CN107435881B - Light distribution lens - Google Patents

Abstract

The invention provides a light distribution lens, which can control the light incident from a light source to be the light distribution of an ideal dipped headlight and can arrange the light source in the same direction as a high beam. The lens body (20) distributes light incident from an LED (41) arranged in a state in which an optical axis (L) extends in a horizontal plane: in a forward target irradiation position, the main irradiation range is set below the horizontal plane, and the light is intensified along the optical axis (L) above the center of the irradiation range or below the optical axis (L) by a predetermined angle.

Description

Light distribution lens

Technical Field

The present invention relates to a light distribution lens including a lens body that distributes light incident from a light source that irradiates light in a predetermined direction to a predetermined range or direction.

Background

Conventionally, as such a light distribution lens, for example, a light distribution lens used for a marker lamp (headlamp) mounted on a vehicle such as a railway vehicle is known. Here, the marker lamp illuminates the front in the traveling direction of the vehicle at night or the like to improve the visibility of the driver. Generally, a marker light is distinguished into a high beam light and a low beam light according to its light distribution characteristics, and the far side is irradiated with the high beam light and the near side is irradiated with the low beam light.

In recent mainstream LED marker lamps, particularly, a light distribution lens is important to efficiently emit light from an LED forward. Here, as a light distribution lens, for example, a light distribution lens disclosed in patent document 1 is known. That is, in the light distribution, the optical axis of the LED is arranged at the axial center, and the light from the LED is designed to be distributed straight forward in the optical axis direction, as in a general light distribution lens, in order to reduce flare.

Documents of the prior art

Patent document 1: japanese patent No. 5269843

However, the conventional light distribution lens disclosed in patent document 1 can only distribute light from the LED straight forward in the optical axis direction. Therefore, in the case of a high beam, the light source and the light distribution lens are arranged in a state of being oriented in the horizontal direction, and the application is possible in this state.

As described above, in the high beam lamp and the low beam lamp, it is necessary to independently turn the arrangement of each light source and lens, and the manufacturing thereof is troublesome and takes time, which causes a problem of cost increase. Further, it is also conceivable to configure the high beam lamp and the low beam lamp with different lamps, but this is not only a factor of further increasing the cost, but also has a problem that it is difficult to arrange them in a limited vehicle body space.

Disclosure of Invention

The present invention has been made in view of the above-described problems of the conventional technology, and an object thereof is to provide a light distribution lens that can easily control light incident from a light source to an ideal light distribution of a low beam and can install the light source in the same direction as a high beam.

The gist of the present invention for achieving the above object is as follows.

[1] A light distribution lens 10 having a lens body 20, the lens body 20 distributing light incident from a light source 41 for irradiating light in a predetermined direction to a predetermined range or direction, the light distribution lens 10 being characterized in that,

the lens body 20 distributes the light incident from the light source 41 arranged in a state where the optical axis extends on a horizontal plane: in the front irradiation position as a target, the main irradiation range is set below the horizontal plane, and the light is intensified along the optical axis above the center of the irradiation range or below the optical axis by a predetermined angle.

[2] The light distribution lens 10 according to [1], wherein the lens body 20 is formed in a bowl shape with a distal end side facing the light source 41, and includes: an incident portion 21 on which light is incident with the optical axis of the light source 41 as a center at a distal end side; an exit surface 22 through which light passing through the solid bowl-shaped interior exits on the opposite side of the tip side; a bottomed hole portion 23 that is open at a position on the emission surface 22 that faces the incident portion 21 on the optical axis, and that is recessed inward toward the incident portion 21; and a reflecting surface 24a which is an inner surface of the bowl-shaped peripheral wall 24,

the surface of the incident portion 21 and the bottom surface of the hole 23 face each other to form a predetermined lens shape, and by the lens shape, light centered on the optical axis of the light source 41 passes through the hole 23 along the optical axis or at a predetermined angle below the optical axis and is emitted from the opening,

the light incident from the bottom surface of the hole 23 to the surroundings through the incident portion 21 is totally reflected by the reflecting surface 24a, and then is emitted from the emitting surface 22 toward the lower side of the horizontal plane without passing through the hole 23.

[3] The light distribution lens 10 according to [2], wherein the incident portion 21 is concentric with the optical axis of the light source 41 and is recessed in a circular arc cross-sectional shape toward the exit side, and an incident lens surface 21a protruding in a circular arc cross-sectional shape toward the light source 41 side is formed at the center bottom of the recessed surface.

[4] The light distribution lens 10 according to item [3], wherein the bottom surface of the hole 23 has an upper emission lens surface 23a on which light having passed through the incident lens surface 21a advances straight in the optical axis direction, and a lower emission lens surface 23b on which light having passed through the incident lens surface 21a advances in a downward direction intersecting the optical axis at a predetermined angle, with a horizontal plane extending along the optical axis intersecting the bottom surface as a center.

[5] The light distribution lens 10 according to the above [4], wherein the inner peripheral surface of the hole 23 has an upper side extending parallel to the optical axis and a lower side inclined in a downward direction intersecting the optical axis at a predetermined angle, with the horizontal plane dividing the inner peripheral surface vertically being defined as the middle.

[6] The light distribution lens 10 according to [2], [3], [4] or [5], wherein the upper side of the reflection surface 24a is set to a critical angle at which light that is diffused upward from the bottom surface of the hole 23 is totally reflected in a downward direction that intersects the optical axis at a predetermined angle, and the lower side is set to a critical angle at which light that is diffused downward from the bottom surface of the hole 23 is totally reflected in a downward direction that intersects the optical axis at a predetermined angle, with the horizontal plane that vertically divides the reflection surface 24a being the middle.

[7] The light distribution lens 10A according to the above [1], [2], [3], [4], [5] or [6],

a plurality of the above-mentioned lens bodies 20 are integrally formed on one base body 11,

the emission surface 22 of each lens body 20 is continuous with the surface of the base body 11, the bowl-shaped peripheral wall 24 of each lens body 20 is protruded from the back surface of the base body 11,

the base body 11 is disposed in a state of facing in parallel to the light source substrate 40 in front of the light source substrate 40 on which the light source 41 corresponding to each lens body 20 is mounted,

the light sources 41 are arranged on the light source substrate 40 with their optical axes directed in the same direction.

[8] A light distribution lens 10A is characterized in that,

a plurality of lens bodies 20 are integrally formed on one base body 11,

at least one of the lens bodies 20 is the lens body 20 described in the above [1], [2], [3], [4], [5] or [6], which is a low beam lamp lens body 20,

at least one lens body 20A for high beam, out of the lens bodies 20 for low beam, other than the lens body 20 for high beam, is configured to distribute light incident from the light source 41 so as to be emitted toward a predetermined irradiation range centered on the optical axis of the light source 41 at a target irradiation position in the front direction,

the emission surfaces 22 of the lens bodies 20, 20A are continuous with the surface of the base body 11, the bowl-shaped peripheral wall 24 of each lens body 20 is protruded from the back surface of the base body 11,

the base body 11 is disposed in a state of facing in parallel to the light source substrate 40 in front of the light source substrate 40 on which the light sources 41 corresponding to the respective lens bodies 20, 20A for the low beam lamp and the high beam lamp are mounted,

the light sources 41 are arranged on the light source substrate 40 with their optical axes directed in the same direction.

Next, the operation of the solution based on the above will be described.

In the light distribution lens 10 according to [1], the lens body 20 distributes light incident from the light source 41 arranged in a state where the optical axis extends on a horizontal plane: in the front irradiation position as a target, the main irradiation range is set below the horizontal plane, and the light is intensified along the optical axis above the center of the irradiation range or a predetermined angle below the optical axis.

Thus, the entire light having passed through the lens body 20 is directed below the horizontal plane through which the optical axis passes, but only the optical axis direction above the center of the irradiation range and below the center can be irradiated with locally strong light. Therefore, the desired low beam light distribution with high or low intensity can be achieved.

Specifically, the lens body 20 can be configured as described in [2 ]. That is, the lens body 20 is formed in a bowl shape with the distal end side facing the light source 41, and is configured by: an incident portion 21 at a tip end side thereof to which light with the optical axis of the light source 41 as a center is incident; an exit surface 22 on the opposite side of the tip end side for light exiting after passing through the solid bowl-shaped interior; a bottomed hole portion 23 that is open at a position on the emission surface 22 that faces the incident portion 21 on the optical axis and is recessed inward toward the incident portion 21; and a reflecting surface 24a as an inner surface of the bowl-shaped peripheral wall 24.

Here, the surface of the incident portion 21 and the bottom surface of the hole 23 face each other and are formed in a predetermined lens shape. By this lens shape, light centered on the optical axis of the light source 41 passes through the hole 23 along the optical axis or at a predetermined angle below the optical axis, and is emitted from the opening. The light entering the periphery from the bottom surface of the hole 23 through the entrance portion 21 passes through the solid bowl-shaped interior and is totally reflected by the reflection surface 24a, and then is emitted downward from the emission surface 22 without passing through the hole 23. With such a configuration, the entire light distribution lens 10 can be downsized, and the light distribution of the low beam lamp can be controlled to be ideal.

As described in [3], the incident portion 21 of the lens body 20 may be formed in a concentric circle shape centered on the optical axis of the light source 41 and recessed in a circular arc sectional shape toward the exit side, and an incident lens surface 21a protruding in a circular arc sectional shape toward the light source 41 side may be formed at the center bottom of the recessed surface.

In this way, when the incident portion 21 has a concave shape, light emitted from the light source 41 whose optical axis is orthogonal to the center thereof can be efficiently received without leaking. Further, the incident lens surface 21a formed integrally with the depressed center bottom allows light near the optical axis of the light source 41 to be efficiently directed toward the bottom surface of the hole 23 paired with the incident lens surface 21 a.

As described in [4], in the bottom surface of the hole 23, when a horizontal plane extending along the optical axis intersecting the bottom surface is defined as the middle, the upper side may be an upper emission lens surface 23a for linearly advancing the light passing through the incident lens surface 21a in the optical axis direction, and the lower side may be a lower emission lens surface 23b for advancing the light passing through the incident lens surface 21a in the downward direction intersecting the optical axis at a predetermined angle.

Accordingly, even in a limited space, the light having passed through the incident lens surface 21a can be efficiently made to travel along the optical axis or at a predetermined angle below the optical axis, and light distribution control can be realized in which a specific region particularly above the center thereof is brightly irradiated in an irradiation range located entirely below the horizontal line.

As described in [5], in the inner circumferential surface of the hole 23, when a horizontal plane vertically dividing the inner circumferential surface is defined as an intermediate plane, an upper side may be formed to extend parallel to the optical axis, and a lower side may be formed to be inclined in a downward direction intersecting the optical axis at a predetermined angle. This prevents the light emitted downward from the downward emission lens surface 23b from being reflected to the lower side of the inner peripheral surface of the hole 23, and can be directly guided to the outside from the opening of the hole 23.

As described in the above [6], in the reflecting surface 24a, when a horizontal plane vertically dividing the reflecting surface 24a is defined as the middle, the upper side is set to a critical angle at which light diffused upward from the bottom surface of the hole 23 is totally reflected in a downward direction intersecting the optical axis at a predetermined angle, and the lower side is set to a critical angle at which light diffused downward from the bottom surface of the hole 23 is totally reflected in a downward direction intersecting the optical axis at a predetermined angle.

Thus, the light diffused upward of the incident portion 21 and the light diffused downward of the incident portion 21 can be efficiently emitted downward by the reflection surface 24a on the entire circumference of the bowl-shaped peripheral wall 24.

In the light distribution lens 10A according to [7], the plurality of lens bodies 20 are integrally formed on the single base body 11. The emission surface 22 of each lens body 20 is continuous with the surface of the base body 11, and the bowl-shaped peripheral wall 24 of each lens body 20 bulges out from the back surface of the base body 11. Such a base body 11 is disposed in a state of facing the light source substrate 40 in parallel in front of the light source substrate 40 on which the light sources 41 corresponding to the respective lens bodies 20 are mounted. This enables the lens unit to be used as a single unit including a plurality of lens bodies 20.

Further, in the light distribution lens 10A according to [8], the plurality of lens bodies 20 and 20A are integrally formed on the single base body 11, and at least one of the lens bodies 20 and 20A is used as the lens body 20 for low beam. On the other hand, at least one lens body 20A for high beam, out of the lens bodies 20 and 20A for low beam, is configured to distribute the light incident from the light source 41 so as to be emitted to a predetermined irradiation range around the optical axis of the light source 41 at a forward target irradiation position.

Thus, the low beam and the high beam can be realized by the light sources 41 mounted in the same orientation on the single light source substrate 40. In this way, according to the design in which the light distribution lens 10A directs a part of the light to the lower side, the straight-ahead traveling property for illuminating the front can be secured, and the performance of also illuminating the lower side can be achieved.

The effects of the invention are as follows.

According to the light distribution lens of the present invention, it is possible to easily control light incident from the light source to an ideal light distribution of the low beam and to provide the light source in the same direction as the high beam.

Drawings

Fig. 1 is a perspective view showing a lens body of a light distribution lens according to an embodiment of the present invention.

Fig. 2 is a vertical cross-sectional end view showing a lens body of a light distribution lens according to an embodiment of the present invention.

Fig. 3 is a cross-sectional end view showing a lens body of a light distribution lens according to an embodiment of the present invention.

Fig. 4 is a rear view of the incident side of the lens body of the light distribution lens according to the embodiment of the present invention.

Fig. 5 is a front view of the lens body of the light distribution lens according to the embodiment of the present invention on the emission side.

Fig. 6 is a right side view of a lens body of the light distribution lens according to the embodiment of the present invention.

Fig. 7 is a plan view of a lens body of the light distribution lens according to the embodiment of the present invention.

Fig. 8 is a vertical cross-sectional view showing a light distribution state of light incident from a light source to a lens body as a light distribution lens according to an embodiment of the present invention.

Fig. 9 is a cross-sectional end view showing a light distribution state of light incident from a light source to a lens body as a light distribution lens according to an embodiment of the present invention.

Fig. 10 is an explanatory view showing an irradiation range of a lens body of a light distribution lens according to an embodiment of the present invention.

Fig. 11 is a front view showing a light distribution lens according to another embodiment of the present invention.

Fig. 12 is a rear view of a light distribution lens according to another embodiment of the present invention.

Fig. 13 is a perspective view of a light distribution lens according to another embodiment of the present invention, as viewed from the front.

Fig. 14 is a perspective view of a light distribution lens according to another embodiment of the present invention, as viewed from the rear.

Fig. 15 is a cross-sectional end view (end view of a cut portion along line a-a' in fig. 11) showing a light distribution lens according to another embodiment of the present invention.

Fig. 16 is a vertical cross-sectional end view (a cross-sectional end view taken along line B-B' in fig. 11) showing a light distribution lens according to another embodiment of the present invention.

Fig. 17 is a front view showing a light distribution lens according to another embodiment of the present invention.

Fig. 18 is a rear view showing a light distribution lens according to another embodiment of the present invention.

Fig. 19 is a perspective view of a light distribution lens according to another embodiment of the present invention, as viewed from the front.

Fig. 20 is a perspective view of a light distribution lens according to another embodiment of the present invention as viewed from the rear.

Fig. 21 is a cross-sectional end view (end view of a cut portion along line C-C' in fig. 17) showing a light distribution lens according to another embodiment of the present invention.

Fig. 22 is a vertical cross-sectional end view (end view of a cut portion on line D-D' in fig. 17) showing a light distribution lens according to another embodiment of the present invention.

Fig. 23 is an exploded perspective view showing a marker lamp including a light distribution lens according to an embodiment of the present invention.

Fig. 24 is a perspective view showing a marker lamp including a light distribution lens according to an embodiment of the present invention.

In the figure:

10-light distribution lens, 10A-light distribution lens, 11-base, 20-lens, 20A-lens, 21-incident portion, 21 a-incident lens surface, 22-emission surface, 23-hole portion, 23 a-upper emission lens surface, 23 b-lower emission lens surface, 23 c-tapered surface, 24-peripheral wall, 24 a-reflection surface, 40-LED substrate, 41-LED, 1-marker light, 2-lamp body, 3-receiving portion, 4-heat sink, 5-heat sink.

Detailed Description

Hereinafter, embodiments representing the present invention will be described based on the drawings.

The light distribution lens 10 of the present embodiment includes a lens body 20, and the lens body 20 distributes light incident from an LED41 as a light source for irradiating light in a predetermined direction to a predetermined range or direction. The light distribution lens 10 may include the lens body 20 as a part of its structure, or may be regarded as the light distribution lens 10 only at the portion of the lens body 20.

First, as shown in fig. 1 to 10, an example in which the light distribution lens 10 is configured only by the portion of the lens body 20 will be described. As shown in fig. 1 to 9, the lens body 20 of the light distribution lens 10 is formed in a bowl shape whose tip end side faces the LED41 (see fig. 8). Here, the LED41 is, for example, a surface-mount type LED chip, and its structure is a general structure, and detailed description thereof is omitted, but the LED is of a type that emits light in an emission range of a predetermined angle around an optical axis L orthogonal to the chip surface.

The LED41 is basically disposed in a state where the optical axis L extends in a horizontal plane, but here, "horizontal" does not mean only a level in an accurate sense, and it is sufficient to observe and confirm the LED approximately horizontally. Further, the light emission color of the LED41 is arbitrarily selected. The LED41 is not limited to a surface-mount LED chip, and may be an LED lamp in which a chip is embedded in a bullet-shaped mold, or may be another lamp or the like as a light source.

The lens body 20 includes: an incident portion 21 at the top end side of the bowl shape into which light is incident centered on the optical axis L of the LED 41; an exit surface 22 on the opposite side of the tip end side for light exiting after passing through the solid bowl-shaped interior; a bottomed hole portion 23 that is open at a position on the emission surface 22 that faces the incident portion 21 on the optical axis L and is recessed inward toward the incident portion 21; and a reflecting surface 24a as an inner surface of the bowl-shaped peripheral wall 24. The lens body 20 is integrally molded with a transparent material such as acrylic or polycarbonate.

In lens body 20, the surface of incident portion 21 and the bottom surface of hole 23 face each other and are formed in a predetermined lens shape. Due to this lens shape, light centered on the optical axis L of the LED41 passes through the hole 23 along the optical axis L or at a predetermined angle below the optical axis L, and is emitted from the opening. The light that has passed through the incident portion 21 and entered the outer periphery of the bottom surface of the hole 23 is totally reflected by the reflecting surface 24a, which is the inner surface of the peripheral wall 24, and then is emitted from the emitting surface 22 toward the lower side of the horizontal plane without passing through the hole 23.

In this way, the lens body 20 as the light distribution lens 10 is designed and configured as follows: the optical distribution incident from the LED41 arranged in a state where the optical axis L extends in the horizontal plane is: as shown in fig. 8 to 10, at the front irradiation position as a target, the light is intensified along the optical axis L above the center of the irradiation range or below the optical axis L by a predetermined angle while the light is mainly irradiated below the horizontal plane. Further, the predetermined angle is set in a range of, for example, 0 to-30 degrees in the up-down direction centering on the LED41, and is set to spread in a range of, for example, ± 25 to-30 degrees centering on the LED41 also in the horizontal direction.

As shown in fig. 1 to 7, the entire lens body 20 is not bowl-shaped like a truncated cone, and as shown in fig. 5, the emission surface 22 on the opening side of the bowl shape is not a perfect circle in a front view seen from the optical axis L direction. That is, the emission surface 22 is in a shape surrounded by straight side edges parallel to each other at both sides of a circular arc-shaped upper edge having a large curvature and a circular arc-shaped lower edge having a small curvature, and is in a bowl shape having a cross section similar to that of the incident portion 21 toward the rear and gradually decreasing in diameter.

As shown in fig. 2 and 3, the incident portion 21 located on the top end side of the bowl shape is formed in a concentric circle shape with the optical axis L of the LED41 (see fig. 8) as a center, and is recessed inward in a circular arc sectional shape toward the emission side. The recessed axis coincides with the optical axis L of the LED41, and the incident portion 21 is disposed so as to surround the light emission side of the LED 41. Further, an incident lens surface 21a that protrudes in a small circular cross-sectional shape in a direction opposite to the LED41 side is formed on the center bottom of the recessed surface of the incident portion 21. The optical axis L of the LED41 is orthogonal to the center of the incident lens surface 21 a.

As shown in fig. 5, the hole 23 is opened substantially at the center of the emission surface 22, and the hole 23 is formed so as to be inwardly recessed toward the incident portion 21 along an optical path including the optical axis L. The opening of such a hole portion 23 is formed in a horseshoe shape in a front view viewed from the optical axis L direction, that is: the circular arc-shaped upper edge and the lower edge extending linearly in the lateral direction are surrounded by linear side edges parallel to each other at both sides of each of them.

As shown in fig. 2 and 3, the bottom surface of the hole 23 and the incident lens surface 21a of the incident portion 21 face each other to form a predetermined lens shape. More specifically, the upper side of the bottom surface of the hole 23 is formed as an upward-emitting lens surface 23a that rectilinearly advances (collimates) light that has passed through the incident lens surface 21a in the direction of the optical axis L, with a horizontal plane extending along the optical axis L intersecting the bottom surface as the middle. On the other hand, the lower side is formed as a downward-exit lens surface 23b that allows the light that has passed through the incident lens surface 21a to travel in a downward direction that intersects the optical axis L at a predetermined angle.

As shown in fig. 2 and 5, the inner peripheral surface of the hole 23 has a cross-sectional shape extending in parallel with the optical axis L on the upper side and a tapered surface 23c inclined in a downward direction intersecting the optical axis L at a predetermined angle on the lower side, with the horizontal plane dividing the inner peripheral surface in the vertical direction being defined as the middle. Here, "parallel" does not mean exactly parallel, and it is sufficient that the confirmation can be observed substantially in parallel.

As shown in fig. 8 and 9, the reflecting surface 24a as the inner surface of the peripheral wall 24 of the lens body 20 totally reflects downward light diffused outside the bottom surface of the hole 23, which is incident light from the incident portion 21 and is mainly incident light diffused around the incident lens surface 21a without passing through the incident lens surface 21 a.

More specifically, the upper side of the reflecting surface 24a is set to a critical angle at which light diffused upward of the bottom surface of the hole 23 is totally reflected downward at a predetermined angle with respect to the optical axis L, with the horizontal plane vertically dividing the reflecting surface 24a being defined as the middle. On the other hand, the lower side of the reflecting surface 24a is set to a critical angle at which light diffused downward of the tapered surface 23c of the hole 23 is totally reflected downward so as to intersect the optical axis L at a predetermined angle.

Here, the upper and lower reflecting surfaces 24a in the case of taking the horizontal plane as the middle may be set to reflect light downward at the same angle or may be set to reflect light downward at different angles. The phrase "with a horizontal plane as the middle" does not mean that the structures are arranged in the upper and lower directions with the horizontal plane as a precise boundary, and means that only the horizontal plane is present between the different structures in the upper and lower directions to a sufficient extent. The same applies to the bottom surface of the hole 23 between the upper emission lens surface 23a and the lower emission lens surface 23 b.

Next, an operation of the light distribution lens 10 of the present embodiment will be described.

As shown in fig. 8 and 9, the light distribution lens 10 of the present invention is disposed directly in front of the LED41 such that the optical axis L thereof is orthogonal to the incident portion 21 of the lens body 20. Here, the LED41 itself is arranged in a state where the optical axis L extends on a horizontal plane. In such a state, light emitted from the LED41 around the optical axis L first enters the entrance section 21 located on the bowl-shaped distal end side of the lens body 20.

The incident portion 21 is recessed inward in a circular arc cross-sectional shape having the optical axis L of the LED41 as a center, the axis of the recess coincides with the optical axis L of the LED41, and the incident portion 21 is disposed so as to surround the emission side of the LED 41. This allows light from the LED41 to be received without leaking to the outside. In addition, for example, the incident portion 21 may be a flat end surface obtained by cutting the top end of the bowl shape, but the incident efficiency is lower than the above-described recess, and the light distribution control is not as good as the light distribution control described later.

At the depressed central bottom of the incident portion 21, there is an incident lens surface 21a projecting small, and light near the optical axis L of the LED41 is made to travel toward the bottom surface of the hole portion 23 paired with the incident lens surface 21a by this incident lens surface 21 a. The light incident on the outside of the incident lens surface 21a spreads to the outer periphery of the bottom surface of the hole 23, which will be described later, but reaches the reflection surface 24a as the inner surface of the peripheral wall 24. If the incident lens surface 21a is not provided, the light is not converged toward the bottom surface of the hole 23, and the light is diffused in the entire circumferential direction, and the light emitted from the emission surface 22 is blurred.

In this way, the incident lens surface 21a of the incident portion 21 and the bottom surface of the hole 23 recessed from the exit surface 22 side toward the incident portion 21 face each other and are formed in a predetermined lens shape. More specifically, the upper side of the bottom surface of the hole 23 is formed as an upper emission lens surface 23a with a horizontal plane extending along the optical axis L intersecting the bottom surface as a middle, and the light having passed through the incident lens surface 21a is collimated (linearly advanced) in the optical axis L direction by the upper emission lens surface 23a as it is. The light passes through the hole 23 as it is, and is emitted to the outside of the opening of the hole 23.

On the other hand, the lower side of the bottom surface of the hole 23 is formed as a downward-projecting lens surface 23b with the horizontal surface being the middle, and the light having passed through the incident lens surface 21a advances downward at a predetermined angle with respect to the optical axis L by the downward-projecting lens surface 23 b. Such light passes through the hole 23 as it is, and is emitted to the outside of the opening of the hole 23. In this way, light centered on the optical axis L of the LED41 is distributed along the optical axis L or below the optical axis L by a predetermined angle due to the lens shape made up of the surface of the incident portion 21 and the bottom surface of the hole portion 23.

In this way, the light incident from the LED41 can efficiently travel along the optical axis L or below the optical axis L by a predetermined angle even in a limited space. In such a lens shape, the incident lens surface 21a is only a convex lens shape, and the light is collimated according to the curvature and angle of the upper emission lens surface 23a, while the light distribution control is not particularly performed in the lower emission lens surface 23b, and the light from the lens surface 21a may be made to travel downward as it is. Such light distribution control in different directions may be realized not only by setting the bottom surface side of hole 23 but also by setting the surface side of incident portion 21.

Further, if the upper side of the inner peripheral surface of the hole 23 is formed to extend parallel to the optical axis L, the upper emission lens surface 23a does not interfere with the travel of the collimated light, but if the lower side is also formed to extend parallel to the optical axis L, the light interferes with the light directed downward from the upper emission lens surface 23a and is reflected. Therefore, by forming the tapered surface 23c, which is particularly inclined downward, on the lower side of the inner peripheral surface of the hole 23, it is possible to prevent interference with light directed downward.

Further, as the bottom surface of hole 23 is closer to the front surface side of incident portion 21, the lens shape becomes thinner. Therefore, the influence of strain sink marks generated when the lens body 20 is integrally molded is reduced. Therefore, more accurate light distribution characteristics can be designed. With the lens shape of the present embodiment, light distribution control of the light can be efficiently and accurately performed to enhance the light along the optical axis L or at a predetermined angle below the optical axis L even with a limited size.

Of the light incident from the incident portion 21, the light that is diffused and incident to the outer periphery thereof without passing through the incident lens surface 21a reaches the reflection surface 24a which is the inner surface of the peripheral wall 24, and is totally reflected downward. More specifically, the reflecting surface 24a totally reflects light, which is diffused upward from the bottom surface of the hole 23, downward at a predetermined angle with respect to the optical axis L, upward, with the horizontal plane as the center. On the other hand, when the horizontal plane is defined as the middle, the lower side totally reflects the light diffused downward of the bottom surface of the hole 23 toward the downward direction intersecting the optical axis L at a predetermined angle.

In this way, by the reflection surface 24a of the entire circumference of the bowl-shaped peripheral wall 24, light diffused upward of the incident portion 21 and light diffused downward of the incident portion 21 can be efficiently emitted downward at the same angle. Therefore, light distribution for low beam can be performed. The upper and lower reflecting surfaces 24a in the case of the horizontal plane being the middle may be set to reflect light downward at the same angle, or may be set to reflect light downward at different angles.

In addition, as shown in fig. 10, the lens body 20 distributes the light irradiated from the emission surface 22 and the bottom surface of the hole 23 to an illumination range having a substantially elliptical shape. Here, the irradiation surface illustrated in the drawing is assumed to be a plane orthogonal to the optical axis L at an irradiation position intended for a linear distance forward by 10m from the LED41, for example. In the irradiation range E1 of the irradiation surface, as described above, the illuminance is increased in the portion E2 along the optical axis L or below the optical axis L by a predetermined angle.

As described above, according to the light distribution lens 10, the light distribution lens can distribute the light incident from the LED41 arranged in the state where the optical axis L extends in the horizontal plane: in the front irradiation position as a target, the lower side of the horizontal plane is set as a main irradiation range, and the light is intensified along the optical axis L above the center of the irradiation range or a predetermined angle below the optical axis L. Accordingly, the entire beam passing through the lens body 20 is directed downward from the horizontal plane through which the optical axis L passes, and only the direction of the optical axis L located above the center of the irradiation range and the downward direction thereof can be irradiated with locally strong light, so that the desired intensity distribution of the low beam can be achieved.

Further, the LED41 and the light distribution lens 10 are disposed at a predetermined height position with respect to the floor surface, but the irradiation surface at the irradiation position for the purpose of the front may be the floor surface located below the LED41 or the like, or a horizontal surface parallel to the floor surface, or may be a plane orthogonal to the optical axis L, that is, a surface vertically standing with respect to the floor surface, or another surface obliquely intersecting the floor surface, as described above. Further, the distance from the light distribution lens 10 to the irradiation position becomes a design matter that can be appropriately determined.

Next, as shown in fig. 11 to 16, a device in which, in addition to the plurality of lens bodies 20, another lens body 20A is integrally formed on one base body 11 as a light distribution lens 10A of another embodiment will be described. The light distribution lens 10A includes a disk-shaped base body 11, and a plurality of lens bodies 20 and 20A corresponding to the LEDs 41 are provided on the base body 11. Here, the base 11 is integrally molded with a transparent material such as acrylic or polycarbonate, similarly to the lens bodies 20 and 20A.

Specifically, the plurality of lens bodies 20 and 20A are the lens body 20 described above as a low beam lamp and the other lens body 20A for a high beam lamp, four lens bodies 20 are arranged in a vertical row at the center of the base body 11, and six lens bodies 20A are arranged in a circumferential direction along the outer periphery of the base body 11. As described above, the specific number and arrangement of the respective lens bodies 20 and 20A are design matters that can be appropriately determined, and the arrangement is not particularly limited if at least one is the lens body 20 for low beam and at least one other than the lens body 20 is the lens body 20A.

The lens body 20 for low beam corresponds to the lens body described with reference to fig. 1 to 10, but the lens body 20A for high beam is configured to distribute light incident from the LED 41: the light is emitted to a predetermined irradiation range centered on the optical axis L of the LED41 at a forward irradiation position as a target. The lens body 20A is a well-known structure, and is formed in a bowl shape having a truncated cone as a whole, unlike the lens body 20, and the axis thereof coincides with the optical axis L of the LED 41.

The bowl-shaped distal end side of the lens body 20A is formed with an incident portion 21, and the incident portion 21 is formed in a concentric circle shape centered on the optical axis L of the LED41 and is recessed inward in a circular arc cross-sectional shape toward the emission side, but the incident lens surface 21a is not provided. Further, although the output surface 22 is originally a perfect circle, in a close arrangement relationship in a limited space on the surface of the base 11, a part of the outer periphery of the lens body 20A overlaps with each other, and a chord of the part is cut into a shape of a bow shape with a middle. Further, although the hole 23 is opened at the center of the emission surface 22, the lens body 20A itself is known, not a member having a bottom surface and an inner peripheral surface as in the above-described hole 23 of the lens body 20.

The emission surfaces 22 of the respective lens bodies 20, 20A are continuous with each other on the surface of the base 11, and the bowl-shaped peripheral walls 24 of the respective lens bodies 20, 20A are protruded from the back surface of the base 11. The base 11 is disposed in a state of facing in parallel to an LED substrate (light source substrate) 40 on which the LEDs 41 corresponding to the respective lens bodies 20 and 20A are mounted (see fig. 23). The respective LEDs 41 on the LED substrate 40 are arranged on the LED substrate 40 such that the optical axes L all face in the same direction, as will be described later.

According to the light distribution lens 10A, the plurality of lens bodies 20 and 20A can be used as one unit, and the irradiation of the high beam or the low beam can be selectively realized by selectively lighting each lens body 20 or the LED41 corresponding to each lens body 20A. Especially low beam and high beam can be realized by LEDs 41 mounted in the same orientation on one LED substrate 40.

The overall shape of the lens bodies 20 and 20A, the curved surface of the peripheral wall 24, the specific shapes and configurations of the incident portion 21, the emission surface 22, and the hole 23 are not limited to the illustrated examples, and can be appropriately modified. For example, as another modification, as in the light distribution lens 10B shown in fig. 17 to 22, the lens body 20B for low beam may be designed to have a large lateral width, or the lens bodies 20C for high beam may be designed to have a shape that does not overlap with each other.

As another embodiment not shown, all the same low beam lens bodies 20 and 20B may be integrally formed on the single base 11.

Next, as shown in fig. 23 and 24, the marker lamp 1 including the light distribution lens 10A as a component will be described. The marker lamp 1 is mounted on a front end vehicle of a railway vehicle, for example. As shown in fig. 21, the marker lamp 1 includes a lamp body 2 serving as a heat sink, an LED substrate 40, and a light distribution lens 10A. The marker lamp 1 is assembled mainly from these three components, and each component is unitized in advance. Instead of the light distribution lens 10A, another light distribution lens 10B may be used.

The lamp body 2 is integrally formed of a metal such as an aluminum alloy, for example, and a cylindrical housing portion 3 for housing the LED substrate 40 and mounting the light distribution lens 10A is provided on the front surface side. The housing portion 3 is open at the front, and an outer peripheral edge 3a protrudes in a flange shape. The bottom of the housing portion 3 is formed as a flat mounting surface, and is provided with an insertion hole or the like at an appropriate position through which a wiring for supplying electric power from a power source mounted on a vehicle, not shown, passes. A heat sink 5 is provided on the back surface side of the lamp body 2, and a plurality of heat radiating fins 4 extending in parallel with each other are provided on the heat sink 5 in a rearward standing manner.

The LED board 40 is formed in a circular shape having a size corresponding to the bottom mounting surface of the housing portion 3, and a wiring circuit is formed on the surface thereof, and a plurality of LEDs 41 are mounted on the wiring circuit. Here, the LED41 is a surface-mount type LED chip as described above. The LEDs 41 are arranged on the surface of the LED board 40 such that the optical axes L are oriented in the same direction perpendicular to the surface.

The light distribution lens 10A is formed to have a size that matches the bottom mounting surface of the housing portion 3, and the lens bodies 20 and 20A on the base body 11 correspond to the LEDs 41 on the LED board 40. The light distribution lens 10A is mounted in a state of covering the opening of the housing section 3 in a state of facing in parallel to the LED substrate 40 mounted on the bottom of the housing section 3 in front thereof.

According to the marker lamp 1, the route of a part of the light rays is directed downward by the light distribution lens 10A, so that the straight advancing property for illuminating the traveling direction of the vehicle can be secured by the normal lens body 20A, and the performance of also illuminating the lower part on the track of the vehicle can be realized by the lens body 20. Further, the number of components to be configured can be reduced, and the entire device can be downsized.

In particular, in the light distribution lens 10A, since the emission surfaces 22 of the respective lens bodies 20 and 20A having different light distribution characteristics are formed on the same plane on the front surface side of the base body 11, the configuration of the light distribution lens 10A itself as one unit can be further simplified with respect to the arrangement facing the LED substrate 40. The location and arrangement of the LEDs 41 to be mounted are not particularly limited, but the LEDs are arranged on the single LED board 40 such that the optical axes L are oriented in the same direction, so that the LEDs can be mounted collectively and easily, and the LEDs can be easily manufactured.

While the embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to the embodiments described above, and modifications and additions within the scope not departing from the gist of the present invention are also included in the present invention. For example, as described above, the overall shape of the lens bodies 20 and 20A, the curved surface of the peripheral wall 24, the specific shapes and configurations of the incident portion 21, the emission surface 22, and the hole 23 are not limited to the illustrated example, and may be appropriately changed, and the light distribution lenses 10, 10A, and 10B may be used as optical components of various illumination devices without being limited to the marker lamp 1.

Industrial applicability

The light distribution lens of the present invention can be widely used as an optical member of various illumination devices.

Claims (5)

1. A light distribution lens includes a lens body for distributing light incident from a light source for irradiating light in a predetermined direction to a predetermined range or direction,

the above-mentioned light distribution lens is characterized in that,

the lens body distributes light incident from the light source arranged in a state where the optical axis extends in a horizontal plane: a main irradiation range is set below the horizontal plane at a forward irradiation position as a target, and the light is intensified along the optical axis above the center of the irradiation range or a predetermined angle below the optical axis,

the lens body is formed in a bowl shape with a tip end side facing the light source, and includes: an incident portion on which light is incident with an optical axis of the light source as a center at a tip side; an exit surface through which light passing through the solid bowl-shaped interior exits at a side opposite to the tip side; a hole portion having a bottom, which is opened at a position on the emission surface, which is opposed to the incident portion on the optical axis, and which is recessed inward toward the incident portion; and a reflecting surface which is an inner surface of the bowl-shaped peripheral wall,

the surface of the incident portion and the bottom surface of the hole portion are formed to face each other in a predetermined lens shape, and light centered on the optical axis of the light source passes through the hole portion along the optical axis or at a predetermined angle below the optical axis by the lens shape and is emitted from the opening,

the light incident from the bottom surface of the hole to the surroundings through the incident portion is totally reflected by the reflecting surface and then emitted from the emitting surface toward the lower side of the horizontal plane without passing through the hole,

in the bottom surface of the hole, when a horizontal plane extending along the optical axis intersecting the bottom surface is defined as a middle, an upper side is formed as an upper emission lens surface for linearly advancing the light passing through the incident lens surface in the optical axis direction, and a lower side is formed as a lower emission lens surface for advancing the light passing through the incident lens surface in a downward direction intersecting the optical axis at a predetermined angle,

the opening of the hole is formed in a horseshoe shape in a front view viewed from the optical axis direction,

in the inner peripheral surface of the hole, when the horizontal surface vertically dividing the inner peripheral surface is defined as the middle, the upper side extends parallel to the optical axis, and the lower side is inclined in a downward direction intersecting the optical axis at a predetermined angle.

2. The light distribution lens of claim 1,

the incident portion is concentric with the optical axis of the light source, and is recessed toward the exit side in a circular arc sectional shape, and an incident lens surface protruding toward the light source side in a circular arc sectional shape is formed at the center bottom of the recessed surface.

3. The light distribution lens according to claim 1 or 2,

in the above-described reflective surface, when the horizontal plane that vertically divides the reflective surface is defined as the middle, the upper side is set to a critical angle at which light that has diffused upward from the bottom surface of the hole is totally reflected in a downward direction that intersects the optical axis at a predetermined angle, and the lower side is set to a critical angle at which light that has diffused downward from the bottom surface of the hole is totally reflected in a downward direction that intersects the optical axis at a predetermined angle.

4. The light distribution lens according to claim 1 or 2,

a plurality of the above-mentioned lens bodies are integrally formed on one base body,

the emitting surface of each lens body is connected to the surface of the base body, the bowl-shaped peripheral wall of each lens body is protruded from the back surface of the base body,

the base body is arranged in a state of facing in parallel to the light source substrate at the front of the light source substrate on which the light source corresponding to each lens body is mounted,

the light sources are arranged on the light source substrate with their optical axes directed in the same direction.

5. A light distribution lens is characterized in that,

a plurality of lens bodies are integrally formed on one base body,

at least one of the lenses is used as a lens for low beam light, and the lens for low beam light distributes light incident from a light source arranged in a state that an optical axis extends on a horizontal plane: a main irradiation range is set below the horizontal plane at a forward irradiation position as a target, and the light is intensified along the optical axis above the center of the irradiation range or a predetermined angle below the optical axis,

at least one lens body for high beam, excluding the lens body for low beam, among the lens bodies is configured to distribute light incident from the light source to a predetermined irradiation range centered on the optical axis of the light source at a forward target irradiation position,

the emitting surface of each lens body is connected to the surface of the base body, the bowl-shaped peripheral wall of each lens body is protruded from the back surface of the base body,

the base body is arranged in a state of facing in parallel to the light source substrate in front of the light source substrate on which the light sources corresponding to the respective lens bodies for the low beam lamp and the high beam lamp are mounted,

the light sources are arranged on the light source substrate with their optical axes facing in the same direction,

the lens body is formed in a bowl shape with a tip end side facing the light source, and includes: an incident portion on which light is incident with an optical axis of the light source as a center at a tip side; an exit surface through which light passing through the solid bowl-shaped interior exits at a side opposite to the tip side; a hole portion having a bottom, which is opened at a position on the emission surface, which is opposed to the incident portion on the optical axis, and which is recessed inward toward the incident portion; and a reflecting surface which is an inner surface of the bowl-shaped peripheral wall,

in the bottom surface of the hole, when a horizontal plane extending along the optical axis intersecting the bottom surface is defined as a middle, an upper side is formed as an upper emission lens surface for linearly advancing the light passing through the incident lens surface in the optical axis direction, and a lower side is formed as a lower emission lens surface for advancing the light passing through the incident lens surface in a downward direction intersecting the optical axis at a predetermined angle,

the opening of the hole is formed in a horseshoe shape in a front view viewed from the optical axis direction.

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