JP2002117708A - Lighting fixture for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems of a conventional lighting fixture for a vehicle for a signal that when a lens is made transparent in order to make match in design to a lighting fixture for illumination such as a headlamp, adjustment of transparency is made difficult and appearance is damaged. SOLUTION: This lighting fixture for a vehicle is composed of a light source 2; a parabolic system reflecting surface 3 almost placing a focal point on the light source 2; and a lens 4 covering an illumination direction side of the light source 2, and a Fresnel lens having a focal distance of a 1.5-2.5 times the distance between the lens 4 and the light source 2 and a pitch of 2 mm or less is installed in the lens 4, and thereby, transparency can be freely adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular lamp used as a signal for notifying another vehicle or a pedestrian, such as a tail lamp or a stop lamp, of the intention and action of the vehicle.

[0002]

2. Description of the Related Art FIGS. 6 and 7 show examples of the structure of a conventional vehicle lamp of this type. First, in a vehicle lamp 80 shown in FIG. 6, a light source 81 such as an incandescent lamp is used.
A parabolic reflecting surface 82 such as a paraboloid of revolution having the light source 81 as a focal point, and the light source 81 and the reflecting surface 82 are covered from the irradiation direction side.
and a lens 83 to which a is applied.

[0003] With this configuration, of the light from the light source 81, the light that reaches the reflection surface 82 is converted into parallel rays and enters the lens 83, and is appropriately diffused by the fish-eye lens cut 83a so that the light distribution characteristics are improved. Is formed. Since the light directly entering the lens 83 from the light source 81 is originally diffused light, it is further diffused by the fish-eye lens cut 83a, and is not directly involved in the formation of the light distribution characteristics.

In the vehicle lamp 90 shown in FIG. 7, the above-mentioned reflecting surface is omitted, and a surface of the lens 92 on the light source 91 side is provided with a Fresnel lens cut 92a having the light source 91 as a focal point. On the irradiation side of the same lens 92, a fish-eye lens cut 92b is formed.

In this way, the light from the light source 91 is converted into parallel rays by the Fresnel lens cut 92a and travels through the lens 92. When the light reaches the fisheye lens cut 92b, the light is diffused, and the light distribution characteristics are improved. To be formed. In the vehicular lamp 90, since the fish-eye lens cut 92b is formed on the surface on the irradiation surface side of the lens 92 to form irregularities, an outer lens 93 that further covers the irradiation surface side in order to prevent dirt from adhering to dust is usually used. Is provided. In the vehicle lamp 90, light that does not directly enter the Fresnel lens cut 92a does not participate in light distribution formation.

[0006]

However, in the vehicular lamps 80, 90 having the above-described structure, since the light distribution characteristics are formed by using the fish-eye lenses 83a, 92b, the fish-eye lens cuts 83a, Due to the strong curvature of the individual elements that make up
3, 92 have a strong opacity, and there is a problem that a design match cannot be achieved with a headlamp having high transparency recently.

It is assumed that the vehicle lamp 80 shown in FIG. 6 has a light distribution characteristic only by the reflection surface 83, and can be made transparent even with the same configuration as a headlamp through which the lens 83 passes. Is too high in transparency and the internal structure is completely exposed, which in turn increases the sense of incongruity. Further, in each of the conventional examples, the light amount from the light sources 81 and 91 is only approximately half or less than that incident on the reflection surface 82 or only the incident light on the Fresnel lens cut 92a, and the efficiency is low. It was low.

[0008]

According to the present invention, as a specific means for solving the above-mentioned conventional problems, a light source,
It comprises a parabolic reflecting surface having the light source as a substantially focal point, and a lens covering the irradiation direction side of the light source. The lens has a focal length of 1 with respect to the distance between the lens and the light source.
The range is 5 to 2.5 times, and the pitch is 2 mm
An object of the present invention is to solve the problem by providing a vehicular lamp provided with the following Fresnel lens.

[0009]

Next, the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1 shows a first embodiment of a vehicular lamp 1 according to the present invention. The first embodiment has a basic configuration of a vehicular lamp 1 according to the present invention, and will be described below. Each of the second and subsequent embodiments is also provided with the configuration of the first embodiment.

The vehicular lamp 1 includes a light source 2 such as an incandescent light bulb, a parabolic reflecting surface 3 such as a rotating paraboloid having the light source 2 as a focal point, and a lens 4.
Is provided with a Fresnel lens cut 41 on the surface on the light source 2 side. The Fresnel lens cut 41 is not considered to have a focus on the light source 2 in the present invention,
1.5 to 2.5 times the distance L from the lens 4 to the light source 2
The focal length is within a range up to, for example, twice.

In the present invention, the width (ie, pitch P) of one element 41a (see also FIG. 3) constituting the Fresnel lens cut 41 is set to 2 mm or less, as will be described later in detail. In addition to giving the lens 4 an appropriate transparency, the concentric pattern is prevented from being strongly recognized at a distance normally viewed as the vehicular lamp 1, and a viewer such as a driver of a succeeding vehicle may feel uncomfortable. It is not given.

Next, the operation and effects of the vehicular lamp 1 of the present invention having the above configuration will be described. First, the light from the light source 2 that has reached the parabolic reflective surface 3 is converted into substantially parallel light rays and is incident on the lens 4. At this time, since the lens 4 has been subjected to the Fresnel lens cut 41, the light is once focused at the focal length of the Fresnel lens cut 41 after passing through the lens 4, and then diverged after being converged. I do.

Further, according to the present invention, the direct light from the light source 2 enters the lens 4 together with the light reflected from the parabolic reflecting surface 3. Here, since the Fresnel lens cut 41 has a focal length longer than the distance to the light source 2, the angle radiated from the light source 2 is narrowly fitted but does not converge but diverges. Becomes

Accordingly, the vehicular lamp 1 of the present invention includes the light transmitted through the fresnel lens cut 41 via the parabolic reflecting surface 3 and the light transmitted through the fresnel lens cut 41 of the direct light from the light source 2. In both cases, the light distribution characteristics are formed, that is, the luminous flux utilization rate for the light source 2 is improved, and a bright lamp is obtained.

Therefore, the lens 4 of the vehicular lamp 1 of the present invention.
In the above, the fisheye lens cut, which deteriorates the transparency of the lens 4 used in the conventional example, is not adopted. Here, the Fresnel lens cut 4
Reference numeral 1 denotes a lens which is obtained by dividing a convex lens into concentric circles and flattening the lens. Therefore, the lens 1 is basically transparent, although a magnification is required at the time of fluoroscopy.

At this time, if the Fresnel lens cut 41 is positioned at the focal point of the light source 2, when viewed from the outside, the light source 2, specifically, the filament of the incandescent light bulb is enlarged on the lens surface and is unsightly. At the same time, the direct light to the lens 4 is emitted to the outside as parallel rays, and the divergence angle is too narrow for forming the light distribution characteristics.

Therefore, the numerical value obtained as a result of the examination by the inventor for making the present invention is a Fresnel lens cut 4
The focal length of 1 is the distance of 1 from the lens 4 to the light source 2.
The range is 5 to 2.5 times, and by setting the range, the appearance is not unsightly, and at the same time, a desired light distribution characteristic can be formed.

FIG. 2 shows a second embodiment of a vehicular lamp 1 according to the present invention. In this second embodiment, the configuration such as the arrangement of the light source 2, the reflecting surface 3, and the lens 4 is the same as that of the first embodiment. This is exactly the same, and the same applies to the lens 4 in which the Fresnel lens cut 42 is provided.

However, in the second embodiment, the focal length of the Fresnel lens cut 42 at the center of the lens 4 is approximately twice (2) the distance L between the lens 4 and the light source 2.
L), at the outer end of the lens 4 is set at approximately the same magnification, that is, at the distance L, and at the middle, it gradually changes from approximately 2 to approximately 1 at the middle.

By doing so, a filament image or the like is not visible at the center, and parallel rays are radiated at the outer end that does not significantly affect the aesthetic appearance. Become. Therefore, a decrease in illuminance in the peripheral portion, which is likely to occur when a single light source 2 shines the lens 4 having a large area, is prevented, and the surface of the lens 4 emits light with uniform brightness.

FIG. 3 shows a third embodiment of the present invention in a main part. In each of the first and second embodiments, only the Fresnel lens cuts 41 and 42 are provided. . Therefore, it is necessary to adjust the degree of visibility when the inside of the lamp is seen through or to adjust the light distribution characteristics within the range of the focal length described above.For example, the inside of the lamp can be seen too far from the design aspect of the vehicle. In some cases, such as being unfavorable, the situation may become insufficient depending on market requirements.

This third embodiment is designed to cope with the above situation, and the Fresnel lens cut 4
1 (represented by a Fresnel lens cut 41. The same applies to the Fresnel lens cut 42). The light incident surface of an element 41a constituting the element 41a is appropriately formed along the radial direction of the element 41a. An arcuate surface 41b is formed.

By doing so, if only the Fresnel lens cut 41 is used, for example, if the focal length is shortened in order to reduce the divergence angle from the lens 4, the filament (light source 2) image will be seen and the appearance will be impaired. In the third embodiment, by adjusting the curvature of the arc surface 41b, it is possible to prevent the filament image from being clearly seen.

In the conventional example, a Fresnel lens cut for obtaining a parallel light beam is disposed on the light source side of the lens, and a fisheye lens cut for obtaining light distribution characteristics is disposed on the front surface of the lens. In this third embodiment, an outer lens must be provided from the irradiation direction side in order to prepare for irregularities due to the adhesion of dust (see FIG. 7). Since no irregularities occur on the surface, the outer lens can be omitted.

FIG. 4 shows a fourth embodiment of the present invention as a main part. In the present invention, the basic thickness t of the lens 4 can be freely changed in addition to the formation of the arc surface 41b. However, for the purpose of adjusting light distribution characteristics, improving aesthetics, and the like, for example, the entire lens 4 may be formed into a convex lens shape, a concave lens shape, or a prism shape.

FIG. 5 shows a fifth embodiment of the present invention, which relates to a parabolic reflecting surface. In the above-described first to fourth embodiments, the parabolic reflecting surface 3 has been described as a rotating paraboloid that reflects parallel rays toward the lens 4, but the present invention is not limited to this. is not.

For example, in a headlamp or the like, a free-form surface, a compound reflection surface, or the like, which forms a light distribution characteristic by the reflection surface itself and makes the lens transparent, is often used. Also, in the vehicle lamp 1 of the present invention, since one of the objects is to make the lens transparent, a parabolic reflecting surface 5 such as a free-form surface or a composite reflecting surface may be employed. .

In the case of the fifth embodiment, since the basic shape of the light distribution characteristic is already formed on the parabolic reflecting surface 5, the Fresnel lens cut 41 or the Fresnel lens cut 41 is added. The arc surface 41b and the like to be performed may be small enough to finely adjust the light distribution characteristics.
The transparency of the lens 4 can be further improved. Therefore, it is possible to further improve the aesthetic appearance by, for example, applying a lattice-like pattern to the parabolic reflective surface 5.

[0029]

As described above, according to the present invention, a light source, a parabolic reflecting surface whose focal point is substantially the light source, and a lens which covers the irradiation direction of the light source are provided. The conventional vehicular lamp has a fresnel lens with a focal length in the range of 1.5 to 2.5 times the distance between the light source and the light source and a pitch of 2 mm or less. This enables the vehicle lamp for this type of signal to be made transparent, which was required from the market to match the design with the headlamp, etc., and has an extremely excellent effect on improving the aesthetics of the vehicle. To play.

Further, according to the present invention, both the light from the light source through the parabolic reflecting surface and the direct light from the light source can be used as the irradiation light for the vehicle lamp, and the efficiency with respect to the light source is improved. It also provides an excellent effect of improving the performance as a bright lamp or reducing costs by reducing the number of light sources.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a vehicular lamp according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of the vehicular lamp according to the present invention.

FIG. 3 is a sectional view showing a main part of a third embodiment of the vehicle lamp according to the present invention.

FIG. 4 is a cross-sectional view showing a main part of a fourth embodiment of the vehicular lamp according to the present invention.

FIG. 5 is a perspective view showing a fifth embodiment of the vehicular lamp according to the present invention in a partially broken state.

FIG. 6 is a sectional view showing a conventional example.

FIG. 7 is a sectional view showing another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Vehicle lamp 2 ... Light source 3, 5 ... Parabolic reflective surface 4 ... Lens 41, 42 ... Fresnel lens cut 41a ... Element 41b ... Arc surface

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kazuho Nakajima 2-13-13 Nakameguro, Meguro-ku, Tokyo F-term in Stanley Electric Co., Ltd. (reference) 3K080 AA01 AB01 BA01 BB02 BB08 BC01 BC03

Claims (5)

[Claims] 1. A light source, a parabolic reflecting surface having a substantially focal point at the light source, and a lens covering an irradiation direction side of the light source, wherein the lens has a distance between the lens and the light source. A fresnel lens having a focal length in a range from 1.5 times to 2.5 times and a pitch of 2 mm or less. 2. A light source, a parabolic reflecting surface having a substantially focal point on the light source, and a lens covering an irradiation direction side of the light source, wherein the lens has a distance between the lens and the light source. On the other hand, there is provided a Fresnel lens in which the focal length is gradually changed so that the focal length is substantially doubled at the center of the lens and substantially equal at the outer end, and the pitch is 2 mm or less. Vehicle lighting. 3. The vehicular lamp according to claim 1, wherein a light incident surface of at least a part of the element of the Fresnel lens has a circular cross section along a radial direction. 4. The vehicular lamp according to claim 1, wherein a reference thickness of the lens is changed. 5. The parabolic reflector according to claim 1, wherein said parabolic reflector is a free-form surface or a complex reflective surface which forms light distribution characteristics by itself. The vehicle lighting device according to any one of the above.