JP2000215593A - Electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption and to reduce noise of a drive motor. SOLUTION: This electronic instrument performs drive control so that after the rotational frequency of a drive motor became to be within the prescribed lockable frequency range of a phase-locked loop(PLL) by inputting a signal based on the rotational frequency of the motor rotatingly driving a medium to the PLL, when the rotational frequency of the motor reaches an arbitrary upper limit value H1 of the prescribed lockable frequency range 19 by raising the revolving speed of the motor, the motor is made to be natually decelerated, while instantaneously interrupting the supplying of power to the motor and also when the rotational frequency of the motor reached a lower limit value L1, the rotational frequency of the motor is raised again such as by starting the supplying of power to the motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device, and more particularly, to an electronic device with low power consumption and reduced motor noise.

[0002]

2. Description of the Related Art Conventionally, various types of electronic devices with low power consumption have been studied. In particular, portable type C
In electronic devices such as D (compact disk) and MD (mini disk), extending the battery life is an important technical issue. Note that the device is not a portable type device.
No. 2 discloses the CPU load state, the remaining battery capacity,
By variably setting the clock frequency to an appropriate value according to the system state such as the heat generation state of the CPU, there is a technical issue to save unnecessary power consumption of the battery and to prevent destruction of the CPU and malfunction of the system. It has been disclosed.

[0003]

However, the reduction in power consumption of electronic devices such as a personal computer (hereinafter referred to as a personal computer) of the prior art, including the above-described devices, is based on a situation in which an input signal from a keyboard or the like is not input for a certain period of time. It depends on a change in some state, such as when the remaining battery level is very low, or as a result of temperature detection, the temperature inside the apparatus has risen abnormally. Therefore, when these are detected and a change is not particularly felt, that is, when a normal operation is apparently performed, a high-power output is maintained. As a result, there arises a problem that power consumption is not reduced particularly during normal use.
Further, for example, as a result of continuously rotating a medium or the like with high power, there is a problem that noise is generated from the drive motor.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce power consumption based on a unique drive control different from the conventional one and to reduce noise of a drive motor, thereby further reducing power consumption and noise. To provide an electronic device.

[0005]

According to another aspect of the present invention, there is provided an electronic apparatus comprising: a drive motor for rotating a medium; and a servo system for controlling the number of rotations of the drive motor. And a control means for controlling and driving the servo system, and by inputting a signal based on the rotation frequency of the drive motor, a signal that follows the rotation frequency of the drive motor in a predetermined lockable frequency range is transmitted to the servo system. An electronic device having an oscillating PLL (Phase Locked Loop), the control means increases the rotational speed of the drive motor after the rotational frequency of the drive motor falls within a predetermined lockable frequency range of the PLL; When the rotation frequency of the drive motor reaches an arbitrary upper limit within a predetermined lockable frequency range, the supply of power to the drive motor is cut off, and When the lower limit value within the frequency range that can be used is reached, the supply of power to the drive motor is started and the servo system is controlled and driven again to increase the rotation frequency of the drive motor. The motor is driven to rotate intermittently.

[0006] For this reason, although the normal operation is apparently performed, the drive motor is once rotated by the power supply from the servo system, and the rotation frequency is arbitrary within the lockable frequency range of the PLL. When the power rises to the upper limit, the supply of power is temporarily stopped, and the motor is continuously rotated by inertia. Further, when the rotation frequency of the rotation due to the inertia decreases to an arbitrary lower limit, power is supplied again this time. By intermittently repeating the on / off of the power supply in this manner, it is possible to reduce the power consumption while maintaining the rotation of the drive motor within a predetermined rotation speed range.

According to a second aspect of the present invention, in the electronic device according to the first aspect, an arbitrary upper limit is set to a value lower than an upper limit within a predetermined lockable frequency range by a predetermined amount, and the arbitrary lower limit is set. Is a value higher by a predetermined amount than the lowermost limit within a predetermined lockable frequency range. Therefore, the rotation frequency of the drive motor is controlled in a range narrower than the lockable frequency range of the PLL.
The configuration is such that the LL can be prevented from falling outside the lockable frequency range to some extent.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the electronic device will be described as a CD (compact disk) reproducing device.

A CD reproducing apparatus 1 as an electronic apparatus according to the present embodiment is an example of a CD reproducing apparatus designed in various ways. As shown in FIG. 1, a CD (compact disk) 2 as a medium is provided. A spindle motor 3 serving as a drive motor for rotating the spindle motor; a servo system 4 for rotation for controlling the number of revolutions of the spindle motor 3; a CPU 5 as control means for controlling and driving the servo system 4;
(Phase locked loop) 6.

Further, the CD reproducing apparatus 1 comprises an optical pickup 7 for reading information written on the CD 2, a focus servo 8 for moving the optical pickup 7 in a distance direction with respect to the CD 2, and a CD 2 for the optical pickup 7. And a tracking servo 9 for moving in the radial direction with respect to. The optical pickup 7 is moved to C by the focus servo 8 and the tracking servo 9.
By moving it moderately with respect to the board of D2, CD
2 accurately reads the information written therein.

The CD reproducing apparatus 1 further comprises an analog waveform shaping section 10 for shaping an analog waveform formed by reading recorded contents from the surface of the CD 2 with the optical pickup 7, that is, an analog waveform shaping section 10 for binarizing the analog waveform. 2
A synchronization detection unit 11 for synchronizing the digitized data at predetermined intervals (7.35 kHz); and a digital signal processing unit 12 for performing EFM demodulation on the synchronized data and performing predetermined digital processing such as error correction. And R for temporarily storing data digitally processed by the digital signal processing unit 12.
It has an AM 13 and a D / A converter 14 that converts digitally processed data into an analog value.

The CD reproducing device 1 having the above-described components is a device that reproduces a sound source written on the CD 2 by reading digital information written on the CD 2. That is, the CD reproducing device 1 rotates the CD 2 at a predetermined rotational speed by rotating the spindle motor 3 under the drive control of the servo system 4. CD2
A pattern of digital information for reproducing a sound source is formed inside one surface of the CD. When the CD 2 is rotated, the pattern recorded on the CD 2 is read by the optical pickup 7 one after another. .

The data input to the optical pickup 7 is initially input as an analog waveform, but after being binarized and synchronized by the analog waveform shaping section 10 and the synchronization detecting section 11, the digital signal is input. The processing unit 12 performs a predetermined digital process. Further, the digital signal processor 12 also performs code error correction for dealing with dropouts such as scratches and dust. The data subjected to the predetermined digital processing is temporarily stored in the RAM 13 and sent from the digital signal processing unit 12 to the D / A converter 14 according to an instruction from the CPU 5. The information of the sound source sent to the D / A converter 14 as a digital signal in this manner is converted into an analog signal by the D / A converter 14 and reproduced by a speaker or the like.

The CD reproducing apparatus 1 generates a signal based on the data shaped by the analog waveform shaping section 10 when reading the contents recorded on the rotating CD 2 like other various CD reproducing apparatuses. It has become. This signal, that is, the reference signal vr (t) of the frequency fr based on the rotation frequency of the spindle motor 3 is input to the PLL 6. When the frequency fr of the reference signal vr (t) is within a preset frequency range in which the PLL 6 can be locked (hereinafter referred to as a lock range) 19 (see FIG. 3), the PLL 6 is in a locked state. That is, P
When the reference signal vr (t) of the frequency fr input to the LL 6 is within the lock range 19, the reference signal v
The output signal v0 (t) of the frequency f0 output from the VCO 15 in the PLL 6 approaches r (t), and eventually coincides with r (t). Therefore, the rotation frequency of the spindle motor 3 is
The output signal v0 (t) output from the CO 15 follows. With such a configuration, the CD playback device 1
Are designed to stabilize the rotational speed of the spindle motor 3.

As shown in FIG. 2, the PLL 6 has a VCO 1
5, a phase comparator 16, a low-pass filter 17, and an amplifier 18. The PLL 6 adjusts the oscillation frequency of a VCO (voltage controlled oscillator) 15 as an oscillation circuit to a certain reference frequency, or to a frequency fr of an input signal (reference signal vr (t)) that changes with time.
By causing the oscillation frequency f0 of the VCO 15 to follow,
By oscillating to the servo system 4 for rotation,
This is a phase locked loop capable of stably operating the servo system 4 and the like.

In other words, the PLL 6 is a rotating CD.
In the lock range 19, the reference signal vr (t) based on the information
r (t), that is, the rotation frequency f of the spindle motor 3
An output signal v0 (t) of a frequency f0 that follows r oscillates with respect to the servo system 4. With this configuration, the CD reproducing device 1 stabilizes the rotation speed of the CD 2, that is, the rotation frequency of the spindle motor 3 within a frequency range in which the PLL 6 can lock, and suppresses the rotation speed of the spindle motor 3 within a certain width. It is designed to rotate stably.

The lock range 19 is a value programmed in advance, and is a value in a range assuming a rotation frequency corresponding to the rotation speed of the spindle motor 3 which is optimal for reproducing the CD 2. The lock range 19 is, for example, a CD2
The range may be such that the sound is not interrupted, or the range may be further narrowed to enhance the sound quality level. Note that other devices, for example, an embodiment of the
(Digital video disk) In the case of a reproducing apparatus, for example, the lock range 19 may be set to a range where video is not interrupted, but the range may be further narrowed to increase the image quality level.

The spindle motor 3 is rotated at a rotation speed α′r so as to fall within the lock range 19 set as described above.
pm to β 'rpm, the spindle motor 3
Is in the range of α kHz to β kHz, which is a range of the rotation frequency suitable for reproduction of CD2 (see FIG. 3). When rotating the spindle motor 3 in this range, V
The control voltage vc (t) applied to the CO 15 is α ″ v
β ″ v. The CPU 5 outputs the output signal v0
(T) is input.

As shown in FIG. 3, an arbitrary upper limit H1 which is the highest value for controlling the rotation frequency of the spindle motor 3 of the CD reproducing apparatus 1 according to the present embodiment is within the range of the lock range 19. And an arbitrary lower limit L1 that is the lowest value for control. Then, as will be described later, the CD reproducing apparatus 1 of the present embodiment drives the spindle motor 3 and when the frequency reaches the lock range 19 of the PLL 6, the rotation frequency of the spindle motor 3 becomes close to an arbitrary upper limit value H1. The spindle motor 3 is accelerated until it becomes.
Further, when the rotation frequency of the spindle motor 3 reaches an arbitrary upper limit value H1, the supply of power to the spindle motor 3 is cut off. As a result, when the rotation frequency of the spindle motor 3 is naturally reduced to near an arbitrary lower limit value L1, the control is performed so that the supply of power to the spindle motor 3 is started.

That is, the CD reproducing apparatus 1 uses the upper limit H which is an arbitrary range within the lock range 19 in this manner.
The rotation of the spindle motor 3 is controlled in a frequency range between 1 and the lower limit L1. As a result, the average rotation speed of the spindle motor 3 is (α ′ + β ′) /
As a result, the reproduction operation of the CD reproducing apparatus 1 is not hindered.

Such control is intended to stabilize the rotation of the spindle motor 3 by keeping the rotation frequency of the spindle motor 3 out of the range of the lock range 19, that is, at least to prevent the sound from being interrupted. While controlling the drive of the motor 3, the spindle motor 3
This is performed to reduce power consumption by intermittently supplying power to the power supply. In addition, by performing such control, no motor noise is generated while power is not supplied to the spindle motor 3, so that the motor noise is reduced as a whole. As a result, the error rate characteristics are improved,
As a result, sound quality is improved.

The arbitrary upper limit value H1 in FIG. 3 is a value obtained by taking a margin t1 from the uppermost limit value PLLH of the lock range 19, that is, a value lower than the uppermost limit value PLLH by t1. This is because if the frequency of the spindle motor 3 is in the lock range 19 due to an impact or the like while the spindle motor 3 is operating.
This is to prevent the PLL 6 from returning to the initial value when it becomes equal to or more than the upper limit value PLLH. Further, the arbitrary lower limit L1 in FIG. 3 is a value obtained by taking a margin t2 from the lowermost limit PLLL of the lock range 19, that is, a value higher by t2 than the lowermost limit PLLL. This is because if the frequency of the spindle motor 3 is lower than the lower limit value PLLL of the lock range 19 due to an impact or the like while the spindle motor 3 is operating.
This is to prevent the PLL 6 from returning to the initial value due to the following.

The VCO 15 includes a rotation servo 4 and a CPU.
5. An oscillation circuit that oscillates at a predetermined oscillation frequency in each section of the synchronization detection section 11 and the digital signal processing section 12. The oscillation frequency from the VCO 15 to each section becomes an appropriate frequency by being divided by a frequency dividing circuit (not shown). The VCO 15 receives no reference signal vr (t) based on the rotation of the CD 2 (C
When D2 is not rotating), it oscillates with the initially set unique frequency (free running frequency) f0f with respect to the rotating servo system 4. The output signal at this time is v0f (t). The free running frequency f0f is set in advance to a frequency very close to the rotation frequency fr of the spindle motor 3 according to the rotation speed when the CD 2 rotates stably.

The phase comparator 16 receives a signal input to the PLL 6, that is, an input signal (reference signal vr (t)) having a frequency fr based on the rotation frequency of the spindle motor 3, and a free signal which is a signal having a preset frequency. An error signal ve (t) proportional to the phase difference from the output signal v0f (t) corresponding to the running frequency f0f is output. The low-pass filter 17 sends a signal vd (t) obtained by removing an unnecessary high-frequency component from the error signal ve (t) output from the phase difference comparator 16 to the amplifier 18. Further, the amplifier 18 amplifies the signal vd (t) and generates a control voltage signal vc (t) for the VCO 15.

The control voltage signal vc (t) generated by the amplifier 18 has an oscillation frequency f0 oscillated from the VCO 15 (initially a free running frequency set in advance) f0, Frequency f
r, ie, the error signal ve
(T) is changed so as to decrease. As a result, the oscillation frequency f0 oscillated from the VCO 15 eventually becomes the rotation frequency fr of the spindle motor 3.
And the PLL 6 is locked.

The frequency f0 (kHz) of the signal oscillated from the VCO 15 of the PLL 6 varies depending on the rotation speed (rpm) of the spindle motor 3. As described above, the VCO 1
This is because the frequency f0 of the output signal v0 (t) oscillated from 5 follows. That is, when the spindle motor 3 is rotated at a high speed by the control drive of the servo system 4, the frequency f0 increases following the frequency fr based on the rotation speed. Conversely, when the spindle motor 3 is rotated at a low speed by the control drive of the servo system 4, the frequency f0 decreases following the frequency fr based on the number of rotations.

Generally, when the output signal oscillated from the above-described PLL 6 deviates from the lock range 19 of the PLL 6 shown in FIG. 3, the frequency f0 of the signal oscillated from the VCO 15 of the PLL 6 is set in advance. It returns to the initial value of the free running frequency f0f. In such a state, the CD reproducing device 1 cannot reproduce the sound source because the PLL 6 does not operate normally (is not in the locked state). Therefore, the normal CD reproducing apparatus controls the spindle motor to rotate in the above-mentioned frequency range while controlling the rotation frequency by the drive control of the servo system. However, when the PLL is operating normally,
Such a disturbance does not occur at all, and the PLL always keeps the locked state.

In the case of the normal use described above, PL
In the CD reproducing apparatus 1 according to the present embodiment, the servo system 4
As described above, low power consumption and reduction of motor noise can be realized by intentionally changing the voltage under the control of the CPU 5 serving as the control means.

The CPU 5 controls the drive of a rotation servo system 4 for controlling the drive of the spindle motor 3. That is, the CPU 5 controls the rotation speed of the CD 2. The CPU 5 detects the number of rotations of the spindle motor 3 based on the information on the CD 2 input from the optical pickup 7.

That is, the CPU 5 monitors the value of the output signal v0 (t) output from the PLL 6 by the monitoring means 5a.
And issues a drive command to the servo system 4 for rotation based on the content read by the monitoring means 5a.

As a result of monitoring by the monitoring means 5a, P
When the value of the output signal v0 (t) from the LL 6 is within the above-described lock range 19 (with an upper limit H1 as an upper limit), the CPU 5 sends the rotation of the spindle motor 3 to the servo system 4 for rotation. A command signal for increasing the number of revolutions is sent. Thus, even after the PLL 6 is locked, the rotation speed of the CD 2 driven by the spindle motor 3 slightly increases.

When the value of the output signal v0 (t) reaches an arbitrary upper limit H1 in the lock range 19, the CPU
5 is a spindle motor 3 for the servo system 4 for rotation.
A command signal for interrupting the supply of power to the power supply is sent. As a result, the spindle motor 3 rotates only by the inertia (inertia) force, and the number of rotations gradually decreases.

When the number of revolutions of the spindle motor 3 decreases due to the interruption of the supply of power to the spindle motor 3, the value of the reference signal vr (t) input to the PLL 6 decreases. As a result, the output signal v0 (t) that follows the rotation frequency of the spindle motor 3 also decreases. And
When the value of the output signal v0 (t) reaches an arbitrary lower limit value L1 in the lock range 19, the CPU 5 instructs the rotation servo system 4 to start supplying power to the spindle motor 3 again. It sends a signal. As a result, the spindle motor 3 receives power again and rotates.

In the CD reproducing apparatus 1 according to the present embodiment, the output signal v0 (t) based on the rotation frequency of the spindle motor 3 is controlled by two set values (= arbitrary upper limit value) provided in the lock range 19. H1, the servo system 4 turns on and off the spindle motor 3 so as to move up and down between an arbitrary lower limit value L1). As a result, during the time period in which the spindle motor 3 is rotated only by the inertia (inertia) force, no power is consumed and no motor noise is generated. According to the driving method based on this control, that is, the method of intermittently supplying power to the spindle motor 3, the power consumption at the first startup is the same as that of the conventional driving method, but the power consumption in the middle is In the supply, the power is supplied to the spindle motor 3 already rotating by the inertia (inertia) force, so that the power is not so large.

A specific control method of the CD reproducing apparatus 1 configured as described above will be described below with reference to FIG.

When power is input to the CD reproducing apparatus 1 by a user's operation or the like (step S1) and a reproduction instruction is given (step S2), first, an instruction signal is sent from the CPU 5 to the servo system 4 for rotation. To start the drive of the spindle motor 3 by the drive control of the servo system 4 (step S
3). As a result, the CD 2 rotates (Step S)
4). At the same time, the CPU 5 starts up the PLL 6 (step S5). As a result, the output signal v0f (t) of the free running frequency f0f, which is the initial setting value, is oscillated to the CPU 5 from the VCO 15 of the PLL 6 (step S6).

When the CD 2 rotates in this manner, the recorded contents recorded on the surface of the CD 2 are read by the optical pickup 7.
Is read (step S7). The optical pickup 7
As described above, the information read in is input as an analog waveform, binarized by the analog waveform shaping unit 10 (step S8), and synchronized by the synchronization detecting unit 11 (step S8).
9) The digital signal processing unit 12 performs predetermined digital processing such as EFM decoding and error correction (step S1).
0). Further, the data subjected to the predetermined digital processing is temporarily stored in the RAM 13 and stored in the RAM 13 until an output command is issued by the digital signal processing unit 12 (step S11). In the subsequent operation, the data stored in the RAM 13 is converted into analog data by the D / A converter 14 and output from a speaker or the like, but the operation after step 11 is not shown. I do.

On the other hand, the CD reproducing apparatus 1 detects the rotation speed of the CD 2, that is, the rotation frequency of the spindle motor 3 rotating the CD 2, based on the information read from the CD 2 by the optical pickup 7. . That is, the CD reproduction device 1 uses the digital signal binarized in step S8 to generate the reference signal vr having the frequency fr.
(T) is input to the PLL 6 (step S12).

When the frequency fr of the reference signal vr (t) input to the PLL 6, that is, the rotation frequency of the spindle motor 3 rises to a level within the lock range 19 of the PLL 6, the CD reproducing apparatus 1 locks the PLL 6. The state is reached (step S13). The step S13 will be described with reference to FIG.

In step S5, when the CPU 5 starts up the PLL 6, the VCO 1 of the PLL 6
5 to the output signal v0f of the free running frequency f0f
(T) is oscillated for each block (step S
31). On the other hand, the above-described steps S1 to S8
Is performed, and as in step S12, the frequency fr
When the reference signal vr (t) is input to the PLL 6, the phase comparator 16 outputs the input reference signal vr (t) and VC
The phase with the output signal v0f (t) output from O15 is compared (step S32), and an error signal ve (t) is output (step S33).

Then, the low-pass filter 17 outputs the error signal v
e (t) is input, and a signal vd (t) obtained by removing unnecessary high-frequency components from the error signal ve (t) is output (step S34). Further, the amplifier 18 outputs the signal vd
(T), and amplifies the signal vd (t) to form a control voltage signal vc (t) for the VCO 15.
Is output (step S35). This allows the VCO
15 of the output signal v0 (t)
Changes in a direction approaching the frequency fr of the reference signal vr (t) input to the PLL 6 (step S36). Then, the frequency f0 of the output signal v0 (t) is equal to the reference signal vr
If the frequency fr coincides with the frequency fr of (t), the PLL 6 is locked (step S37).

As described above, in step S13, the input signal vr (t) that causes the PLL 6 to enter the locked state is output from the PLL 6
When the rotation frequency of the stepping motor 3 enters the lock range 19 of the PLL 6, the CPU
5 instructs the rotation servo system 4 to further increase the rotation speed of the spindle motor 3. Thus, the rotation speed of the spindle motor 3 is increased by the drive control of the servo system 4 (step S14). For this reason, PL
The frequency fr of the reference signal vr (t) input to L6 increases, and the error signal ve (t) changes with the change of the reference signal vr (t).
(T), the signal vd (t) with the high frequency removed and the VCO
The fifteen control voltage signals vc (t) also rise. As a result,
The output signal v0 (t) output from the VCO 15 also increases (step S15).

As described above, the change of the reference signal vr (t) input to the PLL 6 causes the output signal v
0 (t) also changes, the CPU 5 outputs the output signal v
If 0 (t) is monitored by the monitoring means 5a, it is possible to monitor a change in the rotation frequency of the spindle motor 3. Since vc (t) and v0 (t) are proportional, the DC voltage of vc (t) can be input to an AD converter built in the CPU 5 and monitored.

Then, as a result of monitoring by the monitoring means 5a,
When the output signal v0 (t) has reached an arbitrary upper limit value H1 within the lock range 19 (YE in step S16).
S), the CPU 5 controls the servo system 4 to cut off the supply of power to the spindle motor 3. As a result, the power supply to the spindle motor 3 is cut off by the drive control of the servo system 4 (step S17). In addition,
If NO in step S16, repeat step S1
Return to 6.

As a result of step S17, when the rotation speed of the spindle motor 3 decreases and the output signal v0 (t) reaches an arbitrary lower limit L1 within the lock range 19 (YES in step S18), the CPU 5 Performs control for causing the servo system 4 to start supplying power to the spindle motor 3. Thus, the supply of power to the spindle motor 3 is started by the drive control of the servo system 4 (step S19). If the answer is NO in step S18, the process returns to step S18.

As described above, when power is supplied to the spindle motor 3 in step S19, the rotation speed of the spindle motor 3 increases again, and the rotation frequency also increases accordingly. In such a state, the process returns to step S16, and the operation is repeated thereafter.

In the CD reproducing apparatus 1 serving as the electronic apparatus of the present embodiment, the CD 2 is rotated at an average speed within a certain frequency range by the control described above, and the data read by the optical pickup 7 from the CD 2 is read. The data is reliably stored in the RAM 13. As a result, the recorded contents of the CD 2 can be reliably and smoothly output from a speaker or the like.
For this reason, even though the supply of power to the spindle motor 3 is interrupted, the user does not understand this fact and is not bothered at all. In addition, since the power supply to the spindle motor 3 is interrupted, the power consumption is reduced, and the motor noise of the spindle motor 3 is not generated while the power is not supplied. This achieves a reduction.

The embodiments of the present invention have been described above. However, the present invention is not limited to the CD reproducing apparatus 1, and various modifications and modifications can be made as long as the rotation speed of the motor is locked within a certain frequency range by a PLL. Application is possible. That is, the present invention provides a recording medium reproducing device other than a CD reproducing device,
For example, the present invention can be applied to an MD (mini-disc) player, a DVD (digital video disc) reproducing device, and the like.
In the above-described embodiment, the rotation frequency of the drive motor is detected based on input information from the medium (CD2), and a signal is input to the PLL 6. However, the present invention is not particularly limited to this. Alternatively, a rotation detector may be provided in the drive motor, and information on the rotation frequency may be directly input to the PLL 6 or the CPU 5 from the detector.

If the rotation speed of the spindle motor 3 for rotating the CD 2 is set to about 200 rpm when the optical pickup 7 reads the outer peripheral portion of the CD 2 and about 500 rpm when reading the inner peripheral portion, the medium reading of the CD reproducing apparatus 1 is performed. Operation becomes more precise. Therefore, CD
2, the lock range 19
Any of the upper limit H1 and lower limit L1 in the above control may be changed to appropriate positions, and the value of the control signal to the servo system 4 for rotation may be changed to perform high-precision control. .

[0050]

According to the present invention, power consumption can be reduced without deteriorating device performance, and in particular, the operating time of a portable electronic device can be extended. In addition, during the period when power is not supplied to the motor at the same time, motor noise does not occur and motor noise is reduced as a whole operation time, so that error rate characteristics are improved and sound quality is expected to be improved.

[Brief description of the drawings]

FIG. 1 is a main block diagram of a CD reproducing apparatus serving as an electronic apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a PLL in the block diagram of FIG. 1;

FIG. 3 is a graph showing a control driving method of a spindle motor of a CD reproducing apparatus serving as an electronic apparatus according to an embodiment of the present invention.

FIG. 4 is a flowchart illustrating a method for controlling and driving a spindle motor of a CD reproducing apparatus serving as an electronic apparatus according to an embodiment of the present invention.

FIG. 5 is a step S13 in the flowchart of FIG. 4;
3 is a flowchart showing the operation of the first embodiment in detail.

[Explanation of symbols]

Reference Signs List 1 CD playback device (electronic device) 2 CD = compact disc (medium) 3 spindle motor (drive motor) 4 servo system 5 CPU (control means) 6 PLL = phase locked loop 19 lock range (predeterminable lockable frequency of PLL) H1 Arbitrary upper limit L1 Arbitrary lower limit vr (t) Reference signal (input signal based on rotation frequency of drive motor) v0 (t) Output signal (VCO output signal that follows rotation frequency of drive motor) signal)

Claims (2)

[Claims] 1. A drive motor for rotationally driving a medium, a servo system for controlling the number of rotations of the drive motor, control means for controlling and driving the servo system, and a signal based on a rotation frequency of the drive motor. And a PLL (Phase Locked Loop) that oscillates a signal that follows the rotation frequency of the drive motor in the predetermined lockable frequency range to the servo system by inputting the control signal. After the rotation frequency of the drive motor falls within a predetermined lockable frequency range of the PLL, the rotation speed of the drive motor is increased, and the rotation frequency of the drive motor falls within the predetermined lockable frequency range. When the upper limit value becomes arbitrary, the supply of electric power to the drive motor is cut off, and an arbitrary value within the predetermined lockable frequency range is set. When the lower limit value is reached, the supply of power to the drive motor is started and the servo system is controlled and driven again so as to increase the rotation frequency of the drive motor, thereby intermittently rotating the drive motor. An electronic device characterized by being driven. 2. The method according to claim 1, wherein the arbitrary upper limit is a value lower than an upper limit in the predetermined lockable frequency range by a predetermined amount, and the arbitrary lower limit is a lower limit in the predetermined lockable frequency range. 2. The electronic device according to claim 1, wherein the value is higher by a predetermined amount.