JPS61101902A - Direct lighting for vehicles - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a direct-light type vehicular lamp, and in particular, it has been improved so that its shape can be easily made thin and the amount of light around the lens can be increased. This invention relates to a direct-light type vehicle lamp.

[Background of the invention]

For example, a vehicular lamp such as a combination lamp is required to have its overall shape as thin as possible, and is also required to emit light as uniformly as possible over the entire surface of the lens.

In the prior art, it has been difficult to satisfy both of the above requirements.

FIG. 9 shows a cross section of a part of a conventional combination lamp.

In this conventional example, in order to make the overall shape as thin as possible, the light source bulb 1 is configured to be placed horizontally at right angles to the optical axis zz', and the front opening of the lamp housing 2 is covered. A refractive Fresnel prism 3a is integrally formed in the center of the inner lens 3, and a reflective Fresnel prism 3b is integrally formed in the peripheral area. 4 is an outer lens.

In a lamp having the above structure, the peripheral part of the lens tends to be darker than the central part.

In order to increase the amount of light at the periphery as much as possible, it is known that it is effective to curve the periphery of the lens 3' provided with the Fresnel prism into a convex shape toward the front, as shown in Figure 1.0. It is being

However, there are technical difficulties in curving or bending the periphery of a lens provided with a Fresnel prism.

FIG. 11 is an explanatory diagram of the above-mentioned rotatability, in which an optical path is added to a cross section of a part of the reflective Fresnel prism 3b at the lens periphery.

In the figure, JJ' is a line parallel to the optical axis i, and χ-χ' is a horizontal axis perpendicular to this.

3b represents one peak of the reflective Fresnel prism, and 3C represents an approximate plane of the lens surface.

When the Fresnel prism 3b is configured to have the cross-sectional shape shown by the solid line, the direct light arrow A from the light source bulb is refracted as shown by the arrow opening, reflected as shown by the arrow C, and perpendicular to the χ-axis as shown by the arrow 2. Emit light in the J-J axis direction (parallel to the optical axis).

However, when the reflective Fresnel prism 3b is configured as shown by the solid line, the inner surface 3b-1 is aligned with the axis J parallel to the optical axis.
Since it is tilted at an angle θ with respect to -, ), it is impossible to cut out the mold even if you try to injection mold it with plastic.

In order to make mold cutting possible, if the inner surface of the prism is arranged in parallel with the axis J-J as shown by the chain line 3b-2, the path of the incident light as shown by the arrow E will be directed to the same direction as the arrow. The opening will look like the same chi, and will be offset by an angle of 0□ with respect to the optical axis.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and the periphery of a lens having a Fresnel prism that refracts and reflects incident light from a light source bulb and emits it parallel to the optical axis is convex toward the front. It is an object of the present invention to provide a direct-projection type vehicular lamp equipped with a lens having a curved shape and easy to cut out in injection molding.

[Summary of the invention]

The principle of the present invention created to achieve the above object will be explained.

When a lens having a Fresnel prism 3b having a shape drawn by a solid line in FIG. 11 is made of a flexible material and the lens surface 3c is bent along the axis It deforms as shown in 3b', and its inner surface 3b-1' becomes inclined to open with respect to the optical axis.

The present invention reversibly utilizes the above phenomenon, and first forms a lens having a prism shaped like the virtual line 3b' into a flat plate shape, and then bends the lens to obtain the desired prism shape 3b.

In order to achieve the above purpose (constructing a prism lens of a desired shape that can be cut out) based on the above principle,
A direct-illuminated vehicular lamp according to the present invention is a direct-illuminated vehicular lamp in which a lens integrally formed with a Fresnel prism is attached to a front opening of a lamp housing, wherein the lens is made of a flexible material into a flat plate shape. In addition, a notch for bending is provided along the groove of the Fresnel prism, and the lens is bent at the groove and attached to the front opening of the lamp housing.

[Embodiments of the invention]

Next, one embodiment of the present invention will be described with reference to FIGS. 1 to 8.

1 and 2 show the lens 5 of this embodiment, and the first
The figure is a sectional view, and FIG. 2 is a plan view.

The lens 5 of this example is made of flexible transparent plastic material,
A refractive Fresnel lens 5a is formed at the center and a reflective Fresnel lens 5b is formed at the periphery, which are integrally molded into a flat plate by injection molding. However, the reflective Fresnel lens 5b does not have perfect optical performance in the flat state shown in FIG. 1, and when it is bent and attached as shown in FIG. It is configured to have a shape having optical properties.

FIG. 3 is an optical path diagram with the lens 5 bent forward into a convex shape.

The light emitted from the light source bulb 1 toward the refractive Fresnel prism 5a as shown by the arrow is directed toward the refractive Fresnel prism 5a.
After being refracted by the arrow a parallel to the optical axis Z-Z, the outer lens 4' directs the arrow.

The light is dispersed appropriately as shown in the figure.

Since the periphery of the lens 5 provided with the Fresnel prism 5b is curved, a large amount of light is emitted toward the periphery of the reflective Fresnel prism 5b as shown by the arrow. After being refracted parallel to the optical axis Z-Z as shown by the arrow wa, the light is appropriately scattered by the outer lens 4' as shown by the arrows force and force'.

In order to bend the flat Fresnel prism lens 5 shown in FIG. 1 as shown in FIG.
FIG. 4 shows an enlarged detailed view of the part (■) surrounded by 6 imaginary lines where the notch 5b-+ is provided along the groove.

In this embodiment, a groove-shaped notch 5b-2 is also provided on the lens surface 5e, facing the groove-shaped notch 5b-1. Notch sb-+ 15 of lens 5 shown in Fig. 4
When an upward force is applied to the vicinity of b-2, the groove bends as shown in FIG. 5.

FIG. 6 is an exploded perspective view showing specific components for bending the flexible lens 5 and attaching it to the front opening of the lamp housing 6 in this embodiment.

The edge 6a of the front opening of the lamp housing 6 is configured to follow a desired bent shape, and a rivet-like protrusion 6b is integrally connected to the edge, and is made of thermoplastic synthetic resin.

On the other hand, the lens 5 is made of flexible transparent plastic with rivet holes 5c arranged around its periphery.

The rivet-like protrusion 6b is inserted into the rivet hole 5c, its tip is made to protrude, and the protrusion is heated, softened, and crimped. Thereby, the lens 5 is fixed while covering the front opening of the lamp housing 6 in a bent state following the shape of the edge 6a.

FIG. 7 shows an embodiment different from the above. Lens 5' in this example
is integrally molded with hooks 5d, and on the other hand,
along the edge 6a' of the lamp housing 6'.

A row of hook hooks 6c are provided to engage with the hooks 5d. When the hook 5d is engaged with the hook hook 6c, the lens 5' is bent along the edge 6a' and fixed to the lamp housing 6'.

FIG. 8 is a chart showing the distribution of luminous flux in the embodiment shown in FIG. 6, in which the horizontal axis indicates the distance from the lens center, and the vertical axis indicates the luminous flux ratio.

Curve A shows the light intensity distribution of a vehicle lamp using a conventional flanto lens, shown for comparison.

Curve B shows the light intensity distribution of the vehicle lamp equipped with the conventional curved lens shown in FIG. 1O.

Curve C shows the light intensity distribution of the embodiment of the present invention (Fig. 6), and a remarkable improvement is recognized compared to the conventional example (Fig. 10), and the areas shown with spots are the areas of the present invention. It shows the amount of light increased by application.

The reason why the lamp of this example (Fig. 6) has a remarkable improvement effect compared to the conventional lamp with a curved lens (Fig. 10) is that the lens 3' in Fig. 10 is curved. The fact that the lens 5 in FIG. 6 is bent is not so much that the prism shape of the conventional example is the shape 3b-z shown by the chain line in FIG. Therefore, it is judged that the fact that the prism shape of this example is the shape 3b-1 shown by the solid line has a greater effect.

〔Effect of the invention〕

As detailed above, in the vehicle lamp of the present invention, since the periphery of the Fresnel prism is bent in a convex shape toward the front, the amount of peripheral light is large, and moreover, the light passing through the Fresnel prism is aligned with the optical axis. Since the prism shape can be made parallel, it is possible to further increase the amount of peripheral light, and in addition, injection molding (especially mold cutting) of lenses equipped with Fresnel prisms is easy. It has the desired effect.

[Brief explanation of the drawing]

1 to 6 show one embodiment of the present invention, FIG. 1 is a cross-sectional view of a lens provided with a Fresnel prism, FIG. 2 is an open plan view, and FIG. FIG. 4 is an enlarged detailed view of the section ``■'' in FIG. 1, and FIG. 5 is an explanatory view of the portion shown in FIG. 4 in a bent state. FIG. 6 is an exploded perspective view of the components for bending and attaching the lens. FIG. 7 is a perspective view of a lens mounting portion in an embodiment different from the above. FIG. 8 is a chart showing the effects of the embodiment shown in FIG. FIG. 9 is a sectional view of an example of a conventional vehicular lamp, FIG. 10 is an explanatory diagram of an improvement plan for the conventional vehicular lamp, and FIG. 11 is an explanatory diagram of technical difficulties regarding the above improvement plan. 1... Light source bulb, 2... Lamp housing, 3...
・Inner lens, 3a... refractive Fresnel prism,
3b... Reflective Fresnel prism, 4.4'...
Outer lens, 5, 5'...Lens, 5a...Refraction Fresnel prism, 5b...Reflection Fresnel prism, sb-+y 5b-2...Bending groove provided in prism lens Notch, 5c...Rivet hole, 5d...
・Hook, 6.6'...Lamp housing, 6a,
6a'...Edge of lamp housing opening. 6b...Rivet-like protrusion, 6c...Hook hanging.

Claims (1)

[Claims] In a direct-illuminating vehicle lamp in which a lens integrally formed with a Fresnel prism is attached to the front opening of the lamp housing, the lens is made of a flexible material in the form of a flat plate, and is folded along the grooves of the Fresnel prism. 1. A direct-emitting vehicle lamp, characterized in that a bending notch is provided, and the lens is bent at the groove portion and attached to the front opening of the lamp housing.