JPH0467463A - Rotating driving device for disk - Google Patents

Abstract

PURPOSE:To surely discriminate the kind of a disk being driven and rotated through simple configuration by discriminating directly the state of the change of the period of a rotation detection pulse at the time when impressed voltage to a spindle motor to drive and rotate the disk is changed. CONSTITUTION:The spindle motor 3 is provided with a rotation detector 4, which detects the rotation of the motor 3 and outputs the pulse signal SP of the period corresponding to a rotating period. The rotation detection pulse signal SP is sent to a waveform shaping amplifier 6 through an amplifier 5. Then, the pulse signal SP from the amplifier 6 is sent to the pulse period detection circuit 13 of a digital signal processing block 10, and the detection of the pulse period is executed. The detected pulse period is sent to a comparison circuit 14, and by comparing it with a prescribed reference period tauREF, the kind of the disk is discriminated. Thus, the kind of the disk can be surely discriminated without providing any exclusive disk detecting mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of Application B1 Summary of the Invention The present invention provides a method for controlling the voltage applied to a spindle motor that rotationally drives a disk in a disk rotation drive device that rotationally drives a plurality of types of disks. By directly determining the state of change in the period of the rotation detection pulse when the rotation detection pulse is changed, the type of disk being rotationally driven can be reliably determined with a simple configuration.

C1 Conventional technology In a disc rotation drive device, for example, a so-called compact disc player, the rotation of a spindle motor is controlled in phase based on a phase comparison signal between a clock signal separated from a reproduction signal and a predetermined reference signal. ing. As a result, the spindle motor and its entire drive circuit become PLL (Phase Locked [,oo
p) A circuit is configured to rotate the disk with high precision.

By the way, compact discs have a diameter of 8 (
There are two types of disks: cm) and 12 (cm), and each of these disks has a different mass. In this way, in a device that rotationally drives disks of different sizes (particularly masses), the Nil of the disk and the PL
It is necessary to switch the servo gain etc. of the L circuit. Therefore, it is desired to automatically determine the size of the disk.

In conventional compact disc players and the like, the type of disc as described above is determined by an optical method or a mechanical method. In other words, as an optical type discrimination method, a photoreflector, photointerrupter, etc. is installed at a predetermined position in the head area between the outer periphery of a large-diameter disk and the outer periphery of a small-diameter disk, and the diameter is determined based on the light receiving condition. It is used to determine the size, and the mechanical type determination method is based on whether a mechanical contact placed at a predetermined position is turned on or off.

D0 Problems to be Solved by the Invention However, the above-described optical or mechanical type discrimination method requires a dedicated disc detection mechanism or the like, which complicates the configuration of the disc player.

Furthermore, in the case of so-called compact discs,
There are cases where an 8 (cm) compact disc is fixed to the adapter and rotated, and in this case, the 12 cm
It requires the same servo gain as driving a (cm) compact disc. However, when using a reflective disc detection device, since the reflected light from the adapter cannot be obtained, it may erroneously detect an 8 (CIll) compact disc, resulting in insufficient servo gain due to the phase control of the spindle motor. There's a problem.

In addition, when detecting the diameter of a compact disc optically, when the outermost circumference of the compact disc is transparent,
There is a risk that a 12 (cm) compact disc may be mistakenly detected as an 8 (cm) compact disc.

By the way, the applicant of the present invention has previously proposed in the specification and description of Japanese Patent Application No. 1-35665 an optical disk device that detects the startup response state of a spindle motor that drives the rotation of a disk. This makes it possible to reliably detect the type of rotationally driven object (disk type) without providing a dedicated disk detection mechanism or the like. However, the frequency generator (FC) output for rotation detection)
After wave number/f pressure (F/V) conversion and A/D conversion, the type of compact disc is detected by a control circuit using a microcomputer, etc. Since a /D converter is required and the circuit configuration tends to become complicated, further improvements are desired.

Therefore, the present invention has been considered in view of the above points, and provides a disk rotation drive device that can reliably identify the disk type without providing a dedicated disk detection mechanism and that has a simple configuration. The purpose is to

Means for Solving the E0 Problem A disk rotation drive device according to the present invention is a disk rotation drive device that rotationally drives a plurality of types of disks, and includes means for changing a voltage applied to a disk rotation drive motor, and a disk rotation drive device that rotates a plurality of types of disks. means for detecting the rotation of the motor and outputting pulses with a period corresponding to the rotation period; and a means for rotating the motor in response to a change in the output pulse period from the rotation detecting means when the voltage applied to the motor changes. The above-mentioned problem is solved by comprising means for determining the type of disc that is being used.

61 action Since the pulse output from the rotation detecting means of the disk rotation drive motor can be directly digitally processed to determine the state of period change, the frequency / can be changed to the pressure (F /
V) Disc type can be determined without using a converter or A/D converter.

F. Examples Specific examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a block circuit diagram showing a schematic configuration when the present invention is applied to a so-called compact disk player as an embodiment of a disk rotation drive device according to the present invention.

In the compact disc player 1 shown in FIG. 1, when playback is started by operating the playback button,
When the disc type discrimination operation is started, a rotation switching control signal is input to the rotation speed switching circuit 12 of the digital signal processing processor 10. At this time, the rotational speed switching circuit 12 outputs rotational drive data Sc that changes in a stepwise manner, and this data S is converted into an analog signal by the D/A converter 11 and is converted into a rotational drive signal SST.
and is output from the digital signal processing block 10. For example, as shown in FIG. 2, this rotational drive signal Sst changes stepwise from voltage V to V at a predetermined time i1JLo. Incidentally, at the time of starting the motor, such as at the start of the above-mentioned regeneration, the above-mentioned voltage (2) becomes QV.

This signal Ssr is amplified by an amplifier circuit 8 and supplied to a drive circuit 9, and the drive circuit 9 drives the spindle motor 3 so that its rotational speed changes from the speed corresponding to the voltage v1 to the speed corresponding to the voltage v2. do.

This spindle motor 3 is provided with a rotation detector 4 such as a so-called FC (frequency generator ftm), which detects the rotation of the spindle motor 3 and outputs a pulse signal S2 with a period corresponding to (proportional to) the rotation period. do. This rotation detection pulse signal is sent to a waveform shaping amplifier 6 via an amplifier 5. This waveform shaping amplifier 6 is a type of interface circuit that shapes the input signal into a rectangular waveform and adjusts it to the operating voltage level of the subsequent digital signal processing block IO.

The pulse signal S from the waveform shaping amplifier 6 is sent to the pulse period detection circuit 13 of the digital signal processing block 10, and the pulse period is detected. The detected pulse period is sent to the comparator circuit 14 and determined as a predetermined reference period τI.
The disc type is determined by comparing it with the IEF. Specifically, this disc type is a compact disc with a diameter of 12 (cm) (and a compact disc with a diameter of 8 (cm) fixed to an adapter),
8 (cm) compact disc. The discrimination output signal S is used, for example, to control switching of the servo gain of the PLL circuit as described above.

Here, FIG. 2(A) shows an example of the rotational drive signal SST for changing the voltage applied to the disk rotational drive motor in a stepwise manner. The voltage is switched from V to v2. Further, in FIG. 2(B), the state of change in the period of the rotation detection pulse from the rotation detector 4 at this time is shown as a curve B1 in the case of the disk diameter of 8 (cm), and 12 (
c++) is shown in curve B2.

As shown in FIG. 2, the rotational drive signal S output from the D/A converter 11 of the digital signal processing block 10
When ST changes stepwise from a predetermined voltage V1 to v2, the rotational speed of the spindle motor 3 changes under a predetermined mechanical response characteristic so as to follow this stepwise change. At this time, the rotational response state differs depending on the weight of the compact disc 20 being rotationally driven. i.e. 12 (cm) compact disc (and 8 (cm) compact disc fixed in adapter)
When driving an 8 cm compact disc, the rotational speed increases more slowly because the object to be rotated is heavier than when driving a single 8 cm compact disc. Therefore, the period detection curve B2 in Fig. 2 (B) when driving a 12 (ca+) compact disc is 8 (cm).
Compared to the interphase detection curve Bl in the case of driving a single compact disc, the pulse period changes showing a gentler descending curve. In other words, when driving a compact disc of 8 (cs), the speed changes more rapidly.

In order to determine the state of the change in morph rotational speed (change in period) during such stepwise drive voltage application U,
A method of comparing the pulse period after a certain period of time Tc with a predetermined reference period (dark value) τ□, and a method of comparing the pulse period with a predetermined reference period (dark value) τ□, and a predetermined reference time (dark value) that takes the time until the pulse period reaches the fixed period τ□1.
One possible method is to compare the size with TltF.

In the embodiment shown in FIG. 2, a specific example of the former method is shown.
A timer is started at the same time (time to) when a control signal is input from the rotational speed switching circuit 12, and the pulse period τ detected after a certain period of time T has elapsed (also at time) is set as the reference period which becomes the above-mentioned threshold value. The size is compared with τ□.

Now, when the pulse period output from the rotation detector 4 changes as shown by curve B1 in FIG. 2, the step change point of the voltage is determined. The pulse P1tAτ detected at time t1, T seconds after, becomes τ1, which is smaller than the above WfaτREF. At this time, it is determined that the 8 (cm) compact disc is being rotated.

On the other hand, the pulse period changes as shown by curve B2 in FIG. 2, and the pulse period at time t becomes τ2, and the threshold value 71
When the value is 4 or more, it is determined that the l 2 (cm) compact disc (and the 8 (cm) compact disc fixed to the adapter) is being rotationally driven.

Incidentally, in an actual circuit configuration, most of the circuits in the digital signal processing program 10 are realized by software. Therefore, a specific example of a software program for realizing the above-mentioned functions will be explained while taking a look at the third area. That is, the third part shows a flowchart for realizing the disk type discrimination function by the pulse period detection circuit 13, comparison circuit 14, etc. by means of a software program.

In FIG. 3, when the servo gain determination is started in step St, in the next step S2, a rotational voltage corresponding to a predetermined rotational speed v1 is set as rotational drive data SC to be supplied to the D/A converter 11. Set data X1 (sc
=x, ). In the next step S3, a cycle detection subroutine 5UBI (so-called subroutine call) to be described later is called, and the cycle τ of the output pulses from the rotation detector 4 is detected. The period τ detected in step s3 is stored in the variable τ in the next step S4 (τ,=
τ) 0 Next, in step s5, data x2 is set as rotational drive data Sc in order to change the rotation of the spindle motor 3 stepwise to another rotation speed (sc""x
z) By supplying L to the D/A converter 11, the rotational drive signal SST is switched from the above voltage V to Vz.

This switching time is time L0 shown in FIG. 2, a timer is started at this time, and in the next step s6 it is determined whether a predetermined time Tc has elapsed. If the determination in step S6 is No (7 seconds have not elapsed), the process returns to step s6 and waits for a certain amount of time. Yes(7
(seconds have passed) (time 1), the process advances to step S7, and the pulse period ejection subroutine 5U
Call BI. Next, the process advances to step S8, and the cycle τ detected by the above-mentioned time IL is set to the above-mentioned threshold τ1. Determine whether the value is greater than or not. If the determination is No (151 value τREF or less), the process advances to step S9, and the diameter is 8.
(c+++) compact disc is performed, and when the determination is Yes (threshold value τ, y, larger), in step SIO, processing is performed for a compact disc with a diameter of 12 (cm). Specifically, for example, the servo gain is switched to correspond to the size of the compact disc, and the servo of the spindle motor is performed. After each of the above steps, the software program for determining different diameter compact discs is terminated in step S11.

Here, FIG. 4 shows a specific example of the pulse cycle detection subroutine 5UBI shown in the flowchart for determining the type of compact disc with a different diameter in FIG.

In FIG. 4, in step 312, a cycle detection subroutine 5UBI is started. The timer is reset in S13, and the rising edge of the pulse is detected in steps S14 and S15. That is, in step 514, if the level of the spindle motor output pulse signal S, which is manually input to the pulse period detection circuit 13, is not 0'', the routine of step 14 is repeated.The level of the spindle motor output pulse signal S, If is 0, the process moves to step 15. In step S15, it is determined whether the level of the output pulse signal S has reached "I", that is, the rising edge of the pulse signal is detected. If the level of the output pulse signal S is not at "°1", the routine is repeated at step 15 until a rising edge is detected.

If a rising edge is detected, step 316
Start time measurement (timer). Next step S17
And step 318 detects the rising edge of the output pulse signal S, similar to steps 514 and 315 above. If a rising edge is detected, the time measurement (timer) is stopped in step 519. The time (pulse period) from the rising edge of a pulse signal to the next rising edge is detected by each step operation described above. In step 20, the timer count value (cycle τ) is read, and in the next step S21, this subroutine is ended and the process returns to the main routine.

According to the above configuration, the rotation response state of the spindle motor 3 is determined and rotation is detected! By directly handling the digital signal detected in ii4 and inputting it as a digital signal to the digital signal processing block 10, an F/V converter and an A/D converter are unnecessary, and a simple configuration can be achieved. Moreover, the type of rotationally driven object of the spindle motor 3 can be detected reliably. In this way, the servo gain of the PLL circuit can be switched to reliably reproduce the audio signal.

Next, another embodiment of the present invention will be described with reference to FIG. As mentioned above, the signal waveform shown in FIG. 5 has a constant pulse period τ. The time it takes to reach the specified reference time (darkness value) TIL! This is a specific example of a method for comparing the magnitudes of , , and , and can be realized with the same circuit configuration as in the first example described above.

FIG. 5 is a signal waveform diagram showing a specific example of the above method.

FIG. 5(A) shows an example of a rotational drive signal Sst for changing the voltage applied to the disk rotational drive motor in a stepwise manner.
Switched from 1 to v2. Further, FIG. 5(B) shows the state of the rotation detection pulse period from the rotation detector 4 at this time. In this example, the case of a compact disc with a diameter of 8 (cm) is shown as curve B3, and l 2 (
cm) compact disc (and 8
(cm) compact disc) song vAB4
It is shown in

In the embodiment shown in FIG. 5, the rotational response state differs depending on the weight of the compact disc 2 that is rotationally driven, as in the case of FIG. The period detection curve B4 shows a steeper landing curve than that of the 8 (cm) compact disc alone, and also shows a steeper speed change when the 8 (cm) compact disc is driven.

Now, in order to determine the state of change in motor rotational speed (change in period), if the pulse period output from the rotation detector 4 changes as shown by curve B3 in FIG. Point time t.

The time T from which the pulse period τ reaches the constant period τ
becomes T3, and when it is smaller than a predetermined reference time (threshold value) T11EF, it is determined that the 8 cm compact disc is being rotated. On the other hand, the pulse period changes as shown in the song %9tB4 in Figure 5, and the time T from the step change point time t0 until the pulse period τ reaches the constant period τC1 becomes T4, and the predetermined reference time ( threshold) T
When it is 11EF or more, it is determined that the I 2 (cm) compact disc (and the 8 (cm) compact disc fixed to the adapter) is being rotationally driven.

The above-described method for determining the disk diameter is realized by the circuit in the digital signal processing block 10 using software, similarly to the above-described method. Therefore, an example of a software program for realizing the above-mentioned functions will be explained with reference to FIG. 6. In other words, the sixth circle is
A flowchart is shown for realizing the disc type discrimination function by the pulse period detection circuit 13, comparison circuit 14, etc. 5 by means of a software program.

In FIG. 6, when the servo gain determination is started in step S30, in the next step S31, the D/A
As rotation drive data So supplied to the converter 11, rotation voltage data X corresponding to a predetermined rotation speed V is set (S
e=xl).

In the next step S3, the above-mentioned cycle detection subroutine 5UBI is called (so-called subroutine call) to detect the cycle τ of the output pulses from the rotation detector 4. The period τ detected in step S32 is stored in the variable τ (rA=r) in the next step S33. Next, in step 34, data x2 is set as rotational drive data Sc (Sc=x2) (,,D/
By supplying the rotational drive signal S to the A converter 11,
□ is switched from the above voltage V1 to v2.

This switching time is the time to shown in the fifth time, and in step S35, a timer is started from this time, and the process proceeds to the next step S36. Call the pulse period detection subroutine 5UBI. Next, the process advances to step S37, and the pulse period τ detected in step S36 is the constant period τ. Determine whether or not the value is greater than or equal to the value. If it is determined No (constant period τ, smaller), return to step 536, perform pulse period detection, and Yes (constant period τ6 or more).
When it is determined that
Stop the timer count. In step S39, the counted time is stored as T, and the next step S40
It is determined whether or not the time T counted until reaching a certain period τ6 or more is longer than a predetermined reference time (IiliI(I)T□).

If the determination is No (less than the constant period τC), the process advances to step S41 and the processing for a compact disc with a diameter of 8 (cm) is performed; if the determination is Yes (the constant period τ is larger), Processing is performed for a compact disc with a diameter of 12 (cm).

Specifically, for example, the servo gain is switched to correspond to the size of the compact disc, and the servo of the spindle motor is performed, and in step S43, the software program for determining a compact disc of a different diameter is terminated.

With this determination method, the rotational response state of the spindle motor 3 is determined in the same manner as in the above-described embodiment, and the digital signal detected by the rotation detector 4 is directly handled and inputted as a digital signal to the digital signal processing block 10. Therefore, it is possible to have a simple configuration without using an FG servo system, an F/V converter and an A/D converter, and it is possible to reliably detect the type of rotationally driven object of the spindle motor 3. can.

Note that the present invention is not limited to the above-described embodiments (for example, when a general Hall motor is used in place of a spindle motor in a compact disc player, etc., the output from the Hall element of the Hall motor is The pulse can be used as a rotation detection pulse.Therefore, the Hall motor becomes a spindle motor and a rotation detector integrated, and there is no need to provide a separate rotation detector such as a frequency generator.

Further, in the above-described embodiment, the type of rotationally driven object is detected and the servo gain of the PLL circuit is switched based on the detection result, but the present invention is not limited to the above-mentioned case. It can be widely applied to displaying the type of object or controlling the position of a P/7 amplifier corresponding to the type of rotationally driven object, and can be used in so-called multi-disc players that play compact discs and video discs. It can be widely applied to disk devices and the like.

H1 Effects of the Invention As is clear from the above explanation, the disk rotation drive device of the present invention provides the following effects in response to changes in the cycle of the rotation detection pulse of the disk rotation drive motor when the motor applied voltage changes: The type of disk being rotated is determined, and the pulse signal from the rotation detector is almost directly sent to the #IM determining means such as a digital signal processing block.
Frequency-voltage conversion and A/
It is possible to obtain an inexpensive disk rotation drive device that can reliably detect a rotationally driven object with a simple configuration that does not require D conversion.

[Brief explanation of drawings]

The first panel is a block circuit diagram showing a schematic configuration of an embodiment of a disk rotation drive device according to the present invention, the second panel is a waveform diagram showing a rotation drive signal and a pulse period detection signal, and the third panel is a block circuit diagram showing a schematic configuration of an embodiment of a disk rotation drive device according to the present invention.
The figure is a flowchart showing a specific example of the operation of determining a compact disc of a different diameter from the signal waveform characteristics shown in Fig. 2, the fourth part is a flowchart showing an example of a subroutine for period detection, and the fifth part is a flowchart showing the present invention. FIG. 6 is a waveform diagram showing a rotational drive signal and a pulse period detection signal in another embodiment of the disk rotational drive device according to the 50th embodiment, and FIG. FIG. 1 ・ ・ ・ ・ 2 ・ ・ ・ ・ 3 ・ ・ ・ ・ 4 ・ ・ ・ 10 ・ ・ 12 ・ ・ 13 ・ ・ ・ l 4 ・ ・ ・ ・ ・ ・Compact disc player ...Spindle motor...Rotation detector/Digital signal processing block...Rotation speed switching circuit...Pulse period detection circuit...・Comparison circuit patent Applicant: Sony Corporation Representative, Patent attorney: Mitsumi Koike 1) Eido Mura Katsui-Kai Corepa'7
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Claims (1)

[Claims] A disk rotation drive device for rotationally driving a plurality of types of disks, comprising means for changing a voltage applied to a disk rotation drive motor, and detecting the rotation of the disk rotation drive motor according to a rotation period. and means for determining the type of disk being rotationally driven according to a change in the output pulse period from the rotation detecting means when the voltage applied to the motor changes. A disk rotation drive device comprising: