JPH06309006A - Electronic equipment and driving control method - Google Patents

Abstract

PURPOSE:To suppress variation in gain even if the source voltage of the electronic equipment equipped with a driving circuit varying in gain with the source voltage varies. CONSTITUTION:The electronic equipment has a drive signal Generating means 10 which generates a signal for driving the driving system and can control the gain of the signal and a driving circuit 20 which receives the output signal of this driving signal generating means 10 to drive the driving system and also varies the gain of the signal driving the driving system according to the source voltage Vin. A source voltage monitor means 30 monitors and detects variation in the source voltage Vin. The gain control part of the driving signal generating means 10 is controlled according to the variation in the source voltage Vin detected by the source voltage monitoring means 30 and the gain of the signal supplied to the driving circuit 20 is controlled to make the gain of the signal driving the driving system constant irrelevantly to the variation in the source voltage Vin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device such as an optical disk device and a drive control method for its drive system.

[0002]

2. Description of the Related Art Electronic equipment such as an optical disk device and the above-mentioned tape device has various drive systems such as a disk rotation drive system, a tape running drive system, an optical pickup feed mechanism, and an actuator for an objective lens. Is generally composed of a drive signal forming circuit and a drive circuit which receives a drive signal from the drive signal forming circuit and drives a drive system. The drive signal forming circuit 3 is generally a digital servo circuit, and the drive system is driven by a PWM signal.

FIG. 6 shows a drive circuit system of a compact disc player. Reference numeral 1 is a disc, which is rotated at a predetermined rotational speed by a spindle motor 2.

An optical pickup 3 has an objective lens 3L.
Although not shown, a laser light source, an actuator (two-axis device) for vertically moving the objective lens 3L in a direction orthogonal to the signal surface of the disc 1 and a tracking direction parallel to the disc surface, and a split photodetector. Is included. Further, the optical pickup 3 is configured to be transported at a predetermined speed in the radial direction of the disc 1 by the thread feeding mechanism 4.

The received light output signal of the reflected light from the disk 1 obtained from the split photodetector of the optical pickup 3 is supplied to the RF circuit 5. The reproduced RF signal obtained by adding the outputs of the divided photo detectors from the RF circuit 5 is supplied to the digital audio signal processing system and decoded into an analog audio signal.

The reproduced RF signal from the RF circuit 5 is also
It is supplied to the servo circuit 6. The servo circuit 6 constitutes a drive signal forming circuit. In the case of this example, the drive system is the PWM drive system, and various drive signals are output from the servo circuit 6 in the state of the PWM signal. The PWM signal from the servo circuit 6 is supplied to each drive unit via the PWM drive circuit 7.

In the case of a compact disc, a driving unit to be driven is a focus coil for moving the objective lens 3L in a direction orthogonal to the disc surface by an actuator as a biaxial device. Tracking coil for moving in the same direction Thread pickup motor for moving the optical pickup 3 in the radial direction of the disk 1 to feed the scanning position A spindle motor 2 for rotating the disk 1 at CLV (constant linear velocity) is there.

Then, the servo circuit 6 to the drive circuit 7
As a PWM signal as a drive signal to be supplied to the lens 3, which can turn on the focus servo,
In order to search the position of L, the focus search signal is supplied to the focus coil to move the lens 3L up and down. The focus servo signal is supplied to the focus coil to control the focus error to zero. Tracking servo signal for controlling tracking error to zero by using a track jump signal of a predetermined voltage (a constant voltage instead of the PWM signal) supplied to the tracking coil during a track jump. Sled feed signal to be supplied CLV servo signal to be supplied to the spindle motor 2 to rotate the disk in the CLV state. There is a CLV kick signal to start the spindle motor 2 to the pull-in range of the CLV servo. .

The CLV kick signal is not the PWM signal, but the spindle motor 2 is rapidly activated to
A predetermined voltage continues for a certain period of time in order to increase the disk rotation speed to a predetermined rotation speed at which V-servo is possible.

Further, the signal supplied to the focus coil is a focus search signal until the focus servo reaches such an area, and is switched to the focus servo signal when the focus servo error signal FE is obtained in the area.

The signal supplied to the spindle motor 2 is a CLV kick signal for a predetermined time from the start-up until the CLV servo reaches such an area, and is thereafter switched to the CLV servo signal. Further, a tracking jump signal and a tracking error signal are switched and supplied to the tracking coil.

[0012]

By the way, generally, the voltage stabilized by the DC-DC converter is supplied as the power supply voltage to the servo circuit 6, but the drive circuit 7 receives the voltage from the battery or the AC adapter. Vin is applied as the power supply voltage.

Therefore, when the battery is exhausted or the power supply is changed from the battery to the AC adapter, the power supply voltage Vin varies. When the power supply voltage Vin fluctuates in this way, even if the amplitude of the PWM signal as the various drive signals output from the servo circuit 6 is constant, in the drive circuit 7, the amplitude of the PWM signal depends on the fluctuation of the power supply voltage Vin. Will change. Then, the duty ratio as the PWM signal determined by the servo circuit 6 becomes the drive circuit 7.
Even if the input and output are the same, the gain changes due to the change in amplitude.

If the overall gains of the servo circuit 6 and the drive circuit 7 fluctuate in this way, various inconveniences will occur as follows.

The focus search speed fluctuates, which makes it difficult to detect the focus servo-on point, and the time to reach the focus servo-on point becomes long.

The focus servo, tracking servo, and CLV servo become unstable.

The thread feeding speed fluctuates, and it takes time to set the desired scanning position.

When the CLV kick signal is supplied to the spindle motor 2 for a predetermined fixed time T, the disk rotation speed after start-up becomes excessive and insufficient, and the transition to the CLV servo and the pull-in of the CLV servo are smoothly performed. Not done.

In view of the above points, an object of the present invention is to prevent the gain of the entire drive system from changing even if the power supply voltage changes.

[0020]

In order to solve the above-mentioned problems, the wind noise reducing apparatus according to the present invention, a drive system for driving a driven body, and a drive system for driving the driven body, when the reference numerals of the embodiments described later correspond to each other. A drive signal forming means 10 capable of forming a signal for driving the system and controlling the gain of the signal, and an output signal of the drive signal forming means 10 for driving the drive system,
The drive circuit 20 having a property that the gain of the signal for driving the drive system changes according to the power supply voltage, and the power supply voltage monitoring means 30 for monitoring and detecting the fluctuation of the power supply voltage.
And controlling the gain control section of the drive signal forming means 10 according to the fluctuation of the power supply voltage detected by the power supply voltage monitoring means 30 to control the gain of the signal supplied to the drive circuit 20. It is characterized in that the gain of the signal for driving the drive system is made constant regardless of the fluctuation of the power supply voltage.

[0021]

According to the present invention having the above-described structure, the drive signal forming circuit is configured to be able to control the gain of the output drive signal, and the drive is formed in accordance with the power supply voltage detected by the power supply voltage monitoring means. The gain of the signal can be changed. Therefore, even when the power supply voltage fluctuates and the output gain of the drive circuit fluctuates, the total gain of the drive signal forming circuit and the drive circuit can be controlled so as not to change.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings, taking the case of the aforementioned CD player as an example.

FIG. 1 is a block diagram of essential parts of an embodiment according to the present invention. In FIG. 1, 10 is a servo circuit,
Reference numeral 20 is a drive circuit, and 30 is a microcomputer (hereinafter referred to as a microcomputer) for monitoring the power supply voltage Vin of the drive circuit 20 to detect the voltage fluctuation and control the servo circuit as described later.

In the case of this example, the drive circuit 20 drives the actuator as a biaxial device for moving the objective lens in the direction orthogonal to the disc surface and in the direction parallel to the disc surface, in the direction orthogonal to the disc. A focus coil 21 for driving, a tracking coil 22 for driving in a direction parallel to the disc, a feed motor 23 of a sled feed mechanism, and a spindle motor 24 for rotationally driving the disc are connected to each other.

The servo circuit 10 includes a focus drive signal forming circuit 11 and a tracking drive signal forming circuit 1.
2, a sled drive signal forming circuit 13, a spindle drive signal forming circuit 14, and a decoder 15.

As described above, the focus drive signal forming circuit 11 is supplied with the focus error signal FE from the RF circuit (not shown). Similarly, in the tracking drive signal forming circuit 12,
The tracking error signal TE is supplied. Further, the sled drive signal forming circuit 13 is supplied with the sled feed signal SLE, and the spindle drive signal forming circuit 1
A signal SPE for CLV servo is supplied to 4.

In the case of this example, the servo circuit 10 is configured as a digital servo circuit. For example, the focus drive signal forming circuit 11 is configured as shown in FIG.

That is, 121 is a register for latching an input focus error signal, and the output of this register 121 is supplied to the digital filter 122. The output of the digital filter 122 is passed through the weight control weighting circuit 123 for gain control and the switch circuit 124 to output PW.
It is supplied to the M signal generator 125. The weighting circuit 123 is supplied with coefficient data for gain adjustment from the servo gain register 126.

When the switch circuit 124 is switched to the state shown in the figure, the information formed from the focus error signal FE is supplied to the PWM signal generating section 125 in the state of the focus servo, and the state shown in the figure is obtained at the time of the focus search. The state is switched to the opposite state, and the information from the search register 127 is supplied to the PWM signal generator 125. The search register 127 generates information for focus search.

The PWM signal generator 125 outputs a PWM signal having a pulse width corresponding to the information given thereto as the focus drive signal FC. The switch circuit 124 is switched to the state shown in the figure when the focus search is performed and the focus error signal FE is obtained.

The information in the servo gain register 126 and the search register 127 is rewritten with the data sent from the microcomputer 30 when the load pulse from the decoder 15 is given.

Other drive signal forming circuits 12, 13, 1
4 has a similar structure. Then, in the case of the tracking drive signal forming circuit 12, the track error signal is fetched in the register 121. The register 127 serves as a track jump voltage setting register, and the switch circuit 124 is used at the time of track jump.
However, by switching to the register 127 side, the track voltage corresponding to the track jump is supplied to the drive circuit 20 as the tracking drive signal TR.

Further, the thread drive signal forming circuit 13
In this case, the servo signal SLE is loaded into the register 121. The register 127 is used for setting the sled move voltage described above.

Further, the spindle drive signal forming circuit 1
In case of 4, the CLV error signal SP is sent to the register 121.
Take in E. The register 127 is used for setting a kick voltage for raising the spindle motor. Then, the voltage of a constant value determined by the information of the kick register is supplied to the motor 24 as the spindle drive signal SP through the drive circuit 25 for the predetermined time T determined by the command from the microcomputer 30. .

The microcomputer 30 includes a CPU 31, a program ROM 32, a work area RAM 33, a communication interface 34, and an I / O port 35. Then, the power supply voltage Vin of the drive circuit 20 is taken in via the A / D converter 36 via the I / O port 35, and the fluctuation of this voltage Vin is constantly monitored. The A / D converter 36 can be realized as software of a microcomputer.

Serial data is transferred from the communication interface 34 of the microcomputer 30 to the servo circuit 10. That is, in this case, the latch signal LA, the serial data DA, and the clock CLK are supplied to the servo circuit 10 through the interface 34.

The servo circuit 10 decodes the data from the microcomputer by the decoder 15 and determines which register of which drive signal forming circuit the transmitted data is. And the microcomputer 30
The serial data from is also sent to the registers of the drive signal forming circuits 11, 12, 13 and 14, and the load signal is sent to the register of the destination of the data detected by the result decoded by the decoder 15. The data is supplied from the decoder 15 and the data is written in the corresponding register.

Next, the control of the servo gain according to the fluctuation of the power supply voltage Vin will be described below.

[During Servo ON] When the power supply voltage Vin of the drive circuit 20 fluctuates while the servo is on, the microcomputer 30 operates as shown in the flowchart of FIG. 1
The contents of the servo gain registers 2, 13, and 14 are rewritten according to the power supply voltage fluctuation.

That is, referring to the flowchart of FIG. 3, first, the microcomputer 30 converts the power supply voltage Vin into a digital signal by the A / D converter 36 and takes it from the I / O port 36 (step 101).

Then, K = a / Vin + b is calculated for each filter. In this case, K is
Servo gain register 126 of each drive signal forming circuit
Is a coefficient value supplied to. It should be noted that a and b are unique values that are predetermined in correspondence with the servo gain registers of the respective drive signal forming circuits, but for simplicity of explanation, they are all represented by a and b. The coefficients are similarly different, but are represented by K. The same applies hereinafter.

Next, step 102 to step 103
Then, the identification data indicating which register it belongs to is added before each coefficient value data to form transmission data DA, which is serially transferred to the servo circuit 10. The operation of the microcomputer 30 is completed as described above.
The servo circuit 10 controls the decoder 15 to discriminate the identification data in the data sent by the serial transfer and write the data of each coefficient value into the corresponding register.

When the servo is turned on, the filters controlled are all the focus drive signal forming circuit 11, the tracking drive signal forming circuit 12, the sled drive signal forming circuit 13, and the spindle drive signal forming circuit 14.

In this case, the output PWM signal is as shown in FIG.
When the power supply voltage Vin rises in the case of A, the weighting circuit 123 is set so that the output pulse width becomes narrow and the total gain does not change, as shown in FIG. 4B. When the power supply voltage Vin becomes low, the coefficient supplied to the weighting circuit 123 is controlled so as to widen the pulse width, as shown in FIG. 4C.

[During track jump and thread move]
When a track jump occurs, it is necessary to supply a predetermined track jump voltage to the tracking coil 22. Further, it is necessary to supply a predetermined voltage to the sled motor 23 even when the sled move is performed such as moving the optical pickup 3 to the home position. In this case, the switch circuits 124 of FIG.
The desired operation is performed by switching to the 27 side,
The contents of the register 127 are rewritten according to the fluctuation of the power supply voltage.

That is, FIG. 5A shows a flowchart of the operation of the microcomputer 30 at this time. First, the power supply voltage Vin is converted into a digital signal by the A / D converter 36 and is taken in from the I / O port 35 (step). 20
1).

Digital power supply voltage V obtained as a result of this calculation
Using in, the calculation of K = a / Vin + b is performed for each of the track jump coefficient and the thread move coefficient in the same manner as described above (step 202).

Each coefficient thus obtained is stored in the microcomputer 30.
Is sent to the servo circuit 10 by serial transfer (step 203). In the same manner as described above, the servo circuit 10 recognizes that the decoder 15 is a coefficient value rewriting command for the track jump register and a thread move voltage coefficient rewriting command, and the corresponding registers are respectively stored in the corresponding registers. Data is written (step 203).

[At CLV kick] Spindle motor 24
When the power supply voltage Vin fluctuates when the CLV kick for raising the voltage is performed, the supply time T of the CLV kick voltage is controlled in this example. That is, FIG. 5B
Is a flowchart of the operation of the microcomputer 30 at that time, and the microcomputer takes in data obtained by converting the power supply voltage Vin into a digital signal (step 301).

Then, in the same manner as described above, the calculation is performed with T = a / Vin + b above the time T at which a constant voltage is supplied to the spindle motor 24 (step 302).

Next, the microcomputer 30 sends a CLV to the spindle drive signal forming circuit 14 of the servo circuit 10.
Send a kick start command (step 303). Then, the process proceeds to step 304 and waits for the time T calculated as described above. After a lapse of time T, the microcomputer 30 sends a CLV kick stop command as data to the spindle drive signal forming circuit 14 of the servo circuit 10.

The CLV kick voltage may be controlled according to the fluctuation of the voltage Vin without changing the time T. In that case, the register 1 for setting the CLV kick voltage.
The coefficient value of 27 is changed and controlled.

[At the time of focus search] This focus search is exactly the same as that of the power supply voltage Vin.
Is taken in as a digital signal (step 401), a coefficient value to be supplied to the search register 127 is calculated (step 402), and the coefficient value is searched for in the search register 1 of the focus drive signal forming circuit 11 of the servo circuit 10.
It is sent to 27 and rewritten (step 403). Then, the process proceeds to step 404, and from the set focus search speed and the value of the power supply voltage Vin, the time in the search-up direction for bringing the objective lens closer to the disc and the time in the search-down direction for moving the objective lens away from the disc are obtained and adjusted. .

The above example is a case where the present invention is applied to a CD player, but not limited to a CD player, a cassette player and various other drive systems are provided, and an electronic device having a control means for controlling the drive system is provided. The present invention can be applied to equipment. Further, the drive circuit is not limited to the PWM drive type, but can be applied to all circuits in which the gain changes according to the power supply voltage.

[0055]

As described above, according to the present invention, in an electronic device including a drive circuit whose gain changes according to the fluctuation of the power supply voltage, the fluctuation of the power supply voltage is monitored, and according to the fluctuation, Since the gain of the drive signal supplied to the drive circuit is adjusted so that the gain does not change when viewed as a whole, it is possible to avoid various drawbacks that have conventionally occurred.

That is, stable servo can be performed. Further, in the case of the spindle motor, the startup can be performed smoothly. Furthermore, the shift from focus search to focus servo can be stabilized. The optical pickup can be fed stably.

[Brief description of drawings]

FIG. 1 is a block diagram of an essential part of an embodiment of the present invention.

FIG. 2 is a block diagram of a part of FIG.

FIG. 3 is a flowchart for explaining the operation of an example of the present invention.

FIG. 4 is a waveform diagram for explaining gain control of the present invention.

FIG. 5 is a flowchart for explaining an example of the operation of the present invention.

FIG. 6 is a block diagram of an example of a CD player.

[Explanation of symbols]

 10 Servo Circuit 20 Drive Circuit 30 Microcomputer 122 Digital Filter 123 Weighting Circuit 125 PWM Signal Generator 126 Gain Adjustment Register

Claims (7)

[Claims] 1. A drive system for driving a driven body, a drive signal forming means capable of forming a signal for driving the drive system and controlling a gain of the signal, and an output of the drive signal forming means. A drive circuit that receives a signal and drives the drive system, and has a property that the gain of the signal that drives the drive system changes according to the power supply voltage; and a change in the power supply voltage is monitored and detected. A power supply voltage monitoring means, and controls the gain control section of the drive signal forming means according to a variation in the power supply voltage detected by the power supply voltage monitoring means to control the gain of a signal supplied to the drive circuit. An electronic device characterized by controlling the gain of a signal for driving a drive system to be constant irrespective of fluctuations in power supply voltage. 2. The drive signal forming means is a servo circuit which forms the drive control signal as a drive signal in accordance with the movement of the driven body, and by changing the coefficient of the weighting circuit of the output section. The electronic device according to claim 1, wherein the gain of the output drive signal can be controlled, and the coefficient of the weighting circuit is changed according to the fluctuation of the power supply voltage. 3. An electronic device for driving a driven body by supplying a drive signal to a drive system via a drive circuit, the gain of which changes according to the fluctuation of the power supply voltage, and monitoring the power supply voltage, and the fluctuation. Is detected and the gain of the drive signal is adjusted according to the detected power supply voltage fluctuation, and the gain of the signal that drives the drive system is made constant regardless of the fluctuation of the power supply voltage. Drive control method. 4. The electronic device is an optical disc device, the drive system is a feed mechanism for moving an optical pickup in a radial direction of the optical disc, and the drive signal is when the optical pickup scanning position makes a track jump. In addition, the gain of the signal supplied to the feed mechanism for returning to the original position is controlled by controlling the gain control section of the drive signal forming means according to the fluctuation of the power supply voltage. The electronic device according to claim 1, wherein the electronic device is controlled to be constant. 5. The electronic device is an optical disk device, the drive system is a feed mechanism for moving the optical pickup in the radial direction of the optical disk, and the drive signal is a predetermined signal in the radial direction of the optical disk. The transfer is performed at a speed, and the gain control unit of the drive signal forming unit is controlled according to the fluctuation of the power supply voltage so that the gain of the signal supplied to the feeding mechanism is controlled to be constant. The electronic device according to claim 1, which is characterized in that. 6. The electronic device is an optical disk device, the drive system is a motor for rotationally driving the optical disk, and the drive signal is a signal for raising the optical disk to near a predetermined rotational speed. According to the fluctuation of the power supply voltage, the gain control unit of the drive signal forming means is controlled so that the gain of the signal for starting the motor supplied to the motor is controlled to be constant. The electronic device according to claim 1. 7. The electronic device is an optical disk device, the drive system is an actuator for changing the distance between the objective lens of the optical pickup and the optical disk surface, and the drive signal is A focus search signal for bringing the objective lens position by the actuator to a range in which the distance between the objective lens and the optical disk surface can be constantly controlled by the focus servo while keeping the just focus state. The gain control section of the drive signal forming means is controlled according to the fluctuation of the control signal to control the gain of the focus search signal to be constant regardless of the fluctuation of the power supply voltage. Electronic device described.