Patent Publication Number: US-2019193562-A1

Title: Display system and driving method thereof

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims the priority benefit of China application serial no. 201711437936.0, filed Dec. 26, 2017. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a display system and a driving method thereof, and more particularly, to a display system and a driving method applied to displaying a cluster of a vehicle. 
     2. Description of the Prior Art 
     In recent years, more and more automobile manufacturers have begun to use the display panel for displaying an electronic instrument cluster, which is a set of instrumentation including the speedometer displayed with a digital readout rather than with traditional analog gauges. As more vehicle-related information is presented on the cluster for accuracy and safety, the display is required to have a larger size and higher resolution. The transmission speed of a conventional transmission interface is not sufficient to support these high resolution requirements. Using a transmission interface with higher transmission speed, however, not only increases the technical threshold, but also increases the risk of electromagnetic interference (EMI) or data loss. 
     SUMMARY OF THE INVENTION 
     The technical problem to be solved by this invention is that of displaying a high resolution cluster image in the display panel without requiring upgrading of the interface of the timing controller. 
     In order to solve the above problems, the present invention provides a driving method of a display system. The driving method of the display system includes the following steps. A background image signal is read from a nonvolatile memory of a timing controller. The timing controller receives a group of external signals and outputs an image signal to the display panel according to the background image signal and the group of external signals. The display panel displays a display image according to the image signal. 
     The present invention further provides a display system. The display system includes a timing controller and a display panel. The timing controller includes a nonvolatile memory, wherein a background image signal is stored in the nonvolatile memory. The timing controller is capable of receiving a group of external signals and outputting an image signal according to the group of external signals and the background image signal read from the nonvolatile memory. The display panel is coupled to the timing controller, wherein the display panel is capable of receiving the image signal outputted from the timing controller and displaying a display image according to the image signal. 
     In the driving method of the display system of this invention, a portion of the cluster image that will not vary is stored in the nonvolatile memory of the timing controller as the background image signal in advance. The timing controller only needs to receive external signals related to the information of the vehicle, and the timing controller can output the image signal by calculating or processing the background image signal in the nonvolatile memory and the external signals to make the display panel display the cluster image. The timing controller does not need to have the high-end interface with a high transmission speed to receive high resolution image data provided by other devices, which reduces the cost of manufacturing the display system. In addition, avoiding using the high-end interface with a high transmission speed can also reduce the problem of electromagnetic interference (EMI). Further, preventing transmission of large amounts of image data related to the high resolution image through the interface can reduce the risk of data loss during transmission. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram illustrating a display system according to an embodiment of the present invention. 
         FIG. 2  is a schematic diagram illustrating a process flow of a driving method of the display system according to the embodiment of the present invention. 
         FIG. 3  is a schematic diagram illustrating a cluster image displayed by the display system according to the embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     To provide a better understanding of the present invention to those skilled in the technology, preferred embodiments will be detailed as follows. The preferred embodiments of the present invention are illustrated in the accompanying drawings with numbered elements to elaborate on the contents and effects to be achieved. It should be noted that the drawings are simplified schematics, and therefore show only the components and combinations associated with the present invention, so as to provide a clearer description of the basic architecture or method of implementation. The components would be complex in reality. In addition, for ease of explanation, the components shown in the drawings may not represent their actual number, shape, and dimensions; details can be adjusted according to design requirements. 
     Referring to  FIG. 1  to  FIG. 3 ,  FIG. 1  is a schematic diagram illustrating a display system according to an embodiment of the present invention,  FIG. 2  is a schematic diagram illustrating a process flow of a driving method of the display system according to the embodiment of the present invention, and  FIG. 3  is a schematic diagram illustrating a cluster image displayed by the display system according to the embodiment of the present invention. A display system  10  of this embodiment may be applied to being used as a cluster of a vehicle. For example, a display image displayed by the display system  10  of this embodiment can include a cluster image  20  (as shown in  FIG. 3 ) of the vehicle, but is not limited thereto. The display system  10  and a driving method for the display system  10  to display the cluster image  20  are described in detail hereinafter. As shown in  FIG. 1 , the display system  10  includes a display panel  100 , a timing controller (t-con)  102 , and a microcontroller unit (MCU)  104 . One terminal of the timing controller  102  is coupled to the display panel  100 , and another terminal of the timing controller  102  is coupled to the microcontroller unit  104 . In this embodiment, the timing controller  102  is disposed on a printed circuit board  106 , and the timing controller  102  includes a nonvolatile memory  1021 . A background image signal S 1  is stored in the nonvolatile memory  1021 , and the timing controller  102  can read the background image signal S 1  stored in the nonvolatile memory  1021 . For example, the background image signal S 1  can include image data of a portion of the cluster image  20  in  FIG. 3 , wherein the portion can be a portion of the cluster image  20  that does not need to change its figures, such as a frame appearance. It is noteworthy that the cluster image  20  of this embodiment can have a high resolution, and therefore the background image signal S 1  stored in the nonvolatile memory  1021  can include the image data of the frame appearance of the cluster image  20  with high resolution. For example, the resolution range of the cluster image  20  in this embodiment can be equal to or greater than 1920×720 or 167 ppi (pixels per inch), but is not limited thereto. In addition, the nonvolatile memory  1021  of this embodiment can include a read only memory (ROM), programmable read only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), or flash memory, but is not limited thereto. 
     As shown in  FIG. 1 , the timing controller  102  of this embodiment further receives a group of external signals S 2 , wherein the external signals S 2  are provided by the microcontroller unit  104 . In this embodiment, the microcontroller unit  104  is disposed on the printed circuit board  108 , and the microcontroller unit  104  can receive information detected by detecting devices disposed in the vehicle. The aforementioned information can be integrated and transformed into the external signals S 2  by the microcontroller unit  104 . For example, the external signals S 2  include at least one signal related to the speed, the fuel level, the engine temperature, the engine revolution speed, and the gearbox information of the vehicle, but the invention is not limited thereto. In addition, the timing controller  102  can output an image signal S 3  to the display panel  100  according to the background image signal S 1  read from the nonvolatile memory  1021  and the external signals S 2 , and the display panel  100  can display the cluster image  20  shown in  FIG. 3  according to the image signal S 3 . Since the information detected by the detecting devices varies when the vehicle is moving, the external signals S 2  outputted from the microcontroller unit  104  to the timing controller  102  will also vary. In short, the image signal S 3  is obtained from the timing controller  102  by calculating and processing the stored background image signal S 1  and the external signals S 2  that change with time, such that the cluster image  20  displayed according to the image signal S 3  can provide instant information of the vehicle to the driver. The timing controller  102  of this embodiment includes an interface  1022  coupled to the microcontroller unit  104 , and the external signals S 2  can be transmitted from the microcontroller unit  104  to the timing controller  102  through the interface  1022 . Since the image data of the frame appearance of the cluster image  20  with high resolution is stored in the nonvolatile memory  1021  in advance, the interface  1022  is not required to transmit image data related to the high resolution image, and only needs to transmit the external signals S 2  provided by the microcontroller unit  104 . In addition, since the amount of data of the external signals S 2  is relatively small compared to signals related to the high resolution image, the interface  1022  is not required to adopt the interface with high transmission speed. For example, the transmission frequency of the interface  1022  of the timing controller  102  in this embodiment ranges from 20 Megahertz (MHz) to 120 MHz. The interface  1022  can include an inter integrated circuit (I2C) interface, serial peripheral interface (SPI), transistor-transistor logic (TTL) interface or single low voltage differential signal (single LVDS) interface, but is not limited thereto. In short, according to the design of the display system  10  in this embodiment, the timing controller  102  is not required to use the high-end interface with a high transmission speed (such as an embedded display port (eDP), dual port LVDS interface, etc.) to receive the external signals, and the display panel  100  can still display the cluster image  20  with high resolution. Therefore, the cost of manufacturing the display system  10  can be reduced, as well as reducing the problem of electromagnetic interference (EMI) and the risk of data loss during transmission. In some embodiments, the external signals S 2  outputted by the microcontroller unit  104  can be transformed into an image signal by a graphic process unit (GPU) first and then transmitted to the timing controller  102  through the interface  1022 . 
     In this embodiment, the timing controller  102  can have the functions of calculating, transforming, or other data or signal processing functions. The timing controller  102  can obtain the image signal S 3  by calculating or processing the background image signal S 1  and the external signal S 2 , and then outputs the image signal S 3  to the display panel  100 . To achieve the aforementioned functions of the timing controller  102 , the timing controller  102  of this embodiment can include programmable integrated circuits for conducting calculation. For example, the timing controller  102  can include a central processing unit (CPU), system on chip (SoC), or application specific integrated circuit (ASIC), but is not limited thereto. In addition, the display panel  100  can include a non-self-luminous display panel such as a liquid crystal display panel, a self-luminous display panel such as an organic light emitting diode display panel, or other types of display panel. The display panel  100  includes a display region  1002  and a peripheral region  1004 , wherein the peripheral region  1004  is disposed on at least one side of the display region  1002 . The display region  1002  includes a plurality of pixels configured to display the display image. The peripheral region  1004  includes one or more source drivers  1006  and one or more gate drivers  1008  configured to provide signals to each pixel, so as to make the display region  1002  display images. Although only four source drivers  1006  and one gate driver  1008  are shown in  FIG. 1 , the number of the source drivers  1006  and the number of gate drivers  1008  are not limited thereto. For example, as shown in  FIG. 1 , the image signal S 3  outputted to the display panel  100  by the timing controller  102  in this embodiment can be transmitted to each source driver  1006 . In addition, the timing controller  102  can output a corresponding signal to the gate driver  1008 , but is not limited thereto. 
     The driving method of the display system.  10  in this embodiment includes the steps S 10  to S 16  shown in  FIG. 2 , but the driving method of the display system  10  is not limited to the following sequence. 
     S 10 : reading a background image signal from a nonvolatile memory of a timing controller; 
     S 12 : receiving a group of external signals by the timing controller; 
     S 14 : outputting an image signal to the display panel by the timing controller according to the background image signal and the group of external signals; and 
     S 16 : displaying a display image according to the image signal by the display panel. 
     As shown in  FIG. 3 , the cluster image  20  is an example of the display image displayed by the driving method of the display system  10  in this embodiment. The cluster image  20  in this embodiment can be a high resolution image, and a portion of the cluster image  20  that does not need to change frequently (e.g. frame appearance) can include four round patterns R 1 , R 2 , R 3 , and R 4  and a decoration pattern R 5 . The round pattern R 2  is disposed between the round pattern R 1  and the round pattern R 3 , the round pattern R 4  is disposed in the round pattern R 3 , and the decoration pattern R 5  fills in the space outside the round patterns R 1 , R 2 , and R 3 . In the cluster image  20  of this embodiment, each round pattern can include scales I 10  and characters I 12 , wherein the scales I 10  can be disposed in each round pattern and along the rim of each round pattern, and the characters I 12  can include numbers or letters of the alphabet, but is not limited thereto. Additionally, the round pattern R 3  and the round pattern R 4  of this embodiment further include icons I 14 . For example, the round pattern R 1  can be configured to display the engine revolution speed and the gearbox information of the vehicle, the round pattern R 2  can be configured to display the speed of the vehicle, the round pattern R 3  can be configured to display the fuel level of the vehicle, and the round pattern R 4  can be configured to display the engine temperature, but is not limited thereto. The image data related to the aforementioned frame appearance is stored in the nonvolatile memory  1021  of the timing controller  102  as the background image signal S 1 . In addition, the timing controller  102  outputs the image signal S 3  to the display panel  100  according to the external signal S 2 , and the display panel  100  displays indicators I 20 , I 22 , I 24 , and I 26  and characters I 30 , I 32 , I 34 , and I 36  as a portion of the cluster image  20 . The positions of the indicators I 20 , I 22 , I 24 , and I 26  and the characters I 30 , I 32 , I 34 , and I 36  displayed by the display panel I 00  will change as the external signals S 2  change. For example, in the cluster image  20 , the indicator I 20  and the character I 30  (e.g. a number) displayed in the round pattern R 1  provide information related to the engine revolution speed of the vehicle to the driver. The character I 32  (e.g. a letter of the alphabet) displayed in the round pattern R 1  provides gearbox information of the vehicle to the driver. The indicator I 22  and the character I 34  (e.g. a number) displayed in the round pattern R 2  provide the information related to the speed of the vehicle to the driver. The indicator I 24  and the character I 36  (e.g. a number) displayed in the round pattern R 3  provide the information of related to the fuel level of the vehicle to the driver. The indicator I 26  displayed in the round pattern R 4  provides the information related to the engine temperature of the vehicle to the driver. The design of the cluster image  20  described above is only an example, and the cluster image  20  can have different pattern configurations according to different requirements. In addition, when the nonvolatile memory  1021  of the timing controller  102  is a ROM, different images with different designs can be stored in the nonvolatile memory  1021  as the background image signal S 1  in advance, so as to provide different cluster images  20  to select. In another aspect, when the nonvolatile memory  1021  of the timing controller  102  is the programmable memory, the data of the background image signal S 1  stored in the nonvolatile memory  1021  is changeable, and the design of the cluster image  20  is capable of being modified. 
     In summary, when the display image displayed by the display system is the cluster image with high resolution, since the cluster image of the vehicle does not contain a large amount of animation, a portion of the cluster image that will not vary is stored in the nonvolatile memory of the timing controller as the background image signal in advance. Therefore, the timing controller only needs to receive external signals related to information of the vehicle, and the timing controller can output the image signal by calculating or processing the background image signal in the nonvolatile memory and the external signals to make the display panel display the cluster image. The timing controller does not need to have a high-end interface with high transmission speed in order to receive high resolution image data provided by other devices, which reduces the cost of manufacturing the display system. In addition, by avoiding using a high-end interface with high transmission speed, the problem of EMI can be reduced, and by avoiding transmitting large amounts of image data related to the high resolution image through the interface, the risk of data loss during transmission can also be reduced. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.