TWI764394B - Current attenuation method for display driving, flat panel display, and information processing device - Google Patents

Abstract

The present invention discloses a current decay method for display driving, which is applied in a flat panel display including at least one display driving chip and a self-luminous display panel. In the process of performing an ACL operation on a flat display panel such as an OLED display panel, after calculating an initial current decay parameter, the current decay method of the present invention first performs a gamma mapping conversion process on the initial current decay parameter Thereby, a current attenuation parameter is obtained, and then a weighted operation is performed on the brightness data of each display pixel included in the one frame of display image by using the current attenuation parameter, so that the display pixel brightness included in the one frame of display image after the operation is processed. It conforms to the regular curve of human vision. In the case of applying the current attenuation method of the present invention, the display driving chip only needs to have an automatic current limiting unit, and no additional data preprocessing unit and/or data postprocessing unit is required.

Description

Current attenuation method for display driving, flat panel display, and information processing device

The present invention relates to the field of display driving technology, and more particularly, to a current attenuation method for display driving of a flat display panel.

It is known that a flat panel display includes a non-self-emissive flat panel display and a self-emissive flat panel display, wherein a liquid crystal display is a non-self-emissive flat panel display that has been used for a long time, and an organic light-emitting diode (OLED) Displays and light-emitting diode (LED) displays are known as self-luminous flat panel displays. FIG. 1 shows a block diagram of a conventional OLED display. As shown in FIG. 1, the structure of the OLED display 1a mainly includes: an OLED display panel 11a, a gate (column) driving unit 12a, a source (row) driving unit 13a, a display controller 14a, and a voltage Conversion unit 15a.

Electronic engineers familiar with the design and manufacture of OLED displays know that the source driving unit 13a may be a source driving chip alone, or may be integrated with the gate driving unit 12a into a single display driving chip. In practical design, the source driving unit 13a usually includes a gamma voltage generating unit 131a for converting a working voltage provided by the voltage converting unit 15a into a plurality of reference gamma voltages , so that a plurality of data display driving units in the source driving unit 13a can generate corresponding complex numbers according to a plurality of the reference gamma voltages and a sequence of data signals and a data clock signal transmitted by the display controller 14a A driving signal is transmitted to the OLED display panel 11a.

It should be known that the OLED display panel 11a includes M×N OLED sub-pixels 111a and M×N pixel circuit units 112a. Due to the self-luminous and high-brightness characteristics of the OLED sub-pixel 111a, in order to reduce system power consumption, the design and manufacturer of the display driver chip will make the source driver unit 13a have an auto current limit (ACL) unit 133a, Its main function is to attenuate the excessive current when the current (brightness) is high, so as to achieve the purpose of reducing system power consumption.

FIG. 2 shows the conversion curve of the average brightness of a frame of display image to the digital brightness value (DBV), and FIG. 3 shows the conversion curve of the pixel brightness of the input display data to the pixel brightness of the output display data. When performing the current attenuation operation, the automatic current limiting unit 133a first calculates the average brightness of a frame of display images, and then obtains the parameters to be attenuated for the frame of display images according to the average brightness of a frame (as shown in FIG. 2 ). After the current (brightness) attenuation parameter is obtained, each sub-pixel in the input display data of a frame of display image is scaled down according to the current attenuation parameter (as shown in FIG. 3 ). This operation can effectively reduce the system power consumption. Unfortunately, enabling the automatic current limiting unit 133a will cause the brightness adjustment of the OLED display panel 11a to deviate from the preset human visual law curve (ie, the gamma curve).

In order to solve the aforementioned problems, the design and manufacturer of the display driver chip specially makes the automatic current limiting unit 133a include a gamma correction function. FIG. 4 shows a block diagram of a conventional automatic current limiting unit 133a with gamma correction function. As shown in FIG. 4 , the automatic current limiting unit 133a with gamma correction function includes: a first gamma correction unit 1331a, an ACL execution unit 1332a and a second gamma correction unit 1333a. In this way, after receiving the input display data of one frame of display image, the first gamma correction unit 1331a of the automatic current limiting unit 133a performs a gamma correction on the pixel brightness of the display data according to a gamma parameter (eg gamma2.2). The gamma correction operation (ie, data preprocessing), then the ACL execution unit 1332a performs a current limit operation on the pixel brightness of the display data that has completed the gamma correction operation. Finally, the second gamma correction unit 1332a of the automatic current limiting unit 133a performs another gamma correction operation on the pixel brightness of the display data of the current limiting operation according to another gamma parameter (eg, gamma0.45) post-processing).

Practical experience has pointed out that the automatic current limiting unit 133a with gamma correction function shown in FIG. 4 must sequentially enable the first gamma correction unit 1331a, the ACL execution The unit 1332a and the second gamma correction unit 1333a not only prolong the overall running time of the ACL operation, but also increase the overall system power consumption of the display driving chip (source driving unit 13a).

From the above description, it can be seen that a novel current decay method for display driving is urgently needed in the art.

The main purpose of the present invention is to provide a current attenuation method for display driving, which is applied in a flat panel display including at least one display driving chip and a self-luminous display panel. In the process of performing an ACL operation on a flat display panel such as an OLED display panel, after calculating an initial current decay parameter, the current decay method of the present invention first performs a gamma mapping conversion process on the initial current decay parameter Thereby, a current attenuation parameter is obtained, and then a weighted operation is performed on the brightness data of each display pixel included in the one frame of display image by using the current attenuation parameter, so that the display pixel brightness included in the one frame of display image after the operation is processed. It conforms to the regular curve of human vision. In the case of applying the current attenuation method of the present invention, the display driving chip only needs to have an automatic current limiting unit, and no additional data preprocessing unit and/or data postprocessing unit is required.

In order to achieve the above object, the present invention proposes an embodiment of the current attenuation method for display driving, which is applied to a flat panel display including at least one display driving chip and a flat panel display panel, and includes the following steps:

calculating the average brightness of a frame of display images, and then obtaining an initial current attenuation parameter according to the average brightness of a frame;

performing a gamma mapping conversion process on the initial current decay parameter according to a segmented gamma conversion curve, thereby obtaining a current decay parameter; and

After performing a weighting operation on the luminance data of each display pixel included in the one frame of display image by using the current decay parameter, the output is output.

In one embodiment, the display pixel luminance data may represent a red sub-pixel gray-scale value, a green sub-pixel gray-scale value, or a blue sub-pixel gray-scale value.

In one embodiment, the weighting operation is a multiplication operation.

In one embodiment, the flat display panel includes M×N sub-pixels, and the sub-pixels are selected from organic light-emitting diodes (OLEDs), light-emitting diodes (Light-emitting diodes). Diode, LED), Quantum light-emitting diode (QLED), micro light-emitting diode (Mirco LED) and sub-millimeter light-emitting diode (Mini LED) is a light-emitting element in the group consisting of .

The present invention also provides a flat panel display, which includes at least a display driver chip and a flat panel display panel, and the display driver chip has an automatic current limiting unit for executing a current decay method; the current decay method includes the following steps:

calculating the average brightness of a frame of display images, and then obtaining an initial current attenuation parameter according to the average brightness of a frame;

performing a parameter adjustment process on the initial current decay parameter according to a gamma parameter, thereby obtaining a current decay parameter; and

After performing a weighting operation on the display pixel brightness data and the current attenuation parameter included in the one frame of display image, the output is output.

In one embodiment, the display pixel luminance data may represent a red sub-pixel gray-scale value, a green sub-pixel gray-scale value, or a blue sub-pixel gray-scale value.

In one embodiment, the weighting operation is a multiplication operation.

In one embodiment, the flat display panel includes M×N sub-pixels, and the sub-pixels are selected from organic light-emitting diodes (OLEDs), light-emitting diodes (Light-emitting diodes). Diode, LED), Quantum light-emitting diode (QLED), micro light-emitting diode (Mirco LED) and sub-millimeter light-emitting diode (Mini LED) is a light-emitting element in the group consisting of .

The present invention also provides an information processing device having the flat panel display of the present invention as described above.

In a possible embodiment, the information processing device can be a smart phone, a smart watch, a smart bracelet, a tablet computer, a notebook computer, an all-in-one computer, an access control device, a desktop computer, or an industrial computer.

In order to enable your examiners to further understand the structure, characteristics, purpose, and advantages of the present invention, drawings and detailed descriptions of preferred embodiments are attached as follows.

The present invention mainly discloses a current decay method for display driving, which is applied in a flat panel display including at least one display driving chip and a self-luminous display panel. In the process of performing an ACL operation on a flat display panel such as an OLED display panel, after calculating an initial current decay parameter, the current decay method of the present invention first performs a gamma mapping conversion process on the initial current decay parameter Thereby, a current attenuation parameter is obtained, and then a weighted operation is performed on the brightness data of each display pixel included in the one frame of display image by using the current attenuation parameter, so that the display pixel brightness included in the one frame of display image after the operation is processed. It conforms to the regular curve of human vision. In the case of applying the current attenuation method of the present invention, the display driving chip only needs to have an automatic current limiting unit, and no additional data preprocessing unit and/or data postprocessing unit is required.

FIG. 5 shows a block diagram of an OLED display to which a current decay method for display driving of the present invention is applied. As shown in FIG. 5, the structure of the OLED display 1 mainly includes: an OLED display panel 11, a gate (column) driving unit 12, a source (row) driving unit 13, a display controller 14, and a voltage Conversion unit 15. The source driving unit 13 has a gamma voltage generating unit 131 and an auto current limit (ACL) unit 133 for implementing the current decay method.

Electronic engineers who are familiar with the design and manufacture of OLED displays know that the source driver unit 13 can be a source driver chip alone, or can be integrated with the gate driver unit 12 into a single display driver chip. As can be seen from FIG. 5 , the OLED display panel 11 includes M×N OLED sub-pixels 111 and M×N pixel circuit units 112 . Due to the element characteristics of self-illumination and high brightness of the OLED sub-pixel 111, in order to reduce system power consumption, the source driving unit 13 has the automatic current limiting unit 133 for higher current (brightness) Attenuate the excessive current at this time, so as to achieve the purpose of reducing the power consumption of the system.

FIG. 6 shows a block diagram of the automatic current limiting unit 133 , and FIG. 7 shows a flowchart of a current decay method for display driving according to the present invention. In the process of the automatic current limiting unit 133 performing an automatic current limiting (ALC) operation, the current decay method of the present invention will first perform step S1: calculate the average brightness of a frame of display images, and then obtain an initial image according to the average brightness of a frame. Current decay parameters (shown in Figure 2). Next, the method flow continues to perform step S2: performing a mapping conversion process on the initial current decay parameter according to a segmented conversion curve, so as to obtain a current decay parameter. The abscissa of the segmented conversion curve has a plurality of binding points, and the corresponding value of the ordinate of each binding point is calculated using the following mathematical formula (1): (1-&%)'= (1-& %) ^gamma_x …………………………(1)

In the above formula (1), (1-&%) represents the value of the binding point, and (1-&%)' represents the corresponding value of the ordinate of the binding point. It should be noted that gamma_x is a positive real number less than 1, and its value is preferably 0.45. In addition, the mapping conversion process includes: when the initial current decay parameter is located between the two binding points, performing an interpolation calculation to obtain the current decay parameter.

…………………………(2) pixel_ out＝

……(3) In addition, assuming that the display data is 8 bits, the formula (2) representing the technical characteristics of the present invention can be expressed by the following formula (3): pixel_out = pixel_in

…………………………(2) pixel_out =

...(3)

Among them, gamma_x1 and gamma_x2 are reciprocals of each other.

In the above equations (2) and (3), PIXEL_IN refers to the input display data, which can be a red sub-pixel grayscale value, a green sub-pixel grayscale value, or a blue subpixel grayscale value, pixel_in represents the normalized value of PIXEL_IN, on the other hand, pixel_out represents the normalized value of the output display data. Also, in a feasible embodiment, gamma_x1 and gamma_x2 can be exemplarily 0.45 and 2.2, respectively. Electronic engineers familiar with display gamma correction should understand that gamma_x2 is generally used for gamma correction (conversion) operations, while gamma_x1 is used for de-gamma correction (de-gamma) operations. It should be added that, as shown in FIG. 6 , the mathematical operation formulas listed above can be edited into a parameter adjustment unit 1331 in the form of a function library or a look-up table, so as to facilitate application in the source driving unit 13 . in the automatic current limiting unit 133 described above.

Figure 8 shows a conversion plot of the initial current decay parameter versus the current decay parameter. As shown in FIG. 8 , corresponding to different gamma binding points 0, 1, 2, . also changed. Further, as shown in FIG. 6 and FIG. 7 , the method flow finally executes step S3 : using the current attenuation parameter to perform a weighting operation on the luminance data of each display pixel included in the one frame of display image, and output it. In one embodiment, the weighting operation is a multiplication operation. After steps S1-S3 are completed, the brightness of the display pixels included in a frame of display image after the arithmetic processing will conform to the human visual law curve.

Thus, the above has completely and clearly explained a current decay method for display driving of the present invention; and, from the above, it can be known that the present invention has the following advantages:

(1) The present invention discloses a current decay method for display driving, which is applied to a flat panel display including at least one display driving chip and a self-luminous display panel. In the process of performing an ACL operation on a flat display panel such as an OLED display panel, after calculating an initial current decay parameter, the current decay method of the present invention first performs a gamma mapping conversion process on the initial current decay parameter Thereby, a current attenuation parameter is obtained, and then a weighted operation is performed on the brightness data of each display pixel included in the one frame of display image by using the current attenuation parameter, so that the display pixel brightness included in the one frame of display image after the operation is processed. It conforms to the regular curve of human vision. In the case of applying the current attenuation method of the present invention, the display driving chip only needs to have an automatic current limiting unit, and no additional data preprocessing unit and/or data postprocessing unit is required.

(2) The present invention also provides a flat panel display, which includes at least one display driving chip and a flat display panel, and the display driving chip has an automatic current limiting unit for performing the current attenuation for display driving according to the present invention method. In one embodiment, the flat display panel includes M×N sub-pixels, and the sub-pixels are selected from organic light-emitting diodes (OLEDs), light-emitting diodes (Light-emitting diodes). Diode, LED), Quantum light-emitting diode (QLED), micro light-emitting diode (Mirco LED) and sub-millimeter light-emitting diode (Mini LED) is a light-emitting element in the group consisting of .

(3) The present invention also provides an information processing device having the flat panel display of the present invention as described above. And, the information processing device is selected from the group consisting of smart phones, smart watches, smart bracelets, tablet computers, notebook computers, all-in-one computers, access control devices, desktop computers, and industrial computers of an electronic device.

It must be emphasized that the above-mentioned disclosure in this case is a preferred embodiment, and any partial changes or modifications originating from the technical ideas of this case and easily inferred by those who are familiar with the art are within the scope of the patent of this case. category of rights.

To sum up, regardless of the purpose, means and effect of this case, it shows that it is completely different from the conventional technology, and its first invention is practical, and it does meet the patent requirements of the invention. Society is to pray for the best.

1a: OLED display 11a: OLED display panel 12a: Gate drive unit 13a: source driver unit 131a: Gamma voltage generation unit 133a: Automatic current limiting unit 1331a: First Gamma Correction Unit 1332a: ACL Execution Unit 1333a: Second Gamma Correction Unit 14a: Display Controller 15a: Voltage conversion unit 1: OLED display 11: OLED display panel 12: Gate drive unit 13: Source drive unit 131: Gamma voltage generation unit 133: Automatic current limiting unit 1331: Parameter adjustment unit 14: Display Controller 15: Voltage conversion unit S1: Calculate the average brightness of a frame of display images, and then obtain an initial current decay parameter according to the average brightness of a frame S2: Perform a parameter adjustment process on the initial current decay parameter according to a gamma parameter, thereby obtaining a current decay parameter S3: After performing a mathematical operation on the display pixel brightness data and the current attenuation parameter included in the one frame of display image, output the data

1 is a block diagram of a conventional OLED display; Fig. 2 is a conversion curve diagram of the average brightness of a frame of display image with respect to digital brightness data; Fig. 3 is the conversion curve diagram of the pixel brightness of input display data with respect to the pixel brightness of output display data; 4 is a block diagram of a conventional automatic current limiting unit with a gamma correction function; 5 is a block diagram of an OLED display to which a current decay method for display driving of the present invention is applied; 6 is a block diagram of an automatic current limiting unit to which the current decay method for display driving of the present invention is applied; 7 is a flow chart of a current decay method for display driving according to the present invention; and FIG. 8 is a conversion graph of the initial current decay parameter relative to the current decay parameter.

S1: Calculate the average brightness of a frame of display images, and then obtain an initial current decay parameter according to the average brightness of a frame

S2: Perform a parameter adjustment process on the initial current decay parameter according to a gamma parameter, thereby obtaining a current decay parameter

S3: After performing a mathematical operation on the display pixel brightness data and the current attenuation parameter included in the one frame of display image, output the data

Claims (10)

A current decay method for display driving, which is applied to a flat panel display including at least one display driving chip and a flat panel display panel, and includes the following steps: calculating the average brightness of a frame of display images, and then according to the average brightness of a frame brightness to obtain an initial current decay parameter; perform a mapping conversion process on the initial current decay parameter according to a segmented conversion curve, thereby obtaining a current decay parameter, wherein the abscissa of the segmented conversion curve has a plurality of binding point; and after performing a weighting operation on the brightness data of each display pixel included in the one frame of display image by using the current attenuation parameter, outputting it. The current decay method for display driving according to claim 1, wherein the display pixel luminance data represents a gray-scale value of red sub-pixels, a gray-scale value of green sub-pixels, and a gray-scale value of blue sub-pixels A value selected by the group. The current attenuation method for display driving according to claim 1, wherein the weighting operation is a multiplication operation. The current decay method for display driving according to claim 1, wherein the flat display panel comprises M×N sub-pixels, and the sub-pixels are selected from organic light-emitting diodes, light-emitting diodes, A light-emitting element among the group consisting of quantum dot light-emitting diodes, micro light-emitting diodes and sub-millimeter light-emitting diodes. A flat panel display includes at least one display driver chip and a flat panel display panel, and the display driver chip has an automatic current limiting unit for executing a current decay method; the current decay method includes the following steps: calculating a frame of display image , and then obtain an initial current decay parameter according to the average brightness of a picture; perform a mapping conversion process on the initial current decay parameter according to a segmented conversion curve, thereby obtaining a current decay parameter, wherein the segment The abscissa of the conversion curve has a plurality of binding points; and After performing a weighting operation on the luminance data of each display pixel included in the one frame of display image by using the current decay parameter, the output is output. The flat-panel display of claim 5, wherein the display pixel luminance data represents selected from the group consisting of red sub-pixel gray-scale values, green sub-pixel gray-scale values, and blue sub-pixel gray-scale values a value of . The flat panel display of claim 5, wherein the weighting operation is a multiplication operation. The flat panel display according to claim 5, wherein the flat panel display panel includes M×N sub-pixels, and the sub-pixels are selected from organic light-emitting diodes, light-emitting diodes, and quantum dot light-emitting diodes , a light-emitting element in the group consisting of micro light-emitting diodes and sub-millimeter light-emitting diodes. An information processing device having the flat panel display according to any one of claim 5 to claim 8. The information processing device according to claim 9, which is selected from the group consisting of smart phones, smart watches, smart bracelets, tablet computers, notebook computers, all-in-one computers, access control devices, desktop computers, and industrial computers An electronic device in a group.

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