JPS6364003B2 - - 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.

This type of vehicle light uses a direct prism on the front lens to reduce the depth and thickness of the light, and does not use a space-consuming paraboloid of revolution reflector to emit light from the light source. A vehicle lamp has been proposed in which direct light is controlled by the direct-light Fresnel prism.

As shown in FIG. 1, a conventional vehicle lamp equipped with a front lens formed with a direct-light Fresnel prism has a light source c disposed within a lamp chamber defined by a housing a and a front lens b. The front lens b includes an outer lens d having a fisheye prism e formed on its inner surface, and a central portion facing the light source c in order to control the emitted light (direct light) from the light source c as a ray almost parallel to the optical axis X. It consists of an inner lens f that forms a refractive prism g and has reflective prisms h and h' on the outer periphery on both sides, and directs the emitted light (direct light) from the light source c by the Fresnel prism, approximately parallel to the optical axis X. The light beam is made into parallel light beams and condensed by the fisheye prism e of the outer lens d to obtain a desired light distribution pattern.

However, in such a conventional vehicle lamp, since the lens surface b is formed in a planar shape and is disposed in the housing a, the center of the direct-ray Fresnel prism facing the light source c formed in the inner lens f is The radiation (direct light) that enters the refractive prism g provided at the center and the reflective prisms h and h' provided on the outer periphery on both sides is only within the angle α° as shown in the figure. Therefore, the utilization rate of the luminous flux is low, and in particular, the light that enters the reflective prisms h and h' that are far from the light source c falls within the range of angles β ₁ and β ₂ and has a small luminous flux amount and a low luminous flux density. As a result, the central part where the refractive prism g is provided looks bright, but the outer peripheral part becomes a dark part, which causes the problem that not only is the lighting filling unsightly, but also the display function of a signal light or the like cannot be sufficiently achieved.

In order to improve these points, we installed an inner lens with a Fresnel cut on the side of the light source almost parallel to the optical axis, and a light source that is oriented almost perpendicular to the optical axis emitted from the inner lens. A lamp has been proposed in which a reflective surface is formed to completely reflect the light 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 becomes large, 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 improves the problems of the prior art as described above, and provides a vehicular lamp that is thin and does not produce dark areas on the outer periphery even when the front lens is horizontally long and large. That is.

In order to achieve the above objects, the present invention disposes a light source in a lamp chamber defined by a housing and a lens disposed on the front surface of the housing, and the lens is composed of an outer lens and an inner lens. In a vehicle lamp, the inner lens is provided with a Fresnel prism that emits direct light from the light source substantially in the direction of the optical axis in the central portion facing the light source, and a first side is provided on the side of the light source substantially parallel to the optical axis. the side lens and the second side lens are arranged with a distance between them, and
The first side lens has an inner surface facing the light source made smooth, and an outer surface facing the second side lens that directs light emitted laterally from the light source almost parallel to a horizontal axis perpendicular to the optical axis. a Fresnel prism is formed to refract the light, and the second side lens
A Fresnel prism is formed on the outer surface so that the inner surface facing the side lens is made a smooth surface, and the light incident from the first side lens substantially parallel to the horizontal axis is emitted toward the outer periphery of the lens, and ,
It is characterized in that a Fresnel prism is formed on the outer periphery of the inner lens to control the light incident on the Fresnel prism of the second side lens to be substantially parallel to the optical axis.

As described above, in the vehicle lamp of the present invention, a light ray made substantially parallel to the horizontal axis perpendicular to the optical axis by the Fresnel prism of the first side lens is made incident on the second side lens, and the horizontal axis The second ray parallel to
A Fresnel prism formed on the outer surface of the side lens emits light toward the outer periphery of the lens, and the light incident from the second side lens is emitted toward the outer periphery of the inner lens, which is substantially parallel to the optical axis. Since the Fresnel prism is formed, the sideward radiation captured by the first side lens can be emitted from the outer periphery of the front lens almost parallel to the optical axis. The side lens can be installed at a position where a desired amount of light can be obtained, and the distance between the first side lens and the second side lens can be arbitrarily set according to the distance between the light source and the outer periphery of the lens. Therefore, even if the lens is horizontally long and large, it is possible to make the lamp thinner and emit a sufficient amount of light almost parallel to the optical axis from the outer periphery of the lens, so that it can cover the entire surface of the lens. It is possible to obtain a lamp having substantially uniform brightness throughout.

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

2 to 4 show the application of the present invention to a tail light for an automobile. Reference numeral 1 indicates a housing, and a light chamber 10 defined by the housing 1 and a lens 2 disposed in front of the housing 1 is provided. A valve 5 is attached to the holder via a socket 51. The lens 2 consists of an outer lens 21 having a fisheye prism 21a formed on its inner surface, and an inner lens 22 disposed inside the outer lens 21.

A central portion 6 of the outer surface of the inner lens 22 near the optical axis X (reference axis of the lamp) facing the bulb 5
A refractive Fresnel prism 22a is formed in which controls the light emitted forward from the light source (filament) P of the bulb 5 into a ray substantially parallel to the optical axis X and emits it in the direction of the outer lens 21. The outer surfaces of the outer circumferential parts 7 and 8 (the parts far from the light source P) on both sides of the inner lens 22 are provided with light beams incident on the second side lenses 32 and 42, which will be described later, to be controlled to be almost parallel to the optical axis X. The refractive Fresnel prisms 22b and 22c emit light in the direction of the outer lens 21.
is formed.

Furthermore, on both sides of the bulb 5, optical lenses 3 and 4 consisting of first side lenses 31 and 41 and second side lenses 32 and 42 are fixed approximately parallel to the optical axis X within the housing 1 as appropriate. It is arranged by. That is, the right optical lens 3 includes the first side lens 31 and the second side lens 32;
The left optical lens 4 consisting of a first side lens 41 and a second side lens 42 is provided so as to correspond to the right outer circumference 7 and the left outer circumference 8 of the inner lens 22, respectively. .

The optical lens 3 and the optical lens 4 disposed on both sides of the bulb 5 include first side lenses 31 and 41, respectively, disposed on the bulb 5 side,
The first side lenses 31 and 41 have smooth inner surfaces facing the light source, and Fresnel prisms 31a and 41a are respectively formed on the outer surfaces around the horizontal axis Y of the bulb 5 perpendicular to the optical axis X. and
The Fresnel prisms 31a, 41a are cut so as to control the refraction of the light emitted laterally from the light source P into rays substantially parallel to the horizontal axis Y.

Further, each of the first side lenses 31 and 4
1, second lateral lenses 32 and 42 are arranged parallel to the first lateral lenses 31 and 41 at a predetermined distance from the first lateral lenses, and The side lenses 32 and 42 have smooth inner surfaces facing the first side lenses, and Fresnel prisms 32a and 42a are formed on the outer surfaces.
The Fresnel prisms 32a, 42a are refracted into lines substantially parallel to the horizontal axis Y by the Fresnel prisms 31a, 41a formed on the first side lenses 31, 41, and are incident on the second lenses 32, 42. It is designed so that the light beams are directed toward the outer peripheral portions 7 and 8 on both the left and right sides of the inner lens 22, respectively.

The Fresnel prisms 32a, 42a of the second side lenses 32, 42 are connected to the inner lens 22.
In relation to the refractive Fresnel prisms 22b and 22c formed on the outer peripheral parts 7 and 8 on both sides of
The light source entering the outer circumferential portions 7, 8 of the inner lens from the side lenses 32, 42 is configured to be emitted substantially parallel to the optical axis X toward the outer lens.

In the embodiment shown in FIG. 3, a Fresnel prism is formed on the outer surface of the inner lens 22, but the present invention is not limited to this example. You can also do that. However, in this case, reflective prisms are formed on the outer peripheral portions 7 and 8 on both sides.
This is determined by the angle of the incident light from the Fresnel prisms 32a, 42a formed on the outer surfaces of the second side lenses 32, 42.

Since the vehicle lamp of the present invention has the above-described configuration, when the bulb 5 is turned on, the lights shown in FIGS.
As shown in the figure, out of the light emitted from the light source P, the light emitted forward is incident on the flat surface of the inner surface of the central portion 6 of the inner lens 22, as shown by the solid line, and passes through the lens thickness to form the outer surface. Refractive Fresnel prism 2
2 a , the light beam is refracted into a ray substantially parallel to the optical axis X and directed toward the outer lens 21 . Furthermore, the light emitted laterally from the light source P enters the smooth inner surfaces of the first lateral lens 31 on the right side and the first lateral lens 41 on the left side, as shown by the dotted line, and passes through the lens thickness. The Fresnel prisms 31a and 41a formed on the outer surface control the refraction into rays almost parallel to the horizontal axis Y, and the rays enter the smooth surfaces of the second side lenses 32 and 42, respectively, and pass through the lens thickness to form Fresnel rays on the outer surface. The prisms 32a and 42a emit light toward the right outer circumferential portion 7 and left outer circumferential portion 8 of the inner lens 22, and the refractive Fresnel prisms 22b and 22c on the outer surface of the inner lens refract the light into a ray substantially parallel to the optical axis X. The light is controlled and emitted toward the outer lens 21, condensed and diffused by the fisheye prism 21a of the outer lens 21, and emitted in front of the lens to form a desired light distribution pattern.

Accordingly, in the vehicle lamp of the present invention, as shown in FIG. 4, out of the emitted light from the light source P, the forward emitted light that enters the central portion 6 near the optical axis X of the inner lens 22 is represented by a solid line. The same amount of light as in the conventional case is incident within the range of angle α ₁ ° shown. In addition, the light emitted from the light source P to the side has a luminous flux in the range of angle α ₂ ° on the right side and the range of angle α ₃ ° on the left side, as shown by the dotted line, from the first side lens 3.
1 and 41, and this luminous flux is incident on the outer peripheral portions 7 and 8 of the inner lens 22 as described above, so that the emitted light from the light source P is α ₁ ° + α ₂ ° +
The luminous flux in the range of α ₃ ° is effectively utilized.

In this case, in the present invention, since the light incident surfaces of the first side lens and the second side lens are smooth surfaces, although there is some transmission loss, the loss of light is extremely small. and a second side lens, the first side lens is arranged at a position where a luminous flux in a desired angular range can be obtained, and the first side lens is
The distance between the side lens and the second side lens can be set arbitrarily, so even if the lamp is horizontally long and large in size, a large amount of light can be incident on the outer peripheral parts 7 and 8 of the lens. The brightness of the entire surface can be made uniform.

5 and 6 show other embodiments of the invention. Since both embodiments are basically the same as the above-mentioned embodiments, the same parts are given the same reference numerals and detailed explanations are omitted. However, in the embodiment shown in FIG. 5, the valve 5 is placed horizontally. In the embodiment shown in FIG. 6, the bulb 5 is of a horizontal type and a reflecting mirror 9 is installed below it so that a larger amount of light can be emitted from the center of the lens.

As described above, according to the present invention, even when the front lens is horizontally long and large in size, it is possible to make the lamp thinner and to make it possible to make the lens almost parallel to the optical axis from the outer periphery as well as from the center of the lens. Emit enough light,
A lamp having substantially uniform brightness over the entire surface of the lens can be provided.

[Brief explanation of drawings]

FIG. 1 is a sectional view illustrating the optical function of a conventional lamp. 2 to 4 show an embodiment of the vehicle lamp of the present invention, FIG. 2 is a front view of the lamp, FIG. 3 is a sectional view of the main part, and FIG. 4 is an explanatory diagram showing the optical function. be. FIGS. 5 and 6 are sectional views of main parts showing other embodiments of the present invention. 1...Housing, 2...Front lens, 21...
...Outer lens, 22...Inner lens, 2
2a, 22b, 22c... Fresnel prism of the inner lens, 31, 41... first side lens,
31a, 41a... Fresnel prism, 32, 4
2... Second side lens, 32a, 42a... Fresnel prism, P... Light source, 7, 8... Lens outer periphery, 10... Lamp chamber, X... Optical axis.

Claims (1)

[Claims] 1. A light source is disposed within a light 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 vehicular lamp is provided with a Fresnel prism that emits direct light from the light source substantially in the direction of the optical axis in the center portion of the inner lens facing the light source. a first side lens and a second side lens are arranged at a distance substantially parallel to the optical axis, and the first side lens has a smooth inner surface facing the light source, and A Fresnel prism is formed on the outer surface facing the second side lens, and the Fresnel prism refracts the light emitted laterally from the light source substantially parallel to a horizontal axis orthogonal to the optical axis. A Fresnel prism is formed on the outer surface so that the inner surface facing the side lens is made a smooth surface, and the light incident from the first side lens substantially parallel to the horizontal axis is emitted toward the outer periphery of the lens, and A vehicular lamp characterized in that a Fresnel prism is formed on the outer periphery of the inner lens to control the light incident on the Fresnel prism of the second side lens to be substantially parallel to the optical axis.