CN1467700A - Brightness regulating method and equipment for LCD - Google Patents
Brightness regulating method and equipment for LCD Download PDFInfo
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- CN1467700A CN1467700A CNA021264228A CN02126422A CN1467700A CN 1467700 A CN1467700 A CN 1467700A CN A021264228 A CNA021264228 A CN A021264228A CN 02126422 A CN02126422 A CN 02126422A CN 1467700 A CN1467700 A CN 1467700A
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Abstract
The invention relates to the method and apparatus for adjusting liquid crystal display brightness, characterized by that the brightness of the display is divided into a plurality of stages, during the high brightness stage the linear mode is used to control the intensity of the tube so a good color tracking effect is obtained, while during the low brightness stage the digital control mode is used to regulate the shading degree of the liquid crystal panel for improving the brightness ratio of the overall display, wherein during the medium brightness stage the tube and the liquid crystal panel are adjusted simultaneously, thus the brightness control characteristic curve can link the high and low intensity control smoothly.
Description
(1) technical field
Relevant a kind of LCD brightness method of adjustment of the present invention and device.
(2) background technology
Means are adjusted in the brightness that is applied to LCD at present, commonly at light source fluorescent tube or liquid crystal panel both one of adjust, wherein control the light source fluorescent tube and comprise following several means:
(1) linear adjust (Linear Mode): in LCD, its illuminating source is the fluorescent tube that is arranged at the liquid crystal panel rear from, and this kind mode is promptly directly adjusted the overall brightness of display by the luminous intensity that changes fluorescent tube, and wherein the luminous intensity of fluorescent tube is to present direct ratio to change according to strength of current.The advantage of this kind practice is that Control current intensity is to be a kind of linear adjustment, and only do not involve liquid crystal panel control at the adjustment of light source fluorescent tube, so having preferable color, display follows the tracks of (color tracking) effect, but disadvantage is brightness ratio and only can reaches 2: 1, if will reach the more requirement of high brightness ratio, will cross the weak operating voltage that can't be maintained fluorescent tube because of electric current, and then make picture generation scintillation or can't start fluorescent tube.Wherein so-called color tracking (color tracking) means when colour temperature is adjusted according to brightness and can be linear change, for example the red signal value (R value) of control can present redness when brightness 50, and when brightness 100, also can not become pink or other distortion phenomenon, i.e. representative has preferable color to follow the tracks of (color tracking).In addition, the definition of brightness ratio is the liquid crystal panel high light degree that can present and the ratio of low light level degree.
(2) pulse mode (Burst Mode): this kind is to adjust the lamp tube current size and reach brilliance control in pulse-length modulation (PWM) mode, its advantage is the brightness ratio of display greatly was increased to 10: 1～15: 1, yet working current is to drop on audiorange (about 150Hz ~ 300Hz) is so picture is interfered easily and easily produces the different sound of audio frequency because of being PWM kenel and frequency; Though its brightness ratio is increased to more than 10: 1, general user the brightness ratio of normal use to be about 5: 1 enough, the means of Given this planting belong to expensive control mode again, its commodity competitiveness relatively greatly weakens.
On the other hand, if the luminous intensity of light source fluorescent tube is fixed, and only adjust at the gain (Gain) of liquid crystal panel.The Gain that supposes liquid crystal panel has 100%, and 60% must keep for brightness (Brightness) adjustment and use wherein, its contrast (Contrast) part only accounts for 40% as adjustment, thereby the contrast effect on the sacrifice LCD picture.It is the shading degree of liquid crystal molecule that the Gain of wherein said liquid crystal panel can be considered, because of the physical characteristics of liquid crystal molecule is to arrange in order when the energising, light is passed through easily, otherwise during no power then fall into disarray light can't pass, so liquid crystal molecule institute role promptly as one deck optical gate with control light intensity.
(3) summary of the invention
Fundamental purpose of the present invention provides a kind of brightness adjustment technology of LCD, when adjusting light source fluorescent tube intensity simultaneously in conjunction with the gain (Gain) of digital form with the control liquid crystal panel, and make display have high brightness when color follow the tracks of (color tracking) effect.
For achieving the above object, one aspect of the present invention provides a kind of method of adjustment of LCD, includes:
The brightness setting range of definition display is the high, medium and low brightness stage;
Judge brightness adjustment command value, be positioned at what person in described high, medium and low brightness stage;
Wherein, if this brightness is adjusted command value in the high brightness stage, then change the light source fluorescent tube intensity of display; Adjust the shading degree of liquid crystal panel if when low-light level, then adopt digital form; If then adjust the shading degree of light source fluorescent tube intensity and liquid crystal panel synchronously in the middle brightness stage.
When carrying out the brightness adjustment of display in this way, by changing the brightness change family curve that fluorescent tube intensity can obtain linear smoothing, and have preferable color and follow the tracks of (color tracking), and when being aided with digital form and adjusting liquid crystal panel, then can when lighting tube brightness is more weak, obtain preferable contrast (contrast).
And implement the concrete device of described method of adjustment, include:
One microprocessor receives brightness adjustment instruction;
One pulse-length modulation control module receives the control signal that described microprocessor is exported, and adjusts the output current power of a fluorescent tube current transformer;
One voltage quasi position adjuster is by the control of described microprocessor, and the magnitude of voltage of exporting the accurate position of different direct currents is to adjust the shading degree of a liquid crystal panel;
Wherein this microprocessor according to brightness adjustment instruction decision with the output pulse bandwidth of PWM control module adjusting the luminous intensity of light source fluorescent tube, or with this voltage quasi position adjuster control liquid crystal panel, also or both adopt common control.
The present invention is the output brightness by control its lamp tube light source intensity of LCD and liquid crystal panel, avoids problem such as display produces colour cast, overflow look, flicker and possesses the method for adjustment that high brightness is followed the tracks of than, high comparative and excellent color
For further specifying purpose of the present invention, design feature and effect, the present invention is described in detail below with reference to accompanying drawing.
(4) description of drawings
Fig. 1 is a structure calcspar of the present invention.
Fig. 2 is the performance diagram of brightness of the present invention (longitudinal axis) to brightness adjusted value (transverse axis).
Fig. 3 is a process flow diagram of implementing the inventive method.
(5) embodiment
See also shown in Figure 1, LCD brightness adjusting gear of the present invention, be with a microprocessor 10 controls one PWM control module 20, the output pulse wave that utilizes these PWM control module 20 different in width is to adjust the output current 30 of fluorescent tube current transformer (inverter), and then can change the brightness that liquid crystal panel 50 is presented, in addition, described microprocessor 10 also can be controlled a voltage quasi position adjuster 40 simultaneously, utilizes the shading degree of the accurate position of the different direct current of output with this liquid crystal panel 50 of direct control.
See also shown in Figure 2, when utilizing adjustment technology of the present invention to implement, the brightness of display (Luminance) is to the performance diagram of brightness adjusted value (Adjust value), wherein the brightness adjusted value of transverse axis part can be considered the operation screen (OSD on display, On screen display) the adjustable brightness value range that is presented generally is to be defined as the 0-100 rank to adjust for the user.
At first the adjustable extent with 0-100 is defined as several stages, and present embodiment is that 100-50 is defined as the high brightness Phase I, if brightness Phase between 49-35, then being defined as, and 34 with the next low-light level Phase I that is considered as.Wherein the adjustment mode in each stage is as described below:
See also shown in Fig. 1,3, when the user utilizes OSD to adjust display, microprocessor 10 judges at first whether the scope of adjusted value is higher than 49 and fall within the high brightness stage, if, then microprocessor 10 will be controlled this PWM control module 20 output controlling values according to brightness adjustment instruction, this fluorescent tube current transformer 30 will be adjusted output current according to this controlling value, and then change lamp luminescence intensity, and this moment, this voltage quasi position adjuster 40 was to keep definite value and do not change.Wherein 20 its resolutions of the PWM control module in the present embodiment are to be example 0 ~ 256 with 256 rank, and the resolutions (+128 ~-127) on 256 rank are divided into dc voltage value in this voltage quasi position adjustment 40 equally.
If adjusted value is lower than at 49 o'clock, microprocessor 10 is not higher than 35 with judging further that again adjusted value has, if between 35-49, in the brightness stage in then belonging to, described PWM control module 20 will be controlled the display brightness of liquid crystal panel 50 jointly with voltage quasi position adjuster 40; Otherwise, if the brightness adjusted value is in 35 when following, then the output of this PWM control module 20 is to keep definite value and do not change, reduce the luminous intensity of fluorescent tube simultaneously, utilize the shading degree of voltage quasi position adjuster 40 this moment with digital form control liquid crystal panel 50, because of the intensity of fluorescent tube greatly reduces, so problems such as colour cast, the look that overflows can be avoided, preferable brightness ratio was higher than 4: 1 and good color is followed the tracks of (color tracking) and show.
Certainly, those of ordinary skill in the art will be appreciated that, above embodiment is used for illustrating the present invention, and be not to be used as limitation of the invention, as long as in connotation scope of the present invention, all will drop in the scope of claims of the present invention variation, the modification of the above embodiment.
Claims (6)
1. a LCD brightness method of adjustment is characterized in that, includes:
The brightness setting range of definition display is several brightness stages;
Judge the brightness adjustment pairing brightness stage of command value;
Adjust the lamp tube light source intensity of display according to the different brightness stages, or adjust the shading degree of liquid crystal panel.
2. LCD brightness method of adjustment as claimed in claim 1 is characterized in that, belongs to the high brightness stage if command value is adjusted in this brightness, then changes the light source fluorescent tube intensity of display; Adjust the shading degree of liquid crystal panel if when low-light level, then adopt digital form; If then adjust the shading degree of light source fluorescent tube intensity and liquid crystal panel jointly in the middle brightness stage.
3. as LCD brightness method of adjustment as described in the claim 2, it is characterized in that the light source fluorescent tube intensity that changes display is to adopt the PWM mode to adjust.
4. as LCD brightness method of adjustment as described in claim 2 or 3, it is characterized in that the digital form of adjusting liquid crystal panel is a shading degree of utilizing the DC voltage control liquid crystal panel of different accurate positions.
5. a LCD brightness adjusting gear is characterized in that, includes:
One microprocessor receives brightness adjustment instruction;
One pulse-length modulation control module receives the control signal that described microprocessor is exported, and adjusts the output current power of a fluorescent tube current transformer;
One voltage quasi position adjuster is by the control of described microprocessor, and the magnitude of voltage of exporting the accurate position of different direct currents is to adjust the shading degree of a liquid crystal panel;
It is characterized in that, this microprocessor according to brightness adjustment instruction decision adjust the luminous intensity of light source fluorescent tube with the pulse-length modulation control module, or with this voltage quasi position adjuster control liquid crystal panel, also or both adopt common control.
6. as LCD brightness adjusting gear as described in the claim 5, it is characterized in that brightness is adjusted the instruction area and is divided into the high, medium and low brightness adjusting stage, belong to the high brightness stage, then change the light source fluorescent tube intensity of display if command value is adjusted in this brightness; Adjust the shading degree of liquid crystal panel if when low-light level, then adopt digital form; If then adjust the shading degree of light source fluorescent tube intensity and liquid crystal panel jointly in the middle brightness stage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA021264228A CN1467700A (en) | 2002-07-11 | 2002-07-11 | Brightness regulating method and equipment for LCD |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA021264228A CN1467700A (en) | 2002-07-11 | 2002-07-11 | Brightness regulating method and equipment for LCD |
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| CN1467700A true CN1467700A (en) | 2004-01-14 |
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| CNA021264228A Pending CN1467700A (en) | 2002-07-11 | 2002-07-11 | Brightness regulating method and equipment for LCD |
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Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100433126C (en) * | 2005-09-06 | 2008-11-12 | 台达电子工业股份有限公司 | Display device and method capable of reinforcing image comparison |
| CN101441861B (en) * | 2007-11-23 | 2010-10-13 | 佛山市顺德区汉达精密电子科技有限公司 | Apparatus and method for low brightness display |
| CN101453608B (en) * | 2007-12-07 | 2010-12-01 | 瑞昱半导体股份有限公司 | Video data processing method and apparatus |
| CN101932159A (en) * | 2009-06-23 | 2010-12-29 | 启攀微电子（上海）有限公司 | Adaptive dimming control method for light emitting diode (LED) |
| CN101562936B (en) * | 2009-05-07 | 2013-05-22 | 福州华映视讯有限公司 | Method for improving and driving reaction time of backlight lighting tube brightness |
| US8654058B2 (en) | 2005-08-30 | 2014-02-18 | Delta Electronics Inc. | Apparatus and method for enhancing image contrast |
| CN103714797A (en) * | 2013-11-29 | 2014-04-09 | 青岛威力电子科技有限公司 | Frame brightness control device and method of image display equipment |
| CN103730100A (en) * | 2013-12-19 | 2014-04-16 | 青岛威力电子科技有限公司 | Image luminance adjusting method of image display device |
| CN110444180A (en) * | 2019-02-12 | 2019-11-12 | 南京中电熊猫平板显示科技有限公司 | A kind of abnormity display device |
| CN111048616A (en) * | 2019-12-16 | 2020-04-21 | 重庆邮电大学 | Variable resistor |
-
2002
- 2002-07-11 CN CNA021264228A patent/CN1467700A/en active Pending
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8654058B2 (en) | 2005-08-30 | 2014-02-18 | Delta Electronics Inc. | Apparatus and method for enhancing image contrast |
| CN100433126C (en) * | 2005-09-06 | 2008-11-12 | 台达电子工业股份有限公司 | Display device and method capable of reinforcing image comparison |
| CN101441861B (en) * | 2007-11-23 | 2010-10-13 | 佛山市顺德区汉达精密电子科技有限公司 | Apparatus and method for low brightness display |
| CN101453608B (en) * | 2007-12-07 | 2010-12-01 | 瑞昱半导体股份有限公司 | Video data processing method and apparatus |
| CN101562936B (en) * | 2009-05-07 | 2013-05-22 | 福州华映视讯有限公司 | Method for improving and driving reaction time of backlight lighting tube brightness |
| CN101932159A (en) * | 2009-06-23 | 2010-12-29 | 启攀微电子（上海）有限公司 | Adaptive dimming control method for light emitting diode (LED) |
| CN101932159B (en) * | 2009-06-23 | 2014-03-12 | 启攀微电子（上海）有限公司 | Adaptive dimming control method for light emitting diode (LED) |
| CN103714797A (en) * | 2013-11-29 | 2014-04-09 | 青岛威力电子科技有限公司 | Frame brightness control device and method of image display equipment |
| CN103730100A (en) * | 2013-12-19 | 2014-04-16 | 青岛威力电子科技有限公司 | Image luminance adjusting method of image display device |
| CN110444180A (en) * | 2019-02-12 | 2019-11-12 | 南京中电熊猫平板显示科技有限公司 | A kind of abnormity display device |
| CN111048616A (en) * | 2019-12-16 | 2020-04-21 | 重庆邮电大学 | Variable resistor |
| CN111048616B (en) * | 2019-12-16 | 2021-06-18 | 重庆邮电大学 | Variable resistor |
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