JPS58190174A - Direct access device - Google Patents

Abstract

PURPOSE:To searth the program of a video disk having group numbers with designation of time and position, by comparing the designated time and the group number converted into a time data, and discriminating the coincidence. CONSTITUTION:A code signal (corresponding to a group number) is detected out of a video disk 12 having group numbers recorded. The decoded code signal is transferred to a time converting circuit 17, and the circuit 17 converts the code signal into a minute data 18, a second data 19 and a frame data 20 respectively. Both data 19 and 20 are supplied to compensating circuits 21, 22 to catch accurately the boundary between frames. The data 18 and the compensated data 19 and 20 are supplied to comparators 26-28 to be compared with the time data for program searching which is supplied from a keyboard 31. An arm sending control circuit 29 controls the switching between stop and start of an arm sending motor 30 with the outputs of circuits 26-28.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a direct access device [EIM] used in a video disc player, etc., and its position detection function.

[Technical background of the invention]

In a video disc player, a rotary disc (hereinafter referred to as a video disc) is used as a video signal recording medium, and this is placed on a turntable of the player. A spiral recording line is set on the surface of a video disc, and signal information is recorded along the line. As a signal recording method, a capacitance method, an optical method, etc. are known. This video disc is
By rotating together with the turntable and moving the pickup means to follow the signal recording line, a reproduced signal can be obtained from the pickup means.

When the recording method is an optical method, a light source and a light-receiving confectionery are used as the pickup means, and when the recording method is a capacitive method, a stylus electrode or the like facing the electrode on the recording line is attached to the use end. The stylus arm is conveyed by an arm arrangement that can be translated in the radial direction of the disk. Usually, the arm device is controlled to move in parallel from the outer periphery of the upper part of the turntable toward the center or in the opposite direction. When the arm device moves in parallel and comes to the surface of the video disk, the stylus arm brings the stylus into contact with or away from the recording line of the disk by means of magnetic repulsion or attraction. It is controlled to cause them to leave.

[Problems with background technology]

In the video disc player as described above, it has been considered to provide a direct access function that can quickly locate any position on the video disc (the beginning of the recording signal).

When this direct access authority is provided, the group number etc. recorded on the video disc is played back, and this is compared with the signal that indicates the desired location input from the operation keys, and the desired location is obtained by obtaining a matching output. You can bring the stylus directly to this point and start playback from there. The nature of the signal that generates the group number is that it is a binary representation of the number itself, which is counted sequentially from the outside with one revolution of the recording line as one unit, and that it is required when normal playback is performed sequentially from the outside recording line. There are records in which the playing time is converted into a signal. In the former case, you have to guess where the desired group number is on the board, but in the latter case, for example, if the playing time is 60 minutes in total, 30 minutes is exactly in the middle. It's easy to judge because there is. For example, during a performance, there was a scene that I wanted to revisit later, so
This may be required when you want to make a note of the location. Here, if you look at something with the performance time position recorded, it will pass through several grooves (recording lines) per second, so if you specify the distribution position in seconds, you will be able to select one specific groove. It becomes difficult to search for. For this reason, it has been considered that the time code itself is recorded on the recording line, and a frame number is recorded next to the code indicating the seconds.

However, some video discs have group numbers recorded thereon, and there are systems in which group numbers are assigned up to 27,000. For such video discs, there is a demand for a circuit that can perform cueing by time specification rather than cueing by group number specification. Normally, this disc would take 60 minutes to play, and would pass through 75 unit recording lines per second. Therefore, to specify the cue, it is necessary to specify the second and frame number (line γ of 7 or 5).The specification of the second and frame number can be determined by converting the group number. Since a four-field video signal is recorded in each unit recording line, the group number is recorded as a binary code in the vertical synchronization (if number part).

As mentioned above, when considering specifying the cue by time position for a video disc that has group numbers, if the grain is an even number, it is 7.5 X (even number), and the unit recording line You can specify each opening accurately and start from there, but if it is an odd number of grains,
7.5×(odd number), resulting in a fraction of 0°5 lines (frames), which is inconvenient.

[Purpose of the invention]

This invention was made in view of the above circumstances, and it is possible to perform direct access to a self-recorded video disc with a group number, by converting the access position into the playing time, and in addition, it is possible to perform direct access to a self-recorded video disc with a group number. An object of the present invention is to provide a direct access device that can reliably locate a recorded line in a book.

[Summary of the invention]

In this invention, a time conversion circuit 17 that converts the group number into time data (2), a key manual input designated, and a determination circuit 2 that determines whether the second data is an even number or an odd number.
3,31! In the case of an odd number of grains, a second correction circuit 21 is provided.
．． 36 corrects the second data and the frame correction circuits 22 and 37 correct the frame data, thereby making it possible to reliably locate a specific unit recording line (frame).

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings. 1st
In the figure, reference numeral 1 indicates a turntable of a video disc player, and a video disc 12 is placed on the turntable 1, and is rotated by a motor 13. 14 is a signal detection circuit that detects a signal from a stylus that is in sliding contact with the video disk 12 and introduces it to the video signal processing circuit 15. In the video signal processing circuit 15,
FM detection, frequency conversion, etc. of the detection signal are performed to create a video signal that can be monitored. The code signal representing the group number is also included in the detection signal, and this code signal is extracted by the code detection circuit 16, and the extracted code signal is input to the time conversion circuit 17. . In the time conversion circuit 17, the code signal is
A process of converting it into the playing time of a frame is performed. The minute data converted into performance time is applied to the first input terminal of the first comparator 26 via the minute data transmission circuit 18. Also,
The second data is applied to the first input terminal of the first data selector 24 via the second data transmission circuit 19 (=, -
1 correction circuit 21, and is further input to the even/odd judgment circuit 2.
3 is also input.

The second data input to the -1 correction circuit 2) is corrected by 11 seconds! It is applied to the second input terminal of the data selector 24 of i81. Further, the frame data is applied to the first input terminal of the second data selector 25 via the frame data transmission circuit 20, and is also input to the +7 sleeve correction circuit 22. The frame data input to the +7 correction circuit 22 is corrected by +7 pieces of frame data and then added to the second input terminal of the second data selector 25.

The first and second data selectors 24 and 25 select the data at the first or second input terminal according to the judgment output of the even/odd judgment circuit 23, and transmit the selected data to the second and third comparators, respectively. 27. Add to the first input terminal of 28.

On the other hand, 31 is a keyboard, and from this keyboard 31, using the operation keys, you can specify the cue position, which is the position of the frame on the minutes and seconds side during normal playback. It is specified as follows. The operation signal of the operation key is converted into minute data, second data, and frame data by the key manual processing circuit 32. Between the key manual processing circuit 32 and the first to third comparators 2B, 27.28, the time conversion circuit 17 and '$1 to the first to third comparators 26, 27.28 are connected.
A circuit completely similar to the circuit provided in between is provided. That is, 33 is a minute data transmission circuit, 34 is a seconds data transmission circuit, 35 is a frame data transmission circuit, 36 is a 11 correction circuit, 37 is a +7 correction circuit, 38 is an even/odd judgment circuit, and 39
．． 40 are third and fourth data selectors. and,
The output of the minute data transmission circuit 33 and the output of the 3.14th data selector 39.40 are connected to the comparators 26 and 2, respectively.
7.28 is applied to the second input terminal. Each output of the first to third comparators 26, 27, and 28 is processed into an arm feed motor control circuit 29 for feeding the arm device. This arm feed motor control circuit 29 can stop or start the arm feed motor 3o by determining the output from the comparator 26, 27° 28 or an external operation input.

The present invention is constructed as described above, and its operation will now be described. First, to explain the recording form of the video disc 12, its spiral recording lines are 27.
It is assumed that the disc is made up of 000 level recording lines (one unit corresponds to one round), and that it takes 60 minutes to normally reproduce this on a video disc player. Therefore, in 1 second, there are 7.5
The groove of duty will be played. The following 1-ma signal also includes code No. 41, and this code signal is detected by the code signal detection circuit 16. The code signal (corresponding to the group number) detected by the code signal detection circuit 16 is processed by the time conversion circuit 17.
Converted to minute data, second data, and frame data.

Here, the minute 9 second frame data is data that indicates the minute, second, and line (frame) at which the code signal is detected during normal playback. The second data is also input to the even/odd number judgment circuit 23 (:), and a judgment is made as to whether the seventh second is an even number or an odd number. If the second is an odd number, the -1 correction circuit 21 selects data obtained by subtracting 1 second, and the +7 correction circuit 22 selects data obtained by adding 7 frames. Introduced in .28.

On the other hand, from the keyboard 3), one video disc (4
) When normal playback is started from the beginning, it is possible to specify the minute, second, and frame position from which to start, and the operation input is processed in the same way as the output processing of the time conversion circuit 17 described above. It can be set as specified data in each of the second manual terminals of the crack comparators 26, 27, and 28.

When the matching outputs from the comparators 26, 27, and 211 are received at the same time, the arm feed control circuit 29 sends the keyboard 31
, stopping or starting the arm feed motor 30 according to the program input from the key manual processing circuit 32;
Alternatively, switching control such as reverse feeding or high-speed feeding can be performed.

Here, in the present invention, the correction circuits 21, 36 . . . correct the seconds data by 11 seconds. Correction circuit zx, sv that corrects frame data by +7 frames, even/odd judgment circuit 23.38
This is due to the following reasons. That is, to explain by showing the recording lines as a frame sequence in Fig. 2, there are 7.5 lines (frames) in 1 second, so if an even number of grains is specified, 7.5 X (g4 number) , the number of frames is determined accurately. However, if an odd number of grains is specified, the value of 7.5 There is no group number that occurs during the half cycle, and all group numbers for the same unit recording line (4 fields) are the same. Therefore, the second and frame data are corrected by the correction circuit so that the frame separation points can be accurately captured. As shown in Figure 2, from the starting point of even-numbered grain, 1,
2, 3. ...7, 8, 9°... Frame numbers are set up to the 15th, and the number of frames for 2 seconds is treated as one cycle. In this way, the 1st to 8.5th correspond to frames i2 of even-numbered grain, and the 8.5th to 15th correspond to frames of odd-numbered grain.

Now, if an even number of grains is specified, this means that you can start from the first frame.

Also, if an odd number of grains is specified, the 1 second data will be corrected by 11, and the number of frames will be corrected by +7, so if an even number of seconds is specified,
The result is the same as specifying the number of frames to 8, and you can start from the beginning of the 48th frame. Changes in frames are captured by changes in group numbers.

Note that in order to reproduce the group number, the stylus is brought into sliding contact with the surface of the video disc, but in the case of direct access, various methods can be adopted to feed the stylus at high speed to near the target position. For example, someone who rotates the arm feed motor at high speed and moves the arm while keeping the stylus in contact with #i, or from keyboard 3.
When the start position is specified, this is judged, the approximate movement position of the arm device is predicted, the arm feed motor is driven by the predicted amount, the stylus is lowered, and the group number is reproduced.

〔Effect of the invention〕

As mentioned above, according to this invention, by converting the group number into performance time and providing means for specifying the return position, stop position, switching position, etc. using time data, it is possible to It is possible to provide direct access 5Itit that allows you to reliably search for.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing the operation of the apparatus of the present invention. 14... Signal detection circuit, 15... Video signal processing circuit, 16... Code signal detection circuit, 17... Time conversion circuit, 18.23... Minute data transmission circuit, 19°34
...Second data transmission circuit, 20,35...Frame data transmission circuit, 21.36...-1 correction circuit, 22, J7...
・+7 correction circuit, 23.38... Even and odd correction circuit,
24, 25. 39, 40... data selector, 26.
27.28...Comparator, 29...Arm feed control circuit.

Claims (1)

[Scope of Claims] Detecting means for detecting a signal corresponding to a number from a rotating disk-shaped recording medium in which a number is set for each frame as one frame per revolution of a spiral recording line; (The desired signal is input, and this is converted into the time position required when the eradication medium is normally played. Minute data. Outputs second data and frame data = m means, and the second data is an even number. a first determination means for determining whether it is a sand grain or a wild number second, and a first determining means that corrects the second data by 11 seconds and adds frame data
It is controlled by a first correction means for correcting 7 frames and an error output from the f+i first discrimination means. and a data selection means for selecting the excerpt data and frame data from the correction means of S1 for the odd-numbered grain, and a data selection means for selecting the frame data from the correction means of S1, and an arbitrary digit "1" of the chronology recording medium is operated as data corresponding to the time position. an input means for outputting designated "minute data", designated "second data", and designated "frame data" that can be input from keys; and the designated "second data".
a second determination means for determining whether the grain is an even grain or an odd grain;
Controlled by a second correction means that corrects the specified "second data" by -1 second and corrects the specified "frame data" by +7 frames, and a judgment output from the second judgment means, is the designated "seconds data" directly output from the input means. Select the specified "frame data" and enter the above 's4 for odd numbered grains.
a second data selection means for selecting designated "second data" and designated "frame data" from the second correction means;
1. A direct access device comprising: a data selection means and a comparison means for comparing the corresponding data from the second data selection means and obtaining a match/failure output.