneto-optic disk is split by a small amount, a second splitting function by which the beam is split into a P-polarized-component and an S-polarized-component, and a third splitting function by which the beam is split into a first optical path and a second optical path. The second splitting function is carried out by an optical element carrying out one of the first and third splitting functions. A first photo sensor is provided with a beam receiving area divided into four parts, and an undivided beam receiving area, and a second photo sensor is provided with a beam receiving area divided into two parts and an undivided beam receiving area.

Abstract: In the optical recording element of the invention, alignments of long thin pits inclined in various directions with respect to the track direction are formed on the tracks and information is recorded therein according to the different inclines of the pits, thereby performing higher-density and larger-volume recording without reducing the spacing between each pit and the track pitch. The invention also discloses an optical data retrieval system for use with the above optical recording element, which scans the pit alignments with a laser beam spot, detects the inclines of the pits by obtaining the distribution of the intensity of reflected light which is caused by light diffraction at the pits, and plays back information in accordance with the inclines. Therefore, not only can the substantially same structure as that of a standard type optical data retrieval system be applied to the invention without making any complicated change, but also cross-talk is less likely to be produced in the read out signals.

Abstract: A tray on which a cassette is mounted can be reciprocated between a first projected position and a second set position in the horizontal direction by a carriage system. When the tray is positioned above a cassette drive section, it can be reciprocated up and down by a lifter system while holding the cassette therein. A cassette adapter can house therein a second cassette, smaller in size than the first-mentioned cassette, having a magnetic tape wound arround it, and the cassette adapter is attached to and detached from the ray. The cassette adapter is provided with an unloaded cassette detecting lever to detect whether or not the second cassette, having the magnetic tape, is inserted in the cassette adapter. A lever detecting device, which also serves as a component of the carriage system, detects that the unloaded cassette detecting lever is projected to prevent the tray from being moved from the first to the second position when the tray is on the way of being inserted into a cabinet.

Abstract: A high-speed search apparatus for use with a video disk player, which is adapted to retrieve any position where desired information is recorded while moving an information reading point at high speed in a radial direction of a video disk. This apparatus is characterized by counting pulses generated in proportion to the rotation of a movable member such as a rotary knob, etc., determining the amount of displacement of the information reading point, on the basis of the thus-counted value, and then displacing at high speed the information reading points by said amount of displacement.

Abstract: The servo field includes at least one sub-field of prerecorded information that simultaneously provides (i) data for a first servo function and (ii) data for at least one other servo function. In another embodiment, a prerecorded embedded servo field includes a first sub-field of prerecorded information that simultaneously provides (i) automatic gain control data for a third sub-field and (ii) data for a first servo function, and a second sub-field of prerecorded information that simultaneously provides (i) automatic gain control (AGC) data for the third sub-field and (ii) data for a second servo function. Since the first and the second sub-fields in the servo field of this invention are used for AGC and another servo function, the sub-fields are arranged within the servo field so that the sub-field that requires the least precise AGC control is first and the sub-field that requires the most precise AGC control is last.

Abstract: In an electro-magnetic actuator, a pair of magnetic circuits are separately arranged in a tracking direction and a carriage is located between the magnetic circuits and is movably supported or guide rails extending along the tracking direction. On the carriage, a lens holder for holding an objective lens is movably suspended and focusing coils are fixed on side surfaces of the lens holder. A tracking coil is fixed in the carriage and is extended in the magnetic circuit. Focusing permanent magnets of the magnetic circuits are so extended along the tracking direction as to produce, focusing magnetic fluxes penetrating the focusing coil and leakage magnetic fluxes penetrating the tracking coil. A focus drive force is generated by an interaction between a current supplied to the focusing coil and the focusing magnetic fluxes and a biasing track drive force is generated by an interaction between a current supplied to the tracking coil and the leakage magnetic fluxes.

Abstract: In an electro-magnetic actuator, an objective lens is mounted on a lens holder which is elastically supported by two leaf springs and a focusing coil is wound around the lens holder. The lead springs is fixed on a carriage to which tracking coil is also fixed. Guide roller mechanisms are provided on the both sides of the tracking coil and are slidably mounted on guide rails, respectively. The tracking coil are so arranged as to be extended in magnetic gaps of magnetic circuits disposed between the carrier and the guide rails. In each of the magnetic circuit, first and second yokes are so faced to each other as to defined the magnetic gap, a pair of permanent magnets are interposed between the first and second yokes, a third yoke also so faced to the second yoke as to defined the magnetic gap, a pair of permanent magnets are also interposed between the second and third yokes, and a permanent magnet is provide at the first yoke to apply a magnetic flux to the focusing coil.

Abstract: A device for reading information from or writing information to an optical disc memory system using light from a laser diode includes an upper and lower flexure suspension. Both flexure suspensions are mounted on both an objective lens holder and its base. Each of these flexures is U-shaped and the central part of each leg of the U is a stiff beam. At each end of the control beam is provided a tracking hinge. Outward from the tracking hinges are a pair of focusing hinges which are separated from the tracking hinges by means of spacing beam sections. The unique configuration of the system allows these parallel mounted flexures to move in only two rigid modes namely, displacement along the x-axis (tracking) and displacement along the z-axis (focusing). These two rigid modes allow the objective lens to be re-positioned so that light beams may strike the information medium correctly.

Abstract: When dubbing information from a first recording medium to a second recording medium, control information including a start ID is recorded at appropriate timing. For example, when the fourth music selection recorded on a CD is reproduced for recording on a magnetic tape, the reproducing operation is started at a position (4, 00, 36) (represented by data TNC, INDEX, and FRAME) preceding the start position (4, 01, 46) of the fourth music. When a position (4, 00, 40) is detected, a record directing signal for directing the recording of the start ID is output to a digital magnetic tape recorder selection. This ensures the recording of the start ID prior to the recording on the magnetic tape of the start position of the fourth music selection.

Abstract: The present invention is concerned with a recording medium wherein, in a recording medium in which the information may be regenerated optically, a track is pre-recorded or pre-formatted by being deviated along the track width with a signal which the baseband signal of a read-only information signal freed of high-frequency components. The present invention is also concerned with a recording apparatus for forming a track of an optical recording medium from which an information can be reproduced optically, wherein the apparatus includes a deviating device for deviating a track-forming recording beam along the width of the track of the optical recording medium, a deviation control signal generating device for generating deviation control baseband signals for controlling the deviation device, and a low-pass filter for eliminating the high-frequency components of the deviation control baseband signals.

Abstract: An optical tracking system 10 is provided which comprises a beam source 12 which generates a light beam. The light beam travels through a splitter/filter 14 and proximate a DMD array 16. The DMD array 16 is controlled by a DMD array control system 18 which causes a single element within the DMD array to deflect the light beam towards a selected track on an optical storage medium 22. The optical storage medium 22 reflects the beam dependent upon the data stored on the selected track. The reflected beam is deflected by the DMD array 16 back to the splitter/filter 14 which separates the reflected beam from the impinging beam and directs the reflected beam to a detector 24 which discerns the information stored in the storage medium 22 responsive to the receipt of the reflected beam.

Abstract: A method and apparatus for controlling the readout rate of information from a sequential storage medium, such as a CD-ROM, to maintain synchronism between the device containing the medium and an independent receiver receiving the information. Information is loaded from the media into a buffer at a rate controlled by pulses from a device clock. Information is unloaded from the buffer for utilization by the receiver independently of the loading of the buffer. The amount of free space available in the buffer is measured as information is loaded into the buffer. The rate of the clock is dynamically adjusted in response to the amount of free buffer space to maintain the full state of the buffer within predetermined limits. In this manner, the buffer never empties or fills in response to the unloading by the independent receiver.

Abstract: A circuit for controlling the optical pickup position in an optical disc reproducing apparatus is constructed such that when the power is applied, a user recognizes the position of the pickup which is used to pickup information from a disc with information recorded on both sides, by recognizing whether the pickup is facing the upward side or downward side of the disc. The circuit further controls the pickup to be positioned on the innermost circumference of the reproducing side in the reproducing stop or ending operation. Therefore, the time needed to recognize which the first reproducing side for successive reproducing is decreased, while reducing power consumption needed to move the pickup in the reproducing stop operation.

Abstract: An objective lens driving apparatus includes a lens holder holding an objective lens, a focusing coil wound around the vertical outer periphery of the lens holder, yoke members each constituted by an inner yoke and an outer yoke, permanent magnets each retained on the outer yoke to oppose the focusing coils, and tracking coil fixed to the focusing coil. Each tracking coil is twice bent at right angles to wrap around the front, rear and one side of the inner yoke. Electromagnetic forces generated from each upper and lower parts of the tracking coil when the lens holder moves in the horizontal direction, and capable of causing the rolling of the lens holder, offset each other, so that the position of the lens holder is controlled without its axis being inclined and the driving range of the lens holder is wide.

Abstract: The present invention is a photo compact disk (CD) 10 combined with a disk reading system or player 62 in which the disk 10 has a user markable surface on the opposite side of the disk 10 from the picture information storage surface or layer. The user markable side includes a first space 12 for indicating the contents of the photo CD. A second area 14 is provided for indicating how the photos stored on the CD should be displayed. The second area 14 is divided into tracks 18-24 and each track is divided into photograph frame regions 21. Each picture stored on the compact disk has one four quadrant user markable region 21 where the quadrants indicate whether the picture should be skipped, turned clockwise or counterclockwise 90 degrees or turned 180 degrees before display. The printing which outlines the areas and provides photograph numbers is LED light transparent. The photo CD player 62 includes an LED scanner 64 for scanning the second area as the CD rotates.

Abstract: An optical head device for recording and/or reproducing information by using an optical recording medium includes a light source, an objective lens, a photo detector, an optical system including a collimator lens, a beam splitter, a convergent lens and a cylindrical lens, a housing for accommodating the light source, the photo detector and the optical system, and an optical glass plate for reducing aberration of the optical system and the objective lens. A light beam from the light source is turned to a parallel beam flux by the collimator lens to irradiate the objective lens, which provided drivably converges the parallel beam flux on the optical recording medium. The light beam reflected from the optical recording medium passes through the objective lens and reflected by the beam splitter in the optical system toward the photo detector. The light beam reflected by the beam splitter is converged on the photo detector by the convergent lens and the cylindrical lens.