DE2347381C2 - Playback device for a disk-shaped recording medium, in particular video disk player with a scanner which jumps transversely to the direction of the groove - Google Patents

Description

40

The main patent relates to a reproducing device for a disk-shaped recording medium with signals stored in a groove, in particular video disk players, with one during the playback process Carriage moved radially to the plate and a scanner mounted on it spring-loaded and guided through the groove, wherein means are provided that a jumping of the scanner transversely to the groove direction over the groove webs in so cause adjacent groove turns.

The invention according to the main patent is based on the object of a display device for to create a disk-shaped recording medium of the type described which has a defined jumping of the scanner at predetermined times and by predetermined amounts.

This object is achieved by the invention according to the main patent in that a force-wise on the Sampler acting active force pulse generator is provided, each of which when it is excited Force pulse exerts on the scanner that this jumps over a defined number of grooves. Through this it is achieved that when reproducing television signals, a defined freeze frame, slow motion or playback running backwards in time can take place.

The present invention is based on the object of the time scale for the modes of operation To make slow motion and fast motion adjustable and to provide a further mode of operation in which a playback running backwards in time is possible for any length of time.

This object is achieved by the invention specified in claim 1

By supplying the synchronous motor for the radial feed of the slide and the force pulse generator for the jump movement of the scanner from a common pulse generator is achieved that at a change in the frequency of the pulse generator, the speed of the radial feed and the jump frequency of the scanner can be changed simultaneously and proportionally. The pulse frequency regulator allows also the setting of the frequency zero, i.e. the suppression of the activation of the force pulse generator and at the same time stopping the radial feed. With every setting of the pulse frequency controller - except the setting of the frequency zero - and at any point in time the synchronous motor reversed for the radial feed of the slide, i.e. the direction of the radial feed is reversed will.

Compared to the main patent, the area for setting the time scale is therefore in the invention extended for the operating modes »slow motion« and »time lapse«, whereby all the subject of the Main patent existing benefits are retained.

Advantageous further developments of the invention are characterized in the subclaims.

The specified in claim 2 change in the phase position of the synchronous motor supplied Impulse allows a particularly advantageous reversing of the synchronous motor.

If, as stated in claim 3, the synchronous motor is followed by a reversing gear, then a phase shift element for reversing the synchronous motor can be dispensed with.

The invention is illustrated below using an exemplary embodiment with reference to drawings described. It shows

F i g. 1 a playback device for disk-shaped recording media with a coupling device for the simultaneous triggering of scanner jumps and changes in the speed of the radial feed,

F i g. 2 shows an embodiment of a scanner and its holder with a device for displacing of the scanner transversely to the direction of the groove.

In the schematic sectional view of FIG. 1 becomes a record carrier 1 over a stationary one The base 2 is rotated by a drive motor 3 with the aid of a driver 4 Recording medium 1 rotates over an air cushion formed by an air flow 5. One on A scanner 10 attached to a carriage 6 is used to reproduce the data on the recording medium 1 located signals by means of a cable 7 through a second drive motor 8 via a gear 9 the tracked grooves located on the recording medium 1.

The previously mentioned parts of the playback device according to FIG. 1 correspond to those with the same number Share the FIG. 1 of the main patent.

The means for coordinating the jumps of the scanner 10 caused by force pulses and the change of the feed drive for the carriage 6 according to

Direction and / or speed are in the circuit with the steps 22, ZA _S 25,26,29,30,40 and 41 shown in block form.

For the functions of lifting out of the groove and offsetting in the radial direction, the Sampler 10 electromagnetic or equivalent transducers, which via the leads 31 and 32 be fed. On an embodiment of such a converter, which is already in the main patent has been described, in connection with FIG. 2 received.

The circuit with the steps mentioned in block form allows, after preselection of the jump frequency of the Sampler 10 on a controller 41a of the control stage 41 and after preselecting the direction and speed of the radial advance of the carriage 6 on the controller 416 of the same control unit 41 by pressing the button switch 41c one scanner jumping and one with regard to speed and / or direction according to the preselection Movement of the radial feed coordinated with the jump frequency of the scanner 10, d. H. of Slide 6 to trigger.

For this purpose a pulse generator 22 is provided which emits pulses of a frequency which is a multiple of the mains frequency or which is derived from the rotational frequency of the recording medium. With this pulse train selector, derived pulse trains can be formed in which every /? Th pulse of the original pulse train is suppressed, where π can be a positive integer including 1. The pulse train at the output of pulse sequence selector 25 is supplied to an amplifier 26 via a phase shifter 40 whose setting is influenced b from the controller 41, is fed by the output of the drive motor 8 for the feed of the carriage. 6 By changing the phase position at the output terminals of the phase rotating element 40, the direction of rotation of the self-starting synchronous motor 8 can be reversed. ίο

With the pulse sequence selector 24, as is already described in the main patent, the frequency of on the scanner 10 acting force pulses set. For this purpose, the controller 41a of the control unit 41 is connected to the Setting of the pulse train selector 24 coupled. A phase regulator 29 shifts the times of the pulses, based on the scanned circumference of the Rilien, in such a way that a displacement of the scanner 10 in the Playback of television pictures is only made during the vertical blanking periods. To do this, receives the phase regulator 29 reference pulses from the television signal via the connection 28. An amplifier part 30 is used for controlling the electromagnetic transducers of the scanner 10 via the lines 31 and 32.

To reverse the drive direction of the carriage 6, the drive motor 8 can also have a reversing gear be downstream.

A circuit that is used to generate various force pulse trains (jump pulse trains) for temporal stretched playback (slow motion playback) is suitable and the movement of the drive motor for the Makes feed of the carriage dependent on the force pulse sequence generated is described in more detail in the older application DE-OS 23 44 126.

F i g. 2 shows an arrangement suitable for the controlled displacement of the scanner 10 by means of force pulses. This drawing corresponds to Figure 3 of the main patent.

In Fig.2 the construction is that with the scanner 10 and the mechanical-electrical signal converter U connected device for the reference pulses for the vertical blanking controlled scanner jumping is shown schematically. The scanner 10 is with the Recording medium 1 in contact. It forms with the signal converter 11 and the prism-shaped armature 13 a structural unit attached to the holding tube 12. The holding tube is on the carriage 6 attached.

The V-shaped arrangement of the electromagnets with the cores 14 and 15 and the lines 31 and 32 energized excitation coils 16 and 18 allow both vertical and lateral movements of the armature 13 to initiate.

1 sheet of drawings

Claims (3)

Patent claims: 1. Playback device for a disc-shaped recording medium with signals stored in a groove, in particular video disk player, with a slide moved radially to the disk during the playback process and a resiliently mounted scanner guided through the groove as well as with an active force pulse generator which acts on the scanner in terms of force, which in each case when it is excited it exerts such a force impulse on the scanner that it jumps transversely to the groove direction over a defined number of grooves, according to patent 2318871, characterized in that a common pulse generator (22), the pulse repetition frequency of which can be adjusted by means of a controller (4Ia ^, is provided as a clock pulse source for the excitation of the force pulse generator (14,15,16,18) and for the drive, designed as a self-starting synchronous motor (8), which causes the radial movement of the slide (6) and which is controlled by means of a switch (controller 41b) is reversible and that the pulse sequence ge of the pulse generator (22) is synchronized with the rotation of the drive motor (3) of the recording medium (1) temporally correlated signals 2. Playback device according to claim t, characterized in that the synchronous motor (8) is reversible by changing the phase position of the pulses of the pulse generator (22) fed to the synchronous motor (8) by means of a phase-shifting element (40) that can be influenced by the changeover switch (controller A \ b) ). 3. Playback device according to claim 1, characterized in that the drive which the radial movement of the carriage (6) is effected by a reversing gear connected downstream of the synchronous motor (8) is reversible.