JP2000236478A - Electronic camera device - Google Patents

Abstract

(57) [Problem] To provide an electronic shutter speed in pixel units in accordance with the amount of incident light in a situation where a subject becomes unclear due to backlight, simultaneous indoor / outdoor shooting, and the like.
It is an object of the present invention to provide an electronic camera device capable of obtaining a proper exposure over the entire screen. A video signal output from a MOS type solid-state imaging device via a digital signal processing circuit is analyzed by an incident light amount analyzing circuit to detect an incident light amount, and the light amount is in a saturated state (or a certain threshold or more). An electronic camera device in which the timing controller 7 controls the electronic shutter speed of the MOS type solid-state imaging device 3 for pixels to be short, and controls the other pixels to be long for other pixels.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electronic camera apparatus that performs exposure control using an output signal of a MOS solid-state imaging device.

[0002]

2. Description of the Related Art A conventional electronic camera apparatus automatically adjusts the brightness of an image by changing the shutter speed of an electronic shutter in accordance with the brightness of a subject under backlighting, simultaneous indoor / outdoor shooting, and the like. Exposure adjustment was performed for the entire image. Hereinafter, the configuration and operation will be described with reference to the drawings.

[0003] As shown in FIG. 4, the electronic camera device includes a lens 1, an aperture 2, a solid-state image sensor 3, an analog signal processing circuit 4, an A / D converter 5, and a digital signal processing circuit 6. And a timing controller 7 having an electronic shutter function.

A video signal output from the solid-state image sensor 3 via the analog signal processing circuit 4 is applied to the entire image according to the amount of incident light of the entire image by a timing controller 7 having an electronic shutter function. Control of the electronic shutter speed.

When the solid-state imaging device 3 is a CCD type solid-state imaging device, the exposure start and end times are the same for all pixels for batch resetting and batch reading. In addition, the conventional M
The timing control of the OS-type solid-state imaging device has different exposure start and end times, but the exposure time is the same for all pixels.

[0006]

In such a conventional electronic camera device, in a backlight, simultaneous indoor / outdoor photographing state,
When shooting at a long electronic shutter speed for indoor shooting, the outdoor image becomes saturated, and the image becomes a white-out image as shown in FIG. In addition, if the electronic shutter speed is shot with a short electronic shutter speed for outdoor shooting, the interior will be underexposed, resulting in an image in which the interior is blackened out as shown in FIG. Therefore, there has been a case where proper exposure cannot be obtained over the entire screen.

The present invention has been made in consideration of the above conventional problems, and has
This is an electronic camera device that performs exposure control using the output signal of a solid-state image sensor, and can obtain proper exposure over the entire screen in situations where the subject is unclear due to backlight, simultaneous indoor / outdoor shooting, etc. It is intended to be.

[0008]

In order to achieve the above object, the present invention analyzes the incident light amount of a video signal output from a MOS type solid-state imaging device via a signal processing circuit for each pixel, and the light amount is saturated. For a pixel having a certain threshold value or more), the timing controller adjusts the interval between the reset pulse and the readout pulse for each pixel, determines the exposure time, and controls the electronic shutter speed. .

According to the electronic camera device of the present invention, a proper exposure can be obtained over the entire screen by simultaneously securing and combining signals of long and short shutter speeds in one field by timing control of the MOS solid-state image pickup device. It is possible. For example, in simultaneous indoor and outdoor shooting, the indoor image portion is shot with long exposure (shutter speed: long) and the outdoor image portion is shot with short exposure (shutter speed: short) using the same aperture value. And by combining both images, it is possible to realize gradation from indoor to outdoor, and it is possible to expand the dynamic range, that is, under the situation where the subject becomes unclear due to backlight, simultaneous indoor and outdoor shooting, etc. It is possible to obtain proper exposure over the entire screen.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, a MOS solid-state imaging device for photoelectrically converting imaging light from a subject and a video signal output from the MOS solid-state imaging device are processed. A signal processing circuit, an incident light amount analyzing circuit for analyzing an incident light amount of a video signal passing through the signal processing circuit, and a timing controller for controlling an electronic shutter speed of a predetermined pixel based on an analysis result by the incident light amount analyzing circuit. An electronic camera device having the function of controlling the electronic shutter speed for each pixel.

According to a second aspect of the present invention, in the electronic camera device according to the first aspect, the timing controller includes an electronic shutter for a pixel or a block whose incident light amount is in a saturated state (or a certain threshold or more). The speed is controlled to be short and the other pixels are controlled to be long, and has an effect that the electronic shutter speed can be controlled for a pixel or a block in which the incident light amount is saturated (or a certain threshold or more). .

According to a third aspect of the present invention, in the electronic camera device according to the first aspect, the timing controller is configured to control an electronic camera in an arbitrary area designated in a subject situation where an output image is unnatural. The shutter speed is controlled to be short and the other pixels are controlled to be long, so that the electronic shutter speed of a specified arbitrary area can be controlled under the subject situation where the output image is unnatural. Having.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram of an electronic camera device according to Embodiment 1 of the present invention, and FIG. 2 is a diagram showing control of an electronic shutter speed for each pixel in an indoor / outdoor simultaneous shooting state by the electronic camera device. It is explanatory drawing of the imaging example which performed and corrected.
In the drawings, the same components as those of the conventional example are shown in FIG.
The same reference numerals as in the conventional example shown in FIG.

As shown in FIG. 1, the electronic camera device according to the first embodiment has a lens 1, an aperture 2, a MOS solid-state image pickup device 3 into which image pickup light from a subject enters, and a MOS solid-state image pickup device. An analog signal processing circuit 4 to which an electric signal (video signal) photoelectrically converted by the analog signal 3 is input and subjected to analog processing such as AGC (auto gain control), CDS (correlated double sampling), and gamma; A / D converter 5 for A / D (analog / digital) conversion of the output of signal processing circuit 4, digital signal processing circuit 6 for performing digital signal processing, and incident light amount analyzing circuit 8 for analyzing the incident light amount for each pixel And a timing controller 7 for outputting a predetermined timing.

The operation of the electronic camera device according to the first embodiment will be described below with reference to FIGS.

The imaging light from the subject, which has entered through the lens 1 and the aperture 2, is photoelectrically converted by the MOS type solid-state imaging device 3 and is subjected to AGC (auto gain control), CDS (correlation) by the analog signal processing circuit 4. Analog processing such as double sampling) and gamma is performed. The output of the analog signal processing circuit 4 is output as an image via the A / D converter 5, while the incident light amount analyzing circuit 8 analyzes the incident light amount on a pixel basis, and the light amount is in a saturated state (or a certain threshold or more). For the pixel, the timing controller 7
, The interval between the reset pulse and the read pulse for each pixel of the MOS solid-state imaging device 3 is adjusted, and a predetermined timing is output so as to shorten the exposure time.

By controlling the shutter speed for each pixel, an image in which the electronic shutter speed is long and the outdoors are overexposed, or an image in which the electronic shutter speed is short and the indoors are crushed in the black, as shown in FIG. ,
Appropriate exposure is obtained over the entire screen, and a clear image can be obtained.

In the first embodiment, the output from the digital signal processing circuit 6 is fed back to the incident light quantity analyzing circuit 8, but the output of the analog signal processing circuit 4 is input to the incident light quantity analyzing circuit 8. You may.

(Embodiment 2) FIG. 3 is a block diagram of an electronic camera apparatus according to Embodiment 2 of the present invention.

In the electronic camera device according to the second embodiment, under the control of the electronic camera device according to the first embodiment, an arbitrary region for controlling the electronic shutter speed can be set under a subject situation where the output image is unnatural. Area specification circuit 1
0 is provided.

Hereinafter, the operation of the electronic camera device according to the second embodiment will be described with reference to FIG. Lens 1, aperture 2
The image pickup light from the subject incident through the device is photoelectrically converted by the MOS type solid-state image pickup device 3 and is converted into an analog signal processing circuit 4.
AGC (auto gain control), C
Analog processing such as DS (correlated double sampling) and gamma is performed. The output of the analog signal processing circuit 4 is A / D
While the image is output via the converter 5, the incident light amount analysis circuit 8 analyzes the incident light amount on a pixel-by-pixel basis. The interval between the reset pulse and the read pulse for each pixel of the element 3 is adjusted, and a predetermined timing is output so as to shorten the exposure time. In a situation where the output image is unnatural in this state, the switch 9 is switched to the area designating circuit 10, and the timing controller 7 controls the pixels of the MOS solid-state imaging device 3 for an arbitrary area designated by the area designating circuit 10. The interval between each reset pulse and read pulse is adjusted, and a predetermined timing is output so as to shorten the exposure time.

The electronic camera device according to the second embodiment is different from the electronic camera device according to the first embodiment in that when an image becomes unnatural due to shutter speed control for each pixel, the electronic camera is manually designated to specify an area. By controlling the shutter speed, a natural image can be obtained with proper exposure over the entire screen.

[0024]

As is apparent from the above description, according to the present invention, in a scene where a wide dynamic range is required, such as backlighting, simultaneous indoor / outdoor photographing, etc., the electronic shutter speed can be set in pixel units according to the amount of incident light. Since control is performed, it is possible to realize an electronic camera device that obtains appropriate exposure over the entire screen.

[Brief description of the drawings]

FIG. 1 is a block diagram of an electronic camera device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of an example of imaging by the electronic camera device.

FIG. 3 is a block diagram of an electronic camera device according to a second embodiment of the present invention.

FIG. 4 is a block diagram of a conventional electronic camera device.

FIG. 5 is an explanatory view of an example of an image of an overexposure in the outdoor in a state where the electronic camera device is simultaneously photographing indoors and outdoors.

FIG. 6 is an explanatory diagram of an example of an image of an indoor blackout in an indoor / outdoor simultaneous shooting state by the electronic camera device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lens 2 Aperture 3 MOS type solid-state image sensor 4 Analog signal processing circuit 5 A / D converter 6 Digital signal processing circuit 7 Timing controller 8 Incident light amount analysis circuit 9 Switch 10 Area designation circuit

Claims (3)

[Claims] 1. A MOS for photoelectrically converting imaging light from a subject.
A solid-state imaging device, a signal processing circuit for processing a video signal output from the MOS solid-state imaging device, an incident light amount analysis circuit for analyzing an incident light amount of the video signal passing through the signal processing circuit, and the incident light amount An electronic camera device comprising: a timing controller that controls an electronic shutter speed of a predetermined pixel based on an analysis result by an analysis circuit. 2. The system according to claim 1, wherein the timing controller controls the electronic shutter speed to be shorter for pixels or blocks in which the amount of incident light is saturated (or higher than a certain threshold value), and to be longer for other pixels. Electronic camera device. 3. The timing controller according to claim 1, wherein the electronic shutter speed of the designated arbitrary area is shortened and the other pixels are lengthened under an object situation where the output image is unnatural. An electronic camera device according to claim 1.