JP2004355795A - Optical disk device, camera device, and method for controlling light emitting operation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide control means for suppressing power consumption and temperature rise of a semiconductor laser of an optical disk device.
SOLUTION: This is a recording / reproducing operation for performing a data recording operation or a data reproducing operation on an optical disk, and a predetermined operation is performed during at least one of a starting operation, a seek operation, an address reading operation and an idling operation. Laser control means for intermittently emitting a semiconductor laser at an intermittent cycle comprising a reproduction section and a pause section; signal detection means for detecting a focus error (FE) signal and a tracking error (TE) signal in the reproduction section; A servo control unit that performs focusing control and tracking control based on the TE signal, and reduces the power consumption and temperature rise of the semiconductor laser other than during recording and reproduction to reduce the total power of the optical disc device. Reduce consumption and extend operating life of semiconductor laser.
[Selection diagram] Fig. 1

Description

  The present invention relates to an optical disk device, a camera device, and a method for controlling a light emitting operation. More specifically, the present invention relates to an optical disk device, a camera device, and a method for controlling a light emitting operation, which suppress power consumption and temperature rise of a laser light emitting unit mounted on an optical head unit.

  In recent years, technology for increasing the density of a phase-change rewritable optical disk using a blue laser and an objective lens having a high NA of 0.85 has been developed, and even if the diameter is as small as about 5 to 8 cm, 4 to 16 GB (maximum) A large-capacity optical disk is being realized with a capacity of two-layer technology. If an image compression technique such as MPEG2 is used, an optical disc of this capacity can be photographed with the same image quality as a conventional tape for the same time, so that a full-fledged optical disc video camera can be realized. Further, by improving the transfer rate, it is possible to record a higher definition HD image.

  In addition, using an optical disk makes it possible to take advantage of random access and eliminate the need for rewinding to avoid irritation, or to select a thumbnail image to play back a desired video in one shot. Can be provided. Also, JPEG-compressed still images can be stored on the same optical disk, and a new concept can be provided to the user as a next-generation video camera, which is expected to be commercialized.

  Generally, a laser light emitting unit used in an optical disk device generates a larger amount of heat per volume than other ICs and electronic components. On the other hand, there is a problem that the upper limit temperature of the operation guarantee is as low as 60 ° C. to 70 ° C., and even if it is lower than the upper limit temperature, the life becomes shorter as the operating temperature becomes higher. Therefore, in the optical disk device, there has been a strong demand for suppressing the rise in the internal temperature of the optical disk device by reducing the power consumption of the entire device and improving the heat radiation structure, and reducing the operating temperature of the laser light emitting unit mounted on the optical head. The present invention relates to the former method of reducing power consumption, and more particularly to suppressing the power consumption of the laser emitting unit itself. If the power consumption of the laser light emitting unit is reduced, the temperature rise of the laser light emitting unit can be reduced even when the ambient temperature (inside temperature) is the same, which is very effective.

  As a conventional example of reducing the power consumption of the laser light emitting unit, there is an intermittent reproduction of a music MD (for example, see Patent Document 1). This example is a method of intermittently performing a reproducing operation by moving or stopping an optical disk device. According to this, by making the power including the laser light emitting unit zero during the suspension period, the power of the optical disk drive unit including the laser light emitting unit can be reduced on average. This extends the life of the battery.

  Hereinafter, the operation of the intermittent reproduction will be specifically described. First, it is assumed that the reading speed of the music data from the optical disk is sufficiently higher than the input speed of the music data to the decoder. When playing music, the optical disk drive is first activated, music data is played back at high speed, and temporarily stored in the buffer memory (read state). When the buffer memory becomes full, the optical disk driving unit is temporarily stopped, and the power of the laser emitting unit and other optical disk driving units is reduced to almost zero (pause state). On the other hand, music data is sent from the buffer memory to the decoder at a constant speed and music is continuously reproduced. When the remaining amount of music data in the buffer memory falls below a predetermined level, the optical disk drive is started again, and the subsequent music data is read out at high speed and stored in the buffer memory. The above operation is repeated during music reproduction. During music playback, music data is sent to the decoder at a constant speed.

  In the above-mentioned read state, the optical disk drive consumes power for starting and reading. However, in the above-mentioned pause state, there is no power consumption, so that the read-state time (read time) and the pause state time (pause time) are different. The average power consumption can be reduced according to the ratio. Also, during reading, the laser light emitting unit is continuously turned on, but the laser light emitting unit is brought into a halt state before the temperature of the laser light emitting unit rises significantly. Can be reduced.

  However, at the time of starting from the rest state to the reading state, start-up operations such as motor rotation, laser lighting, focusing and tracking pull-in are required, and it takes about several seconds. Also, at the time of startup, power may slightly increase from the read state due to the rotation control of the motor and the like. Therefore, in the reproduction of music data such as MDs, the pause time can be made sufficiently long with respect to the reproduction time, which is an extremely effective means for reducing the power and preventing the temperature rise of the laser light emitting unit. This intermittent reproduction technique can also be used for recording, that is, writing to an optical disk.

On the other hand, means for reducing the power consumption of the laser light emitting unit during reproduction for driving the optical disk have been devised. For example, means for pulse-driving the laser light-emitting unit in synchronization with the data cycle during reproduction (see Patent Document 2) and means for pulse-driving the laser light-emitting unit at a frequency sufficiently faster than the data cycle (see Patent Document 3) ) Is disclosed. The former is a data channel bit cycle, in which a laser emits light intermittently, detects a data edge during light emission, does not detect an edge in a non-light emitting section, and has little effect on information reproduction while consuming the laser light emitting unit. Power is being reduced. In the latter case, the laser is turned on and off at a speed sufficiently faster than the data cycle, and the data is reproduced by data envelope detection, eliminating the effects of the blinking and reducing the average current of the laser light emitting section to reduce power consumption. ing.
JP-A-7-161043 JP-A-2002-63726 JP 2001-331960 A

  However, if the optical disk device is used for a system requiring a high data processing speed such as a video image, the effect of the above-described intermittent reproduction technique (hereinafter referred to as a stop type intermittent operation) is small. The reason is that the ratio between the image data processing speed and the image data recording / reproducing speed on the optical disk cannot be increased as much as the transfer rate ratio between the audio data and the image data. As a result, it is necessary to lengthen the read time from the optical disk and shorten the pause time under a certain period, and the effects of reducing the power of the stop type intermittent operation and suppressing the temperature rise are reduced.

  Furthermore, when the data processing speed increases and approaches the data recording / reproducing speed from the optical disk, the pause operation itself cannot be performed in consideration of the time from the stop to the restart, and the stop-type intermittent operation becomes difficult. .

  Consider a specific example. It is assumed that the maximum transfer rate is limited to, for example, 20 Mbps because the number of rotations is limited in a small-diameter optical disk. For example, a transfer rate of about 9 Mbps is required for the image transfer rate in order to realize a mixed audio stream having an image quality comparable to that of a DV tape in MPEG2. If the stream has a constant rate, intermittent operation can be performed at this level. However, since the start-up time of about several seconds is included in the reproduction time, an intermittent operation of several tens of seconds can be realized, but it is difficult to reduce the pause time by more than half. In addition, in view of a margin for retry at the time of starting, the time allotted to the suspension time has to be shortened. Therefore, a sufficient intermittent effect cannot be expected in this application. Furthermore, if the stream is set to a so-called variable bit rate in order to improve the image quality, the maximum image transfer rate is, for example, 15 Mbps even if the image transfer rate is 9 Mbps on average. Assuming that 15 Mbps continues for several tens of seconds or more, the stop-type intermittent operation itself becomes difficult in consideration of securing a margin for the start-up time. In other words, in applications such as video cameras, new measures to reduce power consumption (and to prevent temperature rise) are required.

  From this point of view, the methods described in Patent Documents 2 and 3 are effective for reducing power consumption. Since the blinking duty of the laser light emitting unit at the time of reproduction is required to be about 50%, the power reduction at that level can be expected. However, as in the example of Patent Document 2, the blinking means in the data channel period is not practical when reproducing ultra-high-density data using a blue laser due to the loss of information at the time of turning off the light and the deterioration of the quality of the reproduced signal. It is not considered. For example, when the jitter is large, it is predicted that data loss will occur.

  In the method disclosed in Patent Document 3, the power of the laser light emitting unit is reduced by half by driving the laser light emitting unit using a clock signal having a frequency sufficiently higher than the data frequency. In a light-emitting system that operates at a frequency higher than the data frequency, there is an example in which a high-frequency module (HFM) that performs current superposition for reducing noise generated by return light from a laser light-emitting unit is used. However, if the laser light emitting unit is driven at a high speed as high as the operation of the HFM and at a current amplitude larger than the current amplitude in the HFM, there is a concern that the driving means may generate heat. In addition, since the laser light emitting unit is driven at a high frequency, in order to avoid the problem of unnecessary radiation, it is required that the driving unit is disposed close to the laser light emitting unit. In this case, it is predicted that the heat generated by the driving means causes the temperature of the laser light emitting unit to rise, and it is difficult to obtain the effect of preventing the temperature from rising.

  The present invention has been made in view of the above problems, and has as its object to provide an optical disk device, a camera device, and a method for controlling a light emitting operation, which suppress a temperature rise and power consumption of a laser light emitting unit.

  An optical disc device according to the present invention includes a laser emitting unit that generates a laser beam for irradiating an optical disc, and a laser control unit that controls a light emitting operation of the laser emitting unit, wherein the laser control unit performs a first operation. In some cases, the laser light emitting section emits light in a first cycle, and in the second operation, the laser light emitting section emits light in a second cycle. The first cycle and the second cycle are different from each other. Thereby, the above object is achieved.

  At least one of the first cycle and the second cycle may have a length of a section where the laser light emitting unit emits light and a length of a section where the laser light emitting unit does not emit light.

  The length of the section where the laser light emitting unit emits light may be shorter than the length of the section where the laser light emitting unit does not emit light.

  The first operation may be a read preparation operation for preparing to read information from the optical disk, and the second operation may be a read operation for reading the information from the optical disk.

  The first operation is a first read preparation operation for preparing to read information from the optical disc, and the second operation is a second read preparation for preparing to read the information from the optical disc. It may be a preparation operation.

  The first operation is a first recording preparation operation for preparing to record information on the optical disk, and the second operation is a second recording preparation operation for preparing the information on the optical disk. Recording preparation operation.

  The first operation executes the focusing control and the tracking control in a state where neither a read preparation operation for preparing to read information from the optical disk nor a read operation for reading the information from the optical disk is performed. The second operation may be an operation of executing focusing control and tracking control in a state where one of the read preparation operation and the read operation is being executed.

  Each value of the first cycle and the second cycle may be equal to or less than a value that can maintain the focusing control and the tracking control.

  Each of the first cycle and the second cycle may be 250 μs to 500 μs.

  The laser control unit may not substantially apply a drive current to the laser light emitting unit during a section in which the laser light emitting unit does not emit light in each of the first cycle and the second cycle.

  The laser control unit applies a drive current of a value that does not cause the laser light emitting unit to emit light to the laser light emitting unit during a section in which the laser light emitting unit does not emit light in each of the first cycle and the second cycle. You may.

  The apparatus may further include a high-frequency module configured to reduce noise generated by light reflected from the optical disk, and the high-frequency module may stop operating during a period in which the laser light emitting unit does not emit light.

  A high-frequency module for reducing noise generated by light reflected from the optical disk; a read preparation operation for preparing to read information from the optical disk and a recording preparation operation for preparing to record information on the optical disk; During at least one of the operations, the high-frequency module may stop operating.

  An address reproducing unit that reads address information from the reproduction signal; a reproduction signal processing unit that demodulates the reproduction signal; and a recording control unit that controls recording of information on the optical disc. The unit and each of the recording control units may stop operating when idling.

  The image processing apparatus may further include a light detection unit that generates a reproduction signal based on the reflected light from the optical disk, and a signal generation unit that generates a focusing error signal and a tracking error signal by sampling and holding the reproduction signal.

  The laser control unit and the signal generation unit may be integrated in one semiconductor chip.

  An optical head unit including the laser light emitting unit, and a tracking control unit for performing tracking control, the tracking control unit controls the optical head unit so that the focal point of the laser light is along the same track when idling. You may.

  An optical head unit including the laser light emitting unit and a tracking control unit that performs tracking control may be further provided, and the operation of the tracking control unit may be stopped during idling.

  The first operation may be a read preparation operation for preparing to read address information from the optical disc, and the second operation may be a read operation for reading the address information from the optical disc.

  The address information is previously recorded on the optical disk by wobbling a guide groove provided in the optical disk, and the second cycle may be shorter than a wobble cycle of the guide groove.

  The laser control unit may cause the laser light emitting unit to continuously emit light during a seek operation.

  The laser control unit may make a light emitting cycle of the laser light emitting unit when the focusing control is performed shorter than a light emitting cycle of the laser light emitting unit when the focusing control is not performed.

  The optical disc apparatus further includes a vibration detection unit that performs at least one of detection and prediction of the vibration amount of the optical disc device, wherein the laser control unit sets a light emission cycle of the laser light emitting unit when the vibration amount is equal to or more than a predetermined amount. The light emission cycle of the laser light emitting unit when the vibration amount is less than a predetermined amount may be shorter.

  The optical disc device further includes a vibration detection unit that performs at least one of detection and prediction of a vibration amount, and the laser control unit causes the laser light emitting unit to emit light continuously when the vibration amount is equal to or more than a predetermined amount. Is also good.

  The laser light emitting unit further includes a temperature detecting unit that detects a temperature of the laser light emitting unit, wherein the laser control unit is configured to emit light of the laser light emitting unit when the temperature of the laser light emitting unit is lower than a guaranteed operation temperature of the laser light emitting unit by a predetermined value or more. The cycle may be shorter than the emission cycle of the laser emitting unit when the temperature of the laser emitting unit is not lower than the operation guarantee temperature by a predetermined value or more.

  The laser control unit sets a light emission cycle of the laser light emitting unit while waiting for execution of reading of information from the optical disc to be longer than a light emission cycle of the laser light emitting unit during execution of the reading. May be.

  The laser control unit is configured to set a light emitting cycle of the laser light emitting unit while waiting for execution of recording of information on the optical disc to be longer than a light emitting cycle of the laser light emitting unit during execution of the recording. May be.

  The camera device of the present invention includes a camera unit that generates video information indicating a video from incident light, a display unit that displays a video indicated by the video information, a recording of the video information on an optical disc, and a recording on the optical disc. An optical disk drive for executing reproduction of video information, the optical disk drive including a laser light emitting unit for generating a laser beam for irradiating the optical disk, and a laser control unit for controlling a light emitting operation of the laser light emitting unit Wherein the laser control unit causes the laser light emitting unit to emit light at a first cycle during a first operation, and causes the laser light emitting unit to emit light at a second cycle during a second operation; The period and the second period are different from each other, thereby achieving the above object.

  The method of the present invention is a method of controlling a light emitting operation of a laser light emitting unit that generates a laser beam for irradiating an optical disc, wherein the first light emitting unit emits light at a first cycle in a first operation. During the second operation, causing the laser light emitting unit to emit light at a second cycle, wherein the first cycle and the second cycle are different from each other, thereby achieving the object. Is done.

  According to the present invention, during the first operation, the laser light emitting section emits light at the first cycle, and during the second operation, the laser light emitting section emits light at the second cycle. Further, the first cycle and the second cycle are different from each other. By adjusting the light emission cycle of the laser light emitting unit according to each operation, each operation can be reliably performed, and the temperature rise and power consumption of the laser light emitting unit can be suppressed. In addition, the temperature rise of the laser light emitting unit can be suppressed, and the driving time of the laser light emitting unit can be shortened, so that the life of the laser light emitting unit can be extended.

  According to the present invention, the power consumption of the laser emitting unit is drastically reduced to substantially zero (1% or less of continuous emission) by intermittently driving the laser emitting unit during the recording or reproducing preparation operation of the optical disk device. it can. Therefore, especially in an optical disk device that records or reproduces information intermittently, the laser light emitting unit is used substantially only during recording or reproduction, and the temperature rise of the laser light emitting unit can be extremely reduced. As a result, the optical disk device of the present invention or a device incorporating the same can be used in a high-temperature atmosphere where a device to which the present invention is not applied cannot be used. Looking at this feature from a different angle, if the ambient temperature of the optical disk device is the same, the optical disk device to which the present invention is applied can reduce the rise in temperature of the laser light emitting unit, thereby extending the operating life of the laser light emitting unit. Can be.

  Further, according to the present invention, the life of the laser emitting unit can be extended in terms of the use time of the laser emitting unit. In general, an optical disk device requires a period for a recording or reproducing preparation operation before and after recording or reproducing. By performing the intermittent idling at the time of this preparation operation, the driving of the laser light emitting unit can be stopped during the off period, and the laser light emitting unit can be made inoperative. Thereby, the cumulative operation time of the laser light emitting unit during the preparation operation can be made substantially negligible, so that the life of the laser light emitting unit seen from the user is greatly extended. In other words, the life of the optical disk device is substantially determined by the accumulated time of the recording and reproduction operations, and the time during the preparation operation for recording and reproduction does not substantially affect the life of the optical disk device. Furthermore, according to the present invention, the optical disk device can be maintained in a recording or reproducing ready state with low power consumption and can be immediately put into the recording or reproducing state, so that it can be quickly operated in response to a user request for reproducing video information from the optical disk. Response is possible.

  Further, according to the present invention, since the power of the laser emitting unit and other circuits can be suppressed, an optical disk device with low power consumption can be provided. Particularly, a portable and battery-operated device can provide an advantage that the battery life can be extended or that a smaller battery can be driven for the same time. In addition, since a rise in temperature is suppressed by reducing power consumption, a smaller optical disk device can be provided.

  The present invention realizes low power consumption of the optical disk device and its mounting device, and also guarantees operation at high temperatures, while ensuring the operation reliability and extending the life of the laser light emitting unit.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows an optical disc device 100 according to Embodiment 1 of the present invention. 2, 3 and 4 are timing charts for explaining the operation of the optical disc device 100.

  In order to facilitate understanding of the present invention, FIG. 1 shows only main parts related to the present invention, and illustration and description of other known components of the optical disc apparatus are omitted.

  The optical disk 101 is mounted on the optical disk device 100. The optical disk device 100 may be a recording device, a reproduction device, or a recording / reproduction device that performs at least one of recording and reproduction of information on the optical disk 101. Information such as user data is recorded on a guide groove provided on the optical disc 101. The address information is recorded in advance on the optical disc 101 by wobbling the guide groove provided on the optical disc 101.

  The optical disc device 100 includes a disc motor 102, an optical head unit 103, a laser control unit 104, a recording control unit 105, an ATAPI interface 106, an interface unit 107, a buffer memory 108, a system controller 109, It includes a unit 110, an OR circuit unit 111, a signal generation unit 112, an address reproduction unit 113, a reproduction signal processing unit 114, a focusing control unit 115, and a tracking control unit 116.

  The optical head unit 103 includes a laser emission unit 1, a power detection unit 2, a light detection unit 3, an optical component (not shown), an actuator (not shown), and the like. The laser emitting unit 1 that generates laser light for irradiating the optical disc 101 is, for example, a semiconductor laser element. The optical head unit 103 reads and writes information by irradiating the optical disc 101 with laser light.

  The optical disk 101 is rotated by a disk motor 102, and information is recorded and reproduced by an optical head unit 103. The power detection unit 2 measures the power of the laser light emitting unit 1. The light detection unit 3 generates a reproduction signal for detecting a high-frequency signal (RF signal), a focus error signal (FE signal), and a tracking error signal (TE signal) based on the reflected light from the optical disc 101. The actuator performs focusing control and tracking control so that a light spot is formed on the guide groove of the optical disc 101.

  The laser control unit 104 controls the light emitting operation of the laser light emitting unit 1. The power of the laser emitting unit 1 is controlled by the laser control unit 104. More specifically, upon receiving the PO signal from the power detection unit 2, the laser emission unit 1 is set to a predetermined power via the LD signal by feedback control. At times other than the recording operation (for example, in the reproduction mode), the laser light emitting section 1 is turned on when the PL signal is at a high level (hereinafter, referred to as high), and is turned off when at a low level (hereinafter, referred to as low). The laser control unit 104 operates as described above. The power value is controlled by feeding back the value of the PO signal when the PL signal is high so that the target level is set. In the recording mode, the laser light emitting unit 1 emits light with a multi-pulse having a multi-valued recording power level (a so-called write strategy) indicated by the WT signal group output from the recording control unit 105, so that the optical disc 101 Irradiate laser light with optimal power pattern.

  At the time of information recording, the recording information is sent from an external PC or application (not shown) to the interface unit 107 via the ATAPI interface 106, and is temporarily stored in the buffer memory 108, and then added with an error correction code or modulated. The data is processed by the recording control unit 105 into data of a predetermined format, and is recorded on the optical disc 101. These operations are controlled by the system controller 109 which controls the operation of the entire optical disc device 100. The system controller 109 includes a microcomputer, a hardware device, and the like.

  In order to perform information recording, the laser control unit 104 performs control for recording preparation. That is, the motor control unit 110 rotates the disk motor 102 at a predetermined rotation speed. Then, the power of the laser light emitting unit 1 is controlled so as to be at the reproduction level. At this time, the reproduction power is intermittently turned on and off in accordance with the PL signal output from the OR circuit unit 111, so that the recording or reproduction preparation operation (focusing control) can be performed by turning on the minimum required laser light emitting unit 1. , Tracking control, address information reading, seek control, idling control, etc.). This is the point of the present invention. As a result, power consumption, temperature rise, and cumulative lighting time of the laser light emitting unit 1 are suppressed, and reliability is improved and the life of the device is extended. As described above, preparation for recording and reproduction while driving the laser light emitting unit 1 in a pulse manner is also referred to as “intermittent idling” and used for description. The off period of the light emission cycle is sufficiently longer than the on period. As a result, the power consumption, temperature rise, and cumulative lighting time of the semiconductor laser can be further reduced. The light emission period varies depending on the operation mode of the optical disc device 100, but is preferably equal to or less than a value that can maintain the focusing control and the tracking control.

  The signal generation unit 112 receives the reproduction signal output from the light detection unit 3 and generates an RF signal, an FE signal, and a TE signal by sampling and holding the reproduction signal. The RF signal is input to the address reproduction unit 113 and the reproduction signal processing unit 114. The FE signal and the TE signal are input to a focusing control unit 115 and a tracking control unit 116, respectively, which perform servo control. The pulse signals of the PA signal, the PF signal, and the PT signal for turning on the laser light emitting unit 1 are sent from the system controller 109 to the OR circuit unit 111 in accordance with the operation state during reproduction. At the same time, the PA signal, the PF signal, and the PT signal are sent to the address reproduction unit 113, the focusing control unit 115, and the tracking control unit 116, respectively. The address reproduction unit 113, the focusing control unit 115, and the tracking control unit 116 perform address reproduction, focusing control, and tracking control, respectively, when the pulse signal is high.

  Although detailed pulse timings of the above three types of pulse signals will be described later, for example, the PL signal is controlled to remain high during information reproduction, and the address is reproduced by the address reproduction unit 113 from a continuous RF signal. At the same time, the continuous RF signal is input to the reproduction signal processing unit 114. The reproduction signal processing unit 114 performs demodulation and error correction according to the data format on the RF signal to restore and read reproduction information. After the read reproduction information is temporarily stored in the buffer memory 108, it is sent from the interface unit 107 via the ATAPI interface 106 in response to a request from an external PC or application.

  In the first embodiment, a typical example of intermittent idling in which the laser light emitting unit 1 is pulse-driven is an idling operation called still-on (STON). In the idling operation called still-on (STON), the rotation of the optical disc 101 is maintained, and the focusing control and tracking control of the optical head unit 103 are performed by the focusing control unit 115 and the tracking control unit 116 so that the focus of the laser light is on the same track. Follow along. Of the waveforms of the PF signal and the PT signal shown in FIG. 1, the first three pulses indicate the still-on state, and the second high section indicates the information reproduction section. If the next track to be recorded or reproduced is known in advance, the optical disc apparatus 100 can be switched to the recording or reproducing operation in a short time without performing the seek operation by setting the optical disc device 100 to the still-on state.

  Note that each block (the laser control unit 104, the signal generation unit, and the like) illustrated in FIG. 1 is integrated into a plurality of semiconductor chips (for example, LSIs) by appropriate block division, or all blocks are integrated into one. It is desirable that the optical disk device 100 be miniaturized by being integrated in a semiconductor chip (for example, an LSI).

  FIG. 2 shows the basic timing of controlling the laser emission unit during typical intermittent idling. The PL signal, the S / H (sample and hold) signal, the driving current of the laser light emitting unit 1 and the light emitting power of the laser light emitting unit 1 are shown in order from the top. The PL signal at the time of idling is a pulse signal having a period T (a basic period of intermittent idling), and the high section is from time t1 to t4. Upon receiving the PL signal, the laser control unit 104 supplies a drive current to the laser light emitting unit 1 at a predetermined slew rate, and keeps the drive current at a desired current value from time t3 to time t4. From time t4 when the PL signal becomes low, the drive current value is reduced at a predetermined slew rate, and is set to 0 at time t6. The laser light emitting section 1 emits light and emits laser light from time t2 to time t5 when the drive current exceeds the threshold current. From time t3 to t4, the laser light emitting unit 1 outputs a laser beam having a desired constant power. The S / H signal is a signal that specifies the time during which the laser light emitting unit 1 emits light at a desired constant power, and is a signal used for power control inside the laser control unit 104. When the S / H signal is high, it is a sample period, and when it is low, it is a hold period.

  At the time of idling, the reproduction signal is sampled for each light emitting section to generate the FE signal and the TE signal. At this time, the frequency of the PL signal at the time of idling is a sampling frequency at which the focusing control and the tracking control can be maintained. If only the focusing control and the tracking control are maintained, the servo band (frequency band of the servo operation) can be set to a lower range (for example, about 1 kHz to 2 kHz) than the servo band at the time of recording and reproduction. If the FE signal and the TE signal are sampled at the high timing of the PL signal, the sampling frequency can be lowered to at least twice the servo band, that is, 2 kHz to 4 kHz. The light emission cycle at this time is 250 μs to 500 μs. The FE signal and the TE signal are also obtained by sampling / holding based on the S / H signal.

  The high section of the PL signal is shortened so that the light emitting section (from time t3 to t4) of the laser light emitting section 1 is 1 μs or less. Even in such a short time, the FE signal, the TE signal, and the power detection signal generated by the power detection unit 2 can be sufficiently sampled. It is considered that the light emitting section can be further reduced by the configuration of the laser control unit 104 and the improvement of the operation speed of the amplifier of the signal generating unit 112. If the slew rate of the drive current is increased, the high section of PL and the light emitting section of the laser light emitting section 1 can be made substantially the same.

  In the intermittent idling, the optical disc device 100 is controlled at the basic timing indicated by the PL signal as described above. Since a signal related to control is obtained by sampling at the time when the laser light emitting unit 1 emits light at a desired power, such a sampling operation can be said to be a kind of sample servo operation. However, a major difference from the normal sample servo operation is that the laser light emitting unit 1 emits light only at a timing when a control signal is required without causing the laser light emitting unit 1 to emit light continuously.

  As a result, the laser light emitting unit 1 consumes only power corresponding to the duty ratio of the PL signal compared to continuous light emission. The temperature rise due to this power consumption is also proportional to the duty ratio. In the above example, since one cycle of the PL signal is 100 μs or more and the light emission period is 1 μs, the temperature rise can be very small, on average, 1% or less of the continuous light emission. In addition, the time during which the laser light emitting unit 1 is driven can be reduced to substantially 1% or less of that during continuous light emission, and the element life determined by the cumulative energizing time can be greatly extended. Furthermore, since the operating temperature of the laser light emitting section 1 can be lower than that of continuous light emission, there is an effect of extending the life of the element by reducing the temperature. In another sense, the laser light emitting unit 1 can be used at a temperature lower than the limit temperature of the laser light emitting unit 1 even in a high temperature environment. Since the intermittent idling produces the above-mentioned effects, it is possible to shift to the recording / reproducing operation in the same time as the continuous light emission without requiring the time until the recording / reproducing as in the above-mentioned stop type intermittent operation, so that the present invention is enormous. It can be said that the effect is realized.

  The sampling frequency needs to be set higher depending on the required servo band. However, if only idling is to be maintained, at least several tens of kHz is sufficient, so the above effect can be said to be sufficient. In addition, if measures such as shortening the light emitting section are adopted, it is possible to suppress power consumption and temperature rise to 1% or less, which are equivalent to the above. For example, if the light emitting section is shortened to 0.1 μs, the duty ratio can be reduced to 1% even if the sampling frequency is increased to 100 kHz.

  However, at the time of recording and reproduction, it is preferable to supply the same drive current to the semiconductor laser as usual. In applications in which reproduction or recording occurs for several tens of minutes continuously, even when intermittent idling is used, the temperature rise may not be sufficiently reduced. However, if the speed of writing or reading information to or from the optical disk is faster than the information processing speed, the writing or reading operation can be performed while pausing at intervals of several seconds to several tens of seconds, and the temperature rise due to intermittent idling will occur. Is sufficiently suppressed.

  Further, in the case where the performance of the laser light emitting unit 1 is not ensured by the operation at an extremely low temperature, the laser control unit 104 completely reduces the drive current in the intermittent idling off section in order to warm the laser light emitting unit 1. Instead of being set to 0, a drive current that does not emit light from the laser light emitting unit may be applied to the laser light emitting unit. Further, continuous emission may be performed until the temperature of the laser emitting section rises to a predetermined temperature. When the laser light emitting unit 1 rises to an appropriate predetermined temperature, the laser control unit 104 does not substantially apply a drive current to the laser light emitting unit 1 during a period in which the laser light emitting unit 1 does not emit light. Thereby, the power consumption of the laser light emitting unit 1 and an unnecessary temperature rise are suppressed while the laser light emitting unit 1 is kept at an appropriate temperature.

  FIG. 3 is a diagram showing the light emission timing of the laser light emitting unit 1 for each control operation. Except during information recording, the light emission timing matches the waveform of the PL signal. FIG. 3A shows the basic timing at the time of the simplest idling as described above. The vertical solid line indicates one pulse, but the timing is schematically shown, and the relationship between the actual number of pulses and the operation does not correspond to 1: 1.

  In the example of FIG. 3, at the time of each control operation other than the information reproduction and the information recording, the lighting period necessary for the basic timing is superimposed. Since only focusing control and tracking control are performed during idling, the PF signal and the PT signal have the same waveform. During idling, power is supplied to blocks that are not necessary for focusing control and tracking control, such as the recording control unit 105, the address reproduction unit 113, and the reproduction signal processing unit 114, in order to reduce the power of the entire optical disc device 100. The sleep state is established by cutting or stopping the clock, and the operation is stopped.

  That is, the current consumption of the circuit means other than for maintaining the focusing control and the tracking control is reduced. In addition, in any state, not only at the time of idling, the related block is set to the operating state only when necessary, and to the sleep state otherwise, the power is finely reduced to reduce power consumption and prevent temperature rise. Thereby, the power consumption and temperature rise of the entire optical disc device 100 can be reduced more effectively.

  FIG. 3B is a light emission timing chart when the optical disk is started. First, the laser light emitting section 1 is turned on at the basic timing before the focusing control. The section T3b1 is the timing of the focusing control, and a sampling pulse indicated by an arrow is added to improve the focusing accuracy. Here, the sampling pulse indicated by the arrow is a pulse that causes the laser emitting unit 1 to emit light in order to perform a sampling operation at a timing other than the basic timing. The sampling pulse is embedded in the PL signal. When the focusing control is performed, the light emission cycle is shorter than when the focusing control is not performed. Thus, the FE signal, the TE signal, the total light amount signal, and the like can be accurately obtained at high speed. The section T3b2 is a tracking control section, and a sampling pulse indicated by an arrow is added similarly to the focusing control. As described above, the laser control unit 104 sets the light emitting cycle of the laser light emitting unit 1 when executing the focusing control and the tracking control to be shorter than the light emitting cycle of the laser light emitting unit 1 when the focusing control and the tracking control are not performed. Thus, the intermittent idling operation can be realized even during the start-up operation, and the focusing control and the tracking control can be executed without error.

  FIG. 3C is a light emission timing chart at the time of jumping. In the jumping sections T3c1 and T3c2, a sampling pulse indicated by an arrow is added to increase the detection accuracy of the TE signal and the control frequency band, thereby achieving stable jumping. Realize. In the above description, the operation is performed at the basic timing at the time of simple idling. However, at the time of the actual jumping operation of the STON operation, the idling operation can be stabilized by adding a sampling pulse similar to this timing.

  FIG. 3D is a light emission timing chart when vibration is detected during idling. The optical disk device 100 includes a vibration detection unit (for example, a vibration / temperature detection unit shown in FIG. 7) that performs at least one of detection and prediction of the amount of vibration of the optical disk device 100, thereby detecting vibration, or detecting an FE signal or TE. Detection of vibration due to the signal residual is performed. When the vibration amount becomes equal to or more than a predetermined value, a sampling pulse indicated by an arrow is added as in the section T3d, and the focusing and tracking control frequencies are increased to prevent a focus jump and a tracking jump. Further, when the vibration amount is larger than the predetermined amount, the light is continuously turned on without the off period, the sample period of the FE signal and the TE signal is shortened, and the control frequency of the focusing control and the tracking control is further increased to thereby reduce the vibration. To improve control performance. For example, the light emission cycle is reduced to 1/2, 1/3, 1/4, ... of the basic timing cycle according to the amount of vibration. As described above, the laser control unit 104 sets the emission cycle of the laser emission unit to be shorter than the emission cycle of the laser emission unit when the oscillation amount is equal to or more than the predetermined amount. Alternatively, the laser light emitting section emits light continuously. This makes it possible to provide an optical disk device with high operation reliability even under a vibration environment while performing intermittent idling.

  FIG. 3E is a light emission timing chart when a defect is detected during idling. During idling, since the vehicle is on the same track, a defect can be detected from the FE signal and the TE signal by one rotation of scanning. Focusing and tracking control are performed so as to avoid defects from the next rotation. Here, the defect section is set to T3e2, and since there is no need to detect the FE signal and the TE signal, the laser light emitting unit 1 is turned off. On the other hand, for T3e1 and T3e3 before and after the defect section, a sampling pulse indicated by an arrow is added. Before the defect, the number of sampling points is increased to increase the control accuracy. The defect section is set in the hold state, but the position shift at the time of the hold is corrected using a dedicated memory storing the absolute position of focus and tracking. After passing through the defect, the number of sample points is increased in a certain section indicated by T3e2 in order to quickly and stably suppress the positional deviation.

  FIG. 3F is a light emission timing chart during a seek operation. Here, it is assumed that the seek is performed in the section from T3f1 to T3f3. During the seek, the tracking control is removed, and the optical head unit 103 is moved at a predetermined speed profile. However, the lighting section is added to accurately count the number of guide grooves from the TE signal at the time of the seek. . Since the transfer speed is slow in the sections T3f1 and T3f3 corresponding to acceleration and deceleration, respectively, a change in the TE signal is detected by pulse lighting according to the transfer speed. When the transfer speed becomes high, the laser control unit 104 causes the laser light emitting unit to continuously emit light as indicated by a section T3f2. As a result, a high-speed change in the TE signal can be accurately detected. Of course, since the period of the TE signal is long, if the transfer speed is equal to or less than a certain value, the seek operation can be realized only by the pulse lighting of the period capable of generating the TE signal. Focusing control during seek can be achieved in principle at the basic timing. However, in reality, there is the influence of the groove crossing signal and so on. Can be improved. Thus, the intermittent idling operation can be realized even during the seek operation, and the tracking control can be executed without error.

  FIG. 3G is a light emission timing chart at the time of reading address information. As described above, the address of the optical disc 101 is recorded in advance by wobbling the guide groove. In a read preparation operation for preparing to read address information from the optical disc 101, the laser light emitting section 1 emits light at the light emission cycle of the basic timing. In the read operation (T3g section) for reading address information from the optical disc 101, in order to sufficiently detect the wobble state of the guide groove, a sample pulse indicated by an arrow is added to the basic timing so that the light emission cycle is shorter than the wobble cycle. The laser light emitting section 1 emits light at the set light emission cycle, and the address information is read. Thus, the intermittent idling operation can be realized even during the address information reading operation, and the address information reading operation can be executed without error. The light emission period is determined by the method of forming the address information. However, when the wobble frequency becomes as high as about 1 MHz, the light may be continuously turned on in consideration of the stability of the laser light emitting unit 1.

  FIG. 3H is a light emission timing chart when reproducing information such as user data. In the first read preparation operation (section T3h1) for preparing to read information from the optical disc 101, the laser light emitting unit 1 emits light at the light emission cycle of the basic timing. The second read preparation operation (section T3h2) for preparing to read information from the optical disc 101 is an address information read operation for specifying an area in which information to be reproduced is recorded, as shown in FIG. Operation is the same as The light emission cycle of the section T3h2 is shorter than the light emission cycle of the basic timing. In a read operation (section T3h3) for reading information from the optical disc, the laser light emitting unit 1 is continuously turned on. In the section T3h3, the high-frequency module (FIG. 5) for reducing noise generated by the reflected light from the optical disk 101 is also operated. Regarding the focusing control and the tracking control, the control frequency is increased and the accuracy is increased as the process shifts during idling, address reading, and information reproduction.

  FIG. 3 (i) shows the light emission timing when information such as user data is recorded. In the first recording preparation operation (section T3i1) for preparing to record information on the optical disc 101, the laser light emitting unit 1 emits light at the light emission cycle of the basic timing. The second recording preparation operation (section T3i2) for preparing to record information on the optical disc 101 is an address information reading operation for specifying an area where information is to be recorded, and the operation shown in FIG. Is the same as The light emission cycle of the section T3i2 is shorter than the light emission cycle of the basic timing. In a recording operation (section T3i3) for recording information on the optical disc 101, the recording control unit 105 switches the laser control unit 104 to the recording mode. In the recording mode, the optical disk 101 is irradiated with a laser beam having an optimum power by driving the laser emitting unit 1 using a multi-pulse having a multi-level recording power level. Generally, the highest control performance is required during recording. Therefore, high-speed and high-precision FE, TE, and RF signals are detected by appropriate signal processing, and servo control and address information reading are performed in parallel. During information recording, the high-frequency module is not operated. The high-frequency module does not need to be operated in the above-described read preparation operation and recording preparation operation. Thereby, power consumption of the high-frequency module during the read preparation operation and the recording preparation operation and a rise in the temperature of the laser light emitting unit 1 close to the high-frequency module can be suppressed.

  Note that the operation of the high-frequency module may be stopped even during a period in which the laser light emitting unit 1 does not emit light. This can suppress power consumption of the high-frequency module during a section in which the laser light emitting unit 1 does not emit light and a rise in the temperature of the laser light emitting unit 1 close to the high-frequency module.

  The laser control unit 104 keeps the laser light emitting unit 1 intermittently emitting light for tracking control and focusing control even while waiting for execution of information reproduction or recording. The light emission cycle at this time is set longer than the light emission cycle during execution of reproduction or recording. As a result, the power consumption and temperature rise of the entire optical disk device can be effectively reduced even while waiting for execution of information reproduction or recording.

  The light emission timing is the same as the PL signal timing except for recording. As described above, the PL signal is an OR of the PA signal, the PF signal, and the PT signal. Basically, the PA signal is generated only at the time of address reading, and the PF signal and the PT signal are generated according to the servo control state and the servo band. Is output. However, these signals control the optical disc apparatus 100 optimally in various combinations depending on the operation state. Also, the detection of the TE signal and the tracking control during the seek need not always be at the same timing, so the PT signal may be a signal group. In addition, it is assumed that the operation mode of the address reproducing unit 113, the focusing control unit 115, and the tracking control unit 116 in the recording high section is designated by a control signal (not shown) different from the PA signal, the PF signal, and the PT signal.

  In addition, in the description of the timing of each operation described above, a section in which a sampling pulse is added is set for each control operation. However, it is of course possible to continuously turn on the laser light emitting unit 1 in that section. However, from the gist of the present invention, it is desirable to perform pulse lighting so that power can be reduced as much as possible even if the section is short.

  In addition, the high-frequency module (HFM) during pulse lighting does not need to be basically operated because the lighting time of the laser emitting unit is short. Since the HFM does not need to be operated during the idle period, the HFM is stopped. However, when operating the HFM in the lighting section of the laser light emitting unit, it is necessary to drive the HFM in advance for the response time of the HFM. During continuous lighting, operation is performed only when necessary according to the performance and operation mode of the laser light emitting unit, except during information reproduction. Regarding the laser light emitting unit during intermittent idling, there is a concern about a power difference within a pulse due to a mode hop or between pulses, but this part is mitigated by using an AGC technique for normalizing a detection signal by the total amount of light.

  As will be described repeatedly, at the time of address reading, at the time of information reproduction, and at the time of information recording, it is necessary to increase the control accuracy of focusing and tracking. Therefore, the sampling period of the FE signal and the TE signal is increased, and I do. Especially during recording and reproduction, the original continuous servo control is performed.

  In addition, in the unlit section of the laser light emitting unit, the power of the related detection system is reduced as described later, so that the optical disk device 100 with lower power can be provided.

  In the above description, the basic idling is performed while tracking control is performed. However, in a ROM disk of a type in which the optical disk is formed of prepits and needs to emit light continuously by the laser light emitting portion to obtain a TE signal, During idling, tracking control may be stopped and only focusing control may be executed. If the idling time until the recording / reproducing operation is long to some extent, the system temporarily shifts to the second idling state and performs the information recording operation or the information reproducing operation through the tracking control before the recording / reproducing operation. You may. Further, when the standby period for executing the recording or the reproduction is long to some extent, the tracking control may be stopped to reduce the power for the tracking control.

  FIG. 4 is a diagram showing a series of control operation timings at the time of information recording and reproduction, and shows how data is reproduced or recorded by a combination of the control operations described in FIG.

  FIG. 4A shows a series of information reproducing procedures. As shown in the operating state, the procedure is, in order, stop, start, address reading, seek, address reading (for seek confirmation), idling, seek, address reading (confirmation of a playback track), information reproduction (read), idling, and stop. I do. The control state of the laser light emitting unit 1 in each operation is shown by a pattern diagram of the operation state, and specific lighting control is performed as shown in FIG. In the section T4a during information reproduction, continuous light emission is performed.

  FIG. 4B shows a series of information recording procedures. As shown in the operation status, the procedure is as follows: stop, start, address reading, seek, address reading (for seek confirmation), idling, seek, address reading (confirmation of recording track), information recording (write), idling, and stop. I do. The control state of the laser light emitting unit 1 in each operation is shown by a pattern diagram of the operation state, and specific lighting control is performed as shown in FIG. In the section T4b at the time of information recording, pulse light emission by a write strategy is used.

  In the above description, the seek operation is performed twice before recording and reproducing both data reproduction and recording. However, the first seek and subsequent address reading and idling are performed by recording and reproducing the optical head unit 103 in advance. It is positioned near the track to be used to reduce the time required for recording and playback. Therefore, these three steps are not necessarily required when the optical head unit 103 is already positioned near the track to be recorded next. The series of information reproduction procedures described here are also applied to reproduction other than user data, such as reading of control data at the time of starting the optical disc apparatus 100, reading of management data for replacement processing, or reading of key information for copyright protection. . Similarly, the information recording procedure is applied to recording of related information other than the user data.

  Further, the series of information reproduction procedure and information recording procedure described here can be unit operations of information reproduction and information recording when a stop type intermittent operation is required.

  Basically, regardless of the application, if it is predicted or known that a recording / reproducing operation will occur at a predetermined interval or less, control is performed so that intermittent idling operation without stop and recording / reproducing operation are repeated. I do. In particular, when the optical disk device 100 is used as a normal PC peripheral, if there is no access for a certain period of time, the operation temporarily enters a stop operation (sleep operation) and restarts when a recording / reproduction request is made, and the above operation is performed. A series of data recording / reproducing procedure is performed without intermittent idling operation without stopping operation. Furthermore, if an extended command that can specify an idle state is prepared as a command of the PC, and an intermittent idling operation or a stop operation is explicitly instructed so that control from the host can be performed, a more appropriate low-level system can be realized. Power processing can be realized.

  Although the optical disk device 100 in the first embodiment is a device with an ATAPI interface built in a PC, the optical disk device 100 may be an external storage device of a PC having a serial interface such as USB or IEEE1394.

(Embodiment 2)
In the second embodiment, the operation of the components of the optical disc device 100 such as the optical head unit 103, the laser control unit 104, and the signal generation unit 112 will be further described.

  FIGS. 5 and 6 are diagrams showing the optical head unit 103 and the laser control unit 104, and their peripheral components. The components of the optical disk device 100 described in the second embodiment are designed so as to realize the intermittent idling of the present invention without largely changing the configuration of the conventional optical disk device. The cost can be significantly reduced.

  In FIG. 5, the same components as those in FIG. 1 are denoted by the same reference numerals. The optical disc 101 has a structure in which a recording film is formed on a groove (guide groove) 101G formed on a substrate and a land 101L therebetween, and a cover layer 101C as thin as 0.1 mm, for example, is formed thereon. . The track pitch is as fine as 0.32 μm, for example. In the address information, the groove 101G is recorded in advance in a laterally shifted state (wobble) toward the paper surface.

  The optical head unit 103 includes a laser emission unit 1, a power detection unit 2, a light detection unit 3, a beam splitter 201, an objective lens 202, a high-frequency module 204, and a temperature sensor 206. The signal generation unit 112 includes a signal generation matrix amplifier 203 and sample and hold circuits (S / H) 209, 210, and 211. The laser control unit 104 includes a laser driving circuit 205, a power detection signal amplifier 207, and a sample and hold circuit (S / H) 208.

  The laser light emitting section 1 provided in the optical head section 103 is a blue-violet laser having a wavelength of about 405 nm, and the light emitted therefrom is converted into substantially parallel light by a collimator (not shown), passes through the beam splitter 201, and has a NA0. The recording / reproducing light beam 202B is formed on the groove 101G by the .85 objective lens 202. The recording / reproducing light beam 202B is narrowed down very small in proportion to the short wavelength and inversely proportional to the NA, thereby realizing high density recording / reproducing. Specifically, in comparison with a DVD using a red laser having a wavelength of 650 nm and a lens having an NA of 0.6, the diameter is 以下 or less and the recording density is 4 times or more. The light reflected by the optical disk 101 returns to the objective lens 202, the optical path is changed by the beam splitter 201, and is transmitted to the light detecting unit 3 composed of a plurality of patterned light receiving areas via a detection optical system (not shown). Incident. The information detected by the light detection unit 3 is input to the signal generation matrix amplifier 203.

  On the other hand, the laser light emitting unit 1 is driven in parallel by a high frequency module (HFM) 204 and a laser driving circuit 205 outside the optical head unit 103. In the ordinary optical disc apparatus 100, the HFM 204 is driven also during continuous light emission of the laser light emitting unit 1 during the recording / reproducing preparation operation. However, in the second embodiment, the HFM 204 is driven basically when information is reproduced. . The output power of the laser emitting unit 1 is detected by a power detecting unit 2. In FIG. 5, the power is detected by the back light emitted from the surface opposite to the emission surface of the laser light emitting unit 1. However, a so-called front light detection is performed in which a part of the emitted light is introduced into the power detection unit 2 to detect the power. Is also good. The temperature sensor 206 is for measuring the package temperature of the laser light emitting unit 1, and in particular, the low power consumption depends on the temperature range of the laser light emitting unit 1 with respect to the upper limit of the guaranteed temperature of 60 to 70 ° C. It is installed for the purpose of changing the recording and recording / reproducing control method and giving a warning to the device user. Further, for example, when the temperature is lower than the operation guarantee temperature of the laser light emitting unit 1 by a predetermined value or more, the period of the PL signal is shortened to shorten the sampling period of the FE signal and the TE signal, and the control of the focusing control and the tracking control is performed. The control performance can be improved by increasing the frequency band. As described above, when the temperature of the laser light emitting unit 1 is lower than the operation guarantee temperature of the laser light emitting unit 1 by a predetermined value or more, the laser control unit 104 sets the light emitting cycle of the laser light emitting unit 1 to the temperature of the laser light emitting unit 1. The light emission cycle of the laser light emitting unit 1 when the temperature is not lower than the operation guarantee temperature by a predetermined value or more is set shorter. Even in an operating environment where the temperature of the laser light emitting unit 1 is lower than the operation assurance temperature, an optical disk device with high operation reliability can be provided while performing intermittent idling.

  The power detection signal detected by the power detection unit 2 is amplified by the power detection signal amplifier 207 and fed back to the laser drive circuit 205 via the sample and hold circuit (S / H) 208. The S / H 208 samples the power detection signal when the PL signal is high and holds the signal when the PL signal is low, so that the power is controlled by the power detection signal when the laser light emitting unit 1 is on. The PL signal is also input to the laser drive circuit 205, and ON / OFF of the laser light emitting unit 1 is controlled. At the time of information reproduction, the laser drive circuit 205 keeps the PL signal high and causes the laser light emitting section 1 to emit light continuously. At the time of information recording, a pulse-like recording power suitable for the write strategy is emitted by the WT signal group.

  On the other hand, an RF signal, an FE signal, and a TE signal are obtained from the signal generation matrix amplifier 203 through sample / hold circuits (S / H) 209, 210, and 211, respectively. The S / H 209 samples the RF signal when the laser light emitting unit 1 is turned on by the PA signal at the time of address reproduction during recording / reproducing. The S / H 210 samples the FE signal when the laser light emitting unit 1 is turned on by the PF signal during the focusing control during the recording / reproducing. The S / H 211 samples the TE signal when the laser light emitting unit 1 is turned on by the PT signal at the time of tracking control during recording / reproducing and at the time of groove counting during seek. At the time of information reproduction and information recording, the PA signal, the PF signal, and the PT signal are always set to H, and the address reading, focus, and tracking control performance are improved by always sampling. As in the first embodiment, the PL signal is a logical OR of the PA signal, the PF signal, and the PT signal.

  As described above, in the second embodiment, the intermittent idling of the present invention can be easily realized only by adding the sample and hold circuit (S / H) to the control circuit of the ordinary optical disk device.

  In addition, the signal in the non-light emitting section where the laser light emitting section is turned off is separately detected, and the circuit offset, drift, and optical system offset are canceled from the sampled and held RF signal, FE signal, and TE signal, thereby detecting the signal. Control performance can be improved. It is preferable that the FE signal and the TE signal are subjected to AGC processing by detecting the AS sum signal of the laser light emitting unit.

  FIG. 6 shows the configuration of the laser control unit 104 and its peripheral parts more specifically. In FIG. 6, the laser emitting unit 1 and the power detecting unit 2 are indicated by diode symbols, respectively. A current source 303 is a current source for determining a reproduction power current of the laser light emitting unit 1, and is turned on / off by a switch 304 controlled by a PL signal. The recording current control unit 305 includes a current source group that determines the recording power of the laser light emitting unit 1, and a switch group connected to each of the current sources. Although details of the recording operation are omitted, the switch 304 is turned off at the time of recording, and a multi-pulse having a multi-level recording power level is generated by the recording current control unit 305, and the laser emission unit 1 emits light by the multi-pulse.

  The amplifier 306 amplifies the power detection current of the power detection unit 2. The amplifier 306 is driven by a current source 307 for flowing a steady current and a current source 309 turned on / off by a switch 308. When the PL signal is high, the switch 308 is turned on by the signal adjusted by the timing adjustment unit 310. As a result, the operating frequency band of the amplifier 306 becomes higher only during the laser light emitting section 1 lighting section. When the PL signal is low, only the current output from the current source 307 flows to the amplifier 306 to reduce current consumption.

  The switch 311, the capacitor 312, and the amplifier 313 function as a sample and hold circuit and an error amplifier. When the PL signal is high and low, the switch 311 is turned on and off, respectively, the power detection signal when the laser light emitting unit 1 is turned on is sampled by the capacitor 312, and when the light is turned off, it is held. The control signal of the switch 311 is adjusted by the timing adjustment unit 310 so that only the power detection signal at the time of light emission of the laser light emitting unit 1 is sampled. The output of the amplifier 313 is fed back to the current source 303 so that the light emission power is controlled so that the voltage value of the sampled and held signal becomes equal to the value of the reproduction power reference voltage Vp. The amplifier 313, like the amplifier 306, is driven by a current source 314 that supplies a steady current and a current source 316 that is turned on and off by a switch 315. When the PL signal is high, the switch 315 is turned on by the signal adjusted by the timing adjustment unit 310. As a result, the operating frequency band of the amplifier 313 increases only when the power detection signal is sampled during the lighting period of the laser light emitting unit 1. When the PL signal is low, only the current output from the current source 314 flows to the amplifier 313 to reduce current consumption.

  As described above, in the circuit configuration shown in FIG. 6, the current consumption of the power detection signal amplifying unit and the sample-and-hold unit is reduced when the laser light emitting unit is turned off, thereby realizing low power consumption other than the laser light emitting unit. ing.

  Also, in the signal generation matrix amplifier 203 and the S / Hs 209, 210 and 211 shown in FIG. 5, like the amplifiers 306 and 313, the current consumption is controlled when the laser light emitting section 1 is turned on and off, so that It is also possible to reduce the current consumption. By doing so, the optical disk device 100 with lower power can be realized.

  In addition, for the purpose of miniaturization, low noise, and high performance, the above-described light detection unit 3, signal matrix amplifier 203, and the like may be integrated as an OEIC (Opto-Electronic Integrated Circuit). In this case, intermittent idling of the present invention can be easily realized by integrating the S / Hs 209 to 211 as well. Since the OEIC is provided on the optical head unit 103, the power consumption of the amplifier mounted on the optical head unit 103 can be reduced similarly to the laser light emitting unit 1. Thereby, power consumption and temperature rise of the optical head unit 103 can be suppressed. Further, it is possible to realize a compact and compact optical disk device capable of performing the intermittent idling operation.

  Note that the OEIC may further integrate the power detection system (the power detection unit 2, the amplifier 306, and the amplifier 313) described with reference to FIG. Further, an integrated optical module may be formed by bonding the chip of the laser light emitting unit 1 on the OEIC and further integrating a light detection optical system and the like, thereby providing a wide range of intermittent idling functions. However, since it is difficult to integrate a high-power and high-speed laser drive circuit with the OEIC, it is necessary to arrange it on a chip separate from the OEIC and at a position where the influence of temperature is reduced as far as the performance can be secured. Although desirable, it may be implemented in the OEIC depending on the development of manufacturing technology.

(Embodiment 3)
FIG. 7 is a block diagram showing a video camera device 400 equipped with an optical disk drive according to Embodiment 3 of the present invention. The video camera device 400 can also be called an optical disk device with a video camera function.

  The intermittent idling of the present invention can reduce the power consumption and increase the temperature without stopping the operation of the optical disk device even when the data processing speed is close to the writing speed to the optical disk, when the video data is compressed and recorded on the optical disk. This is particularly effective because suppression can be easily realized. According to the present embodiment, it is possible to provide a convenient video camera device that is excellent in temperature resistance and makes use of the random accessibility of an optical disc.

  The video camera device 400 includes an optical disk drive unit 401, a camera unit 402, a video processing unit 403, a video display unit 404, a buffer memory 405, a vibration / temperature detection unit 407, an external AV input / output unit 409, An operation unit 410 and a video camera / system control unit 411 are provided. The video camera device 400 has a flash memory card 406 and a battery 408 mounted thereon.

  The optical disk 101 is mounted on an optical disk drive 401. The optical disk drive 401 includes the same components as those of the optical disk device 100 that performs the above-described intermittent idling. The optical disk drive 401 performs recording of video information and audio information on the optical disk 101 and reproduction of video information and audio information recorded on the optical disk 101.

  The camera unit 402 that generates video information indicating a video from incident light includes a lens and a CCD for capturing a video, a microphone for capturing audio, and the like. Video information and audio information output from the camera unit 402 are subjected to compression / expansion processing in the video processing unit 403. At the same time, the video display unit 404 including the LCD displays the video indicated by the video information. The compressed video information and audio information are temporarily stored in the buffer memory 405 and then sent to the optical disk drive 401 in order. It is assumed that the data compression processing speed is lower than the speed at which the optical disk drive unit 401 records video information and audio information on the optical disk 101. Is performed in an intermittent operation such that a section in a waiting state for suspending the operation is alternately repeated. The intermittent idling of the present invention particularly reduces the power consumption in this waiting section.

  Regarding the recording operation, data to be temporarily stored so that video and audio are not interrupted by combining a buffer memory 405, a buffer memory built in the optical disk drive 401, and a built-in or removable flash memory card 406. Manage quantity. In particular, when the vibration / temperature detection unit 407 detects the vibration / shock and cannot control the optical disc drive unit 401, or when the high temperature of the optical head unit is detected and the operation of the laser light emitting unit cannot be guaranteed, recording is performed. When the operation cannot be continued and the buffer memory overflows, the optical disk drive unit 401 is stopped, the compressed data is temporarily stored in the flash memory card 406, and the optical disk drive unit 401 can operate normally. Then, the optical disk drive unit 401 is operated to record data at the position of the optical disk 101 where the recording should be performed.

  Since the flash memory card 406 is a non-volatile memory, management data to be recorded on the optical disk 101 is recorded in parallel with the optical disk 101, and backup of the management data that could not be written on the optical disk 101 due to battery exhaustion or removal due to a voltage drop of the battery 408. it can. Then, when the optical disk drive unit 401 becomes operable again by the recovery or installation of the battery 408, the backup information can be written to the optical disk 101 to preserve the data. In this case, the ID number and recording time of the optical disk 101 or the flash memory card 406, the ID number of the optical disk drive unit 401, and the like are simultaneously written so that data consistency is not lost when the optical disk 101 or the flash memory card 406 is inserted or removed. Recording ensures data consistency. In the case where data consistency is lost, it is also effective to mechanically lock the optical disc 101 and / or the flash memory card 406 so that the data cannot be extracted, thereby ensuring data consistency.

  This apparatus can record video and audio data from an external AV input / output unit 409 other than the camera unit 402. Naturally, only recording based on the copyright protection rule can be performed. Each block control in the shooting and recording operations is performed via the video camera / system control unit 411 based on the operation of the operation unit 410 by the user.

  Next, the reproducing operation will be described. The reproduction operation is performed based on the operation of the operation unit 410. Normally, the content of the optical disc 101 is displayed as a thumbnail on the video display unit 404, and the moving image is reproduced when the user selects it. First, the target compressed data is read from the optical disk 101 and stored in the buffer memory 405. When the compressed data reaches a certain amount, the video processing unit 403 expands (decompresses) the recorded video and audio data into video data. Output to the display unit 404 and output to an external TV or the like via the external AV input / output unit 409. Also in the case of reproduction, the data input speed to the video processing unit 403 is lower than the read speed from the optical disc 101. Therefore, during reproduction, the compressed data read from the optical disk 101 is temporarily stored in the buffer memory 405, and the compressed data is continuously supplied from the buffer memory 405 to the video processing unit 403. However, the operation of reproducing information from the optical disk 101 stops once the buffer memory 405 is about to overflow. While the reproduction operation is stopped, the optical disk drive unit 401 enters a waiting state using intermittent idling to reduce power consumption. When a predetermined space is created in the buffer memory 405, the reproduction operation is restarted. As in the case of recording, intermittent reproduction in a burst manner is performed.

  The above-described optical disk device with a video camera function is generally housed in a single small housing, and power consumption of each block causes an increase in the temperature inside the refrigerator. Therefore, appropriate heat radiation is required. In particular, as described above, the rise in the temperature of the laser emitting section is critical in determining the operating temperature and reliability of the apparatus. Therefore, if the intermittent idling of the present invention is applied to the optical disk drive unit 401, it is possible to efficiently lower the power of the laser light emitting unit and other peripheral circuits and suppress the temperature rise. In the video camera device 400 (optical disc device with a video camera function) according to the third embodiment, it can be said that the effect of intermittent idling is particularly large.

  Although the device described in the third embodiment is an optical disk device with a video camera function, the present invention is also applicable to an optical disk device having an audio-only function, a data collection function, and the like.

  The description of the third embodiment is completed above. However, through the description of the first to third embodiments, it is assumed that the quality of the error signal at the sampling point is poor and the control at a low frequency is insufficiently controlled. . In that case, the track to be STON is inspected by continuous lighting in advance, and then, the track is moved to a track having no defective portion and intermittent idling is performed, or a lighting portion is determined so as to avoid the defective portion, and a good FE signal is determined. And the intermittent idling may be maintained using only the TE signal. The quality check of the error signal checks whether the FE or TE is not disturbed by a defect or dust on the disk. However, after intermittent idling, the track to be accessed is determined, and it may be desirable to continue STON on a track having a quality defect of a length equal to or less than a certain level. Therefore, as described above, At the time of STON at the time of intermittent idling, it is only necessary to hold each error signal of the quality defective section.

  Further, in the above description of the embodiment, the laser light emitting portion is a can type and is mounted at a position different from the OEIC. However, a so-called integrated module in which the laser light emitting portion, the OEIC, and the optical system are integrated is used. In the case of an ultra-small head, the present invention is particularly effective because heat radiation becomes more difficult.

  Further, in the above description of the embodiment, the driving of the laser light emitting unit is performed by switching, so that a current for generating normal reproduction power is supplied during light emission, and the current is interrupted when no light is emitted, so that the laser light emitting unit is pulsed. Driving minimized the average current to the laser emitting part. However, in order to apply a slight thermal bias to stabilize the performance of the laser emission unit during pulse driving, a small amount of bias current less than the threshold current may be applied, or a predetermined current may be applied only to a specific section of the pause section. May flow. Furthermore, in addition to controlling the current slew rate to reduce the noise in the drive current, the method of changing the current in an analog manner can also sufficiently implement the inherent effects of the present invention.

  Further, as the optical disk described in the above embodiment, an optical disk having a continuous groove represented by an MD, a DVD-R, a Blu-ray, or the like has been described. However, in an optical disk of the sample servo system, after a pit section to be servo-controlled is specified in advance, the laser light emitting section only needs to be turned on for that section, and the present invention is particularly suitable. Further, in the sample servo method, if the address information is included in the pit section to be servo-controlled, the laser light emitting section emits light when passing through the pit section to be servo-controlled, thereby performing idling while reading the address. be able to. In an optical disc having a sector structure, such as a PD or a DVD-RAM, the laser light emitting section emits light continuously during an address information recording section and blinks during a data recording section, thereby obtaining an effect unique to the present invention. .

  When the TE signal can be obtained only by irradiating the blinking light to the prepits of the ROM disk, the intermittent idling of the present invention can be performed as it is. However, when the TE cannot be accurately detected unless light is continuously irradiated to some extent, such as the detection of the phase difference TE, it is necessary to wait for the execution of recording and reproduction in a preparation state for intermittent idling only during the focusing control. Is also possible.

  Further, the intermittent idling of the present invention can be applied to any optical disk device regardless of the type of the optical disk and the wavelength of the laser light emitting unit.

  According to the present invention, during the first operation, the laser light emitting section emits light at the first cycle, and during the second operation, the laser light emitting section emits light at the second cycle. Further, the first cycle and the second cycle are different from each other. By adjusting the light emission cycle of the laser light emitting unit according to each operation, each operation can be reliably performed, and the temperature rise and power consumption of the laser light emitting unit can be suppressed. In addition, the temperature rise of the laser light emitting unit can be suppressed, and the driving time of the laser light emitting unit can be shortened, so that the life of the laser light emitting unit can be extended.

  According to the present invention, the power consumption of the laser emitting unit is drastically reduced to substantially zero (1% or less of continuous emission) by intermittently driving the laser emitting unit during the recording or reproducing preparation operation of the optical disk device. it can. Therefore, especially in an optical disk device that records or reproduces information intermittently, the laser light emitting unit is used substantially only during recording or reproduction, and the temperature rise of the laser light emitting unit can be extremely reduced. As a result, the optical disk device of the present invention or a device incorporating the same can be used in a high-temperature atmosphere where a device to which the present invention is not applied cannot be used. Looking at this feature from a different angle, if the ambient temperature of the optical disk device is the same, the optical disk device to which the present invention is applied can reduce the rise in temperature of the laser light emitting unit, thereby extending the operating life of the laser light emitting unit. Can be.

  Further, according to the present invention, the life of the laser emitting unit can be extended in terms of the use time of the laser emitting unit. In general, an optical disk device requires a period for a recording or reproducing preparation operation before and after recording or reproducing. By performing the intermittent idling at the time of this preparation operation, the driving of the laser light emitting unit can be stopped during the off period, and the laser light emitting unit can be made inoperative. Thereby, the cumulative operation time of the laser light emitting unit during the preparation operation can be made substantially negligible, so that the life of the laser light emitting unit seen from the user is greatly extended. In other words, the life of the optical disk device is substantially determined by the accumulated time of the recording and reproduction operations, and the time during the preparation operation for recording and reproduction does not substantially affect the life of the optical disk device. Furthermore, according to the present invention, the optical disk device can be maintained in a recording or reproducing ready state with low power consumption and can be immediately put into the recording or reproducing state, so that it can be quickly operated in response to a user request for reproducing video information from the optical disk. Response is possible.

  Further, according to the present invention, since the power of the laser emitting unit and other circuits can be suppressed, an optical disk device with low power consumption can be provided. Particularly, a portable and battery-operated device can provide an advantage that the battery life can be extended or that a smaller battery can be driven for the same time. In addition, since a rise in temperature is suppressed by reducing power consumption, a smaller optical disk device can be provided.

  The present invention realizes low power consumption of the optical disk device and its mounting device, and also guarantees operation at high temperatures, while ensuring the operation reliability and extending the life of the laser light emitting unit.

  As described above, the practical effects of the present invention are very large.

FIG. 2 is a block diagram of the optical disc device according to the first embodiment. Basic timing chart of semiconductor laser control of the first embodiment Laser emission timing chart for each control operation of the first embodiment Information recording / reproducing timing chart of the first embodiment Configuration diagram of an optical head unit and peripheral roads of an optical disk device according to a second embodiment FIG. 3 is a configuration diagram of a laser driving unit of the optical disc device according to the second embodiment. Block diagram of optical disc device with video camera function according to Embodiment 3

Explanation of reference numerals

REFERENCE SIGNS LIST 1 laser emission unit 2 power detector 3 photodetector 101 optical disk 102 disk motor 103 optical head 104 laser control unit 105 recording control unit 106 ATAPI interface 107 interface unit 108 buffer memory 109 syscon unit 110 motor control unit 111 OR circuit unit 112 signal Generation unit 113 Address reproduction unit 114 Reproduction signal processing unit 115 Focusing control unit 116 Tracking control unit PL Semiconductor laser on / off signal during reproduction PA Address reproduction section signal PF Focus error (FE) signal detection section signal PT Tracking error (TE) signal detection Section signal 101C Cover layer 101G Groove 101L Land 201 Beam splitter 202 Objective lens 202B Recording / reproducing light beam 203 Signal generation matrix Width 204 RF module (HFM)
205 Laser drive circuit 206 Temperature sensor 207 Power detection signal amplifier 208 to 211 Sample hold circuit (S / H)
301, 302 Power supply 303 Current source (for reproduction power)
304 switch (for low extinction)
305 Recording current control unit 306,313 Amplifier 307,309,314,316 Current source (for amplifier)
308,315 switch (for power reduction)
311 switch (for S / H)
312 Capacitor (for S / H)
310 Timing adjustment unit (PL signal width adjustment)
401 optical disk drive unit 402 camera unit 403 video processing unit 404 video display unit 405 buffer memory 406 flash memory card 407 vibration / temperature detection unit 408 battery 409 external AV input / output unit 410 operation unit 411 video camera / system control unit

Claims (29)

A laser emitting unit that generates a laser beam for irradiating the optical disc;
A laser control unit for controlling the light emitting operation of the laser light emitting unit,
The laser control unit causes the laser light emitting unit to emit light at a first cycle during a first operation, and causes the laser light emitting unit to emit light at a second cycle during a second operation,
An optical disc device, wherein the first cycle and the second cycle are different from each other.   The optical disc according to claim 1, wherein a length of a section in which the laser light emitting unit emits light of at least one of the first cycle and the second cycle is different from a length of a section in which the laser light emitting unit does not emit light. apparatus.   3. The optical disk device according to claim 2, wherein a length of a section where the laser light emitting unit emits light is shorter than a length of a section where the laser light emitting unit does not emit light. The first operation is a read preparation operation for preparing to read information from the optical disc,
The optical disk device according to claim 1, wherein the second operation is a read operation for reading the information from the optical disk. The first operation is a first read preparation operation for preparing to read information from the optical disc,
The optical disk device according to claim 1, wherein the second operation is a second read preparation operation for preparing to read the information from the optical disk. The first operation is a first recording preparation operation for preparing to record information on the optical disc,
The optical disk device according to claim 1, wherein the second operation is a second recording preparation operation for preparing to record the information on the optical disk. The first operation executes focusing control and tracking control in a state where neither a read preparation operation for preparing to read information from the optical disk nor a read operation for reading the information from the optical disk is performed. Behavior
2. The optical disk device according to claim 1, wherein the second operation is an operation of executing focusing control and tracking control in a state where one of the read preparation operation and the read operation is being executed. 3.   2. The optical disk device according to claim 1, wherein each value of the first cycle and the second cycle is equal to or less than a value capable of maintaining focusing control and tracking control. 3.   The optical disc device according to claim 8, wherein each of the first cycle and the second cycle is 250 µs to 500 µs.   The laser control unit according to claim 1, wherein the laser control unit does not substantially apply a drive current to the laser light emitting unit during a period in which the laser light emitting unit does not emit light in each of the first cycle and the second cycle. Optical disk device.   The laser control unit applies a drive current of a value that does not cause the laser light emitting unit to emit light to the laser light emitting unit during a section in which the laser light emitting unit does not emit light in each of the first cycle and the second cycle. The optical disk device according to claim 1. A high-frequency module that reduces noise generated by light reflected from the optical disc,
2. The optical disk device according to claim 1, wherein the high-frequency module stops operating during a period in which the laser light emitting unit does not emit light. A high-frequency module that reduces noise generated by light reflected from the optical disc,
The high-frequency module stops operation during at least one of a read preparation operation for preparing to read information from the optical disk and a recording preparation operation for preparing to record information on the optical disk. 2. The optical disc device according to 1. An address reproducing unit that reads address information from a reproduction signal;
A reproduction signal processing unit for demodulating the reproduction signal;
A recording control unit that controls recording of information on the optical disc,
2. The optical disc device according to claim 1, wherein each of the address reproduction unit, the reproduction signal processing unit, and the recording control unit stops operating when idling. A light detection unit that generates a reproduction signal based on reflected light from the optical disc,
The optical disc device according to claim 1, further comprising: a signal generation unit that generates a focusing error signal and a tracking error signal by sampling and holding the reproduction signal.   The optical disc device according to claim 15, wherein the laser control unit and the signal generation unit are integrated in one semiconductor chip. An optical head unit including the laser emitting unit,
And a tracking control unit that performs tracking control.
2. The optical disk device according to claim 1, wherein the tracking control unit controls the optical head unit so that a focal point of the laser light is along the same track during idling. An optical head unit including the laser emitting unit,
And a tracking control unit that performs tracking control.
The optical disk device according to claim 1, wherein the tracking control unit stops operating when idling. The first operation is a read preparation operation for preparing to read address information from the optical disc,
The optical disk device according to claim 1, wherein the second operation is a read operation for reading the address information from the optical disk. The address information is recorded in advance on the optical disc by wobbling a guide groove provided in the optical disc,
20. The optical disc device according to claim 19, wherein the second cycle is shorter than a wobble cycle of the guide groove.   The optical disk device according to claim 1, wherein the laser control unit causes the laser light emitting unit to continuously emit light during a seek operation.   The optical disc device according to claim 1, wherein the laser control unit sets an emission cycle of the laser emission unit when the focusing control is performed shorter than an emission cycle of the laser emission unit when the focusing control is not performed. The apparatus further includes a vibration detection unit that performs at least one of detection and prediction of a vibration amount of the optical disc device,
The laser control unit, the light emission cycle of the laser light emitting unit when the vibration amount is equal to or more than a predetermined amount, shorter than the light emission cycle of the laser light emission unit when the vibration amount is less than a predetermined amount. Item 2. The optical disk device according to item 1. The apparatus further includes a vibration detection unit that performs at least one of detection and prediction of a vibration amount of the optical disc device,
The optical disk device according to claim 1, wherein the laser control unit causes the laser light emitting unit to continuously emit light when the vibration amount is equal to or more than a predetermined amount. Further comprising a temperature detection unit for detecting the temperature of the laser emitting unit,
The laser control unit determines an emission cycle of the laser emission unit when the temperature of the laser emission unit is lower than the operation guarantee temperature of the laser emission unit by a predetermined value or more. 2. The optical disk device according to claim 1, wherein the light emission period is shorter than a light emission period of the laser light emitting unit when the light emission period is not lower than the value.   The laser control unit is configured to set a light emitting cycle of the laser light emitting unit while waiting for execution of reading of information from the optical disc to be longer than a light emitting cycle of the laser light emitting unit during execution of the reading. The optical disk device according to claim 1, wherein:   The laser control unit, the emission cycle of the laser emission unit while waiting to execute the recording of information on the optical disk, longer than the emission cycle of the laser emission unit during the execution of the recording The optical disk device according to claim 1, wherein: A camera unit that generates image information indicating an image from incident light,
A display unit that displays an image indicated by the image information,
An optical disc driving unit that executes recording of the video information on the optical disc and reproduction of the video information recorded on the optical disc,
The optical disk drive,
A laser emitting unit that generates a laser beam for irradiating the optical disc,
A laser control unit for controlling the light emitting operation of the laser light emitting unit,
The laser control unit causes the laser light emitting unit to emit light at a first cycle during a first operation, and causes the laser light emitting unit to emit light at a second cycle during a second operation,
The camera device, wherein the first cycle and the second cycle are different from each other. A method for controlling a light emitting operation of a laser light emitting unit that generates laser light for irradiating an optical disc,
Causing the laser light emitting unit to emit light at a first cycle during a first operation;
Causing the laser light-emitting unit to emit light at a second cycle during a second operation;
The method, wherein the first period and the second period are different periods.

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