KR20150072816A - Monitoring camera having infrared cut filter - Google Patents

Abstract

The present invention relates to a monitoring camera having an IR CUT filter, wherein day or night is sensed, and a clear image is photographed by applying an IR CUT filter of a particular wavelength band at night according to a sensed result. The monitoring camera equipped with an IR CUT filter comprises: a day or night determining unit for sensing a day or night change by sensing illuminance, and generating a day or night signal according to a sensed result; a lighting unit lighted by a lighting control signal at night as a sensed result of the day or night determining unit, and extinguished by an extinguishing control signal during the day; a filtering unit for filtering image light inputted from a subject at night according to a sensed result of the day or night determining unit, and passing the image light during the day; a lens for forming an image from the image light passing through the filtering unit; a photographing device for converting the image light injected through the lens into an electrical signal; and a digital signal treating unit for outputting a lighting or extinguishing control signal according to a sensed result of the day and night determining unit, and controlling the operation of the filtering unit. The filter unit includes: an IR CUT filter for filtering the image light in a particular wavelength band at night; and a motor for transferring the IR CUT filter to a particular position to enable the same to perform filtering operation at night by the controlling of the digital signal treating unit, and transferring the same to an original position during the day.

Description

[0001] MONITORING CAMERA HAVING INFRARED CUT FILTER [0002]

The present invention relates to a surveillance camera that captures a clear image by detecting day and night and applying an infrared (infra-red) CUT filter of a specific wavelength band at night according to a detection result.

Generally, CCTV (Closed Circuit Television) is installed in places such as houses, department stores, banks, exhibition halls where security is required for preventing or preventing disasters including intrusion, theft or fire.

In particular, it is difficult to conduct security surveillance by people on business sites, military facilities, public facilities such as border lines, coastline, harbors, and large-scale parking lots. Therefore, Security facilities became necessary.

Accordingly, at least one camera is installed in each of the above-mentioned business sites, public facilities, and borders, and at least one camera is installed in the area to be monitored. Based on the image screen shot by the camera, the intruder detection, theft of the article, Measures to Prevent It is used to record intruders, theft or crime in order to accurately identify the situation.

The apparatus and method for operating the day / night mode of the surveillance and surveillance camera using the brightness measurement of the video signal disclosed in Korean Patent Publication No. 2004-0093887 include a camera for photographing a region to be photographed, A control unit for controlling the overall operation of the camera and determining the daytime mode or the nighttime mode according to the brightness of the object to be imaged inputted from the sensing unit, and for turning off the illumination unit in the daytime mode, And a control unit for generating a control signal for turning on the lighting unit in the night mode and outputting the control signal to the lighting unit; and an illumination unit for turning on and off according to the on / And stores the video signal photographed by the camera, and outputs the stored video signal at the request of the control means Consists of a storage means for the like.

The conventional surveillance camera as described above has high power consumption and light of the lighting means is weak, so that it is difficult to capture a clear image when it is dark. In particular, at night, there is a problem in that it is difficult to capture a clear image because the function of improving the sensitivity of the camera can not be performed by a lighting device (e.g., streetlight, automobile, etc.)

Korean Patent Publication No. 2004-0093887

The technical problem to be solved by the present invention is to provide an IR CUT filter capable of capturing a clearer image by sensing an illuminance to detect day and night and applying an IR CUT filter for passing a specific wavelength at night in accordance with a detection result And a surveillance camera.

According to an aspect of the present invention, there is provided a surveillance camera having an IR CUT filter for sensing a change in day and night by sensing an illuminance and generating a day / night signal according to a detection result; A lighting unit that is turned on by a lighting control signal when the nighttime determination unit detects that it is at night and blinks by a blinking control signal when it is a daytime; A filtering unit for filtering the image light input from the subject at a specific wavelength band in the nighttime according to the detection result of the day / night determination unit and for passing the image light in the case of a week; A lens that forms an image from the image light having passed through the filtering unit; An imaging element for converting the image light incident through the lens into an electrical signal; And a digital signal processor for outputting the on / off control signal to the illumination unit according to the detection result of the day / night determination unit, and controlling the operation of the filtering unit, wherein the filtering unit converts the video light into a specific wavelength band An IR CUT filter; And a motor for transmitting the IR CUT filter to a predetermined position for performing the filtering operation when it is at night under the control of the digital signal processing unit, or for transporting the IR CUT filter to an original position in the daytime.

In the present invention, the IR CUT filter is characterized in that image light between 800 nm and 900 nm wavelength band is passed.

As described above, according to the present invention, it is possible to capture a clearer image by sensing the illuminance to detect day and night, and applying an IR CUT filter that passes a specific wavelength in the nighttime according to the detection result.

1 is a block diagram showing the configuration of a surveillance camera having an IR CUT filter according to an embodiment of the present invention.
FIG. 2 is a view showing a wavelength band through which the IR CUT filter passes in FIG. 1; FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Referring to the accompanying drawings, the same or corresponding components are denoted by the same reference numerals, do.

1 is a block diagram showing the configuration of a surveillance camera having an IR CUT filter according to an embodiment of the present invention.

1, the surveillance camera 100 includes a digital signal processing unit 110, a day / night determination unit 120, an illumination unit 130, a filter unit 140, a motor control unit 150, a zoom lens 160, A focus lens 180, a focus lens driving unit 190, an image pickup device 200, an image pickup device control unit 210, and a video signal processing unit 220, as shown in FIG.

The digital signal processor 110 controls the entire operation of the surveillance camera 100 and outputs a control signal for lighting / blinking the illumination unit 130 according to the day / night determination result of the day / night determination unit 120, 140). The digital signal processing unit 110 controls the operation of the zoom lens driving unit 170, the focus lens driving unit 180 and the imaging device control unit 210 and controls the video signal processing operation of the video signal processing unit 220.

The day / night determination unit 120 senses the illuminance to detect day and night change, and generates a day / night signal according to the detection result and outputs the signal to the digital signal processing unit 110. The day / night determination unit 120 determines that the daytime (daytime mode) when the roughness sensing result is about 4 LUX or more, and determines that it is the nighttime (nighttime mode) when the roughness sensing result is about 4 LUX or less. On the other hand, the surveillance camera 100 is preferably provided with a light sensor (CdS sensor, not shown) to sense the illuminance of the light to determine day and night. Preferably, the photosensor is formed of a CdS photoconductive cell having cadmium sulfide (CdS) as a main component and having an internal resistance variable depending on incident light energy. The larger the energy of the incident light is, the lower the resistance value of the CdS photoconductive cell becomes. That is, when there is no light energy, it is almost close to the insulator, and when the incident energy is received, the internal resistance becomes small corresponding to the incident energy, so that current can be flowed. This feature has the effect of turning off the streetlight or the apartment stairway at night and turning off during the day, and thus the optical sensor of the present invention also applies the principle of this effect. In addition, the day / night determiner 120 may include a separate illuminance sensor (not shown) to determine the day or night from the result of the illumination sensor.

The illumination unit 130 is operated by a lighting control signal or a flicker control signal from the digital signal processing unit 110 and may be constituted by an element such as a light emitting diode (LED), for example. The digital signal processing unit 110 outputs the blinking control signal to the illumination unit 130 so that the illumination unit 130 outputs the blinking control signal to the illumination unit 130. The daylight- 130) is flickered. The digital signal processing unit 110 outputs a lighting control signal to the illumination unit 130 so that the illuminating unit 130 illuminates the illuminating unit 130. [ (130) is turned on. Furthermore, the digital signal processing unit 110 can adjust the blinking and lighting operations of the illumination unit 130 according to day or night conversion within a certain range of the critical point. That is, it is possible to prevent repeated lighting and lighting of the illumination unit 130, which may occur on the critical point, by controlling the lighting unit 130 to be controlled to be equal to or less than a predetermined range of the critical point, .

The filter unit 140 filters the image light input from the subject at a specific wavelength band according to the detection result of the day / night determination unit 130 under the control of the digital signal processing unit 110, . To this end, the filter unit 140 may include an IR CUT filter 141, a filter fixing unit 142, and a motor 143.

The IR CUT filter 141 can filter the image light to a specific wavelength band, that is, between 800 nm and 900 nm wavelength band, as shown in FIG. 2. Further, the IR cut filter 141 can filter the image light at a specific wavelength band, for example, 850 nm, 880 nm, Can be filtered. When the IR CUT filter 141 is positioned at the filter fixing portion 142 by the motor 143, filtering is performed.

The motor control unit 150 operates the motor 143 to turn on the IR CUT filter 141 to the filter fixing unit 142 in accordance with the detection result of the day and night judgment unit 130 under the control of the digital signal processing unit 110, And is returned to the original position from the filter fixing portion 142 in the case of the daytime.

The optical signal from the subject in the daytime or the optical signal filtered by the IR CUT filter 141 in the nighttime reaches the light receiving surface of the imaging element 200 after passing through the zoom lens 160 and the focus lens 180, Is formed. The image formed on the light receiving surface of the image pickup device 200 is converted into an electrical image signal by photoelectric conversion processing.

As the image pickup device 200, a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor Image Sensor) that converts an optical signal into an electric signal can be used. The CMOS image pickup device 200 has low power consumption for capturing a large amount of power for maintaining the power of the surveillance camera 100 and is relatively inexpensive to manufacture so that it is advantageous to make the area of the image pickup device large and easy to mass- Do. The image pickup device 200 as a CCD has a merit that noise generation is much less than that of a CMOS, image information transfer speed is very fast, storage speed is high during continuous shooting, and image quality is excellent.

The position of the zoom lens 160 and the focus lens 180 are controlled by the zoom lens driving unit 170 and the focus lens driving unit 180, respectively. For example, when a wide angle-zoom-out signal is generated, the focal length of the zoom lens 160 is shortened to enlarge the angle of view, and telephoto-zoom (zoom-in) When a signal is generated, the focus distance of the zoom lens 160 becomes longer and the angle of view becomes narrower. Since the position of the focus lens 180 is adjusted in a state where the zoom lens 160 is set, the angle of view is hardly affected by the position of the focus lens 180. [

The zoom lens driving unit 170, the focus lens driving unit 190 and the image pickup device control unit 210 control the corresponding components according to the results calculated by the digital signal processing unit 110 based on exposure information,

Next, a description will be given of the video signal forming process. The video signal outputted from the image pickup device 200 is outputted to the video signal processing section 220. In the video signal processing unit 220, when the video signal inputted from the image pickup device 200 is an analog signal, it is converted into a digital signal, and various kinds of image processing are performed on the converted digital video signal. The video signal subjected to such processing may be temporarily stored in the surveillance camera 100 and then transmitted to a digital video recorder or a network video recorder.

Specifically, the image signal processing unit 220 performs signal processing such as Auto White Balance, Auto Exposure, and Gamma Correction to convert image data according to the human vision, And outputs a video signal of an improved image quality. The signal processor 130 performs image processing such as color filter array interpolation, color matrix, color correction, color enhancement, and the like.

By applying the IR CUT filter which detects the day and night by sensing the illuminance and passes a specific wavelength in the nighttime according to the detection result, a clearer image can be taken.

The present invention has been described above with reference to preferred embodiments. It will be understood by those skilled in the art that the present invention may be embodied in various other forms without departing from the spirit or essential characteristics thereof. Therefore, the above-described embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is indicated by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

110: digital signal processing unit 120: day /
130: illumination part 140: filter part
150: motor control unit 160: zoom lens
170: zoom lens driving unit 180: focus lens
190: focus lens driving unit 200:
210: Imaging element control section 220: Video signal processing section

Claims (2)

A day / night discrimination unit sensing a change in day / night by sensing the illuminance and generating a day / night signal according to the detection result;
A lighting unit that is turned on by a lighting control signal when the nighttime determination unit detects that it is at night and blinks by a blinking control signal when it is a daytime;
A filtering unit for filtering the image light input from the subject at a specific wavelength band in the nighttime according to the detection result of the day / night determination unit and for passing the image light in the case of a week;
A lens that forms an image from the image light having passed through the filtering unit;
An imaging element for converting the image light incident through the lens into an electrical signal; And
And a digital signal processor for outputting the on / off control signal to the illumination unit according to the detection result of the day / night determination unit and controlling the operation of the filtering unit,
Wherein the filtering unit comprises:
An IR CUT filter for filtering the image light to a specific wavelength band in the nighttime; And
And a motor for transmitting the IR CUT filter to a predetermined position for performing a filtering operation in the case of a night time under the control of the digital signal processing unit, And a security camera. The apparatus of claim 1, wherein the IR CUT filter comprises:
And passing image light between a wavelength band of 800 nm and 900 nm.

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