JPH0845171A - Dick reproducing device - Google Patents

Abstract

PURPOSE:To quickly discriminate the standardized linear velecity of a set disk by positioning pickups at respective positions in the radial direction becoming standardized linear velocity at the time of a prescribed angular velocity and detecting recorded information. CONSTITUTION:When a disk D is set in this device and the reproducition of the disk is commanded, pickups 2a, 2b are positioned at positions, 100mm, 78mm apart respectively from the center of the disk and detected by switches 3a, 3b. When the positionings of pickups are completed, the driving of a disk motor M is started and then the disk D starts toward a prescribed rotational speed and generates a lock signal at the time the rotational speed becomes the prescribed speed to output it to a discrimination circuit 9. Outputs of pickups 2a, 2b are also inputted to address signal detecting circuits 7a, 7b via FM demodulation circuits 5a, 5b. In the circuit 9, at the time of a start-up, in the case where an address signal is sent from the circuit 7a with a prescribed roatational speed, the circuit 9 discriminates the disk as a standard disk, and in the case where an address signal is sent from the circuit 7b, the circuit discriminates that a high density disk is set in the device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc reproducing apparatus having a compatibility function for reproducing discs of different types (discs having different recording densities).

[0002]

2. Description of the Related Art A baseband high-definition signal is divided into two and recorded on corresponding portions on the front and back of a disc.
A channel recording video disc record is provided, which is reproduced by a device having two pickups. That is, the recording signals on the respective surfaces are read by two pickups, one on each side of the disk, and the read recording signals are FM-demodulated and then combined to output as a high-definition signal. To be done. Also, as the above-mentioned double-sided recording type video disc,
There is provided a so-called constant linear velocity type video disc record (CLV disc) whose rotation is controlled so that the linear velocity of the disc becomes constant.

On each side of the above-mentioned double-sided recording type CLV video disc, an address signal is biphase-modulated and recorded on a video signal in a multiplexed manner for reproduction control and random access control. This address signal can be read when the video disk is rotated within the range of the standard linear velocity ± 10 [%]. Here, the standard linear velocity is 18.8 [m / sec] for the current recording density (standard density) base band type video disk.

[0004]

Along with the development of semiconductor lasers for short wavelength optical pickups, the development of high recording density discs and reproducing apparatus therefor is underway. It is desired that this reproducing apparatus has a compatibility function capable of reproducing not only a high recording density disc but also a conventional recording density (standard density) disc.

While the standard linear velocity of a standard density (normal density) CLV disk in which a high-definition signal is recorded in two divisions is 18.8 [m / sec] as described above, the same signal is recorded for a long time. The standard linear velocity of the produced high density CLV disk is 14.7 [m / sec], and the two are different. Therefore, in a compatible device that reproduces both standard density discs and high density discs, in order to control the rotation of the set discs at an optimum speed according to the recording density, the recording density of the discs should be increased quickly. Need to determine. SUMMARY OF THE INVENTION It is an object of the present invention to provide a reproducing apparatus that can quickly determine the standard linear velocity of a set disc.

[0006]

The present invention is a disc reproducing apparatus having a plurality of pickups and capable of reproducing recorded information of a plurality of types of discs having different standard linear velocities,
A means for detecting information recorded on the disc at a standard linear velocity of the disc; a means for positioning the plurality of pickups at respective radial positions at which the standard linear velocity is obtained at a predetermined angular velocity; A means for rotating and reproducing at a predetermined angular velocity, and a linear velocity at the position of the pickup where recording information is detected when the plurality of pickups are positioned at the respective positions and the disc is rotated at the predetermined angular velocity. And a means for discriminating that a disc having a standard linear velocity is set. Here, there are cases where all of the plurality of pickups are provided only on one side of the disc, and cases where a certain number of pickups are provided on both sides.

Further, the present invention is a disc reproducing apparatus having two pickups and capable of reproducing the record information of a disc having two kinds of recording densities, wherein the address information multiplexed in the record information of the disc is concerned. A means for detecting at a standard linear velocity defined corresponding to the recording density of the disk, and a means for detecting at a predetermined angular velocity at each position in the radial direction where two types of standard linear velocities corresponding to the two types of recording densities are obtained. Addressing information is detected when the pickups are respectively positioned, the disk is rotated at the predetermined angular speed to reproduce, and the pickups are positioned at the respective positions and the disk is rotated at the predetermined angular speed. And a means for discriminating that a disc having a recording density whose linear velocity at the position of the pickup is the standard linear velocity is set. Here, two pickups are provided, one on each side of the disc,
There are cases where two are provided on one side.

Further, in the above-mentioned invention, the present invention further comprises:
And a means for executing the discrimination when the disc is set, and a means for rotating the disc at a standard linear velocity to start reproduction after positioning each pickup at the program start position according to the discrimination result. It is a disk reproducing device.

Further, according to the present invention, a video disc, in which a video signal is divided into two channels and recorded on corresponding portions on both sides of the disc, is rotated at a standard linear velocity defined corresponding to the recording density of the disc. A disc reproducing apparatus that reproduces by using two pickups, one on each side of the disc, wherein the address signals multiplexed on the recording signals on each side of the video disc are standardized for the disc. A means for detecting the linear velocity, and one pickup is positioned at a first position in the radial direction where the first standard linear velocity is obtained at a predetermined angular velocity, and the second standard linear velocity is obtained at the predetermined angular velocity. A means for positioning the other pickup at a second position in the radial direction, a means for rotating the video disc at the predetermined angular velocity for reproduction, and one pickup for the front. When the video disc is rotated at the predetermined angular velocity while the other pickup is positioned at the first position and the other pickup is positioned at the second position, the address is detected based on the signal from the pickup at the first position. If the address is detected, the video disk having the first recording density corresponding to the first standard linear velocity is set, and if the address is detected based on the signal from the pickup at the second position, the second speed is set. And a means for determining that a video disc having a second recording density corresponding to the standard linear velocity is set.

[0010]

In the disc reproducing apparatus of the present invention, when a plurality of pickups are respectively positioned at respective radial positions where the standard linear velocity is obtained at a predetermined angular velocity, and the disc is rotated at the predetermined angular velocity. When the recording information is detected by a certain pickup, it is determined that the disc having the linear velocity at the radial position of the pickup as the standard linear velocity is set.

Further, in the disc reproducing apparatus of the present invention, one pickup is positioned at the first position in the radial direction where the first standard linear velocity is obtained at a predetermined angular velocity, and the second pickup is arranged.
When the other pickup is positioned at the second position in the radial direction where the standard linear velocity becomes, and the address information is detected by one of the pickups when the disc is rotated at the predetermined angular velocity, It is determined that a disc having a recording density whose linear velocity at the radial position of the pickup is the standard linear velocity is set.

Further, in the disc reproducing apparatus of the present invention, disc discrimination is executed when the disc is set, and each pickup is positioned at the program start position according to the discrimination result, and at the discriminated standard linear velocity. The disk is rotation controlled.

Further, in the disc reproducing apparatus of the present invention, one pickup is placed at a first radial position (eg, a position of 100 mm from the center) where the first standard linear velocity is obtained at a predetermined angular velocity. And the second radial direction in which the second standard linear velocity is reached at the predetermined angular velocity.
When the other pickup is positioned at the position (eg, a position of 78 [mm] from the center) and the video disc is rotated at the predetermined angular velocity, based on the signal from the pickup at the first position. When the address is detected by the video disc having the first recording density corresponding to the first standard linear velocity, the address is detected based on the signal from the pickup at the second position. Indicates that the video disc having the second recording density corresponding to the second standard linear velocity is set.

[0014]

Embodiments of the present invention will be described below. The apparatus of the first embodiment shown in FIG. 2 divides a baseband high-definition signal and records it on both sides for standard time, and a standard-density disc that divides the baseband high-definition signal for long-term recording on both sides. This is a device capable of reproducing both of the high density discs. The program start position is 66 [mm] from the center of the standard density disc and 55 [mm] from the center of the high density disc.
Further, the rotation directions of the recording signals on the respective surfaces are opposite to each other so that the recording signals on the front and back surfaces of the disc can be reproduced simultaneously.

The standard linear velocity of a standard density disc is 18.8.
[M / sec], and address detection is possible within a range of ± 10 [%]. The standard linear velocity is equal to the linear velocity realized at a position of 100 [mm] from the center when the rotational speed is 30 [rev / sec]. On the other hand, the standard linear velocity of the high-density disc is 14.7 [m / sec], and address detection is possible within the range of ± 10 [%]. The standard linear velocity is 30
It is equal to the linear velocity realized at a position of 78 [mm] from the center when the rotation speed is [rev / sec].

Therefore, the disk is 30 [rev / sec].
The address is detected at a position of 78 [mm] from the center when rotated by, or 100 [m] from the center.
By checking whether the address is detected at the position [m], the standard linear velocity of the video disk, that is, the recording density can be determined. This device uses this to discriminate the disk.

The circuit configuration and operation of the reproducing apparatus will be described with reference to FIG. When the disk D is set in the apparatus and a reproduction command is issued, the pickup servo circuit 1a positions the pickup 2a so that the laser irradiation position of the pickup 2a is 100 mm from the center of the disk. Similarly, the pickup 2b is picked up by the pickup servo circuit 1b so that the laser irradiation position of the pickup 2b is 78 mm from the center of the disc.
Is positioned. The positioning to each of the above positions is detected by the switches 3a and 3b, respectively. The pickups 2a and 2b each have a short wavelength (670 nm) laser beam.
The beam spot diameter is smaller than the laser wavelength (780 [nm] of the conventional device. Therefore, not only the standard density disc but also the high density disc with a narrow track pitch is reproduced. Is also possible.

When the above positioning is completed, the disk servo circuit 4 starts driving the disk motor M, and the disk record D starts to rotate toward a rotational speed of 30 [revolutions / second]. Also, the pickup servo circuit 1
Focus servo and tracking servo depending on a and 1b
The read / write of the recording signal of the disk D is started by performing the body and feed servo. The disk servo circuit 4
Is the disk mode when the disk is started and accessed.
F that outputs a frequency clock synchronized with the rotation speed of the M
By comparing the phase of the output of the G circuit 8 with the reference signal,
During the reproduction of the recorded signal, the servo is performed by comparing the phase of the horizontal synchronizing signal and the reference signal. At the time of start-up, a lock signal is generated and output to the discrimination circuit 9 when the rotation speed reaches 30 [revolutions / second].

The reproduced signals output from the pickups 2a and 2b are input to the FM demodulation circuits 5a and 5b, demodulated into the original channel signals, and then combined in the high-definition signal processing circuit 10 to the outside as high-definition signals. Is output. The output of the FM demodulation circuit 5a is also input to the synchronization detection circuit 6 and the address signal detection circuit 7a. The output of the FM demodulation circuit 5b is also input to the address signal detection circuit 7b. A horizontal sync signal is detected by the sync detection circuit 6, and this horizontal sync signal is sent to the disk servo circuit 4 and used for rotation control of the disk motor M during reproduction as described above.

On the other hand, the address signal detection circuits 7a and 7b detect the address signals multiplexed within the vertical blanking period of each channel. As described above, this address signal is ± 1 of the standard linear velocity of the video disc.
It can be detected when rotating in the range of 0%. That is, when the disk is rotated at a linear velocity within this range, the PLL of the address signal detection circuits 7a and 7b is locked and the address signal can be read. Therefore, if the standard density disk is set, the address should be detected by the address signal detection circuit 7a corresponding to the 100 [mm] position.
Also, if a high density disc is set,
Address signal detection circuit 7b corresponding to 78 [mm] position
The address should be detected by. The outputs of the address detection circuits 7a and 7b are sent to the disc discrimination circuit 9. It should be noted that each address signal detected during normal reproduction (reproduction after disc discrimination) is a controller (not shown).
Then, on the basis of this, the pickup servo circuit 1 performs the cueing of the program portion and the random access control.

The disc discriminating circuit 9 discriminates that the standard density disc is set when the address signal is sent from the address signal detecting circuit 7a at 30 [revolutions / second] at the time of starting. Also, at startup 3
When the address signal is sent from the address signal detection circuit 7b at 0 [revolutions / second], it is determined that the high density disk is set. The rotation speed of 30 [revolutions / second] means that the disk servo circuit 4 sends a lock signal (a signal locked at 30 [revolutions / second]) as described above. Can be detected.

The output of the disc discriminating circuit 9 is sent to a controller (not shown) for pickup control by the pickup servo circuits 1a and 1b and disc motor control by the disc servo circuit 4. It That is, the pickup is moved to the program start position (the position 66 [mm] from the center when the disc is a standard density disc, and the position 55 [mm] from the center when the disc is a high density disc). It is controlled to rotate at a standard linear velocity (18.8 [m / sec] when it is discriminated as a standard density disc and 14.7 [m / sec] when it is discriminated as a high density disc). Playback starts. In this way, reproduction is performed at the standard linear velocity corresponding to the recording density of the set disc.

In addition, in the above embodiment, 30
Address signal detection circuit 7 when [revolutions / second] is reached
When the address signals are sent from both a and 7b, it means that a disk with a constant angular velocity (CAV disk) is set. Also, the address signal detection circuit 7
If no address signal is sent from either a or 7b, it means that a non-reproducible disc is set.

In the first embodiment, one pickup is arranged on each side of the disc, and the pickups 2a and 2b are simultaneously used to simultaneously reproduce the related information on both sides of the disc. There is a second shown in FIG.
As in the above embodiment, two pickups 20a, 20b are arranged on one side of the disc, and when these pickups are appropriately used to edit / reproduce recorded information on one side of the disc, The present invention can be applied similarly to the first embodiment. In addition, the embodiment shown in FIGS.
Although both are examples in the case of a video disc, the present invention is not limited to a video disc and can be applied to a CD or the like. That is, the present invention can be applied to an apparatus having two or more pickups and having a compatibility function capable of reproducing discs of different types.

[0025]

As described above, according to the present invention, when the pickup is positioned at each position in the radial direction where the standard linear velocity is obtained at the predetermined angular velocity and the disc is rotated at the predetermined angular velocity, a certain pickup is performed. When the recorded information or address is detected by, it is determined that the disc whose standard linear velocity is the linear velocity at the radial position of the pickup is set, so the standard linear velocity and the recording density of the disc can be determined quickly. Is. Therefore, it is possible to quickly shift to the reproduction at the standard linear velocity.

[Brief description of drawings]

FIG. 1 is a characteristic diagram showing rotation speeds of a standard density disc and a high density disc with respect to a disc radial position.

FIG. 2 is a block diagram showing a main part of a circuit configuration of the first embodiment device.

FIG. 3 is a block diagram showing a main part of a circuit configuration of a second embodiment device.

Claims (5)

[Claims] 1. A disc reproducing apparatus having a plurality of pickups, capable of reproducing recorded information of a plurality of types of discs having different standard linear velocities, wherein the recorded information of the disc is detected at the standard linear velocity of the disc. Means, means for positioning the plurality of pickups at respective radial positions that attain the standard linear velocity at a predetermined angular velocity, means for reproducing a disc by rotating the disc at the predetermined angular velocity, When the individual pickups are positioned at the respective positions and the disc is rotated at the predetermined angular velocity, it is determined that the disc whose standard linear velocity is the linear velocity at the pickup position where the recorded information is detected is set. And a disc reproducing apparatus provided with. 2. A disc reproducing apparatus having two pickups capable of reproducing recorded information on a disc having two kinds of recording densities, wherein address information multiplexed on the recorded information on the disc is recorded on the disc. And a means for detecting at a standard linear velocity specified in accordance with, and one pickup is positioned at a first radial position where the first standard linear velocity is obtained at a predetermined angular velocity, and at the predetermined angular velocity A means for positioning the other pickup at a second position in the radial direction where the second standard linear velocity is reached, a means for playing the disc by rotating the disc at the predetermined angular velocity, and positioning each pickup at the respective positions. When the disc is rotated at the above-mentioned predetermined angular velocity, a disc having a recording density whose standard linear velocity is the linear velocity at the position of the pickup where the address information is detected is set. Disk reproducing apparatus equipped with that the means for discriminating, the. 3. The disc reproducing apparatus according to claim 2, wherein two pickups are provided on each side of the disc. 4. The method according to claim 1, 2, or 3, further comprising means for executing the determination when a disc is set, and a program start position for each pickup according to the determination result. And a means for rotating the disc at a standard linear velocity, the disc reproducing device comprising: 5. A video disc, in which a video signal is divided into two channels and recorded in corresponding portions on both sides of the disc, while rotating at a standard linear velocity specified corresponding to the recording density of the disc, A disc reproducing apparatus for reproducing by using two pickups, one on each side of the disc, for detecting an address signal multiplexed with a recording signal on each side of a video disc at a standard linear velocity of the disc. And one of the pickups is positioned at a first radial position where the first standard linear velocity is obtained at a predetermined angular velocity, and a second radial linear position where the second standard linear velocity is obtained at the predetermined angular velocity. 2 means for positioning the other pickup, a means for rotating the video disc at the predetermined angular velocity for reproduction, and one pickup for the first position. If the address is detected based on the signal from the pickup at the first position when the other pickup is positioned and the video disc is rotated at the predetermined angular velocity while the other pickup is positioned at the second position, If the video disc having the first recording density corresponding to the standard linear velocity of 1 is set and the address is detected based on the signal from the pickup at the second position, the video disc corresponds to the second standard linear velocity. And a means for determining that the video disc having the second recording density is set, and a disc reproducing apparatus comprising: