JP7713808B2 - Wiring structure, light-emitting panel, and method for manufacturing wiring structure - Google Patents

Description

The present invention relates to a light- emitting panel and a method for manufacturing the same .

As shown in Patent Documents 1 and 2 below, transparent light-emitting bodies (e.g., transparent light-emitting displays) are provided in which light-emitting elements such as LEDs (Light Emitting Diodes) and OLEDs (Organic Light Emitting Diodes) are mounted on a transparent electrode substrate. Patent Documents 1 and 2 also disclose examples of applications of the transparent light-emitting bodies, such as vehicle windows and building window glass (hereinafter referred to as "vehicle windows, etc.") incorporating the transparent light-emitting bodies.

Japanese Patent Application Laid-Open No. 2020-17730 JP 2019-114394 A

When incorporating a transparent light-emitting device into a vehicle window or the like, wiring is provided inside or on the surface of the vehicle window or the like to electrically connect the power source and the transparent light-emitting device and supply power from the power source to the transparent light-emitting device. However, if the transparent light-emitting device is located, for example, in the center of the vehicle window or the like, the visible area of the wiring on the vehicle window or the like becomes larger (longer). As a result, the presence of the wiring becomes noticeable, detracting from the design of the vehicle window or the like.

In contrast, if the transparent light-emitting element is placed near the edge of a vehicle window, etc., the visible area of the wiring can be minimized (shortened). However, in this case, the position of the transparent light-emitting element on the vehicle window, etc. is restricted, reducing the degree of freedom in the design of the transparent light-emitting element and vehicle window, etc.

In light of the above issues, the present invention aims to provide a wiring structure that properly ensures power supply to power-receiving components (e.g., light-emitting components) while not compromising aesthetics or design freedom. It also aims to provide a light-emitting panel equipped with this wiring structure.

In order to solve the above-mentioned problems, the light-emitting panel according to the present invention comprises:
A light-emitting panel including a light-emitting unit and a wiring structure that supplies power to the light-emitting unit,
The wiring structure includes a wiring portion and
a plate-shaped transparent base that supports the light-emitting panel;
a high refractive index transparent portion extending within the transparent base and having a higher refractive index than the transparent base;
a wiring portion is provided through the high refractive index transparent portion,
The interface between the high refractive index transparent portion and the transparent base is formed so that light incident on the high refractive index transparent portion from one surface side of the plate-shaped transparent base at an incident angle larger than a predetermined critical angle is totally reflected and exits from the other surface side of the plate-shaped transparent base .
It is characterized by:

According to this aspect of the present invention, light that enters the high-refractive-index transparent portion and is totally reflected at the interface between the high-refractive-index transparent portion and the transparent base portion exits from the high-refractive-index transparent portion. Therefore, the shadow of the wiring portion is less likely to be cast on the exit side of the high-refractive-index transparent portion, making the presence of the wiring portion less noticeable. This allows for a light-emitting panel that properly ensures the power supply function to the power-receiving portion (e.g., the light-emitting portion) and does not impair the design freedom or aesthetic appeal.

Preferably, the wiring portion has a rectangular shape in which the length of the wiring portion in the direction from the one surface side to the other surface side is shorter than the length in a direction perpendicular to the direction.

According to this aspect of the present invention, light that enters the high-refractive transparent portion and reaches the wiring portion is reflected, for example, toward the incident side. As a result, light that reaches the wiring portion is not emitted toward the exit side of the high-refractive transparent portion. This makes it even more difficult for the shadow of the wiring portion to be cast onto the exit side of the high-refractive transparent portion, making the presence of the wiring portion less noticeable.

The highly refractive transparent portion preferably has a plate-like cross section or a shape with a convex portion formed in the center of the cross section .

According to this aspect of the present invention, light that enters the high-refractive transparent portion and is totally reflected at the interface between the high-refractive transparent portion and the transparent base portion exits from the high-refractive transparent portion. As a result, the shadow of the wiring portion is less likely to be cast on the exit side of the high-refractive transparent portion, making the presence of the wiring portion less noticeable. This ensures proper power supply to the light-emitting portion, while providing a light-emitting panel that does not impair aesthetics or design freedom.

It is also preferable that the wiring portion has a light reflecting layer on the outer peripheral surface thereof.

Further, a method for manufacturing a light-emitting panel according to the present invention is a method for manufacturing the light-emitting panel, comprising:
connecting the light emitting portion and the wiring portion;
a step of arranging at least two highly refractive transparent members made of resin so as to face each other with the wiring portion connected to the light emitting portion interposed therebetween , and then crimping the at least two highly refractive transparent members using a predetermined crimping means to manufacture the highly refractive transparent portion;
and a step of bonding the high refractive index transparent portion and the transparent base portion together .

According to the present invention , at least two high refractive index transparent portions are joined by a predetermined pressure bonding means, and therefore these high refractive index transparent portions can be joined more firmly.

According to the present invention, it is possible to provide a light-emitting panel that properly ensures the function of supplying power to a power-receiving part (for example, a light-emitting part) and does not impair the design freedom or aesthetics.

FIG. 1 is a schematic perspective view of a light-emitting panel according to an embodiment of the present invention. AA cross-sectional view of the light-emitting panel (wiring structure) according to the present embodiment. 1 is a diagram showing the path of light incident on a light-emitting panel (wiring structure) according to an embodiment of the present invention. FIG. 10 is a cross-sectional view of a light-emitting panel (wiring structure) according to a modified example of the embodiment. 5A to 5C are explanatory diagrams of a manufacturing method for a wiring structure (light-emitting panel) according to the embodiment. 5A to 5C are explanatory diagrams of a manufacturing method for a wiring structure (light-emitting panel) according to the embodiment. 5A to 5C are diagrams showing an example of a method for joining a first high refractive index transparent portion and a second high refractive index transparent portion that sandwich a wiring portion in the wiring structure according to the embodiment. FIG. 1 is a diagram illustrating the outline of the setup for this simulation test. FIG. 10 is a diagram showing a screen projected image in a conventional wiring structure. 3A and 3B are diagrams showing a screen projected image in this embodiment.

[Configuration of wiring structure (light-emitting panel)]
A wiring structure according to one embodiment of the present invention and a light-emitting panel including the same will be described in detail below with reference to the drawings. First, a light-emitting panel 1 according to this embodiment will be described with reference to Figs. 1 to 4. Fig. 1 is a schematic perspective view of the light-emitting panel 1, Fig. 2 is an A-A cross-sectional view of the light-emitting panel 1 (wiring structure 20) (a cross-sectional view of the light-emitting panel 1 shown in Fig. 1 taken along line A-A), Fig. 3 is a diagram showing the path of light incident on the light-emitting panel 1 (wiring structure 20), and Fig. 4 is a cross-sectional view of a light-emitting panel 1 (wiring structure 30) according to a modified example.

As shown in FIG. 1, the light-emitting panel 1 according to this embodiment includes a light-emitting unit 10 and a wiring structure 20. The light-emitting unit 10 includes, for example, a transparent electrode substrate and a light-emitting element such as an LED or OLED mounted on the transparent electrode substrate. The transparent electrode substrate includes, for example, a substrate such as glass or a transparent polymer film (e.g., a film such as PET, PC, PCT, PEN, PU, TPU, PI, or silicone resin), and a transparent conductive material (ITO, FTO, IZO, IZTO, ZnO, etc.) formed in a predetermined location on the surface of the substrate. However, the configuration of the light-emitting unit 10 is not limited to this.

Next, as shown in Figures 1 and 2, the wiring structure 20 includes a wiring portion 21, a transparent base portion 22, and a highly refractive transparent portion 23. Note that although the wiring structure 20 of this embodiment is intended to supply power to the light-emitting portion 10, it may also be intended to supply power to devices other than the light-emitting portion 10 (for example, an ETC antenna module attached to the windshield of a vehicle).

As shown in FIG. 1, one end of the wiring unit 21 is electrically connected to a power source (e.g., an on-board battery) and the other end is connected to the light-emitting unit 10. Power from the power source is supplied to the light-emitting unit 10 via the wiring unit 21.

The configuration of the wiring section 21 is not particularly limited, but preferably includes, for example, a conductor located in the core of the wiring section 21, a protective layer covering the conductor, and a light-reflecting layer (e.g., a metal thin film) formed on at least the outer peripheral surface of the protective layer. This causes light that enters the high-refractive transparent section 23 and reaches the wiring section 21 to be reflected, for example, toward the incident side. Therefore, light that reaches the wiring section 21 does not exit toward the exit side of the high-refractive transparent section 23.

The transparent base 22 is a transparent member for supporting the light-emitting unit 10 (in this embodiment, for embedding the light-emitting unit 10). The light-emitting panel 1 according to this embodiment can be used, for example, as a vehicle window, various vehicle lamps, a sunroof, a rearview mirror installed inside a vehicle, a traffic sign, a display, and the like. Therefore, for example, when the light-emitting panel 1 is used as a vehicle window, the transparent base 22 corresponds to the window glass portion. Furthermore, when the light-emitting panel 1 is used as various vehicle lamps, the transparent base 22 corresponds to the cover portion of the lamp exterior.

Also, as shown in FIG. 2, the high-refractive transparent portion 23 extends within the transparent base portion 22. Furthermore, the aforementioned wiring portion 21 passes through the high-refractive transparent portion 23. In this embodiment, the high-refractive transparent portion 23 is arranged to surround the wiring portion 21 from above, below, and from the front and back.

Furthermore, the refractive index of the high-refractive-index transparent portion 23 is higher than that of the transparent base portion 22. Therefore, as shown in Figure 3, light L that enters the high-refractive-index transparent portion 23 at an angle of incidence greater than a predetermined critical angle is totally reflected at the interface between the high-refractive-index transparent portion 23 and the transparent base portion 22. Furthermore, the totally reflected light L exits from the exit side of the high-refractive-index transparent portion 23.

As a result, the shadow of the wiring section 21 is less likely to be cast on the output side of the high-refractive transparent section 23, making the presence of the wiring section 21 less noticeable. Therefore, according to this embodiment, it is possible to provide a light-emitting panel 1 (wiring structure 20) that properly ensures the power supply function to the light-emitting section 10 and does not impair the design or freedom of design.

Here, the materials for the high-refractive transparent portion 23 and the transparent base 22 are not particularly limited, as long as the refractive index of the high-refractive transparent portion is higher than that of the transparent base 22. For example, the high-refractive transparent portion 23 and the transparent base 22 can be made of acrylic polymers such as polytetrafluoroethylene and polymethyl methacrylate, polycarbonate, polyethylene terephthalate, polystyrene, silicone resin, epoxy resin, glass, etc., and of these, those with a high refractive index are used for the high-refractive transparent portion 23. However, other materials may also be used.

Note that while the high-refractive transparent portion 23 of the wiring structure 20 shown in Figures 1 to 3 is a plate-shaped member, the shape of the high-refractive transparent portion is not limited to this. For example, as in the high-refractive transparent portion 33 shown in Figure 4 (a modified example of this embodiment), it may have a shape in which, in a cross-sectional view, an upwardly convex portion is formed approximately in the center of the top surface 331 and a downwardly convex portion is formed approximately in the center of the bottom surface 332. Other shapes are also possible.

[Method of manufacturing wiring structure]
Next, a method for manufacturing the wiring structure 20 (light-emitting panel 1) according to this embodiment will be described with reference to Fig. 5 to Fig. 7. Fig. 5 and Fig. 6 are diagrams for explaining the steps of the method for manufacturing the wiring structure 20. Fig. 7 shows an example of a method for joining the first high-refractive transparent portion 231 and the second high-refractive transparent portion 232 that sandwich the wiring portion 21 in the wiring structure 20.

First, as shown in FIG. 5(a), the wiring portion 21 of the wiring structure 20 is connected to the light-emitting portion 10. Next, as shown in FIG. 5(b), at least two high-refractive transparent portions 23 (a first high-refractive transparent portion 231 and a second high-refractive transparent portion 232) are arranged above and below the wiring portion 21. After that, as shown in FIG. 5(c), the wiring portion 21 is sandwiched (bonded) between the first high-refractive transparent portion 231 and the second high-refractive transparent portion 232.

Next, as shown in FIG. 6(a), at least two transparent bases 22 (a first transparent base 221 and a second transparent base 222) are prepared. Then, as shown in FIG. 6(b), the light-emitting unit 10 and the high-refractive transparent unit 23 sandwiching the wiring unit 21 are placed in predetermined positions on the transparent base 22 (in the illustrated example, the light-emitting unit 10 and the high-refractive transparent unit 23 are placed in predetermined positions above the second transparent base 222). Finally, as shown in FIG. 6(c), the first transparent base 221 and the second transparent base 222 are joined, and the light-emitting unit 10 and the high-refractive transparent unit 23 are housed within the transparent base 22. This method allows for easy manufacturing of the wiring structure 20 and light-emitting panel 1.

Also, as shown in FIG. 7, when joining the first high refractive index transparent portion 231 and the second high refractive index transparent portion 232 with the wiring portion 21 sandwiched between them, the first high refractive index transparent portion 231 and the second high refractive index transparent portion 232 may be pressed together using rollers 41, 42 (pressing means). This allows the first high refractive index transparent portion 231 and the second high refractive index transparent portion 232 to be more firmly joined.

Specific examples of the wiring structure 20 described above are shown below. However, the present invention is not limited or restricted by the following examples.

As shown in Figure 8, multiple light sources 51 for reproducing pseudo-natural light are arranged vertically at predetermined positions on the incident side of the wiring structure 20 (five light sources 51 are arranged at 5 mm intervals), and a screen is placed on the exit side of the wiring structure 20. This shows the results of a simulation test of the image projected onto the screen when the wiring structure 20 is illuminated by the light sources 51.

Here, in this simulation test, the thickness 23T of the high refractive index transparent portion 23 was varied. More specifically, a sample with a thickness 23T of the high refractive index transparent portion 23 of 9 mm corresponds to Example 1, a sample with a thickness 23T of the high refractive index transparent portion 23 of 7 mm corresponds to Example 2, a sample with a thickness 23T of the high refractive index transparent portion 23 of 5 mm corresponds to Example 3, and a sample with a thickness 23T of the high refractive index transparent portion 23 of 3 mm corresponds to Example 4.

By the way, when a similar simulation test was conducted on a conventional wiring structure (a wiring structure without a highly refractive transparent portion 23), a rectangular image (shadow) 21P corresponding to the wiring portion 21 was clearly projected onto the screen within the image 511 of the light source 51, as shown in Figure 9.

In contrast, as shown in Figure 10, in none of the test results for Examples 1 to 4 was a rectangular image corresponding to the wiring portion 21 projected. In particular, for Example 1 (a sample in which the thickness 23T of the high-refractive transparent portion 23 was 9 mm), not only was the rectangular image of the wiring portion 21 not generated at the corresponding location 211 of the wiring portion 21, but also no discontinuous image that divided the image 511 of the light source 51.

On the other hand, for Examples 2 to 4 (samples having a thinner high-refractive transparent portion 23 than Example 1), a cut-like image dividing the image 511 of the light source 51 into upper and lower portions appeared at the corresponding location 211 of the wiring portion 21. This suggests that the wiring portion 21 can be made less noticeable by adjusting the thickness 23T of the high-refractive transparent portion 23 to, for example, 9 mm or more.

Embodiments of the present invention have been described in detail above. However, the above description is provided to facilitate understanding of the present invention and is not intended to limit the present invention. The present invention may be modified or improved without departing from its spirit. The present invention also includes equivalents thereof.

REFERENCE SIGNS LIST 1... light-emitting panel 10... light-emitting section 20, 30... wiring structure 21, 31... wiring section 22, 32... transparent base section 23, 33... high-refractive transparent section

Claims (5)

A light-emitting panel including a light-emitting unit and a wiring structure that supplies power to the light-emitting unit,
The wiring structure includes a wiring portion and
a plate-shaped transparent base that supports the light-emitting panel;
a high refractive index transparent portion extending within the transparent base and having a higher refractive index than the transparent base;
a wiring portion is provided through the high refractive index transparent portion,
The interface between the high refractive index transparent portion and the transparent base is formed so that light incident on the high refractive index transparent portion from one surface side of the plate-shaped transparent base at an incident angle larger than a predetermined critical angle is totally reflected and exits from the other surface side of the plate-shaped transparent base .
A light-emitting panel characterized by: The light-emitting panel according to claim 1 , wherein the wiring portion has a rectangular shape in which a length in a direction from the one surface side to the other surface side of the wiring portion is shorter than a length in a direction perpendicular to the direction. The light-emitting panel according to claim 1 or 2, wherein the high-refractive transparent portion has a plate-like shape in cross section or a shape with a convex portion formed in the center of the cross section. The light-emitting panel according to claim 1 , further comprising a light-reflecting layer on an outer peripheral surface of the wiring portion. A method for manufacturing the light-emitting panel according to claim 1,
connecting the light emitting portion and the wiring portion;
a step of arranging at least two highly refractive transparent members made of resin so as to face each other with the wiring portion connected to the light emitting portion interposed therebetween, and then crimping the at least two highly refractive transparent members using a predetermined crimping means to manufacture the highly refractive transparent portion;
and bonding the high refractive index transparent portion and the transparent base portion together.