An improved reflective color display electronic paper and a manufacturing method thereof

Abstract

The application discloses a kind of promotion reflection type color display electronic paper and its manufacturing method.The manufacturing method of promotion reflection type color display electronic paper includes the following steps: microstructure is made on light guide substrate, which includes a plurality of grooves arranged in array.Color photoresist is filled in groove to form color filter layer, and light guide substrate and color filter layer jointly constitute light guide filter layer.Electrophoretic display film is attached on TFT driving array.Light guide filter layer is attached on electrophoretic display film, and the position of color unit of color filter layer corresponds to the position of driving unit of TFT driving array.By making microstructure on light guide substrate, and filling color photoresist in the groove of microstructure to form color filter layer, microstructure can significantly improve the light penetration and reflection ability of ambient light source.At the same time, color filter layer arranged on the groove can obviously reduce the overall thickness of light guide filter layer, so as to improve display brightness and saturation, and achieve the purpose of enhancing display effect.

Description

Technical Field

[0001] This invention relates to the field of electrophoretic display technology, and in particular to an enhanced reflective color display electronic paper and its manufacturing method. Background Technology

[0002] Electronic paper, with its advantages of repeated rewriting and low power consumption, is widely used in applications such as electronic tags, billboards, and e-readers. Conventional electronic paper displays can only display black and white; how to enable color display of electronic paper has been a problem that researchers have been working to solve.

[0003] There are currently two methods for manufacturing color electronic paper display modules:

[0004] 1. A color filter is overlaid on black and white electronic paper. The disadvantage of this structure is that due to the high thickness between the filter layer and the electronic ink layer, there is a color shift phenomenon, so the photoresist cannot be made smaller, resulting in poor resolution.

[0005] Second, the electronic paper capsule contains multi-color particles. The disadvantages of this structure are: the manufacturing process is complex, and currently only three-color electronic paper with black and white plus another color (such as black and white red or black and white blue) is available. It still cannot quickly and effectively display complex color images, and mass production is difficult.

[0006] At the same time, none of the above methods of manufacturing electronic paper can avoid the problem of low material utilization caused by cutting electronic paper, and cannot effectively reduce costs.

[0007] To avoid the problem of low material utilization and inability to manufacture large-size display devices due to traditional cutting methods, some researchers have started with the substrate and developed a matching display module manufacturing method.

[0008] One method involves directly coating and curing a frame adhesive around the perimeter of the TFT driver backplane, then covering the frame adhesive with a transparent conductive layer to form a box. After that, a fluid microcapsule electrophoretic display material is infused into the box using a capillary tube, and finally cured to produce an electronic paper display device.

[0009] Another method involves coating a padding frame onto the driver backplane, then applying an electronic ink capsule using a dispensing machine, drying and curing it, applying conductive silver paste, pressing the upper transparent electrode together, then using laser cutting to expose the IC bonding position, and finally dispensing and encapsulating it to form an electronic paper display module.

[0010] The above methods represent a significant improvement over traditional methods, but the processes are complex. While laser cutting on the substrate after lamination can achieve the desired pattern, there are doubts about whether the cutting will damage the circuitry. Since the multi-colored charged particles currently under development cannot display complex color images, only color electronic paper can be prepared using a filter method. Traditional lamination methods suffer from color shift due to excessive thickness between the filter and the capsule, preventing the reduction of photoresist and resulting in poor resolution. Summary of the Invention

[0011] This invention provides an improved reflective color display electronic paper and its manufacturing method to solve the problem of low resolution in existing color electronic paper.

[0012] The objective of this invention is achieved through the following technical solution:

[0013] One embodiment of the present invention provides a method for manufacturing reflective color display electronic paper, comprising the following steps:

[0014] Microstructures are fabricated on a light guide substrate, the microstructures including multiple grooves arranged in an array;

[0015] Colored photoresist is filled into the groove of the microstructure to form a color filter layer, and the light guide substrate and the color filter layer together constitute the light guide filter layer;

[0016] The electrophoretic display film is attached to the TFT driving array;

[0017] The light guide filter layer is attached to the electrophoretic display film, and the position of the color unit of the color filter layer corresponds to the position of the driving unit of the TFT driving array.

[0018] In some embodiments, the microstructure includes a plurality of first grooves, the first grooves being elongated and arranged in parallel with each other.

[0019] In some embodiments, the microstructure further includes a plurality of second grooves, the second grooves being elongated and arranged in parallel with each other, the second grooves being arranged perpendicular to the first grooves, and the colored photoresist being disposed at the intersection of the first grooves and the second grooves.

[0020] In some embodiments, the microstructure includes a plurality of dot-shaped grooves distributed in an array, and the colored photoresist fills the interior of the dot-shaped grooves.

[0021] In some embodiments, the dotted grooves are shaped like an inverted pyramid or a truncated pyramid.

[0022] In some embodiments, the filling thickness of the color photoresist is less than the depth of the groove in the microstructure, so that the color filter layer does not protrude from the outside of the microstructure.

[0023] In some embodiments, the grooves of the microstructure are fabricated on the light guide substrate by etching, embossing, laser engraving, or machining.

[0024] In some embodiments, the colored photoresist is fabricated on the grooves of the microstructure using a mask and etching process or a spraying method.

[0025] In some embodiments, the electrophoretic display film includes a capsule or microcup electrophoretic display medium containing black and white electronic ink particles. The TFT driving array controls the vertical position of the black and white electronic ink particles through voltage to achieve the absorption or reflection of external light.

[0026] Another embodiment of the present invention provides an enhanced reflective color display electronic paper, including a TFT driving array, an electrophoretic display film attached to the TFT driving array, and a light guide filter layer attached to the electrophoretic display film;

[0027] The light guide filter layer includes a light guide substrate, the surface of which has a microstructure. The microstructure includes a plurality of grooves arranged in an array. The grooves of the microstructure are filled with colored photoresist to form a color filter layer. The positions of the color units of the color filter layer correspond to the positions of the driving units of the TFT driving array.

[0028] Compared with the prior art, the reflective color display electronic paper and its manufacturing method provided in this invention have the following advantages and beneficial effects:

[0029] 1. By fabricating microstructures on a light guide substrate and filling the grooves of the microstructures with colored photoresist to form a color filter layer, a color filter layer is formed. On the one hand, the microstructure can significantly improve the light transmission and reflection capabilities of ambient light sources. On the other hand, the color filter layer set on the grooves of the microstructure can significantly reduce the overall thickness of the light guide filter layer, thereby improving the brightness and saturation of the electronic paper's color display and enhancing the display effect. In the traditional electrophoretic colorization process, if the color filter layer is fabricated using a traditional color filter layer stacking method, ambient light penetrates the color filter layer to the electronic ink capsule and then reflects and penetrates the color filter layer again, easily causing secondary light loss and resulting in poor brightness and color saturation of the color display. However, this invention uses a microstructure + a color filter layer filled on the grooves of the microstructure, which can improve the light transmission and reflection capabilities by more than 40%, while simultaneously improving the brightness and saturation of the reflective color electronic paper, thus enhancing the display effect.

[0030] 2. In one embodiment, the filling thickness of the color photoresist is less than the depth of the groove in the microstructure, so that the color filter layer does not protrude beyond the microstructure. By making the filling thickness of the color photoresist less than the depth of the groove in the microstructure, the groove boundary of the microstructure can serve as a physical spacing between adjacent filter areas during the fabrication of the color filter, ensuring that adjacent color filter areas do not interfere with each other, thereby more effectively improving the resolution of the color electronic paper. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating a method for manufacturing an enhanced reflective color electronic paper according to one embodiment of the present invention;

[0032] Figure 2 yes Figure 1 A schematic diagram illustrating the brightening function of the microstructure in the image;

[0033] Figure 3 yes Figure 1 A schematic diagram of the microstructure in it;

[0034] Figure 4 yes Figure 1 A schematic diagram of the structure of the color filter layer in the image;

[0035] Figure 5 yes Figure 4 A front view of the microstructure and color filter layer in the image;

[0036] Figure 6 This is a front view of the microstructure and color filter layer provided in another embodiment;

[0037] Figure 7 This is a front view of the microstructure and color filter layer provided in another embodiment;

[0038] Figure 8 This is a front view of the microstructure and color filter layer provided in another embodiment;

[0039] Figure 9 This is a schematic diagram of the structure of electronic paper provided in one embodiment of the present invention. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0041] Please see Figure 1 One embodiment of the present invention provides a method for manufacturing a boost-reflective color display electronic paper. The method for manufacturing the boost-reflective color display electronic paper includes the following steps:

[0042] Microstructures are fabricated on a light guide substrate, the microstructures including multiple grooves arranged in an array;

[0043] Colored photoresist is filled into the groove of the microstructure to form a color filter layer, and the light guide substrate and the color filter layer together constitute the light guide filter layer;

[0044] The electrophoretic display film is attached to the TFT driving array;

[0045] The light-guiding filter layer is attached to the electrophoretic display film, and the positions of the color units of the color filter layer correspond to the positions of the driving units of the TFT driving array. In this embodiment, the driving units of the TFT driving array are TFT pixel electrodes.

[0046] In the above-described method for manufacturing reflective color electronic paper, a microstructure is fabricated on a light guide substrate, and colored photoresist is filled into the grooves of the microstructure to form a color filter layer. On one hand, the microstructure significantly improves the light transmission and reflection capabilities of ambient light sources. On the other hand, the color filter layer disposed in the grooves of the microstructure significantly reduces the overall thickness of the light guide filter layer, thereby improving the brightness and saturation of the electronic paper's color display and enhancing the display effect. In the traditional electrophoretic colorization process, if a conventional color filter layer stacking method is used to fabricate the color filter layer, ambient light penetrates the color filter layer to the electronic ink capsule and then reflects back through the color filter layer, easily causing secondary light loss and resulting in poor brightness and color saturation. This invention, using a microstructure + a color filter layer filled in the grooves of the microstructure, can improve light transmission and reflection capabilities by more than 40%, while simultaneously improving the brightness and saturation of the electronic paper's color display, thus enhancing the display effect.

[0047] In this embodiment, the color electronic paper utilizes an external light source to achieve color display. Specifically, the electrophoretic display film includes a capsule or microcup electrophoretic display medium, which contains black and white electronic ink particles. The TFT driving array controls the vertical position of the black and white electronic ink particles via voltage to achieve the absorption or reflection of external light. Please refer to [further details omitted]. Figure 2During operation, ambient light L enters the electronic paper through the light guide substrate A. The microstructure B on the light guide substrate A significantly enhances the light transmission and reflection capabilities of the incoming ambient light. Experiments have shown that, compared to traditional light guide substrates, the light transmission and reflection capabilities of the light guide substrate with the microstructure are improved by more than 40%. Ambient light passes through the light guide substrate and the color filter layer before reaching the surface of the electrophoretic display film. Inside the capsule or microcup electrophoretic display medium, black and white electronic ink particles carry different types of charges. Therefore, the TFT driving array can control the vertical position of the black and white electronic ink particles through voltage. For example, assuming the black electronic ink particles are positively charged and the white electronic ink particles are negatively charged, when the voltage of the pixel electrode of the TFT driving array is positive, the black electronic ink particles will be repelled and located away from the pixel electrode, while the white electronic ink particles will be attracted and located closer to the pixel electrode. When the black electronic ink particles are at the top, the ambient light on the surface of the electrophoretic display film will be absorbed. When the voltage of the pixel electrode of the TFT driving array is negative, white electronic ink particles will be repelled and located away from the pixel electrode, while black electronic ink particles will be attracted and located closer to the pixel electrode. When the white electronic ink particles move closer, the ambient light on the surface of the electrophoretic display film will be reflected, and then emitted into the external environment through the color filter layer and the light guide substrate. In some embodiments, the color filter layer includes red, green, and blue color filters, and countless colors can be created by overlapping the three colors.

[0048] In this embodiment, the electronic paper display module includes a driving array substrate, an electrophoretic display film layer, and a light guide filter layer. The light guide filter layer is formed by fabricating colored photoresist on a brightness enhancement structure. The color filter layer uses the RGB "three primary color light model," meaning that all colors of light are composed of red (R), green (G), and blue (B), also known as the three primary colors of light. The superposition of red, green, and blue can create countless colors. In this embodiment, if colorization is achieved by mixing red, green, and blue, the electronic ink is composed of capsules or microcup electrophoretic display media containing black and white particles.

[0049] During the fabrication process, the following components can be prepared separately: 1. A TFT driving array; 2. An electrophoretic display film, which can be a capsule or microcup electrophoretic display medium; 3. A light guide and filter layer. The light guide and filter layer is created by first fabricating a brightness-enhancing prism microstructure on the substrate to improve light transmission and reflection by more than 40%, and then fabricating colored photoresist in the grooves. The design of the brightness-enhancing prism microstructure must be coordinated with the relative position of the TFT driving array, ensuring that its color units are aligned with the driving array units below.

[0050] In terms of manufacturing process, the electrophoretic display film can be attached to the TFT driving array. Then, the light guide filter layer is precisely aligned with the TFT driving array substrate and attached to the electrophoretic display film, ensuring that its color units are aligned with the driving array units below. Next, a ring of sealing adhesive is applied around the electronic paper and cured. Finally, a protective layer is applied and hot-pressed to complete the encapsulation of the color display module.

[0051] The structure of electronic paper produced using the above methods has the following advantages:

[0052] 1. Avoid the traditional method of stacking color filter layers, which causes secondary loss due to light penetration and reflection of the color filter layer.

[0053] 2. The microstructure of the brightening prism enhances light transmission and reflection capabilities by more than 40%.

[0054] 3. Improve the brightness and saturation of color displays.

[0055] Please see also Figure 3 The process of fabricating microstructures on a light guide substrate includes:

[0056] Provide a light guide substrate 110;

[0057] Microstructure 120 is fabricated on light guide substrate 110.

[0058] In this embodiment, the light guide substrate 110 is a PET film. The microstructure 120 includes grooves 121 disposed on the surface of the PET film. In some embodiments, the grooves 121 of the microstructure 120 are fabricated on the light guide substrate 110 by etching, embossing, laser engraving, or machining.

[0059] Please see also Figure 4 The process of fabricating a color filter layer on the grooves of the microstructure includes:

[0060] A first photoresist 131 is filled into a portion of the groove 121 of the microstructure 120. In this embodiment, the first photoresist 131 is a red photoresist.

[0061] A second photoresist 132 is filled into another portion of the groove 121 of the microstructure 120. In this embodiment, the second photoresist 132 is a green photoresist.

[0062] A third photoresist 133 is filled into a portion of the groove 121 of the microstructure 120. In this embodiment, the third photoresist 133 is a blue photoresist.

[0063] The first photoresist 131, the second photoresist 132, and the third photoresist 133 together form the color filter 130. It should be noted that adjacent first photoresist 131, second photoresist 132, and third photoresist 133 units together constitute a color unit of the color filter 130. The color unit of the color filter 130 corresponds to the position of the driving unit of the TFT driving array, thereby enabling each pixel structure of the electronic paper to generate light of any color through the mixing of red, green, and blue light. In this embodiment, the first photoresist 131, second photoresist 132, and third photoresist 133 are fabricated on the groove 121 of the microstructure 120 using a mask and etching process. If necessary, the first photoresist 131, second photoresist 132, and third photoresist 133 can also be fabricated on the groove 121 of the microstructure 120 by inkjet printing.

[0064] Please see also Figure 5 In some embodiments, the microstructure 120 includes a plurality of first grooves 122. The first grooves 122 are elongated strips. The first grooves 122 are arranged in parallel. In this embodiment, the color photoresist is distributed in a stripe pattern. Adjacent first photoresist 131, second photoresist 132, and third photoresist 133 together form a color unit of the color filter 130.

[0065] Understandably, color photoresist is not limited to the above arrangement. Please refer to [other options]. Figure 6 The microstructure 120 still includes several first grooves 122. Each first groove 122 is elongated and arranged in parallel. Unlike the previous embodiment, the colored photoresist is distributed in a dot matrix pattern. Within the same first groove 122, first photoresist 131, second photoresist 132, and third photoresist 133 are sequentially distributed. However, in the combination of color units, each dot matrix of photoresist, the photoresist of another color in the same row adjacent to it, and the photoresist of yet another color in the same column adjacent to it together form a color unit. That is, in this embodiment, the three colors of photoresist are arranged in a triangular relationship.

[0066] Understandably, the grooves in the microstructure are not limited to the embodiments described above. Please refer to... Figure 7 In some embodiments, the microstructure 120 further includes a plurality of second grooves 123. The second grooves 123 are elongated strips. The second grooves 123 are arranged in parallel with each other. The second grooves 123 are arranged perpendicular to the first grooves 122. The colored photoresist is disposed at the intersection of the first grooves 122 and the second grooves 123.

[0067] In this embodiment, by setting the second groove 123 and arranging it perpendicular to the first groove 122, the microstructure 120 can better enhance the penetration and reflection capabilities of ambient light. Furthermore, since the second groove 123 is perpendicular to the first groove 122, the background light distribution in the electronic paper can also be made more uniform.

[0068] Understandably, the grooves in the microstructure are not limited to strip-shaped grooves. See also... Figure 8 In some embodiments, the microstructure 120 includes a plurality of dot-shaped grooves 124. The dot-shaped grooves 124 are distributed in an array. The colored photoresist fills the interior of the dot-shaped grooves 124. In this embodiment, the shape of the dot-shaped grooves 124 is an inverted pyramid or a truncated pyramid.

[0069] In some embodiments, the filling thickness of the color photoresist is less than the depth of the groove 121 of the microstructure 120, so that the color filter layer 130 does not protrude from the outside of the microstructure 120.

[0070] By making the filling thickness of the color photoresist less than the depth of the grooves in the microstructure, the groove boundaries of the microstructure can serve as physical intervals between adjacent filter areas when fabricating color filters, so that adjacent color filter areas do not interfere with each other, thereby more effectively improving the resolution of electronic paper.

[0071] Please see Figure 9 Another embodiment of the present invention provides an enhanced reflective color display electronic paper. The electronic paper includes a TFT driving array 200, an electrophoretic display film 300 attached to the TFT driving array 200, and a light guide filter layer 100 attached to the electrophoretic display film 300.

[0072] The light guide filter layer 100 includes a light guide substrate 110. The surface of the light guide substrate 110 has a microstructure 120. The microstructure 120 includes a plurality of grooves 121 arranged in an array. The grooves 121 of the microstructure 120 are filled with colored photoresist to form a color filter layer 130. The positions of the color units of the color filter layer 130 correspond to the positions of the driving units of the TFT driving array 200.

[0073] Compared with the prior art, the reflective color display electronic paper provided in this invention has the following advantages and beneficial effects:

[0074] By fabricating a microstructure 120 on a light guide substrate 110 and filling the grooves 121 of the microstructure 120 with colored photoresist to form a color filter layer 130, a color filter layer 130 is formed. On one hand, the microstructure 120 can significantly improve the light transmission and reflection capabilities of ambient light sources. On the other hand, the color filter layer 130 disposed on the grooves 121 of the microstructure 120 can significantly reduce the overall thickness of the light guide filter layer 100, thereby improving the brightness and saturation of the electronic paper's color display and enhancing the display effect. In the traditional electrophoretic colorization process, if a traditional color filter layer stacking method is used to fabricate the color filter layer, ambient light penetrates the color filter layer to the electronic ink capsule and then reflects back through the color filter layer, easily causing secondary light loss and resulting in poor brightness and color saturation of the color display. However, this invention uses a microstructure + a color filter layer 130 filled on the grooves 121 of the microstructure 120, which can improve light transmission and reflection capabilities by more than 40%, while simultaneously improving the brightness and saturation of the color display electronic paper, thus enhancing the display effect.

[0075] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the embodiments described above. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for manufacturing reflective color display electronic paper, characterized in that, Includes the following steps: Microstructures are fabricated on a light guide substrate, the microstructures including multiple grooves arranged in an array; Colored photoresist is filled into the groove of the microstructure to form a color filter layer, and the light guide substrate and the color filter layer together constitute the light guide filter layer; The electrophoretic display film is attached to the TFT driving array; The light guide filter layer is attached to the electrophoretic display film, and the position of the color unit of the color filter layer corresponds to the position of the driving unit of the TFT driving array.

2. The method for manufacturing reflective color electronic paper according to claim 1, characterized in that, The microstructure includes several first grooves, each groove being elongated and arranged in parallel.

3. The method for manufacturing reflective color display electronic paper according to claim 2, characterized in that, The microstructure also includes several second grooves, which are elongated and arranged in parallel. The second grooves are arranged perpendicular to the first groove, and the colored photoresist is disposed at the intersection of the first groove and the second groove.

4. The method for manufacturing reflective color display electronic paper according to claim 1, characterized in that, The microstructure includes a plurality of dot-shaped grooves, which are distributed in an array, and the colored photoresist fills the interior of the dot-shaped grooves.

5. The method for manufacturing reflective color display electronic paper according to claim 4, characterized in that, The dotted grooves are in the shape of an inverted pyramid or a truncated pyramid.

6. The method for manufacturing reflective color display electronic paper according to any one of claims 1-5, characterized in that, The filling thickness of the colored photoresist is less than the depth of the groove in the microstructure, so that the colored filter layer does not protrude from the outside of the microstructure.

7. The method for manufacturing reflective color display electronic paper according to claim 1, characterized in that, The grooves of the microstructure are fabricated on the light guide substrate by means of etching, embossing, laser engraving or machining.

8. The method for manufacturing reflective color display electronic paper according to claim 1, characterized in that, The colored photoresist is fabricated on the grooves of the microstructure using a mask and etching process or a spraying method.

9. The method for manufacturing reflective color display electronic paper according to claim 1, characterized in that, The electrophoretic display film includes a capsule or microcup electrophoretic display medium, which contains black and white electronic ink particles. The TFT driving array controls the vertical position of the black and white electronic ink particles through voltage to achieve the absorption or reflection of external light.

10. A type of reflective color display electronic paper, characterized in that, It includes a TFT driving array, an electrophoretic display film attached to the TFT driving array, and a light guide filter layer attached to the electrophoretic display film; The light guide filter layer includes a light guide substrate, the surface of which has a microstructure. The microstructure includes a plurality of grooves arranged in an array. The grooves of the microstructure are filled with colored photoresist to form a color filter layer. The positions of the color units of the color filter layer correspond to the positions of the driving units of the TFT driving array.

Images