Patent Publication Number: US-9898982-B2

Title: Display method, device and computer-readable medium

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Chinese Patent Application No. 201510695453.5, filed on Oct. 22, 2015, which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure generally relates to the field of image processing, and more particularly, to a display method, device, and computer-readable medium. 
     BACKGROUND 
     The power consumption of a display, which takes up a large portion of power consumption of a smart device, significantly affects battery lifetime of the smart device. Traditionally, reduction of power consumption of a display is achieved by reducing refresh frequency of the display. However, reduction of refresh frequency of the display will result in screen flicker. 
     SUMMARY 
     According to a first aspect of the present disclosure, there is provided a display method for use in a device configured with a display, including: detecting whether there is any change in a displayed content for the display; and controlling the display to alternately update display data corresponding to a first portion and a second portion of display units in each row if it is detected that the displayed content does not change, wherein the display unit comprises n rows of pixels, and wherein n is a positive integer. The first portion of the display units comprises i first cells, the second portion of the display units comprises j second cells, and the first cells are alternate with the second cells, wherein i and j are positive integers. Moreover, the first cell comprises p successive pixels, and the second cell comprises q successive pixels, wherein p and q are greater than 1. 
     According to a second aspect of the present disclosure, there is provided a device, including: a display; a processor; and a memory to store instructions executable by the processor; wherein, the processor is configured to: detect whether there is any change in a displayed content for the display; and control the display to alternately update display data corresponding to a first portion and a second portion of display units in each row if it is detected that the displayed content does not change, wherein the display unit comprises n rows of pixels, and wherein n is a positive integer. The first portion of the display units comprises i first cells, the second portion of the display units comprises j second cells, and the first cells are alternate with the second cells, wherein i and j are positive integers. Moreover, the first cell comprises p successive pixels, and the second cell comprises q successive pixels, wherein p and q are greater than 1. 
     According to a third aspect of the present disclosure, there is provided a non-transitory computer-readable storage medium having stored therein instructions that, when executed by a processor of a device configured with a display, causes the device to perform a display method, the method including: detecting whether there is any change in a displayed content for the display; and controlling the display to alternately update display data corresponding to a first portion and a second portion of display units in each row if it is detected that the displayed content does not change, wherein the display unit comprises n rows of pixels, and wherein n is a positive integer. The first portion of the display units comprises i first cells, the second portion of the display units comprises j second cells, and the first cells are alternate with the second cells, wherein i and j are positive integers. Moreover, the first cell comprises p successive pixels, and the second cell comprises q successive pixels, wherein p and q are greater than 1. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and, together with the description, serve to explain the principles of the disclosure. 
         FIG. 1  is a schematic diagram of an implementation environment for a display method according to an exemplary embodiment. 
         FIG. 2  is a flow chart of a display method according to an exemplary embodiment. 
         FIG. 3A  is a flow chart of a display method according to an exemplary embodiment. 
         FIG. 3B  is a schematic diagram illustrating a first type of display updating according to an exemplary embodiment. 
         FIG. 3C  is a schematic diagram illustrating a second type of display updating according to an exemplary embodiment. 
         FIG. 3D  is a schematic diagram illustrating a third type of display updating according to an exemplary embodiment. 
         FIG. 3E  is a schematic diagram illustrating a fourth type of display updating according to an exemplary embodiment. 
         FIG. 3F  is a flow chart of procedure of a display method related to a first type of display according to an exemplary embodiment. 
         FIG. 3G  is a flow chart of procedure of a display method related to a second type of display according to an exemplary embodiment. 
         FIG. 3H  is a flow chart of procedure of a display method related to a third type of display according to an exemplary embodiment. 
         FIG. 3I  is a circuit diagram showing procedure of a display method related to a certain type of display according to an exemplary embodiment. 
         FIG. 4  is a block diagram of a display apparatus according to an exemplary embodiment. 
         FIG. 5  is a block diagram of a display apparatus according to another exemplary embodiment. 
         FIG. 6  is a block diagram of a display device according to an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings in which the same numbers in different drawings represent the same or similar elements unless otherwise represented. The implementations set forth in the following description of exemplary embodiments do not represent all implementations consistent with the disclosure. Instead, they are merely examples of devices and methods consistent with aspects related to the disclosure as recited in the appended claims. 
     Display methods provided by various embodiments of the disclosure may be implemented by an electronic device with a display. The electronic device may be a smart phone, a smart television, a tablet computer, an ebook reader, an MP3 (Moving Picture Experts Group Audio Layer III) player, an MP4 (Moving Picture Experts Group Audio Layer IV) player and a laptop computer (camera, vidicon), etc. The display may employ an LCD (Liquid Crystal Display), an LED (Light Emitting Diode), or an OLED (Organic Light-Emitting Diode), or any other display using pixels for display. 
     As shown in  FIG. 1 , a schematic diagram of an implementation environment for the display methods provided by various exemplary embodiments of the disclosure is illustrated. The implementation environment may be an internal environment of an electronic device with a display. The implementation environment may include a processor  120 , a transmission bus  140 , a display  160  and a driving IC  180  corresponding to the display  160 . 
     The processor  120  may be a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit) configured to generate display data corresponding to a displayed content and to transmit the display data to the driving IC  180  via the transmission bus  140 . 
     The processor  120  and the driving IC  180  may be electrically connected to the transmission bus  140  respectively and the display data may be transmitted via the transmission bus  140 . 
     The driving IC  180  may be used to receive the display data sent by the processor  120  via the transmission bus  140  and to control corresponding pixel units of the display  160  to update the displayed content according to the display data. The driving IC  180  may be electrically connected with the display  160 . 
     For simplicity of the description, a display method which is exemplarily performed by a terminal device is illustrated below, but it is not limited thereto. 
       FIG. 2  is a flow chart of a display method according to an exemplary embodiment. As shown in  FIG. 2 , the display method includes following steps. 
     In step  201 , whether there is any change in a displayed content for a display is detected. 
     In step  202 , the display is controlled to alternately update display data corresponding to a first portion and a second portion of display units in each row if there is no change in the displayed content. Herein, the display unit comprises n rows of pixels, and wherein n is a positive integer. 
     The first portion of the display units may include i first cells. The second portion of the display units may include j second cells. The first cell alternates with the second cell. The numbers i and j may be positive integers. Each of the first cells may include p successive pixels, and each of the second cells may include q successive pixels, wherein both p and q may be greater than 1. 
     In conclusion, for the display method provided by the disclosure, by detecting whether there is any change in the displayed content for the display and controlling the display to alternately update display data corresponding to a first portion and a second portion of display unit of each row if the displayed content does not change, the number of the pixels to be updated by the display in each update can be reduced while maintaining the original refresh frequency, thereby the problem of screen flicker due to the reduction of refresh frequency can be solved. Moreover, the screen flicker can be avoided and power consumption of the display can be reduced while maintaining the original refresh frequency. 
       FIG. 3A  is a flow chart of a display method according to an exemplary embodiment. As shown in  FIG. 3A , the display method may include the following steps. 
     In step  301 , whether a displayed content for a display meets a predetermined condition is detected. 
     When a display of a terminal device displays contents, display data are required to be sent by a processor to a driving IC corresponding to the display at a predetermined frequency. The driving IC controls the display to display a content to be displayed according to the display data. The processor may be a CPU or a GPU, and the predetermined frequency generally may be 60 Hz. In certain cases, however, the displayed content for the display may remain unchanged within a short period of time. For a display configured with a random-access memory (RAM), the driving IC may read history display data from the RAM when the displayed content remains unchanged to avoid a waste of resources caused by generation of the same display data by the processor. However, for a display configured without a RAM, the processor is still required to generate the same display data continuously although the displayed content remains unchanged, resulting in a waste of computing resources of the processor. 
     In order to avoid the waste of computing resources of the processor caused by the generation of the same display data, the terminal device may detect in real time whether the displayed content meets certain predetermined condition. Step  302  is performed when it is detected that the displayed content meets the predetermined condition. The predetermined condition may include at least one of the following: the displayed content being generated by a preset application, a required frames per second (FPS) by the displayed content being lower than a preset FPS threshold. 
     The preset application may be an application such as an ebook, a picture browser and the like. The displayed content generated by such application is generally a static image and remains unchanged within a period of time. 
     Additionally, the preset FPS threshold may be a default refresh frequency of the display. That is, when the displayed content includes dynamic pictures but the FPS is smaller than the refresh frequency of the display, the displayed content also meets the predetermined condition. For example, if the displayed content is a video with an FPS of 24 frames/second and the refresh frequency of the display is 60 Hz (i.e., 60 frames/second), the displayed content meets the predetermined condition as well. 
     In step  302 , whether there is any change in the displayed content for the display is detected. 
     Upon detection of the displayed content meeting the predetermined condition, the terminal device then detects whether there is any change in the displayed content. If there is any change in the displayed content, the terminal device generates complete display data corresponding to the displayed content. If there is no change in the displayed content, step  303  is performed. 
     As an alternative implementation, if the displayed content is generated by a preset application, upon receiving a Display Content Change signal triggered by a user, the terminal device determines that the displayed content changes, wherein the Display Content Change signal may be triggered when the user touches the display. 
     As another alternative implementation, if the FPS required by the displayed content is smaller than the preset FPS threshold, the terminal device determines a variation period of the displayed content according to the FPS required by the displayed content and the refresh frequency of the display, and detects whether there is any change in the displayed content according to the variation period. For example, if the FPS required by the displayed content is 15 frames/second and the refresh frequency of the display is 60 Hz (i.e., 60 frames/second), then the variation period of the displayed content is 4 frames, that is, the displayed content changes once for every 4 frames refreshed by the display. 
     In step  303 , the display is controlled to alternately update display data corresponding to a first portion and a second portion of display unit of each row if it is detected that the displayed content does not change. Herein, the display unit comprises n rows of pixels, where n is a positive integer. 
     When it is detected that the displayed content does not change, the terminal device controls the display to alternately update display data corresponding to the first portion and the second portion of display units of each row. Since the display (e.g., the liquid crystal in LCDs) is capable of keeping the image displayed thereon for a while, during the time when the display data corresponding to the first portion of the display units is being updated, the display data corresponding to the second portion of the display units will not disappear but become slightly darker, which affects little to the overall display effect of the displayed content and will not affect the user experience. 
     The first portion of the display unit may include i first cells. The second portion of the display units may include j second cells. The first cells may alternate with the second cell. The number i and j may be positive integers. Each of the first cells may include p pixels, and each of the second cells each may include q pixels, wherein both p and q may be greater than 1. 
     Since the display unit comprises n rows of pixels, the update of the display data corresponding to a row display unit may be divided into N updates and 1/N portion of the row of display unit is sequentially updated. For example, when N=2, the update of the display data corresponding to the row display unit is divided into two updates, that is, the first update is conducted with respect to display data corresponding to the first portion of the display units, and the second update is conducted with respect to display data corresponding to the second portion of the display units. Then the first update and the second update are repeated in an alternate manner. When N=3, the update of the display data corresponding to a row display unit is divided into three updates, that is, the first update is conducted with respect to display data corresponding to the first portion of the display unit, the second update is conducted with respect to display data corresponding to the second portion of the display unit, the third update is conducted with respect to display data corresponding to the third portion of the display unit. Then the first update, the second update and the third update are repeated in an alternate manner. 
     It should be noted that, if the refresh frequency of the display is fixed, the greater the value of N is, the more the screen may flicker. For example, supposed that the refresh frequency of the display is 60 Hz, when N=2, the update frequency of display data corresponding to each portion of the display units is 30 Hz; when N=3, the update frequency of display data corresponding to each portion of the display unit is 20 Hz. The lower the update frequency of display data corresponding to each portion of the display units is, the more the screen may flicker. 
     In order to mitigate the phenomenon of screen flicker, in an alternative scenario, the refresh frequency of the display is kept unchanged and N is set to a smaller value, e.g., N is set to 2. The update frequency of display data corresponding to each portion of the display units is 30 Hz. In another alternative scenario, the refresh frequency is increased and N is set to a larger value, e.g., the refresh frequency changes from 60 Hz to 90 Hz and N is set to 3. The update frequency of display data corresponding to each portion of the display units is also 30 Hz. 
     When display units of a row are divided into a first portion of display units and a second portion of display units, any number of pixels may be selected from the display units as the first portion of display units and the remaining pixels of the display units serve as the second portion of display units. The number of pixels included in the first portion of display units may be the same as or different from the number of pixels included in the second portion of display units. For example, if a row of display units is a row of pixels including 1920 pixels, 960 pixels of the 1920 pixels may serve as the first portion of the display units and the remaining 960 pixels serve as the second portion of the display units. 
     A plurality of successive pixels may be selected as the first portion of the display units. For example, the first 960 pixels of a row of 1920 pixels may form the first portion of the display units and the remained 960 pixels of the row of 1920 pixels may form the second portion of the display units. Alternatively, the middle 960 pixels of a row of 1920 pixels may form the first portion of the display units and the remained 960 pixels may form the second portion of the display units. 
     A plurality of non-successive pixels may also be selected as the first portion of the display units. For example, the first portion of the display units may include i first cells, and the second portion of the display units may include j second cells. The first cell may alternate with the second cell. Each of the first cells each may include p pixels, and each of the second cells each may include q pixels. Referring to  FIGS. 3B and 3C , where the p pixels of the first cell and the q pixels of the second cell constitute a matrix of b*b pixels, wherein the dashed areas represent the first portion and the blank areas represent the second portion. The number p and q, however, may also be different and their values are not limited to the embodiment. 
     When p and q are both equal to 2,  FIGS. 3D and 3E  may be referred to. The dashed areas represent the first portion of the display units and the blank areas represent the second portion of the display units. 
     In this embodiment, for each two adjacent row of display units, all of the first cells of a first row of display units and all of the first cells of a second row of display units interlace with each other in columns; and for the two adjacent rows display unit, all of the second cells of the first row of display units and all of the second cells of the second row of display units interlace with each other in columns. In above  FIG. 3B-3E , the dashed areas of the two adjacent row of display units interlace with each other in columns. 
     It should be supplemented that when the row of display units is a row of pixels, the p pixels of the first cell are successive in the row; when the row of display unit is a combination of two or more rows of pixels, the p pixels of the first cell and the q pixels of the corresponding second cell form a matrix of b*b pixels, where b pixels of each row of the first cell or the second cell are successive and pixels of each column (simply referred to “C” in figures) of the first cell or the second cell are not successive. For example, the p pixels of the first cell include 1 to b pixels of the first row, 1 to b pixels of the third row, 1 to b pixels of the fifth row; the q pixels of the second cell include 1 to be pixels of the second row, the 1 to b pixels of the fourth row, and so on, with reference to  FIGS. 3B and 3C . 
     When it is detected that the displayed content does not change, the terminal device may control the display to update only the display data corresponding to the first cells at an odd-numbered update, and to update only the display data corresponding to the second cells at an even-numbered update. In other words, the dashed areas in  FIGS. 3B and 3D  are updated at the odd-numbered update, and the dashed areas in  FIGS. 3C and 3E  are updated at the even-numbered update. 
     It is understandable that, with the above method, only a part of display data rather than the entire display data is required to be updated each time the display refreshes if the displayed content does not change. For example, when a first portion and a second portion of row display units are alternately updated, the amount of display data to be updated is half of the original amount at each refresh, thereby significantly reducing power consumption of the display. 
     There are three alternative implementations as follows regarding the terminal device controlling the display to update the displayed content. 
     In the first alternative implementation, as shown in  FIG. 3F , the above step  303  may include the following steps. 
     In step  303 A, when it is detected that the displayed content does not change, the display data corresponding to all of the displayed content is generated by the processor. 
     When detecting the displayed content does not change, the processor of the terminal device generates the display data corresponding to all of the displayed content according to the resolution of the display. The processor may be a CPU or a GPU. For example, if the resolution of the display is 1080*1920, the amount of the display data corresponding to the displayed content generated by the processor is 1080*1920=2073600 pixels. 
     In step  303 B, when the display unit comprises n rows of pixels, the processor alternately transmits the display data corresponding to a first portion and a second portion of the display unit to the driving IC of the display via a transmission bus. The driving IC controls the update of the display according to the display data. 
     In order to decrease the amount of the display data to be updated by the display when the displayed content does not change, when detecting that the displayed content does not change, the processor alternately transmits the display data corresponding to the first portion and the second portion of the display units to the driving IC of the display via the transmission bus if the display unit is a combination of n rows of pixels. 
     After receiving the display data via the transmission bus, the driving IC controls corresponding pixels in the display to update the displayed content according to the display data. Since the transmission bus alternately transmits the display data corresponding to the first portion of the display units and the second portion of the display units, only the display data corresponding to the first portion of the display unit or the second portion of the display unit is updated in each refresh of the displayed content by the display. Compared with traditional updating methods, the amount of data to be updated required by the method of alternatively transmitting the display data corresponding to a portion of the display units is significantly reduced. Moreover, the user&#39;s visual perception will not be significantly affected. Additionally, since the amount of the data transmitted via the transmission bus is significantly reduced, the electromagnetic interference caused by the data transmission is reduced accordingly, thereby ensuring normal operation of other components in the terminal device. 
     It should be noted that, upon detection of any change in the displayed content, the processor may send the complete display data to the driving IC via the transmission bus. The driving IC may then control the display to update the display data corresponding to the displayed content. 
     In this embodiment, when there is no change in the displayed content, the processor alternately transmits the display data corresponding to the first portion of the display units and the second portion of the display units to the driving IC of the display via the transmission bus if the display unit comprises n rows of pixels. The driving IC controls the display to refresh the displayed content according to the received display data. Thus, the power consumption of the transmission bus is reduced and the electromagnetic interference caused by the transmission of the display data through the transmission bus can also be reduced. 
     In the second alternative implementation, as shown in  FIG. 3G , the above step  303  may include following steps. 
     In step  303 C, if it is detected that the displayed content does not change, the display data corresponding to the displayed content is generated by the processor. 
     The implementation manner of this step is similar to that of the above step  303 A and thus its description is not provided here. 
     In step  303 D, the display data is transmitted by the processor to the driving IC of the display via the transmission bus. 
     Different from the above step  303 B, in step  303 D the complete display data is transmitted by the processor to the driving IC via the transmission bus. 
     In step  303 E, when the display unit is a combination of n rows of pixels, an alternate update instruction is sent by the processor to the driving IC. The driving IC controls the display to alternately update the display data corresponding to the first portion of the display units and the second portion of the display units according to the alternate update instruction. 
     While transmitting the complete display data to the transmission bus, the processor sends the alternate update instruction to the driving IC to instruct the driving IC to control the display to alternately update the display data corresponding to the first portion of the display units and the second portion of the display units when the display unit comprises n rows of pixels, thus the display data of the display is updated alternatively, thereby reducing the power consumption when the displayed content of the display does not change. 
     It should be noted that when there is any change in the displayed content, the processor transmits the complete display data to the driving IC via the transmission bus and does not send the alternate update instruction, and accordingly, the driving IC controls the display to update the display data for all of the display units. 
     In the embodiment, when there is no change in the displayed content, while transmitting the display data corresponding to all of the display units to the driving IC, the processor also transmits an alternate update instruction to the driving IC to instruct the driving IC to control the display to alternately update the display data corresponding to the first portion of the display units and the second portion of the display units, thereby reducing the amount of the display data in the display to be updated and reducing the power consumption of the display if the displayed content does not change. 
     In the third alternative implementation, as shown in  FIG. 3H , the above step  303  may include the following steps. 
     In step  303 F, if it is detected that the displayed content does not change, if the display unit comprises n rows of pixels, the display data corresponding to the displayed content of the first portion of the display units and the second portion of the display units is alternately generated by the processor. 
     Unlike the above step  303 A and step  303 C, if it is detected that the displayed content does not change, the processor alternately generates the display data corresponding to the displayed content of the first portion of the display units and the second portion of the display units during display data generation stage. Instead of generating complete display data, only a portion of the display data is generated. Thus, the processing resources consumed by the processor when generating the display data is significantly reduced, thereby reducing the power consumption of the processor. 
     In step  303 G, the generated display data is transmitted by the processor to the driving IC of the display via the transmission bus. The driving IC controls the display to refresh the displayed content according to the received display data. 
     The processor alternately generates the display data corresponding to the displayed content of the first portion of the display units and the second portion of the display units and transmits the generated display data to the driving IC via the transmission bus. The driving IC then controls the display to refresh the displayed content accordingly based on the display data. Thus, when the displayed content remains does not change, not only the amount of data to be updated is reduced, but also the amount of data to be transmitted through the transmission bus is reduced, such that the electromagnetic interference caused by the transmission of the display data through the transmission bus is reduced. 
     In this embodiment, when the displayed content does not change, the processor alternately generates the display data corresponding to the displayed content of the first portion of the display units and the second portion of the display units and transmits the generated display data to the driving IC of the display via the transmission bus. The driving IC then controls the display to refresh the displayed content alternately based on the display data. Thus, not only the amount of the display data to be generated by the processor and then the power consumption of the display can be reduced, but also the power consumption of the transmission bus and then the electromagnetic interference caused by the transmission of the display data through the transmission bus can be reduced. 
     After the driving IC obtains the display data through the above three methods, it may control the display to refresh the displayed content. In implementations, step  303  may further includes: during an odd-numbered update, switch of each pixel of each of the first cells is controlled by the driving IC to be in a first state and switch of each pixel of each of the second cells is controlled by the driving IC to be in a second state; and during an even-numbered update, the switch of each pixel of each of the first cells is controlled by the driving IC to be in the second state and the switch of each pixel of each of the second cells is controlled by the driving IC to be in the first state. 
     In circuit implementation, each pixel may be electrically connected to the driving IC through an enable line, and each pixel may be electrically connected to a data line through a switch. The driving IC may control the state of the switches corresponding to the pixels through respective enable lines. The first state may be an on state and the second state may be an off state. Alternatively, the first state may be the off state and the second state may be the on state. 
     For example, when the driving IC controls a switch of a pixel through an enable line to be in on state, the display data is transmitted through the data line to update the display data of the pixel; when the driving IC controls the switch of the pixel through the enable line to be in the off state, the display data of the pixel remains unchanged. 
     In this embodiment, a data line may be provided for each pixel or for a plurality of pixels, which is not limited to the embodiment. Referring to  FIG. 3I , in this example, a data line is provided for a row of pixels for example. Assuming that the first cell and the second cell each includes 2 successive pixels, when a first row of pixels are scanned, that is, when the display data corresponding to the first row of display units is updated, switches  1  and  2  are controlled to be in the on state by enable line  1 , switches  3  and  4  are controlled to be in the off state by enable line  2 , . . . . , and so on, switches b- 1  and b are controlled to be in the on state by enable line b/ 2 ; when a second row of pixels are scanned, switches  1  and  2  are controlled to be in the off state by enable line  1 , switches  3  and  4  are controlled to be in the on state by enable line  2 , . . . . , and so on, and switches b- 1  and b are controlled to be in the off state by enable line b/ 2 . 
     From the above, according to the display methods provided by the embodiments, by detecting whether the displayed content changes and controlling the display to alternately update the display data corresponding to a first portion and a second portion of the display units if it is detected that the displayed content does not change, the number of the pixels to be updated by the display in each update can be reduced while keeping the refresh frequency of the display unchanged, thereby solving the problem of screen flicker due to the reduction of refreshing frequency and reducing power consumption of the display. 
     Additionally, by applying the above embodiments of controlling a display to update contents, power consumption of a transmission bus can be reduced, and electromagnetic interference caused by transmission of display data through the transmission bus can be reduced. 
       FIG. 4  is a block diagram of a display apparatus according to an exemplary embodiment. As shown in  FIG. 4 , the display apparatus may include: a detection module  410  and a control module  420 . 
     The detection module  410  may be configured to detect whether there is any change in a displayed content for a display. 
     The control module  420  may be configured to control the display to alternately update display data corresponding to a first portion and a second portion of display units of each row if it is detected by the detection module  410  that the displayed content for the display does not change, wherein the display unit comprises n rows of pixels, where n is a positive integer. 
     The first portion of display units may include i first cells. The second portion of display units may include j second cells. The first cell may be alternate with the second cell. The number i and j may be positive integers. 
     Each of the first cells may include p successive pixels. Each of the second cells may include q successive pixels. Both p and q may be greater than 1. 
     From the above, the display apparatus provided by the disclosure, by detecting whether there is any change in a displayed content for the display and controlling the display to alternately update display data corresponding to the displayed content of the first portion and the second portion of the display unit if it is detected that the displayed content does not change. The number of the pixels to be updated by the display in each update can be reduced while keeping the refresh frequency of the display unchanged. Thus, the issue of screen flicker due to the reduction of refresh frequency of a display can be solved and power consumption of the display is reduced while keeping the refresh frequency of the display unchanged. 
       FIG. 5  is a block diagram of a display apparatus according to an exemplary embodiment. As shown in  FIG. 5 , the display apparatus may include: a detection module  510  and a control module  520 . 
     The detection module  510  may be configured to detect whether there is any change in a displayed content for a display. 
     The control module  520  may be configured to control the display to alternately update display data corresponding to a first portion and a second portion of all row display units if it is detected by the detection module  510  that the displayed content does not change, wherein the display unit comprises n rows of pixels, where n is a positive integer. 
     Each first portion of the display unit may include i first cells. Each second portion of the display unit may include j second cells. The first cell may be alternate with the second cell. Moreover, i and j may be positive integers. 
     Each of the first cells may include p pixels. Each of the second cells may include q pixels. Moreover, p and q may be both greater than 1. 
     Alternatively, for each two adjacent row display units, all of the first cells of the first row of display units of the two adjacent rows of display units and all of the first cells of the second row of display units of the two adjacent rows of display units interlace with each other in columns, and all of the second cells of the first row of display units and all of the second cells of the second row of display units interlace with each other in columns. 
     Alternatively, each pixel is electrically connected to the driving IC through an enable line and each pixel is electrically connected to a data line through a switch, and the control module  520  may include: a first control sub-module  521  and a second control sub-module  522 . 
     The first control sub-module  521  may be configured to control, by a driving IC, switches of all of the pixels of each of the first cells to be in a first state and to control switches of all of the pixels of each of the second cells to be in a second state during an odd-numbered update. 
     The second control sub-module  522  may be configured to control, by a driving IC, the switches of all of the pixels of each of the first cells to be in the second state and to control the switches of all of the pixels of each of the second cells to be in the first state by the driving IC during an even-numbered update. 
     Alternatively, the control module  520  may further include: a first generation sub-module  523  and a first transmission sub-module  524 . 
     The first generation sub-module  523  may be configured to generate, by a processor, display data corresponding to all of the display units if it is detected by the detection module  510  that the displayed content does not change. 
     The first transmission sub-module  524  may be configured to control, by the processor, a transmission bus to alternately transmit the display data corresponding to the first portion and the second portion of the display units generated by the first generation sub-module  523  to the driving IC of the display such that the driving IC controls the display to refresh the displayed content according to received display data. 
     Alternatively, the control module may further include: a second generation sub-module  525 , a second transmission sub-module  526  and an instruction sending sub-module  527 . 
     The second generation sub-module  525  may be configured to generate, by the processor, display data corresponding to all of the display units if it is detected by the detection module  510  that the displayed content does not change. 
     The second transmission sub-module  526  may be configured to transmit, by the processor, the display data generated by the second generation sub-module  525  to the driving IC of the display via a transmission bus. 
     The instruction sending sub-module  527  may be configured to send, by the processor, an alternate update instruction to the driving IC such that the driving IC controls the display to alternately update the display data corresponding to the first portion and the second portion of the display units of the display data transmitted by the second transmission sub-module  526  according to the alternate update instruction. 
     Alternatively, the control module  529  may further include: a third generation sub-module  528  and a third transmission sub-module  529 . 
     The third generation sub-module  528  may be configured to generate alternately, by the processor, the display data corresponding to the first portion and the second portion of the display units within the displayed content if it is detected by the detection module  510  that the displayed content does not change. 
     The third transmission sub-module  529  may be configured to transmit, by the processor via a transmission bus, the display data generated by the third generation sub-module  528  to the driving IC of the display such that the driving IC controls the display to refresh the displayed content according to received display data. 
     From the above, for the display apparatus provided by the disclosure, by detecting whether there is any change in displayed content for the display and controlling the display to alternately update display data corresponding to the displayed content of the first portion and the second portion of the display units if it is detected that the displayed content does not change, the number of the pixels to be updated by the display in each update can be reduced while keeping the original refresh frequency unchanged. Thus, an issue of screen flicker due to the reduction of refresh frequency of the display can be solved and power consumption of the display can be reduced. 
     Additionally, by applying the above implementations of refreshing displayed content for a display, power consumption of a transmission bus can be reduced and electromagnetic interference caused by transmission of display data in the transmission bus can be reduced. 
     With respect to the devices in the above embodiments, the specific manners for performing operations for individual modules therein have been described in detail in the corresponding method embodiments and thus will not be elaborated herein. 
     A display apparatus capable of implementing the display methods provided by the disclosure is provided herein according to an exemplary embodiment of the present disclosure. The apparatus may include: a processor, a memory to store instructions executable by the processor, wherein the processor may be configured to: detect whether there is any change in displayed content for a display; control the display to alternately update display data corresponding to a first portion and a second portion of all row display units if it is detected that the displayed content does not change, wherein the display unit comprises n rows of pixels, where n is a positive integer; wherein the first portion of the display unit may include i first cells, the second portion of the display unit may include j second cells, and the first cell may be alternate with the second cell, wherein i and j may be positive integers; and each of the first cells may include p successive pixels, and each of the second cells may include q successive pixels, wherein p and q may be both greater than 1. 
       FIG. 6  is a block diagram of a display device illustrated according to an exemplary embodiment. For example, the device  600  may be a mobile phone, a computer, a digital broadcast terminal, a messaging device, a gaming console, a tablet, a medical device, exercise equipment, a personal digital assistant, and the like. 
     Referring to  FIG. 6 , the device  600  may include one or more of the following components: a processing component  602 , a memory  604 , a power component  606 , a multimedia component  608 , an audio component  610 , an input/output (I/O) interface  612 , a sensor component  614 , and a communication component  616 . 
     The processing component  602  typically controls overall operations of the device  600 , such as the operations associated with display, telephone calls, data communications, camera operations, and recording operations. The processing component  602  may include one or more processors  618  to execute instructions to perform all or part of the steps in the above described methods. Moreover, the processing component  602  may include one or more modules which facilitate the interaction between the processing component  602  and other components. For instance, the processing component  602  may include a multimedia module to facilitate the interaction between the multimedia component  608  and the processing component  602 . 
     The memory  604  is configured to store various types of data to support the operation of the device  600 . Examples of such data include instructions for any applications or methods operated on the device  600 , contact data, phonebook data, messages, pictures, video, etc. The memory  604  may be implemented using any type of volatile or non-volatile memory devices, or a combination thereof, such as a static random access memory (SRAM), an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a programmable read-only memory (PROM), a read-only memory (ROM), a magnetic memory, a flash memory, a magnetic or optical disk. 
     The power component  606  provides power to various components of the device  600 . The power component  606  may include a power management system, one or more power sources, and any other components associated with the generation, management, and distribution of power in the device  600 . 
     The multimedia component  608  includes a screen providing an output interface between the device  600  and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes the touch panel, the screen may be implemented as a touch screen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touches, swipes, and gestures on the touch panel. The touch sensors may not only sense a boundary of a touch or swipe action, but also sense a period of time and a pressure associated with the touch or swipe action. In some embodiments, the multimedia component  608  includes a front camera and/or a rear camera. The front camera and/or the rear camera may receive an external multimedia datum while the device  600  is in an operation mode, such as a photographing mode or a video mode. Each of the front camera and the rear camera may be a fixed optical lens system or have focus and optical zoom capability. 
     The audio component  610  is configured to output and/or input audio signals. For example, the audio component  610  includes a microphone (“MIC”) configured to receive an external audio signal when the device  600  is in an operation mode, such as a call mode, a recording mode, and a voice recognition mode. The received audio signal may be further stored in the memory  604  or transmitted via the communication component  616 . In some embodiments, the audio component  610  further includes a speaker to output audio signals. 
     The I/O interface  612  provides an interface between the processing component  602  and peripheral interface modules, such as a keyboard, a click wheel, buttons, and the like. The buttons may include, but are not limited to, a home button, a volume button, a starting button, and a locking button. 
     The sensor component  614  includes one or more sensors to provide state assessments of various aspects of the device  600 . For instance, the sensor component  614  may detect an open/closed state of the device  600 , relative positioning of components, e.g., the display and the keypad, of the device  600 , a change in position of the device  600  or a component of the device  600 , a presence or absence of user contact with the device  600 , an orientation or an acceleration/deceleration of the device  600 , and a change in temperature of the device  600 . The sensor component  614  may include a proximity sensor configured to detect the presence of nearby objects without any physical contact. The sensor component  614  may also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor component  614  may also include an accelerometer sensor, a gyroscope sensor, a magnetic sensor, a pressure sensor, or a temperature sensor. 
     The communication component  616  is configured to facilitate communication, wired or wirelessly, between the device  600  and other devices. The device  600  can access a wireless network based on a communication standard, such as WiFi, 2G or 3G or a combination thereof. In one exemplary embodiment, the communication component  616  receives a broadcast signal or broadcast associated information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, the communication component  616  further includes a near field communication (NFC) module to facilitate short-range communications. For example, the NFC module may be implemented based on a radio frequency identification (RFID) technology, an infrared data association (IrDA) technology, an ultra-wideband (UWB) technology, a Bluetooth (BT) technology, and other technologies. 
     In exemplary embodiments, the device  600  may be implemented with one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, micro-controllers, microprocessors, or other electronic components, for performing the above described methods. 
     In exemplary embodiments, there is also provided a non-transitory computer-readable storage medium including instructions, such as the memory  604  having stored therein instructions, when executed by the processor  618  in the device  600 , for performing the above-described methods. For example, the non-transitory computer-readable storage medium may be a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disc, an optical data storage device, and the like. 
     Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed here. This application is intended to cover any variations, uses, or adaptations of the disclosure following the general principles thereof and including such departures from the present disclosure as come within known or customary practice in the art. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims. 
     It will be appreciated that the present disclosure is not limited to the exact construction that has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made without departing from the scope thereof. It is intended that the scope of the disclosure only be limited by the appended claims.