JPS63316375A - Moving distance detector for converting means - Google Patents

Abstract

PURPOSE:To accurately detect a moving distance and to rapidly retrieve a required track by counting up signals from a track crossing detecting means and signals from a rotation detecting means to detect the moving distance of a scanning point of a converting means. CONSTITUTION:When a signal from a synthesizing circuit 41 is inputted to the drain of an FET 51 by using the FET 51 and a capacitor 52 and an output from a synthesizing circuit 47 is inputted to the gate of the FET 51, a primary low pass filter (LPF) changing cut-off frequency in accordance with the voltage of the gate can be formed. Plural band pass filters (BPFs) or plural LPFs can be formed by combining said primary LPFs. When the speed of a carrying board 20 is detected by a signal outputted from a speed detector 21, the speed of a crossing track is detected and only the component of the crossing track is transmitted to a waveform shaping circuit, influence due to drop-out or the like can be reduced and more accurate track crossing signal detection can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an apparatus for rotating a disc-shaped record carrier having a spiral track and recording a signal on the track or reproducing the signal recorded on the track. In particular, it relates to a moving amount detection device for a converting means that detects the moving amount of the converting means for recording a signal on a track or reproducing a recorded signal when searching for a desired recording area. It is something.

BACKGROUND OF THE INVENTION As the above-mentioned devices, there are known devices that record signals on a record carrier or reproduce signals recorded on a record carrier using a light source such as a semiconductor laser.
In this type of apparatus, it is strongly required to search a specific recording area on a record carrier at high speed and record a signal or reproduce a recorded signal.

The conventional device includes a moving means for relatively moving the scanning point of the converting means in a direction substantially perpendicular to the track direction, and detecting that the scanning point of the converting means crosses the track when the moving means is driven. The amount of movement of the conversion means when searching for a desired track is determined by counting the signal of the track crossing detection means (for example, Japanese Patent Laid-Open No. 54-92155). Problem to be Solved by the Invention However, if the track on the record carrier is spiral, it is possible to move the track once per rotation without relatively moving the scanning point of the converting means and the record carrier. Because of this, even if the signals of the track crossing detection means are counted, the amount of movement of the scanning point of the conversion means cannot be accurately detected, resulting in a long search time.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a device that can accurately detect the amount of movement of the converting means with a simple configuration and can search for a desired track at high speed.

Means for Solving the Problems In order to solve the above problems, the present invention provides a rotating means for rotating a disc-shaped record carrier having a spiral track, and a rotating means for rotating a disk-shaped record carrier having a spiral track, and for recording a signal on the track. converting means for reproducing a signal; moving means for moving the scanning point of the converting means and/or the record carrier such that the scanning point of the converting means traverses the track; track crossing detection means for detecting that the carrier has crossed a track; rotation detection means for generating a pulse signal each time the carrier rotates once; and counting the signals of the track crossing detection means and the rotation detection means. and a movement amount detection means for detecting the movement amount by which the scanning point of the conversion means has moved.

According to the above-described structure, the scanning point of the converting means crosses the track as the record carrier rotates, and a track crossing signal is generated as if the scanning point of the converting means and the record carrier were moved relative to each other. However, since this is corrected by the signal from the rotation detecting means, the relative movement amount between the scanning point of the converting means and the record carrier can be accurately detected.

Example The present invention will be described in detail below with reference to the drawings.

Note that the same numbers are used for the same numbers used in the explanation of the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to an optical recording/reproducing apparatus. To explain the recording and reproducing of this device, a light beam 2 generated by a light source 1 such as a semiconductor laser is made into parallel light by a coupling lens 3, and then is converted into a disk-shaped light beam via a semi-transparent mirror 4, a reflecting mirror 6, and a converging lens 6. Reflected light 8 that is focused on the record carrier 7 (hereinafter referred to as a record disk) and reflected by the record disk is irradiated onto a photodetector 9 via a converging lens 6, a reflecting mirror 5, and a semi-transparent mirror 4. ing. Record disk 7
is attached to the rotating shaft 11 of the motor 1o and rotates. Since a spiral track is recorded on the recording disk 7 at a high density with a track width of 1 μm and a track width of 2 μm, the light beam focused on the recording disk 7 is controlled so that it is on the track. (Hereinafter, this control will be referred to as tracking control.) Tracking control is performed by obtaining the difference between the respective outputs of the photodetector 9 having a two-split structure using a differential amplifier 12, and driving this signal through a switch 13, a compensation circuit 14, and a drive circuit 16 to drive an element 16. This is done by rotating a reflecting mirror 6 attached to the recording disk γ to scan a light beam in a direction substantially perpendicular to the trunk direction on the recording disk γ. To detect when the light beam 2 focused on the recording disk γ deviates from the track, the dividing line direction of the photodetector 9 is set in the track direction of the track pattern included in the reflected light 8, and the photodetector The differential amplifier 12 obtains the difference between the outputs of the 9 outputs. The output of the differential amplifier 12 is also input to a compensation circuit 17 and drives a transfer motor 19 via a drive circuit 18.
The transfer table 20 linked to the transfer motor 19 is moved in the radial direction of the recording disk 7 so that the element 16 rotates around its natural state and the output of the pick drive circuit 15 becomes zero on average. control (hereinafter referred to as transfer control). The transfer table 20 includes a light source 1, a coupling lens 3, a semi-transparent mirror 4, a reflecting mirror 5, a converging lens 6, and a photodetector 9.
, the moving parts of the element 16 and the speed detector 21 are attached and configured to move together with the transfer table 2o. The speed detector 21 detects the moving speed of the transfer table 2o, and detects the speed magnetically, for example. The compensation circuit 14 compensates the phase of the tracking control system, and the compensation circuit 17 compensates the phase of the transfer control system. The signal of the speed detector 21 is transmitted to the drive circuit 18
is fed back to the transfer motor 19 via
Control of the transfer motor 19 is stabilized by controlling the speed.

The relationship between tracking control and transfer control is that tracking control is used to correct relatively high-speed track deviations such as eccentricity and vibration, and transfer control is performed so that the element 16 rotates around its natural state. is being carried out.

Switches 1-3 are used to disable tracking control and transfer control and to operate them. When switch 13 is open, the signal from differential amplifier 12 is transmitted to compensation circuit 14 and If the switch 13 is short-circuited, the tracking control and the transfer control are in operation.

1 on the track on the recording disk T from the inner circumference to the outer circumference.
2.3...N search for a desired track when address signals are recorded in sequence will be described. When the address B of a desired track is input to the address input device 22, the address input device 22 sends an address signal to the information processing control device 23. The information processing control device 23 passes through a combining circuit 24 that combines the respective outputs of the photodetector 9 and an address sampling circuit 26 that extracts the address signal from the output of the combining circuit 24, where the light beam 2 is currently located. Read track address A, calculate (A-B), and determine whether the absolute value of (A-B) is greater than or less than M (M is a positive integer). )M, the value of the movement amount detection circuit 26K (A-B) is preset through the line 1, and a start signal for starting the movement of the transport motor 19 is sent to the flip-flop 27 through the line L2. At the same time, the information processing control device 23 sends a movement direction signal to the movement amount detection circuit 26 through the line L3. 7 rip 70
The knob 27 sends a LOW signal for disabling tracking control and transfer control to an AND circuit 29, and the AND circuit 29 sends a LOW signal to the switch 13 to turn off the switch 13.
is opened, and at the same time, a HIGH signal is sent to the movement amount detection circuit 26 and the transfer signal generation circuit 28 through the line L4,
The counting operation of the movement amount detection circuit 26 is started, and the transfer signal generation circuit 28 is also operated. The count value of the movement amount detection circuit 26 is inputted to the transfer signal generation circuit 28 through the line L6, and the movement amount detection circuit 26 generates a signal corresponding to this count value, that is, a desired track and a light beam on the recording disk 7. A signal corresponding to the distance between the drive circuit 18 and the drive circuit 18 is generated, and this signal is transmitted to the drive circuit 18. The transfer signal generation circuit 28 generates a signal that determines the direction of movement of the transfer motor 19, for example (A
-B)) If 0, then the positive polarity signal, (A-B)<
In the case of O, a negative polarity signal is generated. Therefore, the transfer motor 19 moves the transfer table 20 at high speed in the direction of a desired track based on the signal from the transfer signal generating circuit 28. The respective outputs of the photodetector 9 and the output of the speed detection circuit 31 are input to the track crossing signal generation circuit 30.
When the light beam 2 crosses the track, a signal is generated, and this signal is transmitted to the movement amount detection circuit 26 and the jumping circuit 32 through the line L11. When the transfer motor 19 is driven to move the transfer platform 2o and the light beam 2 crosses the track, the movement amount detection circuit 26 adds the signal from the track crossing signal generation circuit 3o using the value (A-B) as an initial value. Or subtract. To explain further, in the case of (AB))O, subtraction is performed, and in the case of (A-B)<O, addition is performed.

The track crossing signal is counted, and when the value of the counting circuit becomes zero, the movement amount detection circuit 26 sends a coincidence signal to the flip-flop 27 and the information processing control device 23 through the line L6.

The flip-flop 27 sends a LOW signal to the movement amount detection circuit 26 and the transfer signal generation circuit 28 through the line L4, and stops the counting operation of the movement amount detection circuit 26.
Transfer signal generation circuit 2 for causing the transfer motor 19 to transfer
The generation of the signal No. 8 is stopped. Mana flip 70 tube 2
7 sends a HIGH signal to the AND circuit 29 during the cycle, short-circuits the switch 13, and operates tracking control and transfer control. The information processing control device 23 again reads the address A1 of the track where the light beam 2 is located, and determines that A1=B.
If so, end the search, if A1 and B do not match, calculate (A1-B), if 1A1-Bl>M, perform the above search, and if lAl-B15M, then , the value of 1A1-Bl through line L7, and the value of 1A1-Bl through line L8
The scanning direction signals are transmitted through the jumping circuits 32 and 32 respectively.
send to

As will be detailed later, the jumping circuit 32 is the AND circuit 2.
9 to disable the trunking control and transfer control, and at the same time apply an acceleration pulse to the drive circuit 16 to move the element 16, detect the middle of the tracks, apply a brake pulse, and again to the AND circuit 29. HIGH
A signal is sent to perform one jumping scan. The jumping circuit 32 has one jumping circuit 1iflA.
After repeating I-B once, a jumping end signal is sent to the information processing charge # device 23 through line L9. The information processing control device 23 reads the address A2 of the track where the light beam is located and ends the search if A2=B.

The above-described rough search (search performed by driving the transport motor 19) and fine search (search performed by moving the element 16) are repeated to search for a desired track.

The track crossing signal generation circuit 30 and the speed detection circuit 31 will be explained with reference to FIG. The track crossing signal generation circuit 30 includes a combining circuit 41 that combines the respective outputs of the photodetector 9, a filter circuit 42, and a waveform shaping circuit 43.
The output of the synthesis circuit 41 is input to the filter circuit 42, the output of the filter circuit 42 is input to the waveform shaping circuit 43, and the output of the waveform shaping circuit 43 is input to the movement amount detection circuit 26 in the first figure. and jumping circuit 32
has been entered. The speed detecting circuit 31 is composed of rectifying circuits 44 and 46, an inverting circuit 46, and a combining circuit 4. The output is rectifier circuit 4
6, the outputs of the rectifying circuits 44 and 45 are each input to a combining circuit 47, and the output of the combining circuit 47 is input to a filter circuit 42. Rectifier circuits 44 and 45
For example, the inverting circuit 46 is for inverting the input signals, and the synthesizing circuit 47 is for synthesizing the input signals. The filter circuit 42 changes the band through which the output signal from the combining circuit 41 passes, depending on the signal from the combining circuit 47. For example, as shown in Figure 3, FET51
By inputting the signal of the synthesis circuit 41 to the drain of the FET 51 and inputting the output of the synthesis circuit 47 to the gate using the capacitor 62 and the capacitor 62, a first-order low-pass signal whose cutoff frequency changes according to the gate voltage is generated. You can create filters. By combining these, it is possible to create any order band-pass filter or low-pass filter. By detecting the speed of the transfer platform 20 using the signal from the speed detector 21, detecting the speed of the crossing truck, and transmitting only the component of the crossing truck to the waveform shaping circuit, the influence of dropouts etc. can be reduced. , more accurate detection of the track crossing signal is possible.

Although removal of dropouts and the like has been explained in an analog manner in FIGS. 2 and 3, it can also be done digitally. This will be explained in conjunction with FIG. A combining circuit 61 combines the outputs of the photodetector 9 with the track crossing signal detection circuit 30, a waveform shaping circuit 62 forms the waveform of the signal of the combining circuit 61, and converts the signal of the waveform shaping circuit 62 into a signal of the speed detection circuit 31. It is composed of a monomulti 63 that shapes the waveform accordingly, and the output of the monomulti 63 is input to the movement amount detection circuit 26 and the jumping circuit 32. The time constant of the mono multi 630 is changed so that the pulse width of the mono multi 63 changes according to the signal from the speed detection circuit 31. Explaining with reference to FIG. 6, (a) is the output of the combining circuit 61, and (l) is the output of the first
The output of the differential amplifier 12 in the figure, (C) is the waveform shaping circuit 62
The output of (d) is the output of the mono multi 63, and even if there is a dropout 71, it is not output to the output of the mono multi 63, and the influence of dropout can be removed.

The combining circuit 41 in FIG. 2 and the combining circuit 61 in FIG.
The synthesis circuit 24 shown in the figure can also be used.

Furthermore, the combining circuits 41 and 61 can be differential amplifiers, and in this case, the differential amplifier 12 in FIG. 1 can also be used.

In addition, the output of the waveform shaping circuit 43 in FIG.
1, and the signal of this mono multi is input to the movement amount detection circuit 26.
By inputting the signal to the jumping circuit 32, it is possible to detect the track crossing signal more accurately.

It goes without saying that the present invention can also be applied to the case where the direction in which the light beam 2 traverses the tracks and the number of tracks traversed are detected from the output of the photodetector 9.

In FIG. 1, a signal from a rotation detector 33 that generates a signal every time the recording disk 7 or the motor 10 rotates is inputted to a movement amount detection circuit 26 through a line 1o, and the amount of movement due to the rotation of the recording disk 7 is detected. Errors are corrected, which will be explained in conjunction with FIG. The oscillation circuit 71 is a circuit that generates a signal of a predetermined frequency, for example, a 10 MHz two-phase rectangular wave signal, and the first phase signal is generated by D-type 7 lip-flops 72, 73 and 74
is input to the clock input terminal. The signal from the track crossing detection circuit 3o is passed through the line 11 to the D input terminal of the flip-flop 72, and the signal from the flip-flop 73 is coupled to the D input terminal of the flip-flop 73.
The signals No. 3 are input to the D input end of the flip-flop 74, respectively. Therefore, the signal from the cross-track signal generation circuit 3° is transmitted to the oscillation circuit 71 by the flip-flop 72.
The signal is shaped into a signal synchronized with the signal , and is further delayed by one clock by flip-flops 73 and 74. A
The ND circuit 76 receives a signal from an inverting circuit 77 that inverts the signal from the flip-flop 74 and a signal from the 7-lip-flop 73, and the AND circuit 76 receives a signal corresponding to the logical product of both signals, that is, a signal from the flip-flop 73. A pulse signal is output according to the rising edge of . AN
A signal from an inversion circuit 78 that inverts the signal from the flip-flop 72 and a second phase signal from the oscillation circuit 71 are respectively input to the D circuit 79, and the AND circuit 79 receives a signal corresponding to the logical product of both signals. Name flip flop 72
outputs a pulse signal from the oscillator 71 during the LOW state, and this signal is input to the clock input terminals of the D-type 7 lip-flops 80 and 81. Rotation detector 3
The signal of No. 3 is waveform-shaped by a waveform shaping circuit 82 and input to the D input terminal of the flip-flop 8o, and the signal of the flip-flop 80 is input to the D input terminal of the flip-flop 81. Therefore, the signal of the rotation detection circuit 33 is the flip 70 knob 8.
0 into a signal synchronized with the signal of the fiAND circuit 79, and further shaped into a signal synchronized with the signal of the fiAND circuit 79.
(to be precise, one rising edge period).

The AND circuit 83 receives a signal from the inverting circuit 8-4, which is the inversion of the signal from the flip-flop 81, and a signal from the 7-lip-flop 8o. P8
A pulse signal is output according to the rising edge of the 0 signal.

The -AND circuit signal and the second phase signal of the oscillation circuit 71 are input to the edge detection circuit 75, and the edge detection circuit 76 outputs a signal corresponding to the rising edge of the signal of the AND circuit 83. The edge detection circuit 76 has two D
-TYPE It can be easily configured with a flip-flop, an inversion circuit, and an AND circuit (for example, a configuration such as a flip-flop 80.81, an inversion circuit 84, and an AND circuit 83).

The AND circuit 85 receives the signal from the AND circuit 76 and the line L3.
The moving direction signal is input through the AN
D circuit 85 outputs a signal according to the AND of both signals.

Further, a signal from an inverting circuit 87' that inverts the moving direction signal and a signal from the AND circuit 76 are respectively input to the AND circuit 86, and the AND circuit 86 outputs a signal corresponding to the logical product of both signals.

The AND circuit 88 has the signal of the AND circuit 86 and the 2-in L4.
Signals for starting or stopping the counting operation are inputted through the line L4, and when the signal on the line L4 becomes HIGH, the signal from the AND circuit 85 is transmitted to the counting circuit 89. Further, the signal from the edge detection circuit 75 and the signal from the AND circuit 88 are respectively input to an OR circuit 9o, and the OR circuit 9o outputs a signal corresponding to the logical sum of both signals, and transmits this signal to an AND circuit 91. do. AND circuit 91 has O
A signal for starting or stopping the counting operation is input through the signal of the R circuit 9o and the line L4, and when the signal on the line L4 becomes HIGH, the signal of the OR circuit @90 is transmitted to the counting circuit 89.

When the track addresses on the recording disk 7 are recorded in order like 1, 2, 3...N, and the tracking control and transfer control are operated, the transfer table 20 moves from the outer circumference to the inner circumference. When the recording disk 7 is being rotated so that S is excited, the signal from the AND circuit 91 is input to the count-up input terminal of the counting circuit 89, and the signal from the AND circuit 88 is input to the count-down input terminal.

Therefore, when (A-B)>o, the moving direction signal of line L3 becomes HIGH, and the transfer table 2o is transferred from the inner circumferential direction to the outer circumferential direction, and the counting circuit 89 sets the value of (A-B) to the initial value. Each time a signal from the track crossing signal generation circuit 30 is generated, the count is counted down, and every time a signal from the rotation detector 33 is generated, the count is counted up. Also (A-B)<o
In this case, the moving direction signal of the line L3 becomes LOW, the transfer table 20 is transferred from the outer circumferential direction to the inner circumferential direction, and the counting circuit 89 uses the value (A-B) as the initial value and outputs the track crossing signal generating circuit 30. The signal from the rotation detector 33 and the signal from the rotation detector 33 are counted up.

The operation of the movement amount detection circuit 26 shown in FIG. 6 will be explained with reference to the timing chart shown in FIG. 7.

Waveform (a) is the amount of movement input through line L3
The direction signal waveform is shown, and the HIGH state indicates the transfer table 20.
shows a state in which it is moving from the inner circumferential direction to the outer circumferential direction of the recording disk 7, and a LOW state indicates a state in which it moves from the outer circumferential direction to the inner circumferential direction. Waveform (b) is the first phase signal waveform of the oscillation circuit 71, waveform (C) is the signal waveform of the trunk crossing detection circuit 3o, and waveforms (d), (e) and (f) are the signal waveform of the flip-flop. 72, 73 and 74 are shown, respectively. Waveform (q) is AND circuit 7
6, the signal from the AND circuit 76 generates a pulse signal at the rising edge of the flip-flop 73.

waveform) shows the second phase signal waveform of the oscillation circuit 71, which has a different phase from the first phase signal (waveform (b)). Waveform (i) is the signal waveform of the AND circuit 79,
Waveform 0) is the signal waveform of the waveform shaping circuit 82, and waveform (1c
) shows the signal waveform of the flip 70 and the tip 80, and waveform ν) shows the signal waveform of the edge detection circuit 76, respectively. If the pulse width of the signal from the waveform shaping circuit 82 (waveform (1)) is extremely narrow, that is, it is narrower than the sum of the pulse width of the signal from the 7-resop flop 72 and twice the period of the clock of the generation circuit 71. In some cases, a pulse signal may not be generated in the edge detection circuit 75.Therefore, the signal width of the rotation detection circuit 33 requires a certain amount of time.However, since it is difficult to make it very long, It is desirable to shorten the signal width of the detection circuit 30.

To achieve this, the rising edge or falling edge of the signal of the waveform shaping circuit 43 in FIG. 2 or the monomulti 63 in FIG. 4 may be detected and the signal width may be shortened.

Waveform (n) shows the signal waveform of the AND circuit 88, and waveform (n) shows the signal waveform of the AND circuit 91. Even if the signal from the track crossing detection circuit 30 and the signal from the rotation detector 33 occur at the same time, they are accurate. This indicates that the counting circuit 89 is operated.

The operation of the movement amount detection circuit 26 has been explained above under certain conditions. For example, when the tracking control and transfer control are operated, when the transfer table 20 moves from the inner circumferential direction to the outer circumferential direction, the movement It is necessary to invert the polarity of the direction signal and input the signal from the AND circuit 88 to the count-up input terminal of the counting circuit 89 and the signal from the AND circuit 91 to the count-down input terminal.

That is, in the case of (A-B))O, the moving direction signal of line L3 is set to LOW, and when the transfer table 20 is transferred from the inner circumference to the outer circumference, the counting circuit 89 calculates the value of (A-B). As an initial value, both the signal of the track crossing detection circuit 3o and the signal of the rotation detector 33 are counted down, and (A-
B) (In the case of O, the moving direction signal of line L3 is
In the iH state, when the transfer table 20 is transferred from the outer circumference to the inner circumference, the counting circuit 89 sets the value of (A-B) as the initial value,
The configuration is such that the signal from the track crossing detection circuit 3o is counted up and the signal from the rotation detector 33 is counted down.

In other words, when the transfer table 2o moves in the direction of movement of the spiral track on the recording disk 7, the signals from the rotation detector 33 are counted so that the distance to the desired track becomes small, and the When the transfer table 20 moves in the direction opposite to the direction of movement of the spiral, the rotation detector 33 is set so that the distance to the desired track becomes large.
It may be configured to count the signals of .

The jumping circuit 32 for performing accurate fine retrieval will be explained with reference to FIG.

The oscillation circuit 101 generates a rectangular wave signal of a predetermined frequency,
The frequency dividing circuit 102 is a frequency dividing circuit that divides the frequency of the signal from the oscillation circuit 101. The counting circuit 103 is configured such that the number of fine searches is set by the information processing control device 23 of FIG. The comparator 104 is a bit controller that compares the output of the counting circuit 103, and is configured to output a LOW signal when the output of the counting circuit 103 is zero, and output a HIGH signal when the output is not zero. .

The signal from the rotation detector 33 is input to the waveform shaping circuit 105, and the waveform shaping circuit 105 shapes the waveform of the signal from the rotation detector 33. The signal of the waveform shaping circuit 105 is input to the monomultis 106 and 107, respectively, and the monomultis 106 and 107 output all the signals that are in a HIGH state for a predetermined period in synchronization with the rising edge of the signal of the waveform shaping circuit 105. . Monomulti 106 and 107 HIGH
If the period in which the state occurs is t11t2, then t=2
It is set to be t2.

The signals of the frequency dividing circuit 102, the comparator 104, and the NOR circuit 109 are input to the AND circuit 108, respectively.
A signal corresponding to the logical product of three input signals is output.

When the number of fine searches is set in the counting circuit 103, the output of the comparator 104 becomes HIGH, and the NOR circuit 109
When the output of is in the HIGH state, the AND circuit 108 transmits the frequency divider circuit 102(7) signal to the D input terminal of the D-TYPE flip-flop 110.

The oscillator 1 is connected to the clock input terminal of the slip 70 and the clock 110.
01 signal is input, flip 70 knob 110
outputs a signal obtained by delaying the signal from the AND circuit 108 by one clock. The signal of the flip 70 knob 110 is the counting circuit 1
03 and the monomulti 111, the counting circuit 103 counts down by one, and the monomulti 111id
It is in a HIGH state for a predetermined period in synchronization with the rising edge of the 70 lip 110. The period of this HIGH state is approximately equal to T2. Mono multi 111 signal is NO
It is input to the R circuit 109, and when the output of the monomulti 111 becomes HIGH, the output of the NOR circuit 109 becomes L.
The state is OW, and the signal from the frequency divider circuit 102 is not transmitted to the flip-flop 110.

The signal from the monomulti 106 is also input to the NOR circuit 109, and when the output of the monomulti 106 is in a HIGH state, the output of the NOR circuit 109 is in a LOW state.
Similarly, the signal of the frequency divider circuit 102 is applied to the flip-flop 1.
10 is not transmitted.

The signal of the slip 70 and the direction signal of the fine search are inputted to the AND circuit 112 through the line L8. In addition, the AND circuit 114 is connected to an inverting circuit 113 in which the signal of the flip-flop 110 and the direction signal of the fine search are connected to the AND circuit 114.
The inverted signals are input respectively.

The track addresses on the recording disk 7 are 1, 2, 3, etc. from the outer circumference to the inner circumference. ...N, and the recording disk 7 is rotated so that the spiral of the track moves from the outer circumference to the inner circumference, then when jumping in the direction of the larger address, The direction signal of the line L8 is set to HIGH state, and the pulse signal of the flip-flop 110 is passed through the AND circuit 112 to the scanning circuit 115.
input to the up input terminal of. The scanning circuit 116 generates an acceleration pulse to move the element 16 from the outer circumference toward the inner circumference through the line L12, and sends a signal for disabling tracking control and transfer control to the AND circuit 29 through the line L13.

The intermediate point between the tracks is detected through the line L11, a brake pulse to immediately stop the movement of the element 16 is sent to the drive circuit 16 through L12, and then a signal to operate the tracking control and transfer control again is sent to the AND circuit 29. Send him to do one jump.

When jumping in the direction of a smaller address, the direction signal on the line L8 is set to LOW, and the pulse signal of the flip-flop 110 is transferred to the AND circuit 114 and the OR circuit 1.
16 to the down input terminal of the scanning circuit 116. The scanning circuit 116 generates an acceleration pulse to move the element 16 from the inner circumference to the outer circumference through the line L12, and sends a signal for disabling tracking control and transfer control to the AND circuit 29 through the line L13.

The intermediate point between the tracks is detected through the line L11, a brake pulse to immediately stop the movement of the element 16 is sent to the drive circuit 15 through L12, and then a signal is sent to the AN to activate the tracking control and transfer control again.
The signal is sent to the D circuit 29 to perform one jump.

When the value of IA-Bl is preset in the counting circuit 103, the above-mentioned one-line jumping is repeated once 1A-B.

Mono multi 117 is a retriggerable mono multi,
It is in a HIGH state for a predetermined period in synchronization with the rising edge of the clip-flop 110, and one jumping
-B, it is set so that the HIGH state continues during the period in which it is performed once.

When one jump of IA-B is performed once, the output of the monomulti 117 becomes LOW, and the information that the dense search has been completed is sent to the information processing control device 23 through the line L9.

Since the track on the recording disk 7 has a spiral shape, when the tracking control and the transfer control are operated, the transfer table 20 moves in the direction in which the spiral travels.

In the embodiment of the present invention shown in FIG. 1, still control is performed so that the light beam 2 on the recording disk T always scans the same track, that is, the same circumference in a normal state.

This still control is performed in accordance with the signal from the rotation detector 33 so that each time the recording disk 7 makes one revolution, the recording disk 7 jumps one line in the direction opposite to the direction in which the spiral travels and scans on the same track.

To further explain with reference to FIG. 8, the mono multi 118 generates a pulse signal in response to the rising edge of the mono multi
By transmitting the signal to the down input terminal of the rotation detector 33, one track is jumped in the direction opposite to the direction in which the track spiral travels each time the signal from the rotation detector 33 is generated.

To explain the still control and dense search during a dense search, when a signal is generated in the rotation detector 33, the output of the monomulti 106 is in a HIGH state, and the output of the NOR circuit 109 is in a LOW state.
state, and the signal from the frequency divider circuit 102 is transferred to the flip-flop 1.
Since the signal is not transmitted to the flip-flop 110, a fine search is not performed. When jumping for still control is completed and the output of the monomulti 106 becomes LOW, the signal from the frequency dividing circuit 102 is transmitted to the flip-flop 110, and a fine search is performed.

Therefore, it operates as if it were composed of concentric tracks, and errors due to the rotation of the recording disk 7 do not occur, so accurate and high-speed fine retrieval can be performed.

The operation of the jumping circuit 32 shown in FIG. 8 will be further explained with reference to the timing chart shown in FIG. 9.

FIG. 9 shows a timing chart when the frequency dividing ratio of the frequency dividing circuit 102 is set as a bar and four dense searches are performed in the spiral direction of the track. , waveform (B) show the signal waveforms of the frequency dividing circuit 102, respectively. Waveform q is the signal waveform of the waveform shaping circuit 105, waveform q is the signal waveform of the monomulti 106, waveform (2
) shows the signal waveform of the mono multi 107, and waveform (g) shows the signal waveform of the mono multi 118, respectively. Furthermore, waveform q is the signal waveform of the AND circuit 108, waveform □ is the signal waveform of the flip-flop 110, and waveform (I) is the signal waveform of the monomulti 110.
1, waveform (a) shows the signal waveform of the NOR circuit 109, waveform (a) shows the signal waveform of the AND circuit 112, and waveform (-) shows the signal waveform of the OR circuit 116, respectively.

The period t3 of the HIGH state of the monomulti 111 is t2=t
3 and t3 is set to be longer than the operation time of one-line jumping, a very stable and dense search can be performed.

As is clear from FIG. 9, even if jumping for a dense search is performed immediately before the signal from the rotation detector 33 is generated, the setting is such that t, = 2t2, After the jumping is performed stably, the still control jump is performed, so that a very stable and accurate detailed search can be performed.

In FIG. 9, the waveform (T) indicates the signal waveform of the monomulti 117, and the waveform line indicates the signal waveform of the differential amplifier 12 in FIG. Waveform N shows a waveform that jumps to the next track due to jumping, and 121 shows a waveform during still control.

In the case of fine search, it can be performed with the same configuration as coarse search. In other words, when performing a dense search, the steal control is disabled and the value (A-B) is preset in the counting circuit, and when jumping in the advancing direction of the track spiral, the rotation is performed so that the number of tracks up to the target track is reduced. A counting circuit counts the signals of the rotation detector 33, and on the other hand, when the track is caused to jump in the direction opposite to the direction in which the spiral travels, the signal of the rotation detector 33 is counted so that the number of tracks to the target track increases. may be operated, and the still control may be operated after the dense search is completed.

Further, even when the fine search is not performed by jumping one line at a time but by jumping many lines at once, accurate fine search can be performed by using the same configuration as the coarse search.

The present invention is not limited in any way by the embodiments, and can be applied to magnetic recording and reproducing devices, magneto-optical recording and reproducing devices, and the like.

Effects of the Invention By applying the present invention, when a record carrier having a spiral track is used and a desired track is searched by detecting that the scanning point of the converting means on the record carrier traverses the track, the recording Since detection errors in the amount of movement of the scanning point of the conversion means caused by rotation of the carrier can be removed, accurate and high-speed searches can be performed.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a block diagram of the track crossing detection circuit 3o and speed detection circuit 31, FIG. 3 is a block diagram of the filter circuit 42, and FIG. 4 is a track crossing detection circuit. Another block diagram of the circuit 3°, FIG. 6 is a timing chart for explaining the operation of the block diagram of the cross-track detection circuit 30 of FIG. 4, FIG. 6 is a block diagram of the movement amount detection circuit 26, 7 is a timing chart for explaining the operation of the movement amount detection circuit 26 of FIG. 6, FIG. 8 is a block diagram of the jumping circuit 32, and FIG. 9 is a diagram for explaining the operation of the jumping circuit 32 of FIG. 8. This is a bad timing chart. 1... Light source, 7... Recording disc, 9...
...Photodetector, 1o...Motor, 15.1
8...Drive circuit, 19...Transfer motor, 2o...Transfer table, 21...Speed detector, 22...Address input Device, 23...
Information processing control device, 26...address extraction circuit, 26...movement amount detection circuit, 28...
Transfer signal generation circuit, 3o...Track crossing signal generation circuit, 32...Jumping circuit, 33
...Rotation detector. Figure 2 L, t, J Figure 3 I Figure 4 Figure 5 :::: ” : (d) 'jS6@O+
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Claims (1)

[Claims] (1) a rotating means for rotating a disc-shaped record carrier having a spiral track; a converting means for recording a signal on the track or reproducing the recorded signal; a moving means for relatively moving in a direction substantially perpendicular to the track direction; a track crossing detecting means for detecting that a scanning point of the converting means crosses the track when the moving means is driven; A rotation detecting means generates a pulse signal each time the carrier rotates once, and the amount of movement of the scanning point of the converting means is detected by counting the signal of the track crossing detecting means and the signal of the rotation detecting means. 1. A movement amount detection device for a conversion means, comprising a movement amount detection means.