JPH0430785B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a camera having a zooming function for causing a viewfinder of the camera to perform special imaging.

According to a camera having a zooming function, for example, a television camera having a zooming function by making full use of a microcomputer, the field of view (range) of the subject image on the screen can be variably controlled by changing the zoom position. Furthermore, during photographing, the image of the subject is displayed on the viewfinder, and the photographer can perform zoom photographing while viewing this.

However, with a conventional television camera having a zooming function, it is not possible to know the screen range at the most telephoto end on the viewfinder when zooming other than at the most telephoto end (zooming in). Therefore, there was a drawback that the screen range of the subject image at the maximum telephoto end had to be determined solely by experience and intuition at the time of shooting.

The present invention has been made in order to overcome the drawbacks of the prior art, and provides a camera with a zooming function that allows a photographer to easily and in advance recognize the screen range at the most telephoto end during zooming. With the goal.

In order to achieve the above object, the present invention provides a display means for displaying the screen range at the most telephoto end of a zoom lens superimposed on the field of view, and a display means for displaying the screen range at the most telephoto end that is displayed by this display means. and a variable means that changes according to zooming of the lens.

As a result, the present invention displays the subject image on the viewfinder during zooming, detects the zoom position at that time, determines the screen range at the most telephoto end based on this, and then superimposes the subject image on the viewfinder to obtain the maximum image. To provide a camera having a zooming function that displays the screen range at the telephoto end.

An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram of an embodiment of a display device according to the present invention. This embodiment includes a mixer 1, a viewfinder 2, a microcomputer 3, a display selection switch 4, and a gate circuit 5.
It is equipped with In this embodiment, the display means:
The viewfinder 2 is a variable means that includes a mixer 1, a microcomputer 3, a display selection switch 4, and a gate circuit 5.

In this embodiment, a video signal a from a television camera relating to a subject image obtained through a zoom lens (not shown) is supplied to a viewfinder 2 via a mixer 1, where it is displayed as a subject image. Further, a vertical synchronization signal b and a horizontal synchronization signal c emitted from a control circuit of a television camera (not shown) and a zoom position signal d as information corresponding to a zoomed-in image emitted from a zoom lens detection device (not shown) are given to the microcomputer 3. . Here, the microcomputer 3 has a storage means for storing in advance the screen range of the viewfinder 2 at the most telephoto end corresponding to the zoom position, and is operated by switching the display selection switch 4 operated by the photographer. Further, the microcomputer 3 uses the zoom-in field of view setting means to output a signal related to the scanning range of the electron beam corresponding to the screen range at the most telephoto end as an output permission signal e, and outputs a signal related to the scanning range of the electron beam corresponding to the screen range at the farthest telephoto end as an output permission signal e. Give it to the input terminal.

A setting signal f for displaying the screen range at the most telephoto end, which is generated from a control circuit (not shown), is applied to the other input terminal of the gate circuit 5. and,
The gate circuit 5 passes the setting signal f within the range set by the output permission signal e, and supplies it to the mixer 1 as a zoom-in display signal g. Since the mixer 1 mixes the video signal a of the television camera and the zoom-in display signal g, the viewfinder 2 displays the screen range at the most telephoto end superimposed on the subject image.

2 to 3 are explanatory diagrams of the display on the viewfinder 2, and FIG. Figure b shows the display state of the viewfinder at the highest TV end.
FIG. 3 shows how the electron beam is scanned in FIG. 2a. In FIG. 3, the horizontal scanning line is n,
When the scanning time is t, the four vertices of the rectangular screen range B are (n ₁ , t ₁ ), (n ₁ , t ₂ ), (n ₂ ,
t ₁ ) and (n ₂ , t ₂ ). In this way, in order to display the screen range at the most telephoto end,
It can be seen that the zoom-in display signal g must be applied to the mixer 1 only during the scanning time t ₁ -t ₂ for the horizontal scanning lines n ₁ -n ₂ . Therefore, it can be seen that the output permission signal e given from the microcomputer 3 to the gate circuit 5 must be limited to the scanning time period _t1 to _t2 for the horizontal scanning lines _n1 to _n2 .

FIG. 4 is a flow chart of the operation of the microcomputer 3. First, when the control program starts, the zoom position signal d is read (block 100), is counted in correspondence with the pre-stored information regarding the screen range at the most telephoto end, and is calculated from the horizontal scanning lines n ₁ , n ₂ and horizontal scanning. Calculate times t ₁ and t ₂ (block 200). Then, an output permission signal e is issued within that range (blocks 300 to 5
00). Here, in the relationship between n and t, n is fixed and t varies, and when n=n ₂ and t=t ₂ , the counting is reset (block 600) and the program is repeated.

In this way, in cases other than the highest television position, the screen range at the highest television position can be adjusted to the viewfinder 2.
You can check it here.

As described above, according to the present invention, since the subject image and the screen range at the most telephoto end can be superimposed and displayed on the viewfinder during zooming, the photographer can easily recognize the field of view at the most telephoto end. It is possible to obtain a camera having a zooming function that improves the efficiency of zoom photography and enables zoom photography with high video effects.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of a zoom-in image display device for a television camera according to the present invention, FIGS. 2 and 3 are explanatory diagrams of display in a viewfinder, and FIG. Fig. 2b shows the screen range at the most telephoto end when superimposed on the screen, Fig. 3 shows the screen range on the scanning line, and Fig. 4 shows the microcomputer in Fig. 1. 2 is a flowchart showing an example of the operation. 1... Mixer, 2... Viewfinder, 3...
...Microcomputer (storage means, zoom-in field of view setting means), 5...Gate circuit, a...TV camera video signal, b...Vertical synchronization signal, c...
...Horizontal synchronization signal, g...Zoom-in display signal.

Claims (1)

[Claims] 1. In a camera having a zooming function and equipped with a viewfinder that changes the size of the field of view according to zooming of the zoom lens, the screen range at the most telephoto end of the zoom lens is displayed superimposed on the field of view. 1. A camera having a zooming function, comprising a display means for displaying the following: and a variable means for changing the screen range displayed by the display means at the most telephoto end according to zooming of a zoom lens.