KR910001217B1 - Index detecting method for the compact disk player system - Google Patents

Abstract

The method available to compact disk player system which recordes start time of the track recorded in Read In region by converting to code by 4-minute unit, detects index fast not recorded in Read In resion. A DSP transmits control signal to a pick-up and motor through command terminal of a micro computer and transmits data recorded on a disk during play to a micro computer so that index is detected.

Description

Index Detection Method in Compact Disc Player Systems

1 is a circuit diagram for realizing the index detection method according to the present invention.

2 is a waveform diagram of each part of FIG.

3 is a flowchart of an index detection method according to the present invention.

* Explanation of symbols for main parts of the drawings

MIC: Microcomputer DSP: Signal Processor.

The present invention relates to an index detection method in a compact disc player system.

Inside the compact disc, there is a read-in area, a program area, and a read-out area. The lead-in area includes the total number of tracks, the total playing time, Information on the start time of each track is recorded. In the program area, information indicating the end of the disc is recorded as index information which further subdivides the track as a portion where actual data is recorded.

In the related art, in order to find an index that is not in the lead-in area, it is necessary to continuously listen from the beginning, so there is a problem in that there is no index after a long time.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and is an index in a compact disc player system in which the start time of a track in the lead-in area is changed and stored in code every four minutes. It is an object to provide a detection method.

In the above-described code, the code is changed every four minutes, and the number of tracks that can be recorded on one disc is 99. It is impossible to store all the track start time 00 minutes and 00 seconds in a limited RAM of a microcomputer every four minutes. Remember, the relationship between start time and code is:

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a circuit diagram for realizing a method of detecting an index of a disk according to the present invention, in which a microcomputer MIC and a signal processor DSP detect data by performing mutual data transfer. The signal processor DSP is a user. In order to perform the desired operation, the control signal for pick up or motor is applied through the command terminal of the microcomputer (MIC), and the result and data recorded on the disk during play are performed. Is a circuit for applying to a microcomputer (MIC).

The operation of the above circuit will be described in detail with reference to the waveform diagram in FIG.

FIG. 2 (a) is a waveform diagram of communication from the signal processor DSP to the microcomputer MIC. When the WQ signal is output from the signal processor DSP, the clock CLK waveform of the microcomputer MIC is output. Therefore, the signal processor (DSP) outputs an 8-bit byte according to the clock signal of the Q-DATA waveform, and then formats the Q-TATA with a time difference of 10 µm or more from the final clock waveform as shown in Table 1 below. appear.

TABLE 1

FIG. 2 (b) is a waveform diagram of the communication from the microcomputer MIC to the signal processor DSP. When the R / W signal of the microcomputer MIC is output, the clock signal is output to display the signal processor DSP. Four bytes are output from the command terminal by eight bits, and the R / W signal of the microcomputer MIC is output with a time difference of 10 µm or more from the final clock signal to stop signal output.

At this time, the format of the command data is shown in Table 2 below.

TABLE 2

In case of search, all 4 bytes are transmitted (μMIN, μSEC, UFRAME: time to search), but in other cases, only 1 byte of command is transmitted.

3 is a flowchart of an index detection method according to the present invention, in which a search time is extracted from a changed code of a track to be searched for, and then the signal processor (DSP) is first detected by a microcomputer (MIC). The signal processor DSP determines whether the detection is completed (20). When the detection is completed, the current track is compared with the track to be detected (30).

If the current track is larger than the track to be detected, the data of the disc is read out through the signal processor (DSP) while the pickup is reversed (FFB) at about 100 times faster than the normal play state. Continue backing up until the tracks are equal.

However, in the above, it is determined whether the current track and the track to be detected are the same (50), and if not, the pickup is advanced (FFF) at a speed about 100 times faster than the normal play state (60). If it is less than 70, and if the current track is not less than the track to be detected, it returns to step 30 to determine whether the current track is greater than the track to be detected, and the current track is less than the track to be detected. If so, the picking method continues to advance (60).

If the current track is the same as the track to be detected (50), it is determined whether the current index is greater than the index to be detected (80). If the current index is greater than or equal to the index to be detected, about 10 times the normal play state. Reverse the pickup at high speed (90), and continue backwards. Compare the current index with the index to be detected (100). If the current index is less than the index to be detected, the current index is less than the index to be detected. If the current index is less than the index to be detected, mute for a predetermined time (110), and then compare the current index with the index to be detected (120). Drive the pickup at normal play speed (130), mute the audio signal for a period of time and then index Indicates detection completion and plays.

This is because the last part of the index search becomes a play mode at the end of the index before the index to be searched, and thus the contents of the index before the search is not muted.

If the current index is smaller than the index to be detected in the index comparison 80, the pickup is advanced (140). If the current track differs from the current track to be detected (150), the index to be searched is returned. Determines that the track does not exist in the track to be found, displays the index mode release, and detects the first portion of the track to find (160).

If the current track is the same as the track to be detected (150), if the current track is smaller than the track to be detected (70), the pickup is advanced to step 140, where the current index is greater than the index to be detected. If it is larger, the pickup is reversed at a speed about 10 times faster than the normal play state (180), and the current index is compared with the index to be detected (190). If the current index is less than the index to be detected, the audio signal is muted (200) for a predetermined time until the current index is equal to the index to be detected (210), and then played (220).

As described above, according to the present invention, the index which is not recorded in the lead-in area in the compact disc can be detected accurately and quickly.

Claims (1)

Detect the time for the track's code, determine if the detection is complete, compare the current track with the track to be detected, and advance or retract the pickup until the current track is the same as the track to be detected. If the current track and the track to be detected are the same, the current index is compared with the index to be detected. If the current index is larger than the index to be detected, the pickup is reversed, and the current index is compared with the index to be detected. If and the index to be detected are equal, drive the pickup at the normal play speed, mute the audio signal for a certain time, and indicate the completion of the index detection. If the current index is smaller than the index to be detected, advance the pickup and then the current index. Is equal to the index to be detected Drive at the normal play speed, then mute the audio signal for a certain period of time, indicating completion of the index detection, drive pickup at a speed 100 times faster than the normal play speed when detecting tracks, and normal when detecting an index. An index detection method in a compact disc player system that drives a pickup at a speed about ten times faster than the play speed.

Images