JPH04304780A - Telecamera - Google Patents

Abstract

PURPOSE:To observe the surrounding of a pattern area of an output video signal with a view finder. CONSTITUTION:A picture memory 2 stored by 2 fields of a high resolution video signal Si digitized by an A/D converter circuit 1 alternately for each field. An NTSC encoder 3 converts a signal read from an area of the picture memory corresponding to the middle part of the pattern area of the high resolution video signal into an NTSC television signal. On the other hand, an NTSC encoder 5 converts a signal read from the picture memory corresponding to the pattern area of the high resolution video signal into the NTSC television signal. An addition circuit 6 adds a signal representing a pattern area to an output video signal So of the NTSC encoder 5. A changeover circuit 8 selects either the output video signal So from a D/A converter circuit 4 or a view finder video signal Sv from a D/A converter circuit 7 and displays the selected signal on a view finder 9.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television camera, and more particularly to a television camera having a wide-angle viewfinder function.

0002

2. Description of the Related Art In conventional television cameras, the screen area that can be seen through a viewfinder is output as a video signal of the television camera.

0003

Problems to be Solved by the Invention With conventional television cameras, it is not possible to see beyond the screen area of the viewfinder. For this reason, when operating a television camera to perform pan shots, tilt shots, zooming, etc., there is a problem in that it is difficult to grasp the surroundings of the screen area and the operations are difficult.

An object of the present invention is to enable the surroundings of the screen area of the output video signal to be viewed through a viewfinder;
To provide a television camera convenient for operating the television camera.

[0005]

[Means for solving the problem] 1 of the imaged screen area
An A-D conversion circuit that converts a high-resolution video signal whose frame consists of two fields into a digital signal, an image memory that stores two fields of the digital signal alternately for each field, and a first readout means for alternately reading out the digital signal corresponding to the output area field by field from the image memory; and a first readout means for converting the digital signal read by the first readout means into a standard television signal. an encoder; a first D-A conversion circuit that converts the signal from the first encoder into an analog signal and sends it out as an output video signal;
a second readout means for alternately reading out the digital signal corresponding to the screen area field by field from the image memory; and a second readout means for converting the digital signal read by the second readout means into a standard television signal. encoder, an additional circuit that adds a signal indicating the output area to the signal from the second encoder, and a second D-A that converts the signal from the additional circuit into an analog signal and sends it out as a viewfinder signal. It is configured to include a conversion circuit, a switching circuit that selects one of the output video signal and the viewfinder signal, and a viewfinder that displays the signal selected by the switching circuit.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, in which a high-resolution image pickup tube (not shown) is used to capture images that are vertically and horizontally larger than the screen area of the video signal output from the television camera. An input terminal 11 receives a high-resolution video signal Si obtained by photographing a twice as wide area.

[0008] The video signal Si is a high-resolution signal in which one frame has two fields with the same frame synchronization as the NTSC system, and is converted into a digital signal by the A/D conversion circuit 1 and written into the image memory 2. The image memory 2 has memory addresses corresponding to each pixel of the high-resolution imaging screen, and stores two fields worth of signals so as to correspond to the screen. Furthermore, the stored signals are sequentially updated frame by frame.

[0009] Here, a case will be explained in which the length of the high-resolution imaging screen area is 1/2 both vertically and horizontally, and the central part of the screen area is output as an output video signal. The signals of each field are alternately written into the image memory 2, and the NTSC
Read out sequentially at the scanning speed of the method. In this case, the area from which signals are read from the image memory 2 is a central area that is half the length and width of the entire screen area, as shown in FIG. The signal read out from the image memory 2 in this way is
The signal is sent to the NTSC encoder 3 and converted into an NTSC television signal, further converted into an analog signal by the D/A conversion circuit 4, and outputted from the output terminal 12 as an NTSC output video signal So.

On the other hand, in order to view the entire area of the high-resolution imaging screen on the viewfinder 9, each field is alternately read from the signals of the fields already written in the image memory 2.
The entire area is read every other horizontal line at 1/2 of the write clock speed in accordance with the scanning speed of the C method. The signal of the entire area of the high resolution screen read out in this way is NT
After being converted into an NTSC television signal by the SC encoder 5, an output area adding circuit 6 adds a signal indicating the screen area of the output video signal. Thereafter, it is converted into an analog signal by the D/A conversion circuit 7 and output as a viewfinder video signal Sv. The viewfinder video signal Sv and the output video signal So are selected by the switching circuit 8 and sent to the viewfinder 9.

The viewfinder 9 displays a screen of a selected video signal from among the viewfinder video signal Sv of the entire area of the high-resolution imaging screen and the output video signal So output from the television camera. teeth,
A part of the imaged screen is enlarged to make the entire screen, but since the image pickup tube has a high resolution, the resolution of the image does not drop significantly compared to a general television camera.

0012

As explained above, the present invention stores a high-resolution video signal in which one frame consists of two fields in an image memory for two fields alternately for each field. The video signals of the central output area, which is narrower than the imaging screen area, are read out alternately field by field and used as output video signals, while the video signals of the high-resolution imaging screen area stored in the image memory are read out alternately field by field. By adding a signal indicating the output area to this read signal and displaying it on the viewfinder, you can see the surroundings of the screen area of the output video signal on the viewfinder, so it is possible to see the surroundings of the screen area of the output video signal. This is convenient for performing operations such as shooting or zooming.

[Brief explanation of drawings]

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

FIG. 2 is a diagram showing a screen area of an output video signal of this embodiment.

[Explanation of symbols]

1 A/D conversion circuit 2 Image memory 3,5 NTSC encoder 4,7 D/A conversion circuit 6 Output area addition circuit 8 Switching circuit 9 Viewfinder

Claims (1)

[Claims] [Claim 1] One frame of the imaged screen area is 2
an A-D conversion circuit that converts a high-resolution video signal consisting of fields into a digital signal; an image memory that stores two fields of the digital signal alternately for each field; and an output area in the center that is narrower than the screen area. a first readout means for alternately reading out the corresponding digital signals field by field from the image memory; a first encoder for converting the digital signals read by the first readout means into a standard television signal; A first D-A conversion circuit converts the signal from the first encoder into an analog signal and sends it out as an output video signal; a second readout means for outputting the digital signal; a second encoder for converting the digital signal read by the second readout means into a standard television signal;
an additional circuit that adds a signal indicating the output area to the signal from the encoder; and a second circuit that converts the signal from the additional circuit into an analog signal and sends it out as a viewfinder signal.
A television camera comprising: a D-A conversion circuit; a switching circuit that selects one of the output video signal and the viewfinder signal; and a viewfinder that displays the signal selected by the switching circuit. .