Electronic paper display panel and application and driving method thereof

Abstract

The invention discloses an electronic paper display panel and an application and driving method thereof. The electronic paper display panel comprises an electrowetting display layer, a transparent driving backboard layer and an electrophoretic display layer which are sequentially arranged in an overlapped mode. The electrowetting display layer comprises first color electrowetting ink; the electrophoretic display layer comprises electrophoretic ink; the electrophoretic ink comprises second color electrophoretic particles and third color electrophoretic particles; and the polarities of charges carried by the second color electrophoretic particles and the third color electrophoretic particles are opposite. According to the electronic paper display panel and the application and driving method thereof, the electronic paper display panel is of a double-layer display structure, and three-primary-color full-color display can be achieved after the electronic paper display panel and the double-layer display structure are combined.

Description

Technical Field

[0001] The present invention relates to the field of displays, and more particularly, to an electronic paper display panel, its applications, and driving methods. Background Art

[0002] As a new type of display technology, electrowetting display technology has become one of the potential display technologies due to its advantages of low power consumption and high contrast. Its principle is mainly to apply an external voltage between two electrodes, which changes the hydrophobicity of the hydrophobic insulating layer, resulting in a change in the tension between water, oil, and the pixel wall, pushing the ink to the small corners of the pixel grid, allowing light to pass through this area, revealing the white substrate, and achieving the purpose of display. On the other hand, with the development of optoelectronic display technology and semiconductor manufacturing technology, thin-film transistor (TFT) displays have become increasingly mature. Electronic paper displays with TFTs and electrophoretic particles are more energy-efficient and eye-friendly, and are increasingly favored by the market. To achieve color display, currently, mainly by adding color filters in a single-layer structure. Compared with the three-layer stacked structure, the single-layer structure requires the use of RGB color filters. Since part of the light is absorbed when passing through the color filters, the display effect is low. While the three-layer structure does not require additional color filters, the overall reflectivity and color saturation are relatively high. And the color display of the three-layer structure can be achieved by controlling the voltage of each layer to control the on / off of the pixels, and full-color display can be easily realized. However, currently, for three-layer stacked color display devices, traditional electrowetting displays and electrophoretic display devices can only quickly switch between two display states. Therefore, electrowetting display achieves full-color display through three display superpositions, but the three display layers have high complexity, high cost, and extremely poor viewing angles for multiple layers. For color electrophoretic display, multiple color particles are often mixed and driven. Since there are only two polarities, positive and negative, complex driving waveforms are required for more than two charged particles, and it often takes several seconds or more than ten seconds to distinguish three or more particles to achieve color display, and dynamic picture display cannot be performed. Summary of the Invention

[0003] The present invention aims to solve the above technical problems existing in the prior art. For this purpose, the present invention provides an electronic paper display panel, its applications, and driving methods. The electronic paper display panel has a double-layer display structure, and full-color display of the three primary colors can be achieved after combination.

[0004] According to one aspect of the present invention, an electronic paper display panel is provided, including: an electrowetting display layer, a transparent driving backplane layer, and an electrophoretic display layer that are sequentially stacked;

[0005] The electrowetting display layer includes a first-color electrowetting ink;

[0006] The electrophoretic display layer includes electrophoretic ink;

[0007] The electrophoretic ink includes positively charged second-color electrophoretic particles and negatively charged third-color electrophoretic particles.

[0008] According to an embodiment of the first aspect of the present invention, it has at least the following beneficial effects:

[0009] By combining electro-wetting display and electrophoretic display technologies, the present invention realizes the rapid switching of three different colors of display. Compared with traditional electrophoretic displays, the structure of the electronic paper display panel of the present invention significantly improves the response speed of the third-color display, avoids the delay problem of traditional electrophoretic displays when displaying multiple colors, enables the display structure to maintain efficient and smooth color conversion in dynamic pictures, and has a broader application prospect. Since the oil film of the upper electro-wetting display layer can effectively block the lower electrophoretic display layer, reducing light loss and enhancing the display brightness. At the same time, the electrophoretic display layer can precisely adjust the saturation and contrast of the displayed color by controlling the distribution of positively and negatively charged particles, thereby improving the overall display effect.

[0010] In some embodiments of the present invention, thin-film transistors are provided on the surface of the transparent driving backplane in contact with the electro-wetting display layer.

[0011] In some embodiments of the present invention, a fluoride coating is coated on the thin-film transistors.

[0012] In some embodiments of the present invention, the thickness of the coating is 0.5 - 2 μm.

[0013] In some embodiments of the present invention, a transparent conductive layer is provided on the surface of the transparent driving backplane in contact with the electrophoretic display layer.

[0014] In some embodiments of the present invention, the transparent conductive layer includes ITO conductive glass.

[0015] According to the second aspect of the present invention, a display device is proposed, including the electronic paper display panel described above.

[0016] According to the third aspect of the present invention, a driving method for an electronic paper display panel is proposed, including A1, A2 or A3:

[0017] A1. Apply a voltage greater than 0 - 15 V to the electro-wetting display layer, the first-color electro-wetting ink is driven into oil droplets, the negatively charged third-color electrophoretic particles in the driving electrophoretic liquid are pushed in the electric field and move towards the light-emitting side of the electronic paper display panel, and the positively charged second-color electrophoretic particles move towards the side opposite to the light-emitting side, realizing the display of the electronic paper display panel;

[0018] A2. Apply a voltage greater than -15 to 0 V to the electro-wetting display layer. The second color electrophoretic particles with positive charges are pushed in the electric field and move towards the light-emitting side of the electronic paper display panel, while the third color electrophoretic particles with negative charges move towards the side opposite to the light-emitting side, realizing the display of the electronic paper display panel.

[0019] A3. Apply a voltage less than the electro-wetting threshold voltage to the driving backplane, and the electro-wetting ink of the first color is displayed on the electronic paper display panel.

[0020] In some embodiments of the present invention, when the applied voltage is -15 to 0 V, the second color electrophoretic particles with positive charges move towards the light-emitting side of the electronic paper display panel, and the third color electrophoretic particles with negative charges move towards the side opposite to the light-emitting side.

[0021] When the applied voltage is 0 to 15 V, the third color electrophoretic particles with negative charges move towards the light-emitting side of the electronic paper display panel, and the second color electrophoretic particles with positive charges move towards the side opposite to the light-emitting side.

[0022] Through the double-layer structure of electro-wetting ink and electrophoretic ink and precise voltage control, the system of the present invention can achieve rapid switching between different colors. The oil film and oil droplet states of the electro-wetting layer and the precise control of different charged particles in the electrophoretic display layer make it possible to quickly display three colors, overcoming the display limitations caused by slow particle switching speed in traditional electrophoretic displays. It is applicable to display occasions that require high speed, multi-color switching, and high stability, especially in the display of dynamic images (such as advertising screens, e-books, paper-like displays, etc.), and has broad application potential. In addition, this display technology can also be combined with existing electronic paper technologies, broadening the application scope of the electronic display field.

[0023] By combining electro-wetting display and electrophoretic display technologies, the present invention realizes the display of rapid switching between three different colors. Compared with traditional electrophoretic displays, this structure significantly improves the response speed of the display of the third color and avoids the delay problem in the display of multiple colors in traditional electrophoretic displays. This enables the display structure to maintain efficient and smooth color conversion in dynamic images and has a broader application prospect.

[0024] When the electro-wetting ink exists in the form of oil droplets, the color of the electrophoretic layer can be displayed. By controlling the coverage of the electro-wetting ink (oil film thickness or oil droplet size) and the electric field strength of the electrophoretic particles, smooth transitions between different colors can be achieved. For example, by adjusting the strength and time of the electric field, the display intensities of the second and third colors can be finely adjusted, thereby realizing various color transition effects.

[0025] In some embodiments of the present invention, in the steps of A1, A2 or A3, the time for applying voltage is 0.05 to 0.1 s.

[0026] By adjusting the voltage and time, a smooth transition from light color to dark color is achieved to meet the display requirements of different application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 It is a schematic diagram of color development for Example 1;

[0029] Figure 2 It is a schematic diagram of color development for Example 2;

[0030] Figure 3 It is a schematic diagram of color development for Example 3. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The following will clearly and completely describe the concept of the present invention and the technical effects produced in combination with the embodiments to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present invention.

[0032] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0033] Unless otherwise specified, "room temperature" in the present invention means 25°C ± 5°C.

[0034] Unless otherwise specified, "about" in the present invention means an allowable error within ±2%.

[0035] For those without specific conditions noted in the examples, they are carried out under conventional conditions or conditions recommended by the manufacturer. For reagents or instruments without the manufacturer noted, they are all conventional products that can be obtained through commercial purchase.

[0036] Example 1

[0037] This example provides an electronic paper display panel and its driving method, specifically:

[0038] The electronic paper display panel has the following structure: an electrowetting display layer, a transparent driving backplane layer, and an electrophoretic display layer stacked in sequence;

[0039] Electrowetting display layer: The bottom of the electrowetting display layer is a transparent window, which is used to expose the electrophoretic display layer when the electrowetting display layer is opened. The electrowetting display layer contains green electrowetting ink;

[0040] Transparent driving backplane layer: The surface of the transparent driving backplane in contact with the electrowetting display layer is provided with thin film transistors, and the surface of the transparent driving backplane in contact with the electrophoretic display layer is provided with ITO conductive glass;

[0041] Electrophoretic display layer: The electrophoretic display layer contains positively charged red electrophoretic particles and negatively charged blue electrophoretic particles.

[0042] The electronic paper display panel and its driving method are as follows: No voltage or a voltage less than the electrowetting threshold voltage is applied to the electrowetting display layer, and the green electrowetting ink in the electrowetting display layer spreads into an oil film state, and the electronic paper display panel displays the first color electrowetting ink.

[0043] The color display schematic diagram of Example 1 is as Figure 1 shown.

[0044] Example 2

[0045] This example provides an electronic paper display panel and its driving method, specifically:

[0046] The electronic paper display panel has the following structure: an electrowetting display layer, a transparent driving backplane layer, and an electrophoretic display layer stacked in sequence;

[0047] Electrowetting display layer: The bottom of the electrowetting display layer is a transparent window, which is used to expose the electrophoretic display layer when the electrowetting display layer is opened. The electrowetting display layer contains green electrowetting ink;

[0048] Transparent driving backplane layer: The surface of the transparent driving backplane in contact with the electrowetting display layer is provided with thin film transistors, and the surface of the transparent driving backplane in contact with the electrophoretic display layer is provided with ITO conductive glass;

[0049] Electrophoretic display layer: The electrophoretic display layer contains positively charged red electrophoretic particles and negatively charged blue electrophoretic particles.

[0050] An electronic paper display panel and its driving method are as follows:

[0051] The electrowetting ink is driven into an oil droplet state. In this state, light passes through the transparent window at the bottom of the electrowetting display layer and the transparent driving backplane layer and enters the electrophoretic display layer. Through the action of an electric field (-15V, 0.05s) in the electrophoretic display layer, the positively charged red electrophoretic particles are pushed in the electric field and move towards the light-emitting side of the electronic paper display panel, while the negatively charged blue electrophoretic particles move towards the side opposite to the light-emitting side, forming a red display. By adjusting the application time and intensity of the voltage, the color depth of the red can be changed, as Figure 2 shown.

[0052] Example 3

[0053] This example provides an electronic paper display panel and its driving method, specifically:

[0054] The electronic paper display panel has the following structure: an electrowetting display layer, a transparent driving backplane layer, and an electrophoretic display layer stacked in sequence;

[0055] Electrowetting display layer: The bottom of the electrowetting display layer is a transparent window, which is used to expose the electrophoretic display layer when the electrowetting display layer is opened. The electrowetting display layer contains green electrowetting ink;

[0056] Transparent driving backplane layer: A thin-film transistor is provided on the surface of the transparent driving backplane in contact with the electrowetting display layer, and ITO conductive glass is provided on the surface of the transparent driving backplane in contact with the electrophoretic display layer;

[0057] Electrophoretic display layer: The electrophoretic display layer contains positively charged red electrophoretic particles and negatively charged blue electrophoretic particles.

[0058] An electronic paper display panel and its driving method are as follows:

[0059] The electrowetting ink is driven into an oil droplet state. In this state, light passes through the transparent window at the bottom of the electrowetting display layer and the transparent driving backplane layer and enters the electrophoretic display layer. Through the action of an electric field (15V, 0.1s) in the electrophoretic display layer, the negatively charged blue electrophoretic particles are pushed in the electric field and move towards the light-emitting side of the electronic paper display panel, while the positively charged red electrophoretic particles move towards the side opposite to the light-emitting side, forming a blue display. By adjusting the application time and intensity of the voltage, the color depth of the red can be changed, as Figure 3 shown.

[0060] Comparative Example 1:

[0061] This comparative example discloses a full-color wetting display device, specifically as shown in the embodiment of CN 107167916 A.

[0062] It should be readily understood that the terms "on", "above", and "over" in this application should be construed in the broadest manner such that "on" not only means "directly on something", but also includes the meaning of "on something" with intermediate features or layers therebetween, and "above" or "over" not only includes the meaning of "above" or "over something", but may also include the meaning of "above" or "over something" with no intermediate features or layers therebetween (i.e., directly on something).

[0063] The term "layer" as used herein may refer to a portion of a material that includes a region having a certain thickness. The layer may extend over the entire underlying or overlying structure, or may have a smaller extent than the underlying or overlying structure. Additionally, the layer may be a region of a homogeneous or non-homogeneous continuous structure, the thickness of which is less than the thickness of the continuous structure. For example, the layer may be located between the top and bottom surfaces of the continuous structure or between any pair of lateral planes at the top and bottom surfaces. The layer may extend laterally, vertically, and / or along a tapered surface. The driving array layer may be a layer, may include one or more layers therein, and / or may have one or more layers located thereon, above it, and / or below it. A layer may include multiple layers. For example, an interconnect layer may include one or more conductors and contact layers (in which contacts, interconnect lines, and / or vias are formed) and one or more dielectric layers.

[0064] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them; although this application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An electronic paper display panel, characterized in that, Comprising: An electrowetting display layer, a transparent driving backplane layer, and an electrophoretic display layer which are sequentially stacked; The electrowetting display layer comprises a first-color electrowetting ink; The electrophoretic display layer comprises electrophoretic ink; The electrophoretic ink comprises positively charged second-color electrophoretic particles and negatively charged third-color electrophoretic particles.

2. The electronic paper display panel according to claim 1, wherein Thin film transistors are disposed on the surface of the transparent driving backplane in contact with the electrowetting display layer.

3. The electronic paper display panel according to claim 2, wherein A fluoride coating is coated on the thin film transistors.

4. The electronic paper display panel according to claim 3, wherein, The thickness of the coating is 0.5 - 2 μm.

5. The electronic paper display panel according to claim 1, characterized in that A transparent conductive layer is disposed on the surface of the transparent driving backplane in contact with the electrophoretic display layer.

6. The electronic paper display panel according to claim 5, characterized in that, The transparent conductive layer comprises ITO conductive glass.

7. A display device, characterized in that, An electronic paper display panel as described in any one of claims 1 - 7 is included.

8. The display device according to claim 7, wherein The display device comprises an advertising screen, an e-book, and a paper-like display.

9. A driving method for an electronic paper display panel according to any one of claims 1-6, characterized in that, Including A1, A2, or A3: A1. Applying a voltage greater than 0 - 15 V to the electrowetting display layer, the first-color electrowetting ink is driven into oil droplets, and the negatively charged third-color electrophoretic particles in the driving electrophoretic fluid are pushed in the electric field and move towards the light-emitting side of the electronic paper display panel, and the positively charged second-color electrophoretic particles move towards the side opposite to the light-emitting side, thereby realizing the display of the electronic paper display panel; A2. Applying a voltage greater than -15 - 0 V to the electrowetting display layer, the positively charged second-color electrophoretic particles are pushed in the electric field and move towards the light-emitting side of the electronic paper display panel, and the negatively charged third-color electrophoretic particles move towards the side opposite to the light-emitting side, thereby realizing the display of the electronic paper display panel; A3. Applying a voltage less than the electrowetting threshold voltage to the driving backplane, and the first-color electrowetting ink of the electronic paper display panel is displayed.

10. The driving method according to claim 9, wherein In the steps of A1, A2, or A3, the time for applying the voltage is 0.05 - 0.1 s.

Images