JPH0129921Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a lens that is used by being attached to a vehicle lamp such as a headlamp having a plurality of filaments.

(Prior art) In general, lenses in this type of lamp are cut only on the light-emitting surfaces that are effective when multiple filaments are lit, and are effective in the non-light-emitting surface area that occurs when one filament is lit, that is, in the dark area. The reality is that there is no typical lens cut.

To explain this state with reference to FIGS. 1 to 9, in a general lamp, a lens 2 is attached to the front of a reflector 1, a filament 3 is disposed at the focal point F of the reflector, and a portion in front of the filament is Another filament 4 is arranged.
Furthermore, when these filaments are attached to a lamp as one bulb, a bulb attachment portion 5 is provided approximately at the center of the reflector 1. The lens 2 used in this case is as shown in FIG. 2 when viewed from the front. As is clear from this figure, the lens cut is divided into several sections, and the lens cuts in each section are all made in the vertical direction. In addition, the code 6 is a screen,
It is set at a sufficient distance from the light fixture.

Therefore, when removing the lens 2 of the lamp and examining the optical images of the filaments 3 and 4 reflected by the reflector 1, first of all, in Fig. 3 A, B, and C, the optical image at a sufficiently distant position is The light image when the filament 4 is turned on is shown in FIG. 3B, and the light image when the filament 4 is turned on is shown in FIG. 3C.
As is clear from looking at this optical image, a dark area 7 as shown by diagonal lines appears in the optical image of the filament 4 at a sufficiently distant position.

These optical images are examined by examining the optical images on the lens surface. In FIGS. 4A, B, and C, the position Z is the mounting position of the lens in a normal lamp, and the light image generated at this position is the light image in FIG. 4B when the filament 3 is lit, and The light image shown in Figure 4C is obtained when the light is turned on. As is clear from these light images, when the filament 3 is lit, a relatively noticeable dark area 7a is generated in the center, and when the filament 4 is lit, a relatively small dark area 7b is generated in the center.
is occurring. Therefore, as is clear from FIG. 4C, the area 8 indicated by dotted diagonal lines is a dark area when the filament 3 is lit, but becomes a bright area when the filament 4 is lit.

Taking these things into consideration and referring to FIG. 1, the dark areas in both filaments 3 and 4 described above and the dark areas 7 and 7a in both filaments 3 and 4 described above are within the range P of the valve mounting portion 5 of the reflector 1. It can be seen that the dark area range P ₁ is approximately equal to ₀ . Therefore, FIG. 5 shows a diagram of the dark area P ₁ in FIG. 1 viewed from the V direction,
A view from the direction is shown in FIG. Particularly in this dark area range, as shown in FIG. 4, when the filament 3 is lit, it is completely dark, so the explanation will be made in relation to when the filament 4 is lit.

In FIG. 5, if you look at the lens 2 in the area P1 that becomes a dark area when the filament ₃ is lit, you will see that the lens is cut almost evenly in the vertical direction.
It is clear from the figure. The optical image of the part 2a of the lens on the screen 6 in the range _P1 is as shown in FIG. In this optical image, for example, if a part 2a is not provided with a lens cut, the optical image will be as shown by a solid line a, and if a lens cut is made, the optical image will be as shown by a broken line b. As is clear from this light image, when the light passes through the lens cut, the light that has partially passed through 2a is greatly diffused. The lens cut from which this diffused light is obtained has a cross-sectional waveform that is evenly cut as shown in FIG.

Another example of a lens cut in the range _P1 described above is shown in FIG. This FIG. 8 is a sectional view of the same part as FIG. 7, and the vertical lens cuts have stepped portions extending from the center toward the outside, and are formed approximately evenly in parallel. Regarding this lens cut, when looking at the optical image of the part 2a of the lens on the screen 6, the part indicated by the solid line a' is the optical image without the lens cut, and the part indicated by the broken line b' is the optical image without the lens cut. This is the optical image that was created. As is clear from these optical images, the lens cut in FIG. 8 merely moves the optical image in parallel. In any case, in the conventional example, most of the dark area on the lens when one filament is lit turns into a bright area when another filament is lit, and the lens cut in that area is as shown in FIGS. 7 and 8. Since the structure is as shown in the figure, it has the disadvantage that it is inefficient because it only diffuses or moves the light in parallel and does not focus the light.

(Purpose of the invention) The present invention was made in order to eliminate such drawbacks of the conventional lens, and its purpose is to provide an efficient lens with a unique lens cut in the dark area. It is.

(Structure of the invention) The invention made to achieve this purpose is:
In a lamp equipped with multiple filaments, the dark area on the lens that is approximately the same as the non-light emitting area corresponding to the bulb attachment part of the reflector or the filament fixing part that occurs when any of the filaments is lit, is the dark area area. A lens for a vehicle lamp, characterized in that all or part of the lens cut has a lens cut that becomes thicker from the center outward or has a step, the lens cut provided in the dark area being thicker from the center to the outside. Since it is formed so that it becomes thicker toward the outside, the light is focused in this area, making it more efficient.

(Examples) Next, the present invention will be explained in more detail with reference to illustrated examples. Note that the same parts as in the conventional example are given the same reference numerals, and the explanation thereof will be omitted. The lens 12 according to the first embodiment of the present invention shown in FIG. 10 has a unique lens cut within the range _P1 which is the dark area in the conventional example. That is, as shown in FIG. 11, a lens cut 13 is formed on the entire surface, the thickness of which increases from the center 0 toward the outside, in other words, a convex lens-shaped cut 13. If the light image passing through the part 14 (indicated by the broken line) of the lens cut formed in this way is expressed as shown in FIG.
It will be as shown in the diagram.

In FIG. 12, the light image when there is no convex lens-shaped cut 13 in the dark area _P1 is a solid line.
This is as shown by a'', and the optical image when a convex lens-shaped cut is made is as shown by the broken line b''.
As is clear from this figure, the light image b'' of the lens-cut side is closer to the center, and it is clear that the light is condensed, and the dark part in the center is eliminated.

What is shown in FIGS. 13 and 14 is a second embodiment, in which a convex lens-shaped cut 13a similar to that of the previous embodiment is provided in a part of the dark area _P1 . In this case as well, the light image passing through the portion 14' of the convex lens-shaped cut 13a is approximately the same as that shown in FIG. 12.

What is shown in FIGS. 15 and 16 is a third embodiment, in which a cut 15 with a plurality of steps is formed outwardly in a part of the dark area _P1 . In this case as well, the light image passing through the portion 14'' of the cut 15 with the step is approximately the same as that shown in _FIG . Cuts 13, 13a and cut 15 with steps
As a result, the light is focused on the center, and the dark area that occurs in the center can be completely or partially eliminated. Particularly when it is formed in a part, the light image is formed in the lower part so as to cut out the upward light beam. The same applies even if the filaments 3 and 4 are not on the same line but are shifted from each other.

(Function) When the lens 12 of the present invention having the above configuration is used in place of the conventional lens 2 shown in FIG. 1, if the filament 3 is for traveling and the filament 4 is for passing. Even if the traveling filament 3 is lit, it does not pass through the dark area _P1 of the lens 12, so it can be illuminated without any effect on the irradiated light, and it is exactly the same as a conventional traveling beam. . When the passing filament 4 lights up, the light passes through the dark area _P1 , so the convex lens-shaped cuts 13, 13 provided on the
A or the stepped cut 15 allows the light to be focused at the center or to take out a downward traveling beam near the center, and since it becomes light that is superimposed on the conventional beam, the overall downward illuminance is increased. This improves efficiency.

(Effect of the invention) As explained above, the lens of the vehicle lamp according to the invention has a dark area on the lens surface when one of the filaments is turned on, and all or part of the dark area is directed outward from the center. By making the lens cut thicker or having steps, the light is focused by the lens cut when the other filament is turned on, making it much more efficient than conventional diffused or parallel illumination. It has this excellent effect.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view for explaining the state of the light image of the lamp in the conventional example, Fig. 2 is a front view of the lens in the conventional example, and Fig. 3 shows the optical image of the light reflected by the reflector at a sufficient distance. Figure A is a schematic cross-sectional view of the reflector, Figure B is the light image pattern when the filament 3 is lit, and Figure C is the pattern at the filament 4.
The light image pattern when A is turned on is also shown in Fig. 4 to explain the light image of the light reflected by the reflector as a pattern at the lens position.
The figure is a schematic cross-sectional view of the reflector, the figure B is a light image pattern when the filament 3 is turned on, the figure C is a light image pattern when the filament 4 is turned on,
Fig. 5 is a partial front view of the lens showing the dark area of the lens, Fig. 6 is a light image pattern in a part of the lens, Fig. 7 is an enlarged sectional view taken along the - line in Fig. 5, and Fig. 8 is a partial front view of the lens showing the dark area of the lens. The figure is an enlarged sectional view similar to FIG. 7 showing another example, and FIG. 9 is the sixth section in the example of FIG.
10 is a front view of the lens of the first embodiment according to the present invention, and FIG. 11 is a front view of the lens of the first embodiment according to the present invention.
12 is an optical image pattern in a part of the lens in FIG. 10, FIG. 13 is a front view showing only the main parts of the lens in the second embodiment, and FIG. 14 is an enlarged sectional view taken along line XI-XI in FIG. The figure is an enlarged sectional view taken along the - line in Figure 13, Figure 15 is a front view showing only the main parts of the lens in the third embodiment, and Figure 15 is a front view showing only the main parts of the lens in the third embodiment.
FIG. 6 is an enlarged sectional view taken along the - line in FIG. 15. 1...Reflector, 3, 4...Filament, 5...Bulb mounting part, P ₁ ...Dark area, 7,7a...Dark area, 12...Lens, 1
3, 13a... Lens cut (convex lens cut) whose wall thickness becomes thicker toward the outside, 14... Partial, 15... Lens cut with a step.

Claims (1)

[Scope of utility model registration request] In a lamp equipped with multiple filaments,
In the dark area on the lens that is approximately the same as the non-light emitting area corresponding to the bulb attachment part or filament fixing part of the reflector that occurs when any of the filaments is lit, there is a light beam directed outward from the center in all or part of the dark area. A lens for a vehicle lamp characterized by having a thicker wall thickness or a lens cut with steps.