Deutsche Thomson-brandt Gmbh

Hans-Robert Kuhn

Dieter Storz

Friedrich Fuldner

Engelbert Laufer

Reinhard Gehringer

Hartmut Richter

Dieter Baas

Richard Rutschmann

Arthur Kurz

Peter Hoch

Method and apparatus for eliminating disturbances encountered during

Resilient scanning head support made of deformable material

A process and an arrangement for identifying the type of defects in optical information from an optical information carrier includes circuitry for detecting the displaying various types of defects which can occur in the information carrier. A processing circuit is linked to a display device to enable the cause of the defect to be displayed. The invention facilitates evaluation of the fidelity of reproduction of optical information carriers,

Signalization of types of defects of an optical information carrier

A method for recording and reproducing compressed data to improve the utilization of the storage capacity of a moving recording medium. The data are compressed prior to a recording step. Prior to reproduction the data are expanded to retrieve the original data signal. To increase the storage capacity of the recording medium even further, the velocity of the recording medium is regulated as a function of the degree of compression. With a high degree of compression, a smaller velocity of the recording medium is selected, than with a low degree of compression.

Method for the recording and reproducing of data

Apparatus for reproducing coded audio signals includes interpolation circuitry for substituting interpolated signal values for erred or lost audio signal. To minimize undesirable audible artifacts which may be introduced into the audio signal by virtue of the substitution process, the rate of substitution is monitored. When the rate of substitution exceeds a predetermined rate, the higher frequency components of the audio signal, including the substituted values, are attenuated.

Audio signal reproduction apparatus with frequency response dependent

With an optical playback device, for example, with a compact disk player, care should be taken to see that the light beam scanning the data radiates as perpendicular as possible onto the disk. However, as a consequence of disk slap or chattering, the radial and the tangential angles alter during every revolution of the disk. As a result of the tolerances in the disk and the device, the optical axis deviates from the perpendicular in many cases. In order to regulate the radial angle .phi.R and the tangential angle .phi.T, under which the light beam strikes the disk, the data signal is demodulated in an amplitude demodulator. The regulating signal UR=C* sin .phi.* cos .alpha. for the radial angle .phi.R and the regulating signal UT=-C* cos .phi.* sin .alpha. for the tangential angle .phi.T are generated from the amplitude C and the phase position .phi. of the demodulated data signal.

Method for measuring and regulating the radial and tangential angles of

In CD-players with a memory having A storage positions for the storage of titles recorded on a CD-record it can happen, that more titles C are on the CD-record than storage positions A provided therefore in the CD-record. In order to use the storage space better in these cases and to keep the access times to the single titles low, the difference of the start times of each two consecutive titles are stored, instead of storing the start times of the individual titles. The more titles that are recorded on a inserted CD-record, the better the storage space is used, and the more the access times are reduced.

Method for reducing access time in a CD-player with a memory by storing

A compact disc recorder and/or playback unit in which a display is provided at an operational side of the set for displaying data that is intended for operation use of single record operation. A static and a dynamic display are provided. The dynamic display is related to the performance of searches or selection operations, and has a flow of motion of data elements related to search for selection operations that are arranged perpendicular to each other in respect to their direction of motion. Title or track search is carried out horizontally according to a horizontal plane of motion of a pick-up. Magazine compartment search is carried out vertically according to a vertical plane of motion corresponding to a direction of a record gripper or record lift, when using a magazine having record compartments one above the other.

CD apparatus with dynamic function generation

A record player with a scanner for record disks is provided, where the vertical recording track angle .alpha. is to be placed within predetermined limits, but where, in general, the value of .alpha. is not known. The scanner comprises a transducer which generates useful signals and which is provided with elastically supported and therefore movable scanning elements. According to the invention, means are provided for determining the difference .alpha.-.beta. of the recording track angle .alpha. and of the tracking track angle .beta.. The angle difference determining means generate a voltage which depends on the longitudinal motion of the scanning elements moved during the useful modulation and which is displayed and/or employed for correcting the track angle. A record player with a tracking sound pick-up arm for the tracking of record disks is provided. Means for tracking a groove on a side of a record disk are disposed elastically supported and thus movable on the sound pick-up arm. A first transducer is disposed on the tone arm for generating useful signals. A second transducer is provided for transducing of the voltage generated by detection of a longitudinal motion of the scanner.

Record player with means for capturing recording and scanning angle

The invention provides a reader and scanner, in particular for the reading of audio and/or video information recorded on plate-shaped information carriers. A scanning head can be pivoted around an axis in order to provide fine control. The scanning head is maintained in a defined middle position with springs. A magnetic circuit is constructed of a permanent magnet, pole shoes and a coil with a core provides a controllable or automatically controllable movement of the scanning head. The displacement of the scanning head can be determined with a piezoelectric converter, which is disposed between one of the two springs and the support associated with the pole shoes. Desired displacements of the scanning head can be obtained with a second electromechanical converter, which is disposed between the other spring and the other support, after application of a suitable voltage.

Optical scanner and reader for information contained in light reflected

A radially acting track follower system is provided with an optical scanner pickup for an audio or video record playback apparatus. The system generates three light spots disposed on a line with a movable phase grating (diffraction grating) and the three spots can be adjusted relative to the tangent at the track pickup scanning location. The middle or main light spot serves to provide scanning of the track signal information. The two outer or auxiliary light spots serve to provide readjustment. They are displaced radially oppositely to each other by equal amounts and are disposed at equal distances from the middle spot. The light intensity of the outer spots is picked up by detectors and processed into control signals. These are used as a drive for the phase grating, which can be controlled around its center point and the rotation axis of the phase grating coincides with the light beam, which can be provided by a semiconductor laser. The drive can operate electrodynamically or can be provided by a piezoelectrical torsion converter. The control signal can have for example 10 kilohertz and is superposed to the control signal for the drive and it improves the sensing and following properties of the system without the disadvantage of the superposition of the scanned information signal with the control signal.

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St. Georgen, Germany

Hans-Robert Kuhn