JPS6050766A - Protecting circuit of reproducing device for disk record - Google Patents

Abstract

PURPOSE:To secure the safety of a system by detecting an abnormal operation state in the track jumping operation of a pickup, and stopping the track jumping operation. CONSTITUTION:The coincidence signal I generated when the number of tracks between the current position of a pickup and a target position coincides with the number of tracks that the pickup crosses is not outputted if a pickup control circuit 16 is abnormal, the output signal Q of an FF circuit 20 is held at ''H'', so an N-scale counter 21 continues to count a clock signal CK and then outputs a pulse signal (i) from its output terminal QN when counting up to N. The signal (i) is outputted as a pseudo coincidence signal to a system control part 17 and the reset terminal R of the FF circuit 20 instead of the coincidence signal. Consequently, a control part 17 stops the output of a track jump control signal T and a driving signal K to stop the track jumping operation of the pickup.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a disc record playback device suitable for, for example, a CD (optical converter disc) system DAD (digital audio disc), and in particular a pickup device. This invention relates to a system that protects the system from malfunctions that occur during track jumping operations.

[Technical background of the invention]

Recently, in the field of audio equipment, digital recording and reproducing methods using PCM (base code modulation) technology are being adopted in order to achieve high-fidelity reproduction as much as possible. In other words, this is what is called digital audio, and the audio characteristics do not depend on the characteristics of the DL recording medium, and are far superior to those using conventional analog recording and playback methods. This is because it has been established in principle.

In this case, a system that targets all disks (discs) as a recording medium is called a DAD system, and optical, electrostatic, and mechanical methods have been proposed for its %i recording and reproducing methods. However, no matter which method is adopted, the playback device that fully embodies it must satisfy various advanced control functions and performance that are not found in conventional devices. is required.

In other words, if you look at this as a CD-type hardware,
A disk made of a transparent resin disk with a diameter of 12 crn and a thickness of 1.2 crn, coated with a metal thin film that forms pits (irregularities with different reflectances) corresponding to EFM-modulated digital PCM data. , ch, v (constant m speed) method to rotate at a variable rotational speed of about 500 to 200 [rpm], and then drive it to the inner circumference using an optical pickup with a built-in semiconductor laser and photoelectric conversion element. The disc is played back using a linear tracking method from the side to the outer circumference, and the track pitch of this disc is 1.6 [μm], and a huge amount of information is programmed for approximately one hour of stereo playback on one side. It can be easily seen from the fact that the area (radius 25 to 58 [■]) is not recorded, and the index data etc. are recorded in the lead-in area (radius 23 to 25 [in order]). be.

FIG. 1 shows a schematic configuration of a CD type disc record reproducing apparatus as described above. That is, the symbol +j1 in the figure is a disk, on one side of which a bit string corresponding to the above-mentioned digitized data is recorded.

A pickup 12 is provided below the disk 11 in the drawing. This pickup 12 is moved to the disk 11 by a pickup feed motor (not shown).
The disk 11 is movable in the radial direction.
By irradiating a focused light beam onto the bit string recording surface and receiving the reflected light, a detection signal having a frequency characteristic of 1-minus corresponding to the presence or absence of the pit is output. The detection signal &;i extracted by this pickup 12 is supplied to an RF signal generation and demodulation circuit 13.

This RF signal generating tone circuit 13 is configured to perform the R
This is to generate an F-fold signal and perform the RF signal EFM<M tuning to extract the original digitized data. This digitized data is supplied to a data demodulation processing circuit 14. This data demodulation processing circuit 14it1 performs processing such as deinterleaving, error correction, and error correction on the digitized data, and then converts it into an analog signal by a DA converter (not shown). This analogue No. 1 t
It is supplied as a J1 reproduction sound through an output end 15 to an acoustic restraint device (not shown) and is reproduced and output.

Further, in the disc record reproducing apparatus, in order to obtain the RF signal in a good condition as described in 5. above, the pickup control circuit 16 controls the tracking sensor and the focus sensor If of the pickup 12.

That is, this pickup control circuit 16 inputs the detection signal output from the pickup 12, and based on this detection signal, outputs a tracking error signal corresponding to the shift of the pickup in the forward and reverse directions with respect to the bit string and a light beam directed toward the bit string recording surface. A focus error signal corresponding to the focus shift is generated. Then, based on the tracking error signal and the focus error signal, the pickup 12 and an objective lens (not shown) built in the pickup 12 are driven and controlled so that the pickup 12 correctly traces the bit string on the disk 11. The tracking sensor also controls (focus servo) so that the focus of the light beam is correctly aligned with the bit string recording surface on the disk 11.

6- Furthermore, in this glazed disc record playback device, V
jl For example, in order to quickly select (search) an arbitrary data portion from among the digitized data recorded on the disk 1, the pickup 12 is moved at high speed in the radial direction of the disk 1, so-called track skipping of the pickup 12. Track skipping control +1
41 II H4'fr, there is. This track jumping 1① control mechanism will be explained below.

That is, in FIG. 1, 17 is a system controller, and this system controller 17 is composed of, for example, a microcontroller. - The system controller 17 controls the various operations and various display systems of the ShibuisfRecord birthing device in accordance with operation commands from the computer.
The digitized data output from the F signal generation and demodulation circuit 14 is supplied via an address detection circuit 18, which will be described later. 17.This system controller 17t,
The index data portion recorded in the lead-in area when t7'' (Sufu 1) is installed is stored in a lead-in data memory (not shown).

Here, the address detection circuit 18 inputs the digitized data extracted by the RF signal generation and demodulation circuit 14, separates all synchronization signals for address detection from this digitized data, and converts the digitized data currently being reproduced. This detects the current address data of the data. This current address detection circuit is configured to be supplied to the system controller 17.

Then, when the system controller '7 C N key is given a track skip operation command (this means specifying the target data to be selected on the disk 11) to the - key, the lead-in data memory is The entire target address data indicating the part where the target data is recorded is extracted from the stored index data. Furthermore, from this target address data and the current address data supplied from the address detection circuit 18, movement direction data indicating whether to move the pickup 12 toward the outer circumference or the inner circumference of the disk 1 is calculated. , calculate the distance data based on the number of tracks (the number of bit rows crossed) to be moved completely by 7°12. Then, at the same time as the track jumping control signal T (j) consisting of the movement direction data and distance data is supplied to the pickup control circuit 16, a drive signal K as shown in Fig. 8g2 (,) is supplied from time t. .

On the other hand, when the pickup control circuit 16 is supplied with the drive signal K, it moves the pickup 12 in the specified direction of the disk 1 based on the track skipping control signal T, and tracks the pickup driver f12. Have them perform a jump. At this time, in the detection period outputted from the pickup 12, a sol is generated as shown in FIG. 2(h) every time the track is skipped. The pickup control circuit 16 to which all such detection signals are input slices all levels of the detection signals, shapes them into a pulse waveform as shown in FIG. 2(c), and counts all the number of non-pulses. Then, this count number is compared with the number of tracks designated by the track skipping control signal T, and at a time point t1 when the two match, FIG.
) is output to the system controller 17.

Then, the system controller 17 immediately stops outputting the track jumping control signal T and the signal, and causes the pickup control circuit 16 to control the pickup 12.
is returned to the original playback state, and this completes the track skipping operation.

[Problems with background technology]

However, in a track skipping control mechanism that continues track skipping until a matching signal is detected, such as the disc record playback device described above, for some reason, the detection signal obtained during the track skipping operation may be offset. If this occurs and the waveform shaping is not performed well, the pickup will remain in a permanent track-jumping state, and in the worst case, there is a danger that the pickup will run out of control and a marking failure will occur.

[Purpose of the invention]

This invention was made in consideration of the above-mentioned circumstances, and it is possible to detect all abnormal operating conditions during the truck jumping operation of the pickup and stop the truck jumping operation, thereby improving the system. It is an object of the present invention to provide a production circuit for an extremely good disc record playback device a that can ensure safety.

[Summary of the invention]

That is, the protection circuit of the disc record reproducing apparatus according to the present invention outputs the entire information No. 4M from the disc on which the information data and the address data indicating the position and other information signals are recorded through the pickup. Set all the positions on the disc to be output, calculate the number of tracks between the current position of the pickup and the target position from the address data of that position and the address data of the position where the pickup is currently playing, and calculate the number of tracks. A pickup control device that moves the pickup toward a target position based on data, counts the number of tracks crossed by the pickup when the pickup moves, and matches when this counted value matches the track number data. In a disc record playback device configured to output a signal to completely stop the movement of the pickup, the device includes means for detecting whether or not the coincidence signal is output within a predetermined time; The present invention is characterized in that it is completely equipped with a means for outputting a pseudo-coincidence signal to completely stop the movement of the pickup when it is detected that the pickup is not output.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIG. However, in FIG. 3, the same parts as in FIG. 1 are denoted by the same reference numerals, and only the different parts will be described here.

FIG. 3 shows a protection circuit for a disc record reproducing apparatus according to the present invention. That is, the coincidence 4='@r outputted from the pickup control circuit 16 is supplied to the system controller 17 through the OR circuit (hereinafter referred to as an OR circuit) 19, and also to the S-
The signal is supplied to the reset terminal R of the R flip-flop circuit 20. This S-R flip-flop circuit 20 has reset priority, and the drive signal K output from the system controller 17 is connected to the set terminal s.
are being supplied. And this S-R
The output terminal (1 & clear terminal of the iN-adjustable counter 21) of the free rough 0 float circuit 20 are connected to each other.

The clock input terminal CK of this N-ary counter 2) is supplied with the clock number 2218 CK output from the timer reference clock oscillator (hereinafter referred to as the clock oscillator) 22, and the above-mentioned clear terminal level (when No. 8 is supplied, the above clock signal CK?f-η1 is N
The pulse signal i is outputted from the output terminal QN13-. The output signal i of the N-ary counter 2 is supplied to the OR circuit 19.

The operation of the above configuration will be described below. That is, when a track jumping operation command is given as described above and the track jumping control signal T and drive signal K are output from the system controller 17, the pickup control circuit 16 outputs the track jumping control signal T and the drive signal K.
While this is supplied, the pickup 12 is caused to perform a track jumping operation based on the track jumping control signal T. At the same time, the drive signal K is supplied to the set terminal S of the S-R frizzo flop circuit 20, so that the S-R frizzo flop circuit 20 sets its output signal (1"H" level).

Then, the N-ary counter 21Fi and the clock oscillator 2
When the clock signal CKi supplied from the clock signal CKi is counted N times, the pulse signal i' (I-) is outputted from the output terminal QN.

14-Here, the time required from when the upper 6 self-driving counter number is supplied to the S-R flip frozzo circuit 2θ until the signal i is output from the N-ary counter 2 is expressed as If the time is set sufficiently longer than the time from when the drive signal K is supplied to the control circuit 16 until the coincidence signal is fully output, if the pickup control circuit 16 operates normally, the detection signal When the counted value matches the track number data included in the above-mentioned track skipping 1ljlJ fI41 Shino T, the above-mentioned pickup control +
The matching ID number I is output from the 111 circuit 16.

This coincidence No. 18 I is output to the system controller 17 via the OR circuit 19 (ll-), and the track skip 1
-i1ilJ Gohakugo T and all outputs to the drive signal are stopped, and at the same time upper H+28-R Fritsuno 70 Tsuno circuit 20
This S-R frizzo 70 is output to the reset terminal R of
Tube circuit 20'ft: Reset and its output No. 48 Q
f Invert to “L” level.

As a result of this, the operation of the N-ary counter 21 is cleared, so that it does not output the Noculus signal if.

However, if the pickup control circuit 16 is in an abnormal operating state for some reason and the coincidence signal ■ is not output, the output signal Q of the S-R79217021 circuit 20 remains at the "H" level, so the N-ary counter 2] continues counting the clock signal CK, and when the clock signal CK has been counted N times, a pulse +"tik is output from the output terminal qN.

This mother pulse signal i is output as a pseudo-coincidence signal to the reset terminal R of the system controller 17 and the S-R flip-flop circuit 20 via the OR circuit 19 in place of the coincidence signal. For this reason, system controller 1
7 stops the output of the track jumping control signal T and the drive signal, thereby stopping the track jumping operation of the pickup 12. 1, the above S-R79
The 217121 circuit 21 sets its output signal Q't to "L" level to clear the N-ary counter 21.

Therefore, a disc record playback device configured with the above-mentioned protection circuit can detect all abnormal operating conditions during the track jumping operation of the pickup and stop the track jumping operation, thereby ensuring the safety of the system. It becomes like this.

In addition, the above-mentioned installation circuit uses 814 instead of the N-ary counter 21.
As shown in Fig. 4, using a resettable counter 23,
This re-settable counter 23 contains the track number data of the upper U own track skipping control signal and all preset data P.
By supplying it as S, -He 5L clock I a
It is also possible to obtain a pseudo-coincidence (Noyals signal i of g) by changing the maximum count value N of the number of tracks. Since it can be set accordingly, it can be made even more effective.

〔Effect of the invention〕

(As shown above, according to the present invention, it is possible to detect the abnormal operating state 17- during the truck jumping operation of the pickup and stop the truck jumping operation, and it is possible to ensure the safety of the system by kneading.) It is possible to provide a disk record amphibious device.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the general configuration of a conventional disc record playback device, Fig. 2 is a waveform diagram showing output waveforms of each main part of the disc record playback device, and Fig. 3 is a waveform diagram showing the output waveforms of each main part of the disc record playback device according to the present invention. FIG. 4 is a block circuit diagram showing another embodiment of the protection circuit of the disc record playback device d according to the present invention. 11...disc, 12... Pickup, 13.
...RF signal generation and demodulation circuit, 14...Data recovery sub-processing circuit, 15...Output end, 16...Pickup control circuit, i y...System controller, 18...
Address detection circuit, 19...OR circuit, 20...S
-R Frizzo Frozzo circuit, 21... N-ary counter,
22...Clock oscillator, 23...Presetter pull counter, T...Track skip control signal, 18-K...Drive November, ■...-Kaishin bow, cK...Clock I M "l, z...mushi ε (Lt -i ii la sum). Application fee 1 (11 patent attorneys" - Takehiko Suzue 19) Figure 3 Figure 4

Claims (1)

[Claims] The information signal is read out from a disc on which information data, address data indicating its position, and various information signals are recorded, through a pick-a-way ff.The position on the disc to be selected is set, and the address data of that position and the above information signal are read out. Pickup control that calculates track number data between the current position of the pickup and a destination position from the address data of the position where the pickup is currently playing, and moves the pickup toward the target position based on this track number data. A disk comprising a device that counts the total number of tracks crossed by the pickup when the pickup moves, and outputs a coincidence signal when the counted value matches the track number data to stop the movement of the pickup. In the record playback device, means for detecting whether or not the coincidence signal is output within a predetermined time; and when the means detects that the coincidence signal is not output within the predetermined time, a pseudo coincidence signal is outputted, and the A protection circuit for a disc record playback device, characterized in that it is completely equipped with means for stopping the movement of a pickup.