JP2733695B2 - Optical pickup transfer control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a transfer control device in an information recording / reproducing device, and particularly to a case where an optical recording / reproducing device is used in an inclined state. The present invention relates to an optical pickup transfer control device that enables accurate tracking control.

[Related Art] In recent years, an optical recording / reproducing apparatus using a disk-shaped recording / reproducing medium such as an optical disk or a magneto-optical disk using an optical or magneto-optical signal recording / reproducing method has been developed. In these devices, focus control means for driving an objective lens in a direction perpendicular to the disk surface in order to converge a light beam on a disk, and in order to accurately irradiate a concentric or spiral track with a light beam. Tracking control means for driving the objective lens in a direction orthogonal to the track, and optical pickup moving means for moving the optical pickup including the tracking control means in the radial direction of the disk for track access operation. ing.

When performing track access, the tracking control is temporarily stopped, the optical pickup is moved to the target track by the optical pickup moving means, and the tracking control is started again when the optical pickup stops.

FIG. 8 is a block diagram of a conventional example of an optical recording / reproducing apparatus. In FIG. 1, concentric or spiral tracks are formed on the disk 1 in advance. Disc 1
Is mounted on the motor 2 and rotated at a predetermined rotation speed (for example, 1800 rpm) by the motor drive control circuit 3.

In order to reproduce the information recorded on the disc 1,
The light beam emitted from the laser 4 is applied to the disk 1 via the beam splitter 5 and the objective lens 6. The light beam reflected by the disk 1 again enters the beam splitter 5 via the objective lens 6, where it is deflected at right angles and projected on the photoelectric conversion element 7.

The reproduction signal converted into an electric signal by the photoelectric conversion element 7 is subjected to processing such as amplification by the preamplifier 8, and a focus error signal (s) corresponding to the distance between the position of the light beam and the recording surface of the disk 1; A tracking error signal (t) corresponding to a positional relationship between a light beam irradiated on the disk 1 and a track formed on the disk 1 and information recorded on the disk 1 as irregularities or changes in reflectance are converted into electric signals. And the reproduction information signal (u) detected as the output.

The focus error signal (s) is input to the focus control circuit 9, and the focus control circuit 9 controls the focus actuator 10 so that the light beam is focused on the recording surface of the disk 1.

The tracking error signal (t) is a tracking control circuit
11, the tracking control circuit 11 outputs a control signal (f) to a tracking actuator 13, which is fine movement means of the objective lens 6, via a multiplexer 12 so that the light beam accurately follows the track of the disk 1. I do. The tracking actuator 13 finely moves the objective lens 6 in a direction orthogonal to the recording track according to the control signal (f).

The reproduction information signal (u) is input to an address signal reproduction circuit 14, and the address signal reproduction circuit 14 reproduces a track address recorded on the disk 1 from the reproduction information signal (u), and outputs this to an arithmetic circuit 15. Output.

Laser 4, beam splitter 5, objective lens 6, photoelectric conversion element 7, preamplifier 8, focus actuator
An optical pickup 16 composed of a tracking actuator 13 is attached to a movable portion of a linear motor 17, and can move at high speed in the radial direction of the disk 1.

When reproducing information recorded on the disk 1 or recording information on the disk 1, a DC voltage component of a voltage applied to the tracking actuator 13 is extracted by an LPF (low-pass filter) 18 and the DC voltage component is extracted. The voltage component is output to the linear motor drive circuit 20 via the multiplexer 19. The linear motor drive circuit 20 controls the drive of the linear motor 17 so that the tracking actuator 13 always operates around the average position (the position where the applied voltage of the tracking actuator 13 is 0 V), so that the stability of the tracking control is improved. Optical pickup 16
Control the position of.

When performing track access, first, an access track address and an access instruction are input from the input device 21 to the arithmetic circuit.
Entered in 15. The arithmetic circuit 15 compares the current reproduction track address and the access track address output from the address signal reproduction circuit 14, and the difference between the two is a preset registered value.
For example, when the number of tracks is 10 or more, the coarse search operation described below is performed.

In the coarse search operation, first, the movement amount and polarity (positive / negative polarity depending on whether the disk moves in the circumferential direction or the outer circumferential direction) according to the difference between the current playback track address and the access track address are determined. Along with setting the counter 22, the multiplexer 19 is switched so that the output signal of the digital / analog (D / A) converter 23 is selected as the input signal of the linear motor drive circuit 20, and the tracking on / off (ON / OFF) The signal (v) is output to make the tracking control circuit 11 inactive.

The output signal of the counter 22 is input to the D / A converter 23, and the D / A
Converter 23 outputs a voltage corresponding to the difference between the addresses. As a result, the linear motor 17 is driven in a direction in which the address difference decreases.

The movement detecting circuit 24 outputs a pulse corresponding to the moving direction and the number of tracks of the linear motor 17 based on the tracking error signal (t) and the reproduction information signal (u), and sets the counter 22 to subtract the value. When the linear motor 17 moves by the number of tracks set on the counter 22, the counter 22 outputs a signal indicating that the count value has become 0 to the arithmetic circuit 15. Tracking in arithmetic circuit 15
The tracking control circuit 11 is turned on by the ON / OFF signal (v), and the multiplexer 19 is switched so that the output signal of the LPF 18 is selected as an input signal to the linear motor drive circuit 20 to be in a reproduction state.

Next, the arithmetic circuit 15 compares the current reproduction track address output from the address signal reproduction circuit 14 with the access track address, and when both are the same, terminates the access operation.
If the difference between them is 10 or more tracks, the rough search operation is repeated. If the difference between the two is within 10 tracks, the fine search operation described below is performed.

In the fine search operation, first, the tracking ON / OFF signal (v)
The tracking control circuit 1 is brought into a non-operating state, and the drive signal (e)
The multiplexer 12 is switched so that the output signal (g) of the jump pulse generation circuit 25 is selected. The jump pulse generation circuit 25 includes, for example, a voltage generation circuit 26, a counter 27, a current amplification circuit 28, and an interface circuit 29, as shown in FIG.

The arithmetic circuit 15 outputs the difference between the current playback track address and the access track address as a signal (a) to the counter 27 via the interface circuit 29, and sets this.
Further, the arithmetic circuit 15 outputs a jump command signal (c) to the voltage generating circuit 26 via the interface circuit 29.
The voltage generating circuit 26 outputs an output signal of a voltage corresponding to the jump command signal (c) to the current amplifying circuit 28,
28 amplifies the input signal and generates a signal (g) for driving the tracking actuator 13 in the radial direction of the disk 1.

The pulse signal (b) output from the movement detection circuit 24 every time the light beam crosses the track is input to the counter 27 via the interface circuit 29, and the value set by this is subtracted. When the value of the counter 27 becomes 0, a signal (d) indicating the end of the jump is output from the counter 27 to the arithmetic circuit 15 and the voltage generating circuit 26, and the voltage generating circuit 26 stops generating the signal.

On the other hand, the arithmetic circuit to which the jump end signal (d) is input
15 is such that the tracking control circuit 11 is immediately activated by the tracking ON / OFF signal (v) and the output signal (f) of the tracking control circuit 11 is selected as the drive signal (e) of the tracking actuator 13. The multiplexer 12 is switched to the reproducing state.

Here, the arithmetic circuit 15 compares the current reproduction track address and the access track address output from the address signal reproduction circuit 14 again, and terminates the access operation if they are the same, and jumps again if they are not the same. repeat.

Japanese Patent Application Laid-Open No.
-92155 or JP-A-55-125542.

[Problem to be Solved by the Invention] In the above-described conventional technology, when the optical recording / reproducing apparatus is used in a state of being inclined with respect to the moving direction of the linear motor 17, the movable portion of the linear motor 17 and the optical pickup 16 Depending on the weights ML and MP, the forces FL and FP as shown in FIG.
Is applied to the movable part of the linear motor 17.

In such a state, a DC component is generated in the tracking error signal (t) in order to correct a relative displacement between the light beam and the track center due to the forces FL and FP, and the DC component is generated by the tracking control circuit 11, Multiplexer 12, LP
Since the linear motor 17 is driven via the F18, the multiplexer 19, and the linear motor drive circuit 20, this force (FL + F
A force that substantially cancels P) is generated in the linear motor 17.

As a result, the movable portion of the linear motor 17 is moved to a position where the position of the optical pickup 16 is stabilized with the position slightly shifted from the recording track.

However, since the tracking control is in the OFF state during the coarse search, even if the tracking control is restarted after the coarse search, a DC component that generates the force F is not immediately supplied to the linear motor 17. Therefore, the linear motor 17 moves in the direction of the force (FL + FP) until a DC component that generates the force F is generated at the output of the LPF 18.
As a result, the position of the optical pickup 16 shifts, and the tracking control becomes unstable immediately after resumption.

Further, when performing a fine search after the coarse search is completed, the track jump is performed from a state where the optical pickup 16 is shifted, so that the track jump becomes unstable, the track jump fails, and the access time is long. Problem arises.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems, and even when an optical recording / reproducing apparatus is used in a state of being inclined with respect to the moving direction of a linear motor, the position of an optical pickup after completion of a coarse search. An object of the present invention is to provide a transfer control device of an optical recording / reproducing device capable of performing stable tracking control and track jump without deviation.

[Means for Solving the Problems] In order to solve the above problems, the present invention has the following means.

(1) means for detecting a DC component of a tracking control signal, means for outputting a correction signal for driving a transfer means so that the DC component becomes substantially zero, and adding an access signal and the correction signal. And an adding means for outputting an addition signal, wherein the transfer means is driven by the correction signal at the time of recording / reproduction, and is driven by the addition signal at the time of access.

[Operation] According to the above configuration, a correction signal for making the DC component of the tracking control signal substantially zero is output to the transfer unit even during access, so that the transfer unit is held at the expected position.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an example of a basic configuration of a transfer control device to which the present invention is applied. The same functional portions as those in FIG. 8 are denoted by the same reference numerals, and description thereof will be omitted unless otherwise required. .

In the figure, the output signal (m) of the LPF 18 is sample /
The signal is input to a hold (hereinafter abbreviated as S / H) circuit 31. S
The output signal of the / H circuit 31 is input to the adding circuit 32. Also,
The output signal of the D / A converter 23 is input to the addition circuit 32 via the switch 30. The output signal of the adding circuit 32 is input to the linear motor driving circuit 20.

In the transfer control device having such a configuration, at the time of normal tracking control, that is, at the time of recording / reproduction, the S / H circuit 3
1 is a sample state, and the DC component (m) of the tracking actuator drive signal (f) output from the LPF 18
Is input to the linear motor drive circuit 20 as a linear motor drive signal (o).

The linear motor 17 is controlled by the output signal of the linear motor drive circuit 20, whereby the movable part of the linear motor 17 is driven to move the position of the optical pickup 16, and the optical pickup 16 is moved from the track being recorded / reproduced. The displacement is substantially corrected.

Here, when performing the coarse search, first, the moving amount and the polarity according to the difference between the current reproduction track address and the access track address are set in the counter 22 by the arithmetic circuit 15, and the switch 30 is turned on. . Further, the S / H control signal (w) causes the S / H circuit 31 to change from the sample state to the hold state, and further, the tracking ON / OFF signal (v)
As a result, the tracking control circuit 11 becomes inoperative.

The output signal of the counter 22 is input to the D / A converter 23, and the D / A
Converter 23 outputs a voltage corresponding to the difference between the addresses. S /
The H circuit 31 has a direct current component (m) of the tracking actuator drive signal (e) during normal reproduction immediately before access, that is, a direct current component (m) corresponding to a force (FL + FP) generated by the inclination of the optical liquid recording / reproducing apparatus. Is held,
The held DC component (m) and the output signal (n) of the D / A converter 23 are added by the adding circuit 32 and then input to the linear motor driving circuit 20 as a linear motor driving signal (o).

As described above, in the present configuration, the rough search is performed while the state where the force (FL + FP) is substantially canceled by the DC component (m) output from the S / H circuit 31, so that the linear motor 17 It is accurately driven in a direction in which the address difference decreases in accordance with the output signal of the / A converter 23.

When the linear motor 17 is driven, the movement detection circuit 24 outputs a pulse corresponding to the moving direction and the number of moving tracks of the linear motor 17 from the tracking error signal (t) and the reproduction information signal (u). Subtract the set value.

When the linear motor 17 moves by the number of tracks set in the counter 22, the counter 22 outputs a signal indicating that the value of the counter has become 0 to the arithmetic circuit 15. The arithmetic circuit 15 activates the tracking control circuit 11 by the tracking ON / OFF signal (v),
Turn 30 off.

Next, the arithmetic circuit 15 compares the current reproduction track address output from the address signal reproduction circuit 14 with the access track address, and when the two are the same, the S / H circuit 31 by the S / H control signal (w). In the normal reproduction state in which the linear motor 17 is driven by the DC component signal (m) of the tracking actuator drive signal (e), and the access operation is completed.

On the other hand, when the difference between them is, for example, 10 tracks or more, the rough search operation is repeated. If the difference between them is within 10 tracks, for example, a fine search operation by a jump operation is performed.

The arithmetic circuit 15 compares the current reproduction track address and the access track address output from the address signal reproduction circuit 14 after the end of the jump operation, and if they match, S / H
The control signal (w) changes the S / H circuit 31 from the hold state to the sample state, and ends the access operation. If they do not match, the fine search operation by the jump operation is repeated.

By the way, in the above configuration, the S / H circuit 3
Since the transfer means is driven so as to substantially cancel the force (FL + FP) with the DC component held at 1, the transfer means is almost held at the expected position. Since the transfer means is driven by the DC component (m) of the tracking error signal corresponding to the relative displacement between the light beam and the track center to substantially cancel the force (FL + FP), the DC component (m) Compensates the force (FL + FP) caused by the tilt of the optical recording / reproducing apparatus, and as a result, the pickup
As the 16 positions are corrected and approach the expected position, the DC component (m) decreases accordingly.

However, when the DC component (m) decreases, the force (FL)
+ FP), the DC component (m) increases because the compensation amount of the pickup 16 decreases.

As described above, in the above-described configuration, since control is performed to correct the displacement of the linear motor 17, that is, the displacement of the pickup 16 using the displacement of the linear motor 17, that is, the displacement of the pickup 16, tracking is performed. The correction is not performed until the DC component of the actuator drive signal (e) becomes substantially zero.

Therefore, in each embodiment of the present invention described below, in order to solve such a problem, a configuration is adopted in which the DC component of the tracking actuator drive signal (e) during recording / reproduction is always substantially zero. .

FIG. 2 is a block diagram of a transfer control device according to a first embodiment of the present invention. The same functional portions as in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted unless otherwise required.

In this embodiment, a D / A converter 34 is provided as a means for generating a correction signal that makes the DC component of the tracking actuator drive signal (e) in a normal reproduction state substantially zero.
It is characterized in that the correction signal is always added to the linear motor drive circuit 20 to drive the linear motor 17.

In order to obtain a correction signal, first, the arithmetic circuit 15 turns off the switch 30 and turns on the switch 35, and the D / A converter 3
Normal reproduction is performed with the output signal of 4 set to 0. At this time,
Since the DC component (m) of the tracking actuator drive signal (e) is input to the linear motor drive circuit 20 as a linear motor drive signal (o), a force for compensating the force (FL + FP) generated by the inclination is applied to the linear motor 17. Occur.

Here, when the output signal (m) of the LPF 18 is converted into a digital signal by the analog / digital (A / D) converter 33 and input to the arithmetic circuit 15, the arithmetic circuit 15 generates the tracking actuator drive signal (e). DC component of (m)
In order to output a correction signal (p) for driving the linear motor 17 from the D / A converter 34 so that the value becomes substantially 0, a correction corresponding to the correction signal (p) is performed based on the input digital signal. Data is obtained, and the correction data is output to the D / A converter 34.

Thereafter, the correction signal (p) output from the D / A converter 34
And a DC component (m) (approximately 0) of the tracking actuator drive signal (e) output from the LPF 18 are added by the adder circuit 32 and input to the linear motor drive circuit 20 as a linear motor drive signal (o). You.

As a result, a force F for canceling the tilt is generated in the linear motor 17 by the correction signal (p), so that the optical pickup 16 is stabilized at the expected position, and the tracking actuator drive signal (e) does not include a DC component. This DC component becomes substantially zero.

When a coarse search is performed by the transfer control device having the above-described configuration, first, a movement amount and a polarity corresponding to the difference between the current playback track address and the access track address are set in the counter 22, and the switch 30 is turned on. The switch 35 is turned off, and the tracking control circuit 11 is turned off by the tracking ON / OFF signal (v).

The output signal of the counter 22 is input to the D / A converter 23, and the D / A
Converter 23 outputs a voltage corresponding to the difference between the addresses. D /
The correction signal (p) output from the A converter 34 and the D / A converter 23
The output signal is added by the adding circuit 32 and input to the linear motor driving circuit 20 as a linear motor driving signal (o).

According to such a configuration, in a state where the force generated by the inclination of the optical recording / reproducing device is canceled by the correction signal (p) output from the D / A converter 34, the linear motor 17 is driven by the D / A converter. The output signal of 23 drives in the direction in which the address difference decreases.

When the linear motor 17 moves by the number of tracks set in the counter 22, the count value is counted from the counter 22 to 0.
Is output to the arithmetic circuit 15. In the arithmetic circuit 15, the tracking control circuit 11 is turned on by the tracking ON / OFF signal (v), the switch 30 is turned off, the switch 35 is turned on, and the correction signal output from the D / A converter 34 is output. (P) and the DC component (m) of the tracking actuator drive signal output from the LPF 18 are added by the addition circuit 32 and input to the linear motor drive circuit 20 as a linear motor drive signal (o).

Next, the arithmetic circuit 15 compares the current reproduction track address output from the address signal reproduction circuit 14 with the access track address, and ends the access operation if they match. On the other hand, if the difference between the two is, for example, 10 tracks or more, the above-described rough search operation is repeated. If the difference between them is within 10 tracks, for example, a fine search operation by a jump operation is performed.

FIG. 3 is a block diagram of a transfer control means according to a second embodiment of the present invention. The same functional portions as those in FIG. 1 or FIG. Omitted.

In the present embodiment, first, the arithmetic circuit 15 turns on the switch 35 and sets the output signal of the D / A converter 34 to 0, thereby performing normal reproduction. The output signal of the LPF 18 at this time is converted into a digital signal by the A / D converter 33 and output to the arithmetic circuit 15.

Next, the arithmetic circuit 15 detects a DC component (m) of the tracking actuator drive signal (e) from the output signal of the D / A converter 33, and outputs a correction signal (q) having a level corresponding to the DC component to D / A. The correction data to be output from the A converter 34 to the addition circuit 32 is output to the D / A converter 34.

Thereafter, the correction signal (q) output from the D / A converter 34 and L
The DC component (m) of the tracking actuator drive signal (e) output from the PF 18 is added by the adder circuit 32,
The signal is input to the linear motor drive circuit 20 as a linear motor drive signal (o).

Since a force F is generated in the linear motor 17 by the correction signal, no DC component is generated in the tracking actuator drive signal (e), and the DC component is substantially zero.

When performing a rough search by the transfer control device having the above-described configuration, first, the moving amount and the polarity according to the difference between the current playback track address and the access track address are set in the counter 22, and the switch 35 is turned off. I do. further,
The tracking control circuit 11 is disabled by the tracking ON / OFF signal (v).

The output signal of the counter 22 is input to the arithmetic circuit 15, and the arithmetic circuit 15 arithmetically processes the count value and the correction data, and adds a signal corresponding to the address difference and a correction signal (q).
From the D / A converter 34
Output to the converter 34. That is, the signal (q) becomes a signal including the correction signal at this time.

The output signal (q) of the D / A converter 34 is input to the linear motor drive circuit 20 via the addition circuit 32 as a linear motor drive signal (0). As a result, in a state where the force generated by the inclination of the optical recording / reproducing device is corrected by the correction signal component of the signal (q) output from the D / A converter 34, the linear motor 17 moves in the direction in which the address difference decreases. Driven.

When the arithmetic circuit 15 detects from the output signal of the counter 22 that the linear motor 17 has moved by the number of tracks set on the counter 22, the tracking control circuit 11 is activated by the tracking ON / OFF signal (v) and the switch is turned on. 35 is turned on, and the D / A converter 34 outputs correction data for outputting the DC component.

Next, the arithmetic circuit 15 compares the current reproduction track address output from the address signal reproduction circuit 14 with the access track address, and ends the access operation if they match. On the other hand, if the difference between the two is, for example, 10 tracks or more, the above-described rough search operation is repeated. If the difference between them is within 10 tracks, for example, the fine search operation by the above-described jump operation is performed.

In this embodiment, the D / A converter 34 serves as both a D / A converter for outputting a signal for access and a D / A converter for outputting a correction signal. The converter 23 can be omitted.

FIG. 4 is a block diagram of a transfer control device according to a third embodiment of the present invention. The same functional portions as those in FIGS. 1 to 3 are denoted by the same reference numerals, and will not be described unless otherwise necessary. Omitted.

In this embodiment, in order to obtain a signal (q) including the correction signal, first, the tracking actuator drive signal (e) is converted into a digital signal by the A / D converter 33, and this digital signal is converted into a digital LPF 36 by an arithmetic operation. Circuit 15, D
Input to the linear motor drive circuit 20 via the / A converter 34. Then, a normal reproduction state is set in which the linear motor 17 is driven by the DC component signal of the tracking actuator drive signal (e).

At this time, the arithmetic circuit 15 detects the DC component of the tracking actuator drive signal (e) from the output signal of the digital LPF 36, and obtains correction data for setting the DC component to 0. Thereafter, the arithmetic circuit 15 corrects the correction data and the digital data.
The output signal of the LPF 36 is added, and the processing result is output to the D / A converter 34 as a signal (q).

The D / A converter 34 outputs a signal obtained by adding the correction signal and the signal of the DC component (approximately 0) of the tracking actuator drive signal (e), and this is output as a linear motor drive signal (o). Is input to

At this time, since a force F is generated by the correction signal component of the linear motor drive signal (o) in the linear motor 17, no DC component is generated in the tracking actuator drive signal (e), and the DC component is It is almost 0.

When a coarse search is performed by the transfer control device having the above-described configuration, first, a movement amount and a polarity corresponding to the difference between the current playback track address and the access track address are set in the counter 22, and the tracking ON / OFF signal ( The tracking control circuit 11 is made inoperative by v).

The output signal of the counter 22 is input to the arithmetic circuit 15, and the arithmetic circuit 15 performs arithmetic processing on the count value and the correction data, and outputs the arithmetic result to the D / A converter. The D / A converter 34 outputs a signal (q) having a level obtained by adding a voltage corresponding to the address difference and a correction signal.

The output signal of the D / A converter 34 is input to the linear motor drive circuit 20 via the addition circuit 32 as a linear motor drive signal (o). Thus, the linear motor 17 is driven in a direction in which the address difference decreases in a state where the force F generated by the inclination of the optical recording / reproducing device is corrected by the output signal of the D / A converter 34.

When the arithmetic circuit 15 detects from the output signal of the counter 22 that the linear motor 17 has moved by the number of tracks set in the counter 22, the tracking ON / OFF signal (v)
With this, the tracking control circuit 11 is put into an operating state, the correction data and the output signal of the digital LPF 36 are added, and the calculation result is output to the D / A converter 34.

Next, the arithmetic circuit 15 compares the current reproduction track address output from the address signal reproduction circuit 14 with the access track address, and ends the access operation if they match. On the other hand, when the difference between them is, for example, 10 tracks or more, the rough search operation is repeated. Also, the difference between the two is, for example,
If it is within 10 tracks, a fine search operation is performed.

However, in the first, second and third embodiments, since a force F is generated in the linear motor 17 by the correction signal, no DC component is generated in the tracking actuator drive signal, and the light beam and the center of the track are maintained even in a normal reproducing state. Relative displacement with respect to.

FIG. 5 is a block diagram showing an example of a basic configuration of another transfer control device to which the present invention is applied. The same functional portions as in FIGS. The description is omitted unless otherwise.

In the figure, the optical position sensor 37 is a linear motor 17
Upon receiving the light from the light emitting element 38 attached to the movable portion of the linear motor 17, a signal indicating the amount of displacement of the movable portion of the linear motor 17 caused by the inclination is output to the linear motor position control circuit 39.

During normal playback, the arithmetic circuit 15 switches
30 is in an off state, the S / H circuit 40 is in a sample state, and the linear motor position control circuit 39 moves the linear motor 17 to the current reproduction position based on the output signal of the optical position sensor 37, that is, the optical pickup. The linear motor 17 is controlled so that the position of 16 is maintained.

When the optical recording / reproducing device is tilted, a DC component is generated in the output signal (i) of the linear motor position control circuit 39, whereby a force F for maintaining the position of the movable portion of the linear motor 17 is generated. Occurs.

When a coarse search is performed by the transfer control device having the above-described configuration, first, a movement amount and a polarity corresponding to the difference between the current playback track address and the access track address are set in the counter 22, and the switch 30 is turned on. And Also,
The S / H circuit 40 is set in the hold state by the S / H control signal (h). Further, the tracking control circuit 11 is made inoperative by the tracking ON / OFF signal (v).

The output signal of the counter 22 is input to the D / A converter 23, and the D / A
Converter 23 outputs a voltage corresponding to the difference between the addresses. S /
The H circuit 40 holds the DC component of the output signal (i) of the linear motor position control circuit 39 at the time of normal reproduction immediately before access, and holds the held signal (j) and the D / A converter 23.
Is added to the output of the linear motor drive circuit 20 as a linear motor drive signal (o).

According to such a configuration, the linear motor 17 performs the D / A conversion while the force F generated by the inclination of the optical recording / reproducing apparatus is substantially corrected as the output signal (j) of the S / H circuit 40. Container 2
The output signal of (3) drives in a direction in which the address difference decreases.

Note that the subsequent control process is the same as in each of the above-described embodiments, and a description thereof will be omitted.

FIG. 6 is a block diagram showing an example of the circuit configuration of the S / H circuit 40. In the sample state, the input signal (i) is input to the amplifier 42 via the switch 41 and output as it is. At this time, the LPF consisting of the resistor 43 and the capacitor 44
As a result, a charge corresponding to the DC component of the input signal (i) is stored in the capacitor 44. Next, in the hold state, the switch 41 is turned off, and the electric charge stored in the capacitor 44 causes the signal of the DC component of the input signal (i) to be amplified by the amplifier 42.
Output from

By the way, in the above-described configuration, similarly to the configuration described with reference to FIG.
The movement of the pickup 17 corrects the movement of the pickup 16, and when the pickup 16 approaches the expected position, the DC component (i) decreases accordingly. Therefore, the correction is not performed until the DC component becomes substantially zero.

Therefore, in a fourth embodiment described below, in order to solve such a problem, a position sensor is used during recording / reproduction.
The configuration is such that the DC component (i) of the 37 output signal is always substantially zero.

FIG. 7 is a block diagram of a transfer control device according to a fourth embodiment of the present invention. The same functional portions as those in FIGS. 1 to 5 are denoted by the same reference numerals, and will not be described unless otherwise necessary. Omitted.

In the present embodiment, a correction signal such that the DC component of the output signal of the linear motor position control circuit 39 in the normal reproduction state becomes substantially zero is input to the linear motor drive circuit 20. The feature is that the addition is performed to drive the linear motor 17.

In order to obtain the correction signal, the arithmetic circuit 15 first performs normal reproduction with the switch 30 turned off, the switch 35 turned on, and the output signal of the D / A converter 34 set to 0. When the optical recording / reproducing apparatus is tilted during normal reproduction, a DC component is generated in the output signal (i) of the linear motor position control circuit 39, and the force for holding the position of the movable portion of the linear motor 17 is thereby reduced. Generated in the linear motor 17.

At this time, the LPF 18 detects the DC component of the output signal of the linear motor position control circuit 39, converts the DC component (m) into a digital signal by the A / D converter 33, and outputs the digital signal to the arithmetic circuit 15. In the arithmetic circuit 15, the linear motor position control circuit 39
Correction signal (p) for reducing the DC component of the output signal of
Is output from the D / A converter 34 to the D / A converter 34 in accordance with the DC component (m).

Thereafter, the correction signal (p) output from the D / A converter 34 and the output signal of the linear motor position control circuit 39 are added to the addition circuit 32
And this is input to the linear motor drive circuit 20 as a linear motor drive signal (o).

According to such a configuration, since the force F is generated in the linear motor 17 by the correction signal (p), the DC component of the output signal of the linear motor position control circuit 39 is substantially zero.

When performing a rough search by the transfer control device having the above-described configuration, first, a moving amount and a polarity corresponding to a difference between a current playback track address and an access track address are set in the counter 22, and the switch 30 is turned on, The switch 35 is turned off. Furthermore, tracking ON / OFF signal (v)
Causes the tracking control circuit 11 to be in an inactive state.

The output signal of the counter 22 is input to the D / A converter 23, and the D / A
Converter 23 outputs a voltage corresponding to the difference between the addresses. D /
The correction signal (p) output from the A converter 34 and the D / A converter 23
The output signal is added by the adder circuit 32 and input to the linear motor drive circuit 20 as a linear motor drive signal (o).

As a result, in a state where the force F generated by the inclination of the optical recording / reproducing device is corrected by the correction signal (p) output from the D / A converter 34, the linear motor 17 is output by the output signal of the D / A converter 23. Are driven in a direction in which the address difference decreases.

Note that the subsequent control process is the same as in each of the above-described embodiments, and a description thereof will be omitted.

In this embodiment, as in the second embodiment, the A / D converter 34 that outputs the correction signal (p) and the D / A converter 23 that outputs a signal for access are shared. You may do it. Further, as in the third embodiment, the output signal of the linear motor position control circuit 39 is A / D-converted, and its DC component is detected by a digital filter. Calculation of correction data, addition of the correction data and the linear motor position control signal (i) during normal reproduction, and output of the addition signal to the D / A converter;
At the time of access, addition of the access signal and the correction signal and output of the added signal to the D / A converter may be performed.

In the first, second, and fourth embodiments, the arithmetic circuit 15
Has been described as obtaining a correction signal in accordance with a DC component converted into a digital signal.However, the present invention is not limited to this. For example, a comparator detects the positive and negative polarities of a DC component. And, depending on the polarity,
The arithmetic circuit adjusts the correction data to the D / A converter that outputs the correction signal, and according to the correction data when the positive and negative polarities of the DC component change or when the positive and negative polarities are detected at an equal ratio. The output signal of the D / A converter may be used as a correction signal.

In the first, second, third, and fourth embodiments,
It is preferable that the correction signal is not determined only once, but at a predetermined time, or may be determined each time an access is made. Thereby, it is possible to cope with a case where the inclination of the optical recording / reproducing apparatus changes during the reproducing.

Further, in the above embodiment, the correction signal is described as being adjusted according to only the DC component.
15 may detect the position of the optical pickup 16 in the radial direction, and the level of the correction signal may be adjusted according to the DC component and the position in the radial direction. If you do this,
It is also possible to cancel the tension and the like due to the wiring and the like of the optical pickup 16 which differ depending on the position in the radial direction, so that a more stable track jump can be performed.

Further, in this embodiment, the disc-shaped recording / reproducing medium has been described as an example, but it is apparent that the present invention can be applied to a card-shaped recording / reproducing medium such as an optical card.

[Effects of the Invention] As is clear from the above description, according to the present invention, a signal corresponding to the relative displacement between the light beam and the track center immediately before access is held, and during access, the signal is maintained. Since the power is supplied to the linear motor, a stable track jump can be performed even when the apparatus is used in an inclined state, and in particular, the fine search can be performed accurately and stably. become.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a basic configuration of a transfer control device to which the present invention is applied, FIG. 2 is a block diagram of a first embodiment of the present invention, and FIG. FIG. 4 is a block diagram of a third embodiment of the present invention.
FIG. 5 is a block diagram showing an example of the basic configuration of another transfer control device to which the present invention is applied, FIG. 6 is a block diagram showing an example of the configuration of the sample and hold circuit of FIG. 5, and FIG. FIG. 8 is a block diagram of a prior art, FIG. 9 is a block diagram of a jump pulse generating circuit, and FIG. 10 is a diagram showing a force acting on a linear motor movable portion due to the inclination of the device. FIG. Reference Signs List 1 disk 4 laser 5 beam splitter 6 objective lens 7 photoelectric conversion element 8 preamplifier 9 focus control circuit 10 focus actuator 11 Tracking control circuit, 12,
19: Multiplexer, 13: Tracking actuator, 14: Address signal reproduction circuit, 15: Operation circuit, 16 ...
… Optical pickup, 17… linear motor, 18 …… LPF, 2
0 ... linear motor drive circuit, 21 ... input device, 22 ...
Counter, 23, 34… D / A converter, 24… Movement detection circuit, 25… Jump pulse generation circuit, 26… Voltage generation circuit, 27… Counter, 28 …… Current amplification circuit, 29… Interface circuit, 31, 40 S / H circuit, 30, 35 Switch, 32 Addition circuit, 33 A / D converter, 36 Digital LPF, 37 Optical position sensor, 38 …… Light emitting element, 39 …… Linear motor position control circuit

Claims (2)

(57) [Claims] 1. A control device for a transfer means of an optical pickup, comprising at least a means for outputting a tracking control signal including a DC component corresponding to a shift between a light beam and a recording track, wherein the DC component of the tracking control signal is detected. Means for outputting a correction signal for driving the transfer means so that the DC component is substantially zero; means for outputting an access signal according to an access amount in response to an access command; And an adder for adding the correction signal and outputting the addition signal, wherein the transfer means is driven by the correction signal at the time of recording / reproducing, and is driven by the addition signal at the time of access. Optical pickup transfer control device. 2. A control device for a transfer means of an optical pickup, comprising: means for outputting a transfer control signal corresponding to a deviation of the transfer means from a predetermined position; means for detecting a DC component of the transfer control signal; Means for outputting a correction signal for driving the transfer means so that the value becomes substantially 0; means for outputting an access signal corresponding to an access amount in response to an access command; Adding means for adding and outputting an addition signal, wherein the transfer means is driven by the correction signal at the time of recording / reproducing and is driven by the addition signal at the time of access. apparatus.