JPS62229703A - Lighting apparatus - 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 [Industrial Application Field] The present invention relates to a lighting device that uses a light emitting element such as a light emitting diode (hereinafter abbreviated as LED) as a light source.

In particular, the light emitted forward from the light emitting element is effectively used to improve the lighting effect.

[Conventional technology]

In recent years, with the development of semiconductor technology, high-brightness LEDs have been developed, and as they are now available at low prices, they are being considered for use in place of light bulbs as light sources for vehicle lights, especially brake lights and taillights. As an example, the one shown in FIG. 4 is known. That is, this lighting device f1.

A printed circuit board 3 on which a large number of LEDs 2 are arranged at predetermined intervals in the form of an IJ, and this printed circuit board 3
The lens 4 is disposed on the 0 surface and extends beyond the LED 2. On the surface of the 5 lens 4, a multivalued condenser lens 5 is formed corresponding to each of the LEDs 2. The condensing lens 5 is for condensing the light 6 emitted from the LED 2 and passing through the inner lens 4 and projecting it forward. It is made of a substantially hemispherical spherical lens (fisheye lens), and as shown in FIG. By being densely formed without gaps, the bottom portion 5a forms a rectangle. Note that T is a conductive pattern.

8 is wire bonding.

[Problem that the invention seeks to solve]

However, in such a conventional lighting device 1, the LED 2
The light that is emitted from the LED and directed diagonally forward cannot be effectively made to enter the condenser lens 5 corresponding to the LED 2, which poses a problem in terms of effective use of the light. That is, LP01
If the solid angle of the light 6 that passes through the condensing lens 5 corresponding to the LED 2 is θ, then the light 6' that is emitted at an angle larger than 0 will be reflected in the adjacent condensing lens 5. Since the light is emitted in a direction other than the direction in which it is incident, it does not participate as illumination light, in other words, it results in a loss of light and reduces the illumination effect. Therefore, it is desirable to set the solid angle θ large, but since this solid angle θ is determined by the distance between the LED 2 and the lens 4, the size of the condensing lens 5, the refractive index of the lens itself, etc., these dimensions However, it was not possible to increase the light utilization efficiency unless the refractive index was changed.

[Failure to decide the issue]

The lighting device according to the present invention has been made to solve the above-mentioned problems, and includes an outer lens in which a large number of diffusion lenses are formed on the inner surface, and a large number of light emitting elements arranged at predetermined intervals on one surface. A large number of condensing lenses are formed on the surface of the inner lens, corresponding to each of the light emitting elements, and a large number of condensing lenses are formed on the back surface of the inner lens, and the outer surface of the inner lens has a convex curved surface at least on the periphery. Auxiliary lenses are formed corresponding to each of the condensing lenses.

[Effect]

In the present invention, the oblique light that has come out of the light emitting element and entered the convex curved surface of the auxiliary lens can be emitted from the condensing lens corresponding to the element, so the solid angle of the light that passes through the condensing lens is becomes larger, and more efficient use of light can be achieved.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below based on embodiments shown in the drawings.

FIG. 1 is a sectional view of a main part of an embodiment of a lighting device according to the present invention. In the figure, in this embodiment, an outer lens 10 and a back cover 11 constitute a lamp body 12, an inner lens 13 and a substrate 14 are arranged inside the lamp body 12, and a large number of LEDs 2 are arranged on the surface of this substrate 140 in a predetermined manner. They are arranged in a matrix at intervals, and a resistor (not shown) for lighting the LED is arranged on the back surface.

The outer lens 10 is attached to the back cover 11 so as to cover the front opening of the cover 11.

On the inner surface is a diffusion lens 15 consisting of many small convex lenses.
are densely formed.

The inner lens 13 is disposed behind the outer lens 10, and a large number of condensing lenses 5 are formed protruding from the surface of the inner lens 13, corresponding to each of the LEDs 2. The condensing lenses 5 are substantially hemispherical spherical lenses (fisheye lenses), and the condensing lenses 5 are provided in close contact with each other, as in the conventional device shown in FIG.

On the other hand, a large number of auxiliary lenses 16 are formed protruding from the back surface of the inner lens 13, corresponding to each of the condensing lenses 5. This auxiliary lens 16 is located at the bottom 5a of the condensing lens 5.
The convex curved surface part 17 is formed by chamfering one peripheral edge with an appropriate curvature so that the boundary with the adjacent auxiliary lens is clearly defined. I have to.

The substrate 14 is disposed behind the inner lens 13. The LEDs 2 are connected in series for each column (or row) and connected in parallel to a power source (not shown).

Thus, according to the lighting device having such a configuration, L
The solid angle of light can be set large without changing the distance between the ED 2 and the inner lens 13, the size of the condensing lens 5, the refractive index of the inner lens 13, etc., and the loss of light can be reduced. be. That is, as shown in FIG.
7 and is refracted at the boundary 2 with the adjacent condensing lens 5'.
Assuming that the solid angle of the light 20 emitted from the inner lens is 01, this solid angle θl is smaller than the solid angle 0 of the light 6' at the incident point in the conventional device shown in FIG. ) Since Pl moves to the outside of Po, it becomes large (θ1>θ), thus increasing the light utilization efficiency and enabling brighter illumination. In this case, the convex curved surface portion 1
It will be easily understood that the solid angle θl can be changed by the curvature of 7.

Further, in this embodiment, since the light passing through the lens 10 is diffused by the diffusion lens 15 of the outer lens 10, the portion corresponding to the LED 2 is not locally brightened, and the entire surface of the outer lens 10 is can be illuminated with almost uniform brightness.

FIGS. 3(a) and 3(b) are diagrams showing other embodiments of the auxiliary lens, respectively. FIG. 3(a) shows the auxiliary lens 16 composed of a convex lens, and FIG. 3(b) shows the concave lens 25 and the concave lens. 25 and a convex curved surface 17 provided around the auxiliary lens 16 (i-configuration).It is clear that the solid angle of light can be increased in the auxiliary lens 16 having such a configuration as well as in the above embodiment. However, the light distribution will differ depending on the shape of the auxiliary lens 16. That is, in the structure of the embodiment shown in FIGS. Because I haven't done it,
Compared to the structure of the embodiment shown in FIG. 3(&), the condenser lens 5
Prevents the center from becoming brighter than the periphery.

In the above embodiments, the condensing lenses 5 are provided closely together. However, the present invention is not limited to this, and it goes without saying that the condensing lenses 5 may be provided separately.

〔Effect of the invention〕

As explained above, in the lighting device according to the present invention, a large number of condensing lenses are provided on the front surface of the inner lens corresponding to each light emitting element, and a large number of auxiliary lenses whose periphery has a convex curved surface are provided on the back surface of each of the condensing lenses. Since it is provided in correspondence with the lens, the solid angle of the light incident on the condenser lens can be made larger by the convex curved surface compared to a conventional device that does not include an auxiliary lens.

Therefore, there is less light loss, enabling brighter illumination and improving the illumination effect. Furthermore, the formation of the auxiliary lens is also simple.

[Brief explanation of drawings]

FIG. 1 is a sectional view of essential parts showing an embodiment of the present invention. Figure 2 is a diagram for explaining the present invention in detail, Figure 3 (a
) and (b) are views showing other embodiments of the auxiliary lens, respectively, and FIG. 4 is a sectional view of essential parts showing an example of a conventional device. FIG. 5 is a perspective view of the lens. 2...LED, 3...Printed circuit board, 4...
... Lens, 5 ... Condensing lens, 10φ00. Outer lens, 11--・Pack cover, 12--...
Light body, 13... Inner lens, 14... Base
15-... Diffusion lens, 16... Auxiliary lens,
17...Convex curved surface part.

Claims (1)

[Claims] an outer lens having a large number of diffuser lenses formed on its inner surface and forming the front surface of the lamp; a substrate having a plurality of light emitting elements arranged on its surface at predetermined intervals and located behind the outer lens; an inner lens disposed between the outer lens, a number of condensing lenses are formed on the surface of the inner lens corresponding to each of the light emitting elements, and the back surface has a convex curved surface at least at the peripheral edge. An illumination device characterized in that a large number of auxiliary lenses are formed corresponding to each of the condenser lenses.