JPH0439161B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a signal light, such as a tail light, which is mounted on a vehicle such as an automobile, and specifically relates to a structure suitable for thinning.

[Conventional technology]

FIG. 3 shows the structure of a conventional lamp 21 of this type in a thinner state, in which a light source 22 placed approximately at the center of the lamp 21 and a Fresnel lens 23 with the light source 22 as a focal point are arranged in parallel. The light distribution characteristic required for this lamp 21 is formed by obtaining the light beam and making a lens cut on the outer lens 24 provided in front of the light beam.

[Problem to be solved by the invention]

However, the lamp 21 with the conventional configuration described above
The thinner the light source 2 is, that is, the closer the distance between the light source 22 and the Fresnel lens 23 is, the more the light source 2 that enters the periphery of the Fresnel lens 23 becomes smaller.
The incident angle of 2 becomes shallow, leading to a decrease in the amount of peripheral light. Therefore, when trying to make the lamp 21 thinner while maintaining the conventional configuration, the problem of the decrease in the amount of peripheral light cannot be ignored, and the current state of use is practically at its limit, and vehicle manufacturers and other market Although there is a strong desire to make the device thinner, it has been considered impossible to make it any thinner, creating the problem that market demands cannot be met. Additionally, compared to lamps that use reflectors, lamps that use the Fresnel lens 23 tend to have a lower luminous flux utilization rate, and this becomes more noticeable as they become thinner, making it even more difficult to make them thinner. It has become something to do.

[Means to solve the problem]

As a specific means for solving the problems that occur in the conventional configuration, the present invention provides a conical hole-shaped reflecting mirror, a light source disposed on the center line of the reflecting mirror, and a light source disposed on the center line of the reflecting mirror. By providing a vehicle signal lamp characterized by comprising a Fresnel lens obtained by rotating a composite prism cut around the center line to form a focal point on a virtual image of the light source generated on one side of the cross section, The present invention is intended to solve the above-mentioned conventional problems by providing a lamp that is bright as a whole while also eliminating the lack of peripheral light.

【Example】

Next, the present invention will be explained in detail based on an embodiment shown in the drawings. What is indicated by reference numeral 1 in FIG. 1 is a vehicle signal lamp according to the present invention, and this vehicle signal lamp 1 is provided with a conical hole-shaped reflector 2, and a light source 3 is positioned on the center line Z of the vehicle signal lamp 1. Furthermore, a Fresnel lens 4 is provided in front of the reflecting mirror 2 and the light source 3. Furthermore, an outer lens 5 is provided further in front of the Fresnel lens 4, but since this outer lens 5 is formed using substantially the same design means as that of the conventional example, the detailed description will not be given here. Explanation will be omitted. FIG. 2 shows the inclination angle α of the reflecting mirror 2 and the light source 3.
This figure shows the design principle of the prism cut 4a of the Fresnel lens 4, which is determined by the position of . First of all, the inclination angle α of the reflecting mirror 2 is determined by taking into consideration, for example, the desired thickness of the vehicle signal light 1, the physical dimensions of the light source 3, the mounting dimensions of the Fresnel lens 4 and the outer lens 5, etc. but,
At this time, if the vehicle signal light 1 is rectangular, it goes without saying that it is preferable to form the vehicle signal light 1 so that its starting point is on a diagonal and the entire surface of the vehicle signal light 1 is covered with an effective reflective surface. Nor. When the conical hole-shaped reflecting mirror 2 formed as described above is cut along an arbitrary straight line leading to the center line Z, the cross section of one side of the reflecting mirror 2 becomes a straight line with an inclination angle α, and the straight line is A virtual image 3K of the light source 3 is obtained as a symmetry. Therefore, if a composite prism cut 4a made of a refractive prism or a reflective prism with the virtual image 3K as the focal point is formed, the light source 3 can be
The light rays from the above become parallel rays parallel to the center line Z, and if the composite prism cut 4a is further rotated about the center line Z to obtain a Fresnel lens 4, this Fresnel lens 4 will be formed so that the light source 3 is parallel to the center line Z. The light from the ring-shaped virtual image 3K reflected by the reflecting mirror 2 is made parallel to the irradiation direction, and the outer lens 5 placed further in front of the Fresnel lens 4 is the same as that of the conventional example. It will be good depending on the conditions. At this time, the angle of the light beam incident on the Fresnel lens is determined by, firstly, that the virtual image 3K is generated at two locations on both sides of the center line Z, and secondly, that it moves backward from the position of the light source 3. , compared to the conventional example, is much deeper, that is, closer to a right angle, and the amount of change in the angle is also within a narrow range, so the difference in luminous intensity over the entire light emitting surface of the lamp 1 is small. Incidentally, as explained above, the conical hole-shaped reflecting mirror 2
By using the light source 3, the reflected light from the light source 3 has the same effect as a plane mirror in the cross section described above and is not given a specific directionality. The light source 3
It also reaches in front of the light source 3, and does not cast a shadow on the socket in which the light source 3 is installed. Further, when a reflecting mirror is generally used, it is possible to obtain a large effective solid angle of the light ray from the light source 3, and a bright lamp can be realized.

【Effect of the invention】

As explained above, according to the present invention, the light from the light source is reflected by the conical hole-shaped reflecting mirror, and a Fresnel lens is provided to convert the reflected light into parallel light to enter the outer lens, thereby reducing the amount of peripheral light. This reduces the drop in the thickness and enables even thinner
This has the extremely excellent effect of making it possible to respond to market demands, and also has the effect of making it possible to provide even brighter lamps.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of a vehicle signal lamp according to the present invention, FIG. 2 is a partial sectional view taken along the line - in FIG. 1, and FIG. 3 is a sectional view showing a conventional example. be. 1...Vehicle signal lamp, 2...Reflector, 3...
Light source, 3K...virtual image, 4...Fresnel lens, 4
a... Prism cut, 5... Outer lens,
Z...Center line.

Claims (1)

[Claims] 1. A conical hole-shaped reflecting mirror, a light source placed on the center line of this reflecting mirror, and a composite prism cut that forms a focal point on a virtual image of the light source that is generated on one cross section of the reflecting mirror reaching the center line. A vehicle signal lamp comprising a Fresnel lens obtained by rotating around a line.