JPS6126877B2 - - Google Patents

Description

[Detailed Description of the Invention] With the spread of compact color VTRs, televisions are now used not only as receivers but also as display devices (screens), and a high level of image reproducibility is required. It is becoming more and more common. Furthermore, from the standpoint of recorded videotape manufacturers, the quality of reproduced images is one of the important factors that influences the contents of programs and copying techniques. Therefore,
From this point of view as well, televisions require high reproducibility.

In this case, professional monitor receivers used at broadcasting stations are equipped with a switch that turns on and off the screen grid of the color picture tube, so a color barge generator is used to monitor the color saturation and hue. can be adjusted. In addition, the monitor receiver is designed to be able to fully reproduce the DC component, so using a white balance adjuster in conjunction with the IRE75
By measuring and adjusting the brightness of % and 25%, the white level can be set to approximately 40 ft-L, and at this time, there is no change in the black level due to changes in screen brightness.

Therefore, the monitor receiver can have extremely high image reproducibility.

However, general color television receivers have
There is no switch to turn the color picture tube's screen grid on or off. In addition, since the DC component regeneration circuit is simplified, the gradation and color saturation change slightly depending on the brightness of the image. Furthermore, there are no color verge generators or white balance adjusters available to general users. Therefore, the adjustment method described above cannot be applied to general color television receivers.

Therefore, for general use, another adjustment method is required, but as there is currently no specific method for image adjustment, image quality is determined by the user's adjustment method. For this reason, general color television receivers are sometimes set to a state where the image reproducibility is low.

This invention attempts to solve these problems.

Therefore, in the present invention, a video signal to be reproduced as a screen as shown in FIGS. 1 to 6, for example, is recorded on a video tape, and this tape is used as an adjustment jig.

That is, FIG. 1A shows the first screen (pattern) to be reproduced, and FIG. 1B shows its signal waveform. This screen is used to adjust contrast and brightness, and is divided vertically into areas 1 to 4, which are approximately 1/4 each. Then, in area 1, the left 4/7 portion W is the first
As shown in Figure B as broken line 11, it is white at the IRE100% level, and the remaining 3/7th part on the right side Bl
As shown by the broken line 11, is black (absolute black) at the IRE 0% level (pedestal level).

Further, the following area 2 is equally divided into 1/7 portions G ₁ to G ₇ in the left and right direction, and these portions G ₁ to _{G 7} are divided into the first
As shown as a broken line 12 in FIG. B, the level of gray varies from seven levels starting from the left side. In this case, part _G1 is gray close to white, and part
G ₇ is considered to be a black color with an IRE of 7.5%, that is, a black color that can exist as an image.

Furthermore, region 3 has portions W, just like region 1,
It is composed of Bl.

Area 4 is, for example, gray at a level of 40% IRE, and here is the letter L that says "Please adjust the brightness of the receiver on this screen."
It is written in thin white with IRE100% level.

In addition, there are frame parts 5 on the top, bottom, left and right edges of this screen.
However, as shown in FIG. 1B, it is formed in a gray color with an IRE of 40%, for example.

In FIG. 1B, Ph is a horizontal synchronizing pulse and Sb is a burst signal.

The video signal to be reproduced as such a screen is recorded over, for example, 40 seconds in the first section of the tape. Also, at this time, the following announcement is recorded on the tape in response to this video signal.

"This screen is a black and white pattern for contrast and brightness adjustment. Please adjust the picture knob to the extent that the text does not become thick or smeared. Also, among the seven density change patterns in the center of the screen, Adjust the brightness knob so that the black at the edge is equal to the surrounding black."The "picture knob" is a knob that allows you to adjust color saturation and contrast at the same time.
For models that do not have this knob, use the contrast knob instead.

FIG. 2A shows the second reproduced screen, and FIG. 2B shows its signal waveform. This screen is for adjusting color saturation and hue, and like the screen in Figure 1A, this screen is for area 1.
It is divided into 4 parts and has a frame part 5, and the areas 1, 3, 4 and the frame part 5 are the same as the screen in FIG. 1A.

However, area 2 is equally divided into 1/7 parts in the left and right direction, and the seven parts are, in order from the left, gray part G ₁ , yellow part Y, cyan part C,
They are a green part G, a magenta part M, a red part R, and a blue part B. Note that the signal waveform in this region 2 is shown as a broken line 22 in FIG. 2B.

The video signal to be reproduced as such a screen is recorded over, for example, 40 seconds in the second section of the tape so as to be continuous with the video signal in the first section. Also, at this time, the following announcement was recorded on the tape in response to this screen.

"Use this color bar to adjust the color saturation and hue. From the left, the colors are gray, yellow, cyan, green, magenta, red, and blue." And in Figures 3 to 6, The third to sixth screens to be played are shown. These screens are for users who cannot adjust the color saturation and hue on the screen of FIG. 2A, and are designed to allow the user to adjust the color saturation and hue using memory colors.

In other words, Figure 3 shows a scene in which a half-peeled red apple is placed on a white plate with a yellow tablecloth in the background, and Figure 4 shows a scene in which a half-peeled red apple is placed on a white plate with a green tablecloth in the background. In this scene, a orange and a red strawberry are placed on a white plate. Figure 5 shows a scene in which a brown pineapple with green leaves, a red apple wrapped in a white protective net, and a yellow lemon are placed on a blue tablecloth; A brown pineapple with green leaves, a orange, a red apple, and a yellow banana are placed in a light brown basket against a wall and blue fabric, and in front of it are yellow lemons and , a scene where green peppers and red strawberries are placed. In addition, these screens also
It has a frame part 5.

The video signal that is reproduced as such a screen is recorded in the third to sixth sections of the tape.
For example, the video signal is recorded for 20 seconds so as to be continuous with the video signal of the second section. Also, at this time,
The following announcements were also recorded on tape in correspondence with the screens shown in FIGS. 3 and 4.

``Please adjust the color depth and hue knobs so that this apple has the desired tone.'' ``Please make sure that the screen from now on appears clearly.'' Please note that the screen above is , which was determined based on the results of various experiments, and in particular, the average level (power) is set to IRE50% due to the structure of the pattern. In addition, the video signals of the screens shown in FIG. 1A and FIG. By the way,
The video signals of the screens shown in FIGS. 3 to 6 may be obtained by photographing the actual objects with a television camera. And frame part 5
may be added by wiping or the like.

According to such an adjustment tape, if this tape is played back on a VTR and adjustments are made as described above while watching the playback screen, the reproducibility of the image on the television receiver can be extremely improved.

That is, in the screen of FIG. 1A, area 1,
The part Bl of 3 is considered to be absolute black (IRE0%), and the part _G7 of area 2 is considered to be a black color (IRE7.5%) that can be used as an image, so the part Bl
By adjusting the picture or contrast so that G7 and _G7 have the same density, the contrast can be adjusted to an appropriate level. Also, if the brightness is increased too much, blooming will occur and the characters will become thicker or blurred, but since there is a character L in area 4, the brightness should be adjusted so that this character L does not cause blooming. can, therefore,
This allows you to adjust the brightness to an appropriate level.

And in this case, the average level of the screen is IRE50
%, the operating point of the receiver can be set almost at the center, and the DC component regeneration circuit is simplified and the gradation and color saturation may vary slightly due to differences in the brightness of the image. Even if there is a change, the change can be minimized and stability can be increased.

Furthermore, since contrast and brightness can be set optimally and their stability can be increased, details in dark areas of an image can be reproduced very naturally. Furthermore, the quality is not impaired due to excessive adjustments, and individual differences in these adjustments are unlikely to occur.

Furthermore, in the screen shown in FIG. 2A, area 2 becomes a color bar, so that the color saturation and hue can be adjusted.

As for the color saturation and hue, since the screens shown in Figures 3 to 6 are sequentially reproduced, the color saturation and hue can be converged based on the memory color.
It can be adjusted with relatively no individual differences.

Furthermore, since there is a frame 5 throughout all the screens, the horizontal position of the raster can be adjusted.
In addition, since this frame portion 5 exists, when the screen is bent, tilted, or changes in size due to a drop in power supply voltage or a malfunction,
This can be discovered.

Thus, according to this adjustment tape, this
Just by playing it on a VTR, even ordinary users can adjust their color TV receiver to the best possible condition. Moreover, since it is a tape, you can simply include this as a demo tape with the VTR when it is sold. Or it's cheap to sell.

[Brief explanation of the drawing]

1 to 6 are diagrams for explaining this invention.

Claims (1)

[Claims] 1 A video signal having a first signal portion, a second signal portion, and a text signal instructing an adjustment method is recorded, the first signal portion is set at a level to be reproduced as a black image, and the first signal portion is set to a level that is reproduced as a black image. The second signal portion has a level lower than the level of the first signal, and has a first reproduction screen portion based on the first signal portion and a second reproduction screen portion due to the second signal portion. are adjacent to each other, and the text according to the signal of the text is displayed on the same screen as the first and second playback screen portions.