TWI840854B - Display device - Google Patents

Abstract

A display device including a substrate, a plurality of light emitting elements, a light cutting layer and a plurality of light conversion elements is provided. The light emitting elements are disposed on the substrate, and configured to emit a plurality of excitation lights. The light emitting elements are disposed between the substrate and the light cutting layer. The light cutting layer has a plurality of grooves, and positions of the grooves respectively correspond to positions of the light emitting elements. The light conversion elements are respectively disposed in the grooves. The excitation lights are irradiated to the light conversion elements. The light conversion elements are configured to convert the excitation lights into a plurality of color lights. The light cutting layer is configured to reflect the excitation lights and to be transmitted by the color lights.

Description

Display device

The present invention relates to a display device.

For LED display devices that use ultraviolet light as the excitation light source, a UV cut filter is added to the light-emitting side to prevent ultraviolet light from overflowing and penetrating and harming the human eye. For example, a display device using ultraviolet micro-luminescent diodes (UV MicroLEDs) has a quantum dot (QD) layer that can convert ultraviolet light to emit different colors of light on the light source layer (UV MicroLEDs), and a UV cut filter structure is added to the light-emitting side. However, in the current UV MicroLED display device manufacturing process, the UV cut filter and quantum dot layer processes are continued on the completed MicroLEDs, and the cost of process failure is relatively high.

Furthermore, currently available quantum dot technologies are mostly made of semiconductor materials, such as cadmium sulfide (CdS) and cadmium selenide (CdSe), most of which are toxic and easily produce products that are harmful to the environment during the device manufacturing process, raising environmental concerns.

The "prior art" section is only used to help understand the content of the present invention. Therefore, the content disclosed in the "prior art" section may contain some content that does not constitute the common knowledge of the person skilled in the art. The content disclosed in the "prior art" section does not mean that the content or the problem to be solved by one or more embodiments of the present invention has been known or recognized by the person skilled in the art before the application of the present invention.

The present invention provides a display device, which has a higher overall manufacturing process success rate and reduces costs.

Other purposes and advantages of the present invention can be further understood from the technical features disclosed in the present invention.

In order to achieve one or part or all of the above purposes or other purposes, an embodiment of the present invention provides a display device, which includes a substrate, a light-emitting element, a light-cutoff layer and a plurality of light conversion elements. The light-emitting element is arranged on the substrate to emit a plurality of excitation light beams. The light-emitting element is arranged between the substrate and the light-cutoff layer. The light-cutoff layer has a plurality of grooves, and the positions of the grooves correspond to the positions of the light-emitting elements, respectively. The light conversion elements are respectively arranged in the grooves. The excitation light beam is irradiated to the light conversion element. The light conversion element is used to convert the excitation light beam into a plurality of color light beams. The light-cutoff layer is used to reflect the excitation light beam and to allow the color light beams to pass through.

In an embodiment of the present invention, the opening of the groove faces the light emitting element.

In an embodiment of the present invention, the display device further includes a reflective layer. The reflective layer is disposed on a surface of the substrate opposite to the light-emitting element.

In one embodiment of the present invention, the light-emitting element is a micro-luminescent diode.

In one embodiment of the present invention, the excitation light beam emitted by the light emitting element is ultraviolet light.

In one embodiment of the present invention, the material of the light conversion element may be carbon quantum dots.

In one embodiment of the present invention, the display device further includes a plurality of filters. The filters are respectively disposed on the surface of the light cutoff layer relative to the light conversion element, and the positions of the filters respectively correspond to the positions of the light conversion elements. The filters are respectively used to allow light having the same wavelength as that of the light converted by the light conversion element after the light emitted by the light emitting element is absorbed by the corresponding light conversion element to pass through.

In one embodiment of the present invention, the display device further includes an adhesive layer disposed between the light-cutting layer and the light-emitting element.

In one embodiment of the present invention, the display device further includes a plurality of metal elements. The metal elements are disposed between the light-cutting layer and the substrate. The metal elements form a patterned layer. The light-emitting elements are located between the metal elements, and the range of the orthographic projection of the metal elements on the substrate does not overlap with the range of the orthographic projection of the light-emitting elements on the substrate.

In an embodiment of the present invention, the display device further comprises a plurality of micro lenses, which are disposed between the light emitting element and the light cut-off layer, and the positions of the micro lenses correspond to the positions of the light emitting elements respectively.

In an embodiment of the present invention, the height of the metal element is greater than the height of the light-emitting element.

In one embodiment of the present invention, the metal elements form a patterned layer. The microlenses are located between the metal elements, and the orthographic projection range of the metal elements on the substrate does not overlap with the orthographic projection range of the microlenses on the substrate.

Based on the above, in the embodiment of the present invention, the light cutoff layer of the display device is designed to have a groove, and the light conversion element is arranged in the groove, so that the light cutoff layer and the light conversion element are independently arranged and manufactured. Therefore, the display device of the embodiment of the present invention reduces the process risk of the overall element, improves the process success rate, and further reduces the cost.

In order to make the above features and advantages of the utility model more obvious and easy to understand, the following is a detailed description of the embodiments with the help of the attached drawings.

The above-mentioned other technical contents, features and effects of the present invention will be clearly presented in the detailed description of the preferred embodiment with reference to the following drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front or back, etc., are only referenced to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and are not used to limit the present invention.

Fig. 1 is a schematic diagram of a display device according to a first embodiment of the present invention. Referring to Fig. 1 , an embodiment of the present invention provides a display device 10, which includes a substrate 100, a plurality of light emitting elements 200, a light cutting layer 300, and a plurality of light conversion elements 400.

In this embodiment, the light-emitting elements 200 are disposed on the substrate 100 to emit a plurality of excitation light beams L. The light-emitting elements 200 may be arranged in an array, and a black photoresist (not shown) may be disposed around any light-emitting element 200 to avoid crosstalk between pixels. The light-emitting elements 200 may be micro LEDs, and the excitation light beams L emitted by the light-emitting elements 200 may be ultraviolet light, but the present invention is not limited thereto.

In this embodiment, the light-emitting element 200 is disposed between the substrate 100 and the light-cutting layer 300. The light-cutting layer 300 is used to reflect light whose wavelength falls within the cut-off wavelength range (reflection wavelength range) and to allow light beams with wavelengths outside the cut-off wavelength range to pass through. In this embodiment, the cut-off wavelength range of the light-cutting layer 300 covers the wavelength range of the excitation light beam of the light-emitting element 200. The light-cutting layer 300 has a plurality of grooves 302, and the positions of these grooves 302 correspond to the positions of these light-emitting elements 200, respectively. Specifically, the thickness of the light-cutting layer 300 (in the direction from the substrate 100 to the light-cutting layer 300) is, for example, greater than the depth of each groove 302.

In the present embodiment, the material of the light conversion element 400 may be quantum dots. In a preferred embodiment, the light conversion element 400 may be carbon quantum dots, which reduce the impact and influence on the environment, and the material source is secure. The light conversion elements 400 are respectively disposed in the grooves 302. The excitation light beam L is irradiated to the light conversion element 400. The light conversion element 400 is used to convert the excitation light beam L into a plurality of color light beams C1, C2, and C3. For example, in the present embodiment, the light conversion element 400 may include three types of light conversion elements (as shown in FIG. 1), and each type of light conversion element may convert the excitation light beam L into a color light beam C1, a color light beam C2, and a color light beam C3, respectively. The light cutoff layer 300 is used to reflect the excitation light beam L, and to allow the color light beams C1, C2, and C3 to penetrate. That is, the light cutoff layer 300 is used to reflect light whose wavelength falls within the cutoff wavelength range, and the main wavelength of the excitation light beam L, for example, falls within the cutoff wavelength range. For example, the excitation light beam L can be an ultraviolet light beam, and the color light beams C1, C2, and C3 can be red light, green light, and blue light beams, respectively. The light cutoff layer 300 is used to reflect the ultraviolet light beam and allow the red light, green light, and blue light beams to pass through, but the present invention is not limited to the wavelength range of the excitation light beam L or the color light beams C1, C2, and C3.

In this embodiment, the opening of the groove 302 of the light-cutting layer 300 faces the light-emitting element 200. Therefore, the portion of the excitation light beam L that is transmitted to the light conversion element 400 and cannot be converted into the color light beams C1, C2, and C3 will be reflected back to the light conversion element 400 by the light-cutting layer 300 after passing through the light conversion element 400, thereby improving the efficiency of converting the excitation light beam L into the color light beams C1, C2, and C3 and reducing energy loss.

In this embodiment, the display device 10 further includes a reflective layer 600. The reflective layer 600 is disposed on the surface of the substrate 100 opposite to the light-emitting element 200 (the surface of the substrate 100 away from the light-emitting element 200). The provision of the reflective layer 600 helps the excitation light beam L to be transmitted between the light cutoff layer 300 and the reflective layer 600, thereby improving the efficiency of converting the excitation light beam L into the color light beams C1, C2, and C3 and reducing energy loss.

In this embodiment, the display device 10 further includes an adhesive layer 500. The adhesive layer 500 is disposed between the light cutoff layer 300 and the light emitting element 200. For example, one side of the adhesive layer 500 is bonded to the light conversion element 400, and the other side of the adhesive layer 500 is bonded to the light emitting element 200. The adhesive layer 500 is preferably made of a material that matches the light cutoff layer 300 and the light emitting element 200. For example, a mechanically matching material is selected to increase the yield of the overall process. Alternatively, an optically matching material is selected, such as the refractive index of the adhesive layer 500 falls between the refractive index of the light cutoff layer 300 and the refractive index of the light emitting element 200, so as to improve the optical efficiency of the display device 10.

Based on the above, in the embodiment of the present invention, the light-cutting layer 300 of the display device 10 has a groove 302, and the light conversion element 400 is disposed in the groove 302. That is, the light-cutting layer 300 provided with the light conversion element 400 and the light-emitting element 200 are independently disposed (independently manufactured), and then the manufactured light-emitting component (for example, including the substrate 100, the light-emitting element 200 and/or the reflective layer 600) and the manufactured light conversion component (for example, including the light-cutting layer 300 and the light conversion element 400) are bonded together by the adhesive layer 500 to form the display device 10. Compared to conventional display devices that directly form a light cutoff layer 300 and a light conversion element 400 on a light-emitting element, the display device 10 of the embodiment of the present invention reduces the process risk of the entire element, improves the process success rate, and further reduces the cost. The groove 302 of the light cutoff layer 300 is designed in the form of a reflective cavity so that the light that would have been lost to other pixels can be rebounded and recovered, thereby increasing the overall optical efficiency. In addition, the independent design of the light cutoff layer 300 can change the quantum dot array design according to demand. For example, the pattern design of the groove 302 of the light cutoff layer 300 and the ratio of different quantum dots can be changed according to actual use requirements (such as special shapes, special color ratios, etc.).

FIG. 2 is a schematic diagram of a display device according to a second embodiment of the present invention. Referring to FIG. 2 , the display device 10A of the present embodiment is similar to the display device 10 of FIG. 1 , and the main difference is that the display device 10A further includes a plurality of filters 700. The filters 700 are respectively disposed on the surface of the light cutoff layer 300 relative to the light conversion element 400 (i.e., the light cutoff layer 300 is located between the filter 700 and the light conversion element 400), and the positions of the filters 700 respectively correspond to the positions of the light conversion element 400. The filters 700 are respectively used to allow the light (i.e., the color light beam) converted from the light emitted by the light conversion element 200 absorbed by the corresponding light conversion element 400 with the same wavelength to pass through (e.g., the light within the wavelength range passes through), and absorb the light within other wavelength ranges. Since the display device 10A is provided with the filter 700, the color contrast of the light emitted by the system is increased (for example, the crosstalk between pixels is reduced). The remaining advantages of the display device 10A are similar to those of the display device 10, which will not be elaborated here.

FIG3 is a schematic diagram of a display device according to a third embodiment of the present invention. Referring to FIG3 , the display device 10B of this embodiment is similar to the display device 10A of FIG2 , and the main difference is that the display device 10B further includes a plurality of metal elements 800, and the reflectivity of the metal elements 800 is, for example, greater than 75%. The metal elements 800 are disposed between the light-cutting layer 300 and the substrate 100. The metal elements 800 form a patterned layer, and the light-emitting elements 200 are located between the metal elements 800, and the range of the orthographic projection of the metal elements 800 on the substrate 100 does not overlap with the range of the orthographic projection of the light-emitting elements 200 on the substrate 100. That is, the display device 10B uses the metal element 800 to replace the black photoresist disposed between the light-emitting elements 200 of the display device 10 or 10A, so that the light path design is replaced by reflection instead of absorption. Therefore, in addition to avoiding crosstalk between pixels, the metal element 800 can also reduce the overall light leakage ratio, reduce energy loss, and further increase optical efficiency. The remaining advantages of the display device 10B are similar to those of the display device 10A or 10, which will not be repeated here.

FIG4 is a schematic diagram of a display device according to a fourth embodiment of the present invention. Referring to FIG4 , the display device 10C of this embodiment is similar to the display device 10B of FIG3 , and the main differences are as follows. In this embodiment, the display device 10C further includes a plurality of microlenses 900. The microlenses 900 are disposed between the light-emitting element 200 and the light-cutting layer 300, and the microlenses 900 are disposed between the adhesive layer 500 and the light-emitting element 200, and the positions of the microlenses 900 correspond to the positions of the light-emitting element 200, respectively. In addition, the metal element 800C forms a patterned layer, the microlens 900 is located between the metal elements 800C, and the range of the orthographic projection of the metal element 800C on the substrate 100 does not overlap with the range of the orthographic projection of the microlens 900 on the substrate 100. The microlens 900 can be a concave or convex lens. The height H1 of the metal element 800C (in the direction from the substrate 100 to the light-cutting layer 300) is greater than the height H2 of the light-emitting element 200 (in the direction from the substrate 100 to the light-cutting layer 300). In other words, compared with the display device 10B, the metal element 800C of the display device 10C is extended to the light-cutting layer 300, so that the excitation light beam L emitted by each light-emitting element 200 will not cross and enter other non-corresponding light conversion elements 400 after entering the light-cutting layer 300. The remaining advantages of the display device 10C are similar to those of the display device 10B and will not be elaborated here. In particular, in order to make the light-emitting component and the light conversion component bond better, the upper surface of the adhesive layer 500 (the surface close to the light-cutting layer 300) is, for example, coplanar with the upper surface of the metal element 800C, or the upper surface of the adhesive layer 500 is slightly higher (for example, greater than 0 mm and less than 0.5 mm) than the upper surface of the metal element 800C.

In summary, in the embodiment of the present invention, the light cutoff layer of the display device has a groove, and the light conversion element is arranged in the groove, so that the light cutoff layer and the light conversion element are independently arranged and manufactured. Therefore, the display device reduces the process risk of the overall element, improves the process success rate, and further reduces the cost.

However, what is described above is only the preferred embodiment of the present invention, and it cannot be used to limit the scope of the implementation of the present invention. That is, all simple equivalent changes and modifications made according to the scope of the patent application and the content of the invention description are still within the scope of the present invention. In addition, any embodiment or patent application of the present invention does not need to achieve all the purposes, advantages or features disclosed by the present invention. In addition, the abstract and title are only used to assist in searching for patent documents, and are not used to limit the scope of rights of the present invention. In addition, the terms "first", "second", etc. mentioned in this specification or patent application are only used to name the name of the element or distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of elements.

10, 10A, 10B, 10C: display device 100: substrate 200: light-emitting element 300: light-cutting layer 302: groove 400: light-converting element 500: adhesive layer 600: reflective layer 700: filter 800, 800C: metal element 900: microlens C1, C2, C3: color light beam H1, H2: height L: excitation beam

FIG. 1 is a schematic diagram of a display device according to a first embodiment of the present invention. FIG. 2 is a schematic diagram of a display device according to a second embodiment of the present invention. FIG. 3 is a schematic diagram of a display device according to a third embodiment of the present invention. FIG. 4 is a schematic diagram of a display device according to a fourth embodiment of the present invention.

10: Display device

100: Substrate

200: Light-emitting element

300: Light cutoff layer

302: Groove

400: Light conversion element

500: Adhesive layer

600:Reflective layer

C1, C2, C3: Color light beams

L: Excitation beam

Claims (11)

A display device includes: a substrate; a plurality of light-emitting elements disposed on the substrate and used to emit a plurality of excitation light beams; a light cut-off layer, wherein the light-emitting elements are disposed between the substrate and the light cut-off layer, the light cut-off layer having a plurality of grooves, and the positions of the grooves respectively correspond to the positions of the light-emitting elements; a plurality of light conversion elements, respectively disposed in the grooves, wherein the excitation light beams are irradiated to the light conversion elements, the light conversion elements are used to convert the excitation light beams into a plurality of color light beams, and the light cut-off layer is used to reflect the excitation light beams and to allow the color light beams to penetrate; and an adhesive layer, disposed between the light cut-off layer and the light-emitting elements. A display device as described in claim 1, wherein the openings of the grooves face the light-emitting elements. The display device as described in claim 1 further includes: a reflective layer disposed on the surface of the substrate opposite to the light-emitting elements. A display device as described in claim 1, wherein the light-emitting elements are micro-light-emitting diodes. A display device as described in claim 1, wherein the excitation light beams emitted by the light-emitting elements are ultraviolet light. A display device as described in claim 1, wherein the material of the light conversion elements is carbon quantum dots. The display device as described in claim 1 further comprises: a plurality of filters, which are respectively arranged on the surface of the light cutoff layer relative to the light conversion elements, and the positions of the filters respectively correspond to the positions of the light conversion elements, wherein the filters are respectively used to allow the light with the same wavelength as the corresponding light conversion element to pass through after the light emitted by the light-emitting elements is absorbed. The display device as described in claim 1 further comprises: a plurality of metal elements disposed between the light-cutting layer and the substrate, wherein the metal elements form a patterned layer, the light-emitting elements are located between the metal elements, and the range of the orthographic projection of the metal elements on the substrate does not overlap with the range of the orthographic projection of the light-emitting elements on the substrate. A display device comprises: a substrate; a plurality of light-emitting elements disposed on the substrate and used to emit a plurality of excitation light beams; a light cut-off layer, wherein the light-emitting elements are disposed between the substrate and the light cut-off layer, the light cut-off layer having a plurality of grooves, and the positions of the grooves respectively correspond to the positions of the light-emitting elements; a plurality of light conversion elements, respectively disposed in the grooves, wherein the excitation light beams are irradiated to the light conversion elements, the light conversion elements are used to convert the excitation light beams into a plurality of color light beams, and the light cut-off layer The layer is used to reflect the excitation light beams and to allow the color light beams to penetrate; a plurality of metal elements are arranged between the light cut-off layer and the substrate, wherein the metal elements form a patterned layer, the light emitting elements are located between the metal elements, and the range of the orthographic projection of the metal elements on the substrate and the range of the orthographic projection of the light emitting elements on the substrate do not overlap with each other; and a plurality of micro lenses are arranged between the light emitting elements and the light cut-off layer, and the positions of the micro lenses correspond to the positions of the light emitting elements respectively. A display device as described in claim 9, wherein the microlenses are located between the metal elements, and the range of the orthographic projections of the metal elements on the substrate and the range of the orthographic projections of the microlenses on the substrate do not overlap with each other. A display device comprises: a substrate; a plurality of light-emitting elements disposed on the substrate and used to emit a plurality of excitation light beams; a light cut-off layer, wherein the light-emitting elements are disposed between the substrate and the light cut-off layer, the light cut-off layer having a plurality of grooves, and the positions of the grooves respectively correspond to the positions of the light-emitting elements; a plurality of light conversion elements, respectively disposed in the grooves, wherein the excitation light beams are irradiated to the light conversion elements, and the light conversion elements are used to convert the excitation light beams into A plurality of color light beams, and the light cutoff layer is used to reflect the excitation light beams and to allow the color light beams to penetrate; and a plurality of metal elements are arranged between the light cutoff layer and the substrate, wherein the metal elements form a patterned layer, the light emitting elements are located between the metal elements, the range of the orthographic projection of the metal elements on the substrate does not overlap with the range of the orthographic projection of the light emitting elements on the substrate, and the height of the metal elements is greater than the height of the light emitting elements.