JPH01118269A - Variable delay device - Google Patents

Abstract

PURPOSE:To delay and output a signal for a long time without being missed by varying the positions of plural recording heads and reproducing heads corresponding to recording areas divided equally, and making access them by rotating sequentially. CONSTITUTION:By supplying an input signal IN, the recording heads 40 and 41 are selected alternatively by a control part 7, and recording is performed in the recording area ARO and ARI on a disk 3. Also, the control part 7 makes the reproducing head 50 or 51 follow the recording head by applying position control so as to set a difference in a radius direction of the recording head 40 or 41 corresponding to a commanded delay time. Thus, a signal obtained from the reproducing head 50 or 51 is outputted as a delay signal via switch circuits 80 and 81, whose opening/closing is controlled so that the timing of the signal can be set alternatively by switching signals W3 and W4 and also, a change-over timing can be set at the timing to reproduce a signal part overlapped and recorded by the recording heads 40 and 41.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a variable delay device that delays an input signal by an arbitrary delay time within a very wide range of delay times and outputs the delayed signal.

[Prior Art] Recent video tape recorders have a recording reservation function.
Even television broadcasts whose broadcast time is during the user's absence can be viewed by using the recording reservation function. However, even if the user returns home during recording, the recorded broadcast program cannot be viewed until all recording is completed.

In order to meet such demands, a variable delay device is required that can read out the recorded signal from any point in time in parallel with recording, that is, can realize an arbitrary delay time Td shorter than the television program time T1. becomes.

[Problems to be Solved by the Invention] Conventionally, semiconductor memory has been used as a variable delay device. There is a problem that the number of memories becomes very large, and both the writing and reading structures become complicated and large in size.There is also a problem that the entire device becomes expensive because a large number of expensive semiconductor memories are used.

Therefore, it is conceivable to construct a variable delay device using a tape-shaped recording medium or a disk-shaped recording medium.

For example, one idea is to use a disk recording/playback device, provide a recording head and a playback head independently, and make the movement of the playback head follow the movement of the recording head by a time Td to obtain an arbitrary delay time. It will be done. However, according to this method, in the case of a television program that is longer than the recording time of the disc, all the signals cannot be delayed because the recording head and playback head require return time in the middle, and the signal during the return period is lost. There is a problem with this.

Furthermore, if you want to be able to watch long-duration television programs without signal loss, it is conceivable to install multiple disk recording/playback devices and have them operate alternately and complementarily; However, it has disadvantages in terms of size, operability, and economy.

The present invention has been made in consideration of the above points, and it is an object of the present invention to provide a variable delay device that can delay a long-term signal by an arbitrary amount of time without signal dropout.

[Means for solving the problem] In order to solve the problem, the present invention provides a recording medium in which the recording area is divided into A (A is 2 or more) equal parts, and a recording medium in which the recording area is divided into A (A is 2 or more) equal parts, and A number of recording heads corresponding to each recording area for recording an input signal to the area, A number of playback heads corresponding to each recording area for reproducing the recorded signal of each recording area, each recording head and each head selection means for sequentially rotating and accessing the playback heads;
The apparatus includes head position control means for varying the positions of the recording head and reproducing head corresponding to each recording area in accordance with the delay time.

[Operation] Since the head position control means varies the positions of the recording head and the reproducing head according to the delay time, the reproducing head follows the recording head with a delay of the delay time, thereby realizing the desired delay time.

Furthermore, since the recording head and playback head corresponding to each recording area are sequentially rotated and accessed, during the return period of one of the recording heads and playback heads, other recording heads and playback heads cannot access the area. This allows the signal to be delayed without any signal loss.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In FIG. 1, a delay unit 1 to which an input signal IN is applied is connected to a CAV (c) loaded with one disk.

n5tant angular velocity)
The system is equipped with a disc recording/reproducing section 2 of As shown in FIG. 2, the disc recording/reproducing unit 2 includes two recording heads 4o that are movable in the radial direction with respect to the loaded disc 3.
, and has two playback heads of 50.5 mm.

The recording area of the disk 3 is divided into two in the radial direction, with one recording head 40 and reproducing head 50 accessing the outer recording area ARO, and the other recording head 40 accessing the inner recording area ARI. and the playback head 5I.

In order to prevent the movement of each head from interfering with each other, the image recording heads 40 and 4■ are arranged in a 180-degree angular interval, and the two doctor heads 50 and 5■ are arranged at an angular interval of 180 degrees.
The recording heads 40 and 5 are arranged at an angle of 90 degrees at angular intervals with respect to the recording heads 40 and 5.

An input signal IN is applied to each of the recording heads 40 and 4* through corresponding switch circuits 60 and 6I, respectively. Switch circuits 60 and 6
I is configured to close alternately, although there is some overlapping time T1, depending on the switching control signals W1 and W2 from the control section 9 shown in FIGS. , the closing times of the switch circuits 6o and 6■ are such that the corresponding recording heads 40 and 4■ are in the recording areas ARO and ARI, respectively.
The time taken to scan from the beginning to the end of the line is selected.

Therefore, as shown in FIG. 4(A), the input signal IN is recorded in the outer recording area ARO and the inner recording area AR1 alternately and overlappingly for a time T1.

The reason why two recording heads are provided is to avoid a situation where an incoming signal is not recorded only during the time required for the recording head to return from the end to the beginning. Then, the other recording head returns to the scanning start position.

The reproduction heads 50 and 5■, which reproduce the recording signals recorded by the recording heads 40 and 4■ in this manner, are directed to the corresponding recording heads 40 and 4 according to the position control signal PCON from the control section 7. The radial positions are made to differ by a predetermined amount.

Here, as shown in FIG. 5, for example, a pair of recording heads 4
0 and the reproducing head 50 move from the inner circumference to the outer circumference at a speed of {circle around (2)} during access, and the radial distance between the recording head 40 and the reproducing head 50 is R (= rl - r2), the reproducing head 50 moves from the recording head to the outer circumference. 40 reproduces a signal recorded a time Td previously as shown in the following formula % Formula % (1) Therefore, the disc recording/reproducing section 2 functions as a delay circuit having a delay time Td according to the distance R. .

Note that the time Tr is a delay time that occurs when the recording head 40 and the reproducing head 50 differ in angular interval by 90 degrees, and is the time for the disk 3 to rotate 1/4. Therefore, even if a delay command is not given, the delay time Tr is always delayed.

The delayed signals alternately reproduced by the reproducing heads 50 and 5■ are outputted via corresponding switch circuits 80 and 8■, respectively.

The switch circuits 80 and 8I are connected to the control unit 7 by
C) and (D>), the switching timing is set to the recording head 4
Opening/closing is controlled to coincide with the timing at which signal portions 0 and 4I are being reproduced. Further, the switch circuit 80 is closed while the reproducing head 50 is reproducing, and the switch circuit 88 is closed while the reproducing head 5I is reproducing. Note that while one reproducing head is performing reproduction, the other reproducing head returns to the scanning start position.

Therefore, the output signal is continuous as shown in FIG. 4(B), and is delayed by the delay time 'rd.

In addition, in the case of this embodiment, the same area ARO or ARI
Since the recording operation is performed again after a predetermined period of time, the limit of the delay time is the time required to record again in the same area.

In the above configuration, when the input signal IN is applied, the recording heads 40 and 4I are selectively selected by the control unit 7 and recording is alternately performed in the recording areas ARO and ARI on the disk 3. Further, the control section 7 controls the position of the reproducing head 50 or 5I according to the commanded delay time so as to provide a difference in the radial direction from the recording head 40 or 4I, thereby causing the recording head to follow the recording head. Thus, the playback head 50
Alternatively, the signal obtained from 5.2 and passed through the switch circuit 80 or 8.2 is output as a delayed signal.

Therefore, according to the above embodiment, an output signal having a long delay time with respect to an input signal can be obtained with a simple configuration. For example, if the input signal is a television signal, by giving a playback command during recording, it is possible to watch the program from the beginning.

In the above-described embodiment, a disc recording/reproducing device such as an optical disk or a magnetic disk is used as the delay unit 1, but a drum recording/reproducing device may also be used.

Further, in the above embodiment, the area on the disk of the disk recording/reproducing device is divided into two, but it is also possible to divide the area into three or more areas and delay each area. It may also be used as a region.

Further, the input signal may be a video signal, an audio signal, or a simple data string. Moreover, either an analog signal or a digital signal may be used.

[Effects of the Invention] As described above, according to the present invention, the recording area of a recording medium is equally divided, a recording head and a playback head are associated with each other, and each recording head and each playback head are selectively operated. ,
At this time, since the reproducing head is made to follow the recording head with a delay of a predetermined time, it is possible to obtain a variable delay device that can delay a long-time signal by a desired delay time without dropping the signal. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the variable delay device according to the present invention, FIG. 2 is a plan view showing details of the disc recording/reproducing section thereof, FIG. 3 is a switching timing chart of the switch circuit of the delay section, and FIG. FIG. 4 is an explanatory diagram for explaining recording and reproducing operations, and FIG. 5 is an explanatory diagram for explaining the delay principle. 1... Delay section, 2... Disk recording/reproducing section, 3...
・Disk, 40.41... Recording head, 5Q, 5I
...Reproduction head, 60.6I, 80.8■...Switch circuit, 7...Control unit.

Claims (1)

[Scope of Claims] A recording medium having a recording area divided into A (A is 2 or more) equal parts, and A corresponding to each recording area for recording an input signal in each of the equal divided recording areas. A number of recording heads corresponding to the recording areas for reproducing recorded signals in each of the recording areas; head selection means for sequentially rotating and accessing the recording head and each of the reproduction heads; A variable delay device comprising head position control means for varying the relative positions of the recording head and the reproducing head corresponding to each recording area in accordance with a delay time.