Deutsche Thomson-brandt Gmbh

Thomson Licensing

Thomson Licensing S.a.

Gerhard Reiner

Peter Mahr

Jurgen Kaaden

Juergen Kaaden

Klaus Oldermann

Hartmut Peters

Werner Scholz

Christian Büchler

Friedrich Timmermann

Dietmar Braeuer

Martin Kuner

Bernd Wessolly

Eric Fani

Bruno Weihs

Andreas Kluger

A method for track jumping for optical recording media exhibiting eccentricity, and to an apparatus for reading from and/or writing to optical recording media using such method is disclosed. The method for track jumping for optical recording media exhibiting eccentricity, whereby a sled and/or an actuator are moved from a start track to an end track, includes the steps of: determining the eccentricity of the optical recording medium, initiating the track jump at minimum eccentric acceleration, and completing the track jump at minimum eccentric acceleration.

Track jumping for optical recording media

A method for controlling the status of a drive of an apparatus for reading from and/or writing to recording media is proposed. According to the method, a plurality of drive states are reported to a controller of the apparatus by applying drive state signals to an interface. To ensure that no drive state remains unnoticed by the controller, the drive state signals are applied to the interface for at least a predetermined period of time, even if one or more drive state actually lasts for a shorter period of time. To guarantee that the drive state reported to the controller is identical to the real state of the drive, one or more of the drive states, which last shorter than the predetermined period of time are artificially extended.

Method for controlling the status of a drive of an apparatus for reading from and/or writing to recording media

The invention relates to a tracking device in which a position of a coil driven actuator is determined using a sensor coil. A reference signal 12 having a determined voltage and frequency is fed to a driven coil. A position of the coil driven actuator is proportional to a distance between the driving coil and the sensor coil. The sensor coil produces an alternating voltage induced by an alternating magnetic field emitted by the driving coil. The alternating voltage is used to determine the position of the actuator.

Tracking device with a coil driven actuator and a sensor coil to

An information storage medium has at least a longitudinal bundle comprising three servo tracks (3, 4, 5). The bundle is arranged in consecutive tracking units (T(N)) of a determined longitudinal length. Surfaces of said servo tracks present either a first or a second characteristic (6, 7) and vary in size and distribution inside the tracking units. The bundles may contain longitudinally stored identification information. Methods for obtaining tracking signals indicating a transversal offset between a reading head and the bundle and for retrieving identification information are disclosed. Also methods for obtaining tracking units in which transversal tracking code is combined with distinct information are described.

Combined longitudinal and transversal tracking

Method and apparatus for tracking a helical track recording

In digital, magnetic and optical storage systems for audio/video/data, a Viterbi detector is extended by a control output, and a PLL is controlled by a variable delay line at the output or inside of the PLL.

Signal processing system for digital signals

The invention relates to a method for recording longitudinal track bundles on an information medium. The method involves recording tracking information in special tracks in said track bundles. The special tracks are contiguous between each other. When recording a new track bundle a recording and/or reading head may be positioned using tracking information contained in special tracks of a previously recorded track bundle. Several examples of patterns used for coding tracking information in the special tracks we described.

Recording method and information medium for a plurality of longitudinal

Electronic circuit having a digital controller operation of a synchronous motor. Precision motors for driving, for example, a video head drum in video recorders are normally designed as externally commutated synchronous motors. These motors are driven with square-wave voltages by a digital controller (CON), whose circuitry can easily be implemented. The object of the present invention is to specify an electronic circuit of the type mentioned initially for controlling a synchronous motor, which enables good synchronism and the motor to be operated with little electrical noise. This object is achieved in that the synchronous motor is driven by sinusoidal signals, a separate control signal from the controller (CON) influencing the amplitudes of the drive signals (U1, V1, W1). A regulating signal for regulating the synchronous motor is produced by a sensor (GE) which is arranged on the synchronous motor, which regulating signal produces a fixed phase relationship between rotor revolution and drive signals. The circuit can be implemented in a simple manner and manages without any digital/analogue converters. The applications which result are, in particular, for digital video recorders and for camcorders.

Circuit having a digital controller for operation of a synchronous T

In order to produce synchronous control signals of a video recorder, in particular of a digital video recorder, a position pulse of the scanner motor, which coincides with the beginning of the video frame, is used as time zero point. Time markers in which changes in the control signals take place are calculated starting from this time zero point. These time markers and the bit patterns occurring at these time markers are stored as data words in a data field and, for corresponding time markers, the corresponding data word is output in parallel, that is to say synchronously. A realization is possible by means of a microcontroller and a controllable output memory, the microcontroller containing the functions of capture register, timer, calculation unit and comparator.

Method and circuit for producing synchronous control signals in video

A time coding system of high resolution for a digital audio and video recording system is disclosed. Various methods of structuring: time code for recording are disclosed which enable time code reading at high tape transport speeds to facilitate automatic search/forward and reverse. A time and control code generator for video recording and replay use comprises a pulse generator generating a pulse having a television frame frequency repetition rate. A source of a time code signal is related to the television frame frequency, and comprises data bits representing hours minutes seconds and frames. A pulse position modulation means is coupled to the pulse and in response to the data its representing hours minutes seconds, modulates a trailing edge of the pulse to a first position responsive to the data bits having a logical 1 value and modulates the trailing edge to a second position responsive to the data bits having a logical 0 value. A generating is means coupled to the data bits representing frames and generates a first signal frequency responsive to the frame data bits having a logical 0 value and a second signal frequency responsive to the frame data bits having a logical 1 value. The second frequency is double the first frequency. The first and second frequencies are added symmetrically to the trailing edge to maintain the modulated positions.

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Villingen-Schwenningen, Germany

Gerhard Reiner