Photoluminescence quantum dot electrophoresis electronic paper based on reflective grating structure
By combining a reflective grating structure with quantum dot photoluminescence electrophoresis technology, the problems of high energy consumption and poor display quality in the traditional electrophoretic electronic paper full-color process are solved, achieving a high-efficiency and low-energy full-color display effect.
Patent Information
- Application Number
- CN202510673280.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-23
- Publication Date
- 2025-11-11
AI Technical Summary
Traditional electrophoretic electronic paper suffers from problems such as contrast loss, low color gamut coverage, insufficient color saturation, and uneven color display during the full-color process. Furthermore, photoluminescence requires an additional backlight, resulting in high energy consumption.
By combining a reflective grating structure with quantum dot photoluminescence electrophoresis technology, the reflective grating structure selectively reflects and focuses light of a specific wavelength to excite quantum dot photoluminescent particles. Combined with a beam-splitting prism layer and a focusing lens layer, the light utilization efficiency is improved, thus achieving full-color display.
While reducing energy consumption, it improves display quality, achieves high brightness and high color saturation, enhances imaging quality, and improves light utilization efficiency.
Smart Images
Figure CN120928616A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electronic paper displays, and in particular to a photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure. Background Technology
[0002] Flexible display panels are a major development direction for new display technologies. Electronic paper display technology, with its ultra-low power consumption and comfortable viewing in outdoor lighting conditions, is one of the ideal carriers 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 much attention due to their paper-like appearance, low power consumption, and environmental friendliness.
[0003] However, traditional electrophoretic electronic paper typically relies on color filters or color pigment particles to achieve full-color display. These two methods suffer from poor display quality due to contrast loss, low color gamut coverage, insufficient color saturation, and uneven color distribution. Achieving full-color display through quantum dot emission can effectively improve display quality, but photoluminescence requires an additional backlight, resulting in high energy consumption. Summary of the Invention
[0004] In view of the aforementioned deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure, which aims to improve display quality while avoiding excessive power consumption.
[0005] To achieve the above objectives, the present invention discloses a photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure. The photoluminescent quantum dot electrophoretic electronic paper includes: a first light-transmitting upper electrode plate disposed on the light-emitting side of the photoluminescent quantum dot electrophoretic electronic paper, and a second light-transmitting lower electrode plate disposed opposite to the first light-transmitting upper electrode plate; an electrophoretic microcavity is disposed between the first light-transmitting upper electrode plate and the second light-transmitting lower electrode plate.
[0006] The electrophoretic microcavity includes an array of display pixel units, which are divided into red, green, and blue display pixel units. Each display pixel unit includes an electrophoretic solution and quantum dot photoluminescent electrophoretic particles and photoabsorbent electrophoretic particles dispersed in the electrophoretic solution, each corresponding to the color of the display pixel unit. Pixel walls are provided between each display pixel unit to block crosstalk between quantum dot photoluminescent electrophoretic particles of different colors. A micro-transmitting hole is also provided between each display pixel unit, and the micro-transmitting hole penetrates the first light-transmitting upper electrode plate and the second light-transmitting lower electrode plate.
[0007] Below the second light-transmitting electrode plate, from the light-emitting side downwards, are sequentially arranged a converging lens functional microstructure layer, a reflective layer, a mask layer, and a first substrate. The converging lens functional microstructure layer, the reflective layer, and the mask layer are etched to form a reflective grating structure. The reflective grating structure corresponds one-to-one with the display pixel unit, and the period of the reflective grating structure varies depending on the color of the corresponding display pixel unit. The reflective grating structure selectively reflects natural light from the micro-transmitting aperture through its grating structure. The wavelength of the reflected light matches the excitation wavelength of the quantum dot photoluminescent electrophoretic particles in the corresponding display pixel unit. The reflective grating structure converges the reflected light through the converging lens functional microstructure layer so that the intensity of the reflected light meets the excitation intensity of the quantum dot photoluminescent electrophoretic particles in the corresponding display pixel unit.
[0008] Optionally, adjacent red display pixel units, green display pixel units, and blue display pixel units form a pixel group; a beam-splitting prism layer and a focusing lens layer are sequentially arranged along the light-emitting direction on the first light-transmitting upper electrode plate; the beam-splitting prism layer includes a beam-splitting prism structure, and the focusing lens layer includes an ambient light focusing structure, with the beam-splitting prism structure and the ambient light focusing structure corresponding one-to-one with the pixel group; the ambient light focusing structure is used to focus the ambient light of the corresponding area of the pixel group to the light-inlet end of the beam-splitting prism structure, and the beam-splitting prism structure is used to split the ambient light into light of various colors and distribute the light of each color to the display pixel unit of the corresponding color; wherein, the quantum dot photoluminescent electrophoretic particles in the display pixel units of different colors reflect the light of the assigned color to present the corresponding color.
[0009] Optionally, the micro-perforation extends through the beam splitter prism layer and the focusing lens layer.
[0010] Optionally, the photoluminescent quantum dot electrophoretic electronic paper further includes a spectral sensor, which is used to collect the ambient light and obtain the current spectral composition of the ambient light; the photoluminescent quantum dot electrophoretic electronic paper corrects the light emission intensity of the red, green and blue components of each display pixel unit according to the current spectral composition to adapt to the corresponding gray level to be displayed in order to reduce the pixel display color difference; wherein, the current spectral composition includes at least the components of red, green and blue light.
[0011] Optionally, the quantum dot photoluminescent electrophoretic particles and the absorbent electrophoretic particles carry opposite charge polarities.
[0012] Optionally, the reflective layer is an aluminum metal reflective layer, and the mask layer is a chromium thin film layer.
[0013] Optionally, the brightness of the red display pixel unit, the green display pixel unit, and the blue display pixel unit is adjusted by the voltage between the corresponding regions of the first light-transmitting upper electrode plate and the second light-transmitting lower electrode plate. The voltage between the first light-transmitting upper electrode plate and the second light-transmitting lower electrode plate determines the distribution area of the quantum dot photoluminescent electrophoretic particles and the photoabsorbent electrophoretic particles, thereby determining the brightness of each display sub-pixel.
[0014] Optionally, the quantum dot photoluminescent electrophoretic particles include a first carrier and photoluminescent quantum dots attached to and coated on the surface of the first carrier, wherein the intrinsic color of the quantum dots is the same as that of the display pixel unit to which they belong; the intrinsic color of the photoabsorbent electrophoretic particles is dark.
[0015] The beneficial effects of this invention are as follows: 1. This invention innovatively combines reflective gratings with electrophoretic display technology. By precisely reflecting light of the wavelength required for quantum dot luminescence excitation through a total internal reflection grating, it directly excites the quantum dot material, achieving high-efficiency photoluminescence. This invention precisely reflects and enhances the light of the wavelength required to excite quantum dot luminescence in ambient light through the reflective grating structure, reducing the use of a backlight and effectively lowering the energy consumption of electronic paper displays. 2. This invention precisely designs the grating period to reflect light of a specific wavelength band, thereby exciting the photoluminescent material in the electrophoretic particles and providing more flexible color display effects. 3. This invention effectively converges the quantum dot excitation light reflected by the reflective grating through a converging lens functional microstructure layer, significantly increasing the light intensity of the quantum dot excitation light in local areas of the electrophoretic display layer, thereby enhancing the excitation efficiency of quantum dots and other luminescent materials, achieving high brightness and high color saturation luminescence effects. 4. The electrophoretic display particles of this invention use quantum dot materials, which can produce highly efficient photoluminescence effects under the action of excitation light. Quantum dots can provide more vivid and stable color display, improving the quality of the display effect. 5. This invention features regularly distributed micro-apertures, allowing more natural white light to enter, which, together with the grating and lens structure, enhances the excitation and display effects of quantum dot excitation light. The micro-aperture design effectively prevents natural white light from being reflected by other layers (e.g., the first transparent upper electrode plate), thus allowing more quantum dot excitation light to be reflected. 6. The intrinsic color of the quantum dot photoluminescent electrophoretic particles in this invention is the same as that of their respective display pixel units, enabling imaging through the reflection of natural light. Therefore, this invention effectively combines reflective and emission (photoluminescence) electrophoretic display technologies, resulting in full-bodied imaging and reduced energy consumption. 7. This invention, through the setting of a beam-splitting prism layer and a focusing lens layer, first splits the ambient light (mixed light), allowing most of the red, green, and blue light in the ambient light to enter their corresponding color display sub-pixels. While achieving full color, it avoids filtering out other useful colors, thus preventing a decrease in light utilization efficiency. This effectively improves light utilization efficiency, increases contrast, and enhances image quality.
[0016] In summary, this invention can effectively combine a reflective grating structure and quantum dot electrophoresis technology to improve display quality while avoiding excessive energy consumption. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of a photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure according to a specific embodiment of the present invention;
[0018] Figure 2 This is a schematic diagram of the optical path of a photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure, provided in a specific embodiment of the present invention;
[0019] Figure 3 This is a schematic diagram of the structure of a photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure provided in the first specific embodiment of the present invention;
[0020] Figure 4 This is a schematic diagram of the preparation process of photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure according to a specific embodiment of the present invention. Detailed Implementation
[0021] This invention discloses a photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure. Those skilled in the art can refer to the content of this document and appropriately modify the technical details to achieve the desired implementation. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The apparatus and application of this invention have been described through preferred embodiments. Those skilled in the art can obviously make modifications or appropriate alterations and combinations to the apparatus and application described herein without departing from the content, spirit, and scope of this invention to implement and apply the technology of this invention.
[0022] The applicant's research revealed that traditional electrophoretic electronic paper typically relies on color filters or pigment particles to achieve full-color display. These two methods suffer from poor display quality due to contrast loss, low color gamut coverage, insufficient color saturation, and uneven color distribution. While achieving full-color display through quantum dot emission can effectively improve display quality, photoluminescence requires an additional backlight, resulting in higher energy consumption and a more complex structure.
[0023] Therefore, embodiments of the present invention provide a photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure, such as... Figure 1 As shown, the photoluminescent quantum dot electrophoretic electronic paper includes: a first light-transmitting upper electrode plate 1 disposed on the light-emitting side of the photoluminescent quantum dot electrophoretic electronic paper, and a second light-transmitting lower electrode plate 2 disposed opposite to the first light-transmitting upper electrode plate 1; an electrophoretic microcavity 3 is disposed between the first light-transmitting upper electrode plate 1 and the second light-transmitting lower electrode plate 2.
[0024] The electrophoretic microcavity 3 includes arrayed display pixel units 4, which are divided into red, green, and blue display pixel units. Each display pixel unit 4 includes an electrophoretic solution 5 and quantum dot photoluminescent electrophoretic particles 6 and photoabsorbent electrophoretic particles 7, which are dispersed in the electrophoretic solution 5 and correspond to the colors of the respective display pixel units 4. Pixel walls 8 are provided between each display pixel unit 4 to block crosstalk between quantum dot photoluminescent electrophoretic particles 6 of different colors. A micro-transmitting hole 9 is also provided between each display pixel unit 4, which penetrates the first light-transmitting upper electrode plate 1 and the second light-transmitting lower electrode plate 2.
[0025] Below the second light-transmitting lower electrode plate 2, from the light-emitting side downwards, are sequentially arranged a converging lens functional microstructure layer 10, a reflective layer 11, a mask layer 12, and a first substrate 13. The converging lens functional microstructure layer 10, the reflective layer 11, and the mask layer 12 are etched to form a reflective grating structure 14. The reflective grating structure 14 corresponds one-to-one with the display pixel unit 4, and the period of the reflective grating structure 14 varies depending on the color of its corresponding display pixel unit 4. The reflective grating structure 14 selectively reflects natural light from the micro-transmitting aperture 9 through its grating structure. The wavelength of the reflected light matches the excitation wavelength of the quantum dot photoluminescent electrophoretic particles 6 in its corresponding display pixel unit 4. The reflective grating structure 14 converges the reflected light through the converging lens functional microstructure layer 10 so that the intensity of the reflected light meets the excitation intensity of the quantum dot photoluminescent electrophoretic particles 6 in its corresponding display pixel unit 4.
[0026] In this specific embodiment, the optical path of the photoluminescent quantum dot electrophoretic electronic paper can be as follows: Figure 2 As shown, in Figure 2 In this process, quantum dot photoluminescent electrophoretic particles can not only emit light, but their intrinsic color is the color corresponding to the pixel unit, which can reflect natural light for imaging. Figure 2 In the diagram, 17 represents natural light, 18 represents grating reflected light, 19 represents quantum dot photoluminescent electrophoretic particles, 20 represents quantum dot photoluminescent electrophoretic particles reflected light, and 21 represents photoabsorbent electrophoretic particles. 7 absorbs light and appears black. Figure 2 The diagram only shows the optical path of the red quantum dot photoluminescent electrophoretic particle corresponding to the red pixel unit. It is for illustrative purposes only. In actual applications, red, green and blue quantum dot photoluminescent electrophoretic particles are generally used.
[0027] This invention combines reflection and emission methods for imaging, which improves imaging quality while reducing energy consumption.
[0028] It should be noted that the electronic paper of this invention consists of a double-layer structure. The lower layer is a reflective grating structure with a specific period. Through photolithography, gratings with different periods are designed, and these grating periods can reflect light of different wavelengths. By adjusting the grating period, blue light or other light of the desired wavelength band can be precisely selected. Above the grating is a microstructure layer with a converging lens function. This layer is composed of a regularly distributed array of microlenses, which can effectively converge the blue light reflected from the grating, increase the local light intensity of the blue light, and thus excite the photoluminescent electrophoretic particles 6 in the electrophoretic display layer, thereby producing a light-emitting effect. The upper layer is the electrophoretic display layer, which includes upper and lower transparent electrodes and an electrophoretic display material in the middle. The transparent electrodes can control the movement of the charged electrophoretic particles, thereby achieving different color display effects. The particles in the electrophoretic display layer contain two types of colored particles with opposite charges. One type of particle is coated with photoluminescent materials such as red and green CdSe / ZnS and CsPbBr3 quantum dots, while the other type of particle is a non-luminescent electrophoretic particle, which displays color solely based on its own color. The display layer also features specially designed micro-light channels. These micro-light-transmitting holes 9 allow more natural white light to enter, thereby enhancing the blue light excitation effect inside the grating. By precisely designing the grating period and the configuration of the electrophoretic display layer, this invention can achieve high-quality display effects with low power consumption, making it suitable for applications such as e-books and billboards.
[0029] In this specific embodiment, the upper and lower electrodes are made of transparent conductive materials (such as ITO, silver nanowires or PEDOT:PSS) to ensure that natural light is efficiently incident on the lower grating.
[0030] Electrophoretic microcavity 3 structure: The space between the electrodes is filled with a transparent dispersion medium (such as Isopar G, M, L, tetrachloroethylene, CH-5, Span80, Span85, T-151, silicone oil, polyvinyl alcohol solution, etc.), containing two types of electrophoretic particles with opposite charges.
[0031] Photoluminescent particles: These are quantum dots coated on the surface (such as CdSe / ZnS red quantum dots and CsPbBr3 green perovskite quantum dots). They are excited to emit light by blue light (e.g., 450nm) reflected through a grating. Photoluminescent quantum dots (such as CdSe / ZnS and CsPbBr3) require light of a specific wavelength to be excited. Reflected blue light (e.g., 450nm) can excite quantum dots because the band structure of quantum dots determines their ability to absorb and emit light of a specific wavelength. Although natural light does contain a blue component (approximately 400nm to 500nm), quantum dots could also be excited by blue light if exposed to natural light. However, the intensity of natural light is usually much lower than that of a dedicated blue light source (e.g., 450nm light), resulting in a weaker excitation effect. The role of the grating is to focus the natural light to a specific wavelength of blue light after it passes through the grating. This makes the intensity and directionality of the blue light more concentrated, thus more effectively exciting the quantum dots. In contrast, natural light is usually scattered and its wavelength components are more dispersed, which means that the blue light component may be diluted or difficult to concentrate on the quantum dots.
[0032] Non-luminescent particles: Dark-colored particles (such as carbon black or TiO2@polymer core-shell particles) are used to mask the background or adjust the contrast.
[0033] Micro-optical channel design: Periodically arranged micro-transparent holes 9 (aperture diameter 1-5μm, spacing 50-100μm) are embedded in the electrophoretic layer, which is achieved by photolithography or laser drilling to increase the incident light flux and improve excitation efficiency.
[0034] The micro-transmitting channels are light-transmitting holes in the electrophoretic display layer. Their function is to increase the amount of natural light passing through the electrophoretic display layer and allow more light to reach the grating. After being reflected by the grating, the natural light outputs blue light of a specific wavelength, thereby effectively exciting the photoluminescent quantum dots. The electrophoretic display layer is formed by encapsulating two layers of transparent electrodes, and contains porous electrophoretic microcavities, two types of electrophoretic particles with different charges, and an electrophoretic display solution. These electrophoretic particles have different colors. One type of particle is coated with a photoluminescent material, such as red-green CdSe / ZnS and CsPbBr3 quantum dots, while the other type of particle is a non-luminescent particle, displaying only by its own color (such as black or white). The micro-transmitting channels run through the space between the upper and lower transparent electrodes.
[0035] In the first specific embodiment, such as Figure 3As shown, adjacent red, green, and blue display pixel units form a pixel group; a beam splitter layer 15 and a focusing lens layer 16 are sequentially arranged on the first light-transmitting upper electrode plate 1 along the light-emitting direction; the beam splitter layer 15 includes a beam splitter structure, and the focusing lens layer 16 includes an ambient light focusing structure, with the beam splitter structure and the ambient light focusing structure corresponding one-to-one with the pixel group; the ambient light focusing structure is used to focus the ambient light of the corresponding area of the pixel group to the light-inlet end of the beam splitter structure, and the beam splitter structure is used to split the ambient light into light of various colors and distribute the light of each color to the corresponding color display pixel unit 4; wherein, the quantum dot photoluminescent electrophoretic particles 6 in the display pixel units 4 of different colors reflect the light of the assigned color to present the corresponding color.
[0036] It should be noted that the electrophoretic particles in this embodiment of the invention can not only emit light but also reflect light; the combination of both results in higher image quality. In the prior art, the three pixel units (red, green, and blue) typically reflect light from their respective areas, leading to the waste of some colors of light. This invention, however, uses a beam-splitting prism layer 15 and a focusing lens layer 16 to converge and then split the natural light from the three pixel units, avoiding the waste of some colors of light, improving light utilization efficiency, and resulting in richer, more vibrant colors in the image.
[0037] Furthermore, the micro-aperture 9 penetrates the beam splitter prism layer 15 and the focusing lens layer 16.
[0038] It should be noted that this step is to prevent the light of the corresponding wavelength of the quantum dot from being focused by the beam splitter layer 15 and the focusing lens layer 16, resulting in no light entering the micro-transmitting aperture 9.
[0039] In this specific embodiment, the photoluminescent quantum dot electrophoretic electronic paper also includes a spectral sensor, which is used to collect ambient light and obtain the current spectral composition of the ambient light; the photoluminescent quantum dot electrophoretic electronic paper corrects the light emission intensity of the red, green and blue components of each display pixel unit 4 according to the current spectral composition to adapt to the corresponding gray level to be displayed in order to reduce the pixel display color difference; wherein, the current spectral composition includes at least the components of red, green and blue light.
[0040] It should be noted that reducing color difference can effectively improve display quality.
[0041] In this specific embodiment, the quantum dot photoluminescent electrophoretic particles 6 and the absorbent electrophoretic particles 7 carry opposite charge polarities.
[0042] In this specific embodiment, the reflective layer 11 is an aluminum metal reflective layer 11, and the mask layer 12 is a chromium thin film layer.
[0043] In this specific embodiment, the brightness of the red display pixel unit, the green display pixel unit, and the blue display pixel unit is adjusted by the voltage between the corresponding regions of the first light-transmitting upper electrode plate 1 and the second light-transmitting lower electrode plate 2. The voltage between the first light-transmitting upper electrode plate 1 and the second light-transmitting lower electrode plate 2 determines the distribution area of the quantum dot photoluminescent electrophoretic particles 6 and the photoabsorbent electrophoretic particles 7, thereby determining the brightness of each display sub-pixel.
[0044] In this specific embodiment, the quantum dot photoluminescent electrophoretic particle 6 includes a first carrier and photoluminescent quantum dots attached to and wrapped on the surface of the first carrier. The intrinsic color of the quantum dots is the same as that of the display pixel unit 4 to which they belong. The intrinsic color of the photoabsorbent electrophoretic particle 7 is dark.
[0045] In this specific embodiment, the first substrate 13 is made of glass.
[0046] In one specific embodiment, the photoluminescent quantum dot electrophoretic electronic paper preparation process corresponding to the embodiments of the present invention can be as follows: Figure 4 As shown, Figure 4 The fabrication process is divided into two parts. First, the reflective grating structure 14 is fabricated. A mask layer 12, a reflective layer 11, and a converging lens functional microstructure layer 10 are sequentially fabricated on the first substrate 13, followed by etching out the reflective grating structure 14. Second, the electrophoretic display layer is fabricated, including a first transparent upper electrode plate 2, a second transparent lower electrode plate 2, and an electrophoretic microcavity 3. During the fabrication process, micro-transparent holes 9 are also fabricated. Combining the two parts yields the photoluminescent quantum dot electrophoretic electronic paper of this embodiment. Figure 4 The optical path of the reflective grating structure 14 and the optical path of the photoluminescent quantum dot electrophoretic electronic paper are also illustrated. Figure 4 In the diagram, 17 represents natural light, 18 represents grating reflected light, 19 represents quantum dot photoluminescent electrophoretic particles, 20 represents quantum dot photoluminescent electrophoretic particles reflected light, and 21 represents photoabsorbent electrophoretic particles. 7 absorbs light and appears black. Figure 4 The diagram only shows the optical path of the red quantum dot photoluminescent electrophoretic particle corresponding to the red pixel unit. It is for illustrative purposes only. In actual applications, red, green and blue quantum dot photoluminescent electrophoretic particles are generally used.
[0047] This invention innovatively combines reflective gratings with electrophoretic display technology. By precisely reflecting light of the wavelength required to excite quantum dot emission through a total internal reflection grating, the quantum dot material is directly excited, achieving high-efficiency photoluminescence. This invention precisely reflects and amplifies the light of the wavelength required to excite quantum dot emission from ambient light through the reflective grating structure 14, thereby reducing the use of a backlight and effectively lowering the energy consumption of the electronic paper display.
[0048] This invention, through precise design of the grating period, enables it to reflect light of a specific wavelength, thereby exciting the photoluminescent material in the electrophoretic particles and providing more flexible color display effects.
[0049] In this embodiment of the invention, the converging lens functional microstructure layer 10 can effectively converge the quantum dot excitation light reflected by the reflective grating, significantly improving the light intensity of the quantum dot excitation light in the local area of the electrophoretic display layer, thereby enhancing the excitation efficiency of quantum dots and other light-emitting materials, and achieving a high brightness and high color saturation light emission effect.
[0050] The electrophoretic display particles in this embodiment of the invention utilize quantum dot materials, which can produce a highly efficient photoluminescence effect under the action of excitation light. Quantum dots can provide more vivid and stable color display, improving the quality of the display effect.
[0051] This invention features regularly distributed micro-apertures that allow more natural white light to enter, working in conjunction with the grating and lens structure to enhance the excitation and display effects of quantum dot excitation light. The micro-aperture design effectively prevents natural white light from being reflected by other layers (e.g., the first transparent upper electrode plate 1), thereby allowing more quantum dot excitation light to be reflected.
[0052] The intrinsic color of the quantum dot photoluminescent electrophoretic particle 6 in this embodiment of the invention is the same as that of its corresponding display pixel unit 4, which can be used to image by reflecting natural light. Therefore, this embodiment of the invention effectively combines reflective and emissive (photoluminescent) electrophoretic display technologies, resulting in full imaging and reduced energy consumption.
[0053] In this embodiment of the invention, by setting up a beam-splitting prism layer 15 and a focusing lens layer 16, the ambient light (mixed light) is first split 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, this avoids the problem of filtering out other useful colors of light, which would lead to a decrease in light utilization efficiency. This can effectively improve light utilization efficiency, increase contrast, and improve image quality.
[0054] In summary, the embodiments of the present invention can effectively combine the reflective grating structure 14 and quantum dot luminescent electrophoresis technology to improve display quality while avoiding excessive power consumption.
[0055] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.
[0056] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.
[0057] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.
Claims
1. A photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure, characterized in that, The photoluminescent quantum dot electrophoretic electronic paper includes: a first light-transmitting upper electrode plate disposed on the light-emitting side of the photoluminescent quantum dot electrophoretic electronic paper, and a second light-transmitting lower electrode plate disposed opposite to the first light-transmitting upper electrode plate; an electrophoretic microcavity is disposed between the first light-transmitting upper electrode plate and the second light-transmitting lower electrode plate. The electrophoretic microcavity includes an array of display pixel units, which are divided into red, green, and blue display pixel units. Each display pixel unit includes an electrophoretic solution and quantum dot photoluminescent electrophoretic particles and photoabsorbent electrophoretic particles dispersed in the electrophoretic solution, each corresponding to the color of the display pixel unit. Pixel walls are provided between each display pixel unit to block crosstalk between quantum dot photoluminescent electrophoretic particles of different colors. A micro-transmitting hole is also provided between each display pixel unit, and the micro-transmitting hole penetrates the first light-transmitting upper electrode plate and the second light-transmitting lower electrode plate. Below the second light-transmitting electrode plate, from the light-emitting side downwards, are sequentially arranged a converging lens functional microstructure layer, a reflective layer, a mask layer, and a first substrate. The converging lens functional microstructure layer, the reflective layer, and the mask layer are etched to form a reflective grating structure. The reflective grating structure corresponds one-to-one with the display pixel unit, and the period of the reflective grating structure varies depending on the color of the corresponding display pixel unit. The reflective grating structure selectively reflects natural light from the micro-transmitting aperture through its grating structure. The wavelength of the reflected light matches the excitation wavelength of the quantum dot photoluminescent electrophoretic particles in the corresponding display pixel unit. The reflective grating structure converges the reflected light through the converging lens functional microstructure layer so that the intensity of the reflected light meets the excitation intensity of the quantum dot photoluminescent electrophoretic particles in the corresponding display pixel unit.
2. The photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure according to claim 1, characterized in that, Adjacent red, green, and blue display pixel units form a pixel group; a beam-splitting prism layer and a focusing lens layer are sequentially arranged along the light-emitting direction on the first light-transmitting upper electrode plate; the beam-splitting prism layer includes a beam-splitting prism structure, and the focusing lens layer includes an ambient light focusing structure, with the beam-splitting prism structure and the ambient light focusing structure corresponding one-to-one with the pixel group; the ambient light focusing structure is used to focus the ambient light of the corresponding area of the pixel group to the light-inlet end of the beam-splitting prism structure, and the beam-splitting prism structure is used to split the ambient light into light of various colors and distribute the light of each color to the display pixel unit of the corresponding color; wherein, the quantum dot photoluminescent electrophoretic particles in the display pixel units of different colors reflect the light of the assigned color to present the corresponding color.
3. The photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure according to claim 2, characterized in that, The micro-aperture penetrates both the beam splitter prism layer and the focusing lens layer.
4. The photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure according to claim 1, characterized in that, The photoluminescent quantum dot electrophoretic electronic paper also includes a spectral sensor, which is used to collect the ambient light and obtain the current spectral composition of the ambient light; the photoluminescent quantum dot electrophoretic electronic paper corrects the light emission intensity of the red, green and blue components of each display pixel unit according to the current spectral composition to adapt to the corresponding gray level to be displayed in order to reduce the pixel display color difference; wherein, the current spectral composition includes at least the components of red, green and blue light.
5. The photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure according to claim 1, characterized in that, The quantum dot photoluminescent electrophoretic particles and the absorbent electrophoretic particles carry opposite charge polarities.
6. The photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure according to claim 1, characterized in that, The reflective layer is an aluminum metal reflective layer, and the mask layer is a chromium thin film layer.
7. The photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure according to claim 1, characterized in that, The brightness of the red display pixel unit, the green display pixel unit, and the blue display pixel unit is adjusted by the voltage between the corresponding regions of the first light-transmitting upper electrode plate and the second light-transmitting lower electrode plate. The voltage between the first light-transmitting upper electrode plate and the second light-transmitting lower electrode plate determines the distribution area of the quantum dot photoluminescent electrophoretic particles and the photoabsorbent electrophoretic particles, thereby determining the brightness of each display sub-pixel.
8. The photoluminescent quantum dot electrophoretic electronic paper based on a reflective grating structure according to claim 1, characterized in that, The quantum dot photoluminescent electrophoretic particles include a first carrier and photoluminescent quantum dots attached to the surface of the first carrier. The intrinsic color of the quantum dots is the same as that of the display pixel unit to which they belong. The intrinsic color of the photoluminescent electrophoretic particles is dark.