CN201355552Y - Backlight control system and multimedia telephone using same - Google Patents
Backlight control system and multimedia telephone using same Download PDFInfo
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- CN201355552Y CN201355552Y CNU2009201055735U CN200920105573U CN201355552Y CN 201355552 Y CN201355552 Y CN 201355552Y CN U2009201055735 U CNU2009201055735 U CN U2009201055735U CN 200920105573 U CN200920105573 U CN 200920105573U CN 201355552 Y CN201355552 Y CN 201355552Y
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Abstract
The utility model discloses a backlight control system, which comprises a photoresistor, a central processing unit and a backlight control module which are connected in sequence, wherein the photoresistor is connected with a divider resistor in series to form a divider circuit; the two ends of the divider circuit are respectively connected with a direct-current power supply and the ground; the middle point of the divider circuit is connected with one analog quantity input port of the central processing unit; and one output port of the central processing unit is connected with the backlight control module. The backlight control system can automatically monitor the change of ambient light, control the brightness of a backlight module accordingly, and can lead a user to set the brightness control strategy of the backlight module according to needs.
Description
Technical field
The present invention relates to phone, particularly be applied to mediaphone and backlight control system thereof.
Background technology
Along with the development of digital communication, the application of mediaphone is increasing, and different with black phone is, existing mediaphone mostly use LCDs as image-display units to carry out video calling.And phone liquid crystal display backlight be if light for a long time, the one, cause the lost of life of liquid crystal display easily, and the 2nd, at strong excessively light or influence people's rest at night.
Existing mediaphone or do not establish backlight control is lighted for a long time; State backlight is set to closing under the default conditions, when activation incidents such as push-button dialing produce, lights backlight according to the activation incident.These modes all can't realize backlight and automatic adaptation external environment, or can't regulate, or need at all people's participation.
It is very fast relatively that the display screen automatic backlight regulation technology of mobile phone then develops.For example, Chinese patent application number is that 01120659.4 patented claim discloses a kind of method that can adjust backlight illumination automatically.This method is provided with a photo-sensitive cell on an appropriate location on a mobile phone surface, this photo-sensitive cell is connected with a control circuit of this mobile phone, when the user starts the backlight of this mobile phone is when adjusting the state of brightness automatically, one CPU (central processing unit) (CPU) of this mobile phone will be judged the magnitude of voltage at these photo-sensitive cell two ends, and according to this magnitude of voltage, that adjusts this mobile phone is backlight for to brightness that should magnitude of voltage, so, to reduce by this photo-sensitive cell its resistance value under the environment of strong illumination, the magnitude of voltage at its two ends is reduced, and its resistance value will raise under the environment of dark, make the characteristic of the magnitude of voltage rising at its two ends, make the brightness backlight of this mobile phone be adjusted to suitable high low-light level, thereby can under the environment of high light, reduce power consumption backlight.But this application only discloses a kind of but also unexposed concrete circuit realization of idea of adjusting backlight illumination according to environment.
Summary of the invention
The purpose of this utility model is, present situation at the multimedia landline telephone of present employing large screen display scheme adjusting shortcoming backlight, a kind of automatic backlight regulation and control system is provided, make the backlight of display screen can be according to ambient brightness, automatically adjust according to the rule that the user presets, for example can under complete dark situations, liquid crystal display can be closed automatically, realize prolonging the life-span of liquid crystal display, avoid the light influence to have a rest.
For reaching this purpose, the utility model proposes a kind of backlight control system, it is characterized in that, comprise the photoresistance that connects successively, CPU (central processing unit) and backlight control module, wherein said photoresistance are connected with a divider resistance and are constituted bleeder circuit, and the two ends of this bleeder circuit connect direct supply and ground connection respectively, its mid point is connected to an analog quantity input port of CPU (central processing unit), and an output port of described CPU (central processing unit) is connected to described backlight control module.The mediaphone that uses this backlight control system also is provided simultaneously.
The beneficial effect that technical solutions of the utility model are brought is: monitoring of environmental light changes and controls brightness of backlight module according to this automatically, can allow the user according to self-demand the brightness of backlight module control strategy be set.Can avoid the mediaphone of giant-screen design to be placed on the hotel when inner, because start throughout the year causes liquid crystal display aging rapidly, and when night, all light were closed, but liquid crystal display is lighted and influence also saves energy of guest's rest.And the entire backlight control system is simple in structure, and working stability can low-costly be realized.
Description of drawings
Fig. 1 is the volt-ampere characteristic of photoresistance;
Fig. 2 is the light characteristics curve of photoresistance;
Fig. 3 is the backlight control system synoptic diagram of the utility model one embodiment;
Fig. 4 is a workflow diagram embodiment illustrated in fig. 3.
Embodiment
Backlight control system of the present utility model is by the photoresistance that connects successively, and CPU (central processing unit) and backlight control module three parts are formed.Wherein, photoresistance is arranged at the device that uses backlight module, for example on the shell of mediaphone, is used to respond to surrounding environment brightness, and luminance signal is converted to different resistance values.CPU (central processing unit) is then regularly sampled to the resistance of photoresistance, and generate a control signal according to the resistance of this photoresistance, afterwards this control signal is sent to backlight control module, by the corresponding backlight illumination of adjusting of backlight control module, realize changing function backlight according to the variation of ambient brightness.
Wherein, photoresistance is the variable-parameter component that a kind of resistance value changes with ambient brightness.The volt-ampere characteristic of general photoresistance and light characteristics curve are respectively as depicted in figs. 1 and 2.As seen from the figure, under certain illumination, photoresistance volt-ampere characteristic near linear, and do not have saturated phenomenon, can be considered as linear resistive element.But be subjected to the restriction of dissipated power, in use, the voltage at photoresistance two ends can not surpass maximum operating voltage, for allowing the power consumption curve, can determine the photoresistance normal working voltage as curve among Fig. 1 thus.Reference when this figure also selects as photoresistance.
The backlight control system synoptic diagram of the utility model one preferred embodiment as shown in Figure 3.Among Fig. 3, backlight control system comprises the bleeder circuit that is made of divider resistance and photoresistance series connection, and one carries out the CPU of data processing, and the output port of described CPU is connected to the backlight control module of liquid crystal display.Wherein, the mid point of described bleeder circuit is coupled to the analog quantity input port of CPU so that the sampled value of this analog quantity input port can be with the change in resistance of photoresistance respective change.
In Fig. 3, CPU preferably uses the monarch of Chinese independent research positive 4740, but obviously be not limited to this, any can sampling to analog quantity, carry out analog to digital conversion afterwards, and carry out numerical evaluation according to transformation result according to the program of establishment in advance, and the CPU, microprocessor, single-chip microcomputer etc. that produce signal output all can be applicable to this.In the present embodiment, the mid-point voltage LIG_STA of bleeder circuit is connected to monarch CPU positive 4740 ADINI pin, and it is that pulsewidth level control register GPD27 output pulse width modulator control signal PWM4 gives backlight control module that the control signal that CPU sends is then utilized.
Be noted that wherein the position of divider resistance and photoresistance can exchange, as long as can realize same function by the change of CPU operation program.
Principle of work of the present utility model is: the resistance of photoresistance changes according to Strength Changes with ambient light.When illumination strengthened, the photoresistance resistance diminished, and when the light intensity deepening, it is big that the photoresistance resistance becomes.Because resistance change, thereby produce different magnitudes of voltage on the ADINI pin.
In this kind backlight control system, owing to adopt the variation of CPU (central processing unit) detection photoresistance, again by the central processing unit controls backlight illumination.Can be arranged on the different brightness of a certain brightness sub-screen easily by the demand of user according to oneself.Eternal unlatching backlight obviously also can be set.
Preferably, after CPU (central processing unit) detects the variation of photoresistance, when lighting screen, can adopt the gradually bright mode of screen, the soft screen of lighting.Also can receive system directive, according to user's demand change screen intensity by CPU (central processing unit).
Below in conjunction with Fig. 4 and one group of concrete hardware parameter, workflow of the present utility model is illustrated.
For example, the divider resistance resistance is 100K ohm, and MG41-21 is selected in photoresistance for use, the variation range of its resistance from 1k to 100K ohm.VCC is 5 volts of direct currents, and the voltage range that can calculate dividing potential drop on the ADINI pin thus is 0.05 volt to 2.5 volts.
Register GPD27 is a pulsewidth level control register.The positive 4740 model cpu of monarch utilize the effective impulse width of this register controlled output level, and the effective range of this register value is 0 to 99, and when writing 0, pulsewidth is 0%, the output power minimum, and when writing 99, pulsewidth is 100%, the output power maximum.Utilize the light on and off degree of this Characteristics Control display screen in the utility model.
When control law for will when intensity of illumination is 10Lx (darkness), extinguish liquid crystal display, when intensity of illumination is 60Lx (daybreak), light liquid crystal display, then the embodiment of the control flow of program as shown in Figure 4.At first by simple computation as can be known, when intensity of illumination was 10Lx, the voltage of pin ADINI was approximately 2.30V, and when intensity of illumination was 60Lx, the value of ADINI was approximately 0.8V.
CPU reads the magnitude of voltage of ADINI, and this magnitude of voltage judged, when voltage the time less than 0.8V, illustrate that it is bright, thus write " 99 " to register GPD27, if voltage is more than or equal to 0.8V, then continue to judge that whether it is greater than 2.3V, if this voltage then illustrates darkness greater than 2.3V, need extinguish liquid crystal display, so write " 0 " to register GPD27; If voltage between 0.8V and 2.3V, then is failure to actuate.Wait for the time (present embodiment was an example with 10 seconds) of appointment afterwards, beginning sampling and judgement next time.
For the light on and off of more flexible control liquid crystal display, also can artificially set other light on and off threshold value, program is judged according to setting value when comparing operation, controls the light on and off of liquid crystal display then.To the numerical value that register GPD27 writes, can realize more humane light on and off liquid crystal display operation by control, for example:
Write numerical value to register GPD27 pin, increase to 99 gradually from 0, bright gradually;
Think that the GPD27 pin writes numerical value, be reduced to 0 gradually from 99, go out gradually;
Control writes the gradual change speed that data frequency just can be controlled screen intensity;
Control the scope that writes data and just can control the bright dark degree of screen.
Claims (4)
1, a kind of backlight control system, it is characterized in that, comprise the photoresistance that connects successively, CPU (central processing unit) and backlight control module, wherein said photoresistance is connected with a divider resistance and is constituted bleeder circuit, the two ends of this bleeder circuit connect direct supply and ground connection respectively, and its mid point is connected to an analog quantity input port of CPU (central processing unit), and an output port of described CPU (central processing unit) is connected to described backlight control module.
2, backlight control system according to claim 1 is characterized in that, described CPU (central processing unit) comprises a width modulation level control register, and this CPU (central processing unit) is connected to backlight control module by this width modulation level control register.
3, a kind of mediaphone, it is characterized in that, described mediaphone comprises a backlight control system, described backlight control system comprises the photoresistance that connects successively, CPU (central processing unit) and backlight control module, wherein said photoresistance is connected with a divider resistance and is constituted bleeder circuit, the two ends of this bleeder circuit connect direct supply and ground connection respectively, its mid point is connected to an analog quantity input port of CPU (central processing unit), an output port of described CPU (central processing unit) is connected to described backlight control module, and this photoresistance is arranged on the shell of described mediaphone.
4, according to claim 1, it is characterized in that described CPU (central processing unit) comprises a width modulation level control register, this CPU (central processing unit) is connected to backlight control module by this width modulation level control register.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2009201055735U CN201355552Y (en) | 2009-02-26 | 2009-02-26 | Backlight control system and multimedia telephone using same |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2009201055735U CN201355552Y (en) | 2009-02-26 | 2009-02-26 | Backlight control system and multimedia telephone using same |
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| CN201355552Y true CN201355552Y (en) | 2009-12-02 |
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| CNU2009201055735U Expired - Fee Related CN201355552Y (en) | 2009-02-26 | 2009-02-26 | Backlight control system and multimedia telephone using same |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102572455A (en) * | 2010-12-09 | 2012-07-11 | 承景科技股份有限公司 | 2D--to-3D delay compensation system and method thereof |
| CN103401970A (en) * | 2013-07-23 | 2013-11-20 | 广东欧珀移动通信有限公司 | Method and system for adjusting display screen backlight and mobile terminal |
| CN106128416A (en) * | 2016-08-16 | 2016-11-16 | 广东欧珀移动通信有限公司 | Control method, control device and electronic installation |
| CN109748182A (en) * | 2017-11-06 | 2019-05-14 | 上海三菱电梯有限公司 | The cover board test device of passenger conveying equipment |
| CN112992040A (en) * | 2021-04-13 | 2021-06-18 | 成都天马微电子有限公司 | Adjusting circuit and display device |
-
2009
- 2009-02-26 CN CNU2009201055735U patent/CN201355552Y/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102572455A (en) * | 2010-12-09 | 2012-07-11 | 承景科技股份有限公司 | 2D--to-3D delay compensation system and method thereof |
| CN103401970A (en) * | 2013-07-23 | 2013-11-20 | 广东欧珀移动通信有限公司 | Method and system for adjusting display screen backlight and mobile terminal |
| CN103401970B (en) * | 2013-07-23 | 2015-11-18 | 广东欧珀移动通信有限公司 | A kind of method, system and mobile terminal regulating display backlight |
| CN106128416A (en) * | 2016-08-16 | 2016-11-16 | 广东欧珀移动通信有限公司 | Control method, control device and electronic installation |
| CN109748182A (en) * | 2017-11-06 | 2019-05-14 | 上海三菱电梯有限公司 | The cover board test device of passenger conveying equipment |
| CN109748182B (en) * | 2017-11-06 | 2020-12-22 | 上海三菱电梯有限公司 | Cover plate detection device of passenger conveying equipment |
| CN112992040A (en) * | 2021-04-13 | 2021-06-18 | 成都天马微电子有限公司 | Adjusting circuit and display device |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20091202 Termination date: 20110226 |