摘要:
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.
摘要:
The invention relates to a device for positioning a first element relatively to a second element. The device according to the invention uses lifting means comprising a cam element and actuator means to actuate the cam element. The cam element has a plurality of contiguously arranged sectors with machined edges belonging to first and second interleaved groups. The machined edges are shaped such that a response of the lifting means to the actuator means has different values for sectors of said first and second group thereby providing alternately a coarse positioning and a fine positioning. The device may for example be used to position a multitrack magnetic tape and a magnetic writing/reading head relatively to each other.
摘要:
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.
摘要:
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.
摘要:
In a tape transport for recording and/or reproducing signals by means of a recording medium using separate winding motors for driving the winding plates, the drive of the winding motors servo units is constructed as open-loop control devices and/or closed-loop control devices. Such servo units can advantageously be used for open-loop control and/or closed-loop control of the drive of the winding motor even during a braking operation.
摘要:
The present invention relates to a device for reading from or writing to recording media in disc form which has an unbalance compensation means. The object of the invention is to propose a device of this type which has the smallest possible unbalance even when exchangeable recording media are used. This object is achieved according to the invention by virtue of the fact that the unbalance compensation means is a centrifugal force generation means which generates a centrifugal force which is variable during operation. According to another aspect of the present invention, provision is made for the unbalance compensation means to be a positioning means for positioning the recording medium. The field of application of the invention includes, inter alia, devices for reading from and/or writing to optical recording media such as CD, CD-ROM, DVD, DVD-ROM, DVD-RAM and the like.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A disc speed control device for use in a disc player and/or recorder having a pick-up for reading/recording data. The device comprises an inner loop which regulates a determined disc rotation speed value received at its input and an outer loop which delivers this speed value depending on a frequency at which data is read by the pick-up. The present invention is particularly useful in multistandard disc drives which need to adjust to different disc speed modes, for example, constant angular velocity, or constant linear velocity.