JPH0736255B2 - Optical disc player - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an optical disc reproducing apparatus for reproducing an optical disc such as a compact disc or a video disc.

<Prior Art> When reproducing an optical disk, the optical disk reproducing apparatus reads data to be reproduced, such as audio signals recorded on the optical disk, reading index data recorded on the optical disk, and track access. All the reading of time data is processed by one reference clock.

Therefore, since the processing speed is restricted by the clock signal from the reference clock, it takes time to read the data of the index section and the data at the time of track access,
There is a drawback that the waiting time until the data to be reproduced is reproduced is long.

<Objects of the Invention> The present invention solves the above-mentioned technical problems, processes the data reading of the index section and the data reading at the time of track access in a short time, and waits until the data to be reproduced is reproduced. It is an object of the present invention to provide an optical disc reproducing apparatus having a short length.

<Structure of the Invention> An optical disc reproducing apparatus according to the present invention has a first reference clock signal for reading data recorded on an optical disc and to be reproduced, and a frequency higher than the frequency of the first reference clock signal. And a reference clock signal generating means for generating the data of the index portion recorded on the optical disc and the second reference clock signal for reading the data at the time of track access, and the first reference signal at the time of reading the data to be reproduced. Clock signal switching means for selectively outputting the clock signal, and the second reference clock signal when reading the data of the index portion and the data at the time of track access, from the reference clock signal generating means based on the switching command; Recorded on the optical disc according to the reference clock signal from the reference clock signal generating means. Signal processing means for reading and processing the stored data.

According to this structure, when the data of the index portion and the data at the time of track access are read, the second reference clock signal having a higher frequency is selected by the clock signal switching means and then the signal from the reference clock signal generating means is selected. As a result of being output to the processing means, it is possible to perform reading at a higher speed than when reading the data of the index portion and the data at the time of track access based on the first reference clock signal.

<Example> Hereinafter, an example of the present invention is described in detail based on a drawing.

FIG. 1 is a block circuit diagram of a compact disc reproducing apparatus according to an embodiment of the present invention.

A compact disc reproducing device 1 as an optical disc reproducing device includes a spin motor 2, an optical pickup 3, a signal processing device (signal processing means) 4, a D / A converter 5,
Audio amplifier and filter 6, and audio signal output terminal 7
A system controller 8, an audio reproduction reference clock 10 for outputting a first reference clock signal for reading data to be reproduced, a servo amplifier 11, and a driver 12. Such a configuration is basically the same as that of the conventional compact disc reproducing apparatus.

In the compact disc reproducing apparatus 1 of this embodiment, in order to increase the reading speed of the data of the index portion and the data at the time of track access, the audio reproducing reference clock 10 is used.
It includes an index reading clock 9 for outputting a second reference clock signal having a frequency higher than the oscillating frequency, and a signal processing speed changeover switch (clock signal changeover means) 13, which is used as a reference by both clocks 9 and 10. Clock signal generating means is configured. When reproducing the audio signal, the signal processing speed changeover switch 13 is connected to the audio reproduction reference clock 10 to perform the signal processing. In this case, the audio signal output terminal 7 is operated at a speed faithful to the original sound. The audio signal will be reproduced. Also,
At the time of reading the data of the index portion and the data at the time of track access, the signal processing speed changeover switch 13 is connected to the clock 9 for reading the index or the like, thereby increasing the speed of reading the data of the index portion and the data at the time of track access. be able to.

On a compact disc 14 as an optical disc, data to be reproduced, that is, audio data, data of an index portion, track data, that is, the number of tunes and the like are recorded.
The compact disc 14 is rotationally driven by the spin motor 2. The data recorded on the compact disc 14 is read by the optical pickup 3. Thereby, the optical pickup 3 detects the servo error information from the optical disc 1 and the written digital information.

The servo error information is an analog quantity, and the servo amplifier
Proper control signal is generated by 11. This control signal is given to the optical pickup 3 via the driver 12. This allows control of data reading (focus control,
Trace control) is performed.

On the other hand, the music information included in the digital information is the signal processing device 4
Thus, after correcting the error, it is input to the D / A converter 5, and is output from the audio signal output terminal 7 as an analog amount via the audio amplifier and the filter 6.

Information other than music, that is, the data of the index portion and the like are input to the system controller 8. System controller 8
Receives commands from the user by key operations such as PLAY, STOP, FF, RFW, etc., controls the servo amplifier 11, and performs track search, play, stop, etc.
Further, the track number (the number of pieces of music) and the time of the information currently read by the optical pickup 3 are displayed. Furthermore, when reading the audio data, the first reference clock signal output from the audio reproduction reference clock 10
At the time of reading the data of the index portion and the data at the time of track access, the signal processing speed changeover switch 13 is instructed to give the signal processing device 4 the second reference clock signal output from the index reading clock 9.

The signal processing device 4 performs processing and execution based on the input first or second reference clock signal, and outputs a digital audio signal or another digital signal according to one of the first and second reference clock signals. The signal is output. Therefore, at the time of voice reproduction, since the voice reproduction reference clock 10 corresponding to the sampling frequency of the voice is operated, the reproduction is performed at a speed faithful to the original sound. Moreover, when the data of the index portion and the data of the track access are read, the clock for reading the index 9 operates, so that the data of the index portion and the data of the track access are read at high speed. At this time, the speed of the spin motor 2 is controlled according to the amount of data output from the signal processing device 4, and the optical disk 1 is transferred to the signal processing device 4.
The amount of information flowing in from is controlled so that there is no excess or deficiency.

In a normal compact disc player, there is only the audio reproduction reference clock 10, and data reading such as reading of the index portion operates at a constant speed. In this embodiment, a clock 9 for reading the index etc. is separately provided, and the signal processing speed changeover switch 13 is provided for the system controller 8 only when reading the data of the index portion and the data at the time of track access.
And the signal processing is performed at a speed according to the clock 9 for reading the index or the like. At this time, since the oscillation frequency of the index reading clock 9 is set to be higher than that of the audio reproduction reference clock 10, the index portion data and the data reading at the time of track access can be performed faster than a normal compact disc player. Can be done.

The present invention can be implemented not only in the compact disc reproducing device but also in other optical disc reproducing devices such as a CD-ROM reproducing device and a video disc reproducing device.

<Effects of the Invention> According to the present invention as described above, for example, when the data of the index portion and the data at the time of track access are read, the second
If the reference clock signal is given to the signal processing means, the data of the index portion and the data at the time of track access can be read in a short time, and therefore the waiting time until the data to be reproduced can be shortened.

[Brief description of drawings]

FIG. 1 is a block circuit diagram of a compact disc reproducing apparatus according to an embodiment of the present invention. 1 ...... Compact disc playback device 4 ... Signal processing device 8 ... System controller 9 ... Clock for reading index etc. 10 ... Reference clock for audio playback 13 ... Signal processing speed changeover switch 14 ... Compact disc

Claims (1)

[Claims] 1. A first reference clock signal for reading data to be reproduced that is recorded on an optical disc, and has a frequency higher than the frequency of the first reference clock signal and is recorded on the optical disc. Reference clock signal generating means for generating a second reference clock signal for reading the data of the index portion and the data at the time of track access, a first reference clock signal for reading the data to be reproduced, and a reference clock signal of the index portion. Clock signal switching means for selectively outputting the second reference clock signal from the reference clock signal generating means based on a switching command when reading data and data during track access, and a reference clock from the reference clock signal generating means. A signal for reading and processing the data recorded on the optical disk according to the signal. Optical disk reproducing apparatus characterized by comprising a processing means.