A kind of high-definition image multiplier (-icator) automatic gain control system
Technical field
The utility model relates to a kind of high-definition image and increases instrument, particularly relates to a kind of high-definition image multiplier (-icator) automatic gain control system.
Background technology
As the application television of one of two large class TVs, it is mainly used in traffic, business, finance, health care, military affairs and security field, is one of the important means of modern management, monitoring, control.Along with the development of science and technology, industrial production, management automation, the raising of up-to-dateness, application television obtains developing more and more widely in the application of industrial aspect, application television can be in real time, image, the monitored object controlled of reflection truly, people utilize this feature, the information that timely acquisition is enriched in a large number, application television is multiple spot often, each PASS VIDEO attenuated output signal degree is different, so then can not reach an agreement to the video frequency output multiplication factor of each passage, for this reason, need to increase automatic gain control circuit at video output terminals make stable output signal and automatically can regulate input voltage, electric current, can produce in gain control signal simultaneously without the need to high fdrequency component affect output image quality.
Utility model content
In order to solve the problem, the utility model provides a kind of novel in structural design, control voltage can input size, and can export the technical scheme of high-definition signal:
A kind of high-definition image multiplier (-icator) automatic gain control system, mainly comprise picture signal acquisition module, signal processing module, gain control module, signal filtering module, signal input part connection layout image signal acquisition module, picture signal acquisition module output connection signal processing module input, signal processing module comprises voltage, current control circuit, signal processing module output connects gain control module input, gain control module output connection signal filtration module input.
As preferably, voltage, current control circuit bag is by resistance, electric capacity, diode, gate pipe, amplifier forms, diode D1, diode D2, resistance R1 is connected in series signal input part and the base stage of connection door keyholed back plate T1, collector electrode contact resistance R2 one end respectively of gate pipe T1, the anode of diode D3, the emitter contact resistance R3 successively of gate pipe T1, resistance R4, electric capacity C1 parallel resistance R4 ground connection, diode D3 negative electrode connects electric capacity C2 one end respectively, the base stage of gate pipe T2, adjustable resistance RL contact resistance R7 the electrode input end of contact resistance R9 and amplifier V, the resistance R8 other end connects the negative input of amplifier V, resistance R10 bridging amplifier V, the output contact resistance R11 of amplifier V, resistance R11 connects electric capacity C4 one end and gain control module respectively.
As preferably, gain control module triode T3, triode T4 form differential amplifier, resistance R12 connecting triode T3 collector electrode, triode T3 emitter contact resistance R16, triode T3 base stage contact resistance R14, diode D3 parallel resistance R16, diode D3 negative electrode connecting triode T5 collector electrode, triode T5 emitter contact resistance R18, triode T5 base stage connection control voltage end.
As preferably, signal filtering module comprises low pass filter, resistance R19 series resistance R20 connects the electrode input end of electric capacity C6, amplifier LMH6715-A respectively, and the negative input of amplifier LMH6715-A and the signal output part of amplifier LMH6715-A are also accessed in electric capacity C5 contact resistance R19 one end.
The beneficial effects of the utility model are:
(1) the utility model gain control module adopts emitter degeneration gain control circuit, can increase along with signal and reduce by control inputs voltage, emitter degeneration gain control circuit is directly connected video amplifier adjustable resistance, can output signal be stablized, realize automatic growth control.
(2) the utility model signal filtering module adopts binary channels broadband operational amplifier LMH6715 to build quadravalence Butterworth active low-pass filter, can by output signal filtering after amplify again, thus in filtering gain control signal without the need to high fdrequency component to export high-definition image.
Accompanying drawing explanation
Fig. 1 is syndeton block diagram of the present utility model;
Fig. 2 is signal processing module of the present utility model and gain control module connecting circuit figure.
Fig. 3 is signal filtering module circuit diagram of the present utility model.
Embodiment
For making goal of the invention of the present utility model, technical scheme and advantage clearly, below in conjunction with accompanying drawing, execution mode of the present utility model is described in further detail.
As shown in Figure 1, a kind of high-definition image multiplier (-icator) automatic gain control system, mainly comprise picture signal acquisition module 1, signal processing module 2, gain control module 3, signal filtering module 4, signal input part connection layout image signal acquisition module 1, picture signal acquisition module 1 output connection signal processing module 2 input, signal processing module 2 comprises voltage, current control circuit, signal processing module 2 output connects gain control module 3 input, gain control module 3 output connection signal filtration module 4 input.
As shown in Figure 2, voltage, current control circuit bag is by resistance, electric capacity, diode, gate pipe, amplifier forms, diode A D1, diode B D2, resistance A R1 is connected in series signal input part and the base stage of connection door keyholed back plate A T1, collector electrode contact resistance B R2 one end respectively of gate pipe A T1, the anode of diode C D3, the emitter contact resistance C R3 successively of gate pipe A T1, resistance D R4, electric capacity A C1 parallel resistance D R4 ground connection, diode C D3 negative electrode connects electric capacity B C2 one end respectively, the base stage of gate pipe B T2, the collector electrode contact resistance B R2 other end of gate pipe B T2 also accesses power end, emitter contact resistance E R5 one end respectively of gate pipe B T2, resistance H R8 one end, resistance F R6 series capacitance C C3 is connected on both ends of power, adjustable resistance RL contact resistance G R7 the electrode input end of contact resistance I R9 and amplifier V, the resistance H R8 other end connects the negative input of amplifier V, resistance J R10 bridging amplifier V, the output contact resistance K R11 of amplifier V, resistance K R11 connects electric capacity D C4 one end and gain control module 3 respectively.
Gain control module 3 triode C T3, triode D T4 forms differential amplifier, resistance L R12 connecting triode C T3 collector electrode, triode C T3 emitter contact resistance P R16, triode C T3 base stage contact resistance N R14, diode C D3 parallel resistance P R16, resistance M R13 connecting triode D T4 collector electrode, triode D T4 emitter contact resistance Q R17, triode D T4 base stage contact resistance O R15, diode D D4 parallel resistance Q R17, the negative electrode connecting triode E T5 collector electrode of diode C D3 negative electrode and diode D D4, triode E T5 emitter contact resistance R R18, triode E T5 base stage connection control voltage end.When outputing signal as weak signal, signal processing circuit does not work, the current potential sending into amplifier V is determined by resistance E R5, resistance F R6 dividing potential drop, amplifier V exports definite value positive voltage signal, control is minimum depending on putting adjustable resistance, makes controlled gain maximum, thus completes and follow vision signal change automatically adjustment video amplifier adjustable resistance, stable output signal, realizes automatic growth control.
As shown in Figure 3, signal filtering module 4 adopts binary channels broadband operational amplifier LMH6715 to build quadravalence Butterworth active low-pass filter, resistance S R19 series resistance T R20 connects electric capacity F C6 respectively, the electrode input end of amplifier LMH6715-A, the negative input of amplifier LMH6715-A and the signal output part of amplifier LMH6715-A are also accessed in electric capacity E C5 contact resistance S R19 one end, the output contact resistance U R21 of amplifier LMH6715-A, resistance V R22 also connects electric capacity G C7 respectively, the electrode input end of amplifier LMH6715-B, the negative input of amplifier LMH6715-B and the signal output part of amplifier LMH6715-A are also accessed in electric capacity H C8 contact resistance U R21 one end, this pass band gain is 1, can amplify after output signal filtering again, thus in filtering gain control signal without the need to high fdrequency component to export high-definition image.
Above-described embodiment is preferred embodiment of the present utility model; it is not the restriction to technical solutions of the utility model; as long as without the technical scheme that creative work can realize on the basis of above-described embodiment, all should be considered as falling within the scope of the rights protection of the utility model patent.