Abstract: A CCD pixel pattern for receiving an image to be recorded by a rotary head printer as a series of record track scans each having a predetermined curve geometry. The pixels are arranged in rows having a curvature proportional to the record track scan geometry so that the physical location of incident image light seen by each pixel will correspond directly to the physical location of the printed image increment originating with each pixel, respectively.

Abstract: An information recording and reproducing system for a magneto-optical disk having first and second optical systems each including at least first and second optical heads arranged in the positions displaced for example, by 1/4 sectors with each other. A single sector address control unit connected to the first and second optical heads for detecting each sector address on a disk and for controlling each access of the first and second optical means to each of desired sectors on the disk, through a magneto-optical disk control unit. The first and second optical heads are positioned at a first position, e.g., sector head position, of one sector, the second optical head is positioned at a second position, e.g., data position of the other sector, such that when either one of the first or second optical head is detecting one sector address, the other has finished in the address detection for the other sector address.

Abstract: An optical pickup is provided below an optical disk. A laser beam is emitted from a semiconductor laser onto a track, through an objective lens. The objective lens is capable of shifting, and is shifted in the direction of the track width by a magnetic force from a tracking actuator, thereby performing lens tracking. The optical pickup is mounted on a carriage. The carriage is shifted along the radial direction of the optical disk by a voice coil motor. This shifts the laser beam along the radial direction of the optical disk, thereby performing track access. Upon reception of an access command, a velocity control mode commences, and the shift velocity of the carriage is controlled in accordance with a velocity control signal corresponding to the distance between a target track and a current track. When the pickup arrives near the target track, the generation of velocity control signal ceases and the location control mode commences.

Abstract: In an optical head apparatus for an optical information carrier comprising a semiconductor laser beam source, a condenser lens system and a beam splitter interposed therebetween in an optical system wherein the noise level may be beyond the allowable limit due to the excessive amount of the laser beam which is made incident on the laser beam source after being reflected by the information carrier, the reflected light attenuating means is provided between the optical information carrier and the semiconductor laser beam source, so that the noise level can be set to remain within the allowable limit.

Abstract: An optical memory apparatus employs an optical disc having a plurality of guide-grooves in spiral and concentrical form and a plurality of flat tracks each arranged between adjacent two of the guide-grooves for recording information thereon, and the depth of the guide-grooves is suitably selected to increase the degree of modulation of a track cross signal, thereby performing a stable cross track counting by the use of the track cross signal and a tracking signal. One feature of the invention relies in that the modulation degree of the track cross signal is in the range between 30 and 60%. A second feature of the invention is that the guide-grooves are formed into a V shape and have an optical depth of .lambda./6 to .lambda./5 (.lambda. is the wavelength of the light used).

Abstract: An improved optical memory disc is disclosed which has a liquid crystal layer on which information is written by applying electric field. The liquid crystal layer is sectioned into a plurality of concentric tracks by concentric grooves. When information is written or read, an auto-tracking method can implemented by aid of the grooves.

Abstract: The storage unit comprises an array of tunnel tips (13) arranged at tunneling distance from a recording surface (2a) of a storage medium (2) which is capable of permitting digital information to be written or read through variations of the tunneling current. The storage medium (2) is attached to the free end of a piezoceramic bendable tube (3). In operation, the free end of the tube (3) is moved in a circular orbit by repetitive sequential energization of oppositely arranged pairs of 90.degree. phase shifted electrodes (4,6 and 5,7). This tube movement causes each tunnel tip (13) to scan a respective unique associated annular area of the storage medium (2). To address a particular concentric track in a particular annular area, tunneling current is applied to the associated tip (13) via respective electrodes (16,18) while, concurrently, a potential is applied via electrodes (4,6 and 5,7) to tube (3) of a magnitude corresponding to the desired orbital diameter for the tube.

Abstract: Disclosure is made of an optical memory wherein a cylindrical information carrier (2) is disposed in a stationary cylindrical container (14) filled with a liquid or gaseous medium transparent for the radiation flux emitted by a source (1) of modulated coherent radiation. The cylindrical information carrier (2) is equipped with a rotational drive. A recording coating (12) is applied on a tubular base (11) of the cylindrical information carrier (2). The cylindrical information carrier (2) is optically connected with the source (1) of modulated coherent radiation and with an addressing unit (3) arranged so that its optical elements can move axially with respect to the cylindrical information carrier (2).

Abstract: A recording disc on which a frequency modulated (FM) signal is recorded as pits or dots along a track formed as a concentric or spiral shape in such a manner that the pits or dots are arranged on a radial line during at least a predetermined interval.

Abstract: A high density spiral track forming apparatus according to the present invention a linear motion mechanism for moving an optical recording system in a radial direction of a disk-shaped substrate, and a length measurement machine for detecting the distance travelled by the optical recording system in the radial direction of the substrate disk. The apparatus further includes a velocity computing device for detecting the travel velocity of the optical recording system according to the detected result of the length measurement instrument, and a velocity control device which detects the difference between the travel velocity of the optical recording system which is detected by the velocity computing device and a predetermined velocity, and controls the linear motion mechanism so as to eliminate that difference.

Abstract: An apparatus for recording or reproducing information in or from an optical disc, has a semiconductor laser system, a split photosensor, a signal processing circuit, and a disc controller with a CPU and a memory. Defective sectors of the optical disc are detected, and information recording/reproduction is performed for only nondefective sectors.

Abstract: An optical disk and an apparatus for recording/reproducing on the disk. The disk has extra tracks that are used for tracing by the pickup when the apparatus is started or remains in a pause mode longer than a predetermined time. The intensity of the light emitted by the pickup can be reduced while scanning the extra tracks.

Abstract: Audio signals that correspond with still images are recorded in an electronic still camera on the same magnetic disc as the visual images. By time-base compressing the audio signal and dividing each record track into a number of segments, ten seconds of audio can be recorded for each image without requiring a large processor memory. Identification codes are added to the time-base compressed audio to permit multiple audio tracks to be associated with a recorded image and to record audio signals of time length less than the allotted duration, so that a number of images can be recorded in rapid succession without waiting for each of the successive allotted audio time periods to expire.

Abstract: Disclosure is made of an optical storage device wherein a cylindrical information carrier (2) with a recording medium (12) applied on a tubular base (9) is disposed in a stationary cylindrical container (3) having a window (4) in the lateral wall thereof. A lens (5) is secured in the window (4) of the cylindrical container (3) to let through the radiation flux from a source (1) of modulated coherent radiation. The cylindrical container (3) is filled with a liquid or gaseous medium transparent for the radiation flux. The length of this cylindrical container (3) is at least twice as long as that of the recording coating (12) applied on the tubular base (9) of the cylindrical information carrier (2) equipped with drives for rotation and axial motion.

Abstract: A laser drum which can optically record and reproduce information on optical tapes. The laser drum comprises an upper drum which has two projection holes, rotates and is fitted with semiconductor lasers, a total reflective prism, stoppers, diffraction gratings, beam splitters, object lenses, condensing lenses and photodetectors.

Abstract: An optical disk servo system includes a coarse access and tracking system for optical head control and a fine access and tracking system for read/write beam control. Enlarged servo tracks are pre-recorded on the optical disk between bands of data track locations. The coarse system illuminates a relatively large area of the disk surface encompassing at least one of the servo tracks and detects light from the enlarged illuminated area. Suitable means including a photo-detector array identifies and controls the optical head position by means of the light returned from the illuminated servo track. Such photo-detection means are insensitive to light reflected from the data tracks. The fine access and tracking system uses a conventional, three spot tracking and read system, two spots for data track following and one spot for data track reading. The fine access and tracking system controls a galvanometer mirror or other suitable means steering the read spot beams.

Abstract: A disc comprises a recording surface which is divided into a plurality of equiangular sectoral regions and a guide track formed on the recording surface. Each track turn of the guide track is constituted by a row of pits formed in every other equiangular sectoral regions, and the pit is only formed in one of two mutually adjacent track turns of the guide track in each equiangular sectoral region so that the pits are formed in every other track turns in a radial direction of the disc in each equiangular sectoral region.

Abstract: A set of high density codes for optical recording of binary data. The data bits of each set are encoded into a block code having a plurality of symbols, each symbol having a plurality of symbol position with an even number of holes with the constraint that there be at least two symbol positions between holes or groups of holes. Additionally, a least one hole is never recorded at a predetermined boundary symbol position. This "empty" symbol position permits symbol position dimensions to be reduced while maintaining good read margins to provide high density recording.

Abstract: An optical read/write system is provided in which a laser diode for supplying read and write beams is mounted at a fixed location on a temperature stabilized platform. A single mode, polarizing-preserving optical fiber is connected between the read head and the diode to reduce the mass of the system. The light beam, which upon leaving the laser diodes is generally elliptical in shape, is passed through a magnifying lens before it impinges upon the receiving end of the optical fiber. This changes the generally elliptical shape of the laser beam to a generally circular shape. After passing through the optical fiber the light beam proceeds through an optical assembly which directs a portion of it onto the storage media. Some of the energy of the incoming laser light is reflected to monitoring diode which is coupled to a power control means that controls the power output of the laser.

Abstract: The method comprises the steps of:a. providing an optical recording element comprising an amorphous thin film of a GeTe alloy;b. preparing the thin film for writing and erasing cycles by crystallizing the film;c. writing on selected portions of the prepared film with modulated laser beam, thereby converting portions on the films to a phase-segregated amorphous state.

Abstract: A method and apparatus for scanning a plurality of concentric or spiral tracks on the surface of a rotating disc-shaped record carrier with a beam of radiation which may be modulated with information to be recorded on such surface. The beam is produced by an optical head and is directed at a target point on the record carrier by a positioning device and a deflection device, the positioning device radially displacing the optical head and the deflection device radially deflecting the radiation beam produced by the optical head. The composite resultant motion of the target point on the carrier is in a radial direction and includes a non-reversing component produced by the positioning device and a reciprocating component produced by the deflection device.

Abstract: There is disclosed an information recording and reproducing apparatus which is provided with a disk-shaped recording medium having a recording face allowing information recording and reproduction from both sides; a recording head positioned at a side of the recording face to record information thereon; a reproducing head positioned at the other side of the recording face to reproduce information recorded on the recording face; and a rotary drive unit for independently driving at least two of the disk-shaped recording medium, recording head and reproducing head about a same axis and in the circumferential direction of the recording medium.

Abstract: In case of rewriting data by means of an erasable optical disc memory recording new data after having erased a series of data already stored, directory data written in an optical disc memory in order to control the written data are transferred to an external directory memory and write-in and read-out are controlled by using the directory memory. For rewriting data, which have been already recorded and which are recorded under a specified file name, the data are not erased and renewed data are written in another recording region, where recording is possible. The data, which have become unnecessary as the result of renewal, are erased during a period of time, when the optical disc memory is not accessed.

Abstract: Method and apparatus for driving an optical pickup of an optical information recording and reproducing apparatus having the optical pickup movable on an information track of an optical information recording medium having information tracks formed thereon side by side, and an optical pickup drive device for intermittently moving the optical pickup, wherein a distance of movement in one intermittent movement of the optical pickup is smaller than the pitch of the information tracks.

Abstract: An Optical Disk Storage system and method for the storage of magnetic tape records including an optical disk and a system for writing variable-length records to the disk with a plurality of embedded directories in close proximity to a plurality of records associated therewith. A high-level directory is constructed providing a list of addresses for the embedded directories. The embedded directories comprise a fixed maximum number of entries each indicating the length of a corresponding record. In a read operation, the high-level directory is accessed first to provide addresses for the embedded directories, with reference to positional information permanently written to the disk. Bytes of data are then counted in accordance with the stored record length information to access a record of interest. In this way, varying-length records can be efficiently stored on an optical disk divided into fixed-length data blocks.

Abstract: A method and apparatus for rapidly moving a reading beam of light radially relative to a rotating record disc, to impinge on a selected target track on the disc and recover information recorded on it. The apparatus first radially translates an optical system that directs the beam onto the disc at a relatively high speed until it is within a prescribed radial distance of the target track. Thereafter, an element of the optical system is controllably deflected such that the beam moves incrementally across a prescribed plurality of tracks during each disc revolution, until reaching the target track. The information recorded on each track includes a unique address signal, and movement of the beam relative to the disc is controlled according to the difference between the respective addresses of the track currently being scanned and the target track.

Abstract: A film of a crystal - crystal phase transformation type optical recording alloy is formed on an insulating substrate. Information is erased from the alloy film by heating it with an expedient other than a laser beam. Information is read by sensing reflected light of light projected on the alloy film.

Abstract: An optical recording and reproducing apparatus with a first light source for generating a recording laser beam, a second light source for generating a reproducing beam which has shorter wavelength than that of the recording laser beam. Information is recorded by forming pits on a recording member by the recording laser beam, and reproduced by directing the reproducing laser beam onto the pits and obtaining the beam reflected beam from the pits.

Abstract: In an optically readable information recording disc (D), a spiral guide track (T1) is formed in the form of geometrical variations to provide not only a tracking signal (Sc) but also synchronous signals (Sb, Sr) and cumulative time data (St) which varies depending on the place in the recording layer of the disc. This spiral guide track, which is referred to as ROM track, is formed when a disc is manufactured by stamping and the information uneraseably written in the guide track is read during recording and reproducing main information which is written and read out on and from another sprial track (T2) or land portion formed between two adjacent spiral guide tracks. This spiral track used for recording/reproducing main information is referred to as RAM track.

Abstract: A disc is provided with the equal-interval pits along tracks, at which digital signals are recorded bit by bit. Such a disc is rotated at the constant angular velocity. A signal processing apparatus according to the present invention detects the linear velocity of the track which is at present followed by a pickup. The filtering of a source signal to be recorded and the analog-to-digital conversion of the filtered signal, in the signal processing for recording, are controlled and timed in accordance with the detected linear velocity. Further, the digital-to-analog conversion of a signal read out from the disc and the filtering of the converted signal, in the signal processing for reproducing, are also timed and controlled in response to the detected linear velocity. Thereby, a disc memory device having the large storage capacity and suited for the random access memory can be realized.

Abstract: A transducer head, held in a fixed position as a preformatted disk is rotated a full revolution, reads any sector address accessible to the head. The addresses read come from a plurality of track revolutions that depend on the magnitude of the eccentricity of the disk. A computer, programmed with a least squares algorithm, first coordinates (1) data corresponding to the angular position of the disk each time an address is read, with (2) data corresponding to the actual radius of each address.

Abstract: A track skipping detection and control arrangement for an optical recording and reproducing disc formed with guide tracks for use in an optical information recording and reproducing apparatus. According to the track skipping detection and control arrangement of the present invention, any sudden track skipping which may take place during recording can be instantaneously detected by the track traversing signal so as to reduce the recording power for the prevention of erroneous recording to neighboring tracks. Moreover, by distinguishing the track traversing signal detected during the jumping operation for repeated continuous reproduction of the particular one track of the optical disc having spiral tracks, from the traversing signal due to the track skipping, erroneous recording may be similarly prevented also with respect to the optical disc having the tracks in the spiral configuration.

Abstract: A rotation control apparatus for a CLV system disc sets an initial value based on an address signal reproduced from the CLV system disc and carries out a rotation control by use of the initial value, so that it is possible to carry out the rotation control even with respect to a CLV system disc on which an information signal is only recorded up to an intermediate position within a program region of the disc. An information signal is newly recordable in conformance with the CLV system from a position in a vicinity of the intermediate position where the previous recording had been discontinued.

Abstract: An optical system for writing and reading data from a rotating optical storage disk, comprising a first, second and third coherent light source, providing coarse seek, reading, and writing functions, the three writing sources sharing a plurality of optical elements in common, all cooperating to provide for the coarse seek, fine seek, focus and tracking functions of the device. The read and the write optical beams are optically coupled together to ensure proper spacing of a newly written track with regard to the previously written track.

Abstract: An optical disk apparatus has an optical head for recording information on or reproducing information from an optical disk. The optical disk has a number of spiral or concentric tracks and a number of sectors formed along the circumferential direction of the disk. The sectors are divided into a plurality of sector blocks along the circumferential direction of the disk. Each sector block includes a different number of sectors which are continuous along the circumferential direction and which have a substantially constant linear length. A memory stores at least the speed data for maintaining a constant relative speed between the optical head and optical disk and is determined for each block group having a predetermined number of blocks. Speed data corresponding to the designated sector block is read out from the memory and is supplied to a velocity control circuit. A motor is driven to maintain a constant linear velocity between the optical head and the tracks of the optical disk.

Abstract: An optical disk player is provided with a casing or base which need not be substantially larger than a square inscribed by the circular perimeter of the compact disk which it plays by causing the optical pick-up to radially scan the disk along a path at a predetermined angle to the sides of the square, preferably at about 45.degree. thereto. At the outermost position of the pick-up, its object lens is centered at the outermost track on the disk, and a corner of the casing conveniently accommodates the portion of the pick-up which then necessarily extends outwardly beyond the outermost track.

Abstract: The optical head in the recording-reading device of a data carrier comprises a semiconductor laser source. A lens makes it possible to focus the beam from this source on to the data carrier via a reflecting or deviating mirror. According to the invention the rotation axis of this mirror is in the plane of the entrance pupil and of the focus of the focusing lens.

Abstract: An optical head device comprising a light source unit, a deflecting element for changing the direction of travel of a light beam emitted from the light source unit, and a condensing element for condensing the light beam on a recording medium. A movable portion is formed so that the deflecting element and the condensing element move substantially together with each other relative to the recording medium, and the deflecting element is designed such that the variation in direction of the emergent light beam from the movable portion caused by the rotative displacement of the movable portion with respect to at least one axis can be decreased.

Abstract: A high density spiral track forming apparatus according to the present invention includes a linear motion mechanism for moving an optical recording system in a radial direction of a disk-shaped substrate, and a length measurement machine for detecting the distance travelled by the optical recording system in the radial direction of the substrate disk. The apparatus further includes a velocity computing device for detecting the travel velocity of the optical recording system according to the detected result of the length measurement instrument, and a velocity control device which detects the difference between the travel velocity of the optical recording system which is detected by the velocity computing device and a predetermined velocity, and controls the linear motion mechanism so as to eliminate that difference.

Abstract: A disc rotation control device for a compact disc player comprises a stable rotation detection circuit for detecting whether rotation of a compact disc is in a stable state or in an unstable state, a phase control loop for phase-controlling the disc rotation and direct control means for directly controlling the disc rotation. The disc rotation is controlled by the phase control loop when the disc rotation is in a stable state and, if the disc rotation has become unstable, the control of the disc rotation is switched to one by the direct control means. During the phase control, even if an EFM signal reproduced from a disc has become unavailable for some reason, preceding phase difference data is held and used for the disc rotation control.

Abstract: An optical data storage system includes automatic compensation for shifting movements of the reading/writing beam and other imperfections which otherwise would affect the focusing or location of focus of a laser light beam onto a data storage record. Servo motors and associated apparatus common in the prior art are avoided. The recording or reading laser beam is directed as parallel light toward the data recording medium, but is first focused generally to a line by a first cylindrical lens supported by the laser source apparatus and transverse with respect to the orientation of data tracks of the data storage record. This produces a beam which is parallel in one direction as it approaches the data storage record. The beam is then focused substantially to a point by a second cylindrical lens perpendicular to the first lens and attached to and moveable with the data storage record as an integral part of a disk or card or other data storage structure.

Abstract: An optical data reproducing device including an illuminating system for respectively, simultaneously illuminating at least two separate tracks of an optical disk with at least two light beams; a photo-electric conversion device for respectively converting the at least two light beams reflected from the tracks into at least two electrical signals; and processing circuitry for processing the at least two electrical signals. The processing circuitry may include a switch for switching from one track to another to execute a trick jump play. This circuitry may also simultaneously read the track outputs. One or more diffraction gratings which may be perpendicularly oriented with respect to each other establish the beams projected on the tracks.

Abstract: In an optical disk having grooves, pits representing reference signals in header regions of the grooves are disposed to be spaced apart from each other in a longitudinal direction of the groove to suppress undesirable interference or crosstalk of the reference signals in adjacent V-grooves. In the reproduction of such reference signals, two laser beam spots are respectively irradiated on the first and second oblique surface tracks in the V-groove. Two electric signals made by detecting the light reflected from the spots are examined to determine whether they are in coincidence. When coincidence is confirmed, the signals are used as valid reference signals.

Abstract: A read/write optical disk system for performing high-density recording, reproduction and erasing of information signals by utilizing reversible structural changes between the crystalline and amorphous states of a chalcogenide glass film or the like and a recording, reproducing and erasing method therefor. In the method of this invention, during the period of recording and erasing, respectively, an exposed film area is first heated beyond its melting point to obtain a random state of its atomic arrangement and the rate of cooling from this melted state is controlled so as to obtain a recorded state or an erased state. This method is realized in the system by arranging a plurality of laser spots of different intensities and lengths in proximity to each other on the same track thereby ensuring high-quality erasing involving no danger of any incomplete erasure.

Abstract: A video signal play back device derives video signals from successive tracks formed as a continuous spiral on a video disc using a light source and a lens system, which is carried by a rotatable element at a predetermined spacing from the surface of the disc and which defines a folded optical path. The rotatable element translates the lens system in the radial direction relative to the disc for "coarse" steering of the light beam along the information tracks as the disc is rotated by a turntable. The optical path includes a mirror which is articulated for rotational motion about an axis which shifts the point of impingement of the transmitted light beam upon the disc in the radial direction. The returned beam is directed to a photosensitive pick-up which provides input signals to a circuit which generates a "fine" servo control signal to drive the articulated mirror.

Abstract: The method of reading data from a data record carrier on which data has been recorded in arcuately nested, equal radii data rows which are equally spaced apart along a common centerline that is coextensive with a radius for each data row, comprises the steps of: incrementally moving the data record carrier in steps transversely of the data rows; projecting a light beam onto the plane in which the data record carrier moves; rotating the light beam about an axis parallel to the axis of said light beam to rotate said light beam in an arcuate path across the data record carrier, the radius of the arcuate path being the same or approximately the same radius of each data row; detecting scattered light outside the cone of specular reflection from the light beam impinging on the data record carrier, or the lack of scattered light, as the light beam traverses each data row; and sensing, and correcting for, difference between the arcuate path of said light beam and the arcuate path of the data row being traversed by sa

Abstract: A light beam emitted from a semiconductor laser passes through optical elements which include a condenser lens, a magnifier prism, and a focussing lens to obtain a substantially circular spot of light on a disc. The magnifier prism is constructed such that only the narrower cross-section of the elliptical light beam emitted from the condenser lens is magnified by the incidence surface of the magnifier prism to obtain a substantially circular light beam. The light beam thus obtained is reflected by the prism so that it becomes substantially perpendicular to the beam emitted from the condenser lens. After reflection by the disc, the light passes through a splitter prism. The splitter prism has a reflecting surface and a transmitting surface which spatially bisect the light beam reflected from the disc, a lens and other components. The bisected portions of the beam fall on a photodetector for focussing control and a photodetector for tracking control.

Abstract: An optical recording and reproducing apparatus in which a laser beam is converged to a tiny beam spot and projected onto an optical disc to change thermally the optical disc, thereby effecting recording and reproducing of a signal and which detects a mark (17) for determining a recording polarity of the optical disc which is provided on an optical disc or a disc jacket and effects switching between analog gate switches (23a), (23b) in accordance with the result of the detection thereby to control a polarity of a signal to be recorded or reproduced in a positive or negative direction, whereby it is made possible to stably effect recording and reproduction of signals on optical discs which provide reproduced signals of different polarities because of the characteristics of their recording materials, such as erasable optical discs and unerasable optical discs, by using one and the same recording and reproducing apparatus.

Abstract: A method and apparatus for selectably retrieving information from any of a plurality of spirally-formed information tracks formed in a video disc by means of controlling a carriage for translating the video disc in a forward or a reverse direction relative to radiant beam information recovery means in a video disc player. Each information track is identified by a unique address and means are provided for selecting the address of a particular track to be retrieved. A prescribed sequence of drive signals is applied to a carriage motor dependent on the distance to be traveled by the carriage to retrieve the selected information, the drive signals being successively stepped downward to intermittently redetermine carriage motor speed as predetermined location thresholds are reached during carriage translation.

Abstract: In an optical recording system, a media disk for writing information has a plurality of information tracks with preformatted clock location indications written on the tracks. Writing is accomplished by making a written indication at a predetermined location between preformatted clock locations where the predetermined location is representative of the particular data to be written. Proper location of the preformatted clock location indicia on adjacent tracks provides for proper track crossing information when track addressing occurs as well as proper address location on particular tracks.