JPS597302A - Lens of lighting fixture for vehicle - Google Patents

Abstract

PURPOSE:To obtain adequately distributed light and to provide excellent visibility by forming many prism-like columnar lenses which are formed to have the wall thickness increasing downward in such a way as to extend horizontally. CONSTITUTION:A light source 3 is fitted nearly in the focal position of a reflecting mirror 2, and an inner lens 5 in a front opening 4. A prism part 6 is formed nearly in the central part on the rear surface of the lens 5, and elements which refract or reflect the direct light from a light source 3 in the direction nearly in parallel with the optical axis are so formed as to draw concentrical patterns. Prism-like columnar lenses 7, 7... and circular cylindrical lenses 8, 8... having the refraction effect in vertical directions are formed respectively alternately in the vertical directions on the front face of the lens 5. The lenses 7, 7 have arc faces 9, which are so formed as to have the wall thickness 11 increasing downward. Bottom faces 12 projecting approximately in an overhang shape from a lens base plate 10 are formed on the bottom end face by said arc faces.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a novel lens for a vehicle lamp, and provides a lens that provides a suitable light distribution and provides a vehicle lamp with excellent visibility. There are things I'm trying to do.

Background technology and problems In a vehicle lamp, the light distribution is extremely important.

In order to obtain the desired light distribution, attempts were made to utilize the so-called direct light emitted from the light source toward the target lens and the so-called reflected light that was once reflected by the refracting mirror, and each light was directed toward the front of the lamp. A lens cut is used to diffuse the light with a predetermined directivity in the vertical and horizontal directions.

A fisheye lens cut is often used as a lens cut for achieving such diffusion.

FIG. 1 shows an example of a conventional vehicular lamp having a lens in which such a fisheye lens cut is formed. That is, b is a reflecting mirror, a light source c is arranged on the X-X axis of the reflecting mirror, a lens d is attached to the front opening of the reflecting mirror b, and a small rectangular shape is attached to the rear surface of this lens d. A large number of fisheye lens cuts e, e, . . . are arranged in a grid pattern. As shown in FIG. 1(C), these fisheye lens cuts e, e, . . . are curved surfaces f, f, . ...and g, g. ..., and the direct light and reflected light from the above-mentioned light source are diffused and irradiated in the vertical and horizontal directions in front of the lens d by the fisheye lens cuts e, e, .... A pattern of light distribution is formed.

As shown in FIG. 2, the light distribution by the lens d having such fisheye lens cuts e, e, . Although such a rounded light distribution may be considered an advantage in some cases, when it comes to vehicular lighting, waste light with a pattern similar to a horizontal strip is generally better for visibility and light distribution. This is suitable for design. Furthermore, when light is diffused only by fisheye lens cuts e, e, etc. as shown in FIG. However, the disadvantage is that more light is not emitted, and the light utilization efficiency is also poor.

SUMMARY OF THE INVENTION Various attempts have been made in the past to improve the shortcomings in light distribution performance due only to the fisheye lens cut, and the present invention has also been made in view of the shortcomings of the conventional vehicle lamp lens described above. The objective is to provide a new lens that can provide a vehicle light with suitable light distribution and excellent visibility. It is characterized by a large number of prism-like columnar lenses, each of which becomes thicker as it goes along, extending in the horizontal direction.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following, details of the present invention will be explained according to embodiments shown in the accompanying drawings.

FIG. 3 shows an example of the lens of the vehicle lamp according to the present invention.

In the figure, 1 is a lamp equipped with a lens according to the present invention. 2 shows a counter mirror consisting of a paraboloid of revolution, and counter mirror 2
A light source 3 is placed approximately at the focal point of the image. An inner lens is attached to the front opening 4 of the reflecting mirror 2, and an outer lens is further attached in front of the inner lens.

Reference numeral 5 denotes an inner lens, which is made of glass or transparent synthetic resin, and has lens cuts formed on its rear surface, that is, the surface facing the light source 3, and on its front surface.

Reference numeral 6 denotes a refractive prism portion formed approximately in the central region of the rear surface of the inner lens 5, which is a refractive prism element that refracts or reflects direct light from the light source 3 in a direction approximately parallel to the optical axis. It is formed to draw a pattern.

Therefore, on the front surface of the inner lens 5, prismatic lenses 7, 7, . has been done. Prism-like columnar lenses 7, 7,...
* has a circular arc surface 9, as shown in the vertical cross section in FIG. 3(C). These prismatic columnar lenses 7, 7,
. . are formed so that the thickness 11 becomes thicker toward the F direction, so that a bottom surface 12 protruding from the lens substrate 10 in a substantially overhang shape is formed at the end surface. This prismatic columnar lens 7, for example, the circular arc surface 13 of the columnar lens shown by the two-dot chain line in FIG.
It has a shape that looks like the lower part has been cut off at the position. The bottom surface 12 is the apex 0 of the arc surface in the same figure.
Since it is formed at a position slightly above the center line 14 passing through the prismatic columnar lens, the wall thickness 11 of this prismatic columnar lens gradually increases from the top to the bottom as described above. .

However, this prismatic columnar lens 7 in the present invention,
7, . . . are not limited to those having a wall thickness of 1 l over the entire range of the arcuate surface 9 or being elongated from the top to the bottom. For example, if the bottom surface is provided at the position indicated by the broken line 15 in the same figure, the arcuate surface 9 will be extended to the position of the broken line 15, and therefore, in that case, one piece of gradually increasing thickness 11 will be approximately the same as the arcuate surface. It will be progressively formed in most but not all areas.

In other words, the thickness 11 of the prismatic columnar lens 7 in that case
is gradually thickened from the upper base point 16 of I to the vertex 0, but from the vertex 0 to the bottom position l5, although only partially,
Conversely, the wall thickness 11 will become thinner.

In this way, the thickness of the prismatic columnar lenses 7, 7, . . . in the lens of the vehicle lamp of the present invention may be made to gradually increase in the downward direction. This is to refract all or most of the light emitted from each prism, cylindrical lens 7, 7, ... downward, and to once condense it at the focal point F1 of the front force. By being a thing. and prismatic lens 7
, 7, . . . are arranged to extend in the horizontal direction.

Further, the Ensha lenses 8, 8, . . . are similarly arranged so as to extend in the water/Ii direction.

Reference numeral 17 denotes an outer lens, and on the rear surface of the outer lens I7, a large number of left and right diffusing lenses 18, 18, . . . each having a concave semicircular arc surface in horizontal section are formed. According to the vehicle lamp 1 equipped with such a lens,
The light distribution is similar to the light distribution 19 shown in FIG.
-Bright isophotonic curve 20 extending in a horizontal strip along H
You can get a pattern containing That is, the direct light from the light source 3 is appropriately refracted or reflected by the prism portion formed in the substantially central region of the rear surface of the inner lens 5, and the prismatic columnar lenses 7, 7 formed on the front surface of the inner lens are refracted or reflected.
... and the cylindrical lenses 8, 8, ... are irradiated in a direction parallel to the light beam X-X, and the reflected light once reflected by the reflecting mirror 2 is also a light flux parallel to the light beam X-X. The prismatic columnar lenses 7, 7,... and the cylindrical lenses 8, 8,...
・Irradiated by. These lights irradiated onto the cylindrical lenses 8, 8, . , further here, it is given a diffusivity in the left and right direction and is emitted forward, and this emitted light is
As shown in Figure (D), the light is once condensed at the focal point F2 and then diffused upward and downward again. In this way, the cylindrical lenses 8, 8
, . . . is diffused in the vertical and horizontal directions to form a rounded light distribution pattern as shown at 21 in FIG. Also, prismatic social lenses 7, 7,...
Here, the light that has been illuminated is refracted so as to have directivity in the direction of C, and then passes through the left and right diffusing lens l8 of the outer lens 17.
, 18, . After that, it spreads up and down again. In this way, the prismatic columnar lenses 7, 7, . Form the light distribution pattern shown. Since the luminous intensity in the range surrounded by this curve 20 overlaps with the light in the range surrounded by the curve 2l mentioned above, it becomes significantly brighter than the luminous intensity outside that range, and eventually this light distribution 19 as a whole, a horizontally long sharp pattern of light distribution is formed.

FIG. 5 shows another embodiment of the lens of the wheel lamp according to the present invention. 1A is a lamp using the lens,
This figure shows an example in which the lens of the present invention is applied as a lens of a so-called slant type lamp whose upper side is tilted backward.

The light distribution provided by this type of slant type lamp is extremely inconvenient as it results in a pattern in which both sides are curved downward, as shown by 35 in FIG. The purpose of this embodiment is to correct the curved light distribution pattern into a suitable pattern extending in the shape of a horizontally long strip. The slant of the lens in this example is upwardly oriented with its upper edge offset backwards.

In the figure, reference numeral 22 indicates a reflecting mirror made of a paraboloid of revolution, and 23 indicates a light source placed approximately at the focal point of the reflecting mirror 22.

An inner lens 24 is attached in front of the reflecting mirror 22, and an outer lens 25 is attached further in front of the inner lens 24 with a slight interval. The inner lens 24 and the outer lens 25 are opposed to each other so that their lens surfaces are parallel to each other, and as described above, α
Each upper side portion thereof is deviated toward the rear, that is, toward the light source 23 so as to be tilted. Note that the light beam XX of the reflecting mirror 22 is positioned parallel to the longitudinal direction of the vehicle body.

A prism portion 26 having a concentric Fresnel pattern is formed in a substantially central region of the rear surface of the inner lens 24 . The planel-like pattern of the prism portion 26 is formed in a concentric circle with the center point 27 having the shortest distance from the light source 23 on the rear surface of the inner lens, and extends over a certain circumferential area from the center point 27. A refraction prism section 28 is formed, and a reflection prism section 29 is formed in the outer peripheral area of the refraction prism section 28.

30, 30, . . . are cylindrical lenses formed on the rear surface of the inner lens 24 in the outer peripheral region of the central region where the prism portion 26 is formed, and have a semicircular surface convex toward the light source 23 in the vertical cross section. They are formed in large numbers in parallel vertically so as to extend in the left-right direction.

Further, in the approximately central region of the front surface of the inner lens 24, that is, the region corresponding to the prism portion 26 in the front-rear direction, the prism-like columnar lenses 7, 7, . . .
Prism-like columnar lenses 31, 3 having exactly the same form as
A large number of l, . . . are formed.

On the other hand, on the rear surface of the outer lens 25, there are provided left and right lenses 32, 32, .
On the front surface thereof, a large number of strip-shaped non-transparent films 33, 33, . This non-transparent film 33
, 33, . . . are so-called false lighting prevention members.

Slant type lamp 1A equipped with such a lens
According to the invention, the light distribution can correct the above-mentioned inconvenient pattern in which both sides are curved to a horizontally long band-like pattern. That is, the reflected light reflected by the reflecting mirror 23 becomes a light beam parallel to the optical axis XX, and the cylindrical lenses 30, 30, . . .
・The light is refracted in the vertical direction and is once condensed within the translucent windows 34, 34, . It is diffused and ejected in the direction. The light distribution pattern formed by this emitted light is a pattern in which both sides are curved downward as described above, as shown by 35 in FIG.

Further, the direct light from the light source 23 is turned into a parallel light beam by the refraction prism part 28 and the reflection prism part 29 in the prism part 26 on the rear surface of the inner lens, and is shaped like a prism with directivity in a direction perpendicular to the lens surface of the inner lens 24. The light enters the rod lenses 31, 3l, . . . Then, as explained in the above-mentioned embodiment, the prismatic columnar lenses 31, 31, . Translucent windows 34, 34,...
The light is once condensed within the lens, and this is also done by the left and right diffusive lenses 32, 32,
. . ., the light is appropriately diffused in the left and right directions and emitted. The light distribution pattern formed by this emitted light is concentrated at the corner of the above-mentioned light distribution 35, as shown by 36 in FIG. In other words, this light distribution 36 refracts a non-curved light flux pattern, which is once turned into an upward parallel light flux by the prism section 26, downward by the prism-shaped magnified lenses 3l, 3l, . The light distribution pattern is a sharp oblong band-like pattern with no curvature. Moreover, since this light distribution 36 is mainly formed by direct light from the light source 23, its luminous flux density is higher than that in the light distribution 35, and therefore, the light distribution 36 is higher than that in the light distribution 35. When viewed as a whole, the light distribution obtained by synthesizing the light beams 36 can be a good horizontally long one along the horizontal line HH.

Effects As is clear from the description below, in the lens of the vehicle lamp of the present invention, the lens used in the vehicle lamp is a prismatic social lens whose wall thickness increases as it goes downward. Since a large number of lenses are formed to extend in the horizontal direction, the drawbacks of lenses with conventional fisheye lens cuts are eliminated, and light distribution suitable for a vehicle lamp with a relatively horizontal pattern is obtained. I can do it.

In the description of the above embodiments, only the case in which the prism-like columnar lens is provided on the front surface of the lens is shown, but it goes without saying that it may be formed on the rear surface of the lens, that is, the surface facing the light source.

Further, the prism-like columnar lenses do not need to be arranged every other lens in the vertical direction, and several lenses may be arranged together.

Further, the cylindrical lenses do not necessarily need to be formed in the portions other than the portions where the prismatic columnar lenses are formed, and a transparent portion having no diffusing effect at all may be formed.

[Brief explanation of drawings]

Figure 1 shows a lamp using an example of a lens of a conventional vehicle lamp, where (A) is a front view and (B) is a B in Figure (A).
- A vertical side view taken along line B, (C) is a perspective view of a main part with a part of the lens enlarged, Fig. 2 is a light distribution diagram of the lamp shown in Fig. 1, and Fig. 3 is a diagram of the vehicle lamp of the present invention. A lamp using an example of the implementation of the lens is shown, (A) is an exploded perspective view, (B) is a rear perspective view of the inner lens, (C) is a vertical sectional side view showing an enlarged view of one of the lens cuts, ( D) is a central longitudinal side view, (
E) is a central cross-sectional plan view, FIG. 4 is a light distribution diagram of the lamp shown in FIG. 3, and FIG. 5 is a lamp using another embodiment of the lens of the vehicle lamp of the present invention. ) is an exploded perspective view,
(B) is a front perspective view of the inner lens, (C) is a central vertical sectional side view, and FIG. 6 is a light distribution diagram of the vehicle lamp shown in FIG. 5. Explanation of the code 1...Vehicle light, 1 A...Vehicle light, 7.
...Prismatic columnar lens, 8... Ensha lens, 9.
...Curved surface, l1...Thickness, 30...Cylindrical lens, 3
l...Prismatic columnar lens

Claims (1)

[Scope of Claims] (1) A lens used in a vehicle lamp, characterized by a large number of prism-like columnar lenses, the thickness of which increases as it goes downward, extending in the horizontal direction. (2) A lens for a vehicle lamp according to claim 1, wherein the entrance surface or the exit surface of the prismatic columnar lens is an arcuate surface (3) A prismatic columnar lens (4) The lens of the vehicle lamp according to claim 1 or 2, wherein the lenses are arranged at intervals in the vertical direction. (5) A lens for a vehicle lamp according to claim 3, characterized in that a cylindrical lens having a substantially semi-cylindrical shape is arranged between the arrays of prismatic columnar lenses. Lenses for vehicle lamps listed in range 3