JP7732946B2 - Vehicle lighting fixtures - Google Patents

Description

The present invention relates to a vehicle lamp configured to irradiate light emitted from a light source forward through a lens.

Conventionally, a known vehicle lighting configuration is one in which light emitted from a light source is directed forward through a lens.

Patent Document 1 describes a lens configuration for such a vehicle lamp that includes a central region centered on an optical axis extending in the longitudinal direction of the lamp, and a peripheral region positioned around the central region, with multiple total internal reflection prism elements formed on the rear surface of the peripheral region in a concentric arrangement centered on the optical axis.

JP 2009-187859 A

By adopting a configuration in which light emitted from a light source is incident on multiple total reflection prism elements and then totally reflected forward toward the lamp, as in the lens of the vehicle lamp described in Patent Document 1 above, it is possible to use the light emitted from the light source as forward illumination light over a wide range.

However, in the vehicle lamp shown in Figure 1 of Patent Document 1, the lens is formed so as to extend like a flat plate along a vertical plane perpendicular to the optical axis. This means that in many cases, a sufficient amount of light is not obtained from the light source that is directed toward the outer edge of the lens, making it difficult to ensure a sufficient amount of light is emitted from the outer edge of the lens.

On the other hand, if the lens is configured to extend and curve toward the rear of the lamp relative to a vertical plane perpendicular to the optical axis, as in the vehicle lamp shown in Figure 11 of Patent Document 1, it is possible to obtain a sufficient amount of light even with respect to the light emitted from the light source toward the outer edge of the lens.

However, when such a lens is used, the total internal reflection prism elements formed on the outer periphery of the lens are inevitably large in size, resulting in significant variations in thickness at the outer periphery of the lens. This makes it difficult to precisely form the total internal reflection prism elements at the outer periphery of the lens when molding the lens, which in turn makes it difficult to precisely control the light distribution using the lens.

The present invention was made in light of these circumstances, and aims to provide a vehicle lamp that is configured to irradiate light emitted from a light source toward the front of the lamp through a lens, and that ensures a sufficient amount of light emitted from the outer edge of the lens while allowing the lens to accurately control the light distribution.

The present invention aims to achieve the above objective by devising an innovative design for the rear surface in the peripheral region of the lens.

That is, the vehicle lamp according to the present invention is
A vehicle lamp including a light source and a lens, and configured to irradiate light emitted from the light source toward a front of the lamp through the lens,
The lens has a central region centered on an optical axis extending in a front-to-rear direction of the lamp, and a peripheral region located around the central region,
a plurality of total reflection prism elements that cause the incident light from the light source to be totally reflected toward the front of the lamp are formed on the rear surface of the peripheral area in a state of being arranged concentrically around the optical axis,
The rear surface of the peripheral region is divided into an inner peripheral region and an outer peripheral region,
The plurality of total reflection prism elements are characterized in that in the inner peripheral region, a first annular concave curved surface centered on the optical axis is formed as an envelope surface, and in the outer peripheral region, a second annular concave curved surface centered on the optical axis is formed as an envelope surface.

The type of "vehicle lighting fixture" mentioned above is not particularly limited, and examples that can be used include headlamps, fog lamps, tail lamps, clearance lamps, etc.

The type of "light source" mentioned above is not particularly limited, and examples include light-emitting elements such as light-emitting diodes and light source bulbs.

The specific dimensions and external shapes of the above "central region" and "peripheral region" are not particularly limited.

The specific curvature of each of the above-mentioned "first annular concave curved surface" and "second annular concave curved surface" is not particularly limited.

The vehicle lamp of the present invention is configured to irradiate light emitted from a light source forward through a lens. The lens has a peripheral area around a central area centered on an optical axis extending in the longitudinal direction of the lamp. The peripheral area has a plurality of total reflection prism elements arranged concentrically around the optical axis on the rear surface of the lens. The light incident on the peripheral area is then totally reflected forward. This allows the light emitted from the light source to be used as forward illumination light over a wide area.

In addition, the rear surface of the peripheral region of the lens is divided into an inner region and an outer region, and the multiple total reflection prism elements are formed in the inner region with a first annular concave curved surface centered on the optical axis as the envelope surface, and in the outer region with a second annular concave curved surface centered on the optical axis as the envelope surface, thereby achieving the following effects.

In other words, in the inner peripheral region on the rear surface of the peripheral region, multiple total reflection prism elements are formed with the first annular concave curved surface centered on the optical axis as an envelope surface, so that light emitted from the light source that enters this inner peripheral region can be totally reflected by the multiple total reflection prism elements toward the front of the lamp as light of approximately uniform brightness.

In addition, in the outer peripheral region on the rear surface of the peripheral region, multiple total reflection prism elements are formed with a second annular concave curved surface centered on the optical axis as an envelope surface, so that light emitted from the light source that enters this outer peripheral region can also be totally reflected by the multiple total reflection prism elements toward the front of the lamp as light of approximately uniform brightness.

Furthermore, by configuring the multiple total internal reflection prism elements in this way so that the first and second circularly concave curved surfaces set twice form an envelope surface, it is possible to prevent the size of not only the total internal reflection prism elements formed on the outer peripheral edge of the inner peripheral region, but also the total internal reflection prism elements formed on the outer peripheral edge of the outer peripheral region from becoming too large. Therefore, when molding the lens, it is possible to mold the multiple total internal reflection prism elements with high precision, thereby enabling precise light distribution control.

In this way, the present invention allows a vehicle lamp configured to irradiate light emitted from a light source forward through a lens to ensure a sufficient amount of light emitted from the outer peripheral edge of the lens, while also enabling precise light distribution control by the lens.

Furthermore, by configuring the multiple total reflection prism elements in such a way that the first and second circularly concave curved surfaces set in duplicate are formed as the envelope surface, as in the present invention, the lens can be made thinner than when a configuration is used in which a single circularly concave curved surface is formed as the envelope surface.

In the above configuration, if each of the multiple total reflection prism elements formed in the inner peripheral region is configured to totally reflect, within a plane including the optical axis, light emitted from a first imaginary point light source located rearward of the light source as parallel light directed toward the front of the lamp, and if each of the multiple total reflection prism elements formed in the outer peripheral region is configured to totally reflect, within a plane including the optical axis, light emitted from a second imaginary point light source located rearward of the light source and forward of the first imaginary point light source as parallel light directed toward the front of the lamp, the following advantageous effects can be achieved.

In other words, although the light source has a fixed size, by setting the positions of the first and second virtual point light sources as described above, it is easy to totally reflect the light emitted from the light source as approximately parallel light directed toward the front of the lamp by multiple total reflection prism elements in both the inner and outer peripheral regions.

In this case, if the position of the first virtual point light source is set on the opposite side of the optical axis from the incident area of the light emitted from the first virtual point light source in the inner region, and the position of the second virtual point light source is set on the opposite side of the optical axis from the incident area of the light emitted from the second virtual point light source in the outer region, then the light emitted from a light source of a certain size can be totally reflected with even greater precision by the multiple total reflection prism elements in both the inner region and the outer region as approximately parallel light directed toward the front of the lamp.

In the above configuration, if the light source is configured as a light-emitting element positioned with its light-emitting surface facing forward toward the lamp, it becomes easy to form a light distribution pattern with a cutoff line using light emitted from the vehicle lamp.

In the above configuration, if multiple lens elements that control the emission of light arriving from multiple total internal reflection prism elements are formed on the front surface of the lens, and if the horizontal cross-sectional shape of these lens elements, including the optical axis, is formed as an envelope curve that is a convex curve centered on the optical axis, then it becomes easy to form a light distribution pattern formed by light emitted from the vehicle lamp in a light distribution pattern with reduced light unevenness.

FIG. 1 is a front view showing a vehicle lamp according to an embodiment of the present invention; Cross-sectional view of line II-II in Figure 1 1A is a front view showing a first lamp unit of the vehicle lamp, and FIG. 1B is a front view showing a second lamp unit of the vehicle lamp. 4A is a cross-sectional view taken along line IVa-IVa in FIG. 3, and FIG. 4B is a cross-sectional view taken along line IVb-IVb in FIG. 3. 4A is a cross-sectional view taken along line Va-Va in FIG. 4, and FIG. 4B is a cross-sectional view taken along line Vb-Vb in FIG. 4. 4A is a perspective view showing the lens of the first lamp unit as viewed from the direction of arrow VIa in FIG. 4A, and FIG. 4B is a perspective view showing the lens of the second lamp unit as viewed from the direction of arrow VIb in FIG. 4B. 4A is a perspective view showing the lens of the first lamp unit as viewed from the direction of arrow VIIa in FIG. 4A, and FIG. 4B is a perspective view showing the lens of the second lamp unit as viewed from the direction of arrow VIIb in FIG. 4B. Detailed view of part VIII in FIG. 5(a) 9A is a detailed view of part IXa in FIG. 8, and FIG. 9B is a detailed view of part IXb in FIG. 8. FIG. 1 is a perspective view showing a low beam light distribution pattern formed by light emitted from the vehicle lamp; FIG. 10 is a diagram showing a first light distribution pattern formed by light emitted from the first lamp unit; FIG. 10 is a diagram for explaining a process of forming a part of the first light distribution pattern. FIG. 10 is a diagram showing a second light distribution pattern formed by light emitted from the second lamp unit; FIG. 4 is a view similar to FIG. 3, illustrating a modification of the above embodiment. FIG. 11 is a diagram similar to FIG. 10 illustrating the operation of the modified example.

The following describes an embodiment of the present invention with reference to the drawings.

Figure 1 is a front view showing a vehicle lamp 10 according to one embodiment of the present invention. Figure 2 is a cross-sectional view taken along line II-II in Figure 1.

In Figures 1 and 2, the direction indicated by X is "in front of the lamp," the direction indicated by Y is "leftward" (or "rightward" when viewed from the front of the lamp) which is perpendicular to "in front of the lamp," and the direction indicated by Z is "upward." This is the same for figures other than Figures 1 and 2.

As shown in Figures 1 and 2, the vehicle lamp 10 according to this embodiment is a headlamp located at the front end of the vehicle, and is configured such that first and second lamp units 20, 40 are installed side-by-side in the vehicle width direction within a lamp chamber formed by a lamp body 12 and a transparent cover 14 attached to the front end opening.

The first lamp unit 20 includes a light-emitting element 22 and a lens 30 arranged on the front side of the lamp, and is configured to irradiate light emitted from the light-emitting element 22 toward the front of the lamp via the lens 30.

The second lamp unit 40 includes a light-emitting element 42 and a lens 50 arranged on the front side of the lamp, and is configured to irradiate light emitted from the light-emitting element 42 toward the front of the lamp via the lens 50.

The light-emitting elements 22, 42 of the first and second lamp units 20, 40 are supported on the lamp body 12 via a common substrate 24, and their lenses 30, 50 are supported on the lamp body 12 via a mounting structure (not shown).

The vehicle lamp 10 is designed to form a low-beam light distribution pattern (described below) using light emitted from the first and second lamp units 20, 40.

Next, the specific configuration of each of the first and second lamp units 20, 40 will be described.

First, we will explain the configuration of the first lamp unit 20.

Figure 3(a) is a front view showing the first lamp unit 20. Also, Figure 4(a) is a cross-sectional view taken along line IVa-IVa in Figure 3, and Figure 5(a) is a cross-sectional view taken along line Va-Va in Figure 4(a). Furthermore, Figure 6(a) is a perspective view showing the lens 30 of the first lamp unit 20 as viewed from the direction of arrow VIa in Figure 4(a), and Figure 7(a) is a perspective view showing the lens 30 as viewed from the direction of arrow VIIa in Figure 4(a).

As shown in these figures, the lens 30 of the first lamp unit 20 has an optical axis Ax extending in the front-to-rear direction of the lamp, and has a circular outer shape centered on the optical axis Ax when viewed from the front of the lamp. The outer dimensions of the lens 30 are set to a value of 50 mm or less (for example, approximately 35 mm).

The light-emitting element 22 is a white light-emitting diode, and is arranged with its light-emitting surface 22a facing forward (specifically, toward the front of the lamp). The light-emitting surface 22a of the light-emitting element 22 has a rectangular outer shape (specifically, a square of approximately 1 x 1 mm). The light-emitting element 22 is arranged with the center position in the left-right direction of the lower edge of its light-emitting surface 22a (hereinafter referred to as the "reference position") positioned on the optical axis Ax of the lens 30.

The lens 30 is an injection-molded product made of transparent resin, and has a central region 32 centered on the optical axis Ax and a peripheral region 34 located around this central region 32.

The rear surface 32b of the central region 32 is composed of a single convex lens surface centered on the optical axis Ax, and is designed to deflect and incident light emitted from the light-emitting element 22 in a direction closer to the optical axis Ax. Specifically, the surface shape of this rear surface 32b is set so that light emitted from the reference position of the light-emitting element 22 is guided to the front surface 30a of the lens 30 as parallel light directed toward the front of the lamp.

The rear surface 34b of the peripheral region 34 is divided into an inner peripheral region 34b1 and an outer peripheral region 34b2.

In the inner peripheral region 34b1, multiple total internal reflection prism elements 34s1 are formed, arranged concentrically around the optical axis Ax, and in the outer peripheral region 34b2, multiple total internal reflection prism elements 34s2 are formed, arranged concentrically around the optical axis Ax.

The multiple total internal reflection prism elements 34s1, 34s2 are all Fresnel lens type total internal reflection prisms that are configured to receive the light emitted from the light emitting element 22 and then totally reflect it toward the front of the lamp. Specifically, each of the multiple total internal reflection prism elements 34s1, 34s2 receives the light emitted from the reference position of the light emitting element 22 in a manner that refracts the light in a direction away from the optical axis Ax, and then guides the light to the front surface 30a of the lens 30 as parallel light directed toward the front of the lamp.

The boundary between the central region 32 and the peripheral region 34 is defined by a circle with a radius of 3 to 5 mm (e.g., a radius of approximately 4 mm) centered on the optical axis Ax. The boundary between the inner region 34b1 and the outer region 34b2 is defined by a circle with a radius of 8 to 12 mm (e.g., a radius of approximately 10 mm) centered on the optical axis Ax.

Figure 8 is a detailed view of part VIII in Figure 5(a). Also, Figure 9(a) is a detailed view of part IXa in Figure 8, and Figure 9(b) is a detailed view of part IXb in Figure 8.

As shown in FIG. 8, of the multiple total internal reflection prism elements 34s1, 34s2 formed on the rear surface 34b of the peripheral region 34, the multiple total internal reflection prism elements 34s1 located in the inner peripheral region 34b1 are formed with an envelope surface that is a first annular concave surface C1 (the cross-sectional shape of which is shown by a two-dot chain line in the figure) centered on the optical axis Ax, and the multiple total internal reflection prism elements 34s2 located in the outer peripheral region 34b2 are formed with an envelope surface that is a second annular concave surface C2 (the cross-sectional shape of which is shown by a two-dot chain line in the figure) centered on the optical axis Ax.

Each of the multiple total reflection prism elements 34s1 formed in the inner peripheral region 34b1 is configured to totally reflect, within a plane including the optical axis Ax, light emitted from a first imaginary point light source S1 located rearward of the light-emitting surface 22a of the light-emitting element 22 as parallel light directed toward the front of the lamp. This first imaginary point light source S1 is located on the opposite side of the optical axis Ax from the incident region of the light emitted from the first imaginary point light source S1 in the inner peripheral region 34b1. Specifically, this first imaginary point light source S1 is located at the intersection of a straight line L1a connecting the inner peripheral edge of the inner peripheral region 34b1 to the right edge (left edge in FIG. 8 ) of the light-emitting surface 22a of the light-emitting element 22 and a straight line L1b connecting the outer peripheral edge of the inner peripheral region 34b1 to the left edge of the light-emitting surface 22a of the light-emitting element 22.

Furthermore, each of the multiple total reflection prism elements 34s2 formed in the outer peripheral region 34b2 is configured to totally reflect, in a plane including the optical axis Ax, light emitted from a second virtual point light source S2 located rearward of the light-emitting surface 22a of the light-emitting element 22 and forward of the first virtual point light source S1 as parallel light directed toward the front of the lamp. This second virtual point light source S2 is located on the opposite side of the optical axis Ax from the incident region of the light emitted from the second virtual point light source S2 in the outer peripheral region 34b2. Specifically, this second virtual point light source S2 is located at the intersection of a straight line L2a connecting the inner peripheral edge of the outer peripheral region 34b2 to the right edge of the light-emitting surface 22a of the light-emitting element 22 and a straight line L2b connecting the outer peripheral edge of the outer peripheral region 34b2 to the left edge of the light-emitting surface 22a of the light-emitting element 22.

In addition, since the multiple total reflection prism elements 34s1, 34s2 are formed around the entire circumference centered on the optical axis Ax, the first and second virtual point light sources S1, S2 are also arranged to trace circular loci centered on the optical axis Ax.

The first annular concave curved surface C1 is formed so that the inner and outer peripheral edges of the inner peripheral region 34b1 are positioned approximately in the longitudinal direction of the lamp. Furthermore, the second annular concave curved surface C2 is formed so that the inner and outer peripheral edges of the outer peripheral region 34b2 are positioned approximately in the longitudinal direction of the lamp.

In addition, as shown in Figure 9(a), in the inner peripheral region 34b1, the pitch of the plurality of total reflection prism elements 34s1 and the curvature of the first annular concave curved surface C1 are set so that light emitted from the light-emitting element 22 is incident on each of the plurality of total reflection prism elements 34s1 approximately evenly. Furthermore, as shown in Figure 9(b), in the outer peripheral region 34b2, the pitch of the plurality of total reflection prism elements 34s2 and the curvature of the second annular concave curved surface C2 are set so that light emitted from the light-emitting element 22 is incident on each of the plurality of total reflection prism elements 34s2 approximately evenly.

As a result, of the multiple total reflection prism elements 34s1 formed in the inner peripheral region 34b1, the total reflection prism elements 34s1 located closer to the outer peripheral edge have a larger cross-sectional shape than the total reflection prism elements 34s1 located closer to the inner peripheral edge of the inner peripheral region 34b1. Similarly, the multiple total reflection prism elements 34s2 formed in the outer peripheral region 34b2 also have a larger cross-sectional shape than the total reflection prism elements 34s2 located closer to the outer peripheral edge of the outer peripheral region 34b2.

The multiple total internal reflection prism elements 34s2 formed in the outer peripheral region 34b2 have a cross-sectional shape that is larger overall than the multiple total internal reflection prism elements 34s1 formed in the inner peripheral region 34b1. However, because the multiple total internal reflection prism elements 34s1, 34s2 are formed with the double first and second annular concave curved surfaces C1, C2 as their envelope surfaces, the cross-sectional shape of the total internal reflection prism elements 34s2 located near the outer edge of the outer peripheral region 34b2 does not become excessively large.

The lens 30 has a central region 32 that is partially thicker, but a peripheral region 34 that is generally thinner. Specifically, the central region 32 has a maximum thickness of approximately 4 to 6 mm along the optical axis Ax, while the peripheral region 34 has a generally constant thickness of approximately 2 to 4 mm.

As shown in Figures 3 to 6, the front surface 30a of the lens 30 is configured with multiple lens elements (described below) formed on a vertical plane perpendicular to the optical axis Ax.

The front surface 30a of the lens 30 is divided into five emission areas 30a1, 30a2, 30a3, 30a4, and 30a5.

Emission area 30a1 is a semicircular area located in the upper half of front surface 30a, emission areas 30a2 and 30a4 are semicircular arc-shaped areas extending in a band along the outer edge of the lower half of front surface 30a, emission area 30a3 is an area in the lower region of front surface 30a that has a vertically elongated outer shape that spreads out like a fan downward, and emission area 30a5 is the remaining area in the lower half of front surface 30a.

The emission area 30a1 is divided into a horizontally long (e.g., approximately 2 x 4 mm) grid pattern, with a convex curved lens element 30s1 assigned to each section. Each lens element 30s1 is configured to deflect light from the light-emitting element 22 that arrives as parallel light from the rear surfaces 32b, 34b of the lens 30 downward and then emit the light toward the front of the lamp by diffusing it significantly in both the left and right directions.

Emission areas 30a2 and 30a4 are divided into vertical stripes (e.g., approximately 2 mm wide), and convex curved lens elements 30s2 and 30s4 are assigned to each of these stripes.

Each lens element 30s2 constituting the emission region 30a2, located to the left of the emission region 30a3 (to the right when viewed from the front of the lamp), is configured to deflect the light from the light-emitting element 22 that arrives as parallel light from the rear surface 34b of the lens 30 slightly downward and then diffuse it significantly to the right, emitting it toward the front of the lamp.

Each lens element 30s4 constituting the emission region 30a4 located to the right of the emission region 30a3 is configured to deflect the light from the light-emitting element 22 that arrives as parallel light from the rear surface 34b of the lens 30 slightly upward and then diffuse it significantly to the left, emitting it toward the front of the lamp.

The left edge of the emission region 30a3 (the right edge when viewed from the front of the lamp) is formed as a straight line extending directly downward from the optical axis Ax, and the right edge is formed as a straight line extending in a direction tilted to the right from the direction directly downward from the optical axis Ax (specifically, in a direction tilted approximately 15° to the right from the direction directly downward). The upper edge of this emission region 30a3 is formed as an arc centered on the optical axis Ax. This arc is located slightly outer than the boundary between the central region 32 and peripheral region 34 of the lens 30. The lower edge of the emission region 30a3 is formed by the outer edge of the front surface 30a.

The emission region 30a3 is composed of a single lens element 30s3. This lens element 30s3 has a surface shape consisting of a convex free-form surface. In other words, the surface of this lens element 30s3 is composed of a free-form surface in which the curvature of the convex surface gradually changes from its right half 30s3A to its left half 30s3B. This lens element 30s3 is configured to deflect light from the light-emitting element 22 that arrives as parallel light from the rear surface 34b of the lens 30 slightly upward and emit it toward the front of the lamp in a manner that gradually changes the emission direction from the right half 30s3A to the left half 30s3B.

Like emission area 30a1, emission area 30a5 is divided into vertical and horizontal grid sections, with a convex curved lens element 30s5 assigned to each section. However, each lens element 30s5 is configured to deflect the light from the light-emitting element 22 that arrives as parallel light from the rear surfaces 32b and 34b of the lens 30 slightly downward and then diffuse it significantly to the left, emitting it toward the front of the lamp.

Next, the configuration of the second lamp unit 40 will be described.

Figure 3(b) is a front view showing the second lamp unit 40. Also, Figure 4(b) is a cross-sectional view taken along line IVb-IVb in Figure 3, and Figure 5(b) is a cross-sectional view taken along line Vb-Vb in Figure 4(b). Furthermore, Figure 6(b) is a perspective view showing the lens 50 of the second lamp unit 40 as viewed from the direction of arrow VIb in Figure 4(b), and Figure 7(b) is a perspective view showing the lens 50 as viewed from the direction of arrow VIIb in Figure 4(b).

As shown in these figures, the configuration and arrangement of the light-emitting elements 42 in the second lamp unit 40 are the same as the light-emitting elements 22 in the first lamp unit 20, and the basic configuration and arrangement of the lens 50 are the same as the lens 30 in the first lamp unit 20, but the configuration of its front surface 50a is different from that of the lens 30.

In other words, the lens 50 of the second lamp unit 40 is also an injection-molded product made of transparent resin, and has a central region 52 centered on the optical axis Ax extending in the fore-and-aft direction of the lamp, and a peripheral region 54 located around this central region 52.

The configuration of the rear surface 52b of the central region 52 and the rear surface 54b of the peripheral region 54 is exactly the same as that of the lens 30 of the first lamp unit 20. That is, the rear surface 54b of the peripheral region 54 is divided into an inner region 54b1 and an outer region 54b2, each of which has a plurality of total internal reflection prism elements 54s1, 54s2 arranged concentrically around the optical axis Ax.

The front surface 50a of the lens 50 is divided into nine emission regions 50a1, 50a2L, 50a2R, 50a3L, 50a3R, 50a4L, 50a4R, 50a5L, and 50a5R, each of which is configured with multiple lens elements (described below).

The nine emission regions 50a1-50a5R are formed as strip-shaped regions extending vertically along a cylindrical surface that bulges out towards the front of the lamp.

Emission region 50a1 is formed with a wide width (for example, a width of approximately 6 mm) centered on optical axis Ax, and on both the left and right sides thereof, emission regions 50a2L, 50a2R, emission regions 50a3L, 50a3R, emission regions 50a4L, 50a4R, and emission regions 50a5L, 50a5R are formed adjacent to it in this order, each with a width of, for example, approximately 4 mm.

The nine emission regions 50a1-50a5R are each divided by a fixed vertical width (e.g., approximately 2 mm), and each is assigned a convex curved lens element 50s1, 50s2L, 50s2R, 50s3L, 50s3R, 50s4L, 50s4R, 50s5L, or 50s5R. Each of these lens elements 50s1-50s5R is configured to deflect light from the light-emitting element 42 that arrives as parallel light from the rear surface 52b, 54b of the lens 50 downward and then diffuse the light in the left-right direction, emitting it toward the front of the lamp.

As shown in Figure 5(b), the horizontal cross-sectional shapes of the multiple lens elements 50s1-50s5R, including the optical axis Ax, are formed with an envelope of a convex curve C3 centered on a point on the optical axis Ax. As a result, light emitted from each lens element 50s1 constituting the central emission region 50a1 is diffused evenly to the left and right, while light emitted from each lens element 50s2L-50s5R constituting the other emission regions 50a2L-50a5R is diffused unevenly to the left and right because the inclination angle of the convex curve C3 toward the rear of the lamp gradually increases as the distance from the optical axis Ax increases to the left and right. In other words, the degree of left-right imbalance increases in the following order: lens elements 50s2L, 50s2R, lens elements 50s3L, 50s3R, lens elements 50s4L, 50s4R, lens elements 50s5L, 50s5R.

Figure 10 is a perspective view of the low-beam light distribution pattern PL-1 formed on a virtual vertical screen positioned 25 m in front of the vehicle lamp 10 by light emitted from the lamp.

Low beam light distribution pattern PL-1 is a low beam light distribution pattern for left light distribution, and a stepped cutoff line CL is formed at its upper end.

The stepped cutoff line CL has a shape in which a lower cutoff line CL1 and an upper cutoff line CL2, which extend horizontally at different levels on the left and right, are connected by a sloped portion CL3. The stepped cutoff line CL is formed so that the lower cutoff line CL1 is located on the oncoming lane side of the V-V line, which is a vertical line passing through H-V, the vanishing point in front of the lamp, and the sloped portion CL3 and upper cutoff line CL2 are located on the own lane side. The upper cutoff line CL2 is located slightly above the H-H line, which is a horizontal line passing through H-V.

In the low beam light distribution pattern PL-1, elbow point E, the intersection point between the lower cutoff line CL1 and inclined portion CL3, is located approximately 0.5 to 0.6° below HV, and inclined portion CL3 extends diagonally upward and to the left from elbow point E at an inclination angle of 15° relative to the horizontal. In this low beam light distribution pattern PL-1, a high luminous intensity region HZ is formed near the lower left of elbow point E.

The low-beam light distribution pattern PL-1 is formed as a composite light distribution pattern by superimposing a first light distribution pattern PL-1A formed by light emitted from the first lamp unit 20 and a second light distribution pattern PL-1B formed by light emitted from the second lamp unit 40.

Figure 11 shows the first light distribution pattern PL-1A.

As shown in Figure 11, the first light distribution pattern PL-1A is formed as a composite light distribution pattern by superimposing five light distribution patterns PA1, PA2, PA3, PA4, and PA5.

Light distribution pattern PA1 is a light distribution pattern formed by light emitted from emission area 30a1 on the front surface 30a of lens 30, and is formed as a horizontally elongated light distribution pattern that has a relatively large vertical width and extends widely in the left-right direction below line H-H. This light distribution pattern PA1 forms a wide diffusion area of low-beam light distribution pattern PL-1.

Light distribution pattern PA2 is a light distribution pattern formed by light emitted from emission area 30a2 on the front surface 30a of lens 30. It is formed as a bright, horizontally elongated light distribution pattern that has a narrow vertical width below line H-H and expands to the right from near line V-V. The upper edge of light distribution pattern PA2 forms the lower cutoff line CL1 of low-beam light distribution pattern PL-1.

This type of light distribution pattern PA2 is formed because the angle of view of the light-emitting surface 22a of the light-emitting element 22 from the outer edge of the outer peripheral region 34b2 of the peripheral region 34 is extremely small. As a result, the light distribution pattern formed by the light emitted from the emission region 30a2 located in front of the lamp tends to be small and bright.

Light distribution pattern PA3 is a light distribution pattern formed by light emitted from the emission area 30a3 on the front surface 30a of lens 30. It is formed as a small, bright light distribution pattern extending diagonally upward to the left with a narrow vertical width near the bottom of H-V. The upper edge of this light distribution pattern PA3 forms the inclined portion CL3 of the low beam light distribution pattern PL-1 and the right end of the upper cutoff line CL2. The process of forming this light distribution pattern PA3 will be described later.

Light distribution pattern PA4 is a light distribution pattern formed by light emitted from emission region 30a4 on front surface 30a of lens 50, and is formed as a bright, horizontally elongated light distribution pattern that extends leftward from near the left side of line V-V with a narrow vertical width approximately along line H-H. This light distribution pattern PA4 is designed to form the upper cutoff line CL2 of low beam light distribution pattern PL-1 with its upper edge. Light distribution pattern PA4 is formed so that its right end overlaps with light distribution pattern PA3, smoothly connecting them.

The reason why this light distribution pattern PA4 is formed is that, as with light distribution pattern PA2, the angle of view of the light-emitting surface 22a of the light-emitting element 22 from the outer edge of the outer peripheral region 34b2 of the peripheral region 34 is extremely small. As a result, the light distribution pattern formed by the light emitted from the emission region 30a4 located in front of the lamp tends to be small and bright.

Light distribution pattern PA5 is a light distribution pattern formed by light emitted from emission area 30a5 on the front surface 30a of lens 30. It is formed as a relatively bright, horizontally elongated light distribution pattern with a relatively narrow vertical width that extends leftward from near the left side of line V-V, straddling light distribution pattern PA4 and light distribution pattern PA1, with its right end overlapping light distribution pattern PA3.

Figure 12 is a diagram illustrating the process of forming the light distribution pattern PA3, showing a perspective view of a portion of the front surface 30a of the lens 30 and a portion of the first light distribution pattern PL-1A.

As shown in Figure 12, the light distribution pattern PA3 formed by light emitted from the lens elements 30s3 that form the emission area 30a3 on the front surface 30a of the lens 30 is formed so that its upper edge extends from the inclined portion CL3 of the low beam light distribution pattern PL-1 to the right end of the upper cutoff line CL2, as described above.

On the other hand, the light distribution pattern PA3o shown by the two-dot chain line in Figure 12 is the light distribution pattern that would be formed if lens element 30s3 were not formed in emission region 30a3, and is formed so as to extend diagonally in an upper left direction near the bottom of inclined portion CL3. The upper edge of this light distribution pattern PA3o is formed as a clear light-dark boundary line. This is because the light-emitting element 22 is positioned with the lower edge of its light-emitting surface 22a positioned on the optical axis Ax of lens 30.

In reality, lens element 30s3 is formed in emission region 30a3, so light distribution pattern PA3o changes to resemble light distribution pattern PA3. This is because lens element 30s3 is composed of a free-form surface whose convex curvature gradually changes from its right half 30s3A to its left half 30s3B, deflecting the parallel light that reaches the front surface 30a of lens 30 slightly upward and gradually changing the emission direction from right half 30s3A to left half 30s3B.

Furthermore, the emission area 30a3 is composed of a single lens element 30s3, and there are no steps on its surface, so there is no risk of light pools accidentally forming in the space above the inclined portion CL3 of the light distribution pattern PA3, which could cause glare.

Figure 13 shows the second light distribution pattern PL-1B.

As shown in Figure 13, the second light distribution pattern PL-1B is formed as a composite light distribution pattern by superimposing nine light distribution patterns PB1, PB2L, PB2R, PB3L, PB3R, PB4L, PB4R, PB5L, and PB5R.

Light distribution pattern PB1 is a light distribution pattern formed by light emitted from emission area 50a1 on the front surface 50a of lens 50, and is formed as a horizontally elongated light distribution pattern below line H-H, spreading equally to both the left and right of line V-V.

The pair of left and right light distribution patterns PB2L and PB2R are light distribution patterns formed by light emitted from the pair of left and right emission areas 50a2L and 50a2R on the front surface 50a of the lens 50.They are horizontally elongated light distribution patterns smaller than light distribution pattern PB1 and are formed in a symmetrical positional relationship with their centers offset from the V-V line.

The pair of left and right light distribution patterns PB3L and PB3R are light distribution patterns formed by light emitted from the pair of left and right emission areas 50a3L and 50a3R on the front surface 50a of the lens 50.They are horizontally elongated light distribution patterns smaller than the light distribution patterns PB2L and PB2R, and are formed in a symmetrical positional relationship with their centers offset from the V-V line.

The pair of left and right light distribution patterns PB4L and PB4R are light distribution patterns formed by light emitted from the pair of left and right emission areas 50a4L and 50a4R on the front surface 50a of the lens 50.They are horizontally elongated light distribution patterns smaller than the light distribution patterns PB3L and PB3R, and are formed in a symmetrical positional relationship with their centers offset from the V-V line.

The pair of left and right light distribution patterns PB5L and PB5R are light distribution patterns formed by light emitted from the pair of left and right emission areas 50a5L and 50a5R on the front surface 50a of the lens 50.They are horizontally elongated light distribution patterns smaller than the light distribution patterns PB4L and PB4R, and are formed in a symmetrical positional relationship with their centers offset from the V-V line.

These four pairs of left and right light distribution patterns PB2L to PB5R are formed in a symmetrical positional relationship with their centers offset from the V-V line because the horizontal cross-sectional shapes of the multiple lens elements 50s2L to 50s5R are formed with the convex curve C3 as an envelope, as shown in Figure 5(b).

As a result, the second light distribution pattern PL-1B is formed as a light distribution pattern with a luminous intensity distribution in which the luminous intensity gradually decreases in both directions from the V-V line, thereby effectively suppressing the occurrence of uneven light distribution.

The second light distribution pattern PL-1B is formed so that the upper edges of the nine light distribution patterns PB1 to PB5R are positioned approximately in line below the lower cutoff line CL1. This is achieved by appropriately adjusting the vertical tilt angles of the multiple lens elements 50s1 to 50s5R that make up the nine emission regions 50a1 to 50a5R.

As shown in Figure 10, the low-beam light distribution pattern PL-1 is formed as a composite light distribution pattern of the first light distribution pattern PL-1A and the second light distribution pattern PL-1B, so the high-intensity area HZ formed near the lower left of the elbow point E is extremely bright.

Next, we will explain the effects of this embodiment.

The vehicle lamp 10 according to this embodiment is configured to form a low-beam light distribution pattern PL having a stepped cutoff line CL by directing light emitted from the light-emitting elements 22, 42 (light sources) of the first and second lamp units 20, 40 through the lenses 30, 50 toward the front of the lamp. In each lens 30, 50, the rear surfaces 34b, 54b of the peripheral regions 34, 54, which are located around the central regions 32, 52 centered on the optical axis Ax extending in the fore-and-aft direction of the lamp, are formed with a plurality of total-reflection prism elements 34s1, 34s2, 54s1, 54s2 arranged concentrically around the optical axis Ax. The total reflection prism elements 34s1, 34s2, 54s1, 54s2 allow the light emitted from the light-emitting elements 22, 42 to be used as forward illumination over a wide area.

In addition, the rear surfaces 34b, 54b of the peripheral regions 34, 54 are divided into inner peripheral regions 34b1, 54b1 and outer peripheral regions 34b2, 54b2. In the inner peripheral regions 34b1, 54b1, a plurality of total internal reflection prism elements 34s1, 54s1 are formed with a first annular concave curved surface C1 centered on the optical axis Ax as an envelope surface. Therefore, the light emitted from the light-emitting elements 22, 42 that enters the inner peripheral regions 34b1, 54b1 is substantially The light can be totally reflected toward the front of the lamp as light of uniform brightness. Furthermore, in the outer peripheral region 34b2, 54b2, the multiple total reflection prism elements 34s2, 54s2 are formed with the second annular concave curved surface C2 centered on the optical axis Ax as the envelope surface, so that light emitted from the light-emitting elements 22, 42 that enters the outer peripheral region 34b2, 54b2 can also be totally reflected toward the front of the lamp as light of approximately uniform brightness by the multiple total reflection prism elements 34s2, 54s2.

Furthermore, by configuring the multiple total internal reflection prism elements 34s1, 34s2, 54s1, 54s2 so that the first and second doubly set circular concave curved surfaces C1, C2 form the envelope surfaces, it is possible to prevent the sizes of not only the total internal reflection prism elements 34s1, 54s1 formed on the outer peripheral edge of the inner peripheral region 34b1, 54b1, but also the total internal reflection prism elements 34s2, 54s2 formed on the outer peripheral edge of the outer peripheral region 34b2, 54b2 from becoming too large. Therefore, when molding the lenses 30, 50, it is possible to mold the multiple total internal reflection prism elements 34s1, 34s2, 54s1, 54s2 with high precision, thereby enabling precise light distribution control.

As such, according to this embodiment, in a vehicle lamp 10 configured to irradiate light emitted from the light-emitting elements 22, 42 of the first and second lamp units 20, 40 toward the front of the lamp via the lenses 30, 50, it is possible to ensure a sufficient amount of light emitted from the outer peripheral edges of the lenses 30, 50, while also enabling precise light distribution control by the lenses 30, 50.

Furthermore, as in this embodiment, by configuring the multiple total reflection prism elements 34s1, 34s2, 54s1, 54s2 so that the first and second circularly-concave curved surfaces C1, C2 set in duplicate are formed as enveloping surfaces, it is possible to make the peripheral regions 34, 54 of the lenses 30, 50 thinner than when a single circularly-concave curved surface is formed as the enveloping surface.

In the present embodiment, the lenses 30, 50 are formed with a thicker central region 32, 52 than the peripheral region 34, 54. However, by locating a gate in the central region 32, 52 for injection molding the lenses 30, 50, the lenses 30, 50 can be easily molded.

In this embodiment, each of the multiple total reflection prism elements 34s1, 54s1 formed in the inner peripheral region 34b1, 54b1 of the rear surface 34b, 54b of the peripheral region 34, 54 is configured to totally reflect, in a plane including the optical axis Ax, light emitted from a first imaginary point light source S1 located rearward of the light-emitting element 22, 42 as parallel light directed toward the front of the lamp. Furthermore, each of the multiple total reflection prism elements 34s2, 54s2 formed in the outer peripheral region 34b2, 54b2 is configured to totally reflect, in a plane including the optical axis Ax, light emitted from a second imaginary point light source S2 located rearward of the light-emitting element 22, 42 and forward of the first imaginary point light source S1 as parallel light directed toward the front of the lamp. Therefore, the following advantageous effects can be obtained.

In other words, the light-emitting elements 22, 42 have light-emitting surfaces 22a, 42a of a fixed size, and the light emitted from these light-emitting elements 22, 42 is totally reflected by the multiple total reflection prism elements 34s1, 54s1 in the inner peripheral regions 34b1, 54b1 as approximately parallel light directed toward the front of the lamp, and is totally reflected by the multiple total reflection prism elements 34s2, 54s2 in the outer peripheral regions 34b2, 54b2 as approximately parallel light directed toward the front of the lamp.

In this case, the first virtual point light source S1 is located on the opposite side of the optical axis Ax to the incident area of the light emitted from the first virtual point light source S1 in the inner peripheral regions 34b1 and 54b1, and the second virtual point light source S2 is located on the opposite side of the optical axis Ax to the incident area of the light emitted from the second virtual point light source S2 in the outer peripheral regions 34b2 and 54b2, thereby achieving the following effects.

In other words, light emitted from the light-emitting surfaces 22a, 42a of the light-emitting elements 22, 42, which have a certain size, can be totally reflected with high precision by the multiple total reflection prism elements 34s1, 54s1 in the inner peripheral region 34b1, 54b1 as approximately parallel light directed toward the front of the lamp, and in the outer peripheral region 34b2, 54b2, it can be totally reflected with high precision by the multiple total reflection prism elements 34s2, 54s2 as approximately parallel light directed toward the front of the lamp.

In this embodiment, the light sources of the first and second lamp units 20, 40 are composed of light-emitting elements 22, 42 arranged with their light-emitting surfaces 22a, 42a facing forward toward the lamp, making it easy to form a low-beam light distribution pattern PL-1 with a stepped cutoff line CL using light emitted from the vehicle lamp 10.

In this embodiment, the first light distribution pattern PL-1A formed by the light emitted from the first lamp unit 20 forms a stepped cutoff line CL of the low beam light distribution pattern PL-1. The lens 50 in the second lamp unit 40 is configured such that the front surface 50a is divided into nine vertically extending emission regions 50a1, 50a2L, 50a2R, 50a3L, 50a3R, 50a4L, 50a4R, 50a5L, and 50a5R, and multiple lens elements 50a1, 50a2L, 50a2R, 50a3L, 50a3R, 50a4L, 50a4R, 50a5L, and 50a5R are formed. Furthermore, the horizontal cross-sectional shape of these elements, including the optical axis Ax, is formed with a convex curve C3 centered on the optical axis Ax as an envelope, resulting in the following advantageous effects.

In other words, the second light distribution pattern PL-1B formed by the light emitted from the second lamp unit 40 is a composite light distribution pattern of nine light distribution patterns PB1, PB2L, PB2R, PB3L, PB3R, PB4L, PB4R, PB5L, and PB5R formed by the light emitted from the nine emission regions 50a1 to 50a5R. However, because these patterns are formed with mutually varying sizes and formation positions, the second light distribution pattern PL-1B can be formed as a light distribution pattern with reduced light unevenness.

In the above embodiment, the light-emitting surface 22a of the light-emitting element 22 was described as having an outer shape of approximately 1 x 1 mm, but it is also possible to use light-emitting surfaces with other shapes.

In the above embodiment, the rear surface 32b of the central region 32 of the lens 30 of the first lamp unit 20 was described as being configured as a single convex lens surface, but other configurations (such as a Fresnel lens configuration) may also be used.

In the above embodiment, the lenses 30, 50 of the first and second lamp units 20, 40 were described as having circular outer shapes when viewed from the front of the lamp, but configurations with outer shapes other than this may also be used.

In the above embodiment, the lenses 30 and 50 were described as being injection-molded products, but other configurations (such as compression-molded products) may also be used.

In the above embodiment, the light emitted from the vehicle lamp 10 is described as forming a low-beam light distribution pattern PL-1 for left-side light distribution having a stepped cutoff line CL, but it is also possible to configure the lamp to form other light distribution patterns.

Next, we will explain a variation of the above embodiment.

Figure 14 is a diagram similar to Figure 3, showing the first and second lamp units 120, 140 of a vehicle lamp according to this modified example.

As shown in Figure 14, in this modified example, the configuration of the second lamp unit 140 is exactly the same as in the above embodiment, but the configuration of the lens 130 of the first lamp unit 120 is partially different from that in the above embodiment.

That is, as shown in Figure 14(a), the lens 130 of this modified example also has a central region 132 and a peripheral region 134, and the configuration of the rear surfaces 132b, 134b is exactly the same as in the above embodiment, and the rear surface 134b of the peripheral region 134 is divided into an inner peripheral region 134b1 and an outer peripheral region 134b2.

In addition, the front surface 130a of the lens 130 of this modified example is divided into five emission regions 130a1, 130a2, 130a3, 130a4, and 130a5. Specifically, the front surface 130a of the lens 130 is divided into two large concentric regions centered on the optical axis Ax, with a pair of upper and lower emission regions 130a1 and 130a5 located on the inner periphery, and a pair of left and right emission regions 130a2 and 130a4 and a pair of upper and lower emission regions 130a3 located on the outer periphery.

The emission area 130a1, located at the top of the inner periphery, is divided into horizontally elongated vertical and horizontal grid patterns, similar to the emission area 30a1 of the lens 30 of the first lamp unit 20 in the above embodiment, with a convex curved lens element 130s1 assigned to each of these sections. Each lens element 130s1 is configured to deflect light from the light-emitting element 22 that arrives as parallel light from the rear surfaces 132b, 134b of the lens 130 downward and then emit the light toward the front of the lamp by diffusing it significantly in the left-right direction.

The pair of left and right emission areas 130a2, 130a4 are divided into two vertical sections, one above the other, and are arranged in a vertical stripe pattern, with convex curved lens elements 130s2, 130s4 assigned to each section.

Each lens element 130s2 constituting the emission region 130a2 located on the left side is configured to deflect the light from the light-emitting element 22 that arrives as parallel light from the rear surface 134b of the lens 130 slightly downward and then diffuse it significantly to the right, emitting it toward the front of the lamp.

Each lens element 130s4 constituting the emission region 130a4 located on the right side is configured to deflect the light from the light-emitting element 22 that reaches the rear surface 134b of the lens 130 as parallel light slightly upward and then diffuse it significantly to the left, emitting it toward the front of the lamp.

The pair of upper and lower emission regions 130a3 are divided into diagonal vertical stripes, each of which is assigned a convex curved lens element 130s3. Each lens element 130s3 is formed to extend in a direction tilted 15° to the left (right when viewed from the front of the lamp) relative to the vertical direction, so that light from the light-emitting element 22 that arrives as parallel light from the rear surface 134b of the lens 130 is deflected slightly upward and then slightly deflected and diffused in a direction perpendicular to the 15° tilt, before being emitted toward the front of the lamp.

The emission area 130a5, located at the bottom of the inner periphery, is divided into vertical stripes, similar to the emission area 30a5 of the lens 30 of the first lamp unit 20 in the above embodiment, and each stripe is assigned a convex curved lens element 130s5. Each lens element 130s5 is configured to deflect light from the light-emitting element 22 that arrives as parallel light from the rear surfaces 132b, 134b of the lens 130 slightly downward and then diffuse the light significantly to the left, emitting it toward the front of the lamp.

Figure 15 is a perspective view of the low-beam light distribution pattern PL-2 formed on the virtual vertical screen by light emitted from the vehicle lamp according to this modified example.

The low-beam light distribution pattern PL-2 is formed as a composite light distribution pattern by superimposing a first light distribution pattern PL-2C formed by light emitted from the first lamp unit 120 and a second light distribution pattern PL-2B formed by light emitted from the second lamp unit 140.

The second light distribution pattern PL-2B is exactly the same as the second light distribution pattern PL-1B (see Figure 13) formed by the light emitted from the second lamp unit 40 in the above embodiment.

On the other hand, the first light distribution pattern PL-2C is formed as a composite light distribution pattern by superimposing five light distribution patterns PC1, PC2, PC3, PC4, and PC5.

Light distribution pattern PC1 is a light distribution pattern formed by light emitted from emission area 130a1 on front surface 130a of lens 130, and is formed as a horizontally elongated light distribution pattern that has a relatively large vertical width and extends widely in the left-right direction below line H-H. This light distribution pattern PC1 forms a wide diffusion area for low-beam light distribution pattern PL-2.

Light distribution pattern PC2 is a light distribution pattern formed by light emitted from emission area 130a2 on front surface 130a of lens 130, and is formed as a bright, horizontally elongated light distribution pattern that has a narrow vertical width below line H-H and expands to the right from near line V-V. The upper edge of light distribution pattern PC2 forms the lower cutoff line CL1 of low beam light distribution pattern PL-2.

Light distribution pattern PC3 is a light distribution pattern formed by light emitted from a pair of upper and lower emission areas 130a3 on the front surface 130a of lens 130. It is formed as a small, bright light distribution pattern that extends diagonally upward and to the left with a narrow vertical width near the lower H-V. The upper edge of this light distribution pattern PC3 forms the sloped portion CL3 of the low beam light distribution pattern PL-2.

Light distribution pattern PC4 is a light distribution pattern formed by light emitted from emission region 130a4 on front surface 130a of lens 130, and is formed as a bright, horizontally elongated light distribution pattern that extends leftward from near the left side of line V-V with a narrow vertical width approximately along line H-H. This light distribution pattern PC4 is designed to form the upper cutoff line CL2 of low beam light distribution pattern PL-2 with its upper edge. At this time, this light distribution pattern PC4 is formed with its right end overlapping with light distribution pattern PC3.

Light distribution pattern PC5 is a light distribution pattern formed by light emitted from emission area 130a5 on front surface 130a of lens 130. It is formed as a relatively bright, horizontally elongated light distribution pattern with a relatively narrow vertical width that extends leftward from near the left side of line V-V, straddling light distribution pattern PC4 and light distribution pattern PC1, with its right end overlapping light distribution pattern PC3.

Even when adopting the configuration of this modified example, substantially the same effects as those of the above embodiment can be obtained.

Furthermore, by adopting the configuration of this modified example, it is easy to ensure sufficient brightness near the stepped cutoff line CL in the low beam light distribution pattern PL-2.

Note that the numerical values shown as specifications in the above embodiment and its variations are merely examples, and it goes without saying that these may be set to different values as appropriate.

Furthermore, the present invention is not limited to the configurations described in the above embodiment and its variations, and various other modified configurations are also possible.

10 Vehicle lamp 12 Lamp body 14 Light-transmitting cover 20, 120 First lamp unit 22, 42 Light-emitting element (light source)
22a, 42a: light-emitting surface 24: substrate 30, 50, 130: lens 30a, 50a, 130a: front surface 30a1, 30a2, 30a3, 30a4, 30a5, 50a1, 50a2L, 50a2R, 50a3L, 50a3R, 50a4L, 50a4R, 50a5L, 50a5R, 130a1, 130a2, 130a3, 130a4, 130a5: emission region 30s1, 30s2, 30s3, 30s4, 30s5, 50s1, 50s2L, 50s2R, 50s3L, 50s3R, 50s4L, 50s4R, 50s5L, 50s5R, 130s1, 130s2, 130s3, 130s4, 130s5 Lens element 30s3A Right half 30s3B Left half 32, 52, 132 Center region 32b, 34b, 52b, 54b, 132b, 134b Rear surface 34, 54, 134 Peripheral region 34b1, 54b1, 134b1 Inner region 34b2, 54b2, 134b2 Outer region 34s1, 34s2, 54s1, 54s2 Total internal reflection prism element 40, 140 Second lamp unit Ax Optical axis C1 First circular annular concave curved surface C2 Second circular annular concave curved surface C3 Convex curve CL Stepped cutoff line CL1 Lower cutoff line CL2 Upper cutoff line CL3 Inclined portion E Elbow point HZ High luminous intensity region L1a, L1b, L2a, L2b Straight line PA1, PA2, PA3, PA4, PA5, PB1, PB2L, PB2R, PB3L, PB3R, PB4L, PB4R, PB5L, PB5R, PC1, PC2, PC3, PC4, PC5 Light distribution pattern PL-1, PL-2 Light distribution pattern for low beam PL-1A, PL-2C First light distribution pattern PL-1B, PL-2B Second light distribution pattern S1 First virtual point light source S2 Second virtual point light source

Claims (5)

A vehicle lamp including a light source and a lens, and configured to irradiate light emitted from the light source toward a front of the lamp through the lens,
The lens has a central region centered on an optical axis extending in a front-to-rear direction of the lamp, and a peripheral region located around the central region,
a plurality of total reflection prism elements that cause the incident light from the light source to be totally reflected toward the front of the lamp are formed on the rear surface of the peripheral area in a state of being arranged concentrically around the optical axis,
The rear surface of the peripheral region is divided into an inner peripheral region and an outer peripheral region,
a plurality of total reflection prism elements each having an envelope surface formed as a first annular concave curved surface centered on the optical axis in the inner peripheral region, and a second annular concave curved surface centered on the optical axis in the outer peripheral region. each of the plurality of total reflection prism elements formed in the inner peripheral region is configured to totally reflect, within a plane including the optical axis, light emitted from a first imaginary point light source located rearward of the light source, as parallel light directed toward a front direction of the lamp;
2. The vehicular lamp according to claim 1, wherein each of the plurality of total reflection prism elements formed in the outer peripheral region is configured to totally reflect light emitted from a second imaginary point light source located rearward of the light source and forward of the first imaginary point light source in a plane including the optical axis as parallel light directed toward a front of the lamp. the first virtual point light source is located on an opposite side of the optical axis to an incident region of the inner peripheral region into which light emitted from the first virtual point light source is incident,
3. The vehicle lamp according to claim 2, wherein the second imaginary point light source is located on an opposite side of the optical axis from an incident area of the light emitted from the second imaginary point light source in the outer peripheral area. A vehicle lamp according to any one of claims 1 to 3, characterized in that the light source is composed of a light-emitting element arranged with its light-emitting surface facing forward of the lamp. a plurality of lens elements are formed on the front surface of the lens to control the emission of light that has reached the lens from the plurality of total reflection prism elements;
The vehicle lamp according to any one of claims 1 to 3, characterized in that the horizontal cross-sectional shape of the plurality of lens elements, including the optical axis, is formed with a convex curved envelope centered on the optical axis.