JPS60182568A - Position controller of information recording and/or reading means - Google Patents

Abstract

PURPOSE:To control highly stably and precisely the movement of a head without bad influences of contraction and skew of a recording material by controlling the head position by digital signal processing. CONSTITUTION:A detecting mechanism part 10 provided with a light emitting part 21 constituting a photo encoder together with an optical scale 9, half mirror 23, light receiving parts 27 and 28, etc. is moved in the radial direction of a disc in one body with the head. Interrupted pulses are generated from light receiving parts 27 and 28 in accordance with two optical spots passing the scale 9, and a clock pulse generating circuit 11 generates clocks different by 90 deg. in phase where lead and lag are inverted in accordance with the head moving direction. One or the other clock is counted up or down by a counter in accordance with the head moving direction until the counted value reaches a set value corresponding to a target position, and thus, a position error detecting potentiometer is not used to control the moving position of the head in the disc radial direction stably with high precision without bad influences of contraction and skew of the disc by digital processing.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is useful for recording emotions on a disc-shaped recording medium, for reproducing information recorded on a disc-shaped recording medium, or for reproducing information recorded on a disc-shaped recording medium. In a device (hereinafter referred to as a disk player) in which a disk-shaped LA medium is installed and used for both recording information on the medium and reproducing information from the disk-shaped recording medium, a disk-shaped recording medium is used. A head which moves an information recording and/or reading means (hereinafter referred to as a head) disposed opposite to the disk in the radial direction of the disk-shaped recording medium to a desired position on the disk-shaped recording medium. The present invention relates to a position control device.

BACKGROUND TECHNOLOGY AND PROBLEMS The screw 15 is prepared in advance, for example by irradiating a light beam modulated by information, in a rotated state:
C-shaped recording 1 - A writable optical disc, which is a disc-shaped recording medium that allows information to be optically recorded along a rack part, or a rotating disc-shaped recording medium, is digitized. In digital audio discs, etc., in which the recorded audio signals are recorded so as to be optically readable as information, and a spiral recording trunk is formed, there is a recording track section on which information is to be recorded, and a recording trunk where information is to be recorded. Address information is recorded on the recorded recording track at a location on the disk that is distinguished from information to be recorded or reproduced. Therefore, in a disc player that is loaded with such a writable optical disc, digital audio disc, etc. and performs a recording operation or a reproducing operation, the above-mentioned address 1'r? Using n,
Information can be recorded or reproduced from any location on the disc. And for this reason,
It is necessary to control the position of the head, which is placed facing the disk and directly participates in recording information on the disk and reading information from the disk, in order to move it in the radial direction of the disk and position it at an arbitrary location on the disk. It is said that

Conventionally, such head position control in a disk player involves arranging a potentiometer whose movable terminal is moved in conjunction with the radial movement of the head on the disk, and controlling the radial position of the head on the disk. The output of the potentiometer is detected by the output of the potentiometer, and the target position on the disk where the head should be positioned is compared with the target value. This is carried out by a control system configured to operate and increase the driving means for moving in the direction,
Alternatively, a pulse generating device using light called a photoencoder is arranged, and this photoencoder determines the position ij'7 on the disk in the radial direction. is taken as the distance from the reference position and the number of pulses corresponding to that distance is obtained, and these pulses are counted by a counter and the counting result obtained from the number of photo encoders corresponding to the target value is calculated without detecting the target position. A target value pulse corresponding to the pulse is generated, and this 1" target value pulse is counted by a counter and compared with the 1i1 number result obtained. Based on the comparison result, the head is moved in the radial direction of the disk. This is carried out by a control system that operates the driving means for causing this.

However, when the above-mentioned former control system is adopted in such conventional control, the position iξ of the head is detected by a potentiometer, so the position iξ detection accuracy is low, and an analog signal processing circuit is used. However, there are disadvantages such as not being able to control the position of the head with high precision, and noise being generated from the sliding resistance of the potentiometer, or the lack of stability as a control system due to the low durability of the potentiometer. . In addition, when the latter control system described above is adopted, the head position is always determined as the distance Ult from the fixed memorial service position, so the effects of disk contraction and disk surface elongation (skew) are eliminated. This has the disadvantage that control becomes inaccurate when a disk that has shrunk or is skewed is mounted.

OBJECTS OF THE INVENTION In view of the above, the present invention provides a disc player that is highly accurate due to digital signal processing and that reduces the shrinkage and gap of the disc-shaped recording medium. - It is possible to control the position related to the movement of the head in the radial direction of the disk-shaped recording medium while the influence of It is our intention to provide a control device.

The position control device according to the present invention includes a drive unit that moves a head disposed facing the disk-shaped recording medium 1iiJ4 times in the radial direction of the disk-shaped recording medium. and the radial displacement of the disk-shaped recording medium of the head fsJ
When G is carried out in the first direction, the number of first pulses corresponding to the moving distance is generated, and when G is carried out in the second direction, the number of second pulses corresponding to the moving distance is generated. The pulse generator receives the position designation data and obtains the difference data between the device designation data and the position data for the position of the head on the disk-shaped recording medium, and transmits this difference data to the pulse generator. The system which sends out the corresponding numerical data due to the double series of first or second pulses from the
In addition to the control, there is also a presecpull counter that performs a count amplifier or a countdown to bring the counting result toward zero each time the first or second pulse of Jl jl < obtained from the pulse generator arrives, and a presettable counter. 51 of the counter is supplied, and a voltage generating section generates a driving voltage having a polarity and level corresponding to the counting result and supplies it to the driving section. Then, the drive unit or head is applied to a drive voltage and moved in a direction according to the polarity, and the disk-shaped recording medium-1-
It operates so that the position designation data does not correspond to the position.

By doing this, the drive signal for moving the head in the radial direction of the disk-shaped recording medium is also used for digital signal processing, so highly accurate control can be performed, and the control Since the driving conditions for the disk-shaped recording medium are set based on the relative difference between the position of the disk-shaped recording medium and the target position, shrinkage and skew of the disk-shaped recording medium cannot be controlled and are not affected. It can be made extremely small.

Example 1. Please see the diagram! 1,<! l, -iZ Four examples of B,':, and III of the present invention will be explained.

The 1st I is the tree block Aki Otsuko (elephant roheno 1 position side '<'J
An example of an optical disc player is shown below, and the example is applied to an optical disc player. Saw disk l is, for example &amp; plcrum 1'+'i (4
j and address l+'th u, etc., are said to be recorded with a spiral Jjc-shaped recording track so that they can be read out optically P, and each piece of information is recorded on an optical hemometer placed opposite to this disc i. (・Read by 2.Optical・＼7
1 and 2 are, for example, beams of light beams such as laser beams 2 to another disk 1, a recording track of disk 1, and a beam (modulated and reflected light beam J). Light detection: (
)) to produce read output. Therefore, this is the point where the light beam from the optical head 2 reaches the disk 1''2, or the position 3,'5 where the optical head 2 picks up the disk 1''2. The optical head 2 properly tracks the optical beam entering the disk 1 to the 1.1 1-rank (iL
It has a built-in racking control means 7 for tightening the racking error, and this racking control means detects the racking error 1 from the read output from the optical taper of 12.
The output of the detection circuit 3 is as follows. ; is connected to the I/racking control circuit 4, and trasokink/repo control is performed.

This optical stylus [2 is moved by a motor 5 in the radial direction of the disk 1, that is, in the direction of cutting the recording track. The motor 5 is controlled by a motor control circuit 7 which is supplied with a drive voltage Vd having a predetermined polarity and level from a digital/analog conversion circuit [j]. As the motor 5 is rotated by the motor control circuit 7, the optical head 2 moves in the radial direction of the disk 1 depending on whether the polarity of the drive voltage Vd is positive or negative. The innermost circumference side of the screw J::I knee-shaped recording track, 1111
1, 1[starting point:; from the 1st part side to the outermost peripheral part side, that is,
il life end ◇:i; towards the part side (hereinafter referred to as positive direction), or the opposite direction (hereinafter referred to as negative direction)
It will be sent with

In order to detect the movement of the optical head 2, a photo sensor is used:
An optical scale 9 extending in the radial direction of the disk 1 along the movement path of the optical head 2 moves integrally with the optical head 2. A detection mechanism section 1O is arranged as shown in FIG.
The result was +117. Then, when it moves from the detection mechanism section 10 to the optical system, two pulse train signals a and b having a phase difference of 90 degrees from each other are generated. For example, when the optical head 2 moves in the positive radial direction of the disk 1, the phase of the pulse train signal a leads the phase of the pulse train signal a by 90 degrees. , on the contrary, moves with a negative direction - old, pulse train 15
The phase of the signal is obtained as being 90 degrees ahead of the phase of the pulse train signal a, and is supplied to the clock pulse generation circuit 11. The clock pulse generation circuit 11 generates a pulse train signal η
When the phase of the pulse train signal a leads the phase of the pulse train signal A, the first pulse i is emitted, and when the phase of the pulse train signal A leads the phase of the pulse train signal a, the second pulse i is emitted.
A clock pulse j is generated. And these, the first
and the second black, Kubals i and j, gate circuit 12
are supplied to the down count terminal and up count terminal U of the presettable counter 13 as a down count 1 clock pulse and an amplifier count 1 clock pulse, respectively.

A specific example of the photo encoder 8 and clock pulse generating circuit 11 described above is constructed as shown in FIGS. 2A and 13. First, as shown in FIG. 2A, the optical scale 9 of the first encoder 8 has a reflective surface portion 9a and a slit 9b having the same width.
They are said to be arranged alternately along the movement path of
Two light beams from the detection mechanism section IO are irradiated onto the irregular surface section 9a and the arrangement section of the Surins 1 to 9b. These two light beams are transmitted to the irregular surface portion 9a on the optical scale 9.
Alternatively, spots Pa and Pb having an interval of 172 times the width of the slit 9b are formed. As shown in FIG. 2, the detection mechanism unit 10 that forms the spots Pa and Pb on the optical scale 9 includes a light source 21 such as a half-λq body laser element, and a light beam emitted from the light source 21. The diffraction grating 22. Beam splitter 23
．． A collimator lens 24, a 1/4 wavelength plate 25, and an objective lens 26 are arranged to form a beam of ζ47.1, and the light beam from the light source 21 is focused onto the optical scale 9 by the objective lens 26. In this case, due to the presence of the diffraction grating 22, the light A
The two first-order diffracted light beams (zl) for the light beam from j21 are focused on the optical scale 9 to form spots Pa and pb. 4 is reflected by the reflective surface portion 9a of the optical scale 9, and is reflected again by the objective lens 2.
6 and 174 return through the wavelength plates 25, are refracted by the beam sprinkling 23, and are transmitted to the light receiving elements 27 and 2, respectively.
Enter 8.

Under such an optical arrangement, when the detection mechanism section 10 moves along with the movement of the optics/nose 2, two spots P a and P b on the optical scale 9 are moved to the reflective surface section 9a.
and move in the arrangement direction of Surin 1-9b, reflecting surface portion 9a
Reflections occur intermittently. Therefore, the light receiving elements 27 and 28 intermittently receive the two first-order diffracted light beams forming the spots Pa and Pb, and as a result, the pulse train signal a
and b are generated. At this time, pulse train signals a and b o
)4s7 phase difference is Subol-P a on optical scale 9
In this case, since the distance between Subono) Pa and pb is 172 mm, which is the width of the irregular surface portion 9a and the slit 9b, the mutual phase difference between the pulse train signals a and b is 90 degrees.

The pulse train signals a and b obtained in this way are supplied to the clock pulse generation circuit 11. For example, as shown in FIGS. 3A and 3B, the phase of the pulse train signal a is higher than the phase of the pulse train signal If the pulse train signal a is advanced by 90 degrees, the pulse train signal a is output to the exclusive OR circuit 30.
, :Ai and is also supplied to a delay circuit 31, from which a delayed pulse train signal C as shown in FIG. is supplied to one input end of the .

In addition, the pulse train signal is an exclusive OR circuit 3.
2 is supplied to the other input terminal and the first one is delayed ;)
33, a delayed pulse train signal d as shown in FIG. As a result, exclusive OR circuits 30 and 32
From these, pulse train signals e and g are obtained as shown in FIGS. 1i and 3, respectively. The pulse train signal e is supplied to one input terminal of the AND circuit 34 and is also supplied to the inverter 35, from which an inverted pulse train signal f as shown in FIG. is supplied to the input end of Further, the pulse train signal g is supplied to the other input terminal of the AND circuit 36 and is also supplied to the inverter 37, and an inverted pulse train signal g as shown in FIG. 3H is obtained from the inverter 37. is supplied to the other input end of the .

As a result, the first clock pulse l as shown in FIG. 3 is obtained from the AND circuit 34, and no pulse as shown in FIG. 3J is obtained from the AND circuit 36.

On the other hand, as shown in FIGS. 4A and 4B, when the phase of the pulse train signal S is 90 degrees ahead of the phase of the pulse train signal a, the pulse train signal a and the pulse train signal are supplied to the delay circuit 33 and The delayed pulse train signal d as shown in the fourth diagram is sent to the exclusive OR circuit 30.
A pulse train signal e as shown in FIG.
is obtained, and the delayed pulse train signal C as shown in FIG. A pulse train signal g as shown in FIG. 4G is obtained. Then, these pulse train signals e and g are supplied directly or via inverters 35 and 37 to AND circuits 34 and 36 as inverted pulse train signals f and 11 as shown in FIG. 4F and H. , from the AND circuit 34 there are no 11 clock pulses shown at 41'AI +, but from the AND circuit 36 a second clock pulse j as shown at 41st father 1.1 is obtained.

1 to run 5 from running error detection circuit 3
The tracking error is also supplied to the low-pass filter 14, and the tracking error is output from the low-pass filter 14.
A low frequency component of the error signal is obtained and supplied to the pulse generation circuit 15. Then, third and fourth clock pulses i' and j' are obtained from the pulse generation circuit 15 in accordance with the fluctuation of the low-frequency component of the tracking error signal from the low level side to the high level side. - is supplied to the gate circuit 12. These third and fourth clock pulses B and j are supplied from the zero output terminal Z of the presettable counter 13,
After the presec pull counter 13 is preset, it is counted down or counted up, and the output signal Z is sent out when the counting result becomes zero.
'h<When obtained, down count 916 child I of presettable counter 13 via gate circuit 12]
and Amp Karan) 3jj, j child (supplied to J.

Furthermore, clearing presettable counter 13◇:
h: The output from the reproduction start edge detector 16 is supplied to the child C via the OR circuit 17. The reproduction start end detector 1G detects when the optical head 2 is positioned at the reproduction start end, for example, by mechanical or optical contact with a retaining part provided on the optical head 2, and outputs a detection output. will occur. As a result, when the optical head 2 is located at the reproduction start end, the presec pull counter 13 is cleared by the output from the reproduction start end detector 16, and the initial 1υ1 setting is performed.

On the other hand, the read output from the photodetector of the optical head 2 is supplied to a reproduced information signal detection circuit 40, and a reproduced information signal is obtained at its output terminal. This reproduction information signal is sent to the decoder 4
1, and in the normal playback state, the decoder 4
1, reproduction program information Sp and reproduction address information Q are obtained. The reproduction program information QilSp is supplied to a program information processing circuit 42, and a reproduction program 1 and an information signal are obtained at its output side. Further, the playback address 11'tleQ is supplied to the P+'i reading circuit 43, and this decoding circuit 43 is supplied with the read address 11'j+uc.
Is there any address data? is obtained and supplied to the input terminal n2 of the system control unit 44.

In addition, system computer 1 ~ roll part 44 human power 0ii
A command signal generator 45 is connected to the t-wire n1, and when the command signal generator 45 is operated, the position designation data (■) specifying the position of the optical head 2 on the disk 1 is sent to the system control unit 44. supplied to system con 1
When the position designation data I is supplied, the Ll-ru section 44 calculates the difference data between this position designation data and the address data R supplied to the input terminal n2 at that time, and calculates the difference data. It sends out to the launch circuit 4G as numerical data Dx corresponding to the number of first or second clock pulses i or j from the clock pulse generation circuit 11, and also sends a clear signal W via the OR circuit 17. The signal is supplied to the clear terminal C of the presettable counter 13 to clear the presettable counter 13.

The numerical data Dx sent to the latch circuit 46 is supplied to the presettable counter 13 and preset by sending an i-code signal from the system controller 44.

The output terminal of the presettable counter 13 is connected to the input terminal of the digital/analog conversion circuit 6, and the counting result Dd of the presettable counter 13 is sequentially supplied to the digital/analog conversion circuit 6 to convert it into a digital signal. /A driving voltage Vd having a level corresponding to the counting result Dd is obtained from the analog conversion circuit 6. Furthermore, from the polarity determination terminal 1) of the presettable counter 13,
A polarity discrimination signal PL corresponding to the polarity of the numerical data Dx sent from the launch circuit 46 and preset is obtained and supplied to the digital/analog conversion circuit 6, whereby,
The polarity of the drive voltage Vd corresponds to the polarity of the preset Dx in the presettable counter 13.

Based on this configuration, when an operation is performed to move the optical head 2 to a position corresponding to a desired position on the disk 112, a command signal is sent from the 3/:1 part 45 to the optical head 2. Position designation data (2) designating the target position of the disk 11- to be reached is sent to the input terminal n1 of the system control unit 44. As a result, the system control unit 44 determines that the optical head 2
The reproduction address information i13Q obtained based on the ak output from the disk 1 in 11) is supplied to the decoding circuit 43 to obtain the optical head 2 on the disk I at that time.
address data R and position specification data I.
The data of the difference between j and the radial direction of the disk 1 from the current position of the optical head 2 to the target position: ? + Fortune 1
The difference data is converted into numerical data Dx corresponding to the number of first or second clock pulses i or j from the clock pulse generation circuit 11.

At this time, for example, if the target position is farther than the position of the optical disc 2 when viewed from the innermost end of the recording 1 rack of the disk L, the polarity of the numerical data Dx will be positive,
If the current position of the optical head 2 is far from the target position, the polarity of the numerical data l)x is set to be negative. This memory data I)x is sent to the launch circuit 46.

In addition, the clear signal W from the system I, the control unit 44 is supplied to the clear terminal C of the presettable counter 13 via the OR circuit 17, and
Counter 13 is cleared. After that, System J...
A load signal is sent from the control unit 44, and a t/J. Value data I) x is supplied to the presettable counter 13 and precented.

Here, assuming that the polarity of the numerical data Dx is positive, first, the counting result Dd from the presettable counter 13
corresponds to the numerical data Dx and is supplied to the digital/analog conversion circuit 6, and the polarity determination signal PL becomes a signal indicating positive polarity and is converted into a digital/analog converter.
The signal is supplied to the analog conversion circuit 6. Therefore, a drive voltage Vd of positive polarity and a level corresponding to the numerical data Dx is obtained from the digital/analog conversion circuit 6. Then, the motor 5 is driven based on this drive voltage Vd,
The optical head 2 is moved in the positive direction together with the detection mechanism section 10 of the photo encoder 8. As a result, the pulse train signals a and b are obtained from the detection mechanism section 10 in a state where the phase of the pulse train signal a is 90 degrees ahead of the phase of the pulse train signal S. As a result, the clock pulse generation circuit 1
1, the first clock pulse i is obtained, and the presettable counter 13 is down-loaded via the gate circuit 12.
Supplied to the count terminal. At this time, the third or fourth clock pulse i' or jo from the pulse generating circuit 15 is stopped by the gate circuit 12 and is not supplied to the presettable counter 13. By supplying this first clock pulse i, the presettable
Preset numerical data Dx in counter 13
The count result Dd gradually decreases, and the level of the drive voltage Vd also decreases accordingly.

Thereafter, when the first clock pulses i of the number corresponding to the numerical data Dx are supplied to the down count terminal of the presettable counter 13 to perform counting down, the counting result Dd is zero. Therefore, the drive voltage Vd also becomes zero, and the movement of the optical head 2 is stopped. The optical head 2 has a number of ? corresponding to the numerical data Dx before its movement is stopped. SL clock pulse 1
The distance obtained is that the optical head 2 has been moved by the distance from the position of the optical head 2 before movement to the target position, and therefore, the target position has been reached when the optical head 2 is stopped.

Then, the counting result Dd of the presettable counter 13
When Z becomes zero, the output signal Z from the presettable counter 13 is obtained by the gate circuit 12, and after that, the output signal Z obtained from the pulse generation circuit 15 is also applied to the low-frequency component of the tracking error signal. When the third and fourth clock pulses i' and jo are sent out, they are supplied to the down count terminal and up count terminal U of the presettable counter 13 via the data 1 circuit 12, and The counter 13 quickly performs a countdown and count amplification,
A comparatively small counting result Dd is generated, whereby a driving voltage Vd is obtained to drive the motor 5, and the optical head 2 receives the third and fourth clock pulses i' and j' from the pulse generating circuit 15. The position is controlled so that it is no longer possible.

That is, the position of the optical head 2 is controlled based on the low-frequency component of the tracking error signal, so that it follows the spiral recording track of the rotating disk l.

Next, assuming that the polarity of the numerical data Dx is negative, first, the counting result Dd from the presettable counter 13 corresponds to the vi value data Dx and is supplied to the digital/analog conversion circuit 6. At the same time, the polarity determination signal PL indicates negative polarity and is supplied to the digital/analog conversion circuit 6. For this reason, digital/
From the analog conversion circuit 6, 1'1. Numerical data D with polarity
A drive voltage Vd of a level corresponding to x is obtained. Then, the motor 5 is driven based on this drive voltage Vd, and the optical head 2 detects the detection mechanism section 1 of the photo encoder 8.
0 and is moved in the negative direction. As a result, the detection mechanism unit IO outputs the pulse train signals a and b with the phase of the pulse train signal leading 90 degrees from the phase of the pulse train signal a, and as a result, the clock pulse generating circuit 11 outputs the second pulse train signals a and b. A clock pulse j is obtained and supplied to the amplifier count terminal U of the presettable counter 13 via the gate circuit 12.
The third or fourth clock pulse i' or jo from the pulse generating circuit 15 is stopped by the gate circuit 12 and is not supplied to the presettable counter 13.

By supplying this second clock pulse j, the preset numerical data Dx in the brisec pull counter 13 is counted up, and the counting result D
d gradually increases (towards zero), and the level of the drive voltage Vd also increases accordingly.

Thereafter, when the second clock pulses j of the number corresponding to the numerical data Dx are supplied to the up-count terminal U of the presettable counter 13 and the count l-up is performed, the counting result 1) d becomes zero. It becomes a hailstorm,
The drive voltage Vd also becomes zero, and the movement of the optical head 2 is stopped. The optical head 2 moves by a distance at which a number of second clock pulses j corresponding to the numerical data Dx can be obtained, that is, a distance from the position of the optical head 2 before movement to the target position, before the movement of the optical head 2 is stopped. Therefore, it means that the target position has been reached at the time of stopping.

Also in this case, the presettable counter 13
Counting result 1) Since d becomes zero, gate circuit 1
2, the output signal 2 from the presettable counter 13 is obtained, and after that, the third output signal obtained from the pulse generation circuit 15 is also obtained from the low frequency component of the tracking error signal.
When the fourth clock pulses i' and jo are sent out, they are precentered through the gate circuit 12.
It is supplied to the down count terminal of the counter 13 and the up count terminal U of the presettable counter 1.
3 quickly counts down and counts up, resulting in a relatively small counting result, d, which provides a drive voltage Vd to drive the motor 5, and the optical head 2 The position of the optical head 2 is controlled so that the third and fourth clock pulses i° and j'' are no longer obtained from the pulse generating circuit 15. That is, the position of the optical head 2 is controlled so that the position of the optical head 2 is close to the low frequency component of the dragging error signal. It follows the record 1 to easy.

In the above example, the head position control device according to the present invention is applied to an optical disc player, but the head position control device according to the present invention is applicable to other types of discs other than optical type. This can also be applied to players.

Effects of the Invention As is clear from the above description, the head position control device according to the present invention allows the head disposed facing the disc-shaped recording medium to be moved at a desired distance in the radial direction of the disc-shaped recording medium. The drive signal for controlling the movement by
As a digital signal processing method (4), it is possible to perform extremely precise control.Also, the driving conditions for controlling the movement of the head are Since it is set based on the relative difference between the head position and the target position, even if the disk-shaped recording medium is shrunk or skewed, the adverse effects thereof are significantly reduced. Furthermore, since a potentiometer or the like is not used to move the head relative to the disk-shaped recording medium or to detect its position, it is possible to control the movement of the head with less noise and excellent stability.

[Brief explanation of the drawing]

FIG. 1 is a block connection diagram showing an example of a head position control device according to the present invention applied to an optical disc player, and FIGS. 2A and B show a specific configuration of a part of the example shown in FIG. 1. Configuration diagrams showing examples, Figures 3A-J and 4A-
J is a waveform diagram used to explain the operation of the example of the installation structure shown in FIGS. 2A and 2B. In the figure, ■ is a disk, 2 is an optical head, 5 is a motor, and 6
8 is a digital/analog conversion circuit, 8 is a photo encoder, 11 is a clock pulse generation circuit, 12 is a data 1~ circuit, 13 is a presettable counter, 41 is a decoder, 43 is a decoding circuit, 44 is a system control section,
45 is a command signal generator, and 46 is a launch circuit.

Claims (1)

[Claims] A drive section for moving information recording and/or G31 reading means disposed facing the disc-shaped recording medium in the radial direction of the disc-shaped recording medium, and - for recording information and/or ;)'. When the disc-shaped recording medium is moved in the first direction in the radial direction described in - of the means, a number of pulses corresponding to the moving distance are generated and the disc-shaped recording medium is moved in the second direction. a pulse generating section that generates a number of second pulses corresponding to the moving distance t;
Receiving position designation data - C corresponding record: The data of the difference between the designation data and the position of the recording and/or reading means of the disk-shaped recording medium, 1.) 141, a controller that sends the difference data as corresponding numerical data due to the first or second pulse from the pulse generator, and the system controller. The numerical data from the I control section is preset, and -) each time the first or second pulse obtained from the second pulse generation section arrives, the 31 number result is set to zero. A presettable counter that counts up or counts down, and a count result of the presettable counter is supplied, and a drive voltage having a polarity and level corresponding to the count result is generated and supplied to the drive section. and a voltage generating section for recording and/or recording information on the drive section.
Or, set the reading means to the above drive voltage, move it in the direction according to its polarity, and set the position on the "2-record disk-shaped recording medium" to the position where the above position designation data does not exist. position control device for information recording and/or reading means.