CN102222420A - Electronic book reader and picture refreshing realization method thereof - Google Patents

Abstract

The invention discloses an electronic book reader, which includes a central processing unit, an electronic paper display controller (EPDController), FlashROM, a storage unit, control buttons and an electronic paper display screen; the central processing unit, the storage unit, the electronic paper display The controller is connected through the bus, the storage unit stores file data, and the central processing unit reads the data from the storage unit and sends it to the electronic paper display controller; the FlashROM is connected to the display controller as an external look-up table memory; it is characterized in that , and also includes two slices of SRAM connected to the display controller as a buffer for the display controller. The electronic book reader disclosed by the invention can reduce system power consumption, improve electronic paper display response speed, and reduce picture flickering. The invention also discloses a method for realizing the screen refresh of the e-book reader.

Description

E-Book Reader and Its Screen Refreshing Implementation Method

technical field

The invention relates to an electronic book reader and a method for realizing refresh of its screen, belonging to the field of electromechanical control products.

Background technique

In recent years, a kind of paper-like flexible and thin rewritable display called electronic paper has been more and more popular.

It is noteworthy that this flexible and thin electronic paper screen can maintain the display of images in the state of no power supply. e-paper is dedicated to

An electronic device for reading, which has high contrast, clear text, supports screen handwriting, consumes very little power, and can

Gently bend. The electronic paper screen can erase or rewrite the image kept displayed on the screen, and can be reused,

Thereby saving paper resources.

The e-paper reader designed with e-paper can achieve exactly the same display effect as traditional paper, and it will not affect reading at all even in sunlight. Electronic paper relies on voltage pulses to drive electronic ink, and the image displayed on electronic paper can still be maintained after power failure. The electronic paper reader only consumes power when refreshing the displayed image, which is more power-saving than LCD. By expanding the memory, the electronic paper reader can store a large amount of books.

Contents of the invention

The purpose of the present invention is to provide an electronic book reader which can improve the display response speed of the electronic paper display screen, reduce screen flicker and reduce power consumption.

The present invention is realized as follows: an electronic book reader, which includes a central processing unit, an electronic paper display controller (EPD Controller), Flash ROM, a storage unit, control buttons and an electronic paper display screen; The storage unit and the electronic paper display controller are connected through a bus, the storage unit stores file data, the central processing unit reads the data from the storage unit, and sends it to the electronic paper display controller; the Flash ROM is connected to the display controller as an external A look-up table memory; it is characterized in that it also includes two slices of SRAM connected to the display controller as a cache of the display controller.

In a preferred embodiment, each SRAM can store two frames of image data, that is, store the previously displayed image data, the data currently displayed on the electronic paper and the next frame of data to be displayed.

In a preferred embodiment, the control keys include page turning control keys, the page turning control keys are electrically connected to the display controller, and the control keys directly output page turning signals to the display controller in response to user operations.

In a preferred embodiment, the control buttons also include a screen refresh effect selection key, and the screen refresh effect selection key is electrically connected to the display controller to realize scrolling display from top to bottom and from left to right and full page refresh Three display effects.

In a preferred embodiment, after the display controller receives the page turning signal, it judges the position of the picture data of the target page in the two SRAMs, and the display controller reads the corresponding SRAM according to the page turning signal Look up the screen data of the target page in the table and drive the electronic paper display screen to display it.

The invention also discloses a method for realizing the screen refresh of the above-mentioned e-book reader, which is characterized in that: the e-book display screen is divided into areas of equal size; each area adopts the minimum rectangular area partial refresh method, and two SRAMs are compared In the data, calculate the different area of the smallest rectangle, refresh and display the image of the rectangular area.

The electronic book reader and its picture refreshing method disclosed by the invention can reduce system power consumption, improve the display response speed of electronic paper, and reduce picture flickering.

Description of drawings

Fig. 1 is the overall module block diagram of the electronic book reader of preferred embodiment of the present invention;

Fig. 2 is a schematic diagram of the storage situation of each frame of image data in the SRAM in a preferred embodiment of the present invention;

Fig. 3 is a flow chart of the screen refresh operation in a preferred embodiment of the present invention;

Fig. 4 is a schematic diagram of three screen refresh modes in a preferred embodiment of the present invention;

Fig. 5 is a schematic diagram of the coding of the divided area of the electronic paper screen according to the preferred embodiment of the present invention;

Fig. 6 is a schematic diagram of a method for calculating the smallest rectangular area of different pixels according to a preferred embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below through specific embodiments and related drawings.

Referring to Fig. 1, it is a block diagram of the system module of the present invention. Including central processing unit, electronic paper display controller (EPD Controller), 2 pieces of SRAM, Flash ROM, storage unit, control buttons and electronic paper display screen. The central processing unit is connected to the storage unit and the electronic paper display controller through the bus, the storage unit stores file data, the central processing unit reads the data from the storage unit, and sends it to the electronic paper display controller; 2 pieces of SRAM are connected to the display controller , as a cache of the display controller, storing previously displayed image data, image data currently displayed on the screen, and data to be displayed; control buttons include page turning control keys, screen refresh effect control keys; page turning control keys and display control The control button responds to the user's operation and directly outputs the page turning signal to the display controller; the Flash ROM is connected to the display controller as an external look-up table memory.

Please refer to FIG. 2 , which is a schematic diagram of storage of each frame of image data in the SRAM according to a preferred embodiment of the present invention. The e-book reader of the present invention adopts a double buffering mechanism, namely SRAM1 and SRAM2, and each piece of SRAM can store two frames of image data, that is, store the image data displayed before, the data currently displayed on the electronic paper, and the next frame to be displayed. Frame data, for example, when the first picture is displayed, its data is stored in SRAM1, and the second picture data is stored in SRAM2; when the second picture is displayed, its data is stored in SRAM2, and the third picture data is stored in In SRAM1, it is displayed alternately to improve the processing speed of the system.

Please refer to Figure 3-6. First, the CPU reads a frame of image data from the storage unit and sends it to the electronic paper display controller. The display controller writes these data into SRAM1; at the same time, the display controller reads the data in SRAM2 (initially, the internal data is all 1), Flash ROM parameters, etc., controls the electronic paper display screen, and displays images. At this time, the electronic paper displays The screen displays a full white screen. Then the display controller sends a power-on display completion signal to the central processing unit to complete the initialization operation. After the central processing unit receives the signal, it reads the next frame of image data from the storage unit, and the display controller writes these data in the SRAM2. At the same time, read the data in SRAM1, control the electronic paper display, and display the first frame of image. In view of the bistable characteristics of electronic paper, after the screen image is displayed, no power supply is required, and it is only powered on when the screen image needs to be refreshed, which can greatly save power consumption.

When the page turning operation is performed, a page turning signal is generated to the display controller through the page turning button operation, and the display controller first recognizes the page turning signal; position, read data from SRAM, control the display screen display, and send a control signal to the central processing unit at the same time, and the central processing unit reads the next frame of data and sends it to the display controller, so that the display controller can store it in the SRAM Medium; if it is a page-up signal, the display controller will judge the storage position of the previous frame image data, read the data from the SRAM, and control the display on the display screen. At this time, the CPU is not required to participate, which can save power consumption and improve System processing time; if the last frame of image data is not in the SRAM, then send a control signal to the central processing unit to notify it to read the last frame of image data to the display controller, and then display it. The storage situation of each frame image data in SRAM is shown in Fig. 3 .

In this embodiment, the screen refresh effect can be selected by controlling the buttons, scrolling display from top to bottom, left to right, and full page refresh display. As shown in Figure 4, the screen resolution of the electronic paper is 800*600. a) For scrolling display from top to bottom, one row of images is displayed each time refreshed, that is, 800 pixels, and the entire screen display is completed after refreshing and displaying 600 lines of images in this way; b) For scrolling display from left to right, each time Refresh and display a column of images, that is, 600 pixels. After refreshing and displaying 800 columns of images, the display of one frame of images is completed; c) Refresh and display the entire screen, using the method of refreshing the display screen by region. By default, the whole screen is refreshed and displayed when the machine is powered on. When the user presses the control key for the first time, the user selects to scroll from top to bottom, and when the user presses the key for the second time, selects to scroll from left to right, and so on. Way. When the scrolling display mode is selected, the display controller selects a lower frequency to control the display of the electronic paper screen to achieve a scrolling display effect.

In this embodiment, as shown in Figure 5-6, the method of refreshing the display screen by region is used to divide the entire screen into regions of equal size; the method of partial refresh of the smallest rectangular region is used for each region, and the comparison between SRAM1 and SRAM2 The current screen displays the image data and the image data to be displayed, calculates the different area of the smallest rectangle, refreshes and displays the rectangular area, and does not operate on the same part. The main steps are as follows:

(1) First divide the electronic paper screen image into areas of equal size, as shown in Figure 5, if the screen resolution is 800*600, divide it into 8*6 areas, each area is 100*100 in size, and number each region;

(2) Compare the currently displayed image in each area with the image to be displayed to determine whether to refresh;

(3) Comparison, the method is shown in Figure 6. Starting from the first pixel in the upper left corner, compare the current display image and the image data to be displayed in a clockwise direction, and find out the uppermost Y0, the lowermost Y1, the leftmost X0, and the rightmost X1 is different image data, so the rectangular area formed by these four points is the required minimum different rectangular area;

(4) The display controller looks up the table to output the corresponding voltage according to the obtained minimum rectangular area, and drives the electronic paper screen to display.

Therefore, the e-book reader of the present invention adopts a double buffering mechanism, which improves the system processing speed; every slice of SRAM can store 2 frames of image data, and when the user turns pages, especially when turning pages backwards, due to the picture data of the target page It is stored in SDRAM without the participation of the central processing unit. It only needs to drive the electronic paper display screen through the display controller. In addition, the screen is refreshed in different areas to compare whether the current screen is the same as the next frame of image data to be displayed. Only for different areas Refreshing the display saves system power consumption, improves the response speed of the electronic paper display, and reduces screen flickering.

The above-listed preferred embodiments have further described the purpose, technical solutions and advantages of the present invention in detail. It should be understood that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Within the spirit and principles of the present invention, any modifications, equivalent replacements, improvements, etc., shall be included within the protection scope of the present invention.

Claims (6)

1. E-book reader, it comprises central processing unit, Electronic Paper display controller, Flash ROM, storage unit, control button and electronic-paper display screen; Described central processing unit links to each other by bus with storage unit, Electronic Paper display controller, the cell stores file data, and central processing unit is reading of data from storage unit, and sends to the Electronic Paper display controller; Described Flash ROM is connected with display controller, as external inquiry table storer; It is characterized in that, also comprise two SRAM that link to each other with display controller, as the buffer memory of display controller.

2. E-book reader according to claim 1 is characterized in that: every SRAM can store two frame image datas, i.e. the view data that showed before the storage, current data on the Electronic Paper and the next frame data to be shown of being presented at.

3. E-book reader according to claim 1, it is characterized in that: described control button comprises the page turning operating key, described page turning control button is electrically connected with display controller, and control key response user operation directly exports the page turning signal to display controller.

4. E-book reader according to claim 1, it is characterized in that: described control button also comprises picture refreshing effect selection key, described picture refreshing effect selection key is electrically connected with display controller, realizes from top to bottom, from left to right roll display and whole page or leaf refresh three kinds of display effects.

5. E-book reader according to claim 3, it is characterized in that: after described display controller receives the page turning signal, judge picture data position in described two SRAM of page object, described display controller reads the picture data of the page object among the corresponding SRAM according to described page turning signal, and tabling look-up and driving electronic-paper display screen is shown.

6. the implementation method of the described E-book reader picture refreshing of aforesaid right requirement 1-5 is characterized in that: the e-book display screen is divided into equal-sized each zone; The local method for refreshing of minimum rectangular area is adopted in each zone, compare data among two SRAM, calculate the zone inequality of minimum rectangle, refresh this rectangular area image of demonstration.

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