JP2013254565A - Thin, light, and economical waterproof led light emitting plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem of an increase of the weight and production cost of a module on which LEDs and electrical components are soldered for waterproofness when used outdoors, since the entire module should be covered by transparent resin or the whole of a light emitting plate should be housed in a waterproof box because of difficult waterproof processing resulting from the module having unevenness, thus causing a large scale of equipment in either case.SOLUTION: An LED module is manufactured as thin as possible to enable lighting up. To attain waterproofness, the thin module is sealed tightly by a transparent film. The transparent film covering the module surface absorbs its thickness and expanded to adhere to the module. Waterproof processing can be carried out because of the expansion and adhesion. For the waterproofing of a wide area, waterproof processing can be performed module by module, and thereby there is no problem even if the module is installed on a widest possible area. As compared with the case that the entire module is housed in a waterproof case, an increases of its weight, size, and cost or the like can be suppressed largely.

Description

  The present invention is a technique for providing a waterproof function of an LED. The LED module is made thin, sealed with a transparent film to block moisture, and light-weight and low-cost waterproofing can be performed by thinning the electronic parts such as LED.

  LED light sources have become widespread, but waterproofing is necessary for outdoor use. Since it is necessary to install a lot of light emitters that are smaller than other light sources, the problem can be solved by covering the whole with a waterproof cover, but problems such as the weight, thickness, and high cost of the cover. There was a need to resolve. This problem can be solved by directly sealing the LED module with a transparent film, and this waterproofing method can be realized by realizing a transparent film with elongation.

  The transparent film used for the cover of the LED module is a transparent film with sufficient elongation to follow the thickness of the LED module within 5 mm. When the transparent film is pressure-bonded from above the LED module, it is possible to completely seal the whole including the plane and thickness of the module.

  There are various types of stretchable transparent films such as fluorine unstretched film, acrylic film, polycarbonate film, unstretched polyester film, etc. Absorbs the thickness and adheres to the back plate to provide a waterproof function.

  When the LED module is screwed to the back plate, it is automatically grounded. The back plate is used in accordance with the conditions of use, with the thickness around a 3 mm aluminum composite plate. The aluminum composite plate has a thin aluminum plate attached to both sides of the foamed polypropylene. When the LED module is fastened with an M3 × 5 mm tapping screw, it stops at the position where it penetrates the front surface aluminum plate of the composite plate and reaches the back surface aluminum plate, and the finished state is safe. If it is connected to the cathode at somewhere on the aluminum plate on the surface, it can be connected to the cathode of all LED modules.

JP 2000-113917 A

  The LED and electronic components are soldered on the module, which requires waterproofing when the LED is used outdoors, but it is uneven and very difficult to waterproof. For this reason, the entire module is covered with a transparent resin or the entire light-emitting plate is housed in a waterproof box. However, both increase the equipment, increase the weight, and increase the manufacturing cost.

  When an LED is used for a large signboard or the like, it is very difficult to waterproof a large area. It is difficult to waterproof an individual LED, and it is inevitably necessary to waterproof to some extent. These waterproofing methods are complicated in their cleaning methods, and are prone to troubles such as flooding from seams.

  When an LED is used as a light source of a light emitting plate, the LED elements are small and need to be dispersed at multiple points. Flat light emitters need to be uniform as a whole, and their brightness is not allowed to change due to waterproofing, so that the treatment requires high-precision management.

  Finish the LED module as thin as possible so that it can be lit. A thin module is sealed with a transparent film to enable waterproofing. For example, as shown in FIG. 2, when the whole is finished within 5 mm thickness, the transparent film stuck on the surface absorbs the thickness sufficiently and stretches and adheres. It can be completely waterproofed by stretching and sticking.

  As for waterproofing over a large area, it can be waterproofed in units of modules, so it can be handled without problems no matter how wide the modules are installed. New equipment and equipment for waterproofing are not required. In addition, the transparent film used for waterproofing has a slight weight and does not increase the cost. Compared with the case where the whole is housed in a waterproof case, the weight, size, and cost can be significantly reduced.

  The aluminum composite plate for screwing the LED module has a thin aluminum plate on both sides of the foamed resin, and is light and resistant to bending and warping. When the LED module is screwed to the aluminum composite plate, it is automatically grounded. This means that only the anode needs to be wired when wiring to the LED module. Therefore, only one wire is required, and when waterproofing with a transparent film, the adhesion is good and the waterproof function is exhibited.

  When the LED module is attached to the back plate and wired, the wiring is lowered below the module, that is, the wiring is upward. If the module and the wiring are sealed with a transparent film in this state, the water from the top does not enter and can be waterproofed. In order to further strengthen the waterproofing of the wiring portion, a strong waterproofing is realized by applying a silicone resin or the like around the wiring.

  When a large amount of flat light emitters are required, the entire light emitting plate may be film laminated to be waterproofed instead of waterproofing in units of LED modules. In this case, the cost can be reduced by laminating a large amount of transparent film using a device such as a laminator.

As shown in Table 1 below, the waterproof performance when the LED module is waterproof is equivalent to the waterproof performance IPX6 class. In the test in which the surface light emitter is set up vertically and water is sprayed from all directions from the discharge nozzle, there is no problem in lighting even if the specified time has elapsed.

  In order to waterproof the light emitting plate by the LED, a method of placing the entire light emitting plate in a waterproof case is the mainstream. The storage case requires a large amount of equipment and increases manufacturing costs. For this reason, waterproofing was expensive and hindered its spread. It is considered that a special storage case is not required due to the waterproofing of the LED module unit, and the manufacturing cost is suppressed and the spread is promoted.

FIG. 1 is a front view of a surface light emitter. 2 is a cross-sectional view of a surface light emitter. FIG. 3 is a front view of the surface light emitter with the light diffusion plate removed. Fig. 4 is a front view of the LED module and a film attached to the surface. Fig. 5 is a cross-sectional view of the LED module and film on the top surface

When forming a surface light emitter, it is necessary to disperse the LEDs at arbitrary intervals to create a uniform light surface. When the amount of light (lumen) of the LED module (2) is the same, a difference in brightness appears as shown in Table 2 depending on the distance between the LED modules and the height to the light diffusion plate. In order to reduce the manufacturing cost, it is desirable to install as few LED modules as possible according to the required brightness.

  If the installation space is too small to be high, narrow the interval between the LED modules. However, the number of LED modules to be used increases and the manufacturing cost increases, which is contrary to economic activity. In addition, the amount of light increases and the brightness becomes higher than necessary. Although measures to control the amount of energization are necessary to reduce the brightness and power consumption, an increase in cost is inevitable and an appropriate height based on Table 2 is desirable.

  When waterproofing the installed LED module, as shown in FIG. 5, the LED module is screwed to an aluminum composite plate or the like of the back plate (3) and wired, and then a transparent film (6) is attached. A special tool is used to paste the transparent film, and the sticking is done to prevent wrinkling. If the surface issuer is vertical, moisture flows from top to bottom, so there is no water intrusion from the wiring part located at the bottom, and a waterproof display board can be made.

  Place the LED modules vertically and horizontally at the same interval, and screw them to the back plate (3). The back plate is made of metal such as aluminum composite plate, and has the function of grounding by screwing. The LED module is determined according to the surface brightness or according to the space where it can be installed. Once the LED module is screwed, the LED is lit by wiring only the anode. Depending on the purpose of use, the anode and cathode may be reversed and the back plate may be used as the anode and the lead wire as the cathode.

  Wiring only the anode (5) simplifies the wiring, reduces the number of contacts on the transparent film to be attached to the surface, and improves the waterproof performance. A current flows from the simplified anode wiring, passes through the LED, flows into the back plate, and LED lights up. Illuminance is averaged by the light diffusing plate (4) installed on the surface of the luminous box, and a uniform luminous plate (1) can be realized.

  The LED module is screwed (7) to the back plate (3), and anode wiring (5) is made. A transparent film (6) slightly larger than the LED module (2) is attached after wiring. Adhesive processing is applied to the transparent film, and it adheres to the LED module as a whole and slightly larger than that to prevent water from entering and waterproof. The transparent film uses a stretchable non-stretched film or the like, and follows and adheres within the thickness of the LED module within 5 mm to exert a waterproof function.

  The applications of LEDs are expanding. Waterproofing is required for use outdoors or in places with high moisture. When enclosing the whole light emission part, a storage box becomes large and it becomes a high cost also to an installation. The method of sealing the film only to the LED module part can realize cost reduction, thickness reduction, and weight reduction. Thin and light waterproofing can be used for lighting devices and display light sources infinitely.

DESCRIPTION OF SYMBOLS 1 Anti-light-emitting part 2 LED module 3 Back plate 4 Light diffusing plate 5 Anode wiring 6 Transparent film 7 Screwing 8 Lead wire 9 LED

Claims (3)

  When constructing a waterproof surface light emitter, the LED module is placed on a metal flat plate and screwed, and after wiring, a transparent film is attached to the LED module to create a waterproof light emitting box, A waterproof LED light-emitting plate with a light diffusing plate on the surface of the light-emitting box so that uniform brightness can be displayed.   An LED module is an LED and electronic components mounted on a printed circuit board. The LED module has a thickness of 5 mm or less and absorbs unevenness of the LED module when a transparent film is applied. The waterproof LED light-emitting plate according to claim 1, wherein the waterproof LED light-emitting plate prevents infiltration of water by being in close contact with the LED. When the LED module is screwed to the metal back plate, the screw part is grounded, and the LED module can be lit by wiring only the anode, and the infiltration of water is more prevented when a transparent film is applied with a single wire wiring. The waterproof LED light-emitting plate according to claim 1, wherein