KR100633198B1 - Method for self-detecting temperature of optical driver and method for controlling of optical driver - Google Patents

Abstract

The present invention utilizes an automatic power control (APC) circuit in the R / F to self-detect the temperature of the optical device, and thus to optimally set the servo and operating state values of the device. A temperature detection method and a control method according thereto, comprising: detecting, in an optical device, a recording power voltage output corresponding to an input voltage of an automatic power control unit; Confirming a temperature corresponding to the detected recording power voltage from correlation information between previously stored output voltage and temperature; And reading out the pre-stored control information corresponding to the checked temperature and performing a control operation according to the temperature. Thus, the temperature and the volume of the device can be self-detected without a separate component such as a thermistor. It is a very useful invention that the optimum operation for the temperature condition of the device is achieved by setting the servo gain and the recording related values optimally according to the temperature of the self-detected device.

Temperature, APC, Target Beta, Write Strategy, OPC

Description

Method for self-detecting temperature of optical driver and method for controlling of optical driver             

1 illustrates a configuration of an optical system of an optical apparatus in which a self-temperature detecting method according to the present invention is implemented,

FIG. 2 illustrates the characteristics of the manufacturer of grease applied to the stepping motor and temperature (viscosity) according to temperature.

3 is a graph showing the output voltage of the APC circuit for each temperature detected through the experiment,

Figure 4 shows the APC circuit output voltage for each temperature detected through the experiment in the form of a table,

5 and 6 illustrate an operation flow of an embodiment of a temperature detection method and a control method according to the optical device according to the present invention,

Figure 7 shows an example of adjustment to tracking, focus, sled, and spindle servo gain depending on the temperature of the device.

※ Explanation of code for main part of drawing

10: optical disk 20: APC circuit

21: Gain & Sample / Holder 22: OP Amplifier

30: optical pickup 31: LD driver

32: FPD 40: VWDC Detector

50: microcomputer 51: memory

The present invention utilizes an automatic power control (APC) circuit in the R / F to self-detect the temperature of the optical device, and thus to optimally set the servo and operating state values of the device. It relates to a temperature detection method and a control method accordingly.

In general, in order to stabilize the servo operation and the various operating states of the optical device (optical disk device), the servo and various operating state related values should be optimally set in response to the temperature change of the apparatus.

To this end, conventionally, the temperature of the device is mainly detected by using a chip-type component such as a thermistor, and the servo gain (for example, tracking, focus, sled, Spindle servo gain) and various operating state related values (eg, target power, target beta (or target gamma), optimal light strategy, etc., related to OPC operation) are optimally set.

However, as described above, in order to detect the temperature of the optical disk apparatus, a separate component such as a thermistor has to be provided, so that the cost and volume of the apparatus have corresponding problems.

Therefore, the present invention was created to solve the above problems, and it is an optical device that self-detects the temperature of the device without a separate component such as a thermistor, and thereby optimally sets servo gain and various operating state related values. It is an object of the present invention to provide a temperature detection method and a control method accordingly.

According to an aspect of the present invention, there is provided a method of detecting a temperature in an optical device, the method comprising: detecting, in an optical device, a recording power voltage output corresponding to an input voltage of an automatic power control unit; And confirming a temperature corresponding to the detected recording power voltage from correlation information between prestored output voltage and temperature.

Detecting, in the optical device, a recording power voltage output corresponding to the input voltage of the automatic power control unit; And confirming a temperature corresponding to the detected recording power voltage from correlation information between pre-stored input voltage, output voltage and temperature, respectively.

In addition, the control method according to the temperature detection method in the optical device according to the present invention includes the steps of: detecting in the optical device the recording power voltage output corresponding to the input voltage of the automatic power control unit; Confirming a temperature corresponding to the detected recording power voltage from correlation information between previously stored output voltage and temperature; And reading out previously stored control information corresponding to the checked temperature, and performing a control operation according to the read temperature.

 Detecting, in the optical device, a recording power voltage output corresponding to the input voltage of the automatic power control unit; Confirming a temperature corresponding to the detected recording power voltage from correlation information between previously stored input voltage, output voltage and temperature; And reading the pre-stored control information corresponding to the identified temperature and performing a control operation according thereto.

Hereinafter, a preferred embodiment of a temperature detection method and a control method according to the optical device according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram illustrating an optical system of an optical device (optical disk device) in which a self-temperature detection method according to the present invention is implemented, and includes a gain & sample / holding device 21 and an OP amplifier 22. An automatic power control (APC) circuit 20 for outputting a recording power voltage VWDC based on the FPDO signal and the input voltage WDAC; LD driver 31 for outputting a light beam corresponding to the output recording power voltage, and a front photo detector for detecting the light beam output from the LD driver 31 and outputting the FPDO signal corresponding thereto. An optical pickup (30) consisting of a front photo detector (32); A VWDC detector 40 for detecting a write power voltage VWDC output from the APC circuit 20; The data related to the temperature of the device detected in the design and manufacturing process of the optical disk device and the target power, target beta, and optimal light strategy by each disk manufacturer in each temperature condition of the device are in the form of firmware. Memory (EEPROM) 51 to be stored; And a microcomputer 50 for optimally setting servo gain and various operating state related values according to the detected output voltage and controlling and performing a requested operation.

In the above configuration according to the present invention, the APC circuit 20 is a circuit configured inside the R / F IC of the optical disk apparatus, and the laser disk (recording power) is required for the optical disk apparatus to record data. The laser power is determined by the input voltage (WDAC) of the APC circuit 20, and typically the laser power is constantly maintained by the APC circuit 20 after being set at the time of initial laser power setting.

The FPDO signal corresponds to a light beam output from the LD driver 31, which is fed back by the FPD 32, and the input voltage WDAC is a value corresponding to a set recording power. 20) outputs a recording power voltage VWDC corresponding to the FPDO signal fed back from the FPD 32 and the input voltage WDAC applied through an external digital / analog converter DAC, whereby the set recording power is constant. Keep output.

When the sled motor for moving the optical pickup 30 in the optical disk device is configured as a stepping motor, grease is included in the lead screw of the stepping motor to prevent wear when the stepping motor is driven. A suitable amount of liquid, such as), is applied, and the liquid has different dominant (viscosity) characteristics depending on the manufacturer and temperature, as illustrated in FIG. 2.

Therefore, in the present invention, the microcomputer 50 performs the control operation for the stepping motor according to the current temperature of the optical disk device, which will be described in detail below.

On the other hand, in the design stage of the optical disk device (Set), T1 (low temperature-about 0 degrees), T4 (room temperature-about 23 degrees), T7 (high temperature-about 50 degrees) for each set of the same model Detects the output voltage VWDC of the APC circuit 20 to the constant input voltage WDAC at, wherein the values of the output voltages detected for each set are not the same but are similar in normal distribution as in FIG. 3. Has

FIG. 4 illustrates an example of the output voltage detected through experiments for various sets of the same model. The output voltage and temperature of the APC circuit 20 are compared with the graph of FIG. 3 and the table of FIG. 4. It can be seen that the correlation, ie the output voltage is proportional to the temperature of the device.

The output voltage at T1 is referred to as Vt1, the output voltage at T4 is referred to as Vt4 (= Vroom), and the output voltage at T7 is referred to as Vt7.

When Vt1, Vt4, and Vt7 are obtained for each of the sets of the same model, the average value of them, that is, the average value of several Vt1, several Vt4, and several Vt7, is calculated, and then dV and dV ' Detect.

(Calculation type)

dV = average value of Vt7 (high temperature)-average value of Vt4 (room temperature)

dV '= average value of Vt4 (room temperature)-average value of Vt1 (low temperature)

The dV and dV 'detected according to the calculation formula are stored in the memory 51 of each of the various sets of the same model in the form of firmware.

Further, in the design stage of the set, target power, target beta, and optimal light of each disc manufacturer in the normal temperature condition (room temperature) of the set are recorded. A write strategy is detected by an experiment and stored in the memory 51 in the form of firmware. The result value of the OPC operation, that is, the optimum recording power, may vary depending on the set temperature conditions. . That is, the optimum recording power value detected at a low temperature than at room temperature may be larger, and the optimum recording power value detected at a higher temperature than at room temperature may be smaller.

As a factor for this, at low or high temperatures, the OPC result may be changed due to the change in the characteristics of the disk material.

In addition, when irradiating light at a low temperature or high temperature, a slight change occurs in the delay time of the light pulse, which results in a change in the light strategy. At this time, since the write strategy means the recording pulse, the OPC result value may vary according to the change of the write strategy.

In addition, most of the optical pickup 30 is bound to the adhesive site (adhesive), the tilt of the light beam may occur at a low temperature or high temperature according to the temperature characteristics of the adhesive, and thus the OPC results may vary.

Therefore, in the present invention, in the design stage of the set, not only at room temperature (about 23 degrees), but also at low temperature (about 0 degrees) and high temperature (about 50 degrees), the target power of each disc manufacturer by recording speed, target beta, and By detecting each of the Optimum Light Strategies by experiment and storing them in the memory 51 in the form of firmware, the optimum recording power can be obtained through OPC operation regardless of the set temperature later based on the stored values. do.

On the other hand, in the manufacturing process step of the set, the output voltage of the APC circuit 20 corresponding to the constant input voltage in the T4 (room temperature-about 23 degrees) environment is detected, at this time a constant input voltage for the set Is applied several times (eg, five times) in units of 1 second, and the average value of the various output voltages detected therefrom is detected as an output voltage (Vroom = Vt4) at T4 and stored in the memory 51.

5 and 6 are flowcharts illustrating an exemplary embodiment of a temperature detection method and a control method according to the present invention. Hereinafter, FIGS. 5 and 6 according to the present invention will be described with reference to the configuration of FIG. 1. The temperature detection method and the control method according to it will be described in detail.

First, in the initial operation according to the insertion and mounting of the optical disk 10 (S10), the microcomputer 50 is to apply a constant input voltage (WDAC) to the APC circuit 20 (S11), the VWDC detector ( 40 detects the recording power voltage VWDC output corresponding to the input voltage (S12), and the microcomputer 50 detects whether the current temperature of the set is high or low from the detected voltage value ( S13) In this case, the microcomputer 50 continuously applies the predetermined input voltage several times (for example, five times) in the unit of 1 second as described above, and sets the microcomputer 50 based on the average value of various output voltages detected therefrom. The temperature is detected, the temperature detection conditions are as follows.

That is, Vtmp <Vroom + dV → high temperature detection, Vtmp <Vroom-dV '→ low temperature detection.

The microcomputer 50 stores the temperature of the detected device, and when the detected temperature of the device is high or low (S20), performs a control operation on a sled motor (stepping motor) of the optical disk device. That is, when detected at a low temperature, the microcomputer 50 increases the sled gain value of the stepping motor, which is lower in grease than the room temperature at low temperature as shown in FIG. Is relatively large.

On the other hand, when detected at a high temperature, the microcomputer 50 reduces the sled gain value of the stepping motor (S21), which is higher in grease than the room temperature at high temperature as shown in FIG. Is relatively small.

Fig. 7 shows an example of adjusting the tracking, focus, sled, and spindle servo gains according to the temperature of the apparatus. The above embodiment adjusts the sled servo gain according to the temperature of the apparatus. Accordingly, the tracking and focus servo gain of the stepping motor and the spindle servo gain of the spindle motor for rotating the optical disc 10 can be adjusted together.

On the other hand, the microcomputer 50 performs an OPC operation for optimum recording power detection, which is as follows.

First, for the OPC operation, the microcomputer 50 stores the target power, target beta, and optimum light strategy stored in association with the detected device temperature, the manufacturer of the optical disc 10, and the corresponding OPC recording speed. The memory 51 is read from the memory 51 (S22).

The microcomputer 50 controls the recording power to be changed by a predetermined size based on the read target power (for example, 8 mW), and the optical pickup 30 changes the optical disc to the recording power that is changed by the predetermined size. The test data of a predetermined (= 15 blocks) is recorded in the test area in the PCA area of (10), and the recording pulse at this time depends on the detected light strategy.

When the recording of the test data is completed, the microcomputer 50 controls the optical pickup 30 to sequentially read the recorded test data, and sequentially reproduces the read signal output from the R / F unit. Β value is detected from the β value, which indicates the asymmetry of the reproduced RF signal.

When the β value detection is completed, the microcomputer 50 fits a function of the curve by each recording power obtained the detected β value, and then obtains the optimal recording power from the obtained curve and the detected target beta. It is detected (S23).

In the state where the optimum recording power is detected at the current temperature condition of the set through the OPC operation, when a recording operation is requested (S30), the microcomputer 50 corresponds to the requested recording speed from the detected optimal recording power. While calculating the optimal recording power (S31), the corresponding optimum write strategy stored in association with the requested recording speed is read out from the memory 51, and the calculated optimal recording power and the readout are confirmed until the end of recording. The write operation is performed by applying the optimal write strategy (S32 and S40).

In the above embodiment, the target beta (Target β) is applicable to a write once disc (eg CD-R), and in the case of a rewritable disc (eg CD-RW) Gamma (Target γ) is applied.

In the meantime, the above-described embodiment detects in advance the correlation between the output voltage of the APC circuit 20 and the set temperature corresponding to a fixed input voltage, and based on this, the output voltage of the APC circuit 20. Detecting the current temperature of the set and performing a control operation according thereto, or detecting a correlation between each input voltage, the output voltage, and the set temperature in advance in consideration of a case where the input voltage may vary depending on a situation; Based on this, it is possible to detect the current temperature of the set from the input voltage and the corresponding output voltage of the APC circuit 20 and perform a control operation according thereto.

The above-described preferred embodiments of the present invention are disclosed for purposes of illustration, and those skilled in the art can improve, change, and substitute various other embodiments within the technical spirit and scope of the present invention disclosed in the appended claims below. Or addition may be possible.

The temperature detection method and the control method according to the present invention according to the present invention made as described above, the output voltage of the R / F internal automatic power control (APC) circuit for a constant input voltage, without a separate component such as thermistor Based on the self-detection of the temperature of the device, the cost and volume of the device are not unnecessarily increased, and the servo gain and recording-related values are optimally set according to the temperature of the self-detected device. It is a very useful invention in which the optimum operation is achieved.

Claims (16)

Detecting, in the optical device, a recording power voltage output corresponding to the input voltage of the automatic power control unit; And And confirming a temperature corresponding to the detected recording power voltage from correlation information between previously stored output voltage and temperature. Detecting, in the optical device, a recording power voltage output corresponding to the input voltage of the automatic power control unit; And And confirming a temperature corresponding to the detected recording power voltage from correlation information between pre-stored input voltage, output voltage, and temperature. Detecting, in the optical device, a recording power voltage output corresponding to the input voltage of the automatic power control unit; Confirming a temperature corresponding to the detected recording power voltage from correlation information between previously stored output voltage and temperature; And And reading out previously stored control information corresponding to the checked temperature and performing a control operation according to the temperature. The method of claim 3, wherein And said control information comprises a gain of a sled servo. The method of claim 3, wherein And said control information comprises a gain of a tracking servo. The method of claim 3, wherein And the control information includes a gain of a focus servo. The method of claim 3, wherein And said control information comprises a gain of a spindle servo. The method of claim 3, wherein The control information, the control method according to the temperature detection method in the optical device, characterized in that it comprises write strategy (Write Strategy) information for the optimal recording power. The method of claim 3, wherein And the control information includes target power information. Detecting, in the optical device, a recording power voltage output corresponding to the input voltage of the automatic power control unit; Confirming a temperature corresponding to the detected recording power voltage from correlation information between previously stored input voltage, output voltage and temperature; And And reading out previously stored control information corresponding to the checked temperature and performing a control operation according to the temperature. The method of claim 10, And said control information comprises a gain of a sled servo. The method of claim 10, And said control information comprises a gain of a tracking servo. The method of claim 10, And the control information includes a gain of a focus servo. The method of claim 10, And said control information comprises a gain of a spindle servo. The method of claim 10, The control information, the control method according to the temperature detection method in the optical device, characterized in that it comprises write strategy (Write Strategy) information for the optimal recording power. The method of claim 10, And the control information includes target power information.

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