A kind of television set backlight brightness control system and method and television set
Technical field
The present invention relates to the regulation technology of the backlight illumination of television set, the television set that particularly relates to a kind of television set backlight brightness control system and method and adopt this system.
Background technology
Along with society and scientific and technological progress, television set is popularized day by day, in occupation of the status of can not ignore, makes that people's life is more rich and varied in daily life.
At present, the liquid crystal TV set of using lcd technology also appears on the market, and because liquid crystal TV set has self original strong point with respect to traditional television set, therefore is expected to become main product in the future.For liquid crystal TV set,, therefore need to adopt backlight to throw light on because liquid crystal display screen self can not active illuminating.
The liquid crystal TV set of prior art can apply big voltage, big electric current by unexpected backlight to liquid crystal display screen, thereby backlight is impacted when start, makes be affected inevitably its useful life, and can cause the harmful effect to liquid crystal display screen; Add that this mode must cause the display brightness of LCD TV to be brightened by dark moment, also can cause the infringement to user's eyesight.
In addition, the liquid crystal TV set of prior art also is unexpected deepening when shutdown, has bad influence equally.
Summary of the invention
The television set that the technical problem that the present invention solves is to provide a kind of television set backlight brightness control system and method and adopts this system can be controlled the television set backlight illumination and realize changing more slowly.
For this reason, the technical scheme of technical solution problem of the present invention is: a kind of television set backlight brightness control system is provided, is used to regulate the brightness of the backlight of TV display panel, comprising:
Television program control centre is used for the pulse-width signal that output changes when needs are regulated the backlight illumination of television set;
The demodulation control circuit is connected to this television program control centre, amplifies and changes aforementioned pulse-width signal, and the power control signal that output voltage values gradually changes gradually changes its brightness to the backlight of described display floater.
Preferably, described demodulation control circuit comprises:
Triode, its base stage are connected to the pulse-width signal port of television program control centre, grounded emitter, and collector electrode is connected to the VCC power supply;
Be connected on first resistance and the 3rd electric capacity between VDDM power supply and the ground; The node of described first resistance and the 3rd electric capacity is connected to the base stage of described triode;
The 5th resistance that connects the backlight control interface of the collector electrode of this triode and described display floater.
Preferably, described demodulation control circuit also comprises: first electric capacity and second electric capacity are connected in parallel between the node and ground of the 5th resistance and backlight control interface.
Be set to regulate the time of the backlight illumination of television set when preferably, the user regulates brightness by menu mode under this television program control centre television boot-strap, unused time and/or the normal rating state.
Preferably, the pulse-width signal of described television program control centre output is a continually varying.
The present invention also provides a kind of television set, comprises the display floater with backlight, also comprises the television set backlight brightness control system, is used to regulate the brightness of the backlight of TV display panel, and this control system comprises:
Television program control centre is used for the pulse-width signal that output changes when needs are regulated the backlight illumination of television set;
The demodulation control circuit is connected to this television program control centre, amplifies and changes aforementioned pulse-width signal, and the power control signal that output voltage values gradually changes gradually changes its brightness to the backlight of described display floater.
Preferably, described demodulation control circuit comprises:
Triode, its base stage are connected to the pulse-width signal port of television program control centre, grounded emitter, and collector electrode is connected to the VCC power supply;
Be connected on first resistance and the 3rd electric capacity between VDDM power supply and the ground; The node of described first resistance and the 3rd electric capacity is connected to the base stage of described triode;
The 5th resistance that connects the backlight control interface of the collector electrode of this triode and described display floater.
The present invention also provides a kind of television set backlight brightness control method, comprises step:
1) television program control centre resolves backlight illumination change instruction;
2) television program control centre changes instruction according to this backlight illumination, and the output pulse width modulation signal is to the demodulation control circuit;
3) the demodulation control circuit amplify and change the power control signal of backlight of this pulse-width signal display floater after export;
4) backlight is under the control of this power control signal, and its brightness gradually changes.
Preferably, described step 1) also comprises: produce this backlight illumination change instruction when television boot-strap, shutdown and/or when the user regulates backlight illumination by menu mode.
Preferably, pulse-width signal described step 2) is a continually varying.
With respect to prior art, the invention has the beneficial effects as follows: because the present invention is when the brightness of the backlight of regulating TV display panel, the pulse-width signal that output changes, realization is to the automatic control of the power supply of the backlight of television set, and utilize this power supply that automatically changes to regulate brightness slowly to change, thereby avoid brightness variation suddenly to the impact of backlight, prolong the useful life of backlight and display floater, and reduce infringement user's eyesight.
In preferred version of the present invention, when start, when shutdown and user regulate brightness, the brightness of display panels is controlled.
Description of drawings
Fig. 1 is the block diagram of television set of the present invention;
Fig. 2 is the circuit diagram of an embodiment of demodulation control circuit shown in Figure 1;
Fig. 3 is the flow chart of television set backlight brightness control method of the present invention.
Embodiment
Seeing also Fig. 1, is the block diagram of television set of the present invention.
Television set comprises television set backlight brightness control system 100, user input unit 200, menu information control interface 300, display panels 900.
User input unit 200 is used to generate and the pairing various control commands of user's operation, comprises the instruction of open and close machine, and operates pairing control command etc. by the menu regulative mode under the normal rating state.
User input unit 200 can be to carry out remote controlled remote controller, also can be arranged on the devices such as button on the television set.
Menu information control interface 300 is mainly used in and realizes menu adjusting transmission of Information under normal rating state.
The brightness that this television set backlight brightness control system 100 is used for the backlight 910 of control display panels 900 when TV power on and off slowly changes, television program control centre (CPU) 110, demodulation control circuit 120, wherein television program control centre 110 receive users by user input unit 200 inputs operational order and handle; Television program control centre 110 connects demodulation control circuit 120, the work of control and coordination each several part; 120 of demodulation control circuits are used for output control power supply to backlight 910.
Television program control centre 110 is core devices of television set, storage inside and the relevant program code of backlight illumination control, be mainly used in when TV power on and off and send PWM (pulse-width modulation) signal, with the backlight illumination of slow adjusting television set by software control.In addition, under normal rating state, also can realize adjusting by sending pwm signal to backlight illumination.
Demodulation control circuit 120 is used to amplify the pwm signal that this television program control centre 110 sends, and exports display panels 900 to after converting thereof into the power control signal of backlight 910.
Seeing also Fig. 2, is the circuit diagram of an embodiment of demodulation control circuit shown in Figure 1.
In the described demodulation control circuit 120, first resistance R 1 and the 3rd capacitor C 3 are connected between VDDM power supply and the ground.The base stage 1 of triode Q1 is connected to first node between first resistance R 1 and the 3rd capacitor C 3 (indicating) by the 7th resistance R 7; Emitter 2 ground connection of triode Q1; The collector electrode 3 of triode Q1 connects the VCC power supply by second resistance R 2.
Wherein, this first node is connected to a PWM I/O mouth of television program control centre 110 as the input of demodulation control circuit 120 by the 6th resistance R 6; Section Point between the collector electrode 3 of triode Q1 and second resistance R 2 (not indicating) is connected to the backlight control interface 920 of display panels 900 by the 5th resistance R 5; First capacitor C 1 and second capacitor C 2 are connected in parallel between the node of resistance R 5 and backlight control interface 920 and ground.
Seeing also Fig. 3, is the flow chart of television set backlight brightness control method of the present invention.
Step S310, television program control centre 110 resolve backlight illumination and change instruction;
Described backlight illumination change instruction be created in television boot-strap, when shutting down or when being created in the user and regulating brightness by menu mode.
Step S320, television program control centre 110 changes instruction according to this backlight illumination, and the output pwm control signal is to demodulation control circuit 140;
Step S330, demodulation control circuit 120 amplifies these pwm control signals, and exports after converting the power control signal of backlight 910 to;
Step S340, backlight 910 are under the control of this power control signal, and its brightness takes place to change slowly.
For ease of understanding the present invention, the start process with television set is that example describes the present invention below.
After the television startup system initialization was finished, by a PWM I/O mouth of software control chip (CPU), the television set backlight brightness control system was exported one group of finally stabilised magnitude of voltage of continually varying from low to high in the short time automatically.Utilize described continually varying magnitude of voltage to control corresponding backlight control interface on the display panels automatically, reach the purpose of control display panels soft start (slowly by dark to bright and stable) in start process.
In sum, the present invention mainly realizes is the automatic control of one group of power supply of the backlight of television set, and utilize this power supply that changes automatically when start, shutdown and the user brightness of display panels 900 is controlled when regulating brightness.
The above only is a preferred implementation of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.