Electrophoretic display device based on transmission-type diffraction grating
By introducing a transmissive diffraction grating and a dynamic adjustment module into the electrophoretic display device, the problems of insufficient contrast and low light utilization efficiency of traditional electrophoretic display technology are solved, and full-color display and high-quality imaging are achieved.
Patent Information
- Application Number
- CN202510716321.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-30
- Publication Date
- 2025-09-05
AI Technical Summary
Traditional electrophoretic display technology suffers from insufficient contrast, color uniformity, viewing angle dependence, and low light utilization efficiency, resulting in reduced image quality.
An electrophoretic display device based on a transmissive diffraction grating is used, including a transmissive diffraction grating layer, a beam splitter prism layer and a focusing lens layer. Wavelength selective diffraction is performed through the transmissive diffraction grating structure, and combined with a dynamic adjustment module and a spectral sensor to optimize the distribution and utilization of light.
While achieving full-color display, it also improves light utilization efficiency, enhances imaging quality and contrast, reduces interference from ambient light, and improves display effects.
Smart Images
Figure CN120595523A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of electronic paper display, and in particular to an electrophoretic display device based on a transmission diffraction grating. Background Art
[0002] The flexibility of display panels is a major development trend in emerging display technologies. Electronic paper display technology, with its ultra-low power consumption and comfortable viewing in outdoor lighting conditions, is an ideal carrier for portable and wearable flexible display terminals. Therefore, its flexibility is currently a hot topic in international research. In recent years, electronic paper display devices have attracted considerable attention due to their paper-like appearance, low power consumption, and environmentally friendly features.
[0003] Electrophoretic display electronic paper (EPD) is widely used in e-readers, electronic tags and other fields due to its low power consumption, paper-like texture and wide viewing angle. However, traditional electrophoretic display technology has limitations such as insufficient contrast, single color and viewing angle dependence. Summary of the Invention
[0004] The applicant's research has discovered that a grating structure can filter red, green, and blue light, allowing white reflective electrophoretic particles to reflect the red, green, and blue light. This, combined with a preset brightness ratio, can achieve full-color electrophoretic display electronic paper. However, each sub-pixel used to display a corresponding color filters light from other colors, resulting in reduced light utilization efficiency, lowering contrast and image quality. For example, a sub-pixel used to display red will have its corresponding grating filter out blue and green light from the ambient light.
[0005] In view of some of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide an electrophoretic display device based on a transmission diffraction grating, aiming to achieve full-color electronic paper while improving light utilization efficiency and image quality.
[0006] To achieve the above objectives, the present invention provides an electrophoretic display device based on a transmissive diffraction grating, the electrophoretic display device comprising: a first light-transmitting conductive upper electrode plate disposed on a light-emitting side of the electrophoretic display device, and a second light-transmitting conductive lower electrode plate disposed opposite the first light-transmitting conductive upper electrode plate; an electrophoretic display layer disposed between the first light-transmitting conductive upper electrode plate and the second light-transmitting conductive lower electrode plate; the electrophoretic display layer comprising an electrophoretic fluid in which white reflective electrophoretic particles and black light-absorbing electrophoretic particles having opposite charge polarities are dispersed;
[0007] The electrophoretic display layer is divided into a plurality of display pixel units, each of which includes a red display sub-pixel, a green display sub-pixel, and a blue display sub-pixel. A transmissive diffraction grating layer, a dichroic prism layer, and a focusing lens layer are sequentially arranged on the first light-transmitting conductive upper plate along the light-emitting direction; the transmissive diffraction grating layer includes a transmissive diffraction grating structure, which is used to selectively diffract corresponding wavelengths and corresponds one-to-one to the red display sub-pixel, the green display sub-pixel, and the blue display sub-pixel; the dichroic prism layer includes a dichroic prism structure. The focusing lens layer includes an ambient light focusing structure, the dichroic prism structure and the ambient light focusing structure correspond to the display pixel units one by one, the ambient light focusing structure is used to focus the ambient light in the corresponding area of the display pixel unit to the light input end of the dichroic prism structure, the dichroic prism structure is used to separate the ambient light into lights of different colors and distribute the lights of different colors to the display sub-pixels of corresponding colors; the transmissive diffraction grating structure is connected to a dynamic adjustment module, and the dynamic adjustment module is used to adjust the wavelength of the light transmitted by the transmissive diffraction grating structure;
[0008] The white reflective electrophoretic particles in the electrophoretic display layer reflect light of corresponding color wavelengths entering the red, green, and blue display sub-pixels, so that the red, green, and blue display sub-pixels display corresponding colors.
[0009] Optionally, the electrophoretic display device further includes a spectral sensor, which is used to collect the ambient light and obtain the current spectral composition of the ambient light; the electrophoretic display device corrects the light output intensity of the red, green and blue components of the display pixel unit according to the current spectral composition to adapt to the corresponding grayscale to be displayed to reduce the pixel display color difference; wherein, the current spectral composition includes at least the components of red, green and blue light.
[0010] Optionally, the ambient light focusing structure includes a collimating lens and a focusing lens, the collimating lens is used to make the ambient light with chaotic directions parallel in the same direction, and the focusing lens is used to converge and focus the parallel ambient light to the light input end of the beam splitting prism structure.
[0011] Optionally, the transmissive diffraction grating structure is composed of a periodic nanostructure, and the transmissive diffraction grating structure filters light of a required wavelength by controlling its corresponding period.
[0012] Optionally, the dynamic adjustment module includes an electrically controlled liquid crystal layer or a MEMS micromirror array, which controls the period or tilt angle of the transmission diffraction grating structure through an electrical signal to achieve filtering of light of a required wavelength.
[0013] Optionally, the surface of the transmission diffraction grating structure is coated with a SiO2 / MgF2 multilayer film, and the SiO2 / MgF2 multilayer film is used to reduce interface reflectivity.
[0014] Optionally, the brightness of the red display sub-pixel, the green display sub-pixel, and the blue display sub-pixel is adjusted by the voltage between the corresponding first light-transmitting conductive upper electrode and the first light-transmitting conductive upper electrode area. The voltage between the first light-transmitting conductive upper electrode and the first light-transmitting conductive upper electrode determines the distribution area of the white reflective electrophoretic particles and the black light-absorbing electrophoretic particles, thereby determining the brightness of each display sub-pixel.
[0015] Optionally, the red display sub-pixel, the green display sub-pixel, and the blue display sub-pixel of the same display pixel unit are mixed with light of corresponding colors having different brightnesses, so that the display pixel unit presents a required color.
[0016] Beneficial effects of the present invention: 1. A transmissive diffraction grating layer, a beam splitter prism layer, and a focusing lens layer are sequentially arranged on the first light-transmitting conductive upper electrode plate of the present invention along the light-emitting direction; the transmissive diffraction grating layer includes a transmissive diffraction grating structure, and the transmissive diffraction grating structure is used to selectively diffract the corresponding wavelength, and corresponds one-to-one to the red display sub-pixel, the green display sub-pixel, and the blue display sub-pixel; the beam splitter prism layer includes a beam splitter prism structure, and the focusing lens layer includes an ambient light focusing structure. The beam splitter prism structure and the ambient light focusing structure correspond one-to-one to the display pixel unit. The ambient light focusing structure is used to focus the ambient light in the corresponding area of the display pixel unit to the light-incoming end of the beam splitter prism structure. The beam splitter prism structure is used to divide the ambient light into light of each color, and distribute the light of each color to the display sub-pixel of the corresponding color. Compared to directly using grating filtering which will lead to waste of red, green and blue light, the present invention first splits the ambient light (mixed light) through the above structure, so that most of the red, green and blue light in the ambient light can enter the display sub-pixels of their corresponding colors, while achieving full colorization, avoiding the problem of filtering out other useful colors of light, which leads to a decrease in light utilization efficiency, and can effectively improve light utilization efficiency, increase contrast, and improve imaging quality. 2. The electrophoretic display device of the present invention also includes a spectral sensor, which can detect the spectral composition of the ambient light and adjust the distribution of electrophoretic particles according to the spectral composition, which can effectively match the imaging of the electrophoretic display device with the ambient light, thereby increasing the contrast and clarity and improving the imaging quality. 3. The present invention is also provided with a dynamic adjustment module for adjusting the wavelength of the transmitted light corresponding to the transmission diffraction grating structure, which can ensure that the light filtered by the transmission diffraction grating structure matches the requirements (including environmental requirements), thereby improving the display quality. 4. The surface of the transmission diffraction grating structure of the present invention is coated with a SiO2 / MgF2 multilayer film, which is used to reduce the interface reflectivity and avoid interference from other stray light, thereby improving imaging quality.
[0017] In summary, the present invention improves light utilization efficiency and imaging quality while achieving full-color electronic paper. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 1 is a schematic structural diagram of an electrophoretic display device based on a transmissive diffraction grating provided in accordance with a specific embodiment of the present invention;
[0019] Figure 2 This is a schematic diagram of the optical path of a display pixel unit provided by a specific embodiment of the present invention. DETAILED DESCRIPTION
[0020] The present invention discloses an electrophoretic display device based on a transmissive diffraction grating. Those skilled in the art may refer to the contents of this document and appropriately improve the technical details for implementation. It should be noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in the present invention. The device and application of the present invention have been described through preferred embodiments. It is obvious that relevant personnel can modify or appropriately change and combine the device and application described herein without departing from the content, spirit, and scope of the present invention to implement and apply the technology of the present invention.
[0021] The applicant's research has discovered that a grating structure can filter red, green, and blue light, allowing white reflective electrophoretic particles to reflect the red, green, and blue light. This, combined with a preset brightness ratio, can achieve full-color electrophoretic display electronic paper. However, each sub-pixel used to display a corresponding color filters light from other colors, resulting in reduced light utilization efficiency, lowering contrast and image quality. For example, a sub-pixel used to display red will have its corresponding grating filter out blue and green light from the ambient light.
[0022] Therefore, an embodiment of the present invention provides an electrophoretic display device based on a transmissive diffraction grating, such as Figure 1 and Figure 2 As shown, the electrophoretic display device includes: a first light-transmitting conductive upper electrode plate 1 arranged on the light-emitting side of the electrophoretic display device, and a second light-transmitting conductive lower electrode plate 2 arranged opposite to the first light-transmitting conductive upper electrode plate 1; an electrophoretic display layer 3 is arranged between the first light-transmitting conductive upper electrode plate 1 and the second light-transmitting conductive lower electrode plate 2, and the electrophoretic display layer 3 includes an electrophoretic fluid 31, in which white reflective electrophoretic particles 32 and black light-absorbing electrophoretic particles 33 with opposite charge polarities are dispersed.
[0023] The electrophoretic display layer 3 is divided into a plurality of display pixel units 4, each of which includes a red display sub-pixel 41, a green display sub-pixel 42, and a blue display sub-pixel 43. A transmissive diffraction grating layer 5, a dichroic prism layer 6, and a focusing lens layer 7 are sequentially arranged on the first light-transmitting conductive upper electrode plate 1 along the light-emitting direction; the transmissive diffraction grating layer 5 includes a transmissive diffraction grating structure 51, which is used to selectively diffract the corresponding wavelength and corresponds one-to-one to the red display sub-pixel 41, the green display sub-pixel 42, and the blue display sub-pixel 43; the dichroic prism layer 6 includes a dichroic prism layer 6, and a focusing lens layer 7. The optical prism structure 61 and the focusing lens layer 7 include an ambient light focusing structure 71. The dichroic prism structure 61 and the ambient light focusing structure 71 correspond one-to-one to the display pixel unit 4. The ambient light focusing structure 71 is used to focus the ambient light in the corresponding area of the display pixel unit 4 to the light input end of the dichroic prism structure 61. The dichroic prism structure 61 is used to divide the ambient light into lights of different colors and distribute the lights of different colors to the display sub-pixels of the corresponding colors. The transmissive diffraction grating structure 51 is connected to the dynamic adjustment module 8, and the dynamic adjustment module 8 is used to adjust the wavelength of the light transmitted by the transmissive diffraction grating structure 51.
[0024] The white reflective electrophoretic particles 32 in the electrophoretic display layer 3 reflect light of corresponding color wavelengths entering the red display sub-pixel 41 , the green display sub-pixel 42 , and the blue display sub-pixel 43 , so that the red display sub-pixel 41 , the green display sub-pixel 42 , and the blue display sub-pixel 43 display corresponding colors.
[0025] In this specific embodiment, the light path in a single display pixel unit 4 can be as follows: Figure 2 As shown, Figure 2 The ambient light (mixed light) is first focused by the ambient light focusing structure 71, then distributed to the corresponding display sub-pixels by a beam splitter prism. Finally, the transmissive diffraction grating structure 51 filters out unnecessary light other than the three colors, achieving full color. Compared to direct grating filtering, the lack of beam splitting in the grating structure will filter out the other two useful colors of mixed light in the corresponding area of the grating structure, resulting in reduced light utilization efficiency.
[0026] In this specific embodiment, the electrophoretic display device also includes a spectral sensor, which is used to collect ambient light and obtain the current spectral composition of the ambient light; the electrophoretic display device corrects the light output intensity of the red, green and blue components of the display pixel unit according to the current spectral composition to adapt to the corresponding grayscale to be displayed to reduce the pixel display color difference; wherein the current spectral composition includes at least the components of red, green and blue light.
[0027] The electrophoretic display device specifically adjusts the voltage between the first light-transmitting conductive upper electrode 1 and the second light-transmitting conductive upper electrode 1 according to the current spectral composition to change the distribution of the white reflective electrophoretic particles 32 and the black light-absorbing electrophoretic particles 33. This corrects the light intensity of the red, green, and blue components of the display pixel unit to adapt to the corresponding grayscale to be displayed, thereby reducing pixel display color difference.
[0028] In a specific application, the spectral sensor may be an AS7262 sensor produced by ams AG.
[0029] It should be noted that the ambient light is sensed by the spectral sensor, and the distribution of the electrophoretic particles is adjusted to match the imaging of the electrophoretic display device with the ambient light, thereby improving the display quality.
[0030] In this specific embodiment, the ambient light focusing structure 71 includes a collimating lens and a focusing lens. The collimating lens is used to make the ambient light with chaotic directions parallel in the same direction, and the focusing lens is used to converge and focus the parallel ambient light to the light input end of the beam splitting prism structure 61.
[0031] In this specific embodiment, the transmissive diffraction grating structure 51 is composed of a periodic nanostructure. The transmissive diffraction grating structure 51 filters light of a desired wavelength by controlling its corresponding period.
[0032] It should be noted that the period Λ of the transmissive diffraction grating structure 51 satisfies λmin≤Λ≤λmax (λ is the wavelength range of visible light).
[0033] In this specific embodiment, the dynamic adjustment module 8 includes an electrically controlled liquid crystal layer or a MEMS micromirror array, which controls the period or tilt angle of the transmissive diffraction grating structure 51 through electrical signals to filter light of a desired wavelength.
[0034] It should be noted that, based on the electrophoretic display, the grating parameters are adjusted to suppress the reflection of ambient light and reduce the interference of ambient reflected light, thereby improving the contrast. At the same time, the wavelength-selective diffraction characteristics of the grating are utilized to enhance the transmittance of red, green and blue light, thereby achieving color enhancement of the image display. Compared with traditional electrophoretic display electronic paper, the embodiments of the present invention can effectively solve the problems of low contrast and large interference from ambient light in traditional electrophoretic display.
[0035] In this specific embodiment, the transmissive diffraction grating layer 5 (active modulation layer) and the electrophoretic display layer 3 (image generation layer) are vertically integrated on the first light-transmitting conductive upper electrode plate 1 by nanoimprinting, and a dynamic adjustment module 8 that can adjust the grating parameters in real time is added.
[0036] In this specific embodiment, the surface of the transmissive diffraction grating structure 51 is coated with a SiO 2 / MgF 2 multilayer film, which is used to reduce the interface reflectivity.
[0037] It should be noted that coating the grating surface with a SiO2 / MgF2 multilayer film reduces the interface reflectivity from 4% to <1%, thereby reducing stray light interference.
[0038] In this specific embodiment, the brightness of the red display sub-pixel 41, the green display sub-pixel 42 and the blue display sub-pixel 43 are adjusted by the voltage between the corresponding first light-transmitting conductive upper electrode 1 and the first light-transmitting conductive upper electrode 1 area. The voltage between the first light-transmitting conductive upper electrode 1 and the first light-transmitting conductive upper electrode 1 determines the distribution area of the white reflective electrophoretic particles 32 and the black light-absorbing electrophoretic particles 33, thereby determining the brightness of each display sub-pixel.
[0039] It should be noted that the display panel is divided into red, green, and blue sub-pixel areas, each corresponding to specific grating parameters. The brightness of each sub-pixel is independently controlled by the electrophoretic layer, and mixed to generate color. Each pixel is composed of three sub-pixels: red, green, and blue, each integrating different grating parameters: red sub-pixel: Λ = 650nm, θ = 10°; green sub-pixel: Λ = 580nm, θ = 5°; blue sub-pixel: Λ = 480nm, θ = 0° (Λ is the grating period, θ is the grating tilt angle).
[0040] In one embodiment, the electrophoretic display device of the present invention can also adapt to different ambient light conditions by changing the wavelength of light transmitted by the transmissive diffraction grating structure 51. For example, in low-color-temperature ambient light (such as an incandescent lamp), a red-light-enhancing grating can compensate for the lack of red light from the light source, making the white display closer to neutral. In high-color-temperature ambient light (such as sunlight), a blue-light-enhancing grating can suppress blue light reflection and reduce glare.
[0041] In this specific embodiment, the optical parameters (e.g., period, duty cycle, and refractive index) of the transmissive diffraction grating layer 5 are adjusted in real time based on the electrophoretic display content using an electrodeformable material (e.g., liquid crystal polymer). When displaying text, the transmissive grating reduces the scattering interference of ambient light through Bragg diffraction or anti-reflection design, improving contrast by 50%. Adjusting the grating parameters suppresses ambient light reflection, improving display contrast and clarity, and presenting clearer images under varying ambient light conditions.
[0042] In this embodiment, the red display sub-pixel 41 , the green display sub-pixel 42 and the blue display sub-pixel 43 of the same display pixel unit 4 are mixed with light of corresponding colors with different brightnesses, so that the display pixel unit 4 presents a desired color.
[0043] A transmissive diffraction grating layer 5, a beam splitter prism layer 6, and a focusing lens layer 7 are sequentially arranged on the first light-transmitting conductive upper electrode plate 1 of the embodiment of the present invention along the light-emitting direction; the transmissive diffraction grating layer 5 includes a transmissive diffraction grating structure 51, which is used to selectively diffract corresponding wavelengths and corresponds one-to-one to the red display sub-pixel 41, the green display sub-pixel 42, and the blue display sub-pixel 43; the beam splitter prism layer 6 includes a beam splitter prism structure 61, and the focusing lens layer 7 includes an ambient light focusing structure 71. The beam splitter prism structure 61 and the ambient light focusing structure 71 correspond one-to-one to the display pixel unit 4. The ambient light focusing structure 71 is used to focus the ambient light in the corresponding area of the display pixel unit 4 to the light input end of the beam splitter prism structure 61. The beam splitter prism structure 61 is used to split the ambient light into light of each color and distribute the light of each color to the display sub-pixel of the corresponding color. Compared with directly using grating filtering, which will result in waste of red, green and blue light, the embodiment of the present invention uses the above structure to first split the ambient light (mixed light) so that most of the red, green and blue light in the ambient light can enter the display sub-pixels of their corresponding colors. While achieving full color, it avoids filtering out useful other colors of light, which leads to a decrease in light utilization efficiency. It can effectively improve light utilization efficiency, increase contrast, and improve image quality.
[0044] The electrophoretic display device of the embodiment of the present invention also includes a spectral sensor, which can detect the spectral composition of ambient light and adjust the distribution of electrophoretic particles according to the spectral composition, thereby effectively matching the imaging of the electrophoretic display device with the ambient light, thereby increasing the contrast and clarity and improving the imaging quality.
[0045] The embodiment of the present invention is further provided with a dynamic adjustment module 8 for adjusting the wavelength of light transmitted by the transmissive diffraction grating structure 51, which can ensure that the light filtered by the transmissive diffraction grating structure 51 matches the requirements (including environmental requirements), thereby improving the display quality.
[0046] The surface of the transmissive diffraction grating structure 51 of the embodiment of the present invention is coated with a SiO2 / MgF2 multilayer film. The SiO2 / MgF2 multilayer film is used to reduce the interface reflectivity and avoid interference from other stray light, thereby improving imaging quality.
[0047] In summary, the embodiments of the present invention improve light utilization efficiency and imaging quality while achieving full-color electronic paper.
[0048] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.
[0049] Each embodiment in this specification is described in a related manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiment is generally similar to the method embodiment, so the description is relatively simple. For related parts, refer to the description of the method embodiment.
[0050] The above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention are included in the scope of protection of the present invention.
Claims
1. An electrophoretic display device based on a transmissive diffraction grating, characterized in that: The electrophoretic display device includes: a first light-transmitting conductive upper electrode plate disposed on a light-emitting side of the electrophoretic display device, and a second light-transmitting conductive lower electrode plate disposed opposite the first light-transmitting conductive upper electrode plate; an electrophoretic display layer is disposed between the first light-transmitting conductive upper electrode plate and the second light-transmitting conductive lower electrode plate, the electrophoretic display layer including an electrophoretic fluid in which white reflective electrophoretic particles and black light-absorbing electrophoretic particles having opposite charge polarities are dispersed; The electrophoretic display layer is divided into a plurality of display pixel units, each of which includes a red display sub-pixel, a green display sub-pixel, and a blue display sub-pixel. A transmissive diffraction grating layer, a dichroic prism layer, and a focusing lens layer are sequentially arranged on the first light-transmitting conductive upper plate along the light-emitting direction; the transmissive diffraction grating layer includes a transmissive diffraction grating structure, which is used to selectively diffract corresponding wavelengths and corresponds one-to-one to the red display sub-pixel, the green display sub-pixel, and the blue display sub-pixel; the dichroic prism layer includes a dichroic prism structure. The focusing lens layer includes an ambient light focusing structure, the dichroic prism structure and the ambient light focusing structure correspond to the display pixel units one by one, the ambient light focusing structure is used to focus the ambient light in the corresponding area of the display pixel unit to the light input end of the dichroic prism structure, the dichroic prism structure is used to separate the ambient light into lights of different colors and distribute the lights of different colors to the display sub-pixels of corresponding colors; the transmissive diffraction grating structure is connected to a dynamic adjustment module, and the dynamic adjustment module is used to adjust the wavelength of the light transmitted by the transmissive diffraction grating structure; The white reflective electrophoretic particles in the electrophoretic display layer reflect light of corresponding color wavelengths entering the red, green, and blue display sub-pixels, so that the red, green, and blue display sub-pixels display corresponding colors.
2. The electrophoretic display device based on a transmissive diffraction grating according to claim 1, wherein: The electrophoretic display device also includes a spectral sensor, which is used to collect the ambient light and obtain the current spectral composition of the ambient light; the electrophoretic display device corrects the light output intensity of the red, green and blue components of the display pixel unit according to the current spectral composition to adapt to the corresponding grayscale to be displayed to reduce the pixel display color difference; wherein, the current spectral composition includes at least the components of red, green and blue light.
3. The electrophoretic display device based on a transmissive diffraction grating according to claim 1, wherein: The ambient light focusing structure includes a collimator and a focusing lens. The collimator is used to make the ambient light with disordered directions parallel in the same direction. The focusing lens is used to converge and focus the parallel ambient light to the light input end of the beam splitter prism structure.
4. The electrophoretic display device based on a transmissive diffraction grating according to claim 1, wherein: The transmissive diffraction grating structure is composed of a periodic nanostructure, and the transmissive diffraction grating structure filters light of a required wavelength by controlling its corresponding period.
5. The electrophoretic display device based on a transmissive diffraction grating according to claim 1, wherein: The dynamic adjustment module includes an electrically controlled liquid crystal layer or a MEMS micromirror array, which controls the period or tilt angle of the transmissive diffraction grating structure through electrical signals to filter light of a required wavelength.
6. The electrophoretic display device based on a transmissive diffraction grating according to claim 1, wherein: The surface of the transmission diffraction grating structure is coated with a SiO2 / MgF2 multilayer film, and the SiO2 / MgF2 multilayer film is used to reduce the interface reflectivity.
7. The electrophoretic display device based on a transmissive diffraction grating according to claim 1, wherein: The brightness of the red display sub-pixel, the green display sub-pixel, and the blue display sub-pixel is adjusted by the voltage between the corresponding first light-transmitting conductive upper electrode and the first light-transmitting conductive upper electrode area. The voltage between the first light-transmitting conductive upper electrode and the first light-transmitting conductive upper electrode determines the distribution area of the white reflective electrophoretic particles and the black light-absorbing electrophoretic particles, thereby determining the brightness of each display sub-pixel.
8. The electrophoretic display device based on a transmissive diffraction grating according to claim 1, wherein: The red display sub-pixel, the green display sub-pixel, and the blue display sub-pixel of the same display pixel unit are mixed by light of corresponding colors with different brightnesses, so that the display pixel unit presents a required color.