JPS60120675A - Signal extractor of optical device - Google Patents

Abstract

PURPOSE:To prevent shortage of object information and unnecessary information from being introduced and to improve accuracy such as automatic focusing and automatic photometry. CONSTITUTION:An area-type solid-state image element 11 converts photoelectrically an image projected to an effective light-receiving area by a lens 12, and transmits an output signal as an image signal to an image processing circuit through an amplifier 13. At this moment, a signal extraction area is preset preliminarily in horizontal and vertical clock counters 16 and 17 by an area setting circuit 20, and only when the signal extraction area is scanned, a gate circuit 21 generates a pulse. An output signal from a waveform processing circuit 24 is added to an integrating circuit 25 through an analogue switch 22 only when said signal scans the signal extraction area. The signal is compared with the value which is set in a comparison decision circuit 26, outputted as a focusing signal or a photometry signal, and a moving amount of the lens 12 is calculated. As a result, the lens 12 or a diaphragm is shifted by a motor 29.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a signal for an optical device that extracts a signal from an area that conforms to subject conditions of the solid-state image sensor in an optical device such as a video camera that uses an area-type solid-state image sensor. Regarding the extraction device.

(Conventional technology) Bisicon is the conventional image sensor for video cameras.

Image pickup tubes such as Zachicon have been used, but recently (Yo'f
4 is a video camera that is compact and has high reliability 1/, I: by using an area 9 active single image sensor such as l'r, JT & i combined element, photo diode array, etc.
7 is now being served.

On the other hand, solid-state image sensors are easily self-scanning by external clock pulses.

Various methods have been proposed for performing automatic focusing or automatic aperture control by directly obtaining a focusing signal or a photometric signal from a video signal from a fixed area.

However, in all of these methods, the above area is fixed 1+
As a result, the frequency of malfunctions was extremely high. For example, lenses used in video cameras usually have 4 to 3
Although the zoom lens is 0 times, when shooting a subject at a close distance and wide-angle, the subject is almost within the area of the screen, whereas when shooting a subject at a wide-angle distance, the subject only takes up a part of the screen. Therefore, if the area is fixed, only part of the subject information will be used for focusing and photometry, which may cause malfunctions. That is, when wide-angle photography is performed at a close distance, subject information is insufficient, and when wide-angle photography is performed at a long distance, difficult information is mixed in.

(Purpose) The present invention is a signal extraction device for optical equipment that extracts signals in accordance with subject conditions.
The purpose of D is to provide a device that can prevent malfunctions of 1111J light and the like.

(Structure) The present invention will be described in detail with reference to the μ lower mold surface.

To summarize, the principle of the present invention is based on the principle that the subject is always located in the center of the image when photographed using an optical device such as a video camera. )＼ and change it.

Figure 2 shows an example of a reliable extraction area according to the present invention. Necessary and sufficient subject information can be obtained by setting narrow area 2, which is the extraction area.Here is the signal extraction area, 2 is solid]@The center is the same as the effective light receiving area 3 of the image element, and the effective light receiving area is Area: The signal extraction area will be varied depending on the subject conditions with the center of the fish as a reference.

The relationship between the subject condition and the signal extraction area is generally uniquely determined by the subject distance and imaging magnification, and this can be converted into the moving distance of the photographing lens. The distance to the subject and the imaging magnification are calculated by sequential inspection, and as a result, an appropriate signal extraction area is determined.

FIG. 1 shows an embodiment of the civil engineering invention.

For the area-wide solid-state image sensor layered in the video camera, the image projected onto the effective light-receiving area 3 by lens j2 is scanned, photoelectrically converted, and output in time series. The output signal of this solid-state image sensor [ ] is amplified by an amplifier J3.

It is sent to the video processing circuit as a video signal. The solid-state image sensor j is driven by the clock pulses generated by the timing generation circuit 14 at a drive frequency of ff63.5 and performs self-scanning. Pulse V is horizontal clock counter 6° vertical clock counter j
7 is counted as 1. This horizontal clock counter 16,
@, Direct clock counter j7 and Tijikuru combination
/-Evening 18:39 A preset value corresponding to the signal extraction area is preset from the IJA setting circuit 20.''1.
6. Digital comparators J8 and 19 are horizontal clock counters. By comparing the printing number of vertical clock counter J7 with Briceratoy 1o, the self-scanning for the solid-state image sensor is condensed in the horizontal and vertical directions.
It is detected whether or not it is being performed within the code extraction area. Kate circuit 2J (Mati/tal comparator 38, 19
A pulse is generated at scan 1 of the signal extraction area by ANDing the output signals of the analog switch 22.
Vc is added.

On the other hand, the displacement of the lens J2 is detected by the lens state detection circuit 23K.
Signal extraction is performed by setting the area setting circuit 2 (the output signal of the lens state detection circuit 23, subject distance and scanning rate). For example, set the area to one of the areas 1 and 2 according to the subject conditions, and set the preset value corresponding to the signal extraction area to the horizontal clock counter 16. The 1° waveform processing circuit 24 connected to the vertical clock counter/7° tee/tal comparators 18 and 19 is composed of a differentiating circuit, a detection circuit, etc., and converts the video signal from the amplifier 3 into a form that is easy to process. . The output signal of this waveform processing circuit 24 passes through the analog switch 22 when the υ signal extraction area is scanned by the output pulse of the gate circuit 21, so that only the signal from the signal extraction area is extracted and integrated by the integration circuit 25. Ru. Comparison judgment image i'? i26 compares the output signal of the integrating circuit 25 with a previous value or a predetermined value, outputs a focusing signal or a photometry signal, and outputs a movement amount calculation circuit 27.
divides the amount of movement of the lens 12 or the amount of movement of the diaphragm by the output signal of the comparison/judgment circuit 26. A motor drive circuit 28 drives a motor 29 based on the output signal of the moving claw trace 9 circuit 27 to move the lens 2 or the diaphragm. At this time, if the subject conditions change, the position of the lens 2 also changes, so the signal extraction area changes according to the above operation, and accurate focusing or vertical illumination is always performed.

(Effects) As described above, according to the present invention, the signal extraction area can be adjusted to the subject condition in optical equipment such as a video camera.
], it is possible to prevent the lack of subject information or the incorporation of unnecessary information, and it is possible to prevent automatic focusing or self-focusing.
(When using II light, etc., the accuracy can be improved and malfunctions can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing an example of a signal extraction area in the present invention. J6...Horizontal clock counter, 37...-j7i
: i72 clock counter, )8, J9...T7tal converter 1/-ta, 20...Area setting circuit,
2"...Gate circuit, 22...Analog switch, 2
: Two-lens state (output circuit.

Claims (1)

[Claims] 1. An optical device having an area-type solid-state image pickup device that scans a subject image and converts it into a video signal. A signal extracting device for an optical device, comprising means for changing an object line (/l) by i, iJ at l1ji with the center of the element as a reference.