JPH0638096A - Video camera - Google Patents

Abstract

PURPOSE:To provide video signals with small blur even at the time of being out of focus. CONSTITUTION:This apparatus is provided with an out-of-focus signal processing circuit 8 and at the time of being out of focus, it is corrected by emphasizing the contour of the video signal while controlling an aperture correcting circuit 4. Therefore, since the contour of the video signal is emphasized even at the time of being out of focus at the video camera, there are effects such as reducing the feeling of blur in the camera output video signal and easily confirming an object or setting an angle of view.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera, and more particularly to a video camera which can obtain good image quality without blur even when the video camera is out of focus.

[0002]

2. Description of the Related Art A conventional device is disclosed in Japanese Patent Laid-Open No. 63-30358.
As described in No. 6, there is a method of recording defocus information on a tape with a VTR, reading the defocus information from the tape at the time of reproduction, and controlling a reproduction video signal processing circuit of the VTR.

[0003]

However, the above-mentioned prior art aims at controlling the playback image quality of the VTR,
No consideration was given to the image quality of the video signal output from the camera.

It is an object of the present invention to obtain a good camera output video signal with less blur by controlling the aperture correction circuit by the focus shift detection circuit even when the focus is shifted.

[0005]

The above object can be achieved by detecting a focus shift by a focus shift detection circuit, converting it into a voltage value change or a pulse width change, and controlling an aperture correction circuit.

[0006]

The focus shift detection circuit detects the focus shift and sends a voltage value or a pulse proportional to the shift amount to the aperture correction circuit. The aperture correction circuit changes the aperture amount of the video signal by changing the voltage value or the pulse width sent from the focus shift detection circuit. When the focus shift amount is large, the aperture correction amount is large, that is, the outline emphasis amount is large, and when the shift amount is small, the correction amount is small and the blurring is small even before the focus is focused. A video signal is obtained.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. In FIG. 1, the imaging light that has passed through the lens 1 passes through the imaging element 2, the AGC circuit 3, and the aperture correction circuit 4, and is output as a video signal by the camera signal processing circuit 5. On the other hand, the sensor 10 obtains the focus information when the image is taken by the camera, and sends this information to the focus shift detection circuit 7. The focus shift detection circuit 7 controls the focus motor 9 based on the focus shift information 11, and the focus motor 9 controls the focus mechanism 7 of the lens 1 to focus. Further, the focus shift information 11 is sent to the focus shift signal processing circuit 8, converted into a voltage value change or a pulse width change, etc., and input to the aperture correction circuit 4. The amount by which the contour of the video signal from the AGC circuit 3 is emphasized is changed by changing the voltage value or changing the pulse width.

For example, when the focus shift amount is large, the output voltage value from the focus shift signal processing circuit 8 becomes high, the contour is emphasized, and when the focus is in focus,
If the output voltage value from the focus signal processing circuit 8 is 0V and the amount of edge enhancement by the aperture correction circuit 4 is also 0, a camera output video signal with less blurring can be obtained even when the focus is deviated. .

[0009]

According to the present invention, the aperture correction circuit can be controlled by the amount of focus shift to enhance the contour of the video signal, so that an image quality with less blurring can be obtained. In particular, in a camera having an autofocus function, the feeling of blurring of the screen until autofocus is achieved is reduced, so that it is possible to easily confirm the subject and set the angle of view.

[Brief description of drawings]

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

[Explanation of symbols]

1 ... Lens, 2 ... Image sensor, 3 ... AGC circuit, 4 ... Aperture correction circuit, 5 ... Camera signal processing circuit, 6 ... Focus mechanism, 7 ... Defocus detection device, 8 ... Defocus signal processing circuit, 9 ... Focus Motor, 10
... sensor, 11 ... defocus information.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hiromasa Yamamoto 292 Yoshida-cho, Totsuka-ku, Yokohama Hitachi, Ltd. Image Information System (72) Inventor Masashi Homuraite 292 Yoshida-cho, Totsuka-ku, Yokohama Hitachi, Ltd. In the image information system

Claims (1)

[Claims] 1. A video camera capable of continuously changing the focal length of a lens, comprising a focus shift signal processing circuit, wherein the focus shift signal processing circuit is an aperture correction circuit until focus is achieved. Hideo camera characterized by controlling.