JPS623435A - Optical disk reproducing device - Google Patents

Abstract

PURPOSE:To decrease the power consumption by turning off the tracking servo and driving the pick-up feeding motor with a constant voltage at the time of the repeat shifting of the pick-up. CONSTITUTION:A key is set 23, and all information repeating reproducing commands are given to a CPU 21a. Then, when a CPU 21b supervises the address information of a processor 16 and a disk outer-most circumferential information is reproduced, a switch SL is opened, a laser output is turned off, further, ST and SF are opened, the tracking servo and the focus servo are turned off and a disk 11 is stopped. Next, the constant voltage is applied to a motor 14, and a pick-up 13 is shifted at the constant speed to the disk inner circumference. When a starting point switch-on is detected, the focus scanning is executed, the focus servo and the track servo are set to on, the pick-up 13 is shifted in the outer direction, the inner-most information recording column is looked for, again, the reproducing condition is set and the operation is continued until the stop command is executed. By the constitution, the power consumption of the servo part and the motor part is decreased.

Description

[Detailed Description of the Invention] [Field of the Invention] This invention is applicable to, for example, a CD (compact disc) system.
The present invention relates to an optical disc playback device for playing AD (digital audio disc), and particularly to one having an all-information repeat mode.

[Technical background of the invention and its problems] Conventionally, for example, a CD system optical disc playback device (
Some CD playback devices (hereinafter referred to as CD playback devices) have an all-information repeat mode for repeatedly playing all the information signals recorded on the disc.2Such CD playback devices have an all-information repeat mode. When set, the audio output system is turned off when the reproduction of the information recorded on the outermost circumference of the disc is completed. After that, while the tracking servo and focus servo are intermittently or continuously applied to the objective lens of the pickup, a kick pulse is given to the pickup feed motor to move the pickup intermittently toward the inner circumference of the disk, and from time to time, the pickup is moved toward the inner circumference of the disk. While reading the information signal, the first information signal recording start point is approached, and when this point is searched, the audio output system is turned on and the information signal is reproduced again.

However, when performing the all-information repeat mode operation as described above, the tracking servo circuit and focus servo circuit consume approximately 1 watt of power, and the pickup feed motor is repeatedly accelerated and decelerated. The feed motor drive circuit consumes several times as much power as normal playback. Such power consumption is an extremely important problem, especially since portable playback devices use batteries such as dry cells as power sources.

[Object of the invention] This invention was made to improve the above-mentioned problems, and an object of the invention is to provide an optical disc playback device that can operate in all-information repeat mode with low power consumption. .

[Summary of the invention] That is, the optical disc playback device according to the present invention has the following features:
An optical pickup that reads information signals from a disk by irradiating a laser beam onto a disk on which information signals are recorded in a spiral array from the inner circumference to the outer circumference and receiving the reflected light, and this pickup. A focus servo and a tracking servo are applied to the laser beam so that the laser beam correctly matches the information signal recording surface of the disk and traces the recording row, and the disk is rotated at a predetermined speed and the output of the laser beam is controlled to be constant. a pickup feed motor that moves the pickup in the radial direction of the disk; and a pickup feed motor that moves the pickup from the outermost playback end point to the innermost playback start point to repeat playback of all information. In those having a full information repeat mode,
a first control means that turns off at least a tracking servo of the control means during repeated movements of the pickup; and a second control means that controls driving of the pickup feed motor with a constant voltage during repeated movements of the pickup.
In particular, the first control means turns off the tracking servo, focus servo, and laser output of the control means, or turns off the tracking servo, focus servo, and laser output of the control means. The servo, laser output, and disk rotation may be turned off.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the circuit configuration of a CD reproducing apparatus to which the present invention is applied. In other words, 11 in the figure is a disk on which information signals converted into digital data are recorded in a spiral array from the inner circumference to the outer circumference.This disk 11 is rotated by a disk motor 12 at a constant linear velocity (CLV servo). At the bottom of the disk 11 is an optical pickup 13 for reading data from the disk 11.
is provided. The pickup 13 is movable in the radial direction of the disk 11 by a pickup feed motor 14, and moves from the inner circumference side to the outer circumference side of the disk 11 during reproduction. This moving distance is electrically regulated by a start limit switch (not shown) on the inner circumferential side and an entry limit switch (not shown) on the outer circumferential side. The data read by this pickup 13 is supplied to a processor 16 via a head amplifier 15.

This processor 16 waveform-shapes and demodulates input data, and then separates the demodulated data into audio data and a synchronization signal that becomes address data.

Among these, the audio data is further subjected to processing such as error correction and correction, and is converted into an analog audio signal by a DA (digital-to-analog) converter 17, amplified by an audio output amplifier 18, and connected to an output terminal 19. The recorded audio is output to the audio playback device 20. On the other hand, the synchronization signal is supplied to a microcomputer 21 that controls the overall operation of this CD playback device, and is also supplied to a servo circuit 21.
2.

The servo circuit 22 generates various servo signals from a signal from the head amplifier 15 (so-called RF multiplied signal and a synchronization signal from the processor 16) in accordance with a control signal sent from the microcomputer 21, although the details will be described later. , linear velocity servo for the disk motor 12, tracking servo and focus servo for the pickup 13, and feed servo for the feed motor 14.

In this case, the pickup 13 is connected through the servo circuit 22.
The laser output and the disk motor 12 can be controlled on and off.

The microcomputer 21 has an input/output circuit (Ilo
) 21a, arithmetic processing circuit (CPU) 21b, memory 21
It consists of c. The l1021a sends address data from the processor 16, various operation mode command data from the keyboard 23, etc., and detection signals from switches provided in each part of the playback device to the CPU 21b.
The control signal and display data from 1b are sent to the processor 16, servo circuit 22 and display 24, respectively.
It is for outputting to etc. CP Ll 211)
are various playback modes (including all information repeat mode) given from the keyboard 24 through the I10 circuit 21a.
The program is read from the memory 210 in accordance with the address data from the processor 16, and the servo circuit 22 is controlled based on the address data from the processor 16.
4. It displays necessary information.

FIG. 2 shows a specific configuration of the servo circuit 22, and only the control section for the pickup 13 is shown here. That is, in the figure, 22a is an APC circuit (automatic output control circuit) for keeping the laser output of the pickup 13 constant, and this APC circuit 22a supplies a driving current to the laser diode LD of the pickup 13 via the switch SL. A laser beam is generated, and its driving current is increased or decreased according to the current generated by the monitor diode MO, thereby controlling the output of the laser diode LD to be constant.

Further, 22b in the figure is a tracking servo circuit, which includes an error detection section T1, a switch 37. Consisting of a phase compensation circuit T2 and a drive circuit T3, it generates a tracking error signal @TE from the output signal of the pickup 13 inputted via the head amplifier 15, compensates the phase of this error signal TE, and converts it into a corresponding drive signal. After the conversion, the objective lens A is controlled to move in the radial direction of the disk 110 (in the direction of arrow a) by supplying it to the tracking actuator coil LT of the pickup 13, so that the laser beam accurately traces the information recording row. Tracking servo is applied. Further, 22C is a focus servo circuit which, like the tracking servo circuit 22b, includes an error detection section Fl, a switch SF, a phase compensation circuit F2, and a drive circuit F.
A focus error signal F is generated from the output signal of the pickup 13 which is input via the head amplifier 15.
After the error signal FE is phase-compensated and converted into a corresponding drive signal, the error signal FE is supplied to the focus actuator coil of the pickup 13 to move the objective lens A in the direction perpendicular to the disk 11 (arrow c). −
d direction) and performs focus servo so that the focus (spot) of the laser beam is correctly aligned on the reflective surface of the disk 11.

The switches SL, ST, and SF are controlled on and off by control signals from the microcomputer 21, and thereby the laser output, tracking servo, and focus servo can be controlled on and off. .

In the above configuration, operation control in the all information repeat mode will be explained below with reference to FIG.

FIG. 3 is a flowchart showing the structure of an operation control program in the all information repeat mode. This program is stored in the memory 21C.

First, operate the keyboard 23 to set the all information repeat mode, and then set it to the playback state (step a
) and an all information repeat reproduction command are supplied to the CPU 21a. Here, the CP tJ 21b outputs a playback control signal and puts the playback device into a playback state (step b
). Thereafter, the CP tJ 21b monitors the address information from the processor 16 and continues to output the reproduction control signal until the information on the outermost circumference of the disc is reproduced (step C). Then, when the outermost circumference information is reproduced, a laser output off signal is supplied to switch SL to cut off the APC loop and turn off the laser output (step d).
. Furthermore, it outputs a control signal that turns off the tracking servo, focus servo, and CLV servo, turns off switches ST, SF, etc., cuts off each loop of the tracking servo and focus servo, and turns off the servo. 12 is stopped (step e).

Here, the CPU 21b controls the servo circuit 22 to supply a constant voltage to the pickup feed motor 14, thereby moving the pickup 13 toward the inner circumference of the disk 11 at a constant speed (step f).

When it is detected that the start limit switch is turned on (step Q), a focus search is performed and the focus servo is turned on (step h
). Furthermore, set the tracking servo to the on state,
A kick pulse is applied to the pickup feed motor 14 to move the pickup 13 toward the outer circumference of the disk 11 to search for the innermost circumference information recording row (step i). After the search is completed, the reproduction control signal is outputted again to set the reproduction state, and thereafter the above operation is executed in the same manner until a reproduction stop command is input.

The movement of the pickup 13 may be controlled as shown in FIG. That is, steps a to e and i in FIG. 4 are the same as those shown in FIG. Calculate the distance (step j), supply a constant voltage to the pickup feed motor 14 for a time T obtained from the distance and the average speed of the feed motor 14, and move the pickup 13 to the vicinity of the innermost regeneration start point (step k). ). Then, after T time has elapsed, a focus search is performed (step 1), and when the focus servo is turned on, the tracking servo is immediately turned on, and a kick pulse is given to the rough feed motor 14 to reach the innermost circumference playback starting point. (step i). After the search is completed, the process returns to step b and the reproduction state is set. The following is the same as in the case of FIG. In other words,
In this case, there is no need to use a start limit switch.

That is, in the above-described all-information repeat operation, when moving the pickup 13 from the outermost circumference to the innermost information recording column, the laser output is turned off, the tracking servo and the focus servo are also turned off, and the disk 11 is turned off.
Since the rotation of the pickup and feed motor 14 is stopped, the power consumed in each of these parts can be omitted.Furthermore, by driving the pickup feed motor 14 with a constant voltage, the motor drive efficiency is increased, so power consumption can be reduced here as well. can be reduced.

For example, the power consumption per second during focus search is 0.5W/sec, and the power consumption by kick pulse, focus servo, and tracking servo is 1.0W/s.
ec, and assuming that the distance from the outermost disc playback end point to the innermost playback start point is 35m+, the time and power consumption from the end of outermost playback to the start of innermost playback are compared to the conventional innermost playback start point. Comparing the method of moving the pickup while searching with the method of this invention, the conventional method takes about 4 seconds to search, but since no focus search is required, the total search time is 4 seconds.
It is about seconds. On the other hand, in the method according to the present invention, the pickup moving time is 2.5 seconds, and the focus search is 1 second.
It takes 0.5 seconds to search for the innermost playback start point, and the total time is about 4 seconds, the same as before. However, the power consumption PO of the conventional method is PO = 1, 0 [W/5ecJ x 4 [se
c]-4[w), whereas the power consumption P~ of the method according to the present invention is PN = 0. 5 [W/sec] x 1 1secC
] + 1 , 0 [W/5eclx0.5 [5ec
J-1[WJ, so the power consumption is about 1/4 of the conventional one. Furthermore, the power consumption of the laser output per second is 0.
If it is 2W/sec, then 0.2[W/sea
can be reduced by x2.5 [sec] -0.5 [WJ].

Therefore, the above-mentioned CD playback device consumes much less power when moving the pickup from the outermost track to the innermost track even when all information is played repeatedly, compared to conventional devices, and this makes it possible to use dry cell batteries as a power source. Long-term playback is possible even with batteries such as

Note that this invention is not limited to the above embodiments,
For example, when moving the pickup from the outermost circumference to the innermost circumference, if only the tracking servo is turned off and the pickup feed motor 14 is driven with a constant voltage, the power consumption can be sufficiently reduced compared to the conventional one. be able to. For example, when calculating the travel time and power consumption PN- when moving the pickup based on the above conditions, the pickup travel time is 2.5 seconds, the focus search is 0 seconds,
It takes 0.5 seconds to search for the innermost playback start point, and the total time is about 1 second faster than before. Then, the power consumption PN − at this time is PN −−0,'5 [W/sec]x2. S r
secl 10 Q, 5 [W/36C xQ
, 5 rsecl-1,5[Wl, which is less than half of the conventional value.

[Effects of the Invention] As detailed above, according to this invention, all information liby 1
It is possible to provide an optical disc playback device that can operate in ~ mode with low power consumption.

[Brief explanation of drawings]

The drawings show an embodiment of the optical disc playback device according to the present invention, and FIG. 1 is a block circuit diagram showing the configuration of the CD playback device to which the invention is applied, and FIG. 2 shows the configuration of the CD playback device of FIG. FIG. 3 is a block circuit diagram showing the configuration of a servo circuit of the reproducing apparatus, FIG. 3 is a flowchart for explaining the operation control means of the CD reproducing apparatus, and FIG. 4 is a flowchart showing another embodiment of the present invention. 11... Disc, 12... Disc motor, 13
... Optical pickup, 14... Pickup feed motor, 15... Head amplifier, 16... Processor, 11... OA converter, 18... Audio output amplifier, 20... Audio playback device , 21... Microcomputer 21. 21a... Input/output circuit, 21b.
...Arithmetic processing circuit, 21c...Memory 21C122.
...Servo circuit, 23...Keyboard, 24...Display, 22a...APC circuit, 22b...Tracking servo circuit, 22G...Focus servo circuit.

Claims (3)

[Claims] (1) An optical system that reads information signals from a disk on which information signals are recorded in a spiral array from the inner circumference to the outer circumference by irradiating a laser beam onto the disk and receiving the reflected light. a pickup, and a focus servo and a tracking servo are applied to the pickup so that the laser beam correctly matches the information signal recording surface of the disk and traces the recording row, and the disk is rotated at a predetermined speed to emit the laser beam. a control means for controlling the output to be constant; a pickup feed motor for moving the pickup in the radial direction of the disk; and a pickup feed motor for moving the pickup from the outermost playback end point to the innermost playback start point. In an optical disc playback device having an all-information repeat mode for repeating playback of all information, a first control means turns off at least a tracking servo of the control means during repeat movement of the pickup; and and second control means for controlling the drive of the pickup feed motor at a constant voltage. (2) The optical disk reproducing apparatus according to claim 1, wherein the first control means turns off tracking servo, focus servo, and laser output of the control means. (3) The optical disk reproducing apparatus according to claim 1, wherein the control means turns off tracking servo, focus servo, laser output, and disk rotation of the control means.