JP2768410B2 - Optical information recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording / reproducing apparatus for optically recording or reproducing information by reciprocatingly moving an information recording medium and an optical head.

[0002]

2. Description of the Related Art Magnetic and optical methods have been known as information recording / reproducing apparatuses for recording or reproducing information by relatively reciprocating an information recording medium and a head. In recent years, an optical method using a light beam has attracted attention. As the shape of the recording medium of the optical information recording / reproducing apparatus, there are an optical disk for rotating a disk-shaped recording medium, an optical card for reciprocating a card-shaped recording medium, and an optical tape. Each of these has advantages and disadvantages, and is properly used depending on the purpose, application, and the like. Among them, optical cards are excellent in productivity, portability, accessibility, and have a wide range of applications.
There are various methods for scanning an optical card with a light beam.The irradiation position of the light beam is relatively linearly moved on a recording medium to reciprocate, and the irradiation position of the light beam is set in a direction orthogonal to the reciprocation. The method of relatively moving and scanning has advantages that the mechanism is simple and accuracy is easily obtained.

As a means for reciprocating such an optical card, a system using a voice coil type linear motor has recently been proposed. FIG. 5 is a side view showing a reciprocating device using the voice coil type linear motor,
FIG. 6 is a sectional view thereof. 5 and 6, reference numeral 1 denotes a carriage on which the optical card W is placed. The carriage 1 has a holding mechanism 23 for the optical card W on the upper surface, and a slide bearing portion 24 is provided on the lower portion. Two slide shafts 33 are fixed to the apparatus main body 25, and the shafts 33 are slidably fitted to the slide bearing portions 24. With this structure, the carriage 1 can move in the Y direction along the slide shaft 33. The linear motor coil 1 is provided between the two slide shafts 33.
4 is attached, and moves in the Y direction integrally with the carriage 1. At the upper and lower portions of the linear motor coil 14, yokes 26, 2 having both ends fixed to the apparatus main body 25 are provided.
7 are installed along the Y direction. This yoke 26,
Numeral 27 forms a magnetic circuit coupled with the iron pieces 29 and 30 together with the yoke 28 provided inside the linear motor coil 14. Further, permanent magnets 31 and 32 are attached to the yokes 26 and 27 such that the N poles or S poles face each other.

In the reciprocating device, a current is supplied to the linear motor coil 14 and the direction of the current is reversed to obtain a driving force in the Y direction, so that the carriage 1 reciprocates. Accordingly, an optical head (not shown) provided above the carriage 1 relatively moves in the X direction, and at this time, a track on the optical card W is selected.
The light beam of the optical head is scanned on the information track of the optical card W.

FIG. 7 is a block diagram showing a control system of the optical card reciprocating device. In the figure, 2 is an encoder for detecting the speed of the linear motor, 3 is a waveform shaping circuit for shaping the encoder signal into a rectangular wave, and 4 is a reference signal of a constant frequency output from a reference frequency generating circuit 5 and a waveform shaping circuit. An FV converter that generates a frequency error signal from the output signal of 3, and a lock detection circuit 6 that detects that the speed of the linear motor has reached a predetermined speed based on the output of the FV converter 4. Reference numeral 7 denotes a main control circuit for controlling each part of the apparatus, 8 denotes a phase compensator, and 9 denotes one of the polarity switching circuit 12 and the phase compensator 8 or the acceleration / deceleration drive voltage generation circuit 10 according to an instruction from the main control circuit 7. Switch to connect. The acceleration / deceleration drive voltage generation circuit 10 is a circuit that generates acceleration and deceleration voltages of the linear motor in accordance with an instruction from the main control circuit 7, and is forcibly applied to the linear motor coil 14 when the linear motor starts and stops. . The polarity switching circuit 12 is a circuit that switches the polarity of the coil drive voltage in accordance with the moving direction of the carriage 1 according to an instruction from the main control circuit 7. 13 is a driver for amplifying the drive voltage of the linear motor coil 14, and 15 and 17 are the carriage 1 respectively.
A reversing sensor 16 for detecting the end of the reversing sensor, and a light shielding plate 16 provided between the reversing sensors.

Next, the operation of the optical card reciprocating movement control device will be described with reference to a time chart shown in FIG. FIG. 3A shows the speed of the carriage 1 in the L direction and the R direction, and shows the speed of the optical card on the carriage 1 during the reciprocating movement. FIG. 3B shows the drive voltage of the linear motor coil 14 output from the driver 13, and FIG.
FIG. 3D shows a switch switching signal output from the main control circuit 7 to the switch 9.
This is an acceleration / deceleration signal for instructing acceleration / deceleration to speed. Also,
FIG. 7E shows a lock detection signal output from the lock detection circuit 6 to the main control circuit 7 when the speed of the carriage 1 reaches a predetermined speed, and FIG. Is a polarity switching signal output to the switch.

The main control circuit 7 first outputs a high-level acceleration / deceleration signal to the acceleration / deceleration driving voltage generation circuit 10 and outputs a high-level polarity switching signal to the polarity switching circuit 12 at point A in the initial state. As a result, the polarity of the drive voltage of the driver 13 is switched to move the carriage 1 in the L direction, and the acceleration drive voltage is applied to the linear motor coil 14. The carriage 1 has a linear motor coil 14
As shown in FIG. 8A, the driving is accelerated in the L direction. On the other hand, the encoder signal of the encoder 2 attached to the carriage 1 is converted into a rectangular wave by the waveform shaping circuit 3 and then output to the FV converter 4. The FV converter 4 compares this signal with the reference signal of the reference frequency generation circuit 5 to create a frequency error signal, and outputs it to the lock detection circuit 6. The lock detection circuit detects the speed of the carriage 1 from the frequency error signal, and outputs a high-level lock detection signal to the main control circuit 7 as shown in FIG.

The main control circuit 7 outputs a switch switching signal to the switch 9 at the point B receiving the lock detection signal. As a result, the switch 9 is connected to the (A) side,
Switching to closed loop speed control. In this case, the frequency error signal from the FV converter 4 is phase-compensated by the phase compensator 8 and then output to the driver 13 to drive the linear motor coil 14. As a result, the carriage 1
As shown in (a), it is sent in the L direction at a constant speed. When the carriage 1 reaches the vicinity of the stop position in the L direction during this movement process, the reversing sensor 15 outputs the high-level detection signal (FIG. 8 (g)) to the main control circuit 7 at point C. The main control circuit 7 sets the switch switching signal to a low level in accordance with the detection signal, connects the switch 9 to the (b) side, and sets the polarity switching signal to a low level so that the linear motor coil 14
Is switched to a polarity for deceleration, and the acceleration / deceleration signal is set to a high level to generate a deceleration drive voltage.
As a result, the speed control is released, and the deceleration drive voltage is applied to the linear motor coil 14, so that the carriage 1
The brakes are applied and the speed drops rapidly. Then, at a point D where the carriage 1 decelerates and reaches a predetermined speed, the main control circuit 7 sets the acceleration / deceleration signal to low level and stops the application of the deceleration drive voltage to the linear motor coil 14. The carriage 1 continues to move due to the inertial force even after the drive voltage is stopped, but further decelerates due to friction and stops at the point E.

Thereafter, the main control circuit 7 controls the carriage 1 to move in the opposite R direction. First, G
At this point, the driving voltage for acceleration is applied to the linear motor coil 14 in the same manner as described above, and when the lock detection signal is output at point H, the switch 9 is switched to switch the control mode to speed control. Further, the carriage 1 is detected by the reversing sensor 17.
Is detected to have reached the vicinity of the stop position in the R direction, the main control circuit 7 applies a drive voltage for deceleration to the linear motor coil 14 at the point I. Thereafter, the main control circuit 7 stops the application of the deceleration drive voltage to the linear motor coil 14 at the point J where the speed of the carriage 1 has been reduced to the predetermined speed. The carriage 1 is further decelerated by friction as described above, and stops at the point K. After that, the main control circuit 7 performs the movement control in the L direction again and alternately repeats the movement control in the L and R directions, thereby reciprocating the carriage 1.

[0010]

However, in the above-mentioned conventional reciprocating movement control device, when the device main body is tilted, there is an effect due to a component force of gravity or a force due to elasticity of a cable connected to the carriage. Therefore, it is difficult to surely stop the carriage. In addition, when the carriage is stopped, the speed is sufficiently reduced near the target stop position, and the carriage is stopped by a frictional force.

The present invention has been made to solve such a problem, and its object is to move a carriage to a target position.
Another object of the present invention is to provide an optical information recording / reproducing apparatus capable of stopping smoothly in a short time .

[0012]

The purpose of the present invention, in order to solve the problems] controls a voice coil type linear motor for driving a carriage card-like information recording medium is placed, the driving of the linear motor, the carriage Means for reciprocating the recording medium at a constant speed, an optical information recording and reproducing apparatus for recording or reproducing information on a medium by irradiating the recording medium with a light beam while the carriage is moving; A sensor for detecting a position; a means for generating a position error signal with respect to a target position of the carriage from an output signal of the sensor; and a method for stopping or reversing the carriage based on the position error signal.
Hand that performs position control to stop the carriage at the target position
And a position control means, wherein the carriage is located
This is achieved by the optical information recording / reproducing apparatus , wherein the position control is started after decelerating to a constant speed .

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the optical information recording / reproducing apparatus of the present invention. In FIG. 1, the same components as those of the conventional device shown in FIG. 7 are denoted by the same reference numerals, and the description thereof will be omitted in this embodiment.

In FIG. 1, reference numeral 20 denotes a low-speed drive voltage generating circuit for outputting a drive voltage for moving the carriage 1 at a low speed to a target inversion sensor after the carriage 1 has been decelerated to a predetermined speed, and 21 is a main control circuit. A switch for selectively switching the phase compensator 8, the acceleration / deceleration drive voltage generation circuit 10, the low-speed drive voltage generation circuit 20, and a phase compensator 23 to be described later according to an instruction from 22. 24 is the main control circuit 2
A switch for selecting one of the inversion sensors 15 and 16 in accordance with the instruction of 2. The output signal of the inversion sensor 15 or 16 selected by the switch 24 is compared at a constant level, and the comparison signal is mainly controlled. Circuit 2
2 is a comparator circuit. This comparator signal is a start signal for controlling the position of the carriage 1 as described later. 26 is a differential amplifier for comparing the output signal of the inversion sensor selected by the switch 24 with a constant voltage corresponding to the target position outputted from the constant voltage generating circuit 27 to generate a position error signal, Is a phase compensator for compensating the phase. These inversion sensors, constant voltage generation circuits, differential amplifiers, and phase compensators
When the carriage 1 is stopped by forming a closed position control system, the carriage 1 is stopped at a predetermined position by the operation of the position control system. The other configuration is the same as that of FIG.

FIG. 2 is a circuit diagram showing a specific configuration of the reversing sensor 15. The reversing sensor 15 is a light emitting diode D
And a photo-interrupter in which a photo-transistor Q is combined, and is mounted at a predetermined position in a casing of the apparatus. Further, the light shielding plate 16 is fixed to the carriage 1, and the end of the light shielding plate 16 shields the photo interrupter when the carriage 1 moves in the L direction. FIG. 3 shows the relationship between the output voltage v of the inversion sensor 15 and the position of the light-shielding plate 16. When the inversion sensor 15 is not shielded from light by the light-shielding plate 16, the phototransistor Q is turned on. 0V. When the end of the light-shielding plate 16 reaches an intermediate position of the photo-interrupter in the direction of travel of the light-shielding plate, the photocurrent of the phototransistor Q is halved, and the output voltage v is almost の of the power supply voltage. In this case, it is when the carriage 1 reaches the target position in the L direction, and the output voltage at this time becomes a voltage corresponding to the target position. Therefore, the voltage of the constant voltage generation circuit 27 is set to this voltage, and the differential amplifier 26 generates a position error signal based on this voltage. Further, when the light shielding plate 16 completely shields the reversing sensor 15, the output voltage becomes substantially equal to the power supply voltage. On the other hand, the reversing sensor 17 in the R direction is also constituted by a photo interrupter in the same manner, and is fixed at a predetermined position in the housing of the apparatus. Therefore, also in the inversion sensor 17, the output voltage changes depending on the positional relationship with the other end of the light shielding plate 16, and when the output voltage of the inversion sensor 17 becomes almost 電源 of the power supply voltage in the same manner as described above. , When the carriage 1 reaches the target position in the R direction.

Next, the operation of this embodiment will be described with reference to a time chart shown in FIG. The main control circuit 22
First, at a point A in the initial state, a switch switching signal ((c) in the figure) is sent to the switch 21 and the switch 21 is turned (
To the side. At this time, the polarity switching circuit 12 switches the polarity of the driving voltage of the driver 13 in advance so as to move the carriage 1 in the L direction according to an instruction from the main control circuit 22. In this state, the main control circuit 22 sends the acceleration / deceleration drive voltage generation circuit 1
The acceleration / deceleration signal ((d) in the figure) is sent to 0, whereby the acceleration drive voltage ((b) in the figure) power-amplified by the driver 13 is applied to the linear motor coil 14. By this driving, the carriage 1 is accelerated as shown in FIG. The linear motor coil 14
As described above, it is fixed to the carriage 1 and generates a thrust proportional to the supplied current, and serves as a drive source for moving the carriage.

On the other hand, the FV converter 4 generates a frequency error signal from the encoder signal converted into a rectangular wave by the waveform shaping circuit 3 and the reference frequency signal of the reference frequency generation circuit 5 and outputs the signal to the lock detection circuit 6. The lock detection circuit 6 detects that the moving speed of the carriage 1 has reached a predetermined speed based on the frequency error signal, and outputs a lock detection signal (FIG. 9E) to the main control circuit 22. At point B where the lock detection signal is output, the main control circuit 22 sets the acceleration / deceleration signal ((d) in the figure) to low level, and switches the switch 21 to the (a) side. As a result, the control mode is switched from the acceleration mode to the speed control mode, the linear motor coil 14 is driven based on the frequency error signal phase-compensated by the phase compensator 8, and the carriage 1 is moved in the L direction at a constant speed k. Can be Further, the main control circuit 22 outputs a high-level switching signal ((i) in the figure) to the switch 24 at the point B,
4 to the (e) side. That is, since the carriage 1 is now moving in the L direction, the reversing sensor 15
Is selected. At the time of speed control, the optical card placed on the carriage 1 is irradiated with a light beam from the optical head, and the light track is scanned on the information track. As a result, information is recorded or reproduced on the information track.

The main control circuit 22 measures the initial moving distance from the position A by counting the number of encoder pulses input from the waveform shaping circuit 3. At a point C which has moved a predetermined moving distance, the main control circuit 22
Connects the switch 21 to the (b) side again, sets the polarity switching signal ((f) in the figure) to a low level, and outputs a deceleration voltage, so that the deceleration drive voltage (the figure) is applied to the linear motor coil 14. (B)) is applied. As a result, FIG.
The brake is applied to the carriage 1 as shown in FIG. At the time of this deceleration, the main control circuit 22 determines that the speed of the carriage 1 is equal to the predetermined speed
, The acceleration / deceleration signal ((d) in the figure) is set to a low level at the detection point D, and the deceleration operation is released. The carriage 1 further decelerates due to frictional force and the like even after the deceleration is released. In this case, when the end of the light shielding plate 16 has not reached the position where the reverse sensor 15 is shielded from light, the main control circuit 22 switches the switch 21 at time E when the speed of the carriage 1 is reduced to the predetermined speed m (c). , And the polarity switching signal (FIG. 9 (f)) is set to a high level so as to be further moved in the L direction. At the same time, a low-speed drive signal ((k) in the figure) is output to the low-speed drive voltage generation circuit 20, and a drive voltage ((b) in the figure) for driving the carriage 1 at a low speed is applied to the linear motor coil 14. As a result, the carriage 1 continues to move in the L direction at a low speed, and during this movement, the output voltage of the reversing sensor 15 is applied to the comparator circuit 25.
Has been sent to The comparator circuit 25 is the reverse sensor 1
When the output voltage of No. 5 reaches a predetermined voltage, a high-level comparator signal (FIG. 10 (j)) is output to the main control circuit 22. The main control circuit 22 switches the switch 21 to the (d) side at the point F where the comparison signal is output, and inverts the polarity switching signal (FIG. 7 (f)) to a low level. If the light shielding plate 16 shields the reversing sensor 15 while the carriage 1 reaches the point E from the point D, the switch 21 is moved to the (d) side when the comparator output signal rises to the high level. What is necessary is just to switch.

On the other hand, in the differential amplifier 26, the inversion sensor 15
Is compared with the constant voltage of the constant voltage generating circuit 27 to generate a position error signal. The output voltage of the constant voltage generation circuit 27 is set to a voltage corresponding to the target position of the inversion sensor 15 as described with reference to FIG.
6 generates a position error signal by taking the difference between this voltage and the output signal of the inversion sensor 15. Therefore, the position error signal changes according to the relative position between the reversing sensor 15 and the light shielding plate 16. For example, when both voltages match, the carriage 1
Reaches the target position in the L direction, and the position error signal becomes 0. After this position error signal is phase-compensated by the phase compensator 23, it is output to the driver 13 through the switch 21.
It is provided to the linear motor coil 14. As a result, the position control loop is closed, and the control mode shifts to the position control mode. In the position control, the feedback control works so that the output voltage of the constant voltage generation circuit 27 where the output voltage of the reversing sensor 15 is the target value matches, so that the carriage 1 automatically moves to the target position in the L direction. To stop. This completes the movement of the carriage 1 in the L direction.

The main control circuit 22 closes the position control loop for a necessary time to hold the carriage 1 in a stopped state, and then starts control to feed the carriage 1 in the R direction. Since the control operation in the R direction is basically the same as the control operation in the L direction described above, a brief description will be given below. First, at the point G, the switch 21 is switched to the (b) side, the acceleration / deceleration signal is set to the high level, and the driving voltage for acceleration is set to the linear motor coil 1.
4 is applied. Thus, the carriage 1 is accelerated in the R direction, and when a lock detection signal is output at the H point, the carriage 1 is switched to speed control and further sent in the R direction. After that, the main control circuit 22 applies a drive voltage for deceleration to the linear motor coil 14 at a point I, and applies a brake to the carriage 1 to decelerate. Further, the deceleration brake is released at the point J decelerated to the predetermined speed, the low-speed drive is switched at the point K further decelerated, and at the point L, the position control loop is closed again and the feedback control using the position error signal of the differential amplifier 26 is performed. Switch to. In this case, the switch 24 is switched to (f) at the point H, and the differential amplifier 26 generates a position error signal using the output signal of the inversion sensor 17 in the R direction. As described above, the carriage 1 stops at the target position in the R direction, and one reciprocating movement ends. When the carriage 1 is reciprocated several times, the same operation as described above may be repeated.

In the above embodiment, the comparator circuit detects that the output signal of the inversion sensor has reached the predetermined level, and switches to the position control by the comparator signal. However, the present invention is not limited to this. Alternatively, the control may be switched to position control at a predetermined shuttle position according to the number of count pulses of the encoder. Further, an example has been described in which the speeds l and m are detected after deceleration, the brake is released at the speed l, and the low-speed driving is switched at the speed m. However, the low-speed driving may be omitted by setting the speed l = m. Further, the timing of brake release and the timing of low-speed drive are determined by detecting the speeds l and m. However, when the movement resistance of the carriage and the like are stable, D and E are obtained after a certain time from point C, respectively. Points may be set.
Although the drive voltage during acceleration and deceleration is constant, the drive voltage may be changed. In this case, the drive of the linear motor coil is not limited to voltage drive but may be current drive. Furthermore, although an example of a transmission type optical detection device has been described as an inversion sensor, a reflection type sensor or another sensor may be used. Further, although an example in which acceleration and deceleration are performed by the constant voltage (or constant current) applying means has been described, acceleration and deceleration can be performed by changing the target speed of the speed control means. Further, an example in which an FV converter is used for speed control has been described.
Speed control may be used.

[0022]

As described above, according to the present invention, when stopping or reversing the carriage on which the card-shaped information recording medium is placed, the carriage is stopped at the target position.
Position control, and the position control
By starting after deceleration, the camera is
The ridge can be stopped at the target position reliably and in a short time.
As well as reduce overshoot
Can be smoothly stopped at the target position .

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of one embodiment of the present invention.

FIG. 2 is a circuit diagram showing a specific example of an inversion sensor.

FIG. 3 is an explanatory diagram showing a relationship between an output voltage of a reversing sensor of FIG. 2 and a target position of a carriage.

FIG. 4 is a time chart showing the operation of the embodiment of FIG. 1;

FIG. 5 is a side view showing the structure of an optical card reciprocating device using a voice coil type linear motor.

FIG. 6 is a sectional view of the optical card reciprocating device of FIG. 5;

FIG. 7 is a block diagram showing a control system of a conventional optical card reciprocating device.

FIG. 8 is a time chart showing the operation of the control system of FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Carriage 2 Encoder 4 FV converter 6 Lock detection circuit 8,23 Phase compensator 10 Acceleration / deceleration drive voltage generation circuit 12 Polarity switching circuit 13 Driver 14 Linear motor coil 15,17 Inversion sensor 21,24 Switch 25 Comparison circuit 26 Difference Dynamic amplifier

Claims (1)

(57) [Claims] 1. A control and voice coil type linear motor card-like information recording medium drives the placed carriage, the driving of the <br/> linear motor, said carriage at a constant speed <br/> degree An optical information recording / reproducing apparatus for recording or reproducing information on or from a medium by irradiating the recording medium with a light beam while the carriage is moving. A sensor for detecting the position of the carriage, means for generating a position error signal with respect to a target position of the carriage from an output signal of the sensor, and when stopping or reversing the carriage, the key based on the position error signal.
Means for performing position control for stopping the carriage at the target position;
Wherein the position control means controls the carriage to move at a predetermined speed.
The optical information recording / reproducing apparatus , wherein the position control is started after the vehicle decelerates .