Inside display chip is realized the method for analog-to-digital conversion calibration
Technical field
The present invention relates to a kind of method of display calibration, particularly a kind of inside display chip is realized the method for analog-to-digital conversion calibration.
Background technology
At present, in the process that display is researched and developed and produced, need to carry out auto color calibration (Auto Color) operation to display, change to bright homogeneous so that display can show by dark from low GTG (0) to high gray (255).This process is mainly finished by two parameters biasings of adjustment (offset) and gain (gain).Concrete grammar is: the 16 GTG test patterns that sent standard by signal generator to display, the relevant register of display image process chip is set, can capture so the magnitude of voltage (Vmax) of bright spot in the picture and the magnitude of voltage (Vmin) of dim spot, become digital signal through analog to digital conversion, by adjusting the value of offset and gain, it is corresponded to respectively 255, and (hexadecimal representation is: 0xFF) with 0, as shown in Figure 1.At last
,Vmin is corresponded to respectively 0 ~ 0xFF to the voltage homogenization of Vmax.
It is this that display is carried out the method for Auto Color calibration is commonplace.Wherein must use signal generator to send test pattern, although this test pattern is 16 GTG test patterns of standard, but can produce certain error in this process of the picture processing chip from the signal generator to the display, thereby affect the result of auto color correction.On the other hand, from the angle of producing, technique more complicated, operability are not strong, use signal generator cumbersome yet, and productivity is not strong, and cost is also higher; The deficiency that more than exists all can affect the quality of product integral body; Yields is lower, and the consistance of assembling product is relatively poor.
Therefore, for the quality of Effective Raise product, its packaging technology, structural design are rationalized more, continually developed the more novel product of efficient energy-saving, improve market share, become one of new problem that this field technology personnel are badly in need of solving.
Summary of the invention
The object of the invention is to overcome above-mentioned weak point, provide a kind of technique simple, density is high, dependable performance, and the inside display chip that improves product quality is realized the method for analog-to-digital conversion calibration.
The technical solution adopted in the present invention is for achieving the above object: a kind of inside display chip is realized the method for analog-to-digital conversion calibration, it is characterized in that implementation step is as follows:
The first step: get chip internal and produce minimum voltage value (Vmin) and maximum voltage value (Vmax);
Second step: by analog to digital conversion, the minimum voltage value is converted to digital signal, because there is certain error in analog to digital conversion, so the minimum voltage value can not be converted to digital signaling zero; By regulating the value of biasing, so that minimum voltage can correspond to digital signaling zero;
The 3rd step: by analog to digital conversion, maximum voltage value is converted to digital signal, because there is certain error in analog to digital conversion, so maximum voltage value can not be converted to digital signaling zero xFF; By regulating the value of gain, so that maximum voltage can correspond to digital signaling zero xFF;
The 4th step: the voltage between minimum voltage value (Vmin)~maximum voltage value (Vmax) is carried out homogenization process, by analog to digital conversion, it is corresponded to digital signaling zero~0xFF;
Computing formula is:
Wherein:
Vdigital---digital signal;
Vanalog---simulating signal;
The minimum voltage that Vmin---chip internal produces, ideal value is 0V;
The maximum voltage that Vmax---chip internal produces, ideal value is 0.7V;
Int---rounding operation or the computing that rounds up.
The invention has the beneficial effects as follows: the present invention proposes and a kind ofly realize analog-to-digital conversion calibration by chip internal, thereby finish the new method of auto color calibration.The method does not use signal generator to send test pattern, produce minimum voltage value (Vmin) and maximum voltage value (Vmax) by chip internal, by adjusting the value of biasing and gain, be digital signal through analog to digital conversion with analog signal conversion again, and correspond to respectively 0 and 0xFF.Adopt the inventive method not only to save the process that signal generator is sent out test pattern, improved in process of production work efficiency, simultaneously, also reduced by signal generator issuing a signal to the possibility that picture processing chip produces error, made the result more accurately rationally.All processes of this chip internal realization analog-to-digital conversion calibration are all finished by chip, do not need to use outside any signal just can finish.
In a word, technique of the present invention is simpler, dependable performance, and Effective Raise product overall quality, and guarantee the consistance that machine product is assembled.
Description of drawings
Fig. 1 is existing display chip circuit side connector block diagram;
Fig. 2 is display chip circuit side connector block diagram of the present invention;
Fig. 3 adopts the inventive method result curve to analyze synoptic diagram.
Embodiment
Below in conjunction with accompanying drawing and preferred embodiment, to according to embodiment provided by the invention, details are as follows for feature:
As shown in Figure 2, a kind of inside display chip is realized the method for analog-to-digital conversion calibration, it is characterized in that implementation step is as follows:
The first step: get chip internal and produce minimum voltage value (Vmin) and maximum voltage value (Vmax);
Second step: by analog to digital conversion, the minimum voltage value is converted to digital signal, because there is certain error in analog to digital conversion, so the minimum voltage value can not be converted to digital signaling zero; By regulating the value of biasing, so that minimum voltage can correspond to digital signaling zero;
The 3rd step: by analog to digital conversion, maximum voltage value is converted to digital signal, because there is certain error in analog to digital conversion, so maximum voltage value can not be converted to digital signaling zero xFF; By regulating the value of gain, so that maximum voltage can correspond to digital signaling zero xFF;
The 4th step: the voltage between minimum voltage value (Vmin)~maximum voltage value (Vmax) is carried out homogenization process, by analog to digital conversion, it is corresponded to digital signaling zero~0xFF;
Computing formula is:
Wherein:
Vdigital---digital signal;
Vanalog---simulating signal;
The minimum voltage that Vmin---chip internal produces, ideal value is 0V;
The maximum voltage that Vmax---chip internal produces, ideal value is 0.7V;
Int---rounding operation or the computing that rounds up.
The method does not use signal generator to send test pattern, and the voltage by chip internal generation 0V and 0.7V is converted to digital signal through ADC, corresponds to respectively 0 and 255 (FF).Like this, save signal generator and sent out the process of testing Pattern, improved in process of production work efficiency.Simultaneously, also reduced the possibility that is issued a signal to Scaler chip generation error by signal generator.
For example, minimum voltage value Vmin=0.01V and maximum voltage value Vmax=0.68V, the then Vdigital(0.01 of chip internal generation)=int((0.01-0.01)/(0.68-0.01) * 255)=0;
Be that the corresponding digital quantity 0(of minimum voltage value 0.01V hexadecimal representation is 0).
Vdigital(0.68)=int((0.68-0.01)/(0.68-0.01) * 255)=255; Be that the corresponding digital quantity 255(of maximum voltage value 0.68V hexadecimal representation is FF).
For the arbitrary value between Vmin ~ Vmax, such as 0.5V, Vdigital(0.5 then)=int((0.5-0.01)/(0.68-0.01) * 255)=186; Be that digital quantity 186(hexadecimal representation corresponding to 0.5V magnitude of voltage is BA).
The result that the inventive method obtains as shown in Figure 3.
Above-mentioned detailed description of the method for this inside display chip realization analog-to-digital conversion calibration being carried out with reference to embodiment; illustrative rather than determinate; therefore in the variation and the modification that do not break away under the general plotting of the present invention, should belong within protection scope of the present invention.