JP4582460B2 - Optical recording medium reproducing apparatus, optical recording medium recording apparatus, optical recording medium reproducing method, and optical recording medium recording method - Google Patents

Description

  In the present invention, when performing recording and reproduction on an optical disc while performing tracking control in the normal direction of the disk-type recording medium, the movement of the optical head for recording and reproduction on the medium is sent using a stepping motor. The present invention relates to an optical recording medium reproducing apparatus, an optical recording medium recording apparatus, an optical recording medium reproducing method, and an optical recording medium recording method that perform recording and reproducing operations with high accuracy and low power consumption.

Recently, portable DVD recording and reproducing devices have been introduced into the market.
On the other hand, although the battery for driving the portable device has been increased in capacity, reduced in size and weight, the proportion of the battery incorporated in the portable device has not been reduced in size and weight that can be ignored as compared with the device main body. In order to effectively use the power of a limited battery, it is preferable that the power consumption of the portable device can be reduced. It is desirable to reduce the power consumption of the device even in a stationary device, considering the environmental load.

Patent Document 1 discloses an objective lens, a tracking actuator that drives the objective lens in the width direction of the recording track of the optical disc, an optical pickup that includes the objective lens and the tracking actuator, and a stepping that drives the optical pickup in the radial direction of the optical disc. After the amount of displacement of the objective lens from the center position in the optical pickup becomes smaller than a predetermined value in realizing low power consumption of the apparatus having the motor, the tracking actuator control unit, and the stepping motor drive unit An optical disc apparatus is disclosed in which when the stepping motor reaches a mechanically stable position, the driving of the stepping motor is stopped and the current flowing through the stepping motor is reduced.
JP 2004-55008 A

  However, in the optical disk device disclosed in Patent Document 1, since the recording / reproducing operation is performed by positioning the rotor of the stepping motor only at the mechanically stable position, the optical pickup is mounted on the moving thread. The position is not always at the optimum position. Even though the position error of the sled can be corrected by the tracking control function of the optical pickup and the reproduction operation can be performed, the power consumption required for the tracking control increases, and further, the angular error generated between the optical pickup and the recording medium For this reason, it has been impossible to realize an optical disc apparatus with low power consumption while maintaining good recording and reproducing characteristics such as deterioration of optical characteristics.

  Therefore, the present invention has been made to solve the above-described problems. A high-quality information signal can be obtained with low power consumption while maintaining the control position of the optical pickup controlled by the stepping motor at an appropriate level. An object of the present invention is to provide an optical recording medium reproducing apparatus, an optical recording medium recording apparatus, an optical recording medium reproducing method, and an optical recording medium recording method that enable recording and reproduction.

According to a first aspect of the present invention, information is intermittently read from an optical recording medium using an optical pickup , the read information is temporarily stored in a memory unit, and the information stored in the memory unit is read. In an optical recording medium reproducing apparatus that continuously decodes and reproduces data by a decoder ,
A memory amount detection unit for detecting the amount of data stored in the memory unit;
A data rate estimation unit for estimating a bit rate of information decoded by the decoder;
A stepping motor linked to the optical pickup and having a stator and a rotor that rotates in the stator;
A detection unit for detecting a rotation angle and a rotation direction of the rotor;
When the amount of data detected by the memory amount detection unit is greater than or equal to a first predetermined amount by storing the information read by the optical pickup,
The waiting time is obtained by dividing a value obtained by subtracting a second predetermined amount that is smaller than the first predetermined amount from the first predetermined amount by the bit rate estimated by the data transfer rate estimation unit. When the obtained waiting time is equal to or longer than the first predetermined time, the rotation direction of the rotor is rotated or the anti-rotation direction is stabilized based on the rotation angle of the rotor detected by the detection unit. Stop the rotor in position,
When the data amount of the memory unit detected by the memory amount detection unit becomes equal to or less than the second predetermined amount due to the progress of decoding by the decoder,
The calculation of the rotation angle and the rotation direction of the rotor detected by the detection unit is performed, and the position of the rotor of the stepping motor is returned to the position where the information was read immediately before, or the information is There is provided an optical recording medium reproducing device comprising: a stepping control unit that sets a position after reading in advance.
A second invention includes an encoder that encodes continuous information, and a memory unit that temporarily stores information encoded by the encoder, and the information encoded by the encoder is temporarily stored in the memory unit. stored, reads the information stored in the memory unit, an optical recording medium recording apparatus for recording intermittently optical recording medium using an optical pickup,
A memory amount detection unit for calculating the amount of data stored in the memory unit;
A data rate estimation unit for estimating a bit rate of information encoded by the encoder;
A stepping motor linked to the optical pickup and having a stator and a rotor that rotates in the stator;
A detection unit for detecting a rotation angle and a rotation direction of the rotor;
When the information stored in the memory unit is read out toward the optical pickup and the amount of data is equal to or less than a first predetermined amount,
Obtained by dividing the value obtained by subtracting the first predetermined amount from the second predetermined amount, which is a value larger than the first predetermined amount, by the bit rate estimated from the data transfer rate estimation unit. When the waiting time is equal to or longer than the first predetermined time, the rotation is performed at a stable position in the rotation direction or the counter-rotation direction in which the rotor is rotating based on the rotation angle of the rotor detected by the detection unit. Stop the child,
When the amount of data in the memory unit becomes equal to or greater than the second predetermined amount due to the progress of encoding by the encoder,
The calculation of the rotation angle and the rotation direction of the rotor detected by the detection unit is performed, and the position of the rotor of the stepping motor is returned to the position where the information was read immediately before, or the information is There is provided an optical recording medium recording apparatus comprising: a stepping control unit configured to set to a preset position after reading.
A third invention uses an optical pickup to intermittently read information from an optical recording medium , temporarily store the read information in a memory unit, read the information stored in the memory unit, and use a decoder In an optical recording medium reproducing method for continuously decoding and reproducing,
While calculating the amount of data stored in the memory unit, estimating the bit rate of information decoded by the decoder,
Rotating the rotor of the stepping motor linked to the optical pickup in the stator,
The detection unit detects the rotation angle and rotation direction of the rotor,
When the amount of data detected by the memory amount detection unit is equal to or greater than the first predetermined amount by storing the information read by the optical pickup,
Standby detected by dividing a value obtained by subtracting a second predetermined amount that is smaller than the first predetermined amount from the first predetermined amount by the bit rate estimated by the transfer rate estimation unit. If the time is greater than or equal to the first predetermined time,
Based on the rotation angle of the rotor detected by the detection unit, the rotor is stopped at a stable position in the rotation direction or the counter-rotation direction in which the rotor is rotating,
When the decoding progresses, the amount of data stored in the memory unit detected by the memory amount detection unit becomes equal to or less than the second predetermined amount.
The calculation of the rotation angle and the rotation direction of the rotor detected by the detection unit is performed, and the position of the rotor of the stepping motor is returned to the position where the information was read immediately before, or the information is Provided is an optical recording medium reproduction method characterized in that the position is set in advance after reading.
A fourth invention encodes a continuous information by the encoder, is temporarily stored in the memory unit, and records the intermittently optical recording medium using the optical pickup by reading the information stored in the memory unit In the optical recording medium recording method,
While calculating the amount of data stored in the memory unit, estimating the bit rate of the information encoded by the encoder,
A rotor of a stepping motor linked to the optical pickup is rotated in a stator, and a rotation angle and a rotation direction of the rotor are detected by a detection unit;
When the information stored in the memory unit is read out to the optical pickup and the data amount becomes equal to or smaller than the first predetermined amount, the second place is a value larger than the first predetermined amount. When the standby time obtained by dividing the value obtained by subtracting the first predetermined amount from the fixed amount by the bit rate is equal to or longer than the first predetermined time , the rotation angle of the rotor detected by the detection unit The rotor is stopped at a stable position in the rotational direction or counter-rotating direction in which the rotor is rotating,
When the amount of data in the memory unit becomes equal to or greater than the second predetermined amount due to the progress of encoding,
The rotation angle and the rotation direction of the rotor detected by the detection unit are calculated, and the position of the rotor of the stepping motor is returned to the position where the information was recorded immediately before or the information was recorded. Provided is an optical medium recording method characterized in that a later preset position is set.

According to the present invention, while properly maintaining the control position of the optical pickup which is position control in the scan stepping motor, recording high-quality information signal with low power consumption, optical recording medium reproducing apparatus can be reproduced, the optical recording A medium recording apparatus, an optical recording medium reproducing method, and an optical recording medium recording method can be realized.

An optical recording medium recording / reproducing apparatus according to an embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 is a block diagram showing a configuration example of an optical recording medium recording / reproducing apparatus according to an embodiment of the present invention. FIG. 2 is a diagram (part 1) for explaining the operation of the optical recording medium recording / reproducing apparatus according to the embodiment of the present invention. FIG. 3 is a diagram (part 1) for explaining the operation of the main part of the optical recording medium recording / reproducing apparatus according to the embodiment of the present invention. FIG. 4 is a flowchart (part 1) showing the operation of the optical recording medium recording / reproducing apparatus according to the embodiment of the present invention. FIG. 5 is a flowchart (part 2) showing the operation of the optical recording medium recording / reproducing apparatus according to the embodiment of the present invention. FIG. 6 is a diagram (No. 2) for explaining the operation of the main part of the optical recording medium recording / reproducing apparatus according to the embodiment of the invention. FIG. 7 is a diagram (No. 3) for explaining the operation of the principal part of the optical recording medium recording / reproducing apparatus according to the embodiment of the invention. FIG. 8 is a block diagram showing a configuration example of a main part of the optical recording medium recording / reproducing apparatus according to the embodiment of the present invention. FIG. 9 is a diagram (No. 4) for explaining the operation of the main part of the optical recording medium recording / reproducing apparatus according to the embodiment of the invention. FIG. 10 is a diagram (No. 5) for explaining the operation of the principal part of the optical recording medium recording / reproducing apparatus according to the embodiment of the invention. FIG. 11 is a diagram (No. 2) for explaining the operation of the optical recording medium recording / reproducing apparatus according to the embodiment of the invention. FIG. 12 is a diagram (No. 3) for explaining the operation of the optical recording medium recording / reproducing apparatus according to the embodiment of the invention.

  The optical recording medium recording / reproducing apparatus aims to realize an apparatus capable of recording and reproducing a high-quality information signal with low power consumption while maintaining an appropriate control position of an optical pickup whose position is controlled by a stepping motor. A tracking control unit that outputs a tracking signal for tracking the laser light applied to the track of the optical recording medium, a stepping motor that drives an optical pickup in the radial direction of the optical recording medium, and the tracking signal, A stepping control unit for controlling the stepping motor; and when information is not written to the optical recording medium or when information is not read from the optical recording medium, the rotor position of the stepping motor is set as a reference position. And writing the information on the optical recording medium or the optical recording When the from the body for reading the information was realized as a control unit back to writing or reading the position was of the information just before the rotor position of the stepping motor.

The configuration of the optical recording medium recording / reproducing apparatus will be described.
An optical recording medium recording / reproducing apparatus 1 shown in FIG. 1 includes an encoder 11, a memory unit 12, a recording unit 13, a reproducing unit 14, a memory unit 15, a decoder 16, an optical disc 21, a spindle 22, a spindle motor 23, a pickup unit 24, a stepping unit. The motor 25, the motor drive unit 26, the tracking drive unit 27, and the control unit 28 are included. The pickup unit 24 includes a semiconductor laser 241 and a lens 242. The control unit 28 includes a CPU 281 and includes control programs for a spindle rotation control unit 282, a tracking control unit 283, a stepping motor control unit 284, a memory monitoring unit 285, and a video signal control unit 286.
The stepping motor control unit 284 shown in FIG. 3 includes a standby operation table 284a, a standby operation program 284b, and a retraction position determination program 284c. The memory monitoring unit 285 includes a memory amount detection program 285a, a data transfer rate estimation program 285b, A division program 285c is provided.
A stepping motor 25 shown in FIG. 6 includes a stator 251 having armature teeth 251a to 251d, a rotor (also referred to as a rotor) 252 and windings 253 and 254. Both ends of the windings 253, 254 are connected to terminals 253a, 253b, 254a, 254b.
The motor drive unit 26 shown in FIG. 8 includes an up / down counter 261, a drive current generation circuit 262, and a rotor position detection circuit 263.

The operation of the optical recording medium recording / reproducing apparatus will be described.
The optical recording medium recording / reproducing apparatus 1 records an encoded signal obtained by encoding a digital video signal input to the encoder 11 on an optical disc 21, and reproduces and decodes the encoded signal recorded on the optical disc 21. A reproduction operation for outputting a digital video signal is performed. First, the reproduction operation will be described.
First, the spindle motor 23 rotates the optical disc 21 at a rotational speed exceeding a predetermined rotational speed. The lens 242 of the pickup unit 24 irradiates laser light emitted from the semiconductor laser 241 so that the optical disk 21 is focused. The reproduction unit 14 amplifies the reflected light from the optical disk 21 to obtain a reproduction signal. The tracking drive unit 27 obtains tracking information from the reproduction signal, and performs drive control of a tracking actuator (not shown) so as to irradiate a laser beam onto a pit row (not shown) of the optical disc 21. The reproducing unit 14 demodulates the signal recorded by digital modulation by the recording unit 13 to obtain a demodulated signal. The memory unit 15 stores the demodulated signal. The decoder 16 obtains a demodulated signal temporarily stored in the memory unit 15, that is, an encoded digital video signal, and decodes it to obtain a digital video signal.

  Since the optical disk 21 is rotated at a rotational speed exceeding a predetermined rotational speed, a reproduction signal more than that obtained by the decoder 16 is input to the memory unit 15. The video signal controller 286 of the controller 28 estimates the amount of decoded data per second that the decoder 16 uses for decoding. The memory monitoring unit 285 detects the data amount of the reproduction signal stored in the memory unit 15, and the pickup unit 24 interrupts reading of the optical disc 21 based on the decoded data amount per second estimated by the video signal control unit 286. The waiting time that may be used is calculated.

  When the standby time exceeds a predetermined time, the tracking control unit 283 stops the driving operation of the tracking driving unit 27 and stops the light emission of the semiconductor laser 241 of the pickup unit 24. The stepping motor control unit 284 moves the rotor of the stepping motor 25 to a mechanically stable position with respect to the motor driving unit 26, and turns off the driving current of the stepping motor 25 after the movement. The optical recording medium recording / reproducing apparatus 1 performs a reproducing operation in the low power mode.

  The memory monitoring unit 285 generates a standby time end signal when it is detected that the data amount of the reproduction signal stored in the memory unit 15 is equal to or less than a predetermined value, or when the standby time elapses. The stepping motor control unit 284 moves the rotor of the stepping motor 25 from the mechanically stable position to the original position with respect to the motor driving unit 26. The tracking control unit 283 turns on the semiconductor laser 241 to the tracking control unit 27, starts a focus control operation, and starts a tracking control operation. The reproduction unit 14 demodulates the signal reproduced by the pickup unit 24 and inputs the demodulated signal to the memory unit 15. Thereafter, the amount of data stored in the memory unit 15 is detected, and the above operation is repeated.

  Here, when the power is turned off without moving the rotor of the stepping motor 25 to a mechanically stable position, the rotor rotates to a mechanically stable position. When the rotor is between a mechanically stable position and an adjacent mechanically stable position, it is not specified to which mechanically stable position the rotor rotates. The stepping motor control unit 284 turns off the power of the stepping motor 25 after rotating the rotor of the stepping motor 25 to a mechanically stable position, turns on the power of the stepping motor 25, and then moves the rotor to the original position. Since the tracking control operation is performed after the stepping motor 25 is turned on, the tracking error increases when the power of the stepping motor 25 is turned on, or the pickup unit 24 tilts due to the forced tracking error control, and the error rate of the reproduction signal increases. Do not cause problems such as

  The recording operation of the optical recording medium recording / reproducing apparatus 1 is similarly performed. That is, the encoder 11 encodes the input digital video signal to obtain an encoded signal having a predetermined bit rate. The memory unit 12 stores the encoded signal. The recording unit 13 digitally modulates the encoded signal at a speed exceeding a predetermined bit rate to generate a modulated signal. The pickup unit 24 records the modulation signal on the optical disc 21. For recording on the optical disc 21, the spindle motor 23 rotates at a rotational speed exceeding a predetermined rotational speed, and the pickup unit 24 performs recording while performing a tracking control operation and a focus control operation. The memory monitoring unit 285 operates in the same manner as during reproduction while detecting the data amount of the encoded signal stored in the memory unit 12 and performs the recording operation while suppressing the power consumption of the optical recording medium recording / reproducing apparatus 1.

  The above operation is performed without turning off the power of the spindle motor 23. When the standby time greatly exceeds the predetermined time, the power supplied to the spindle motor 23 can be turned off and the operation can be performed in the low power mode. However, when the spindle motor 23 is restarted, a current larger than the steady state is required, and a predetermined start-up time is required until the steady rotation is reached. Turning off the power of the spindle motor 23 can reduce power consumption when the standby time greatly exceeds the predetermined time.

Next, this will be described in detail.
2A shows the data amount of the demodulated signal stored in the memory unit 15, and FIG. 2B shows the reproduction mode. When the amount of data stored in the memory unit 15 decreases to a1, the playback mode of the optical disc 21 is set to the read mode. The demodulated signal obtained by reproduction is stored in the memory unit 15. The reproduction mode after the stored data amount reaches a2 is set as a standby mode. The standby mode is a mode in which the emission of the semiconductor laser 241 is stopped, the focus servo is turned off, the driving current of the stepping motor 25 is turned off, and the tracking servo is turned off. When the data amount stored in the memory unit 15 decreases to a1, the demodulated signal is obtained by operating in the read mode. Here, since the spindle motor 23 is rotated at a predetermined rotational speed without being turned off, the focus servo and tracking servo can be returned to normal operation in a short time.

The stepping motor control unit 284 and the memory monitoring unit 285 will be described with reference to FIG.
The memory amount detection program 285a of the memory monitoring unit 285 detects the amount of data stored in the memory unit 12 or the memory unit 15. The data transfer rate estimation program 285 b obtains information on the encoding bit rate of the encoder 11 that operates under the control of the video signal control unit 286 or information on the decoding bit rate of the decoder 16. The information on the bit rate includes information on a bit rate that may operate in a few seconds ahead (future) in addition to the current operation speed. The division program 285c divides the amount of data stored in the memory unit by the bit rate to obtain the standby time. The standby time Ta when the bit rate is b is the time from when the data amount a2 shown in FIG. 2A is obtained until it decreases to the data amount a1.
Ta = (a2-a1) / b
Is required.

The standby operation table 284a of the stepping motor control unit 284 stores specific standby processing contents in the standby time obtained by the memory monitoring unit 285 in the table. The standby operation program 284b calculates a detailed standby operation related to the contents of the standby processing. The retraction position determination program 284c is a program for determining the mechanically stable position including the operation time when the power of the stepping motor is turned off as the content of the standby process. . The rotor position information is input to the stepping motor 25 via the motor drive unit 26, and a predetermined standby operation is performed.
Here, the standby operation program 284 b and the standby operation table 284 a operate as a system control unit in the control unit 28.

The standby operation of the optical recording medium recording / reproducing apparatus 1 will be described with reference to FIG.
First, in S (step) 71, the memory monitoring unit 285 obtains a standby time. In S72, it is detected whether or not the standby time is 0.4 seconds or more, for example. If it is less than 0.4 seconds, the still operation is performed in S73, and the process proceeds to C for the return operation. If it is 0.4 seconds or longer, the current supply to the semiconductor laser 241 is turned off in S74, and the light emission is stopped. In S75, the motor driving unit 26 detects a mechanically stable position in the vicinity of the rotor position of the stepping motor 25. In step S76, the position of the rotor of the stepping motor 25 is rotated to a mechanically stable position. In step S77, the stepping motor is turned off. That is, the sled carrying the pickup unit 24 moves to the retracted position and stops. In S78, it is detected whether the standby time obtained in S71 exceeds, for example, 6 seconds. If not, the process proceeds to A of the return operation. If exceeded, the spindle rotation control unit 282 turns off the power of the spindle motor 23 in S79 and proceeds to B of the return operation.

The return operation of the optical recording medium recording / reproducing apparatus 1 will be described with reference to FIG.
First, the return operation when the standby operation ends at B is started from B. In S81, it is detected whether or not the standby time detected by the memory monitoring unit 285 is less than 2 seconds. If it is detected that the time is less than 2 seconds, the spindle motor is turned on in S82.
S83 is the operation following S82 and the operation when the standby operation is terminated at A, and it is detected whether or not the standby time detected by the memory monitoring unit 285 is less than 1 second. If it is less than 1 second, the stepping motor 25 is turned on in S74. In S85, the position of the rotor is returned from the mechanically stable position to the position before being rotated in S76. Thereafter, the semiconductor laser 241 is turned on in S86. In S87, the focus control operation is performed. In S88, tracking control is started. S89 is an operation when the operation following S88 and the standby operation are completed at C, and the pickup unit 24 receives the reflected light from the optical disc 21 and performs a reproducing operation.

The stepping motor will be described with reference to FIG.
In the stepping motor 25 shown in the figure, a winding 254 is wound around the armature teeth 251a and 251c, and a winding 253 is wound around the armature teeth 251b and 251d. When the current Ia is passed from the terminal 254a to the terminal 254b, the armature tooth 251c becomes the N pole, the armature tooth 251a becomes the S pole, and the rotor 252 rotates so that the angle θ with respect to the armature tooth 251a becomes zero. Similarly, when the current Ib is passed through the winding 253 in the direction from the terminal 253a to the terminal 253b, the rotor 252 is at a position where θ is π / 2. When the current Ia and the current Ib having the same value are supplied simultaneously, the angle θ of the rotor 252 is π / 4.

With reference to FIG. 7, the relationship between the current flowing through the winding and the angle of the rotor will be described.
FIG. 7A shows the magnitude of the current Ia, and FIG. 7B shows the magnitude of the current Ib. (C) is the angle θ of the rotor 252 given by these current values. (D) shows a trigger pulse for rotating the rotor 252 of the stepping motor in steps of π / 8. The trigger pulse adjusts the position of the pickup unit 24 by rotating the stepping motor so that the angle of the light beam applied to the optical disc 21 is always a right angle. During random access, the pickup unit 24 is moved to the target position by a predetermined number of trigger pulses, and the portion is reproduced in a short time.

  Here, when the angle θ of the rotor 252 is at a position of π / 4, for example, if both the currents Ia and Ib are turned off at the same time, the rotor 252 cannot remain at the position of π / 4. Absent. The magnetic poles of the rotor 252 rotate so as to stick to either one of the armature teeth 251a or the armature teeth 251b. In order to keep the angle θ of the rotor 252 at a position of, for example, π / 4, it is necessary to keep the currents Ia and Ib flowing, which is not preferable in terms of power saving operation. Therefore, when turning off the current flowing through the stepping motor 25, it is necessary to move the rotor 252 in advance to a position adjacent to one of the armature teeth 251a to 251d, that is, a mechanically stable position in the vicinity.

The motor drive unit 26 will be described with reference to FIG.
The up / down counter 261 is supplied with a trigger pulse for normal rotation or reverse rotation of the rotor 252 every π / 8 from the stepping motor control unit 284, and generates a count value. The drive current generation circuit 262 supplies currents Ia and Ib to the windings 253 and 254 of the stepping motor 25 in correspondence with the count value. The rotor position detection circuit 263 detects the angle θ of the rotor 252 based on the current values Ia and Ib. Information on the angle θ is supplied to the stepping motor control unit 284. Stepping motor control unit 284 generates a trigger pulse for normal rotation or reverse rotation for moving rotor 252 when performing a power saving operation, and moves rotor 252 to a mechanically stable position. Using a switch (not shown), the power of the stepping motor 25 is turned off.

The power saving operation of the stepping motor will be described with reference to FIG.
In FIG. 9A, the horizontal axis represents time, and the vertical axis represents the position of the sled driven by the stepping motor 25. (B) is a partially enlarged view.
In FIG. 9B, the step positions of the rotor 252 are indicated by Q1 to Q5 on the right side of the figure. Q1 and Q5 are mechanically stable step positions. The position of Q2 is a step position having an angle that is π / 8 larger than Q1. Points p1 to p20 indicate the positions of the rotor 252 when the reproduction is performed while repeating the read and standby modes. Points p1 to p2 indicated by bold lines are the read period (a period in which reproduced data is stored in the memory unit 15) shown in FIG. Points p2 to p3 indicated by thin lines are standby periods (decoding periods using a reproduction signal stored in the memory unit 15). Since the position of the rotor 252 at this time is a mechanically stable position of Q1, the rotor 252 does not move even during standby. Next, a period from p3 to p6 is a read period. In the period from P4 to p5, the stepping motor 25 is sent by one step in order to obtain a good tracking performance. p7 to p8 are standby states. At p6, the laser beam is turned off, and a mechanically stable position where the rotor 252 should be retracted is detected. p7 is a point where the rotor 252 is moved to a mechanically stable position, and the current supplied to the stepping motor 25 is turned off. At p8, a current is supplied to the stepping motor 25 to return to the position at the time of reading immediately before p9. Thereafter, laser lighting, focus control operation, and tracking control operation are performed, and the data reproduced from the optical disk 21 is stored in the memory unit 15. The reading of p11 to p12 is performed at the step position of Q3. Here, at p13 to p14, the current is turned off after moving to the step position Q1. In p19 to p20, the standby operation is performed at the step position of Q5.

The position of the sled moved by the stepping motor 25 will be described with reference to FIG.
The horizontal axis is a time axis, and the lead period and the standby period are repeated three times. The vertical axis represents the position of the thread (position of the pickup unit 25). In the figure, the period from p21 to p22 is the period of the first lead, and in the subsequent standby period, the rotor 252 rotates to the position of p23, where the current supplied to the stepping motor 25 is turned off. The waiting period ends at p24. The current supplied to the stepping motor 25 is turned on, and the position of the rotor 252 is returned to the position of p25. The reading operation is performed up to p26, the mechanical stable position of p27 is set, and the process waits until p28.
Here, there is a case where the read operation is performed at the position of p27 without returning the rotor 252 to the position of p26 and performing the read operation. This is because when the position of the pickup unit 24 is small from the reference reading position indicated by a dotted line in the drawing, the read operation may be performed up to the position p29 while keeping the rotor 252 at the position p27. . Thereafter, a read operation is performed up to p30, the rotor 252 is moved to a mechanically stable position, and the power of the stepping motor 25 is turned off at p31.

A standby mode when the spindle motor is turned off will be described with reference to FIG.
In the figure, the horizontal axis is time, and the vertical axis is power consumption. The waiting period starts at time t0. The spindle motor is turned off at time t0. The spindle motor is turned on at t1 before time t2 when the standby period ends. A large amount of power is consumed during the return period until the spindle motor at t1 to t2 reaches a predetermined rotational speed. Whether or not the spindle motor power is turned off during the standby period depends on the sum of the power consumption during the period from t0 to t1 and the power necessary for the return period from t1 to t2 (power amount) and the rotation of the spindle motor during the period from t0 to t2. Compared with the power consumption when maintaining the power consumption, the power consumption is determined to be smaller.

Table 1 shows an example of power consumption necessary for reproducing a DVD.

The optical disk used for the measurement was a DVD-R with a diameter of 8 cm, the position of the pickup was near the middle circumference, and the rotational speed was about 2400 rpm.
The power consumption for turning on the semiconductor laser 241 is 450 mW. The focus control operation and tracking control operation of the pickup unit 24 consumes 190 mW of power. The stepping motor 25 consumes 150 mW of power to keep the position of the rotor 252 at a predetermined position regardless of whether or not the rotor 252 is rotating. The power consumption for moving the rotor 252 to a mechanically stable position is 15 mJ (millijoule = milliwatt second). After moving the rotor 252 to a mechanically stable position, the power consumption for keeping the rotor 252 at that position is 0 mW.

With reference to FIG. 11, the power required for each operation period will be described.
In the figure, time t0 to t2 is a standby period, and t2 to t3 is a read period. The standby period t0 to t2 is composed of a sleep period of t0 to t1 and a return period of t1 to t2.
Table 2 shows the sleep period, the power consumption in the return period, and the length of the return period in each standby operation.

  The operation of B that turns off the laser diode and the stepping motor consumes 150 mW less power during the sleep period than the operation of A that turns off the laser diode. The power consumption during the return period is 70 mW larger. On the other hand, in the operation of C in which the spindle motor is turned off in addition to the operation of B, the power consumption in the sleep period is the smallest, but the power consumption in the return period is 980 mW larger than A and 910 mW larger than B. The return period requires 970 milliseconds.

The length of the standby period and the power consumption during standby will be described with reference to FIG.
In the figure, a is the power consumed during the operation of A. The straight lines b1 and b2 are the power consumption during the operation of B, and the straight lines c1 and c2 are the power consumption during the operation of C. b1 and b2 and c1 and c2 intersect at a point xp. That is, when the waiting time exceeds 6 seconds, the operation of C is smaller, and when it is 6 seconds or less, the power consumption of B is small. When the standby time is less than 0.4 seconds, the operation of A is performed. When the standby time is from 0.4 seconds to 6 seconds, the operation of B is performed. Can be small.

  During the standby period when the pickup unit 24 does not read the optical disk 21, the semiconductor laser 241 is turned off, the focus control operation and the tracking control operation are turned off, and the rotor 252 is moved to a mechanically stable position to perform stepping. The motor 25 is turned off. The capacity of the memory units 12 and 15 can be increased to increase the standby period. When the capacity of the memory units 12 and 15 is increased and the reading speed of the optical disk 21 is increased, a larger amount of power is consumed for the high-speed rotation of the optical disk 21, the speeding up of the control operation, and the speeding up of the circuit operation. In the example shown here, in consideration of power efficiency and economy, it was preferable to set the standby period to about 6 seconds or less. The optimal standby time changes with the times as the performance of semiconductors and batteries progresses.

  As described above, according to the optical recording medium recording / reproducing apparatus 1 shown in the present embodiment, the tracking control unit 27 that outputs the tracking signal for tracking the laser light applied to the track of the optical recording medium 21, the optical A stepping motor 25 that drives the pickup 24 in the radial direction of the optical recording medium 21, stepping controllers 26 and 284 that control the stepping motor 25 based on the tracking signal, and information on the optical recording medium 21. When writing is not performed or when information is not read from the optical recording medium 21, the position of the rotor (rotor 252) of the stepping motor 25 is set to a reference position (mechanically stable position). When writing the information on the recording medium 21 or reading the information from the optical recording medium 21 In this case, since there is a configuration including a control unit 284 for returning the rotor position of the stepping motor 25 to the position where the information has been written or read immediately before, an optical pickup whose position is controlled by the stepping motor Thus, it is possible to realize a device that can record and reproduce a high-quality information signal with low power consumption while maintaining an appropriate control position.

  The present invention can be applied to an optical recording medium recording / reproducing apparatus that uses a stepping motor to move in the normal direction of an optical head for recording and reproducing a disk type recording medium.

It is a block diagram which shows the structural example of the optical recording-medium recording / reproducing apparatus based on implementation of this invention. FIG. 6 is a diagram (No. 1) for explaining the operation of the optical recording medium recording / reproducing apparatus according to the embodiment of the invention. FIG. 6 is a diagram (No. 1) for explaining an operation of a principal part of the optical recording medium recording / reproducing apparatus according to the embodiment of the present invention. It is the figure which showed the operation | movement of the optical recording medium recording / reproducing apparatus based on implementation of this invention with the flowchart (the 1). It is the figure which showed the operation | movement of the optical recording-medium recording / reproducing apparatus based on implementation of this invention with the flowchart (the 2). FIG. 6 is a diagram (No. 2) for explaining the operation of the main part of the optical recording medium recording / reproducing apparatus according to the embodiment of the invention. FIG. 10 is a diagram (No. 3) for explaining the operation of the main part of the optical recording medium recording / reproducing apparatus according to the embodiment of the invention. It is a block diagram which shows the structural example of the principal part of the optical recording medium recording / reproducing apparatus which concerns on implementation of this invention. FIG. 10 is a diagram (No. 4) for explaining the operation of the principal part of the optical recording medium recording / reproducing apparatus according to the embodiment of the invention. FIG. 10 is a diagram (No. 5) for explaining the operation of the principal part of the optical recording medium recording / reproducing apparatus according to the embodiment of the invention. FIG. 6 is a diagram (No. 2) for explaining the operation of the optical recording medium recording / reproducing apparatus according to the embodiment of the present invention. FIG. 9 is a diagram (No. 3) for explaining the operation of the optical recording medium recording / reproducing apparatus according to the embodiment of the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical recording medium recording / reproducing apparatus 11 Encoder 12 Memory part 13 Recording part 14 Reproducing part 15 Memory part 16 Decoder 21 Optical disk 22 Spindle 23 Spindle motor 24 Pickup unit 25 Stepping motor 26 Motor drive part 27 Tracking control part 28 Control part 241 Semiconductor laser 242 Lenses 251a to 251d Armature teeth 251 Stator 252 Rotor 253, 254 Winding 253a, 253b, 254a, 254b Terminal 261 Up / down counter 262 Drive current generation circuit 263 Rotor position detection circuit 281 CPU
282 Spindle rotation control unit 283 Tracking control unit 284 Stepping motor control unit 284a Standby operation table 284b Standby operation program 284c Retraction position determination program 285 Memory monitoring unit 285a Memory amount detection program 285b Data transfer rate estimation program 285c Division program 286 Video signal control unit

Claims (4)

Information is intermittently read from an optical recording medium using an optical pickup , the read information is temporarily stored in a memory unit, the information stored in the memory unit is read, decoded by a decoder, and continuously reproduced. In an optical recording medium playback device,
A memory amount detection unit for detecting the amount of data stored in the memory unit;
A data rate estimation unit for estimating a bit rate of information decoded by the decoder;
A stepping motor linked to the optical pickup and having a stator and a rotor that rotates in the stator;
A detection unit for detecting a rotation angle and a rotation direction of the rotor;
When the amount of data detected by the memory amount detection unit is greater than or equal to a first predetermined amount by storing the information read by the optical pickup,
The waiting time is obtained by dividing a value obtained by subtracting a second predetermined amount that is smaller than the first predetermined amount from the first predetermined amount by the bit rate estimated by the data transfer rate estimation unit. When the obtained waiting time is equal to or longer than the first predetermined time, the rotation direction of the rotor is rotated or the anti-rotation direction is stabilized based on the rotation angle of the rotor detected by the detection unit. Stop the rotor in position,
When the data amount of the memory unit detected by the memory amount detection unit becomes equal to or less than the second predetermined amount due to the progress of decoding by the decoder,
The calculation of the rotation angle and the rotation direction of the rotor detected by the detection unit is performed, and the position of the rotor of the stepping motor is returned to the position where the information was read immediately before, or the information is An optical recording medium reproducing device comprising: a stepping control unit that sets the position after reading to a preset position. An encoder that encodes continuous information; and a memory unit that temporarily stores information encoded by the encoder, the information encoded by the encoder is temporarily stored in the memory unit, and the memory unit reading the stored the information, the optical recording medium recording apparatus for recording intermittently optical record medium by using the optical pickup,
A memory amount detection unit for calculating the amount of data stored in the memory unit;
A data rate estimation unit for estimating a bit rate of information encoded by the encoder;
A stepping motor linked to the optical pickup and having a stator and a rotor that rotates in the stator;
A detection unit for detecting a rotation angle and a rotation direction of the rotor;
When the information stored in the memory unit is read out toward the optical pickup and the amount of data is equal to or less than a first predetermined amount,
Obtained by dividing the value obtained by subtracting the first predetermined amount from the second predetermined amount, which is a value larger than the first predetermined amount, by the bit rate estimated from the data transfer rate estimation unit. When the waiting time is equal to or longer than the first predetermined time, the rotation is performed at a stable position in the rotation direction or the counter-rotation direction in which the rotor is rotating based on the rotation angle of the rotor detected by the detection unit. Stop the child,
When the amount of data in the memory unit becomes equal to or greater than the second predetermined amount due to the progress of encoding by the encoder,
The calculation of the rotation angle and the rotation direction of the rotor detected by the detection unit is performed, and the position of the rotor of the stepping motor is returned to the position where the information was read immediately before, or the information is An optical recording medium recording apparatus comprising: a stepping control unit configured to set to a preset position after reading. Using an optical pickup, information is intermittently read from an optical recording medium , the read information is temporarily stored in a memory unit, and the information stored in the memory unit is read and continuously decoded and reproduced by a decoder. In the optical recording medium reproducing method to
While calculating the amount of data stored in the memory unit, estimating the bit rate of information decoded by the decoder,
Rotating the rotor of the stepping motor linked to the optical pickup in the stator,
The detection unit detects the rotation angle and rotation direction of the rotor,
When the amount of data detected by the memory amount detection unit is equal to or greater than the first predetermined amount by storing the information read by the optical pickup,
Standby detected by dividing a value obtained by subtracting a second predetermined amount that is smaller than the first predetermined amount from the first predetermined amount by the bit rate estimated by the transfer rate estimation unit. If the time is greater than or equal to the first predetermined time,
Based on the rotation angle of the rotor detected by the detection unit, the rotor is stopped at a stable position in the rotation direction or the counter-rotation direction in which the rotor is rotating,
When the decoding progresses, the amount of data stored in the memory unit detected by the memory amount detection unit becomes equal to or less than the second predetermined amount.
The calculation of the rotation angle and the rotation direction of the rotor detected by the detection unit is performed, and the position of the rotor of the stepping motor is returned to the position where the information was read immediately before, or the information is An optical recording medium reproducing method, wherein the position is set in advance after reading. Continuous information encoded by the encoder, is temporarily stored in the memory unit, an optical recording medium recording method for recording to intermittently optical recording medium using the optical pickup by reading the information stored in the memory unit ,
While calculating the amount of data stored in the memory unit, estimating the bit rate of the information encoded by the encoder,
A rotor of a stepping motor linked to the optical pickup is rotated in a stator, and a rotation angle and a rotation direction of the rotor are detected by a detection unit;
When the information stored in the memory unit is read out to the optical pickup and the data amount becomes equal to or smaller than the first predetermined amount, the second place is a value larger than the first predetermined amount. When the standby time obtained by dividing the value obtained by subtracting the first predetermined amount from the fixed amount by the bit rate is equal to or longer than the first predetermined time , the rotation angle of the rotor detected by the detection unit The rotor is stopped at a stable position in the rotational direction or the counter-rotating direction in which the rotor is rotating,
When the amount of data in the memory unit becomes equal to or greater than the second predetermined amount due to the progress of encoding,
The rotation angle and the rotation direction of the rotor detected by the detection unit are calculated, and the position of the rotor of the stepping motor is returned to the position where the information was recorded immediately before or the information was recorded. An optical medium recording method characterized in that a predetermined position is set later.

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