JPS6233375A - Carrying control device for recording disk signal detecting means - Google Patents

Abstract

PURPOSE:To lower a generation of an unstable movement of a signal detecting part carrying part by interrupting the use of a tracking control signal for a driving control of a signal detecting part carrying part when an address signal cannot be correctly detected for a fixed time and using the tracking control signal after the fixed time or when the address signal is detected again. CONSTITUTION:An address signal deciding part 22 decides an address signal 103 obtained in an address signal sampling part 21, when the state in which the address signal 103 cannot be correctly detected for a fixed time continues, outputs a tracking control signal change over signal 101 and controls not to input a tracking control signal 100 to a signal detecting means carrying control part 20. A tracking control signal change over part 23 receives the designation of the tracking control signal change over signal 101, prohibits the transmission of the tracking control signal 100 to a signal detecting means carrying control part 20, and generates a correction tracking control signal 102 in place of the tracking control signal 100 while the transmission is prohibited. Thereby, a signal detecting part carrying part 13B can be stably controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a disc-shaped recording medium (hereinafter referred to as
The present invention relates to a conveyance control device for a signal detection means that detects a signal recorded on a disk (abbreviated as a disk).

BACKGROUND OF THE INVENTION It is known that there are various types of video discs. Here, one of these methods, the VHD method, will be explained as an example. FIG. 2 is a typical conventional configuration diagram regarding the conveyance control of the signal detection means of a Vl-ID system player, and shows the recording of information signals, tracking signals, index signals, and address signals of a Vl-ID system disc. A schematic diagram is shown in Fig. 3. In Fig. 3, the solid line indicates the track of the information signal, the one-dot chain line indicates one tracking signal, the two-dot chain line number indicates the other tracking signal, the diagonal line indicates the index signal, and Δo, A+, A2, A3 indicate the positions on the disk. This is the recording position of the address signal. 13 is a signal detection means, which is equipped with a signal detection section 13A that detects signals recorded on the disk, and a signal detection section 13A.
The signal detection section 1313 includes a signal detection section and a transportation section 1313.

Generally, in order for the signal detecting means 13 to accurately scan the track of the information signal, the signal detecting section 13A detects the track 2
The signal detection unit 13A is driven in the radial direction of the disk so that the detection levels of the different types of tracking signals are approximately equal, and the radial drive control direction is reversed at the recording position of the index signal. At this time, with the signal detection unit transport unit 133 stopped, only the signal detection unit 13A is driven and controlled in the radial direction of the disk, for example from the outer circumference of the disk to the direction of position BO=81 in FIG. As the track of the information signal g is scanned in the circumferential direction, the inclination of the signal detecting section 13A with respect to the signal detecting section conveying section 13B becomes larger at position B1 than at position Bo.

Since the movable range of the signal detection unit 13A is limited, when the tilt reaches its limit, it becomes impossible to accurately scan the track of the information signal. For this reason, the following means have been used to minimize the inclination of the signal detection section 13A, in other words to control the signal detection section 13A to approximately the center of its movable range.

In order to cause the signal detecting means 13A to accurately scan 1 to 1 rack of information signals, a differential tracking signal, which is the difference between the detection levels of the two types of tracking signals, is used. To actually drive the signal detecting means 13A, phase compensation is applied to this differential tracking signal to generate a tracking control signal suitable for driving.

110 in FIG. 4 is the position Bo, that is, the signal detection means 13A.
This is the tracking control signal when the slope of is the minimum. 1
11 is a tracking control signal for position B+. It is generally known that when the slope of the signal detection section 13A changes, the DC component of the tracking control signal changes in proportion to the slope. For this reason, the signal detection section 13
When A reaches position r3+, the DC component of the tracking control signal changes like signal 111 compared to signal 110. Therefore, in order to minimize the fluctuation of this DC component,
In other words, the signal detection section transport section 13B is driven and controlled so as to minimize the inclination of the signal detection section 13A. That is, as the signal detection unit 13A moves in the direction of position Bo −+ [3+, the signal detection unit conveyance unit 13B also moves from position 80→in proportion to the variation in the DC component of the tracking control signal.
B! It moves in the direction of. By performing such control, it is possible to accurately scan the information signal track from the outermost circumference to the innermost circumference of the disk.

FIG. 2 is a diagram showing a conveyance control configuration of a typical conventional signal detection means having this control means.

10 is a disk, 11A is a turntable on which the disk is mounted, 11 [3 is a turntable motor that rotationally drives the turntable 11A, 12 is a turntable motor control section, 13 is from a signal detection section 13A and a signal detection section transport section 13B. The signal detecting means 14 includes a detection signal amplifying section 1 for amplifying the signal detected by the signal detecting means 13;
5 is a circuit for extracting one tracking signal from the signal amplified by the detection signal amplifying section 14, 16 is a circuit for extracting the other tracking signal, and 17 is a circuit for extracting an index signal. , differential tracking signal generator 18
is a differential tracking signal 104 based on the difference in the detection level of the two types of tracking signals and the index signal.
occurs.

The phase compensation unit 24 performs phase compensation on the differential tracking signal, and generates a tracking control signal 100 necessary for the signal detection unit 13A to accurately scan the information signal track.

Reference numeral 19 denotes a tracking control drive unit that drives the signal detection unit 13A in the radial direction of the disk using the tracking control signal 100. 20 is the tracking control signal 10
This is a signal detection means conveyance control section that detects a DC component of 0, drives and controls the signal detection section conveyance section 13B in proportion to the DC component, and minimizes the inclination of the signal detection section 1.3A.

Problems to be Solved by the Invention These conventional techniques have the following problems. That is, when the signal detection section i3A is detecting a signal from the disk 10, the signal on the disk 10 or the signal detection section 1
There are cases where foreign matter such as dust adheres to the disk 3A, making it impossible to accurately detect signals from the disk 10.

At this time, the two types of tracking signals or index signals cannot be detected, and as a result, the tracking control signal 100 becomes an abnormal signal as shown by the curve 113 in FIG. This results in a large swing and a large change in the slope.

Due to the sudden change in the slope of the signal detection section 13A, the DC component of the tracking control signal changes greatly as shown by the curve 114 in FIG. 5, and the signal detection section conveyance section 13B moves violently.
It becomes increasingly difficult to detect the signal from disk 10,
As a player, you will be in an extremely unstable situation.

The present invention prevents the occurrence of unstable movement of the signal detection unit transport unit due to an abnormality in the tracking control signal when a situation occurs in which an accurate signal cannot be detected from the disc due to foreign matter such as dust adhering to the disc or the signal detection unit. The purpose is to reduce

Means for Solving the Problems In the present invention, in order to solve the above-mentioned problems, address signals recorded on the disk are used, and if the address signal cannot be detected accurately for a certain period of time, the signal A function has been added that suspends the use of the tracking control signal to control the drive of the detection unit transport section and resumes the use of the tracking control signal after a predetermined period of time or when an address signal is detected again.

In the present invention, by using the above-mentioned means, the tracking control signal is not used to control the drive of the signal detection unit transport unit in a state where an accurate signal cannot be detected from the disc, so that the signal detection unit detects an abnormality on the disc. Even when the signal detecting unit transport unit operates, unstable movement of the signal detecting unit conveying unit is reduced.

Embodiment FIG. 1 is a block diagram showing an embodiment of drive control of the signal detection means in the present invention. Components that are the same as those shown in FIG. 2 are given the same reference numerals. Reference numeral 21 denotes an address signal extraction section that extracts an address signal from the signal amplified by the detection signal amplification section 14. The address signal determination section 22 determines the address signal 103 obtained by the address signal extraction section 21, and if the address signal 103 cannot be detected accurately for a certain period of time, the tracking control signal is switched as shown in FIG. It has a function of outputting the signal 101 and controlling the tracking control signal 100 not to be input to the signal detection means conveyance control section 20.

The tracking control signal switching section 23 receives the instruction of the tracking control signal switching signal 101, and prohibits the sending of the tracking control signal 100 to the signal detection means conveyance control section 20, and during this period in which sending is prohibited, the tracking control signal Deliver a constant voltage instead of 100. In other words,
The switching unit 23 generates the correction 1-racking control signal 102 so that the signal detection unit transport unit 13 [3 does not operate unstablely. In addition, in FIG. 6, the time for determining whether or not the address signal can be detected accurately in the address signal determining section 22 is the period from when an abnormality in the tracking control signal occurs to when the signal detecting section conveying section 13B moves unstablely. It is preferable to set it in advance to be shorter than the time it takes to complete the process.

Moreover, when the address signal starts to be detected again as shown in Go+ in FIG. to exercise control.

In this embodiment, the case of the V1-ID method was explained, but
Even in the case of other systems, it is similarly effective when carrying out the conveyance control of the signal detection means using the tracking signal.

While using the tracking signal - We have explained an example of restarting the use of the tracking signal on the condition that the address signal is detected after the location, but there are also methods to try to restart the use after a certain period of time has passed after interruption, and methods to display an error message and read It is also possible to interrupt the

Effects of the Invention As described above, according to the present invention, even when the signal detection unit 13Δ is unable to detect a tracking signal from the disk for a certain period of time, the signal detection unit transport unit 133 can be prevented from making unstable movements. Stable control becomes possible.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing control of a signal detection section transport section in an embodiment of the present invention, and FIG. 2 is a block diagram showing control of a typical conventional signal detection section transport section. Figure 3 shows VHD
A schematic diagram of the recording of tracking signals, index signals, and address signals on a disc using this method, Figure 4 is a waveform diagram of the main part of Figure 3, Figure 5 is a waveform diagram of the main part of Figure 2, and Figure 6 is a diagram of the main part of Figure 2. FIG. 2 is a waveform diagram of the main part of FIG. 1; 13...Signal detection means 13A...Signal detection section 1
313...Signal detection conveyance unit 18...Differential tracking signal generation unit 19...Tracking control drive unit
20...Signal detecting means conveyance control section 21...Address signal correcting section 22... Address signal determination section 23... Tracking control signal switching section 24... Phase compensation section 100... Tracking control signal 101... Tracking control signal switching signal 102... Correction tracking control signal 103.
・Address signal

Claims (2)

[Claims] (1) Detecting an information signal recorded concentrically or spirally on a disc-shaped recording medium, a tracking signal for accurately controlling the track of the information signal, and an address signal indicating the position on the recording disc. A conveyance control device for a signal detection means, comprising means for causing the signal detection means to accurately scan a track of the information signal by using the tracking signal, means for conveying the signal detection means, and means for conveying the address signal. A transport control device for a recording disk signal detection means, comprising means for monitoring and interrupting the use of the tracking signal for transport control of the signal detection means when the address signal cannot be read for a predetermined period of time. . (2) Detecting an information signal recorded concentrically or spirally on a disc-shaped recording medium, a tracking signal for accurately controlling the track of the information signal, and an address signal indicating the position on the recording disc. A conveyance control device for a signal detection means, comprising means for causing the signal detection means to accurately scan a track of the information signal by using the tracking signal, means for conveying the signal detection means, and means for conveying the address signal. means for monitoring and interrupting the use of the tracking signal for transport control of the signal detection means when the address signal cannot be read for a predetermined period of time; and means for interrupting the use of the tracking signal for transport control of the signal detection means when the address signal is detected after interruption; A conveyance control device for a recording disk signal detection means, comprising means for restarting the use of the tracking signal.