JPH06168401A - Reference magnetic tape for evaluation of video characteristic - Google Patents

Abstract

PURPOSE:To provide the reference magnetic tape which can shorten the evaluation time of an analog VTR and can make evaluation having interchangeability with the evaluation of video characteristics. CONSTITUTION:The reference tape is formed by recording in-block signal constitution 5 integrating video evaluation signals A to G in the respective blocks of reference tape tracks formed by dividing one frame screen 3 of television signals to 5 blocks in a horizontal synchronization unit. The evaluation reference magnetic tape overcoming the characteristic that the video characteristics are not uniform from the beginning point of the video tracks intrinsic to the analog VTR to the end point is formed and this reference tape is reproduced, by which the evaluation time is shortened and the interchangeability of the evaluation of the video characteristics of the analog VTR is maintained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a standard magnetic tape for evaluating video characteristics for recording and evaluating video characteristics of an analog video tape recorder (hereinafter referred to as VTR).

[0002]

2. Description of the Related Art Conventionally, a video characteristic evaluation signal is composed of one frame unit of a television signal, and when characteristic evaluation is performed by using a plurality of evaluation signals, a video tape is used as a standard tape, such as an analog VTR. When performing self-recording / playback and playback compatibility evaluation using one frame of a television signal in horizontal synchronization units, as shown in FIG. 2, for example, the number of signal elements in blocks 1 to 7 is used in order to shorten the evaluation time. There is proposed a 1-frame standard tape track signal recording pattern 2 in which a matrix signal which is divided into 1 to form a 1-frame screen 1 is recorded with an evaluation signal on each track of one field.

However, when the reference tape recorded with this matrix signal is reproduced by the analog VTR to be measured and the reproduction system video characteristics are evaluated, the video characteristics of the reference tape are changed from the start time to the end time of the video track. It is not uniform, and the measured values cannot be interchanged unless measured and evaluated at multiple points, which is not suitable for video characteristic evaluation.

That is, in the magnetic tape on which the characteristic evaluation signals are recorded, for example, when the evaluation signals of blocks 1 to 7 are referred to as A to G in FIG. Even if a plurality of blocks are recorded, the recording characteristics are different depending on the recording location of the track, and the video characteristics of the recorded evaluation signals A to G, for example, the video level, S / N, and frequency characteristics are not uniform. Compatibility of characteristic evaluation cannot be obtained.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention is to provide a standard magnetic tape capable of shortening the evaluation time and performing compatible evaluation of video characteristic evaluation.

[0006]

According to the present invention, one frame is divided into a plurality of blocks in units of horizontal synchronization, and a plurality of types of video characteristic evaluation signals are recorded in each block of the plurality of blocks to record video characteristics. Create a standard magnetic tape for evaluation of. A plurality of types of video characteristic evaluation signals recorded in each block of the plurality of blocks are recorded in the same or different recording order for each block.

[0007]

1 shows a recording pattern of a standard tape for recording an evaluation signal for evaluating the video characteristics of the present invention. In FIG. 1, in order to dispersively record the video characteristic evaluation signal on the tape, one frame screen 3 of the television signal is divided into, for example, 5 blocks in units of horizontal synchronization. Then, in each block, the in-block signal structure 5 in which the video evaluation signals A to G are collected is recorded to create a standard tape.

Specifically, the video evaluation signals A to G are repeatedly recorded in the order of A, B, ... G for each block obtained by dividing the standard tape track into five areas.
A standard tape recording pattern 4 is created.

The standard tape thus produced is reproduced by the VTR to be measured and the reproduction system video characteristics are evaluated.
In the actual evaluation, an evaluation measuring instrument having a block mode measuring function is used to measure the designated signal portion of each block of the standard tape 4, and the average value of the measurement results of each block is used as the evaluation result.

In the above embodiment, the recording order of each block of the plurality of video evaluation signals is recorded in the order of A, B, ... G, but the recording order of the video evaluation signals A to G is changed in each block. The standard tape may be created by recording in different recording order for each block. Furthermore, it is also possible to record the video evaluation signal by changing the recording order for each field.

[0011]

According to the present invention, it is possible to prepare a standard tape which overcomes the characteristic that the video characteristic is not uniform from the start point to the end point of the video track peculiar to the analog VTR. Further, in this standard tape, a plurality of signals are recorded in each divided block in one frame of a television signal, and the reference tape is composed of a plurality of blocks, so that the signal switching time and the signal recording time are shortened. Compatibility of analog VTR video characterization is maintained.

[Brief description of drawings]

FIG. 1 is a block diagram of the present invention.

FIG. 2 is an explanatory diagram of a conventional block.

[Explanation of symbols]

 4 Standard tape track video evaluation signal recording pattern 5 Video evaluation signal structure in block

Claims (3)

[Claims] 1. A video characteristic evaluation standard characterized in that one frame is divided into a plurality of blocks in units of horizontal synchronization, and a plurality of types of video characteristic evaluation signals are recorded in each block of the plurality of blocks. Magnetic tape. 2. A recording order of a plurality of types of video characteristic evaluation signals recorded in each one block of the plurality of blocks,
The standard magnetic tape for evaluating video characteristics according to claim 1, wherein the standard magnetic tape is the same for each block. 3. A recording order of a plurality of types of video characteristic evaluation signals recorded in each one block of the plurality of blocks,
The standard magnetic tape for evaluating video characteristics according to claim 1, wherein the standard magnetic tape is different for each block.