JPS6248321B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an inner lens for a vehicle lamp,
In particular, it relates to a new inner lens equipped with a direct-lighting Fournel prism.

The inner lens of this type of vehicle light uses direct light from the light source without using a paraboloid of revolution reflector, which takes up space, as the space inside the vehicle body where the light is housed, especially in the trunk, is expanding. However, a vehicular lamp has been proposed in which the light is directly controlled by a lens to emit light, thereby reducing the size, thickness, and weight of the lamp.

That is, the conventional lamp shown in FIG. 1 includes a housing a and an outer lens b on the front surface thereof.
A light source bulb P is disposed within a lamp chamber g in which a light source and an inner lens c are disposed. A fish-eye prism d is provided on the inner surface of the outer lens b, a refractive prism portion e is provided concentrically in the center of the inner surface of the inner lens c, and a reflective prism f is provided on the periphery of the inner lens c to form a Fournel cut. There is. However, as shown in FIGS. 2A to 2C, such a conventional vehicle lamp has a concentric refractive prism e provided near the center of the optical axis of the inner lens c. The prism can be set to satisfy the light distribution, so it looks bright from the outside. However, in this refractive prism e, the angle range in which the light beam from the light source P enters an equal area on the front surface of the lens, for example, an area corresponding to one element of the prism, is an angle θ ₁ near the center, but it becomes far from the center. It gradually becomes smaller, and becomes an angle θ ₂ near the boundary with the reflective prism f. Naturally, since θ ₁ >θ _2, the amount of light incident on the portion far from the center is small, and the surrounding area becomes dark. Also,
As shown in FIG. 2, the light incident on the hanging portion (rising portion) H of the refractive prism e becomes lost light (light emitted far from the optical axis). That is, although direct light from the light source P is incident on the hanging surface (rising portion) H of the refractive prism e, it is diffused as lost light.
Furthermore, the difference between the angle of light toward the inclined surface A of the refractive prism e and the angle of the light toward the hanging surface H increases as the prism e moves away from the optical axis Z. Therefore, the optical loss area increases. The solid angle δ is the solid angle δ ₁ < δ _o
As a result, the loss of light increases and the peripheral area becomes a dark area F, and this dark area F appears particularly prominently in a lamp that is elongated from side to side. Furthermore, as shown in Figure C, the light ray _L1 incident on the refractive prism e is received by the inclined surface A of the prism element, is refracted, passes through the element as it is, and exits from the surface B, which is the outer surface of the lens, so it is attenuated. Although the loss is small, the incident light beam _L2 to the reflective prism f is received by the C-plane of the hanging surface of the prism element, refracted, and further reflected by the inclined surface D to exit from the outer surface of the lens. .

The light rays that are emitted through the reflecting prism f are attenuated more than those passing through the refractive prism e, resulting in a larger loss. Therefore, the output luminous intensity suddenly decreases at the boundary E between the refractive prism e and the reflective prism f, and as a result, when viewed from the outside, there is a sharp difference in brightness near this boundary with the center, and when viewed from the front, it becomes ring-shaped. This results in a dark area F. When looking at the lens surface, the existence of such a dark area F not only causes bad illumination filling and is unsightly, but also makes it impossible for the lens to emit uniform light, which may impair the light distribution function, and may impede display functions such as signal lights. This may cause problems such as not being able to achieve sufficient visibility and ensuring visibility.

In view of the above-mentioned circumstances, the present invention utilizes the luminous flux in the range of the refractive prism part as effectively as possible, eliminates light loss especially at the rising part of the refractive prism part,
Furthermore, the present invention provides an inner lens for a vehicle lamp that eliminates the dark area that occurs at the boundary between the refractive prism part and the reflective prism part, increases the tolerance of the amount of light, enables a uniform light emitting surface, and improves visibility. The purpose is to

DESCRIPTION OF THE PREFERRED EMBODIMENTS The inner lens of a vehicle lamp according to the present invention will be described below with reference to the accompanying drawings.

The illustrated example in FIGS. 3 and 4 is a first embodiment of the present invention, in which 1 is a housing defined by an outer lens 2 and an inner lens 3 disposed on the front surface of the housing 1. A light source bulb 4 is held and placed in a holder 42 via a socket 41 in the lamp chamber.

The outer lens 2 and the inner lens 3
is molded from a translucent synthetic resin such as acrylic resin. In this embodiment, the outer lens 2 is configured as a cover lens, and the inner lens 3 is fixed to the outer lens 2 or the like by suitable fixing means and disposed between the outer lens 2 and the light source 4. This is what has been done. The inner lens 3 is
A concentric refractive prism part 31 is provided on the outer surface 30a of the central part near the optical axis Z, and fisheye prism parts 32 arranged in a grid pattern are provided on the lens inner surface 30b of the refractive prism part 31. Furthermore, a reflective prism section 33 is provided around the fisheye prism section 32.

More specifically, the inner lens 3 has a concentric refractive prism section 31 provided on the outer surface 30a of the central portion near the optical axis Z, and a rising portion H near the center (portion close to the light source) is approximately parallel to the optical axis. A refractive prism section parallel to each other, a so-called simple refractive prism section 3
1a, and the rising portion H is provided in the periphery following this.
A refractive prism part tilted at an angle θ with respect to the optical axis,
A so-called total refraction prism section 31b is provided. The simple refraction system prism section 31a is provided at a distance of 1L from the optical axis center, which is approximately equal to the distance L between the light source 4 and the lens surface, and the total refraction system prism section 31b around it is provided at a distance of 1L from the optical axis center. ~
It is formed between about 2L.

Incidentally, the formation range of the full refraction system prism section 31b is, for example, in the case where the range of the refraction system prism section 31 is expanded on the left and right horizontally long lens surfaces, the formation range of the total refraction system prism section 31b corresponds to the light flux from the light source 4 of the simple refraction system prism section 31a. is formed in a range where the luminous flux density gradually decreases as the distance from the center increases. Further, the lattice-shaped fisheye prism section 32 provided on the lens inner surface 30b of the refraction system prism section 31 transmits the emitted light (direct light) from the optical axis 4 to the refraction system prism section 31 on the outer surface as diffused light. It is configured to control light, and the boundary line X of the refractive prism section 31 on the outer surface is formed into a rectangular shape so as to coincide with the twill line at the end of the fisheye prism section 32.

Furthermore, the reflective prism section 33 formed around the periphery of the fisheye prism section 32 is configured to emit the direct light from the light source 4 in the direction of the outer lens 2 in front as a substantially parallel light beam with respect to the optical axis. ing.

The inner lens 3 configured as described above is
The light effect during lighting will be explained using FIG. 4.
Among the emitted light (direct light) from the light source 4, the simple refraction system prism section 31 of the concentric refraction system prism section 31
The incident light beam _L1 to a enters the fisheye prism section 32, is refracted and transmitted as diffused light, is refracted again by the inclination of the prism element of the simple refraction system prism section 31a on the outer surface, and is all emitted, and is emitted from the outer lens 2. A large amount of light is emitted in the direction. The incident light beams L ₂ and L ₃ to the all-refraction system prism section 31b in the vicinity are similarly incident on the fisheye prism section 32, refracted, and transmitted as diffused light.One light beam _L2 is incident on the all-refraction system prism section 31b. The other ray L ₃ is refracted again at the inclined rising part H of the prism element, and both rays L ₂ and L ₃ are all emitted and a large amount of light is emitted in the direction of the outer lens 2. The amount of light is emitted. In addition, the incident light beam to the reflective prism section 33
The light L ₄ is received by the hanging surface of the prism element, refracted, further reflected by the inclined surface, transmitted as it is, and emitted from the lens outer surface 30a toward the outer lens as a ray substantially parallel to the optical axis. Then, the light rays L ₁ , L ₂ , and
L ₃ and L ₄ are transmitted through the outer lens (cover lens) 2 and emitted to the front of the lens.

The above-mentioned inner lens 3 is provided with a concentric refractive prism part 31 on the outer surface 30a of the central part near the optical axis, and the inner lens 3 of the refractive prism part 31 is provided with a concentric refractive prism part 31.
0b is provided with a fisheye prism section 32, and a reflective prism section 31 is provided around it, and the refraction prism section 31 has a simple refraction prism section 31a near the center of the optical axis, and Since the total refraction system prism part 31b is provided in the part where the luminous flux density decreases, the luminous flux in the area where the luminous flux density is high can be effectively used without loss, and the range of the refraction system prism part 31 can be effectively utilized to the maximum extent. can do. Further, unlike the conventional case, there is no loss of light caused by the rising portion H of the refraction system prism section, and thus the refraction system prism section 3
1 is all emitted forward, so a large amount of light can be emitted in front of the lens, increasing the margin of light amount and increasing the light distribution value. A dark area does not occur at the boundary with the system prism part, and the front surface of the lens can uniformly emit light, improving visibility.

The illustrated examples in FIGS. 5A to 5C are other embodiments of the inner lens of the vehicle lamp according to the present invention. The system prism portion 31' is formed in a lattice shape.

In this embodiment, the refraction system prism section 31' is formed in a lattice shape, and when the lens surface is inclined with respect to the lamp axis, the prism elements of the refraction system prism section 31' are each composed of one prism segment. , so sufficient light distribution characteristics can be obtained.
Furthermore, it is possible to obtain a lens surface that can emit light with a high intensity of light intensity, has a high light distribution value, and improves the utilization efficiency of the luminous flux.

As is clear from the above-described embodiments, the inner lens of the vehicle lamp of the present invention is an inner lens disposed between the lamp and the light source, and the inner lens has a central outer surface near the optical axis. A refractive prism part is provided in the refractive prism part, a fisheye prism part is provided on the inner surface of the lens of the refractive prism part, and a reflective prism part is provided in the periphery of the fisheye prism part. It is possible to effectively utilize the luminous flux in the region with high luminous flux density without any loss, and to maximize the effective use of the luminous flux within the range of the refractive prism section. There is no risk of dark areas occurring at the boundaries and damaging the lighting filling, and it has the effect of providing a uniform light emitting surface, emitting light with a high amount of light, and improving visibility. be.

It should be noted that, as a matter of course, the present invention is not limited only to the examples.

[Brief explanation of the drawing]

Figures 1 and 2 show conventional lamps.
Figure A is a front view, Figure B is a cross-sectional view taken along the line A--A in Figure A, Figures 2 A to C are explanatory diagrams showing the optical action of the conventional inner lens, and Figures 3 and 4 are views of the present invention. An example of the implementation of an inner lens for a vehicle lamp is shown in FIG. 3, where A is a front view and B in FIG.
4 is an enlarged sectional view illustrating the optical action of the inner lens, and FIG. 5 shows another embodiment of the inner lens of the present invention. Figure A is a cross-sectional view taken along the line CC, and Figure C is a cross-sectional view taken along the line D-D in Figure I. DESCRIPTION OF SYMBOLS 1...Housing, 2...Outer lens (cover lens), 3...Inner lens, 31...Refraction system prism part, 31a...Simple refraction system prism part, 31
b...Total refraction system prism section, 32...Fisheye prism section, 33...Reflection system prism section, 4...Light source bulb.

Claims (1)

[Claims] 1. An inner lens disposed between an outer lens of a lamp and a light source, wherein the inner lens has a refractive prism part on the outer surface of the central part near the optical axis, and a refractive prism part is provided on the inner surface of the refractive prism part. An inner lens for a vehicle lamp, characterized in that an eye prism part is provided and a reflective prism part is provided around the fisheye prism part.