JPH0287876A - Image pickup display device with automatic zooming function - Google Patents

Abstract

PURPOSE:To set a target display size to a prescribed value and to contrive the simplification of an operator's handling operation by deriving a target size being proportional to an image area of a target object to be photographed from a binarization video signal and feeding back a difference between the size and a set target size. CONSTITUTION:A binarization signal of high S/N is obtained by reducing a target monitoring area 18 of the necessary minimum from on a display screen of a TV monitor 5 by a gate circuit 9, and subtracting a threshold voltage from a peak value of a wave-form of the target object by a comparator 14. A target size detecting circuit 15 generates data being proportional to the image area of the target object 7 by counting the total number of '1' of the binarization signal, and feeds it back to a zooming ratio control circuit 12 by aligning an interface so that the difference between the data and data which is set by a target size setting circuit 16 becomes zero. In such a manner, the automatic control of a zooming ratio for holding the area of an image of the target object 7 constant can be realized.

Description

[Detailed Description of the Invention] [Summary] This invention relates to an infrared or visible light imaging display device, and in particular to an imaging display device with an auto-zoom function that continuously displays the display image size of a target subject. The purpose of the present invention is to provide an imaging display device with an auto-zoom function that automatically controls the display size to a constant value, and includes a zoom lens equipped with an automatic focus control circuit and a zoom ratio control circuit, and a zoom lens that focuses the light of a target object on the zoom lens. In an imaging display device comprising a photoelectric conversion section that converts a signal into an electrical signal, a video processing circuit that converts the output of the photoelectric conversion section into a video signal suitable for image display on a TV monitor, and the TV monitor, the video signal is a gate circuit that inputs a signal to set a target monitoring area smaller than the screen of the TV monitor; a peak clamp circuit that captures the peak of the video signal of the target subject from the video signal that has passed through the gate circuit; A threshold voltage generation circuit that generates a signal with a higher level than the noise level included in the video signal is compared with both outputs of the peak clamp circuit and the threshold voltage generation circuit.
a comparator circuit that outputs a binary video signal of OJ; and a comparator circuit that outputs a binary video signal of OJ, and counts the total number of "1"s corresponding to address positions within the target monitoring area from the binary video signal, and the count is proportional to the image area of the target subject. a target size detection circuit that creates data; a target size setting circuit that sets a desired target size within the target monitoring area; and a subtraction circuit that creates a difference between each output of the target size setting circuit and the target size detection circuit. is provided, and the output of the subtraction circuit is configured to be fed back to the zoom ratio control circuit.

[Industrial application field]

The present invention relates to an infrared or visible light image capture and display device, and more particularly to an image capture and display device with an auto-zoom function that displays a constant display image size of a target object in m series.

[Conventional technology]

FIG. 3 shows a block diagram of the main parts of a conventional imaging display device.

In the figure, a zoom lens is equipped with an automatic focus control circuit 11 and a zoom ratio control circuit 12. The automatic focus control circuit 11 is manufactured by Tokuko Sho 62-5555, Tokuko Sho 62-
38663, the correlation tracking method disclosed in Japanese Patent Publication No. 62-49587, etc. can be used. Alternatively, the patent application No. 63-84446 r, dated April 5, 1986, proposed that it could be realized by an even simpler means.
In other words, a necessary tracking window is set in the center of the screen of the TV monitor, and the image of the subject is tracked and captured within the area of the tracking window and projected.

The zoom ratio control circuit 12 operates the zoom mechanism manually or in response to the value of the input manual zoom control signal.

It is electrically driven and adjusts the size of the subject image on the screen of the TV monitor to a desired value.

Reference numeral 2 denotes a photoelectric conversion unit that converts the optical signal of the target object focused by the zoom lens 1 into an electric signal. It consists of an imaging optical system, a one-dimensional multi-element detector, etc. 3 is an amplifier that amplifies the electrical signal output from the photoelectric conversion section; 4 is a video processing circuit that converts the output of the amplifier into a video signal suitable for image display on the TV monitor 5; and 7 is a synchronization signal generation circuit that supplies each section. show. 7 is a target object captured by the zoom lens 1.

The function of controlling the zoom ratio of the zoom lens 1 using the zoom ratio control circuit 12 is an operation that is controlled manually or electrically by the observer while visually observing the size of the target subject displayed on the screen of the TV monitor 5. Loop servo systems are known.

[Problem to be solved by the invention]

When the target subject 7 moves vertically and horizontally with respect to the optical axis of the zoom lens l, there is a known technology that automatically tracks and captures the subject image near the center of the TV monitor. When moving while changing the distance to a target object, only manual control means have been developed to control the display size of the target object on the display screen of the TV monitor 5 to a substantially constant value. The downside is that you can't take your eyes off the image because it isn't.

The present invention has been made in view of the above-mentioned drawbacks of the conventional art, and it is an object of the present invention to provide an imaging display device with an auto-zoom function that automatically controls the display size of a target object on a display screen to be constant.

[Means to solve the problem]

FIG. 1 is a block diagram showing the configuration of the present invention. A zoom lens 1 including an automatic focus control circuit 11 and a zoom ratio control circuit 12, a photoelectric conversion section 2 that converts an optical signal of a target subject 7 focused by the zoom lens 1 into an electrical signal, and the photoelectric conversion section 2 In an imaging display device comprising the TV monitor 5 and a video processing circuit 4 that converts the output of a gate circuit 9 that sets a monitoring area; and a peak clamp circuit 10 that captures the peak of the video signal of the target subject 7 from the video signal that has passed through the gate circuit 9.
and a threshold voltage generation circuit 1 that generates a signal with a higher level than the noise level included in the video signal of the target subject 7.
3 and the outputs of the peak clamp circuit 10 and the threshold voltage generation circuit 13 are compared to determine rlJ rOJ.
a comparator circuit 14 that outputs a binary video signal, and a comparator circuit 14 that counts the total number of "1"s corresponding to address positions within the target monitoring area from the binary video signal and is proportional to the image area of the target subject 7. a target size detection circuit 15 that generates data for the target size, a target size setting circuit 16 that sets a desired target size within the target monitoring area, and a difference between the outputs of the target size setting circuit 16 and the target size detection circuit 15; The zoom ratio control circuit 12 is configured by feeding back the output of the subtraction circuit 17 to the zoom ratio control circuit 12.

[For production]

The operation will be explained with reference to the principle diagram shown in FIG. By using the gate circuit 9, it is possible to narrow down the necessary minimum target monitoring area 18 from the display screen 5a of the TV monitor 5 to avoid misrecognition of the target. A binarized signal with a high S/H is obtained by subtracting the threshold voltage vb from the peak value Va of the waveform 7b of the target object via the peak clamp circuit 10 in the comparison circuit 14, and the target size detection circuit 15 By counting the total number of "1"s corresponding to the address positions in the video signal scanning period t in the target monitoring area 18 of the digitized signal, data proportional to the image area of the target subject 7 can be recorded. Therefore, the difference between this data and the desired setting data set by the target size setting circuit 16 is calculated by the subtraction circuit 17, and the interface is adjusted so that the value of this difference becomes zero, and the data is sent to the zoom ratio control circuit 12. By giving feedback, the image 7a of the target subject 7
Automatic control to maintain the area constant, that is, automatic control of the zoom ratio in the imaging display device becomes possible.

(Example〕 Embodiments of the present invention will be described in detail below with reference to the drawings.

Note that, in order to make the explanation of the configuration and operation easier to understand, the same parts are given the same reference numerals throughout all the figures, and repeated explanation thereof will be omitted.

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

In the figure, a signal processor 8 that branches and inputs the video signal output from the video processing circuit 4 includes a gate circuit 9, a peak clamp circuit 10, a threshold voltage generation circuit 13, a comparison circuit 14, and a target size detection circuit 15. It consists of

Furthermore, the configuration is such that the output of a subtraction circuit 17 that creates a difference between the output of the signal processor 8 and the output of the target size setting circuit 16 becomes an auto-zoom command signal.

FIG. 2 is a diagram explaining the principle of the present invention, in which FIG. 2(a) is an example of an image of the target subject displayed on the screen of the TV monitor 5 in FIG. 1, and FIG. ) shows a waveform diagram of each part corresponding to an image example. Please refer to Figure 2 below.
Explain the diagram.

FIG. 2 (5a shown in al is the display screen of the TV monitor 5, 1
Reference numeral 8 denotes a target monitoring area smaller than the display screen 5a of the TV monitor 5 formed by the gate circuit 9 (same as the tracking window described in the automatic focus control circuit 11), in which the image 7a of the target subject 7 is placed in the center of the screen. The target display size and position can be changed in a cursor-like frame to make it easier to limit the target area. Reference numeral 19 indicates one of the scanning lines that crosses the image 7a of the target subject 7, and the waveform corresponding to this scanning line 19 is shown as waveform p in FIG. 2(b).

The waveform p is a video signal waveform corresponding to the scanning line 19 outputted by the video processing circuit 4, and includes the waveform 7b of the target subject 7 at the center. t is the video signal scanning period within the target monitoring area. The peak value Va indicates the peak value of the target subject waveform 7b, and the peak value vb indicates the output of the threshold voltage generation circuit 13. That is, the peak clamp circuit 10
Corresponding to the target subject waveform 7b captured within the video signal scanning period within the target monitoring area, the peak value vb of the threshold voltage that occurs continuously during the output period is near the waveform of the target subject waveform 7b. is set higher than the noise level.

The waveform q is the output waveform of the comparator circuit 14 and has "0" and "1".
It is binarized into . That is, when the peak value Va is higher than the peak value vb input to the comparison circuit 14, the comparison circuit 14 outputs "1", and when it is lower, it outputs "0". As a result, confusing video signals near the noise level are cuffed, and only the video signal of the target subject 7 with a sufficiently high S/N ratio can be selected.

The target size detection circuit 15 detects "1" corresponding to the address position within the target monitoring area 16 from this binary waveform q.
Digital data corresponding to the area of the target object image 7a can be obtained by counting the number of , and summing each count for all vertical scanning lines using the output of the synchronization signal generating circuit 6.

16 is a target size setting circuit, which sets the total number of addresses in the target monitoring area 18 to 50 x 20 = 100, for example.
Then, the set value 25 is 1/4 of the area of the target monitoring area 18.
become. The output of the subtraction circuit 17 that creates a difference between the desired image area set in this way and the output of the target size detection circuit 15 becomes an auto-zoom command signal. Therefore, by adjusting the interface so that the value of this auto-zoom command signal becomes zero and feeding it back to the zoom ratio control circuit 12, the area of the image 7a of the target subject on the target monitoring area 18 becomes the set desired image area. The zoom lens 1 is driven so as to match , and stops at - several points. S indicates a switch for switching to conventional manual zoom control.

Converter, 4 is a video processing circuit, 5 is a TV monitor, 7 is a target subject, 9 is a gate circuit, 10 is a peak clamp circuit, 11 is an automatic focus control circuit, 12 is a zoom ratio control circuit,
13 is a threshold voltage generation circuit, 14 is a comparison circuit, 1
5 is a target size detection circuit, 16 is a target size setting circuit,
Reference numeral 17 indicates a subtraction circuit.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, an auto-zoom function is realized in which the target display size can be set to a constant value, and this has the effect of simplifying operations for the observer.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a diagram illustrating the principle of the present invention, and FIG. 3 is a block diagram of main parts of a conventional imaging display device.

Claims (1)

[Claims] Automatic focus control circuit (11) and zoom ratio control circuit (11)
2), a photoelectric conversion unit (2) that converts the optical signal of the target subject (7) focused by the zoom lens (1) into an electrical signal, and the photoelectric conversion unit (2). ) and a video processing circuit (4) that converts the output of a gate circuit (9) that sets a small target monitoring area; a peak clamp circuit (10) that captures the peak of the video signal of the target object (7) from the video signal that has passed through the gate circuit (9); A threshold voltage generation circuit (
13), a comparison circuit (14) that compares both outputs of the peak clamp circuit (10) and the threshold voltage generation circuit (13) and outputs a binary video signal of "1" and "0"; a target size detection circuit (15) that counts the total number of "1"s corresponding to address positions within the target monitoring area from the binary video signal and generates data proportional to the image area of the target subject 7; A target size setting circuit (16) that sets a desired target size within the monitoring area; and a subtraction circuit (17) that creates a difference between the outputs of the target size setting circuit (16) and the target size detection circuit (15). An image pickup and display device with an auto-zoom function, characterized in that the output of the subtraction circuit (17) is fed back to the zoom ratio control circuit (12).