JPH05205389A - Stoppage controller for motor - Google Patents

Abstract

PURPOSE:To provide a stoppage controller for a motor which can surely stop disk mediums having different diameters and weights without making complication of program processing for computer means. CONSTITUTION:The operation in which speed of the motor 2 is reduced by outputting the speed reduction signal CLV-during specified time is intermittently performed, based on counter electromotive force of the motor 2 and a driving signal of the driver circuit 4 until a detecting signal which detects stoppage state of the motor 2 is obtained. Therefore, the disk mediums 1 having different diameters and weight can be surely stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor stop control device suitable for surely stopping a disk medium rotating at a constant linear velocity.

[0002]

2. Description of the Related Art FIG. 4 shows a motor driving device for rotating a disk medium storing predetermined information signals such as music, images and characters at a constant linear velocity. In FIG. 4, (1) is a disk medium, which stores, for example, any information signal of music, video, characters, and the like, and a synchronization signal for reproducing these information signals. (2) is a motor for rotating the disk medium (1). Disc media (1) is a tray
After being mounted on (not shown), it is fixed to the motor (2) by a magnet (not shown), and rotates at a constant linear velocity based on an output signal of a servo circuit described later. here,
The constant linear velocity means that when the information signal is reproduced by rotating the disk medium (1), the disk medium (1) may be stored at the inner or outer circumference. ) Is the speed for rotating the same distance per unit time. That is, the speed when reproducing the information signal stored on the inner circumference of the disk medium (1) is higher than the speed when reproducing the information signal stored on the outer circumference of the disk medium (1).

A servo circuit (3) controls the rotation of the motor (2) to rotate the disk medium (1) at a constant linear velocity. The synchronizing signal of the disk medium (1) and a reference clock of a predetermined frequency are applied to the servo circuit (3), and the synchronizing signal and the reference clock are compared in frequency. Here, the period of the synchronizing signal when the disk medium (1) is rotating at a constant linear velocity is predetermined so as to be a predetermined multiple of the period of the reference clock. For example, when the cycle of the synchronizing signal obtained from the disk medium (1) is more than a predetermined multiple of the cycle of the reference clock, it is determined that the motor (2) is rotating slower than the constant linear velocity, and the servo circuit (3) Square wave acceleration signal CLV from “H” (high level) to “L” (low level)
The deceleration signal CLV- of + and "L" is output. On the contrary, when the cycle of the synchronizing signal obtained from the disk medium (1) is less than a predetermined multiple of the cycle of the reference clock, it is judged that the motor (2) is rotating faster than the constant linear velocity and the servo circuit (3 ), An acceleration signal CLV + of "L" and a deceleration signal CLV- of a rectangular wave that repeats "H" and "L" are output.

(4) is a driver circuit, which is a servo circuit
Acceleration signal CLV + and deceleration signal CL output from (3)
V- is integrated and a drive signal for accelerating or decelerating the motor (2) is output. Thus, the disk medium
(1) will rotate at a constant linear velocity. (5) is a mechanism for driving the disk medium (1), which is the disk medium (1)
A feed motor for moving an optical pickup or the like for reading an information signal from the disk medium (1) in a radial direction and a perspective direction, and a tray motor for moving a tray on which the disk medium (1) is placed. Say.

(6) is a mechanism control circuit, which is a disk medium
The operation of the mechanical section (5) is controlled in order to read the information signal from (1). Then, the mechanism control circuit (6) detects whether the mechanism section (5) is operating normally and outputs a detection signal indicating that fact. For example, when the mechanism control circuit (6) detects the facing position of the feed motor with respect to the disk medium (1), the disk medium (1) at this time is detected.
The detection signal indicating the storage position of the information signal is output.

(7) is a signal processing circuit, which is a disk medium
"1" read when (1) is rotating at constant linear velocity
Alternatively, an information signal consisting of "0" is applied, and the signal is processed into audio, video, characters, or the like that can be received by a human in a visual sense. By the way, the disk medium (1) also stores data relating to information signals due to its storage format. For example, on a disk medium in which a music information signal is stored, the maximum number of songs, maximum time, absolute elapsed time when the first song to the last song are sequentially played, relative elapsed time when each song is played, etc. Is stored. Then, data relating to these information signals are sequentially applied to the signal processing circuit (7) according to the read position of the information signals.

Reference numeral (8) is a microcomputer, which includes a servo circuit (3), a mechanism control circuit (6), and a signal processing circuit (7).
It outputs a command signal for controlling the. For example, the microcomputer (8) sends a command signal for starting and stopping the motor (2) to the servo circuit.
A command signal for driving the mechanical part (5) is applied to the mechanical control circuit (6). Further, the output of the mechanism control circuit (6) and the output of the signal processing circuit (7) are applied to the microcomputer (8) so that the read position of the information signal with respect to the absolute elapsed time during reproduction of the information signal is normal. Is determined. For example, when the actual read position of the information signal is deviated by one track toward the outer peripheral side from the original read position of the information signal calculated on the basis of the absolute elapsed time, the microcomputer (8) is A command signal for shifting the signal read position by one track to the inner circumference side is applied to the signal processing circuit (7). As a result, the signal processing circuit (7) shifts the irradiation light of the optical pickup or the like by one track toward the inner peripheral side without moving the feed motor.

With the above configuration, the rotation of the disk medium (1) is controlled and the correct information is reproduced from the disk medium (1).

[0009]

As mentioned above, since the disk medium (1) rotates at a constant linear velocity, the disk medium (1)
The speed when reading the information signal stored on the inner circumference side of
The speed is higher than the speed at which the information signal stored on the outer peripheral side of the disk medium (1) is read. That is, the time required to stop the disk medium (1) is
It depends on the read position of (1). Therefore, a plurality of brake data indicating the distance from the inner circumference or the outer circumference is stored in the radial direction of the disk medium (1), and the microcomputer (8) stores a plurality of brake data. A unique stop time is set.

When a command signal for stopping the motor (2) is output from the microcomputer (8) while the disk medium (1) is rotating at a constant linear velocity, the disk medium
The brake data existing at the information signal read position of (1) is transferred to the microcomputer via the signal processing circuit (7).
The command signal applied to (8) and for stopping the motor (2) for the stop time corresponding to the brake data is output again from the microcomputer (8). Therefore, the disk medium (1) is stopped.

However, the stop control of the disk medium (1) is executed by the program of the microcomputer (8), and in addition to the stop control of the disk medium (1) of the same diameter, the stop control of the disk medium of different diameters is performed. However, the number of program steps is increased and the program processing becomes complicated.

Further, even if the disk medium (1) has the same diameter, the weight varies. Therefore, even if the motor (2) is decelerated for a stop time that uniquely corresponds to the brake data, the stop time is too short and the disk medium (1) coasts in the normal direction, or it stops. There is a problem that the disk medium (1) rotates in the opposite direction because the time is too long. Especially, if the disk medium (1) rotates in the opposite direction, the data arrangement of the disk medium (1) will be reversed, and the servo circuit (3) will not be able to detect the synchronization signal and the cycle of the synchronization signal will be lost. Will be mistaken for a very long time. Therefore, the servo circuit (3) applies servo to rotate the motor (2) at high speed in the reverse direction,
As a result, the motor (2) and peripheral circuits may be damaged.

Therefore, an object of the present invention is to provide a motor stop control device capable of surely stopping disk media having different diameters and weights without complicating the program processing of the computer means.

[0014]

The present invention has been made to solve the above problems, and is characterized in that a disk medium in which a predetermined information signal and a synchronization signal are stored is used. A servo means for outputting a motor for rotating at a linear velocity and an acceleration signal for accelerating the rotation of the disk medium or a deceleration signal for decelerating the rotation of the disk medium according to the frequency of the synchronizing signal of the disk medium. Driver means for outputting a drive signal for driving the motor based on an acceleration signal or a deceleration signal of the servo means, and the motor based on the counter electromotive voltage of the motor and the drive signal of the driver means. State detecting means for detecting the stopped state of the motor, and a computer for controlling the servo means by determining the state of the motor based on the detection signal of the state detecting means. The computer means intermittently performs the operation of outputting the deceleration signal for a predetermined time to decelerate the motor until a detection signal for detecting a stopped state of the motor is obtained. Is.

[0015]

According to the present invention, the operation of decelerating the motor by outputting the deceleration signal for a predetermined time is obtained by the detection signal obtained by detecting the stopped state of the motor based on the back electromotive voltage of the motor and the drive signal of the driver means. Until you get it,
This makes it possible to reliably stop disk media having different diameters and weights.

[0016]

The details of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a motor state detection device of the present invention. In addition, when the element of FIG. 1 and the element of FIG. 4 are the same, the same numerals are given and description is abbreviate | omitted. In FIG. 1, (9) is a state detection circuit, which is a signal a obtained by adding the counter electromotive voltage of the motor (2) and the drive signal of the driver circuit (4),
b is applied, the detection signal c indicating the stopped state of the motor (2)
Is output.

Inside the state detection circuit (9), (10) is a comparator, the non-inverting input terminal is connected to the signal b via the resistor (11), and the inverting input terminal is the signal via the resistor (12). The output terminal is connected to the inverting input terminal through the feedback resistor (13). The output terminal of the comparator (10) is derived from the open collector of the NPN transistor, and when the input of the non-inverting input terminal is larger than the input of the inverting input terminal, and the input of the non-inverting input terminal and the inverting input terminal. When is zero, the output of the output terminal is open and depends on the configuration of the latter stage. When the input of the non-inverting input terminal is smaller than the input of the inverting input terminal, the output of the output terminal is "L". Will be Reference numeral (14) is a transistor for amplifying the output of the comparator (10), the base of which is connected to the output terminal of the first comparator (10) via the resistor (15) and the power source V is connected via the resistor (16). _It is connected to _CC , the collector is connected to the power supply V _CC through the resistor (17), and the emitter is grounded. Then, a detection signal c is output from the collector of the transistor (14) according to the signals a and b and applied to the microcomputer (8). Microcomputer
(8) judges the detection signal c and outputs a command signal for surely stopping the motor (2). Experimentally, the resistors (11) and (12) are 1 KΩ, the feedback resistor (13) is 3 KΩ, the resistor (15) is 18 KΩ, the resistors (16) and (17) are 10 KΩ, and the power source V _{CC is}
By setting V to 5 volts, an appropriate detection signal c can be obtained from the signals a and b.

Reference numeral (18) is a capacitor, which absorbs a sharp change in the back electromotive force of the motor (2). Below, Figure 1
2 will be described with reference to the flowchart of FIG. 2 and the waveform diagram of FIG. When the disk medium (1) rotates in the normal direction at a constant linear velocity, the servo circuit (3) always performs a servo operation so that the cycle of the synchronization signal becomes a predetermined multiple of the cycle of the reference clock. A rectangular wave acceleration signal CLV + that repeats "H" and "L" and a deceleration signal CLV- that is "L" are output for a predetermined time, or a rectangular wave that repeats "L" acceleration signal CLV + and "H" and "L". The deceleration signal CLV- of is output alternately for a predetermined period of time. On the other hand, at the m terminal of the motor (2), a counter electromotive voltage according to the read position of the information signal of the disk medium (1) is generated, and n
A counter electromotive voltage of the ground level GND is generated at the terminal. More specifically, at the m terminal of the motor (2), a counter electromotive voltage V _H is generated at the time of reading an information signal on the inner circumference side of the disk medium (1) due to the definition of the constant linear velocity, and the A counter electromotive voltage V _L (<V _H ) is generated when the information signal on the outer peripheral side is read. Therefore, the signal a becomes a signal that repeatedly oscillates with an amplitude l _H around V _H when reading the information signal on the inner circumference side of the disk medium (1), and when reading the information signal on the outer circumference side of the disk medium (1). Amplitude l _L (<l _H ) around V _L
It becomes a signal that repeats oscillation. Further, the signal b is a signal that slightly oscillates around the ground level GND regardless of the read position of the information signal of the disk medium (1). That is, the signal a is larger than the signal b regardless of the read position of the information signal of the disk medium (1).

When the signals a and b are applied to the state detection circuit (9) when the disk medium (1) is rotating in the normal direction at a constant linear velocity, the signal a is larger than the signal b. (1
The "H" detection signal c is output from the collector of 4). The microcomputer (8) determines that the disk medium (1) is in a normal operating state because the "H" detection signal c is applied for a certain time or longer, and outputs a command signal to the servo circuit (3). Prohibit that. Therefore, the servo circuit (3) repeats the frequency comparison between the synchronization signal and the reference clock to continue the normal operation state of the disk medium (1).

At time t ₀ , when a command signal for stopping the disk medium (1) is applied to the servo circuit (3), the acceleration signal CLV + of "L" and "H" and Square wave deceleration signal CLV− that repeats “L”
Is output for a preset deceleration time, and the driver circuit (4) outputs a drive signal for making the counter electromotive voltage of the m terminal of the motor (2) smaller than the counter electromotive voltage of the n terminal.
The deceleration process (2) is performed. As a result, the signal a becomes smaller than the signal b, so that the detection signal c of "L" is output from the collector of the transistor (14) (step-).

At time t ₁ , a preset deceleration time (t _{0 to} t ₁ ) elapses, and a command signal for canceling the deceleration processing of the motor (2) is applied to the servo circuit (3). , Acceleration signal CLV + of “L” and “L” from servo circuit (3)
Since the deceleration signal CLV- of is output, the driver circuit
The drive signal is not output from (4), and the deceleration processing of the motor (2) is canceled (step-).

At time t ₂ , when a preset waiting time (t _{1 to} t ₂ ) elapses, the microcomputer (8)
Determines the level of the detection signal c (step--
). Here, the waiting time is set in order to absorb the state in which the signals a and b are unstable due to the change in the counter electromotive voltage of the motor (2). For example, when the deceleration process of the motor (2) is released and a preset waiting time has elapsed, the motor (2) cannot be stopped and is rotated by inertia in the normal direction. The counter electromotive voltage of the m terminal is larger than the counter electromotive voltage of the n terminal. As a result, the signal a becomes larger than the signal b, so that "H" is output from the collector of the transistor (14).
Detection signal c is output. Microcomputer (8)
Determines that the disk medium (1) cannot be stopped because the detection signal c of "H" is applied even though the command signal for stopping the disk medium (1) is generated. .. Then, at time t ₃ , a command signal for stopping the disk medium (1) is applied to the servo circuit (3) again, and the above-mentioned operation is repeated (step).

At time t ₄ , a command signal for stopping the disk medium (1) is applied to the servo circuit (3),
At time t _5, a preset deceleration time (t ₄ ~t ₅₎
Is passed, a command signal for canceling the deceleration processing of the motor (2) is applied to the servo circuit (3), and at time t ₆ , a preset waiting time (t _{5 to} t ₆ ) has elapsed. do it,
When the motor (2) is stopped, the counter electromotive voltage is not generated at the m terminal and the n terminal of the motor (2). As a result, the signal a and the signal b become zero, and the "L" detection signal c is output from the collector of the transistor (14). Since the detection signal c of "L" is applied to the microcomputer (8),
It is determined that the motor (2) has stopped, and it is prohibited to output a command signal for stopping the disk medium (1) to the servo circuit (3) (step).

As described above, the operation of decelerating the motor (2) by outputting the rectangular wave deceleration signal CLV- for a predetermined time is performed based on the counter electromotive voltage of the motor (2) and the drive signal of the driver circuit (4). The operation is intermittently performed until the detection signal c which detects the stopped state of (2) is obtained, whereby the disk media (1) having different diameters and weights can be surely stopped.

[0025]

According to the present invention, the operation of decelerating the motor by outputting the deceleration signal for a predetermined time is detected by detecting the stopped state of the motor based on the back electromotive voltage of the motor and the drive signal of the driver means. This is carried out intermittently until the above condition is obtained, whereby the disk media having different diameters and weights can be surely stopped without complicating the program processing of the computer means. Therefore, it is possible to prevent the disk medium from rotating in the reverse direction and to prevent damage to the motor and the driver means.

[Brief description of drawings]

FIG. 1 is a diagram showing a motor state detection device of the present invention.

FIG. 2 is a flowchart showing a processing procedure of the microcomputer of FIG.

FIG. 3 is a diagram showing an output waveform of a state detecting means of FIG.

FIG. 4 is a diagram showing a conventional motor driving device.

[Explanation of symbols]

 (1) Disk medium (2) Motor (3) Servo circuit (4) Driver circuit (8) Microcomputer (9) State detection circuit

Claims (2)

[Claims] 1. A motor for rotating a disk medium having a predetermined information signal and a synchronization signal stored therein at a constant linear velocity, and a motor for accelerating the rotation of the disk medium according to the frequency of the synchronization signal of the disk medium. Servo means for outputting an acceleration signal or a deceleration signal for decelerating the rotation of the disk medium; and driver means for outputting a drive signal for driving the motor based on the acceleration signal or deceleration signal of the servo means. A state detection unit that detects a stopped state of the motor based on a back electromotive voltage of the motor and a drive signal of the driver unit; and a state of the motor that is determined based on a detection signal of the state detection unit. Computer means for controlling the servo means, wherein the computer means outputs the deceleration signal for a predetermined time to drive the motor. A motor stop control device characterized in that the operation of speeding up is intermittently repeated until a detection signal for detecting a stopped state of the motor is obtained based on a back electromotive force of the motor and a drive signal of the driver means. .. 2. The state detecting means applies a first counter electromotive voltage generated at one end of the motor to an inverting input terminal and a second counter electromotive voltage generated at the other end of the motor to a non-inverting input terminal. 2. The motor stop control device according to claim 1, further comprising a comparator to which is applied, and which outputs a detection signal indicating a stopped state of the motor based on an output signal of the comparator.