JPH0370310B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording track jump control system for recorded information detection points in a recorded information reproducing apparatus.

In a recorded information reproducing apparatus, a so-called jump operation is sometimes performed to forcibly jump the detection point of recorded information from the recording track currently being traced to another target recording track. FIG. 1 is a conventional circuit block diagram for controlling such a jump operation, in which 1 indicates a certain part of the recording track, and tracking is performed when the center of the scanning spot light 2 for information detection is located in the center of the part of the recording track. The centers of the spot lights 3 and 4 are located on both side edges of the track 1.
Therefore, when the center of the information detection spot light 2 deviates from the center of the track 1 to the left or right, the magnitude and polarity of the difference in light intensity between the tracking spot lights 3 and 4 change depending on the amount and direction of the shift. I will do it. Therefore, the light receiving elements 5 of both spot lights 3 and 4
A tracking servo signal B is obtained by extracting the signal difference between the signals and 6 using a differential amplifier 7. This servo signal B is applied to an equalizer amplifier 9 via a loop switch 8, subjected to phase compensation, passed through an adder 10, and becomes an input to an amplifier 11. The output of the drive amplifier 11 drives the drive coil 13 of the tracking mirror 12 which deflects the spot lights 2 to 4 in a direction perpendicular to the recording track 1, so that the spot lights 2 for information detection, that is, the information detection point, are driven during reproduction. is controlled so as to accurately track on the recording track, and the above forms a tracking servo loop.

The servo signal B is converted into a pulse-like signal C by the waveform shaping circuit 14, and the signal is FWD (forward direction)/
The pulse signal C is input to the FWD/REV switching circuit 15 which inverts the phase of the pulse signal C in response to a REV (reverse direction) reproduction command. This is to match the signal phase at both times since the phase of the servo signal B differs by 180° depending on the forward and reverse directions, and the output pulse of this circuit 15 becomes the clock input of the N-ary counter 16. The counter 16 starts counting in response to a jump command signal from the operating device 18. The base number control is performed by an external control signal, making it a variable base type counter. For example, a high level signal D is generated from the time this N-ary counter is set and starts counting until the arrival of N pulses, and this signal D controls the on/off of the loop switch 8. At the same time, the jump signal generating circuit 17 is activated to generate a drive signal for the jump. This drive signal is input to the adder 10 to forcefully drive the mirror drive coil 13. Furthermore, FWD/
By inputting the signal from the REV command signal generator 19 to the jump signal generation circuit 17,
A drive signal with a polarity depending on the FWD/REV state is generated.

Figure 2 A to D are signals A to D of each part of the circuit in Figure 1.
This figure shows the waveforms of each. It is now assumed that the tracking servo loop switch 8 is closed and the tracking servo is operating normally and in a reproducing state. At this time, the jump command signal is
If it arrives like this, the N-ary counter 16 is set and the counter output D becomes high level.
Therefore, the loop switch 8 is opened and the jump signal generating circuit 17 outputs a drive voltage with a polarity suitable for forward and reverse direction reproduction. Therefore, the tracking mirror 12 is forcibly swung by this driving voltage, so that the information detection spot light sequentially jumps from the current track to adjacent tracks. As a result, the output of the differential amplifier 7 is as shown in FIG. 2B, and the output of the waveform shaping circuit 14 is a pulse signal shown in C. Since this is the clock input of the N-ary counter 16, the number of pulses is counted. Then, when N pulses are counted, the output D of the counter 16 becomes a low level and closes the servo loop switch 8.
Generation of the drive signal is stopped and a reproducing operation is performed. The fact that the counter 16 has counted N pulses means that the pick-up spot light has jumped the recording track by N pulses at once.
Therefore, by controlling the base number of the N-base counter using a command, it is possible to jump an arbitrary number of recording tracks.

However, with this configuration, if the information detection point cannot accurately jump to the target recording track and a so-called overrun phenomenon occurs, this overrun state cannot be detected.
It becomes difficult for the information detection point to accurately track the target recording track.

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording track jump control system that can accurately detect an overrun state during a jump operation and quickly move an information detection point onto a target recording track.

The recording track jump control method according to the present invention is a control method for causing a recording information detection point to jump over a predetermined number of recording tracks while opening a tracking servo loop in response to a jump command. means for counting the number of occurrences of a predetermined signal generated when the information detection point crosses a recording track and generating a difference signal according to the difference between the counted value and a predetermined value; means for forcibly generating a pseudo signal of the predetermined signal by detecting a reversal in the direction in which the signal traverses the recording track, and for controlling the counting direction of the number of occurrences in the reverse direction, according to the difference signal. The reason is that the jump operation of the information detection point is controlled.

The present invention will be explained below using the drawings.

FIG. 3 is a block diagram of an embodiment of the present invention;
Components equivalent to those in FIG. 1 are designated by the same reference numerals, and their description will be omitted. In this example, an up-down counter 20 which can be preset freely is used, and the preset contents of this counter become the jump track number. The clock input of this counter counts a predetermined signal generated each time an information detection point crosses a recording track, and this signal is obtained as follows. That is, the reflected light from the information detection spot light 2 is converted into a signal by the light receiving element 21, and this signal is input to the low-pass amplifier 22.
The envelope signal of the HF (high frequency) component is obtained. This envelope signal is compared with the zero level in the level comparator 23, and the information detection point 2
A so-called on-track signal is derived which has a low level when the recording track is on the recording track and a high level when it is not on the recording track. This on-track signal becomes the counting input of the counter 20 via the OR gate 24, and the counter 20 counts, for example, at the rising edge of this on-track signal.

On the other hand, the information detection point 2 crosses the track using the signal that has passed through the tracking error signal waveform shaping circuit 14 and the FWD/REV switching circuit 15, that is, the waveform shaping output of the error signal or its polarity inverted output and the on-track signal. A return detector 25 is provided to detect a reversal of direction, and when the direction is reversed, that is, the direction of movement of the information detection point is returned, this detector 25 outputs a detection signal. This detection signal controls the counter 20, which was in the down-counting state, to be in the up-counting state, and at the same time, the pseudo signal generator 26 at the next stage operates to forcibly generate a pseudo on-track signal and output the signal via the OR gate 24. applied to the counting input of the counter 20.

A jump signal is generated from the jump signal generator 17 until the count content of this counter becomes zero, and the content of the counter is read by the count content determiner 27 and the FWD/REV command circuit is activated according to the content. 19 is now under control.

In such a configuration, when a predetermined number of tracks are to be jumped once, the counter 20 is preset to a predetermined value and a jump command in the FWD or REV direction is generated. In this case, when the address of the target track is specified, the difference between that address and the address where the information detection point is currently located is calculated, and a predetermined direction in the aforementioned direction is calculated based on the positive or negative value of the difference and its magnitude. The value is set by means not shown. Further, when the direction and the number of tracks to be skipped are predetermined, the direction and the number of tracks to be skipped are set to that direction and the predetermined value.

In response to the jump command, loop switch 8
becomes an oven, and a jump signal of a predetermined polarity is output from the jump signal generator 17, and a jump operation is performed. During this jump, a rising transition occurs in the on-track signal, which is the output of the comparator 23, in synchronization with the timing at which the information detection point crosses the track, so the number of occurrences of this rising transition is counted by the counter 2.
It is counted down at 0. When the count reaches zero, the count determiner 27 determines this and instructs the loop switch 8 to be turned on. Therefore, the servo loop is closed and normal tracking operation is performed thereafter.

The above operation is for the case where no overrun occurs, but if an overrun occurs and the target track is
If you skip one, the following will happen: For example, if an 8-digit binary counter is used as the counter 20 and the number of jump tracks is 100, the counter preset value is "01100100", and the content becomes "11111111" due to an overrun of one track.
becomes. The count content determiner 27 determines that the number of overrun tracks is 1 by obtaining the two's complement of this content. That is,
Since the two's complement of "11111111" is "00000001", it can be seen that the number of overrun tracks is 1. Therefore, since it is sufficient to perform a backward jump by this number of overrun tracks, this number of tracks is again preset in the counter 20, and the same jump operation as described above is repeated.

The aspect of the overrun is shown in Figure 4,
A case can be considered in which the information detection point overruns the target track _T0 by one point and tracks to the next adjacent track _T1 with a trajectory as shown by a, b, and c. The waveforms of the tracking error signal, the output signal of the waveform shaper 14, and the on-track signal for each trajectory a, b, and c are shown in A, B, and C of FIGS. 5, 6, and 7, respectively. has been done.

In the case of trajectory a, the waveforms shown in FIG. 5 are obtained, and the on-track signal rises at the same time as the information detection point passes the target track _T0 , and this rising edge is input to the counter 20, so as mentioned above, the counter contents are Since the number of overruns is 1, there is no problem. However, as shown in trajectories b and c, the target track
A problem arises when the information detection point once crosses the track _T1 following _T0 and then returns to the track _T1 . In such a case, the on-track signal waveforms are shown in Figures 6 and 7C, respectively.
When crossing _T1 once, the on-track signal rises, and the counter 20 counts down this rising edge, and the count becomes "11111110". In other words, the 2-track over state is displayed incorrectly.

Therefore, the return detector 25 and pseudo signal generator 26 shown in FIG. 3 are added. A concrete example of the return detector 25 and the pseudo signal generator 26 is shown in FIG.
(see figure) is one input of a two-input AND gate 252. In addition, Ontrack signal C
is MMV (monostable multivibrator)
This MMV output D serves as the other input to the gate 252. The output E of the gate 252 controls up and down of the counter 20, and this output E is also applied to the delay device 26.
(which is a pseudo signal generator), it becomes a pseudo signal F of the on-track signal. This signal F and the on-track signal C are applied to the clock input G of the counter 20 via an OR gate 24.

FIG. 9 is a diagram showing the operation of the circuit of FIG. 8,
Figures B to G show the waveforms of signals B to G of each part of the circuit of Fig. 8 in correspondence with each other. Signal waveform A is a tracking error signal, and although this is an example of the case of trajectory b in FIG. 4, it is similarly applied to the case of trajectory c. As shown by trajectories b and c, there is a reversal of the direction in which the information detection point crosses the track, and the track is crossed again.
When the phenomenon of returning to _T1 occurs, the on-track signal C
There is a period in which both the MMV output D and the tracking error shaping waveform B, which are triggered by the falling edge of , are at a high level. This is detected by the AND gate 252 to obtain the gate output E, and while the gate output E is at a high level, the counting direction of the counter 20 is controlled from down counting to up counting. This gate output E is delayed by a predetermined time by a delay device 26 to forcibly generate a signal similar to the on-track signal. The rising edge of this pseudo signal is the counter 2
If it is selected to be within the up-count control period of 0, the counter 20 will perform up-counting based on this pseudo signal, so that the counter content will display the normal overrun number 1. Note that it is clear that the number of overruns is not limited to 1 but can be any arbitrary number and that accurate counting of the number of overruns is possible.

FIGS. 10 and 11 are examples of flowcharts showing the operation control procedure when this overrun number is detected by the counter 20 and a jump correction to the target track is performed. In the example shown in Fig. 10, the jump operation is repeated according to the difference between the track where the information detection point has locked in due to overrun and the target track, and the track of the difference is
This is a case of causing a sudden jump. In the example shown in FIG. 11, the target track is reached by performing jump operations one track at a time for the number of differences.

As described above, according to the present invention, since the number of overrun tracks is accurately detected in any case, the jump to the target track is always performed appropriately. There is no need to distinguish between the adjustment means and the fine adjustment means and provide them independently, which simplifies the circuit configuration and enables quick search operations.

Note that as the distance over which an information detection point jumps at one time on a track increases, the relative moving speed of the information detection point to the recording track during the jump operation changes due to eccentricity of the recording disk, etc. As the time fluctuates, there is a risk that the lock-in operation of the tracking servo after the end of the jump operation will become unstable.

Therefore, an example in which stable servo lock-in is enabled by controlling the relative speed during the jump operation period is shown in the form of a block in FIG. In the figure, parts equivalent to those in FIG. 3 are designated by the same reference numerals. The control input of the loop switch 8 is supplied with the Q output a of the R-S flip-flop 29 and the output b of the track detector 23 via an OR gate 28. This track detector 2
3 corresponds to the comparator 23 in FIG. 3, which generates a so-called on-track signal b. A jump command signal from the operating device 18 shown in FIG. 3 is applied to the reset input of the flip-flop 29.

Ontrack signal b is up/down counter 2
It serves as a count input of 0 and also serves as an input to the jump drive signal generator 17. The output of this counter 20 is the zero detection circuit 271 of the count content determiner 27.
and is supplied to the 4-track detection circuit 272.
The zero detection circuit 271 is configured to output a zero detection signal consisting of, for example, a high level signal when the counter content becomes zero. The zero detection signal output from the zero detection circuit 271 is supplied to the reset input terminal of the R-S flip-flop 29. Further, the 4-track detection circuit 272 is configured to output a 4-track detection signal c, which is a high level signal, for example, when the counter content becomes below. This four-track detection signal c is supplied to a drive signal generator 17.

In the drive signal generator 17, the output a of the track detector 23 is input to the trigger input terminal of a monostable multivibrator (hereinafter abbreviated as monostable multi) 171 and one input terminal of a 3-input AND gate 172. Supplied. 3 input AND
The other two input terminals of the gate 172 are supplied with the Q output d of the monostable multiplier 171 and the Q output a of the R-S flip-flop 29, respectively.
An analog switch 173 and a capacitor C ₂ are connected in series between the two external terminals of the monostable multi 21's time setting resistor R ₁ and capacitor C ₁ . The analog switch 173 is configured to be turned on when a high level signal is supplied to the control input terminal. A control input terminal of this analog switch 173 is supplied with a 4-track detection signal c. The output e of the three-input AND gate 172 is supplied to the trigger input terminal of the trigger input 174 of the monostable multi 174. monostable multi 172
The output f is supplied to the control input terminal of the changeover switch 175. One input terminal of the changeover switch 175 is grounded. Further, the other input terminal of the changeover switch 175 is connected to R through a resistor _R2 .
The Q output of the -S flip-flop 29 is supplied. The output terminal of this changeover switch 175 is
The signal applied to one input terminal is derived when a low level signal is applied to the control input terminal, and the signal applied to the other input terminal is derived when a high level signal is applied to the control input terminal. . The signal derived from the output terminal of the changeover switch 175 is supplied to the negative side input terminal of the operational amplifier 176. The positive input terminal of this operational amplifier has a monostable multi-17
A Q output g of 4 is supplied. Further, a feedback resistor R ₃ is connected between the negative input terminal and the output terminal of the operational amplifier 176. The output of this operational amplifier is supplied as a drive signal h to an adder 10 via a polarity inverter 15. The polarity inverter 15 is
It is configured to invert the polarity of the drive signal h in response to a FWD (forward direction)/REV (reverse direction) regeneration command.

In the above configuration, the jump command signal is output from the high-speed reproduction operation control circuit, etc., and the R-S flip-flop 29 is set to the set state, and the Q output a of the R-S flip-flop 29 is set at time _t1 as shown in FIG. 13A. When the level becomes high, a high level signal is supplied to the control input terminal of the loop switch 8.
Then, the loop switch 8 is turned off, and the tracking servo loop is opened.
At the same time, data N, for example, "100" is preset in the counter 20. At this time, the monostable multi 174 is not inverted and the output f is at a high level as shown in F in the figure. For this reason,
The Q output a of the R-S flip-flop 29, which is supplied to one input terminal, is derived from the output terminal of the changeover switch 175 via a resistor _R2 . Also, since the Q output g of the monostable multi 174 is at a low level, the positive input terminal of the operational amplifier 176 is grounded, and the operational amplifier 176 and resistors R ₂ and R ₃ input the Q output a. It functions as an inverting amplifier circuit. Therefore, the drive signal h output from the operational amplifier 176 becomes lower than the ground level as shown in FIG. Start moving to .

As the information detection spot light 2 moves, an on-track signal consisting of a low level signal is generated every time the information detection spot light 2 jumps over a recording track, and the track detector 2 generates an on-track signal consisting of a low level signal.
The output b of No. 3 is as shown in C of the same figure. Then, when the on-track signal disappears, that is, when the output b of the track detector 23 rises, the counter 2
The count value of 0 becomes smaller. Furthermore, when the on-track signal is generated, that is, when the output b falls, the monostable multi 171 is triggered, and the Q output d remains at a high level for a time T ₁ corresponding to the time constant C ₁ R ₁ as shown in FIG. Become.

Thereafter, the moving speed of the spot light 2 relative to the recording track in the radial direction is accelerated, and the time during which the output b is at a low level becomes shorter and becomes less than _T1 , and the output b and the Q output d decrease as shown in Fig. E. The output e of the three-input AND gate 172 remains at a high level for a period of time during which both of them are at a high level. When this output e becomes a high level, the monostable multi 174 is triggered and the output f becomes the output e as shown in F in the same figure.
It remains at a low level for a predetermined period of time _T2 from when it reaches a high level. Then, the operational amplifier 176
The negative input terminal of the operational amplifier 176,
The resistor R ₃ will function as a non-inverting amplifier circuit which receives the Q output g of the monostable multi 174 as an input. The Q output g of the monostable multi 174 continues for a predetermined period of time from when the output e reaches a high level, as shown in G in the same figure.
The level remains high until T ₂ . Therefore, the drive signal h remains for a predetermined period of time from when the output e becomes high level.
Over time T ₂ , the level is higher than the ground level, and the relative moving speed of the spot light 2 is slowed down and controlled to be almost constant at a predetermined speed V ₁ .

After that, spot light 2 covers the recording track by 4 more times.
When the vehicle moves to a position where it reaches the target track by jumping over the track, the count value of the counter 20 becomes 4. Then, as shown in Figure B, a 4-track detection signal c consisting of a high level signal is generated and the analog switch 173 is turned on (time _t2 ).
As a result, the inversion time of the monostable multi 171 becomes a time T ₃ corresponding to the time constant (C ₁ +C ₂ )R ₁ , which is longer than T ₁ . Therefore, _the relative moving speed of the spot light 2 is controlled to be substantially constant at the speed V2, which is lower than the speed _V1 , after time _t2 .

Then, when the spot light 2 skips over the last recording track to be skipped, the count value of the counter 20 becomes zero and the four-track detection signal c disappears (time t ₃ ). At the same time, a zero detection signal is output from the zero detector 23 and the R-S flip-flop 29
is reset, and the Q output a becomes low level. Then, the drive signal h becomes zero level, the tracking servo loop is closed, and the information detection spotlight 2 is positioned on the target track.

FIG. 14 is a circuit block diagram showing another embodiment of the block in FIG. 12, in which only the jump drive signal generator 17 is shown, and the other components are connected in the same manner as in FIG. Omitted.
In the drive signal generator 17 in this example, monostable multi 171, 174, 3-input AND gate 1
72, analog switch 173, resistor R ₁ , and capacitors C ₁ and C ₂ are connected in the same manner as in the device shown in FIG. However, the Q output a of the R-S flip-flop 29 is supplied to one input terminal of the three-input AND gate 172, and the capacitor
C ₃ , operational amplifier 177 via resistor R ₅ , resistor R ₆
~ _R8 is supplied to one input terminal of an adder circuit 178. The cathode of the diode _D1 is connected to the connection point J between the capacitor _C3 and the resistor _R5 . The anode of diode D ₁ is grounded. Furthermore, the anode of the diode D ₂ is connected to the connection point between the resistors R ₅ and R ₆ which is one input end of the adder circuit 178 . The cathode of diode _D2 is connected to the output terminal of monostable multi 174. Further, the output f of this monostable multi 174 is supplied to a level shift circuit 179. The level shift circuit 179 shifts the level of the output f so that when the output f becomes a high level, the output becomes a ground level, and when the output f becomes a low level, the output becomes a level below the ground level. It is configured. The output of this level shift circuit 179 is supplied to the other input terminal of the adder circuit 178. And this addition circuit 17
The output of No. 8 is output as the drive signal h.

In the above configuration, the Q output a of the R-S flip-flop 29, the 4-track detection signal c, the output b of the track detector 23, the Q output of the monostable multi 171
The output d, the output e of the 3-input AND gate 172, and the output f of the monostable multi 174 are the 12th
The apparatus shown in FIGS. 15A to 15F is similar to the apparatus shown in FIG. Then, when the output f is at a high level during the period from time t ₁ to t ₃ , the capacitor
The signal J led to the connection point J between C ₃ and resistor R ₅ is almost constant at a level higher than the ground level, as shown in FIG. At this time, the signal J is supplied to one input terminal of the adder circuit 178, and the output of the level shift circuit 179 supplied to the other input terminal of this adder circuit is at the ground level, so that the drive signal h is lower than the ground level. The level becomes low, and the moving speed of the spot light 2 relative to the recording track in the radial direction is accelerated. Also, the output f
When becomes a low level, one input terminal of the adder circuit 178 becomes the ground level and the output of the level shift circuit 179 becomes lower than the ground level, so the drive signal h becomes a level higher than the ground level, and the relative of the spot light 2 The first movement speed is reduced.
Similar to the device shown in FIG. 2, the speed is controlled to be almost constant at a predetermined speed. In addition, in this example, when the output f becomes a low level, a negative charge is supplied to the capacitor _C3 via the resistor _R5 , and the capacitor _C3
is charged, so that the level of the signal i delivered to the connection point J decreases with a time constant determined by the capacitor _C3 and the resistor _R5 . Therefore, as the relative moving speed of the spot light 2 accelerates, the level of the drive signal h gradually approaches the ground level as shown in H in the figure, and as the spot light 2 approaches the target track, the acceleration force increases. is gradually weakened, and the lock-in operation becomes easier. Therefore, this embodiment is particularly preferred when the number of tracks to jump is known and relatively small.

FIG. 16 is a circuit block diagram showing still another modification of the example shown in FIG. 12, in which only the drive signal generating circuit 17 is shown as in FIG. 14. In this example as well, other blocks are omitted because they are connected and configured in the same manner as in the device of FIG. 12. In this example, the Q output a of the R-S flip-flop 29 is 3 inputs.
It is supplied to one input terminal of the AND gate 172 and the operational amplifier 181, resistors R ₉ , R ₁₀ , R ₁₁
It is supplied to the subtraction input terminal of an addition/subtraction circuit 180 consisting of. The Q output g of the monostable multi 174 is supplied to the addition input terminal of the addition/subtraction circuit 180. Then, the output of this addition/subtraction circuit 180 is output as a drive signal h.

In the above configuration, the gain A ₁ of the adder/subtractor circuit 180 with respect to the Q output a is −R ₁₁ /R ₉ . Also,
The gain A ₂ of the addition/subtraction circuit 180 for the Q output g is 1+R ₁₁ /R ₁₀ . Therefore, if R ₉ = R ₁₀ = R ₁₁ , the gains A ₁ and A ₂ will be -1 and 2, respectively, and a drive signal h similar to that of the device in FIG. 12 will be obtained, and the same as that of the device. This results in the following behavior. In this example, the circuit configuration is simplified, the number of parts can be reduced, and it is possible to reduce costs and improve reliability.

In the above embodiment, the counter 18 was used as the position detecting means, but a timer may also be used as the position detecting means. In addition, in the above embodiment, the inversion time of the monostable multi 174 is constant, but the inversion time of the monostable multi 174 is changed according to the output of the counter 20, so that the relative of the information detection point to the target track can be changed. It is conceivable to further stabilize the lock-in operation of the tracking servo by changing the braking force that reduces the relative moving speed of the information detection point depending on the position of the information detection point. Furthermore, if the 4-track detection circuit in the above embodiment is an M-track detection circuit that detects a relatively small number of tracks with value M, the value M can be set to any design value.

Although the optical information reproducing device has been described above, it is clear that the present invention can also be applied to a capacitive information reproducing device.

As described above, according to the present invention, the number of overrun tracks can be accurately detected, so that jumps to the target track can always be made appropriately, and the first track number can be accurately detected.
When used together with the device shown in FIG. 2, etc., the tracking servo at the end of the jump operation can operate stably, and the time required for the jump operation can be made constant.

[Brief explanation of drawings]

Figure 1 is a block diagram showing a conventional jump control system, Figure 2 is an operation waveform diagram of the block in Figure 1,
FIG. 3 is a block diagram of an embodiment of the present invention, and FIGS.
7 is a diagram for explaining the operation of the block in FIG. 3, FIG. 8 is a circuit diagram of a specific example of a part of the block in FIG. 3, and FIG. 9 is a waveform diagram of the operation of each part of the circuit in FIG. 8. , FIG. 10 and FIG. 11 are flowcharts showing the operating procedure of the blocks in FIG. 3, FIG. 12 is a block diagram of an information detection point relative speed control device suitable for use with the embodiment of the present invention, and FIG. 13. 12 is an operating waveform diagram of the block in FIG. 12, FIG. 14 is a partial circuit diagram of another example of the device in FIG. 12, FIG. 15 is an operating waveform diagram of the circuit in FIG. FIG. 3 is a partial circuit diagram of another example of the device shown in the figure; Explanation of symbols of main parts, 1...recording track,
2...Record information detection point, 8...Loop switch,
17... Jump signal generator, 20... Up-down counter, 25... Return detector, 26... Pseudo signal generator, 27... Count content determiner.

Claims (1)

[Claims] 1 A recording track jump control method in which a recording information detection point jumps over a predetermined number of recording tracks while opening a tracking servo loop in response to a jump command, which occurs when the information detection point crosses a recording track. means for counting the number of times a predetermined signal is generated and generating a difference signal according to the difference between the counted value and a predetermined value; and a reversal of the direction in which the information detection point traverses the recording track. means for detecting this and forcibly generating a pseudo signal of the predetermined signal, and controlling the counting direction of the number of occurrences in reverse, and controlling the jump operation of the information detection point according to the difference signal. A control method characterized by the following.