This application claims the priority to and benefit of Chinese patent application CN201910275200.0, entitled “Driving Method and System of Display assembly, and Display Device” and filed Apr. 8, 2019, and Chinese patent application number CN201910275212.3, entitled “Driving Method and System of Display assembly, and Display Device” and filed Apr. 8, 2019, with China National Intellectual Property Administration, the entire contents of which are incorporated herein by reference.
This application relates to the field of display technology, and more particularly relates to a driving method and system of a display assembly, and a display device.
The statements herein merely provide background information related to the present application but don't necessarily constitute the prior art.
As science and technology continue to develop and progress, liquid crystal displays (LCDs) have become the mainstream forms of displays due to their thin body, power saving, and low radiation, and have been widely used. Most of the LCDs are backlit-type LCDs, which include a liquid crystal panel and a backlight module. The working principle of the liquid crystal panel consists in placing liquid crystal molecules between two parallel glass substrates, and applying a driving voltage to the two glass substrates to control the rotational direction of the liquid crystal molecules thus refracting light emitted from the backlight module to produce pictures.
In an undisclosed solution used by the inventor, the saturation of the signal is adjusted to mitigate the color shift issue, but doing so will cause loss in the presentation of the saturation of the signal.
In view of the above, it is therefore an object of this application to provide a driving method and system for a display assembly, and a display device, which can reduce the color shift while maintaining color purity performance.
The present application discloses a driving method of a display assembly, the driving a driving process of a display panel and a driving process of a backlight module that are synchronously performed.
The backlight module includes a plurality of independently controlled light sources, including a first color light source, a second color light source, and a third color light source. The corresponding light source brightness of the first color light source is a first brightness value, the corresponding light source brightness of the second color light source is a second brightness value, and the corresponding light source brightness of the third color light source is a third brightness value.
The driving process of the display panel includes the following operations:
receiving a first color signal corresponding to the display panel, converting the first color signal into first brightness normalized signals, and converting the first brightness normalized signals into a first HSV (hue, saturation, value) signal;
adjusting a first saturation signal of the first HSV spatial signal using a preset adjustment coefficient to obtain a second saturation signal;
converting the second saturation signal into a second color signal; and
driving the display panel using the second color signal.
The driving process of the backlight module includes the following operations:
receiving the first color signal corresponding to the display panel, and obtaining the first saturation signal and the second saturation signal;
determining a minimum color light source among the first color light source, the second color light source, and the third color light source, and obtaining a light source adjustment coefficient corresponding to the minimum color light source based on the first saturation signal and the second saturation signal; and
driving the minimum color light source using a fourth brightness value.
The present application further discloses a driving system of a display assembly using a driving method of the display assembly, the driving system including: a driving circuitry of a display panel and a driving circuitry of a backlight module, the display panel and the backlight module being driven synchronously. The backlight module includes a plurality of independently controlled light sources, including a first color light source, a second color light source, and a third color light source. The corresponding light source brightness of the first color light source is a first brightness value, the corresponding light source brightness of the second color light source is a second brightness value, and the corresponding light source brightness of the third color light source is a third brightness value. The driving circuitry of the display panel includes a receiver configured for receiving a first color signal corresponding to the display panel, converting the first color signal into first brightness normalized signals, and converting the first brightness normalized signals into a first HSV (hue, saturation, value) signal; an adjuster configured for adjusting a first saturation signal of the first HSV spatial signal using a preset adjustment coefficient to obtain a second saturation signal; a converter configured for converting the second saturation signal into a second color signal; and a driver configured for driving the display panel using the second color signal. The driving circuitry of the backlight module includes a receiver configured for receiving the first color signal corresponding to the display panel, and obtaining the first saturation signal and the second saturation signal; a light source determiner configured for determining a minimum color light source among the first color light source, the second color light source, and the third color light source, and obtaining a light source adjustment coefficient corresponding to the minimum color light source based on the first saturation signal and the second saturation signal; a light source adjuster configured for adjusting the minimum color light source using the light source adjustment coefficient to obtain a fourth brightness value; and a light source driver configured for driving the minimum color light source using the fourth brightness value.
The present application further discloses a display device, including a display assembly and a driving system of the display assembly. The driving system of the display assembly includes a drive circuitry of a display panel and a drive circuitry of a backlight module, the display panel and the backlight module being driven synchronously. The backlight module includes a plurality of independently controlled light sources, including a first color light source, a second color light source, and a third color light source. The corresponding light source brightness of the first color light source is a first brightness value, the corresponding light source brightness of the second color light source is a second brightness value, and the corresponding light source brightness of the third color light source is a third brightness value. The driving circuitry of the display panel includes a receiver configured for receiving a first color signal corresponding to the display panel, converting the first color signal into first brightness normalized signals, and converting the first brightness normalized signals into a first HSV (hue, saturation, value) signal; an adjuster configured for adjusting a first saturation signal of the first HSV spatial signal using a preset adjustment coefficient to obtain a second saturation signal; a converter configured for converting the second saturation signal into a second color signal; and a driver configured for driving the display panel using the second color signal. The driving circuitry of the backlight module includes a receiver configured for receiving the first color signal corresponding to the display panel, and obtaining the first saturation signal and the second saturation signal; a light source determiner configured for determining a minimum color light source among the first color light source, the second color light source, and the third color light source, and obtaining a light source adjustment coefficient corresponding to the minimum color light source based on the first saturation signal and the second saturation signal; a light source adjuster configured for adjusting the minimum color light source using the light source adjustment coefficient to obtain a fourth brightness value; and a light source driver configured for driving the minimum color light source using the fourth brightness value; where the display assembly includes the display panel the a backlight module.
Compared with the scheme of dividing a pixel of the display panel into a main pixel and a sub-pixel to mitigate the color shift problem, an exemplary technique includes adjusting the first saturation to obtain a second saturation, converting the second saturation into a second color signal, and driving the display panel using the second color signal, which can well improve the color shift problem. However, due to the adjustment of the saturation value, the image quality and the saturation will be lacking. This application obtains the light source adjustment coefficient based on the first saturation signal and the second saturation signal to adjust the brightness of the minimum color light source, which improves the hue that experiences loss of saturation, and even enables the adjusted color point return to the original saturated color point in conjunction with the adjusted light source intensity, thereby maintaining the color purity performance while reducing the viewing angle color shift.
The drawings included herein are intended to provide a further understanding of the embodiments of the present application. They constitute a part of the specification, and are used to illustrate the embodiments of the present application, and explain the principle of the present application in conjunction with the specification. Apparently, the drawings in the following description merely represent some embodiments of the present disclosure, and for those having ordinary skill in the art, other drawings may also be obtained based on these drawings without investing creative efforts. In the drawings:
Large-size liquid crystal display panels mostly use negative-type VA (Vertical Alignment) liquid crystal technology or IPS (In-Plane switching) liquid crystal technology. Compared with IPS liquid crystal technology, VA liquid crystal technology has advantages of higher efficiency of production and lower manufacturing costs. However, VA liquid crystal technology has obvious optical defects in terms of optical properties compared with IPS liquid crystal technology, which is significant particularly in commercial applications of large-size panels that require a larger viewing angle.
An exemplary solution is to subdivide each sub-pixel of RGB into a main pixel and a sub-pixel, so that the changes in the overall large viewing angle brightness along with the voltage may become relatively closer to those in the front view.
The ratio of brightness change to the high voltage side viewing angle voltage on the liquid crystal display is more likely to become saturated, so the original signal is divided into a large voltage plus a small voltage signal. As is illustrated in
In this solution, the main and sub-pixels are spatially give different driving voltages to solve the viewing angle color shift defects. However, such pixel design often requires redesigning the metal traces or TFT (Thin Film Transistor) elements for purposes of driving the sub-pixels, resulting in sacrifice of the light transmittable opening area, which affects the transmittance of the panel and directly causes the increase in the cost of the backlight.
Hereinafter, this application will be described in further detail in connection with the drawings and some optional embodiments.
As illustrated in
As illustrated in
The backlight module includes at least one backlight subarea, and each backlight subarea includes a first color light source, a second color light source, and a third color light source that are independently controlled. The corresponding light source brightness of the first color light source is a first brightness value, the corresponding light source brightness of the second color light source is a second brightness value, and the corresponding light source brightness of the third color light source is a third brightness value.
The driving circuitry 110 of the display panel includes a receiver 111, an adjuster 112, a converter 113, and a driver 114. The receiver 111 receives a first color signal corresponding to the display panel, converts the first color signal into first brightness normalized signals, and converts the first brightness normalized signals into a first HSV (hue, saturation, value) signal. The adjuster 112 adjusts a first saturation signal of the first HSV spatial signal by a preset adjustment coefficient to obtain a second saturation signal. The converter 113 converts the second saturation signal into a second color signal. And the driver 114 drives the display panel using the second color signal.
The driving circuitry 120 of the backlight module includes a light source receiver 121, a light source determiner 123, a light source adjuster 124, and a light source driver 125. The light source receiver 121 receives the first color signal corresponding to the display panel, and obtains the first saturation signal and the second saturation signal. The light source determiner 123 determines the minimum color light source among the first color light source, the second color light source, and the third color light source, and obtains a light source adjustment coefficient corresponding to the minimum color light source based on the first saturation signal and the second saturation signal. The light source adjuster 124 uses the light source adjustment coefficient to adjust the minimum color light source to obtain a fourth brightness value. And the light source driver 125 uses the fourth brightness value to drive the minimum color light source.
As illustrated in
The backlight module includes a plurality of independently controlled light sources, including a first color light source, a second color light source, and a third color light source. The corresponding light source brightness of the first color light source is a first brightness value, the corresponding light source brightness of the second color light source is a second brightness value, and the corresponding light source brightness of the third color light source is a third brightness value.
The driving process of the display panel includes the following operations:
S11: receiving a first color signal corresponding to the display panel, converting the first color signal into first brightness normalized signals, and converting the first brightness normalized signals into a first HSV (hue, saturation, value) signal;
S12: adjusting a first saturation signal of the first HSV spatial signal using a preset adjustment coefficient to obtain a second saturation signal;
S13: converting the second saturation signal into a second color signal; and
S14: driving the display panel using the second color signal;
The driving process of the backlight module includes the following operations:
S21: receiving the first color signal corresponding to the display panel, and obtaining the first saturation signal and the second saturation signal;
S22: determining a minimum color light source among the first color light source, the second color light source, and the third color light source, and obtaining a light source adjustment coefficient corresponding to the minimum color light source based on the first saturation signal and the second saturation signal; and
S23: a light source adjuster configured for adjusting the minimum color light source using the light source adjustment coefficient to obtain a fourth brightness value; and
S24: driving the minimum color light source using a fourth brightness value.
Compared with the solution of dividing a pixel of the display panel into a main pixel and a sub-pixel to mitigate the color shift problem, an exemplary technique includes adjusting the first saturation to obtain a second saturation, converting the second saturation into a second color signal, and driving the display panel using the second color signal, which can well improve the color shift problem. However, due to the adjustment of the saturation value, the image quality and the saturation will be lacking. This application obtains the light source adjustment coefficient based on the first saturation signal and the second saturation signal to adjust the brightness of the minimum color light source, which improves the hue that experiences loss of saturation, and even enables the adjusted color point return to the original saturated color point in conjunction with the adjusted light source intensity, thereby maintaining the color purity performance while reducing the viewing angle color shift. In the above description, the color signals can be an RGB three primary-color-signals. In particular, the first color signal may be a first RGB three primary-color-signal, and the second color signal may be a second RGB three primary-color-signal.
The operation of adjusting the first saturation signal of the first HSV spatial signal using the preset adjustment coefficient to obtain a second saturation signal may include:
obtaining the second saturation signal S′n_i,j from the first saturation signal Sn_i,j through the following formula:
S′n_i,j=a×S4n_i,j+b×S3n_i,j+c×S2n_i,j+d×Sn_i,j+e;
where a, b, c, d, e are preset adjustment coefficients.
The operation of converting the second saturation signal into the second color signal may include: converting the second saturation signal to obtain a second HSV spatial signal, and turning down the minimum value of the brightness normalized signals according to the second HSV spatial signal to obtain second brightness normalized signals; and
converting the second brightness normalized signals to obtain the second color signal.
The operation of determining the minimum color light source among the first color light source, the second color light source, and the third color light source, and obtaining the light source adjustment coefficient corresponding to the minimum color light source based on the first saturation signal and the second saturation signal may include: determining the middle color light source and the minimum color light source among the first color light source, the second color light source, and the third color light source; obtaining the light source adjustment coefficient corresponding to the minimum color light source and the light source adjustment coefficient corresponding to the middle color light source based on the first saturation signal and the second saturation signal;
The operation of adjusting the minimum color light source using light source adjustment coefficient to obtain the fourth brightness value, and driving the minimum color light source using the fourth brightness value may include: adjusting the minimum color light source using the light source adjustment coefficient corresponding to the minimum color light source to obtain the fourth brightness value, and adjusting the middle color light source using the light source adjustment coefficient corresponding to the middle color light source to obtain a fifth brightness value; driving the minimum color light source using the fourth brightness value, and driving the middle color light source using the fifth brightness value.
This application not only uses the fourth brightness value to drive the minimum color light source, but also uses the fifth brightness value to drive the middle color light source, so that both the minimum color light source and the middle color light source can enhance the corresponding under-displayed hues to make them return to the original saturated color points, thereby maintaining the color purity of the hues corresponding to the minimum color light source and the middle color light source.
Furthermore, the operation of determining the minimum color light source among the first color light source, the second color light source, and the third color light source, and obtaining the light source adjustment coefficient corresponding to the minimum color light source based on the first saturation signal and the second saturation signal may include: determining the maximum color light source, the middle color light source, and the minimum color light source among the first color light source, the second color light source, and the third color light source; obtaining the light source adjustment coefficient corresponding to the maximum color light source, the light source adjustment coefficient corresponding to the minimum color light source and the light source adjustment coefficient corresponding to the middle color light source, based on the first saturation signal and the second saturation signal.
The operation of adjusting the minimum color light source using light source adjustment coefficient to obtain the fourth brightness value, and driving the minimum color light source using the fourth brightness value may include: adjusting the minimum color light source using the light source adjustment coefficient corresponding to the minimum color light source to obtain the fourth brightness value, and adjusting the middle color light source using the light source adjustment coefficient corresponding to the middle color light source to obtain a fifth brightness value; adjusting the maximum color light source using the light source adjustment coefficient corresponding to the maximum color light source to obtain a sixth brightness value; driving the minimum color light source using the fourth brightness value; driving the middle color light source using the fifth brightness value; and driving the maximum color light source using the sixth brightness value.
That is, this application uses the fourth brightness value to drive the minimum color light source, the fifth brightness value to drive the middle color light source, and the sixth brightness value to drive the maximum color light source, so that all the minimum color light source, the middle color light source and the maximum color light source can enhance the corresponding under-displayed hues to make them return to the original saturated color points, thereby maintaining the color purity of the hues corresponding to the minimum color light source, the middle color light source, and the maximum color light source.
The operation of determining the minimum color light source among the first color light source, the second color light source, and the third color light source, and obtaining the light source adjustment coefficient corresponding to the minimum color light source based on the first saturation signal and the second saturation signal may include:
obtaining the first brightness normalized signals corresponding to the first saturation signal, and separately calculating the first maximum signal, the first middle signal, and the first minimum signal among an average signal of the first red brightness normalized signal, an average signal of the first green brightness normalized signal, and an average signal of the first blue brightness normalized signal;
obtaining the second brightness normalized signals corresponding to the second saturation signal, and separately calculating the second maximum signal, the second middle signal, and the second minimum signal among an average signal of the second red brightness normalized signal, an average signal of the second green brightness normalized signal, and an average signal of the second blue brightness normalized signal;
obtaining the first light source adjustment coefficient corresponding to the minimum color light source based on the first minimum signal and the second minimum signal;
obtaining the second light source adjustment coefficient corresponding to the middle color light source based on the first middle signal and the second middle signal;
where the backlight module is a direct-lit backlight, which includes multiple backlight subareas, and each backlight subarea includes a red light source, a green light source, and a blue light source that are independent of each other;
the first brightness normalized signals include a first red brightness normalized signal, a first green brightness normalized signal, and a first blue brightness normalized signal;
the second brightness normalized signals include a second red brightness normalized signal, a second green brightness normalized signal, and a second blue brightness normalized signal;
Through a comparison between the first maximum signal, the first middle signal, and the first minimum signal in the average signals of the red, green, and blue hues corresponding to the first saturation signal, and the second maximum signal, the second middle signal, and the second minimum signal in the average signals of the red, green, and blue hues corresponding to the second saturation signal (obtained by adjusting the first saturation signal), the first light source adjustment coefficient and the second light source adjustment coefficient are obtained to realize the targeted adjustments of the light sources, so that the light sources can accurately increase the light intensity of the light source according to the amplitudes of the drops of the first minimum signal and the first middle signal, so as to achieve the goal of balance even after adjusting the color saturation. With the aid of the light source, the color point can return to the original saturated color point, thereby reducing the color shift of the display panel while maintaining the color purity performance.
The first maximum signal maxn_ave, the first middle signal midn_ave, the first minimum signal minn_ave, the average signal rn_ave of the first red brightness normalized signal, the average signal gn_ave of the first green brightness normalized signal, and the average signal bn_ave of the first blue brightness normalized signal satisfy the following formulas: maxn_ave=Max(rn_ave, gn_ave, bn_ave); midn_ave=Mid(rn_ave, gn_ave, bn_ave); and minn_ave=Min(rn_ave, gn_ave, bn_ave).
The second maximum signal max′n_ave, the second middle signal mid′n_ave, the second minimum signal min′n_ave, the average signal r′n_ave of the second red brightness normalized signal, the second green brightness normalized signal, and the average signal b′n_ave of the second blue brightness normalized signal satisfy the following formulas: max′n_ave=Max(r′n_ave, g′n_ave, b′n_ave); mid′n_ave=Mid(r′n_ave, g′n_ave, b′n_ave); min′n_ave=Min(r′n_ave, g′n_ave, b′n_ave). The first maximum signal maxn_ave, the first middle signal midn_ave, the first minimum signal mimn_ave, the second maximum signal max′n_ave, the second middle signal mid′n_ave, and the second minimum signal min′n_ave in this application are all obtained by calculation, which improves the accuracy of light source adjustment in this application.
rn_ave=Average(rn_1,1,rn_1,2, . . . ,rn_i,j);
gn_ave=Average(gn_1,1,gn_1,2, . . . ,gn_i,j); and
bn_ave=Average(bn_1,1,bn_1,2, . . . ,bn_i,j).
The second red brightness normalized signals corresponding to the backlight subarea are: r′n_1,1, r′n_1,2, . . . , r′n_i,j. The second green brightness normalized signals corresponding to the backlight subarea are g′n_1,1, g′n_1,2, . . . , g′n_i,j. The second blue brightness normalized signals corresponding to the backlight subarea are b′n_1,1, b′n_1,2, . . . , b′ n_i,j. The average signal r′n_ave of the second red brightness normalized signals, the average signal g′n_ave of the second green brightness normalized signals, and the average signal b′n_ave of the second blue brightness normalized signals satisfy the following formulas:
r′n_ave=Average(r′n_1,1,r′n_1,2, . . . ,r′n_i,j);
g′n_ave=Average(g′n_1,1,g′n_1,2, . . . ,g′n_i,j); and
b′n_ave=Average(b′n_1,1,b′n_1,2, . . . ,b′n_i,j).
By calculating the red, green, and blue brightness normalized signals before and after each adjustment, the average signal of the first red brightness normalized signals, the average signal of the first green brightness normalized signals, the average signal of the first blue brightness normalized signals, the average signal of the second red brightness normalized signals, the average signal of the second green brightness normalized signals, and the average signal of the second blue brightness normalized signals are obtained. The calculation method according to this solution takes into consideration the changes in the brightness normalized signals each pixel, so that the calculated construction is representative and accurate, which realizes accurate and efficient adjustment of the light source, making the light intensity displayed by the adjusted light source have a higher degree of consistency with the expectation.
In addition, for example, when the hue calculated by the first brightness normalized signal satisfies: 0<Hn_i,j<30 (that is, red is the main hue), then the first middle brightness normalized signal and the first minimum brightness normalized signal would maintain the fixed brightness difference of gn_i,j−bn_i,j=g′n_i,j-b′n_i,j.
Assuming that the first light source adjustment coefficient is x and the second light source adjustment coefficient is y, the following formulas are satisfied: midn_ave=x×mid′n_ave, minn_ave=y×min′n_ave. Through the calculation according to the formulas, the signal change ratio is obtained, so that the ratio of the light source to be adjusted can be calculated correspondingly. In addition, the present application may also obtain the third light source adjustment coefficient corresponding to the maximum color light source based on the first maximum signal and the second maximum signal. Let the third light source adjustment coefficient be z, then the following formula is satisfied: maxn_ave=x×max′n_ave.
During the driving process of the display panel, the operation of receiving the first color signal corresponding to the display panel, converting the first color signal into the first brightness normalized signals, and converting the first brightness normalized signals into the first HSV spatial signal may include the following. The input signal of the first color signal is an 8-bit grayscale digital signal of 0, 1, . . . 255, and the grayscale signals are input as first brightness normalized signals (grayscale of 255 is the maximum brightness) with respect to 255, which are r, g, b, respectively,
r=(R/255){circumflex over ( )}γr,g=(G/255){circumflex over ( )}γg,b=(B/255){circumflex over ( )}γb;
where γr, γg, and γb are gamma signals.
As illustrated in
The formulas for converting the brightness normalized signals r, g, b into hue h and saturation signal s are as follows:
where max represents the maximum value in r/g/b, and min represents the minimum value in r/g/b.
S′n_i,j=a×S4n_i,j+b×S3n_i,j+c×S2n_i,j+d×Sn_i,j+e;
where a, b, c, d, e are preset adjustment coefficients, which are constants and can be adjusted according to actual needs.
The operation of converting the second saturation signal into the second color signal may include: converting the second saturation signal to obtain a second HSV spatial signal, and turning down the minimum value of the brightness normalized signals according to the second HSV spatial signal to obtain second brightness normalized signals; and
converting the second brightness normalized signals to obtain the second color signal.
In one embodiment, the present application may also divide the hue H into a number of m hue intervals.
S′(H(m),S)=a(H(m))×S4+b(H(m))×S3+c(H(m))×S2+d(H(m))×S+e(H(m))
where a(H(m)), b(H(m)), c(H(m)), d(H(m)), e(H(m)) are saturation adjustment constants of the corresponding hue interval.
After the hue (H) is divided into multiple intervals, because different intervals have different degrees of color shift, different adjustments to the saturation can be made according to different intervals, which can increase the color vividness of the display panel, and make adjustment of the color shift more even.
The operation of converting the second saturation signal into the second color signal may include: converting the second saturation signal S′n_i,j to obtain second brightness normalized signals, and converting the second brightness normalized signals r′, g′, b′ using the following formulas to obtain the second color signal R′, G′, B′:
R′=255×(r′)1/γr,G′=255×(g′)1/γg,B′=255×(b′)1/γb.
While using the second three primary colors of red, green, and blue to drive the display panel, the fourth brightness value is used to drive the minimum color light source, and the fifth brightness value is used to drive the middle color light source.
In addition, also taking red as an example, where red is the main hue in the pure red hue, this application may also increase the minimum brightness normalized signal in the brightness normalized signals of other colors in the red pure hue, thereby reducing the saturation of hue with red as the main hue. This will make the mixed color close to the white neutral color, and the main reason that the color shift of the neutral color will be reduced is because the three primary colors of red, green, and blue are all allowed to leak, so that the mixture of the leaked colors of the three primary colors will not produce a color, that is, the colors of leaked light at the front and side views are a neutral color.
As another embodiment of the present application, as illustrated in
The driving circuitry 110 of the display panel includes a receiver 111, an adjuster 112, and a driver 113. The receiver 111 receives a first color signal corresponding to the display panel, converts the first color signal into first brightness normalized signals, and converts the first brightness normalized signals into a first HSV (hue, saturation, value) signal. The adjuster 112 adjusts a first saturation signal of the first HSV spatial signal using a preset adjustment coefficient to obtain a second saturation signal with improved color shift and second brightness normalized signals corresponding to the second saturation signal. The converter 113 converts the second brightness normalized signals into the second color signal, and uses the second color signal to drive the display panel.
The driving circuitry 120 of the backlight module includes a light source receiver 121, a light source calculator 122, a light source determiner 123, a light source adjuster 124, and a light source driver 125. The light source receiver 121 receives the first color signal corresponding to the display panel, and calculates the first saturation signals and the second saturation signals corresponding to all pixels in this backlight subarea. The light source calculator 122 separately calculates an average signal of all the first saturation signals and an average signal of the second saturation signals corresponding to this backlight subarea. The light source determiner 123 determines the minimum color light source among the first color light source, the second color light source, and the third color light source, and obtains a minimum light source adjustment coefficient corresponding to the minimum color light source based on the average signal of the first saturation signals and the average signal of the second saturation signals. The light source adjuster 124 uses the minimum light source adjustment coefficient to adjust the minimum color light source to obtain a fourth brightness value. And the light source driver 125 uses the fourth brightness value to drive the minimum color light source.
The light source adjuster includes a first light source adjuster and a second light source adjuster. The first light source adjuster determines the above-mentioned minimum light source and obtains the minimum light source adjustment coefficient. The second light source adjuster determines the minimum color light source among the first color light source, the second color light source, and the third color light source, and obtains the middle light source adjustment coefficient corresponding to the middle color light source based on the first brightness normalized signals and the second brightness normalized signals. The light source driver may include a first light source driver and a second light source driver. The first light source driver uses the minimum light source adjustment coefficient to adjust the minimum color light source to obtain a fourth brightness value, and uses the fourth brightness value to drive the minimum color light source. The second light source driver uses the middle light source adjustment coefficient to adjust the middle color light source to obtain a fifth brightness value, and uses the fifth brightness value to drive the middle color light source.
Correspondingly, as illustrated in
The backlight module includes at least one backlight subarea, and each backlight subarea includes a first color light source, a second color light source, and a third color light source that are independently controlled. The corresponding light source brightness of the first color light source is a first brightness value, the corresponding light source brightness of the second color light source is a second brightness value, and the corresponding light source brightness of the third color light source is a third brightness value.
The driving process of the display panel includes the following operations:
S31: receiving a first color signal corresponding to the display panel, converting the first color signal into first brightness normalized signals, and converting the first brightness normalized signals into a first HSV (hue, saturation, value) signal;
S32: adjusting a first saturation signal of the first HSV spatial signal using a preset adjustment coefficient to obtain a second saturation signal with an improved color shift and second brightness normalized signals corresponding to the second saturation signal;
S33: converting the second saturation signal into a second color signal and driving the display panel using the second color signal; and
The driving process of the backlight module includes the following operations:
S41: receiving the first color signal corresponding to the display panel, and calculating all the first saturation signals and the second saturation signals corresponding to the backlight subarea;
S42: separately calculating an average signal of all the first saturation signals and an average signal of all the second saturation signals corresponding to this backlight subarea;
S43: determining a minimum color light source among the first color light source, the second color light source, and the third color light source, and obtaining a minimum light source adjustment coefficient corresponding to the minimum color light source based on the average value of the first saturation signal and the average value of the second saturation signal; and
S44: adjusting the minimum color light source using the minimum light source adjustment coefficient to obtain a fourth brightness value, and driving the minimum color light source using the fourth brightness value.
Compared with the solution of dividing a pixel of the display panel into a main pixel and a sub-pixel to mitigate the color shift problem, an exemplary technique includes adjusting the first saturation to obtain a second saturation, converting the second saturation into a second color signal, and driving the display panel using the second color signal, which can well improve the color shift problem. However, due to the adjustment of the saturation value, the image quality and the saturation will be lacking. This application obtains the minimum light source adjustment coefficient based on the average value of the first saturation signal and the average value of the second saturation signal to adjust the brightness of the minimum color light source. Herein, the adjustment of the light source intensity takes an individual backlight subarea as a unit, which improves the hues which have undergone loss of color saturation, and may, in conjunction with the adjusted light source intensity, enable the adjusted color saturation return to the original saturation, thereby maintaining the color purity performance while reducing the viewing angle color shift. In the above description, the color signals may be RGB three-primary-color signals. In particular, the first color signal may be a RGB three-primary-color signal, and the second color signal may be a second RGB three-primary-color signal.
The operation of obtaining the minimum light source adjustment coefficient corresponding to the minimum color light source based on the average signal of the first saturation signal and the average signal of the second saturation signal may include the following. In particular, the minimum light source adjustment coefficient y may satisfy the following formula: y=(Sn_ave−1)/(S′n_ave−1), where Sn_ave is the average signal of the first saturation signal, and S′n_ave is the average signal of the second saturation signal. In this formula, the difference between the average signal of the adjusted first saturation signal and the average signal of the second saturation signal is calculated based on the average signal of the first saturation signal and the average signal of the second saturation signal, taking the backlight subarea as a unit. Then the value of the minimum light source adjustment coefficient based is calculated on this, and the minimum color light source is adjusted as a whole according to the minimum light source adjustment coefficient such calculated. Thus, by controlling the light source intensity of the minimum color light source, the adjusted light source intensity may be combined with the second saturation signal corresponding to the minimum color light source to show the color displayed by the first saturation signal, thereby improving or even maintaining the vividness and brilliance of the colors while improving the color shift.
The first brightness normalized signals include a first red brightness normalized signal rn_i,j, a first green brightness normalized signal gn_i,j, and a first blue brightness normalized signal bn_i,j; the second brightness normalized signals include a second red brightness normalized signals r′n_i,j, a second green brightness normalized signal g′n_i,j, and a second blue brightness normalized signal b′n_i,j.
The operation of adjusting the first saturation signal of the first HSV spatial signal using the preset adjustment coefficient to obtain the second saturation signal and the second brightness normalized signals corresponding to the second saturation signal may include: adjusting the first saturation signal Sn_i,j to obtain the second saturation signal S′n_i,j according to the following formula: S′n_i,j=ax S4n_i,j+b×S3n_i,j+c×S2n_i,j+d×Sn_i,j+e, where a, b, c, d, e are preset adjustment coefficients and are constants; adjusting the minimum value in the first brightness normalized signals based on the first saturation signal Sn_i,j and the second saturation signal S′n_i,j to obtain the second brightness normalized signals, in particular, by the following formula.
According to Sn_i,j=1−minn_i,j/maxn_i,j, keep maxn_i,j unchanged, and only reduce minn_i,j to obtain the second saturation signal Sn_i,j′=1−min′n_i,j/maxn_i,j, and the minimum value min′n_i,j in the second brightness normalized signals, where
maxn_i,j=Max(rn_i,j, gn_i,j, bn_i,j)=Max(r′n_i,j, g′n_i,j, b′n_i,j); mid i,j=Mid(rn_i,j, gn_i,j, bn_i,j); minn_i,j=Min(rn_i,j, gn_i,j, bn_i,j); mid′n_i,j=Mid(r′n_i,j, g′n_i,j, b′n_i,j); min′n_i,j=Min(r′n_i,j, g′n_i,j, b′n_i,j). The operation of separately calculating the average signal of all the first saturation signals and the average signal of all the second saturation signals corresponding to the backlight subarea may include: calculating the average value of all the first saturation signals in the backlight subarea by Sn_ave=Average (Sn_1,1, Sn_1,2, . . . , Sn_i,j); and calculating the average value of all the second saturation signals in the backlight subarea by S′n_ave=Average(S′n_1,1, S′n_1,2, . . . , S′n_i,j).
By reducing the minimum value minn_i,j in each first brightness normalized signal, the second brightness normalized signal is obtained, which reduces the components of colors other than the main color, that is, reduces the color mixing, thereby effectively improving the color shift issue. By reducing the minimum value minn_i,j to increase the color saturation, namely removing the other colors in the mixed color, only the main color is retained, so that the color leaking at the large viewing angle would be close to the front-view original color, and so the problem of color shift from the front view to the side views can also be solved. That is, the leaking color at the front view and side views are one of the three primary colors.
In addition, the preset adjustment coefficient in the formula for converting the first saturation signal into the second saturation signal may also be changed according to the actual situation. For example, it is also possible to reduce the saturation by increasing minn_i,j, when needed. In this case, the mixed color will be close to the white neutral color. The main reason for the drop of the color shift of the neutral color is because all the three primary colors of RGB are allowed to leak, so that the leaking colors of the three primary colors when mixed will not produce color, that is, the leaking color at the front view and the side views is a neutral color.
After adjusting the minimum color light source by using the minimum light source adjustment coefficient, the third saturation signal corresponding to all the pixels of the backlight subarea and an third saturation average value is calculated. The operation of obtaining the minimum light source adjustment coefficient corresponding to the minimum color light source based on the average signal of the first saturation signal and the average signal of the second saturation signal may include: obtaining the minimum light source adjustment coefficient y in order that the third color saturation average value S″n_ave obtained after the minimum color light source is adjusted using the average signal S′n_ave of the second saturation signal corresponding to the backlight subarea may satisfy the following formula: S″n_ave=Sn_ave. According to the following three formulas: S″n_ave=1−min′*y/maxn_ave; S′n_ave=1−min′/maxn_ave Sn_ave=1−minn_ave/maxn_ave; we get: y=(Sn_ave−1)/(S′n_ave−1).
where minn_ave is the actual first minimum average value among the average value of the first red brightness normalized signals, the average value of the first green brightness normalized signals, and the average value of the first blue brightness normalized signals of the backlight subarea, maxn_ave is the first maximum average value among the average value of the second red brightness normalized signals, the average value of the second green brightness normalized signals, and the average value of the second blue brightness normalized signals of the backlight subarea, and min′ is the minimum signal among the average values of the second brightness normalized signals calculated by assuming that maxn_ave is unchanged.
After adjusting the first saturation signal to obtain the second saturation signal, the minimum light source intensity corresponding to the second saturation signal is then adjusted, to obtain the display of the color performance of the third saturation signal. The minimum light source adjustment coefficient is y, and the average signal of the adjusted third saturation signal is equal to the average signal of the first saturation signal, so that the color performance level of the third saturation signal is consistent with the color performance level of the first saturation signal, thereby maintaining the color performance while improving the color shift.
The operation of determining the minimum color light source among the first color light source, the second color light source, and the third color light source, and obtaining the minimum color light source adjustment coefficient corresponding to the minimum color light source based on the average signal of the first saturation signal and the average signal of the second saturation signal may further include: determining the middle color light source among the first color light source, the second color light source, and the third color light source; obtaining the middle light source adjustment coefficient based on the first brightness normalized signals and the second brightness normalized signals. The operation of using the minimum light source adjustment coefficient to adjust the minimum color light source to obtain the fourth brightness value, and using the fourth brightness value to drive the minimum color light source may further include: using the middle light source adjustment coefficient to adjust the middle color light source to obtain the fifth brightness value, and using the fifth brightness value to drive the middle color light source.
The first brightness normalized signals include a first red brightness normalized signal, a first green brightness normalized signal, and a first blue brightness normalized signal. The second brightness normalized signals include a second red brightness normalized signal, a second green brightness normalized signal, and a second blue brightness normalized signal. In each backlight subarea, the second maximum average value, the second middle average value, and the second minimum average value among the average value of the second red brightness normalized signals, the average value of the second green brightness normalized signals, and the average value of the second blue brightness normalized signals are calculated. The operation of obtaining the middle light source adjustment coefficient based on the first brightness normalized signals and the second brightness normalized signals may include the following. In particular,
let the middle light source adjustment coefficient be x, which satisfies the following formula: midn_ave=x*mid′n_ave; where midn_ave is the first middle average value, and mid′n_ave is the second middle average value.
By adjusting the light source intensity corresponding to the middle signal, it is possible to reduce the contrast of the mixed color components when adjusting from the first saturation signal to the second saturation signal, thereby reducing the hue deviation issue which may be produced in the saturation adjustment step, so that after adjusting the light source, the hue of the picture can approach or even return to the hue of the first HSV spatial signal, that is, H″n_ave=Hn_ave, where Hn_ave is the average value of the hue in the first color space signal, and H″n_ave is the average value of the hue displayed after the middle light source is adjusted by the middle light source adjustment coefficient x. In other words, the accuracy of the overall hue is maintained before and after the adjustment.
In addition, the operation of obtaining the second saturation signal S′n_i,j=1−min′n_i,j/maxn_i,j, and the minimum value min′n_i,j in the second brightness normalized signals according to Sn_i,j=1−minn_i,j/maxn_i,j, by keeping maxn_i,j unchanged and only reducing minn_i,j may further include:
according to midn_i,j−minn_i,j=mid′n_i,j−min′n_i,j, calculating the middle value mid−min=mid′−min′ in the second brightness normalized signals.
For example, when it is calculated from the brightness normalized signals r, g, b that the hue satisfies 0<Hn_i,j<30, then the second-maximum brightness signal minus the minimum brightness signal gn_i,j−bn_i,j=g′n_i,j−b′n_i,j would maintain a fixed brightness difference. In addition, the original normalized brightness signals are converted to the saturation signal Sn_i,j=1-bn_i,j/rn_i,j, and Sn_i,j is changed to S′n_i,j. After the conversion, the saturation S′n_i,j=1−b′n_i,j/rn_i,j can be used to calculate the minimum signal b′n_i,j in the second brightness normalized signals, and so middle signal g′n_i,j in the second brightness normalized signals can be calculated. This solution maintains the brightness difference between the second-maximum brightness signal and the minimum brightness signal before and after the adjustment, which is combined with the above-mentioned solution of using the middle light source adjustment coefficient to adjust the middle color light source, where the middle light source adjustment coefficient x satisfies midn_ave=x*mid′n_ave. Accordingly, this further improves the hue deviation caused in the saturation adjustment stage, serving the function of correcting the hue.
The relationships between the first maximum average value maxn_ave, the first middle average value midn_ave, the first minimum average value minn_ave, the average value rn_ave of the first red brightness normalized signals, the average value gn_ave of the first green brightness normalized signals, and the average value bn_ave of the first blue brightness normalized signals may satisfy the following formulas:
maxn_ave=Max(rn_ave,gn_ave,bn_ave);
midn_ave=Mid(rn_ave,gn_ave,bn_ave);
minn_ave=Min(rn_ave,gn_ave,bn_ave);
The relationships between the second maximum average value max′n_ave, the second middle average value mid′n_ave, the second minimum average value min′n_ave, the average value r′n_ave of the second red brightness normalized signals, the average value g′n_ave of the second green brightness normalized signals, and the average value b′n_ave of the second blue brightness normalized signals may satisfy the following formulas:
max′n_ave=Max(r′n_ave,g′n_ave,b′n_ave);
mid′n_ave=Mid(r′n_ave,g′n_ave,b′n_ave);
min′n_ave=Min(r′n_ave,g′n_ave,b′n_ave).
The first red brightness normalized signals corresponding to the backlight subarea are: rn_1,1, rn_1,2, . . . , rn_i,j. The first green brightness normalized signals corresponding to the backlight subarea are: gn_1,1, gn_1,2, . . . , gn_i,j. The first blue brightness normalized signals corresponding to the backlight subarea are: bn_1,1, bn_1,2, . . . , bn_i,j. The average value rn_ave of the first red brightness normalized signals, the average value gn_ave of the first green brightness normalized signals, and the average value bn_ave of the first blue brightness normalized signals satisfy the following formulas:
rn_ave=Average(rn_1,1,rn_1,2, . . . ,rn_i,j);
gn_ave=Average(gn_1,1,gn_1,2, . . . ,gn_i,j); and
bn_ave=Average(bn_1,1,bn_1,2, . . . ,bn_i,j);
The second red brightness normalized signals corresponding to the backlight subarea are: r′n_1,1, r′n_1,2, . . . , r′n_i,j. The second green brightness normalized signals corresponding to the backlight subarea are g′n_1,1, g′n_1,2, . . . , g′n_i,j. The second blue brightness normalized signals corresponding to the backlight subarea are b′n_1,1, b′n_1,2, . . . , b′ n_i,j. The average value r′n_ave of the second red brightness normalized signals, the average value g′n_ave of the second green brightness normalized signals, and the average value b′n_ave of the second blue brightness normalized signals may satisfy the following formulas:
r′n_ave=Average(r′n_1,1,r′n_1,2, . . . ,r′n_i,j);
g′n_ave=Average(g′n_1,1,g′n_1,2, . . . ,g′n_i,j);
b′n_ave=Average(b′n_1,1,b′n_1,2, . . . ,b′n_i,j).
This application obtains the average value of the first red brightness normalized signals, the average value of the first green brightness normalized signals, the average value of the first blue brightness normalized signals, the average value of the second red brightness normalized signals, the average value of the second green brightness normalized signals, and the average value of the second blue brightness normalized signals through accurate calculations. Thus, it is accurate to the change of the brightness normalized signals corresponding to each pixel, so that the results obtained according to the precise calculations are also more accurate, leading to a better adjustment effect.
During the driving process of the display panel, the operation of receiving the first color signal corresponding to the display panel, converting the first color signal into the first brightness normalized signals, and converting the first brightness normalized signals into the first HSV spatial signal may include the following. The input signal of the first color signal is an 8-bit grayscale digital signal of 0, 1, . . . 255, and the grayscale signals are input as first brightness normalized signals (grayscale of 255 is the maximum brightness) with respect to 255, which are r, g, b, respectively, r=(R/255){circumflex over ( )}γr, g=(G/255){circumflex over ( )}γg, b=(B/255){circumflex over ( )}γb; where γr, γg, and γb are gamma signals.
As illustrated in
The formulas for converting the brightness normalized signals r, g, b into hue h and saturation signal s are as follows:
where max represents the maximum value in r/g/b, and min represents the minimum value in r/g/b.
S′n_i,j=a×S4n_i,j+b×S3n_i,j+c×S2n_i,j+d×Sn_i,j+e,
where a, b, c, d, e are preset adjustment coefficients, which are constants and can be adjusted according to actual needs.
The operation of converting the second saturation signal into the second color signal may include: converting the second saturation signal to obtain a second HSV spatial signal, and turning down the minimum value of the brightness normalized signals according to the second HSV spatial signal to obtain second brightness normalized signals; and
converting the second brightness normalized signals to obtain the second color signal.
In one embodiment, the present application may also divide the hue H into a number of m hue intervals.
S′(H(m),S)=a(H(m))×S4+b(H(m))×S3+c(H(m))×S2+d(H(m))×S+e(H(m));
where a(H(m)), b(H(m)), c(H(m)), d(H(m)), e(H(m)) are saturation adjustment constants of the corresponding hue interval.
After the hue (H) is divided into multiple intervals, because different intervals have different degrees of color shift, different adjustments to the saturation can be made according to different intervals, which can increase the color vividness of the display panel, and make adjustment of the color shift more even.
The operation of converting the second saturation signal into the second color signal may include: converting the second saturation signal S′n_i,j to obtain second brightness normalized signals, and converting the second brightness normalized signals r′, g′, b′ using the following formulas to obtain the second color signal R′, G′, B′:
R′=255×(r′)1/γr,G′=255×(g′)1/γg,B′=255×(b′)1/γb.
While using the second color signal to drive the display panel, the fourth brightness value is used to drive the minimum color light source, and the fifth brightness value is used to drive the middle color light source.
It should be noted that the various steps defined in this solution are not to be construed as limiting the order in which these steps are performed, on the premise of not affecting the implementation of the specific solution. In other words, the steps written earlier may be performed first, or may also be performed later, or may even be performed simultaneously. As long as the solution is able to be implemented, they variations shall all be regarded as falling in the scope of protection of this application.
The technical solutions of this application may be widely used in various display panels, such as TN (Twisted Nematic) display panels, IPS (In-Plane Switching) display panels, VA (Vertical Alignment) 1) Display panel, MVA (Multi-Domain Vertical Alignment) display panels. Of course, the above solutions may also be applicable to other types of display panels, such as OLED (Organic Light-Emitting Diode) display panels,
The foregoing is merely a further detailed description of the present application in connection with some specific illustrative implementations, and it is to be construed as limiting the implementation of the present application to these implementations. For those having ordinary skill in the technical field to which this application pertains, numerous simple deductions or substitutions may be made without departing from the concept of this application, which shall all be regarded as falling in the scope of protection of this application.
Number | Date | Country | Kind |
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201910275200.0 | Apr 2019 | CN | national |
201910275212.3 | Apr 2019 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2020/078391 | 3/9/2020 | WO |
Publishing Document | Publishing Date | Country | Kind |
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WO2020/207168 | 10/15/2020 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
20040263456 | Miyachi | Dec 2004 | A1 |
20080150863 | Morisue | Jun 2008 | A1 |
20090160747 | Morisue | Jun 2009 | A1 |
20120194537 | Huang | Aug 2012 | A1 |
20190221171 | Zha | Jul 2019 | A1 |
Number | Date | Country |
---|---|---|
109461417 | Mar 2019 | CN |
109509436 | Mar 2019 | CN |
109559692 | Apr 2019 | CN |
110111744 | Aug 2019 | CN |
110189717 | Aug 2019 | CN |
2010079119 | Apr 2010 | JP |
Entry |
---|
Chang Liu, the ISA written comments, Jun. 2020, CN. |
Chang Liu, the International Search Report, dated Jun. 2020, CN. |
Number | Date | Country | |
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20220084476 A1 | Mar 2022 | US |