JP2000113351A - Image device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image device provided with an infrared ray projection means which uniformly radiates a whole area received by an image pickup means. SOLUTION: In an image device provided with an image pickup means photographing the video of a monitoring area and an infrared ray projection means 204 projecting an infrared ray to the monitoring area, the infrared ray projection means 204 is constituted of plural infrared rays LED 21 having different directivity. The infrared rays LED each having different directivities strongly illuminate an area in a remote distance from an image picture and they weakly illuminate an area in a near distance. Since image reception intensity in the image which the image pickup means photographs becomes uniform in a whole screen, a precise processing can be executed even if an image processing is executed on the image obtained from the image device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image apparatus provided with infrared light projecting means for enabling photographing even in a dark area.

[0002]

2. Description of the Related Art Conventionally, as an image apparatus, an apparatus for monitoring an area by continuously photographing the entrance and exit of a building and other areas has been put into practical use. This image apparatus is provided with infrared light projecting means for projecting infrared light to the monitoring area so that an image can be taken even in a dark monitoring area.

FIG. 3 shows an installation state of an image apparatus. The image device 2 is installed on the ceiling, and the
Of the surveillance area in. In addition, the infrared light emitting means 20
4 emits infrared rays to the monitoring area. FIG. 6 shows the vertical projection characteristics of the conventional infrared projection unit 204. The conventional infrared light emitting means 204 includes a plurality of infrared LEDs 21
Constitute the LED module 20. Infrared L
The EDs 21 each have the same projection angle, and
The setting is made so that the infrared light is uniformly emitted in the light emitting range of the infrared light emitting means 204.

[0004]

FIG. 7 shows the relationship between the distance from the image device 2 to the photographing area and the image receiving intensity of the image pickup means 203. When infrared rays are projected, the intensity of the infrared rays received by the shooting area decreases and decreases as the distance from the light projecting means 204 increases. Therefore, the image receiving intensity (brightness) of the image captured by the image capturing unit 203 is large in a short-range imaging region and is small in a long-range imaging region. When this is illustrated, as shown by A in FIG.
Attenuates almost in a quadratic curve according to the distance from the position 04.

In the image apparatus 2, the image pickup means 203 is constituted by a CCD or other photoelectric conversion device, and the brightness of the screen at the time of photographing is controlled by the overall brightness of the screen. Therefore, the image captured by the imaging unit 203 has a dark upper portion and a bright lower portion. Therefore, when a moving object is detected by performing image processing in the image device 2, the lower part of the image is too bright, which affects the extraction of a luminance change, and the upper part of the image is too dark. This makes it impossible to recognize the detected object itself. In the case of directly monitoring the image obtained by the image device 2, the middle part of the image is easy to see, but the upper and lower parts are difficult to see.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image apparatus provided with infrared light projecting means for uniformly illuminating the entire area to be imaged by the image pickup means.

[0007]

According to the present invention, there is provided an image apparatus comprising: an image pickup means for photographing a predetermined area; and an infrared light projecting means for projecting infrared light to the area. The infrared light projecting means is constituted by a plurality of infrared LEDs having different directivities. According to the present invention, infrared LEDs, each having a different directivity,
Intense illumination can be performed on an area at a distance farther than the image apparatus, and weak illumination can be performed on an area at a short distance. Since the intensity of the emitted infrared light attenuates as the distance from the image device increases, the intensity of the emitted infrared light becomes substantially constant in the region where the infrared light is emitted, regardless of the distance from the image device.

Therefore, the image receiving intensity of the image taken by the imaging means becomes uniform over the entire screen. This makes it easier to see the image. In addition, even when image processing is performed on an image obtained from an image device, accurate processing can be performed. In the present invention, the infrared light projecting means can be constituted by an LED module having an infrared LED. Further, the infrared light projecting means can be constituted by a plurality of LED modules. According to this, the arrangement of the LED modules can be freely set, and the infrared light projection range can be set freely.

As a specific arrangement method of infrared LEDs having different directivities, a configuration is adopted in which an infrared LED having a narrow-angle directivity is directed to a long-distance area and an infrared LED having a wide-angle directivity is directed to a short-distance area. can do. According to this, an infrared LED having a narrow-angle directivity has a large infrared intensity per unit area. Therefore, even if the infrared intensity is attenuated in a long-distance area, the image receiving intensity of the imaging unit has an intermediate value. In addition, infrared LED with wide-angle directivity
Since the infrared intensity per unit area is small, even if the infrared intensity is not attenuated in a short-distance area, the image receiving intensity of the imaging means has an intermediate value. Therefore, the brightness of the entire image becomes uniform.

[0010]

FIG. 1 shows the overall configuration of an image monitoring system to which the present invention is applied. A controller 1 is installed in a building to be monitored, and a plurality of image devices 2, a fire sensor 3, an emergency button 4, and a mode setting device 5 are connected to the controller 1. The controller 1 is connected to a security center device 7 installed at a remote monitoring center via a telephone line 6 as a communication line.

The connection between the image device 2 and the controller 1 is as follows.
The processing is performed by the analog signal line 8 and the digital signal line 9.
The analog signal line 8 is composed of a coaxial cable, transmits a video signal (NTSC system), and the digital signal line 9 is
It is composed of a twisted pair line and transmits a control signal based on a digital signal. Here, the overall operation of the image monitoring system of FIG. 1 will be briefly described.

The mode setting unit 5 sets the image monitoring system to the alert release mode or the alert set mode. When an alarm signal is output from any one of the image sensor 2, the fire sensor 3, and the emergency button 4 in the alert set mode, the controller 1 sends data indicating the type of abnormality and the location where the abnormality has occurred to the security center via the telephone line 6. Transmit to the device 7.
In addition, since the detection method and transmission method of these abnormal signals are well known in the technical field, detailed description will be omitted.

A plurality of image devices 2 are installed in a building,
An image of a monitoring area including a monitoring target such as a window or a door is taken. Further, the image device 2 determines whether there is an abnormality such as intrusion from the obtained image. As a method of determining the presence or absence of this abnormality,
Various types have been proposed, and any means can be adopted. In this example, the reference image is stored in the image device 2 in advance, and a difference between the reference image and the current image captured by the imaging unit is determined.

FIG. 2 shows the configuration of the image device 2. The image device 2 includes a control unit 201 including a CPU or the like.
And a power supply 202. Each part inside the image apparatus 2 is controlled by the control unit 201 and receives power from a power supply 202. The power supply 202 includes a conversion device that converts an AC voltage supplied from the outside into a DC voltage. Note that instead of providing the power supply 202 in the image apparatus 2, power may be supplied from the controller 1.

The control means 201 includes a storage means 22
0 is connected. The storage unit 220 stores the image device 2
A program for executing the predetermined operation, a parameter, a status signal indicating whether the current state of the monitoring area is normal or abnormal, a security mode in which the monitoring area is set, and the like are stored. . The storage unit 220 further includes a reference image storage area, a current image storage area, and an abnormal image storage area as areas for storing images captured by the imaging unit 203.

The monitoring means 203 for photographing the monitoring area is
It is configured by a CD camera or the like, and has sensitivity from the visible region to the infrared region. An infrared light projecting unit 204 is provided, and emits infrared light to the monitoring area when it becomes dark such as at night. Note that it is preferable to use near infrared rays as the infrared rays. The image processing unit 205 includes a storage unit 220
Then, it is determined whether or not an abnormality has occurred by comparing the current state image and the reference image stored in.

The display means 206 is constituted by an LED, and is turned on when an abnormality is detected, turned off when no abnormality is detected, and displays the presence or absence of abnormality detection outside the image apparatus 2. Communication means 2
Reference numeral 07 denotes an interface for transmitting and receiving signals to and from the controller 1.
Connected to The image output unit 208 is an interface for outputting an image at the time of occurrence of an abnormality.
9 and connected to the analog signal line 8.

The analog signal line 8 is, as shown in FIG.
The controller 1 and each image device 2 are connected in series. The switching unit 209 of the image device 2 connects the input side and the output side of the analog signal line 8 in a normal state, disconnects the analog signal line in the input state in an abnormal state, and connects the image output unit to the output side of the analog output line 8 To be connected. In FIG. 2, the input side is displayed as "from another image device" and the output side is displayed as "to the controller".

The address setting section 210 is constituted by a dip switch, and sets an address for the controller 1 to specify the image apparatus 2. The operation means 211
This is a means for turning on / off the power. When the operation unit 211 is turned off, the switching unit 209 connects the input side and the output side of the analog signal line 8 to bypass the image apparatus 2 from the analog signal line 8.

FIG. 3 shows an example of installation of the image device 2. The image device 2 is attached and installed on a ceiling at a height of 3 m,
It monitors a monitoring area within a range of up to 10 m.
Infrared light projecting means 204 arranged inside image device 2
Emits an infrared ray to the projection range A, and the imaging means 203
The monitoring area in the imaging range B is photographed.

FIG. 4 is an external view of the LED module 20 forming the infrared light projecting means 204. (A) is a front view. The infrared light projecting means 204 includes two LED modules 20. Twenty infrared LEDs 21 are arranged on the light emitting surface of each LED module 20. Here, the infrared LED 21A disposed above and in the middle of the infrared LED 21 (indicated by a black circle) has a narrow directional angle of 20 degrees, and the infrared LED 21B disposed below (indicated by a white circle) has a directional angle. The angle is as wide as 40 degrees.

FIG. 2B is a side view. The LED module 20 is arranged to be inclined downward by 15 degrees. (C) is a plan view. The two LED modules 20 are arranged at an angle of about 120 degrees along the optical filter 22 provided on the housing of the image device 2. This horizontal angle (120 degrees)
And the tilt angle (15 degrees) shown in (B), the light emitting range A of the infrared light emitting means 204 is determined.

FIG. 5 is a diagram showing the light projection characteristics of the LED module 20 in the vertical direction. Of the infrared LEDs 21 arranged in the vertical direction on the LED module 20, the infrared LED 21 arranged at the uppermost part emits light to an area far away from the monitoring area, and the infrared LED 21 arranged at the lowermost part is monitored at a short distance. The light that is projected on the area and that is disposed in the middle is projected on the monitoring area at an intermediate distance.

Infrared light LE projecting at long distance and intermediate distance
Since D21A has directivity at a narrow angle, the intensity of infrared light per unit area is large. Further, since the infrared LED 21B that projects light at a short distance has a wide-angle directivity, the intensity of infrared light per unit area is small. Therefore, a strong infrared ray is projected on a long distance area, and a weak infrared ray is projected on a short distance area. On the other hand, the received light intensity in each area is
Since the attenuation increases as the distance increases, the intensity of the infrared light received by each area becomes substantially constant regardless of the distance from the image device 2.

Thus, in the imaging means 203,
As shown by B in FIG. 7, a constant image receiving intensity can be obtained irrespective of the distance from the image device 2. That is, in the image device 2, an image with uniform brightness is obtained. As described above, when a uniform image receiving intensity is obtained, there are no portions that are too bright or too dark in the image.Therefore, when performing an abnormality detection or the like by processing the obtained image, the detection accuracy of the detection target is reduced. Does not decrease, and reliable detection can be performed.

[0026]

According to the present invention, almost uniform brightness can be obtained on the image receiving surface of the image pickup means of the image apparatus, so that an easy-to-view screen can be obtained or the detection accuracy of the detection object is not reduced. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of an image monitoring system to which an image device according to the present invention is applied.

FIG. 2 is a diagram illustrating a configuration example of an image apparatus according to the present invention.

FIG. 3 is a diagram showing an installation state of the image device of FIG. 2;

FIG. 4 shows an LED forming the infrared light projecting means in FIG.
The figure which shows the structure of a module.

FIG. 5 is a view showing a vertical light projection characteristic of the infrared light projection unit in FIG. 3;

FIG. 6 is a diagram showing vertical light projection characteristics of a conventional infrared light projection unit.

FIG. 7 is a diagram illustrating a relationship between a distance from an image device to a photographing area and an image receiving intensity in an image pickup unit according to the present invention and a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Controller 2 ... Image device 201 ... Control means 202 ... Power supply 203 ... Imaging means 204 ... Infrared light emitting means 205 ... Image processing means 206 ... Display means 207 ... Communication means 208 ... Image processing means 209 ... Switching means 210 ... Address setting Unit 211 Operating means 220 Memory means 3 Fire sensor 4 Emergency button 5 Mode setting device 6 Telephone line 7 Security center device 8 Analog signal line 9 Coaxial cable 20 LED module 21 Infrared LED 22 Optical filter

Claims (6)

[Claims] 1. An image apparatus comprising: an image pickup means for photographing a predetermined area; and an infrared light projecting means for projecting infrared light to the area, wherein the infrared light projecting means comprises a plurality of infrared rays having different directivities. An imaging device comprising an LED. 2. The image apparatus according to claim 1, wherein said infrared light projecting means is constituted by an LED module having an infrared LED. 3. The image device according to claim 2, wherein a plurality of said LED modules are provided. 4. The LED module according to claim 3, wherein the LED module includes an infrared LED having a narrow-angle directivity disposed on an upper side and an infrared LED having a wide-angle directivity disposed on a lower side. Imaging device. 5. The infrared light projecting means directs an infrared LED having a narrow-angle directivity to a long-distance area of the monitoring area, and directs an infrared LED having a wide-angle directivity to a short-distance area of the monitoring area. The image device according to claim 1, wherein the image device is arranged as follows. 6. The image device according to claim 1, wherein the infrared LED is a near infrared LED.