WO2026014257A1 - Vehicle lamp - Google Patents

Abstract

A vehicle lamp according to the present invention comprises a light source (2), a first lens body (3), and a second lens body (4), wherein: the first lens body (3) includes a first entry part (6) and a first emitting part (7); the first entry part (6) has a lens shape which allows light (L) emitted from the light source (2) to enter the first lens body (3) such that the light (L) emitted from the light source (2) converges at a focal point (S1) positioned in the first lens body (3) and then diffuses from the focal point (S1) toward the first emitting part (7); and the first emitting part (7) has a first emitting surface (7a) from which light (L1) that is included in the light (L) emitted from the light source (2) and that is in a central region (E1) including the optical axis (AX) is emitted while being refracted in the diffusion direction and a second emitting surface (7b) from which light (L2) that is in a region (E2) surrounding the central region (E1) is emitted while being refracted in the convergence direction.

Description

Vehicle lighting fixtures

The present invention relates to a vehicle lamp.
This application claims priority based on Japanese Patent Application No. 2024-109708, filed July 8, 2024, the contents of which are incorporated herein by reference.

For example, a vehicle lighting fixture such as a vehicle headlamp comprises a light source, a reflector that reflects light emitted from the light source in the direction of travel of the vehicle, a shade that blocks (cuts) part of the light reflected by the reflector, and a projection lens that projects the light that has been partially blocked by the shade in the direction of travel of the vehicle.

In such vehicle lamps, the light source image defined by the front edge of the shade is inverted and projected by a projection lens to form a low beam light distribution pattern that includes a cut-off line at the top edge for passing vehicular traffic (low beam).

In addition, in vehicle lighting fixtures, a separate light source that emits light in the direction the vehicle is traveling is placed below the shade, and the light emitted from this light source is projected by a projection lens as a driving beam (high beam), forming a high beam light distribution pattern above the low beam light distribution pattern.

Furthermore, in the field of vehicle lighting, development is underway on adaptive beam headlamps (ADB), which are equipped with multiple light sources arranged in a row across the width of the vehicle and a projection lens that projects the light emitted from the multiple light sources toward the front of the vehicle. The light distribution pattern of the light projected by the projection lens can be variably controlled by switching the lighting of the multiple light sources. ADB is a technology that uses an onboard camera to recognize vehicles ahead, oncoming vehicles, pedestrians, etc., and expands the driver's forward visibility at night without dazzling the driver or pedestrians in front.

By the way, the following Patent Document 1 discloses a vehicle lamp comprising an optical system including a front lens body extending in a predetermined direction inclined at a predetermined angle with respect to the horizontal when viewed from the front, a rear lens portion arranged behind the front lens body, and a light source arranged behind the rear lens portion that emits light that passes through the rear lens portion and the front lens body in this order and is irradiated forward to form a headlamp light distribution pattern, wherein the rear lens portion is a lens portion that focuses light from the light source that passes through the rear lens portion in a first direction, and the front lens body is a lens portion that focuses light from the rear lens portion that passes through the front lens body in a second direction perpendicular to the first direction, and at least one light diffusion element is set in a region of the front lens body through which light from the optical system passes, for diffusing light from the optical system in at least one of the predetermined direction and a direction perpendicular to the predetermined direction.

Japanese Patent Application Publication No. 2019-121469

However, with the vehicle lamp described in Patent Document 1, although the height of the optical system can be reduced and the projected image on the screen can be made smaller, the optical system is long in the front-to-rear direction, making it difficult to reduce the overall size.

This aspect of the present invention provides a vehicle lamp that allows for further miniaturization while also achieving a good light distribution pattern.

The present invention provides the following aspects.
[1] A light source that emits light radially forward;
a first lens body disposed in front of the light source;
a second lens body disposed in front of the first lens body,
A vehicle lamp that projects light emitted from the light source toward a front of the vehicle through the first lens body and the second lens body,
the first lens body includes a first incident portion located on a side facing the light source and a first exit portion located on an opposite side to the first incident portion,
the first incident portion has a lens shape that causes the light emitted from the light source to enter the inside of the first lens body so that the light emitted from the light source is concentrated at a focusing point located inside the first lens body and then diffused from the focusing point toward the first exit portion,
a first exit surface that refracts light from a central region including the optical axis of the light emitted from the light source in a diffusing direction toward the second lens body and emits the light to the outside of the first lens body, and a second exit surface that refracts light from a peripheral region surrounding the central region in a converging direction toward the second lens body, in a vertical cross section including the optical axis of the light emitted from the light source, and emits the light to the outside of the first lens body.
[2] The first light exit surface is formed by a concave lens surface,
The vehicle lamp according to [1], wherein the second light exit surface is formed by a ring-shaped convex lens surface that surrounds the periphery of the concave lens surface.
[3] The vehicle lamp according to [1], wherein a composite focal point of the second lens body and the first light exit portion substantially coincides with the light-converging point.
[4] The second lens body includes, in the cross section in the vertical direction, a second incident portion located on a side facing the first exit portion, and a second exit portion located on an opposite side to the second incident portion,
the second incident portion refracts the light emitted from the first exit portion toward the optical axis, and the light enters the second lens body;
The vehicle lamp described in [1] is characterized in that the second exit portion refracts the light incident from the second entrance portion in a direction parallel to the optical axis and emits it to the outside of the second lens body.
[5] The second incident portion has a first convex lens surface provided corresponding to an area into which the light emitted from the first exit surface is incident, and a second convex lens surface provided corresponding to an area into which the light emitted from the second exit surface is incident,
The vehicle lamp according to [4], wherein the first convex lens surface has a positive refractive power greater than that of the second convex lens surface.
[6] The vehicle lamp according to [1], characterized in that the first incident portion has a first incident surface located at the center of the portion facing the light source, on which light from the central region is incident while being focused toward the focusing point, a second incident surface located on the inner periphery of a protrusion that protrudes toward the light source from a position surrounding the first incident surface, on which light from the peripheral region is incident, and a reflecting surface located on the outer periphery of the protrusion, which reflects the light incident from the second incident surface while being focused toward the focusing point.

This aspect of the present invention provides a vehicle lamp that allows for further miniaturization and produces a good light distribution pattern.

1 is a vertical cross-sectional view showing the configuration of a lamp unit provided in a vehicle lamp according to an embodiment of the present invention. FIG. 2 is a horizontal cross-sectional view showing the configuration of the lamp unit shown in FIG. 1 . 1 is a vertical cross-sectional view showing the configuration of a lamp unit shown in Example 1. FIG. FIG. 3 is a luminous intensity distribution diagram showing a light distribution pattern formed by the lamp unit shown in Example 1. FIG. 10 is a vertical cross-sectional view showing the configuration of a lamp unit shown in Comparative Example 1. FIG. 10 is a luminous intensity distribution diagram showing a light distribution pattern formed by the lamp unit shown in Comparative Example 1. FIG. 10 is a vertical cross-sectional view showing the configuration of a lamp unit shown in Comparative Example 2. FIG. 10 is a luminous intensity distribution diagram showing a light distribution pattern formed by the lamp unit shown in Comparative Example 2.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
It should be noted that the dimensions and the like exemplified in the following description are merely examples, and the present invention is not necessarily limited to them, but can be implemented with appropriate modifications within the scope that does not change the gist of the present invention.

As an embodiment of the present invention, a configuration of a vehicle lamp 1 shown in, for example, FIGS. 1 and 2 will be described.
1 is a vertical cross-sectional view showing the configuration of a lamp unit 20 provided in the vehicle lamp 1. FIG. 2 is a horizontal cross-sectional view showing the configuration of the lamp unit 20.

In addition, in the drawings shown below, an XYZ Cartesian coordinate system is set up, with the X-axis direction representing the front-to-rear direction (length direction) of the vehicle lamp 1, the Y-axis direction representing the left-to-right direction (width direction) of the vehicle lamp 1, and the Z-axis direction representing the up-and-down direction (height direction) of the vehicle lamp 1.

The vehicle lamp 1 of this embodiment is a vehicle headlamp mounted on both corners of the front end of a vehicle (not shown), and emits a passing beam (low beam) that forms a low beam light distribution pattern including a cut-off line at the upper end, and a driving beam (high beam) that forms a high beam light distribution pattern above the low beam light distribution pattern, toward the front of the vehicle (in the +X-axis direction).

Among these, the vehicle lamp 1 of this embodiment is an application of the present invention to an adjustable beam headlamp (ADB) that variably controls the light distribution pattern of light L projected toward the front of the vehicle.

Specifically, as shown in Figures 1 and 2, this vehicle lamp 1 is equipped with an ADB lamp unit 20 arranged inside the lamp body (not shown).

In the ADB, these lamp units 20 are arranged in a row across the width of the vehicle (hereinafter referred to as the "vehicle width direction"), and by switching the illumination of each lamp unit 20 on and off, it is possible to variably control the light distribution pattern of the light L projected in front of the vehicle.

The lamp unit 20 of this embodiment comprises a light source 2 that radially emits light L forward, a first lens body 3 disposed in front of the light source 2, and a second lens body 4 disposed in front of the first lens body 3.

The lamp unit 20 of this embodiment has a configuration in which the optical axis AX of the light L emitted from the light source 2 coincides with the central axes of the first lens body 3 and the second lens body 4.

The light source 2 is, for example, a light-emitting diode (LED) that emits white light, and emits light L radially toward the first lens body 3 in front. Note that, in addition to the LED described above, light-emitting elements such as laser diodes (LDs) can also be used for the light source 2.

The first lens body 3 is made of a light-transmitting material such as a transparent resin such as polycarbonate or acrylic, or glass. The first lens body 3 has a substantially cylindrical light guide section 5 extending in a direction along the optical axis AX, a first entrance section 6 located on the side of the light guide section 5 facing the light source 2 (rear side), and a first exit section 7 located on the side of the light guide section 5 opposite the first entrance section 6 (front side).

The first incident section 6 has a lens shape that causes the light L emitted from the light source 2 to enter the inside of the light guide section 5 so that the light L is focused at a focusing point S1 on the optical axis AX located inside the light guide section 5 (first lens body 3), and then diffuses from this focusing point S1 towards the first incident section 7.

Specifically, the first incident portion 6 has a first incident surface 6a located at the center of the portion of the light guide portion 5 facing the light source 2, on which light L1 from a central region E1 including the optical axis AX (hereinafter referred to as "first light") enters while being focused toward a focusing point S1, out of the light L radially emitted from the light source 2; a second incident surface 6b located on the inner periphery of a protruding portion 5a that protrudes toward the light source 2 (rear side) from a position surrounding the periphery of the first incident surface 6a of the light guide portion 5, on which light L2 from a peripheral region E2 surrounding the periphery of the central region E1 (hereinafter referred to as "second light") enters; and a reflecting surface 6c located on the outer periphery of the protruding portion 5a, which reflects the second light L2 incident from the second incident surface 6b while being focused toward the focusing point S1.

As shown in FIG. 1, in a vertical cross section (hereinafter referred to as the "vertical cross section") including the optical axis AX of the light L emitted from the light source 2 of the light guide 5, the first emission section 7 has a first emission surface 7a provided in correspondence with the central region E1 where the first light L1 of the light L emitted from the light source 2 is mainly incident, and a second emission surface 7b provided in correspondence with the peripheral region E2 where the second light L2 is mainly incident.

The first light exit surface 7a is formed by a concave lens surface with an inwardly curved concave shape at the center of the front side of the light guide unit 5. On the other hand, the second light exit surface 7b is formed by a ring-shaped convex lens surface that curves outwardly and convexly, surrounding the periphery of this concave lens surface.

As a result, in the vertical cross section of the first lens body 3 shown in Figure 1, the first exit surface 7a emits the first light L1 to the outside of the first lens body 3 while refracting it mainly in a direction away from the optical axis AX toward the second lens body 4 in front (hereinafter referred to as the "diffusion direction"). On the other hand, the second exit surface 7b emits the second light L2 to the outside of the first lens body 3 while refracting it mainly in a direction approaching the optical axis AX toward the second lens body 4 in front (hereinafter referred to as the "converging direction").

The first exit surface 7a is not limited to the concave lens surface described above, and may be formed as a flat surface, so that the first light L1 is refracted in a diffusing direction and emitted toward the second lens body 4 in front.

On the other hand, as shown in Figure 2, the first emission section 7 is formed by a convex lens surface that is curved outward in a horizontal cross section (hereinafter referred to as the "horizontal cross section") that includes the optical axis AX of the light L emitted from the light source 2 of the light guide section 5.

As a result, in the horizontal cross section of the first lens body 3 shown in Figure 2, the first emission section 7 emits the first and second light beams L1 and L2 (light L) to the outside of the first lens body 3 while concentrating them toward the second lens body 4 in front of it.

The second lens body 4 is made of a light-transmitting material such as a transparent resin such as polycarbonate or acrylic, or glass. The second lens body 4 has a second incident portion 8 located on the side opposite the first exit portion 7 (rear side), and a second exit portion 9 located on the opposite side from the second incident portion 8 (front side).

In the vertical cross section of the second lens body 4 shown in Figure 1, the second incident portion 8 has a first convex lens surface 8a provided in correspondence with the central region E1 where the first light L1 emitted from the first exit surface 7a is mainly incident, and a second convex lens surface 8b provided in correspondence with the peripheral region E2 where the second light L2 emitted from the second exit surface 7b is mainly incident.

The first convex lens surface 8a has a greater positive refractive power than the second convex lens surface 8b. In other words, the first convex lens surface 8a has a greater curvature than the second convex lens surface 8b and is curved outwardly convexly.

As a result, in the vertical cross section of the second lens body 4 shown in Figure 1, the second incident portion 8 refracts the first and second light beams L1 and L2 (light L) emitted from the first and second exit surfaces 7a and 7b (first exit portion 7) toward the optical axis AX, causing the light beams to enter the interior of the second lens body 4 from the first and second convex lens surfaces 8a and 8b.

On the other hand, the second incident portion 8 is formed by a convex lens surface that is curved outward in a convex shape in the horizontal cross section of the second lens body 4 shown in Figure 2.

As a result, in the horizontal cross section of the second lens body 4 shown in Figure 2, the second incident portion 8 refracts the light L (first and second light L1, L2) in a direction parallel to the optical axis AX, causing the light to enter the interior of the second lens body 4.

The second emission section 9 is curved outwardly in a convex shape in the vertical cross section of the second lens body 4 shown in Figure 1, and is formed by a cylindrical lens surface extending horizontally in the horizontal cross section of the second lens body 4 shown in Figure 2.

As a result, in the vertical cross section of the second lens body 4 shown in Figure 1, the second emission portion 9 refracts the first and second light beams L1 and L2 (light L) incident on the first and second convex lens surfaces 8a and 8b (second incidence portion 8) in a direction parallel to the optical axis AX, and emits the light to the outside of the second lens body 4.

On the other hand, in the horizontal cross section of the second lens body 4 shown in Figure 2, the second exit portion 9 emits the first and second light beams L1 and L2 (light L) incident on the first and second convex lens surfaces 8a and 8b (second entrance portion 8) to the outside of the second lens body 4 while maintaining the direction parallel to the optical axis AX.

As a result, the light L emitted from the second lens body 4 is projected toward the front of the vehicle while being collimated along the optical axis AX.

In the lamp unit 20 of this embodiment, which has the above-described configuration, the light L emitted from the light source 2 is projected toward the front of the vehicle via the first lens body 3 and the second lens body 4 while being expanded. This makes it possible to project a light distribution pattern for ADB toward the front of the vehicle.

Here, in the vertical cross section of the lamp unit 20 shown in Figure 1, the total length of the lamp unit 20 is T (= D1 + D2 + D3), the distance from the rear end of the lamp unit 20 to the focal point S1 is D1, the distance from the front end of the lamp unit 20 to the focal point S2 on the rear side of the second lens body 4 is D2, the distance between the focal point S1 and the focal point S2 is D3, and the distance from the front end of the lamp unit 20 to the focal point S1 is D4 (= D2 + D3).

In the lamp unit 20, the longer the distance D3 between the light condensing point S1 and the focal point S2, the smaller the vertical spread of the light distribution pattern of the light L projected forward from the second lens body 4 can be.

On the other hand, the longer the distance D3 between the condensing point S1 and the focal point S2 is relative to the overall length T of the lamp unit 20, the longer the overall length T of the lamp unit 20 becomes.

In contrast, in the lamp unit 20 of this embodiment, the distance D2 to the rear focal point S2 of the second lens body 4 is shortened, thereby making the overall length T of the lamp unit 20 shorter than in conventional configurations.

On the other hand, in order to shorten the distance D2 (total length T) while lengthening the distance D3 between the condensing point S1 and the focal point S2, it is necessary to increase the refractive power of the second lens body 4. However, in this case, it becomes difficult to align the composite focal point on the rear side of the second lens body 4 and the first emission section 7 with the condensing point S1.

In the lamp unit 20 of this embodiment, therefore, a first exit surface 7a is provided in the vertical cross section of the first lens body 3 shown in FIG. 1, which corresponds to the central region E1 of the first lens body 3 where the first light L1 of the light L emitted from the light source 2 is mainly incident, and which refracts the first light L1 in a diffusing direction. This causes the composite focal point on the rear side of the second lens body 4 and the first exit portion 7 to approximately coincide with the light collection point S1.

Note that the composite focus "approximately coincides" with the focal point S1 here does not necessarily mean that the composite focus is located at the focal point S1 on the optical axis, but rather that the composite focus is located within ±5 mm in front of or behind the focal point S1 on the optical axis.

This makes it possible to obtain a good light distribution pattern while preventing the light distribution pattern formed by the light L projected ahead of the vehicle from becoming blurred or spreading in the vertical direction.

On the other hand, the lamp unit 20 of this embodiment is configured to have a first exit surface 7b that refracts the second light L2 in a converging direction, corresponding to the peripheral area E2 of the first lens body 3 where the second light L2 is mainly incident. This allows the second light L2 to enter the second lens body 4, making it possible to maintain the utilization efficiency of the light L emitted from the first exit portion 7.

As a result, the lamp unit 20 of this embodiment can reduce the overall length T while preventing the light distribution pattern from spreading in the vertical direction.

Therefore, by including such a lamp unit 20, the vehicle lamp 1 of this embodiment can be made even more compact and can also produce a good light distribution pattern.

The present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the lamp unit 20, the first lens body 3 and the second lens body 4 are arranged separately, but the first lens body 3 and the second lens body 4 may also be connected via a connecting portion.

Furthermore, when the lamp units 20 are arranged in a row in the vehicle width direction, it is possible to form a single integrated configuration for the multiple second lens bodies 4 arranged in the vehicle width direction.

The following examples will make the effects of the present invention clearer. Note that the present invention is not limited to the following examples, and can be modified as appropriate within the scope of its gist.

Example 1
In Example 1, in the configuration of the lamp unit 20 shown in FIG. 3, the total length T is set to 61 mm, the distance D1 is set to 24 mm, the distance D2 is set to 30 mm, the distance D3 is set to 7 mm, and the distance D4 is set to 37 mm.

For the lamp unit 20 of Example 1, Figure 4 shows the light distribution pattern obtained by simulation when light L emitted in front of the lamp unit 20 is projected onto a virtual vertical screen directly facing the lamp unit 20.

(Comparative Example 1)
In Comparative Example 1, the configuration of lamp unit 20A shown in FIG. 5 has total length T=65 mm, distance D1=24 mm, distance D2=35 mm, distance D3=6 mm, and distance D4=41 mm.

The lamp unit 20A of Comparative Example 1 has a conventional configuration, with the first light output section 7 formed by a single convex lens surface 7c to match the distance D4. This allows the combined focal point on the rear side of the second lens body 4 and first light output section 7 to coincide with the light convergence point S1 without shortening the overall length T.

For the lamp unit 20A of Comparative Example 1, Figure 6 shows the light distribution pattern obtained by simulation when light L emitted in front of the lamp unit 20A is projected onto a virtual vertical screen directly facing the lamp unit 20A.

(Comparative Example 2)
In Comparative Example 2, the configuration of lamp unit 20B shown in Figure 7 is as follows: total length T = 61 mm, distance D1 = 24 mm, distance D2 = 35 mm, distance D3 = 2 mm, and distance D4 = 37 mm. Also, first light exit portion 7 is formed by one convex lens surface 7c.

Lamp unit 20B of Comparative Example 2 has a shorter overall length T than lamp unit 20A of Comparative Example 1, and in order to keep distance D1 unchanged, distance D4 is shortened. That is, distance D4 is the distance to the combined focal point (focus point S1) on the rear side of the second lens body 4 and first emission portion 7, so the curvature of convex lens surface 7c is greater than in Comparative Example 1 to shorten this combined focal point. On the other hand, because the curvature of the first entrance portion 6 and first emission portion 7 of the second lens body 4 remains unchanged, distance D2 to the focal point S2 on the rear side of the second lens body 4 is the same as in Comparative Example 1.

For lamp unit 20B of Comparative Example 2, Figure 8 shows the light distribution pattern obtained by simulation when light L emitted in front of lamp unit 20B is projected onto a virtual vertical screen directly facing lamp unit 20B.

As shown in Figures 4 and 6, even when the lamp unit 20 of Example 1 has a shorter overall length T than the lamp unit 20 of Comparative Example 1, it is possible to obtain a good light distribution pattern with high luminous intensity near the center while suppressing the light distribution pattern from spreading in the vertical direction.

On the other hand, as shown in Figures 6 and 8, in lamp unit 20B of Comparative Example 2, only the distance D2 (total length T) is shortened from the configuration of lamp unit 20 of Comparative Example 1. As a result, the light distribution pattern becomes wider in the vertical direction compared to the light distribution pattern of lamp unit 20 of Comparative Example 1, and the luminous intensity near the center decreases, making it difficult to meet the luminous intensity requirements of the law.

1... Vehicle lighting fixture; 2... Light source; 3... First lens body; 4... Second lens body; 5... Light guide section; 5a... Protrusion; 6... First incident section; 6a... First incident surface; 6b... Second incident surface; 6c... Reflecting surface; 7... First exit section; 7a... First exit surface (concave lens surface); 7b... Second exit surface (convex lens surface); 8... Second incident section; 8a... First convex lens surface; 8b... Second convex lens surface; 9... Second exit section (convex lens surface); 20... Lamp unit; L... Light; L1... First light; L2... Second light; E1... Central region; E2... Peripheral region

Claims (6)

a light source that emits light radially forward;
a first lens body disposed in front of the light source;
a second lens body disposed in front of the first lens body,
A vehicle lamp that projects light emitted from the light source toward a front of the vehicle through the first lens body and the second lens body,
the first lens body includes a first incident portion located on a side facing the light source and a first exit portion located on an opposite side to the first incident portion,
the first incident portion has a lens shape that causes the light emitted from the light source to enter the inside of the first lens body so that the light emitted from the light source is concentrated at a focusing point located inside the first lens body and then diffused from the focusing point toward the first exit portion,
The first emission section has, in a vertical cross section including the optical axis of the light emitted from the light source, a first emission surface that refracts light in a central region including the optical axis of the light emitted from the light source in a diffusing direction toward the second lens body and emits the light to the outside of the first lens body, and a second emission surface that refracts light in a peripheral region surrounding the periphery of the central region in a converging direction toward the second lens body and emits the light to the outside of the first lens body.
Vehicle lighting fixtures. the first exit surface is formed by a concave lens surface,
the second exit surface is formed by a ring-shaped convex lens surface surrounding the periphery of the concave lens surface,
2. A vehicle lamp according to claim 1. a composite focal point of the second lens body and the first light exit portion substantially coincides with the light-converging point,
2. A vehicle lamp according to claim 1. the second lens body includes, in the cross section in the vertical direction, a second incident portion located on a side facing the first exit portion, and a second exit portion located on an opposite side to the second incident portion,
the second incident portion refracts the light emitted from the first exit portion toward the optical axis, and the light enters the second lens body;
the second exit portion refracts the light incident from the second entrance portion in a direction parallel to the optical axis and outputs the light to the outside of the second lens body.
2. A vehicle lamp according to claim 1. the second incident portion has a first convex lens surface provided corresponding to an area onto which the light emitted from the first exit surface is incident, and a second convex lens surface provided corresponding to an area onto which the light emitted from the second exit surface is incident,
The first convex lens surface has a larger positive refractive power than the second convex lens surface.
5. A vehicle lamp according to claim 4. the first incident portion has a first incident surface located at the center of the portion facing the light source, on which light from the central region is incident while being focused toward the focusing point; a second incident surface located at the inner periphery of a protrusion that protrudes toward the light source from a position surrounding the first incident surface, on which light from the peripheral region is incident; and a reflecting surface located at the outer periphery of the protrusion, which reflects the light incident from the second incident surface while being focused toward the focusing point.
2. A vehicle lamp according to claim 1.