JPS62270073A - Optical recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain optical recording and reproducing with high positional accuracy by providing a first control part which operates a linear motor at an achievable maximum acceleration and a second control part which controls the motor with high accuracy when an optical system arrives in the vicinity of a target position. CONSTITUTION:The first control part to operate a linear motor 1 at the maximum acceleration capacity is provided and the motor 1 is driven. Thus, the motor 1 is operated at a high speed, and a shifting stand 10 arrives at the target position in a short time. Thereafter, the control device of the motor 1 is changed over to the second control part and the highly accurate control is executed by a speed servo and a position servo. In such a case, the changing- over from the first control part to the second control part is executed by comparing a position signal from a position sensor equipped at the motor 1 and a reference signal to show the prescribed changing-over position provided at the counter, etc.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention is a method for optically reading signals recorded on a disk-shaped recording medium or transmitting signals to a recording medium. The present invention relates to a recording/reproducing device for optical recording.

(Prior Art) In recent years, as shown in FIG. 4, a rotating disk (
14) to optically read audio signals written on the signal surface of the disc (14), the position of which is known, and has been put into practical use as a digital audio disc player.

In this type of recording and reproducing apparatus, a linear motor (1) is used as a conveyance device to move the movable table (10) at high speed (see, for example, Japanese Patent Laid-Open No. 142782/1982).

As is well known, the linear motor (1) has a built-in drive control section that generates a drive voltage based on a puff signal input as a control signal.

In general, it is difficult to set a linear motor (1) to an accurate operating speed depending on drive voltage control, so conventionally a speed servo system consisting of a speed sensor (11) and a speed servo circuit is connected to the drive control unit. It is used as.

As the speed sensor (11), it is possible to use, for example, a speed eddy current detection type sensor formed by combining a moving coil and a stator.

In addition, in the recording and reproducing apparatus, the positioning accuracy of the optical system must be set within several tens of microns, so the linear motor (1) is equipped with a speed sensor (1) as shown in FIG.
1) and a speed servo circuit (3), as well as a position sensor (12) and a position servo circuit (4).
As the zero position sensor (12) equipped with a position servo system consisting of, for example, a rotary potentiometer is used.

In the above control means, for example, when moving the optical system from point A to point D as shown in FIG. 5(a), the operating speed of the linear motor is set to a target value S as shown in FIG. 5(b).
Set to 0. Accordingly, the speed servo circuit (3
) and position servo circuit (4) control the linear motor (1), to which a driving voltage (1) for accelerating the linear motor is applied as shown in FIG. 5(e).

Further, in the vicinity of the target position, a drive voltage V2 for decelerating the linear motor is applied as shown in FIG. 5(c).

As a result, the linear motor operates at the speed S shown in FIG. 5(d) to set the optical system at the target position.

(Problem to be Solved) However, in the conventional optical recording/reproducing device, the position servo and speed servo were activated from the beginning of the movement of the moving table (10), so the speed of the moving table (10) was controlled by the linear motor. There was a problem that the ability was considerably lower than (1) and the access time was long.

(Means for Solving the Problems) An object of the present invention is to provide an optical recording/reproducing device that can move the moving table (10) at a higher speed and has high positioning accuracy.

The optical recording/reproducing device according to the present invention has a linear motor (1
), the control means includes a first control section that operates at least in the first half of the section in which the optical system is to be moved and causes the linear motor (1) to operate at the maximum achievable acceleration; The motor is equipped with a second control section that operates when the linear motor (1) is activated and controls the linear motor (1) with high precision.

<Function> In the movement section from the current position of the optical system to the target position, at least in the first half, the first control unit controls the linear motor (1
).

The first control section creates a control signal that causes the linear motor (1) to operate at its maximum acceleration capacity without applying speed servo and position servo to the linear motor (1). to drive.

As a result, the linear motor (1) suddenly accelerates, and the conventional linear motor (1) with speed servo and position servo
The movable table (10) reaches the vicinity of the target position in a shorter time than before.

Thereafter, the control means for the linear motor (1) is switched to the second control section, and highly accurate control is performed by, for example, the same speed servo and position servo as in the prior art.

The switching signal for switching the control means from the first control section to the second control section is a position signal from a position sensor equipped on the linear motor (1), as described later.

It can be created by comparing it with a reference signal representing a predetermined switching position set on a counter or the like.

(Effects of the Invention) In the optical recording/reproducing apparatus according to the present invention, the speed servo and position servo are turned off at least during the first half of the movement of the moving table, and the linear motor operates at the maximum achievable speed. The time to reach the target position is shorter than before.

However, since highly accurate position control is performed by the second control section in the vicinity of the target position, the setting accuracy of the optical system with respect to the signal track of the recording medium is as high as in the prior art.

(Embodiment N) FIG. 1 shows an embodiment of an optical recording/reproducing apparatus according to the present invention.

Like the conventional device, the linear motor (1) has a speed servo system consisting of a speed sensor (11) and a speed servo circuit (3), and a position sensor (12) and a position servo circuit (4).
), and both servo systems constitute a second control section.

The first control unit includes a control processor (2) composed of a CPU, ROM, etc., and first to third counters (21) (
22) (23) Consists of a pulse generation circuit (6) and a waveform shaping circuit (5), and the input signal to the control section is a position signal connected from the position sensor (12) to the waveform shaping circuit (5). Q, and the output signal is a control pulse signal P to the linear motor (1).

Further, the first control section and the second control section are connected to each other via first and second servo switches (7) and (70).

Hereinafter, from the current position A shown in FIG. 2 (a>) to the target value IfD.
The operations leading up to this will be explained.

In the control processor (2), position information corresponding to the current position A and position information corresponding to the target value WD are set, for example, based on the address information written in the signal track, and the 1ti11 control processor ( 2) is based on this position information and a preset control program, and a position B where the acceleration pulse generation period transitions to the deceleration pulse generation period, which will be described later, and from the control by the first control unit to the second
The first to third counters (21)
<22) Initialize 23). That is, the first counter (21) adds the second counter to the number of pulses corresponding to the distance between AB.
The counter (22) is set to the number of pulses corresponding to the distance between BCs, and the third counter (23) is set to the number of pulses corresponding to the distance between CDs.

First, the first control section operates to move the movable table (10) from point A to point C. At this time, the first servo switch (
7) and the second servo switch (71) are both set to the open state.

The control processor (2) operates the pulse generation circuit (6), and the pulse generation circuit (6) sends the acceleration pulse P1 shown in FIG. 2(b) to the linear motor (1), causing the linear motor (1) to Drive in the target direction with maximum acceleration.

When the linear motor (1) is started, the position sensor (12) generates a pulse signal that becomes the position signal Q according to the distance traveled by the moving table (10). The position signal Q passes through the waveform shaping circuit (5) and is sent to the first to third counters (21) (2
2') (supplied to 23 units).

In the process of the mobile platform (10) going from point A to point B, the first counter (21) is counted down by the position signal Q, and when the mobile platform (10) reaches point B,
The count of the first counter (21) becomes zero.

At the same time, a signal is sent to the pulse generation circuit (6) to notify the arrival at point B, and as a result, the pulse generation circuit (6) transmits the deceleration pulse P2 shown in FIG. 2(b) to the linear motor (1). ) to apply the brake.

As a result, as shown in FIG. 2(c), the moving platform (10) increases the speed S at the maximum achievable acceleration until reaching point B, and decreases the speed from point B to point C.

In the process of the mobile platform (10) going from point B to point C, the second counter (22) is counted down by the position signal Q, and when the mobile platform (10) reaches point C, the second counter (22) counts down. becomes zero. As a result, the pulse generation circuit (6) stops supplying pulses to the linear motor (1), and the first servo switch (7)
Then, the second servo switch 70) is switched to the closed state, and the second control section shifts to precision control.

By closing the first servo switch (7), the linear motor (1), position sensor (12), waveform shaping circuit (5), third counter (23), D/A converter (8
), and the position servo circuit (4) constitute a position servo loop.

Further, when the second servo switch (70) is closed, the linear motor (1), the speed sensor (11), and the speed servo circuit (3) form a speed servo loop.

The position signal Q output by the position sensor (12) is sent to the third counter (23) via the waveform shaping circuit (5).
The position and speed control is performed by the second control section until the count of the counter (23) converges to zero.

As a result, as shown in FIG. 2(c), the moving table is not further decelerated until it reaches the swing position.

In the above-mentioned optical recording/reproducing device, as is clear from the comparison between FIG. 2(c) and FIG. 5(d), the linear motor (
In 1), most of the moving distance of the moving table (10) is operated at high speed, so the access time is shorter than that of the conventional method.

Therefore, when the present invention is implemented in a digital audio disc player, operations such as skipping song selection can be performed quickly.

It goes without saying that the configuration of each part of the present invention is not limited to the above-mentioned embodiments, and various modifications can be made within the technical scope of the claims.

For example, in Fig. 2(b), from point B to point C, a deceleration pulse is applied to the linear motor (1) to apply a brake to the movement of the moving platform (10). omitting the application of
It is also possible to shift to position and speed control by the control unit, which can be easily implemented by modifying the program set in the control processor (2).

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the circuit configuration of an optical recording/reproducing device according to the present invention, FIG. 2 is a diagram explaining the operation of the device,
Fig. 3 is a block diagram of a conventional control means, Fig. 4 is a partially cutaway plan view showing the main parts of the drive system of a recording/reproducing device, and Fig. 5 is a block diagram of a conventional control means.
The figure is a diagram explaining the operation of the conventional device. (1)...Linear motor (2)...Control processor (3)...Speed servo circuit (4)...Position servo circuit (11)...Speed sensor (12)...
・Position sensor application Person: Sanyo Electric Co., Ltd. Tsuji IJ″: x:

Claims (3)

[Claims] (1) A linear motor (1) that drives a moving table (10) equipped with an optical system for optically recording or reproducing signals in the radial direction of a disk (14) serving as a recording medium;
In an optical recording/reproducing apparatus comprising a control means for controlling the linear motor (1) to set the optical system at a predetermined track position, the control means has a control means for moving the optical system. a first control section that operates at least in the first half of the section to operate the linear motor (1) at the maximum achievable acceleration; and a first control section that operates when the optical system reaches the vicinity of the target position to operate the linear motor (1) with high precision. 1. An optical recording/reproducing device characterized in that it is equipped with a second control section for controlling. (2) The first control section includes a counter (21) for setting a section in which the linear motor (1) is operated at maximum acceleration, and an acceleration for the linear motor (1) that operates according to a command from the counter (21). The optical recording and reproducing apparatus according to claim 1, further comprising a pulse generating circuit (6) for generating pulses. (3) The second control section consists of a speed servo system and a position servo system, and the speed servo system includes a speed sensor (11) that detects the speed of the moving table (10), and a speed sensor (11) that detects the speed of the moving table (10).
The position servo system consists of a speed servo circuit (3) that controls the linear motor (1) based on the output signal of the
A position sensor (12) that detects the position of the moving platform (10)
and a position servo circuit (4) that controls the linear motor (1) based on the output signal of the position sensor (12). playback device.