JPS6267971A - Video camera - Google Patents

Abstract

PURPOSE:To focus on an object even when the object is at any places in a video by providing a means for generating a frame gate pulse making a vertical and horizontal drive pulse of a camera circuit an input and a means for varying the pulse. CONSTITUTION:A frame gate generating circuit 5 generates a predetermined frame gate signal as a vertical and horizontal drive pulse input source of a camera circuit, and clearly indicates a focusing range in a part of outputs of a video signal processing circuit 4, for instance, only in A of a view finder screen as shown in a figure. At this time, the gate signal of the circuit 5 is made variable by a gate signal variable circuit 9. In this case, even if the circuit 9 is manually operated, according to an output of an object distance detecting means and a focal distance detecting means, a gate variable setting may be automatically performed.

Description

[Detailed description of the invention] Industrial applications TECHNICAL FIELD The present invention relates to video cameras.

2. Description of the Related Art In conventional video cameras, a technique is known in which a fixed image frame is provided in an electronic viewfinder to clearly indicate a focus range. (For example, Japanese Unexamined Patent Application Publication No. 58-40982) 2. Problems to be Solved by the Invention However, in this case, since the area, or image frame, of the clearly focused point is fixed, there is always a problem with the video output. The drawback is that the phone can only be adjusted to a certain position and size.

The present invention eliminates these drawbacks and makes it possible to change the position and size of the focus area (ie, the size of the image frame) depending on the subject.

Means for Solving the Problems The present invention provides means for varying the frame gate pulse when the frame gate pulse is generated by inputting the vertical drive pulse and the horizontal drive puff 1/s of the camera circuit. .

Therefore, no matter where the subject is in the image, the subject can be easily out of focus.

Embodiment The following is a description of an embodiment of the present invention shown in the drawings. In Figure 1, 1
is a lens, 2 is an autofocus device that automatically moves the lens according to the position of the subject, 3 is an imaging device, 4 is a video signal processing circuit, 5 is a frame gate generation circuit, and 6 is an addition circuit. , 7 is the NTSC signal output terminal, 8
9 is an output terminal to the electronic viewfinder, and 9 is a gate signal variable circuit.

In this configuration, the frame gate generation circuit 5 generates a predetermined frame gate signal corresponding to the vertical drive pulse and horizontal drive pulse input sources of the camera circuit, and generates a part of the output of the video signal processing circuit 4, for example, the second frame gate signal. The focus range can be clearly indicated only within A in the viewfinder screen shown in the figure.

This point is no different from the conventional one, but in the present invention, the gate signal of the frame gate generation circuit 5 can be varied by the gate signal variable circuit 9. In this case, the same circuit 9
Even if it is done manually, as shown in FIG.
Circuit 1 that performs gate variable settings from the outputs of 0 and 11
2 may be provided to automatically set the gate signal variable circuit 9. Alternatively, it may be possible to switch between manual and automatic modes.

Therefore, it is possible to change the position and size of the frame, that is, the image frame, depending on the subject.

Effects of the Invention As described above with reference to the embodiments, according to the present invention, it is possible to easily focus on the subject no matter where the subject is in the video.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a main part of a video camera according to an embodiment of the present invention, FIG. 2 is a diagram showing a viewfinder screen, and FIG. 3 is a block diagram of main parts of another embodiment. Frame game 1. Generation circuit, 9. Gate signal variable circuit.

Claims (2)

[Claims] (1) Input the vertical and horizontal drive pulses of the camera circuit,
A video camera provided with a circuit for generating a frame gate signal to an electronic viewfinder and means for arbitrarily varying the frame gate area. (2) The video camera according to claim 1, wherein the variable means is at least either manual or automatic based on subject distance and lens focal length information.