KR-20260067321-A - TRANSMISSIVE DISPLAY DEVICE AND LIGHT EMISSION STRUCTURE THEREOF

KR20260067321AKR 20260067321 AKR20260067321 AKR 20260067321AKR-20260067321-A

Abstract

[Problem] To provide a “transmissive display and its light-emitting structure” capable of suppressing the decrease in brightness of the observation surface caused by light that passes through the gap between electrodes and is irradiated toward the back surface of the display when a light source is turned on. [Solution] In a light-emitting structure (10) of a transmissive display having a plurality of sets of electrodes (3, 4) arranged in an array and a plurality of light-transmitting LEDs (8) arranged to span between each set of electrodes (3, 4), a reflective part (9) is provided in a target area including a region that shields the light path in the light path in the direction toward the transparent substrate (1) from the part of the back surface of the LED (8) that is opposite to the gap between the electrodes (3, 4), so that when the LED (8) is turned on, the light irradiated from the back surface of the LED (8) in the direction toward the transparent substrate (1) is reflected by the reflective part (9) and becomes light directed toward the observation surface, thereby suppressing the decrease in brightness toward the observation surface.

Inventors

요시이 가츠마사
우마가미 도모미

Assignees

알프스 알파인 가부시키가이샤

Dates

Publication Date: 20260512
Application Date: 20251027
Priority Date: 20241105

Claims (12)

Multiple sets of electrodes arranged in an array, and A plurality of light sources having light transparency arranged to span between each set of electrodes for the above plurality of sets of electrodes, and A reflector disposed in a target area including a region that shields the light path on a light path in the direction toward a transparent substrate from a portion of the back surface of the light source facing the gap between the electrodes. A light-emitting structure of a transparent display characterized by the following.
In paragraph 1, having a laminated structure including the above-mentioned transparent substrate and insulating layer, A light-emitting structure of a transparent display, characterized in that the reflection portion is formed in the gap between each set of electrodes in a layer such as the layer where the plurality of sets of electrodes are formed.
In paragraph 1, having a laminated structure including the above-mentioned transparent substrate and insulating layer, A light-emitting structure of a transparent display characterized in that the above-described reflective portion is formed on a layer different from the layer on which the above-described plurality of electrodes are formed.
In paragraph 3, A light-emitting structure of a transparent display characterized in that the above-mentioned reflective part is a wiring electrode different from the above-mentioned plurality of electrodes.
In paragraph 4, The target area where the wiring electrode is formed is a rectangular area having edges in a first direction, which is a direction connecting the electrodes, and a second direction, which is a direction orthogonal to the first direction. A light-emitting structure of a transparent display characterized in that the length of the first direction is longer than the length of the gap between the electrodes in the first direction, and the length of the second direction is longer than the length of the gap between the electrodes in the second direction.
In paragraph 2 or 3, The light-emitting structure of a transparent display, characterized in that the above-mentioned reflective portion is a reflective layer formed by a metal film, plate, film, or sheet.
In paragraph 6, The target area where the reflective layer is formed is a rectangular area having edges in a first direction, which is a direction connecting the electrodes, and a second direction, which is a direction orthogonal to the first direction. The length of the first direction of the above target area is less than or equal to the longer of the maximum length between the edges of the first direction of a pair of electrodes or the length of the first direction of the light source, and The length of the second direction of the above target area is less than or equal to the longer of the length of the second direction of a pair of electrodes or the length of the second direction of the light source. A light-emitting structure of a transparent display characterized by the following.
In paragraph 3, The above-mentioned reflective part is a reflective layer formed by a metal film, plate, film, or sheet, and The target area where the reflective layer is formed is a rectangular area having edges in a first direction, which is a direction connecting the electrodes, and a second direction, which is a direction orthogonal to the first direction. The length of the first direction of the above target area is greater than or equal to the length of the first direction of the gap between the electrodes, and less than or equal to the longer of the maximum length between the edges of the first direction of a pair of electrodes or the length of the first direction of the light source. The length of the second direction of the above target area is greater than or equal to the length of the second direction of the gap between the electrodes, and less than or equal to the longer of the length of the second direction of a pair of electrodes or the length of the second direction of the light source. A light-emitting structure of a transparent display characterized by the following.
In paragraph 6, A light-emitting structure of a transparent display, characterized in that the above-mentioned reflective portion is a metal film formed on the surface of the above-mentioned transparent substrate or the above-mentioned insulating layer.
In paragraph 6, A light-emitting structure of a transparent display, characterized in that the above-mentioned reflective portion is a metal plate, metal film, or metal sheet formed on the back surface of the above-mentioned transparent substrate.
In paragraph 6, A light-emitting structure of a transparent display characterized by additionally having a light-blocking layer formed at a layer position further away from the reflective layer when viewed from the light source.
A transparent display having a light-emitting structure as described in claim 1.

Description

Transmissive display device and light emission structure thereof The present disclosure relates to a transparent display and a light-emitting structure thereof. Conventionally, a transparent display is known that is configured to allow the background to be visible, unlike a general display. A transparent display can transmit light from the back side of the display to the surface through the openings by arranging a plurality of light sources in an array on a transparent substrate and providing a plurality of openings where electrodes are not placed. The ratio of the area of the openings to the area of a single pixel is called the aperture ratio. The larger the aperture ratio, the more background light can be received, making it possible to achieve a display that is close to transparent in appearance. There are various types of transmissive displays, but among them, transmissive LED displays are expected to be applied to various uses because they can achieve a high transmittance of over 70%. When constructing a transmissive LED display, it is desirable to use a technology called Micro LED, which is achieved by miniaturizing LEDs used as light sources and arranging them in an array. FIG. 8 is a diagram showing the structure of the light-emitting part of a transmissive LED display in a simplified manner. FIG. 8(a) shows the state of the light-emitting part of the transmissive LED display viewed from the surface side, and FIG. 8(b) shows the state of the light-emitting part of the transmissive LED display viewed from the back side. As shown in FIG. 8(a), a plurality of LEDs (101) are arranged in an array, and a plurality of openings (102) are arranged in an array adjacent to the plurality of LEDs (101). Each of the plurality of LEDs (101) is arranged between an anode electrode (103) and a cathode electrode (104). In a transmissive LED display configured in this manner, as shown in FIG. 8(b), light from an LED (101) that emits light to illuminate information on a surface leaks out through the gap between the anode electrode (103) and the cathode electrode (104) to the back side. However, there was a problem in that light irradiated from the LED (101) toward the back side, which is different from the observation surface on the front side, is emitted directly to the back side of the transmissive LED display and becomes lost light that does not contribute to the brightness on the observer side. That is, a micro LED device is generally made by growing a semiconductor thin film on a sapphire substrate by epitaxial growth. Since sapphire and semiconductor thin films have high transmittance, light emitted from within the device is radiated in all directions. In addition, in a transmissive LED display, the substrate placed on the front side of the LED (101) and the substrate placed on the back side are both made of transparent substrates. As a result, when the LED (101) is turned on, light passing through the gap between the electrodes (102, 103) from the back side of the LED (101) further passes through the transparent substrate and leaks out to the back side of the display. As a result, there was a problem in that the light utilization efficiency was reduced and the brightness of the observation surface was reduced due to the light leaking out to the back side. In addition, a technology is known that enables light emission from the back side of an LED chip to be emitted to the front side by configuring the wiring pattern of a circuit board on which an LED chip is mounted with a light-reflective material (e.g., aluminum) (see, for example, Patent Document 1). FIG. 1 is a drawing showing an example of the configuration of a light-emitting structure of a transparent LED display according to a first embodiment. FIG. 2 is a drawing for explaining the effect of a light-emitting structure according to a first embodiment. FIG. 3 is a drawing showing an example of the configuration of a light-emitting structure of a transparent LED display according to a second embodiment. FIG. 4 is a drawing showing an example of the configuration of a light-emitting structure of a transparent LED display according to a third embodiment. FIG. 5 is a drawing showing an example of the configuration of a light-emitting structure of a transmissive LED display according to the fourth embodiment. FIG. 6 is a drawing showing an example of the configuration of a light-emitting structure of a transparent LED display according to the fifth embodiment. FIG. 7 is a drawing showing an example of the configuration of a light-emitting structure of a transparent LED display according to other embodiments. Figure 8 is a diagram showing the structure of the light-emitting part of a transparent LED display. Hereinafter, each embodiment of the present disclosure will be described with reference to the drawings. The display to which each embodiment described sequentially below is applied is a transparent display capable of transmitting light through a plurality of