Source driver and method for color swapping

Abstract

A source driver and a method for color switching are disclosed. The source driver includes a controller, a multiplexer circuit, and an analog amplifier circuit. The controller obtains multiple sub-pixel data from an application processor and performs the following operations on the multiple sub-pixel data: adding a tag to each sub-pixel data to generate multiple new sub-pixel data, and color switching on the multiple new sub-pixel data. The tag indicates the color information of the sub-pixel data. The multiplexer circuit is coupled to the controller, sequentially obtains each new sub-pixel data after switching, and selects a corresponding gamma voltage based on the tag of the new sub-pixel data. The analog amplifier circuit is coupled to the multiplexer circuit, and provides a source drive signal to the corresponding sub-pixel in the pixel array based on the new sub-pixel data and the corresponding gamma voltage.

Description

Source Driver and Method for Color Conversion The present invention relates to a display panel, and more particularly to a source driver and a method for color conversion. For organic light emitting diode (OLED) applications, color conversion is a very important function because the RGB data input from an application processor (AP) must be converted into RGBG-type data for an OLED panel. Generally, the odd display lines output by the source channel are RGBG, and the even display lines output by the source channel are BGRG, which means that the odd and even display lines need to perform color conversion to, for example, convert RGBG to BGRG. Moreover, if the panel is flipped horizontally or vertically for display, the output of the source channel also needs to perform different color conversions. In addition, if the customer uses different PenTile panel architectures, the color conversion will also be different. The source channel is a channel that transmits a mixed data of RGB data and gamma voltage. In particular, the gamma voltage adjustment is very important for color correction. And generally, RGB colors require their own gamma voltage settings for color correction. Therefore, if the RGB data performs color conversion, the gamma voltage also needs to perform corresponding color conversion to match the correct RGB colors. It can be seen that there may be more than 100 types of color conversions, thus increasing the complexity of circuit design. Accordingly, how to design a method for color conversion that can reduce the chip area and circuit complexity has become one of the problems that researchers in this field are eager to solve. It should be noted that the content of the "prior art" paragraph is used to help understand the technology of the present invention. Some (or all) of the content disclosed in the "prior art" paragraph may not be the conventional technology known to those with ordinary knowledge in the technical field. The content disclosed in the "prior art" paragraph does not represent that the content was known to those with ordinary knowledge in the technical field before the filing of the present invention technology. The present invention provides a source driver and a method for color conversion, which add tags for indicating color information to each sub-pixel data. Therefore, after color conversion, the corresponding gamma voltage can be selected according to the tags, so as to reduce the chip area and circuit complexity. An embodiment of the present invention provides a source driver. The source driver includes a controller, a multiplexer circuit, and an analog amplifier circuit. The controller obtains a plurality of sub-pixel data from an application processor, and performs the following operations on the plurality of sub-pixel data: adding a tag to each sub-pixel data to generate a plurality of new sub-pixel data, and performing color conversion on the plurality of new sub-pixel data. The tag indicates the color information of the sub-pixel data. The multiplexer circuit is coupled to the controller, sequentially obtains each new sub-pixel data after conversion, and selects a corresponding gamma voltage according to the tag of the new sub-pixel data after conversion. The analog amplifier circuit is coupled to the multiplexer circuit, and provides a source driving signal to a corresponding sub-pixel in the pixel array according to the new sub-pixel data after conversion and the corresponding gamma voltage. An embodiment of the present invention provides a method for color conversion, which is applicable to a display panel. The display panel includes a source driver and a pixel array. The method includes obtaining a plurality of sub-pixel data from an application processor, and performing the following operations on the plurality of sub-pixel data: adding a tag to each sub-pixel data to generate a plurality of new sub-pixel data, and performing color conversion on the plurality of new sub-pixel data. The tag indicates the color information of the sub-pixel data. The method further includes sequentially obtaining each new sub-pixel data after conversion, selecting a corresponding gamma voltage according to the tag of the new sub-pixel data after conversion, and providing a source driving signal to a corresponding sub-pixel in the pixel array according to the new sub-pixel data after conversion and the corresponding gamma voltage. Based on the above, the source driver and the method for color conversion provided by the embodiments of the present invention can add a tag for indicating color information to each sub-pixel data, and directly select a corresponding gamma voltage according to the tag after performing color conversion on the sub-pixel data. In this way, the source driver and the method for color conversion of the present invention can reduce the chip area and circuit complexity, and are compatible with different types of panels. To make the present invention more obvious and understandable, the following specific embodiments are given and described in detail in conjunction with the accompanying drawings as follows. As used throughout the specification of this case (including the claims), the term "coupled (or connected)" can refer to any direct or indirect connection means. For example, if it is described in the text that the first device is coupled (or connected) to the second device, it should be interpreted that the first device can be directly connected to the second device, or the first device can be indirectly connected to the second device through other devices or certain connection means. The terms "first", "second", etc. mentioned throughout the specification of this case (including the claims) are used to name elements or to distinguish different embodiments or scopes, rather than to limit the upper or lower limits of the number of elements, nor to limit the order of the elements. Additionally, wherever possible, elements / components / steps with the same reference numerals in the drawings and embodiments represent the same or similar parts. Elements / components / steps with the same reference numerals or the same terms used in different embodiments can refer to the relevant descriptions with reference to each other. FIG. 1 shows an OLED panel type according to an embodiment of the present invention. There are mainly two types of OLED panels: No-MUX and 2-to-1 MUX (2MUX). In FIG. 1, S1 to S8 represent source channels, the H-SYNC signal controls the scanning of odd lines ODD_Line or even lines EVEN_Line, and when scanning odd lines ODD_Line or even lines EVEN_Line on a 2MUX type panel, the switching signal switches between the first state MUX0 and the second state MUX1 to control the scanning of the first part or the second part of odd lines ODD_Line or even lines EVEN_Line. It can be seen that 2MUX can reduce the chip area based on time division (compared with No-MUX, the source channels are halved), but the display charging time for high frame rate display quality is relatively poor (compared with No-MUX, the charging time is halved). Since the output of the source channels mixes RGB data and gamma voltage, if the RGB data performs color conversion, the gamma voltage also needs to perform corresponding color conversion to match the correct RGB colors. FIG. 2 shows some conventional color conversion types according to an embodiment of the present invention. In FIG. 2, these conventional color conversion types are only a small part of the known PenTile panel types. If other functions are considered, such as full display camera (FDC) skipping or source channel folding technology, the number of color conversion types can even exceed hundreds. The color conversion of the gamma voltage can be implemented in a logic design or an analog design. However, whether it is an analog design or a logic design, complex color conversion will increase the complexity, area, and error rate of the circuit design and become a burden. Therefore, the present invention provides a source driver and a method for color conversion to achieve compatibility with various types of panels, and cancel the color conversion of the gamma voltage to save chip area and reduce circuit complexity. FIG. 3 is a block schematic diagram of a display panel according to an embodiment of the present invention. Referring to FIG. 3, the display panel 100 of this embodiment includes a source driver 120 and a pixel array 140. The display panel 100 is, for example, a liquid-crystal display (LCD), a thin film transistor liquid crystal (TFT-LCD) display, a light-emitting diode (LED) display, an organic light-emitting diode (OLED) display, or a plasma display, etc., a device with a display function, but is not limited thereto. In this embodiment, the source driver 120 is coupled to the pixel array 140, and the pixel array 140 is an array including a plurality of sub-pixels arranged in a plurality of rows and a plurality of columns. The source driver 120 can drive each row in the pixel array 140, and apply a plurality of source driving signals to the sub-pixels in the pixel array 140 respectively to achieve a display effect. The source driver 120 includes a controller 122, a multiplexer circuit 124, and an analog amplifier circuit 126. The multiplexer circuit 124 is coupled between the controller 122 and the analog amplifier circuit 126. In one embodiment, the multiplexer circuit 104 includes a plurality of multiplexers, and the analog amplifier circuit 106 includes a plurality of analog amplifiers. The number of multiplexers is the same as the number of analog amplifiers, and the plurality of multiplexers are correspondingly coupled to the plurality of analog amplifiers. However, the present invention is not limited thereto. The controller 122 is, for example, a Central Processing Unit (CPU), or other programmable general-purpose or special-purpose microprocessor, Digital Signal Processor (DSP), programmable controller, Application Specific Integrated Circuits (ASIC), or other similar devices, or a combination of these devices, but is not limited thereto. In this embodiment, the controller 122 processes data received from the outside. Specifically, the controller 122 can load firmware code from a storage device (not shown in FIG. 3) to cooperate with the multiplexer circuit 124 and the analog amplifier circuit 126 to execute the method for color conversion according to the embodiment of the present invention, and this method will be further described in detail in FIG. 4. In one embodiment, the source driver 120 further includes a register 128. The register 128 is coupled to the controller 122 and the multiplexer circuit 124, and temporarily stores the data processed by the controller 122. FIG. 4 is a flowchart showing a method for color conversion according to an embodiment of the present invention. Please refer to FIGS. 3 and 4 simultaneously. The method 200 of this embodiment is applicable to the display panel 100 of FIG. 3. The following will describe the detailed steps of the method for color conversion of the present invention in conjunction with the operating relationship between the devices in the display panel 100. First, in step S202, the controller 122 obtains a plurality of sub-pixel data D1-Dn from the application processor. In one embodiment, n is any positive integer. In step S204, the controller 122 adds a tag TAG to each of the sub-pixel data D1-Dn to generate a plurality of new sub-pixel data ND1-NDn. Specifically, the tag TAG indicates the color information of the sub-pixel data D1-Dn. In one embodiment, the color information is one of red (R), green (G), and blue (B), and the label TAG is represented by two bits. However, the present invention is not limited thereto. FIG. 5 is an exemplary schematic diagram of new sub-pixel data according to an embodiment of the present invention. FIG. 5 shows an example where the sub-pixel data D is 10 bits and a 2-bit label TAG is added to the sub-pixel data D. Referring to FIG. 5, a label TAG is added to the sub-pixel data D to generate new sub-pixel data ND. In this embodiment, when the color information of the sub-pixel data D is red (R), the controller 122 adds 11 (label TAG[1:0]) to the sub-pixel data D. When the color information of the sub-pixel data D is green (G), the controller 122 adds 10 (label TAG[1:0]) to the sub-pixel data D. When the color information of the sub-pixel data D is blue (B), the controller 102 adds 01 (label TAG[1:0]) to the sub-pixel data D. It should be particularly noted here that the number of bits of the sub-pixel data D and the label TAG in this embodiment can be appropriately adjusted according to the actual application scenario, and this embodiment is not limited thereto. In step S206, the controller 122 performs color conversion on a plurality of new sub-pixel data ND1-NDn. Specifically, after the controller 122 performs color conversion on the plurality of new sub-pixel data ND1-NDn, the controller 122 stores the converted plurality of new sub-pixel data SND1-SNDn in the register 128. In one embodiment, after step S206, the controller 122 returns to step S202. The controller 122 continuously obtains a plurality of sub-pixel data D from the application processor, and performs the operations of step S204 and step S206 on the plurality of sub-pixel data D until the controller 122 obtains all the sub-pixel data D and has performed the operations of step S204 and step S206 on all the sub-pixel data D. At this time, all the converted new sub-pixel data SND are stored in the register 128. In step S208, the multiplexer circuit 124 sequentially obtains each of the converted new sub-pixel data SND1-SNDn, and selects a corresponding gamma voltage according to the label TAG of the converted new sub-pixel data SND1-SNDn. Specifically, the multiplexer circuit 124 sequentially obtains each of the converted new sub-pixel data SND from the register 128, and selects a corresponding gamma voltage according to the label TAG of the converted new sub-pixel data SND. In one embodiment, the gamma voltage is the gamma voltage RV corresponding to red (R), the gamma voltage GV corresponding to green (G), or the gamma voltage BV corresponding to blue (B). For example, when the tag TAG[1:0] of the new sub-pixel data SND after swapping is 11, it can be known that the color information of the new sub-pixel data SND after swapping is red R, and the multiplexer circuit 124 selects the gamma voltage RV. When the tag TAG[1:0] of the new sub-pixel data SND after swapping is 10, it can be known that the color information of the new sub-pixel data SND after swapping is green G, and the multiplexer circuit 124 selects the gamma voltage GV. When the tag TAG[1:0] of the new sub-pixel data SND after swapping is 01, it can be known that the color information of the new sub-pixel data SND after swapping is blue B, and the multiplexer circuit 124 selects the gamma voltage BV. In step S210, the analog amplifier circuit 106 provides the source drive signals SDS1 - SDSn corresponding to the new sub-pixel data SND1 - SNDn after swapping and the corresponding gamma voltages to the corresponding sub-pixels in the pixel array 140. It is worth mentioning that the new architecture and method proposed by the present invention can be applied to under-screen fingerprint recognition, and the tag TAG indicating the color information of the sub-pixel data D and the bit indicating the Local High Brightness Mode (LHBM) can be combined. That is, the bit indicating LHBM is expanded from 1 bit to 2 bits. For example, when the tag TAG[1:0] is 11, it indicates that the color information of the sub-pixel data D is red R; when the tag TAG[1:0] is 10, it indicates that the color information of the sub-pixel data D is green G; when the tag TAG[1:0] is 01, it indicates that the color information of the sub-pixel data D is blue B; when the tag TAG[1:0] is 00, it indicates that LHBM is turned off. With the new architecture and method proposed by the present invention, the tag TAG is also swapped according to the order of color swapping. Therefore, the color swapping function can be implemented in the logic design to have better flexibility and support more types of PenTile panel types. For the analog design, the present invention only needs to add a 2-bit decoder to select the corresponding gamma voltage, without the need to swap the gamma voltage additionally. Based on the above, the new architecture and method proposed by the present invention can not only reduce the chip area and circuit complexity, but also support many PenTile color swapping panel types. In addition, implementing complex color swapping in the logic design can also be verified using FPGA before the integrated circuit is sent for manufacturing to prevent undetected errors. It should be noted that the specific order and / or hierarchy of steps in the method of the embodiments of the present invention are only exemplary approaches. Based on design preferences, the specific order or hierarchy of the steps of the disclosed method or process can be rearranged while remaining within the scope of the embodiments of the present invention. Therefore, those of ordinary skill in the art will understand that the methods and techniques of the embodiments of the present invention present various steps or actions in a sample order, and the embodiments of the present invention are not limited to the specific order or hierarchy presented, unless otherwise clearly stated. According to different design requirements, the above-mentioned blocks of the source driver 120 and / or the controller 122 can be implemented in the form of hardware, firmware, software (i.e., programs), or a combination of multiple ones of the foregoing. In terms of hardware form, the above-mentioned blocks of the source driver 120 and / or the controller 122 can be implemented as logic circuits on an integrated circuit. The related functions of the above-mentioned source driver 120 and / or the controller 122 can be implemented as hardware using hardware description languages (such as Verilog HDL or VHDL) or other suitable programming languages. For example, the related functions of the above-mentioned source driver 120 and / or the controller 122 can be implemented in various logic blocks, modules, and circuits in one or more controllers, microcontrollers, microprocessors, application-specific integrated circuits (ASICs), digital signal processors (DSPs), field programmable gate arrays (FPGAs), and / or other processing units. In terms of software and / or firmware, the related functions of the above-mentioned source driver 120 and / or controller 122 can be implemented as programming codes / computer program instructions. For example, the above-mentioned source driver 120 and / or controller 122 are implemented using general programming languages (such as C, C++ or assembly language) or other suitable programming languages. The programming codes / computer program instructions can be recorded / stored in a recording medium, which may include, for example, Read Only Memory (ROM), storage devices and / or Random Access Memory (RAM). A computer, a Central Processing Unit (CPU), a controller, a microcontroller or a microprocessor can read and execute the programming codes / computer program instructions from the recording medium to achieve the related functions. As the recording medium, a "non-transitory computer readable medium" can be used, such as a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, etc. Moreover, the program can also be provided to the computer (or CPU) via any transmission medium (such as a communication network or a radio wave). The communication network is, for example, the Internet, wired communication, wireless communication or other communication media. In summary, the source driver and the method for color conversion provided by the above embodiments can add tags for indicating color information to each sub-pixel data, and after performing color conversion on the sub-pixel data, the corresponding gamma voltage can be directly selected according to the tags. In this way, the source driver and the method for color conversion of the present invention can reduce the chip area and circuit complexity, and are compatible with different types of panels. Although the present invention has been disclosed above with embodiments, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to that defined by the appended patent application scope. 100: Display panel 120: Source driver 122: Controller 124: Multiplexer circuit 126: Analog amplifier circuit 128: Register 140: Pixel array 200: Method B, B2, B4: Blue BV, GV, RV: Gamma voltage D, D1-Dn: Sub-pixel data EVEN_Line: Even line G, G1-G4: Green MUX0: First state MUX1: Second state ND: New sub-pixel data ODD_Line: Odd line R, R1, R3: Red S1, S2, S3, S4, S5, S6, S7, S8: Source channels S202, S204, S206, S208, S210: Steps SDS1-SDSn: Source driver signals SND, SND1-SNDn: Transformed new sub-pixel data FIG. 1 is an OLED panel type illustrated according to an embodiment of the present invention. FIG. 2 is some conventional color conversion types illustrated according to an embodiment of the present invention. FIG. 3 is a block schematic diagram of a display panel illustrated according to an embodiment of the present invention. FIG. 4 is a flowchart of a method for color conversion illustrated according to an embodiment of the present invention. FIG. 5 is an example schematic diagram of new sub-pixel data illustrated according to an embodiment of the present invention. 100: Display panel 120: Source driver 122: Controller 124: Multiplexer circuit 126: Analog amplifier circuit 128: Register 140: Pixel array BV, GV, RV: Gamma voltage D1-Dn: Sub-pixel data SDS1-SDSn: Source driver signals SND1-SNDn: Transformed new sub-pixel data

Claims

1. A source driver, comprising: A controller is configured to acquire multiple sub-pixel data from an application processor and perform the following operations on the multiple sub-pixel data: adding a tag represented by multiple bits to each sub-pixel data to generate multiple new sub-pixel data, and color-swapping the multiple new sub-pixel data, wherein the tag indicates the color information of the sub-pixel data; a multiplexer circuit is coupled to the controller to sequentially acquire each new sub-pixel data after swapping and select a corresponding gamma voltage based on the tag of the new sub-pixel data after swapping. An analog amplifier circuit, coupled to the multiplexer circuit, is used to provide a source drive signal to the corresponding sub-pixel in a pixel array based on the changed new sub-pixel data and the corresponding gamma voltage.

2. The source driver as described in claim 1, further comprising: A register is coupled to the controller and the multiplexer circuit, wherein the operation further includes storing the swapped new sub-pixel data in the register, and the multiplexer circuit sequentially retrieving the swapped new sub-pixel data from the register.

3. The source driver as claimed in claim 2, wherein the controller continuously obtains a plurality of sub-pixel data from the application processor and performs the operation on the plurality of sub-pixel data, and until the controller has performed the operation on all sub-pixel data, the multiplexer circuit sequentially obtains the swapped new sub-pixel data from the register.

4. The source driver as claimed in claim 1, wherein the color information is one of red, green and blue.

5. The source driver as described in claim 1, wherein the tag is represented by two bits.

6. A method for color switching, applicable to a display panel, the display panel including a source driver and a pixel array, the method comprising: The application processor obtains multiple sub-pixel data; performs the following operations on the multiple sub-pixel data: adds a tag represented by multiple bits to each sub-pixel data to generate multiple new sub-pixel data, and performs color transposition on the multiple new sub-pixel data, wherein the tag indicates the color information of the sub-pixel data; sequentially obtains each new sub-pixel data after transposition, and selects a corresponding gamma voltage according to the tag of the new sub-pixel data after transposition; and provides a source drive signal to the corresponding sub-pixel in the pixel array according to the new sub-pixel data after transposition and the corresponding gamma voltage.

7. The method of claim 6, wherein the operation further includes storing the swapped plurality of new sub-pixel data in a register, and wherein sequentially retrieving the swapped new sub-pixel data includes sequentially retrieving the swapped new sub-pixel data from the register.

8. The method as described in claim 7, further comprising: The system continuously obtains multiple sub-pixel data from the application processor and performs the operation on the multiple sub-pixel data until the operation has been performed on all sub-pixel data, and then sequentially obtains the new sub-pixel data after replacement from the register.

9. The method as described in claim 6, wherein the color information is one of red, green, and blue.

10. The method as described in claim 6, wherein the tag is represented by two bits.

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