JPS59201087A - Surface illuminator using led lamp - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Technical fields> The present invention relates to a surface illumination device using an LBD lamp.

<Prior Art> Due to its characteristics, LED lamps have traditionally been used primarily as point light sources, but recently they have also come to be used as surface light sources. LED lamps have also come to be used as surface light sources. As a device using an LED lamp as a surface light source, the device shown in FIGS.

That is, in this device, an LED chip 1 and a lead frame 2 are mounted in the same direction as the P arrow direction in which illumination is performed, and a reflective surface 3 is provided so as to surround the front of the chip 1.

Therefore, the reflection plate 4 requires a height, and the overall height is high, which limits the field of use.

<Objective of the Invention> An object of the present invention is to eliminate the above-mentioned conventional drawbacks and to provide a thin surface illumination device that can be used in various thin devices.

<Structure of the Invention> The present invention includes forming a wide range of shallow recesses on the upper surface of a flat substrate to serve as a reflective surface, and fitting the flat head of an LED lamp into the side wall of the substrate. The structure is such that it faces the recess.

<Example> Figures 2(a) and (bl are perspective views showing examples of the present invention, Figure 3 is a perspective view of an LED lamp, and Figure 4 is a perspective view of an LED lamp on a board.
A perspective view showing the vicinity of the D-lamp insertion part, Figure 5 is similar to Figure 2 (a
FIG. 6 is a Y-Y cross-sectional view of FIG. 2 (al).

A substrate 11 made into a flat plate with a reduced thickness is used, a recess 12 is formed in the upper surface 11a, and the surface of the recess 12 is used as a reflective surface 13. The planar shape of the substrate 41 is square, rectangular,
Other shapes are possible. The recess 12 is formed shallowly and over a wide range.

An LED lamp 14 is fitted into the recess 12 from the side wall 11b of the substrate 11 so as to face into the recess 12. L
The head 14A of the ED lamp 14 is formed flat from a transparent synthetic resin, and a tip portion 14b is formed to protrude so that the light emitting portion protrudes somewhat into the recess 12. The stepped portion 14c serves for positioning when the head 14 is fitted. 14d is a lead wire.

The thickness tl of the flattened head 14a can be made very thin within the limits of the thickness required for the LED configuration and the thickness of the lead wire, but from the viewpoint of strength and handling, it is suitable within a range smaller than the thickness t2 of the board 11. The dimensions shall be as follows. This means that the thickness t2 of the substrate 11 can be made very thin.

The LED lamp 14 is fitted in by providing a fitting hole 15 in the side wall portion 11b of the substrate 11 that communicates with the recess 12. The fitting hole 15 is connected to the head 14 of the LED lamp 14.
The shape is similar to that of the head 14a, so that when the head 14a is fitted, the tip 14b of the head 14a is positioned at a position where it slightly protrudes into the recess 12. The LED lamp 14 is fitted in parallel to the substrate 11 and fixed with an adhesive. Sumachi L
The method of inserting the ED lamp 14 is to
It is parallel to a.

The depth of the recess 12 formed in the substrate 11 is determined by the depth of the recess 12 formed in the substrate 11.
The position where the lamp 14 faces is the deepest, and from there the recess 12
It becomes shallower toward the periphery. This is because by tilting the reflective surface 13, which is also the bottom surface of the recess 12, the reflected light from the reflective surface 13 can be effectively taken out as surface illumination. The inclination may be formed of only a completely curved surface, or may be a combination of inclined planes.

Preferably, the recess is filled with a resin forming the head 14a of the LED lamp and a transparent resin 16. As a result, reflection due to a difference in refractive index between the LED lamp 14 and the filling resin 16 does not occur, so that the light from the LED lamp 14 can be efficiently extracted as illumination light.

The LED lamp 14 is molded in advance, but it can also be molded at the same time as filling the synthetic resin 16 into the recess after inserting the LED chip into the fitting hole 15. However, molding the LED lamp in advance improves the molding conditions for the LED lamp, it can also be used for other purposes, and there is no risk of the resin 16 flowing out from the fitting hole 15 when pouring the resin 16 for filling the recess. Therefore, it has advantages such as easy molding.

The substrate 11 can be molded from white resin. The reflective surface 13 can be formed by plating or thermally bonding a metal with high reflectivity such as Aj2 or Ag. In addition, the substrate is made of Aβ or Ag, which has a high reflectance, instead of the white resin.
It is possible to use plated metal such as iron that is pressed so as to function as a reflector.

Further, the fitting hole 15 into which the LED lamp 14 is fitted is formed in the recess 12.
If the resin 16 is filled with the resin 16 to prevent leakage, the groove may be opened upward.

Alternatively, the reflective surface 13 may be provided with fine irregularities (referred to as a matte finish) to diffusely reflect the light from the LED lamp 14, or particles with different refractive indexes may be added to the resin 16 filled in the recess 12, or By making the surface of the filled resin 16 uneven, it is possible to scatter the light emitted from the recess 12 and improve the decorativeness.

Note that holes 17 and notches 18 may be provided in the substrate 11 and used for positioning when incorporating into a device, and for positioning a plate on which a mark is written for a liquid crystal, a switch, etc. to be illuminated using this device.

FIG. 7 shows another embodiment of the invention.

In this example, a side wall portion 11b forming one side of the substrate 11 is shown.

A plurality of lamps 14 are viewed from 18 into the recess 12. By doing so, the wiring of the LED lamp 14 is easy and a large area can be illuminated.

FIG. 8 shows an example in which the LED lamps 14 are fitted into opposing short-diameter side wall portions 14b of the elongated substrate 11, respectively. In this example, the recess 12 is formed such that it is deepest on a line connecting the LED lamps 14, 14 and becomes shallower as it moves away from the line in a perpendicular direction. Since it can illuminate a long and narrow surface, it can be used, for example, to illuminate the liquid crystal display of a calculator or digital watch (as a hack light).

Note that the number of LED lamps 14 may be two or more depending on the area to be illuminated.

FIG. 9 shows yet another example. This is LED lamp 14
Only the fitting hole 15 into which the lamp is attached is provided as a protrusion 19 from the substrate 11. According to this example, almost the entire upper surface 11a of the substrate 11 can be used as a surface light source.

<Effects of the Invention> According to the present invention, a wide range of shallow recesses are formed on the upper surface of a flat substrate to serve as a reflective surface, and the head of an LED lamp formed flat is inserted into the recess from the side wall of the substrate. Since it is designed to face the surrounding area, it is possible to illuminate a wide area with a very small and thin device. Therefore, calculators and other
It is also possible to incorporate it into a thin device such as a liquid crystal display device and use it as a hack light.

[Brief explanation of the drawing]

Figure 1 (al is a sectional view showing the conventional example, Figure 1 (bl is a perspective view thereof, Figure 2 (a), (bl is a perspective view of the embodiment of the present invention viewed from different directions, Figure 3) is a perspective view of the LED lamp, FIG. 4 is a perspective view showing the vicinity of the LED lamp insertion part of the board, FIG. 5 is a sectional view taken along line XX in FIG.
The figures are FIG. 2 (al Y-Y sectional view, FIG. 7). FIG. 8 is a perspective view showing each embodiment, and FIG. 9 is a plan view showing still another embodiment. 11-- ---- One board 11 a- Ura upper surface of the board 1 l b- Side wall part of the board 1 ' 2 ----
---Concavity 13--Reflecting surface 14・-'-
LED lamp 14a - head 14b -
Tip part 15------ One fitting hole 16------
---Filling resin patent applicant Sharp Corporation agent Patent attorney Nishi 1) Arata

Claims (4)

[Claims] (1) A shallow recess is formed over a wide range on the upper surface of a flat substrate to serve as a reflective surface, and the head of the LED lamp, which is formed flat, is inserted into the side wall of the substrate to face the inside of the recess. A surface illumination device using an LED lamp, characterized in that: (2) A surface illumination device using an LED lamp according to claim 1, wherein the recess is formed to become shallower as it goes from the position where the LED lamp faces toward the periphery. (3) A surface illumination device using an LEI) lamp according to claim 1 or 2, wherein a plurality of LED lamps are made to face into the recess from a plurality of locations on the side wall portion. (4) A surface lighting device using an LED lamp according to any one of claims 1 to 3, wherein the recess is filled with the same material as the material forming the head of the LED lamp.