JPS5854791A - Confirming device of video recording function for magnetic video recorder and reproducer - Google Patents

Abstract

PURPOSE:To easily perform recording with a simple contitution, by performing still picture reproduction with two video heads with an azimuth and confirming video recording, after recording magnetic tape for one field while keeping the magnetic tape still. CONSTITUTION:At a location near one of the 1st and 2nd video heads 1, 2, e.g., the head 2, having different azimuth angle and being fitted in 180 deg. interval on a rotary drum, an auxiliary head 3 having the same azimuth angle as that for the head 2 is fitted. Further, a video recording function confirming device 12 is provided and when the device 12 is operated at a video recording pose a magnetic recording medium is kept still and the head 2 makes magnetic recording for a specified length. Further, still picture reproduction is done for the recorded picture by using the heads 2 and 3, allowing to confirm the video recording function.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a magnetic recording and reproducing device (hereinafter referred to as V T
The present invention relates to a recording function confirmation device (abbreviated as R).

With the spread of VTR, multi-functions such as variable speed playback, program reservation, and video camera recording have been developed.
The operation of TYL itself is also becoming more complicated. For this reason, when recording TV programs or camera footage, there have been cases where even beginners and experienced users end up failing to record due to operational errors when in a hurry.On the other hand, even if the operations are correct, V'J used for a long time, "It
Then, due to clogging of the video head or aging of the circuit,
In some cases, proper recording was not performed, and in this case, there was no way to check anything during recording, which was frustrating.

In order to deal with the above-mentioned problems, it is possible to install two independent rotating video heads and a playback circuit that play back the same track as the recorded track, and to monitor the recording. , that is most certain. However, this method not only requires a two-string playback system, making the device complicated and expensive, but also requires simultaneous playback while recording.
It was difficult to put this into practical use because crosstalk interference with the reproduced image through the rotary transformer that connects the commonly used rotating video head and electric circuit could not be ignored.

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording function checking device for a magnetic recording/playback device that eliminates the drawbacks of the above-mentioned prior art, can reliably check the recording mode and performance of the device with a simple configuration, and can prevent recording failures. There is a particular thing.

In order to achieve this object, the present invention checks the recording function from the recording pause state of the VTR, and after recording only 1).
The field is played back as a still image using two rotating video heads with the same azimuth to check the recording function, and the recording position of that field is paused and photographed.
This control is designed to prevent interference from appearing on the screen when there is only one.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory diagram showing the configuration of a rotating video head of a recording function checking device for a magnetic recording and reproducing device according to an embodiment of the present invention. In the figure, an auxiliary head A'3 having the same azimuth as the A head 1 is provided at a predetermined position near the 13 head 2 having an azimuth different from that of the A head 1. (Here, A head 1 and B head 2 may be separate chips or may be the same chip with an integrated structure). 4 is the rotating head 1, 2.3
It is a rotating cylinder equipped with a

The general operation of the present invention will be explained based on FIG. 1 and FIG. 2, which is a recording pattern diagram as seen from the magnetic surface recorded on the magnetic tape 5 in the recording pause state.

The recording pattern shown by the dotted line in FIG. 2 is 7.8°9.
Assuming that 10 is a pattern that has already been recorded, 7 and 9 are patterns written by B head 2, and 8 and 10 are patterns written by A head 1, the trajectory of the rotating head in the recording pause state is a solid line. It will be as shown.

When a recording function confirmation button (not shown) is pressed in this state, only one field is recorded on the magnetic tape 5 by the A head 1, creating a solid line recording pattern 6. After this, for a specified period of time,
If you play back the same recording pattern 6, you can record II by looking at the playback image! ii) The function of function confirmation can be realized.

Even if reproduction is performed alternately using the same A head 1 and B head 2 used for recording, the recorded pattern 6 having the same azimuth as that of the head cannot be correctly reproduced. In the present invention, it is possible to check the recording function by playing back using the head 1 and the auxiliary A' head 3 of the same azimuth.

Next, the specific operation of the embodiment of the present invention is shown in the block diagram of FIG. 3, the flowchart of the operation in FIG. 4, the example of the head signal switching circuit (only the head is shown) in FIG. This will be explained using signal waveform diagrams of each part in the figure.

11 is a signal recording/reproducing circuit for V']"R, and 12 is a recording function confirmation control circuit.
- It is composed of phycrocomputers. Also, 13 is a rotary transformer, 14 is a recording changeover switch, 15
17 is a playback amplifier. When the A head recording control signal Ar is 11" (high level), the switch 14 is turned on, and the A head playback control signal Ap or "II" is turned on. The switch 15 is turned on when the switch 15 is turned on.

First, the recording state (recording pause signal P is "'L'" (
At low level)), when the head switching signal 5W30 synchronized with the rotating cylinder 4 is +1, the A head recording control signals A and r are set to "I-1"' and a recording signal current is applied to the A head to perform recording. and head switching signal 5W30
is '■I''', the B head recording control signal Br is 'T'.
Normal recording is performed by flowing a recording signal current to the B head at 1~h'' (see Figure 6).When the recording pause signal P becomes II HII, the recording pause state is entered and the magnetic tape 5 is stopped. At the same time, the recording control signal A-r
, Set Br to It L jl and stop recording.

Next, the recording function check button (not shown) is pressed and the command signal 1 (111111) is detected, and then the A head recording is controlled only during the period of It J and II of the first head switching signal 5W30. A with signal Ar set to 'H'
Record 1 field with head 1. If the pinch roller is separated in the recording pause state (mainly, to prevent the tape from sagging, press the pinch roller and apply torque to the reel before recording one field, or take measures to put the tape into still image playback mode. Immediately after that (In the embodiment, the period of II J and II of the next head switching signal 5W30) for a predetermined time τ or while both function confirmation buttons are pressed, the reproduction control signal RCP is set to ``II''; During the period when the head switching signal 8W30 is "L"', the head reproduction control signal Ap is set to "H", and during the period when the head switching signal SW30 is 'H', the A' head reproduction control signal A'p is set to "I-1'". Play back still images with both heads A, , A' to enable confirmation of the recording function.Then, the cornering control signal RCP goes low.
1, JJ, the VTR returns to the recording baud state.

Note that some VTRs have a pause continuous shooting function that matches the phases of the control signals before and after the recording pause, so that there is no image disturbance at the seam.

If you apply the above method to this V T f(,) and check the recording function, interference will appear in the reproduced image near the seam (;J). This will be explained using a recording pattern diagram.

When a recording pause command is issued, recording is stopped in the state shown in FIG. 7(a). The shaded areas on the magnetic tape 5 are already recorded areas. Next, the magnetic tape 5 is rewound to the position shown in FIG. 7 (1) and stopped, thereby creating a recording pause state. Thereafter, when a recording command is issued, the continuous recording function is an operation of running the magnetic tape 5 and starting a new recording from the position (arrow 21) where the previously recorded control signal and the vertical synchronization signal to be newly recorded coincide. Therefore, Fig. 7 (
If you check the recording function in the recording pause state of b), a recording pattern for one field for checking the recording function will be written in the already recorded part, and this will be replaced with a new one as shown in Figure 7 (C). Since the recorded data cannot be erased by other recordings, interference occurs in the reproduced image near the seam.

In the present invention, the above-mentioned interference is solved by performing control as shown in FIG. 8 using the recording function confirmation control circuit 12 shown in FIG. In the recording pause state, the magnetic tape 5 is stopped in the state shown in FIG. 8(b).

Then, when the recording function check button is pressed, one field is not recorded immediately, and the magnetic tape 5 is run in the normal direction until the state is approximately as shown in FIG. 8(a) as shown in FIG. 8(C). After that, record one field with A head 1 (
(shown in recording pattern 20) is performed. Thereafter, the film is rewound again to the position shown in FIG. 8(d) and stopped, resulting in a recording pause state. In this way, when making a new record, Figure 8 (e
), since the recording pattern 20 for confirming the recording function is erased, image disturbance near the seam will no longer occur.

In the above description, image quality deterioration (mainly unerased colors) occurs due to overwriting immediately after a recorded magnetic tape cassette is loaded into a cassette holder or when the recording function confirmation operation is repeated. In order to solve this problem, the present invention, as shown in FIG. Primary erase signal E
is output from the recording function confirmation control circuit 12 as 11'',
A method of erasing one field was used. A high frequency oscillator 31 of about 4 MHz and 20 mA is used as the erasing signal, and erasing is performed by applying it to the A head 1 through the erasing changeover switch 30 for one field. In order to further increase the erasing effect, direct current may be applied instead of high frequency current. In this case, a direct connection means such as a slip ring is required instead of a rotary transformer6.In addition, some home VTRs are capable of switching recording speeds (for example, 2-hour and 6-hour modes) for the purpose of long-term recording. be. In this case, it is desirable to use a head with a rad width depending on the speed in terms of high image quality.

By using the idea of the present invention, low-speed recording and playback (6-hour mode) using an auxiliary head for checking the recording function
The possibility of this will be explained in another example. FIG. 10 shows the structure of a rotating video head in this case, in which a B' head 44 having a head width of about 30 .mu.m and the same azimuth as the B head 2 having a head width of about 60 .mu.m is provided near the head 1.

By using this set of A' head 43 and B' head 44, low speed recording and reproduction is possible. In this example, since the azimuth of the head is reversed, the head switching signal SW3
A means is used to supply a signal obtained by inverting 0 to each block as a head switching signal.

As explained above, according to the present invention, the VT can be reliably set by the simple operation of pressing the recording function confirmation button from the recording pause state.
Since the performance of R can be checked, it is possible to prevent recording failures, and even when continuous pose shooting is performed, there is no interference on the screen due to confirmation of the recording function.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the configuration of a rotating video head in one embodiment of the present invention, FIG. 2 is a recording pattern diagram on a magnetic tape, FIG. 3 is a block diagram showing one embodiment of the present invention, and FIG. 5 is a circuit diagram showing a head signal switching circuit in an embodiment of the present invention; FIG. 6 is a signal waveform diagram of each part in an embodiment of the present invention; FIG. 8 is an explanatory diagram of a recording pattern, FIG. 9 is an explanatory diagram of a 1-1 field erasing means employed in the present invention, and FIG. 10 is an explanatory diagram of a head configuration according to another embodiment of the present invention. . Code explanation 1...A head, 2...B head, 3
...A' head, 11 ... Signal recording and reproducing circuit, 12 ... Recording function confirmation control circuit, 14
...Record changeover switch, 15 ...Reproduction changeover switch, 43 ...A' head, 44
...B' Head Agent Patent Attorney Akio Namiki Figure 2 Figure 3 Figure V/N1o. xi -Ln' Canceling 'CC2 0o'TArBrAPA'p ℃-3SW31) p RCp % control eye horse mackerel 1?C

Claims (1)

[Scope of Claims] 1) In a magnetic recording/reproducing device employing an azimuth recording method, either one of first and second video heads having different azimuths is attached to a rotating drum at an interval of 180 degrees. For example, an auxiliary head having the same azimuth as the second head is attached to a predetermined position near the first head, and a recording function confirmation operating means is provided, and when the recording pause state is in the state, by operating the operating means. ,
Magnetic recording of a predetermined length is performed by the second head while the magnetic recording medium is stopped, and then the recording is transferred to the second head.
1. A recording function checking device for a magnetic recording and reproducing device, characterized in that the recording function is checked by playing back a still image using a head and an auxiliary head. 2. In the recording function checking device according to claim 1, after the magnetic recording medium is moved by a certain amount by operating the recording function checking operation means, the recording of the certain length and the still image of a predetermined time are performed. 2. The recording function checking device for a magnetic recording/playback device according to claim 1, wherein the recording function checking device for a magnetic recording/playback device performs playback, then moves the magnetic recording medium backward by the predetermined amount, and then automatically returns to a recording pause state. 3) Percentage allowance In the recording function confirmation device according to claim 1 or 2, the recording function confirmation operation is performed only while the recording function confirmation operation means is being operated. 2. A recording function checking device for a magnetic recording/playback device according to item 2. 4) In the recording function confirmation device according to any one of claims 1 to 3, a direct current or high frequency current is once applied to the second head or the auxiliary head by operating the recording function confirmation operation means. The magnetic recording and reproducing apparatus according to any one of claims 1 to 3, wherein after applying the voltage, recording of the fixed length and reproduction of still images for a predetermined time are performed. Recording function confirmation device. 5) In the recording function confirmation device according to any one of claims 1 to 4, the magnetic recording and reproducing device is a magnetic recording and reproducing device capable of switching recording speeds for long-time recording. In this case, the head width of the auxiliary head is made smaller than the second head, and a fourth head having the same azimuth as the first head and a smaller head width than the first head is also installed at a predetermined position near the second head. Claims 1 to 4 are characterized in that low-speed recording and playback is performed using a set of an auxiliary head and a fourth head.
A recording function confirmation device for a magnetic recording and reproducing device according to any one of the paragraphs.