JPH0124807Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a direct-emitting vehicle lamp such as a rear combination lamp or a front combination lamp.

[Background of the idea]

Direct-light vehicle lights, such as rear combination lamps or front combination lamps, are horizontally elongated and consist of an inner lens in front of the bulb in the center, a refractive prism, and a reflective prism in the periphery. A Fresnel prism is formed, and an outer lens is provided in front of the Fresnel prism.

In such conventional vehicle lamps, the light from the bulb is turned into light approximately parallel to the optical axis by the Fresnel prism, and this light is diffused by the fisheye lens of the outer lens. There is a problem in that the area near the center is bright, and it gradually becomes darker toward the periphery.

In order to improve these points, the
Publication No. 34303 is proposed. In other words, this idea consists of a parallel prism that makes the light emitted directly from the light source parallel to the optical axis, and a diffusing prism that refracts the light so that it is irradiated at a certain angle with the optical axis. Although the above-mentioned problems are improved, since a diffusing prism is used that refracts left and right around the bulb, there is a problem that half of the lens becomes dark when viewed from the front left and right.

[Purpose of invention]

The present invention aims to improve the conventional vehicular lamp as described above and provide a lamp that provides uniform visibility no matter which direction the lamp is viewed from.

[Summary of the idea]

In order to achieve the above object, the present invention includes an outer lens and an inner lens, and forms a Fresnel prism consisting of a refractive prism in the center and a reflective prism in the periphery on the inner surface of the inner lens. A direct lighting type vehicle lamp having a fisheye prism formed on the outer lens is characterized in that a four-way diffusion prism that diffuses vertically and horizontally is provided on a portion of the outer surface of the inner lens that has a refractive prism.

[Example of idea]

Next, an embodiment of the present invention will be explained with reference to FIG. 1 and FIGS. 2a and 2b.

Figure 1 is a sectional view of a direct-light vehicle lamp to which the present invention is applied, Figure 2a is a perspective view of a diffusion prism, and b
is a partial sectional view thereof.

In Figures 1 and 2, 1 is a valve, 2
3 indicates an outer lens, 3 indicates a housing, and 4 indicates an inner lens.

The inner lens 4 has a refractive Fresnel prism 4a at the center of the front surface of the bulb 1, and a reflective Fresnel prism 4b at its periphery. Further, on the opposite side (front surface) of each of the Fresnel prisms 4a, there is provided a four-way diffusion prism 5 that diffuses the light vertically and horizontally.

The diffusion prism 5 is arranged in front of the inner lens ₄ as _shown in FIG _.
It is divided into several sections such as 5d ₁ , 5e ₁ , 5a ₂ , 5a ₃ , 5a ₄ etc., and a pyramid-shaped diffusing prism with an apex angle of 5R is placed in each section as shown in Fig. 2b. There is.

Since the lamp of the present invention has the above-described structure, the light from the bulb 1 passes through the Fresnel prism 4a,
4b, the light becomes substantially parallel to the optical axis l, and this light is diffused not only in one direction but also vertically and horizontally by the diffusion prism 5 as shown in FIG. 1, and then controlled by the fisheye prism of the outer lens. The light is emitted in a direction tilted by a certain angle θ with respect to the optical axis l.

FIG. 8 is a characteristic diagram comparing the brightness at the center and the outer periphery between the lamp of the present invention and a conventional lamp. In this figure, A indicates the brightness of the lamp of the present invention, and B
indicates the brightness of a conventional lamp. As is clear from this figure, in the lamp of the present invention, the brightness A ₁ at the center is slightly lower than the brightness B ₁ of the conventional lamp, but the brightness A ₂ at the outer periphery is lower than the brightness B ₂ of the conventional lamp. It shows that it will be higher. In this way, the luminance of the lamp is made so that there are no areas where it is extremely high or extremely low, so that the lamp appears uniformly no matter which direction it is viewed from. Furthermore, since it is a double-sided prism, it is easy to cut the mold, and it also has the effect of making the Fresnel prism less noticeable when the bulb is not lit.

3a, b to 5 a, b show other embodiments of a diffusing prism having the same effect as the previous embodiment.

3a and 3b show that the top of the pyramid-shaped diffusion prism 5 shown in FIG. 2 is cut horizontally to form a convex diffusion prism 5 having a flat portion 5X, and , b are the plane portions 5X shown in FIG.
This shows that the diffusion prism 5 having a shape is provided in a concave shape. In addition, in FIGS. 5a and 5b, a pyramid-shaped diffusion prism 5 having an apex angle 5R shown in FIG.
It shows that it is provided in a concave shape.

6a, b and 7a, b are a perspective view and a partial side view of a diffusing prism showing another embodiment of the present invention.

The difference between the diffusing prism 5 shown in FIGS. 6a, b and 7 a, b from the diffusing prism 5 shown in FIGS. 2 to 5 is that the diffusing prism formed on the opposite side of the inner lens 4 is partially This is the point that is provided for. That is, in FIGS. 2 to 5,
Diffusing prisms 5 connected to the front surface of the inner lens 4 are provided in a convex or concave shape, and in FIGS. 6 and 7, the diffusing prisms 5 are scattered.

Even in this case, the light made parallel to the optical axis l by the Fresnel prism is diffused vertically and horizontally by the scattered diffusion prisms 5, and the light incident on the flat surface 5c becomes light almost parallel to the optical axis l. Therefore, an appropriate light distribution can be obtained.

[Effect of idea]

As described above, the vehicle lamp of the present invention has a convex or concave four-way diffusing prism that diffuses vertically and horizontally on the opposite side of the Fresnel prism of the inner lens. The light from the parallel bulbs is diffused not only in one direction with respect to the optical axis, but also at a fixed angle up, down, left and right. Therefore, the brightness at the center of the optical axis is lowered and the brightness at the peripheral area is increased, so that an appropriate luminous intensity value can be achieved. Further, there is an effect that the lamp can have uniform brightness without unevenness no matter which direction the lamp is viewed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a direct-emitting vehicle lamp to which the present invention is applied, FIG. 2a is a perspective view of a diffusion prism, and FIG. 2b is a partial sectional view thereof. 3a, b to 7a, b are perspective views and sectional views similar to FIG. 2, showing other embodiments of the present invention. FIG. 8 is a characteristic diagram comparing the brightness of a lamp to which the present invention is applied and a conventional lamp. 1...Bulb, 2...Outer lens, 3...
Housing, 4... Inner lens, 4a... Refractive Fresnel prism, 4b... Reflective Fresnel prism, 5... Diffusion prism.

Claims (1)

[Scope of utility model registration request] Equipped with an outer lens and an inner lens,
In a direct lighting vehicle lamp, a Fresnel prism consisting of a refractive prism in the center and a reflective prism in the periphery is formed on the inner surface of the inner lens, and a fisheye prism is formed in the outer lens. A vehicle lamp characterized in that a four-way diffusing prism that diffuses vertically and horizontally is provided on a portion having a refractive prism.