JPH05244489A - Picture display device - Google Patents

Abstract

PURPOSE:To obtain an easy to see pattern even when the pattern is magnified. CONSTITUTION:A zoom area brightness measurement section 9 measures the brightness of an area to be magnified only in the entire pattern and controls an iris 2 of an image pickup section 1 based on the measured value, that is, when the brightness of the picture element of the magnified area is high, the iris 2 is stopped and when the brightness is lower, the iris 2 is opened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device used for a television intercom, a surveillance camera, etc., and relates to a brightness adjustment of a display screen.

[0002]

2. Description of the Related Art An image display device of this type displays a video signal picked up by an image pickup unit such as a television camera by a television camera or the like, and may have a zoom function. In other words, when enlarging and displaying a part of the screen, the video signal is digitized, and the part of the entire screen that is desired to be enlarged is cut out and enlarged.

Here, the brightness of the display screen is adjusted by obtaining an average value of the analog values of the brightness of all the imaged pixels inside the imaging section and controlling the iris based on this value. .

[0004]

However, in such an image display device, since the iris is controlled based on the brightness of the pixels in the entire image pickup area, a part of the screen is enlarged (zoomed). In this case, if there is a large difference in brightness between the entire image pickup area and the zoom area, there is a problem that the screen becomes difficult to see.

The present invention has been made in view of the above points, and it is an object of the present invention to provide an image display device in which an easy-to-see screen can be obtained even when a screen enlargement operation is performed. is there.

[0006]

SUMMARY OF THE INVENTION The present invention measures the luminance of an enlarged area in an image display device having a zoom function for enlarging a part of the screen while displaying a video signal picked up by an image pickup section. It is characterized in that a zoom area luminance measuring section for controlling and an iris control section for controlling the iris according to the measured luminance of the zoom area are added.

[0007]

In the image display device of the present invention, the zoom area luminance measuring section measures the luminance of only the enlarged area of the entire screen, and the iris of the image pickup section is controlled based on this measured value. Yes, that is, the iris is narrowed down when the brightness of the pixels in the enlarged region is high, and the iris is opened when the brightness is low.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, in which 1 is an image pickup unit including a television camera,
The captured image is output as a video signal.

Reference numeral 2 denotes an iris provided in the image pickup unit 1 for limiting the amount of light incident on the image pickup unit 2, and inside the image pickup unit 1, the brightness of all the imaged pixels or the pixels of the representative points. The average of the analog values is calculated, and the amount of diaphragm is controlled based on this average, and the amount of diaphragm is preferentially controlled by a control signal from an iris control unit described later.

Reference numeral 3 denotes an A / D conversion unit, which A / D converts the video signal in the video signal output from the image pickup unit 1 and outputs it as digital image data. Reference numeral 4 denotes a sync separation unit that separates and outputs only horizontal and vertical sync signals in the video signal.

A video memory 5 is an A / D converter 3
The image data output from the memory is stored in accordance with the sync signal from the sync separator 4.

Reference numeral 6 is a D / A converter, which is a video memory 5.
The D / A conversion of the image data stored in is output as an analog video signal. Reference numeral 7 denotes a monitor television, which displays a video signal on the screen.

Reference numeral 8 denotes a zoom unit for enlarging a part of the entire image. Of the image data stored in the video memory 5, the data of the region to be enlarged is extracted, interpolation calculation is performed, and the result is D / A. It is sent to the conversion unit 6. The D / A converter 6 D / A converts this signal, and the monitor TV 7 displays the enlarged image.

Further, the zoom section 8 sends the digital value of the luminance of each pixel of the area to be enlarged (zoom area) or the pixel of the representative point to the zoom area luminance measuring section described later.

Reference numeral 9 denotes a zoom area brightness measuring section, which measures the brightness of the zoom area by integrating the brightness of the zoom area output from the zoom section 8 and calculating an average value.

An iris control unit 10 outputs a control signal for controlling the iris 2 in accordance with the brightness value of the zoom area output from the zoom area brightness measuring unit 9. That is, when the brightness value of the zoom area is large, the iris 2 is narrowed so that the incident light amount is small, and when the brightness value is small, the diaphragm of the iris 2 is opened so that the incident light amount is large.

Therefore, according to the present embodiment, for example, when the brightness of the entire imaged screen is low and a large amount of incident light is made incident by the iris 2, the brightness of the screen is relatively high. When a part (zoom area) is enlarged, the iris is preferentially controlled according to the brightness of the zoom area, so that the zoom screen is displayed in an easily viewable state.

[0019]

As described above, according to the image display device of the present invention, the zoom partial luminance measuring unit allows
The brightness of only the area to be enlarged is measured, and the iris of the imaging unit is controlled based on this measurement value. That is, when the brightness of the pixels in the expanded area is high, the iris is narrowed down, and when the brightness is low, the iris is opened. Thus, it is possible to provide an image display device in which the screen is easy to see even when the screen is enlarged.

[Brief description of drawings]

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

[Explanation of symbols]

 1 Imaging Unit 2 Iris 3 A / D Converter 4 Sync Separation Unit 5 Video Memory 6 D / A Converter 7 Monitor Television 8 Zoom Unit 9 Zoom Area Luminance Measurement Unit 10 Iris Control Unit

Claims (1)

[Claims] 1. A zoom area luminance measuring section for measuring the luminance of an area to be enlarged in an image display device having a zoom function for enlarging a part of the screen while displaying a video signal imaged by the imaging section on the screen, An image display device comprising an iris control unit for controlling an iris according to the measured brightness of a zoom area.