Summary of the invention
Cause at the distance meeting picture that surpasses 20 meters pitch-dark for what solution existed in existing infrared array lamp technology because of the torch effect, cause not seeing object, 20 meters then a bright circle can occur in the middle of the picture with interior distance, the problem that causes brightness irregularities has proposed a kind of infrared night-vision system and to the control method of infrared night-vision system.
This system comprises: the control signal that communication unit, infrared array lamp group control unit, camera control unit and main control unit, communication unit are used for receiving sends to main control unit; The control command that infrared array lamp group control unit is used for sending according to main control unit is controlled the lens angle or the size of current of infrared array lamp group; The control command that camera control unit is used for sending according to main control unit is controlled the lens location or the visual angle size of video camera, and the visual angle information of video camera is sent to main control unit; Main control unit is used for the control signal according to the communication unit transmission, by infrared array lamp group control unit to infrared array lamp group transmitting control commands, and by camera control unit to the video camera transmitting control commands, and the visual angle information that sends according to camera control unit is by the lens angle or the size of current of infrared array lamp group control unit control infrared array lamp group.
This method comprises:
Step 1 reads the lens location value of video camera;
Step 2, the change that obtains video camera according to the change of video camera the relation between T and the described lens location value of doubly being worth doubly is worth T;
Step 3, according to formula ω=2 * ATAN[2.4212/ (2 * 3.84 * T)] * 57.2958 obtain the visual angles value ω of video cameras;
Step 4 is according to the lens angle or the size of current of described visual angle value ω adjustment infrared array lamp.
The present invention is according to the lens angle and the brightness of the corresponding infrared array lamp of lens location information acquisition of video camera, realized the perfect cooperation of video camera and infrared array lamp, avoided photoelectricity tube effect, the object of 0~100 meter scope can clearly be photographed, and have uniform brightness.
Embodiment
The specific embodiment of the present invention has proposed a kind of infrared night-vision system, as shown in Figure 1, specifically can comprise communication unit 1, infrared array lamp group control unit 2, camera control unit 3 and main control unit 4.Communication unit 1, the control signal that is used for receiving sends to main control unit 4; Infrared array lamp group control unit 2 is used for lens angle or size of current according to the control command control infrared array lamp group 5 of main control unit 4 transmissions; Camera control unit 3 is used for lens location or visual angle size according to the control command control video camera 6 of main control unit 4 transmissions, and the visual angle information of video camera 6 is sent to main control unit 4; Main control unit 4, be used for control signal according to communication unit 1 transmission, by infrared array lamp group control unit 2 to infrared array lamp group 5 transmitting control commands, and pass through camera control unit 3, and control the lens angle or the size of current of infrared array lamp groups 5 by infrared array lamp group control unit 2 according to the visual angle information that camera control unit 3 sends to video camera 6 transmitting control commands.
Be that example describes this embodiment with common infrared ball machine below, the control signal of infrared ball machine outside sends to main control unit 4 by communication unit 1, communication unit 1 can adopt the RS485 bus, and carries out communication with puppy parc (for example PELCO-D/P) and main control unit 4.Main control unit 4 can adopt NS Semiconductor LM3404 cake core, and according to the control signal that communication unit 1 sends, controls by 2 pairs of infrared array lamps of infrared array lamp group control unit group 5.
Infrared array lamp group 5 can adopt by three groups of infrared array lamp 5-1 to be formed, and the lens angle of three groups of infrared array lamp 5-1 is respectively 45 °, 15 ° and 8 °.In order to obtain better display effect, three groups of infrared array lamp 5-1 can be by three independent control switchs of infrared array lamp control unit in the infrared array lamp group control unit 2, and adjustable power, the power of every group of infrared array lamp 5-1 is determined that by input current the size of input current is by main control unit 4 controls.The lens angle that the control of infrared array lamp 5-1 mainly is based on the array lamp is more little, and the infrared light transmitting range is far away more, but can stay photoelectricity tube effect in monitor central authorities closely the time; The array lamp current is directly proportional with luminosity, and electric current is big more, the principle that brightness is strong more.Based on above-mentioned principle, should brightness even for the infrared array lamp 5-1 in 0~100 meter scope irradiation, again apart from problem enough far away, lens location that can obtain according to camera control unit 3 and visual angle size be to the opening and closing of every group of infrared lamp, and the input current size is accurately controlled and realized best night vision effect.
The specific embodiment of the present invention also provides a kind of control method of infrared night-vision system, as shown in Figure 2, specifically can comprise the steps:
Step 1 reads the lens location value of video camera;
Step 2, the change that obtains video camera according to the change of video camera the relation between T and the described lens location value of doubly being worth doubly is worth T;
Step 3, according to formula ω=2 * ATAN[2.4212/ (2 * 3.84 * T)] * 57.2958 obtain the visual angles value ω of video cameras;
Step 4 is according to the lens angle or the size of current of described visual angle value ω adjustment infrared array lamp.
Step 4 wherein specifically can comprise:
Step 41, as the visual angle of video camera value ω during greater than 35 °, it is 45 ° infrared array lamp that full power is opened the lens angle, the lens angle is that the infrared array lamp of 15 ° and 8 ° is closed;
Step 42, when the visual angle of video camera value ω was 15 °~35 °, it was 45 ° infrared array lamp that full power is opened the lens angle, the lens angle is that 15 ° the unlatching power of infrared array lamp is by formula W
1=W * [100-(ω-15) * 4] % determines, the power when wherein W is full power unlatching infrared array lamp, W
1For opening power, the lens angle is that 8 ° infrared array lamp is closed;
Step 43, when the visual angle of video camera value ω was 8 °~15 °, full power was opened the infrared array lamp that the lens angle is 45 ° and 15 °, and the lens angle is that 8 ° the unlatching power of infrared array lamp is by formula W
2=W * [100-(ω-8) * 11] % determines, the power when wherein W is full power unlatching infrared array lamp, W
2For opening power;
Step 44, as the visual angle of video camera value ω during less than 8 °, full power is opened the infrared array lamp that the lens angle is 45 °, 15 ° and 8 °.
When being applied in this method in a kind of infrared night-vision system that provides in the above-mentioned embodiment, specifically by main control unit 4 control method by infrared array lamp group control unit 2 control infrared array lamp 5-1 mainly based on following principle:
1., the relation at the lens location of video camera 6 and visual angle
The camera lens of video camera 6 its visual angle when amplification is dwindled changes, and the camera lens of video camera 6 is condensed to that hour its visual angle is for maximum, and its visual angle is for minimum when being amplified to maximum.
2., the lens angle of infrared array lamp 5-1 and the distance relation of irradiation
Big more its irradiation distance of the lens angle of infrared array lamp 5-1 is near more, and the lens angle more hour distance of irradiation is far away more.
3., the relation of the electric current of infrared array lamp 5-1 and brightness
Big more its brighter display of the electric current of infrared array lamp 5-1, electric current hour its brightness more are dark more.
4., infrared array lamp 5-1 electric current is adjustable
Main control unit 4 sends the DIM mouth of a pwm signal to power supply chip, recently control the size of current of infrared array lamp 5-1 by the duty of this pwm signal, when duty ratio was 0%, infrared array lamp 5-1 closed, infrared array lamp 5-1 full power operation when duty ratio is 100%.
Because of the camera lens of video camera 6 its angular field of view when becoming times changes very greatly, by 40 °~55 ° of maximum to minimum below 5 °, with the SONY480 video camera is example, its angular field of view is 2.8 °~48 °, according to this situation three groups of infrared array lamp 5-1 can be set, its perspective angle is for being respectively 45 °, 15 ° and 8 °, and the electric current of every group of infrared array lamp 5-1 all can be controlled separately.
Main control unit 4 reads the lens location value of video camera 6 by camera control unit 3, the table of comparisons that doubly is worth T and lens location by the change of searching video camera 6, the change that lens location is converted to video camera 6 doubly is worth T, again by formula ω=2 * ATAN[2.4212/ (2 * 3.84 * T)] * 57.2958 changes with video camera 6 doubly are worth the visual angle value ω that T converts video camera to, adjust the electric current of three groups of infrared array lamps 5 at last according to the visual angle value ω of video camera 6 respectively, can make the night vision image of video camera 6 infrared ball machine when different visual angles that best display effect is all arranged.
The visual angle value ω of video camera 6 and the current relationship of three groups of infrared array lamps 5 are as follows: when the visual angle of video camera 6 is worth ω greater than 35 °, it is 45 ° infrared array lamp 5-1 that full power is opened the lens angle, and the lens angle is that the infrared array lamp 5-1 of 15 ° and 8 ° closes; When the visual angle of video camera 6 value ω was 15 °~35 °, it was 45 ° infrared array lamp 5-1 that full power is opened the lens angle, and the lens angle is that 15 ° the unlatching power of infrared array lamp 5-1 is by formula W
1=W * [100-(ω-15) * 4] %, the power when wherein W is full power unlatching infrared array lamp 5-1, W
1For opening power, the lens angle is that 8 ° infrared array lamp 5-1 closes; When the visual angle of video camera 6 value ω was 8 °~15 °, full power was opened the infrared array lamp 5-1 that the lens angle is 45 ° and 15 °, and the lens angle is that 8 ° the unlatching power of infrared array lamp 5-1 is by formula W
2=W * [100-(ω-8) * 11] %, the power when wherein W is full power unlatching infrared array lamp 5-1, W
2For opening power; As the visual angle of video camera 6 value ω during less than 8 °, full power is opened the infrared array lamp 5-1 that the lens angle is 45 °, 15 ° and 8 °.
This embodiment is according to the lens angle and the brightness of the corresponding infrared array lamp of lens location information acquisition of video camera, realized the perfect cooperation of video camera and infrared array lamp, avoided unglazed torch effect, in the open air under the total darkness environment, the scope that night visual range is 0~80 meter can be seen people's face clearly, and 80~100 meters scope can be seen human body contour outline clearly, and the phenomenon of the face whiting of all having no talent in the scope of 0~100 meter of night visual range, personage's clear display, picture brightness is even.
The above; only for the preferable embodiment of the present invention, but protection scope of the present invention is not limited thereto, and anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claims.