JPS60131083A - Drive circuit for spindle motor - Google Patents

Abstract

PURPOSE:To instantaneously stop a spindle motor by applying a brake pulse having an amplitude or pulse width of the magnitude in response to the rotating speed of the motor. CONSTITUTION:When a stop key or an eject key on an operation panel is depressed, a microcomputer 7 generates a stop signal SP. A brake pulse generator 12 which inputs the signal SP generates a brake pulse BLP of the pulse width in response to the rotating speed of a spindle motor 11. A composite circuit 13 combines a drive signal DVS of the output of a CLV circuit 4 and a brake pulse BLP of the output of a brake pulse generator 12 and applies it through an amplifier 14 to the motor 11.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention generates a spindle motor 1 drive signal so that the linear velocity with respect to a disk pickup is constant,
The present invention relates to a spindle motor drive circuit that drives a spindle motor using the drive signal, and particularly to a spindle motor drive circuit that can stop the spindle motor in a short time when no stop request is received.

<Prior Art> Con) In a 4-kt disk player, a disk is rotated at a constant linear velocity relative to a pickup, and the pickup reads digital information recorded on the disk, and the digital information contained in the information is read by the pickup. It demodulates the acoustic signal and outputs the sub-sounding sound, and uses the control information contained in the information to display the currently playing song number, total playing time, etc., or to execute digital access control.

In conventional Konokkuto disc players, operation A? When the stop key or eject key on the channel was pressed, the spindle motor drive signal, which was the output of the CLV circuit (Constant Linear Locity Circuit), was simply set to zero, thereby stopping the rotation of the system spindle motor. .

<Disadvantages of Prior Art> However, when the spindle motor is rotating at a constant linear velocity, even if the spindle motor drive signal is simply set to zero, the spindle motor does not stop immediately due to the inertia of the compact disc, the holding member, etc. For this reason, there is a drawback that the compact disc cannot be taken out immediately during the eject operation.

In addition, since the disk is rotated at a constant linear speed relative to the pickup, the closer the pickup position is to the center of the disk, the faster the rotation speed becomes. Become.

<Object of the Invention> An object of the present invention is to provide a spindle motor drive circuit that can instantly stop the rotation of a spindle motor when a stop request is issued.

Another object of the present invention is to apply a brake signal having an amplitude or pulse width corresponding to the rotational speed of the spindle motor to the spindle motor when a stop request is made, so that the spindle motor instantly rotates regardless of the rotational speed of the spindle motor. An object of the present invention is to provide a spindle motor drive circuit that can stop the motor.

<Summary of the Invention> The present invention includes a rotation speed detector that detects the rotation speed of a spindle motor that drives a disk, a circuit that generates a stop signal that stops the rotation of the spindle motor, and a rotation speed detector that detects the rotation speed of a spindle motor that drives a disk. The amplitude depending on the magnitude or I? ) A circuit that generates a brake signal having a response width, and a circuit that applies a drive signal to the spindle motor so that the linear velocity is constant when the spindle motor is driven, and completely prohibits application of the drive signal to the spindle motor when a stop signal is generated; The present invention is also a spindle motor drive circuit having a circuit for applying a brake signal to the spindle motor. According to this spindle motor drive circuit, the rotation of the spindle motor can be instantaneously stopped in response to a stop request, regardless of the rotation speed of the spindle motor.

<Embodiment> FIG. 1 is a schematic overall view of a compact disc brake including a spindle motor drive circuit of the present invention. On the compact disc 1, audio signals are digitally recorded, and control data called frame synchronization signals and subcoding are also recorded for each predetermined number of data. The subcoding consists of 8 bits: P, Q, R, S, T, U, V, and W. One block is formed by 98 subcodings, and the P channel of the block contains the beginning of the song. The Q channel records (a) the track number corresponding to the current position of pickup 2, and (b) the number of minutes and seconds from the beginning of the track number (called a time record), and the frame in which pickup 2 is located. Information on whether or not it exists, absolute time records from the initial positions of Mr. e and Big Ala 7''2, etc. are recorded.

The big controller 762 optically reads digital information recorded on the compact disc 1 and inputs it to the waveform shaping circuit 3. The RF amplifier 3a of the waveform shaping circuit 3 amplifies the RF signal which is the output of the pickup 2, and the slicing circuit 3b shapes the output signal of the RF amplifier 3a at a predetermined slice level and generates a signal (EFM) obtained by waveform shaping. signal) is connected to CLV circuit (Constant Line
ar velocity circuit) 4 and a digital signal processing circuit 5.

The digital signal processing circuit 5 demodulates the EFM signal, separates the audio data and sub-coding, performs error detection/correction processing on the audio data, and converts the 16-bit audio data input from the next signal processing circuit 5 into DA. The output is input to the audio circuit 8, which performs well-known analog processing and outputs an audio signal from a speaker (not shown). Microcomputer 7 is sub-coding Q
Analyzing the channel, extracting data indicating the current track number, elapsed time for each track, total elapsed time, etc., and inputting and displaying it on the display device 9, as well as information input from the operation panel 10. Based on this, random access processing and spindle motor stop processing, which will be described later, are performed.

On the other hand, the CLV circuit 4 is a well-known PLL (Phase
Lock&1Loop) circuit 4a and phase comparison circuit 4b,
It is composed of many analog gate circuits 40, etc., and P
The EF'M number is input to the LL circuit 4a.

The PLL circuit 4a reproduces the basic unit clock signal included in the EFM signal, and the phase comparator circuit 4b reproduces the reproduced clock signal RC8 outputted from the PLL circuit and the reproduced clock signal RC8 outputted from a crystal oscillator (not shown) in the digital signal processing circuit 5. The drive signal DVS corresponds to the phase difference with the clock signal CLS.
The drive signal DVS is output from the analog gate circuit 4c.
The voltage is applied to the spindle motor 1 via the following. Incidentally, when the reproduced clock signal RC8 and the clock signal CLS are synchronized, the spindle motor 1 rotates at a predetermined linear velocity (1.2 to 1.4 m/s) relative to the pickup 2.

Now, when the STRAG key or ENOECT key (not shown) on the operation panel 10 is pressed while the spindle motor 1 is rotating at a constant linear velocity, the microcomputer T immediately detects this and generates a stop signal SP. This stop signal sp is input to the analog gate circuit 4C of the CLV circuit 4, and as a result, the analog gate circuit 4C immediately prohibits the output of the drive signal DVS. Further, the stop signal sp is also input to the brake pulse generation circuit 12.

When the brake pulse generation circuit 12 detects the rise of the stop signal SP, it immediately generates a heather brake pulse BLP having a pulse width corresponding to the rotational speed of the spindle motor 1. Synthesis circuit 13 cormorant CLV
The drive signal DVS, which is the output of the circuit 4, and the brake pulse BLP, which is the output of the brake pulse generating circuit 12, are combined, and the combined output is applied to the spindle motor 11 via the amplifier 7'14. By the way, when a stop signal is generated, CLv
Since the output of the circuit 4 is zero as described above, only the negative polarity brake pulse is amplified by the up circuit 14 and applied to the spindle motor 11. As a result, the spindle motor 11 will stop instantaneously. Incidentally, the rotational speed of the spindle motor 11 is detected by a rotational speed detector 15 such as a tacho generator or a nozzle coder. Alternatively, the rotational speed may be detected from the position of the pickup.

Figure 2 is a block diagram of an embodiment of the brake pulse generation circuit.
FIG. 3 is a waveform diagram of each part. In FIG. 2, 12a is an integrating circuit that generates a sawtooth wave, 12b is a slice circuit,
2C is a dirt circuit, and 12d is a timing/4 pulse generation circuit. The integrating circuit 12 & repeats charging and discharging using the actual speed voltage signal Va in synchronization with the timing signal TS shown in FIG. Then, it is expressed as e=kEit (where k is a constant and t is time) according to the following equation. Therefore, as the rotational speed increases, the slope increases (see the dotted line in FIG. 3(B)). The slicing circuit 12b slices the output voltage 0 of the integrating circuit 12& at a constant slicing level E8, and generates a pulse signal PS having a pulse width proportional to the rotational speed as shown in FIG. 3 (Q). Since it is configured to be wide open from the first timing signal generation after the stop signal SP (see FIG. 3(D)) to the next timing signal generation, the dirt circuit 12c is One brake pulse BLP shown in is output. Therefore, at the time of a stop request (when a stop signal is generated), only a brake pulse having a pulse width corresponding to the rotational speed is applied to the spindle motor 11. The motor stops instantly regardless of its rotational speed.

In the above description, the brake pulse BLP having a width proportional to the rotational speed is generated, but the present invention is not limited to such a case. For example, it may be configured to generate a constant width brake pulse having an amplitude proportional to the rotational speed. In addition, although the case where the present invention is applied to a compact disk grayer has been explained,
Of course, it can also be applied to video disc players and the like.

<Effects of the Invention> As explained above, according to the present invention, when there is a request to stop the spindle motor, a brake pulse having an amplitude or a Hals width corresponding to the rotational speed of the spindle motor is applied to the spindle motor. Since the spindle motor is configured to be applied with a constant current, the spindle motor can be stopped instantaneously regardless of its rotational speed, and as a result, the disc can be taken out immediately during the eject operation, improving operability. did it.

[Brief explanation of drawings]

Fig. 1 is a schematic overall view of a flat disk solayer including a spindle motor drive circuit according to the present invention, Fig. 2 is a block diagram of a brake/gurus generation circuit according to the present invention, and Fig. 3 is 3 is a waveform diagram of each part of the brake pulse generation circuit of FIG. 2. FIG. Digital signal processing circuit, 1... microcomputer, 10...
・Operation panel, 11... Spindle motor, 12...
- Brake pulse generation circuit, 13... synthesis circuit, 15
...Rotation speed detector patent applicant Chiki Saito, agent of Alpai Y Co., Ltd., patent attorney

Claims (3)

[Claims] (1) In a spindle motor drive circuit that generates a drive signal so that the linear velocity with respect to the disk pickup is constant, and drives the system spindle motor using the drive signal to keep the linear velocity constant, the rotational speed of the spindle motor is means for generating a stop signal for stopping the spindle motor; means for generating a brake signal having a magnitude corresponding to the rotational speed of the spindle motor; 1. A spindle motor drive circuit comprising means for applying a brake signal to a spindle motor, and applying the brake signal to the spindle motor when a stop signal is generated. (2) The spindle motor drive circuit according to claim (1), wherein the brake signal is a pulse signal having a voltage value depending on the rotational speed of the spindle motor. (3) The spindle motor drive circuit according to claim (1), wherein the brake signal is a pulse signal having a pulse width depending on the rotational speed of the spindle motor.