JPS6145417A - Reproducing device of recording information - Google Patents

Abstract

PURPOSE:To attain specific reproducing control even if a CLV type disc having a fixed linear speed is used by controlling the forecasting of the number of jump tracks on the basis of a repeated synchronizing signal obtained from a recording disc and a disc turning signal so that the period of the synchronizing signal is invariably continued before and after jumps. CONSTITUTION:The CLV type video disc 2 is turned by a spindle motor 1 and information recorded on the disc 2 is read out by a pickup 4 and sent to the external as a reproduced video signal output 11 through a demodulator 5. A part of an output from the demodulator 5 is branched and applied to a synchronizing signal separator 8 for extracting a horizontal or vertical synchronizing component and an output from the circuit 8 is sent to a jumping frequency calculating circuit 10. On the other hand, an output from a rotation signal sensor 3 is also applied to the circuit 10 through a waveform shaper 9 in accordance with the turning status of the disc 2 and the output of the circuit 10 is fed back to the pickup 4 through a controller 7 to which a specific reproduction command signal 12 is applied and a servo circuit 6 to control the number of jump tracks.

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a recorded information reproducing device, and in particular to a recording information reproducing device that uses a disk-shaped record carrier (hereinafter referred to as a recording disk) recorded by a constant linear velocity (hereinafter abbreviated as CLV) method. This invention relates to a recorded information reproducing device that enables special reproduction control.

BACKGROUND ART In recording disk playback devices, when performing special playback such as still image playback, slow playback, fast playback, etc., the recording method of the recording disk is limited to the CAM (Constant Angular Velocity) method; Special playback cannot be performed on discs.

On a CAV format video disc, the synchronization signals of the composite video signal are recorded in a radial alignment on the same radius line of the disc, so special playback such as still image playback and slow and fast playback is possible. be. On the other hand,
In the CLv method, the composite video signal is recorded so that the linear velocity of the recording track is constant, so the synchronization signal is not recorded in a line on the same radius line of the disk, so the pickup cannot be track-jumped. Even if you control the jump to another track, the period of the synchronization signal (
(phase) becomes discontinuous and cannot be synchronized. As a result, special playback control has become difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide a recorded information reproducing apparatus that enables a certain degree of special reproduction even for CLV recording discs.

The recorded information reproducing apparatus according to the present invention uses a reproduction synchronization signal reproduced from a CLV recording disk and a rotation signal corresponding to the rotational state of the recording disk, and responds to a special reproduction command to determine the period of the reproduction synchronization signal. The present invention is characterized in that the number of skipped tracks is calculated so that it does not substantially change before and after the pickup jumps over the truck, and the movement of the pickup is controlled by the number of tracks obtained as a result of this calculation.

Example, Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a Prozok diagram of an embodiment of the present invention.

This system consists of a spindle motor 1 that rotationally drives a CLV video disc 2, a pink up 4 that reads recorded information on the video disc 2, a demodulator 5 that demodulates the signal read by this pickup 4, and a horizontal synchronization signal from this demodulated signal. Alternatively, a synchronization signal separator 8 extracts a vertical synchronization signal component, a sensor 3 and a waveform shaper 9 generate a rotation signal according to the rotational state of the disk 2, and the pickup 4 tracks jumps by inputting the reproduction synchronization signal and rotation signal. A calculation circuit 10 that calculates numbers, a controller 7 that controls the system by inputting the calculation results, etc., and is controlled by the controller 7 to control the movement of the pickup 4 in the disk radial direction and the rotation of the spindle motor 1. Includes servo circuit 6 and °.

Reference numeral 11 is the output of the demodulator 5, which serves as a reproduced video signal output. 12 is a special reproduction command signal from a keyboard (not shown) or the like.

Now, with a C'LV system disc, if you control the pickup to randomly jump tracks in so-called scan mode, horizontal synchronization will hardly be disturbed if the spindle servo follows, but
Color status and vertical synchronization are greatly disturbed. In the color state, if you set the circuit time constant etc. to speed up the color re-locking, it is possible to operate it to the extent that there is no visual problem, but with vertical synchronization, the cycle is long. Therefore, it will not be visually continuous unless you use digital memory or devise a circuit on the receiver side.

Therefore, it is desirable to implement a track jump method in the punk shown in FIG. 1 so that vertical synchronization is not disturbed even on a CLV system disc.

For CLV type disks, the disk radius R,
The playback time TP from R2 to R2 is expressed by the following equation.

Tp = It (R2" - R1" /
(Pf; u) ・------(1) This\
, Pt is the track pitch, and υ is the trunk linear velocity. Then, if the number of tracks from R to R2 is R, then uz=nPt+R1"・"・(2), and the number of revolutions per minute N of the disk at the disk radius R is N=30U/(πR,)・・・・・・
(3), so using equations (2) and (3), equation (1) becomes Tp= (Pt/p)πrL”+(2ntr
/v)几、"<Pt/v)rrn"+6Qn/N,
-(It becomes 4 inches.

In addition, for CAV format discs, TP = 60 n/N
Since □ and TP are unrelated to Pt and V, special reproduction is always possible.

In the CLV method, if TP shown by equation (4) is equal to or close to an integral multiple of the period width of the vertical synchronizing signal, then when the pickup jumps by the number of tracks, the period of the vertical synchronizing signal will change approximately d after the jump. Therefore, if we consider an NTSC video disc specifically, Pt and ν are 1.4 to 2.0 μm, 10.1 to xx, and 4 m/y, respectively. Therefore, (42 type tv (Pt/v) is 1.22
8xlo-' ~1.98xlO-? If we set K=TP/l with 0 in the range of

to = (le/1v) ((Pt/υ)πn+60/Ns)
If the value of K such that K is an integer or close to it is found, vertical synchronization disturbance can be prevented even if the pickup jumps by the Lutra node. In other words, 6 is 16.6877L, ? Since (Pt/II+) is within the above range, if the number of revolutions Nl at radius R1 is found, the number of track jumps at that time can be determined. be.

In equation (4), 600<N, ≦1800(rprp
) and (Pt/(tu・υ))π are 2≦(1/1000) (
60tV/(tvNt)), then le ≦
It becomes 168, Luke; below 168, K = 60
Even if n/(tu Nl), there will be an error of 0.1- or less.To jump a track in a short time, it is practical to have about 100, so considering the above conditions, (Pt /v) yrn ≦ 1.98X10-', X,
100=1.98810-'60/N1≧3.33 X
10-11 and 9. Therefore, if 60/N, >> (Pf, / v)wn is obtained and Le≦100, then CPt/')π becomes a negligible symbol for 60/Nl. , K・bow-□60n/(i: ,N □)
...... (This will be 6. This means that it is only necessary to make both C, R, and R very close to integers.0 Now, if 6 o/ (', Nt) = G. ,
G is the ratio of the time required for one revolution to the time equivalent to 174-/redo, or the track length of one revolution and one field.

The ratio to the track length corresponding to 4.9, K=Gi. If the integer part of G is P and the decimal part is Q, then K=(P
+Q)rL=PrL+QfL +・++++
(7), where P is an integer and the decimal part of K is Q: 1
If we find the curve for G that is within the predetermined tolerance range of the field, then when we jump the track, the joints of the fields will be connected continuously within the predetermined error range. Therefore, k-no ≦ QrL≦ + no or k-) ≦ (1-Q) rL≦ as 10 (k is a positive integer, ) is a decimal), (k-) )/Q≦ru≦ (k10) )/ Q or (k-) n/(1-Q) ≦ le ≦ (k+) )/
(Find a le that satisfies 1-Qn, and among the solutions of this le, le ≦
The smaller number of jumps is determined within the range of 100. However, if there is no solution, let = 0.

The circuit for calculating this value is the jump track number calculation circuit 10 shown in FIG.

FIG. 2 is a block diagram showing a specific example of the arithmetic circuit 10, in which four pulses are generated per rotation from a rotation signal generator 3 that generates a rotation signal according to the rotation state of the recording disk. , this is passed through the waveform shaper 9, divided into two by the flip-flop 101, and used as a clear signal for the counter 102. On the other hand, the reproduced horizontal synchronization signal is shaped by the waveform shaper 04, and is converted into VCQ (voltage Controlled oscillator) 106 output to branching unit 1
A phase comparator 105 compares the phase with the frequency divided by 12 by 07. By controlling the 9VCO106 using this comparison output, PLL (phase locked loop)
is formed, and a clock pulse (VCO-OUT) that is phase-synchronized with the reproduced horizontal synchronization signal is obtained. Therefore, this pulse is used as the clock input of the counter 102, and this count output is decoded by the decoder 103 to perform a track jump. I'm trying to get the number 0 Now, when one rotation of the disk is one frame, vco 1
The output of 06 is 262.5X during the IV (vertical synchronization) period.
12 = 3,150 pulses 0 Therefore 3,15
If the presettable decade counter 102 is used to re-count at a count of 0 and the disk is rotated half a turn), the counting result will be as follows:
Q, which represents the remainder from an integer multiple of 3,150, is shown in the timing chart of Figure 3.If the count number of this remainder is 9, then Q= q/3,
150, and the decoder 103 outputs the numerical value corresponding to the shift and sends it to the controller 7.0 In this case, the counter 102 is cleared every 1/2 rotation. If 1/4 rotation is used, by setting the preset value of the counter 102 to 1,575, the determination of the result becomes faster, but the resolution is reduced by half.

In this example, a so-called digital example is shown using a reproduced horizontal synchronizing signal and a presettable decade counter, but Fig. 4 shows an example of finding the value of LE in an analog manner using a reproduced vertical synchronizing signal. 0 The reproduced vertical synchronization signal is input to the sawtooth wave generator 109 via the waveform shaper 108. The sawtooth wave signal synchronized with the 0 vertical synchronization signal is input to the S/H (sample and hold) circuits 110 and 113. On the other hand, the rotation signal is processed by waveform shaper 1.
0 is input to the divider 112 via 11 and divided by 2.
These frequency-divided outputs are converted into rising edge pulses and rising edge pulses by waveform shapers 114 and 115, respectively, and are sent to the S/H circuit 1101.
The hold outputs of both S/I-I circuits 110 and 113, which are sample pulses of 113, are subtracted by a subtracter 116, and this difference signal is input to a comparison circuit 117 consisting of a plurality of window comparators to calculate the number of jump tracks. is required.

FIG. 5 shows the operational waveforms of each part of the block in FIG. 4, and a sawtooth wave as shown in (C) is obtained from the reproduced vertical synchronization signal (α). On the other hand, the division signal (d) whose frequency is divided into 1/2 from the rotation signal (b) is obtained, and each edge pulse of the rising edge and falling edge of this signal (d) corresponds to (e) and ω. You can get it like that. By sampling and holding the sawtooth wave signal (f?) using both signals (g) and V), Q)
If the rotation signal (b) has a cycle that is an integral multiple of the reproduced vertical synchronization signal (α), the levels of the sawtooth wave signals (C) at adjacent sampling points are equal. Therefore, the difference between the signals (&) and (A) becomes zero. This difference output (output of the subtracter 116) represents the deviation from the desired integer value. Therefore, the reference of each window comparator of the comparator 117 If you set the level range to correspond to each of the 6 jump track numbers,
An output corresponding to the difference is derived from the window comparator, and a jump command signal corresponding to the number of jump tracks corresponding to this output is supplied from the controller 7 to the pink-up 4.

As a numerical example, if ゛, No 0.01 (1% of 1 field), G = 2.645, Q = 0.645
Therefore, &=20.30.99≦Le≦31.02, that is, Le=31. If G=2.009, then Q=0.
009 9.110≦Le≦112.2 or 0.999≦Le≦1.019, and based on the condition that Le≦100, Le=1. If set to , it will be possible to jump across the entire recording disk, but
If you set it to a small value, there will be areas where you cannot jump. As for the timing of the jump, the jump should be made during the vertical synchronization signal period immediately after the operation command is generated, and if the jump is made within the vertical retrace interval, there will be no effect on the playback screen. If a solution occurs in the range of Le ≥ 20, if you jump multiple times in several H (horizontal synchronization) periods, the jump operation will be possible even if Le becomes large. Since the jump is based on the actual measured value G immediately before the jump, feedback correction is difficult. Therefore, if the number of jump tracks is incorrect, there will be a small error if the number of jump tracks is a dog, but the If Q = 2, etc., then Q = 0.5, so if there is a difference of one track, it will jump to the middle of the field, and the reproduced image will have the maximum disturbance. Therefore, the process of calculating the number of jumps is If it is not done in as short a time as possible compared to the vertical synchronization period,
Correction for arithmetic processing time delay is required.0 A digital processing method is preferable for the jump number calculation circuit 10 in terms of accuracy. Therefore, it is also possible to use a processor such as a so-called micro combinator together with the controller 7Q.
If the tolerance is increased and the jump zone is decreased, the analog processing shown in FIG. 4 is sufficient and the circuit can be simplified. In the example shown in Fig. 4, the jump number information output is generated with a delay of one rotation, so either the window width of the window comparator can be made smaller to increase accuracy, or the vertical synchronization signal and rotation signal can be cycled at the same integer ratio. It is good to make it small.

Effects of the Invention As described above, according to the present invention, the period (phase) of the synchronization signal is determined by the repeated synchronization signals (V, H, etc. signals) from the recording disk and the rotation signal of the disk before and after the jump. Since the number of jump trunks is predicted and controlled so as to be substantially constant and continuous, special playback control can be realized even for CLV type discs.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a block diagram showing a specific example of a part of the blocks in FIG. 1, and FIG. 3 is a tie showing the operation of the blocks in FIG. 2. FIG. 4 is a block diagram showing another specific example of a part of the blocks in FIG. 1, and FIG. 5 is a timing chart showing the operation of the blocks in FIG. 4. Explanation of symbols of main parts 2...Recording disk 4...Pickup 6
90. Servo circuit 7... Controller 8... Synchronous separator 10... Trunk jump number calculation circuit

Claims (1)

[Claims] A recorded information reproducing apparatus for reproducing a disc-shaped record carrier recorded by a constant linear velocity method, the apparatus comprising: means for extracting a reproduction synchronization signal having a predetermined repetition period from reproduction information; and a number of skipped tracks such that the period of the reproduction synchronization signal does not substantially change before and after the pickup jumps the track by using the reproduction synchronization signal and the rotation signal in response to a special reproduction command. What is claimed is: 1. A recorded information reproducing apparatus comprising: means for calculating , and means for controlling the movement of a pickup by the number of skipped tracks based on the result of this calculation.