WO2005050800A1 - レーザ駆動装置、レーザ駆動装置を備えた光学ヘッドおよび光ディスク装置 - Google Patents
レーザ駆動装置、レーザ駆動装置を備えた光学ヘッドおよび光ディスク装置 Download PDFInfo
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- WO2005050800A1 WO2005050800A1 PCT/JP2004/016929 JP2004016929W WO2005050800A1 WO 2005050800 A1 WO2005050800 A1 WO 2005050800A1 JP 2004016929 W JP2004016929 W JP 2004016929W WO 2005050800 A1 WO2005050800 A1 WO 2005050800A1
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/125—Optical beam sources therefor, e.g. laser control circuitry specially adapted for optical storage devices; Modulators, e.g. means for controlling the size or intensity of optical spots or optical traces
- G11B7/126—Circuits, methods or arrangements for laser control or stabilisation
- G11B7/1263—Power control during transducing, e.g. by monitoring
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
- A61P31/04—Antibacterial agents
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/04—Processes or apparatus for excitation, e.g. pumping, e.g. by electron beams
- H01S5/042—Electrical excitation ; Circuits therefor
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
- H01S5/068—Stabilisation of laser output parameters
- H01S5/06804—Stabilisation of laser output parameters by monitoring an external parameter, e.g. temperature
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
- H01S5/068—Stabilisation of laser output parameters
- H01S5/06808—Stabilisation of laser output parameters by monitoring the electrical laser parameters, e.g. voltage or current
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
- H01S5/068—Stabilisation of laser output parameters
- H01S5/0683—Stabilisation of laser output parameters by monitoring the optical output parameters
- H01S5/06832—Stabilising during amplitude modulation
Definitions
- Laser drive device optical head provided with laser drive device, and optical disk device
- the present invention relates to a laser drive device for driving a semiconductor laser. More specifically, the present invention relates to a laser driving device for writing data on a recording medium such as an optical disk and reading the written data, and to an apparatus having such a laser driving device.
- An optical disk apparatus has an optical head, and supplies a current to a semiconductor laser mounted on the optical head to cause the semiconductor laser to emit light.
- the optical disk apparatus condenses weak reproduction light on the disk, and reads out information recorded as marks, pits and the like on the optical disk by reflectance, deflection angle and the like.
- the optical disk device causes the semiconductor laser to emit light with a large amount of light (high power) by supplying a larger current to the semiconductor laser than at the time of reproduction, and the material on the optical disk is physically By making a change, the information is recorded as a mark, a pit or the like, or the existing information is erased.
- FIG. 1 shows a general connection configuration for driving a semiconductor laser.
- the laser drive unit 2 supplies the current from the power supply 3 to the semiconductor laser 1.
- the semiconductor laser 1 emits light at a power corresponding to the magnitude of the current based on this current.
- the voltage required for the operation of the laser driving unit 2 is referred to as “operating voltage Vtr”, and the voltage required for the operation of the semiconductor laser 1 is referred to as “operating voltage Vop”.
- the operating voltage Vop is a voltage between the anode and the force sword necessary to cause the semiconductor laser 1 to emit light. In order for the semiconductor laser 1 to emit light, each voltage needs to satisfy the following relational expression. [0007] Vld V Vop + Vtr (Equation 1)
- the laser operating voltage Vop changes in accordance with the current (laser drive current) or the like supplied to the semiconductor laser.
- FIG. 2 is a graph showing a laser drive current laser emission power characteristic A (lop-P characteristic A) of a semiconductor laser and a laser drive current laser operating voltage characteristic B (lop-Vop characteristic B).
- Iop-P characteristic A the light emission power of the semiconductor laser changes in accordance with the laser drive current. Therefore, the semiconductor laser can be made to emit light with a desired power by controlling the value (lop) of the drive current.
- the laser operating voltage Vop changes from VopO to Vop2 in accordance with the laser drive current. Therefore, the voltage of the power supply for supplying power to the laser drive unit 2 is
- Patent Document 1 discloses a technique for switching the voltage supplied to the laser driving unit in stages according to the operating voltage of the laser.
- FIG. 3 shows a configuration of functional blocks of a conventional semiconductor laser drive device 300.
- the power setting unit 306 outputs the setting instruction signal b based on the user's instruction.
- the setting instruction signal b is variable depending on, for example, whether it operates in the! /, Shift mode of recording or reproduction of information.
- the laser drive unit 302 supplies a drive current to the semiconductor laser 301 based on the value (instruction value) output from the laser power control unit 307.
- the photodetector 303 is configured to receive the power of the received light, that is, the emission power of the semiconductor laser 301. Outputs a current of the corresponding size.
- the current-voltage converter 304 converts the output current of the photodetector 303 into a voltage signal.
- a light emission power detection unit 305 is configured by the light detector 303 and the current-voltage converter 304, and the light emission power detection unit 305 outputs a power detection signal a indicating the light emission power of the semiconductor laser 301.
- the laser power control unit 307 controls an instruction value to the laser drive unit 302 so that the power detection signal a and the reference voltage signal b become equal. As a result, the amount of current of the laser drive current supplied to the semiconductor laser 301 by the laser drive unit 302 can be controlled, and the light emission power information of the semiconductor laser 301 can be appropriately controlled for reproduction and recording.
- the operating voltage detection unit 308 detects the operating voltage value Vop of the semiconductor laser 301 and sends it to the voltage selection unit 309.
- the voltage selection unit 309 selects the voltage Vc to be supplied to the laser drive unit 302 in accordance with the voltage value of the laser operating voltage Vop detected by the operating voltage detection unit 308, and sends the result to the voltage control unit 310.
- the voltage control unit 310 is constituted by, for example, a DC / DC comparator, and supplies the selected voltage Vc to the laser drive unit 302.
- FIG. 4 shows the determination procedure of the conventional voltage selection process.
- step S41 the voltage selection unit 309 compares the current operating voltage Vop with the first voltage Vop1. As a result of comparison, when the operating voltage Vop is higher than the predetermined voltage Vopl, the process proceeds to step S42, and when the operating voltage Vop is higher than the predetermined voltage Vopl, the process proceeds to step 43.
- Patent Document 1 Japanese Patent Laid-Open Publication No. 2000-244052
- the conventional configuration requires a dedicated component (such as the operating voltage detection unit 308 in FIG. 3) for detecting the operating voltage of the semiconductor laser, which increases the cost.
- a dedicated component such as the operating voltage detection unit 308 in FIG. 3
- the optical head on which the semiconductor laser is mounted There is a limit to miniaturization, because space for installing various components is required.
- An object of the present invention is to provide a semiconductor laser drive device capable of reducing unnecessary power consumption without requiring a dedicated component.
- a laser drive device supplies a drive voltage for emitting a laser, a laser drive unit, a temperature detection unit for detecting the temperature of the laser, and a power supply voltage to the laser drive unit. And a voltage control unit for changing and outputting the voltage value of the power supply voltage according to the temperature detected by the temperature detection unit.
- the laser drive device controls power to cause the laser to emit light with a predetermined light emission power by controlling a command value to the laser drive unit and adjusting a drive current supplied from the laser drive unit. Even equipped with a part.
- the laser drive device may further include a setting unit configured to instruct setting of a reference voltage according to an amount of light that causes the laser to emit light.
- the laser drive device further includes a light emission power detection unit that detects a value corresponding to the light emission power of the laser and outputs a signal corresponding to the value.
- the power control unit controls an instruction value to the laser drive unit based on the voltage of the signal output from the light emission power detection unit and the reference voltage, and the voltage of the signal matches the reference voltage. You may
- the voltage control unit may determine a voltage value of the power supply voltage based on the drive current and the characteristic.
- the operating voltage is low when the temperature is low, and the voltage control unit is high when the temperature is low. So high, you may supply the power supply voltage.
- the laser drive unit may output a drive current for emitting a laser included in the range of wavelength power OO nm to 430 nm.
- the optical head according to the present invention is used to write and read data or read data from and to the information recording surface of a recording medium.
- the optical head includes a laser, a laser driving device for supplying a driving current for emitting the laser, an objective lens for condensing light from the laser on the information recording surface, and reflection by the information recording surface. And a light receiving unit for receiving a light and outputting a signal according to the light amount.
- the laser driving device is a temperature detection unit that detects the temperature of the laser, and a voltage control unit that supplies a power supply voltage to the laser drive unit, and the temperature control unit responds to the temperature detected by the temperature detection unit. And a voltage control unit for changing and outputting the voltage value of the power supply voltage.
- the optical disk apparatus is used to write data and write data to or read data from the information recording surface of the optical disk.
- the optical disk apparatus emits light to the optical disk and generates and outputs a servo signal based on the reflected light from the information recording surface, and the servo signal output from the optical head.
- a control signal generation unit for generating a control signal for controlling the focal position of the light; and a drive circuit for generating a drive signal based on the control signal! /.
- the optical head comprises a laser, a laser driving device for supplying a driving current for emitting the laser, an objective lens for condensing light from the laser on the information recording surface, and the driving signal.
- the optical system further includes an actuator for adjusting the position of the objective lens, and a light receiving unit for receiving a light reflected by the information recording surface and outputting a signal according to the amount of light.
- the laser driving device is a temperature detection unit that detects the temperature of the laser, and a voltage control unit that supplies a power supply voltage to the laser drive unit, and is detected by the temperature detection unit. And a voltage control unit for changing and outputting the voltage value of the power supply voltage in accordance with the temperature.
- a laser driving method comprises the steps of: supplying a driving current for emitting a laser; detecting a temperature of the laser; and supplying a driving current. Supplying a voltage to the detected temperature And changing the voltage value of the power supply voltage in response.
- a driving device of a semiconductor laser capable of suppressing the consumption of power without requiring any new component.
- energy saving can be achieved, and further, temperature rise can be suppressed.
- an optical disk device or the like which writes and reads data to and from an optical disk by using a blue-violet laser beam is suitable.
- a portable type in which suppression of temperature rise of the device and power saving are strictly required. It is suitable for equipment (portable optical disc device etc.).
- FIG. 1 shows a general connection configuration for driving a semiconductor laser.
- FIG. 2 is a graph showing a laser drive current of a semiconductor laser, a laser emission power characteristic A (lop-P characteristic A), and a laser drive current a laser operating voltage characteristic B (lop-Vop characteristic B).
- FIG. 3 A diagram showing a configuration of functional blocks of a conventional semiconductor laser drive device 300.
- FIG. 4 is a diagram showing a determination procedure of conventional voltage selection processing.
- FIG. 5 is a diagram showing the configuration of functional blocks of an optical disc apparatus 50 according to an embodiment of the present invention.
- FIG. 6 is a diagram showing the configuration of functional blocks of a laser drive device 10 according to an embodiment of the present invention.
- FIG. 7 is a diagram showing the configuration of functional blocks of a laser power control unit 12;
- FIG. 8 is a graph showing the laser driving current and the laser operating voltage characteristic (I op-Vop characteristic) according to the temperature of the blue-violet semiconductor laser.
- FIG. 9 A diagram showing a circuit configuration of a temperature detection unit 21 and a voltage control unit 22.
- FIG. 10 (a) is a graph showing the temperature characteristic of the resistance value Rth of the thermistor 21. (b) is a graph showing the temperature characteristic of the output voltage of the voltage control unit 22.
- FIG. 11 is a view showing the configuration of a laser drive unit 20.
- FIG. 12 is a flow chart showing the procedure of processing of the optical disk device 50.
- FIG. 5 shows a configuration of functional blocks of the optical disc apparatus 50 according to the present embodiment.
- the optical disc device 50 can write and read data to and from the optical disc 60.
- the optical disk device 50 is, for example, a portable video reproduction device for reproducing a movie recorded on an optical disk, or a camcorder for recording video and audio on an optical disk.
- a BD Blu-Ray Disc
- the present invention can be applied to an optical information recording medium such as a card capable of reading and writing data optically, for example, in addition to the power described with reference to an optical disc.
- the optical disk device 50 includes an optical head 52, a control signal generation unit 54, a drive circuit 56, and a reproduction processing unit 58.
- the optical head 52 has an optical system that emits a laser beam to the optical disc 60 and receives the reflected light.
- the optical head 52 changes the focal position of the light in the radial and vertical directions of the optical disk 60 to perform control for accurately positioning the optical disk 60 on the track. Then, while the control is being performed, data is written and read or read from the optical disc 60.
- the configuration of the optical head 52 will be described in detail later. It should be noted that the force of describing the optical disc 60 in FIG. 5 is for convenience of explanation and is not a component of the optical disc apparatus 50.
- the optical disc 60 is loaded into the optical disc drive 50 and taken out of the optical disc drive 50.
- the control signal generation unit 54 detects the light spot of the laser light and the optical disc based on servo signals such as a tracking error signal (TE signal) and a focus error signal (FE signal) output from the optical head 52, for example. It generates control signals to control the positional relationship between the 60 tracks in the radial and vertical directions.
- the control signal output from the control signal generation unit 54 is provided to the drive circuit 56.
- the drive circuit 56 generates a drive signal based on the received control signal, and applies it to a transfer stage (not shown) of the actuator 5 or the optical head 52 described later. These respectively adjust the positional relationship between the light spot of the laser beam and the track of the optical disk 60 by moving the objective lens 4 or the entire optical head 52 in the radial and vertical directions of the optical disk 60.
- the reproduction processing unit 58 performs predetermined reproduction processing on the reflected light from the optical disc 60 when servo control such as focus control and tracking control is stably performed, and an image to be reproduced and an image to be reproduced Output each
- the optical head 52 includes a semiconductor laser 1, a beam splitter 2, a collimator lens 3, an objective lens 4, an actuator 5, a diffraction element 6, light receiving sections 7 and 19, a current-voltage converter 8, and a signal. It has a processing unit 9, a laser driving device 10, and a condenser lens 18.
- the semiconductor laser 1 is, for example, a light source that outputs blue-violet laser light having a wavelength of 405 nm.
- the value of this wavelength may not be exact, for example in the range of 400 nm to 415 nm, or in the range of 400 nm power 430 nm! 405 person more preferred if it is in the 5nm range!
- the beam splitter 2 transmits part of the light and reflects the rest.
- Collimator lens 3 is , The light from the semiconductor laser 1 is converted into parallel light.
- the objective lens 4 focuses laser light emitted from the semiconductor laser 1 and forms a focus at a predetermined distance.
- the diffractive element 6 receives the light reflected from the optical disc 60 and diffracts a part of the light by a predetermined diffraction area.
- the light receiving unit 7 has a plurality of light receiving areas, and each of the light receiving areas outputs a photocurrent having a magnitude corresponding to the amount of light received.
- the signal processing unit 9 generates a tracking error signal (TE signal), a focus error signal (FE signal), a reproduction signal and the like based on the photocurrent.
- the TE signal represents the deviation between the light spot position of the laser beam and the desired track of the optical disk 60 in the radial direction of the optical disk 60.
- the FE signal represents the deviation between the light spot position of the laser beam and the information recording surface of the optical disc 60 in the vertical direction of the optical disc 60.
- a part of the light emitted from the semiconductor laser 1 is incident on the condenser lens 18 to make the light receiving portion 19 emit a light beam ⁇ .
- the light receiver 19 outputs a photocurrent having a magnitude corresponding to the amount of light received.
- the current-voltage converter 8 converts the photocurrent output from the light receiving unit 19 into a voltage, and outputs the voltage as a power detection signal a.
- the light reflected by the optical disc 60 passes through the objective lens 4 and the collimator lens 3 again and enters the beam splitter 2.
- the light reflected by the beam splitter 2 is incident on the diffraction element 6, where a plurality of lights are obtained by diffraction.
- Each light receiving area of the light receiving section 7 receives the light divided by the diffraction element 6.
- Each light receiving area outputs a photocurrent according to the amount of light received.
- the photocurrent output from the light receiving unit 7 is sent to the signal processing unit 9.
- the signal processing unit 9 generates a TE signal and an FE signal based on the photocurrent.
- a control signal is generated in the control signal generation unit 54 based on the TE signal and the FE signal, and tracking control and focus control are realized. It is to be noted that how to generate the FE signal and the TE signal and to adjust the positions of the objective lens 4 and the optical head 52 based on these signals is well known, and the explanation thereof is here I omit it.
- part of the light emitted from the semiconductor laser 1 is reflected by the beam splitter 2, is incident on the condensing lens 18, and is condensed on the light receiving unit 19 by the condensing lens 18.
- the photocurrent output from the light receiver 19 is sent to the current voltage converter 8.
- the photocurrent is converted into a voltage in the current-voltage converter 8 and sent to the laser drive unit 10, which controls the amount of current and voltage to be supplied to the semiconductor laser 1 based on the amount of light.
- FIG. 6 shows the configuration of functional blocks of the laser drive device 10 according to the present embodiment.
- the light receiving unit 19 and the current / voltage converter 8 are collectively shown as a light emission power detection unit 24.
- the laser drive device 10 includes a power setting unit 11, a laser power control unit 12, a laser drive unit 20, a temperature detection unit 21, and a voltage control unit 22.
- the laser drive unit 20 supplies a drive current to the semiconductor laser 1 based on the value (instruction value) output from the laser power control unit 12. Therefore, the components related to the laser power control unit 12 will be described, and then the components related to the voltage control unit 22 will be described.
- the laser power control unit 12 receives the setting instruction signal b from the power setting unit 11.
- the setting instruction signal b is output based on an instruction of the user's power or the like.
- the setting instruction signal b instructs the setting of the power corresponding to the operation (recording operation or reproduction operation) selected by the user (reference Voltage).
- the setting instruction signal b sets the power corresponding to the reproduction operation (normal reproduction operation, fast forward reproduction operation, etc.) selected by the user. Includes instructions (reference voltage).
- FIG. 7 shows the configuration of functional patterns of the power setting unit 11 and the laser power control unit 12.
- the power setting unit 11 includes a first reference voltage source 121 a and a second reference voltage source 121 b, and a switch 122.
- the first reference voltage source 121a and the second reference voltage source 12 lb are each a voltage source capable of providing a reference voltage for obtaining, for example, light emission power necessary for recording and reproduction of information on the optical disc 60.
- Switch 122 is written Connect either voltage source to the differential amplifier 123 depending on recording or playback!
- the laser power control unit 12 has a differential amplifier 123, and the differential amplifier 123 is connected to the current-voltage converter 8 and receives a power detection signal a represented by a voltage value.
- the differential amplifier 123 is connected to one of the first reference voltage source 121a and the second reference voltage source 121b to receive a reference voltage as a reference of operation.
- Differential amplifier 123 receives a voltage corresponding to power detection signal a and a reference voltage from a voltage source in power setting unit 11 corresponding to setting instruction signal b, and the difference is calculated and amplified. Then, it is output as a voltage signal Vk and sent to the laser drive unit 20.
- the voltage signal Vk is used as a voltage for adjusting the drive current supplied to the semiconductor laser 1 by the laser drive unit 20. That is, it can be said that the laser power control unit 12 controls the current amount (current value) of the drive current for emitting the semiconductor laser 1.
- the laser power control unit 12 Since the power detection signal a is always sent to the laser power control unit 12 and power control based on the no detection signal a is performed while the semiconductor laser 1 is emitting light, the laser power control unit 12 It operates to match the detection signal a with the reference voltage signal. As a result, the amount of current of the drive current supplied to the semiconductor laser 1 by the laser drive unit 20 can be controlled (adjusted), and the light emission power of the semiconductor laser 1 can be appropriately controlled to have the intensity necessary for operation. Be done.
- the configuration of the laser power control unit 12 shown in FIG. 7 is an example, and the present invention is not limited to this mode.
- the temperature detection unit 21 detects the ambient temperature of the semiconductor laser 1 and provides information corresponding to the detected temperature to the voltage control unit 22. As described later, in the present embodiment, the temperature detection unit 21 is a thermistor. Since the resistance value of the thermistor changes according to the temperature, the change of the resistance value is information provided to the voltage control unit 22. In FIG. 6, the temperature detection unit 21 is disposed apart from the semiconductor laser 1. This is for the convenience of description. The temperature detection unit 21 is disposed, for example, in the vicinity of the package of the semiconductor laser 1.
- the temperature detection unit 21 plays a main role in driving the semiconductor laser 1.
- the temperature detection unit 21 does not have to be a dedicated component for implementing the present invention.
- General equipment using a semiconductor laser such as an optical head
- an element for detecting temperature is already mounted for other purposes as exemplified below. Therefore, it can be said that the temperature detection unit 21 according to the present embodiment uses the components of the optical head that already exist. Therefore, the temperature detection unit 21 does not necessarily have to be provided in the laser drive device 10.
- the laser drive device 10 does not necessarily have to include the temperature detection unit 21 as its component.
- the temperature detection unit 21 may be provided in the optical head 52.
- thermoelectric detection element is mounted on the optical head. That is, since the semiconductor laser may be destroyed or degraded in high temperature operation, it is necessary to stop the reproduction or recording operation at high temperature. Therefore, a temperature detection element is provided and used to detect and protect the ambient temperature of the semiconductor laser.
- the light emission power optimum for reproducing or recording information and the optimum recording strategy for laser light generally differ depending on the temperature. Therefore, a temperature detection element is provided and used to correct the light emission power or the recording strategy according to the detected temperature (for example, Japanese Patent Laid-Open Publication No. 7-182721 or Japanese Patent Laid-Open Publication No. 2 001-297437).
- the voltage control unit 22 supplies the power supply voltage Vc to the laser drive unit 2.
- the power supply voltage Vc is a power supply necessary to drive the laser drive unit 20 and the semiconductor laser 1. More specifically, the voltage control unit 22 adaptively changes the voltage Vc supplied to the laser drive unit 2 in accordance with the temperature detected by the temperature detection unit 21.
- the voltage control unit 22 controls to raise the voltage Vc when the temperature is relatively low, and controls to decrease the voltage Vc when the temperature is relatively high.
- FIG. 8 is a graph showing the laser drive current laser operating voltage characteristics (lop-Vop characteristics) according to the temperature of the blue-violet semiconductor laser.
- the operating voltage of the semiconductor laser is It depends largely on the temperature.
- the laser operating voltage (Vop) when the temperature in the package of the semiconductor laser is relatively high (for example, at about 40 ° C.), the laser operating voltage (Vop) is relatively low and falls below the value (VopH) .
- the temperature in the package of the semiconductor laser is relatively low (for example, at about 20 ° C.)
- the laser operating voltage rapidly increases and its value becomes larger than the previous value of VopH.
- the laser drive current and laser light emission power characteristic A (lop-P characteristic A) of FIG. 2 when the light emission power (P) of the semiconductor laser 1 is specified, the drive current (lop) giving the power is specified. Ru.
- the value of the operating voltage (Vop) for obtaining the drive current (lop) differs depending on the temperature of the semiconductor laser 1.
- the voltage control unit 22 operates as follows according to the temperature detected by the temperature detection unit 21. That is, at high temperatures, the voltage control unit 22
- Vc VopH + Vtr (equation 3)
- the output voltage Vc is controlled such that the voltage Vc obtained as is supplied to the laser drive unit 2.
- Vtr is a voltage required for the operation of the laser drive unit 2.
- Vc VopL + Vtr (Expression 4)
- the output voltage Vc is controlled such that the voltage Vc obtained as is supplied to the laser drive unit 2.
- the value of the output voltage Vc of the voltage control unit 22 is controlled in two steps of the operating voltage VopH shown in the equation 3 and the operating voltage Vop L shown in the equation 4.
- the two stages are examples, and may be more, or the value of the output voltage Vc may be controlled steplessly according to the temperature.
- the operating voltage at each temperature of the semiconductor laser 1 may be sampled in advance and held in a table or the like for each size of the required driving current (lop). If the magnitude of the drive current (lop) and the temperature of the semiconductor laser 1 at that time are specified, The operating voltage (Vop) can be obtained by referring to the table. Substituting the value into VopL of Equation 3 (or VopH of Equation 4), the voltage Vc at that time is identified.
- the temperature detection unit 21 need not be provided exclusively on the optical head 52, power saving can be realized without the need for new components.
- the temperature described above is assumed to be the temperature in the package of the semiconductor laser, and the temperature may change according to the temperature of the surrounding environment in which the package is disposed.
- the temperature of the package is equal to room temperature under an environment where the drive device is not operating, for example, immediately after activation of the drive device.
- the temperature of the package is further raised by about 10 to 20 degrees with respect to the room temperature. Therefore, the difference between the in-package temperature immediately after start-up and the in-package temperature after a lapse of a predetermined time or more may sufficiently be about 20 degrees.
- FIG. 9 shows a circuit configuration of the temperature detection unit 21 and the voltage control unit 22.
- the temperature detection unit 21 so far is described as “thermistor 21”.
- voltage control unit 22 has power supply 31 and resistors 32 and 33.
- the resistor 32 is connected in parallel with the thermistor 21.
- One end of each of the resistor 32 and the thermistor 21 is
- the other end of the resistor 33 is connected to the power supply 31 (voltage value Vcc).
- FIG. 10 (a) shows the temperature characteristic of the resistance value Rth of the thermistor 21.
- the resistance value Rth increases as the temperature decreases, and the resistance value Rth decreases as the temperature increases.
- FIG. 10 (b) shows the temperature characteristic of the output voltage of the voltage control unit 22.
- the resistance value of the resistor 33 is represented as R33 or the like, and the magnitude of the current flowing through the resistor 33 is represented as I, the output voltage Vc of the voltage control unit 22 is
- Vc (R32 // Rtho) / [(R32 // Rtho) + R33] ⁇ I (Equation 5)
- FIG. 11 shows the configuration of the laser driving unit 20.
- the laser driver 20 can be realized as a transistor.
- the collector terminal of the transistor 20 is connected to the voltage control unit 22 and its output voltage Vc is applied.
- the base terminal of the transistor 20 is connected to the laser power control unit 12 and its output voltage Vk is applied.
- the emitter terminal of the transistor 20 is connected to the anode terminal of the semiconductor laser 1.
- VBE is the voltage between the base and the emitter
- z is the impedance of the laser. According to Equation 6, it is understood that the current lop is controlled by the output voltage Vk of the laser power control unit 12 and not controlled by the output voltage Vc of the voltage control unit 22.
- a method of detecting the temperature around the semiconductor laser 1 and changing the voltage Vk in the power setting unit 11 and the laser power control unit 12 is also conceivable.
- This method is effective for adjusting the voltage Vk applied to the base terminal of the laser drive unit 20 and the drive current determined according to the voltage.
- the voltage Vc since the voltage Vc is applied to the collector terminal of the laser drive unit 20, the voltage Vc is independent of the voltage Vk. Therefore, adjusting the voltage Vc to the lowest limit operating does not change the advantage in terms of power consumption.
- the laser driving unit 20 is not limited to a transistor, as long as the component can control the current supplied to the semiconductor laser 1 according to the output value of the laser power control unit 20.
- FIG. 12 shows the procedure of processing of the optical disk device 50.
- the power setting unit 11 receives an instruction from the user etc. on the reproduction mode such as the normal reproduction mode and the fast forward reproduction mode.
- the power setting unit 11 determines a drive current to be supplied to the semiconductor laser according to the reproduction mode, and outputs a setting instruction for obtaining the drive current.
- the laser power control unit 12 outputs a voltage Vk for providing a drive current based on the setting instruction signal b.
- the temperature detection unit 21 detects the ambient temperature of the semiconductor laser 1 in step S124
- the voltage control unit 22 outputs a voltage Vc according to the ambient temperature in step S125. This voltage is a voltage sufficient for the semiconductor laser 1 to emit light, and is not excessively applied.
- step S 126 when the laser drive current determined based on the voltage Vk flows through the semiconductor laser 1, the semiconductor laser 1 emits light.
- step S127 it is determined whether or not the laser driving device 10 has received a predetermined time. If the predetermined time has elapsed, the process returns to step S124, and the temperature around the semiconductor laser 1 is detected. If the predetermined time has not elapsed, the process proceeds to step S128.
- the reason for defining step S127 is to perform laser drive control more flexibly.
- the “predetermined time” means the timing at which the temperature detection unit 21 detects the temperature, and may not necessarily be a fixed value. For example, if it is within 5 minutes after the start of the operation of the optical disc apparatus 50, the "predetermined time” can be set every 1 minute, and after 5 minutes after the operation start, the “predetermined time” can be set every 5 minutes. Since the temperature starts to rise immediately after the start of operation, the temperature of the semiconductor laser 1 is detected relatively frequently. On the other hand, since it is considered that the change in temperature generally converges about 5 minutes after the start of operation, the temperature of the semiconductor laser 1 may be detected relatively infrequently thereafter.
- step S1208 it is determined in the laser drive device 10 whether or not the reproduction is completed.
- the process returns to step S 126, and the laser drive unit 20 continues the flow of the drive current to the semiconductor laser 1.
- the drive current is shut off to stop the light emission of the semiconductor laser 1 and the process is completed.
- the determination in step S128 can be made based on, for example, whether or not the power setting unit 11 is instructed to stop the supply of power or the like.
- the laser drive device 10 can use the voltage necessary for driving the semiconductor laser 1 without excess or deficiency. Therefore, an extremely effective power saving function can be provided in the optical head 52 having the laser driving device 10 and the optical disc device 50 on which the optical head 52 is mounted. It is preferable to apply this power saving function to, in particular, a portable optical disk apparatus etc. which has limited usable power.
- the temperature sensor etc. generally mounted on the optical head Since it is used as the degree detection unit 21, both low temperature laser light emission and high power saving can be achieved without requiring new components.
- the configuration according to the present embodiment in which the output voltage Vc of the voltage control unit 22 is controlled using the temperature detection unit 21 is particularly effective in a laser driving device using a blue-violet laser.
- the first reason is that the fluctuation of the laser operating voltage of the blue-violet laser is reduced if the voltage Vc is controlled according to the change of the laser operating voltage due to the temperature whose influence of the temperature is extremely large as shown in FIG. It is because the effect to power is large.
- the blue-violet laser requires a larger band gap for laser emission than a red laser or the like, the laser operating voltage is higher. Therefore, the power consumption of the blue-violet laser tends to increase as compared with the red laser, and the requirements for power saving and temperature rise of the device (especially at high temperature) are larger than those for the red laser.
- the power setting unit 11 and the laser power control unit 12 are provided in the laser drive device 10. However, these may be provided outside the laser drive device 10. For example, these may be provided in the optical head 52 outside the laser drive device 10 or in the optical disk device 50 outside the optical head 52.
- the present invention is not limited to this.
- An IC chip may be used, or a programmable power supply may be used as a voltage control unit.
- the present embodiment shows an example in which the power sword terminal of the semiconductor laser is grounded, the same effect can be obtained even when the anode terminal is connected to the power supply. It goes without saying that
- a driving device of a semiconductor laser capable of suppressing the consumption of power without requiring a new component.
- energy saving can be achieved, and further, temperature rise can be suppressed.
- an optical disk device or the like which writes and reads data to and from an optical disk using a blue-violet laser beam is preferable, and in particular, the temperature rise of the device Portable equipment (portable optical disc device etc.) ⁇ Z suitable for which suppression of energy consumption and power saving are strictly required.
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Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/595,693 US20090040904A1 (en) | 2003-11-18 | 2004-11-15 | Laser Driving Device, Optical Head Incorporating Laser Driving Device, and Optical Disk Apparatus |
JP2005515598A JPWO2005050800A1 (ja) | 2003-11-18 | 2004-11-15 | レーザ駆動装置、レーザ駆動装置を備えた光学ヘッドおよび光ディスク装置 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2003-387889 | 2003-11-18 | ||
JP2003387889 | 2003-11-18 |
Publications (1)
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WO2005050800A1 true WO2005050800A1 (ja) | 2005-06-02 |
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2004/016929 WO2005050800A1 (ja) | 2003-11-18 | 2004-11-15 | レーザ駆動装置、レーザ駆動装置を備えた光学ヘッドおよび光ディスク装置 |
Country Status (5)
Country | Link |
---|---|
US (1) | US20090040904A1 (ja) |
JP (1) | JPWO2005050800A1 (ja) |
CN (1) | CN100452581C (ja) |
TW (1) | TWI319571B (ja) |
WO (1) | WO2005050800A1 (ja) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2007058981A (ja) * | 2005-08-24 | 2007-03-08 | Pioneer Electronic Corp | レーザ駆動装置、情報記録装置及び情報再生装置 |
JP2007334972A (ja) * | 2006-06-14 | 2007-12-27 | Hitachi Ltd | 光ディスク装置、および、情報記録方法 |
JP2008159909A (ja) * | 2006-12-25 | 2008-07-10 | Sumitomo Electric Ind Ltd | 半導体レーザ駆動回路 |
WO2021199918A1 (ja) * | 2020-03-31 | 2021-10-07 | ソニーセミコンダクタソリューションズ株式会社 | 駆動装置、発光装置、および駆動方法 |
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US11079432B2 (en) * | 2019-02-19 | 2021-08-03 | Nxp B.V. | Integrated laser voltage probe pad for measuring DC or low frequency AC electrical parameters with laser based optical probing techniques |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH02109384A (ja) * | 1988-10-18 | 1990-04-23 | Mitsubishi Electric Corp | 半導体レーザの光出力安定化装置 |
JPH09260720A (ja) * | 1996-03-19 | 1997-10-03 | Nec Corp | 高速apc回路 |
JP2000244053A (ja) * | 1999-02-19 | 2000-09-08 | Fujitsu Ltd | 光出力制御回路 |
JP2001084627A (ja) * | 1999-09-10 | 2001-03-30 | Toshiba Corp | 光ディスク装置と半導体レーザ発振器の制御方法 |
JP2002141617A (ja) * | 2000-11-07 | 2002-05-17 | Sharp Corp | 窒化物半導体発光素子とそれを含む光学装置 |
JP2002217836A (ja) * | 2001-01-15 | 2002-08-02 | Oki Electric Ind Co Ltd | レーザダイオード駆動回路及び光送信システム |
JP2002251735A (ja) * | 2001-02-23 | 2002-09-06 | Matsushita Electric Ind Co Ltd | 光ディスク記録装置 |
JP2003017801A (ja) * | 2001-07-03 | 2003-01-17 | Ricoh Co Ltd | 半導体レーザ制御装置 |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63153455A (ja) * | 1986-12-18 | 1988-06-25 | Yokogawa Electric Corp | 光デイスクテストシステム |
JPH07240554A (ja) * | 1994-02-28 | 1995-09-12 | Fujitsu Ltd | 半導体レーザ駆動装置 |
US6496525B1 (en) * | 1998-09-21 | 2002-12-17 | Matsushita Electric Industrial Co., Ltd. | Laser driver and optical transceiver |
JP2000244052A (ja) * | 1999-02-18 | 2000-09-08 | Sharp Corp | 半導体レーザ駆動装置 |
JP2001216672A (ja) * | 2000-02-02 | 2001-08-10 | Yamaha Corp | レーザ発光体の温度検出装置および発光装置 |
JP2002150590A (ja) * | 2000-11-10 | 2002-05-24 | Pioneer Electronic Corp | 光学式記録媒体による記録装置及び方法 |
JP2002158395A (ja) * | 2000-11-17 | 2002-05-31 | Sony Corp | 半導体レーザのレーザパワー制御方法及び制御装置並びに光磁気記録媒体の記録再生方法及び記録再生装置並びに光記録媒体の記録再生方法及び記録再生装置 |
JP3724377B2 (ja) * | 2001-03-01 | 2005-12-07 | ソニー株式会社 | レーザ駆動方法及び装置、並びに記録再生装置及び方法 |
JP2003067962A (ja) * | 2001-08-27 | 2003-03-07 | Victor Co Of Japan Ltd | 光記録再生装置 |
JP2003168232A (ja) * | 2001-11-29 | 2003-06-13 | Toshiba Corp | 光ディスクドライブ及びレーザ光駆動電源電圧制御方法 |
JP2003242642A (ja) * | 2002-02-13 | 2003-08-29 | Sanyo Electric Co Ltd | 光ディスク記録再生装置 |
JP2004193376A (ja) * | 2002-12-12 | 2004-07-08 | Fuji Xerox Co Ltd | 発光素子駆動装置 |
-
2004
- 2004-11-15 JP JP2005515598A patent/JPWO2005050800A1/ja active Pending
- 2004-11-15 US US10/595,693 patent/US20090040904A1/en not_active Abandoned
- 2004-11-15 CN CNB2004800340370A patent/CN100452581C/zh not_active Expired - Fee Related
- 2004-11-15 WO PCT/JP2004/016929 patent/WO2005050800A1/ja active Application Filing
- 2004-11-17 TW TW093135222A patent/TWI319571B/zh not_active IP Right Cessation
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH02109384A (ja) * | 1988-10-18 | 1990-04-23 | Mitsubishi Electric Corp | 半導体レーザの光出力安定化装置 |
JPH09260720A (ja) * | 1996-03-19 | 1997-10-03 | Nec Corp | 高速apc回路 |
JP2000244053A (ja) * | 1999-02-19 | 2000-09-08 | Fujitsu Ltd | 光出力制御回路 |
JP2001084627A (ja) * | 1999-09-10 | 2001-03-30 | Toshiba Corp | 光ディスク装置と半導体レーザ発振器の制御方法 |
JP2002141617A (ja) * | 2000-11-07 | 2002-05-17 | Sharp Corp | 窒化物半導体発光素子とそれを含む光学装置 |
JP2002217836A (ja) * | 2001-01-15 | 2002-08-02 | Oki Electric Ind Co Ltd | レーザダイオード駆動回路及び光送信システム |
JP2002251735A (ja) * | 2001-02-23 | 2002-09-06 | Matsushita Electric Ind Co Ltd | 光ディスク記録装置 |
JP2003017801A (ja) * | 2001-07-03 | 2003-01-17 | Ricoh Co Ltd | 半導体レーザ制御装置 |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007058981A (ja) * | 2005-08-24 | 2007-03-08 | Pioneer Electronic Corp | レーザ駆動装置、情報記録装置及び情報再生装置 |
JP2007334972A (ja) * | 2006-06-14 | 2007-12-27 | Hitachi Ltd | 光ディスク装置、および、情報記録方法 |
JP4736967B2 (ja) * | 2006-06-14 | 2011-07-27 | 株式会社日立製作所 | 光ディスク装置、および、情報記録方法 |
JP2008159909A (ja) * | 2006-12-25 | 2008-07-10 | Sumitomo Electric Ind Ltd | 半導体レーザ駆動回路 |
WO2021199918A1 (ja) * | 2020-03-31 | 2021-10-07 | ソニーセミコンダクタソリューションズ株式会社 | 駆動装置、発光装置、および駆動方法 |
Also Published As
Publication number | Publication date |
---|---|
CN100452581C (zh) | 2009-01-14 |
TWI319571B (en) | 2010-01-11 |
US20090040904A1 (en) | 2009-02-12 |
JPWO2005050800A1 (ja) | 2007-12-06 |
CN1883090A (zh) | 2006-12-20 |
TW200522022A (en) | 2005-07-01 |
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