JPH06236638A - Optical disk reproducing device - Google Patents

Abstract

PURPOSE:To accurately select music without any errors by calculating the recording linear speed of the disk for each disk to be reproduced and calculating the moving quantity of an optical pick-up at the time of a music selecting operation. CONSTITUTION:In a microprocessor 22, a recording linear speed V on the radial position (r) of a disk 13 specified by a switch 23 is calculated to be 2pir/t from the rotative cycle (t) of the disk 13 rotated at the recording linear speed V. Then, the processing of the movement of an optical pick-up 11 is started against a digital servo LS121 by the microprocessor 22. A traverse driver 16 is controlled by the digital servo LS121, the optical pick-up 11 is moved by rotating a traverse motor 12, the number of tracks crossed by the optical pick-up is simultaneously counted and when a specified track is crossed, the movement of the optical pick-up is stopped. Thus, the optical pick-up is moved to the position of the selected music.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc reproducing apparatus used for a compact disc player or the like.

[0002]

2. Description of the Related Art Conventionally, in this type of optical disc reproducing apparatus, it is not possible to know a different recording linear velocity for each disc. Therefore, in order to calculate the movement amount of the optical pickup when the optical pickup is moved to the designated position on the disc (access operation), the average recording linear velocity is used as an approximate value.

[0003]

However, in the above-mentioned conventional optical disc reproducing apparatus, since the moving amount of the optical pickup is calculated using the average recording linear velocity, the actual recording linear velocity and the actual recording linear velocity are different from each other. The difference in the amount of movement causes an error in the amount of movement, and therefore, in order to move the optical pickup to the specified position, it is necessary to repeatedly perform access operations, which increases the time required to reach the reproduction operation. was there.

The present invention solves such a conventional problem by measuring the recording linear velocity which is different for each disc,
It is an object of the present invention to provide an optical disc reproducing apparatus capable of performing a faster access operation by accurately calculating and moving the amount of movement of an optical pickup during an access operation.

[0005]

In order to achieve the above object, the present invention detects a deviation amount between a position of a track recorded on a rotating disk and a position of an optical pickup to generate a detection signal. Detection means, rotation control means for controlling the disc rotation speed so that the passage time of the pits of a specific length recorded on the disc becomes constant, and when the passage time becomes constant, the periodic detection signal is detected. The rotation speed of the disc is measured from the change, the relative speed between the optical pickup and the disc when the signal is recorded on the disc is estimated, and the light to the specified position is estimated from the relative speed and the address information recorded on the disc. And a calculation means for calculating the movement amount of the pickup.

[0006]

The present invention has the following actions due to the above-mentioned configuration. That is, the recording linear velocity, which is the relative velocity of the disc, is measured and the amount of movement of the optical pickup at the time of access operation is calculated. Accurate calculation of the amount of movement of the pickup enables quick access.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical disc reproducing apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an optical disc reproducing apparatus of this embodiment. In FIG. 1, 11 is an optical pickup for reading recorded information. A traverse motor 12 moves the optical pickup 11 in a radial direction of a compact disc 13 (hereinafter abbreviated as a disc). Reference numeral 14 is a spindle motor that rotates the disk 13. A spindle drive circuit 15 drives the spindle motor 14. A traverse drive circuit 16 drives the traverse motor 12.

Reference numeral 17 denotes a focus drive circuit which drives the optical pickup 11 in the focal direction to focus the optical pickup 11.
Reference numeral 18 denotes a tracking drive circuit that shifts the optical pickup 11 in the radial direction of the disk 13 to follow the track. Reference numeral 19 shapes the signal on the disk read from the optical pickup 11 and outputs an error amount signal in the focus direction (focus error signal) and an error amount signal in the track following direction (tracking error signal) necessary for servo control. It is an RF amplifier as a detection means. Two
Reference numeral 0 is a signal processing LIS for processing a signal read from the disk 13 to take out audio data and a subcode and for controlling the rotation servo of the spindle. Reference numeral 21 is a digital servo LSI as a rotation control means for performing servo control of focus and tracking based on a signal from the optical pickup 11.

Reference numeral 22 is a calculation means for controlling the signal processing LSI 20 and the digital servo LSI 21 to perform disk reproduction and access operations, and to measure the disk rotation speed from the tracking error signal to calculate the recording linear speed of the disk. Is a microprocessor. 23 is
This is a switch for detecting that the optical pickup 11 is at the reproduction start position of the disc 13. 24 is signal processing L
It is a digital-analog converter that converts the digital signal output from SI 20 into analog. An amplifier 25 amplifies the audio signal converted by the digital-analog converter 23. Reference numeral 26 is a speaker that reproduces the audio signal amplified by the amplifier 25.

Reference numeral 27 is an operation display device for displaying a reproduction music number signal output from the microprocessor 22 on the display panel and outputting an operation button pressing signal of the operation panel to the microprocessor 22.

FIG. 2 is an enlarged view of a pit train recorded on the disk 13. Digital data is recorded in the tangential direction of the disc by a combination of pits each having an integral multiple of 3 to 11 times the basic period (T).

FIG. 3 shows a tracking error signal when only focus servo control is performed on a rotating disk.

Next, the operation of the above embodiment will be described. In the above embodiment, the microprocessor 22 is
Traverse motor 1 for traverse drive circuit 16
2 outputs a control signal to rotate the optical pickup 11
The optical pickup 11 by moving the
Stops moving when the switch 23 is pressed. As a result, the optical pickup 11 is moved to the fixed position defined by the switch 23. Next, the microprocessor 22 causes the digital servo LSI 21 to start focus servo control. Digital servo LSI2
1 performs servo control for focusing based on the focus error signal from the optical pickup 11. In addition, the signal processing LSI 20 has a spindle motor 14
In order to rotate at a constant speed, the servo control described later is started.

Here, since tracking servo control is not performed from the optical pickup 11, the disc 1
The pit train of the track on 3 is read in pieces. The signal processing LSI 20 extracts a pit string having a length six times the basic period (T) shown by 28 in FIG. 2 from the fragmentary pit string, and the time passing through this pit is different from that during reproduction. A drive signal is output to the spindle drive circuit 15 so that the same constant time is reached (rough servo). As a result, the disc 13 can be rotated at the linear velocity at the time of recording.

Here, the RF amplifier 19 outputs the tracking error signal as shown in FIG.
That is, since tracking servo is not performed,
The RF amplifier 19 simply outputs a tracking error signal for the track passing over the optical pickup 11, and the signal is deviated from the true center of the rotating disk 13 and the center of the rotation shaft of the spindle motor 14 (eccentricity). ), Wait for a periodic change. Since this cyclic change occurs twice per one rotation of the disk 13, the rotation speed of the disk 13 rotating at the linear velocity at the time of recording can be obtained by measuring this cycle.

In the microprocessor 22, the switch 2
At the radial position r of the disk 13 specified by 3, from the rotation cycle t of the disk 13 rotating at the recording linear velocity v,
The recording linear velocity v is calculated as 2πr / t. This process is performed before the disc 13 is mounted on the spindle motor 14 and is reproduced. Here, the operation display device 2
When the music selection operation button pressing signal from 7 is input to the microprocessor 22, the microprocessor 22 puts the selected number on the disk from the table of contents information (TOC) of the music read in advance from the disk 13. Replace with continuously recorded absolute time information. Further, the relationship between the absolute time t1 recorded on the disc at the linear velocity v and the radial position r1 from the disc center is: v · t1 · tp = π · (r1 · r1-r0 · r0) where π: circumference Ratio r0: Performance start position radius tp: Expressed as track pitch, from which absolute time t specified on disk is specified
The movement amount (r1-r0) of the optical pickup 11 up to 1 is calculated. Further, this moving amount is converted into the number of tracks traversing when the optical pickup 11 is moved in the radial direction to obtain ((r1−r0) ÷ tp), and the microprocessor 22 causes the digital servo L
The SI 21 is caused to start the movement processing of the optical pickup 11. The digital servo LSI 21 controls the traverse driver 16 and rotates the traverse motor 12 to move the optical pick-up 11, and at the same time, counts the number of tracks that the optical pickup 11 has crossed. Pickup 1
Stop the movement of 1. As a result, the optical pickup 11 can be moved to the position of the selected song.

As described above, according to the above-described embodiment, the microprocessor 22 calculates the recording linear velocity of the disk 13 before performing the music selection operation to determine the movement amount of the optical pickup 11 when the music selection is executed. By calculating for each disc to be reproduced, there is an effect that the music selection operation can be accurately performed without error.

[0019]

As is apparent from the above embodiment, the present invention is to calculate the recording linear velocity of each disc to be reproduced and to calculate the movement amount of the optical pickup during the song selection operation. This has the effect that the operation can be performed accurately without error.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of an optical disk reproducing device according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a pit row recorded on a compact disc of a compact disc.

FIG. 3 is a tracking error signal waveform diagram when only focus servo control is performed

[Explanation of symbols]

 11 Optical Pickup 13 Optical Disk 14 Spindle Motor 15 Spindle Drive Circuit 19 RF Amplifier Circuit (Detection Means) 21 Digital Servo Circuit (Rotation Control Means) 22 Microprocessor (Calculation Means)

Claims (1)

[Claims] 1. A detection means for detecting a deviation amount between a position of a track recorded on a rotating disc and a position of an optical pickup to generate a detection signal, and a pit of a specific length recorded on the disc. Rotation control means for controlling the disc rotation speed so that the passage time becomes constant, and when the passage time becomes constant, the disc rotation speed is measured from the periodic change of the detection signal, and the signal is recorded on the disc. The optical system including an arithmetic means for estimating the relative speed between the optical pickup and the disc at the time, and calculating the movement amount of the optical pickup to the designated position from the relative velocity and the address information recorded on the disc. Disc player.