JPH076522A - Optical disk device - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to an optical disk device for reproducing, for example, a CD-ROM, and shortens the access time. According to the present invention, when the second address data Q cannot be reproduced correctly, the optical pickup 4 is controlled with reference to the first address data HD to selectively select the recording data corresponding to the target address data. By playing
The desired data is reproduced by omitting the process of reproducing the second address data Q many times.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention will be described in the following order. Field of Industrial Application Conventional Technology (FIGS. 3 and 4) Problem to be Solved by the Invention (FIGS. 3 and 4) Means for Solving the Problem (FIGS. 1 and 2) Operation (FIGS. 1 and 2) Example) (1) Configuration of Example (FIGS. 1 and 2) (2) Effect of Example (3) Other Example Effect of Invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device,
For example, it can be applied to an optical disk device for reproducing a CD-ROM.

[0003]

2. Description of the Related Art Conventionally, in this kind of optical disk,
There is one that is designed to record image data and the like using a recording format of a compact disk (that is, a CD-ROM).

That is, as shown in FIG. 3, in the compact disc, one frame is formed by the sub-code channel data and the main channel data, and the sub-code channel data and the main channel data are alternately and repeatedly recorded ( FIG. 3 (A)). Of these sub-code channel data, one block is formed in 98 frames (FIG. 3 (B)), the synchronization pattern SY is assigned to the beginning of this block, and the remaining area is composed of eight sub-codes P to P. It is designed to be assigned to W.

As a result, in the compact disc player, the audio data assigned to the main channel data based on the first sub-code P among the sub-codes P to W can be found, and the compact disc player is composed of address data. Time information can be detected from the second sub-code Q, so that the playing time and the like can be confirmed. On the other hand, the remaining sub-codes R to W can be collectively used as user bits, so that the compact disk can record graphic data and the like.

On the other hand, the main channel data is
In the case of a compact disc, audio data to which an error correction code is added is assigned, and in this case as well, it corresponds to a subcode channel and 1 in 98 frames.
It is designed to form two blocks (Fig. 3
(C)). On the other hand, in the case of the CD-ROM, the data of the computer is recorded, and after this data is blocked in a predetermined unit, the block data is scrambled according to a preset mode, A header HD and a sync pattern SYNC are added to this data (FIG. 3 (D)).

Thus, in the case of a CD-ROM, after the error correction capability is strengthened to form frame data, the data string of this frame data is assigned to the main channel data instead of the audio data.
At this time, the CD-ROM allocates and records the address data, which is time information of each frame data, to the header HD, and this header HD is allocated the address data of the same format as the subcode Q. The address data changes so as to follow the code Q. As a result, in the CD-ROM, the data string of the frame data is assigned to the main channel data so that the time information detected from the header HD and the time information detected from the subcode Q are within the range of maximum 2 seconds. It is done like this.

As a result, the optical disk device for reproducing the CD-ROM can reproduce desired data on the basis of the subcode Q and the header HD. That is, a reproducing apparatus of this type demodulates the reproduced signal output from the optical pickup according to the format of the compact disk and then decodes the demodulation result according to the format of the CD-ROM. The data can be reproduced.

At this time, in the optical disc device, the system control circuit for controlling the whole operation roughly detects the reproduction position based on the subcode Q reproduced according to the format of the compact disk, and then the CD- R
The reproducing position is accurately detected with reference to the header HD reproduced according to the format of the OM.

That is, the system control circuit, as shown in FIG. 4, when an access command is issued from a computer connected to the outside, steps SP1 to S are sent.
Moving to P2, the target sub-code Q (sub-Q) is detected according to the target address input together with this access command. By the way, this type of computer is designed to specify the data to be reproduced by designating the address data of the header HD, while the optical disk device, on the other hand, is arranged between the previously detected subcode Q and the header HD. The address data of the target subcode Q (hereinafter referred to as the target subcode Q) is generated from the address data of the header HD designated by the computer on the basis of the difference data of. Then the system control circuit
In step SP3, the subcode Q reproduced according to the format of the compact disk at the current reproduction position is detected, and it is judged whether or not the subcode Q can be correctly reproduced. Here, a negative result is obtained. Step S
Repeat P3.

As a result, when the system control circuit correctly reproduces the subcode Q, the system control circuit proceeds to step SP4 and compares the reproduced subcode Q (that is, the current subcode Q) with the target subcode Q. Based on the above, it is determined whether or not the optical pickup needs to be moved, and if it is determined that the optical pickup needs to be moved, the process proceeds to step SP5, and the movement amount is calculated from the current subcode Q and the target subcode Q. calculate.

Further, the system control circuit moves the optical pickup on the basis of this moving amount, and thereafter, the step SP.
Returning to 3, the current subcode Q is detected again. On the other hand, if it is determined that it is not necessary to move the optical pickup, the system control circuit shifts from step SP4 to step SP6, where the reproduction is performed with reference to the header HD which is reproduced according to the format of the CD-ROM. Detect the position.

Here, the system control circuit determines whether or not the header HD has been correctly detected, and if a negative result is obtained here, step SP6 is repeated. As a result, when the system control circuit correctly reproduces the header HD, the system control circuit proceeds to step SP7 and reproduces the header HD (that is, the current header) and the target header H.
Based on the result of comparison with D, it is determined whether or not the optical pickup needs to be moved. If it is determined that the optical pickup needs to be moved, the process returns to step SP3.

As a result, the system control circuit scans the spirally formed recording track, and when the target head HD is approached, a positive result is obtained in step SP7, and the process moves to step SP8, where the current head HD is present. And the target header HD match, and if a negative result is obtained here, the process returns to step SP6. As a result, the system control circuit successively scans the recording tracks and sequentially demodulates the reproduced data to detect the header HD, and when the current header HD and the target header HD match, a positive result is obtained in step SP8. In step SP9, the frame data with the header HD is reproduced.

As a result, the optical disk device performs error correction processing on this frame data and then sends it to the computer, and the system control circuit moves to step SP10 to complete the processing procedure.

[0016]

However, in this type of sub-code Q, an error may occur due to the influence of scratches, defects, etc., and there is a characteristic that the error occurrence rate is high immediately after a seek. When an error occurs and the correct subcode Q cannot be detected, the optical disk device repeats seeking until the correct subcode Q is detected, and then seeks to the position of the target subcode Q. .

Therefore, in this type of optical disk device, when an access command is issued from the computer, the time until the frame data is transmitted in response to the access command (that is, the access time) becomes long. I got it.

The present invention has been made in consideration of the above points, and is a CD-ROM capable of shortening the access time.
It is intended to propose an optical disk device for use in a computer.

[0019]

In order to solve the above problems, according to the present invention, in an optical disk device 1 for reproducing and outputting recording data D2 recorded on a predetermined optical disk 2, the optical disk 2 is a predetermined disk. The optical disk device records the recording data by adding the first address data HD to the recording data D2 in block units to form the data string D1 and adding the second address data Q in predetermined units to the data string D1. Reference numeral 1 denotes an optical pickup 4 which irradiates the optical disk 2 with a light beam, receives reflected light of the light beam, and outputs a light reception result, and demodulates the light reception result and outputs a data string D1 and second address data Q. The first demodulating means 6 for controlling, the data string D1 to the recording data D2 and the first address data HD
Second demodulation means 7 for demodulating the
In response to the OM, the first demodulator 7 outputs the first
Control means 8, 9, 10, 11 for controlling the optical pickup 4 and selectively outputting the recording data D2 corresponding to the target address data so that the address data HD of the target address data becomes a value designated by the target address data. 12, the control means 8, 9, 10, 11, 12 detect the second address data Q corresponding to the target address data, and output the second address data Q from the first demodulation means 6. Based on the comparison result between the target address data and the second address data Q corresponding to the target address data and the comparison result between the first address data HD output from the second demodulation means 7 and the target address data. By controlling the optical pickup 4 so as to reproduce the designated reproduction position, when the second address data Q cannot be reproduced correctly, the first address data Q is reproduced. Controls the optical pickup 4 data HD and the reference, selectively outputs the recording data D2 corresponding to the target address data.

[0020]

When the second address data Q cannot be reproduced correctly, the optical pickup 4 is controlled with the first address data HD as a reference to selectively output the recording data D2 corresponding to the target address data. Therefore, the waiting time until the second address data Q is correctly reproduced can be shortened accordingly, and the access time can be shortened.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

(1) Configuration of the Embodiment In FIG. 1, reference numeral 1 indicates an optical disk device as a whole,
The optical disc 2, which is a CD-ROM, is reproduced. That is, the optical disk device 1 drives the spindle motor 3 to rotate the optical disk 2 at a predetermined rotational speed, and in this state, the optical beam emitted from the optical pickup 4 is transferred to the optical disk 2.
Focus on.

Further, the optical disk device 1 receives the reflected light of this light beam by an optical pickup, amplifies the reproduction signal RF resulting from the reception by the amplification circuit 5, and outputs it to the reproduction signal processing circuit 6. Here, the reproduction signal processing circuit 6 is formed by a signal processing circuit applied to a compact disc player, demodulates reproduction data from the reproduction signal, and then performs error correction processing and descrambling processing on the reproduction data, and the result is obtained. Main channel data D1 on CD-ROM
Output to the decoder 7.

Further, at this time, the reproduction signal processing circuit 6 demodulates the subcode data which is the decoding result of the subcode channel, and the system control circuit 9 demodulates this subcode data.
Output to. The CD-ROM decoder 7 is a CD-ROM
Which is formed by the data processing circuit applied to the H.S.D.
Is output to the system control circuit 9.

Further, the CD-ROM decoder 7 descrambles the main channel data according to the mode of the main channel data recorded together with the header HD, and then performs error correction processing if necessary, and the processing result. Playback data D2 consisting of input / output circuit (I / O)
Output to 8.

The input / output circuit 8 takes in a control command from an externally connected computer, outputs it to the bus BUS, and outputs the output data D2 of the CD-ROM decoder 7 according to the control code outputted to the bus BUS. Output to. As a result, the optical disc device 1 reproduces and outputs desired data in accordance with a control command from the computer.

Therefore, the system control circuit 9 secures a work area in the random access memory (RAM) 10 and executes the processing program stored in the read only memory (ROM) 11, whereby the bus B
A control code is output to each circuit block according to the control command output to the US to control the entire operation.

That is, as shown in FIG. 2, when the access command COM is issued from the computer via the bus BUS, the system control circuit 9 shifts from step SP11 to step SP2 and the target address input together with this access command. According to the target subcode Q (su
b-Q) address data is detected. Here, the system control circuit 9 corrects the value of the target address designated by the computer as the address data of the header HD on the basis of the difference data between the address data of the subcode Q and the address data of the header HD detected in advance. The lever sub-code Q address data is detected. Subsequently, the system control circuit 9 proceeds to step SP13, where the subcode Q output from the reproduction signal processing circuit 6 is detected to reproduce the subcode at the current reproduction position in accordance with the format of the compact disk. Detect Q,
It is determined whether or not the subcode Q can be correctly reproduced.

If a negative result is obtained here, the system control circuit 9 proceeds to step SP14 where the CD
-Detecting the header HD output from the ROM decoder 7 and determining whether or not the header HD can be correctly reproduced,
If a negative result is obtained here, the process returns to step SP13. As a result, if the sub-code Q cannot be correctly reproduced, the system control circuit 9 judges whether or not the Hedda HD could be correctly reproduced instead of repeating the reproduction of the sub-code Q, and a negative result is obtained here. Play Q again.

That is, the Hezda HD is characterized in that it can be reproduced by performing error correction processing by being recorded by being allocated to the main channel data, and even if the subcode data cannot be reproduced correctly by this. is there. When the sub-code Q cannot be reproduced correctly by this, if the reproduction position is confirmed with reference to the header HD instead of the sub-code Q, the process of repeatedly reproducing the sub-code Q can be omitted, and the access time can be reduced accordingly. Can be shortened.

Further, even if the correct sub-code Q cannot be reproduced no matter how many times it is reproduced due to a scratch or a defect, the reproduction position can be confirmed, whereby the desired data can be surely reproduced.

In accordance with this detection principle, the system control circuit 9
If neither the subcode Q nor the header HD can be correctly reproduced, the steps SP13-SP14-SP13 are executed.
On the other hand, when the sub-code Q can be correctly reproduced, the processing loop LOOP1 is repeated. However, since a positive result is obtained in step SP13, the processing shifts to step SP15. Here, the system control circuit 9 determines, based on the comparison result between the reproduced current sub-code Q and the target sub-code Q,
Judge whether it is necessary to move the optical pickup 4,
If it is determined that it is not necessary to move here, the process directly moves to step SP14, whereas if it is determined that it is necessary to move, the process moves to step SP16 and the current subcode Q
And the target sub-code Q are used to calculate the movement amount.

Further, the system control circuit 9 outputs a control code to the servo circuit 12 based on this moving amount to move the optical pickup 4 according to this moving amount, and then moves to step SP14, where It is judged whether or not the Hedsah HD could be properly reproduced. Accordingly, when the system control circuit 9 moves the optical pickup based on the reproduced subcode Q and determines that the optical pickup 4 does not need to move because it is close to the target position, the subcode Q is further set. In any of the cases where the header cannot be correctly reproduced, it is determined in this step SP14 whether or not the header HD can be correctly reproduced.

If a positive result is obtained in step SP14, the system control circuit 9 causes the step SP1
7, it is determined whether the optical pickup needs to be moved based on the comparison result of the current header HD and the target header HD reproduced here, and if it is determined that the optical pickup needs to be moved here, the step After moving to SP8 to detect the moving amount, the optical pickup 4 is moved according to the moving amount, and then the process returns to step SP13.

As a result, even if the subcode Q cannot be reproduced correctly, the optical pickup 4 can be moved quickly, and the optical disc device 1 can shorten the access time. On the other hand, if it is determined in step SP17 that it is not necessary to move, the system control circuit 9 moves to step SP19, where the current HD
And the target header HD match, and if a negative result is obtained here, the process returns to step SP13.

As a result, the system control circuit successively scans the recording track and sequentially demodulates the reproduced data to detect the header HD, and if the current header HD and the target header HD match, a positive result is obtained in step SP19. As a result, the control code is transferred to the step SP20 and the control code is output to the input / output circuit 8, whereby the reproduced data with the header HD is output to the computer, and then the process is transferred to the step SP21 to complete this processing procedure.

(2) Effects of the Embodiments According to the above configuration, when the sub-code Q cannot be reproduced correctly, the reproduction position is confirmed with reference to the header HD instead of the sub-code Q. It is possible to quickly confirm the playback position and reproduce the desired data without repeating the playback of Q, which shortens the access time and ensures that the desired data can be accessed even in the case of a scratch or a defect. can do.

(3) Other Embodiments In the above embodiments, the case where the present invention is applied to the optical disk device for reproducing a CD-ROM has been described, but the present invention is not limited to this, and the first and second embodiments The present invention can be widely applied to an optical disk device that adds a header corresponding to the second address data, a subcode Q, and the like to reproduce data recorded on the optical disk.

[0039]

As described above, according to the present invention, when the second address data cannot be correctly reproduced, the optical pickup is controlled with reference to the first address data to correspond to the target address data. By selectively reproducing and outputting the recorded data, the process of reproducing the second address data many times can be omitted and desired data can be reproduced, whereby the access time can be shortened. The device can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing an optical disk device according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation.

FIG. 3 is a schematic diagram for explaining the data structure.

FIG. 4 is a flowchart for explaining the operation of the conventional optical disk device.

[Explanation of symbols]

1 ... Optical disk device, 2 ... Optical disk device, 4 ...
Optical pickup, 6 ... Reproduction signal processing circuit, 7 ... CD
-ROM decoder, 8 ... I / O circuit, 9 ... System control circuit.

Claims (1)

[Claims] 1. An optical disk device for reproducing and outputting recorded data recorded on a predetermined optical disk, wherein the optical disk adds a first address data to the recorded data in a predetermined block unit to form a data string. To record the recording data by adding the second address data to the data string in a predetermined unit, and the optical disk device irradiates the optical disk with a light beam, and reflects the reflected light of the light beam. An optical pickup that receives light and outputs a light reception result, a first demodulation means that demodulates the light reception result and outputs the data string and the second address data, and the recorded data and the first data from the data string. Second demodulation means for demodulating the address data of the first address data, and the first address data output from the second demodulation means in response to a predetermined control command. Control means for controlling the optical pickup so as to obtain a value specified by the dress data and selectively outputting the recording data corresponding to the target address data, wherein the control means comprises the target address data. Detecting the second address data corresponding to the second address data, comparing the second address data output from the first demodulating means with the second address data corresponding to the target address data, and the second result. By controlling the optical pickup so as to reproduce the reproduction position designated by the target address data based on the comparison result of the first address data output from the second demodulation means and the target address data, When the second address data cannot be reproduced correctly, the optical pick-up is performed on the basis of the first address data. Controls flop, optical disk device, characterized in that selectively outputs the recording data corresponding to the target address data.