JPH11284905A - Electronic aperture for color camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent baking and discoloration of a CCD color filter for a CCD camera, easily faded by light by reducing direct rays of the sun incident onto a camera and to avoid the deterioration of quality of a video signal even at a dark place at night. SOLUTION: An electronic aperture 4 consisting of an liquid crystal display device LCD is placed in front of a lens 3 and a CCD 1 with a color filter 2 is located at a focal point of the lens 3, a photo sensor signal voltage control circuit 6a controls a signal representing the intensity of a light received by a photo sensor 10 to adjust a transmitted quantity of light by the electronic aperture 4. In the daytime, the photo sensor 10 receives a sufficient light, and the photo sensor signal voltage control circuit 6a applies a voltage to the electronic aperture 4 to activate the electronic aperture 4 (a state of limiting light). Thus, the sunlight is reduced to prevent baking and discoloration of a color filter 2 of the CCD 1. At night, the photo sensor 10 receives weak light and the application of voltage from the photo sensor signal voltage control circuit 6a to the electronic aperture 4 is almost lost, then the electronic aperture 4 is open (a state of easily passing light) and an object is brightly photographed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic aperture device for a color camera used for a color camera such as a TV door phone, and more particularly to an electronic aperture device for a color camera for electronically controlling an aperture.

[0002]

2. Description of the Related Art FIGS. 5 and 6 show the prior art.
A CCD 1 having a color filter 2 is disposed at a position where the filter 9 and the lens 3 are focused. The CCD 1 is connected to a video signal processing circuit 13 b and connected to the parent monitor 5 via a transmission line 12. Base unit video signal processing circuit 13 connected to transmission line 12 in monitor base unit 5
“c” is connected to the LCD monitor 14 and the power supply 15.

Now, when the power supply 15 is turned on, C
The subject image formed on the CD 1 is output to the video signal processing circuit 1.
The image is displayed on the LCD monitor 14 via the transmission line 3b, the transmission line 12, and the parent device video signal processing circuit 13c. When strong light 7 such as direct sunlight in the daylight enters, the ND filter 9 has a function of limiting the amount of light by a certain amount, and can reduce the burn-in of the color filter 2 to some extent. However, if the amount of transmitted light is too limited, the image quality when the light is weak, such as at night, is deteriorated. It is used at about / 4.

[0004]

A simple color camera used for a conventional TV door phone or the like has no mechanical lens aperture, always uses the lens aperture open, and constantly emits light even when the camera is not used. Is irradiated on the color filter 2 of the CCD 1.

Therefore, when direct sunlight enters due to the installation condition, the sunlight focuses on the CCD 1 surface, and the image of the sun is reflected on the CCD 1 for a long time as if condensed by a magnifying glass, causing the color filter 2 to burn. . In addition, the color is changed by long-time exposure. As a result, a locus of burn-in on the screen of the LCD monitor 14 and discoloration of the entire screen occur.

In order to solve the problem, conventionally, an ND filter 9 capable of uniformly reducing light transmission with respect to the wavelength of light is provided on the front surface of the lens 3 to prevent the color filter 2 from burning. However, the attenuation of light in the ND filter 9 affects the image performance at night, and the usability is not good.

The present invention has been made in order to solve the above-mentioned drawbacks. In the daytime, the aperture is automatically increased in accordance with the brightness to prevent burn-in and discoloration of the CCD color filter 2 by sunlight, and Automatically opens the aperture,
It is an object of the present invention to provide an electronic aperture device for a color camera that can display an image well even when it is dark.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, an electronic aperture device for a color camera according to the present invention is an electronic aperture device for a color camera of a camera subunit having a CCD having a color filter and a lens. A light sensor that senses the intensity of light, a light sensor signal voltage control circuit that controls a signal from the light sensor, and an electronic diaphragm that operates by receiving a voltage from the light sensor signal voltage control circuit. It is characterized by the following.

An electronic aperture device for a color camera of a camera subunit including a CCD having a color filter and a lens, comprising: a solar cell receiving light to generate a voltage; and a solar cell controlling a signal from the solar cell. A signal voltage control circuit;
An electronic aperture which operates by receiving a voltage from a solar cell signal voltage control circuit is provided.

According to this electronic aperture device for a color camera, the intensity signal of the light received by the optical sensor is controlled by the optical sensor signal voltage control circuit to control the amount of light transmitted through the electronic aperture, and the light is transmitted to the CCD surface. It is possible to always provide the optimal light amount.

Further, by controlling the intensity signal of the light received by the solar cell by the solar cell signal voltage control circuit and controlling the amount of light transmitted through the electronic aperture, an optimal amount of light can always be given to the CCD surface. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electronic aperture device for a color camera according to the present invention will be described with reference to the drawings showing an embodiment.

FIGS. 1 and 2 show an embodiment of the present invention. A camera slave unit 8 is connected to a monitor master unit 5 via a transmission line 12, and a power supply 15 is connected to a circuit in the monitor master unit 5. Power is supplied to the circuit in the camera slave unit 8. LCD (liquid crystal) on the front of the camera lens 3 in the camera slave unit 8
A CCD 1 having a color filter 2 is disposed at a position where a focus of a lens 3 is formed.
Denotes an electronic aperture 4 connected to the video signal control processing circuit 13a.
Is connected to the optical sensor signal voltage control circuit 6a, and the optical sensor signal voltage control circuit 6a is connected to the optical sensor 10 and the video signal control processing circuit 13a. The video signal control processing circuit 13a receives a signal from the power supply 15 in the monitor base unit 5
A current is supplied via the master unit video signal processing circuit 13 c and the transmission line 12.
The LCD monitor 14 is connected to c. As shown in FIG. 2, the optical sensor 10 is always installed in a place where light is easily received.

The optical sensor signal voltage control circuit 6a controls the amount of light transmitted through the electronic diaphragm 4 according to the intensity of light from the optical sensor 10. In the case of strong light, the electronic aperture 4 suppresses the amount of transmitted light, and in the case of weak light, it functions to increase the amount of transmitted light.

Now, when strong light such as the direct sunlight of the sun enters, a voltage is applied to the electronic diaphragm 4 by the optical sensor signal voltage control circuit 6a based on a signal caught by the optical sensor 10 to transmit light. Keep the amount. With this, CCD
Prevents burn-in and discoloration of the color filter 2 provided on one surface. Conversely, when the light at night is weak, the light applied to the optical sensor 10 is weak and the voltage applied from the optical sensor signal voltage control circuit 6a to the electronic diaphragm 4 is weak, so that the amount of transmitted light increases. In this way, a beautiful image can be stably displayed on the screen of the LCD monitor 14 in the monitor base unit 5 when the light is strong or weak.

FIG. 3 and FIG. 4 show another embodiment of the present invention.
An electronic aperture 4 made of an LCD (liquid crystal) is arranged at a position where the lens 3 is focused, and a CCD 1 having a color filter 2 is arranged. The CCD 1 is connected to a video signal processing circuit 13b.
The electronic aperture 4 is connected to a solar cell signal voltage control circuit 6b, and the solar cell signal voltage control circuit 6b is connected to a solar cell 11. The video signal processing circuit 13b is connected to the parent device video signal processing circuit 13c via the transmission line 12, and the parent device video signal processing circuit 13c has an LCD monitor 1
4. Power supply 15 is connected. As shown in FIG. 4, the solar cell 11 is installed in a place where light is easily received.

The solar cell 11 supplies a voltage to the solar cell signal voltage control circuit 6b according to the intensity of light. The solar cell signal voltage control circuit 6b applies the voltage to the electronic aperture 4, and controls the amount of transmitted light. In the case of strong light, the electronic aperture 4 suppresses the amount of transmitted light, and in the case of weak light, it functions to increase the amount of transmitted light.

When a strong light such as the direct sunlight of the sun enters, a voltage generated by the solar cell 11 is applied to the electronic aperture 4 via the solar cell signal voltage control circuit 6b, and a light transmission amount is obtained. Hold down. This prevents burn-in and discoloration of the color filter 2 provided on the CCD 1 surface. Conversely, when the light at night is weak, the voltage generated by the solar cell 11 is weak and the voltage applied to the electronic aperture 4 from the solar cell signal voltage control circuit 6b is almost zero, and the amount of light transmitted through the electronic aperture 4 is increased. .

In this manner, a beautiful image can be stably displayed on the screen of the LCD monitor 14 in the main monitor unit 5 when the light is strong or weak.

[0020]

As is apparent from the above description, according to the electronic aperture device for a color camera according to the present invention, in the daytime when light is strong, the CCD color filter of the door phone color camera is burned in by the sunlight and discolored. Can be prevented, and since the aperture is open at night, the subject can be displayed bright even in a dark place. Also, depending on the light intensity in the daytime, the electronic aperture can be optimized to always produce a beautiful image in any light condition.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of an electronic aperture device for a color camera according to the present invention.

FIG. 2 is an external view showing an electronic aperture device for a color camera according to the present invention.

FIG. 3 is a configuration diagram showing another embodiment of an electronic aperture device for a color camera according to the present invention.

FIG. 4 is an external view showing another embodiment of the electronic aperture device for a color camera according to the present invention.

FIG. 5 is a configuration diagram showing a camera slave unit having a conventional color camera.

FIG. 6 is an external view showing a camera subunit having a conventional color camera.

[Explanation of symbols]

 1 ... CCD 2 ... Color filter 3 ... Lens 4 ... Electronic aperture 6a ... Optical sensor signal voltage control circuit 6b ... Solar cell signal voltage control circuit 8 Camera slave unit 10 Optical sensor 11 Solar cell

Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 9/04 H04N 9/04 B

Claims (2)

[Claims] 1. A CCD having a color filter (2)
An electronic aperture device for a color camera of a camera slave unit (8) including (1) and a lens (3), wherein an optical sensor (10) for detecting the intensity of light and a signal from the optical sensor are controlled. An electronic aperture device for a color camera, comprising: an optical sensor signal voltage control circuit (6a); and an electronic aperture (4) that operates by receiving a voltage from the optical sensor signal voltage control circuit. 2. A CCD having a color filter (2).
An electronic aperture device for a color camera of a camera slave unit (8) including (1) and a lens (3), wherein the solar cell (11) receives light and generates a voltage, and controls a signal from the solar cell. An electronic aperture device for a color camera, comprising: a solar cell signal voltage control circuit (6b); and an electronic aperture (4) that operates by receiving a voltage from the solar cell signal voltage control circuit.