JP3035095B2 - Optical disc player - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk reproducing apparatus for reproducing a compact disk or the like (hereinafter referred to as a disk).

[0002]

2. Description of the Related Art Generally, a disk reproducing apparatus for optically reading and reproducing information recorded on a disk in the form of digital signals reproduces information in the following procedure. First, when a disc is loaded in the disc reproducing apparatus, the disc is rotated by a drive motor, and then the objective lens in the optical pickup is driven in a direction perpendicular to the disc to focus the irradiation beam on the disc. Fit on the surface. Next, the drive motor moves the pickup to a lead-in section provided near the innermost circumference of the disk, and is necessary for reproducing the reproduced information such as the start position and end position of the reproduced information recorded in the lead-in section. The index information is read and stored in the memory, and thereafter, the information is reproduced according to the index information stored in the memory.

In such a disk, data, addresses indicating the positions of the data, and the like are recorded along tracks spirally provided from the inner peripheral side to the outer peripheral side. In such a disk reproducing apparatus, when searching for data of a target address on a disk, generally, the following procedure is performed. (1) If the address of the target data is within a predetermined track (predetermined rotation) from the address of the data currently being read, the pickup is relatively moved along the track to read the data at the target address.

(2) If the address of the target data is later than a predetermined track from the address of the data currently being read, the pickup is moved to the outer peripheral side so as to cross a predetermined number of tracks, and is re-executed. Find the address. Then, procedure (1), procedure (2), or procedure (3) described later is performed based on the difference between the address and the target address.

At this time, the number of tracks crossing is set according to the difference between the two addresses. (3) If the address of the target data is earlier than the address of the data currently being read, the pickup is moved inward so as to cross a predetermined number of tracks, and the address is detected again. Then, procedure (1), procedure (2), or procedure (3) is performed based on the difference between the address and the target address.

At this time, the number of tracks crossing is set according to the difference between the two addresses. When the pickup moves to the outer peripheral portion of the portion where data on the disc is recorded when searching for the target address by the above-described procedure, the address cannot be read. You won't be able to find it.

In such a case, conventionally, the pickup is once moved to the innermost circumference, the address is read out with focus, and the target address is searched again.

[0008]

As described above, in the conventional disk reproducing apparatus, when the pickup moves to a further outer peripheral portion of the portion where data is recorded, the pickup is moved to the innermost periphery again, and is renewed. There is a problem that it takes time because search is performed. The present invention solves such a problem.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to data recorded along a spirally arranged track, and an address indicating the position of the data together with the data on the track. In an optical disk reproducing apparatus for reading desired data by tracing the track of an optical disk on which is recorded with an optical pickup, the distance between the optical pickup and the optical disk is gradually increased or decreased within a predetermined range regardless of a focus error signal. Focusing means for performing an operation of changing the focal position of the read beam of the optical pickup until the focus error signal indicates that the focus is on the data recording surface of the optical disc; and If the current address read and the data to be read are Address difference detection means for detecting an address difference from a target address; and first search means for moving a pickup across the track until the address difference detected by the address difference detection means becomes a predetermined value or less. When the address difference is within a predetermined value,
Second search means for moving the data reading position of the optical pickup in the order of addresses of data recorded on the optical disk so that the reading position of the optical pickup corresponds to the target address; Address error detecting means for detecting that the pickup has moved to a position where the address cannot be read, and when the optical error detection means detects that the optical pickup is at a position where the address cannot be read, A third search unit that moves the address in a direction opposite to the moving direction until an address is read while performing the focusing operation by the focusing unit. Further, the data is recorded along a spirally arranged track, and the track of the optical disk, on which the address indicating the position of the data is recorded together with the data, is traced by an optical pickup to obtain desired data. In the optical disk reproducing apparatus for reading out, the operation of changing the focal position of the read beam of the optical pickup by gradually increasing or decreasing the distance between the optical pickup and the optical disk within a predetermined range irrespective of the focus error signal is called a focus error. Focusing means that performs until the focus is detected on the data recording surface of the optical disk by a signal, and an optical pickup detects an address difference between a current address read from the optical disk and a target address having data to be read. Address difference detection means First search means for moving a pickup across the track until the address difference detected by the address difference detection means is equal to or less than a predetermined value; A second search unit that moves a data reading position of the optical pickup in the order of addresses of recorded data to set the reading position of the optical pickup to a position corresponding to the target address;
Out of focus detecting means for detecting that the focus of the optical pickup has deviated from the signal recording surface of the optical disc when the optical pickup is moved by the search means, and reading the address from the output of the optical pickup. Address error detecting means for detecting that the pickup has moved to a non-position, and performing the focusing operation by the focusing means when the out-of-focus state is detected by the out-of-focus detecting means. The out-of-focus moving means for moving in the opposite direction to the direction, and the optical error detection means detects that the optical pickup is at a position where the address cannot be read by the address error detecting means while the optical pickup is in focus. Sometimes the optics The said movement direction Kkuappu is characterized in that a third search means for moving up read addresses in the opposite direction.

[0010]

When the first search means moves the pickup to a position corresponding to a portion other than the portion on the disk where data is recorded, the address cannot be read from the disk. The address error detecting means detects this and outputs a signal to the third searching means. The third searching means responds to the signal from the address error detecting means to cause the focusing means to perform a focusing operation while moving the optical pickup in a direction opposite to the moving direction of the first moving means, that is, a signal. Moves in the direction of the area where is recorded.

When the first search means moves the pickup to a position other than the portion where data on the disc is recorded, the address cannot be read from the optical disc, and in some cases, the address of the optical pickup is further increased. Focus deviates from the signal recording surface of the optical disk. If the focus error detecting means detects that the focus of the optical pickup has deviated from the signal recording surface of the optical disc, it outputs a signal to the out-of-focus moving means, and the out-of-focus moving means performs a focusing operation. The optical pickup is moved until it is focused in the direction opposite to the moving direction of the first moving means, that is, in the direction of the area where the signal is recorded. Further, the address error detecting means detects that the address cannot be read from the optical disk, and
A signal is output to the search means. The third search means responds to the signal from the address error detection means,
The optical pickup is moved in the direction opposite to the moving direction of the first moving means, that is, in the direction of the area where the signal is recorded, until the address can be read.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention.
Reference numeral 1 denotes a disk on which information to be reproduced and index information necessary for the reproduction are recorded as a digital signal including a synchronization signal. The disc 1 is loaded and unloaded to a reproduction position (on a turntable (not shown)) by a loading mechanism (not shown) in accordance with an operation of a key operation unit.

The motor M drives the loaded disk 1 at a predetermined rotation speed. The information to be reproduced and the index information recorded on the recording tracks of the disk 1 are optically read by the pickup 2. The signal read by the pickup 2 is sent to the signal conversion circuit 12 via the preamplifier 3, and is also input to the tracking error detection unit 4, the focus error detection unit 6, the disk rotation servo circuit 9, and the disk signal level detection unit 11. .

The tracking error detector 4 detects from the output signal of the pickup 2 that the focal position of the read beam emitted from the pickup 2 is shifted inward or outward from the track on the information recording surface of the disk 1, and detects each of them. The corresponding positive / negative analog signal is output to the tracking servo circuit 5. When the position of the pickup 2 matches the position of the recording track, 0 is output.

The operation and non-operation of the tracking servo circuit 5 are controlled by an output signal from the microcomputer 13, and in the operating state, the read beam follows the track on the disk 1 in response to a signal from the tracking error detection unit 4. (Not shown), the tracking actuator is driven. For a large movement that cannot be followed by the tracking actuator, the pickup feed servo circuit 15 operates in response to a signal from the tracking error detection unit 4, and the pickup 2 is moved to a predetermined position by a motor by a pickup transfer mechanism (not shown). Let it.

The focus error detector 6 detects whether the focal position of the read beam is above or below the information recording surface of the disk 1 from the output signal of the pickup 2 and outputs a corresponding positive or negative analog signal. Is output to the zero-cross detection unit 10 and the terminal X of the switch SW3. still,
If the focal position of the read beam is on the recording surface of the disk, the output signal of the focus error detector 6 is 0. Zero-cross detector 10 is focus error detector 6
If the output signal is 0, an "H" signal is output to the microcomputer 13. The output of this zero-cross detector 10
Reference numeral 13 indicates whether the focal position of the read beam of the pickup 2 is on the recording surface of the disk.

The scan signal generator 8 outputs positive and negative analog signals to the terminal Y of the switch SW3 in response to a signal from the microcomputer 13. The switch SW3 connects the focus servo circuit 7 to one of the terminal X and the terminal Y in response to a signal from the microcomputer 13. The focus servo circuit 7 has a focus error detector 6 connected via a switch SW3.
Alternatively, an objective lens (not shown) of the pickup 2 is moved up and down by a focus actuator (not shown) provided in the pickup 2 in response to an output signal of the scan signal generator.

If the switch SW3 is connected to the X side, the focus servo circuit 7
, Negative feedback control is performed so that the focus of the read beam is on the recording surface of the disk 1. The disk signal level detector 11 shapes the waveform of the signal from the pickup 2 and inputs the signal to the microcomputer 13. The disk rotation servo circuit 9 determines the frequency of the internal reference signal and the pickup 2
A servo operation for controlling the rotation speed of the motor M so that the frequency of the synchronization signal included in the output signal of the motor M matches, a kick-up operation for driving the motor M at a predetermined rotation speed at the start of reproduction, and a non-operation. There are three operating states, microcomputer
13 switches its operating state.

The signal conversion circuit 12 performs processing such as error correction and EFM demodulation on the signal from the pickup 2 to convert the signal into a digital audio signal, and outputs the digital audio signal to an analog circuit via a digital / analog converter (not shown). Then, a sub-code, which is control data recorded mixed with the digital audio signal, is extracted and output to the microcomputer 13.

Note that the signal conversion circuit 12 outputs an error signal to the microcomputer 13 when the extracted subcode is abnormal due to a scratch on the disk 1 or the like. Next, the operation of this embodiment will be described. FIG. 2 is a flowchart showing the operation of the microcomputer 13. For example, when the target address is determined from the lead-in information read from the disc in advance and the music number of the music to be reproduced determined by the operation of the operator, the process proceeds to step S1.

In step S1, based on the address detected by the pickup 2 and the target address, the direction to jump and the number of tracks to jump are determined in the same manner as in the prior art, and the process proceeds to step S2. In step S3, step S
Step S2 also in the direction to jump determined in step 2
Move by the number of jump tracks determined in step
Move to 3.

In step S3, it is determined from the focus error signal whether or not the focus of the pickup 2 is on the recording surface of the disc 1. If the focus is not on, the beam from the pickup 2 is determined to have jumped out of the disc. By connecting the scan signal generator 8 to the focus servo circuit 7 via SW3 and causing the scan signal generator 8 to repeatedly increase and decrease the output within a predetermined range, the read beam is output via the focus servo circuit 7. While performing the focusing operation by periodically changing the focal length of the lens, the pickup is returned to the inside (step S4), and the process returns to step S3 again. As a result, the beam of the pickup 2 is focused on the disc 1
Steps S3 and S4 are repeatedly performed until the recording surface is matched.

If it is determined in step S3 that the image is in focus, the process proceeds to step S5. In step S5, it is determined whether or not the address data can be read from the pickup. If the address data cannot be read, the beam of the pickup 2 is applied to a mirror portion outside the area where the information of the disc is recorded. Then, the pickup is moved inward by a predetermined amount (several mm) (step S6), the process returns to step S5, and steps S5 and S6 are repeated until the address can be read out in this manner.

On the other hand, if it is determined in step S5 that the address can be read, the process proceeds to step S7. Step S
At 7, an address is read by the pickup 2, and it is determined whether or not the read address is equal to the target address (step S8). If the current address and the target address are equal, the process proceeds to step S9, and thereafter, data is read. Etc. are performed.

On the other hand, if it is determined in step S8 that the current address is not equal to the target address, the process returns to step S1 to search for the target address.
As described above, according to the present embodiment, even if the pickup 2 moves to an area where the address data of the disk 1 cannot be read, the address search is restarted from the outer peripheral side of the disk 1, so that the conventional technique is used. Pickup 2 once
Is moved to the innermost circumference before resuming the address search, the amount of movement of the pickup 2 can be reduced, and the search time can be reduced by the time required for the movement.

In particular, when the pickup 2 moves to an area where the address data of the disk 1 cannot be read, that is, to the outside of the disk or the outer periphery of the lead-out, the target address at that time is an address near the lead-out. it is conceivable that. Therefore, as in the present embodiment, the pickup 2
When the address is detected by moving the beam inward while focusing on the disk 1, the detected address and the target address are considered to be close to each other. Address can be detected.

[0027]

As described above in detail, according to the present invention, in response to the output of the address error detecting means, the third
The search means moves the pickup in a direction opposite to the direction moved by the first search means, that is, in a direction toward a portion where data is recorded, while searching for the address while focusing the pickup on the disk;
When an address is detected, the target address is searched based on the address and the target address, so that the pickup is moved to the innermost circumference and the target address is searched again as in the related art. The moving distance of the pickup is short, and the search time can be shortened accordingly.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the microcomputer 13;

[Explanation of symbols]

 1: Disc 2: Pickup 3: Preamplifier 4: Tracking error detector 5: Tracking servo circuit 6: Focus error detector 7: Focus servo circuit 8: Scan signal generator 9: Disk servo circuit 10: Zero cross detector 11: Disk Signal level detection unit 12: Signal conversion circuit 13: Microcomputer 14: Key operation unit 15: Pickup feed servo circuit M: Motor 100: Disk playback device.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 27/10 G11B 21/08 G11B 7/085

Claims (2)

(57) [Claims] 1. An optical pickup, wherein data is recorded along a spirally arranged track, and the track of an optical disk on which an address indicating the position of the data is recorded along with the data is traced by an optical pickup. In an optical disk reproducing device for reading desired data, an operation of changing a focal position of a read beam of the optical pickup by gradually increasing or decreasing a distance between the optical pickup and the optical disk within a predetermined range regardless of a focus error signal. Focusing means for performing until the focus is detected on the data recording surface of the optical disk by the focus error signal; and an address of a current address read from the optical disk by the optical pickup and a target address having data to be read. Address difference detection to detect differences Means, first search means for moving a pickup across the track until the address difference detected by the address difference detection means is equal to or less than a predetermined value, and when the address difference is within a predetermined value, A data reading position of the optical pickup is moved in the order of addresses of data recorded on the optical disk, and a reading position of the optical pickup is set to a position corresponding to the target address.
Search means; address error detection means for detecting that the pickup has moved to a position where the address cannot be read from the output of the optical pickup; and the optical pickup is at a position where the address cannot be read by the address error detection means. And a third search means for moving the optical pickup in a direction opposite to the moving direction until the address is read while performing the focusing operation by the focusing means. An optical disc reproducing apparatus characterized by the following. 2. The optical pickup according to claim 1, wherein data is recorded along a spirally arranged track, and the track of the optical disk on which an address indicating the position of the data is recorded along with the data is traced by an optical pickup. In an optical disk reproducing apparatus for reading desired data, an operation of changing a focal position of a read beam of the optical pickup by gradually increasing or decreasing a distance between the optical pickup and the optical disk within a predetermined range regardless of a focus error signal. Focusing means for performing until the focus is detected on the data recording surface of the optical disk by the focus error signal; and an address of a current address read from the optical disk by the optical pickup and a target address having data to be read. Address difference detection to detect differences Means, first search means for moving a pickup across the track until the address difference detected by the address difference detection means is equal to or less than a predetermined value, and when the address difference is within a predetermined value, A data reading position of the optical pickup is moved in the order of addresses of data recorded on the optical disk, and a reading position of the optical pickup is set to a position corresponding to the target address.
Defocus detection means for detecting that the focus of the optical pickup has deviated from the signal recording surface of the optical disk when the optical pickup is moved by the first search means; and Address error detecting means for detecting that the pickup has moved to a position where the address cannot be read from the output of the pickup; and when the out-of-focus detecting means detects out-of-focus, the pickup is focused by the focusing means. An out-of-focus moving means for moving in the direction opposite to the moving direction while performing the operation, and the optical pickup cannot read an address by the address error detecting means while the optical pickup is in focus. In position An optical disc reproducing apparatus, comprising: a third search means for moving the optical pickup in a direction opposite to the moving direction until an address can be read when と is detected.