JPH0371446A - Disk evaluation device - Google Patents

Abstract

PURPOSE:To keep the quality of a stamper with eligibility constant and to stabilize the quality of a copy disk obtained from the stamper by applying quantitative evaluation on a video and a voice signal recorded on the disk with a specific parameter. CONSTITUTION:A drop out pulse 17a, a C1 flag 25a, a C2 flag 25b, a CRC error flag 26b and a 24/40 bit code error 13a are introduced to a judging circuit 28. The judging circuit 28 is comprised of, for example, a counter, etc., and when either a pulse for evaluation or one of the error flags, for example, the number of drop out pulses 17a or the length of the error flag 26b exceeds a prescribed value, a defect detection signal 28a is outputted to an output terminal. Therefore, the quantitative evaluation of the video or the voice signal recorded on the disk can be performed with the specific parameter. In such a way, the quality of the disk with eligibility can be kept constant, and also, the quality of the video disk copied from the disk of the stamper, etc., can be stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a disc evaluation device used for video and audio evaluation of a metal disc of a video disc (hereinafter referred to as a stamper) or a molded disc.

[Summary of the invention]

The present invention relates to a disc evaluation device used for video and audio evaluation of video disc stands or molded discs, and includes dropout detection for detecting dropouts in RF signals during playback of discs on which video and audio signals have been recorded. a time code error detection means for detecting a time code error in the RF signal; and a decoding means for detecting correctable and uncorrectable error flags and subcode error flags included in the audio signal of the RF signal. , a dropout detection means, a dropout pulse obtained from a time code error detection means and a decoding means, a time code error flag, a correctable/uncorrectable flag, and at least one of a subcode error flag. By providing a determining means that selectively outputs a defect detection signal when the number of pulses or the length of the flag signal exceeds a predetermined value, it is possible to quantitatively evaluate the disk.

[Conventional technology]

In conventional video discs, the video signal and audio signal are
It is recorded as shown in the frequency allocation in the figure.

That is, in FIG. 2, a video signal and two-channel audio signals are first converted into FM signals by an FM modulator. The video signal has a center frequency of 8.5MHz (frequency deviation of 1.7MHz)
video FM carrier signal (30), and stereo 2
The channel audio signal has a center frequency of 2.3 for the l channel.
It is converted into an audio FM carrier signal (hereinafter referred to as analog audio signal) (31) of MHz and 2 channels of 2.8 MHz (frequency deviation ±100 kHz). 2 more
Change the channel audio signal to 16 bit pulse code 1
(PCM) conversion L, EFM (Eight to Four)
(teen Modulation) The code-converted digital audio signal (33) is inserted into the band below 2 MHz as shown in FIG.

The video FMg transmission signal (30) described above is a square wave whose pulse width is changed (PWM) by an analog audio signal, and a recording laser light source is activated according to the signal waveform to which the digital audio signal is added. A master disc (recording master disc) is formed by forming bits on a glass master disc coated with a photoresist after turning on and off. Based on this master disc, a stanbar is made by electroforming nickel.
Based on this, synthetic resin video discs are reproduced by injection.

Figure 3 shows the master disc obtained as described above.

Play a standby or duplicated video disc (hereinafter referred to as a disc including each of these discs and discs),
1 shows a system diagram of an evaluation device for evaluating video signals and audio signals.

FIG. 3 shows an embodiment of a device for evaluating the audio and video of a stand bar (2) as a disk.

The sources of the 2-channel analog audio signal (31) and the 2-channel digital audio signal (33) recorded in this standber (2) may be the same, or different sources may be used. In many cases, the same content is recorded using the same source. Of course, recording of video signals is also becoming popular.

A stand bar (2) is placed on a turntable (1), and the turntable (1) is rotated by a motor (3). Reproduction optical system (4) with optical pickup, etc.
is moved in the radial direction of the stanbar (2) by a feed control circuit (5), and the motor (3) and the feed control circuit (5) are controlled via a regeneration control circuit (6). When reproducing and evaluating the stand bar (2) among the discs mentioned above, the turntable (1) is rotated in a direction opposite to the normal rotation direction.

Of course, when evaluating the playback of master discs, molded discs, etc., it is sufficient to simply rotate it clockwise as usual.

The RF multiplied signal obtained based on the laser beam irradiated onto the stanbar (2) is amplified by the first stage amplifier (7), and the video signal is converted to an FM mirrored carrier wave signal ( 30) and the video demosulator (9)
demodulates the video signal. The demodulated output is output from an IH delay circuit (lO
), the video signal delayed by the IH period and the video signal not delayed are switched by a switch means (14), and displayed on a monitor CRT (16) via a video amplifier (15) to evaluate the image quality of the video signal. .

The switching of the switch means (14) is controlled by the detection output of the dropout detection circuit (17) supplied with the RF multiplied signal,
If there is a dropout, the previous price compensation will be imposed.

The video demodulated output is decoded by a time code 24/40 bit code decoder and displayed on the display means (12) for time code data inspection.

The analog audio signal (31) and digital audio signal (33) included in the RF signal are B P F (19) (24
) are separated from each other. That is, analog audio signal (31)
is 2 to 3 MHz, and the digital audio signal (33) is 2 MHz.
z and below are bandpass filtered. B P F (19) (2
The outputs of 4) are the FM demosimulator (20) and the EFM
Decoder (25) performs demodulation and code conversion, and the respective outputs are supplied to fixed contacts a and b of switch means (21). An audio amplifier (22) is connected to the movable contact C, and the output of the audio amplifier (22) is supplied to sound emitting means (23) such as headphones or speakers. Furthermore, (2
6) is a subcode decoder which displays the subcode supplied from the EFM decoder (25) on the display means (27) and evaluates the subcode.

[Problem to be solved by the invention]

According to the configuration of the disc evaluation apparatus described above, first, in order to evaluate the reproduced video and two-channel analog/digital audio signals of the disc, for example, the standber (2), the inspector displays the images on the monitor CRT (16). Observe the captured image, and
Time code errors and the like are also monitored by the cover means (I2). Furthermore, sound emitting means such as headphones (23
), the analog/digital audio signal is listened to by switching the contact piece of the movable contact C of the switch means (21) to evaluate the analog audio signal or the digital audio signal, and detect errors in subcodes in the digital audio signal. CRC errors and the like were similarly monitored by the display means (27).

These video and audio signals have a problem in that the tester subjectively judges the quality of the video and audio signals by viewing the video and listening to the audio, so the evaluation is not quantitative and is not objective.

Furthermore, during the inspection, the inspector had to use the standby bar (2) because there was no proper way to detect the defective parts of the disc's video and audio signals.
While playing back the whole screen in real time, you can note down the defective parts and judge whether the standby is good or bad based on the number of defective parts.If you are unsure, you can access the defective part again and check the quality of the video and audio signals. A re-evaluation was performed to determine whether it was good or bad. This has the drawback of not only taking a lot of time but also being complicated.

The present invention was developed to solve the above-mentioned problems, and its purpose is to provide a disk evaluation device that can quantitatively evaluate video and audio signals recorded on a disk using specific parameters. This is what I am trying to do.

[Means to solve the problem]

An example of the disk evaluation device of the present invention is a dropout detection means for detecting dropouts in the RF multiplied signal during playback of a disk on which video and audio signals have been recorded, as shown in FIGS. 1 and 2. (17) and time code error detection means (13) for detecting time code errors in the RF multiplied signal.
and decoding means (25) (26) for detecting correctable and uncorrectable error flags and subcode error flags included in the audio signal of the RF signal, a dropout detecting means (17), and a time code error flag. Detection means (1
3) as well as a dropout pulse (17a) obtained from the decoding means (25) (26), a time code error flag (13a), and a correctable and uncorrectable flag (2).
5a) (25b) and subcode error flag (26
A determination means (28) is provided which selects at least one of b) and outputs a defect detection signal when the number of pulses or the length of the flag signal exceeds a predetermined value. be.

[Effect]

According to the disc evaluation device of the present invention, simply by placing the disc (2) to be examined on the turntable (1) and setting it in the playback state, the judgment circuit (28) can detect the video or audio signal recorded on the disc. Since the evaluation can be quantitatively evaluated using specific parameters, the quality of passing discs will be constant, and the quality of video discs copied from discs such as standalone discs will also be stable.

〔Example〕

Hereinafter, one embodiment of the disk evaluation apparatus of the present invention will be described with reference to FIG.

Figure 1 shows an example of the configuration when inspecting a stand bar (2) as a disc. This stand bar (2) is placed on a turntable (1), and the turn table (1) is driven by a motor (
3) is rotated by A reproducing optical system (4) having an optical pickup etc. performs various servos such as focus, tracking, and slider, and these servos are controlled by a reproducing control circuit (6) and a feed control circuit (5).

The reproducing optical system (4) is moved in the radial direction of the stanbar and reads out signals from the innermost track of the stanbar (2).

If the disc is a stand bar (2), turntable (1)
The direction of rotation must be counterclockwise.

The RF signal obtained based on the laser beam irradiated onto the stamper (2) is amplified by the first stage amplifier (7), and the video signal is amplified by the bandpass filter (BPF) (8), where the FM video carrier wave signal (30 ) and video demosulator (9)
demodulates the video signal. The demodulated output is output from an IH delay circuit (10
〉, the video signal delayed by the IH period and the video signal not delayed are switched by the switch means (14) and displayed on the monitor CRT (16) via the video amplifier (15) to evaluate the image quality of the video signal. be called.

The switching of the switch means (14) is controlled by the detection output of the dropout detection circuit (17) supplied with the RF signal,
If there is a dropout, the previous price compensation will be imposed.

Further, the dropout pulse (17a) from the dropout detection circuit (17) is output to the output terminal T2. This output terminal T is connected to the input terminal T2' of the determination circuit (28).

The video demodulated output demodulated by the video demodulator (9) is decoded into a time code by a 24/40 bit code decoder (11), and a time code error is detected by an error detection circuit (13), and then sent to the output terminal T+. 24/
A 40-bit code error (13a) is output. This output terminal T1 is connected to the input terminal TI' of the determination circuit (28).

The RF signal (7a) extracted from the first stage amplifier (7) is separated into necessary bands by B P F (19) (24). That is, the analog audio signal (31) is bandpass filtered at 2 to 3 MHz, and the digital audio signal (3) is bandpass filtered at 2 MHz or less. BPF (19) (24) (7) Outputs are 1M demosimulator (2o) and EFM decoder (25), respectively.
Demodulation and decoding are carried out at , and the respective outputs are supplied to fixed contacts a and b of switch means (21). An audio amplifier (22) is connected to the movable contact C, and the output of the audio amplifier (22) is supplied to sound emitting means (23) such as headphones or speakers. (26) is a subcode decoder that outputs the subcode representing the track number etc. supplied from the EFM decoder (25) to the output terminal T3, and also outputs a CRC (Cyclic Red
under+ey Check) error flag (26b
) is output to the output terminal T4, and the output terminal T4 is connected to the input terminals T, 1 and T4' of the determination circuit (28), respectively.

Furthermore, from the EFM decoder (25), C, which represents a correctable error, a flag (25a), and Cz, which represents an uncorrectable error.
The flag (25b) is output to output terminals T and T6,
These output terminals Ts and T are connected to input terminals T,' and T,' of the determination circuit (28).

The evaluator observes the images and sounds by guiding the video signal to the monitor CRT (16) and the analog/digital audio signal to the sound emitting means (23) such as headphones using a dual system configuration. .

In this example, the determination circuit (28) includes the above-mentioned dropout pulse (17a), C, flag (25a),
Cz flag (25b), CRC error flag (
26e) as well as 24/40 bit code error (13a)
is guided.

The determination circuit (28) is composed of, for example, a counter, and detects when any one of the above-mentioned evaluation pulses or error flags, such as the number of dropout pulses or the length of the error flag signal, exceeds a predetermined value. or by combining the conditions such as the number and length of these pulses or error flag signals using logic such as AND or OR, and when this logic circuit is satisfied, the defect detection signal (28a) is output as the first output. Make it output at the end.

In other words, under what conditions and in what cases does the defect detection signal (28
Make sure to specify whether to output a). Judgment circuit (2
8), an output signal (28b) that outputs all the input signals inputted to the determination circuit (28) as they are, for example, is derived. The defect detection signal (28a) derived from the determination circuit (28) is guided to the trigger input terminal (18a) of the digital oscilloscope (18).

First stage amplifier (7) for digital oscilloscope (18)
An RF signal (7a) is supplied from the computer (hereinafter referred to as CPU) (29), and a control signal (29a) is supplied from the computer (hereinafter referred to as CPU) (29).
) is supplied. The CPU (29) receives the above-mentioned defect detection signal (28a) and all the output signals (28b) manually input to the determination circuit (28), and also receives a 24/40 bit code (35) representing a time code. A subcode (36) representing the song title, etc., radius information on the stand bar (37), etc. are input, and the output of the CPU (29) is printed out to the printer (34) and sent to the playback control circuit (6). Control.

To explain the operation of the disc evaluation apparatus with the above-mentioned configuration, the stub bar (2) of the disc to be evaluated is placed on the turntable (1), and the motor (3) is rotated to perform playback. Move the optical system (4) in the width direction of the stand bar (2),
Two channels of analog/digital audio signals are extracted through B P F (19) and (24) as well as an FM demosimulator (20) and an EFM decoder (25). By switching the contact piece of the movable contact C of the switch means (21) to the fixed contact A side, the analog audio signal is transmitted to the audio amplifier (
22) to the headphones (23).

Further, by switching the contact piece of the movable contact C of the switch means (21) to the fixed contact side, a digital audio signal is supplied to the headphones (23).

At this time, if there is an error in the subcode in the digital audio signal, a CRC error flag (26b) is set and supplied to the input terminal T4' of the determination circuit (28). Similarly EFM
The decoder (25) sends a CI flag (25a) representing a correctable error and a C2 flag (25a) representing an uncorrectable error.
b) is output and the input terminal TS'+ of the judgment circuit (2nd day)
It is supplied to T4'.

The dropout pulse (17a) detected by the dropout detection circuit (17) based on the RF multiplied signal 7a) obtained from the first stage amplifier (7) is transferred from the output terminal T2 to the input terminal T2' of the determination circuit (28). Supplied. Another 24/
40-bit code decoder (11) and error detection circuit (
The 24/40 bit code error (13a) available at the output terminal T+ via the circuit 13) is also supplied to the input terminal TI' of the decision circuit (28).

In the end, the input terminal TI'+'r2'T of the judgment circuit (28)
4' * 'rs' + 'r,' is 24/
40-bit code error (13a), dropout pulse (17a), CRC error flag (2)
6b), C, flag (25a) will be supplied.

The determination circuit (28) counts the number of at least one of these pulses or flags, and if the counted value exceeds a predetermined count value, or the number of these individual pulses or flags, Conditions such as length are combined, and when the conditions are satisfied, a defect detection signal (28a) is output. This defect detection signal (28a) is detected by the digital oscilloscope (18).
), it is possible to capture and store defects in the RF multiplied signal 7a) that is supplied to the digital oscilloscope (18) via the first stage amplifier (7). Post-trigger conditions are set in advance for the digital oscilloscope (18) so that defective locations can be easily observed. In this way, the inspector can not only monitor the image and audio signals but also observe the RF multiplied signal of the defective part, which is useful for determining the cause of abnormalities in the image and audio signals. The above-mentioned various flags and pulses supplied to the judgment circuit (28) are output as they are or the results of conditional judgment are outputted to the second output terminal as an output signal (28b) to the CPU.
(29). Since the defect detection signal (28a) is also led to the CPU (29), the 2 signals supplied from the input terminals T7, T, and T9 within the CPU (29) are
4/40 bit code (35), sub code (3
6) is stored in correspondence with the disk radius information (37).

In the above example, the determination circuit (2 days) was constructed from hardware, but it is clear that it can be constructed from software within the CPU (29) if the processing speed within the CPU (29) is sufficient. .

As a judgment method of the judgment circuit (28), for example, a standby method is used.
The determination conditions can be selected as appropriate, such as determining that the product is defective if there is a defect detection signal at even one location in (2). Also, C
The various data stored in the P U (29) may be output to the printer (34), and the inspector may comprehensively judge the quality based on the printed data. Furthermore, it is also possible to install software that causes the CPU (29) to make a suitable condition judgment in advance so that the judgment can be made automatically.

Since the present invention is configured and operates as described above, it is now possible to quantitatively evaluate the standby bar by using the length and number of various error flag signals, instead of the conventional evaluation done subjectively by the inspector. Objective evaluations can be made.

In addition, since the present invention allows the position recording of defective locations, when the inspector wants to confirm the defective location again, the CPU
(29) If software is installed to sequentially search for defective locations, the evaluation device will sequentially search for defective locations and provide the inspector with local video and audio of the defective locations during reconfirmation. The time can be significantly reduced. Furthermore, if the evaluation of all recorded data in the standber (2) is performed automatically without the judge having to do it, and the judge is present to check the video and audio signals when searching and reproducing only the defective parts, the inspection can be made easier. It can be further rationalized.

It is clear that the present invention is not limited to the embodiments on the ridges, and can be modified in various ways without departing from the gist of the present invention.

〔Effect of the invention〕

According to the disk evaluation device of the present invention, quantitative evaluation can be performed when determining the quality of disks such as stanbars, and the RF multiplied signal of the defective location can be observed, making it easier to identify the cause of the defect. . Furthermore, since the inspector can selectively evaluate only the video and audio of the defective location, the inspection time can be shortened. Furthermore, since the standard for passing the standber is determined quantitatively, the quality of the passing standber becomes constant, which has the effect of stabilizing the quality of the duplicate disc obtained from the standber.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of the disc evaluation device of the present invention, FIG. 2 is a system diagram showing frequency allocation of a video disc, and FIG. 3 is a system diagram of a conventional disc evaluation device. (1) is a turntable, (2) is a stand bar 1 (4)
is the reproduction optical system, (8) (19) (24) is the BPF,
(18) is a digital oscilloscope, (28) is a determination circuit, (29) is a CPU, and (34) is a printer.

Claims (1)

[Scope of Claims] Dropout detection means for detecting a dropout in an RF signal during playback of a disc on which video and audio signals are recorded; and time code error detection means for detecting a time code error in the RF signal. , comprising decoding means for detecting correctable and uncorrectable error flags and sub-code error flags included in the audio signal of the RF signal, and comprising a decoding means for detecting correctable and uncorrectable error flags and subcode error flags included in the audio signal of the RF signal; Select at least one of the dropout pulse, time code error flag, correctable/impossible flag, and subcode error flag to ensure that the number of pulses or the length of the flag signal reaches a predetermined value. 1. A disk evaluation device characterized by being provided with a determination means that outputs a defect detection signal when a defect detection signal is exceeded.