JPH01120704A - Vehicle lighting appliance - Google Patents

Abstract

PURPOSE: To provide a vehicular lighting fixture which is free of a fisheye prism element that is seen black by arranging a piece of Fresnel prism element to each prism element of a fisheye prism. CONSTITUTION: At an inner lens 24, rays of light from lamp bulbs 22 and 23 go in respective Fresnel prism elements 28, optical paths of the rays being diverted therein as shown by solid lines 30 in the figure, enter respective fisheye prism elements 27a, and are diffused there. In this moment, the amount of incident light entering each fisheye prism element 27a is represented by a hatched area as shown in the figure. That is, the amount of each incident light 31 entering each fisheye prism element 27a shown as a hatched area is increased up to half or more of the amount of light defined by a pitch γof prism elements 27a and hence a fisheye prism element 27a that is seen black goes out of existence. Accordingly, attractiveness in appearance of the vehicular lighting fixture is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vehicular lamp, and more particularly to an improvement of an inner lens incorporated into the lamp.

(Prior Art) As an inner lens incorporated into a conventional vehicle lamp, a structure as shown in FIG. 4 is generally known.

The illustrated portion of the inner lens 1 is a curved portion that is located on the side of the vehicle.

This inner lens 1 is provided with a fisheye prism 2 on its front surface, and a direct grating Fresnel prism 3 on its back surface.

The fisheye prism 2 is formed by forming a plurality of prism elements 2a with the same pitch α over the entire surface of an inner lens l.

The direct lattice Fresnel prism 3 is a prism that is molded in a part where an ordinary concentric Fresnel prism cannot be molded because the inner lens l is molded into a curved shape. It is formed by arranging prism elements 3a in parallel along a curved surface.

In the conventional inner lens 1, the direct lattice-like Fresnel prism 3 is formed at the same pitch β with respect to a constant reference plane on both the flat portion 1a and the curved portion 1b on the back surface of the lens 1. In other words, they are formed at the same pitch β using the flat part 1a of the inner lens 1 as a reference plane, and the curved part 1b is inclined with respect to the reference plane, so the interface between the inner lens 1 and the Fresnel prism element 3a is pitch β
It is larger than.

(Problem to be Solved by the Invention) However, if each prism element 3a of the Fresnel prism 3 is formed at the same pitch β with respect to the reference plane regardless of the inclination of the curved portion ib, the fisheye prism element at the curved portion 1b 2a
and the Fresnel prism element 3a cannot be matched.

In a portion where the deviation between the fisheye prism element 2a and the Fresnel prism element 3a is significant, the fisheye prism element 2a
The amount of light incident from the light source (the area of light incidence relative to the area of the fisheye prism element 2a) becomes less than half.

Specifically, the light beams 4a and 4b in FIG. 4 have their optical paths changed by one Fresnel prism element 5 among the Fresnel prism elements 3a, and are incident on the fisheye prism elements 6 and 7. be done. The optical paths of the light rays 9a and 9b are changed by the Fresnel prism element 1O, and the optical paths are changed by the fisheye prism element 7.
, 8. Note that the hunting portion in the figure indicates the width of light, that is, the amount of incident light.

As a result, as shown in FIG.
．． The amount of light incident on any of the fisheye prism elements 6, 8 (hatched portion) is less than half, and
7.8 has a problem in that it appears black against the surrounding fisheye prism element 2a, which is unfavorable in terms of appearance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle lamp in which the amount of light incident on all prism elements of a fisheye prism is reduced to more than half, thereby improving the appearance.

(Means for Solving the Problems) The vehicle lamp of the present invention includes a light source disposed inside the housing, a curved inner lens and an outer lens attached to the front opening of the housing, and a fisheye prism applied to the surface of the inner lens. A vehicle lamp having a direct-lighting lattice-like Fresnel prism on the back surface, wherein each prism element of the direct-lighting lattice-like Fresnel prism on the back surface of the inner lens has a surface area on the surface of the inner lens, whether it is a flat part or a curved part of the inner lens. It is characterized by being molded to a size that always corresponds to one prism element of a fisheye prism.

(Function) Since one Fresnel prism element is associated with each prism element of the fisheye prism, the amount of light incident on all the fisheye prism elements on the inner lens surface is more than half, which reduces the possibility of black fish. Since the eye prism element is eliminated, the appearance is improved.

(Example) FIG. 3 shows a vehicle lamp according to the present invention. Reference numeral 21 in the figure indicates a housing, and within this housing 21, lamp bulbs 22 and 23 as light sources are provided. An inner lens 24 and an outer lens 25 are attached to the entire opening of the housing 21.

As shown in FIG. 1, the inner lens 24 has
A fisheye prism 27 is provided on its front surface, and a direct grating Fresnel prism 28 is provided on its back surface. Each prism element 27a of the fisheye prism 27 is formed at the same pitch γ along the entire inner lens surface.

The prism elements 28a of the Fresnel prism 28 are arranged at a one-to-one ratio on the back surface of the inner lens, corresponding to each fisheye prism element 27a on the surface of the inner lens. The width of the interface between the Fresnel prism element 28a and the inner lens 24 is determined by the width of the interface between the Fresnel prism element 28a and the inner lens 24.
a and the curved portion 24b. Note that the width of the boundary surface is almost constant because the width of the boundary surface set corresponding to the pitch γ is slightly smaller than the pitch T due to the thickness of the inner lens 24 in the curved portion 24b. In the flat portion 24a, the pitch T and the width of the boundary surface are completely the same, and are slightly different from the width of the boundary surface in the curved portion 24b.

When viewed from the perspective of the mold for molding the inner lens 24, this mold
Since a is the reference plane, the Fresnel prism element 28
The pitch δ of a becomes gradually smaller as it approaches the curved portion 24b. For this reason, the mold has a pitch δ of the curved portion 24.
It will be set gradually smaller toward b.

In the inner lens 24 configured as described above, the light from the lamp bulbs 22 and 23 enters each Fresnel prism element 28a and changes its optical path, as shown by the solid line 30 in FIG. The light enters the element 27a and is diffused. At this time, each fisheye prism element 27a
The amount of light incident on the lens is shown by hatching in FIGS. 1 and 2. In other words, each fisheye prism element 27
The amount of light incident on a (hatching) 31 is all more than half of the pitch γ of the prism element 27a,
The prism element 27a that becomes black disappears. This results in
Improved appearance.

In this embodiment, the direct grating Fresnel prism 28
prism element 28a into one fisheye prism element 27
Although one prism element 28a is set to correspond to a, it may be set to correspond to two prism elements 28a.
In this case as well, as in the case of the single prism element 28a described above, more than half of the amount of incident light 31 is ensured.

<Effects of the Invention> In the vehicle lamp of the present invention, each Fresnel prism element on the back surface of the inner lens is formed to correspond to each prism element of the fisheye prism on the surface of the inner lens, so that each More than half of the amount of light incident on the eye prism elements can be ensured, and no single fisheye prism element becomes black. This improves the appearance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an inner lens which is a characteristic part of the vehicle lamp of the present invention, FIG. 2 is a partial front view of the inner lens shown in FIG. 1, and FIG. 3 is a cross-sectional view of the vehicle lamp of the present invention. FIG. 4 is a schematic cross-sectional view showing the overall configuration, FIG. 4 is a cross-sectional view showing an inner lens of a conventional vehicle lamp, and FIG. 5 is a partial front view of the inner lens shown in FIG. 21...Housing, 22.23...Lamp pulp, 24...Inner lens, 25...Outer lens,
27...Fisheye prism, 27a...Fisheye prism 2
7 prism element, 28... Direct grating Fresnel prism, 28a... Prism element of the direct grating Fresnel prism 28. Agent Patent attorney Tetsuji Iwakura (1 other person) Figure 1 Figure 2

Claims (1)

[Claims] A vehicle lamp in which a light source is disposed inside a housing, a curved inner lens and an outer lens are attached to a front opening of the housing, a fisheye prism is applied to the surface of the inner lens, and a direct lattice-shaped Fresnel prism is applied to the back surface of the inner lens, the vehicle lamp comprising: Each prism element of the direct lattice Fresnel prism on the back surface of the inner lens always has a size corresponding to one prism element of the fisheye prism on the surface of the inner lens, both on the flat part and the curved part of the inner lens. A vehicle lamp characterized by being molded.