JPS6267779A - Reproducing device for information recording disk - Google Patents

Abstract

PURPOSE:To reduce the influence of misdetection of an address signal which may be generated on the way of retrieval and to shorten a retrieving time by holding the operation of a control means at retrieval starting state only for a period corresponding to a difference between a current position at the start of retrieval and a specific position. CONSTITUTION:When an address signal indicating a position on a disk is continuously changed from a program starting point, a control pulse corresponding to the value of a storage part 23 is outputted from a storage hold instructing part 21 after the start of retrieval and an address storage updating signal outputted from a retrieval control part 19 every vertically synchronizing signal is restricted by a gate 22. An output of a comparison part 17 is stored in the storage part on the basis of the address storage updating signal restricted in accordance with an address comparing value obtained up to an objective position at the start of retrieval and decided by the retrieval control part 19 to output a movement control output and execute the retrieval. Consequently, retrieval control errors due to address reading errors generated during the execution of retrieval can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an information recording disc playback device capable of searching for a specific position on an information recording disc on which video and audio signals are recorded.

Conventional technical information recording discs (hereinafter referred to as T-discs) have six features: a signal detection section can be moved in the radial direction of the disc, allowing playback from any location on the disc. Various methods are already known for disc reproduction K1ff. In a VHD video disc system that records a tracking control signal in the middle of the main information signal track and reproduces information by detecting electrostatic 8-half changes from a flat disc with no guide grooves, the signal detection unit ( It is possible to freely traverse the information track while getting the live signal.

This VHD video disc system will be explained using FIG. 4. As shown in FIG. 4, position information on the disk is recorded as an address 1gd in the vertical blanking section of the main information signal, and changes as the program progresses. The ↑I button is a number assigned to each break in the contents of the Boogram, and is expressed in two decimal digits. The time information indicates the opening/opening time in minutes and seconds since the start of the disc program, and the page information is a track number assigned to correspond to information about one rotation. In the VHD system, video for four fields can be recorded per disk rotation, and address points (2) and (Y) are recorded in four locations. It is well known that even if the signal detection section is forcibly moved on the disk in the radial direction of the disk, it is possible to read the address signal and that it is possible to specify and search a target information track. (For example, "Introduction to Video Discs and DΔD" edited by So Iwamura, 1981, Coronasha, p. 87-
107) Such a VI-ID video disk player will be explained with reference to FIG. disk(
The information signal recorded in the capacitor (not shown) is detected by the signal detection unit 1 as a change in capacitance and converted into an electric signal. The signal then passes through the FMI1 section 2 and is demodulated through the video signal processing section 3, where the synchronizing signal detecting section 4 detects a vertical synchronizing signal and the address signal reading section 5 detects an address signal indicating the playback position. . On the other hand, the signal detection unit 1 also detects a tracking signal for tracking the information signal sequence. This tracking error signal is detected by a tracking control signal detection section 6, passes through a phase compensation section 7 and a drive section 8, and is moved by a tracking control actuator 9 in the radial direction of the disk by electromagnetic action. Control to track the track. Further, in order to move the @ sign detection unit 1 in the disk radial direction, a transfer mechanism 11 is provided that converts the rotation of the transfer motor 10 into movement in the disk radial direction. The transfer control section 12 controls the transfer motor 10, and the transfer section 13 equipped with the signal detection section 1 can be moved from the outer circumference to the inner circumference of the disk for reproduction.

Next, a method for searching the target information track will be described. The position of the information track desired to be searched is input from the operation unit 14 and stored in the target storage unit 15. The currently reproduced address signal decoded by the address signal read al15 described above is stored in the address storage section 1G, and the storage contents of the target storage section 15 and the storage contents of the address storage section 16 are compared in the comparison section 17 to determine the magnitude. The search control section 19 comprehensively controls the transfer control section 12 and the tracking control section 18 at a transfer speed corresponding to the difference between the two, and searches for a specific position on the disk.

When the target position and the current playback position are far apart, the search control section 19 issues an instruction to the transfer control section 12 for high-speed forced transfer, and moves the transfer section 13 in the disk radial direction. When the target position and the current playback position approach and the difference between the input signals of the comparison section 7 becomes small, the high "a" movement is interrupted, the tracking control section 18 is activated, and the search control section 19 activates the kick pulse generation section. By giving a kick pulse generation instruction to 20 and causing the signal detection unit 1 to jump to the adjacent track, the fllF target position is translocated.In this way, when the address is read in the vertical direction at a period of JlfJ4:R, The method of making decisions each time and approaching the target position is well known.

Problems to be Solved by the Invention However, in the conventional device described above, when performing a search operation for a target position, the apparatus approaches the target position while reading the address signal, but because the apparatus crosses the information track at high speed. , this is a case where reading of the address signal is erroneously detected. Therefore, the comparison value between the target position and the current playback position may be incorrect, and the search control unit 19 may make an incorrect determination regarding the search direction and speed, which may result in a longer search time.

Means for Solving the Problems In order to solve the above problems, the information recording disk reproducing apparatus of the present invention includes a signal detection means for detecting an information signal recorded on a disk-shaped recording medium, and a signal detection means for detecting an information signal recorded on a disk-shaped recording medium. Tracking control means for accurately scanning the information signal train by moving the recording medium in the radial direction, and the signal detection means as described above.
a transport means for transporting the medium in a radial direction; an address signal reading means for extracting from the information signal an address signal superimposed on the information signal indicating a position on the medium;
an instructing means for instructing a search for a specific position on the recording medium; and the transporting means, which determines a search operation based on the difference between the specific position instructed by the instructing means and the current position read by the address signal reading means. and a control means for controlling the tracking control means, and a holding means for maintaining the operation of the control means in the state at the start of the search for a time corresponding to the difference between the current position at the start of the search and the specific position. This is what I did.

Effect: According to the above configuration, the control means is maintained in the state at the start of the search for a period of time corresponding to the difference between the specific position that is the search target and the current position at the time of the start of the search. Therefore, the influence of erroneous detection of an address signal during a search can be reduced as much as possible, and the search time can be shortened.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIGS. 1 to 3.

FIG. 1 is a circuit block diagram of an information recording disk reproducing apparatus in J3 according to an embodiment of the present invention, and the same components as those shown in FIG. 5 are given the same reference numerals and their explanations are omitted. . In FIG. 1, 21 is a memory retention instruction section, 22 is a gate, and 23 is a storage section.

As an example, consider a case where a search is performed from a disk outer circumference fish A1 to a disk inner circumference point with a target of 0 as shown in FIG. FIG. 3 shows a time chart of each signal. The search target input from the operation unit 14 is stored in the target storage unit 15. The vertical synchronization signal (
The output of the address signal reading unit 5 (FIG. 3(b)) which is outputted in each case of FIG. Memorized in time. Furthermore, it is compared with the signal from the target storage section 15 in the comparison section 17, and the comparison result is stored in the storage section 23 at the start of the search. Based on this comparison data, a transfer control instruction signal (FIG. 3(d)) is output from the search control section 19 to the transfer control section 12. In this example, a high speed forward command is output.

In the conventional configuration shown in FIG. 5, the target storage section 15 and the address storage section 16 are compared in accordance with the address signal detected every vertical opening A3. Therefore, if the address signal is erroneously detected and a value larger than the target (for example, corresponding to 02.D5 in FIG. 3(b)) is detected, a direction instruction is sent to the transfer control unit 12 as shown in FIG. 3(d). The search control unit 19 outputs an output as backward movement, and as shown in FIG. 2(A), on the way from point A1 to A9, point A2. The transport direction is reversed from forward to reverse as at point A4. After that, when the data is detected correctly, the transport direction is returned to forward and the robot heads toward the target point, but time is wasted until it reaches the target point.

On the other hand, in this embodiment, when the address signal indicating the position on the disk changes continuously from the program start point, after the start of the search, the value in the storage unit 23 (the difference to the target) is ) corresponding to the control pulse (Fig. 3(e)
)), and the address storage update signal outputted from the search control unit 19 every vertical dome signal (synchronization 1 second) is limited by the gate 22). For example, if the high-speed transfer speed is 1000 mm, 250 tracks will advance per second. However, when performing a search using page data, the width of the limit pulse is determined by the following formula.

(Limited pulse width) - [<Track difference to target position]/
(250 tracks)] - (constant value) The output of the comparator 17 using the limited address memory update @ number (FIG. 5(f)) corresponding to the address comparison value up to the target position at the start of the search. is stored in the storage unit 23, and the search control unit 19 makes a judgment and outputs the transfer control output (FIG. 5(g)) to perform the search. In other words, after the start of the search, the search control unit 19 maintains the determination made by the search control unit 19 for a certain period of time corresponding to the address comparison value up to the target position to perform search control. As a result, Figure 2 (B)
As shown in FIG. 2, errors in search control due to address reading errors that occur during the search process are reduced.

Note that although the above embodiment describes a page search, a search for time information can also be performed in the same way.

Further, the above procedure can be easily carried out using a microcomputer.

As described above, according to the present invention, when searching for a target, by ignoring the address information that is read from time to time during the period predicted at the start of the target search, false detections that occur when reading the address can be avoided. It is possible to reduce the influence and shorten the search time.

[Brief explanation of drawings]

FIG. 1 is a circuit block diagram of an information recording disk reproducing apparatus according to an embodiment of the present invention, FIG. 12 is an explanatory diagram of search operation, and FIG.
1 is a time chart of the circuit shown in FIG. 1, FIG. 4 is an explanatory diagram of an address signal, and FIG. 5 is a circuit block diagram of a conventional information recording disk reproducing apparatus. 1... Signal detection section, 5... Address signal reading section,
12...Transfer control section, 14...Operation section, 17...
Comparison unit, 18... Tracking control unit, 19... Search control unit, 21... Memory retention instruction unit, 22... Gate, 23... Storage unit agent Yoshi Morimoto
Hiroshi Figure 2 (A) rBn Haruma Keidori

Claims (1)

[Claims] 1. a signal detection means for detecting an information signal recorded on a disc-shaped recording medium; a tracking control means for moving the signal detection means in the radial direction of the recording medium to accurately scan the information signal sequence; transport means for transporting the signal detection means in the radial direction of the recording medium; address signal reading means for extracting from the information signal an address signal indicating a position on the recording medium superimposed on the information signal; and the recording medium. an instruction means for instructing a search for a specific position above, and a search operation determined based on a difference between the specific position instructed by the instruction means and the current position read by the address signal reading means, and said transport means and tracking control means. 1. An information recording disc reproducing device comprising: a control means for controlling the operation of the control means; and a holding means for holding the operation of the control means in the state at the start of the search for a time corresponding to the difference between the current position at the time of the start of the search and a specific position.