JPS6236298B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording device that sequentially records signals as a spiral recording trajectory on a rotationally driven disc-shaped recording medium using a signal converting element. By keeping the relative speed of the peripheral portion to the signal conversion element constant, the substantial recording density is improved.

Conventional disk-shaped recording medium (hereinafter referred to as disk)
Recording devices using a disc record signals using a signal conversion element while the disc rotates at a constant speed, so the relative speed of the signal conversion element at the outer and inner peripheries of the disc differs greatly, and the relative speed The recording and reproducing characteristics deteriorated in the inner peripheral area where the recording and reproducing characteristics deteriorated.

The present invention provides a specific means for solving this problem, and uses a simple configuration to make constant the relative speed between the inner and outer peripheral portions of the disk and the signal conversion element.

An example will be described below with reference to the drawings.

In the drawings, reference numeral 1 denotes a disk placed on a turntable 2, and the turntable 2 is rotationally driven by a synchronous motor 3. Reference numeral 4 denotes a recording head fixed to a movable stage 5. The movable head 5 is screwed onto a threaded rod 7 which is rotationally driven by a synchronous motor 6, and moves in the diametrical direction of the disk 1 according to the rotation of the threaded rod 7. It is configured to move sequentially.

Reference numeral 8 denotes an oscillator that generates a clock signal of a constant period, and its output is applied to a counter 9.

This counter 9 starts counting in response to a start signal applied to a terminal 10 when the recording head 4 is located at the outer circumferential portion Xo of the disk 1, which is the recording start point.

The output of the counter 9 is applied to the D/A converter 11, converted into a DC voltage proportional to the count number of the counter 9, and then applied to the variable oscillator 12.

A frequency output of the variable oscillator 12 according to the count number of the counter 9 is applied to the synchronous motor 3 via a frequency divider 13 and a motor drive circuit 14.

That is, after the motor 3 is started, the number of revolutions of the motor 3 increases sequentially as time passes.

Further, a part of the output of the variable oscillator 12 is applied to the synchronous motor 6 via the frequency divider 15 and the motor drive circuit 16, and the rotation speed of the synchronous motor 6 also increases sequentially as time passes after starting. To increase. Therefore, the frequency dividers 13 and 1
By appropriately determining the frequency division ratio of 5, depending on the recording position of the recording head 4 in the radial direction of the disk 1,
The rotational speed of the disks is changed sequentially, and the relative speed between the recording head 4 and the disk 1 is always kept constant, and
It is possible to draw a spiral recording trajectory at a constant pitch.

Note that at this time, if the signal recorded by the recording head 4 is a signal that includes a synchronization signal with a constant period, such as a video signal, the intervals of the synchronization signals on the recorded recording trajectory will be equal intervals. Yes, and during reproduction, the variable oscillator may be controlled so that the frequency of the synchronization signal in the reproduced signal becomes a predetermined value.

Further, in the above embodiment, an example was shown in which a constant frequency signal obtained from the oscillator 8 was used as the clock signal, but a pulse generated every time the recording head 4 moves a certain distance may also be used. It is something.

That is, for example, the threaded rod 7 is provided with means for generating a pulse every time the threaded rod 7 rotates by a predetermined angle,
This output may be applied to the counter 9.

As described above, according to the present invention, since the rotational speed of the disk and the moving speed of the recording head are controlled by an electric circuit, the rotational speed of the disk and the moving speed of the recording head are controlled with high precision by a simple configuration.
The relative speed between the recording head and the disk can be made constant at the inner and outer peripheries of the disk.

Furthermore, since the variable frequency output serving as the control reference is determined by a stable clock such as a crystal oscillation, highly accurate control can be realized and a system with extremely good temperature characteristics etc. can be constructed. Furthermore, there is no need to detect positions other than the recording start position, and the feeding mechanism can be simplified. Furthermore, since the disk motor and the feed motor are independently controlled in phase synchronization, it is extremely stable against disturbances such as load fluctuations. The present invention has excellent effects, such as the relative speed and track pitch can be electrically changed very easily by changing the clock frequency and the dividing ratio of the frequency divider.

[Brief explanation of the drawing]

The drawing is a block diagram showing one embodiment of the present invention. 1... Disk-shaped recording medium, 3, 6... Synchronous motor, 4... Recording head, 5... Moving table, 7
……Threaded rod, 8… Oscillator, 9… Counter, 1
1...D/A converter, 12...variable oscillator,
13, 15... Frequency divider, 14, 16... Motor drive circuit.

Claims (1)

[Claims] 1. In a recording device that sequentially records signals as a spiral recording trajectory on a rotationally driven disk-shaped recording medium by a recording head that sequentially moves in the diametrical direction of the recording medium, a clock signal of a constant frequency is sequentially applied from the start of recording. A feed motor that includes a counter for counting and a variable oscillator that generates a frequency according to the count value of the counter, and that controls a motor that rotates the recording medium in synchronization with the output of the variable oscillator, and that moves the recording head. A recording device using a disc-shaped recording medium, characterized in that the variable oscillator is controlled in synchronization with the variable oscillator.