JPS63282982A - Access method in compact disk player - Google Patents

Abstract

PURPOSE:To contrive the high speed of an access time by setting the number of sectors for one track at a designating address position and when the sector time read after the access comes to be within a prescribed time, completing an access action. CONSTITUTION:After an access is executed less than one second before and after the designating address, one kick is executed. Thereafter, when the accumulated minute, second, and a sector time of designated address which is read after the access is within the scope of the value subtracted by designated one track from the accumulated minute, second and the sector time of reading start position access, an access action is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an access method in a compact disc (CD) player.

Conventional Technology In a CD player having a track conversion table corresponding to cumulative address and second data, the conventional method for accessing an address where minutes, seconds, and sectors are specified is as follows.
The current position, that is, the cumulative minutes, seconds, and sector time (hereinafter referred to as ATN) of the specified address read after access, and the destination, that is, the cumulative minutes, seconds, and sector time (hereinafter referred to as ATN) of the designated address, that is, the specified data read start position. , ATP), refer to the conversion table to find the difference between the two, and access only the predetermined number of tracks. For example, if the second data of AT'N is ATP - 1 second, then Complete access when within range,
Data was read from the data at the location that matched the specified sector.

Problems to be Solved by the Invention However, in the above conventional method, if the sector at the specified address is, for example, 75 sectors, after the access is completed,
There is a problem in that a waiting time of up to 2 seconds is required before data at a specified address is read.

The present invention solves such conventional problems, and aims to provide an access method in a CD player that can realize faster access times.

Means for Solving the Problems In order to achieve the above object, the present invention sets the number of sectors for one track (hereinafter referred to as ΔSOT) at a designated address position, and determines whether the ATN value read after access is A
This is to shorten the waiting time until the access operation is completed for the poem that is within the range of TP-ΔSOT and the data at the specified address is read.

Effect of the Invention With the above configuration, the present invention can shorten the waiting time until data at a designated address is read, thereby making it possible to speed up the access time.

Embodiment FIG. 1 is a flowchart for explaining the access operation according to the present invention, and in the figure, numerals 1 to 8 indicate each step of the flowchart.

First, in the process of step 1, if ATN is smaller than ATP (YES in step 1), the process moves to step 2, where it is determined whether the difference between ATP and ATNO is 1 second or more. .

If it is 1 second or more (step 2ON No), step 5
Through this process, a normal access operation is performed using the number of trunks corresponding to the difference between ATP and ATN. Next, in the process of step 8, the data is read again, and after the reading is completed, the process returns to step 1.

If it is less than 1 second (YES in step 2) 5
In step 7, it is determined whether ATN is within the range of the value obtained by subtracting △SOT from ATP in the process of step 3, that is, whether it is within the range of the track one track before the specified address. The judgment is made, and if it is outside the range (No in step 3), one kick is performed to the outer circumference in the process of step 4, the data is read again in the process of step 8, and after the reading is completed, the process in step 1 is performed. Return to processing.

If it is within the range of the previous trunk (YES in step 3), play mode (data read mode)
and waits until it matches the specified address, and then reads the data.

On the other hand, in the process of step 1, if ATN is larger than ATP (No in step 1), the process moves to step 69, where the difference between ATN and ATP becomes a predetermined time, for example, 1 second or more. Determine whether or not.

If it is 1 second or more (No in step 6), step 5
In the process, normal access operation is performed and step 8
In the process of step 6, read the data again, and after reading is completed, return to the process of step 1.

If it is less than 1 second (YES in step 6), perform a single kick to the inner circumference in the process of step 7,
In the process of step 8, the data is read again, and after the reading is completed, the process returns to step 1.

The above-described access operation is repeated until ATN matches ATP or falls within the range of one track before ATP.

Here, the above △SOT is T from equation (1) as shown below.
It can be determined by determining N (number of racks) and substituting that value into equation (2).

■・tIITP−π((TP−TN+ro)2−ro2
)...(1) V2 Linear velocity [m/S] t: Time (address) [seconds] ro: Program area innermost radius [m] TP Nidrank pitch [m] TN Nidrank number ΔSOT = 75/ TN/l ・・・・・・・・・
(2) FIG. 2 is a graph showing the relationship between the ΔSOT7 difference determined by the above calculation formula and the specified address time (minutes). Although it is possible to sequentially calculate this ΔSOT using the microconbeater of the CD player, in this embodiment, in order to simplify the configuration, the designation as shown in FIG. 3 is used based on FIG. Divide the address time (minutes) into predetermined blocks, create a data table that represents the number of sectors for one track (△5OT) corresponding to each block, and set and use △SOT based on that data table. That's what I do.

Effects of the Invention As is clear from the above embodiment, the present invention performs an access by one kick after accessing a specified address within less than 1 second before and after the specified address, and calculates the accumulated minutes, seconds, and sectors of the specified address read after that access. The access operation is now completed when the time is within the range of the cumulative minutes, seconds, and sector time of the specified read start position specified address minus the number of sectors for one track at the specified address position. Therefore, the time required to read data at a designated address (access time) can be shortened (speeded up).

[Brief explanation of the drawing]

FIG. 1 is a flowchart for explaining the access operation in the present invention, and FIG. 2 is a graph showing the relationship between the number of sectors for one track (Δ5OT) at a designated address position and the designated address time (minutes). FIG. 3 is a table chart of the number of sectors for one track into which the designated address time is divided. Name of agent: Patent attorney Toshio Nakao, 1st person, 2nd person
Figure 1 Figure 3

Claims (1)

[Claims] The cumulative minutes, seconds, and sector time (hereinafter referred to as ATP) of the specified data read start position specified address are the cumulative minutes, seconds, and sector time (hereinafter referred to as ATP) of the specified address read after access.
(hereinafter referred to as ATN), and the difference between them is ATP-
When the ATN is less than a predetermined time, the access operation is completed when the ATN value falls within a value obtained by subtracting the number of sectors for one track at the specified address position (hereinafter referred to as ΔSCT) from the ATP, When it is out of range, perform one kick to the outer circumference, and when ATP is smaller than ATN and the difference ATN - ATP is less than a predetermined time, perform one kick to the inner circumference, and the ATP - ATN or AT
An access method for a compact disc player in which a normal access operation is performed when the difference in N-ATP is longer than a predetermined time, and the access operation is repeated so that the ATN falls within the range.