JP7788352B2 - 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 this central region. The rear surface of the peripheral region is equipped with a plurality of total reflection prism elements that are arranged concentrically around the optical axis and that totally reflect light emitted from a light source toward the front of the lamp after it is incident thereon.

JP 2009-187859 A

In a vehicle lamp such as that described in Patent Document 1, if multiple lens elements that control the emission of light reaching the lamp from multiple total internal reflection prism elements are formed on the front surface of the lens in a vertical and horizontal grid pattern, it is possible to form a light distribution pattern with a cutoff line at the upper end by appropriately adjusting the orientation of these lens elements.

In this case, it is desirable to form a light distribution pattern with as clear a cutoff line as possible.

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 forward through a lens, and that is capable of forming a light distribution pattern with a clear cutoff line.

The present invention aims to achieve the above objective by devising an innovative design for the front surface of the lens.

That is, the vehicle lamp according to the present invention is
A vehicle lamp including a light source and a lens, the vehicle lamp being configured to form a light distribution pattern having a cutoff line by irradiating light emitted from the light source toward a front side 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,
a plurality of lens elements for controlling the emission of light arriving from the plurality of total reflection prism elements are formed on the front surface of the lens in a state where they are divided into vertical and horizontal grid patterns,
At least some of the plurality of lens elements are characterized in that the vertical inclination angles of the plurality of lens elements constituting the vertical columns divided into the vertical and horizontal grid pattern are set to different values, and in the exit region located in the upper half of the front surface of the lens, the vertical inclination angles of the lens elements located closer to the lower edge of the exit region are set to larger values .

The type of "vehicle lighting fixture" mentioned above is not particularly limited, and examples include headlamps and fog lamps.

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 entire area of the "front surface of the lens" may be divided into vertical and horizontal grid patterns, or only a portion of the area may be divided into vertical and horizontal grid patterns.

The "plurality of lens elements" are not particularly limited in their specific shape or size, as long as they are formed in a vertical and horizontal grid pattern.

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 front surface of the lens is formed with multiple lens elements that control the emission of light arriving from multiple total reflection prism elements, and are divided into vertical and horizontal grid patterns. By appropriately adjusting the orientation of these multiple lens elements, it is easy to form a light distribution pattern with a cutoff line at the upper end.

In this case, at least some of the multiple lens elements are set to have different vertical inclination angles between the multiple lens elements that make up the vertical columns divided into vertical and horizontal grid patterns. This makes it possible to align the positions of the upper edges of the light distribution pattern formed by the light emitted from each of these multiple lens elements, making it easy to form a light distribution pattern with a cutoff line at the upper end.

In this way, the present invention makes it possible to form a light distribution pattern with a clear cutoff line in a vehicle lamp that is configured to irradiate light emitted from a light source toward the front of the lamp via a lens.

In the above configuration, if multiple lens elements with different vertical tilt angles are formed continuously in vertical columns divided into vertical and horizontal grids, it is possible to prevent steps from forming between these multiple lens elements. This makes it possible to prevent upward scattered light from being inadvertently emitted from the stepped areas, making it easy to maintain a clear cut-off line. Furthermore, by configuring the lens so that there are no steps between the multiple lens elements, the front surface of the lens can have a simple design, thereby improving the lens's appearance.

In the above configuration, if the multiple lens elements are configured with different vertical inclination angles and multiple types of lens elements with different horizontal cross-sectional shapes, a light distribution pattern with a clear cutoff line can be formed, and the position of the high-intensity area can be appropriately shifted left and right from the front of the lamp, making it easy to obtain a light distribution that is suitable for vehicle driving.

In the above configuration, if the multiple total reflection prism elements are configured so that an annular concave curved surface centered on the optical axis is formed as an envelope surface, a sufficient amount of light can be obtained even for light emitted from the light source toward the outer edge of the lens.

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 even easier to form a light distribution pattern with a cutoff line using light emitted from the vehicle lamp.

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 Cross-sectional view of line III-III in Figure 1 IV-IV line cross section of Figure 1 3A is a view taken in the direction of the arrow Va in FIG. 3, and FIG. 3B is a view taken in the direction of the arrow Vb in FIG. 3. 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 illustrating a process for forming a part of the low-beam light distribution pattern. FIG. 10 is a diagram illustrating a process for forming another part of the low-beam light distribution pattern. FIG. 4 is a view similar to FIG. 3 showing a first modification of the embodiment; FIG. 6 is a diagram similar to FIG. 5 showing the first modified example. FIG. 6 is a view similar to FIG. 5, illustrating a second modification of the embodiment; FIG. 7 is a view similar to FIG. 6, illustrating the operation of the second 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, with a lamp unit 20 incorporated into a lamp chamber formed by a lamp body 12 and a transparent cover 14 attached to the front end opening. The vehicle lamp 10 forms a low-beam light distribution pattern (described below) using light emitted from the lamp unit 20.

The lamp unit 20 includes a light-emitting element 22 and a lens 30 located 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 light-emitting element 22 is supported on the lamp body 12 via a substrate 24, and the lens 30 is supported on the lamp body 12 via a mounting structure (not shown).

Next, the specific configuration of the lighting unit 20 will be described.

Figure 3 is a cross-sectional view taken along line III-III in Figure 1, and Figure 4 is a cross-sectional view taken along line IV-IV in Figure 1. Also, Figure 5(a) is a view taken in the direction of arrow Va in Figure 3, and Figure 5(b) is a view taken in the direction of arrow Vb in Figure 3.

As shown in Figures 1 to 5, the lens 30 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 Fresnel lens with multiple lens elements 32s arranged concentrically around the optical axis Ax, allowing light emitted from the light-emitting element 22 to enter the lens 30 in a manner that refracts it in a direction closer to the optical axis Ax. Specifically, the rear surface 32b of the central region 32 guides light emitted from the reference position of the light-emitting element 22 in each lens element 32s to the front surface 30a of the lens 30 as parallel light directed toward the front of the lamp.

A plurality of total internal reflection prism elements 34s are formed on the rear surface 34b of the peripheral region 34, arranged concentrically around the optical axis Ax. Each of these total internal reflection prism elements 34s is a Fresnel lens-type total internal reflection prism, and is configured to receive light emitted from the light-emitting element 22 and then totally reflect it toward the front of the lamp. Specifically, each of the total internal reflection prism elements 34s receives 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 4 to 6 mm (for example, a radius of approximately 5 mm) centered on the optical axis Ax.

As shown in Figures 3 and 4, the multiple total reflection prism elements 34s formed on the rear surface 34b of the peripheral region 34 are formed with an annular concave curved surface C (the cross-sectional shape of which is indicated by the two-dot chain line in the figure) centered on the optical axis Ax as an envelope surface.

In this case, on the rear surface 34b of the peripheral region 34, the pitch of the multiple total reflection prism elements 34s and the curvature of the annular concave curved surface C are set so that the light emitted from the light emitting element 22 is incident on each of the multiple total reflection prism elements 34s approximately evenly.

As a result, the total reflection prism elements 34s located closer to the outer edge of the rear surface 34b of the peripheral region 34 have a larger cross-sectional shape than the total reflection prism elements 34s located closer to the inner edge.

As shown in Figures 1 to 5, 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 diffuse the light in the left-right direction, emitting it toward the front of the lamp.

The multiple lens elements 30s1 that make up the emission region 30a1 are divided into vertical and horizontal grid-like columns, with the vertical inclination angles set to different values. Specifically, each of the multiple lens elements 30s1 is formed to extend obliquely downward from its upper edge to its lower edge, with the inclination angle with respect to a vertical plane perpendicular to the optical axis Ax set to a larger value for the lens element 30s1 located closer to the lower edge of the emission region 30a1. Furthermore, the left-right curvature of each of the multiple lens elements 30s1 is set to a larger value for the lens element 30s1 located closer to the lower edge of the emission region 30a1.

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 peripheral 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 stripes, each of which is assigned a convex curved lens element 30s5. However, each lens element 30s5 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 slightly downward and then diffuse the light significantly to the left, emitting it toward the front of the lamp.

As shown in Figures 3 and 4, the central region 32 of the lens 30 has a generally constant thickness of approximately 3 to 4 mm, but the peripheral region 34 is thinner than the central region 32 in its middle part, and is approximately 5 to 6 mm thick at its outer edge.

Figure 6 is a perspective view of the low-beam light distribution pattern PL formed on a virtual vertical screen positioned 25 m in front of the vehicle lamp 10 by light emitted from the lamp.

The low beam light distribution pattern PL 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, 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 H-V, and inclined portion CL3 extends diagonally from elbow point E to the upper left at an inclination angle of 15° relative to the horizontal. In this low beam light distribution pattern PL, a high luminous intensity region HZ is formed near the lower left of elbow point E.

The low beam light distribution pattern PL is formed as a composite light distribution pattern by superimposing five light distribution patterns P1, P2, P3, P4, and P5.

Light distribution pattern P1 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 extends widely in the left-right direction with a relatively large vertical width below line H-H. This light distribution pattern P1 forms a wide diffusion area of the low beam light distribution pattern PL. In this regard, light distribution pattern P1 itself also forms a high luminous intensity area HZ1 near the bottom of elbow point E to reinforce the brightness of the high luminous intensity area HZ. The process of forming this light distribution pattern P1 will be described later.

Light distribution pattern P2 is a light distribution pattern formed by light emitted from emission area 30a2 on the front surface 30a of lens 30, 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 P2 forms the lower cutoff line CL1 of the low-beam light distribution pattern PL.

This type of light distribution pattern P2 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 small, and therefore 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 P3 is a light distribution pattern formed by light emitted from the emission area 30a3 on the front surface 30a of lens 30, and 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 P3 forms the inclined portion CL3 of the low-beam light distribution pattern PL and the right end of the upper cutoff line CL2. The process of forming this light distribution pattern P3 will be described later.

Light distribution pattern P4 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 P4 is designed to form the upper cutoff line CL2 of low beam light distribution pattern PL with its upper edge. At this time, this light distribution pattern P4 is formed so that its right end overlaps with light distribution pattern P3, smoothly connecting them.

The reason why such a light distribution pattern P4 is formed is that, as with light distribution pattern P2, 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 small, and therefore 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 P5 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, spanning light distribution pattern P4 and light distribution pattern P1, with its right end overlapping light distribution pattern P3.

Figure 7(a) shows only the light distribution pattern P1 extracted from the low beam light distribution pattern PL.

As shown in Figure 7(a), the light distribution pattern P1 is formed as a horizontally elongated light distribution pattern with a relatively large vertical width that extends widely in the left-right direction around the V-V line, with the position of its upper edge roughly coinciding with the lower cutoff line CL1. Furthermore, at the upper end of this light distribution pattern P1, a horizontally elongated high-luminance region HZ1 is formed with the V-V line as its center, with the position of its upper edge roughly coinciding with the lower cutoff line CL1.

Figure 7(b) is a diagram illustrating the process of forming the light distribution pattern P1.

In Figure 7(b), light distribution pattern P1 is shown as a composite light distribution pattern of three light distribution patterns P1A, P1B, and P1C of different sizes.

Of the three light distribution patterns P1A to P1C, the largest light distribution pattern P1A is a light distribution pattern formed by light emitted from multiple lens elements 30s1 located in the lower region of the emission region 30a1, the smallest light distribution pattern P1C is a light distribution pattern formed by light emitted from multiple lens elements 30s1 located in the upper region of the emission region 30a1, and the medium-sized light distribution pattern P1B is a light distribution pattern formed by light emitted from multiple lens elements 30s1 located in the middle region of the emission region 30a1 in the vertical direction.

The upper edges of the three light distribution patterns P1A-P1C are positioned approximately the same. This is because the inclination angle of each of the multiple lens elements 30s1 relative to a vertical plane perpendicular to the optical axis Ax is set to a larger value for the lens element 30s1 located closer to the lower edge of the emission region 30a1.

The magnitude of the left-right diffusion angle of each of the three light distribution patterns P1A to P1C is set by the magnitude of the left-right curvature of each of the multiple lens elements 30s1.

On the other hand, the light distribution pattern P1o shown by the dashed line in Figure 7(b) is a light distribution pattern that would be formed if the multiple lens elements 30s1 that make up the emission area 30a1 were configured to emit light from the light-emitting elements 22 that reaches the rear surfaces 32b, 34b of the lens 30 as parallel light without deflecting it downward.

In Figure 7(b), the light distribution pattern P1o is shown as a composite light distribution pattern of three light distribution patterns P1oA, P1oB, and P1oC of different sizes, corresponding to the light distribution pattern P1.

The three light distribution patterns P1oA to P1oC are formed in multiple layers with their upper ends straddling the H-H line in the vertical direction, and the positions of their upper edges are shifted downward in the order of light distribution patterns P1oA, P1oB, and P1oC.

In addition, the light distribution pattern P1' shown by the two-dot chain line in Figure 7(b) is a light distribution pattern that would be formed if the inclination angle of each of the multiple lens elements 30s1 relative to a vertical plane perpendicular to the optical axis Ax were standardized to the inclination angle of the lens element 30s1 located at the lower edge of the emission region 30a1.

In Figure 7(b), light distribution pattern P1' is also shown as a composite light distribution pattern of three light distribution patterns P1A', P1B', and P1C' of different sizes, corresponding to light distribution pattern P1.

The three light distribution patterns P1A' to P1C' are obtained by simply shifting the three light distribution patterns P1oA to P1oC downward by the same angle θa'.

In contrast, of the three light distribution patterns P1A to P1C, light distribution pattern P1A is obtained by translating light distribution pattern P1oA downward by angle θa (θa = θa'), light distribution pattern P1B is obtained by translating light distribution pattern P1oB downward by angle θb (θb < θa), and light distribution pattern P1C is obtained by translating light distribution pattern P1oC downward by angle θc (θc < θb).

As a result, the upper edges of the three light distribution patterns P1A to P1C of the light distribution pattern P1 are positioned approximately the same. As a result, as shown in Figure 7(a), a horizontally elongated high-luminous intensity region HZ1 is formed at the upper end of the light distribution pattern P1.

Figure 8 is a diagram illustrating the process of forming the light distribution pattern P3, showing a perspective view of a portion of the front surface 30a of the lens 30 and a portion of the low-beam light distribution pattern PL.

As shown in Figure 8, the light distribution pattern P3 formed by the 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 to the right end of the upper cutoff line CL2, as described above.

On the other hand, the light distribution pattern P3o shown by the two-dot chain line in Figure 8 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 lower side of inclined portion CL3. The upper edge of this light distribution pattern P3o 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 the lens 30.

In reality, lens element 30s3 is formed in emission region 30a3, so light distribution pattern P3o changes to resemble light distribution pattern P3. 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 as a light distribution pattern P3, which could cause glare.

Next, we will explain the operation 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 element 22 (light source) of the lamp unit 20 through the lens 30 toward the front of the lamp. The rear surface 34b of the peripheral region 34 of the lens 30, which is located around a central region 32 centered on the optical axis Ax extending in the longitudinal direction of the lamp, is formed with a plurality of total reflection prism elements 34s arranged concentrically around the optical axis Ax. The light emitted from the light-emitting element 22 is then totally reflected toward the front of the lamp, allowing the light emitted from the light-emitting element 22 to be used as forward illumination light over a wide area.

In addition, the front surface 30a of the lens 30 is divided into five emission regions 30a1, 30a2, 30a3, 30a4, and 30a5, each of which is formed with multiple lens elements 30s1, 30s2, 30s3, 30s4, and 30s5 that control the emission of light from the light-emitting element 22 that arrives as parallel light from the rear surfaces 32b and 34b of the lens 30, thereby increasing the degree of freedom in light distribution control.

In this case, the multiple lens elements 30s1 that make up the output region 30a1 located in the upper half of the front surface 30a are formed in a vertical and horizontal grid pattern. Therefore, by appropriately adjusting the orientation of these lens elements 30s1, it is easy to form the light distribution pattern P1 with any desired light distribution. Specifically, the lens elements 30s1 located closer to the lower edge of the output region 30a1 have larger inclination angles with respect to a vertical plane perpendicular to the optical axis Ax. This allows the upper edges of the multiple light distribution patterns (see the three light distribution patterns P1A, P1B, and P1C shown in Figure 7(b)) formed by the light emitted from the multiple lens elements 30s1 to be aligned. Therefore, the upper edge of the light distribution pattern P1, which is formed as a composite light distribution pattern of these multiple light distribution patterns, can be aligned along the lower cutoff line CL1 of the low-beam light distribution pattern PL.

As such, according to this embodiment, a vehicle lamp 10 configured to irradiate light emitted from the light-emitting element 22 toward the front of the lamp via the lens 30 can form a low-beam light distribution pattern PL having a clear stepped cutoff line CL.

In this embodiment, the light source of the lamp unit 20 is composed of a light-emitting element 22 arranged with its light-emitting surface 22a facing forward of the lamp, making it easy to form a low-beam light distribution pattern PL having a stepped cutoff line CL using light emitted from the vehicle lamp 10.

Furthermore, in this embodiment, the multiple total reflection prism elements 34s are formed with an annular concave curved surface C centered on the optical axis Ax as the envelope surface, so that a sufficient amount of light can be obtained even with respect to the light emitted from the light-emitting element 22 toward the outer peripheral edge of the lens 30.

In the above embodiment, the multiple lens elements 30s1 constituting the entire area of the exit region 30a1 were described as being set so that the inclination angle with respect to the vertical plane perpendicular to the optical axis Ax becomes larger the closer to the lower edge of the exit region 30a1 the elements are located. However, it is also possible to configure the multiple lens elements 30s1 constituting a portion of the exit region 30a1 (for example, the central region or upper region in the left-right direction) in this manner. Furthermore, in the exit region 30a5, it is also possible to adopt a configuration in which the vertical inclination angles of the multiple lens elements 30s5 constituting vertical columns divided into a vertical and horizontal grid pattern are set to different values.

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 lamp unit 20 was described as being formed in the shape of a Fresnel lens, but other configurations (such as a single convex lens surface) can also be used.

In the above embodiment, the lens 30 of the lamp unit 20 has been described as having a circular outer shape when viewed from the front of the lamp, but it is also possible to adopt a configuration with an outer shape other than this.

In the above embodiment, the lens 30 was described as being an injection-molded product, but other configurations (such as a compression-molded product) 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 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.

First, we will explain the first variant of the above embodiment.

Figure 9 is a view similar to Figure 3, showing the lamp unit 120 of a vehicle lamp according to this modified example. Figure 10 is a view similar to Figure 5, showing the lens 130 of the lamp unit 120.

As shown in Figures 9 and 10, the basic configuration of the lamp unit 120 of this modified example is the same as that of the above embodiment, but the configuration of the front surface 130a of the lens 130 is partially different from that of the above embodiment.

Specifically, the lens 130 of this modified example is configured so that each of the multiple lens elements 130s1 that make up the emission area 130a1 on its front surface 130a extends in the vertical direction like a cylindrical lens.

In other words, in this modified example, multiple lens elements 30s1 that form vertical columns divided into vertical and horizontal grid patterns in the emission region 30a1 of the front surface 30a of the lens 30 in the above embodiment are formed contiguously with one another to form a single lens element 130s1.

In this case, each of the multiple lens elements 130s1 is formed with the same left-to-right width as each of the multiple lens elements 30s1 in the above embodiment, and the vertical tilt angle is set to a different value depending on the vertical position of the lens element 130s1.

Specifically, each of the multiple lens elements 130s1 is formed to extend at an angle from its upper edge to its lower edge toward the front of the lamp, with the angle of inclination relative to a vertical plane perpendicular to the optical axis Ax being set to a larger value the closer the portion is to the lower edge of the emission region 130a1. Furthermore, the left-right curvature of each of the multiple lens elements 130s1 is set to a larger value the closer the portion is to the lower edge of the emission region 130a1.

In this modified example, the light emitted from the emission area 130a1 on the front surface 130a of the lens 130 forms a light distribution pattern similar to that in the above embodiment (i.e., light distribution pattern P1 shown in Figure 7(a)).

In addition, the lens 130 of this modified example has the same configuration as the above embodiment with respect to the other emission areas 30a2 to 30a5 on its front surface 130a, and the same configuration as the above embodiment with respect to the rear surfaces 32b and 34b.

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

Furthermore, by adopting the configuration of this modified example, steps are not formed between the multiple lens elements 30s1 that make up the vertical row in the emission region 30a1, as in the lens 30 of the above embodiment, and it is possible to prevent inadvertent upward scattering of light from these steps. This makes it possible to make the stepped cutoff line CL of the low-beam light distribution pattern PL clearer.

Furthermore, by adopting the configuration of this modified example, the front surface 130a of the lens 130 can have a simpler design than in the above embodiment, thereby improving the appearance of the lens 130.

When a configuration is adopted in which each of the multiple lens elements 130s1 extends vertically like a cylindrical lens, as in this modified example, the emission region 130a1 has a rearward-inclined surface shape as shown in Figure 9. However, since the rear surface 34b of the peripheral region 34 of the lens 130 is formed with multiple total reflection prism elements 34s having an annular concave curved surface C centered on the optical axis Ax as an envelope surface, it is possible to prevent the thickness of the lens 130 from becoming excessively thin at its upper end.

In the first variant described above, the multiple lens elements 130s1 that make up the entire area of the exit area 130a1 are described as having a larger inclination angle with respect to the vertical plane perpendicular to the optical axis Ax as they approach the lower edge. However, it is also possible to configure the multiple lens elements 130s1 that make up a portion of the exit area 130a1 (for example, the central area in the left-right direction) to have this setting. Furthermore, it is also possible to adopt a configuration in which multiple lens elements 30s5 that make up vertical columns divided into vertical and horizontal grid patterns are continuously formed in the exit area 30a5.

Next, we will explain a second variant of the above embodiment.

Figure 11 is a diagram similar to Figure 5, showing the lens 230 in the lamp unit of a vehicle lamp according to this modified example.

As shown in Figure 11, the basic configuration of the lens 230 in this modified example is the same as that in the above embodiment, but the configuration of the emission area 230a1 on its front surface 230a is partially different from that in the above embodiment.

That is, the configuration of the multiple lens elements 230s1B that make up the upper region 230a1B of the emission region 230a1 on the front surface 230a of the lens 230 in this modified example differs from that in the above embodiment.

Specifically, each of the multiple lens elements 230s1B is configured to deflect the light from the light-emitting element 22 that reaches the rear surfaces 32b, 34b of the lens 230 as parallel light slightly downward and then emit it toward the front of the lamp in a manner that diffuses the light more to the left than to the right.

The configuration of the multiple lens elements 230s1A that make up the general region 230a1A other than the upper region 230a1B in the emission region 230a1 is the same as in the above embodiment.

Figure 12 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.

Like the low beam light distribution pattern PL in the above embodiment, the low beam light distribution pattern PL-2 is formed as a composite light distribution pattern formed by superimposing five light distribution patterns P1-2, P2, P3, P4, and P5, but the position of the high luminous intensity region HZ1-2 in the light distribution pattern P1-2 is shifted to the left compared to the high luminous intensity region HZ1 in the light distribution pattern P1 in the above embodiment. This is because the multiple lens elements 230s1B that make up the upper region 230a1B of the emission region 230a1 are configured to emit light from the light-emitting elements 22 toward the front of the lamp in a manner that diffuses the light more to the left than to the right.

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

Furthermore, by adopting the configuration of this modified example, the high-intensity area HZ-2 of the low-beam light distribution pattern PL-2 can be formed closer to the shoulder of the road on the vehicle's own lane side than in the above embodiment, thereby achieving a light distribution that is even more suitable for vehicle driving.

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 Lamp unit 22 Light-emitting element (light source)
22a Light-emitting surface 24 Substrate 30, 130, 230 Lens 30a, 130a, 230a Front surface 30a1, 30a2, 30a3, 30a4, 30a5, 130a1, 230a1 Emission region 30s1, 30s2, 30s3, 30s4, 30s5, 130s1, 230s1A, 230s1B Lens element 30s3A Right half portion 30s3B Left half portion 32 Central region 32b, 34b Rear surface 32s Lens element 34 Peripheral region 34s Total reflection prism element 230a1A General region 230a1B Upper region Ax Optical axis C Annular concave curved surface CL Stepped cutoff line CL1 Lower cutoff line CL2 Upper cutoff line CL3 Inclined section E Elbow point HZ, HZ1, HZ-2, HZ1-2 High luminous intensity area PL, PL-2 Light distribution pattern for low beam P1, P1A, P1B, P1C, P1-2, P2, P3, P4, P5 Light distribution pattern θa, θb, θc Angle

Claims (5)

A vehicle lamp including a light source and a lens, the vehicle lamp being configured to form a light distribution pattern having a cutoff line by irradiating light emitted from the light source toward a front side 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,
a plurality of lens elements for controlling the emission of light arriving from the plurality of total reflection prism elements are formed on the front surface of the lens in a state where they are divided into vertical and horizontal grid patterns,
a vehicular lamp characterized in that at least some of the plurality of lens elements are set to have vertical inclination angles that differ from one another among the plurality of lens elements constituting the vertical columns divided into the vertical and horizontal grid pattern, and in that in an exit region located in the upper half of the front surface of the lens, the vertical inclination angles of the lens elements located closer to the lower edge of the exit region are set to larger values . The vehicle lamp according to claim 1, characterized in that, in the vertical and horizontal grid-like vertical columns, the lens elements having different vertical inclination angles are formed contiguously with one another. The vehicle lamp according to claim 1, characterized in that the plurality of lens elements having different vertical inclination angles include a plurality of types of lens elements having different horizontal cross-sectional shapes. A vehicle lamp according to any one of claims 1 to 3, characterized in that the plurality of total reflection prism elements are formed with an annular concave curved surface centered on the optical axis as an envelope surface. 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.