JPS6364841B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicular lamp, and more particularly to a vehicular lamp in which the brightness of a lens surface is made uniform and visibility is improved.

In recent years, this type of vehicular lighting has become shallower and thinner, so instead of using a paraboloid of revolution reflector that takes up space, a direct prism is formed on the front lens to reflect the light emitted from the light source. A vehicular lamp has been proposed in which direct light is controlled by the direct-ray Fresnel prism.

In a conventional vehicle lamp equipped with a front lens formed with a direct-light Fresnel prism, a light source c is disposed in a lamp chamber defined by a housing a and a front lens b, as shown in FIG. The front lens b includes an outer lens d having a fisheye prism e formed on its inner surface, and a refractive prism g in the center facing the light source c to control the direct light from the light source c as a ray approximately parallel to the optical axis X. and an inner lens f with reflecting prisms h and h' provided on the outer periphery of the inner lens f, which directs the emitted light (direct light) from the light source c to the optical axis
The light beam is made into substantially parallel light beams, and is condensed by a fisheye prism e of an outer lens d to obtain a desired light distribution pattern.

However, in such a conventional vehicle lamp, since the front lens b is formed into a planar shape and is disposed in the housing a, the inner lens f
The radiation light (direct light) that enters the refractive prism section g provided at the center facing the light source c of the direct Fresnel prism formed in , and the reflective prisms h and h' provided at the outer circumference is As shown in the figure, the light is incident only within the range of angle α°, and therefore the utilization rate of the luminous flux is low. In particular, the light incident on the reflective prisms h and h' on the outer periphery far from the light source c is at angles β ₁ and β. ₂ , the amount of luminous flux is small and the luminous flux density decreases, so the central part of the inner lens f facing the light source c looks bright, but the outer periphery becomes a dark part, which not only makes the lighting filling unsightly, but also makes it difficult to use for signal lights. There is a problem that display functions such as cannot be fully achieved.

In order to improve this problem, an inner lens with a Fresnel cut is placed on the side of the light source almost parallel to the optical axis, and the light rays emitted from the inner lens are directed in a direction almost perpendicular to the optical axis. A lamp has been proposed in which a reflective surface is formed that causes total reflection in the direction of the optical axis, thereby eliminating the dark area on the outer periphery of the lamp (see Japanese Utility Model Application No. 56-2503).

According to this proposal, the problems of the prior art as shown in FIG. 1 can be solved to some extent.

However, in the lamp having the structure shown in the above-mentioned Japanese Utility Model Publication No. 56-2503, the front lens is horizontally long and the outer periphery of the lens is extended to a position away from the light source, and the depth dimension of the lamp is In cases where the inner lens is limited (thin), the inner lens must be placed away from the light source, so the amount of direct light directed to the side of the light source is reduced, making it possible to sufficiently eliminate dark areas. The problem is that it is not possible to In addition, as mentioned above, when the front lens is horizontally long, it is possible to arrange an inner lens close to the light source to increase the amount of direct light directed to the side. The depth dimension of the lamp increases, making it impossible to make the lamp thinner. As described above, the structure shown in the above-mentioned Japanese Utility Model Publication No. 56-2503 is subject to restrictions on the setting of the lamp design, especially when the front lens is horizontally long and large in size. This is not sufficient to eliminate dark areas.

The present invention aims to improve the problems of the prior art as described above, and to provide a vehicle lamp that is thin enough and bright enough to the outer periphery even when the front lens is horizontally long and large in size. .

In order to achieve the above objects, the present invention has the following features:
A light source is disposed within a lamp chamber defined by a housing and a lens disposed in front of the housing, and the lens is composed of an outer lens and an inner lens, and a central portion of the inner lens facing the light source is provided with light from the light source. In a vehicle lamp equipped with a Fresnel prism that emits direct light substantially in the optical axis direction, a side lens is disposed on the side of the light source, and a reflective surface and an upright surface are provided on the outside of the side lens. Alternately formed stepped reflecting portions are provided, and the side lens has an inner surface facing the light source that controls the emitted light directed laterally from the light source into light that is approximately parallel to a horizontal axis perpendicular to the optical axis. In addition to forming a Fresnel prism,
A plurality of cylindrical prisms are formed on the outer surface of the prism for making light made substantially parallel to the horizontal axis by the Fresnel prism enter each reflective surface of the stepped reflective section, and each reflective surface of the stepped reflective section is It is characterized by having a reflecting surface that directs the light incident from the cylindrical prism mainly toward the outer peripheral portion of the inner lens where the Fresnel prism is not provided.

As described above, the vehicle lamp of the present invention does not directly direct the light rays made almost parallel to the horizontal axis orthogonal to the optical axis by the Fresnel prisms of the side lenses into the stepped reflection section, but instead The cylindrical prism of the lens focuses the light onto each reflective surface of the stepped reflective section, and the reflected light from each reflective surface is made to mainly enter the outer periphery of the inner lens where the Fresnel prism is not provided. Even if the side lenses are placed in positions where they can capture the desired beam, the cylindrical prism allows the light to be incident on a reflective surface located away from the light source, even if the front lens is horizontally long and large. ,
It is possible to obtain a light fixture that is bright all the way to the outer periphery while being thin.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of the implementation of a vehicle lamp according to the present invention will be described below with reference to the accompanying drawings.

FIG. 2 is a cross-sectional view of the main part of the present invention applied to an automobile tail light, in which 1 indicates a housing, and the inside of a light chamber 10 defined by the housing 1 and a lens 2 disposed in front of the housing 1 is shown. A valve 5 is attached to a holder 52 via a socket 51.
The front lens 2 consists of an outer lens (cover lens) 21 and an inner lens 22 inside the outer lens 21. A fisheye prism part 22a is formed on the outer surface of the inner lens 22, and an optical axis X (facing the bulb 5) is formed on the inner surface. A Fresnel prism 22b is formed in the vicinity of the central portion 6 (near the reference axis of the lamp), and flat portions 22c, 22d are formed on the outer peripheral portions 7, 8 of the central portion 6, which are far from the bulb.

In the present invention, the flat portions 22c of the outer peripheral portions 7, 8 of the inner lens 22 far from the bulb 5,
A side lens 3 disposed on the side of the bulb 5 and a stepped reflection section 4 disposed on the side wall of the housing 1 are provided as optical means for making a large amount of light beam incident toward the light beam 22d.

That is, the side lenses 3, as shown in the figure,
A right side lens 31 and a left side lens 32 are fixed on both sides of the bulb 5 in the housing 1 by appropriate means so as to be substantially parallel to the optical axis X. Further, the side lenses 31 and 32 each have a Fresnel prism 31 on the inner surface thereof (on the light source side) centered around the horizontal axis Y of the bulb 5 perpendicular to the optical axis X.
a, 32a are provided, and this Fresnel prism 31
a and 32a control the refraction of the side irradiation light emitted laterally from the bulb 5 into a light beam substantially parallel to the horizontal axis Y. On the other hand, cylindrical prisms 31b, 32b are provided on the outer surfaces of the side lenses 31, 32, and the cylindrical prisms 31b, 32b converge the light rays made substantially parallel by the inner Fresnel prisms 31a, 32a. Each reflective surface 4 formed on the stepped reflective section 4
1a, . . . 42a, . . . Therefore, the stepped reflection parts 41 and 42 are
cylindrical prisms 31b provided on the outer surfaces of the left and right side lenses 31, 32;
Reflecting surfaces 41a, 41a..., 42a, 42a... are provided corresponding to 31b..., 32b, 32b..., respectively. Note that reference numerals 41b and 42b are upright surfaces provided between each of the reflective surfaces 41a and 41a, and between 42a and 42a. A Fresnel prism 22b provided in the central portion 6 of the inner lens 22 focuses light from the side lenses 31 and 32 by the reflecting surfaces 41a..., 42a... of the stepped reflecting portions 41, 42 configured as described above. The structure is such that a large amount of reflected light is emitted toward the peripheral portions of and the flat portions 22c and 22d of the outer peripheral portions 7 and 8.

Since the vehicular lamp of the present invention is constructed as described above, the optical effect when the bulb 5 is lit is the second one.
As shown in the figure, out of the light emitted from the light source, the light emitted forward is incident on the Fresnel prism 22b on the inner surface of the central part 6 facing the light source of the inner lens 22, as shown by the solid line in the figure.
b, the light beam is controlled to be substantially parallel to the optical axis X, passes through the wall thickness as it is, passes through the outer lens 21 through the fisheye prism portion 22a on the outer surface, and is emitted. In addition, the light emitted from the light source to the side, that is, the side light, is
As shown by the dotted lines in the figure, the light enters the Fresnel prisms 31a and 32a on the inner surfaces of the right lens 31 and the left lens 32, respectively, and is refracted into substantially parallel rays with the horizontal axis Y by the Fresnel prisms 31a and 32a. After passing through the wall thickness as it is, the cylindrical prisms 31b and 3 on the outer surface of each
2b as a focused light, and the focused light rays are controlled by the corresponding reflecting surfaces 41a, ... reflecting surfaces 42 of the stepped reflecting parts 41, 42 of the housing 1
It is incident on a,... and each reflective surface 41
a... Reflective surface 42a... causes the inner lens 2 to
A large amount of reflected light with a high luminous flux density is diffused and incident on the flat parts 22c, 22d of the outer peripheral parts 7, 8 of 2 and the peripheral part of the Fresnel prism 22b provided in the central part 6, and the reflected light enters the outer peripheral part 7. , 8 flat part 22
The reflected light incident on the lenses c and 22d passes through the wall thickness, passes through the fisheye prism portion 22a on the outer surface, passes through the outer lens 21, and is condensed in front of the front lens 2 to form a desired light distribution pattern.

In the vehicle lamp of the present invention, as shown in FIG. 3, among the light emitted from the light source, the light emitted forward that enters the central portion 6 of the inner lens 22 is at an angle α° shown by the solid line in the figure. The amount of light incident within the range ₁ is the same as before. The light radiated laterally from the light source is transmitted through the lateral lenses 31 provided on both sides of the bulb 5, and the light beams in the range of angle α° ₂ on the right side and the range of angle α° ₃ on the left side shown by dotted lines in the figure, respectively. Fresnel prisms 31a formed on the inner surfaces of each of 32,
32a into a beam substantially parallel to the horizontal axis, and then focused by the respective cylindrical prisms 31b and 32b provided on the outer surface, and the focused light is reflected by the corresponding reflecting surfaces 41a, 42 of the stepped reflecting portions 41, 42 of the housing 1, respectively. 41a..., reflective surface 42a,
42a..., and the respective reflecting surfaces 41a, 4
1a..., the reflected light diffused by the reflecting surfaces 42a, 42a..., the outer peripheral part 7 of the inner lens 22,
8 and the periphery of the central portion 6. Therefore, the emitted light from the light source has an angle α゜₁
It is possible to effectively utilize the luminous flux in the range of +α゜₂ +α゜₃ , and in particular, the cylindrical prism allows the focused light to be reflected by the reflective surfaces 41a, 42a and incident on the outer circumferential parts 7, 8 of the lens, so that the horizontally long Even if the lenses are large in size, the brightness of the outer peripheral parts 7 and 8 can be compensated for without increasing the depth.

In addition, in the above-mentioned embodiment, the side lens 3
Although a case has been described in which the stepped reflecting portions 4 and 4 are disposed on both sides of the bulb 5, the present invention is not limited to this, and may be disposed on one side or the entire circumference of the bulb 5.

As described above, according to the present invention, it is possible to provide a vehicular lamp that is thin enough and bright enough to reach the outer periphery even if the outer periphery of the lens extends to a position far from the light source. There is an effect that can be done.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a conventional lamp. FIG. 2 is a sectional view of a main part showing an embodiment of a vehicle lamp according to the present invention, and FIG. 3 is an explanatory diagram showing a range of luminous flux utilization of a bulb. DESCRIPTION OF SYMBOLS 1... Housing, 2... Front lens, 22b... Fresnel prism, 31, 32... Side lens, 31
a, 32a...Fresnel prism, 31b, 32b
...Cylindrical prism, 41, 42...Stepped reflection section, 5...Bulb, 6...Center portion, 7, 8...Outer portion, 10...Light chamber, X...Optical axis, Y...Horizontal axis.

Claims (1)

[Claims] 1. A light source is disposed within a lamp chamber defined by a housing and a lens disposed in front of the housing, and the lens is composed of an outer lens and an inner lens, and a light source is disposed in a central portion of the inner lens facing the light source. In a vehicle lamp equipped with a Fresnel prism that emits direct light approximately in the optical axis direction, a side lens is disposed on the side of the light source, and a reflective surface and an upright surface are provided on the outside of the side lens. The side lenses are provided with stepped reflecting portions formed alternately, and the side lenses have an inner surface facing the light source that converts the light emitted from the light source to the side into light substantially parallel to the horizontal axis perpendicular to the optical axis. A Fresnel prism to be controlled is formed, and a plurality of cylindrical prisms are formed on the outer surface of the Fresnel prism to make light made substantially parallel to the horizontal axis by the Fresnel prism enter each reflective surface of the stepped reflection section, and A vehicular lamp characterized in that each reflective surface of the reflective part is a reflective surface that directs the light incident from the cylindrical prism mainly toward the outer peripheral part of the inner lens where the Fresnel prism is not provided.