JPS60140544A - Writing device of master disc of optical disc - Google Patents

Abstract

PURPOSE:To improve write quality by providing a delay circuit which delays write information by a prescribed time, and a circuit which operates AND between write information and the output of the delay circuit, in a modulating part and correcting a laser light with this AND output to write information. CONSTITUTION:A modulator 7 modulates a signal E, which is generated from a reference signal generator 6, in accordance with input information to output a signal F, and this signal F is inputted to a delay circuit 8 and one input terminal of an AND circuit 9. The delay circuit 8 delays the inputted signal F by a prescribed time to output a delay signal G. The AND circuit 9 operates AND between signals F and G to output a signal H whose pulse width is wider than that of the signal F. The laser light is modulated by the signal H to write information on a resist 11 of a master disc 1, and therefore, the reduction of write holes due to a threshold level of the resist 11 is compensated by increase of the pulse width, and as the result, prescribed write holes are obtained to improve the write quality.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an optical disk master writing device for writing information to a disk master of a disk device, and in particular, to an optical disk master writing device for writing information to a master disk of a disk device, and in particular, to widening the pulse width of a writing laser beam to form a writing hole in the master. This invention relates to an optical disc master writing device that can be made into a required size.

(bl) Prior Art and Problems Conventionally, a device as shown in the schematic mechanical diagram of FIG. 1 has been generally used as a device for optically writing information onto a disk master of a disk device.

That is, in the conventional writing device, a master disk 1 coated with a resist 11 is rotated by a spindle motor 2, an argon laser 3 is switched using an optical deflector, for example, an acoustic effect optical modulator 4, and the light is focused by an optical head 5. resist 11
Address information and grooves are written in predetermined locations.

As shown in the signal waveform diagram of FIG. 2, laser light switching is performed by switching a certain voltage Vin with write data A and using the output signal B as the drive input voltage of the acoustic effect light modulator 4. The optical output power signal C is outputted from the device 4 in synchronization with the write data A. This optical output power signal C causes writing of address information and grooves, ie, writing holes, in the resist 11 of the original m1.

However, in the conventional method, as shown in the waveform of FIG. 2, since there is a threshold level in the resist 11, the written signal a becomes small and not proportional to the waveform of the optical output power signal C. For this reason, there was a drawback that the writing hole became somewhat smaller during development and fixing, resulting in a decrease in writing quality.

(C1 Purpose of the Invention The present invention was devised in view of the above-mentioned conventional drawbacks,
The purpose is to provide an optical disk master writing device that improves writing quality by changing the pulse width of a writing laser signal to obtain a writing hole of a predetermined size on the master.

(d) Structure and object of the invention According to the present invention, there is provided an optical disk master writing device that writes information by irradiating a laser beam whose pulse width is modulated according to write information onto a recording medium of a disk master. , a delay circuit that delays write information for a predetermined period of time is provided in the modulation section, and a circuit that takes an AND of the write information and the output of the delay circuit, and writing is performed by correcting the laser beam based on the AND output. This is achieved by an optical disc master writing device characterized by the following.

(el Embodiment of the Invention An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 3 is a block diagram of the optical disc master writing device of the present invention, and the same reference numerals as in FIG. 1 indicate the same parts. ing.

That is, this embodiment includes a reference signal generator 6 that generates a reference signal, a modulator 7 that modulates the reference signal output from the reference signal generator 6 using an input signal such as address information, and an output signal of the modulator 7. Delay circuit 8 to delay and delay circuit 8
An AND circuit 9 which takes the logical product of the delayed output signal of the output signal and the output signal of the modulator 7 is added to the conventional optical disk master writing device described above.

Next, the operation of the writing device of the above mechanism will be explained with reference to the signal waveform diagram in FIG. When an input signal such as address information is input to the modulator 7, the modulator 7 modulates the signal E generated by the reference signal generator 6 in accordance with the input information and outputs the signal F. Signal F is inputted to delay circuit 8 and one input terminal of AND circuit 9 in parallel. The delay circuit 8 delays the input signal F by a predetermined delay amount Δ and outputs it as a delayed signal G. Further, the AND circuit 9 ANDs the signal F and the signal G, and outputs a signal H having a pulse width wider than the signal F by ΔT.

Therefore, since the laser beam is modulated by a signal H whose width is wide by this ΔT and writing is performed on register 1 of master 1, the problem that the writing hole becomes smaller due to the threshold level at register 1 is solved by the pulse width As a result, a predetermined writing hole is obtained, and the writing quality can be improved.

(fl) Effects of the Invention As is clear from the above explanation, the present invention has the advantage of widening the pulse width of the writing laser beam by a predetermined amount, thereby making it possible to write a write hole of a predetermined size on a disk master. This has the effect of improving quality.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the main mechanism of a conventional optical disk master writing device, FIG. 2 is a signal waveform diagram of the device shown in FIG. 1, and FIG. 3 is a block diagram of an embodiment of the present invention. FIG. 4 is a signal waveform diagram of this embodiment. In the figure, 1 is a master disc, 2 is a spindle motor, 3 is an argon laser, 4 is an acoustic effect light modulator, 5 is an optical head, 6 is a reference signal generator, 7 is a modulator, 8 is a delay circuit, 9
indicates an AND circuit, and II indicates a resist, respectively. Figure 1 1 in Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] An optical disk master writing device that writes information by irradiating a laser beam whose pulse width is modulated according to write information onto a recording medium of a disk master, the delay circuit delaying the write information to the modulation section by a predetermined time; , a circuit for calculating an AND of the write information and the output of the delay circuit;
An optical disk master writing device is characterized in that writing is performed by correcting laser light using this AND output.