JPS6144244Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention has a head track width larger than that of a video track pitch, and produces slow still images with excellent image quality.
This article relates to a VTR adjustment tape using the azimuth recording system that enables playback at double speed, etc.

For VTRs whose video head track width is less than the video track pitch, as shown in Figure 1, they are covered with highly compatible adjustment tape that alternately records CH1 track 1 and CH2 track 2 with an equal amount of overlap. Playback on the adjustment VTR (at this time, the recording track width of the adjustment tape and the head track width of the VTR to be adjusted are equal).For example, in the case of video track linearity adjustment, the CH1 head output or b shown in Figure 2a. Adjustments were made while observing the CH2 head output shown in Figure 2 with an oscilloscope and measuring the tracking margin. The center height of the video is also adjusted at the tracking FIX position so that the playback output of the adjustment tape is maximized. In addition, regarding the video head switching position,
Observe the output c when CH is mixed and the reproduction gate signal d using the oscilloscope's two-phenomenon mode.
Center k of overlap parts 3 and 4 of both CHs,
The two rotary cylinders are installed so that the rising and falling edges of the regeneration gate signal are located on the l line.
Adjusted with PG phase. Through this adjustment, the video W position defined by the pattern standard can be accurately reproduced. In addition, the gate signal is generated from one reference PG signal using a delay circuit.
In a VTR, the amount of delay is adjusted.

However, as an inexpensive means to improve image quality during special playback such as slow, still, and double speed, VTRs with a head track width larger than the track pitch have emerged. Because the head widths are different, precise adjustment of video track linearity and video center height is impossible, and as shown in Figure 3, CH1 track 5 and CH2 track 6 are arranged at intervals of three tracks (or an odd number of tracks or more). Adjustments are made using tapes recorded alternately. However, with this recorded content, it is not possible to obtain an overlap signal such as that shown in FIG. 2c, and the head switching position cannot be adjusted accurately. Therefore, a special tape with the recorded content shown in Figure 1 is required for adjusting the head switching position, which wastes time when changing tapes during adjustment, and it becomes difficult to manage when there are many types of adjustment tapes. , disadvantages such as a decrease in tape production efficiency and an increase in the amount of tape production occur.

In FIG. 1, 13 is an audio track, and 14 is an audio track.
indicates a control signal.

The present invention eliminates the drawbacks of the conventional method and makes the head track width larger than the video track pitch, enabling special playback such as slow, still, and double speed with excellent image quality. Compatibility such as positioning can be adjusted with a single tape.
The purpose is to obtain tape for VTR adjustment.

The present invention will be explained based on the drawings.

This invention is suitable for odd track intervals of 3 or more tracks.
The CH1 and CH2 tracks are recorded alternately forming equal front and back overlaps, and other tracks with lengths that temporally coincide with the front and rear overlap portions of the tracks are recorded on the left and right positions immediately on both sides of the tracks. This is a VTR adjustment tape that is installed continuously inside and outside the video width line of the track.

The recording system gate signals of the making machine for making the VTR adjustment tape of the present invention are shown in Fig. 2 e and f. If e is the CH1 gate and f is the CH2 gate, and the configuration is such that current flows to the video head when the signal is LOW, then when the CH1 gate goes LOW and one track is recorded including the overlap before and after, , the other CH2 gate becomes LOW during the overlap period of both CHs (indicating the above-mentioned overlap portions 3 and 4) and records the CH2 track. After that, including CH1 and 2. The contents of the gate signals operate alternately at three-track intervals to form a recording pattern as shown in FIG.
In Figure 4, 7 is CH1 where all one track was recorded.
track, 7-1, 7-2 are overlap parts,
8 and 8' are CH2 tracks recorded only during the overlap period before and after both CHs, and 9, 10, 1
0' means CH1 and CH2 are reversed. 9-1, 9-2
indicates the overlap part. Also, the tape is arrow m
As the video head scans in the direction of the arrow n, the positions p and g that define the video width W are at the second
This corresponds to the k and l positions in the figure. Furthermore, r, s, t, and u of 8 and 8' have the same track lengths based on the p and g positions, and the same holds true for 10 and 10'. When the VTR adjustment tape recorded as described above is played back on the VTR to be adjusted, the playback signals shown in Figure 2g and h are obtained, and the video track linearity and video track center height are adjusted in the same way as before. For video head switching position, both CH
The VTR to be adjusted can be obtained by mixing the output signals of The playback switching position can be adjusted accurately with respect to the video width W. In other words, it is now possible to adjust at least two necessary items using one adjustment tape, instead of having to adjust each item separately as in the past.

The present invention utilizes the tape described above for adjusting a VTR equipped with two rotating magnetic heads having mutual azimuths and a head width larger than the track pitch. At least two main adjustment items can be adjusted at once, and adjustment time can be shortened by eliminating the hassle of changing tapes, and the fact that there are only a few types of VTR adjustment tapes makes it easier to manage tapes.
Not only is storage easier, but the adjustment tape can also be produced continuously under the same setting conditions, resulting in improved efficiency.

[Brief explanation of drawings]

Fig. 1 is a pattern diagram showing the recorded contents of a conventional adjustment tape, Fig. 2 is a timing chart showing the electrical signal waveforms of the conventional example and the present invention, and the timing between each signal, and Fig. 3 is a pattern diagram showing the recording contents of a conventional adjustment tape.
FIG. 4 is a pattern diagram showing the recorded contents of the VTR adjustment tape of the present invention. 3, 4: Overlap part of CH1 and CH2, 1
1, 12: Sensor wire of overlap part, 7,
9: CH1 and CH2 tracks, 7-1, 7-
2, 9-1, 9-2: overlap part, 8,
8': CH2 track, 10,10': CH1 track, r, s, t, u: track length, W: video width, p, g: video width line, 13: audio track,
14: Control signal.

Claims (1)

[Scope of utility model registration request] An image track is formed in a diagonal direction by two rotating heads having azimuths from each other and a head track width larger than the track pitch.
On a VTR recording tape, the video tracks formed by the two heads at odd-numbered track intervals of 3 or more tracks are recorded alternately with overlapping portions formed before and after the video tracks, and the video tracks are recorded at left and right positions immediately on both sides of the recording track. A tape for adjusting a VTR, comprising tracks having a length that temporally coincides with the overlap portions before and after the tracks are continuously provided inside and outside the video width line of the video track.