JP2760106B2 - Cutting system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting system for forming a pit signal on a master disc based on a recording signal reproduced from a source.

[Summary of the Invention] The cutting system of the present invention, when a recording signal reproduced from a source such as a master tape, particularly includes a digital audio signal output, is added to this digital audio signal after modulation, and is simultaneously cut. An attenuator can be automatically supplied to a signal processing circuit for an analog audio signal to be supplied to a device section.

That is, since the storage means has information as to whether or not the recording signal contains a digital signal, the control means controls the turning on / off of the attenuator in the signal processing circuit of the analog audio signal based on the information. Is performed.

2. Description of the Related Art In general, a cutting process executed as a first stage of manufacturing a video disc or the like generally performs FM modulation or the like on a recording signal read from a signal source (master tape) in a cutting signal transmission system. Is supplied to the cutting device, and the modulated recording signal (hereinafter referred to as a cutting signal) is recorded as pit information on the master disc. That is, in the cutting device, a signal is recorded on the glass master by, for example, a process of exposing the glass master coated with the photoresist with the recording laser light modulated by the supplied cutting signal. As is known, pits are formed on the glass master after cutting by a development process, then a stamper is created from each of the glass masters through each process, and the stamper is pressed by a press machine to produce a disk. .

At the time of the cutting process, the recording signal reproduced from the signal source, that is, the signal to be recorded on the disc may be only an analog video signal and an L, R analog audio signal, but may also include a digital audio signal at the same time. Many. The analog video signal and the L and R audio signals are FM-modulated in the cutting signal transmitting unit and output. The digital audio signal output simultaneously from the signal source is EFM modulated (8-14) in the cutting signal transmitting unit. Modulated), added to the FM video signal and the FM audio signal, and supplied to the cutting device as a cutting signal. FIG. 2 shows an example of the frequency allocation of the cutting signal in this case.

That is, as a cutting signal, a video FM band having a black level of 8.1 MHz and L and R audio FM signal bands having a carrier of 2.3 MHz and 2.8 MHz are used together with 0 to 2 MHz.
An EFM signal band is formed in the band of z.

[Problems to be Solved by the Invention] By the way, when the digital audio signal (EFM signal) is included in the cutting signal as described above, the carrier level of the analog audio signal, that is, the audio FM signal is reduced by, for example, about 4 dB. There must be. This aims at preventing the interference between the audio carrier and the EFM signal from becoming strong and stabilizing the video and audio reproduction signals, and has been conventionally performed.

For example, when a digital signal is included, an audio FM signal is output via an attenuator in a cutting signal transmitting unit.

However, the selection of turning on or off the attenuator in the audio FM signal processing system has conventionally had to be manually performed, so that erroneous operation is likely to occur.
Although the signal is included, an accident occurs in which cutting is performed without lowering the level of the audio FM signal, and the process becomes complicated due to the work of connecting the attenuator. There is a problem that causes deterioration of the quality.

[Means for Solving the Problems] The present invention has been made in view of such problems, and when a recording signal reproduced from a signal source includes a digital signal, an audio FM signal is automatically generated. The present invention provides a cutting system capable of attenuating the cutting force.

That is, the analog audio signal processing system of the cutting signal sending unit is provided with an attenuator that is turned on through a switch circuit that is switched and controlled by the system control unit, and is reproduced in the storage unit by the cutting signal sending unit. Data for identifying whether a digital audio signal is included in the recording signal is stored.
Then, the system control means is configured to execute operation control based on the data.

[Operation] Whether or not a digital audio signal is included in the recording signal can be determined by the control data stored in the storage means. Therefore, the switch circuit is controlled by the system control means and the attenuator is turned on. Can be.

Embodiment FIG. 1 is a block diagram showing an embodiment of the cutting system of the present invention.

Reference numerals 1a and 1b denote recording video signal and recording audio signal sources by, for example, a master tape reproducing device.

Reference numeral 10 surrounded by a dashed line indicates a cutting signal transmitting unit that adds a predetermined modulation process to the recording signal supplied from the signal sources 1a and 1b and outputs the signal. 11 is an FM modulation circuit for a video signal, and 12 is an audio signal. FM modulation circuit, 13 is an EFM encoder that performs EFM modulation on digital audio signals,
14 is an EFM processor. 15a, 15b input signal about 4dB
Attenuator that can be attenuated, switch circuit
S ₁ , S ₂ and L _{3 of} the audio FM modulation circuit 12 via S ₃ , S ₄
R Connected to each output side. Switch circuits S ₅ and S ₆ are connected to the output side of the EFM signal. Switch circuit S ₂ ,
The outputs of S ₄ , S ₆ and the video FM modulation circuit 11 are added by an addition circuit 16 and output as a cutting signal via a limiter 17. The switching of the a and b terminals of the switch circuits S _{1 to} S ₆ is interlocked and controlled by the switch control circuit 18.

Numeral 20 modulates the recording laser beam by the cutting signal output from the cutting signal transmitting unit 10, and forms (photosensitizes) pit information on the glass master coated with the photoresist by the modulated laser beam. This is a cutting device section for performing.

A control computer 30 controls the system during the cutting process by supplying various control signals to the cutting signal sending unit 10 and the cutting device unit 20.
Numeral denotes a floppy disk on which control data required at the time of cutting is recorded. The floppy disk is prepared corresponding to a recording source (master tape) for each cutting process of the master disk. Also, floppy disk
The control data recorded in 40 is read into the control computer 30 before the start of the cutting process.

On the floppy disk 40, for example, reproduction time, CAV / CLV discrimination, track pitch, and the like are recorded as control data. Based on these control data, the CPU of the control computer 30 performs necessary control. A signal is output to the cutting device unit 20, and the operation control of the rotation drive system of the master, the head feed system, the recording optical system, and the like in the cutting device 20 is performed.

Further, in the present embodiment, a code for identifying whether or not digital data is included in the recording signal is added as control data, and the control signal is transmitted from the CPU of the control computer 30 based on the identification data. Is output to the switch control circuit 18 of the cutting signal transmitting unit 10.

With the above configuration of the cutting system of the present embodiment, the operation of turning on the attenuators 15a and 15b in the audio FM signal processing system of the cutting signal transmitting unit 10 is automatically performed.

That is, when a digital signal is included in the recording signal, the control computer 30 is started before the start of the cutting process based on the control data recorded on the floppy disk 40 corresponding to the signal source for the cutting.
The switch control circuit 18 is controlled by the switches S ₁ to S ₁ .
All S ₆ are connected to the b terminal. That is, the carrier level of the audio FM signal is 4 dB by the attenuators 15a and 15b.
The output is attenuated. If the recording signal does not include a digital signal, all of the switch circuits S _{1 to} S ₆ are connected to the terminal a before the start of the cutting process.
The audio FM signal is output normally.

By performing such control, a manual malfunction can be avoided, and the efficiency of the disk manufacturing process and the improvement of the quality of the disk can be promoted.

[Effects of the Invention] As described above, the cutting system of the present invention is provided with an attenuator that is input to the audio FM signal processing system via a switch circuit. In addition, data for determining whether or not a digital signal is included in the recording signal is added, and the switch circuit is controlled based on this data. Therefore, it is possible to avoid a malfunction of turning on / off the attenuator. Thus, there is an effect that the efficiency of the process and the improvement of the quality can be promoted.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is an explanatory diagram of frequency allocation of a cutting signal. 10 is a cutting signal sending section, 11 is a video FM modulation circuit,
12 is an audio FM modulation circuit, 13 is an EFM encoder, 14 is E
FM processor, 15a, 15b is an attenuator, 18 switch control circuit, 20 is a cutting device unit, 30 control computer, 40 denotes a floppy disk, S ₁ to S ₆ is a switch circuit.

Claims (1)

(57) [Claims] A cutting signal transmitting unit configured to perform a predetermined modulation on a reproduced recording signal and output the modulated recording signal; and a recording laser beam modulated based on the supplied cutting signal. A cutting device for performing pit recording on a disk master, storage means for storing control data necessary for performing a cutting operation, and control means for performing system control based on the control data stored in the storage means. In the cutting system, the analog audio signal processing system of the cutting signal sending unit is provided with an attenuator that is turned on through a switch circuit that is switched and controlled by the control unit,
In the storage means, data for identifying whether or not the recording signal includes a digital audio signal output is stored. When the recording signal includes a digital audio signal output, the control is performed. A cutting system wherein the switch circuit is controlled by means and the attenuator is turned on.