CN109656076B

CN109656076B - Electrophoretic display device, driving method thereof and electrophoretic display device

Info

Publication number: CN109656076B
Application number: CN201910059458.7A
Authority: CN
Inventors: 田超; 许睿; 马青青; 王哲
Original assignee: BOE Technology Group Co Ltd; Beijing BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Beijing BOE Optoelectronics Technology Co Ltd
Priority date: 2019-01-22
Filing date: 2019-01-22
Publication date: 2022-05-27
Anticipated expiration: 2039-01-22
Also published as: CN109656076A

Abstract

The invention provides an electrophoretic display device and a driving method thereof, and also provides a display device. The electrophoretic display device comprises two substrates which are oppositely arranged, wherein two electrodes are alternately arranged on one substrate at intervals, at least one electrode and an electronic ink layer are also arranged on the other substrate at intervals, the electronic ink layer is arranged between the electrode layers of the two opposite substrates, and charged ink particles positioned in the middle move to the electrode with the opposite polarity to the charged ink particles by applying different voltages so as to display different states. The electrophoretic display device has clear boundary of adjacent pixels during color development, improves the display effect, shortens the motion path of part of ink particles to a certain extent, shortens the response time of the device, and reduces the overall power consumption of the device.

Description

Electrophoretic display device, driving method thereof and electrophoretic display device

Technical Field

The invention relates to the technical field of packaging, in particular to an electrophoretic display device, a driving method of the display device and an electrophoretic display device.

Background

The electronic paper has the advantages of being close to the reading experience of paper in height, free of eye injury, suitable for long-time reading, long in service life of the battery and the like, and is widely used in the fields of electronic price tags, electronic books and the like.

The electronic paper mainly utilizes an E ink electrophoresis technology to realize display, the electronic paper contains charged ink particles, when opposite voltages are applied to electrodes on two sides of the charged ink particles, the charged ink particles can generate electrophoresis action under the action of an electric field and are attracted and repelled by the electrodes on the two sides so as to display a bright state or a dark state. The motion mode of the charged ink particles in the electric field affects the display quality, and also affects the response time of the picture, thereby affecting the power consumption.

It is to be noted that the information invented in the above background section is only for enhancing the understanding of the background of the present invention, and therefore, may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

An object of the present invention is to provide an electrophoretic display device and a driving method of the display device to solve one or more problems of the existing display device.

According to an aspect of the present invention, there is provided an electrophoretic display device including:

a first substrate;

a second substrate disposed opposite to the first substrate;

the first electrode layer is arranged on the surface, close to the second substrate, of the first substrate and comprises a plurality of first electrodes and a plurality of second electrodes which are alternately arranged at intervals, the projection area of the first electrodes on the first substrate is larger than that of the second electrodes on the first substrate, and the first electrodes are transparent electrodes;

the second electrode layer is arranged on the surface, close to the first substrate, of the second substrate and comprises a plurality of third electrodes which are arranged at intervals;

an electronic ink layer located between the first electrode layer and the second electrode layer.

In an exemplary embodiment of the invention, the plurality of third electrodes are disposed opposite to the plurality of first electrodes one to one, or the plurality of third electrodes are disposed opposite to the plurality of second electrodes one to one.

In an exemplary embodiment of the invention, the second electrode layer further includes a plurality of fourth electrodes, the plurality of third electrodes and the plurality of fourth electrodes are alternately arranged at intervals, a projection area of the third electrodes on the second substrate is larger than a projection area of the fourth electrodes on the second substrate, the third electrodes are arranged opposite to the first electrodes one by one, and the fourth electrodes are arranged opposite to the second electrodes one by one.

In an exemplary embodiment of the invention, the third electrode is a transparent electrode; the electrophoretic display device further comprises a reflecting layer arranged on one side of the second substrate far away from the second electrode layer.

In an exemplary embodiment of the invention, at least one of the second electrode and the fourth electrode is a transparent electrode.

In an exemplary embodiment of the invention, a projection of the first electrode on the second substrate coincides with the third electrode, and a projection of the second electrode on the second substrate coincides with the fourth electrode.

In an exemplary embodiment of the invention, the second electrode and the fourth electrode are stripe electrodes.

In an exemplary embodiment of the invention, the second electrode and the fourth electrode have a width of 2 to 6 μm.

In an exemplary embodiment of the present invention, the width of the first electrode and the third electrode is 80 to 120 μm.

In an exemplary embodiment of the invention, a first gap is formed between the adjacent first electrode and second electrode, a second gap is formed between the adjacent third electrode and fourth electrode, and the width of the first gap and the width of the second gap are 4-8 μm.

According to another aspect of the present invention, there is also provided an electrophoretic display device including the above-described electrophoretic display device.

According to still another aspect of the present invention, there is also provided a driving method of an electrophoretic display device, for driving the electrophoretic display device described above, the driving method including:

applying a first voltage to the first electrode, a second voltage to the second electrode, and a first voltage or a second voltage to the third electrode, the first voltage being different from the second voltage, so that the charged ink particles of the electronic ink layer are gathered on the third electrode and the same electrode as the third electrode voltage to display a first state;

applying a third voltage to the first electrode, applying a fourth voltage to the second electrode, and applying either the third voltage or the fourth voltage to the third electrode, the third voltage being different from the fourth voltage, to cause the charged ink particles of the electronic ink layer to collect on an electrode different from the third electrode voltage to display a second state.

In an exemplary embodiment of the present invention, the electrophoretic display device further includes a plurality of fourth electrodes, the plurality of third electrodes and the plurality of fourth electrodes are alternately arranged at intervals, a projection area of the third electrodes on the second substrate is larger than a projection area of the fourth electrodes on the second substrate, the third electrodes are arranged opposite to the first electrodes one by one, and the fourth electrodes are arranged opposite to the second electrodes one by one; the driving method includes:

applying a first voltage to the first and third electrodes and a second voltage to the second and fourth electrodes, the first voltage being different from the second voltage to cause charged ink particles of the electronic ink layer to collect on the first and third electrodes to display a first state;

applying a third voltage to the first electrode and the third electrode, and applying a fourth voltage to the second electrode and the fourth electrode, the third voltage being different from the fourth voltage, to cause charged ink particles of the electronic ink layer to collect on the second electrode and the fourth electrode to display a second state.

In the present invention, two kinds of electrodes are alternately provided on one substrate, and at least one kind of electrode is provided on the other substrate at intervals, and by applying different voltages, the charged ink particles positioned in the middle are moved to the electrode having the opposite polarity to the charged ink particles themselves, thereby displaying different states. On the one hand, the electrodes distributed at intervals enable the boundary of adjacent pixels to be clear when color is displayed, the problem that the boundary of a whole transparent electrode between pixels is not clear is avoided, and the display effect is improved. On the other hand, when different voltages are applied to two electrodes on the same substrate, a weak electric field is formed at the edge position, a small amount of ink particles can directly move between the two electrodes without moving to the opposite electrode, the response time is shortened to a certain extent, and the whole power consumption of the device is favorably reduced.

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 invention, as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

Fig. 1 is a schematic structural view of a conventional electrophoretic display device;

FIG. 2 is a schematic diagram of a conventional electrophoretic display device showing a dark state;

FIG. 3 is a schematic diagram of a conventional electrophoretic display device showing a transition state;

FIG. 4 is a diagram of a conventional electrophoretic display device showing a bright state;

FIG. 5 is a diagram illustrating a conventional electrophoretic display device displaying both a bright state and a dark state;

FIG. 6 is a top view of an electrophoretic display device according to the present invention;

FIG. 7 is a cross-sectional view of the first structure taken along line A-A of FIG. 6 in a bright state;

FIG. 8 is a cross-sectional view of the first structure taken along line A-A of FIG. 6 in a dark state;

FIG. 9 is a cross-sectional view of the second structure taken along line A-A of FIG. 6 in a bright state;

FIG. 10 is a cross-sectional view of a second structure taken along line A-A of FIG. 6 in a dark state;

FIG. 11 is a schematic view of a third configuration in the direction A-A of FIG. 6;

FIG. 12 is a diagram of a third structure along line A-A in FIG. 6 showing a bright state;

FIG. 13 is a schematic view of a third structure along line A-A of FIG. 6 showing a dark state;

FIG. 14 is a schematic diagram of a third structure in the direction A-A of FIG. 6 showing a light state and a dark state.

In the figure, 1, an upper substrate; 2. a lower substrate; 3. the whole surface of the ITO film; 4. a reflective layer; 5. a strip-shaped ITO film; 6. ink particles; 7. a first electrode; 8. a second electrode; 9. a third electrode; 10. and a fourth electrode.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted.

In the related art, the structure of the electrophoretic display device is shown in fig. 1, in which an upper substrate 1 and a lower substrate 2 are disposed opposite to each other, an entire ITO film 3 (indium tin oxide semiconductor transparent conductive film) is covered on an inner side of the upper substrate 1 to form a common electrode, a reflective layer 4 is covered on an outer side of the lower substrate 2, and strip ITO films 5 arranged at intervals are disposed on an inner side of the lower substrate 2 to form pixel electrodes. An electrophoretic fluid containing charged ink particles 6 is filled between the upper substrate 1 and the lower substrate 2.

Taking the example where the charged ink particles are positively charged black ink particles, if it is necessary to form a dark state (black display), a voltage of 0V may be applied to the common electrode on the inner side of the upper substrate, no voltage may be applied to the pixel electrode, and the positively charged black ink particles may freely diffuse to the common electrode until they uniformly diffuse to the entire transparent electrode, thereby forming a dark state, as shown in fig. 2, but the ink particle diffusion speed is slow in this method. In another mode, a voltage of 0V is applied to the common electrode, and a voltage of +10 to +20V is applied to the pixel electrode to form a repulsive voltage to the positively charged ink particles until the ink particles are sufficiently diffused on the entire transparent electrode to form a dark state.

If a bright state (displaying the color of the reflective layer) needs to be formed, a voltage of +10 to +20V can be applied to the common electrode, a 0 potential is applied to the pixel electrode to form a forward voltage, the black ink particles with positive charges can gradually move to one side of the pixel electrode, an intermediate transition state is formed in the moving process, as shown in fig. 3, the forward voltage is continuously applied until all the ink particles move to the vicinity of the pixel electrode to form a black matrix structure similar to an LCD structure, and at this time, the space between the pixel electrodes can reflect the background color of the reflective layer to present a bright state, as shown in fig. 4. If the alternating effect of the bright state and the dark state is required, a voltage of 0V may be applied to the common electrode, and a voltage of +10 to +20V and a voltage of-10 to-20V may be applied to the two pixel electrodes, respectively, to form opposite electric fields, so that the ink particles move in opposite directions to realize the alternating of the bright state and the dark state, as shown in fig. 5.

Because the ITO film 3 of the upper substrate is of a whole-surface structure, the width of each time the ink particles are distributed may be different due to the change of voltage, so that the boundary between pixel units is not clear, and the picture quality is affected. And is limited by the influence of particle concentration at present, and the box thickness is generally great, and the distance between upper substrate and the infrabasal plate is between 10 ~ 30 um. Since the ink particles move in one direction under the action of electrophoresis, the overall response time is relatively slow, which affects the display quality on one hand and causes high power consumption on the other hand.

In the embodiment of the present invention, an electrophoretic display device is provided, which displays a picture by using the principle of electrophoresis technology, and as shown in fig. 6 to 14, the electrophoretic display device of the embodiment includes a first substrate (upper substrate 1) and a second substrate (lower substrate 2) that are oppositely disposed. The surface of the first substrate close to the second substrate is provided with a first electrode layer, the first electrode layer comprises a plurality of first electrodes 7 and a plurality of second electrodes 8 which are alternately arranged at intervals, the projection area of the first electrodes 7 on the first substrate is larger than that of the second electrodes 8 on the first substrate, and the first electrodes 7 are transparent electrodes. A second electrode layer is arranged on the surface, close to the first substrate, of the second substrate, and the second electrode layer comprises a plurality of third electrodes 9 which are arranged at intervals; an electronic ink layer is arranged between the first electrode layer and the second electrode layer.

The first electrode 7 is used as a pixel electrode for displaying pixel colors, and the second electrode 8 is used for providing an electric field to contain or release the charged ink particles 6 to assist the first electrode 7 in developing colors. The third electrode 9 may be the same as the first electrode 7 for displaying the pixel color, or may be the same as the second electrode 8 for storing or releasing the charged ink particles 6 to assist the first electrode 7 in developing the color. Separate through second electrode 8 between the transparent first electrode 7, third electrode 9 also is interval distribution for adjacent pixel limit is clear when showing colour, has avoided the unclear problem of a whole transparent electrode limit between the pixel, has also improved display effect. And the first electrode and the second electrode are different in voltage, a weak electric field can be formed between the edge of the first electrode and the second electrode, a small amount of ink particles can directly move between the first electrode and the second electrode, and do not need to move to the opposite third electrode, so that the response time is saved to a certain extent.

Therefore, on the premise that the electric field can be provided, in order not to disturb the color rendering effect of the first electrode 7, the size of the second electrode 8 should be reduced as much as possible, so that the projection area of the second electrode 8 on the first substrate is much smaller than the projection area of the first electrode 7 on the first substrate. As shown in fig. 6, the second electrode 8 is preferably a strip electrode, and the shape processing process is simple. The first electrode 7 is made of a transparent conductive material, such as Indium Tin Oxide (ITO) film.

The electronic ink layer comprises an electrophoretic fluid and charged ink particles 6 in the electrophoretic fluid, which are moved in the electrophoretic fluid by an electric field. All the charged ink particles are the same color, and can be any color, and all the charged ink particles are the same charge, and can be positive or negative.

The electrophoretic display device according to the embodiment of the present invention will be described in detail below, taking as an example that all the charged ink particles 6 are positively charged black ink particles.

In the first embodiment of the present invention, the third electrode 9 may function the same as the first electrode 7 and be disposed in one-to-one correspondence with the first electrode 7, as shown in fig. 7 to 8. For example, when a voltage of 0V is applied to the third electrode 9 and a voltage of-10V to-20V is applied to the second electrode 8, and an electric field is formed therebetween, the positively charged ink particles 6 move toward the second electrode 8, so as to realize a bright state, as shown in FIG. 7. If a dark state is required, only a reverse voltage needs to be applied, as shown in fig. 8, which is not described herein again. The third electrode 9 may be a transparent electrode or a non-transparent electrode, and if the third electrode is a transparent electrode, a reflective layer is required to be disposed, and the contrast between the color of the reflective layer and the color of black is large, so as to display the color of a bright state; if the electrode is a non-transparent electrode, a metal or non-metal electrode having a reflection effect with a large contrast with black may be used, and in this case, the third electrode 9 serves as both an electrode for supplying an electric field and a reflective layer. Since the first electrode 7 and the third electrode 9 are arranged at intervals, color mixing between pixels is not easy to occur. In addition, the same voltage is applied to the first electrode 7 and the third electrode 9, a weak electric field is formed between the extreme edge of the first electrode 7 and the second electrode 8, a small amount of ink particles move between the extreme edge of the first electrode 7 and the second electrode, the motion track of the ink particles is shortened, and the ink particles can be accelerated.

In the second embodiment of the present invention, the third electrode 9 may also have the same function as the second electrode 8 and be disposed in one-to-one correspondence with the second electrode 8, as shown in fig. 9-10. For example, when a voltage of-10V to-20V is applied to the third electrode 9 and a voltage of 0V is applied to the second electrode 8, an electric field is formed between the two, and the positively charged ink particles 6 move toward the third electrode 9 to realize a bright state, as shown in FIG. 9. If a dark state is required, only a reverse voltage needs to be applied, as shown in fig. 10, which is not described herein again. In this configuration, the third electrode 9 is only used to provide an electric field to assist the display, and may be a transparent electrode or a non-transparent electrode. Since the first electrodes 7 and the second electrodes 9 are alternately arranged at intervals, color mixing between pixels is less likely to occur. In addition, the same voltage is applied to the first electrode 7 and the third electrode 9, a weak electric field is formed between the extreme edge of the first electrode 7 and the second electrode 8, a small amount of ink particles move between the extreme edge of the first electrode 7 and the second electrode, the motion track of the ink particles is shortened, and the ink particles can be accelerated.

In a third embodiment of the present invention, as shown in fig. 11, the second electrode layer further includes a plurality of fourth electrodes 10, the plurality of third electrodes 9 and the plurality of fourth electrodes 10 are alternately arranged at intervals, a projection area of the third electrodes 9 on the second substrate is larger than a projection area of the fourth electrodes 10 on the second substrate, the third electrodes 9 are disposed opposite to the first electrodes 7 one by one, and the fourth electrodes 10 are disposed opposite to the second electrodes 8 one by one.

In this structure, the third electrode 9 has the same function as the first electrode 7 and functions as a pixel electrode for displaying pixel colors, and the fourth electrode 10 has the same function as the second electrode 8 and functions to provide an electric field for receiving or releasing the charged ink particles 6 and assist the first electrode 7 and the third electrode 9 in developing colors. One voltage is applied to the first electrode 7 and the third electrode 9, the other voltage is applied to the second electrode 8 and the fourth electrode 10, the two voltages are different, a bidirectional electric field is formed between the two electrode layers, the charged ink particles 6 positioned in the middle select the electrode which is closest to the electrode and opposite to the polarity of the charged ink particles, the electrodes move and finally gather on the transparent first electrode 7 and the transparent third electrode 9 together, so that the first electrode 7 and the third electrode 9 display one color, or gather on the second electrode 8 and the fourth electrode 10 together, so that the first electrode 7 and the third electrode 9 display another color. Because the ink particles can move by selecting the shortest path upwards or downwards, the moving distance is reduced, and the response speed is further improved.

On the premise that the electric field can be provided, the size of the fourth electrode 10 should be reduced as much as possible so that the projection area of the fourth electrode 10 on the second substrate is smaller than that of the third electrode 9 on the second substrate, in order to not interfere with the color development effect of the first electrode 7 and the third electrode 9, as with the second electrode 8. The fourth electrode 10 is the same as the second electrode, preferably a strip electrode, and the shape processing technology is simple. The third electrode 9 may be a transparent electrode or a non-transparent electrode, and if the third electrode is a transparent electrode, a reflective layer is required to be disposed, and the color of the reflective layer has a large contrast with the color of black to display the bright color; if the electrode is a non-transparent electrode, a metal or non-metal electrode having a reflection effect with a large contrast with black may be used, and in this case, the third electrode 9 serves as both an electrode for supplying an electric field and a reflective layer.

For example, as shown in fig. 11, the first substrate is an upper substrate 1, three first electrodes 7 and four second electrodes 8 are alternately disposed at intervals, the second substrate is a lower substrate 2, and three third electrodes 9 and four fourth electrodes 10 are alternately disposed at intervals. The first electrode 7 and the third electrode 9 which are opposite to each other in the upper and lower positions correspond to a pixel unit. The first electrodes 7 are transparent electrodes. If 0V is applied to all three first electrodes 7 and three third electrodes 9, and-10V to-20V is applied to all four second electrodes 8 and four fourth electrodes 10, the positively charged ink particles 6 will move to the second electrode 8 or the fourth electrode 10 nearest to the positively charged ink particles 6, respectively, until all the ink particles 6 are collected on the second electrode 8 and the fourth electrode 10, and at this time, there is no ink particle blocking on the first electrode 7 and the third electrode 9, and all three pixel cells are in a bright state (color of reflective layer), as shown in fig. 12. If a voltage of-10 to-20V is applied to all three first electrodes 7 and three third electrodes 9, and a voltage of 0V is applied to all four second electrodes 8 and four fourth electrodes 10, the positively charged ink particles 6 will move to the first electrode 7 or the third electrode 9 nearest to the positively charged ink particles 6, respectively, until all the ink particles 6 are distributed on the first electrode 7 and the third electrode 9, and no ink particles are on the second electrode 8 and the fourth electrode 10, at which time all three pixel cells are in a dark state (black), as shown in fig. 13. The first electrode 7 or the second electrode 8 on the same substrate can also be applied with different voltages to make the three pixel units display different states, for example, as shown in fig. 14, the left first electrode and the right first electrode of the upper substrate are applied with +10 to +20V voltages, the middle first electrode is applied with-10 to-20V voltages, and the four second electrodes are applied with 0V voltages. The voltage of each electrode of the lower substrate is consistent with the voltage of the corresponding electrode of the upper substrate. At this time, the charged ink particles of the first pixel unit move to the upper and lower second electrodes and the fourth electrode, the charged ink particles of the second pixel unit move to the upper and lower first electrodes and the third electrode, and the charged ink particles of the third pixel unit move to the upper and lower second electrodes and the fourth electrode, so that the bright state, the dark state, and the bright state are sequentially presented from left to right, as shown in fig. 14.

In other exemplary embodiments, the ink particles 6 may also be negatively charged, as long as the positive and negative of the respective electrode voltage values need to be adjusted. Similarly, the ink particles 6 may be of other colors, and may be in two color states different from the color of the reflective layer. The larger the color difference, the more apparent the display contrast. The invention is not particularly limited to the ink particle color and the reflective coating color.

In addition, it is understood by those skilled in the art that the number of the first electrode 7, the second electrode 8, the third electrode 9, and the fourth electrode 10 in this exemplary embodiment is merely an example, and the number of the electrodes may be other in other embodiments. Other voltages can be applied to the electrodes of each pixel unit to form other display states different from the above embodiments, which are not listed here. The magnitude of the voltage is related to the charge-to-mass ratio of the charged ink particles 6, the electrophoretic fluid composition, and the like, and can be adjusted according to specific conditions.

In the present exemplary embodiment, the electrophoretic display device further includes a separately disposed reflective layer 4, as shown in fig. 7 to 14, the reflective layer 4 may be disposed on a side of the second substrate away from the second electrode layer, that is, an outer side of the second substrate, and the reflective layer 4 may be coated with a coating layer having a large color difference from black and a high reflectivity, such as a white, green, or blue lamp. For example, when the second electrode layer includes the third electrode 9 and the fourth electrode 10, when the black ink particles 6 are both located on the second electrode 8 and the fourth electrode 10, the pixel unit may display the color of the reflective layer coating because the first electrode 7 and the third electrode 9 are both transparent electrodes. If the third electrode 9 is an opaque electrode, the color of the third electrode itself affects the reflection effect of the reflective layer 4, and thus the display image quality. Therefore, the third electrode 9 is provided as a transparent electrode, and a display effect can be ensured. When the second electrode layer includes only the third electrode 9 and the third electrode 9 is the same as the first electrode 7, the third electrode 9 has the same effect on the display effect, and thus, a transparent electrode is also preferable. The third electrode 9 can be made of the same material as the first electrode 7, so that the production process is convenient.

In the present exemplary embodiment, at least one of the second electrode 8 and the fourth electrode 10 is a transparent electrode. The second electrode 8 and the fourth electrode 10 are used for providing an electric field to supply the ink particles for electrophoresis, and the transparent conductive material is used for reducing the influence of the second electrode 8 and the fourth electrode 10 on the reflection effect in a bright state while realizing the electrophoresis phenomenon, thereby ensuring the display effect. The second electrode 8 and the fourth electrode 10 can also be made of the same material as the first electrode 7, so that the production and processing are convenient.

In the present exemplary embodiment, the projection of the first electrode 7 on the second substrate coincides with the third electrode 9, and the projection of the second electrode 8 on the second substrate coincides with the fourth electrode 10. Specifically, the shape and size of the first electrode 7 are consistent with those of the third electrode 9, and the shape and size of the second electrode 8 are consistent with those of the fourth electrode 10, so that the ink particles 6 can be uniformly distributed up and down when moving, the display effects of a bright state and a dark state can be consistent, the electric field can be uniformly distributed, and adjacent pixels can be prevented from being influenced by each other.

In the present exemplary embodiment, the width of the stripe-shaped electrode may be designed to be 20 μm or less, which is invisible to the naked eye. The length can be designed to match the dimensions of the first electrode 7 and the third electrode 9. As shown in fig. 6, the first electrode 7 and the third electrode 9 may be both strip-shaped electrodes, as shown in fig. 10 and fig. 14, the width of the first electrode 7 and the third electrode 9 is greater than that of the second electrode 8 and the fourth electrode 10, and the length is designed according to the display requirement of the pixel unit.

Further, in the present exemplary embodiment, the width of the second electrode 8 and the fourth electrode 10 is preferably 2 to 6 μm. If the width is less than 2 μm, it is difficult to store enough charged ink particles, and if the width is more than 6 μm, the color of the stored ink particles affects the reflection effect in the bright state, and the width also affects the sizes of the first electrode 7 and the third electrode 9, thereby affecting the display effect.

Further, in the present exemplary embodiment, the width of the first electrode 7 and the third electrode 9 is preferably 80 to 120 μm. If the width is less than 80 μm, the display effect of the pixel unit is affected, and the display is not clear. If the width is larger than 120 μm, the cost is increased.

Further, in the present exemplary embodiment, as shown in fig. 6 to 9, a first gap is provided between the adjacent first electrode 7 and the second electrode 8, a second gap is provided between the adjacent third electrode 9 and the fourth electrode 10, and the widths of the first gap and the second gap are equal, that is, the second electrode 8 is located at the middle position of the two first electrodes 7, and the fourth electrode 10 is located at the middle position of the two third electrodes 9, so as to ensure that the charged ink particles can move uniformly to the left and right two pixel regions, and prevent display unevenness. The width of the first gap and the second gap is preferably 4 to 8 μm. If the gap is less than 4 μm, the process requirement is high, which increases the process cost. If the gap is larger than 4 μm, the reflection effect of the bright state is affected, and the display effect is further affected.

In the above embodiments, the first substrate is used as the upper substrate and the second substrate is used as the lower substrate, in other embodiments, the first substrate may be used as the lower substrate and the second substrate as the upper substrate, and the principle of the arrangement of the electrodes is the same, which is not described herein again.

A method of manufacturing an electrophoretic display device of the present invention is explained below:

a first electrode layer is formed on the first substrate, and the first electrode layer may be formed by a process such as photolithography or sputtering. If the same material is used for the first electrode 7 and the second electrode 8, this can be done in one step. Similarly, the second electrode layer may be formed on the second substrate by a photolithography or sputtering process. When the second electrode layer includes the third electrode 9 and the fourth electrode 10, the same material may be used for the third electrode 9 and the fourth electrode 10, which is convenient for one-step completion.

Then, an electronic ink layer is formed on the electrode layer of one of the substrates by a dropping process.

And finally, arranging the first substrate and the second substrate in a box-to-box manner so that the electronic ink layer is positioned between the first electrode layer and the second electrode layer.

The above method is only one manufacturing method of the electrophoretic display device of the present invention, and those skilled in the art can manufacture the electrophoretic display device by various processes, for example, after two substrates are aligned with each other, electronic ink can be filled into the box body by a filling method to form an electronic ink layer. The present invention is not particularly limited thereto.

The embodiment of the invention also provides a driving method of the electrophoretic display device, which is used for driving the electrophoretic display device, and the driving method is different according to the structure of the electrophoretic display device.

When the structure of the electrophoretic display device is as shown in fig. 7-8, the second electrode layer only includes the third electrode 9, and the third electrode 9 has the same action with the first electrode 7 and is disposed in one-to-one correspondence with the first electrode 7, the driving method includes:

applying a first voltage to the first electrode 7 and the third electrode 9, applying a second voltage to the second electrode 8, the first voltage being different from the second voltage, such that the charged ink particles 6 of the electronic ink layer are collected on the first electrode 7 and the third electrode 9 (mostly on the third electrode 9), such that the first electrode 7 and the third electrode 9 show the first state;

a third voltage is applied to the first electrode 7 and the third electrode 9, and a fourth voltage is applied to the second electrode 8, the third voltage being different from the fourth voltage, so that the charged ink particles 6 of the electronic ink layer are gathered on the second electrode 8, and a second state is displayed with the first electrode 7 and the third electrode 9.

When the structure of the electrophoretic display device is as shown in fig. 9-10, the second electrode layer only includes the third electrode 9, and the third electrode 9 has the same action with the second electrode 8 and is disposed in one-to-one correspondence with the second electrode 8, the driving method includes:

applying a first voltage to the first electrode 7, applying a second voltage to the second electrode 8 and the third electrode 9, the first voltage being different from the second voltage, such that the charged ink particles 6 of the electronic ink layer are collected on the second electrode 8 and the third electrode 9 (mostly on the third electrode 9), such that the first electrode 7 shows a first state;

a third voltage is applied to the first electrode 7 and a fourth voltage, different from the fourth voltage, is applied to the second electrode 8 and the third electrode 9 to cause the charged ink particles 6 of the electronic ink layer to collect on the first electrode 7 to cause the first electrode 7 to display the second state.

When the structure of the electrophoretic display device is as shown in fig. 10-14, that is, the second electrode layer further includes a plurality of fourth electrodes 10, the plurality of third electrodes 9 and the plurality of fourth electrodes 10 are alternately arranged at intervals, the projection area of the third electrodes 9 on the second substrate is larger than the projection area of the fourth electrodes 10 on the second substrate, the third electrodes 9 and the first electrodes 7 are arranged in a one-to-one manner, and the fourth electrodes 10 and the second electrodes 8 are arranged in a one-to-one manner. At this time, the driving method includes:

applying a first voltage to the first electrode 7 and the third electrode 9, and applying a second voltage to the second electrode 8 and the fourth electrode 10, the first voltage being different from the second voltage, to cause the charged ink particles 6 of the electronic ink layer to collect on the first electrode 7 and the third electrode 9, so that the first electrode 7 and the third electrode 9 show a first state;

a third voltage, which is different from the fourth voltage, is applied to the first electrode 7 and the third electrode 9, and a fourth voltage, which is different from the fourth voltage, is applied to the second electrode 8 and the fourth electrode 10, so that the charged ink particles 6 of the electronic ink layer are collected on the second electrode 8 and the fourth electrode 10, so that the first electrode 7 and the third electrode 9 show a second state.

The detailed description of the driving method refers to the related description of the electrophoretic display device. Taking the driving of the electrophoretic display device as an example, here the first state represents a dark state and the second state represents a bright state. For example, to make the three pixel cells of fig. 14 sequentially appear bright state, dark state, and bright state from left to right, a first voltage +10 to +20V and a second voltage 0V may be applied to the first pixel cell on the left side; the middle second pixel unit applies a third voltage of-10V to-20V and a fourth voltage of 0V; the third pixel unit on the right applies the first voltage +10 to +20V and the second voltage 0V. If the three pixel units sequentially show a dark state, a bright state and a dark state from left to right, a third voltage of-10V to-20V and a fourth voltage of 0V can be applied to the first pixel unit on the left side; the middle second pixel unit applies a first voltage of +10 to +20V and a second voltage of 0V; the third pixel unit on the right applies a third voltage of-10V to-20V and a fourth voltage of 0V.

In other embodiments, the first state and the second state may be interchanged. The voltage values of the first voltage and the second voltage may be set according to the charge condition of the ink particles. In addition, when different pixel units exhibit the same display state, the corresponding voltage values may be the same or different, for example, two pixel units exhibit bright states, where the first voltage of one pixel unit may be set to +10 to +20V, the second voltage may be set to 0V, the first voltage of the other pixel unit may be set to 0V, and the second voltage may be set to-10 to-20V. The first voltage of the two pixel units can be set to +10 to +20V, and the second voltage can be set to 0V. The specific setting is convenient to control. The present invention is not particularly limited thereto.

The embodiment of the invention also provides an electrophoretic display device which comprises the electrophoretic display device. The display device can be used for displays of various electronic devices such as mobile phones, computers, electronic books, electronic price tags, billboards and the like. The display device has clear picture quality of a display picture, high response speed and low power consumption.

Although relative terms, such as "upper" and "lower," may be used herein to describe one element of an icon relative to another, such terms are used herein for convenience only, e.g., with reference to the orientation of the example illustrated in the drawings. It will be appreciated that if the device of the icon were turned upside down, the element described as "upper" would become the element "lower". When a structure is "on" another structure, it may mean that the structure is integrally formed with the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via another structure.

The terms "a," "an," "the," "said," and "at least one" are used to indicate the presence of one or more elements/components/parts/etc.; the terms "comprising" and "having" are intended to be inclusive and mean that there may be additional elements/components/etc. other than the listed elements/components/etc.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

Claims

1. An electrophoretic display device, comprising:

a first substrate;

a second substrate disposed opposite to the first substrate;

an electronic ink layer between the first electrode layer and the second electrode layer;

the second electrode layer further comprises a plurality of fourth electrodes, the plurality of third electrodes and the plurality of fourth electrodes are alternately arranged at intervals, the projection area of the third electrodes on the second substrate is larger than that of the fourth electrodes on the second substrate, the third electrodes and the first electrodes are arranged in a one-to-one opposite mode, and the fourth electrodes and the second electrodes are arranged in a one-to-one opposite mode;

the projection of the first electrode on the second substrate coincides with the third electrode, and the projection of the second electrode on the second substrate coincides with the fourth electrode.

2. Electrophoretic display device according to claim 1, wherein the third electrode is a transparent electrode; the electrophoretic display device further includes:

and the reflecting layer is arranged on one side of the second substrate, which is far away from the second electrode layer.

3. Electrophoretic display device according to claim 1, wherein at least one of the second and fourth electrodes is a transparent electrode.

4. Electrophoretic display device according to claim 1, wherein the second and fourth electrodes are stripe electrodes.

5. The electrophoretic display device according to claim 4, wherein the second electrode and the fourth electrode have a width of 2 to 6 μm.

6. An electrophoretic display device as claimed in claim 4, wherein the width of the first and third electrodes is 80-120 μm.

7. The electrophoretic display device according to claim 4, wherein a first gap is formed between the adjacent first and second electrodes, a second gap is formed between the adjacent third and fourth electrodes, and the width of the first and second gaps is 4-8 μm.

8. An electrophoretic display device comprising the electrophoretic display device according to any one of claims 1 to 7.

9. A driving method of an electrophoretic display device for driving the electrophoretic display device according to any one of claims 1 to 7, the driving method comprising:

10. The driving method of an electrophoretic display device according to claim 9, wherein the electrophoretic display device further comprises a plurality of fourth electrodes, the plurality of third electrodes and the plurality of fourth electrodes are alternately arranged at intervals, a projected area of the third electrodes on the second substrate is larger than a projected area of the fourth electrodes on the second substrate, the third electrodes are arranged opposite to the first electrodes, and the fourth electrodes are arranged opposite to the second electrodes; the driving method includes: