JPS6282777A - Wipe operation display device in video camera - Google Patents

Abstract

PURPOSE:To facilitate the setting of layout of an object by providing a wipe operation circuit controlling the switching of a gate properly in response to the wiping and a signal changeover circuit using its output signal as a view finder signal. CONSTITUTION:A wipe operation circuit 1 has a gate circuit 2 inputting a camera video signal S1 and a gate signal generating circuit 3 receiving a wiping start trigger so as to give a control pulse S2 controlling the switching of a gate circuit 2 to the gate circuit 2. The output signal of the gate circuit 2 is given to a VTR as a wipe output signal S3 and given as one input of a signal changeover circuit 4 and the camera video signal S1 is given as the other input of the signal changeover circuit 4. The signal changeover circuit 4 is subjected to alternate changeover control by the line changeover pulse S4 of the frequency set to, e.g., 1/2 of the horizontal scanning frequency and the output signal is given as the view finder signal S5. Thus, the setting of layout of the object is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention provides a wipe operation in which the image of the subject, which is originally hidden by the wipe operation, is displayed faintly in the viewfinder when performing a wipe operation when shooting with a video camera. The present invention relates to a wipe operation display device for a video camera that facilitates photographing with the video camera even when the video camera is in operation.

(Prior Art) In recent years, with the spread of video cameras, cameras equipped with various special effects have been proposed and implemented. One of them has a wipe function. This wipe operation includes a wipe-in operation and a wipe-out operation.

An example of the wipe-in operation is shown in FIG. 6(a). In this operation, a white, black, or color curtain is first displayed on the entire screen for 2 to 3 seconds (10 to 5 seconds if title characters are included), as shown in FIG. 1 (a-1). Next, the same figure (a-
As shown in 2), the subject image appears from the center of the screen. Furthermore, as time passes, the display area of the subject image expands to the left and right as shown in Figure (a-3), and in about 3 to 4 seconds, the entire subject image is displayed on the screen as shown in Figure (a-4). appear. In this way, the wipe operation effectively reveals the subject image on the screen.

Next, an example of wipeout operation is shown in FIG. 6(b). At the start of the wipeout operation, the subject image appears on the entire screen, as shown in FIG. 1 (b-1).

Then, as shown in (b-2) and (b-3) of the same figure, the curtain is gradually drawn from both ends of the screen toward the center, and finally, as shown in (b-4> of the same figure), The subject image is erased from the screen. In this way, the wipeout operation effectively erases the subject image from the screen.

However, in conventional devices of this type, during a wipe operation, an image appears in the viewfinder that is the same as the image recorded on a video tape recorder as shown in FIG. Therefore, when the curtain is drawn inside the viewfinder, the subject image in that area becomes invisible to the photographer, so the conventional device has a problem in that it is difficult to set the composition of the subject during the wipe operation.

(Object of the Invention) The present invention has been made in view of the above circumstances, and it is possible to confirm the subject image in the viewfinder even during the wiping operation, thereby making it easy to set the composition of the subject. An object of the present invention is to provide a wipe operation display device in a video camera.

(Structure of the Invention) In order to achieve such an object, the present invention includes a wipe operation circuit that includes a gate into which a camera video signal is input, and that controls opening and closing of the gate as appropriate in accordance with the wipe operation;
A signal that inputs the camera video signal and the wipe output signal of the wipe operation circuit separately, performs a switching operation every predetermined number of horizontal scans, outputs the two signals alternately, and uses the output signal as a viewfinder signal. It is characterized by being equipped with a switching circuit.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings. FIG. 1 is a block diagram schematically showing the configuration of a wipe operation display device in a video camera according to an embodiment of the present invention.

In the figure, a wipe operation circuit 1 includes a gate circuit 2 that inputs a camera video signal S1, and upon receiving a wipe operation start trigger, provides a control pulse S2 for controlling opening and closing of the gate circuit 1 to the gate circuit 2. and a gate signal generation circuit 3. The output signal of the gate circuit 2 is sent to a video tape recorder (V
TR) and as one input of the signal switching circuit 4. Further, the camera video signal Sl is applied as the other input of the signal switching circuit 4. The signal switching circuit 4 has a horizontal scanning frequency of 1, for example.
Switching is controlled alternately by a line switching pulse S4 having a frequency set to /2, and the output signal thereof is provided as a viewfinder signal S5.

Next, a case where this embodiment performs a wipe-in operation will be described.

Now, a camera video signal Sl as shown in FIG. 2(a) is applied from a video camera to one input terminal of the gate circuit 2 and the signal switching circuit 4. On the other hand, the gate signal generation circuit 3 is given a wipe operation start trigger, and at a predetermined time (for example, between 2 to 3 seconds) at the start of the wipe-in operation, the gate signal generation circuit 3 generates the camera video signal as shown in FIG. A control pulse S2 is applied to the gate circuit 2 to block all signals. As a result, as shown in FIG.
A wipe output signal S3 with no black level (for example, black level) is output to the video tape recorder. Therefore, the image recorded on the video tape recorder at this time is as shown in FIG.
-1).

At this time, the control terminal of the switching circuit 4 is connected to the control terminal shown in FIG.
) A line switching pulse S4 having a frequency of 1/2 of the horizontal scanning frequency is applied. This results in
Since the contacts of the signal switching circuit 4 are switched every horizontal scan, the signal switching circuit 4 outputs a viewfinder signal S5 in which the camera video signal appears every horizontal scan as shown in FIG. 2(e). . Therefore, a thin object image as shown in FIG. 5(a) appears throughout the viewfinder at this time.

When a certain period of time has elapsed from the start of the wipe-in operation, the gate signal generation circuit 3 outputs a control pulse S2 as shown in FIG. , a wipe output signal S3 on which only the center portion of the camera video signal is superimposed is output to the video tape recorder and the signal switching circuit 4. Therefore, the image recorded on the video tape recorder at this time is as shown in FIG. 6(a-2). On the other hand, the switching circuit 4 switches between the wipe output signal S3 and the camera video signal S.
1 is output every horizontal scan, so the viewfinder signal S5 at this time becomes as shown in FIG. 2(h).

Therefore, as shown in FIG. 5(b), the viewfinder displays an image of the subject that is dark in the center and light in other areas.

Then, when the gate circuit 2 is controlled so that the proportion of the video signal passing through the gate circuit 2 increases with the passage of time, the wipe output signal S3 is generated in the third wave from the start to the end of the wipe-in operation. The images change as shown in Figures (a) to (d), and the recorded images at this time are Figures 6 (a-1) to (a-1).
(a-4). At this time, the viewfinder signal S5 changes as shown in FIGS. 4(a) to (d), so the subject image displayed on the viewfinder changes as shown in FIGS. 5(a) to (d). .

On the other hand, during the wipeout operation, the wipe output signal changes as shown in FIG. 3(d) to FIG. 3(a), and the viewfinder signal S
5 changes from FIG. 4(d) to FIG. 4(a). Therefore, the image recorded on the videotape recorder at this time will be as shown in Figure 6(b), and the subject image in the viewfinder will change from Figure 5(d) to as shown in Figure 5(a). do.

In addition, in the above-mentioned embodiment, the case where the wipe operation is performed in the horizontal direction from the center of the screen is taken as an example and explained. However, the present invention is not limited to this, and may be applied to cases where the wipe operation is performed from one end of the screen or when the wipe operation is performed in the vertical direction of the screen.

Furthermore, in the description of the embodiment, the switching circuit 4 is switched every horizontal scan, but it goes without saying that the switching circuit 4 may be switched every two or more horizontal scans.

(Effects of the Invention) As described above, the wipe operation display device for a video camera according to the present invention converts the synthesized signal obtained by switching the camera video signal and the wipe output signal every predetermined number of horizontal scans into a viewfinder signal. It is said that

Therefore, according to the present invention, the photographer who is operating the video camera can check the entire image of the subject as well as the state of the wipe operation in the viewfinder, and therefore can easily set the composition of the subject. I can do it.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the outline of the configuration of a wipe operation display device in a video camera according to an embodiment of the present invention, FIG. 2 is an operation waveform diagram of the embodiment shown in FIG. 1, and FIG. 3 is an illustration of the present invention. Waveform diagram showing changes in the wipe output signal in the example, No. 4
The figure is a waveform diagram showing changes in the viewfinder signal in this embodiment, Figure 5 is an explanatory diagram of the subject image in the viewfinder during a wipe operation obtained by this embodiment,
The figure is an explanatory diagram of the wipe operation. l... Wipe operation circuit, 2... Gate circuit, 3...
・Gate signal generation circuit. 4...Signal switching circuit.

Claims (1)

[Claims] (1) A wipe operation circuit that includes a gate that inputs a camera video signal and controls opening and closing of the gate as appropriate according to the wipe operation, and a wipe operation circuit that separately inputs the camera video signal and the wipe output signal of the wipe operation circuit. A wipe operation display device for a video camera, comprising: a signal switching circuit that performs a switching operation every predetermined number of horizontal scans to alternately output both of the signals, and uses the output signal as a viewfinder signal. .