JPH0427046Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a lighting device that uses a large number of light emitting elements as a light source, and in particular, a lighting device that is placed at the rear of a vehicle body and is used to warn following vehicles. The present invention relates to a lighting device suitable for use in a lighting device called a stop lamp.

[Conventional technology]

2. Description of the Related Art A high-mount stop light is known as a lighting device that warns vehicles behind to ensure road traffic safety. This is installed at the driver's eye level on the inside or outside near the rear window, and lights up brightly along with the brake lights when braking, drawing the attention of the driver of the vehicle behind you and preventing rear-end collisions. It is generally constructed as shown in FIGS. 4 to 6. That is, 1 is a housing, 2 is a front lens that closes the front opening of the housing 1, 3 is an element defining member disposed inside the front lens 2,
This demarcation member 3 is made of a through hole and has a large number of storage recesses 5 for accommodating each light emitting element, for example, an LED 4, and the inner wall surface of the front opening forms a reflection surface 6 consisting of a paraboloid of revolution. .

LED4 is usually made as a PN junction diode of an intermetallic compound semiconductor such as gallium aluminum arsenide (GaAlAs), gallium phosphide (GaP), gallium aluminum phosphide (GaAlP), or gallium arsenide phosphide (GaAsP). When a forward current is applied, light of a specific wavelength is emitted.As shown in FIG. 6, the semiconductor chip 7 and an envelope made of highly transparent epoxy resin or the like protect the semiconductor chip 7 from the outside air. 8, a reflector 9 formed into a dish shape made of Al or the like and on which the semiconductor chip 7 is placed. Envelope 8
A dome portion 10 is formed in a cylindrical shape, and the tip thereof forms a part of a spherical surface, thereby increasing the directivity of light. And the envelope 8
is arranged so that the semiconductor chip 7 is located at the focal point of the reflective surface 6. Of the light emitted from the semiconductor chip 7, light 11 emitted toward the side is emitted from the envelope 8.
The light passes through the light and exits to the outside, and when it hits the reflective surface 6 and is reflected, it becomes parallel light 11a substantially parallel to the optical axis and heads forward.

In addition, 12 is a printed circuit board 13a, 13b is a lead wire.

[Problem that the invention attempts to solve]

By the way, the conventional reflecting surface 6 consisting of a single paraboloid
In this case, the entire reflecting surface cannot be used as a reflecting surface, and only a part of the reflecting surface, that is, the semiconductor chip 7
Of the light emitted from the semiconductor chip 7, only the area that can be reflected forward as parallel rays substantially parallel to the optical axis is used as the effective reflective surface area a, so that the light is emitted laterally from the semiconductor chip 7. There have been problems in that the utilization efficiency of the light beam 11 is poor, sufficient light distribution cannot be obtained, and the brightness near the optical axis is extremely brighter than the surroundings, in other words, the directionality is too strong.

In this case, the opening of the parabola is indicated by the two-dot chain line 15 in Figure 6.
If you make it smaller as shown in , the effective reflective surface area starts from a.
a′, and the above problem can be solved. However, in this case, when the thickness T _O of the element defining member 3 is kept constant, the opening diameter of the storage recess 5 becomes smaller from D ₀ to D ₁ . The width of the end face 17 becomes large, which causes the problem that it is visible through the front lens 2 and forms a dark part when the light is turned on. One way to solve this problem is to extend the adjacent reflecting surfaces 6 until they intersect with each other, but simply doing so would significantly increase the thickness T of the element defining member 3, which would cause the illumination device to become The problem arises of increasing the size.

Therefore, the present invention has been developed in view of the above-mentioned conventional problems, and its purpose is to minimize the increase in the thickness of the element-defining member while maintaining the opening diameter of the storage recess. It is an object of the present invention to provide a lighting device that can increase the effective reflective surface area, increase the ratio of reflected light to direct light, and obtain uniform illumination.

[Means for solving problems]

In order to achieve the above object, the present invention includes a housing, a front lens that closes a front opening of the housing, a large number of light emitting elements arranged in at least one row in the longitudinal direction of the housing, and a front lens that closes a front opening of the housing. A plurality of storage recesses are disposed in the housing and accommodate the light emitting elements, and an element defining member is provided, and an inner wall surface of the front opening of the storage recess constitutes a reflective surface, and the reflective surface is A paraboloid is formed with a pseudo focal point located on the circumferential side of the light emitting element as a focal point, and the pseudo focal point is used to direct outgoing light from the light emitting element to the side toward the reflective surface, which is opposite to the emission direction. This is the point where the extended lines in the direction intersect with each other.

[Effect]

In the present invention, when the aperture diameter of the storage recess is kept constant, the paraboloid whose focal point is the pseudo focal point located on the circumferential side of the light emitting element has an average oblique slope compared to the paraboloid whose focus is at the center of the storage recess. The depth and depth are increased, increasing the effective reflective surface area. In that case, the thickness of the element defining member increases, but it is a slight increase compared to the case where the focus position remains unchanged and the aperture of the paraboloid is simply made smaller, and the larger the pseudo focus shift, the smaller the increase. .

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention applied to a high-mount stop lamp, FIG. 2 is a partially cutaway front view, and FIG. 3 is an enlarged sectional view taken along the line of FIG. In these figures, 21 is a high-mounted stop lamp installed outside the vehicle body 20, and this lamp 21 is formed by extrusion molding or the like and has an upper plate 22 made of Al or the like extending in the left-right direction of the vehicle body. , a lower case 23 having an open upper surface and extending in the left-right direction of the vehicle body and forming a housing 24 together with the upper plate 22;
Inner lens 25 and printed circuit board 26 inside 4
A large number of LEDs 27 mounted on the surface of this printed circuit board 26 and an element defining member 28 that accommodates and defines each LED 27 are arranged.

The lower case 2 is located in the front half of the lower surface of the upper plate 22.
A rectangular frame-shaped fitting groove 2 into which the upper end opening of 3 is fitted.
9 and a plurality of screw attachment portions 30 are provided. The lower case 23 is made of a translucent plastic material or glass, so that its front portion constitutes a front lens 31, and its upper end opening is fitted into the fitting groove 29 via a gasket 33, and is fixed with adhesive. Further, a plurality of screw attachment holes 34 are formed in the bottom plate 23a of the lower case 23 in correspondence with the screw attachment portions 30, and screws are inserted into the screw attachment holes 34 and the screw attachment portions 30 from below the vehicle body 20. The high mount stopper lamp 21 is fixed onto the vehicle body 20 by a set screw 35 provided therein.

The inner lens 25 is the front lens 31
The diffuser lens 36 is disposed at the rear of the lens so as to face parallel to the lens, and a diffusion lens 36 consisting of a large number of small convex lenses is densely formed on the entire surface of the lens. On the other hand, on the back surface, a large number of condensing lenses 37 consisting of large convex lenses are formed corresponding to each LED 27.

The printed circuit board 26 is connected to the inner lens 2.
5, arranged in parallel at a predetermined interval behind the
The element defining member 28 is disposed on the surface.
The element defining member 28 is made of an opaque plastic material and has a number of housing recesses 39 for housing each LED 27 independently. The storage recess 39 is made up of a through hole that opens on the front and back surfaces of the element defining member 28, and the inner wall surface of the front opening forms a reflective surface 40 in the shape of a paraboloid of revolution.

In this case, the reflecting surface 40 is formed of two paraboloids 40A having pseudo focal points at two points A ₁ and A ₂ equidistant from each other on both sides of the semiconductor chip 7 of the LED 27, as shown in FIG. 40B. The point _A1 on the right side is the intersection point where the extension lines 43 of the lateral outgoing light 42 from the semiconductor chip 7 toward the reflective surface 40A intersect with each other in a direction opposite to the outgoing direction. Similarly, the point _A2 on the left side is the intersection point where the extension lines of the lateral outgoing light rays from the semiconductor chip 7 toward the reflective surface 40B intersect with each other in the direction opposite to the outgoing direction.

According to the high mount stop lamp 21 having such a configuration, the light 42 directed to the side (strictly speaking diagonally forward) of the LED 27 is directed to the reflective surface 40.
can be effectively reflected forward by
The entire surface of the front lens 31 can be illuminated with substantially uniform brightness.

That is, the front side opening diameter D ₂ of the storage recess 39 is the opening diameter of the conventional single paraboloid shown in FIG.
Even if it is approximately equal to D ₀ , each paraboloid 40A, 40B
The difference between the paraboloids 40A and 40 can be made smaller by the distance d between the pseudo focal points A ₁ and A ₂ .
The average slope of B increases, and the ray 42 goes to the side.
The effective reflective surface area a ₁ increases. Accordingly, the amount of parallel light 46 parallel to the optical axis that is reflected by hitting each paraboloid 40A, 40B and directed forward increases.
As a result, the difference in ratio between the forward direct light 47 and the parallel light 46 is reduced, allowing uniform illumination of the front lens 31. Also, paraboloids 40A, 40
The amount of increase T ₁ in the thickness of the element defining member 28 due to B is:
Since the pseudo focal points A ₁ and A ₂ are shifted from the center of the storage recess 39, the amount of increase (T-T ₀ ) when the focal position is not shifted and the opening of the parabola is simply reduced.
, and the larger the pseudo focus shift, the smaller it becomes.

In addition, although the above-mentioned example was explained about the case where it was commonly implemented in the high mount stop lamp 21,
This invention is not limited to these in any way,
Of course, the present invention can also be applied to various lamps, display devices, etc. using the LED 27.

[Effect of idea]

As explained above, in the lighting device according to the present invention, the storage recess of the element-defining member is made of a reflective surface consisting of a paraboloid whose focal point is located on the circumferential side from the center of the light emitting element, so that the opening of the storage recess is If the apertures are made the same, the effective reflective surface area can be expanded. As a result, the ratio of reflected light that is emitted to the side of the light emitting element and reflected forward by the paraboloid, which is approximately parallel to the optical axis, to the direct light increases, and the front lens is illuminated almost uniformly over the entire surface. can do. Also,
Although the thickness of the element-defining member also increases, the amount of increase is small compared to the case where the focal position is not shifted and the aperture of the paraboloid is simply made smaller, and it is possible to prevent the element-defining member from increasing in size.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the present invention applied to a high-mount stop lamp, Fig. 2 is a partially cutaway front view, Fig. 3 is an enlarged sectional view taken along the line of Fig. 2, and Fig. 4 is an external perspective view showing a conventional example of a high mount stop lamp, Fig. 5 is a sectional view, and Fig. 6 is a sectional view.
The figure is an enlarged sectional view of a main part of the element defining member. 1...Housing, 2...Front lens, 3...
Element defining member, 4... LED, 5... storage recess,
6... Reflective surface, 22... Upper plate, 23... Lower case, 24... Housing, 26... Printed circuit board, 27... LED, 28... Element defining member, 3
1...Front lens, 39...Storage recess, 40...
Reflective surface, 40A, 40B...paraboloid, A ₁ , A ₂ ...
...intersection.

Claims (1)

[Scope of utility model registration request] a housing; a front lens that closes a front opening of the housing; a plurality of light emitting elements arranged in at least one row in the longitudinal direction of the housing within the housing; and each of the light emitting elements also disposed within the housing. and an element defining member in which a plurality of storage recesses are provided for storing the light emitting element, and an inner wall surface of the front opening of the storage recess constitutes a reflective surface, and the reflective surface is a pseudo focal point located on the circumferential side of the light emitting element. The pseudo focal point is formed by a paraboloid having a focal point, and the pseudo focal point is a point where extension lines of the sideward emitted light emitted from the light emitting element and directed toward the reflective surface intersect with each other in a direction opposite to the emitting direction. A lighting device characterized by: