JPS63306573A - Information recording disk reproducing device - Google Patents

Abstract

PURPOSE:To remove beat disturbance to an image based upon a 3rd reference signal and to reproduce the image of high quality by detecting positional information recorded in the outer peripheral part of a disk to switch 1st and 2nd reference signals. CONSTITUTION:Information signals are spirally or concentrically recorded, two kinds of reference signals are alternately recorded on both the sides of the information signals every rotation, positional information is recorded on one or both the sides of the outer or inner peripheral part corresponding to alternate positions, and a positional information detecting means 26 for detecting the positional information is arranged. Tracking is controlled by detecting and comparing the 1st and 2nd reference signals detected by a pickup circuit 12 with each other and the tracking control direction of a stylus is switched by detecting the positional information by the means 26. Consequently, the beat disturbance to the image due to the positional information can be removed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an information recording disk reproducing device, and particularly to tracking control of a video disk reproducing device.

(Prior Art) In some types of video disc systems, information signals such as video signals, audio signals, or digital data are recorded on main tracks formed in spiral or concentric circles on a disc (information recording disc). The first and second reference signals having different frequencies are recorded on both sides of the main track while being alternately exchanged every revolution, and each of the first and second reference signals is recorded at the exchange position. A third reference signal of a different frequency is recorded. and,
In an apparatus for playing such a disc, each of the above-mentioned signals recorded on the disc is picked up and played back, and the first
The frequencies of the reference signal and the second reference signal are selected, the levels of both signals are compared, and the pickup is controlled in the radial direction of the disk so as to eliminate the difference component. This allows the center of the main trunk to be traced. On the other hand, the third reference signal for switching the polarity of the first reference signal and the second reference signal is 4V (V: It is recorded at the position of the vertical sync signal at one interval per vertical sync signal). This results in
Since the positions of adjacent tracks are aligned, there is no effect on the image.

1 (Problem to be solved by the invention) However, such a constant rotation speed (constantangula
r velocity: CAV) The reproduction device generates a constant linear velocity (constant linear velocity)
ty: CLV), there was a problem in that the synchronization signals with the adjacent tracks were not aligned, so that beat interference with the video of the third reference signal appeared. There is also the problem that the reference signal may be missing due to scratches or dust attached to the surface of the disk, causing tracking errors.

(Means for Solving the Problems) ゛In the information recording disk reproducing device of the present invention, an information signal is recorded in a spiral or concentric pattern, and two types of reference signals are placed on both sides of the information signal for one rotation. A device for reproducing an information recording disc on which information is recorded alternately at each location, and location information is recorded on one or both of an outer circumference or an inner circumference corresponding to the interchanged position, and the device detects the location information. The apparatus includes positional information detection means, and when the positional information is detected by the positional information detection means, the tracking control direction of the information signal detection sensor is switched.

(Function) The present invention takes advantage of the fact that the third reference signal is always recorded once per rotation of the disk, and uses the fact that the third reference signal is always recorded once per rotation of the disk to create a discernible notch on one or both of the outer circumference and inner circumference of the disk that does not appear in the reproduced video. A hole or the like is provided to record position information corresponding to the third reference signal. On the other hand, in the playback system, tracking control for each track is performed by detecting and comparing the first reference signal and the second reference signal detected by the pickup circuit, and the stylus tip (information signal detection sensor)
The tracking control direction is switched by detecting the positional information recorded on the outer or inner circumference of the disc using a positional information detection means. This eliminates beat interference with the video caused by the positional information. can be done.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

The disc l to be played back by the playback device of the present invention is
As shown in the figure, information pit strings (main tracks) 2 such as video signals, audio signals, and various data are recorded in a linear (or concentric) manner on the surface of the disk l, and on both sides of this main trunk 2. The first reference signal fPI and the second reference signal f0 are alternately exchanged and recorded every rotation of the disk 1. A notch (position information) 4 corresponding to the conventional third reference signal fFH is provided at a predetermined position in the landing area 3 on the outer periphery of the disk 1.

FIG. 1 shows a schematic configuration of a reproducing apparatus of the present invention for reproducing such a disc 1. As shown in FIG.

In the figure, l is a disk, 11 is an information signal detection sensor, 12 is a pickup circuit, 13 is an O20, 14 is a preamplifier, 15 is a bandpass filter, and 16 is an AGC.
Amplifier, 17.18 is band pass filter, 19.20
is a detection circuit, 21 is a changeover switch, 22 is a differential amplifier,
23 is a phase compensation circuit, 24 is a drive circuit, 25 is a tracking coil, 26 is a position information detection circuit, 27 is a band pass filter, 28 is a detection circuit, and 29 is a switching pulse generation circuit.

Next, the operation of the playback device having the above configuration will be explained.

Various signals detected from the disk 1 by the information signal detection sensor 11 and the pickup circuit 12 are appropriately amplified by a preamplifier 14, and then separated into a first reference signal f□ and a second reference signal rpt by a bandpass filter 15. After the signal level is made constant by the AGC amplifier 16, the signal is input to each bandpass filter 17.18.

The first reference signal fPI separated by the band-pass filter 17 is detected by the detection circuit 19 and then input to one input terminal of the changeover switch 21, and the second reference signal fPI separated by the band-pass filter 18 is After being detected by the detection circuit 20, the signal is input to the other input terminal of the changeover switch 21.

On the other hand, the notch 4 provided on the outer periphery of the disk 1 is detected by the position information detection circuit 26, and after being detected via the band pass filter 27 and the detection circuit 28, the signal is input to the switching pulse generation circuit 29. The switching pulse generated by the switching pulse generation circuit 29 causes the changeover switch 21 to switch to the disk 1.
It is controlled so that the cutting failure occurs once per rotation.

The first reference signal f□ and the second reference signal fP! which are appropriately switched by this changeover switch 21 and outputted! are respectively input to two input terminals of the differential amplifier 22. The output of this differential amplifier 22 is applied to a tracking coil 25 via a phase compensation circuit 23 and a drive circuit 24.
The information signal detection sensor 11 is controlled by swinging in the radial direction of the disk 1 according to the level difference between the first reference signal fPI and the second reference signal fPI.

As described above, in the information recording disc reproducing apparatus of the present invention, since the notch 4 provided on the outer circumference of the disc 1 is detected by the position information detection circuit 26, the detection sensor of the position information detection circuit 26 In addition, by providing a position information detection circuit 26 dedicated to the third reference signal f0 in addition to the conventional pink-up system, there is no need to move the third reference signal f0 in the radial direction of the disk 1. 3 reference signal f2. There is no need to record. Therefore, there is no beat disturbance to the video of the third reference signal rps, and high quality video reproduction can be performed.

In the above embodiment, the notch 4 is provided on the outer periphery of the disk 1, but it goes without saying that it may be provided on the inner periphery. In addition, in the above embodiment, the constant rotation speed disc (CA
Although the case of V) is explained as an example, the same applies to a constant linear velocity disk (CLV).

(Effects of the Invention) As explained above, according to the information recording disk reproducing apparatus of the present invention, switching between the first reference signal and the second reference signal is detected by detecting the position information provided on the outer circumference of the disk. Therefore, there is no beat interference to the video caused by the third reference signal as in conventional playback devices, and high-quality video can be played back.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram of an information recording disc reproducing apparatus of the present invention, and FIG. 2 is a plan view of an information recording disc reproduced by the reproducing apparatus. 1... Disc 2... Information pit row (main trunk) 3... Landing area 4... Notch part 26.
...Position information detection circuit diagram 2

Claims (1)

[Claims] 1) An information signal is recorded in a spiral or concentric pattern, and two types of reference signals are recorded on both sides of this information signal, alternately exchanged every rotation, and an outer peripheral area corresponding to the exchange position. or an apparatus for reproducing an information recording disc having positional information recorded on one or both of its inner peripheral parts, comprising a positional information detection means for detecting the positional information, the positional information being detected by the positional information detecting means. An information recording disk reproducing device characterized in that the tracking control direction of an information signal detection sensor is sometimes switched.