JP7784331B2 - Vehicle lighting fixtures - Google Patents

Description

The present invention relates to vehicle lighting fixtures for use in four-wheeled vehicles, two-wheeled vehicles, etc.

Conventionally, vehicle lighting fixtures for motorcycles have been known that use an internal lens to split the light from a light source device and irradiate it in two directions: toward the front and toward the road.

For example, the vehicle lighting unit disclosed in Patent Document 1 includes a light source and a lens. A portion of the light from the light source enters a first incident portion of the lens, and the remaining portion of the light emitted from the light source enters a second incident portion.

The first exit section of the lens is a section that emits a portion of the light that is emitted from the light source and enters the entrance section in a direction non-parallel to the vertical direction. The first entrance section intersects with the optical axis of the light source and has a concave curved shape facing away from the light source.

The second exit portion of the lens is a portion that emits at least a portion of the internally reflected light toward the road surface. The second entrance portion is located around the first entrance portion when the lens is viewed from the light source side along the optical axis. This realizes a device with a two-way illumination function (Patent Document 1, paragraphs 0028, 0040, 0041, Figure 6).

Japanese Patent Application Laid-Open No. 2021-034309

However, the lens in Patent Document 1 has a continuous, integrated first and second light exit sections, which requires high precision during manufacturing and makes it difficult to adjust the position and size of the light distribution.

The present invention was made in consideration of these circumstances, and aims to provide a vehicle lamp that allows for greater freedom in adjusting light distribution.

In order to achieve the above object, a vehicle lamp of the present invention comprises a light source whose optical axis is substantially parallel to a horizontal direction, a lens unit having a first lens portion that collects a portion of the light from the light source, and a second lens portion that is disposed below the first lens portion and that illuminates a road surface by irradiating a portion of the light from the light source downward relative to the light from the first lens portion,
the lens unit has a neutral portion located between the first lens portion and the second lens portion and connecting the first lens portion and the second lens portion,
The neutral portion has a flat plate shape extending horizontally.

The vehicle lamp of the present invention comprises a light source and a lens unit. A portion of the light emitted from the light source passes through the first lens portion of the lens unit. Although the center of the emission direction of this light is slightly downward relative to the horizontal, it can be used as a first signal light that illuminates following vehicles, etc. Furthermore, the second lens portion, located below the first lens portion, illuminates a portion of the light from the light source downward relative to the light from the first lens portion, allowing this light to be used as a second signal light that illuminates the road surface.

The neutral section is a flat plate that connects the first lens section and the second lens section and extends horizontally. This structure allows the first lens section and the second lens section to become independent optical systems at the neutral section, with their functions separated. Therefore, by simply changing the size (length) of the neutral section during manufacturing, the positions of the first lens section and the second lens section can be changed to generate a light distribution of the desired size and position. Therefore, the vehicle lamp of the present invention can be a vehicle lamp with a high degree of freedom in adjusting light distribution.

In the vehicle lamp of the present invention, it is preferable that the second lens portion is a convex lens.

By making the second lens section a convex lens, the image formed by the light from the light source can be enlarged and projected onto the road surface, creating a large projected image.

Furthermore, in the vehicle lamp of the present invention, it is preferable that the light source is disposed at the focal position of the first lens portion.

When the light source is positioned at the focal position of the first lens unit, it is possible to emit light in a direction parallel to the optical axis of the first lens unit. Furthermore, when the light source is positioned away from the focal position of the second lens unit, the light that passes through the second lens unit travels in a direction different from the light from the first lens unit, thereby generating a light distribution in that direction.

Furthermore, in the vehicle lamp of the present invention, it is preferable that the first lens portion is a Fresnel lens.

By using a Fresnel lens for the first lens section, part of the light from the light source passes through the first lens section and is converted into parallel light, allowing the emitted light to be emitted over a long distance.

Furthermore, in the vehicle lamp of the present invention, it is preferable that the second lens section is positioned so that the focal position of the second lens section is below the light source, and that the optical axis of the second lens section is configured to be parallel to the horizontal direction.

With this configuration, light from the light source enters the second lens unit from diagonally above. Furthermore, because the optical axis of the second lens unit is parallel to the horizontal direction, the light that enters the second lens unit can be emitted downward from the horizontal direction.

Furthermore, in the vehicle lamp of the present invention, it is preferable that the light source is disposed at the focal position of the second lens portion, and that the optical axis of the second lens portion is tilted downward from the horizontal direction.

When a light source is placed at the focal point of the second lens section, the optical axis of the second lens section is tilted downward from the horizontal. This allows light incident on the second lens section to be emitted downward from the horizontal.

Furthermore, in the vehicle lamp of the present invention, it is preferable that the light source, the first lens unit, and the second lens unit are arranged so that the shortest distance from a plane on which the light source is provided to the second lens unit is shorter than the shortest distance from the plane to the first lens unit.

By arranging the light source so that the shortest distance from the plane on which it is located to the second lens unit is shorter than the shortest distance from that plane to the first lens unit, the amount of light incident on the second lens unit from the light source can be increased, thereby improving the illumination efficiency of the second signal light.

Furthermore, in the vehicle lamp of the present invention, it is preferable that the light source has a plurality of lamps arranged in a line, and the first lens portion is a Fresnel lens provided with a plurality of Fresnel cut portions.

With this configuration, the light source is composed of multiple lamps, and the first lens portion is a Fresnel lens with multiple Fresnel cut sections. Light from the multiple lamps is incident on each Fresnel cut section, resulting in a uniform, high-intensity light emission pattern.

1 is a front view of a lamp device according to an embodiment of the present invention. 2 is a cross-sectional view of the lamp device of FIG. 1 taken along the vertical direction (line AA). FIG. 3 is an enlarged view of a region R in FIG. 2 . 2 is a cross-sectional view of the lamp device of FIG. 1 taken along the horizontal line BB. FIG. 5 is an enlarged view of an area S in FIG. 4 . 2 is a cross-sectional view of the lamp device of FIG. 1 taken along the horizontal line CC. FIG. 7 is an enlarged view of region T in FIG. 6.

The following describes preferred embodiments of the present invention, but these may be modified and combined as appropriate. In the following description and accompanying drawings, substantially identical or equivalent parts are designated by the same reference numerals.

Figure 1 is a front view of a lamp device 1 according to an embodiment of the present invention, Figure 2 is a vertical cross-sectional view (line A-A) of the lamp device 1 of Figure 1, Figure 4 is a horizontal cross-sectional view (line B-B) of the lamp device 1 of Figure 1, and Figure 6 is a horizontal cross-sectional view (line C-C) of the lamp device 1 of Figure 1.

The lamp device 1 shown in Figure 1 is primarily used as a tail light or blinker lamp placed at the rear of a saddle-type vehicle such as a two-wheeled vehicle or a three-wheeled vehicle. The following description will use as an example a case in which the lamp device 1 is a tail light with multiple light-emitting elements mounted on a motorcycle.

As shown in the cross-sectional view (cross-section along line A-A) in Figure 2, the lamp device 1 includes light-emitting elements 2 and 4, circuit boards 3 and 5, a lens unit 6, and inner lenses 7a and 7b inside a housing 11. The front side of the housing 11 is covered by an outer lens 10. The periphery of the lens unit 6 is partially covered by an extension 8.

At least one light-emitting element 2 is mounted on the circuit board 3. The circuit board 3 is positioned and fixed within the housing 11. The optical axis of the light-emitting element 2 is set to be approximately parallel to the horizontal direction. As will be described in detail later, the circuit board 3 of this embodiment is provided with light-emitting elements 2 (the "light source" of the present invention) consisting of multiple red LEDs.

Lens unit 6 has a Fresnel lens 6a and a projection lens (convex lens) 6b in region R in the figure. Between Fresnel lens 6a and projection lens 6b is a neutral surface 6c (the "neutral portion" of the present invention) that connects them. In addition, a Fresnel lens 6e is provided below lens unit 6. Lens unit 6 is fixed by a bracket or the like (not shown) inside housing 11.

Figure 3 is an enlarged view of region R in Figure 2. Fresnel lens 6a (the "first lens portion" of the present invention) is a lens that focuses the radial light emitted from the light-emitting element 2. In addition, projection lens 6b (the "second lens portion" of the present invention) is provided below Fresnel lens 6a via neutral plane 6c. Projection lens 6b is an aspheric lens that enlarges and projects an image formed by light from the light-emitting element 2 below the light from Fresnel lens 6a.

The neutral surface 6c connects the Fresnel lens 6a and the projection lens 6b, and has a flat plate shape extending horizontally (the lateral direction perpendicular to the arrangement direction (Z-axis direction) of the Fresnel lens 6a and the projection lens 6b). With this structure, the Fresnel lens 6a and the projection lens 6b become independent optical systems with respect to the light-emitting element 2, and their functions are divided.

As shown in Figure 3, the Fresnel lens 6a and the projection lens 6b each have a planar shape with the light incident surface facing the light-emitting element 2. The lens unit 6 has lower precision requirements than a lens unit that has two types of curved lenses arranged in succession. This simplifies design and reduces manufacturing costs.

When manufacturing and designing the lens unit 6, the focal length L1 from the light-emitting element 2 (the plane on which the light-emitting element 2 is provided) to the Fresnel lens 6a can be changed by changing the size (length) of the neutral plane 6c. Furthermore, the focal length L2 from the light-emitting element 2 (the plane on which the light-emitting element 2 is provided) to the projection lens 6b can be changed by changing the size (length) of the neutral plane 6c and the adjustment surface 6d below the projection lens 6b. In this way, the focal lengths of the Fresnel lens 6a (forward illumination direction) and the projection lens 6b (road surface illumination direction) can be set individually.

The light that passes through the Fresnel lens 6a is further magnified by the inner lens 7a (see Figure 1) and illuminates the front and rear of the motorcycle. The light that passes through the Fresnel lens 6a and is emitted to the outside is used as the first signal light ("Light 1" in the figure) for tail stop.

In this embodiment, the light-emitting element 2 is disposed at the focal position f1 of the Fresnel lens 6a. This allows parallel light to be emitted in a direction parallel to the optical axis (Y-axis direction) of the Fresnel lens 6a. While the Fresnel lens 6a is basically configured as described above, the optical axis of the emitted light and the degree of light concentration can be adjusted as appropriate depending on the light distribution required for the signal light and its relationship with other optical components.

Projector lens 6b is positioned so that its optical axis is parallel to the horizontal. Light that passes through projection lens 6b passes through the area between inner lenses 7a and 7b, illuminating the road surface behind the motorcycle. Light that passes through projection lens 6b is used as a second signal light ("Light 2" in the diagram) for illuminating the road surface.

As shown in Figure 3, the focal position f2 of the projection lens 6b is located below the focal position f1. If the light-emitting element 2 were located at the focal position f2, light would be emitted in a direction parallel to the optical axis (Y-axis direction) of the projection lens 6b, so light from the light-emitting element 2 at the focal position f1 is made incident. In this way, by positioning the projection lens 6b so that the focal position f2 of the projection lens 6b is located below the light-emitting element 2 and configuring the optical axis of the projection lens 6b to be parallel to the horizontal direction, it is possible to illuminate the road surface behind the vehicle with some of the light from the light-emitting element 2.

As a modification of the projection lens 6b, the light-emitting element 2 is disposed at the focal point f1, and the focal point of the projection lens 6b is aligned with the focal point f1. The central axis of the projection lens 6b may then be tilted downward, adjusting the optical axis so that it is tilted downward from the horizontal. This also makes it possible to illuminate the road surface behind the vehicle with some of the light from the light-emitting element 2.

In the examples of Figures 2 and 3, the light-emitting element 2 is at approximately the same height as the neutral plane 6c, but by changing the size and erection angle of the adjustment surface 6d during the manufacturing and design of the lens unit 6, the vertical position (Z-axis direction) of the neutral plane 6c relative to the light-emitting element 2 can be changed.

In the examples shown in Figures 2 and 3, the neutral plane 6c is slightly inclined with respect to the optical axis of the light-emitting element 2 for manufacturing reasons, but the neutral plane 6c may also be configured parallel to the optical axis of the light-emitting element 2. As shown in Figures 2 and 3, by positioning the neutral plane 6c at approximately the same height as the light-emitting element 2, approximately the same amount of light is taken in by each of the Fresnel lens 6a and the projection lens 6b. Furthermore, by moving the position of the neutral plane 6c vertically relative to the light-emitting element 2, the amount of light distributed to each of the Fresnel lens 6a and the projection lens 6b can be changed.

For example, if the neutral plane 6c is shifted downward relative to the light-emitting element 2, and the amount of light incident on the Fresnel lens 6a is increased, the amount of light incident on the projection lens 6b will decrease. Changing the distances L1 and L2 also affects the amount of incident light. Therefore, it is a good idea to perform illuminance tests by shifting the vertical and horizontal positions of the neutral plane 6c by a few millimeters.

A circuit board 5 with a light-emitting element 4 mounted thereon is disposed below the housing 11 (on the vehicle body side) (see Figure 2). The light emitted from the light-emitting element 4 passes through the Fresnel lens 6e and is further diffused by the inner lens 7b (see Figure 1) to illuminate the rear front of the motorcycle. This allows it to be used as the first signal light for tail-stop.

Next, we will explain the cross section of the lamp device 1 taken along line B-B with reference to Figure 4.

Multiple light-emitting elements 2 are arranged horizontally (in the X-axis direction) on the circuit board 3. In Figure 4, only the Fresnel lens 6a portion of the lens unit 6 is visible.

Figure 5 is an enlarged view of region S in Figure 4. The light-emitting element 2 in region S is composed of multiple red LEDs 2a-2e ("lamps" in the present invention). LEDs 2a-2e are arranged at equal intervals in the horizontal direction (X-axis direction).

Fresnel lens 6a has Fresnel lens cutouts 6a1 to 6a5 on the front side of LEDs 2a to 2e, respectively. The distance L1 from the end face of circuit board 3 on which light-emitting element 2 is mounted to the flat end face (incident surface) of Fresnel lens 6a is approximately equal to the focal length of Fresnel lens 6a.

For example, light emitted from LED 2b is mainly incident on Fresnel lens cut portion 6a2, but also on Fresnel lens cut portions 6a1 and 6a3 on either side of Fresnel lens cut portion 6a2. In Fresnel lens cut portions 6a1 to 6a3, the incident light is converted into parallel light and diffused.

In this way, light from each LED 2a-2e is incident on both the front Fresnel cut section and the adjacent Fresnel cut section, allowing the first signal light to be a linear light-emitting section with uniform, high illuminance across the horizontal direction.

Next, we will explain the cross section of the lamp device 1 taken along line CC with reference to Figure 6. In Figure 6, only the projection lens 6b portion of the lens unit 6 is visible. Although the light-emitting element 2 is shown in Figure 6 and Figure 7, which will be described later, it is not actually visible and is shown for convenience of explanation.

Figure 7 is an enlarged view of region T in Figure 6. The light-emitting elements 2 in region T are composed of LEDs 2a to 2e, and the projection lens 6b has convex portions 6b1 to 6b5 on the front side of the LEDs 2a to 2e, respectively. The distance from the end face of the circuit board 3 on which the light-emitting elements 2 are mounted to the flat end face (incident surface) of the projection lens 6b is L2, which is shorter than distance L1.

In this way, the components are arranged so that the shortest distance from the plane on which the light-emitting element 2 is provided to the projection lens 6b is shorter than the shortest distance from that plane to the Fresnel lens 6a. This increases the amount of light (capture amount) incident on the projection lens 6b from the light-emitting element 2. This improves the illumination efficiency of the second traffic light, and enables the light-emitting section to illuminate the road surface with high illuminance.

The present invention is not limited to the above embodiment, and can be embodied in various forms without departing from the spirit of the invention. The lamp device 1 of this embodiment can also be used as a vehicle lamp for other signal lights, such as turn signals. The lamp device 1 can also be applied to vehicle lamps for four-wheeled vehicles.

Instead of the Fresnel lenses 6a and 6e of this embodiment, fisheye Fresnel lenses may be used. Since light passing through the fisheye Fresnel lenses can be controlled in both the X-axis and Z-axis directions, the inner lenses 7a and 7b may be omitted.

1...lamp device, 2, 4...light-emitting element, 2a-2e...LED, 3, 5...circuit board, 6...lens unit, 6a, 6e...Fresnel lens, 6a1-6a5...Fresnel lens cut portion, 6b...projection lens, 6b1-6b5...convex portion, 6c...neutral surface, 6d...adjustment surface, 7a, 7b...inner lens, 8...extension, 10...outer lens, 11...housing.

Claims (8)

a light source whose optical axis is approximately parallel to the horizontal direction;
a lens unit having a first lens portion that collects a portion of the light from the light source, and a second lens portion that is disposed below the first lens portion and that illuminates a road surface by irradiating a portion of the light from the light source downward relative to the light from the first lens portion;
the lens unit has a neutral portion located between the first lens portion and the second lens portion and connecting the first lens portion and the second lens portion,
The vehicle lamp according to claim 1, wherein the neutral portion has a flat plate shape extending horizontally. The vehicle lamp according to claim 1, wherein the second lens portion is a convex lens. The vehicle lamp according to claim 1 or 2, wherein the light source is disposed at the focal position of the first lens portion. The vehicle lamp according to claim 1 or 2, wherein the first lens portion is a Fresnel lens. The vehicle lamp according to claim 1 or 2, wherein the second lens unit is positioned so that its focal position is below the light source, and the optical axis of the second lens unit is configured to be parallel to the horizontal direction. The vehicle lamp according to claim 1 or 2, wherein the light source is disposed at the focal position of the second lens portion, and the optical axis of the second lens portion is tilted downward from the horizontal direction. The vehicle lamp according to claim 1 or 2, wherein the light source, the first lens unit, and the second lens unit are arranged so that the shortest distance from a plane on which the light source is provided to the second lens unit is shorter than the shortest distance from the plane to the first lens unit. The light source includes a plurality of lamps arranged in a line,
3. The vehicular lamp according to claim 1, wherein the first lens portion is a Fresnel lens having a plurality of Fresnel cut portions.