JP3188817U - LED surface emitting sheet to increase the surface illuminance of the signboard - Google Patents

Abstract

An LED surface emitting sheet capable of efficiently extracting light to the surface and an internal illumination signboard using the same are provided.
SOLUTION: A plastic film 15 having a visible light reflectance of 85% or more is used as a surface material, and a tape in which a printed wiring is printed on a heat-resistant plastic film 11 of a wiring substrate to which an LED is attached and an LED 6 is soldered is used as an intermediate material. A plastic film 16 serving as a cover material is used on the back surface, and these three layers are bonded together. Further, the back surface is subjected to adhesive processing with the adhesive 17 and the release paper 18 so that the attachment can be easily performed. The internal lighting signboard is configured by sticking this surface emitting sheet on the entire bottom surface of the box and providing a light diffusion plate on the surface.
[Selection] Figure 5

Description

  The present invention is a technology that efficiently extracts light to the surface when using LEDs for internal lighting signs.

  Due to recent technological evolution, the brightness of LEDs has been increasing. The power consumption is low and the lighting life is about 50,000 hours, which is about 10 times longer than that of fluorescent lamps.

  A plastic film having a high visible light reflectivity has been produced, and a current maximum reflectivity of 98% or more can be produced, thereby further improving the light efficiency.

  With the heat-resistant plastic film, you can wire on the film and solder electronic components.

When an LED with low power consumption is used for an internal lighting signboard, since the amount of light per LED is small, it is necessary to use a large number of LEDs.
If light is efficiently guided to the signboard surface, the number of LEDs can be reduced, and cost reduction and energy saving can be realized.

  If the amount of light is satisfied by the LED, it is possible to make a light, thin, low power consumption, environmentally friendly signboard.

  In order to emit uniform light to the signboard surface, it is necessary to install the LEDs side by side. Since the layout covers the entire signboard, a large automatic soldering machine is required, but the size is limited.

  If a sheet-like illuminant can be easily attached, the workability of signboard production will be improved, the production period will be shortened, and the production cost will be reduced.

When the light from the LED is applied to the light diffusion plate on the surface, a part of the light is transmitted to the surface. Part of it reflects and goes to the bottom of the sign. If this light is efficiently re-reflected and taken out to the surface, the brightness of the signboard can be increased.
As shown in (Table) and (Table 2), it was found that the brightness of the signboard surface rapidly increases when the reflectance exceeds 85%. This effect is enhanced by constructing a highly reflective plastic film on the surface of the light-emitting sheet and installing it on the entire bottom surface.

  When a highly reflective plastic film on the surface of the luminescent sheet and an intermediate plastic film for electrical wiring are bonded together, a flexible, thin and lightweight luminescent sheet can be produced.

A large-area light-emitting sheet can be obtained by automatically soldering a heat-resistant plastic film, cutting it into a string, and arranging the string-like light emitters on a reflective film. This can be manufactured without a device for soldering to a large area.
This also reduces capital investment.

By sticking to the back of the sheet, it can be easily attached to the bottom of the sign box, creating a thin and light light source.
Further, by uniformly pasting, the reflected light can be efficiently re-reflected and the brightness of the signboard can be increased.

The principle of increasing the surface brightness of the internal lighting signboard is as shown in Fig. 1. Light emitted from the light source (6) is directed toward the light diffusion plate (3). Some are transmitted to the surface but some are reflected and go toward the bottom of the box.
When this light is re-reflected (7, 8) with a plastic film having a high reflectance, it goes to the light diffusing plate again, and this is repeated to increase the brightness of the signboard surface.

Table 1 compares various materials with different reflectivities.
For materials with low reflectivity, the surface brightness is determined only by the intensity of the LED light, regardless of the brightness of the signboard surface.

It was discovered that the surface brightness suddenly increased when the reflectance exceeded 85%.
There is a difference of about 20% in surface brightness between general signboard materials such as metal and wood and highly reflective plastic, which can reduce the number of LEDs by about 20% at the same brightness.
This leads to a reduction in power consumption of about 20% in terms of running costs as well as material reduction, thus realizing energy saving.

  The electrical wiring is made of a heat-resistant plastic film (11) and solders electronic components. The highly reflective plastic film (15) on the front surface and the plastic film (16) with adhesive on the back surface are integrated, making it thin, lightweight and flexible. A planar light emitting sheet (FIG. 16) can be formed.

  The flexible sheet-like light emitting sheet has an adhesive finish on the back surface that can be easily attached, and it can also be used for curved interior lighting signs that have been difficult to attach to curved surfaces. It seems to be possible.

This is an internal lighting signboard with a light diffusing plate (3) on the surface, which is a light source by LED.
At the bottom of the signboard, a planar light emitting sheet (Fig. 16) using a highly reflective plastic film (15) with a reflectivity of 90% or more is attached to the bottom of the signboard box, and the signboard surface brightness is reflected using the internal light reflection. Raise.

  In order to obtain the necessary brightness, we will provide a resource- and energy-saving signboard with a minimum of LEDs.

  The surface material (15), electrical wiring material (11), and back material (16) are all made of plastic film, and they are integrated into a thin, lightweight, flexible planar light-emitting sheet (Figure 6). I can do it.

(Table 1) shows the visible light reflectance by material. It is a numerical value obtained by simultaneously measuring the material used for the bottom of the signboard and the brightness of the signboard surface, and it was confirmed that the surface brightness increases only for materials with high reflectivity.

(Table 2) is a line graph representing the above (Table 1). When the reflectance of the bottom material exceeds 85%, the surface brightness increases rapidly.

Cross section of internal lighting sign Front view of interior lighting sign Automatic soldering pattern and punching pattern for heat-resistant plastic film Die-cut string LED strip Integrated front surface film, intermediate string LED tape, back surface adhesive film Planar light emitting sheet

1. Signboard surface light 2 by direct light, internal lighting signboard box 3, light diffusion plate 4, primary reflection, secondary reflection light 5 by surface reflection, surface emitting sheet surface 6, LED
7, LED direct light 8, primary reflected light 9, secondary reflected light 10, power supply lead wire 11, heat-resistant plastic film 12, die cutting line 13, energizing wiring 14, string-like LED tape 15, high reflectivity plastic Film 16, adhesive processed plastic film 17, adhesive 18, release paper 19, pressure bonding

Claims (3)

A plastic film with a visible light reflectance of 85% or more is used as the surface material, the substrate for wiring to which the LED is attached is a heat-resistant plastic film, and the back material is also used as a plastic film. Flexible LED surface emitting sheet. An LED surface emitting sheet using a plastic film having a visible light reflectance of 85% or more according to claim 1 is attached to the entire surface of the bottom of the box, using an LED as a light source and a light diffusing plate on the surface. Internally illuminated signboard. An LED surface emitting sheet, wherein the back surface of the plastic film according to claim 1 is subjected to adhesive processing so that it can be easily attached.