JPS619181A - Drive device of dc motor for feeding - Google Patents

Abstract

PURPOSE:To eliminate a drive of a DC motor for feeding for not long time longer than required even if a tracking error signal is disordered by muting the output of a comparator at every prescribed period. CONSTITUTION:Comparators 2, 3 input a tracking signal from a tracking servo circuit 25 for controlling a pickup 22, and output signals when the pickup 22 tilts at the outer or inner peripheral side of disc-shaped information recording medium 21. A control signal of H level is applied to a terminal 6 or 7 or control signals of H and L levels are alternately applied to the terminal 7 or 6 at normal reproducing time. A controller 4 supplies the output of the comparator 3 or 2 to the control logic input terminal of a motor drive circuit 11 only when the control signal is H level.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a DC motor drive device that feeds a signal converter for reproducing information signals recorded on a disc-shaped information recording medium into a pink amplifier. be.

[Prior art]

FIG. 1 shows an example of an information signal reproducing device and a conventional drive device for driving a feed feeding DC motor in the information signal reproducing device. In FIG. 1, -0 is an information signal reproducing device, which includes a 9-disc-shaped information recording medium 1, a big amplifier section λ that picks up the information signal recorded on this disc-shaped information recording medium 21, and this pink-up section λ. Department
A signal converter 23 is supported by one support, and a fin for moving the signal converter 3 in the radial direction of the disc-shaped information recording medium 21.
The pickup unit λ6 follows the information trunk of the disc-shaped information recording medium 21 in the tracking direction (radial direction of the disc-shaped information recording medium 21). It is provided with a tracking servo circuit λS for controlling the pickup sections 1 and 2, and an information signal processing circuit for appropriately processing the information signals picked up by the pickup sections 1 and 2.

Reference numeral 10 denotes a conventional drive device for driving a feed feed DC motor co-operator in the information signal reproducing device 20. In this drive device IO, l is an input terminal, and a tracking error signal (corresponding to the position of the information track with respect to the signal converter 23) is input from the tracking servo circuit 25. 3 is a comparator connected to the input terminal l to detect a positive threshold voltage, and 3 is a comparator connected to the input terminal l to detect a negative threshold voltage. is a control circuit connected to these converter tachos and the output side of 3. j
, A, 7 are control input terminals connected to the control circuit board, into which control signals from the system controller 1 are input.

9 is the control input terminal! A drive voltage control circuit is connected to the feed feed DC motor 9, and a motor drive circuit is connected to the control circuit DA and the drive voltage control circuit 9.

Next, to explain the operation, the tracking error signal inputted to the input terminal l from the tracking servo circuit a3 that controls the pickup section 2 is zero when the pickup section 2 is located at the center with respect to the signal converter 23. It is. however.

If the pickup 22 is tilted toward the inner circumference of the disc-shaped information recording medium 2/ with respect to the signal converter J, a negative tracking error signal will be generated, and this signal voltage will exceed the set threshold voltage (i.e., the tracking error signal (exceeds a certain value), the output of the comparator 3 is inverted, and this inverted output, that is, the drive pulse for driving the feed feed DC motor 2, is supplied to the control circuit 2. Furthermore, if the pickup section 2.2 is tilted toward the outer circumference of the disk-shaped information recording medium 21 with respect to the signal converter 3, a positive tracking error signal will be generated, and if this signal voltage exceeds the set threshold voltage, the converter tacho The output is inverted, and this inverted output, ie, the drive pulse, is supplied to the control circuit. Control input terminal from system controller g! A feed feeding direct current motor and a control signal for controlling the feed feeding speed of the 2 da are inputted to the feed feeding terminal 6, and control signals for controlling the feed feeding direction and feed feeding stop are inputted to the control input terminals 6 and 7, respectively. Based on these control signals, the control circuit 1 outputs the above-mentioned feed feed direction control signal and feed feed stop control signal to the control logic input terminal of the motor drive circuit //. Figure 2 shows
FIG. 7 is a timing chart of control signals input to the control input terminals 5' and 4.7 during a series of operations of stop, lead-in, normal playback, lead-out, and stop.

During normal playback when the big amplifier unit 22 is transmitting power from the outer circumferential side to the inner circumferential side of the disc-shaped information recording medium 2/, the control input terminal S is at the L level, the control input terminal L is at the H level, and the control input terminal 7 is at the L level. It becomes L level, and only the output of the comparator 3 passes through the control circuit q, and the control logic input terminal of the motor drive circuit // is driven. Conversely, during normal playback when the pickup section is being transferred from the inner circumferential side to the outer circumferential side of the disc-shaped information recording medium 21, the control input terminal j is at L level,
The control input terminal 6 becomes L level and the control input terminal 2 becomes H level, and only the output of the converter tacho is supplied to the control logic input terminal of the motor drive circuit ii through the arrow control circuit DA. That is, when the output of the converter tacho is at H level, the feed feed DC motor tacho is driven.

In this way, during normal playback, only the output of either converter tacho or 3 is supplied to the motor drive circuit /1, so that the hunting phenomenon of the feed feeding DC motor 2 is prevented. Also, during high-speed feed and stop, the control input terminal S becomes H level, the output of the converter tacho 3 is disconnected, and the control logic of the motor drive circuit /1 is determined by the state of the control signal input to the control input terminal 6.7. The state of the input terminal is determined. That is, when the control input terminal 6 is at the H level and the control input terminal is at the L level, high-speed feeding is performed from the outer side to the inner side, and when the control input terminal 6 is at the L level and the control input terminal is at the H level, the inner side is fed at high speed. High-speed feeding from the peripheral side to the outer peripheral side is stopped when both control input terminals 6 and 7 are at H level. The drive voltage control circuit outputs a signal for controlling the drive voltage of the feed feed DC motor cock according to the state of the control input terminal 5;
When the control input terminal +3 is at the H level, high voltage driving and high speed feeding is performed, but when the control input terminal +3 is at the L level, low voltage driving and low speed feeding is performed. The motor drive circuit // drives or stops the feed feed DC motor 2g based on the outputs of the control circuit 1 and the drive voltage control circuit 9 described above.

9 Since the conventional drive device is configured as described above, 1. If the tracking correction is disturbed during normal playback,
The tracking servo circuit allows the pickups to settle on the information track, but since the output of the converter servo or 3 is always supplied to the motor drive circuit, there is a tracking error input to the input terminal. When the signal is disturbed and exceeds the threshold voltage,
The feed feed DC motor 2'l is driven before the tracking correction returns to normal, causing a further negative effect on the tracking correction, further disrupting the tracking error signal, and driving the feed feed DC motor 2'l. A vicious cycle occurred, and the problem was that the tracking did not return to normal for a long time.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and without adding a new circuit.
By changing the control signal from the system controller, the comparator output is muted (disabled) at predetermined intervals during normal playback.
A new drive for the feed feed DC motor that does not cause the feed feed DC motor to be driven open at tJ for an unnecessarily long time even if the tracking correction is disturbed and therefore the tracking error signal input to the input terminal l is disturbed. An embodiment of the present invention will be described below for the purpose of providing an apparatus. Figure 8.7 shows stop, lead-in, normal play, and lead-out.

During a series of stop operations, the control input terminal z in FIG.
FIG. 4 is a timing diagram of control signals inputted to system controllers b and t and used in the present invention. In this invention, during normal playback from the outer circumferential side to the inner circumferential side as described above, as shown in FIG. A control signal that repeats L level and H level every time (conventionally, only L level as shown in Fig. 2) is input, and only when this control signal is at L level, the control circuit controls the output of comparator 3 to drive the motor. circuit/
/ is supplied to the control logic input terminal of /. Also, during normal playback from the inner circumferential side to the outer circumferential side as described above, the control input terminal 6
A control signal that repeats L level and H level at predetermined intervals (conventionally, only L level) is input to t, and at the same time, an H level control signal is input to control input terminal t, so that the control input terminal t is at L level. Only then is the control circuit supplied to the control logic input terminal of the motor drive circuit IT, which is the output of the converter tacho. This prevents the hunting phenomenon of the feed feed DC motor 2da, and even if the tracking correction is disturbed and the tracking error signal input to the input terminal l is disturbed, the output of the comparator 3 or Since it is muted, there is no need to drive the feed feed DC motor for a long time.
Further, there is no longer any adverse effect on tracking correction.

〔Effect of the invention〕

As described above, according to the present invention, in the conventional circuit,
By changing the timing of the control signal from the system controller, the comparator output is muted at predetermined intervals, so even if the tracking correction is disrupted and the input tracking error signal is disrupted, there is no need to add a new circuit. This provides the advantage that the feed feed DC motor is not driven for an unnecessarily long time and tracking correction is not adversely affected.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of an information signal reproducing device and a conventional drive device for driving a feed feeding DC motor in this information signal reproducing device. Timing diagram of control signals, and FIG. 3 is a timing diagram of control signals in one embodiment of the present invention. In the figure, l is an input terminal to which a tracking error signal is applied, ko is a comparator that detects a positive threshold voltage, and 3 is a negative threshold voltage. A detecting comparator, q is a control circuit, 5, 6 and 7 are control input terminals to which control signals are applied, 1 is a system controller, 1 is a drive voltage control circuit, 10 is a drive device, l/ is a motor drive circuit, 2 〇 is an information signal generator, ko 1 is a disk-shaped information recording medium, ko is a pickup section, ko 3 is a signal converter, 2
Hiro is a direct current motor for feed feeding. is a tracking servo circuit, KORO is a tracking control; ILE and KOKU are information signal processing circuits. In each figure, the same reference numerals indicate the same or similar parts.

Claims (1)

[Claims] a disc-shaped information recording medium; a pickup section that picks up an information signal recorded on the disc-shaped information recording medium;
Information signal reproduction comprising a signal converter that supports the pickup section, a feed feeding DC motor that moves the signal converter in the radial direction of the disk-shaped information recording medium, and a tracking servo circuit that controls the pickup section. A drive device for the apparatus, which includes a comparator that generates a drive pulse to drive the feed feed DC motor when the tracking error signal from the tracking servo circuit exceeds a certain range; The drive device includes a system controller that generates a control signal for controlling the feed feed direction and stop of the feed feed, and a control circuit that controls the drive pulse using the control signal. A drive device for a feed feeding DC motor, characterized in that the control circuit mutes the drive pulse at each predetermined period by using a control signal that repeats an L level and an H level.