JPH08287632A - Disk reproducing device and method therefor - Google Patents

Abstract

PURPOSE: To shorten accessing time until detection of the position of a target track by changing the number of track-jumping tracks according to reproduction position at the time of disk reproduction. CONSTITUTION: A pickup in a disk reproducing part 5 is moved to a specified position in the radial direction of a disk 6 and its position is set based on the control of a CPU 1. The difference between a reproduced track position based on address information read from the disk 6 and a track position recording target data is detected and when its positional difference is lower than a specified amount, the pickup is track-jumped only by the number of tracks set according to the positional difference. By changing the number of tracks track-jumped according to the reproduced position at this time, jumping is directly made to a position very close to the target track position and accessing time is thus shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc reproducing apparatus and a disc reproducing method suitable for reproducing a data recording disc called, for example, a CD-ROM, and more particularly to a cueing technique for disc recorded data.

[0002]

2. Description of the Related Art An electronic device in which data (character data, graphic data, etc.) recorded in a book such as a dictionary is recorded by using a compact disc (CD) which has been developed for recording music data etc. Various so-called books have been developed. In this case, the disc (optical disc)
The recording of data on the DVD is performed using, for example, a digital data recording format called CD-ROM. Then, the recorded data is read using an optical disk reproducing mechanism similar to a compact disk, and the read data is decoded according to a predetermined format to obtain the data recorded on the disk. Then, for example, the reproduction data is displayed on a predetermined display panel (such as a liquid crystal display panel) in characters and figures.

When there is a word (word) to be searched for by using a disc on which dictionary data is recorded as the electronic book, the word can be reproduced by simply inputting the word into the reproducing device by a key operation or the like. The device searches the recorded data on the disc and automatically reproduces the data related to the words you need, and the search results can be displayed on the display panel etc., and you can search using books printed on conventional paper. The search can be performed very efficiently as compared to the case of doing.

By the way, when a reproducing apparatus searches for recorded data using a disc on which such electronic book data is recorded, the search is performed using address information added to the recorded data. . That is, based on the index information recorded in a predetermined area of the disc, etc., the address position of the track on which the data such as the necessary word is recorded is determined, and the track at this address position is reproduced by the pickup. When the address information added to the track is judged from the playback data, and the target track is played back by sequentially jumping the playback track position by the pickup until the target track is played. The playback data of is used as the retrieved data.

Here, as the address information used at the time of the search, two kinds of address information are prepared, for example, in the case of a CD-ROM. That is, using a predetermined channel (Q channel) in the subcode, which is data accompanying the main data (that is, data such as characters and figures), the hour, minute, Seconds,
Data of a frame number (75 frames make up 1 second in the case of a CD) is recorded. The address information recorded as the Q channel data is data of a format originally prepared for use in a compact disc for music. The address determination circuit in the reproducing device reproduces the Q channel data. By supplying
The address information of the hour, minute, second and frame number can be immediately judged. In this specification, this address information is hereinafter referred to as a Q channel address.

The other address information is so-called header information recorded at the beginning of the main data, and the address information such as the frame number is the same as the decoding method for the data of other characters and figures. The frame number and the like can be judged by decoding the reproduced data by the decoder and supplying it to the address judgment circuit after decoding the reproduced data by the decoder. In this specification, this address information is hereinafter referred to as a header address.

The two types of address information are used properly as follows. That is, when the target track position (frame number) is known, the pickup for reading the data from the disc is track-jumped and sequentially moved while determining the track position by the reproduced Q channel address. Then, when several tens of frames before the track of the target frame number is detected by the Q channel address, decoding of the reproduction data is started to monitor the reproduced header address, and this header address matches the target address. Then, it is determined that the target data can be accessed, and the reproduction data at that time is used as the retrieved data.

FIG. 4 is a flow chart showing an example of processing when a search is performed using such address information.
First, when the Q channel address in the subcode can be obtained from the reproduction data (step S1), the time indicated by this Q channel address is judged and the time difference from the target track position is calculated (step S2). Then, it is determined whether the detected time difference is less than 1 second (step S3). Here, if it is not less than 1 second, the track jump for jumping the reproduction track at the pickup is continued, and the process returns to step S1.

When it is determined in step S3 that the time difference is less than 1 second (that is, when it is determined that the difference is 75 frames or less), whether it is before or after the track position (target) of the target frame number. If it is after the target, it is judged whether or not the time difference is 40 to 75 frames (step S6). When the time difference is 40 to 75 frames,
The reproduction position by the pickup is jumped by 6 tracks in the-direction (that is, the reverse direction) (step S7). If the time difference is not 40 to 75 frames in step S6 (that is, the time difference is 1 to 39 frames), the reproduction position by the pickup is jumped one track in the-direction (step S7).

By the processing in the steps up to this point, the track position before the target position is reproduced with the time difference from the target position less than 1 second, and the track position before the target is finally reproduced in step S5. Is determined. When the track position before the target position is determined in step S5, it is determined whether or not the time difference at that time is 0 to 9 frames (step S9). When the time difference is 0 to 9 frames, the pickup is performed. After jumping the reproduction position by one track in the-direction (step S10), the process returns to step S1. Also, in step S9, the time difference is 0
If it is determined that the frame is not 9 frames, it is further determined whether the time difference is 41 to 74 frames (step S1).
1) When the time difference is 41 to 74 frames, after jumping the reproduction position by the pickup one track in the + direction (that is, the forward direction) (step S12), the step S12 is performed.
Return to 1.

When it is determined in step S11 that the time difference is not 41 to 74 frames, it is determined that the time difference is 10 to 40 frames in combination with the determination in step S9, and at this time point. Decoding of reproduced data from the pickup is started to detect the header address (step S13). Then, it is determined whether or not the header address and the target address at this time match (step S13), and when the header address and the target address match as the reproduction track position advances, it is determined that the access process is possible. To finish.

[0012]

Although the access processing for searching the target track position is performed by such processing, there is a disadvantage that it takes a relatively long time to reproduce the target track. That is, in the flowchart of FIG. 4, when the time difference from the target position is 10 to 40 frames (NO in step S11), decoding of the header address is started, and the header address and the address of the target position are The process of advancing the reproduction position is performed until they match. Therefore, when the track jump is performed and the time difference from the target position is 40 frames, the time required to reproduce 40 frames (1 frame is 1/7 because one frame of data is composed of 75 frames).
By reproducing only for 5 seconds), that is, for 533 msec, the reproduced header address and the address of the target position match.

When performing the access processing in this way, since it is necessary to continuously reproduce the tracks for about 500 msec at the maximum, the time required for the access processing needs to be extended correspondingly until the search result data is obtained. There was an inconvenience that it took time.

In order to reduce the continuous reproduction time of about 500 msec at the maximum, the time difference from the target is set to 1 by the judgment in steps S9 and S11 in the flowchart of FIG.
When it is determined that the number of frames of 0 to 40 is within the range of 31 frames, instead of moving to the determination processing of the header address in step S13, only when the number of frames is within the range of a narrower range. , Step S1
By proceeding to the determination processing of the header address of 3, it is possible to shorten the continuous reproduction time until the addresses match.

However, if the range of the number of frames for determining the header address is narrowed in this way, the number of times the track jump is repeated increases until the range of the number of frames is reached (that is, step S1 of the flowchart of FIG. 4).
Track jumps due to 0 and S12 increase), which does not lead to reduction in access time.

In view of the above point, the present invention has an object to shorten the access time by making it possible to quickly reproduce a target track when reproducing this kind of disc.

[0017]

In order to solve this problem, the disc reproducing apparatus of the present invention uses the address information read from the pickup (this address information is the address information whose address position can be directly determined from the reproduced data). When the difference between the indicated track position and the track position on which the target data is recorded is detected and a position difference of a predetermined amount or less is detected, only the number of tracks set according to the position difference at this time, The track jump means is provided with reproduction track position control means for causing the pickup to jump to a track and moving the pickup to a track position slightly before the track position where the target data is recorded.

In the disc reproducing method of the present invention, the target data is read based on the first address information read from the disc (the first address information is the information whose address position can be directly determined from the reproduced data). The difference between the recorded track position and the playback track position is detected, and when the detected difference is less than or equal to a predetermined amount, the playback tracks are jumped by the number of tracks set according to the position difference at this time. , A track position slightly before the track position on which the target data is recorded is reproduced, and after this track jump, the reproduction data is decoded to generate the second address information (the second address information is the reproduction data The information which can determine the address position) is determined, and the target data is recorded by the decoded second address information. It is obtained so as to determine the track position.

[0019]

According to the present invention, the number of tracks to be track-jumped is changed according to the reproduction position at that time, so that the track jump can directly jump to a position very close to the target track position.
The access time until the target track position is detected can be shortened.

[0020]

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

FIG. 1 is a diagram showing the overall structure of a disc reproducing apparatus of this example. The reproducing apparatus of this example records data such as a dictionary on an optical disc having a diameter of 8 cm, which is called a CD-ROM, and is an electronic book. A central controller (CPU) 1 which is a system controller for controlling a reproducing operation, and a ROM 2 in which an operating program and font data of display characters are stored.
The RAM 3 for temporarily storing reproduction data and the like and the various operation keys 4 are connected. Then, the predetermined operation key 4
Under the control of the central controller 1, data recorded on a predetermined track of the optical disc 6 mounted on the disc reproducing section 5 is operated by an optical pickup (not shown) in the disc reproducing section 5 by operating the. The read data is read and decoded by a decoder (not shown) in the disk reproducing section 5, and then transferred to the RAM 3. Here, the optical pickup in the disc reproducing unit 5 is driven by a pickup driving mechanism in the disc reproducing unit 5 so that it can be moved to a predetermined position in the radial direction of the disc 6, and the position is the central control unit 1. It is set based on the control of.

Further, the display data read from the disk 6 is data indicating a code of a character to be displayed, etc., and font data of each character stored in the ROM 2 is used to display in the display control unit 7. The data of the character shape to be displayed is sent, and the display memory (not shown) in the display control unit 7 is made to create the image data for display. Display it.

The central controller 1 also monitors the Q channel address and the header address added to the data read from the disk 6 by the disk reproducing section 5. However, the header address is data that can be identified only when the playback data is being decoded in the disc playback unit 5. Therefore, the header address cannot be identified when the playback is not continuous, such as during search.
Only the Q channel address in the subcode can be identified. The address obtained from the disk 6 in this case is address data of hours, minutes, seconds, and frames, and one second is composed of 75 frames. Further, the data recording track formation state of the disk 6 is CLV control (Co
It is set so that the disc is played back at an instant linear velocity (constant speed control), and the number of frames of one track on the inner circumference side of the disc is different from the number of frames of one track on the outer circumference side (one on the outer circumference side is 1 There are many track frames).

Then, the access processing, which is the control for reproducing the data required by the disk reproducing section 5, is executed under the control of the central control unit 1 according to the flowcharts of FIGS. 2 and 3.

First, the overall processing will be described with reference to the flow chart of FIG. 2. When it becomes necessary to reproduce data at a certain track position (hereinafter referred to as a target), the optical pickup in the disk reproducing section 5 moves to the current position. The central controller 1 determines the Q channel address read in (step S11). Then, the central controller 1 obtains the time difference between the hour, minute, second, and frame indicated by the Q channel address at this time and the target hour, minute, second, and frame (step S12). Then, it is determined whether the calculated time difference is less than 1 second (step S1).
3).

If the time difference is 1 second or more, the central controller 1 sends a track jump command to the pickup drive mechanism in the disk reproducing section 5 to jump the reproduction track by a predetermined amount (step S14). . After the track jump, return to step S11,
The Q channel address at the track jump position is determined. Therefore, the track jump is sequentially repeated until the time difference becomes less than 1 second.

If it is determined in step S13 that the time difference is less than 1 second, it is determined whether the position is before or after the target position (step S15). Here, if the current read position of the optical pickup is behind the target, the process proceeds to step S16,
After processing for less than 1 second behind, the process returns to step S11 to determine the Q channel address at the track jump position. The process in less than 1 second behind is the process shown in the flowchart of FIG. 3, and will be described later.

When it is determined in step S15 that the current read position of the optical pickup is ahead of the target, it is determined whether the time difference at that time is 0 to 6 frames (step S17). When the time difference is 0 to 6 frames, the reproduction position by the pickup is jumped one track in the negative direction (that is, the reverse direction) (step S18), and then the process returns to step S11. When it is determined in step S17 that the time difference is not 0 to 6 frames, it is further determined whether or not the time difference is 25 to 74 frames (step S20). When the time difference is 25 to 74 frames, reproduction by the pickup is performed. Position +
After jumping one track in the direction (that is, the forward direction) (step S20), the process returns to step S11.

When it is determined in step S19 that there is no time difference of 25 to 74 frames, step S17
It is determined that the time difference is 7 to 24 frames in combination with the determination in (3), and at this point, the decoding of the reproduction data from the pickup is started and the header address is detected (step S21). Then, it is determined whether or not the header address and the target address at this time match (step S22), and when the header address and the target address match as the reproduction track position advances, it is determined that a search is possible and access processing is performed. To finish.

Next, the processing in step S16 when it is determined that the current reading position of the optical pickup is less than 1 second behind the target will be described with reference to the flowchart of FIG.

In this case, first, it is determined whether the current radial position of the optical pickup with respect to the disc 6 is the outer peripheral side or the inner peripheral side of the disc (step S21). The determination at this time is performed by determining whether the current Q channel address is before or after a preset predetermined address (for example, an address corresponding to a radial position of about half the disk).

Then, when it is judged that it is on the outer peripheral side in this judgment, the time difference between the target and the current address is 5
It is determined whether the frame is 3 to 74 frames (step S2
2), when the time difference is in the range of 53 to 74 frames,
After jumping the reproduction position by the pickup by 6 tracks in the-direction (step S23), the process returns to step S11 in the flowchart of FIG.

When it is determined in step S22 that the time difference is not within the range of 53 to 74 frames, it is further determined whether or not the time difference between the target and the current address is 41 to 52 frames (step S24). Then, when the time difference is in the range of 41 to 52 frames at this time, after the reproduction position by the pickup is jumped by 5 tracks in the-direction (step S25), the process returns to step S11 of the flowchart of FIG.

When it is determined in step S24 that the time difference is not within the range of 41 to 52 frames, it is further determined whether or not the time difference between the target and the current address is 29 to 40 frames (step S26). Then, when the time difference is in the range of 29 to 40 frames at this time, the reproduction position by the pickup is jumped four tracks in the-direction (step S27), and then the process returns to step S11 of the flowchart of FIG.

When it is determined in step S26 that the time difference is not within the range of 29 to 40 frames, it is further determined whether or not the time difference between the target and the current address is 17 to 28 frames (step S28). Then, when the time difference is in the range of 17 to 28 frames at this time, the reproduction position by the pickup is jumped three tracks in the-direction (step S29), and then the process returns to step S11 of the flowchart of FIG.

When it is determined in step S28 that the time difference is not within the range of 17 to 28 frames, it is further determined whether the time difference between the target and the current address is 5 to 16 frames (step S30). Then, when the time difference is in the range of 5 to 16 frames at this time, the reproduction position by the pickup is jumped two tracks in the-direction (step S31), and then the process returns to step S11 of the flowchart of FIG.

When it is determined in step S30 that the time difference is not within the range of 5 to 16 frames, the time difference is within the range of 1 to 4 frames, and the reproduction position by the pickup is jumped one track in the-direction (step S32), and returns to step S11 in the flowchart of FIG.

Next, when it is determined in step S21 that it is on the inner circumference side, it is determined whether or not the time difference between the target and the current address is 47 to 74 frames (step S33). When the time difference is within the range, the reproduction position by the pickup is jumped by 6 tracks in the negative direction (step S34), and then the process returns to step S11 of the flowchart of FIG.

When it is determined in step S33 that the time difference is not within the range of 47 to 74 frames, it is further determined whether or not the time difference between the target and the current address is 29 to 46 frames (step S35). Then, when the time difference is in the range of 29 to 46 frames at this time, the reproduction position by the pickup is jumped by 5 tracks in the negative direction (step S36), and then the process returns to step S11 of the flowchart of FIG.

When it is determined in step S35 that the time difference is not within the range of 29 to 46 frames, it is further determined whether or not the time difference between the target and the current address is 20 to 28 frames (step S37). Then, when the time difference is in the range of 20 to 28 frames at this time, the reproduction position by the pickup is jumped four tracks in the-direction (step S38), and then the process returns to step S11 of the flowchart of FIG.

When it is determined in step S37 that the time difference is not within the range of 20 to 28 frames, it is further determined whether or not the time difference between the target and the current address is 10 to 19 frames (step S39). Then, when the time difference is in the range of 10 to 19 frames at this time, the reproduction position by the pickup is jumped three tracks in the-direction (step S40), and then the process returns to step S11 of the flowchart of FIG.

When it is determined in step S39 that the time difference is not within the range of 10 to 19 frames, it is further determined whether or not the time difference between the target and the current address is 3 to 9 frames (step S41). Then, when the time difference is in the range of 3 to 9 frames at this time, the reproduction position by the pickup is jumped two tracks in the-direction (step S42), and then the process returns to step S11 of the flowchart of FIG.

If it is determined in step S41 that the time difference is not within the range of 3 to 9 frames, the time difference is 1
Within the range of 2 frames, the reproduction position by the pickup is jumped one track in the-direction (step S43), and then the process returns to step S11 of the flowchart of FIG.

In the access processing performed by the above processing, the time from when the time difference between the target and the current position is less than 1 second until the header addresses match can be shortened as compared with the conventional case. That is, as shown in the flowchart of FIG. 3, as the processing with a time difference of less than 1 second behind the target, the number of tracks to be jumped is variably set based on the number of frames of the time difference at that time so that the number of tracks slightly ahead of the target By making the track jump to the position, the time difference after the track jump is 7
The range is up to 24 frames. Therefore, when the process of step S16 of the flowchart of FIG. 2 is ended and the process returns to step S11, it is determined in step S15 that it is before the target, and in steps S17 and S19, the time difference is within the range of 7 to 24 frames. It is judged that there is a certain value, the decoding of the reproduction data is started, the header address is immediately obtained, and the header address and the target address are matched with each other in the reproduction of a maximum of 24 frames.

Therefore, when the time difference between the target and the current position is less than 1 second backward, the track jump is performed only once, and the access is completed. If the time difference between the target and the current position is less than 1 second ahead, the jump of one track in step S18 or step S20 will cause the time difference to fall within the range of 7 to 24 frames in most cases, and similarly, will be small. When the number of frames is reproduced, the header address matches the target address. In this way, when the time difference between the target and the current position is less than 1 second before and after, in most cases, it is only necessary to perform one track jump and determine the header address by continuous reproduction for a short time. , The target address is reached, the access process is performed in a short time, and the time for searching the necessary data can be shortened. For example, a certain word is searched using a disc on which dictionary data is recorded. In this case, the time until the search result is displayed on the display panel can be shortened.

In the example of the flow chart of FIG. 2, the track jump is performed with a target of about 7 frames before the track position of the target, but in the case of the reproducing apparatus of this example, the reproduced data is decoded. This is because a margin of about 6 frames is required to determine the header address, and in the case of a device in which the number of frames required for this margin is shorter, it is necessary to correspondingly change the number of frames determined in step S17. .

Further, in the above embodiment, the correspondence between the number of frames and the number of track jumps when the track jump is performed is changed in two steps of the inner circumference and the outer circumference of the disc, but more finely from the inner circumference to the outer circumference. May be divided into a plurality of stages, and the correspondence between the number of frames and the number of track jumps may be set for each stage. By doing so, more accurate access becomes possible. However, changing the number of tracks to be jumped between the outer circumference and the inner circumference in this manner is limited to the case of reproducing a CLV control (constant speed control) disc, and is not limited to the CAV control (Constan).
t AngularVelocity: constant speed control)
When reproducing the disc, it is not necessary to change the number of tracks jumped between the inner and outer circumferences.

Further, although the above-described embodiment is applied to the case of reading data from a CD-ROM type optical disk, it is needless to say that it is also applicable to the data reading of another disk system.

[0049]

According to the present invention, the number of tracks to be track-jumped is changed according to the reproduction position at that time, so that it is possible to directly jump to a position very close to the target track position by the track jump. Therefore, it is possible to shorten the access time until the target track position is detected.

In this case, the read data is decoded from the position where the track is finally jumped to obtain address information, and the track position where the target data is recorded is determined. It is possible to shorten the time for performing address determination by decoding, shorten the access time, and reduce the amount of data to be decoded during access.

Further, the number of track jumps set according to the difference is changed at least when the recording data of the inner track of the disc is read and when the recording data of the outer track of the disc is read. By doing so, the access processing of the disk reproduced by the CLV control can always be made good.

Further, the first address information is the data of the predetermined channel of the subcode attached to the recording data, and the second address information is the header information which is the data of the head portion of the recording data. Good access processing can be performed by applying the method to the CD-ROM method or the like.

[Brief description of drawings]

FIG. 1 is a block diagram showing a disc reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an entire access process according to an embodiment.

FIG. 3 is a flowchart showing processing in less than 1 second after the access processing according to the embodiment.

FIG. 4 is a flowchart showing an example of conventional access processing.

[Explanation of symbols]

 1 Central Control Unit (CPU) 5 Disc Playback Section 6 Optical Disc

Claims (6)

[Claims] 1. A disc on which data is recorded with first address information for determining an address position directly from reproduced data and second address information for decoding the reproduced data to determine an address position. In a disc reproducing apparatus for reproducing data, a pickup for reading recorded data from the disc, a track jump means for moving the pickup by a designated number of tracks, and address information included in the data read by the pickup. Based on the detecting means for detecting the difference between the indicated track position and the track position where the target data is recorded, and based on the first address information read from the pickup, the detecting means detects a position difference of a predetermined amount or less. When detected, the number of tracks set according to the position difference at this time And the pickup is a track jump rack jump means, the disc reproducing apparatus and a reproducing track position control means for data as a target moves the pickup in a track position slightly before the recording track position. 2. The control of the reproduction track position control means, after the pickup is positioned at a track position slightly before the track position where the target data is recorded,
From the track jump position, the data read by the pickup is decoded to determine the second address information, and the decoded second address information is used to determine the track position where the target data is recorded. The disc reproducing apparatus according to claim 1, wherein 3. The number of track jumps set in accordance with the difference is determined at least when the pickup reads the recording data of the inner track of the disc and when the recording data of the outer track of the disc is recorded. The disc reproducing apparatus according to claim 2, wherein the pickup is changed at the time of reading. 4. The first address information is data of a predetermined channel of a subcode attached to the recording data, and the second address information is header information which is data of a head portion of the recording data. Item 1. The disc reproducing apparatus according to Item 1. 5. A disc on which data is recorded with first address information that can determine the address position directly from the reproduced data and second address information that can determine the address position by decoding the reproduced data. From the above, in the disc reproducing method for reproducing data, based on the first address information read from the disc,
When the difference between the track position where the target data is recorded and the playback track position is detected and the detected difference is less than a predetermined amount, the number of playback tracks set according to the position difference at that time is detected. Track jump is performed to reproduce a track position slightly before the track position where the target data is recorded. After this track jump, the reproduced data is decoded to determine the second address information, and the decoded first A disk reproducing method in which the track position where the target data is recorded is determined by the address information of 2. 6. The number of track jumps set in accordance with the position difference is determined at least when the recorded data on the inner track of the disc is reproduced and when the recorded data on the outer track of the disc is reproduced. The disc reproducing method according to claim 5, wherein the disc reproducing method is changed.