JP2008282498A - Optical disk device - Google Patents

Abstract

【Task】
In the optical disc apparatus, it is possible to shorten the movement time of the optical pickup to the home position and to accurately position the optical pickup.
[Solution]
After the optical disk is loaded, a moving position of the innermost circumference of the optical disk is detected, and the objective lens is a first home position corresponding to the position information read from the memory with reference to the detected position. The data area as the second position which is the final home position after the loading according to the information on the innermost peripheral position of the data area read from the optical disk by the optical pickup. Move to the innermost peripheral position to prepare for recording or playback operation. Further, the position information of the third position, which is the primary home position of the optical pickup after the next loading, is calculated from the position information of the first position and the position information of the second position and stored in the memory. .
[Selection] Figure 1

Description

  The present invention relates to an optical disc apparatus, and more particularly, to an optical pickup positioning technique after an optical disc is loaded.

Prior arts related to the present invention, which are described in patent documents, are described in Japanese Patent Laid-Open No. 2002-298383 (Patent Document 1) and Japanese Patent Laid-Open No. 2003-281745 (Patent Document 2). There is something. Japanese Patent Application Laid-Open No. 2002-298383 discloses an optical disc apparatus that can accurately detect the home position of the optical pickup with respect to the optical disc without a sensor so that the optical pickup can be reliably moved to the home position at low cost. In addition, while reading the data by irradiating the optical disc with the optical beam from the optical pickup, the optical pickup is moved by the carriage from the outer peripheral side to the inner peripheral side of the optical disc, and the signal is output after entering the clamp area past the data area. A technique is described in which the lost position is captured, the optical pickup is moved a predetermined distance in the opposite direction, and the position after the movement is set as the home position. Japanese Laid-Open Patent Publication No. 2003-281745 discloses an optical disk device in which an optical head can be detected without using an inner limiter switch to reduce the cost and simplify the mechanical mechanism. Irradiating the optical disk with laser light while moving it toward the inner circumference of the optical disk, and detecting the optical disk. When the optical disk is detected, the absolute time information is obtained from the optical disk, and the optical time is determined based on the absolute time information. A technique is described in which the head is moved to the initial position (home position) of the optical disk.

JP 2002-298383 A JP 2003-281745 A

  In the techniques described in Japanese Patent Laid-Open No. 2002-298383 and Japanese Patent Laid-Open No. 2003-281745, the home position is detected while reading information on the optical disc. In recent years, optical disks have been used as optical disk apparatuses for recording and reproducing by loading blue laser optical disks such as BD (Blu-ray Disc) and HD-DVD and red laser optical disks such as DVD and CD. In the pickup, an objective lens of an optical system (hereinafter referred to as a blue laser optical system) corresponding to the blue laser optical disk and an optical system (hereinafter referred to as a red laser optical) corresponding to the red laser optical disk. The objective lens of the optical system) is arranged at different positions in the radial direction of the optical disk, and its practical use has been promoted. However, in such an optical disk apparatus, an optical pickup corresponding to the type of optical disk to be loaded When loading an optical disc of a different type, load After the optical pickup or the objective lens is susceptible long time to complete the movement to the home position. In particular, when a blue laser optical disk is loaded, the blue laser optical disk has a narrow track pitch. Therefore, it is necessary to accurately move the optical pickup or the objective lens to the home position. The same applies to the case of an optical disc apparatus in which only the blue laser optical disc is loaded. Further, in the optical disc apparatus of the type having the two optical systems, when the position of the objective lens varies between the two optical systems, the optical pickup or the objective lens is moved in accordance with the variation, and the home position It is necessary to ensure accuracy.

An object of the present invention is to allow an objective lens on an optical pickup to be moved to a home position (hereinafter referred to as a home position) in a short time after the optical disk is loaded in the optical disk apparatus in view of the above-described prior art situation. In addition, the objective lens can be accurately positioned at the home position.
An object of the present invention is to solve such problems and provide an easy-to-use optical disc apparatus.

  In order to solve the above problems, in the present invention, as an optical disc apparatus, after the optical disc is loaded, the moving position on the innermost circumference side of the optical disc is detected, and the objective lens is stored in the memory based on the detected position. The objective lens is moved to the first position, which is the primary home position corresponding to the position information read from the optical disk, and then the objective lens is moved after the loading according to the data area innermost position information read from the optical disk by the optical pickup. Is moved to the innermost circumferential position of the data area as the second position, which is the final home position, to prepare for the recording or reproduction operation. Further, the position information of the third position, which is the provisional home position of the optical pickup after the next loading, is calculated from the position information of the first position and the position information of the second position and stored in the memory. Let After the next loading, the moving position on the innermost circumference side of the loaded optical disc is detected, and then the objective lens is set to 1 corresponding to the information of the calculation result read from the memory with reference to the detected position. Move to the next home position. Thereafter, as in the case after the previous loading, the objective lens is moved to the final home position.

  According to the present invention, in the optical disc apparatus, after loading of the optical disc, it is possible to shorten the movement time of the objective lens to the home position and to accurately position the objective lens to the home position.

Embodiments of the present invention will be described below with reference to the drawings.
1-3 is explanatory drawing of the Example of this invention. FIG. 1 is a configuration example of an optical disc apparatus as an embodiment of the present invention, FIG. 2 is an explanatory diagram of a home position in the optical disc apparatus of FIG. 1, and FIG. 3 is a diagram showing an operation flow of the optical disc apparatus of FIG. is there.
The present embodiment is an example of an optical disk apparatus that records and reproduces by loading a blue laser optical disk such as a BD or HD-DVD and a red laser optical disk such as a DVD or CD. Assume that a blue laser optical system and a red laser optical system are separately provided, and objective lenses of the respective optical systems are arranged in the radial direction of the optical disc (disc radial direction).

  In FIG. 1, 1 is an optical disk device as an embodiment of the present invention, 2 is an optical disk, 3 is a spindle motor that rotationally drives the optical disk 2, 4 is an optical pickup, and 5a is a red laser mounted on the optical pickup 4. An objective lens (hereinafter referred to as a red laser objective lens) constituting the optical system for use 5b is mounted on the optical pickup 4 and an objective lens (hereinafter referred to as a blue laser objective lens) constituting the blue laser optical system. ), 6 is a moving mechanism that moves the optical pickup 4 in the substantially radial direction of the optical disc 2, 7 is a stepping motor that drives the moving mechanism 6, 8 is a motor drive circuit that drives the stepping motor 7, and 9 is a control unit. , 91 are configured in the control unit 9, and are home positions of the red laser objective lens 5a and blue laser objective lens 5b. An arithmetic unit 92 for calculating the motor is configured in the control unit 9, a motor control unit for forming a control signal for controlling the motor drive circuit 8, an EEPROM as a memory, and 11 an optical pickup 4 or an objective. This is a sensor for detecting the movement position of the lenses 5a and 5b on the innermost peripheral side of the optical disc 2.

  The moving mechanism 6 includes a lead screw member (not shown) and a guide member (not shown) arranged in parallel to the disk radial direction, and the optical pickup 4 is engaged with the lead screw member and the guide member. When the lead screw member is driven to rotate by the stepping motor 7, the optical pickup 4 moves while being guided by the guide member in the disc radial direction.

  The stepping motor 7 rotationally drives the lead screw member in accordance with the number of drive pulses supplied from the motor drive circuit 8, whereby the optical pickup 4 is moved in the disc radial direction by a distance corresponding to the number of drive pulses. Move.

  The control unit 9 has a configuration for performing overall control of the optical disc apparatus 1, and is configured by, for example, a DSP (Digital Signal Processor) with a built-in microcomputer. After the loading operation of the optical disk 2, the control unit 9 outputs a control signal from the motor control unit 92 to control the motor drive circuit 8, drives the stepping motor 7, moves and displaces the optical pickup 4, and red laser The objective lens 5a for blue and the objective lens 5b for blue laser are determined with reference to the position on the innermost peripheral side of the optical disc 2 detected by the sensor 11 (the movement position of the optical pickup 4 or the movement position of the objective lenses 5a and 5b). First, positioning is performed at a position in the disc radial direction (hereinafter referred to as a first position) as a primary home position. Thereafter, the control unit 9 controls the motor driving circuit 8 and drives the stepping motor 7 by a control signal from the motor control unit 92 according to the information on the innermost peripheral position of the data area read from the optical disc 2 by the optical pickup 4. Then, the optical pickup 4 is moved and displaced, and the red laser objective lens 5a or the blue laser objective lens 5b is moved from the first position to the disc radial position (hereinafter referred to as the final home position). It is moved to the innermost peripheral position of the data area of the optical disc 2 and is finally positioned at this position. As the first position, the control unit 9 sets, for example, a position where the frequency of the position information becomes the maximum or an average value in the past loading operation.

  After the loading operation of the optical disc 2, the calculation unit 91 includes position information corresponding to the first position (hereinafter referred to as first position information) and position information corresponding to the second position (hereinafter referred to as second position information). The position in the radial direction of the disk where the red laser objective lens 5a or the blue laser objective lens 5b is first positioned as the home position after the next loading operation (hereinafter referred to as the third position). Is calculated (hereinafter referred to as third position information). For example, when the frequency of the position information stored as the first position information in the EEPROM 10 before the loading operation is n, after the loading operation, the calculation unit 91 converts the third position information into the third position information. Calculation is performed as position information = {(position information set as first position information × n) + (second position information × 1)} / (n + 1). The first position information used for the calculation is stored in the EEPROM 10 in advance, and the control unit 9 reads from the EEPROM 10 during the calculation. The calculated third position information is also newly stored in the EEPROM 10 by the control unit 9. The third position information is read by the control unit 9 after the next loading and used as the first position information.

  The motor control unit 92 forms a control signal for controlling the motor drive circuit 8 based on the first, second and third position information, and outputs the control signal to the motor drive circuit 8. . The motor drive circuit 8 forms stepping pulses having the number of pulses corresponding to the control signal and supplies the stepping pulses to the stepping motor 7. When driven by a stepping pulse having the number of pulses corresponding to the first position information, the stepping motor 7 moves and displaces the optical pickup 4 to move the red laser objective lens 5a or the blue laser objective lens 5b to 1 The first home position is moved to the next position. Further, the stepping motor 7 moves and displaces the optical pickup 4 from the first position, and moves the red laser objective lens 5a or the blue laser objective lens 5b to the second position which is the final home position. Let The controller 9 obtains second position information corresponding to the second position from the number of stepping pulses at this time. When the stepping motor 7 is driven by a stepping pulse having the number of pulses corresponding to the third position information after the next loading, the stepping motor 7 moves and displaces the optical pickup 4, and the objective lens 5a for the red laser or the blue laser is moved. The objective lens 5b is moved to the third position, that is, the first position that is the primary home position.

1, after moving the red laser objective lens 5a or the blue laser objective lens 5b to the first position based on the first position information read from the EEPROM 10, The optical pickup 4 is moved to the second position in accordance with the information on the innermost peripheral position of the data area read from the optical disc 2 to obtain the second position information. Further, the third position information is calculated based on the first position information and the second position information, and the calculated third position information is newly stored in the EEPROM 10, and the third position information is stored. Is used as the first position information after the next loading operation. In addition, the calculation unit 91 calculates the third position information for each loading operation. The EEPROM 10 stores the calculated third position information for each loading operation. For example, when a red laser optical disk is loaded, the red laser objective lens 5a is moved to the first position based on the first position information corresponding to the objective lens 5a read from the EEPROM 10. The optical pickup 4 is moved to the second position, that is, the innermost peripheral position of the data area of the red laser optical disk in accordance with the information of the innermost peripheral position of the data area read from the optical disc 2 to obtain the second positional information. The third position information is calculated based on the first position information and the second position information, the calculated third position information is newly stored in the EEPROM 10, and the third position information is stored. The first position information is used after the next loading operation of the red laser optical disk. Similarly, when the blue laser optical disk is loaded, the blue laser objective lens 5b is moved to the first position based on the first position information corresponding to the objective lens 5b read from the EEPROM 10. Thereafter, the second position information is moved to the innermost peripheral position of the data area of the blue laser optical disk to obtain second position information, and based on the first position information and the second position information. The third position information is calculated, the calculated third position information is newly stored in the EEPROM 10, and the third position information is stored in the first position after the next loading operation of the blue laser optical disk. Use as information.
Hereinafter, the same reference numerals as those in FIG. 1 are used for the components of the optical disk apparatus 1 in FIG. 1 used in the description of FIGS.

  FIG. 2 is an explanatory diagram of home positions of the objective lenses 5a and 5b in the optical disc apparatus 1 of FIG. In FIG. 2, the horizontal axis represents the disk radial position, and the vertical axis represents the frequency of the home positions of the objective lenses 5a and 5b set for each loading operation.

In FIG. 2, A is a frequency distribution curve of the home position of the red laser objective lens 5 a when a red laser optical disk such as a DVD is loaded as the optical disk 2 on the optical disk apparatus 1, and B is the optical disk apparatus 1. a frequency distribution curve, r ₀₁ of the home position of the blue-based laser objective lens 5b in the case of the blue-based laser for optical disc such as a BD as the optical disk 2 is loaded, the top of the red-based laser for optical disk sensor 11 detects The position on the inner peripheral side, r _11, is a disk radius position corresponding to position information (first position information) stored in advance in the EEPROM 10, and is 1 for the red laser optical disk of the red laser objective lens 5 a. next manner home position (first position), r ₁₂ is the red of the red-based laser objective lens 5a Finally home position (second position) i.e. innermost position of the data area with respect to the laser optical _{disc, r 02} is the innermost circumference side of the position of the blue-based laser for optical disk sensor 11 _{detects, r 21} is EEPROM 10 A primary home position (first position) of the blue laser objective lens 5b with respect to the blue laser optical disk, which is a disk radial position corresponding to the position information (first position information) stored in advance in r ₂₂ is the final home position (second position) of the blue laser objective lens 5b with respect to the blue laser optical disk, that is, the innermost circumferential position of the data area. P ₁ is the maximum frequency point on the frequency distribution curve A, and P ₂ is the maximum frequency point on the frequency distribution curve B. In FIG. 2, it is assumed that the control unit 9 sets the primary home position (first position) of each of the objective lenses 5a and 5b to the disk radius position of the maximum frequency on the frequency distribution curve of the home position. primarily the home position (first position) r ₁₁ matches the disk radial location of the maximum power point P _1, primarily the home position (first position) r ₂₁ is disc radial position of the maximum power point P ₂ It matches.

In Figure 2, the optical disc device 1, a new, for example, when the red-based laser for an optical disk is loaded as the optical disk 2, the sensor 11 detects the position r ₀₁ of the innermost side of the disc, the control unit 9 The primary home position (first position) r ₁₁ is set from the position information (first position information) read from the EEPROM 10, and the motor control unit 92 uses the innermost position r ₀₁ as a reference. sets the stepping pulses of the stepping motor 7 for driving that requires objective lens 5a for red-based laser to move to the first-order home position (first position) r _11. Stepping motor 7 is driven by a stepping pulse number the pulse, by moving the optical pickup 4 to move the objective lens 5a for red-based laser in the 1-order home position (first position) r _11. Thereafter, the motor control unit 92 moves the optical pickup 4 by the stepping motor 7, the objective lens 5a for red-based laser final manner the home position (second position) is moved to r _12. Red-based laser objective lens 5a is positioned in the final manner the home position (second position) r _12. Control unit 9, the stepping motor 7 when the red-based laser objective lens 5a is moved from the first-order home position (first position) r ₁₁ to the final manner the home position (second position) r ₁₂ based on the stepping pulse number for driving, obtaining a second position information corresponding to the final manner the home position (second position) r _12. Calculating section 91, the second position information corresponding to the first-order home position and a first position information corresponding to the (first position) r _11, the final home position (second position) r ₁₂ Thus, the third position information corresponding to the third position where the red laser objective lens 5a is first positioned as the home position after the next loading operation is calculated. The calculated third position information is newly stored in the EEPROM 10 by the controller 9, and is used as the first position information after the next loading.

Further, the optical disc apparatus 1, new, for example, when blue-based laser for an optical disk as the optical disk 2 is loaded, the sensor 11 detects the position r ₀₂ of the innermost side of the disc, the control unit 9, EEPROM 10 The primary home position (first position) r ₂₁ is set from the position information (first position information) read out from, and the motor control unit 92 sets the blue _color with reference to the innermost position r _02. the objective lens 5b for the system laser to set the stepping pulses of the stepping motor 7 for driving required to move to the first-order home position (first position) r _21. Stepping motor 7 is driven by a stepping pulse number the pulse, by moving the optical pickup 4 to move the objective lens 5b for blue-based laser in the 1-order home position (first position) r _21. Thereafter, the motor control unit 92 further moves the optical pickup 4 by the stepping motor 7, for moving the objective lens 5b ultimately manner home position (second position) r _22. Blue-based laser objective lens 5b is positioned in the final manner the home position (second position) r _22. Control unit 9, the stepping motor 7 when the objective lens 5b is for blue-based laser moves from the first-order home position (first position) r ₂₁ to the final manner the home position (second position) r ₂₂ based on the stepping pulse number for driving, obtaining a second position information corresponding to the final manner the home position (second position) r _22. The calculation unit 91 includes first position information corresponding to the primary home position (first position) r ₂₁ and second position information corresponding to the final home position (second position) r _22. Thus, the third position information corresponding to the third position where the blue laser objective lens 5b is first positioned as the home position after the next loading operation is calculated. The calculated third position information is newly stored in the EEPROM 10 by the controller 9, and is used as the first position information after the next loading.

FIG. 3 is an operation flowchart when the objective lenses 5a and 5b are positioned at the home position in the optical disc apparatus 1 of FIG.
In FIG.
(1) The controller 9 starts the positioning operation of the red laser objective lens 5a or the blue laser objective lens 5b to the home position (step S301). At this time, when the loaded optical disk is a red laser optical disk, the control unit 9 starts the positioning operation with respect to the red laser objective lens 5a, and the loaded optical disk is a blue laser. In the case of the optical disk for positioning, the positioning operation with respect to the blue laser objective lens 5b is started.
(2) The control unit 9 controls the optical disc apparatus 1 to load the optical disc 2 (step S302).
(3) After loading the optical disk 2, the motor controller 92 controls the motor drive circuit 8 to drive the stepping motor 7 to move and displace the optical pickup 4. Thereby, the sensor 11 detects the movement position of the objective lenses 5a and 5b corresponding to the position on the innermost circumference side of the optical disc 2. After loading of the optical disc 2, the motor control unit 92 of the control unit 9 controls the motor drive circuit 8 to drive the stepping motor 7, thereby moving and displacing the optical pickup 4, and the red laser objective lens 5a or the blue laser. The objective lens 5b is moved to the first position as the primary home position (step S303). At this time, the movement is performed with reference to the movement position (the movement position of the optical pickup 4 or the movement positions of the objective lenses 5a and 5b) on the innermost circumference side of the optical disc 2 detected by the sensor 11.
(4) Thereafter, the motor control unit 92 further controls the motor drive circuit 8 to drive the stepping motor 7 to move and displace the optical pickup 4, so that the red laser objective lens 5 a or the blue laser objective lens is obtained. 5b is moved from the first position to the second position as the final home position, that is, the innermost circumferential position of the data area of the optical disc 2, and finally positioned at the position (step S304).
(5) After the loading operation of the optical disc 2, the calculation unit 91 performs the next loading operation from the first position information corresponding to the first position and the second position information corresponding to the second position. Later, the third position information corresponding to the third position where the red laser objective lens 5a or the blue laser objective lens 5b is initially positioned is calculated as the home position. The control unit 9 stores the calculated third position information in the EEPROM 10 (step S305).
(6) The control unit 9 ends the positioning operation of the objective lens 5a or 5b to the home position (step S306).

  According to the optical disk device 1 of the above embodiment, the information stored in the EEPROM 10 in advance as the first position information of the objective lens 5a or 5b is used, and the movement to the first position and the second position is performed. Is obtained by supplying stepping pulses having the number of pulses corresponding to the position information of the respective positions to the stepping motor 7, so that the acquisition of the position information of the objective lens 5a or 5b and the movement to the home position can be performed in a short time. Can be done. Further, since the positioning to the home position is performed every time the optical disk 2 is loaded, the positioning corresponding to the type of the optical disk 2 and the variation of each disk can be performed, and accurate positioning is possible. In addition, since the objective lenses 5a and 5b are independently positioned to the home position, the objective lenses 5a and 5b can be positioned while suppressing the influence of individual position variations or mutual position variations. It becomes possible.

  The above embodiment is an example of an optical disc apparatus that can load two types of optical discs, a blue laser optical disc and a red laser optical disc, and has two objective lenses 5a and 5b corresponding to the optical disc device. Although described above, the present invention is not limited to this. For example, the present invention may be an optical disc apparatus that can load one type of optical disc and has one objective lens, or three or more types of optical discs. And an optical disc apparatus having three or more objective lenses. In FIG. 2, the control unit 9 sets the position where the position information frequency becomes the maximum as the first position of the objective lens. However, the position where the position information frequency becomes the average value is set as the first position of the objective lens. You may make it set as this position.

It is an example of a structure of the optical disk apparatus of the Example of this invention. It is explanatory drawing of the home position of the objective lens in the optical disk apparatus of FIG. FIG. 5 is an operation flowchart when the objective lens is positioned at a home position in the optical disc apparatus of FIG. 1.

Explanation of symbols

1 ... Optical disk device,
2 ... Optical disc,
3 ... Spindle motor,
4 ... Optical pickup,
5a, 5b ... objective lens,
6 ... moving mechanism,
7 ... Stepping motor,
8 ... Motor drive circuit,
9: Control unit,
91 ... arithmetic unit,
92 ... motor control unit,
10 ... EEPROM,
11: Sensor.

Claims (4)

An optical disc apparatus that records or reproduces information by irradiating an optical disc with a laser beam from an objective lens of an optical pickup,
A sensor for detecting a movement position of the optical pickup or the objective lens on the innermost peripheral side of the optical disc;
A stepping motor for moving the optical pickup in the radial direction of the disk by a distance corresponding to the number of drive pulses;
A motor drive circuit for driving the stepping motor;
A disc that is configured in a control unit that controls the optical disc apparatus, and after the loading operation of the optical disc, the objective lens is first positioned as a home position based on the detected movement position of the innermost circumference of the optical disc The first position information corresponding to the first position in the radial direction and the second position where the objective lens is finally positioned as the home position, which is the innermost circumferential position of the data area of the optical disc A calculation unit for calculating third position information corresponding to a third position in the disk radial direction where the objective lens is first positioned as a home position after the next loading operation from the second position information;
A motor control unit configured in a control unit for controlling the optical disc device, and forming a control signal for controlling the motor drive circuit based on the first, second and third position information;
A memory for storing at least the first position information and the third position information;
The objective lens is moved to the first position based on the first position information read from the memory, and then moved to the second position based on the second position information. The third position information is calculated based on the first position information and the second position information, the calculated third position information is stored in the memory, and the third position information is An optical disc apparatus characterized in that the first position information is used after the loading operation. When the frequency of the position information that is the first position information before the loading operation is n, after the loading operation, the calculation unit calculates the third position information as follows:
3rd position information = {(position information regarded as the first position information × n) + (second position information × 1)} / (n + 1)
The optical disk apparatus according to claim 1, wherein the optical disk apparatus is configured to calculate   2. The optical disc apparatus according to claim 1, wherein the calculation unit is configured to calculate the third position information after the loading operation using the position information having the highest frequency before the loading operation as the first position information. .   4. The structure according to claim 1, wherein the calculation unit calculates the third position information for each loading operation, and the memory stores the calculated third position information for each loading operation. An optical disk device according to the above.

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