JP2011076658A - Optical disk reproduction device, optical disk reproduction method, and optical disk reproduction program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk reproduction device which handles the bend of an optical disk. <P>SOLUTION: A detector 6 measures an ambient temperature of an optical disk reproduction section 2. A storage section 4 stores the temperature values measured at a plurality of different positions on the optical disk being reproduced by the optical disk reproduction section 2, and at a plurality of time points which have different temperatures, in association with a focus drive voltage of the optical disk reproduction section 2. A reproduction controller 3 performs reproduction control on the optical disk in the optical disk reproduction section 2 with an approximation expression using the measured values stored in the storage section 4. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an optical disc playback apparatus, an optical disc playback method, and an optical disc playback program that can eliminate the inconvenience of a playback processing operation caused by warping of an optical disc.

In an optical disk reproducing apparatus that reproduces an optical disk such as a CD or a DVD, control of a pickup focus control, tracking servo, and the like is performed during reproduction. However, the optical disk may be deformed due to a difference in the material of each optical disk or a change in environment such as temperature and humidity during reproduction, and the reproduction operation may not be controlled well.

  Patent Document 1 discloses an optical disc that gives a warp that cancels in advance in consideration of the above-mentioned problems, taking into consideration the amount of warpage of the optical disc material, temperature, and humidity.

In addition, the amount of warpage of the optical disc is measured when the disc is loaded (before the disc playback process), and the amount of warpage of the optical disc is determined based on the measured data, or an approximation specified in advance. The amount of warpage is predicted using a curve, the amount of warpage is calculated based on the measured value and temperature, and the amount of warpage at each temperature is calculated to control the reproduction operation of the optical disk reproducing apparatus.

JP-A-8-31011

However, an optical disk that does not actually improve the warp of the optical disk is inserted into the playback device, and there are cases where the user performs printing on the surface of the optical disk or attaches a label or the like on the surface of the optical disk. The adhesive component of the label may change the amount of warping of the optical disk. There was a problem that could not cope with the above-mentioned changed warpage.

In addition, when the control voltage that changes depending on the warp amount is measured before performing the disk reproduction process, and the control voltage is predicted using an approximate expression given in advance, the predicted voltage value and the voltage value necessary for actual control are When the values differ greatly, the playback operation cannot be performed, and there is no choice but to take measures such as ejecting the disc.

An object of the present invention is to provide an optical disc reproducing apparatus, an optical disc reproducing method, and an optical disc reproducing program capable of performing a stable reproducing operation even when the amount of warpage varies depending on the material of the optical disc and the state of the disc.

  In order to solve the above-described problems of the prior art, the present invention provides an optical disc reproducing unit for reproducing an optical disc, a storage unit, and an optical disc at each of a plurality of different positions on the optical disc being reproduced by the optical disc reproducing unit. A storage control unit that stores in the storage unit measurement values that correspond to temperatures at a plurality of times at which the temperatures measured by the detection unit that measures the temperature around the reproduction unit differ from the focus drive voltage in the optical disc reproduction unit; There is provided an optical disc reproducing apparatus comprising: a reproduction control unit that performs reproduction control of the optical disc in the optical disc reproducing unit by an approximate expression using measured values stored in the storage unit.

  In the above configuration, the different positions on the optical disk are positions having different distances from the center of the optical disk.

  In order to solve the above-described problems of the conventional technology, the present invention provides an optical disc playback unit for playing back an optical disc and the optical disc playback at each of a plurality of different positions on the optical disc being played back by the optical disc playback unit. A storage controller that stores, in the storage unit, measurement values in which the humidity at a plurality of time points at which the humidity measured by the detection unit that measures the humidity around the unit is different from the focus drive voltage in the optical disc reproducing unit are associated with each other; There is provided an optical disc reproducing apparatus comprising: a reproduction control unit that performs reproduction control of the optical disc in the optical disc reproducing unit by an approximation formula using measured values stored in a storage unit.

  Furthermore, in order to solve the above-described problems of the related art, the present invention includes a step of measuring a plurality of different temperatures at a plurality of different positions on the optical disc being reproduced by the optical disc reproducing unit, Corresponding to the temperature, the step of acquiring the focus drive voltage in the optical disc reproducing unit, the step of storing the measured value in which the temperature and the focus drive voltage are associated with each other in the storage unit, and the storage unit storing the measured value And a step of performing reproduction control in the optical disk reproducing unit by an approximate expression using measured values.

  In addition, in order to solve the above-described problems of the conventional technology, the present invention provides a measuring step for causing a computer to measure the temperature around the optical disk reproducing unit, and an optical disk reproduced by the optical disk reproducing unit. A storage step of storing, in the storage unit, measured values in which the temperatures at a plurality of times at which the temperatures measured in the measurement step are different from each other and the focus drive voltage in the optical disc reproducing unit correspond to each other at a plurality of different positions; Provided is an optical disc playback program that calculates an approximate expression using a measurement value stored in a section and executes a control step for controlling playback of the optical disc in the optical disc playback section based on the approximate expression. .

  According to the present invention, a stable reproduction operation can be performed even when the amount of warpage varies depending on the material of the optical disk and the state of the disk.

It is a block diagram which shows one Embodiment of this invention. 3 is a schematic diagram showing an optical disk and a pickup in a disk reproducing unit 2. FIG. 3 is a flowchart of the first embodiment. 10 is a flowchart of Example 2. 10 is a flowchart of Example 3.

Hereinafter, the configuration of the present invention will be described with reference to FIG. 1 of the accompanying drawings.
The optical disc playback apparatus 1 includes an optical disc playback unit 2, a playback control unit 3, a storage unit 4, a control unit 5, a detection unit 6, and an output unit 7. The optical disk reproducing unit 2 includes a pickup 11 shown in FIG. 2, a spindle motor not shown, and the like. The pickup 11 irradiates the recording surface of the optical disc 10 with light, and acquires recording data recorded on the optical disc 10 from data obtained by detecting the reflected light. The reproduction control unit 3 supplies a control signal for controlling the pickup 11 to the optical disc reproduction unit 2, measures the rotation of the spindle motor, and outputs a signal for controlling the rotation speed of the spindle motor to the optical disc reproduction unit 2. Also, the recording data of the optical disc 10 obtained by the pickup 11 of the optical disc playback unit 2 is output to the playback control unit 3, and the playback control control unit 3 performs playback processing when the obtained recording data is audio data, and performs output processing. Output to 7. A speaker or the like (not shown) is connected to the output unit 7 and outputs sound.

The storage unit 4 is a storage device such as a memory, and stores data from the reproduction control unit 3 obtained by the control unit 5, a control program for the reproduction device 1, and the like. The detection unit 6 includes a thermometer and a hygrometer, and outputs the detected temperature and humidity to the control unit 5. The storage unit 4 stores the temperature and humidity obtained by the thermometer and hygrometer of the detection unit 6. The control unit 5 functions as a storage control unit that stores various data in the storage unit 4.

Next, the pickup 11 used in this embodiment will be described with reference to FIG. The direction in which the pickup 11 is moved in the Z-axis direction in FIG. 2 (the arrow direction is positive; the same applies hereinafter) is referred to as the focus direction, and the direction in which the pickup 11 is moved in the Y-axis direction (the radial direction of the optical disk 10) is referred to as the thread direction. The direction radially spreading from the center of the optical disc 10 is the outer peripheral direction of the optical disc 10, and the direction approaching the center is the inner peripheral direction. When reading the data on the optical disk 10, the pickup 11 is moved in the focus direction. At this time, a voltage necessary for driving the pickup 11 is referred to as a focus drive voltage (FoDrv). The value at this time corresponds to the focus levitation voltage during reproduction.

Next, Example 1 in the present embodiment will be described with reference to FIG.
The following processing is processing performed by the control unit 5.
Step S1: Set the counter N to 0.
Step S2: The temperature T1 is measured with the thermometer of the detection unit 6. The control unit 5 stores the measured T1 in the storage unit 4.

Step S3: Focus servo is applied to the pickup 11 at a predetermined position address X1 on the inner circumference side of the disk. The focus drive voltage value (FoDrv1 value) Y1 at that time is output to the control unit 5, and the voltage value Y1 is stored in the storage unit 4.

Step S4: Focus servo is applied to the pickup 11 at a predetermined position address X2 on the disc (positioned on the outer peripheral side from the address X1). The focus drive voltage value (FoDrv2 value) Y2 at that time is measured, and the voltage value Y2 is stored in the storage unit 4.

Step S5: The control unit 5 calculates an approximate expression P from the values (X1, Y1, X2, Y2) obtained in steps S3 and S4.
The approximate expression P is, for example,
P = aX ² + bX + c (1)
When the curve approximation is performed, the coefficients a and b are obtained from X1, Y1, X2 and Y2 obtained from steps S3 and S4. The coefficient c corresponds to the FoDrv levitation voltage when the focus is on, and is a value that does not change unless the disk is inserted or removed.

Step S6: Set the counter N to +1 and count up.

Step S7: Determine whether the counter N is 2 or not. If NO in step S7, the process proceeds to step S8. If YES in step S7, the process proceeds to step S10.

Step S8: Measure the temperature with the thermometer of the detector 6 (T2 measurement). Then, the temperature T2 is stored in the storage unit 4.

Step S9: The controller 5 determines whether the difference between the temperature T1 and the temperature T2 is greater than T degrees or less than T degrees.
If the temperature difference between T1 and T2 is equal to or greater than T (YES in step S9), the process proceeds to step S3. When the temperature difference between T1 and T2 is smaller than T (NO in step S9), the process proceeds to step S8.

Step S10: The coefficients of the approximate expression P1 at the temperature T1 and the approximate expression P2 at the temperature T2 are compared, and the temperature coefficient of the approximate expression P depending on the temperature is calculated by the control unit 5. If the temperature coefficient is K1 and K2,
K1 = a2 / a1 (2)
K2 = b2 / b1 (3)
It becomes.

Step S11: The temperature Tn is measured with the thermometer of the detection unit 6.

Step S12: Pn is calculated from K1 and K2 from the coefficient obtained in step S10.
The approximate expression Pn is
Pn = an · X ² + bn · X + c
And an and bn are
an = K1 × (ΔT / ΔT ')
bn = K2 x (ΔT / ΔT ')
It becomes.

Step S13: FoDrvn at the position Xn on the disc is calculated, the pickup 11 is controlled based on the calculated Yn = FoDrvn, and the process proceeds to step S14.
Xn is an address on the optical disc 10 designated by the disc playback control unit 3.

Step S14: It is determined whether or not the optical disk 10 has been ejected. If it is determined that the optical disk 10 has been ejected (YES in step S14), the flow ends. If NO in step S14, the process proceeds to step S11.

By performing the above steps, an approximate expression is calculated based on data obtained from at least two different temperature changes, so that the focus servo can be performed in accordance with the amount of warp of the disk with high accuracy. Further, it is possible to avoid a situation where the focus search becomes impossible and reproduction cannot be performed due to an increase in the amount of warp of the disk due to a temperature change.

Next, Example 2 will be described with reference to FIG. The configuration for realizing the second embodiment is the same as that of FIGS. 1 and 2, and those using the same symbols as those of the first embodiment are the same as those of the first embodiment, and the description thereof is omitted.
Step S22: The counter N is set to zero.
Step S23: The humidity H1 in the optical disc playback apparatus 1 is measured, and the measured humidity value H1 is recorded in the storage unit 4.

Step S24: The temperature T1 is measured and recorded in the storage unit 4.
In step S25, the data reading operation is performed at the inner peripheral address X1, and the voltage value Y1 is measured.
Step S26: A data read operation is performed at the middle peripheral address X2b, and the voltage value Y2 is measured.

Step S27: The approximate expression P is calculated (the above expression (1)).
Step S28: The counter N is incremented by 1 and counted up.

Step S29: The temperature T2 is measured.
Step S30: It is determined whether the environmental temperature change is equal to or higher than t ° C. t ° C. is arbitrarily set. Or you may set to an apparatus. For example, it is about 10 ° C. If YES in step S30, the process proceeds to step S22. If NO in step S30, the process proceeds to step S31.

Step S31: Measure humidity and measure H2. The humidity value H2 is recorded in the storage unit 4.
Step S32: It is determined whether or not the difference between the measured humidity value H2 and the humidity value H1 is a certain value or more. If it is the predetermined humidity (YES in step S32), the process proceeds to step S33.
When the difference between the humidity values H1 and H2 is equal to or smaller than the predetermined value (NO in step S32), the process proceeds to step S29.

Step S33: It is determined whether the counter N is 2 or more. If NO in step S33, the process proceeds to step S25. If YES in step S33, the process proceeds to step S34.

Step S34: The coefficient of the approximate expression P1 at the detected humidity H1 and the approximate expression P2 at the detected humidity H2 are compared, and the humidity coefficient of the approximate expression P depending on the humidity is calculated by the control unit 5. If the humidity coefficient is K´1, K´2,
K´1 ＝ a2 / a1 (4)
K´2 = b2 / b1 (5)
It becomes.

Step S35: When the regenerating operation is being performed, the humidity Hn is measured.
Step S36: The approximate expression Pn at the humidity Hn is calculated.
Step S37: Yn (focus drive voltage) at the disk position Xn is obtained.

Step S38: It is determined whether or not the disc is ejected. If the disc is ejected (YES in step S38), the process proceeds to step S39 and the flow is terminated. If it is determined that the disc has not been ejected (NO in S38), the process proceeds to step S35.

  In this embodiment, the humidity Hn is detected as appropriate, but the steps after step S35 may be performed only when the humidity sensor is used and the humidity changes.

  Next, Example 3 will be described with reference to FIG. The configuration for realizing the second embodiment is the same as that shown in FIGS. 1 and 2, and those using the same symbols as those of the first embodiment are the same as those of the first embodiment, and the description thereof is omitted.

Step S52: The counter N is set to zero.
Step S53: The playback control unit 3 measures the playback speed setting Vn.

Step S54: The temperature T1 is measured.
Step S55: A data read operation is performed at the inner peripheral address X1, and the voltage value Y1 is measured.
Step S56: A data read operation is performed at the middle peripheral address X2b, and the voltage value Y2 is measured.

Step S57: The approximate expression P is calculated using the expression (1).
Step S58: The counter N is incremented by 1.
Step S59: It is determined whether the playback speed setting V has changed. If YES in step S59, the process proceeds to step S52. If NO in step S59, the process proceeds to step S60.

Step S60: It is determined whether or not the counter N is 2. If YES (N = 2) in step S60, the process proceeds to step S63. If NO in step S60 (N is not 2), the process proceeds to step S61.

Step 61: Measure temperature T2.
Step 62: It is determined whether or not the temperature difference between T2 and T1 is greater than a predetermined value T.
When the difference between T2 and T1 is larger than T (NO in step S62), the process proceeds to step S55. If the difference between T2 and T1 is greater than or equal to T (YES in step S62), the process proceeds to step S63.

Step S64: The temperature Tn is detected.
Step S65: An approximate expression Pn at the temperature Tn and the regeneration speed Vn is calculated.
Step S66: Yn at the position Xn is calculated based on Pn obtained in step S65.
Step S67: It is determined whether or not the disc is ejected. If NO in step S67 (when it is not determined that the disc has been ejected from the playback device), the process proceeds to step S64. If YES in step S67 (when it is determined that the disc has been ejected from the playback apparatus), the flow ends.

  According to the third embodiment, it is possible to cope with the influence of the centrifugal force at the reproduction speed (rotational speed) of the disc and the thermal deformation of the disc accompanying the environmental temperature.

As described above, in the first to third embodiments of the present invention, by calculating an approximate expression based on data obtained by at least two different temperature changes, it is possible to perform focus servo according to the amount of warp of the disk with high accuracy. Become.

In addition, it is possible to prevent the focus search from becoming impossible and impossible to reproduce due to the amount of warping of the disk due to the temperature change, the temperature characteristics (FoDrv value / levitation voltage) of the actuator sensitivity of the pickup, the gain of the drive circuit system ( It also supports temperature characteristics related to the driver section, and hysteresis temperature characteristics in sensitivity at the frequency when the focus actuator is driven up / down, and each media material (disc polycarbonate, disc label itself, disc label adhesive, etc.) It can also correspond to the temperature characteristics of each component material.

  In addition, since the amount of warpage due to temperature or humidity can be detected (estimated), it is possible to determine that playback is not possible, in which case "Please lower the temperature" or "High temperature" or "Suspend playback due to high humidity" It is possible to send a message such as “I will” to the user.

The above-described flow of the first to third embodiments may be performed before or during the disk reproduction processing operation, and when a change in temperature, for example, a temperature change is detected, an approximate expression Pn is obtained. Modifications can be made without departing from the spirit of the present invention.

  In addition, it is possible to perform control with higher accuracy by calculating an approximate expression for each disk.

  In Examples 1 to 3 described above, the measurement was performed using the inner peripheral address X1 and the outer peripheral address X2 of the disk. However, the measurement may be performed at two points among the inner periphery, the intermediate periphery, and the outer periphery, or at three or more points. The approximate expression P at that time performs a curve approximation like Expression (1) in the same manner as in the measurement at two points.

  In the first to third embodiments described above, the amount of warp due to temperature is calculated, but instead of temperature change, for example, the amount of warp of the disk at different humidity may be measured, an approximate expression may be calculated, and used for the reproduction operation. . Moreover, you may utilize the parameter which combined temperature and humidity.

  In the above-described first to third embodiments, the temperature and humidity are measured by the detection unit in the reproduction apparatus. However, the temperature and humidity data may not be in the reproduction apparatus, and it is only necessary to acquire the data.

  Although the approximation formula is a quadratic curve in the embodiment, any curve approximation formula may be used.

DESCRIPTION OF SYMBOLS 1 Reproduction | regeneration apparatus 2 Optical disk reproduction | regeneration part 3 Reproduction | regeneration control apparatus 4 Memory | storage part 5 Control part 6 Detection part 7 Output part 10 Optical disk 11 Pickup

Claims (5)

An optical disk playback unit for playing back an optical disk;
A storage unit;
The temperature at a plurality of points in time at which the temperature measured by the detection unit that measures the temperature around the optical disk reproduction unit is different at each of a plurality of different positions on the optical disk being reproduced by the optical disk reproduction unit and the focus in the optical disk reproduction unit A storage control unit for storing a measurement value corresponding to a drive voltage in the storage unit;
An optical disc reproducing apparatus comprising: a reproduction control unit that performs reproduction control of the optical disc in the optical disc reproducing unit by an approximate expression using the measurement value stored in the storage unit. 2. The optical disk reproducing apparatus according to claim 1, wherein the plurality of different positions on the optical disk are positions having different distances from the center of the optical disk. An optical disk playback unit for playing back an optical disk;
A storage unit;
Humidity at a plurality of points in time when the humidity measured by the detection unit that measures the humidity around the optical disk reproduction unit is different at each of a plurality of different positions on the optical disk being reproduced by the optical disk reproduction unit, and the focus in the optical disk reproduction unit A storage control unit for storing a measurement value corresponding to a drive voltage in the storage unit;
An optical disc reproducing apparatus comprising: a reproduction control unit that performs reproduction control of the optical disc in the optical disc reproducing unit by an approximate expression using the measurement value stored in the storage unit. Measuring a plurality of different temperatures at each of a plurality of different positions on the optical disc being played by the optical disc playback section;
Acquiring a focus drive voltage in the optical disc playback unit in response to the different temperatures;
Storing a measurement value corresponding to the temperature and the focus drive voltage in a storage unit;
An optical disc reproducing method comprising: performing reproduction control in the optical disc reproducing unit by an approximate expression using the measurement value stored in the storage unit. On the computer,
A measurement step for causing the detection unit to measure the temperature around the optical disk reproducing unit;
Measured values in which the temperatures at a plurality of times at which the temperatures measured in the measurement step are different from each other at different positions on the optical disc being reproduced by the optical disc reproducing unit correspond to the focus drive voltage in the optical disc reproducing unit. A storage step of storing in the storage unit;
An optical disc reproduction program, comprising: calculating an approximate expression using a measurement value stored in the storage section; and executing a control step of controlling reproduction of the optical disc in the optical disc reproduction section based on the approximate expression.

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