JPH11205805A - Color camera entrance slave set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color camera entrance slave set that baking of a color filter is prevented in both standby and operation states and no effect is imposed on a color characteristic of a photographed image without deteriorating the photographic sensitivity when photographing at night. SOLUTION: This color camera entrance slave set consists of a camera cover 11, a lens unit 12 and a color filter unit 13 having an optical low-pass filter 13d, and a color CCD image-pickup element 14 having a color filter 14a, and a filter 13c the transmittivity of which is changed with a luminous quantity is inserted to a front side of the color filter 14 for preventing baking of the color filter 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color camera entrance device, and more particularly, to a color camera entrance device employing a gray color tone flat glass as a color filter.

[0002]

2. Description of the Related Art Conventionally, a color filter unit 53 has a shutter 53a and a neutral density filter 5 as shown in FIG.
3b and an optical low-pass filter 53d. The light beam that has passed through the camera cover 51 converges through a lens unit 52 and a color filter unit 53 and forms an image on a color CCD image sensor 54. At this time shutter 5
3a is a color filter 54 of the color CCD image pickup device at the time of standby.
a, and the darkening filter 53b prevents image sticking during operation.

[0003]

By the way, the color CC
The color filter of the D image sensor is very weak against strong sunlight, and with the conventional color camera filter configuration, the burn-in of the color filter due to sunlight during standby can be prevented by the shutter, It is difficult to completely prevent the seizure of the color filter by using only the neutral density filter. In addition, since the dimming filter is always on, there is a problem in that the imaging sensitivity is reduced during nighttime imaging and image deterioration is caused. The present invention has been made in order to eliminate the above-described conventional disadvantages, prevents the color filter from burning during standby and operation, and does not reduce the imaging sensitivity during nighttime imaging. It is an object of the present invention to provide a color camera entrance cordless handset that does not affect the color camera.

[0004]

SUMMARY OF THE INVENTION A color camera entrance apparatus according to the present invention comprises a camera cover, a lens unit, a color filter unit having an optical low-pass filter, and a color CCD image pickup device having a color filter. In the slave unit, a filter 13c whose transmittance changes according to the amount of light is inserted in front of the color filter to prevent image sticking of the color filter.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a color camera front-end device according to the present invention will be described in detail with reference to the drawings. The configuration of the color camera entrance device 1 of the present invention is a configuration in which a gray color dimming flat glass 13c whose degree of dimming increases in accordance with an increase in the intensity of sunlight is inserted into the color filter unit 13, As shown in FIG. 1, the gray color tone flat glass 13c is inserted between the lens unit 13 and the optical low-pass filter 13d, and is configured so that the sunlight passes before reaching the color filter 14a. Further, the gray color light control flat glass 13c has a flat shape as shown in FIG. 1 and has a shape which has little influence on the convergent light of the lens unit 13 and has a small influence on the wavelength of light because the gray light control glass is employed. The color characteristics of the imaging screen are not affected. The operation of the color camera entrance device according to the present invention will be described below. At night, the surroundings are dark, so that the light passing through the gray-tone flat glass 13c is weak and the gray-tone flat glass 13c is almost transparent and does not dimm. In this state, the imaging sensitivity is not reduced by the color filter unit 13. . In addition, since the surroundings gradually become brighter during the day, the gray color light control flat glass 13 is used.
As the intensity of the light passing through c increases, the density of the gray color tone flat glass 13c increases and is sufficiently dimmed, so that strong sunlight can be prevented from hitting the color filter 14a of the color CCD image pickup device 14. Burning of the color filter 14a can be completely prevented during operation. However, when the strong sunlight suddenly hits, the density of the gray color light control flat glass 13c cannot follow it, but this is not the case with a color camera entrance device installed outdoors.

[0006]

As is apparent from the above description, according to the color camera entrance device of the present invention, the sticking of the color filter is prevented both during standby and during operation, and the imaging sensitivity is reduced during nighttime imaging. In addition, since the color is gray and the color characteristics of the imaging screen are not affected. In addition, the use of gray-toned flat glass allows the camera to be used as a camera cover to keep visitors from being aware of the camera.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an embodiment of a color camera entrance device of the present invention.

FIG. 2 is a configuration diagram of a conventional color camera entrance terminal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Camera cover 12 ... Lens unit 13 ... Color filter unit 13c ... Filter (gray tone flat glass) 13d ... Optical low-pass filter 14 ... Color CCD image sensor 14a ... Color filter

Claims (1)

[Claims] 1. A color filter unit (13) having a camera cover (11), a lens unit (12), and an optical low-pass filter (13d), and a color filter (1).
4a) a color camera entrance device including a color CCD image pickup device (14), wherein a filter (1) whose transmittance varies depending on the amount of light is provided in front of the color filter.
3c) to prevent image sticking of the color filter.