The disclosure relates to the field of display technology, in particular to an electronic paper display device and a driving method therefor.
Electronic paper display devices have attracted widespread attention due to their eye protection and low power consumption.
The electronic paper display device includes multiple micro-cups. Each micro-cup is encapsulated with electrophoretic particles of different colors. The multiple micro-cups are controlled to display different colors by controlling electrodes located on both sides of the micro-cup to generate vertical electric fields, thus achieving display. However, in the electronic paper display device of the prior art, the micro-cup can display a certain color only when the electrophoretic particles in the micro-cup of the certain color move to a display side, but cannot display colors other than the color of electrophoretic particles.
Embodiments of the disclosure provide an electronic paper display device. The electronic paper display device includes: a first base substrate and a plurality of sub-pixels arranged in an array on a side of the first base substrate. Each of the plurality of sub-pixels includes: a first electrode on the side of the first base substrate; a second electrode, on a side of the first electrode facing away from the first base substrate, where the second electrode includes a plurality of grooves passing through the second electrode along a thickness direction of the second electrode; orthographic projections of the plurality of grooves fall within an orthographic projection of the first electrode on the first base substrate; a microstructure, on a side of the second electrode facing away from the first base substrate, where the microstructure includes: a paper film micro-cavity, and a plurality of charged particles in the paper film micro-cavity; the plurality of charged particles include: a plurality of first color charged particles and a plurality of second color charged particles, where an electrical property of the first color charged particle is opposite to an electrical property of the second color charged particle; and a third electrode, on a side of the microstructure facing away from the second electrode.
In some embodiments, the microstructure further includes: transparent electrophoretic liquid in the paper film micro-cavity. The first electrode, the second electrode and the third electrode are light-transmitting electrodes.
In some embodiments, the plurality of charged particles further include: a plurality of third color charged particles in the paper film micro-cavity. An electrical property of the third color charged particles are same as the electrical property of the first color charged particle; and a charge to mass ratio of the first color charged particle is greater than a charge to mass ratio of the third color charged particle.
In some embodiments, the electronic paper display device further includes: a reflective layer on a side of the first base substrate facing away from the first electrode; and a color of the reflective layer is different from colors of all charged particles.
In some embodiments, in each of the second electrodes, the plurality of grooves extend along a first direction and are arranged along a second direction, or the plurality of grooves extend along a second direction and are arranged along a first direction. Here the first direction intersects the second direction.
In some embodiments, a shape of an orthographic projection of each of the plurality of grooves on the first base substrate is a stripe or a polygonal line.
In some embodiments, at least part of the plurality of grooves each includes: a first portion extending along a first direction; and a second portion extending along a second direction and connecting with the first portion.
In some embodiments, an orthogonal projection of the groove on the first base substrate is an arc. At least part of different grooves corresponds to different arc shapes with different radii; and centers of the arc shapes corresponding to the at least part of different grooves coincide with each other.
In some embodiments, an orthogonal projection of the groove on the first base substrate is a portion of an outline of a polygon. At least part of different grooves correspond to similar polygons, and centers of the polygons corresponding to the at least part of different grooves coincide with each other.
In some embodiments, the electronic paper display device further includes: a plurality of first scanning lines and a plurality of data lines crossing horizontally and vertically, a plurality of first signal lines, and a plurality of thin film transistors. The plurality of first scanning lines and a plurality of data lines divide areas where the plurality of sub-pixels are located; the plurality of thin film transistors are arranged one-to-one corresponding to the plurality of sub-pixels. The first scanning line is electrically connected with a gate electrode of the thin film transistor, the first signal line is electrically connected with the first electrode, the data line is electrically connected with a source electrode of the thin film transistor, and the second electrode is electrically connected with a drain electrode of the thin film transistor.
In some embodiments, the plurality of first scanning lines, the plurality of first signal lines and gate electrodes of the plurality of thin film transistors are formed of a same material and formed in a same process. The plurality of first scanning lines, the gate electrodes of the plurality of thin film transistors and the first electrode are arranged on a same side of a same film layer. The plurality of first signal lines are connected with the first electrode on the side of the first electrode facing away from the first base substrate; the plurality of data lines and source electrodes and drain electrodes of the plurality of thin film transistors are arranged in a same layer; and the plurality of data lines and source electrodes and drain electrodes of the plurality of thin film transistors are arranged between a layer where the plurality of first scanning lines are located and a layer where the second electrode is located.
In some embodiments, the plurality of first scanning lines and the plurality of first signal lines are alternately arranged.
In some embodiments, an orthographic projection of the thin film transistor on the first base substrate and the orthographic projection of the first electrode on the first base substrate do not overlap each other.
Embodiments of the disclosure provide a driving method for an electronic paper display device, including: determining a sub-pixel with a microstructure in a transparent state according to an image to be displayed; in a writing stage, providing driving signals to the first electrode, the second electrode, and the third electrode in the sub-pixel with the microstructure in the transparent state to drive a plurality of charged particles of different electrical properties sequentially to approach a bottom of a paper film micro-cavity, and drive charged particles near the bottom of the paper film micro-cavity to side walls of the paper film micro-cavity.
In some embodiments, in the writing stage, providing driving signals to the first electrode, the second electrode, and the third electrode in the sub-pixel with the microstructure in the transparent state to drive the plurality of charged particles of different electrical properties sequentially to approach the bottom of the paper film micro-cavity, and drive charged particles near the bottom of the paper film micro-cavity to the side walls of the paper film micro-cavity, includes:
In some embodiments, the microstructure further includes a plurality of third color charged particles;
In order to more clearly illustrate the technical solutions in embodiments of the disclosure, a brief introduction will be given below to the drawings needed to be used in the description of embodiments. Obviously, the drawings in the following description are only some embodiments of the disclosure. Those of ordinary skill in the art can also obtain other drawings based on these drawings without exerting creative efforts.
In order to make the purpose, technical solutions and advantages of embodiments of the disclosure more clear, the technical solutions of the embodiments of the disclosure will be clearly and completely described below in conjunction with the drawings of embodiments of the disclosure. Obviously, the described embodiments are some, but not all, of the embodiments of the disclosure. And the embodiments and features in the embodiments of the disclosure may be combined with each other without conflict. Based on the described embodiments of the disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of the disclosure.
Unless otherwise defined, technical terms or scientific terms used in this disclosure shall have the usual meaning understood by a person with ordinary skill in the art to which this disclosure belongs. Words such as “First”, “second” used in the disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as “including” or “comprising” refer to the components or objects that appear before the word, including those listed after the word and their equivalents, without excluding other components or objects. Words such as “connected” or “connecting” are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.
It should be noted that the sizes and shapes of the figures in the drawings do not reflect true proportions and are only intended to illustrate the disclosure. And the same or similar reference numbers throughout represent the same or similar elements or elements with the same or similar functions.
An embodiment of the disclosure provides an electronic paper display device. As shown in
In the electronic paper display device provided by the embodiment of the disclosure, the second electrode includes a plurality of grooves passing through the second electrode along a thickness direction of the second electrode. Voltages are applied to the first electrode and the second electrode, and a curved electric field can be formed between the second electrode and the first electrode. The curved electric field has a parallel component parallel to a plane where the electronic paper display device is located. The parallel component of the electric field is perpendicular to a side wall of the paper film micro-cavity. Therefore, under the action of the parallel component, the charged particles in the paper film micro-cavity move close to the side wall of the paper film micro-cavity under the action of the electric field. The charged particles close to the side wall of the paper film micro-cavity are invisible relative to a light-emitting side of the electronic paper display device, which can make the microstructure transparent. That is, the microstructures can show optical states beyond the color of charged particles, thereby enriching the optical effects of electronic paper display devices and enhancing user experience.
It should be noted that reference symbol “a” in
It should be noted that, as shown in
It should be noted that in the electronic paper display device provided by the embodiments of the disclosure, a vertical electric field perpendicular to the first base substrate is formed between the second electrode and the third electrode. The vertical electric field can drive the charged particles to move in a direction perpendicular to the first substrate. That is, the charged particles can be driven to move towards the display side of the electronic paper display device, or move towards a side away from the display side of the electronic paper display device. When the first color charged particles approach the display side, the microstructure displays the first color. When the second color charged particles approach the display side, then the microstructure displays the second color. That is, the microstructure can present at least three optical states: a first color state, a second color state and a transparent state.
In some embodiments, the third electrodes in the plurality of sub-pixels are integrally connected. That is, the third electrode is a planar electrode covering multiple sub-pixel areas. In this case, the voltage signals applied to the third electrodes included in the plurality of sub-pixels are the same.
Of course, in some embodiments, the third electrodes in multiple sub-pixels may not be connected with each other. In this case, the voltage signals applied to the third electrodes in the plurality of sub-pixels may be the same or different.
In some embodiments, the microstructure further includes: transparent electrophoretic liquid in the paper film micro-cavity; and the first electrode, the second electrode and the third electrode are light-transmitting electrodes. Thus, the transparent state of microstructure can be achieved.
In some embodiments, a material of the first electrode, the second electrode, and the third electrode includes indium tin oxide (ITO).
In some embodiments, as shown in
In some embodiments, the first color charged particles are black charged particles, and the second color charged particles are white charged particles.
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, the first color charged particles are black charged particles, the second color charged particles are white charged particles, and the third color charged particles are colored charged particles.
In some embodiments, the colored charged particles are red charged particles or yellow charged particles.
In some embodiments, as shown in
That is, when the microstructure shows the transparent state, the sub-pixels corresponding to the microstructure shows the color of the reflective layer. This can increase the color types that can be presented by sub-pixels without increasing the types of charged particle colors, and avoid an increase in the difficulty of driving charged particles.
It should be noted that
In some embodiments, the color of the reflective layer is green. That is, the reflective layer shows green when exposed to external light. Of course, in some embodiments, the color of the reflective layer can be set according to actual needs.
In some embodiments, the reflective layers corresponding to different sub-pixels have the same color. That is, a reflective layer covers the entire surface of the side of the first base substrate facing away from the first electrode, thereby simplifying the process.
Of course, in some embodiments, the colors of the reflective layers corresponding to different sub-pixels are not completely the same. For example, the color of the reflective layer corresponding to a part of sub-pixels is a fourth color, and the color of the reflective layer corresponding to at least a part of sub-pixels among the remaining sub-pixels is a fifth color. As a result, the color types that can be displayed by the sub-pixels of the electronic paper display device can be further increased, and the display effect can be further improved.
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, when the scan signal from the first scan signal line controls the thin film transistor to turn on, the drive signal from data line data is provided to the second electrode through the thin film transistor, so that a voltage signal is provided to the second electrode. The signal from the first signal line is provided to the first electrode as a voltage signal.
It should be noted that, in addition to the first electrode and the second electrode forming an electric field having a horizontal component, the first electrode and the second electrode can form a storage capacitor due to the potential of the first electrode. As such, during the refresh scan gap in which the thin film transistor is turned off and the second electrode cannot be provided with a voltage through the data line, the storage capacitor formed by the first electrode and the second electrode can discharge to maintain the potential of the second electrode within one frame.
In some embodiments, as shown in
In some embodiments, the plurality of first scanning lines, the plurality of first signal lines and the plurality of gate electrodes are formed in a same patterning process. For example, a first conductive layer covering the first base substrate and the first electrode is formed, and a patterning process is performed on the first conductive layer to form patterns of the plurality of first scanning lines, the plurality of first signal lines and the plurality of gate electrodes.
It should be noted that,
In some embodiments, as shown in
It should be noted that,
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, the first signal line is in contact with the first electrode, so the first signal line overlaps with the opening area of the sub-pixel.
In some embodiments, as shown in
In some embodiments, as shown in
It should be noted that, as shown in
In some embodiments, the plurality of grooves are all equal in width, and the distance between any adjacent grooves is equal.
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, a width of the first portion is equal to a width of the second portion, and the width of the first portion is equal to a width of the strip-shaped groove extending along the first direction, and the width of the second portion is equal to a width of the strip-shaped groove extending along the second direction.
In some embodiments, as shown in
In some embodiments, as shown in
Of course, in some embodiments, there are some grooves corresponding to arc shapes with the same radius.
In some embodiments, the widths of the plurality of grooves are equal along the extending direction of the radius of the arc shape. Among multiple grooves corresponding to arc shapes with different radii, the distance between any two adjacent grooves is equal.
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, the second base substrate may be a flexible substrate. For example, the material of the second base substrate includes polyethylene glycol terephthalate (PET).
In some embodiments, as shown in
Based on the same inventive concept, embodiments of the disclosure also provide a method for driving the above-mentioned electronic paper display device, as shown in
Based on the method for driving the electronic paper display device provided by embodiments of the disclosure, drive charged particles of different electrical properties can be sequentially driven to approach the bottom of the paper film micro-cavity, and then the charged particles closer to the bottom of the paper film micro-cavity can be driven to the side walls of the paper film micro-cavity by providing driving signals to the first electrode, the second electrode, and the third electrode. Thus, the charged particles close to the side walls of the paper film micro-cavity are invisible relative to the display side of the electronic paper display device, which can make the microstructure transparent, enrich the optical effects of electronic paper display devices and improve user experience.
In some embodiments, in the writing stage, providing driving signals to the first electrode, the second electrode, and the third electrode in the sub-pixel with the microstructures in the transparent state to drive charged particles of different electrical properties sequentially to approach a bottom of a paper film micro-cavity, and drive charged particles near the bottom of the paper film micro-cavity to side walls of the paper film micro-cavity, includes:
After the first writing stage to the fourth writing stage, the first color charged particles and the second color charged particles a are both driven to the sidewall of the paper film micro-cavity under the action of a horizontal electric field, making the microstructure transparent.
It should be noted that, the curvilinear electric field formed between the first electrode and the second electrode has a small range of action, and the film thickness of the under the action of the electric field with the horizontal component is about 2 microns, which is smaller than the vertical thickness of the paper film micro-cavity. Therefore, the electric field with a horizontal component is not sufficient to affect the charged particles at the top of the paper film micro-cavity (i.e. the display side), thus it is necessary to drive the charged particles to approach the bottom of the paper film micro-cavity. In the first writing stage, an electric field is formed between the third electrode and the second electrode in a direction perpendicular to the base substrate. Due to the opposite electrical properties of the first color charged particle and the second color charged particle, the first color charged particle moves towards the display side, while the second color charged particle moves away from the display side, that is, the second color charged particle moves towards the bottom of the paper film micro-cavity. The second colored charged particles are laid flat on the bottom of the paper film micro-cavity, so that during the second writing stage, the second colored charged particles are driven to approach the side walls of the paper film micro-cavity. In the third writing stage, the second colored charged particle are still driven to the side wall of the paper film micro-cavity and moves towards the display side, while the first colored charged particle moves to a side facing away from the display side, that is, the first colored charged particle is driven to move towards the bottom of the paper film micro-cavity. In this case, the first colored charged particles are laid flat at the bottom of the paper film micro-cavity, so that in the fourth writing stage, the first colored charged particles are driven to approach the side walls of the paper film micro-cavity.
In some embodiments, the voltage values of the second level signal and the third level signal are equal. In some embodiments, the voltage values of the second level signal and the third level signal are greater than or equal to −2 V and less than or equal to 0 V. In some embodiments, as shown in
In some embodiments, during the first writing stage, a zero-voltage signal may be provided to the first electrode, while a first level signal is provided to the second electrode, and a zero-voltage signal is provided to the third electrode.
In some embodiments, as shown in
In some embodiments, during the first writing stage and the third writing stage, a zero-voltage signal may be provided to the first electrode, or no driving signal may be provided to the first electrode. Providing a driving signal to the first electrode will not affect the main action result of the vertical electric field formed by the second electrode and the third electrode. Although local charged particles on the bottom of the paper film micro-cavity may be pushed to side walls, the electric field for pushing to side walls is weaker compared with the vertical electric field. In response to the electric field, the charged particles will move out of the coverage range of the horizontal component electric field away from the bottom of the paper film micro-cavity in the vertical direction. Therefore, the charged particles can be normally laid flat on the display side to display the first or second color.
It should be noted that, the second colored charged particles that have been pushed to the side wall in the third writing stage can move vertically to the display side, because the second colored charged particles have been aggregated on the side wall of the paper film micro-cavity in the second writing stage. Therefore, during the upward movement in the third writing stage, the aggregation state of the second colored charged particles on the side wall will not be broken.
It should be noted that “O” in
It should be noted that, in
In some embodiments, the electrical properties of the first level signal and the sixth level signal are the same as the electrical properties of the first color charged particles, and the absolute value of the voltage of the first level signal is greater than the absolute value of the voltage of the sixth level signal.
The electrical properties of the fourth level signal and the fifth level signal are the same as the electrical properties of the second color charged particles, and the absolute value of the voltage of the fifth level signal is greater than the absolute value of the voltage of the fourth level signal.
The absolute voltage value of the first level signal is equal to the absolute voltage value of the fifth level signal, and the absolute voltage value of the fourth level signal is equal to the absolute voltage value of the sixth level signal.
In some embodiments, the absolute value of the voltage of the sixth level signal is smaller than the absolute value of the voltage of the first level signal and the absolute value of the fifth level signal. That is, compared with driving the charged particles to the display side, a voltage with the smaller amplitude can be used to drive the charged particles to the side walls of the paper membrane micro-cavity, which can save power consumption.
In some embodiments, the first level signal is 15 V, the fourth level signal is −5 V, the fifth level signal is −15 V, and the sixth level signal is 5 V.
In some embodiments, based on the image to be displayed, for a sub-pixel for displaying a first color, during the writing stage, a zero-voltage signal is provided to the third electrode, and a first level signal is provided to the second electrode. Based on the image to be displayed, for a sub-pixel for displaying a second color, during the writing stage, a zero-voltage signal is provided to the third electrode and a fifth level signal is provided to the second electrode.
In some embodiments, as shown in
In the first writing stage, while providing the first level signal to the second electrode, and providing the second level signal to the third electrode to drive the first color charged particles to approach the display side of the electronic paper display device, the method further includes:
That is, as shown in
In some embodiments, as shown in
In some embodiments, the electrical properties of the first level signal, the sixth level signal and the eighth level signal are the same as the electrical properties of the first color charged particles. The absolute value of the voltage of the first level signal is greater than the absolute value of the voltage of the sixth level signal. The absolute value of the voltage of the sixth level signal is greater than the absolute value of the voltage of the eighth level signal.
The electrical properties of the fourth level signal, the fifth level signal and the seventh level signal are the same as the electrical properties of the second color charged particles. The absolute value of the voltage of the fifth level signal is equal to the absolute value of the voltage of the seventh level signal. The absolute value of the voltage of the fifth level signal is greater than the absolute value of the voltage of the fourth level signal.
The absolute value of the voltage of the first level signal is equal to the absolute value of the voltage of the fifth level signal, and the absolute value of the voltage of the fourth level signal is smaller than the absolute value of the voltage of the eighth level signal.
In some embodiments, taking the refresh frequency as 20 HZ as an example, the T1-1 sub-stage lasts for 8 to 10 frames, and the T1-2 sub-stage includes multiple cycles in each of which the seventh level signal V5 lasts for 1 frame in each cycle, the eighth level signal V6 lasts for 20 frames, and after the multiple cycles, the third color charged particles are driven to the display side. It should be noted that, in the process of driving the third color charged particles to the display side, since the first color charged particles and the third color charged particles have the same electrical properties and the charge-to-mass ratio of the first color charged particles is greater than the charge-to-mass ratio of the third color charged particles, the driving voltage of the third color charged particles is smaller than the driving voltage of the first color charged particles. The eighth-level signal directly provided to the second electrode cannot drive the third color charged particles to the display side. Thus it is necessary to first make the first colored charged particles and the third colored charged particles to be layered by moving toward different directions. When the seventh level signal is provided to the second electrode, the movement speed of the first colored charged particle is greater than that of the third colored charged particle. That is, the first colored charged particle moves a greater distance away from the display side, and then provides the eighth level signal to the second electrode to ensure that the third colored charged particle is driven to the display side.
In some embodiments, the first level signal is 15 V, the fourth level signal is −5 V, the fifth level signal is −15 V, the sixth level signal is 10 V, the seventh level signal is −15 V, and the eight-level signal is 6 V.
It should be noted that, in order to ensure that both the first charged particles and the third charged particles can be driven to the side wall of the paper film micro-cavity in the fourth writing stage, it is necessary to increase the voltage value of the sixth level signal compared with a case that the paper film micro-cavity includes the two kinds of particles which are the first color charged particles and the second color charged particles.
In some embodiments, based on the image to be displayed, for a sub-pixel for displaying the third color, during the writing stage, a zero-voltage signal is provided to the third electrode, and a driving signal is provided to the second electrode. Where the driving signal provided to the second electrode includes multiple pulse units and the zero-voltage signal between the pulse units. The pulse unit includes an eighth level signal and a seventh level signal applied sequentially.
In some embodiments, before the writing stage, the method further includes: a reverse stage and a dithering stage;
In some embodiments, in the reverse stage, the second electrode is usually written with a voltage that is opposite to the driving voltage of the color to be displayed, to balance the charge of charged particles, preventing polarization of charged particles, avoiding built-in electric fields, and thus avoiding a ghosting problem. In the dithering stage, positive and negative high levels are usually applied alternately to the second electrode for multiple frames and periods to fully mix the charged particles. That is, the dithering stage can have an erasing effect. Continuous multi-frame high-level dithering refreshes the electric field, which will arouse an imbalance in the built-in electric field of the particles in the micro-cup. Therefore, the particles close to the side wall of the paper film micro-cavity will gradually break the balance and move to other areas of the paper film micro-cavity, so that they can be in a flat state during the subsequent writing stages.
The display device provided by embodiments of the disclosure is: a mobile phone, a tablet computer, a television, a monitor, a notebook computer, a digital photo frame, a navigator, or any other product or component with a display function. Other essential components of the display device are understood by those of ordinary skill in the art, and will not be described in detail here, nor should they be used to limit the disclosure. For the implementation of the display device, reference can be made to the above embodiments of the display panel, and repeated details will not be described again.
To sum up, in the electronic paper display device and a driving method therefor provided by embodiments of the disclosure, the second electrode includes a plurality of grooves passing through the second electrode along a thickness direction of the second electrode. Voltages are applied to the first electrode and the second electrode, and a curved electric field can be formed between the second electrode and the first electrode. The curved electric field has a parallel component parallel to the plane where the electronic paper display device is located. The parallel component of the electric field is perpendicular to the side wall of the paper film micro-cavity. Therefore, under the action of the parallel component, the charged particles in the paper film micro-cavity approach the side wall of the paper film micro-cavity under the action of the electric field. The charged particles close to the side wall of the paper film micro-cavity are invisible relative to the light-emitting side of the electronic paper display device, which can make the microstructure transparent. That is, the microstructures can present optical states beyond the color of charged particles, enriching the optical effects of electronic paper display devices and enhancing user experience.
Although the preferred embodiments of the disclosure have been described, those skilled in the art will be able to make additional changes and modifications to these embodiments once the basic inventive concepts are apparent. Therefore, it is intended that the appended claims be construed to include the preferred embodiments and all changes and modifications that fall within the scope of the disclosure.
Evidently those skilled in the art can make various modifications and variations to the disclosure without departing from the spirit and scope of the disclosure. Thus the disclosure is also intended to encompass these modifications and variations therein as long as these modifications and variations to the disclosure come into the scope of the claims of the disclosure and their equivalents.
Filing Document | Filing Date | Country | Kind |
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PCT/CN2021/132588 | 11/23/2021 | WO |