KR960011296B1 - Disc duplication discriminating method for multi laser disk player - Google Patents

Abstract

detecting the existence of a tilt signal (101); determining a focus lock state if the tilt signal is determined as detected (102); determining a disc duplication state if the focus lock state is determined (103); determining a LD (2) if the focus unlock state is determined (104); determining the focus lock state at location (b) and determining CD (2) if the focus lock state is determined (105); and determining the disc not to be exist if the focus unlock state is determined.

Description

How to Determine Disc Overlap in a Multi-Laser Disc Player

1 is a block diagram of a general multi-laser disc player.

2 is a flow chart according to the present invention.

3 is a diagram showing an overlapping structure of LD and CD.

* Explanation of symbols for main parts of the drawings

1: LS 2: CD

3: pickup 4: preamp

5: FM demodulator 6: Servo system

7: CPU 8: Display

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of detecting a disc overlap of a laser disc player (hereinafter referred to as MLP), and more particularly, to a laser disc (hereinafter referred to as a CD) on a compact disc (hereinafter referred to as a CD). When the disc is located, the disc overlap of the multi-laser disc player is shown so that the disc overlap can be known without rotating the disc. 1 shows a block diagram of a general MLP, in which a spindle motor SP for rotating the LD 1 or CD 2 and a pickup 3 for reading information of the LD 1 or CD 2 are shown. ), The preamplifier 4 and the FM demodulator 5 for amplifying and FM demodulating the signal reproduced by the pickup 3, and the signals read by the pickup 3 to control phase and speed. A servo system 5, a CPU 7 for controlling the system as a whole, and a display unit 8 connected to the CPU 6 to display the total number of songs on the disc, the number of songs currently playing, and the like. do. The MLP configured as described above reads information on the LD 1 or CD 2 by using the pickup 3 while rotating the LD 1 or CD 2 by the spindle motor SP. The information read by the pickup 3 is amplified via the preamplifier 4, inputted to the FM demodulator 5, and then FM-demodulated and output as a video signal or an audio signal. The servo-related signal output by the pickup 3 controls the spindle motor SP through the servo system 6. On the other hand, as shown in FIG. 1, the operation in the case where the LD 1 is superimposed on the CD 2 is as follows. First, in a general case, the disc is judged or rotated several times in the stationary state, and then the disc is rotated until the disc is normally played after determining the disc type. At this time, if the CD (2) and LD (1) overlaps, even if the desired number of revolutions is reached, the disc is not properly seated, so normal play is not possible. Therefore, normal play is not possible, so the rotation of the disc is stopped and the play is stopped. That is, in the conventional case, even when the disc is not properly seated and the disc does not play properly because the LD is superimposed on the CD, the disc is rotated for a predetermined time, which may cause damage to the disc. SUMMARY OF THE INVENTION The present invention has been made to solve this problem, and an object of the present invention is to determine the overlap of a disc without rotating the disc by determining the presence of LD by a tilt signal and the presence of CD by a focus signal. The present invention provides a method of detecting disc overlap of a disc player. A feature of the present invention for achieving this object is the step of detecting the presence or absence of a tilt signal at the position of the LD at a distance from the disk rotation axis, determining whether the tilt signal was detected in the step, and the tilt in the step Determining the focus lock state at the position of the CD at a predetermined distance from the disk rotation axis if it is determined that the signal is detected; determining the overlapping state of the disc if the focus lock state is determined at the step; Determining that the LD is determined, and if it is determined that the tilt signal is not detected in the step, determining the focus lock state at the position of the CD at a distance from the disk rotation axis, and if it is determined that the focus lock state Determining that it is a CD; and if it is determined that the focus is unlocked And it has to identify the disc stacking method of the multi-laser disk player comprising the step of determining. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 2 is a flowchart for implementing a disc overlap detection method of a multi-laser disc player according to the present invention, which is performed in a general MLP system as shown in FIG. 1, and FIG. 3 shows an LD and CD overlapping structure for explaining the present invention. (A) is the disc rotation axis, (b) is the read-in area of the CD 2, and is 23-25 mm from the disc rotation axis (a), and (c) is the It is a part of LD (1) which is out of size (12 cm), and was caught here by 70 mm from the disk rotating shaft a. The present invention as described above first determines the presence or absence of a tilt signal at position (c) of FIG. 3 before disc play (100) and (101). Here, the determination of the presence or absence of the tilt signal is determined by irradiating the disk with light from the light emitting element located in the pickup 3 and detecting the return light by the light receiving element. At this time, if the tilt signal is detected in the step 101, this means that the LD (1) is present. When the tilt signal is detected in step 101, it is determined whether the focus is present (focus lock, focus unlock) at the position (b) of FIG. The presence or absence of focus in the step 102 is irradiated with the laser light on the disk to determine the strength of the light coming back, which is also performed by the pickup (3). Since the position (b) is a lead-in area of the CD 2, if the CD 2 exists, it is determined that the disc is overlapped (103). In the step 102, the focus lock means that the pickup 3 focuses the laser beam through an objective lens (not shown) to accurately match the light source on the signal surface of the disk, that is, to read the signal of the disk. . However, if it is determined in the step 102 that the focus lock has not been performed, it is determined that there is no CD 2, so that only the LD 1 exists, not the disks being overlapped (104). Here, the focus unlock state means that the focus lock is not performed, and the focus unlock state refers to a state in which the pickup 3 cannot read a signal of the disc and moves until the focus lock is achieved by driving the objective lens. . In addition, if it is determined that the tilt signal is not detected in step 101, the presence or absence of focus at position (b) is determined in the same manner as step 102 (102a). If it is determined that the disk is in the unlocked state, it is determined that there is no disk (106). In the meantime, the present invention may allow the CPU 6 to display an error state on the display unit 8 at the disc overlap determination. As described above, the present invention can determine the overlap of discs without rotating the discs by judging the presence or absence of the LD by the tilt signal and judging the presence of the CD by the presence or absence of the focus, so that the disc overlaps without rotating the disc. As it rotates, it is possible to prevent the damage of the disk, there is an effect that can know the overlap of the disk more accurately and faster than the conventional.

Claims (2)

If it is determined that the tilt signal is detected in steps 100 and 101 of detecting the presence or absence of the tilt signal at the position c of the LD 1 at a distance from the disk rotation axis a, and the step 101, Determining the focus lock state at the position (b) of the CD (2) at a distance from the disk rotation axis (a) (102), and if it is determined that the focus lock state in the step 102, the disk overlap state is determined In step 103, if it is determined in step 102 that the focus is unlocked, in step 104, it is determined that it is LD (2), and in step 101, if it is determined that no tilt signal is detected, the disc rotation axis (a). Determining the focus lock state at the position (b) of the CD 2 at a predetermined distance from the step 102a; and determining the focus lock state as the focus lock state at the step 102a (105). And if it is determined in step 102a that the focus is unlocked, determining that there is no disk (106). Disc overlap detection method of a multi-laser disc player characterized by a glitch. The method of claim 1, wherein the position (c) in the step (100) is the position of the LD (1) outside the position of the CD (2).