TWI838051B - Gamma adjustment module, display driver chip, display device, and information processing device - Google Patents

Abstract

The present invention mainly discloses a gamma adjustment module, which is applied in a display driver chip and includes: an analog operation unit and a digital operation unit, wherein, according to a red sub-pixel grayscale data, a green sub-pixel grayscale data and a blue sub-pixel grayscale data input externally, the analog operation unit generates a corresponding red sub-pixel gamma voltage, a green sub-pixel gamma voltage and a blue sub-pixel gamma voltage, and the digital operation unit is used to generate a corresponding first digital value, a second digital value and a third digital value. Finally, a digital-to-analog conversion unit generates and outputs a red sub-pixel driving voltage, a green sub-pixel driving voltage, and a blue sub-pixel driving voltage according to the red sub-pixel gamma voltage, the green sub-pixel gamma voltage, the blue sub-pixel gamma voltage, the first digital value, the second digital value, and the third digital value.

Description

Gamma adjustment module, display driver chip, display device, and information processing device

The present invention relates to the field of display technology, and more particularly to a white balance correction method.

FIG1 is a block diagram of a known flat display device. As shown in FIG1 , the known flat display device 1a mainly includes: a display panel 11a (such as an OLED panel or an LED panel) and at least one display driver chip 12a. Electronic engineers familiar with the design and manufacture of displays know that the human eye's response to brightness is not a linear proportional relationship. More specifically, the human eye's ability to resolve low brightness is stronger than high brightness. Therefore, in order for the human eye to correctly and sensitively perceive the grayscale changes of the image displayed by the display panel 11a, the prior art is to add a gamma correction module 121a to the display driver chip 12a.

FIG2 is a block diagram of the gamma adjustment module 121a shown in FIG1. As shown in FIG2, the gamma adjustment module 121a includes a gamma conversion unit 1211a and a gamma voltage generation unit 1212a, wherein the gamma conversion unit 1211a is edited into an intellectual property (IP) file using a programming language and burned into a memory of the display driver chip 12a. On the other hand, the gamma voltage generation unit 1212a is a physical circuit, for example, Chinese Patent Publication No. CN110379396A discloses the topology structure of the physical circuit of the gamma voltage generation unit 1212a.

Electronic engineers familiar with the design and manufacture of the display driver chip 12a know that the gamma conversion unit 1211a uses the following formula (1) to complete a gamma conversion process: ……………………(1)

In the above formula (1), x is the normalized input display data, and y is the function of x, which can be expressed as y=f(x). In addition, k is the maximum brightness of the display, and For example, the gamma setting value is 1.8, 2.0, 2.2, 2.4, or 2.6. In short, the gamma conversion unit 1211a has a gamma curve generated according to the brightness threshold of the display. Furthermore, since a pixel is composed of three sub-pixels R/G/B, there are three gamma curves as shown in Figure 3. As shown in Figure 2, if Rin, Gin and Bin are input R grayscale data, input G grayscale data and input B grayscale data, then the gamma conversion unit 1211a uses the gamma curve to map Rin, Gin and Bin to red sub-pixel grayscale values R1, green sub-pixel G1 and blue sub-pixel B1. Finally, the gamma voltage generating unit 1212a generates corresponding red grayscale voltage _RGV , green grayscale voltage _RGV , and blue grayscale voltage _RGV according to R1, G1, and B1, and provides them to the digital-to-analog converter (ie, DAC) inside the display driver chip 12a.

According to the disclosure of Chinese patent publication number CN110379396A, the gamma voltage generating unit 1212a generates a grayscale voltage corresponding to the grayscale value of the sub-pixel by adjusting the resistance value. Practical experience shows that this grayscale value adjustment method is not flexible enough, and the adjustment accuracy of the grayscale value is limited by the number and value of the resistor. Therefore, the existing technology has defects that need to be improved.

From the above description, it can be seen that a new gamma adjustment module is urgently needed in this field.

The main purpose of the present invention is to provide a gamma adjustment module, which is applied to a display driver chip and includes: an analog operation unit and a digital operation unit, wherein, according to a red sub-pixel grayscale data, a green sub-pixel grayscale data and a blue sub-pixel grayscale data input externally, the analog operation unit generates a corresponding red sub-pixel gamma voltage, a green sub-pixel gamma voltage and a blue sub-pixel gamma voltage, and the digital operation unit is used to generate a corresponding first digital value, a second digital value and a third digital value. Finally, a digital-to-analog conversion unit generates and outputs a red sub-pixel driving voltage, a green sub-pixel driving voltage, and a blue sub-pixel driving voltage according to the red sub-pixel gamma voltage, the green sub-pixel gamma voltage, the blue sub-pixel gamma voltage, the first digital value, the second digital value, and the third digital value.

As can be seen from the above description, the present invention utilizes the first digital value, the second digital value, and the third digital value to adjust the red sub-pixel gamma voltage, the green sub-pixel gamma voltage, and the blue sub-pixel gamma voltage. Therefore, the adjustment accuracy of the gamma voltage is not limited by the number and value of the physical resistors, and has sufficient gamma voltage adjustment flexibility.

To achieve the above-mentioned purpose, the present invention proposes an embodiment of the gamma adjustment module, which is applied to a display driver chip and includes: An analog operation unit uses a red sub-pixel gamma curve, a blue sub-pixel gamma curve, and a green sub-pixel gamma curve to map an externally input red sub-pixel grayscale data, a green sub-pixel grayscale data, and a blue sub-pixel grayscale data into a first red sub-pixel grayscale data, a first green sub-pixel grayscale data, and a first blue sub-pixel grayscale data, and further generates a red sub-pixel gamma voltage, a green sub-pixel gamma voltage, and a blue sub-pixel gamma voltage according to the first red sub-pixel grayscale data, the first green sub-pixel grayscale data, and the first blue sub-pixel grayscale data; and A digital operation unit maps the externally input red sub-pixel grayscale data, green sub-pixel grayscale data and blue sub-pixel grayscale data into a first index value, a second index value and a third index value using a first grayscale value-index value mapping curve, a second grayscale value-index value mapping curve and a third grayscale value-index value mapping curve, and further generates a first digital value, a second digital value and a third digital value according to the first index value, the second index value and the third index value; The analog operation unit and the digital operation unit are coupled to a digital-to-analog conversion unit at the same time in the digital operation unit, so that the digital-to-analog conversion unit generates and outputs a red sub-pixel driving voltage, a green sub-pixel driving voltage and a blue sub-pixel driving voltage according to the red sub-pixel gamma voltage, the green sub-pixel gamma voltage, the blue sub-pixel gamma voltage, the first digital value, the second digital value and the third digital value.

In one embodiment, the analog operation unit includes: A gamma conversion unit, which uses the red sub-pixel gamma curve, the blue sub-pixel gamma curve and the green sub-pixel gamma curve to map the externally input red sub-pixel grayscale data, the green sub-pixel grayscale data and the blue sub-pixel grayscale data into the first red sub-pixel grayscale data, the first green sub-pixel grayscale data and the first blue sub-pixel grayscale data; and A gamma voltage generating unit is coupled to the gamma conversion unit, and is used to further generate the red sub-pixel gamma voltage, the green sub-pixel gamma voltage, and the blue sub-pixel gamma voltage according to the first red sub-pixel grayscale data, the first green sub-pixel grayscale data, and the first blue sub-pixel grayscale data.

In one embodiment, the digital operation unit includes: an index value generating unit, used to map the externally input red sub-pixel grayscale data, the green sub-pixel grayscale data and the blue sub-pixel grayscale data into the first index value, the second index value and the third index value using the first grayscale value-index value mapping curve, the second grayscale value-index value mapping curve and the third grayscale value-index value mapping curve; a digital value providing unit, coupled to the index value generating unit, used to further generate and provide the first digital value, the second digital value and the third digital value to the digital-to-analog conversion unit according to the first index value, the second index value and the third index value.

In one embodiment, the digital operation unit further includes: A memory unit, including a first memory block and a second memory block; Wherein, a display brightness adjustment segment is between a maximum display brightness value (DBV) and a minimum display brightness value, and K interval brightness values are further set in the display brightness adjustment segment, where K is a positive integer; Among them, the K-2 interval brightness values, the highest display brightness value and the lowest display brightness value constitute K display brightness values, K/2 display brightness values have odd serial numbers, and K/2 display brightness values have even serial numbers. The first memory block 12M1 stores P(K/2) groups of first configuration data corresponding to the K/2 display brightness values with odd serial numbers, and the second memory block 12M2 stores P(K/2) groups of second configuration data corresponding to the K/2 display brightness values with even serial numbers, and P is a positive integer.

In one embodiment, when a current display brightness value set by a user falls between the jth display brightness value and the j-1th display brightness value, the index value generating unit reads a set of the first configuration data corresponding to the jth display brightness value and a set of the second configuration data corresponding to the j-1th display brightness value from the memory unit, and then obtains a current configuration data corresponding to the display brightness value by performing a linear interpolation operation on the first configuration data and the second configuration data, and finally generates the first grayscale value-index value mapping curve, the second grayscale value-index value mapping curve and the third grayscale value-index value mapping curve according to the current configuration data; j is a positive integer.

In one embodiment, before executing the linear interpolation operation, the index value generating unit performs a parallel-to-serial conversion operation on the first configuration data and the second configuration data, so that the first configuration data and the second configuration data are converted into serial data through the linear interpolation operation in the form of serial data. Finally, the index value generating unit performs a serial-to-parallel conversion operation on the serial data to generate the current configuration data.

Furthermore, the present invention also provides an embodiment of a display driver chip, which is characterized in that it includes a gamma adjustment module, and the gamma adjustment module includes: An analog operation unit uses a red sub-pixel gamma curve, a blue sub-pixel gamma curve, and a green sub-pixel gamma curve to map an externally input red sub-pixel grayscale data, a green sub-pixel grayscale data, and a blue sub-pixel grayscale data into a first red sub-pixel grayscale data, a first green sub-pixel grayscale data, and a first blue sub-pixel grayscale data, and further generates a red sub-pixel gamma voltage, a green sub-pixel gamma voltage, and a blue sub-pixel gamma voltage according to the first red sub-pixel grayscale data, the first green sub-pixel grayscale data, and the first blue sub-pixel grayscale data; and A digital operation unit maps the externally input red sub-pixel grayscale data, green sub-pixel grayscale data and blue sub-pixel grayscale data into a first index value, a second index value and a third index value using a first grayscale value-index value mapping curve, a second grayscale value-index value mapping curve and a third grayscale value-index value mapping curve, and further generates a first digital value, a second digital value and a third digital value according to the first index value, the second index value and the third index value; The analog operation unit and the digital operation unit are coupled to a digital-to-analog conversion unit at the same time in the digital operation unit, so that the digital-to-analog conversion unit generates and outputs a red sub-pixel driving voltage, a green sub-pixel driving voltage and a blue sub-pixel driving voltage according to the red sub-pixel gamma voltage, the green sub-pixel gamma voltage, the blue sub-pixel gamma voltage, the first digital value, the second digital value and the third digital value.

In one embodiment, the analog operation unit includes: A gamma conversion unit, which uses the red sub-pixel gamma curve, the blue sub-pixel gamma curve and the green sub-pixel gamma curve to map the externally input red sub-pixel grayscale data, the green sub-pixel grayscale data and the blue sub-pixel grayscale data into the first red sub-pixel grayscale data, the first green sub-pixel grayscale data and the first blue sub-pixel grayscale data; and A gamma voltage generating unit is coupled to the gamma conversion unit, and is used to further generate the red sub-pixel gamma voltage, the green sub-pixel gamma voltage, and the blue sub-pixel gamma voltage according to the first red sub-pixel grayscale data, the first green sub-pixel grayscale data, and the first blue sub-pixel grayscale data.

In one embodiment, the digital operation unit includes: an index value generating unit, used to map the externally input red sub-pixel grayscale data, the green sub-pixel grayscale data and the blue sub-pixel grayscale data into the first index value, the second index value and the third index value using the first grayscale value-index value mapping curve, the second grayscale value-index value mapping curve and the third grayscale value-index value mapping curve; a digital value providing unit, coupled to the index value generating unit, used to further generate and provide the first digital value, the second digital value and the third digital value to the digital-to-analog conversion unit according to the first index value, the second index value and the third index value.

In one embodiment, the digital operation unit further includes: A memory unit, including a first memory block and a second memory block; Wherein, a display brightness adjustment segment is between a maximum display brightness value (DBV) and a minimum display brightness value, and K interval brightness values are further set in the display brightness adjustment segment, where K is a positive integer; Among them, the K-2 interval brightness values, the highest display brightness value and the lowest display brightness value constitute K display brightness values, K/2 display brightness values have odd serial numbers, and K/2 display brightness values have even serial numbers. The first memory block 12M1 stores P(K/2) groups of first configuration data corresponding to the K/2 display brightness values with odd serial numbers, and the second memory block 12M2 stores P(K/2) groups of second configuration data corresponding to the K/2 display brightness values with even serial numbers, and P is a positive integer.

In one embodiment, when a current display brightness value set by a user falls between the jth display brightness value and the j-1th display brightness value, the index value generating unit reads a set of the first configuration data corresponding to the jth display brightness value and a set of the second configuration data corresponding to the j-1th display brightness value from the memory unit, and then obtains a current configuration data corresponding to the display brightness value by performing a linear interpolation operation on the first configuration data and the second configuration data, and finally generates the first grayscale value-index value mapping curve, the second grayscale value-index value mapping curve and the third grayscale value-index value mapping curve according to the current configuration data; j is a positive integer.

In one embodiment, before executing the linear interpolation operation, the index value generating unit performs a parallel-to-serial conversion operation on the first configuration data and the second configuration data, so that the first configuration data and the second configuration data are converted into serial data through the linear interpolation operation in the form of serial data. Finally, the index value generating unit performs a serial-to-parallel conversion operation on the serial data to generate the current configuration data.

Furthermore, the present invention also provides an embodiment of a display device, which includes a display panel and at least one display driver chip, wherein the display driver chip includes the gamma adjustment module of the present invention as described above.

In addition, the present invention also provides an information processing device, which includes a display device, and is characterized in that the display device includes a display panel and at least one display driver chip of the present invention as described above. In one embodiment, the information processing device is an electronic device selected from the group consisting of a smart TV, a smart phone, a smart watch, a tablet computer, an all-in-one computer, a notebook computer, an ATM, a car entertainment device, and a video door machine.

In order to enable the Review Committee to further understand the structure, features, purpose, and advantages of the present invention, the following are attached with drawings and detailed descriptions of preferred specific embodiments.

FIG4 is a block diagram of a flat display device having a gamma adjustment module of the present invention, and FIG5 is a block diagram of a gamma adjustment module 121 of the present invention. As shown in FIG4, the flat display device 1 includes: a display panel 11 (such as an OLED panel, an LCD panel or an LED panel) and at least one display driver chip 12, and the display driver chip 12 includes a gamma adjustment module 121 of the present invention. Further, as shown in FIG5, the gamma adjustment module 121 of the present invention includes: an analog operation unit 12C1 and a digital operation unit 12C2. Specifically, the technical solution of the present invention is: according to a red sub-pixel grayscale data Rin, a green sub-pixel grayscale data Gin and a blue sub-pixel grayscale data Bin input externally, the analog operation unit 12C1 generates a corresponding red sub-pixel gamma voltage _RGV , a green sub-pixel gamma voltage _GGV and a blue sub-pixel gamma voltage _BGV , and the digital operation unit 12C2 is used to generate a corresponding first digital value DV1, a second digital value DV2 and a third digital value DV3. Finally, in the display driver chip 12, a plurality of driver units are coupled to a plurality of channels of the display driver chip 12, and a digital-to-analog conversion unit 122 is coupled to the plurality of driver units, the analog operation unit 12C1, and the digital operation unit 12C2, so that the digital-to-analog conversion unit 122 converts the red sub-pixel gamma voltage R _GV , the green sub-pixel gamma voltage G _GV , and the blue sub-pixel gamma voltage B _GV , the first digital value DV1, the second digital value DV2 and the third digital value DV3 to generate and output a red sub-pixel driving voltage Vo_R, a green sub-pixel driving voltage Vo_G and a blue sub-pixel driving voltage Vo_B.

In short, the present invention utilizes the first digital value, the second digital value, and the third digital value to adjust the red sub-pixel gamma voltage R _GV , the green sub-pixel gamma voltage G _GV , and the blue sub-pixel gamma voltage B _GV . Therefore, the adjustment accuracy of the gamma voltage is not limited by the number and value of the physical resistors, and has sufficient gamma voltage adjustment flexibility.

As shown in FIG5 , the analog operation unit 12C1 includes a gamma conversion unit 1211 and a gamma voltage generating unit 1212, wherein the gamma conversion unit 1211 utilizes a red sub-pixel gamma curve, a blue sub-pixel gamma curve, and a green sub-pixel gamma curve (as shown in FIG3 ) to map an externally input red sub-pixel grayscale data Rin, a green sub-pixel grayscale data Gin, and a blue sub-pixel grayscale data Bin into a first red sub-pixel grayscale data R1, a first green sub-pixel grayscale data R2, and a first blue sub-pixel grayscale data R3. Furthermore, the gamma voltage generating unit 1212 is coupled to the gamma conversion unit 1211 to generate a red sub-pixel gamma voltage _RGV , a green sub-pixel gamma voltage GGV, and a blue sub-pixel gamma voltage BGV according to the first red sub-pixel grayscale data R1, the first green sub-pixel grayscale data _G1 , and the first blue sub-pixel grayscale data _B1, and transmit them to the digital-to-analog conversion unit 122.

On the other hand, the digital operation unit 12C2 includes: an index value generating unit 1213, a digital value providing unit 1214 and a memory unit 1215, wherein the index value generating unit 1213 uses a first grayscale value-index value mapping curve, a second grayscale value-index value mapping curve and a third grayscale value-index value mapping curve to map the externally input red sub-pixel grayscale data Rin, the green sub-pixel grayscale data Gin and the blue sub-pixel grayscale data Bin into a first index value In _R , a second index value In _G and a third index value In _B.

FIG6 is a diagram of two grayscale value-index value mapping curves. Under normal circumstances, each display brightness value (DBV) needs to have a corresponding grayscale value-index value mapping curve. As shown in FIG6 , the highest display brightness value DBV_high and the lowest display brightness value DBV_low each correspond to a grayscale value-index value mapping curve. Therefore, it can be inferred that under a fixed display brightness value (such as: user-set DBV), there will be three grayscale value-index value mapping curves for mapping an externally input red sub-pixel grayscale data Rin, a green sub-pixel grayscale data Gin, and a blue sub-pixel grayscale data Bin into a first index value In _R , a second index value In _G , and a third index value In _B , respectively.

Specifically, the first grayscale value-index value mapping curve is drawn based on 25 red sub-pixel grayscale binding points and their corresponding 25 index values (Index), the second grayscale value-index value mapping curve is drawn based on 25 green sub-pixel grayscale binding points and their corresponding 25 index values (Index), and the third grayscale value-index value mapping curve is drawn based on 25 blue sub-pixel grayscale binding points and their corresponding 25 index values. Due to the limited space size of the memory of the display driver chip 12, it is impossible to store all 25 grayscale binding points and 25 index values of the grayscale value-index value mapping curve corresponding to each DBV value in the memory. Therefore, a better solution is to store some grayscale binding points and index values in memory, and then use linear difference operation to generate the required grayscale value-index value mapping curve.

According to the design of the present invention, a display brightness adjustment segment is first defined between a maximum display brightness value (DBV) and a minimum display brightness value, and then K interval brightness values are further set in the display brightness adjustment segment, where K is a positive integer. FIG. 7 is a diagram of a maximum display brightness value, a minimum display brightness value, and a display brightness adjustment segment. Specifically, as shown in FIG. 7 , a display brightness adjustment segment is defined between a maximum display brightness value DBV_high and a minimum display brightness value DBV_low, and K-2 interval brightness values are further set in the display brightness adjustment segment, where K is a positive integer. Thus, the K-2 interval brightness values, the highest display brightness value and the lowest display brightness value constitute K display brightness values, namely, th_band_9, th_band_8, th_band_7, th_band_6, th_band_5, th_band_4, th_band_3, th_band_2, th_band_1, th_band_0. Among them, K/2 display brightness values have odd serial numbers, and K/2 display brightness values have even serial numbers.

Fig. 8 is a block diagram of the memory unit 1215 shown in Fig. 5. It can be understood that one display brightness value (e.g., th_band_9=DBV_high) corresponds to 75 sub-pixel grayscale binding points and 75 index values (Index) for drawing the first grayscale value-index value mapping curve, the second grayscale value-index value mapping curve, and the third grayscale value-index value mapping curve. Based on this requirement, the present invention plans a first memory block 12M1 and a second memory block 12M2 in the memory unit 1215, wherein the first memory block 12M1 stores P(K/2) groups of first configuration data corresponding to K/2 display brightness values with odd numbers, such as Mode0_Bd0_dgm_data, Mode0_Bd2_dgm_data, Mode3_Bd4_dgm_data, Mode0_Bd6_dgm_data, and Mode0_Bd8_dgm_data. On the other hand, the second memory block 12M2 stores P (K/2) sets of second configuration data corresponding to K/2 display brightness values with even numbers, such as Mode0_Bd1_dgm_data, Mode0_Bd3_dgm_data, Mode0_Bd5_dgm_data, Mode0_Bd7_dgm_data, and Mode0_Bd9_dgm_data. Here, P is the number of display modes. For example, the display device 1 has four display modes, namely, a general display mode, an outdoor display mode, a game display mode, and a theater display mode, then P=4. Specifically, mode0 can be exemplarily used to represent the general display mode, and mode3 can be used to represent the theater display mode. To explain in more detail, the configuration data (eg, Mode0_Bd5_dgm_data) includes 75 sub-pixel grayscale binding points and 75 index values (Index) for drawing three grayscale value-index value mapping curves.

To explain in more detail, when the current DBV value set by the user is equal to any of the aforementioned preset display brightness values, the index value generating unit 1213 can read the corresponding configuration data from the memory unit 1215. For example, if the current DBV=th_band_2, the first configuration data Mode0_Bd2_dgm_data is read from the first memory block 12M1. For another example, if the current DBV=th_band_3, the second configuration data Mode0_Bd3_dgm_data is read from the second memory block 12M2.

It is worth noting that, as shown in FIG. 7 , when a current display brightness value (i.e., current DBV) set by the user falls between the j-th display brightness value (e.g., th_band_6) and the j-1-th display brightness value (e.g., th_band_5), the index value generating unit 1213 reads a set of the first configuration data (e.g., Mode0_Bd6_dgm_data) corresponding to the j-th display brightness value and the j-1-th display brightness value from the memory unit 1215. A set of the second configuration data (such as Mode0_Bd5_dgm_data) for displaying brightness values is obtained, and then a current configuration data (i.e., th_band_CurDBV) corresponding to the display brightness value is obtained by performing a linear interpolation operation on the first configuration data and the second configuration data, and finally the first grayscale value-index value mapping curve, the second grayscale value-index value mapping curve and the third grayscale value-index value mapping curve are generated according to the current configuration data. Wherein, j is a positive integer.

After generating the first grayscale value-index value mapping curve, the second grayscale value-index value mapping curve, and the third grayscale value-index value mapping curve according to the DBV value currently set by the user, the index value generating unit 1213 then uses the first grayscale value-index value mapping curve, the second grayscale value-index value mapping curve, and the third grayscale value-index value mapping curve to map the externally input red sub-pixel grayscale data Rin, the green sub-pixel grayscale data Gin, and the blue sub-pixel grayscale data Bin into a first index value In _R , a second index value In _G , and a third index value In _B . Continuing, the digital value providing unit 1214 coupled to the index value generating unit 1213 further generates and provides a first digital value DV1, a second digital value DV2 and a third digital value DV3 to the digital-to-analog conversion unit 122 according to the first index value, the second index value and the third index value. In one embodiment, the digital value providing unit 1214 is a lookup table (LUT) storing a plurality of digital values and a plurality of index values corresponding to the plurality of digital values. Therefore, when the index value generating unit 1213 sends the first index value, the second index value and the third index value to the lookup table, the lookup table outputs a first digital value, a second digital value and a third digital value corresponding to the three index values to the digital-to-analog conversion unit 122. Finally, the digital-to-analog conversion unit 122 generates and outputs a red sub-pixel driving voltage _{Vo_R} , a green sub-pixel driving voltage Vo_G, and a blue sub-pixel driving voltage Vo_B according to the red sub-pixel gamma voltage R GV , the green sub-pixel gamma voltage G _GV , the blue sub-pixel gamma voltage B _GV , the first digital value DV1, the second digital value DV2, and the third digital value DV3.

It must be considered that only the K preset display brightness values (i.e., K DBVs) have configuration data pre-stored in the memory unit 1215, and the index values of the other user-set DBVs are obtained by the interpolation operation shown in FIG7. However, each DBV corresponds to 75 index values, and if the 75 interpolations are calculated simultaneously, the required computing resources are quite huge, and therefore difficult to implement in the IC design of the display driver chip 12. In order to effectively save computing resources, before executing the linear interpolation operation, the index value generating unit 1213 performs a parallel-serial conversion operation on the first configuration data (e.g., Mode0_Bd6_dgm_data corresponding to the display brightness value th_band_6) and the second configuration data (e.g., Mode0_Bd5_dgm_data corresponding to the display brightness value th_band_5) so that the first configuration data and the second configuration data are combined into a first serial data; then, after the linear interpolation operation, the first serial data is processed into a second serial data. Finally, the index value generating unit 1213 performs a serial-parallel conversion operation on the second serial data to generate the current configuration data (i.e., Mode0_BdCurDBV_dgm_data corresponding to the current display brightness value th_band_CurDBV).

FIG9 is a block diagram of the index value generating unit 1213 shown in FIG5. Specifically, as shown in FIG5, FIG7 and FIG9, the index value generating unit 1213 has a parallel/serial conversion unit 1216, a linear interpolation operation unit 1217 and a serial/parallel conversion unit 1218. When the DBV currently set by the user falls between the j-th display brightness value (e.g., th_band_6) and the j-1-th display brightness value (e.g., th_band_5), the index value generating unit 1213 first reads a set of the first configuration data (e.g., Mode0_Bd6_dgm_data) corresponding to the j-th display brightness value and a set of the second configuration data (e.g., Mode0_Bd5_dgm_data) corresponding to the j-1-th display brightness value from the memory unit 1215. Next, the index value generation unit 1213 enables its parallel/serial conversion unit 1216 to perform a parallel-serial conversion process on the first configuration data and the second configuration data to obtain a first serial data, and then enables its linear interpolation operation unit 1217 to perform a linear interpolation process on the first serial data to obtain a second serial data. Finally, the index value generation unit 1213 enables its serial/parallel conversion unit 1218 to perform a serial-parallel conversion process on the second serial data to obtain a current configuration data corresponding to the current DBV. As shown in FIG. 9 and FIG. 7 , the current configuration data includes 75 index values corresponding to 75 sub-pixel grayscale binding points. Therefore, a first grayscale value-index value mapping curve, a second grayscale value-index value mapping curve, and a third grayscale value-index value mapping curve corresponding to the current DBV can be drawn using the current configuration data.

According to the above method, when DBV changes, the gamma adjustment module 121 of the present invention can quickly obtain the required 75 binding point values during the VBP (Vertical Back Porch) period while effectively saving computing resources. It is additionally explained that in order to save computing time and power consumption, the present invention uses a chip select signal (chip section) to perform continuous reading logic control on the memory unit 1215, during which the read address signal will continuously change until the required configuration data is read. At the same time, as shown in FIG8 , the present invention stores P(K/2) sets of first configuration data corresponding to K/2 display brightness values with odd numbers in the first memory block 12M1, and stores P(K/2) sets of second configuration data corresponding to K/2 display brightness values with even numbers in the second memory block 12M2. According to this setting, when we need to read the configuration data of two bands, we can read them out at one time. Therefore, compared with the traditional method, the total reading time of the present invention is reduced by 50%.

In addition, a clock gating signal can be used to control the operation of each circuit unit, thereby effectively managing the chip power consumption. For example, a memory gating signal (memory_clock) used to gate the memory unit 1215 will be enabled only when the configuration data needs to be read from the memory unit 1215. Similarly, a clock gating signal used to gate the linear interpolation operation unit 1217 will be enabled only when the interpolation operation needs to be performed. Therefore, after the clock gating signal is introduced to control the operation of each circuit unit, the power consumption of the display driver chip 12 can be effectively reduced.

It is worth mentioning that the actual operation data shows that the interpolation calculation of the current configuration data (i.e., including 75 index values corresponding to 75 sub-pixel grayscale binding points) using the operation architecture shown in FIG9 only consumes 300 clock cycles (clk_cycle). Moreover, in terms of power consumption, when DBV changes, for a current frame that uses 2400 hsync_cycles to control the display time, under the control of clock gating, only 1 hsync_cycle is enabled, and the power consumption is close to 0. On the other hand, since the present invention uses the operation architecture shown in FIG9 to perform the linear interpolation operation, the operation circuit can be greatly reduced, thereby greatly reducing the chip area.

Thus, the gamma adjustment module of the present invention has been fully and clearly described above; and, from the above, it can be known that the present invention has the following advantages:

(1) The present invention discloses a gamma adjustment module, which is applied to a display driver chip and includes: an analog operation unit and a digital operation unit, wherein the analog operation unit generates a corresponding red sub-pixel gamma voltage, a green sub-pixel gamma voltage and a blue sub-pixel gamma voltage according to a red sub-pixel grayscale data, a green sub-pixel grayscale data and a blue sub-pixel grayscale data input externally, and the digital operation unit is used to generate a corresponding first digital value, a second digital value and a third digital value. Finally, a digital-to-analog conversion unit generates and outputs a red sub-pixel driving voltage, a green sub-pixel driving voltage, and a blue sub-pixel driving voltage according to the red sub-pixel gamma voltage, the green sub-pixel gamma voltage, the blue sub-pixel gamma voltage, the first digital value, the second digital value, and the third digital value. As can be seen from the above description, the present invention uses the first digital value, the second digital value, and the third digital value to adjust the red sub-pixel gamma voltage, the green sub-pixel gamma voltage, and the blue sub-pixel gamma voltage. Therefore, the adjustment accuracy of the gamma voltage is not limited by the number and value of the physical resistors, and has sufficient gamma voltage adjustment flexibility.

(2) Furthermore, the present invention also provides a display driver chip, which is characterized in that it includes the gamma adjustment module of the present invention as described above.

(3) Furthermore, the present invention also provides a display device, which includes a display panel and at least one display driver chip, wherein the display driver chip includes the gamma adjustment module of the present invention as described above.

(4) The present invention further provides an information processing device, which includes a display device, and is characterized in that the display device includes a display panel and at least one display driver chip of the present invention as described above. In one embodiment, the information processing device is an electronic device selected from the group consisting of a smart TV, a smart phone, a smart watch, a tablet computer, an all-in-one computer, a notebook computer, an ATM, a car entertainment device, and a video door machine.

It must be emphasized that what is disclosed in the above-mentioned case is a preferred embodiment. Any partial changes or modifications that are derived from the technical ideas of this case and are easily inferred by people familiar with the art do not deviate from the scope of the patent rights of this case.

In summary, this case shows that its purpose, means and effects are very different from the known technology, and it is the first invention that is practical and indeed meets the patent requirements for invention. We sincerely request the review committee to examine this carefully and grant a patent as soon as possible to benefit the society. This is our utmost prayer.

1a: Flat panel display device 11a: Display panel 12a: Display driver chip 121a: Gamma adjustment module 1211a: Gamma conversion unit 1212a: Gamma voltage generation unit 1: Flat panel display device 11: Display panel 12: Display driver chip 121: Gamma adjustment module 12C1: Analog operation unit 12C2: Digital operation unit 1211: Gamma conversion unit 1212: Gamma voltage generation unit 1213: Index value generation unit 1214: Digital value providing unit 1215: Memory unit 1216: Parallel/serial conversion unit 1217: Linear interpolation operation unit 122: Digital-to-analog conversion unit 1218: Serial/parallel conversion unit 12M1: First memory block 12M2: Second memory block

FIG. 1 is a block diagram of a known flat panel display; FIG. 2 is a block diagram of a gamma correction module shown in FIG. 1; FIG. 3 is a diagram of a gamma curve; FIG. 4 is a block diagram of a flat panel display device having a gamma adjustment module of the present invention; FIG. 5 is a block diagram of a gamma adjustment module of the present invention; FIG. 6 is a diagram of two grayscale value-index value mapping curves; FIG. 7 is a diagram of a maximum display brightness value, a minimum display brightness value, and a display brightness adjustment segment; FIG. 8 is a block diagram of a memory unit shown in FIG. 5; and FIG. 9 is a block diagram of an index value generation unit shown in FIG. 5.

121: Gamma adjustment module

12C1: Analog Arithmetic Unit

12C2: Digital Arithmetic Unit

1211: Gamma transformation unit

1212: Gamma voltage generating unit

1213: Index value generation unit

1214: Digital value providing unit

1215: memory unit

122: Digital to analog conversion unit

Claims (13)

A gamma adjustment module is applied to a display driver chip and includes: An analog operation unit uses a red sub-pixel gamma curve, a blue sub-pixel gamma curve, and a green sub-pixel gamma curve to map an externally input red sub-pixel grayscale data, a green sub-pixel grayscale data, and a blue sub-pixel grayscale data into a first red sub-pixel grayscale data, a first green sub-pixel grayscale data, and a first blue sub-pixel grayscale data, and further generates a red sub-pixel gamma voltage, a green sub-pixel gamma voltage, and a blue sub-pixel gamma voltage according to the first red sub-pixel grayscale data, the first green sub-pixel grayscale data, and the first blue sub-pixel grayscale data; and A digital operation unit maps the externally input red sub-pixel grayscale data, green sub-pixel grayscale data and blue sub-pixel grayscale data into a first index value, a second index value and a third index value using a first grayscale value-index value mapping curve, a second grayscale value-index value mapping curve and a third grayscale value-index value mapping curve, and further generates a first digital value, a second digital value and a third digital value according to the first index value, the second index value and the third index value; The analog operation unit and the digital operation unit are coupled to a digital-to-analog conversion unit at the same time in the digital operation unit, so that the digital-to-analog conversion unit generates and outputs a red sub-pixel driving voltage, a green sub-pixel driving voltage and a blue sub-pixel driving voltage according to the red sub-pixel gamma voltage, the green sub-pixel gamma voltage, the blue sub-pixel gamma voltage, the first digital value, the second digital value and the third digital value. The gamma adjustment module as described in claim 1, wherein the analog operation unit includes: a gamma conversion unit, which uses the red sub-pixel gamma curve, the blue sub-pixel gamma curve and the green sub-pixel gamma curve to map the externally input red sub-pixel grayscale data, the green sub-pixel grayscale data and the blue sub-pixel grayscale data into the first red sub-pixel grayscale data, the first green sub-pixel grayscale data and the first blue sub-pixel grayscale data; and A gamma voltage generating unit is coupled to the gamma conversion unit, and is used to further generate the red sub-pixel gamma voltage, the green sub-pixel gamma voltage, and the blue sub-pixel gamma voltage according to the first red sub-pixel grayscale data, the first green sub-pixel grayscale data, and the first blue sub-pixel grayscale data. The gamma adjustment module as described in claim 2, wherein the digital operation unit comprises: an index value generating unit, for mapping the externally input red sub-pixel grayscale data, the green sub-pixel grayscale data and the blue sub-pixel grayscale data into the first index value, the second index value and the third index value using the first grayscale value-index value mapping curve, the second grayscale value-index value mapping curve and the third grayscale value-index value mapping curve; and a digital value providing unit, coupled to the index value generating unit, for further generating and providing the first digital value, the second digital value and the third digital value to the digital-to-analog conversion unit according to the first index value, the second index value and the third index value. The gamma adjustment module as described in claim 3, wherein the digital operation unit further comprises: A memory unit, comprising a first memory block and a second memory block; Wherein, a display brightness adjustment segment is between a maximum display brightness value (DBV) and a minimum display brightness value, and K-2 interval brightness values are further set in the display brightness adjustment segment, where K is a positive integer; The K-2 interval brightness values, the highest display brightness value and the lowest display brightness value form K display brightness values, K/2 display brightness values have odd numbers, and K/2 display brightness values have even numbers. The first memory block stores P(K/2) sets of first configuration data corresponding to the K/2 display brightness values with odd numbers, and the second memory block stores P(K/2) sets of second configuration data corresponding to the K/2 display brightness values with even numbers, and P is a positive integer. A gamma adjustment module as described in claim 4, wherein, when a current display brightness value set by a user falls between the j-th display brightness value and the j-1-th display brightness value, the index value generating unit obtains a set of the first configuration data corresponding to the j-th display brightness value and a set of the second configuration data corresponding to the j-1-th display brightness value from the memory unit, and then obtains a current configuration data corresponding to the display brightness value by performing a linear interpolation operation on the first configuration data and the second configuration data, and finally generates the first grayscale value-index value mapping curve, the second grayscale value-index value mapping curve and the third grayscale value-index value mapping curve according to the current configuration data; j is a positive integer. A gamma adjustment module as described in claim 5, wherein, before executing the linear interpolation operation, the index value generating unit performs a parallel-to-serial conversion operation on the first configuration data and the second configuration data, so that the first configuration data and the second configuration data are converted into a serial data in the form of serial data through the linear interpolation operation, and finally the index value generating unit performs a serial-to-parallel conversion operation on the serial data to generate the current configuration data. A display driver chip is characterized in that it includes a gamma adjustment module, and the gamma adjustment module includes: An analog operation unit uses a red sub-pixel gamma curve, a blue sub-pixel gamma curve, and a green sub-pixel gamma curve to map an externally input red sub-pixel grayscale data, a green sub-pixel grayscale data, and a blue sub-pixel grayscale data into a first red sub-pixel grayscale data, a first green sub-pixel grayscale data, and a first blue sub-pixel grayscale data, and further generates a red sub-pixel gamma voltage, a green sub-pixel gamma voltage, and a blue sub-pixel gamma voltage according to the first red sub-pixel grayscale data, the first green sub-pixel grayscale data, and the first blue sub-pixel grayscale data; and A digital operation unit maps the externally input red sub-pixel grayscale data, green sub-pixel grayscale data and blue sub-pixel grayscale data into a first index value, a second index value and a third index value using a first grayscale value-index value mapping curve, a second grayscale value-index value mapping curve and a third grayscale value-index value mapping curve, and further generates a first digital value, a second digital value and a third digital value according to the first index value, the second index value and the third index value; The analog operation unit and the digital operation unit are coupled to a digital-to-analog conversion unit at the same time in the digital operation unit, so that the digital-to-analog conversion unit generates and outputs a red sub-pixel driving voltage, a green sub-pixel driving voltage and a blue sub-pixel driving voltage according to the red sub-pixel gamma voltage, the green sub-pixel gamma voltage, the blue sub-pixel gamma voltage, the first digital value, the second digital value and the third digital value. The display driver chip as described in claim 7, wherein the analog operation unit includes: a gamma conversion unit, which uses the red sub-pixel gamma curve, the blue sub-pixel gamma curve and the green sub-pixel gamma curve to map the externally input red sub-pixel grayscale data, the green sub-pixel grayscale data and the blue sub-pixel grayscale data into the first red sub-pixel grayscale data, the first green sub-pixel grayscale data and the first blue sub-pixel grayscale data; and A gamma voltage generating unit is coupled to the gamma conversion unit, and is used to further generate the red sub-pixel gamma voltage, the green sub-pixel gamma voltage, and the blue sub-pixel gamma voltage according to the first red sub-pixel grayscale data, the first green sub-pixel grayscale data, and the first blue sub-pixel grayscale data. The display driver chip as described in claim 8, wherein the digital operation unit comprises: an index value generating unit, for mapping the externally input red sub-pixel grayscale data, the green sub-pixel grayscale data and the blue sub-pixel grayscale data into the first index value, the second index value and the third index value using the first grayscale value-index value mapping curve, the second grayscale value-index value mapping curve and the third grayscale value-index value mapping curve; and a digital value providing unit, coupled to the index value generating unit, for further generating and providing the first digital value, the second digital value and the third digital value to the digital-to-analog conversion unit according to the first index value, the second index value and the third index value. The display driver chip as described in claim 9, wherein the digital operation unit further comprises: A memory unit, comprising a first memory block and a second memory block; Wherein, a display brightness adjustment segment is provided between a maximum display brightness value (DBV) and a minimum display brightness value, and K-2 interval brightness values are further set in the display brightness adjustment segment, where K is a positive integer; The K-2 interval brightness values, the highest display brightness value and the lowest display brightness value form K display brightness values, K/2 display brightness values have odd numbers, and K/2 display brightness values have even numbers. The first memory block stores P(K/2) sets of first configuration data corresponding to the K/2 display brightness values with odd numbers, and the second memory block stores P(K/2) sets of second configuration data corresponding to the K/2 display brightness values with even numbers, and P is a positive integer. The display driver chip as described in claim 10, wherein when a current display brightness value set by a user falls between the jth display brightness value and the j-1th display brightness value, the index value generating unit reads a set of the first configuration data corresponding to the jth display brightness value and a set of the second configuration data corresponding to the j-1th display brightness value from the memory unit, and then obtains a current configuration data corresponding to the display brightness value by performing a linear interpolation operation on the first configuration data and the second configuration data, and finally generates the first grayscale value-index value mapping curve, the second grayscale value-index value mapping curve and the third grayscale value-index value mapping curve according to the current configuration data; j is a positive integer. A display device includes a display panel and at least one display driver chip, wherein the display driver chip includes a gamma adjustment module as described in any one of claim 1 to claim 6. An information processing device includes a display device, wherein the display device includes a display panel and at least one display driver chip as described in any one of claim 7 to claim 11.

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