JP2014086106A - Optical disk drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk drive which can accurately discriminate a type of an optical disk.SOLUTION: An optical disk drive 100 includes an optical pickup 1, an actuator 20, and a control part 8. The control part 8 performs control so as to: measure a time interval T1 starting with detection of reflected light from a recording surface 200a of an optical disk 200 and ending with detection of reflected light from a data layer 201 of the optical disk 200 by causing the optical pickup 1 to move in a direction toward the optical disk 200; measure a time interval T2 starting with detection of reflected light from the data layer 201 of the optical disk 200 and ending with detection of reflected light from the recording surface 200a of the optical disk 200 by causing the optical pickup 1 to move in a direction away from the optical disk 200; and to discriminate the type of the optical disk 200 on the basis of measurement results of the time intervals T1 and T2.

Description

  The present invention relates to an optical disk device, and more particularly to an optical disk device including a control unit that performs control for determining the type of an optical disk.

  2. Description of the Related Art Conventionally, there has been known an optical disc device including a control unit that performs control for discriminating the type of an optical disc (for example, see Patent Document 1).

  Patent Document 1 includes an optical pickup that detects light reflected from an optical carrier by irradiating the optical carrier (optical disk), and a system controller (control unit) that performs control for determining the type of the optical carrier. An optical carrier discriminating device (optical disc device) is disclosed. The system controller of this optical carrier discriminating apparatus moves the optical pickup in the direction approaching the optical carrier (or the direction away from the optical carrier), thereby detecting the detection timing and light of the reflected light from the surface (recording surface) of the optical carrier. The time interval between the detection timing of the reflected light from the signal surface (data layer) of the carrier is measured, and the type of the optical carrier is discriminated based on the measurement result. In this optical carrier discriminating apparatus, the time interval measured when the optical pickup is moved in the direction approaching the optical carrier and the time measured when the optical pickup is moved in the direction away from the optical carrier. It is considered that the type of the optical disc is determined based on only one of the measurement results of the interval.

JP 2000-293932 A

  Here, in the optical carrier discriminating device disclosed in the above-mentioned Patent Document 1, it is considered that since the optical pickup has its own weight, it cannot immediately start moving from a stationary state. That is, in a stationary state before the movement of the optical pickup toward the optical carrier (or away from the optical carrier) starts, for example, the drive value (voltage value) of the actuator for driving the optical pickup is linear. Even if it is changed, it is considered that the position of the optical pickup changes nonlinearly until a predetermined period elapses after the driving of the actuator is started. Therefore, during the period in which the position of the optical pickup changes nonlinearly, the time interval between the detection timing of the reflected light from the surface (recording surface) of the optical carrier and the detection timing of the reflected light from the signal surface of the optical carrier When measurement is performed, it is considered that there is a problem that the type of the optical carrier cannot be accurately determined.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to provide an optical disc apparatus capable of accurately discriminating the type of the optical disc.

  In order to achieve the above object, an optical disc apparatus according to one aspect of the present invention includes an optical pickup for irradiating light on an optical disc to detect reflected light from the optical disc, and the optical pickup perpendicular to the recording surface of the optical disc. An actuator that moves in a direction of approaching or a direction that is perpendicular to the recording surface of the optical disc, and a control unit that controls the movement of the optical pickup by controlling the driving of the actuator, and the control unit approaches the optical pickup to the optical disc. By driving the actuator so that it moves in the direction, the reflected light from the recording surface of the optical disc is detected by the optical pickup until the reflected light from the data layer included in the optical disc is detected by the optical pickup. And measuring the first time interval of the optical pickup By driving the actuator so as to move away from the disk, the reflected light from the data layer of the optical disk is detected by the optical pickup until the reflected light from the recording surface of the optical disk is detected by the optical pickup. A second time interval is measured, and control for discriminating the type of the optical disc is performed based on the measurement results of the first time interval and the second time interval.

  In the optical disc apparatus according to one aspect of the present invention, by configuring as described above, either the first time interval or the second time interval is measured during a period in which the position of the optical pickup changes nonlinearly. As a result, even if the measurement result of one of the first time interval and the second time interval is inaccurate, the type of the optical disc is determined based on the other measurement result. Therefore, the type of the optical disc can be accurately determined.

  In the optical disc apparatus according to the above aspect, the control unit preferably has a first time interval or a second time interval during a period in which the position of the optical pickup changes nonlinearly with respect to a linear change in the driving value of the actuator. When the first time interval and the second time interval are different from each other due to measurement of the optical disc, the type of the optical disc is determined based on the comparison result between the first time interval and the second time interval. Is configured to do. If comprised in this way, even if any one measurement result of a 1st time interval and a 2nd time interval is inaccurate, it will be based on the comparison result of a 1st time interval and a 2nd time interval. Thus, the type of the optical disc can be determined more accurately.

  In this case, preferably, the control unit is configured to determine the type of the optical disk based on the smaller one of the first time interval and the second time interval. According to this configuration, the type of the optical disk can be more accurately determined based on the smaller one of the first time interval and the second time interval.

  In the optical disc apparatus including the control unit that determines the type of the optical disc based on the comparison result of the first time interval and the second time interval, the control unit preferably has a distance between the optical pickup and the optical disc. In a state smaller than the predetermined reference value, the second time interval is subtracted from the first time interval due to the measurement of the first time interval during the period in which the position of the optical pickup changes nonlinearly. When the value is larger than a predetermined threshold, the first time interval is corrected, and the type of the optical disc is determined based on the corrected first time interval. If comprised in this way, based on the 1st time interval after correction | amendment, the kind of optical disk can be discriminate | determined more easily easily.

  In this case, preferably, the control unit is configured to correct the first time interval by multiplying the first time interval by a predetermined first correction coefficient. If comprised in this way, a 1st time interval can be correct | amended easily using a 1st correction coefficient.

  In the optical disc apparatus including the control unit that corrects the first time interval when a value obtained by subtracting the second time interval from the first time interval is larger than a predetermined threshold value, preferably, the control unit includes: The first time interval is based on the third time interval from the start of the movement of the optical pickup in the direction approaching the optical disc until the reflected light from the recording surface of the optical disc is detected by the optical pickup. The first time interval is corrected by multiplying by two correction factors. If comprised in this way, a 1st time interval can be correct | amended easily using a 2nd correction coefficient.

  In the optical disc apparatus including the control unit that corrects the first time interval when a value obtained by subtracting the second time interval from the first time interval is larger than a predetermined threshold value, preferably, the control unit includes: In the first time interval, the actuator in the third time interval from when the optical pickup starts moving toward the optical disc until the reflected light from the recording surface of the optical disc is detected by the optical pickup. The first time interval is corrected by multiplying the third correction coefficient based on the change amount of the drive value. If comprised in this way, a 1st time interval can be correct | amended easily using a 3rd correction coefficient.

  In the optical disk device according to the above aspect, the control unit is preferably configured to determine the type of the optical disk based on an average value of the first time interval and the second time interval. With this configuration, the type of the optical disk can be easily determined accurately based on the average value of the first time interval and the second time interval.

  According to the present invention, as described above, the type of the optical disk can be accurately determined.

1 is a schematic diagram showing an overall configuration of an optical disc device according to a first embodiment of the present invention. It is the schematic which showed the structure of the optical pick-up of the optical disk apparatus by 1st Embodiment of this invention. FIG. 5 is an image diagram showing a change in the position of the optical pickup and a change in the drive value of the actuator when the type of the optical disc is determined by the control unit of the optical disc apparatus according to the first embodiment of the present invention. 5 is a flowchart showing a processing flow executed when the type of the optical disc is determined by the control unit of the optical disc apparatus according to the first embodiment of the present invention. It is the flowchart which showed the processing flow performed when the kind of optical disk is discriminate | determined by the control part of the optical disk apparatus by 2nd Embodiment of this invention. It is the flowchart which showed the processing flow performed when the kind of optical disk is discriminate | determined by the control part of the optical disk apparatus by 3rd Embodiment of this invention.

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

(First embodiment)
First, a schematic configuration of the optical disc apparatus 100 according to the first embodiment of the present invention will be described with reference to FIG.

  The optical disc device 100 according to the first embodiment is configured to be able to reproduce an optical disc 200 such as a CD (Compact Disc), a DVD (Digital Versatile Disc), and a BD (Blu-Ray Disc). The optical disc 200 includes a data layer 201 extending in the left-right direction (X direction), and a resin layer 202 made of polycarbonate or the like formed so as to sandwich the data layer 201 from both sides in the up-down direction (Y direction). The optical disc apparatus 100 includes an optical pickup 1, an RF (Radio Frequency) amplifier 2, a reproduction processing circuit 3, an output circuit 4, a driver 5, a feed motor 6, a spindle motor 7, and a control unit 8. Is provided.

  The optical pickup 1 has a function of reading various information (such as audio information and video information) recorded on the optical disc 200 by irradiating the optical disc 200 with a laser beam (light) and detecting light reflected by the optical disc 200. Have. The detailed configuration of the optical pickup 1 will be described later.

  The RF amplifier 2 has a function of amplifying a reproduction signal based on various information read by the optical pickup 1. In addition, the reproduction processing circuit 3 acquires the reproduction signal amplified by the RF amplifier 2 via the control unit 8, and performs various processes for reproduction (for example, image processing) on the reproduction signal. It is configured. Further, the output circuit 4 outputs a video and audio recorded on the optical disc 200 through a monitor and a speaker (not shown), respectively, so that the signal processed by the reproduction processing circuit 3 is D / A (Digital / Analog). ) It is configured to perform conversion processing.

  The driver 5 is configured to control the operations of the feed motor 6 and the spindle motor 7 based on instructions from the control unit 8. The driver 5 is also configured to control operations of an actuator 20 and a BEX (Beam Expander) motor 21 (see FIG. 2), which will be described later, provided inside the optical pickup 1 based on an instruction from the control unit 8. Has been. The feed motor 6 has a function of moving the optical pickup 1 in the left-right direction (X direction). The spindle motor 7 has a function of rotating the optical disc 200.

  The control unit 8 generates a focus error (FE) signal and a tracking error (TE) signal based on a reproduction signal output from a photodetector 19 (see FIG. 2) described later provided inside the optical pickup 1. Is configured to do. Further, the control unit 8 drives the actuator 20 so as to move the optical pickup 1 in the up and down direction (Y direction) based on the FE signal during reproduction of the optical disc 200, thereby controlling the light from the optical pickup 1. In addition to performing control for adjusting the position of the focal point, tracking servo control (driving position of the optical pickup 1 by moving the optical pickup 1 in the left-right direction (X direction) based on the TE signal) (Control to adjust the).

  Further, the controller 8 adjusts the spherical aberration, the focus balance, and the lens tilt of the optical pickup 1 based on the reproduction signal output from the optical detector 19 before recording / reproducing of the optical disc 200. Configured to do. Here, “before recording / reproducing of the optical disc 200” is a timing before reproducing the optical disc 200 or recording on the optical disc 200, such as immediately after the optical disc 200 is inserted into the optical disc apparatus 100. Note that the control unit 8 is not limited to before recording / reproduction, and even after recording / reproduction is started, the spherical aberration of the optical pickup 1 is adjusted and focused at a predetermined timing based on the change in the environmental temperature of the optical disc apparatus 100. Balance adjustment, lens tilt adjustment, and the like can be performed.

  Next, a detailed configuration of the optical pickup 1 of the optical disc apparatus 100 according to the first embodiment will be described with reference to FIG.

  As shown in FIG. 2, the optical pickup 1 includes a light source 11, a cylindrical lens 12, a beam splitter 13, a mirror 14, a quarter wavelength plate 15, a collimator lens 16, an objective lens 17, and a detection lens. 18, a photodetector 19, an actuator 20, and a BEX motor 21.

  The light source 11 is configured by an LD (Laser Diode) capable of emitting a laser beam. The cylindrical lens 12 has a function of converting the laser beam emitted from the light source 11 into parallel light. The beam splitter 13 functions as a light separation element that separates the laser beam. Specifically, the beam splitter 13 transmits the laser beam incident from the cylindrical lens 12 side to the mirror 14 side and reflects the reflected light from the optical disc 200 incident from the mirror 14 side to the photodetector 19 side. Is configured to do.

  The mirror 14 is configured to reflect the laser beam incident from the beam splitter 13 side to the optical disc 200 side and reflect the reflected light from the optical disc 200 incident from the optical disc 200 side to the beam splitter 13 side. . Specifically, the mirror 14 is provided with an inclination of 45 degrees with respect to the optical axis of the laser beam incident from the beam splitter 13 side, and the laser beam incident from the beam splitter 13 side is directed to the optical disc 200. So that the light is reflected in a substantially orthogonal direction.

  The quarter wavelength plate 15 has a function of converting linearly polarized light into circularly polarized light and converting circularly polarized light into linearly polarized light. As a result, the quarter-wave plate 15 converts the linearly polarized laser beam incident from the mirror 14 side into circularly polarized light and guides it to the collimator lens 16 side, and also reflects the circularly polarized laser beam reflected by the optical disc 200. It is configured to be converted into linearly polarized light and guided to the mirror 14 side.

  The collimator lens 16 is configured to be movable in the optical axis direction (Y direction orthogonal to the optical disc 200) by the BEX motor 21. The collimator lens 16 is moved in the optical axis direction, and the laser beam transmitted through the collimator lens 16 is diverged and converged so that the spherical aberration of the optical pickup 1 is adjusted. .

  The objective lens 17 has a function of condensing a laser beam incident from the collimator lens 16 side onto the optical disc 200. The objective lens 17 is configured to be movable in the left-right direction (X direction) and the up-down direction (Y direction) by the actuator 20, and its position is moved by the focus servo control and tracking servo control by the control unit 8. . The objective lens 17 is configured such that the tilt can be changed by the actuator 20.

  The detection lens 18 has a function of condensing the reflected light from the optical disc 200 on the photodetector 19. That is, the reflected light from the optical disc 200 is collected on the photodetector 19 via the objective lens 17, the collimator lens 16, the quarter wavelength plate 15, the mirror 14, the beam splitter 13, and the detection lens 18. The photodetector 19 has a function of converting optical information received using a light receiving element (not shown) such as a photodiode into an electrical signal and outputting the electrical signal to the control unit 8 (see FIG. 1). ing.

  The actuator 20 is configured to be able to move the objective lens 17 in the left-right direction (X direction) and the up-down direction (Y direction) based on the objective lens drive signal generated by the driver 5 (see FIG. 1). Has been. In addition, the actuator 20 is configured to be able to change the tilt of the objective lens 17 based on the objective lens drive signal generated by the driver 5.

  The electrical signal output from the photodetector 19 to the control unit 8 is used to generate a focus error (FE) signal and a tracking error (TE) signal. The control unit 8 performs arithmetic processing using the electrical signal from the photodetector 19 to generate an FE signal and a TE signal. Specifically, the control unit 8 generates an FE signal and a TE signal by the astigmatism method using the electrical signal from the photodetector 19.

  Here, in the first embodiment, the control unit 8 (see FIG. 1) determines the type of the optical disc 200 (for example, whether the optical disc 200 is a CD, a DVD, or a BD). Discriminating function). Specifically, first, the control unit 8 moves the optical pickup 1 in a direction (upward direction: arrow Y1 direction) approaching perpendicular to the recording surface (surface on the arrow Y2 direction side) 200a of the optical disc 200. The time from when the reflected light from the recording surface 200 a of the optical disc 200 is detected by the optical pickup 1 until the reflected light from the data layer 201 of the optical disc 200 is detected by the optical pickup 200 by driving the actuator 20. It is configured to measure the interval T1 (see FIG. 3). The time interval T1 is an example of the “first time interval” in the present invention. This time interval T1 is measured by a timer (not shown) provided in the control unit 8.

  Further, the control unit 8 measures the time interval T1 (see FIG. 3) as described above, and then moves the optical pickup 1 vertically away from the recording surface (surface on the arrow Y2 direction side) 200a of the optical disc 200 (downward direction). The actuator 20 is driven to move in the direction of arrow Y2), and the reflected light from the data layer 201 of the optical disc 200 is detected by the optical pickup 200, and then the reflected light from the recording surface 200a of the optical disc 200 is picked up by the optical pickup. 1 is configured to measure a time interval T2 (see FIG. 3) until it is detected by 1. The time interval T2 is an example of the “second time interval” in the present invention. This time interval T2 is also measured by a timer (not shown) provided in the control unit 8, similarly to the time interval T1.

  Then, the control unit 8 is configured to perform control for determining the type of the optical disc 200 based on the measurement results of the time intervals T1 and T2 (see FIG. 3). Specifically, the control unit 8 is configured to measure the vertical distance (Y direction) between the recording surface 200a of the optical disc 200 and the data layer 201 based on the measurement results of the time intervals T1 and T2. ing. Note that the distance between the recording surface 200 a of the optical disc 200 and the data layer 201 is determined by the standard according to the type of the optical disc 200. Thus, the control unit 8 can determine the type of the optical disc 200 based on the distance between the recording surface 200a of the optical disc 200 and the data layer 201 measured as described above.

  Here, since the optical pickup 1 has its own weight, it cannot move suddenly from a stationary state, or cannot move suddenly. That is, as shown in FIG. 3, even when the change in the drive value (voltage value) of the actuator 20 (see the alternate long and short dash line) is linear, the optical pickup 1 is used in a predetermined period immediately after the drive of the actuator 20 is started. The change in position (see the two-dot chain line) becomes nonlinear. For example, in FIG. 3, a predetermined period (a period between times t0 and t1) immediately after the optical pickup 1 stationary at the initial position starts to move, and the direction in which the optical pickup 1 moves closer to the optical disc 200 The position of the optical pickup 1 changes nonlinearly in a predetermined period (a period between times t2 and t3) immediately after switching from the direction (arrow Y1) to the direction away from the optical disc 200 (direction arrow Y2). In the case where the time intervals T1 and T2 (see FIG. 3) are measured in the period in which the position of the optical pickup 1 changes nonlinearly as described above, as described later, in the period in which the position of the optical pickup 1 changes linearly. Compared to the case where the time intervals T1 and T2 are measured, the measured time intervals T1 and T2 are likely to be large, and the measurement results are likely to vary. The distance may not be measured accurately.

  Thus, in order to accurately measure the distance between the recording surface 200a of the optical disc 200 and the data layer 201, the detection timing of the reflected light from the recording surface 200a of the optical disc 200 (in FIG. a4, times b1 and b4 in FIG. 3B, and detection timing of reflected light from the data layer 201 of the optical disc 200 (time a2 and a3 in FIG. 3A, time in FIG. 3B) b2 and b3) must both exist in a period in which the position of the optical pickup 1 changes linearly (a period between times t0 and t1 and a period between times t2 and t3).

  As shown in FIG. 3A, the distance between the optical pickup 1 and the optical disc 200 is less than a predetermined reference value due to, for example, surface blurring of the optical disc 200 or a mechanical failure of the optical pickup 1. When the optical pickup 1 is small, the detection timing (time a3) of the reflected light from the data layer 201 of the optical disc 200 and the optical disc 200 when the optical pickup 1 moves in the direction away from the optical disc 200 (the direction of the arrow Y2). Both the detection timing (time a4) of the reflected light from the recording surface 200a exist in a period (period between time t2 and t3) in which the position of the optical pickup 1 changes linearly. On the other hand, when the optical pickup 1 is moving in the direction approaching the optical disc 200 (arrow Y1 direction), the detection timing (time a1) of the reflected light from the recording surface 200a of the optical disc 200 and the data layer of the optical disc 200 Both the detection timing (time a2) of the reflected light from 201 exist in a period (period between time t0 and t1) in which the position of the optical pickup 1 changes nonlinearly.

  Here, the time interval T1 between the times a1 and a2 measured when the optical pickup 1 moves in the direction approaching the optical disk (arrow Y1 direction), and the direction in which the optical pickup 1 moves away from the optical disk (arrow Y2 direction). When the time interval T2 between the times a3 and a4 measured when moving to) is compared, the measurement is performed during a period in which the position of the optical pickup 1 changes linearly (period between the times t3 and t4). The measured time interval T2 is smaller than the time interval T1 measured during the period in which the position of the optical pickup 1 changes nonlinearly (the period between times t0 and t1). In this case, in the first embodiment, the control unit 8 determines the distance in the vertical direction (Y direction) between the recording surface 200a of the optical disc 200 and the data layer 201 based on the time interval T2 smaller than the time interval T1. And the type of the optical disc 200 is discriminated based on the measurement result.

  Further, as shown in FIG. 3B, when the distance between the optical pickup 1 and the optical disc 200 is large (when it is equal to or larger than a predetermined reference value), the direction in which the optical pickup 1 approaches the optical disc 200 (the direction of the arrow Y1). ), The detection timing (time b1) of the reflected light from the recording surface 200a of the optical disc 200 and the detection timing (time b2) of the reflected light from the data layer 201 of the optical disc 200 are both It exists in the period (period between time t1 and t2) when the position of the optical pickup 1 changes linearly. On the other hand, when the optical pickup 1 is moving in the direction away from the optical disc 200 (the direction of the arrow Y2), the detection timing (time b3) of the reflected light from the data layer 201 of the optical disc 200 and the recording surface of the optical disc 200 Both the detection timing (time b4) of the reflected light from 200a exist in a period (period between time t2 and t3) in which the position of the optical pickup 1 changes nonlinearly.

  Here, the time interval T1 between the times b1 and b2 measured when the optical pickup 1 moves in the direction approaching the optical disk (arrow Y1 direction), and the direction in which the optical pickup 1 moves away from the optical disk (arrow Y2 direction). When the time interval T2 between the times b3 and b4 measured when moving to) is compared, it is measured during a period in which the position of the optical pickup 1 changes linearly (a period between times t1 and t2). The measured time interval T1 is smaller than the time interval T2 measured during the period in which the position of the optical pickup 1 changes nonlinearly (period between time t2 and t3). In this case, in the first embodiment, the control unit 8 determines the distance in the vertical direction (Y direction) between the recording surface 200a of the optical disc 200 and the data layer 201 based on the time interval T1 smaller than the time interval T2. And the type of the optical disc 200 is discriminated based on the measurement result.

  As described above, in the first embodiment, the control unit 8 is configured to compare the time intervals T1 and T2 (see FIG. 3) and determine the type of the optical disc 200 based on the comparison result. Yes. Specifically, first, the control unit 8 accurately determines the distance in the vertical direction (Y direction) between the recording surface 200a of the optical disc 200 and the data layer 201 based on the smaller one of the time intervals T1 and T2. Configured to measure. The control unit 8 is configured to determine the type of the optical disc 200 based on an accurate measurement result of the distance between the recording surface 200a of the optical disc 200 and the data layer 201.

  Next, a processing flow executed when the type of the optical disc 200 is determined by the control unit 8 of the optical disc apparatus 100 according to the first embodiment of the present invention will be described with reference to FIG.

  In this processing flow, first, as shown in FIG. 4, in step S1, a process of causing the light source 11 to emit light is executed. Then, the process proceeds to step S2.

  Next, in step S2, a process of starting timing is executed by a timer (not shown) provided in the control unit 8 (see FIG. 1). Then, the process proceeds to step S3.

  Next, in step S3, a process of driving the actuator 20 so as to move the optical pickup 1 in a direction approaching the optical disc 200 (upward direction: arrow Y1) is executed. Then, the process proceeds to step S4.

  Next, in step S4, a process of determining whether or not the reflected light from the recording surface (surface on the arrow Y2 direction side) 200a of the optical disc 200 has been detected by the optical pickup 1 is executed. In step S4, when the reflected light from the recording surface 200a of the optical disc 200 is not detected by the optical pickup 1, the process returns to step S3. If the reflected light from the recording surface 200a of the optical disc 200 is detected by the optical pickup 1 in step S4, the process proceeds to step S5.

  Next, in step S5, a process of driving the actuator 20 so as to further move the optical pickup 1 in a direction approaching the optical disc 200 (upward direction: arrow Y1) is executed. Then, the process proceeds to step S6.

  Next, in step S6, it is determined whether or not the reflected light from the data layer 201 of the optical disc 200 is detected by the optical pickup 1. If the reflected light from the data layer 201 of the optical disc 200 is not detected by the optical pickup 1 in step S6, the process returns to step S5. If the reflected light from the data layer 201 of the optical disc 200 is detected by the optical pickup 1 in step S6, the process proceeds to step S7.

  Next, in step S7, the reflected light from the recording surface 200a (the surface on the arrow Y2 direction side) of the optical disc 200 is detected by the optical pickup 1, and then the reflected light from the data layer 201 of the optical disc 200 is reflected by the optical pickup 200. A process of acquiring a time interval T1 (see FIG. 3) until detection is performed. Then, the process proceeds to step S8.

  Next, in step S8, a process of switching the moving direction of the optical pickup 1 from a direction approaching the optical disc 200 (upward direction: arrow Y1) to a direction away from the optical disc 200 (downward direction: arrow Y2) is executed. Then, the process proceeds to step S9.

  Next, in step S9, a process of driving the actuator 20 so as to move the optical pickup 1 in a direction away from the optical disc 200 (downward direction: arrow Y1) is executed. Then, the process proceeds to step S10.

  Next, in step S <b> 10, processing for determining whether or not the reflected light from the data layer 201 of the optical disc 200 has been detected by the optical pickup 1 is executed. If the reflected light from the data layer 201 of the optical disc 200 is not detected by the optical pickup 1 in step S10, the process returns to step S9. If the reflected light from the data layer 201 of the optical disc 200 is detected by the optical pickup 1 in step S10, the process proceeds to step S11.

  Next, in step S11, a process of driving the actuator 20 so as to further move the optical pickup 1 in a direction away from the optical disc 200 (downward direction: arrow Y2) is executed. Then, the process proceeds to step S12.

  Next, in step S12, it is determined whether or not reflected light from the recording surface (surface on the arrow Y2 direction) 200a of the optical disc 200 is detected by the optical pickup 1. In this step S12, when the reflected light from the recording surface 200a of the optical disc 200 is not detected by the optical pickup 1, the process returns to step S11. In step S12, when the reflected light from the recording surface 200a of the optical disc 200 is detected by the optical pickup 1, the process proceeds to step S13.

  Next, in step S 13, the reflected light from the data layer 201 of the optical disc 200 is detected by the optical pickup 1, and then the reflected light from the recording surface (surface on the arrow Y 2 direction) 200 a of the optical disc 200 is reflected by the optical pickup 200. A process of acquiring a time interval T2 (see FIG. 3) until detection is performed. Then, the process proceeds to step S14.

  Next, in step S14, the time interval T1 (see FIG. 3) acquired by the process of step S7 is compared with the time interval T2 (see FIG. 3) acquired by the process of step S13. The process of selecting the smaller one is executed. Then, the process proceeds to step S15.

  Next, in step S15, a process of determining the type of the optical disc 200 is executed based on the smaller one of the time intervals T1 and T2 (see FIG. 3) selected in the process of step S14.

  Thus, the processing flow for determining the type of the optical disc 200 is completed.

  In the first embodiment, as described above, the control unit 8 controls the time interval T1 (see FIG. 3) measured when the optical pickup 1 is moved in a direction approaching the optical disc 200, and the optical pickup 1 is connected to the optical disc 200. Control is performed to determine the type of the optical disc 200 based on the measurement result with the time interval T2 (see FIG. 3) measured when moving in a direction away from the optical disc. As a result, even if the measurement result of one of the time intervals T1 and T2 is inaccurate due to the measurement of the time intervals T1 and T2 during the period in which the position of the optical pickup 1 changes nonlinearly. Further, since the type of the optical disc 200 is determined based on the other measurement result, the type of the optical disc 200 can be accurately determined.

  Further, in the first embodiment, as described above, the control unit 8 causes the position of the optical pickup 1 to change nonlinearly with respect to a linear change in the drive value of the actuator 20 (time t0 and t1 in FIG. 3). And the time interval T1 and T2 when the time intervals T1 and T2 are different from each other due to the time interval T1 or T2 being measured in the period between and t2 and t3). The type of the optical disc 200 is determined based on the comparison result of T2. Thereby, even if the measurement result of any one of the time intervals T1 and T2 is inaccurate, the type of the optical disc 200 can be more accurately determined based on the comparison result of the time intervals T1 and T2.

  In the first embodiment, as described above, the control unit 8 is configured to determine the type of the optical disc 200 based on the smaller one of the time intervals T1 and T2 (see FIG. 3). Thereby, based on the smaller one of the time intervals T1 and T2, the type of the optical disk 200 can be more accurately discriminated more easily.

(Second Embodiment)
Next, an optical disc device 100a according to a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, unlike the first embodiment in which the type of the optical disc 200 is determined based on the smaller one of the time intervals T1 and T2 (see FIG. 3), the measured value or the time interval of the time interval T1. An example in which the type of the optical disc 200 is discriminated based on the correction value of T1 will be described.

  Also in the second embodiment, as in the first embodiment, the control unit 8a of the optical disc apparatus 100a measures the time interval T1 measured by moving the optical pickup 1 in the direction approaching the optical disc 200 (the direction of the arrow Y1). (See FIG. 3) and the time interval T2 (see FIG. 3) measured by moving the optical pickup 1 in the direction away from the optical disc 200 (the direction of the arrow Y2), and based on the comparison result, the optical disc It is configured to discriminate 200 types.

  Here, in the second embodiment, the control unit 8a determines that the time interval T1 is larger than the time interval T2 due to the distance between the optical pickup 1 and the optical disc 200 being smaller than a predetermined reference value. In FIG. 3A, the time interval T1 is corrected so as to approach the time interval T2, and the optical disc is corrected based on the corrected time interval T1 (a time interval smaller than the actual measurement value of the time interval T1). It is configured to discriminate 200 types. Specifically, the control unit 8a is configured to correct the time interval T1 when a value obtained by subtracting T2 from the time interval T1 is larger than a predetermined threshold T_th (see FIG. 3A). ing.

  In the second embodiment, as a correction method of the time interval T1 (see FIG. 3A) measured when the value obtained by subtracting T2 from the time interval T1 is larger than a predetermined threshold T_th, the following method is used. Three methods are used. Specifically, a method of multiplying the time interval T1 (actually measured value) by a predetermined first correction coefficient (α: α is a constant equal to or less than 1) and driving of the actuator 20 (movement of the optical pickup 1) at the time interval T1. ) Until the reflected light from the recording surface 200a of the optical disc 200 is detected by the optical pickup 1 (see the time interval between time t0 and a1 in FIG. 3A). And a change amount D of the drive value of the actuator 20 corresponding to the time interval τ in the time interval T1 (FIG. 3A). And a method of multiplying by a third correction coefficient (γ × D: γ is a constant equal to or less than 1) based on (see FIG. 4).

  In the second embodiment, when the value obtained by subtracting T2 from the time interval T1 is larger than the predetermined threshold value T_th (see FIG. 3A), the control unit 8a The time interval T1 (actually measured value) is corrected using such one correction method. Thus, the time interval T1 when the value obtained by subtracting T2 from the time interval T1 is larger than the predetermined threshold T_th (the time interval T1 measured during the period in which the position of the optical pickup 1 changes nonlinearly: FIG. a) is corrected so as to approach the time interval T2 (see FIG. 3A) measured during a period in which the position of the optical pickup changes linearly, and between the optical pickup 1 and the optical disc 200. The distance is corrected so as to approach the time interval T1 (see FIG. 3B) when the distance is equal to or greater than a predetermined reference value.

  In the second embodiment, the control unit 8 causes the time interval T1 to be smaller than the time interval T2 due to the distance between the optical pickup 1 and the optical disc 200 being a predetermined reference value or more ( In FIG. 3B, the type of the optical disc 200 is discriminated by using the actually measured time interval T1 without correction. That is, in the case of FIG. 3B, since the time interval T1 is measured during the period in which the position of the optical pickup 1 changes linearly, the actual value of the time interval T1 is used as it is, and the type of the optical disc 200 is changed. Determined.

  In addition, the other structure of 2nd Embodiment is the same as that of the said 1st Embodiment.

  Next, a processing flow executed when the type of the optical disc 200 is determined by the control unit 8a of the optical disc apparatus 100a according to the second embodiment of the present invention will be described with reference to FIG.

  The processing in steps S21 to S33 of the processing flow according to the second embodiment shown in FIG. 5 is the same as the processing of steps S1 to S13 in the processing flow according to the first embodiment shown in FIG. Description is omitted.

  In the processing flow according to the second embodiment, as shown in FIG. 5, in step S34, the time acquired by the processing of step S27 (the same processing as step S7 of the processing flow according to the first embodiment shown in FIG. 4). A value obtained by subtracting the time interval T2 (see FIG. 3) acquired by the processing in step S33 (the same processing as step S4 in the processing flow according to the first embodiment shown in FIG. 4) from the interval T1 (see FIG. 3). Is determined to be greater than a predetermined threshold T_th (a process for determining whether (T1-T2)> T_th).

  If it is determined in step S34 that (T1-T2)> T_th, the process proceeds to step S35. In step S35, a process of correcting the time interval T1 so that the value becomes smaller is executed. That is, the process proceeds from step S34 to step S35 because the distance between the optical pickup 1 and the optical disc 200 is smaller than a predetermined reference value (see FIG. 3A). In S35, the measured value of the time interval T1 obtained by the process of step S27 (see FIG. 3A) is used as the time when the distance between the optical pickup 1 and the optical disc 200 is larger than a predetermined reference value. A correction process is performed so as to approach the interval T1 (see FIG. 3B). Specifically, the measured value of the time interval T1 is multiplied by a predetermined first correction coefficient (α: α is a constant equal to or smaller than 1), or the measured value of the time interval T1 is multiplied by the time interval τ (see FIG. 3A). ) Based on the second correction coefficient (β × τ: β is a constant equal to or less than 1), or the actual value of the time interval T1 is changed to the change amount D of the drive value of the actuator 20 (see FIG. 3A). Is multiplied by a third correction coefficient based on (γ × D: γ is a constant equal to or less than 1). Then, the process proceeds to step S36. In step S34, if it is determined that (T1-T2) ≦ T_th, the process proceeds to step S36.

  In step S36, a process of determining the type of the optical disc 200 based on the actual value of the time interval T1 acquired by the process of step S27 or the corrected time interval T1 corrected by the process of step S35. Executed. Specifically, when it is determined in step S34 that (T1-T2) ≦ T_th (when the distance between the optical disc 200 and the optical pickup 1 is equal to or greater than a predetermined reference value: see FIG. 3B). ), The type of the optical disc 200 is determined based on the actual measurement value of the time interval T1 acquired in step S27. When it is determined in step S34 that (T1-T2)> T_th (when the distance between the optical disc 200 and the optical pickup 1 is smaller than a predetermined reference value: see FIG. 3A). The type of the optical disc 200 is determined based on the corrected time interval T1 corrected by the process of step S35.

  Thus, the process flow according to the second embodiment is completed.

  In the second embodiment, as described above, in the state where the distance between the optical pickup 1 and the optical disc 200 is smaller than a predetermined reference value (see FIG. 3A), the control unit 8a Due to the fact that the time interval T1 is measured during the period in which the position changes nonlinearly (the period between the times t0 and t1), the time interval T1 to the time interval T2 (the time when the position of the optical pickup changes linearly). When the value obtained by subtracting the time interval between the times a3 and a4 (measured during the period between t3 and t4) is larger than a predetermined threshold T_th, the time interval T1 is corrected and corrected. The type of the optical disc 200 is determined based on the later time interval T1. Thereby, the type of the optical disc 200 can be easily determined accurately based on the corrected time interval T1.

  In the second embodiment, as described above, when the distance between the optical pickup 1 and the optical disc 200 is smaller than a predetermined reference value (see FIG. 3A), the control unit 8b The interval T1 (see FIG. 3A) is multiplied by a predetermined first correction coefficient (α: α is a constant equal to or less than 1), or the time interval T1 is multiplied by the time interval τ (see FIG. 3A). The second correction coefficient based on (β × τ: β is a constant equal to or less than 1) is multiplied, or the change amount D of the driving value of the actuator 20 corresponding to the time interval τ is added to the time interval T1 (FIG. 3A) The time interval T1 is corrected by multiplying by a third correction coefficient (γ × D: γ is a constant equal to or less than 1) based on the reference). Accordingly, the time interval T1 when the distance between the optical pickup 1 and the optical disc 200 is smaller than the predetermined reference value easily using the first correction coefficient, the second correction coefficient, or the third correction coefficient. Can be corrected.

  The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

(Third embodiment)
Next, an optical disc apparatus 100b according to a third embodiment of the present invention will be described with reference to FIGS. In the third embodiment, unlike the first embodiment in which the type of the optical disc 200 is determined based on the smaller one of the time intervals T1 and T2 (see FIG. 3), the average value of the time intervals T1 and T2 is obtained. An example in which the type of the optical disc 200 is discriminated based on it will be described.

  Also in the third embodiment, similarly to the first embodiment, the control unit 8b of the optical disc apparatus 100b moves the optical pickup 1 in the direction approaching the optical disc 200 (in the direction of the arrow Y1) to set the time interval T1 (FIG. 3). The optical pickup 1 is moved in the direction away from the optical disc 200 (in the direction of arrow Y2) and the time interval T2 (see FIG. 3) is measured to determine the type of the optical disc 200. ing.

  Here, in the third embodiment, the control unit 8b calculates the average value of the time intervals T1 and T2 when the time intervals T1 and T2 (see FIG. 3) measured as described above are different from each other. The type of the optical disc 200 is determined based on the average value of the time intervals T1 and T2. As shown in FIG. 3, when the distance between the optical pickup 1 and the optical disc 200 is smaller than a predetermined reference value (see FIG. 3A), and between the optical pickup 1 and the optical disc 200 In any case where the distance is equal to or greater than the predetermined reference value (see FIG. 3B), the time intervals T1 and T2 are different from each other. That is, in the case of FIG. 3A, the time interval T1 measured during the period in which the position of the optical pickup 1 changes nonlinearly is greater than the time interval T2 measured during the period in which the position of the optical pickup 1 changes linearly. Is also big. In the case of FIG. 3B, the time interval T1 measured during the period in which the position of the optical pickup 1 changes linearly is greater than the time interval T2 measured in the period in which the position of the optical pickup 1 changes nonlinearly. Is also small.

  The remaining configuration of the third embodiment is similar to that of the aforementioned first embodiment.

  Next, a processing flow executed when the type of the optical disc 200 is discriminated by the control unit 8b of the optical disc apparatus 100b according to the third embodiment of the present invention will be described with reference to FIG.

  The processes in steps S41 to S53 in the process flow according to the third embodiment shown in FIG. 6 are the same as the processes in steps S1 to S13 in the process flow according to the first embodiment shown in FIG. Description is omitted.

  In the processing flow according to the third embodiment, as shown in FIG. 6, in step S54, the time acquired by the processing of step S47 (the same processing as step S7 of the processing flow according to the first embodiment shown in FIG. 4). Average value of the interval T1 (see FIG. 3) and the time interval T2 (see FIG. 3) acquired by the processing in step S53 (the same processing as step S4 in the processing flow according to the first embodiment shown in FIG. 4). The process of calculating is executed. Then, the process proceeds to step S55.

  Next, in step S55, processing for determining the type of the optical disc 200 is executed based on the average value of the time intervals T1 and T2 (see FIG. 3) calculated by the processing in step S54.

  Thus, the processing flow according to the third embodiment is completed.

  In the third embodiment, as described above, the control unit 8b is configured to determine the type of the optical disc 200 based on the average value of the time intervals T1 and T2 (see FIG. 3). Accordingly, the type of the optical disc 200 can be easily determined accurately based on the average value of the time intervals T1 and T2.

  The remaining effects of the third embodiment are similar to those of the aforementioned first embodiment.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the first to third embodiments, an example in which the present invention is applied to an optical disc apparatus compatible with CD (Compact Disc), DVD (Digital Versatile Disc), and BD (Blu-Ray Disc) has been shown. The invention is not limited to this. The present invention can also be applied to an optical disc apparatus compatible with optical discs other than CD, DVD, and BD.

  In the first and second embodiments, when determining the type of the optical disc 200, the time interval T1 measured when the optical pickup 1 is moved in the direction approaching the optical disc 200 (arrow Y1 direction); Although the example in which the time interval T2 measured when the optical pickup 1 is moved in the direction away from the optical disc 200 (the direction of the arrow Y2) is directly compared is shown, the present invention is not limited to this. In the present invention, the time intervals T1 and T2 are indirectly compared by comparing the amount of change in the drive value of the actuator 20 in the time interval T1 with the amount of change in the drive value of the actuator 20 in the time interval T2. May be.

  In the second embodiment, when the value obtained by subtracting T2 from the time interval T1 is larger than the predetermined threshold T_th, the time interval T1 is corrected, and the optical disc 200 is based on the corrected time interval T1. On the other hand, when the value obtained by subtracting T2 from the time interval T1 is equal to or smaller than the predetermined threshold value T_th, the type of the optical disc 200 is determined using the time interval T1 without correction. However, the present invention is not limited to this. In the present invention, when the time interval T1 is larger than T2, the time interval T1 is corrected, and the type of the optical disc 200 is determined based on the corrected time interval T1, while the time interval T1 is T2 or less. In this case, the time interval T2 may be corrected, and the type of the optical disc 200 may be determined based on the corrected time interval T2.

  In the second embodiment, when it is determined that the distance between the optical pickup 1 and the optical disc 200 is smaller than a predetermined reference value (in the case of FIG. 3A), the time interval T1 (FIG. 3). (A)) is multiplied by a predetermined first correction coefficient (α: α is a constant equal to or smaller than 1), or the second correction coefficient based on the time interval T1 (see FIG. 3A). (Β × τ: β is a constant equal to or less than 1) or a time interval T1 based on a change amount D of the driving value of the actuator 20 corresponding to the time interval τ (see FIG. 3A). Although an example has been shown in which the time interval T1 is corrected so as to decrease by multiplying by three correction coefficients (γ × D: γ is a constant equal to or less than 1), the present invention is not limited to this. In the present invention, if the time interval T1 can be corrected so as to decrease the value, the time interval T1 can be corrected by a correction method other than the correction method using the first correction coefficient, the second correction coefficient, or the third correction coefficient. May be corrected.

  In the third embodiment, the distance between the recording surface 200a of the optical disc 200 and the data layer 201 is measured based on the average value of the time intervals T1 and T2 (see FIG. 3). Although the example which discriminate | determines a type was shown, this invention is not restricted to this. In the present invention, the change amount of the drive value of the actuator 20 corresponding to the average value is calculated based on the average value of the time intervals T1 and T2, and the optical disc 200 is calculated based on the calculated change amount of the drive value of the actuator 20. The distance between the recording surface 200a and the data layer 201 may be measured.

DESCRIPTION OF SYMBOLS 1 Optical pick-up 8, 8a, 8b Control part 20 Actuator 100, 100a, 100b Optical disk apparatus 200 Optical disk 200a Recording surface 201 Data layer

Claims (8)

An optical pickup for irradiating the optical disc with light and detecting reflected light from the optical disc;
An actuator for moving the optical pickup in a direction approaching perpendicular to the recording surface of the optical disc or in a direction away from the recording surface of the optical disc;
A controller that controls the movement of the optical pickup by controlling the drive of the actuator;
The control unit drives the actuator so as to move the optical pickup in a direction approaching the optical disc, so that reflected light from the recording surface of the optical disc is detected by the optical pickup and then included in the optical disc. By measuring a first time interval until reflected light from the data layer is detected by the optical pickup and driving the actuator to move the optical pickup away from the optical disc. Measuring a second time interval from when the reflected light from the data layer of the optical disc is detected by the optical pickup to when the reflected light from the recording surface of the optical disc is detected by the optical pickup. Based on the measurement results of the first time interval and the second time interval. There are, and is configured to perform control of discriminating the type of the optical disk, the optical disk apparatus.   The control unit is caused by measuring the first time interval or the second time interval in a period in which the position of the optical pickup changes nonlinearly with respect to a linear change in the driving value of the actuator. Then, when the first time interval and the second time interval are different from each other, the type of the optical disc is discriminated based on the comparison result of the first time interval and the second time interval. The optical disc device according to claim 1, which is configured as follows.   The optical disk apparatus according to claim 2, wherein the control unit is configured to determine the type of the optical disk based on a smaller one of the first time interval and the second time interval.   In the state where the distance between the optical pickup and the optical disc is smaller than a predetermined reference value, the control unit measures the first time interval during a period in which the position of the optical pickup changes nonlinearly. Therefore, when the value obtained by subtracting the second time interval from the first time interval is larger than a predetermined threshold value, the first time interval is corrected to correct the first time interval after correction. The optical disc device according to claim 2, wherein the optical disc device is configured to determine the type of the optical disc based on one time interval.   The optical disc apparatus according to claim 4, wherein the control unit is configured to correct the first time interval by multiplying the first time interval by a predetermined first correction coefficient.   In the first time interval, the control unit starts from the movement of the optical pickup in the direction approaching the optical disc until the reflected light from the recording surface of the optical disc is detected by the optical pickup. 5. The optical disc apparatus according to claim 4, wherein the first time interval is corrected by multiplying a second correction coefficient based on the third time interval.   In the first time interval, the control unit starts from the movement of the optical pickup in the direction approaching the optical disc until the reflected light from the recording surface of the optical disc is detected by the optical pickup. 5. The optical disc according to claim 4, wherein the first time interval is corrected by multiplying a third correction coefficient based on a change amount of the driving value of the actuator in the third time interval. apparatus.   The optical disc apparatus according to claim 1, wherein the control unit is configured to determine a type of the optical disc based on an average value of the first time interval and the second time interval.

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