Transparent display and method for manufacturing the same

Abstract

The present invention provides a transparent display with high transparency and high brightness, and a method for manufacturing the same. [Solution] The transparent display comprises a transparent driver substrate, a plurality of light-emitting elements, and a transparent sealing layer. The plurality of light-emitting elements are provided on the transparent driver substrate. The transparent sealing layer covers the plurality of light-emitting elements and has a microlens array structure on the surface of the transparent sealing layer above the plurality of light-emitting elements. The microlenses of the microlens array structure hardly cover the light-transmitting region of the transparent display. Therefore, the transparent display has high transparency and high brightness.

Description

Technical Field

[0001] The present invention relates to a transparent display, particularly a transparent display having high transparency and high brightness, and a method for manufacturing the same.

Background Art

[0002] FIG. 1 shows a conventional transparent display. The transparent display 10 in FIG. 1 has a transparent driver substrate 11, a plurality of light-emitting elements 12, 13, 14, and a transparent encapsulation layer 15. The plurality of light-emitting elements 12, 13, 14 are provided on the transparent driver substrate 11. The transparent encapsulation layer 15 covers the plurality of light-emitting elements 12, 13, 14. The transparent driver substrate 11 has a plurality of metal wires and a plurality of thin film transistor elements (not shown) that are connected to and drive the plurality of light-emitting elements 12, 13, 14, and the light rays L1 emitted by the light-emitting elements 12, 13, 14 irradiate the outside of the transparent display 10 to form an image observable by an observer. The light-emitting elements 12, 13, 14 emit light rays of different colors. For example, the light-emitting element 12 emits a red light ray, the light-emitting element 13 emits a green light ray, and the light-emitting element 14 emits a blue light ray. The light-emitting elements 12, 13, 14 may be micro light-emitting diodes (micro LEDs), but are not limited thereto. In FIG. 1, the light-emitting elements 12, 13, 14 are independent micro LED chips. In other embodiments, the light-emitting elements 12, 13, 14 that emit different colors are integrated into the same micro LED chip. The plurality of metal wires of the light-emitting elements 12, 13, 14 and the transparent driver substrate 11, and the plurality of thin film transistor elements form a light non-transmissive region Ao, and the other parts form a light transmissive region At.

[0003] As external light rays La pass through the transparent display 10, as shown in Figure 2, the observer 20 can see the image 21 behind the transparent display 10 from in front of the transparent display 10. In other words, with the transparent display 10, the observer 20 can see the image 21 behind the transparent display 10 while simultaneously viewing the screen information. In the automotive industry, the transparency of the transparent display 10 is used to attach the transparent display 10 to the windshield or to replace the windshield with the transparent display 10, thereby displaying driving information (e.g., navigation, speed, etc.) directly on the windshield. Therefore, there is no need to lower one's head to check driving information, which prevents driver distraction. In other words, the driver can check driving information via the transparent display 10 on the windshield while simultaneously checking the road conditions ahead, thus improving driving safety.

[0004] The transparent display 10 is used in many applications besides automobiles. For example, by replacing transparent windows or transparent glass with the transparent display 10, the usability of space can be increased. Specifically, by attaching the transparent display 10 to a shop window or replacing a shop window with the transparent display 10, product information or the latest events can be displayed in the shop window, attracting the attention of consumers. In exhibition spaces such as museums and art galleries, by attaching the transparent display 10 to the glass of exhibits or replacing the glass of exhibits with the transparent display 10, the concept of the artwork, information about the artist, etc., can be dynamically displayed, improving the viewing experience.

[0005] By using the transparent display 10, the user can view the image behind the transparent display 10 while simultaneously viewing the screen information. Therefore, the transparent display 10 can be applied to augmented reality (AR) glasses or devices. In the future, it is conceivable that the lenses of glasses could be replaced with the transparent display 10. This would allow glasses to have various functions in addition to their vision correction function. [Overview of the project] [Problems that the invention aims to solve]

[0006] If the multiple light-emitting elements 12, 13, and 14 are micro-LED chips, the multiple light-emitting elements 12, 13, and 14 may be placed on the transparent driver substrate 11 by mass transfer. After mass transfer, the contact area between the micro-LED chip and the transparent driver substrate 11 is small, resulting in very weak adhesion. Therefore, in order to improve the reliability of the micro-LED chip, it is necessary to seal it as is and form a transparent sealing layer 15 that covers the micro-LED chip. However, since the micro-LED chip is sealed in die form, as shown in Figure 1, some of the light rays L2 from the micro-LED chip undergo total internal reflection and do not reach the outside of the transparent display 10, reducing the light-emitting effect and causing a problem of insufficient maximum brightness of the transparent display 10.

[0007] To improve the problem of insufficient brightness in transparent displays, it has been proposed to provide a microlens array (MLA) on the upper surface of the transparent encapsulation layer. Figure 3 shows a conventional transparent display having a microlens array. The transparent display 30 in Figure 3 has a transparent driver substrate 31, a plurality of light-emitting elements 32, 33, and 34, a transparent encapsulation layer 35, and a microlens array layer 36. The plurality of light-emitting elements 32, 33, and 34 are provided on the transparent driver substrate 31. The transparent encapsulation layer 35 covers the plurality of light-emitting elements 32, 33, and 34. The microlens array layer 36 is attached to the upper surface of the transparent encapsulation layer 35. The transparent driver substrate 31 has a plurality of metal wires and a plurality of thin-film transistor elements (not shown) that are connected to and driven by the plurality of light-emitting elements 32, 33, and 34. The light-emitting elements 32, 33, and 34 each emit light rays of different colors. For example, light-emitting element 32 emits red light rays, light-emitting element 33 emits green light rays, and light-emitting element 34 emits blue light rays. The light-emitting elements 32, 33, and 34 may, but are not limited to, microLEDs. In Figure 3, the light-emitting elements 32, 33, and 34 are each independent microLED chips. In other embodiments, light-emitting elements 32, 33, and 34 emitting different colors are integrated into the same microLED chip. The light-transmitting region Ao is formed by the light-emitting elements 32, 33, and 34, as well as multiple metal wires of the transparent driver substrate 31 and multiple thin-film transistor elements, while the remaining portion forms a light-transmitting region At. The microlens array layer 36 increases the number of light rays L1 and L2 irradiated from the light-emitting elements 32, 33, and 34 to the outside of the transparent display 30, thereby improving the maximum brightness of the transparent display 30, or in other words, improving the luminescence effect of the transparent display 30. The microlens array layer 36 has a microlens array structure in which multiple apertures consist of microlenses 361 at the μm level. The shape of the microlenses 361 may be regular or irregular. Regular shapes include spherical, aspherical, cylindrical, hyperbolic, convex polygonal, and biconcave shapes. The optical function of the microlens array layer 36 can be adjusted by adjusting the shape, focal length, and arrangement of the microlenses 361.The material for the microlens array layer 36 may be polydimethylsiloxane (PDMS), polymethyl methacrylate (PMMA), photoresist, or silicon dioxide (SiO2).

[0008] Generally, adding a microlens array layer 36 to the transparent display 30 in Figure 3 improves the maximum brightness by approximately 45% compared to the transparent display 10 in Figure 1. However, as shown in Figure 4, the microlenses 361 of the microlens array layer 36 of the transparent display 30 are installed throughout the entire microlens array layer 36, that is, they are provided not only above the light-opaque region Ao but also above the light-transmitting region At. Therefore, when external light rays La enter the microlens array layer 36 from behind the transparent display 30 through the light-transmitting region At, they are scattered or focused by the microlenses 361, causing blurring in the image 21 seen by the observer. In other words, the microlens array layer 36 reduces the transparency of the transparent display 30.

[0009] The object of the present invention is to provide a transparent display with high transparency and high brightness, and a method for manufacturing the same. [Means for solving the problem]

[0010] According to the present invention, a transparent display comprises a transparent driver substrate, a plurality of light-emitting elements, and a transparent sealing layer. The plurality of light-emitting elements are provided on the transparent driver substrate. The transparent sealing layer covers the plurality of light-emitting elements and has a microlens array structure on the surface of the transparent sealing layer above the plurality of light-emitting elements.

[0011] In one embodiment, the transparent sealing layer and the microlens array structure of the transparent display are formed in the same process.

[0012] In one embodiment, the plurality of light-emitting elements of the transparent display include microLED chips.

[0013] In one embodiment, the microlens array structure of the transparent display is formed only directly above each of the light-emitting elements.

[0014] In one embodiment, the microlens array structure of the transparent display is formed by hot stamping, microdroplet jetting, photoregistry flow, or laser.

[0015] According to the present invention, a method for manufacturing a transparent display comprises the steps of: providing a plurality of light-emitting elements on a transparent driver substrate; forming a transparent sealing layer that covers the plurality of light-emitting elements; and forming a microlens array structure on the surface of the transparent sealing layer above the plurality of light-emitting elements.

[0016] In one embodiment, the formation of the transparent sealing layer and the formation of the microlens array structure are performed in the same step in the manufacturing method.

[0017] In one embodiment, in the manufacturing method, the plurality of light-emitting elements include microLED chips.

[0018] In one embodiment, in the manufacturing method, the microlens array structure is formed only directly above each of the light-emitting elements.

[0019] In one embodiment, the manufacturing method involves forming the microlens array structure by hot stamping, microdroplet jetting, photoregistry flow, or laser.

[0020] The microlenses in the microlens array structure of the transparent display of the present invention hardly cover the light-transmitting region of the transparent display. Therefore, the transparent display of the present invention has high transparency and high brightness. [Brief explanation of the drawing]

[0021] [Figure 1] This shows a conventional transparent display. [Figure 2] It is a schematic diagram showing a situation where an observer views an image behind a transparent display. [Figure 3] A transparent display having a conventional microlens array is shown. [Figure 4] It is a distribution diagram of microlenses of a microlens array layer in FIG. 3. [Figure 5] An embodiment of the transparent display of the present invention is shown. [Figure 6] Example 1 of a distribution diagram of microlenses of a transparent encapsulation layer in FIG. 5 is shown. [Figure 7] Example 2 of a distribution diagram of microlenses of a transparent encapsulation layer in FIG. 5 is shown. [Figure 8] Example 3 of a distribution diagram of microlenses of a transparent encapsulation layer in FIG. 5 is shown. [Figure 9] It is a flowchart of a manufacturing method of the transparent display of the present invention.

Mode for Carrying Out the Invention

[0022] Figure 5 shows a transparent display of the present invention. The transparent display 40 in Figure 5 has a transparent driver substrate 41, a plurality of light-emitting elements 42, 43, 44, and a transparent sealing layer 45. The plurality of light-emitting elements 42, 43, 44 are provided on the transparent driver substrate 41. The transparent sealing layer 45 covers the plurality of light-emitting elements 42, 43, 44. The transparent driver substrate 41 has a plurality of metal wires and a plurality of thin-film transistor elements (not shown) that are connected to and driven by the plurality of light-emitting elements 42, 43, 44, and the light rays L1, L2 emitted by the light-emitting elements 42, 43, 44 irradiate the outside of the transparent display 10 to form an image that can be observed by an observer. The light-emitting elements 42, 43, 44 each emit light rays of different colors. For example, light-emitting element 42 emits red light rays, light-emitting element 43 emits green light rays, and light-emitting element 44 emits blue light rays. The light-emitting elements 42, 43, 44 may be micro-LEDs, but are not limited to them. In Figure 5, the light-emitting elements 42, 43, and 44 are each independent micro-LED chips. In other embodiments, light-emitting elements 42, 43, and 44 that emit different colors are integrated into the same micro-LED chip. The light-transmitting region Ao is formed by the light-emitting elements 42, 43, and 44, as well as multiple metal wires of the transparent driver substrate 41 and multiple thin-film transistor elements, while the remaining portion forms a light-transmitting region At.

[0023] The transparent sealing layer 45 in Figure 5 has a microlens array structure consisting of a plurality of microlenses 451. The microlens array structure increases the number of light rays L1 and L2 irradiated from the light-emitting elements 42, 43, and 44 to the outside of the transparent display 40, thereby improving the maximum brightness of the transparent display 40, or in other words, improving the luminescence effect of the transparent display 40. The plurality of microlenses 451 of the transparent sealing layer 45 have a μm-level aperture. The shape of the microlenses 451 may be regular or irregular. Regular shapes include circular, elliptical, spherical, aspherical, cylindrical, hyperbolic, convex polygonal, and biconcave shapes. The optical function of the transparent sealing layer 45 can be adjusted by adjusting the shape, focal length, and arrangement of the microlenses 4511.

[0024] In one embodiment, the microlens array structure, consisting of a transparent sealing layer 45 and a plurality of microlenses 451, is formed in different processes. In another embodiment, the microlens array structure, consisting of a transparent sealing layer 45 and a plurality of microlenses 451, is formed in the same process, thereby reducing the number of processes.

[0025] In the present invention, a plurality of microlenses 451 can be formed by hot stamping, microdroplet jetting, photoregistry flow, or laser, and the transparent mirror array structure can be formed further. However, the transparent mirror array structure of the present invention is not limited to those formed by the above methods.

[0026] Figure 6 shows an example 1 of the distribution diagram of microlenses in the transparent sealing layer in Figure 5. In the example in Figure 6, the microlenses 451 are formed only directly above the light-emitting elements 42, 43, and 44. In other words, the microlens array structure is formed only directly above each light-emitting element 42, 43, and 44. Therefore, the light rays L1 and L2 emitted by the light-emitting elements 42, 43, and 44 irradiate the outside of the transparent display 40, improving the maximum brightness of the transparent display 40. Because the microlenses 451 of the microlens array structure of the present invention are not provided above the light-transmitting region At, when external light rays La irradiate the transparent sealing layer 45 from behind the transparent display 40 through the light-transmitting region At, the external light rays La are not scattered or focused by the microlenses 451, so that the observer can clearly see the image behind the transparent display 40. In other words, the transparent display 40 of the present invention has not only high brightness but also high transparency.

[0027] Figure 7 shows an example 2 of the distribution diagram of microlenses in the transparent sealing layer in Figure 5. In the example in Figure 7, the microlens 451 is located above the light-emitting elements 42, 43, and 44 and covers a portion of the light-transmitting region At. The light rays L1 and L2 emitted by the light-emitting elements 42, 43, and 44 irradiate the outside of the transparent display 40 through the microlens 451 above the light-emitting elements 42, 43, and 44, improving the maximum brightness of the transparent display 40. When external light rays La are incident on the transparent sealing layer 45 from behind the transparent display 40 through the light-transmitting region At, they are hardly affected by the microlens 451. Therefore, the observer can still clearly see the image behind the transparent display 40. In other words, even when using the transparent display 40 of the example in Figure 7, high maximum brightness and high transparency are still achieved.

[0028] Figure 8 shows Example 3 of the distribution diagram of microlenses in the transparent sealing layer in Figure 5. In the example in Figure 8, one microlens 451 covers a set of light-emitting elements 42, 43, and 44, and also covers a portion of the light-transmitting region At. Light rays L1 and L2 emitted by the light-emitting elements 42, 43, and 44 irradiate the outside of the transparent display 40 through the upper microlens 451, improving the maximum brightness of the transparent display 40. When external light rays La are incident on the transparent sealing layer 45 from behind the transparent display 40 through the light-transmitting region At, they are hardly affected by the microlens 451. Therefore, the observer can still clearly see the image behind the transparent display 40. In other words, even when using the transparent display 40 of the example in Figure 8, high maximum brightness and high transparency are still achieved.

[0029] Figure 9 is a flowchart of the method for manufacturing the transparent display of the present invention. The explanation will be given with reference to Figures 5 and 9. The method for manufacturing the transparent display 40 of the present invention includes step S10 of providing a plurality of light-emitting elements 42, 43, and 44 on a transparent driver substrate 41. If the plurality of light-emitting elements 42, 43, and 44 are microLED chips, step S10 may be performed by mass transfer.

[0030] After placing multiple light-emitting elements 42, 43, and 44 on the transparent driver substrate 41, the process proceeds to step S11. Because the contact area between the micro-LED chip and the transparent driver substrate 41 is small, the adhesive strength is very weak. To improve the reliability of the micro-LED chip, in step S11, after placing the multiple light-emitting elements 42, 43, and 44 on the transparent driver substrate 41, a transparent sealing layer 45 is formed to cover them. Alternatively, after placing the multiple light-emitting elements 42, 43, and 44 on the transparent driver substrate 41, the substrate is sealed as is to form a transparent sealing layer 45 that covers the micro-LED chip.

[0031] After forming a transparent sealing layer 45 that covers the multiple light-emitting elements 42, 43, and 44, the process proceeds to step S12. Because the micro-LED chips are sealed in die form, some of the light rays L2 emitted by the micro-LED chips may be totally reflected and not reach the outside of the transparent display 40. To improve the light-emitting effect of the transparent display 40, in step S12, a microlens array structure is formed on a portion of the surface of the transparent sealing layer 45 above the multiple light-emitting elements 42, 43, and 44. In step S12, multiple microlenses 451 are formed by hot stamping, microdroplet jetting, photoregistry flow, or laser, and the transparent mirror array structure is further formed. The present invention is not limited to the transparent mirror array structure formed by the above method.

[0032] In one embodiment, in step S12, a microlens 451 is formed only on the surface of the transparent sealing layer 45 directly above the plurality of light-emitting elements 42, 43, and 44. That is, the microlens array structure covers only the light-impermeable region Ao. In one embodiment, in step S12, a microlens 451 is formed above the plurality of light-emitting elements 42, 43, and 44 so as to cover a portion of the spectrally transmitting region At.

[0033] In one embodiment, steps S11 and S12 are different steps, i.e., the formation of the transparent sealing layer 45 and the formation of the microlens array structure consisting of multiple microlenses 451 are carried out in different steps. In another embodiment, steps S11 and S12 are the same step, i.e., the formation of the transparent sealing layer 45 and the formation of the microlens array structure consisting of multiple microlenses 451 are carried out in the same step, thus reducing the number of steps.

[0034] The experiment uses a 13.3-inch transparent display as an example. Under the same conditions, the transparent display 40 of the present invention can increase the maximum brightness by up to 243% compared to the transparent display 10 in Figure 1. In terms of transparency, the transparent display 40 of the present invention is only 3% lower than the transparent display 10 in Figure 1. Therefore, it can be seen that the transparent display 40 of the present invention has both high transparency and high brightness compared to the transparent display 10 in Figure 1.

[0035] In the transparent display 30 of Figure 3, the light rays L1, L2, and external light ray La emitted by the light-emitting elements 32, 33, and 34 all pass through the transparent sealing layer 35 and the microlens array layer 36. Because the transparent sealing layer 35 and the microlens array layer 36 are different media, energy loss occurs during the transmission of light rays L1, L2, and external light ray La, reducing the maximum brightness. Conversely, in the transparent display 40 of the present invention, the light rays L1, L2, and external light ray La emitted by the light-emitting elements 42, 43, and 44 all pass through only the transparent sealing layer 45. Therefore, energy loss during transmission is reduced, resulting in a higher maximum brightness. Also, in the transparent display 30 of Figure 3, the microlenses 361 of the microlens array layer 36 cover most of the light-transmitting region At, so the external light ray La is scattered or focused by the microlenses 361. Therefore, the transparency of the transparent display 30 is reduced. Conversely, in the transparent display 40 of the present invention, the microlenses 451 of the microlens array structure on the surface of the transparent sealing layer 45 are provided almost exclusively in the non-light-transmitting region Ao. Therefore, external light rays La are transmitted through the transparent display 40 with almost no effect, improving the transparency of the transparent display 40. Thus, compared to the transparent display 30 in Figure 3, the transparent display 40 of the present invention has both high transparency and high brightness simultaneously.

[0036] The above description is merely an embodiment of the present invention and does not limit the present invention in any way. The present invention is disclosed by the above embodiments, but this does not limit the present invention. A person with ordinary skill in the art can create equivalent embodiments by making some changes or modifications using the above disclosed technical content, as long as they do not deviate from the scope of the technical solution of the present invention. Therefore, as long as they do not deviate from the content of the technical solution of the present invention, all simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are all included within the scope of the technical solution of the present invention. [Explanation of symbols]

[0037] 10 Transparent Display 11 Transparent driver board 12 Light-emitting elements 13 Light-emitting element 14 Light-emitting elements 15 Transparent sealing layer 20 Observers 21 Video 30 Transparent Display 31 Transparent driver board 32 Light-emitting elements 33 Light-emitting elements 34 Light-emitting elements 35 Transparent sealing layer 36 Microlens array layer 361 Microlenses 40 Transparent Display 41 Transparent driver board 42 Light-emitting element 43 Light-emitting element 44 light-emitting elements 45 Transparent sealing layer 451 Microlens Ao Non-light transmitting area At light transmission area L1 ray L2 ray La external rays S10 process S11 process S12 process

Claims

1. It comprises a transparent driver substrate, multiple light-emitting elements, and a transparent sealing layer. The plurality of light-emitting elements are provided on the transparent driver substrate, The transparent sealing layer covers the plurality of light-emitting elements, and the surface of the transparent sealing layer above the plurality of light-emitting elements has a microlens array structure. Transparent display.

2. The transparent sealing layer and the microlens array structure are formed in the same process. The transparent display according to claim 1.

3. The plurality of light-emitting elements include a microLED chip, The transparent display according to claim 1.

4. The microlens array structure is formed only directly above each of the light-emitting elements. The transparent display according to claim 1.

5. The aforementioned microlens array structure is formed by hot stamping, microdroplet jetting, photoregistry flow, or laser. The transparent display according to claim 1.

6. A step of providing multiple light-emitting elements on a transparent driver substrate, A step of forming a transparent sealing layer that covers the plurality of light-emitting elements, The process includes the step of forming a microlens array structure on the surface of the transparent sealing layer above the plurality of light-emitting elements. A method for manufacturing transparent displays.

7. The formation of the transparent sealing layer and the formation of the microlens array structure are carried out in the same process. The manufacturing method according to claim 6.

8. The plurality of light-emitting elements include a microLED chip, The manufacturing method according to claim 6.

9. The microlens array structure is formed only directly above each of the light-emitting elements. The manufacturing method according to claim 6.

10. The aforementioned microlens array structure is formed by hot stamping, microdroplet jetting, photoregistry flow, or laser. The manufacturing method according to claim 6.

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