JPS61176294A - Electronic view finder for video camera - Google Patents

Abstract

PURPOSE:To recognize easily horizontal and vertical positions of a subject to be photographed by shifting a line signal CONSTITUTION:A vertical synchronizing signal generating part 9 outputs a pulse 9a in synchronizing with a vertical synchronizing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a viewfinder for a video camera.

[Conventional technology]

FIG. 4 shows a method of indicating the horizontal and vertical positions tH of a conventional electronic viewfinder of a video camera. In Figure 4,
(1) is a cathode ray tube (hereinafter referred to as CRT), (2) is a signal processing unit, (3) is a fixed mark, (4) is a video camera, (5) is a subject, and (6) is an electronic viewfinder. show.

Next, the operation will be explained. A subject (5) imaged by a video camera (4) is converted into a video signal and sent to an electronic viewfinder (6). After this signal touches the signal processing section (2), an image is displayed on the CRT (1). At this time, the fixed mark (3) indicates the horizontal and vertical position of the CRT (11), so the subject (5)
To make it horizontal on the CRT (1), check the part of the image on the CRT (1) where you can easily check the horizontal position, and the fixed mark (3).
) The inclination of the video camera (4) may be adjusted so that it is parallel to the horizontal line.

[Problem that the invention seeks to solve]

However, in the horizontal and vertical whine display method using the electronic viewfinder of a conventional video camera, the mark (3) is fixed, so the part where it is easy to check the horizontal and vertical of the image is located away from the mark (3). , it is difficult to align the horizontal and vertical positions of the subject (5), and when the captured subject (5) is transferred to a large screen such as a monitor television receiver, the subject (5) on the screen will be in the frame of the screen. It is often diagonal to about 1.

This invention was made to solve the above-mentioned problems, and provides an electronic viewfinder for a video camera that allows easy confirmation of the horizontal and vertical positions of a captured object image at any location on a CRT. The purpose is to

[Failure to solve the problem]

The electronic viewfinder of a video camera according to the present invention is capable of displaying a movable line signal on a CRT by external operation.

[Effect]

In this invention, the line signal moves up and down or left and right of the CRT by external operation.
Even if the part where it is easy to confirm the horizontal and vertical positions of the subject image is located at the top or bottom of the screen, the shift in the horizontal and vertical position of the subject image can be easily recognized by comparison with the line signal.

[lol example]

FIG. 1 is a block diagram showing the configuration of an electronic viewfinder of a video camera according to an embodiment of the present invention.
The same parts as those in the figures are given the same reference numerals and the explanation will be omitted.

In FIG. 1, +81 and (9) are a blanking signal generating section and a vertical synchronizing signal generating section connected to the video signal input terminal (7), respectively. A second monostable multivibrator (10) is connected to the output end of the vertical synchronization signal generator (9) via a first monostable multivibrator (10) to which a variable pulse width section (11) is connected. (13) is a gate section which gates the output of the blanking signal generator (8) with the output signal of the second monostable multivibrator (12) and outputs the signal to the switch (141). (2) is the input terminal (7).
) and the switch (141, switch Q4) are in a conductive state, add the output of the gate part (13) and the video signal input to the video signal input terminal (7), The blanking signal generating section (8) is set to be sent to the white clip circuit 06),
A line signal generating means (100) is composed of a vertical synchronizing signal generating section α9), first and second monostable multivibrators (101, (121), a gate section (13), etc.).

The signal processing unit (2) uses the video signal input from the adder α5) via the white clip circuit OD), the CRT (
1) Displays an image on top.

Next, the operation of the apparatus having the above configuration will be explained.

FIG. 2 shows signal waveforms at various parts of FIG. 1, the horizontal axis corresponds to time, and the horizontal axis corresponds to signal residual. First, the vertical synchronization signal generator (9) converts the video signal input to the video signal input terminal (7) into the video signal shown in FIG.
As shown in A), a pulse (9a) synchronized with the vertical synchronization signal
) is output. One period of this pulse (9a) corresponds to one vertical period.

The first monostable multivibrator (101) is triggered by the rising edge of the output pulse (9a) of the vertical synchronization signal generator (9), and generates a constant width pulse (10b) as shown in Figure 2 (B). This pulse width can be arbitrarily set within a range not exceeding one vertical period by the pulse width variable section (111).The second monostable multivibrator (121)
is triggered at the falling edge of the output pulse (10b) of the first monostable multivibrator α0), and as shown in Figure 2 (
Generate a constant width pulse (12c) as shown in C),
This is input to the gate section OJ.

The blanking signal generator (8) is connected to the video signal input terminal (7).
) generates a pulse (8d) in which the synchronizing signal component in the video signal inputted to the video signal is at a low level and the other period is at a high level, and outputs it to the gate section (13). This pulse (8d
) is at ^ level corresponds to a video signal period during one horizontal detention period. *f131 opens the gate only during the period when the output pulse (12C) of the second monostable multivibrator (121) is at a high level, and outputs the output pulse (8d) of the blanking generator (8), that is, as shown in FIG. The pulse (14e) shown in E) is output to the switch (141).The waveform of the output pulse (14e) from this gate section (13) is a specific horizontal period within one vertical period (three horizontal periods in the figure). This shows that the pulse is at the cylinder level, and this pulse (1
4e) is added to the original video signal in the adder (15) via the switch (141), and then added to the original video signal in the white clip circuit (16).
) and a signal processing section (2) for display on a CRT (1). In other words, when observed on a CRT (11), a signal corresponding to the high level amplitude of the upper n pulse (14e) appears in a bamboo horizontal period (3 horizontal periods) superimposed on the original video signal.

Now, when the waveform amplitude of the pulse (14e) is set to the white level of the video signal l1viilf, a white line signal is displayed horizontally on the CRT (11).At this time, the white clip circuit (16) This is to prevent the signal added in ) from exceeding the white level of the video signal amplitude.

Figure 3 shows the horizontal line signal obtained in this way.
The figure observed on T fli is shown. In Figure 3, CRT
(1) The horizontal line signal (171) displayed above is transmitted to the CRT (171) by operating the pulse width variable section (11).
It can be freely moved up and down. Still, the horizontal line signal (line width of 171 is monostable multivibrator)
It can be arbitrarily set by changing the width of the output pulse (12c) of 21. That is, the above CRT (
No matter where there is a part where it is easy to confirm horizontal equality on 11,
The horizontal position of the subject can be easily adjusted by simply moving the horizontal line signal (171).

In the above embodiment, the horizontal line signal (171) is
(1) The above display method and line signal movement method were explained using a circuit using a monostable multivibrator.
This is shown as an example for explanation, and other signal processing circuits may be used to display horizontal line signals, and vertical line signals may also be generated in a similar manner. Modifications are readily available to those skilled in the art. Therefore, it is clear that such other modification means are also included within the scope of the technical idea of the present invention.

〔Effect of the invention〕

As described above, according to the present invention, since a line signal that can be moved from the outside is inserted onto the CRT,
It is possible to provide an electronic viewfinder for a video camera that allows easy confirmation of the horizontal and vertical inclinations of a subject image on a CRT.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an electronic viewfinder according to an embodiment of the present invention, FIG. 2 is a signal waveform diagram of each part of the electronic viewfinder of FIG. 1, and FIG. 3 is a horizontal line on a CRT of the electronic viewfinder of the present invention. FIG. 4 is a diagram illustrating a conventional method of displaying vertical and horizontal positions of an electronic viewfinder of a video camera. In the figure, (1) is a CRT, (2) is a signal processing unit, (
5) is the object, (171 is the horizontal line signal, (ioo)
is a means of creating a line ↑. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (4)

[Claims] (1) A signal processing means that receives a video signal from a video camera and displays the image of the subject on a cathode ray tube, and receives the video signal and creates a line signal that can be moved vertically or horizontally by external operation. An electronic viewfinder for a video camera, comprising a line signal generating means for superimposing the line signal on the image of the cathode ray tube and displaying the line signal. (2) The electronic viewfinder for a video camera according to claim 1, wherein the line signal is a horizontal line signal. (3) The electronic viewfinder for a video camera according to claim 1, wherein the line signal is a vertical line signal. (4) The electronic viewfinder for a video camera according to claim 1, wherein the line signal is two signals, a horizontal line signal and a vertical line signal.