JPH06215535A - Searching method for disk - Google Patents

Abstract

PURPOSE:To simplify a process and to shorten the searching time. CONSTITUTION:When a compact disk 1 is set in a player, a system controller 11 starts a servo, the leading absolute position of each music is read from a TOC by an optical pickup 3, an RF amplifier 5 and a digital signal processing circuit 7 and is stored. When a new music selection is made white a certain music is being played, the controller 11 obtains the moving amount and the direction of the movement to the leading point of the desired music from a present absolute time (A-time) and the leading absolute time of the next music specified by the TOC, the pickup 3 is moved, the A-time and a playing time (P-time) of the desired music are read at that location and the correction operation of the leading absolute time of the desired music is made. From the A-time read at this time and the corrected leading absolute time, the moving amount and the direction of the movement to the leading point of the desired music are obtained, the detection position of the pickup is moved and the leading point of the desired music is searched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc search method, and in particular, absolute position information and relative position information for each song are recorded over the entire circumference of a CD, CD-V, etc., and the TOC of each song is recorded in the TOC. The present invention relates to a disc search method for searching for the beginning of a desired song on a disc recording medium in which the absolute start position is recorded.

[0002]

2. Description of the Related Art A compact disc (CD) has a subcode for control recorded together with music data.
O), absolute time (A-) that indicates the absolute position on the disc.
time; minutes / seconds / frames), and elapsed playing time for each song indicating relative position (P-time; minutes / seconds / frames)
Is recorded. Therefore, in the CD player, the P-t of the Q channel data is played during the performance of the compact disc.
By reading the time and the music number, the elapsed playing time of the current performance music can be displayed together with the music number, and by reading the A-time, the optical pickup can be paused at a fixed position.

In the innermost lead-in area of the compact disc, the absolute start time for each song is recorded (TOC information).
When the information is read out and the performance of a certain desired song is instructed during the performance or at the time of stop, the portion corresponding to the start absolute time of the desired song in the TOC information is used by using the A-time recorded on the compact disc. By searching
It is possible to quickly find the desired song and start playing.

That is, the constant linear velocity is v ₀ , the track pitch is p, the radius at the zero point of A-time (00 minutes 00 seconds 00 frame) is r ₀ , the radius of the current position of the optical pickup before the search is r _S , Absolute time is t _AS , radius of target position is r
_E , absolute time t _AE , between radius r and absolute time t _{A at} an arbitrary position of the compact disc, and v ₀ and r ₀ ,
Since the following equation, π (r ² −r ₀ ² ) / p = v ₀ t _A , holds from the area relationship, r = {r ₀ ² + (pv ₀ t _A / π)} ^1/2 is obtained. Therefore, r _S and r _E are as follows: r _S = {r ₀ ² + (pv ₀ t _AS / π)} ^1/2 ... (1) r _E = {r ₀ ² + (pv ₀ t _AE / π) } ^1/2 ... (2) On the other hand, the number N of tracks between r _S and r _E is N = (r _E −r _S ) / p, so if equations (1) and (2) are substituted into this, N = [{r ₀ a ^{_{{r 0 2 + (pv 0}} t AE / π)} 1/2 ] ^{/ p ·· (3) - 2} + (pv 0 t aS / π)} 1/2.

The absolute value of N obtained by the equation (3) shows the amount of movement in track units from the optical pickup position before the search to the search target position, and the sign of N shows the moving direction.
If N is positive, it is the outer circumferential direction, and if N is negative, it is the inner circumferential direction. Therefore, by controlling the pickup servo system and the pickup feed servo system, a track jump is performed in a predetermined direction by a predetermined movement amount, and the detection position of the optical pickup is moved, so that the beginning of a desired song can be searched.

By the way, the position on the compact disc, the A-time, the P-time, and the music number are related as shown in FIG. 5, and ideally, each music (TN) recorded on the TOC is recorded.
On) the absolute start time T _n is the zero point (0) of P-time.
It should match the time T _n ′ in A-time in 0 minutes 00 seconds 00 frame), but A-time and P
Since an error of less than 1 second is allowed between -time,
In reality, there is a maximum error of 1 second between T _n and T _n ′.

Actually, the performance of each music starts at Pt
Since it is from the zero point of time, only A-time, that is,
It is not possible to accurately search for a desired piece of music by using only equation (3). Therefore, conventionally, the movement amount and the movement direction are determined by the formula (3) using A-time as an index, and the detection position of the optical pickup is moved to the vicinity of the beginning of the desired song, and then P-time is used as an index. And the Pt of the desired song
By moving the detection position of the optical pickup to the position where the time is zero, the desired music piece is accurately located.

[0008]

However, when the index is switched to P-time and the second stage search is performed,
Performance elapsed time t _PS relating to the current position of the optical pickup at the start of the search and performance elapsed time t at the beginning of the desired song
_The movement amount N cannot be determined by substituting _PE (= zero) into equation (3) instead of t _AS and t _AE , respectively. This is because the expression (3) is an expression based on the zero point of A-time and needs to be modified to an expression based on the zero point of P-time of the desired song. Then, if the song number of the desired song changes, the correction formula must be changed each time.

Therefore, the conventional music head search method has a drawback in that extremely complicated processing must be performed, and it takes a long time to complete the search. In view of the above, an object of the present invention is to provide a disk search method which is simple in processing and can shorten the search time.

[0010]

SUMMARY OF THE INVENTION In the present invention, the above-mentioned problem is solved by a means for previously reading the absolute start position of each song from the TOC of the disc, the current absolute position of the pickup, and the absolute start position of the desired song. From the above, means for moving the detection position of the pickup by determining the amount of movement and the moving direction to the beginning of the desired song, and reading the absolute position of the disc and the relative position of the desired song at that position, and detecting the absolute position of the beginning of the desired song Of the pickup, and after that, the amount of movement and the moving direction from the current absolute position of the pickup and the correction start absolute position of the desired song to the beginning of the desired song are determined to move the pickup detection position. It is achieved by providing means.

[0011]

According to the present invention, the head absolute position of each music piece is read in advance from the TOC of the disc, and the pickup is moved from the current absolute position and the head absolute position of the desired music piece to the head of the desired music piece. Determine the amount and movement direction, move the pickup detection position, read the absolute position of the disc and the relative position of the desired song at that position, and determine the start absolute position of the desired song from the difference in the deviation of the start absolute position of the desired song. Correction calculation,
Then, the detection position of the pickup is moved by determining the moving amount and the moving direction from the current absolute position of the pickup and the corrected absolute start position of the desired song to the beginning of the desired song.

As a result, the compact disc At
Like "ime", the head of the desired song can be searched using only the absolute position information of the disc as an index, the search process can be simplified, and the search time can be shortened easily.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall block diagram of a CD player embodying a disc search method according to an embodiment of the present invention. 1
Is a compact disc in which music data is recorded together with sub-code data, and A-ti which indicates an absolute position over the entire circumference of the disc by the serve code Q channel.
P-time indicating the relative position of me and music is recorded. Further, in the lead-in of the innermost circumference of the compact disc 1, the absolute start time of each music is recorded as TOC information.

Reference numeral 2 is a spindle motor for rotating the compact disc 1 at a predetermined constant linear velocity, 3 is an optical pickup for irradiating the compact disc 1 with a laser beam, and detecting a signal recorded on the compact disc 1 from the reflected beam, 4 is a feed motor for feeding the optical pickup 3 in the radial direction of the compact disc 1, and 5 is the optical pickup 3
An RF amplifier for creating an EFM signal, an error signal, a CLV control signal, etc. from the detection signal of 6, a spindle motor 2, an optical pickup 3, a feed motor 4 by using an error signal, a CLV control signal, etc. according to a command of a system controller described later. Servo circuit that applies a predetermined servo to, 7 is R
This is a digital signal processing circuit that performs synchronization, deinterleaving, error correction, etc. on the EFM signal output from the F amplifier 5 to demodulate audio sample data and demodulate subcode data.

Reference numerals 8 and 9 are D / A converters for D / A converting the audio sample data output from the digital signal processing circuit for each channel and outputting the same. 10 is a PLAY key, ST
An operation unit including an OP key, a direct music selection key, a music feed key, a music return key, and the like, 11 is a system controller for controlling the entire system according to the operation of the operation unit to perform a desired normal performance operation and a desired music performance operation. Is. When the compact disc 1 is set in the CD player, the system controller 11 activates various servos to move the optical pickup 3 to the lead-in area and
The optical pickup 3, the RF amplifier 5, and the digital signal processing circuit 7 are used to read the TOC information and store it in a built-in memory (not shown).

When a direct music selection key, a music feed key, a music return key or the like of the operation unit 10 is urged to search for the beginning of a desired music, A- relating to the current position of the optical pickup 3 is searched. From the time and the absolute start time of the desired song designated by the TOC information, the amount of movement and the direction of movement to the beginning of the desired song are determined by the equation (3), and the detection position of the optical pickup 3 is moved. At that position, the A-time of the compact disc 1 and the P-time of the desired song are read, the absolute position at the beginning of the desired song is corrected, and then the A-time relating to the current position of the optical pickup 3 is read.
Then, the operation of moving the detection position of the optical pickup 3 by determining the moving amount and the moving direction from the corrected absolute start position of the desired song to the beginning of the desired song by the equation (3) is repeated. Search for.

2 and 3 are flow charts showing the music selection performance processing by the system controller 11, and FIG. 4 is an explanatory view of the search operation, which will be described below with reference to these figures. Incidentally, when the compact disc 1 is set in the CD player in advance, the TOC information of the innermost lead-in area of the disc is read by the control of the system controller 11 and stored in the internal memory of the system controller 11. And

For example, a certain song (here, the song number is n)
In the case where the system controller 11 performs the music selection performance by the user pressing the music feed key on the operation unit 10 during the performance of 1, and instructing the music selection performance of the next music (music number n + 1), the system controller 11 , A-time (current position of the optical pickup 3 with respect to the compact disc 1 before the search is started) of the subcode Q channel input from the digital signal processing circuit 7 at that time is stored in the internal memory as t _AS (see FIG. 2). Of step 101) of the desired song, and the absolute start time designated by the TOC information for the desired song number n + 1 is set to t _AE (step 102).

Then, t _AS and t _AE are substituted into the above equation (3) to determine the amount and direction to move the detection position of the optical pickup 3 (step 103). Then, the servo circuit 6 is controlled so as to perform the track jump in the determined movement direction by the determined movement amount, and the detection position of the optical pickup 3 is moved to the vicinity of the beginning of the music of the music number n + 1 (step 104). After the movement, the optical pickup 3, the RF amplifier 4, and the digital signal processing circuit 7 are caused to read the subcode Q channel data from the compact disc 1 (step 105).

Next, it is checked whether the music number of the read Q channel data is n + 1 corresponding to the desired music (step 106). If NO, the A-time of the Q channel data read this time is set to t _AS . After that (step 107), the process returns to step 103, the moving amount and the moving direction are determined again by using the equation (3), the track jump is performed, and the optical pickup 3 is moved up to near the beginning of the song number n + 1.
After the detection position of (1) is moved (step 104), the operation of reading the Q channel data and checking whether the music number is n + 1 is repeated. When the song number of the Q channel data read at a certain point is n + 1 and YES is obtained in step 106, A-time of the same Q channel data is set as T _AS and P-time is set as T _PS (see FIG. 3). Steps 201 and 202), T _AE = T _AS −T _PS is calculated to find the corrected start absolute position T _AE (Step 203, see FIG. 4).

Then, instead of t _AS and t _AE , T _AS and T _AE are substituted into the above-mentioned equation (3) to determine the amount and direction to move the detection position of the optical pickup 3 (step 20).
4). Then, the servo circuit 6 is controlled to cause a track jump in the determined movement direction by the determined movement amount, and the detection position of the optical pickup 3 is moved to the vicinity of the beginning of the music of the music number n + 1 (step 205). After the movement, the optical pickup 3, the RF amplifier 4, and the digital signal processing circuit 7 are operated to read the subcode Q channel data from the compact disc 1 (step 206).

Then, it is checked whether the A-time of the read Q channel data is T _AE (step 20).
7) If NO, then the A-time read this time is T
_{After the AS} is set (step 208), the process returns to step 204, the movement amount and the direction are determined again, the detection position of the optical pickup 3 is moved to the vicinity of the beginning of the music of the music number n + 1 (step 205), and the Q channel data is obtained. Read A-
The operation of checking whether time is T _AE is repeated. A- of Q channel data read at a certain point
If time matches T _AE , the search for the beginning of the desired song (tune number n + 1) is complete. In this case, the system controller 11 causes the servo circuit 6, the optical pickup 3, and the R pickup.
The F amplifier 5 and the digital signal processing circuit 7 are started to start the performance operation (YES in step 207). The system controller 11 also performs the same search processing as described above when the desired music selection control is performed in response to the operation of the music return key or the direct music selection key.

According to this embodiment, when searching the beginning of a desired music piece, even after the optical pickup is moved to the vicinity of the target position, the At recorded on the compact disc 1 is recorded.
Since the accurate search of the beginning of the desired song can be performed using the time index as an index, it is sufficient to always use the equation (3) as it is to determine the movement amount and the movement direction to the target position. ) You can save the trouble of modifying the formula. Therefore, the search process can be greatly simplified, and the time required to complete the search can be shortened. It should be noted that in the above-described embodiment, a compact disc has been described, but C
The same can be applied to other types of discs such as DV and mini discs.

[0024]

As described above, according to the present invention, the head absolute position of each song is read from the TOC of the disc in advance, and the head of the desired song is determined from the current absolute position of the pickup and the head absolute position of the desired song. Move the detection position of the pickup by determining the amount of movement and the moving direction up to, read the absolute position of the disc and the relative position of the desired song at that position, correct the start absolute position of the desired song, and then, The absolute position information of the disc is configured by moving the pickup detection position by determining the moving amount and moving direction from the current absolute position of the pickup and the corrected start absolute position of the desired song to the beginning of the desired song. By using only this as an index, it is possible to perform an accurate head search of a desired music piece, which simplifies the search process, and accordingly, the search time can be shortened easily.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a CD player embodying a disc search method according to an embodiment of the present invention.

FIG. 2 is a first flowchart showing a music selection performance process of the system controller.

FIG. 3 is a second flowchart showing the music selection performance processing of the system controller.

FIG. 4 is an explanatory diagram of a search operation.

FIG. 5 is an explanatory diagram of a conventional search operation.

[Explanation of symbols]

 1 Compact Disc 3 Optical Pickup 6 Servo Circuit 7 Digital Signal Processing Circuit 11 System Controller

Claims (1)

[Claims] 1. A disc in which absolute position information and relative position information for each song are recorded over the entire circumference, and a TOC in which the absolute position of the beginning of each song is recorded is targeted for a desired song from a certain current position. In the disc search method for searching for the beginning, the absolute position of the beginning of each song is read in advance from the TOC of the disc, and the current absolute position of the pickup and the absolute position of the beginning of the desired song to the beginning of the desired song are read. The amount of movement and the direction of movement are determined to move the pickup detection position, the absolute position of the disc and the relative position of the desired song are read at that position, and the start absolute position of the desired song is corrected and calculated. The pickup detection position is moved by determining the movement amount and the movement direction from the current absolute position and the corrected absolute start position of the desired song to the beginning of the desired song. Disk search method of which is characterized in.