JP2600075Y2 - Video signal level indicator - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal level indicator provided with a high-end video camera or the like.

[0002]

2. Description of the Related Art In a normal video camera, white bun las adjustment is performed, which is fixed. However, when the influence of lighting at the shooting site or when a light source having a different light source is used, the adjustment state of the white balance is not always obtained by the user or the manufacturer. For this purpose, a high-quality video camera is provided with a volume or the like for adjusting the white balance. Even if the volume is adjusted, the adjustment position is determined by feeling while looking at the imaging screen on the monitor.

[0003]

[Problems to be Solved by the Invention] When adjusting the white balance and the hue as described above, in the conventional camera, the adjustment is performed while the user watches the image of the subject which is actually being picked up. May not be able to make satisfactory adjustments.

Therefore, an object of the present invention is to provide a video signal level indicator which can uniformly recognize adjustment of white balance and color tone by simply adding a simple function, and is easy to use.

[0005]

According to the present invention, first, second, and third level detections are performed, in which three primary color video signals are input, and a white tone level and a black tone level of each of the three primary color signals are detected. Means and the level detection signals of the first, second, and third level detection means are input, and the first, second, and third level detection means are used for the three primary color video signals corresponding to the range from the white tone level to the black tone level. A level display signal generating circuit for generating the second and third display period signals, and the three primary color video signals are mixed with the respective display period signals obtained from the level display signal generation circuit in a corresponding manner. e Bei and mixing means for supplying to the display device output, said at mixing means used for displaying the white level and black level at the same time, is displayed in vertical bar graph length proportional to the magnitude of the signal level between them I did it.

[0006]

By such means, each of the three primary color signals can be compared in a bar graph on a display device and viewed in color. In particular, the bar graph is displayed in a vertical direction on the display screen and easily grasped intuitively. It is easy to uniformly adjust the level ratio based on past data or the like.

[0007]

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

FIG. 1 shows an embodiment of the present invention. The input terminals 1a, 1b, and 1c are supplied with R, G, and B signals (video signals) that have been imaged by the imaging device and have undergone signal processing. In the state normally used, R from the camera,
The G and B signals are supplied to the R, G and B signal input terminals of the display device 3 via the mixers 2a, 2b and 2c. No mixing takes place in the mixers 2a, 2b, 2c. Input terminal 1
a is connected to the white side level detector 4 and the black side level detector 5, the input terminal 1b is connected to the white side level detector 6, the black side level detector 7, and the input terminal 1c is connected to the white side level detector. 8. Connected to the black side level detector 9. Each white-side and black-side level detector detects a white-side peak and a black-side peak, and inputs the detection signal to the level display signal generation circuit 10.

A level display signal generating circuit 10 displays a display period signal S corresponding to a range between black and white levels according to the white level and black level detection signals for each of the three primary color signals.
R, SG, and SB are output. The display period signals SR, S
G and SB are input to mixers 2a, 2b and 2c, respectively, and mixed with R, G and B signals. That is, only when the display period signal is at the high level, the corresponding R, G, and B signals are derived. Now, R, G,
If the bar graph of B is displayed, the display period signal S
R, SG, and SB are output at timings as shown in FIG. FIG. 2A shows a vertical synchronization signal, and FIGS. 2B, 2C, and 2D show the display period signals SR, SG, and SB. The signal shown in FIG. 3D is a reference position signal, which is 100% on the monitor screen.
The reference level position and the 0% reference level position are displayed. Normally, when the white balance is maintained and the rating is given, the bar graphs of R, G, and B fill the space between the 100% reference level position and the 0% reference level position as shown in FIG. It is set to be the length. Therefore,
In the display state as shown in FIG. 1, when it is desired to match the white balance and the rating, the white balance can be easily and uniformly adjusted by adjusting the amplifiers of the respective R, G, and B signal paths and controlling the level. Can be taken.

FIG. 3 shows an example of the configuration of a portion of the level display signal generating circuit 10 for obtaining a display period signal SR, for example. The display period signal SR is set by the flip-flop circuit 21;
Obtained by being reset. The set signal of the flip-flop circuit 21 includes a counter 31, a comparator 32,
It is composed of an A / D converter 33, a down counter 34 and the like. When a black level detection signal is input to the A / D converter 33, a digital value corresponding to the level of the detection signal is obtained. This digital value is replaced with the count value of the counter 31. That is, the count value of the counter 31 is compared with the digital value by the comparator 32, and when they match, the count value is preset in the down counter 34 at the timing of the matching pulse. The down counter 34 starts counting clocks from the position of the vertical synchronization signal. At this time, the flip-flop circuit 21
Is set. Further, the A / D converter 41 and the comparator 4
2, the counter 43 and the down counter 44 are circuits for resetting the flip-flop circuit 21 at timing according to the white level. Thus, a display period signal can be obtained.

In the above embodiment, the bar graph is displayed in the vertical direction. However, the bar graph may be displayed in the horizontal direction. This system may be built in the video camera itself, and the mixers 2a, 2b, 2c, the level display signal generation circuit 10, and each level detector are integrated,
A terminal to connect this part is also provided on the camera body,
The connection may be made when necessary. Further, it may be used exclusively for adjusting the rating at the time of factory shipment. As the monitor screen, a screen attached to the video camera may be used, or a display device of an independent receiver may be used. When adjusting the white balance, the amplifier of each primary color video signal system is adjusted.Adjustment data for obtaining a desired white balance state and color is stored in a memory in advance, and this is switched. It may be for reading gain control.

[0012]

As described above, according to the present invention, adjustment of white balance and color tone can be recognized uniformly by adding a simple function, and usability can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a timing chart and a display example for explaining the operation of the circuit in FIG. 1;

FIG. 3 is a circuit diagram showing a specific example of the level display signal generation circuit of FIG. 1;

[Explanation of symbols]

2a to 2c: Mixer, 3: Monitor screen, 4 to 9: Level detector.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-268226 (JP, A) JP-A-51-96237 (JP, A) JP-A-51-96236 (JP, A) JP-A-49-962 43525 (JP, A) JP-A-49-40027 (JP, A) JP-A-58-68777 (JP, U) JP-A-57-43670 (JP, U) (58) Fields investigated (Int. ⁶ , DB name) H04N 17/00-17/06

Claims (1)

(57) [Scope of request for utility model registration] 1. A three-primary-color video signal is input, and
3 primary colorsThe second is to detect the white tone level and the black tone level of the signal.
First, second, and third level detecting means; and level detecting signals of the first, second, and third level detecting means.
No. is input and the range from white tone level to black tone level
For each of the three primary color video signalsThisFirst, second,
A level display signal for generating a third display period signal
And a display period signal obtained from the level display signal generation circuit.
And the three primary color video signals are mixed in correspondence with each other,
Mixing means for supplying the mixed output to the display device.Preparation
And The mixing means displays a white level and a black level simultaneously.
Between which the length is proportional to the magnitude of the signal level
Display as a vertical bar chart Video signal characterized by
No. level indicator.