CN105405411B - A kind of display drive method and system of 16 rank electrophoretic display device (EPD) - Google Patents

Abstract

The invention discloses a display driving method and system of a 16-stage electrophoretic display. The method includes the following steps: A. The display controller receives the gray-scale display command and invokes the waveform lookup table; B. The display controller transmits the gray-scale waveform information to the driving electrode controller according to the gray-scale display command; C. The driving electrode controller Receive the waveform information of the gray scale, apply the voltage of the DC balance recovery waveform corresponding to the gray scale to be wiped to the pixel through the driving electrode, drive the pixel to move, and return to the basic gray scale; For the waveform information of the level, apply the voltage of the appropriate gray-scale driving waveform through the driving electrodes to write the new gray level. The present invention increases the number of gray scales through the gray scale driving method, and realizes and improves the gray scale display effect of the electrophoretic display. Comply with the principle of DC balance, effectively avoiding the damage of driving electrodes and display media due to the accumulation of residual voltage.

Description

A display driving method and system for a 16-stage electrophoretic display

technical field

The invention relates to a display driving method and system for a 16-stage electrophoretic display, belonging to the technical field of electrophoresis.

Background technique

Microcapsule electrophoretic display has become an important electronic paper display technology. Compared with other display technologies, it has the advantage of ultra-low power consumption, so electrophoretic display technology is widely used. There are two kinds of particles in the microcapsules: black particles and white particles. White particles are governed by negative charges and black particles by positive charges. Therefore, when the pixel electrode is supplied with a negative voltage, the electrophoretic display displays white, and when driven with a positive voltage, it displays black. The electrophoretic display needs an active matrix backplane. In order to drive the electrophoretic particles to achieve the correct display of the gray scale, a suitable driving waveform is applied to the electrodes. So far, there have been many studies on driving waveforms of electrophoretic displays.

At present, the 4-level gray scale (black, dark gray, light gray, white) display technology has been relatively mature, and various driving waveform methods have been proposed one after another. A better driving waveform is to edit and design all 4x4=16 gray scale conversion waveforms in a look-up table. Waveforms like black→black, black→light gray→black, black→light gray→dark gray→black are called closed-loop grayscale conversion waveforms. In each closed-loop grayscale conversion waveform, the principle of DC balance is followed to avoid damage to the driving electrodes and display media. This waveform includes two phases of erasing and driving, and the black gray level is used as the reference gray level of the erasing phase.

The electrophoretic screen display technology disclosed at this stage is basically aimed at 4-level grayscale display, and the richness and clarity of the grayscale of the screen need to be improved. Compared with the 4-level gray scale, the 16-level gray scale design makes the interval between each gray scale smaller, the display effect is more delicate, the display screen is clearer, the pixel composition is richer, and the gray scale contrast is more obvious. Compared with the picture driven by 4-level gray-scale technology, the image screen driven by 16-level gray-scale technology has a great improvement, and the viewing comfort is also greatly improved. However, since each gray-scale interval becomes smaller, it is difficult to control the gray-scale accuracy, and it is not suitable to design all 16x16=256 gray-scale conversion waveforms. If the above-mentioned 4-stage driving method is adopted, 256 conversion waveforms need to be designed, and the number is too large to be realistic.

Because it is a 16-level gray scale, the DC balance problem will become much more complicated. If the DC balance cannot be guaranteed, then during the grayscale conversion process, residual voltage will be generated and accumulated, which will damage the driving electrodes and the display medium, and the display screen will gradually turn yellow and dark. Over time, when the residual voltage is too large, the electrodes will be broken down. Display life is also greatly reduced.

Contents of the invention

In order to solve the defects in the prior art, the present invention provides a display driving method for a 16-stage electrophoretic display, comprising the following steps:

A. The display controller receives the grayscale display command and calls the waveform lookup table, where the waveform lookup table is used to store the 16-level grayscale waveform; B. The display controller transmits the grayscale waveform information to the driving electrodes according to the grayscale display command The controller, wherein the waveform information of the gray scale includes the DC balance recovery waveform corresponding to the gray scale to be wiped and the driving waveform of the gray scale to be displayed; The voltage of the DC balance recovery waveform corresponding to the level is used to wipe the gray scale; D. After the drive electrode controller finishes wiping the gray scale, according to the waveform information of the gray scale, the voltage of the appropriate gray scale drive waveform is applied through the drive electrode to refresh the new gray order.

Further, before the step A, the waveform lookup table needs to be set in advance, including: gray scale code: there are 16 gray scales in total, from 0 to 15, where 0 represents the maximum black gray scale, and 15 represents the maximum black gray scale. White gray scale; basic gray scale: set 0 as the basic gray scale; waveform: 16 gray scales have their own DC balance recovery waveform and gray scale driving waveform.

Further, the DC balance restoration waveform described in step B achieves DC balance by the following method: during the i-th gray-scale driving and i+1-th gray-scale wiping of the electrode, the total time for applying a positive voltage is equal to applying a negative voltage. total time of voltage.

Further, the driving electrode voltage is set to 15V to realize display driving.

Further, the process of wiping the gray scale in the step C includes: during the gray scale conversion from nth order to m order, the DC balance recovery waveform drives the gray scale of the pixel to change from nth order to 15th order by changing the voltage, and then from 15th order to 15th order Transform to 0 level, that is, drive the pixel to transform its gray scale to the base gray scale.

Further, the voltage in step C is set to change from negative voltage to positive voltage, so as to ensure the black state as the basic color level.

Further, in step D, a negative voltage is used to write a new gray scale.

The beneficial effects of the present invention are: through the gray scale driving method, the number of gray scales is increased, the gray scale display effect of the electrophoretic display is realized and improved, and the overall driving time is reduced. Comply with the principle of DC balance, effectively avoiding the damage of driving electrodes and display media due to the accumulation of residual voltage.

Description of drawings

Fig. 1 shows the method flowchart of the present invention;

Figure 2 shows the DC balance recovery waveform table of 16 gray scales;

Figure 3 shows the driving waveform table of 16 gray scales;

FIG. 4 is a schematic diagram of conversion from gray scale n to gray scale m;

FIG. 5 is a schematic diagram of closed-loop gray scale conversion to achieve DC balance.

detailed description

According to the first embodiment of the present invention, a display driving method for a 16-step electrophoretic display as shown in FIG. 1 includes the following steps:

A. The display controller receives the grayscale display command and invokes the waveform lookup table, where the waveform lookup table is used to store 16 grayscale waveforms;

B. The display controller transmits the waveform information of the gray scale to the drive electrode controller according to the gray scale display command, wherein the waveform information of the gray scale includes the DC balance recovery waveform corresponding to the gray scale to be wiped and the driving waveform of the gray scale to be displayed;

C. The drive electrode controller receives the waveform information of the gray scale, applies the voltage of the DC balance recovery waveform corresponding to the gray scale to be wiped to the pixel through the drive electrode, drives the pixel to move, and returns to the basic gray scale to achieve the purpose of wiping the gray scale ;

D. After the drive electrode controller finishes wiping the gray scale, according to the waveform information of the gray scale, the drive electrode applies a voltage of a suitable gray scale drive waveform to write a new gray scale.

Before step A, you need to pre-set the waveform lookup table, including the gray scale code, there are 16 gray scales in total, from 0 to 15, where 0 represents the maximum black gray scale, and 15 represents the maximum white gray scale; basic gray Level, set level 0 as the basic gray level, that is, the gray level as a starting point in the conversion process, similarly, you can also set level 15 as the basic gray level; waveform: 16 gray levels have their own DC balance recovery waveforms and grayscale driving waveforms.

According to the second embodiment of the present invention, the waveform table of an edited waveform look-up table includes the DC balance recovery waveform table as shown in Figure 2 and the gray-scale drive waveform table as shown in Figure 3, and the DC balance recovery waveform plays a role in restoring DC balance and activation of the black and white particle activity in the display medium, the driving waveform is used to drive the pixel to the target gray scale.

According to the third embodiment of the present invention, the DC balance recovery waveform described in step B is achieved by the following method: the voltage of the electrode in the driving phase of the i-th gray-scale conversion and the wiping of the i+1-th gray-scale conversion The positive and negative voltage DC balance is maintained during the process, that is, the total time of applying positive voltage in the two-stage process is equal to the total time of applying negative voltage.

The driving electrode voltage was set to 15V to realize display driving.

As shown in Figure 4, the process of step C wiping the gray scale includes:

In the grayscale conversion from nth to mth level, the DC balance recovery waveform drives the gray scale of the pixel from nth to 15th through the change of voltage, and then from 15th to 0th, that is, to drive the pixel to change its grayscale to the basic grayscale.

As shown in Figure 5, the overall current balance is achieved during the gray-scale conversion process: n-level → m-level conversion, first call the DC balance recovery waveform of the n-level waveform in the DC balance recovery waveform table to balance the previous gray-scale conversion process The unbalanced voltage left after driving to n-level; then call the gray-scale driving waveform of the m-level waveform in the driving waveform table, and the unbalanced voltage of this gray-scale driving waveform will be left at this time, waiting for the next gray-scale conversion When calling the DC balance recovery waveform of the m-order waveform in the DC balance recovery waveform table to maintain the DC balance. If the next conversion reaches the nth level and returns to the initial gray scale to form a closed loop, then it is obvious that the entire closed-loop gray scale conversion process follows the DC balance as a whole, avoiding the accumulation of residual voltage, protecting the driving electrodes and display media, and extending the its service life.

The voltage in step C is set from negative voltage to positive voltage to ensure the black state as the basic color scale. In addition, when the basic gray scale is the maximum white gray scale, the voltage is set from positive voltage to negative voltage.

In step D, a negative voltage is used to write a new gray scale, and when the basic gray scale is the maximum white gray scale, a positive voltage is used to write a new gray scale.

According to the fourth embodiment of the present invention, a display driving system for display driving of a 16-step electrophoretic display includes:

A display input device configured to enable the display controller to receive a grayscale display command and call a waveform lookup table, wherein the waveform lookup table is used to store 16-level grayscale waveforms;

The display control device is configured to make the display controller transmit the waveform information of the gray scale to the drive electrode controller according to the gray scale display command, wherein the waveform information of the gray scale includes the DC balance recovery waveform corresponding to the gray scale to be wiped and the gray scale to be displayed. order driving waveform;

The drive electrode wiping device is configured to enable the drive electrode controller to receive the waveform information of the gray scale, and apply the voltage of the DC balance recovery waveform corresponding to the gray scale to be wiped through the drive electrode to wipe the gray scale;

The driving electrode driving device is configured to make the driving electrode controller apply a voltage of a suitable gray-scale driving waveform through the driving electrodes to write a new gray-scale according to the waveform information of the gray-scale after finishing wiping the gray-scale.

The above descriptions are only preferred embodiments of the present invention, and the present invention is not limited to the above-mentioned embodiments, as long as they achieve the technical effects of the present invention by the same means, they should all belong to the protection scope of the present invention. Various modifications and changes may be made to the technical solutions and/or implementations within the protection scope of the present invention.

Claims (7)

1. a kind of display drive method of 16 rank electrophoretic display device (EPD), it is characterised in that comprise the following steps：

A, display controller receives GTG display command, calls waveform inquiry table, and wherein waveform inquiry table is used to store 16 ranks ash Rank waveform；

B, the shape information of GTG is passed to driving electrodes controller, wherein ash by display controller according to GTG display command The shape information of rank includes the drive waveforms that DC balance corresponding to GTG to be wiped recovers waveform and GTG to be shown, wherein,

DC balance recovers waveform and is based on electrode during the driving of ith GTG and i+1 time GTG wipe, and applies positive electricity Be equal to application negative voltage the total time of pressure realizes DC balance total time；

C, driving electrodes controller receives the shape information of GTG, applies direct current corresponding with GTG to be wiped by driving electrodes The voltage of integrated compensation waveform is to wipe GTG；

D, driving electrodes controller, according to the shape information of GTG, is applied by driving electrodes and closed after completing to wipe GTG The voltage of suitable GTG drive waveforms writes with a brush dipped in Chinese ink new GTG.

2. a kind of display drive method of 16 rank electrophoretic display device (EPD) according to claim 1, it is characterised in that the step , it is necessary to pre-set waveform inquiry table before A, including：

GTG code name：A total of 16 rank GTG, from 0 rank to 15 ranks, wherein 0 rank represents maximum black GTG, 15 ranks represent maximum White GTG；

Basic GTG：Set GTG based on 0 rank；

Waveform：16 rank GTGs respectively there is respective DC balance to recover waveform and GTG drive waveforms.

A kind of 3. display drive method of 16 rank electrophoretic display device (EPD) according to claim 1, it is characterised in that driving electrodes electricity Pressure is arranged to 15V to realize display driving.

A kind of 4. display drive method of 16 rank electrophoretic display device (EPD) according to claim 1, it is characterised in that the step C Wiping the process of GTG includes：

GTG changes n ranks into m ranks, and DC balance recovers waveform drives the GTG of pixel to be transformed to from n ranks by voltage change 15 ranks, 0 rank then is transformed to from 15 ranks, that is, drive pixel to make its grey scale transformation to basic GTG.

A kind of 5. display drive method of 16 rank electrophoretic display device (EPD) according to claim 1, it is characterised in that the step C Voltage be arranged to turn to positive voltage by negative voltage, the color range based on ensureing black state.

A kind of 6. display drive method of 16 rank electrophoretic display device (EPD) according to claim 1, it is characterised in that the step D New GTG is write with a brush dipped in Chinese ink using negative voltage.

7. a kind of display driving system of 16 rank electrophoretic display device (EPD), it is characterised in that including following：

Display input device, it is configured to make display controller receive GTG display command, calls waveform inquiry table, wherein waveform is looked into Table is ask to be used to store 16 rank GTG waveforms；

Display control unit, it is configured to make display controller that the shape information of GTG be passed into drive according to GTG display command The shape information of moving electrode controller, wherein GTG includes DC balance corresponding to GTG to be wiped and recovers waveform and ash to be shown The drive waveforms of rank；

Driving electrodes wiping arrangement, the shape information for making driving electrodes controller receive GTG is configured to, is applied by driving electrodes Corresponding with GTG to be wiped DC balance is added to recover the voltage of waveform to wipe GTG；

Driving electrodes drive device, it is configured to make driving electrodes controller after completing to wipe GTG, according to the waveform of GTG Information, the voltage for applying suitable GTG drive waveforms by driving electrodes write with a brush dipped in Chinese ink new GTG.