KR960002040B1 - Optical disk reproducing device - Google Patents

Abstract

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Description

Optical Disc Player

1 is a block diagram showing the main parts of an optical disc reproducing apparatus of the present invention.

2 is an explanatory diagram of a jump line at the time of optical disc reproduction.

* Explanation of symbols for main parts of the drawings

1: disc 2: optical pickup

4: reproduction signal processing circuit 6: servo circuit

7: Q data detection circuit 8: control unit

9: Q data detecting means 10: Focus detecting means

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an apparatus for reproducing an optical disc on which music information is recorded, and more particularly, to an apparatus for reproducing an optical disc suitable as a vehicle-mounted player for reproducing a compact disc.

In an optical disc reproducing apparatus capable of reproducing music information of an optical disc by irradiating laser light, when a lack of continuity of address data obtained from the reproduction signal is detected, the address data at that time is stored, and then the laser beam is stored. The pickup is irradiated with a jump to a predetermined position to reduce the effect of sound skipping due to the impact.

As a device for reproducing high quality music, compact disc (CD) players are widely used. However, since CD players basically read high-density information recorded on narrow recording tracks by non-contact optical heads, tape recorders are used. In comparison with this, the shock resistance is not high.

Therefore, in the portable CD player and the vehicle-mounted CD player, there has been a problem of skipping sound due to impact.

That is, the relative positional relationship between the optical disc and the optical pickup is mainly maintained by the responsiveness of the tracking servo and the focus servo system. However, when a large shock vibration is applied to the player, the mass of the two-axis servo mechanism follows the vibration. The above-mentioned problem has arisen because it became impossible to cause the focus servo to come off and the tracking servo to come off.

Therefore, in the past, when a negative skip occurred due to such an impact, the previous address data was stored and reproduced from the original address data position after the servo system was recovered. Considering the flow, there was a problem that a time shift occurs and a sense of discomfort occurs.

In general, when the tracking servo is out of position, the spot of the laser light irradiated on the optical disc is shifted from the current playback track position to a different track, and a similar phenomenon of negative skipping occurs (temporal approximation). Therefore, there is a problem that a continuous feeling of music being reproduced is lost for several seconds, causing a sense of discomfort.

The present invention has been made in order to alleviate such a problem, and the optical disc reproducing apparatus of the present invention comprises an optical head (2) for irradiating a light beam to an optical disc (1) in which digitized music information and address data are recorded in units of frames. And reading means (3, 4) for reading address data together with digitized music information in accordance with the output signal from the optical head (2), and irradiated from the optical head (2) to the optical disc (1). First detection means (10) for detecting an operating state of a focus servo of a light beam, and focus of the light beam irradiated from the optical head (2) to the optical disc (1) by the first detection means (10). When detecting that the servo is out, the holding means 8d for holding the address data read by the reading means 3 and 4 and the continuity of the address data read by the reading means 3 and 4 are detected. doing Arithmetic means for performing arithmetic processing on the address data read out from the holding means 8d when the second detecting means 9 and the second detecting means 9 detect the discontinuity of the address data; 8c) and the output from the calculation means 8c when the first detection means 10 detects that the focus servo of the light beam irradiated from the optical head 2 to the optical disc 1 is out of the optical head 2. Generating means 8b for generating a jump signal according to the first detection means, and detecting that the focus servo of the light beam irradiated from the optical head 2 to the optical disk 1 is out of the optical head 2 by the first detecting means 10; In response to the jump signal from the generating means 8b, moving the light beam from the optical head 2 to a position downstream in time from the position at which the focus servo is detected to be out of position and restarting the reproducing operation. Characteristic The.

According to the present invention, when the focus servo is off or the tracking servo is off, the time until the light spot is properly tracked by the servos can be generally estimated.

Therefore, when the focus is out of focus, the optical head is applied to the preceding track by the focus search time and the time to find a new address data position by the next track jump. By jumping, continuity occurs in the music information being played back, and the discomfort can be reduced to such an extent that discomfort is hardly felt.

Next, embodiments of the present invention will be described with reference to the drawings.

1 is a block diagram showing the feature points in the optical disc reproducing apparatus of the present invention, where (1) is a compact disc (hereinafter simply referred to as a disc), and (2) is an optical pickup that is an optical head.

In this optical pickup 2, as is well known, a laser light emitting element, a light receiving element for detecting reflected light, an objective lens, and a servo mechanism for driving the objective lens are built in, and the RF signal detected from the light receiving element is read out as follows. It is supplied to the RF amplifier 3 and the reproduction signal processing section 4 which are means. Then, error correction, demodulation, signal conversion, and the like of the recording data are performed, converted into a stereo signal, and input to the output amplifier 5. On the other hand, a part of the detection signal obtained from the RF amplifier 3 is calculated according to the detection method of the focus and tracking error signal, and the formed focus error signal and tracking error signal are supplied to the servo circuit 6. Then, the light spot irradiated from the optical pickup 2 is controlled so as to track a predetermined track at the confocal point.

On the other hand, the reproduction signal processing section 4 separates the digital music information and the Q signal data, and the separated Q signal data (Q signal data is address data indicating the frame number and time code of each block signal of the digital music information, and the song number. Is composed of a music number code indicating the music number and the playing time of the music currently being reproduced, and the data is demodulated by the Q data detection circuit 7. Music search, jump control of optical pickup, and the like can be performed.

Numeral 9 denotes Q data detecting means constituted by registers 9a and 9b, comparison circuit 9c, and the like. During reproduction, new Q signal data is first input into register 9a, and then this register 9a. ) Data is transferred to the register 9b, and the next Q signal data is input to the register 9a.

In the comparison circuit 9c, this new Q signal data loaded into the register 9a and the previous Q signal data transferred to the register 9b are always compared during playback, and continuity is lost. If so, the first track jump command circuit 8a in the controller 8 is driven.

In addition, 10 denotes a focus detecting means for detecting a focus state. For example, when the focus OK signal (FOK signal) indicating the focus lock state output from the servo circuit 6 is not 16mS, the control unit ( The second jump command circuit 8b, which is a jump signal generating means in 8), is driven.

When a signal is input to the track jump command circuit 8a or 8b, the data 8c inputs data to the register 8d, which is a holding means for storing the previous Q signal data. An arithmetic circuit for adding a predetermined number of frames to an absolute address signal XX minutes XX seconds XX frames consisting of a time code and a frame number in the signal data is shown. A predetermined track jump signal is formed in accordance with the arithmetic result. It is input in (6).

As described above, the optical disc reproducing apparatus of the present invention has a focus detecting means (10) for judging the state of the focus servo circuit from the FOK signal, and Q data for detecting continuity of the Q signal data during reproducing and monitoring for tracking off. Since the detection means 9 is disposed, for example, as shown in FIG. 2, when the focus servo is released at Q ₁ due to an impact or the like when the disc 1 is being played back from the inner track to the outer track. jump command circuit (8b) is operated and, at the same time, the Q signal data Q ₁ (X ₁ X ₁ bun X ₁ X ₁ cho X ₁ X ₁ frame) to accept the Q signal data Q ₁ of Q ₁ that the computing circuit Q ₂ (X ₂ X ₂ minutes X ₂ X ₂ seconds X ₂ X ₂ frames = X ₁ X ₁ minutes X ₁ X ₁ seconds X ₁ X ₂ frames + α) The jump pulse of (75 frames) is input to the servo circuit 6.

The jump position by the jump pulse is set to an average value of 1 second (75 frames) of time required for the focus servo to recover and then to reach the jump position by track jump.

Although this time varies somewhat depending on the type of the playback apparatus, it is set about one second after the focus is released, and music information that does not lose continuity can be reproduced, so that a sense of discomfort is reduced.

When the tracking servo is released due to an impact or the like and the light spot moves to another track, the above-described first track jump command circuit 8a is operated to store the Q signal data Q ₁ immediately before the tracking off (8d). ) the computing means is calculated and entered into the circuit (8c), when a jump to access the 50 frames in front of a position Q signal data Q ₃ from the Q signal data Q _1, be that there is no discomfort to the continuity of the music information being reproduced Can be.

In the case of the tracking servo, this is only an operation of accessing the position of the Q data signal Q ₃ , so the operation is completed in a relatively short time. It is preferable that the mute signal Sm is supplied to the output amplifier 5 in accordance with the output of the track jump command circuit 8c while the Q signal data Q ₂ of the jump line is accessed so as to eliminate the reproduction noise.

However, when there is an impact, the concentration of the human auditory sense in the music information is momentarily lowered, so that a significant improvement effect is recognized without necessarily setting the jump line strictly.

As described above, the optical disc reproducing apparatus of the present invention moves to the position of the Q signal data preceding a predetermined time or a predetermined number of frames from the reproducing position stopped by the servo when the servo system of the optical pickup is out of the optical pickup due to an impact or the like. Since the jump is made to start playback from the position, especially when the shock is frequently applied, such as a vehicle-mounted CD player, there is an effect that a high-quality playback sound that maintains the continuity of music when the servo is released can be heard. .

Claims (1)

An optical head 2 for irradiating an optical beam to the optical disc 1 on which digitalized music information and address data are recorded in units of frames, and address data together with digitalized music information in accordance with an output signal from the optical head 2; Reading means (3, 4) for reading the first, first detecting means (10) for detecting an operating state of the focus servo of the light beam irradiated from the optical head (2) to the optical disc (1), and the first When the detection means 10 of 1 detects that the focus servo of the light beam irradiated from the optical head 2 to the optical disc 1 is out of position, the address data read by the reading means 3, 4 is read. The holding means 8d for holding, the second detecting means 9 for detecting the continuity of the address data read by the reading means 3, 4, and the second detecting means 9 are address data. When the discontinuity of the A focus servo of the light beam irradiated from the optical head 2 to the optical disc 1 by the arithmetic means 8c for performing arithmetic processing on the address data read out from 8d; Generation means 8b for generating a jump signal in accordance with the output from said calculation means 8c when detecting that the deviation is out, and by said first detection means 10 from said optical head 2; When detecting that the focus servo of the light beam irradiated to the optical disc 1 is out of position, the light beam from the optical head 2 is detected from the position where the focus servo is out of focus according to the jump signal from the generating means 8b. An optical disc reproducing apparatus, wherein the reproducing operation is resumed by moving to a position downstream in time.

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