JPS634480A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain very accurate count entirely by superimposing a specific signal on a control signal at each prescribed period, detecting a signal at the reproduction to calibrate the count value thereby eliminating the missing caused at this time or an error due to noise invasion by the calibration. CONSTITUTION:A control signal from a flip-flop 4 is fed to a counter 10, e.g., 10 periods of the control signal are detected and a signal at each 10 periods is fed to a circuit 11 for generating a specific signal. Then the generated specific signal is fed to an adder 5, where the signal is added to the control signal and recorded on a tape 9 together with the control signal. A reproducing signal of the control signal is fed to a counter 13 at the reproduction to apply count and the specific signal is detected by a detection circuit 14, and its detection output is given to a latch circuit 18 thereby correcting the count value of the counter 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording and reproducing apparatus for recording and reproducing a control signal together with a main signal of a video tape recorder or the like.

[Summary of the invention]

The present invention relates to a recording/reproducing device, which performs recording by superimposing a specific signal at every predetermined cycle of a control signal during recording, counts control signals during playback, detects the specific signal, and calibrates the count value. This allows accurate linear count values to be obtained during recording and reproduction.

[Conventional technology]

For example, when editing a video signal using a video tape recorder, the accuracy of editing points is required to be approximately ±2 to 3 frames per program. Therefore, it is impossible to obtain such precision with conventional so-called tape counters.

On the other hand, so-called professional equipment adds a time code to each frame of the video signal and uses it for editing, etc., but general consumer equipment does not have such a configuration. It is difficult to implement this in terms of product price, etc.

By the way, in a video tape recorder or the like, in addition to a main signal such as a normal video signal, a control signal for smoothly reproducing the main signal is recorded. For example, in a video tape recorder, a control signal of one cycle is recorded on the edge of the magnetic tape for each frame of the video signal, and by performing servo etc. using the reproduction signal of this control signal during playback, a good video signal can be obtained. playback is performed.

Therefore, the applicant of the present application previously proposed a tape counter device that was able to detect each frame by counting the period of the control signal during playback (see Utility Model Application No. 57-19594). ).

However, since these control signals are recorded at the edge of the tape, there is a high risk of noise being mixed in due to omissions or disturbances, and when editing a relatively long program, there is a risk that these signals may accumulate and cause large errors. There is. Further, it is not desirable to further provide a structure for removing the above-mentioned omissions and noises from the viewpoint of product price and the like.

[Problems to be Solved by the Invention] As described above, the conventional technology has problems such as errors easily occurring due to lack of control signals and mixing of noise.

[Means for solving problems]

The present invention provides a recording/reproducing device in which a control signal is recorded at a predetermined interval in connection with the recording of a main signal.
) is recorded by superimposing a specific signal (generating circuit (11)) on the control signal (adder (5)), and at the time of playback, the reproduced signal of the control signal is sent to the counter (13).
) to perform counting and detect the above specific signal (detection circuit ('14)) L, calibrate the count value of the above counter with this detection output (latch circuit (18))
This is a recording and reproducing device designed to perform.

[Effect]

According to this, recording is performed by superimposing a specific signal at every predetermined cycle of the control signal, and this specific signal is detected during playback to calibrate the count value, so that omissions and noise that occur during this time can be eliminated. Errors due to contamination are removed by calibration and extremely accurate counts can be obtained throughout.

〔Example〕

In Figure 1, a video signal supplied to an input terminal (1) is supplied to a vertical synchronization separation circuit (2) to separate a vertical synchronization signal.This separated vertical synchronization signal is sent to a servo circuit (3). At the same time, the vertical synchronizing signal from the separation circuit (2) is supplied to the T flip-flop (4) to form a control signal with a period of 1 frame.This control signal is sent to the adder. (5
), a recording amplifier (6), and a recording/reproduction selector switch (7) to supply the magnetic head (8) to the magnetic tape (9).
recorded in

Further, a control signal from the flip-flop (4) is supplied to a counter (10), and, for example, 10 cycles of the control signal are detected, and a signal every 10 cycles is supplied to a specific signal generation circuit (11).

The generated specific signal is then supplied to an adder (5), added to the control signal, and recorded on the tape (9) together with the control signal.

Here, the flip-flop (4) outputs a control signal as shown in FIG. A signal is formed. This signal is supplied to a specific signal generation circuit (11), and as shown in FIG. (5) and added to the control signal. Alternatively, as shown in the figure, a specific signal having a pulse width different from that of the control signal is formed, and this signal is added to the control signal, so that the duty ratio of the control signal is changed every 10 cycles as shown in the figure.

In this way, the control signal and the specific signal superimposed thereon are recorded.

When playing this tape, first the magnetic tape (9)
The signal is reproduced by the magnetic head (8), and the selector switch (
7), the signal is supplied to the servo circuit (3) through the reproduction amplifier (12) to perform servoing during reproduction, and the signal from this reproduction amplifier (12) is supplied to the counting terminal of the counter (13) for control. The periods of the signal are counted.

Further, the signal from the reproduction amplifier (12) is supplied to the above-mentioned specific signal detection circuit (14), and the period during which the specific signal is superimposed is detected by frequency discrimination or the like. This detection signal is supplied to an AND circuit (15).

Furthermore, a reset terminal (16) is provided, and this terminal (1
The signal from 6) is supplied to the clear terminal of the counter (13) and also to the cent terminal of the SR flip-flop (17). And this flip-flop (17
) is supplied to the AND circuit (15), and this AND output is supplied to the reset terminal of the flip-flop (17), and this AND output is connected to the 1's data terminal of the counter (13). It is supplied to the launch terminal of the latch circuit (18) and the pre-sent terminal of the counter (13).

Therefore, during reproduction, a signal as shown in Figure 3A is extracted from the reproduction amplifier (12), and this signal and B in the same figure are
The counter (
The count value of 13) is changed as shown in C of the figure.

Further, a reset signal is supplied to the flip-flop (17), and the Q output is set to a high potential as shown in the figure.

On the other hand, the signal from the reproduction amplifier (12) is sent to the detection circuit (14)
The period of the specific signal superimposed on the control signal is detected as shown in FIG. Then, while the Q output of the flip-flop (17) is at a high potential, this detection signal is supplied to the launch circuit (18), and as shown in FIG. Latched.

Furthermore, when the next specific signal period is detected from this state, the signal is supplied to the preset terminal of the counter (13), and the 1's digit of the counter (13) is preset to the value latched by the launch circuit (18). be done.

That is, in this device, a specific signal superimposed on every 10 cycles of the control signal is detected, and the 1's value of the counter (13) that counts the control signal is latched during the first specific signal period after reset. Thereafter, this latched value is precented to the 1's digit of the counter (13) every period of the specific signal. by this,
For example, even if a dropout occurs in the reproduced control signal as shown in the figure, the count value is calibrated during the next specific signal period. Conversely, even when the count value increases due to noise or the like, calibration is performed in the same way.

By calibrating the count value in this way, it is possible to obtain an extremely accurate count value throughout, and furthermore, this count value can be supplied to the display bag ff (19) or to the system control circuit (20). Various operations can be controlled very accurately.

Further, in this device, the actual signal processing etc. can be performed by a microcomputer, and therefore there is a very small possibility that this will lead to an increase in the product price.

〔Effect of the invention〕

According to this invention, the specific signal is multiplied by M and recorded at every predetermined period of the control signal, and the specific signal is detected during playback to calibrate the count value, so that any omissions that occur during this time can be corrected. Calibration removed errors due to noise contamination, resulting in highly accurate counts throughout.

[Brief explanation of drawings]

FIG. 1 is an elliptical diagram of an example of the present invention, and FIGS. 2 and 3 are diagrams for explaining the same. (1) is the input terminal, (2) is the vertical synchronization separation circuit, (3)
is a servo circuit, (41<17) is a flip-flop, (
5) is an adder, (61 (12) is an amplifier, (7) is a switch, (8) is a head, (9) is a tape, (10)
(13) is a counter, (11) is a signal generation circuit, (14)
) is a signal detection circuit, (15) is an AND circuit, (16) is a reset terminal, (18) is a latch circuit, (19) is a display device, and (20) is a system control circuit.

Claims (1)

[Claims] In a recording and reproducing device in which a control signal is recorded at predetermined intervals in connection with recording of a main signal, a specific signal is superimposed on the control signal and recorded at every predetermined period of the control signal during recording. A recording/reproducing device which performs the following, supplies a reproduction signal of the control signal to a counter during reproduction, performs counting, detects the specific signal, and calibrates the count value of the counter using this detection output.