JP2024049455A - Vehicle lighting fixtures - Google Patents

Abstract

[Problem] To provide a vehicle lamp having an improved design of a projection lens in a lamp unit in which a plurality of light source units with different configurations are configured to correspond to one projection lens. [Solution] The lamp unit includes low beam light source units 1, 2, a high beam light source unit 3, and a projection lens 4 that projects light from each light source unit to form a required light distribution, and the projection lens 4 is integrally formed with low beam lens sections 41, 42 that project light from the low beam light source units 1, 2 to form a low beam light distribution, and a high beam lens section 43 that projects light from the high beam light source unit 3 to form a high beam light distribution. The front surface of the projection lens 4 is formed of a uniform curved surface or flat surface, and at least one of the lens sections 41, 42, 43 on the rear surface of the projection lens 4 is formed of a different curved surface. [Selected Figure] Figure 2

Description

The present invention relates to a vehicle lamp suitable for mounting on vehicles such as automobiles.

In order to simplify the structure of vehicle lighting fixtures, particularly automobile headlamps, lamp units have been proposed that integrate the projection lenses of multiple light source units, including low beam light source units and high beam light source units. For example, in Patent Document 1, a low beam light source unit and a high beam light source unit are arranged to correspond to one projection lens, and light emitted from each light source unit is projected by the one projection lens to form the required low beam light distribution and high beam light distribution, respectively. In Patent Document 2, three low beam light source units are arranged to correspond to one projection lens.

International Publication No. 2021-261559 International Publication No. 2013-183240

In this way, in a lighting lamp unit that projects low-beam and high-beam light distributions with a single projection lens, the appearance when the projection lens is observed from the front side, i.e., design, becomes an issue. That is, on a light distribution characteristic diagram, the low-beam light distribution illuminates the area below the horizon, and the high-beam light distribution illuminates the area above the horizon, so the lens shapes for realizing each light distribution are different. That is, the lens shapes of the lens part for forming the low-beam light distribution and the lens part for forming the high-beam light distribution, which are integrally formed with the projection lens, are different. In the projection lens of Patent Document 1, the shape of the front surface of the lens part corresponding to the high-beam light source unit is different from the lens part corresponding to the low-beam light source unit.

In addition, even in an illumination lamp unit equipped with multiple light source units that are configured with separate light source units for low-beam light distribution, such as light distribution that illuminates a central area and light distribution that illuminates a peripheral area, the lens shapes of the lens parts for realizing light distribution in each low-beam light source unit are different. In the projection lens of Patent Document 2, the shape of the front surface of the lens parts corresponding to some of the low-beam light source units is different from that of the other lens parts.

When multiple different lens shapes, usually convex spherical or curved surfaces, are formed on the front surface of a single projection lens, when the projection lens is observed from the front side, the multiple different lens shapes that appear on the front surface detract from the appearance of the lighting lamp unit, resulting in a decrease in design quality.

The object of the present invention is to provide a vehicle lamp that enhances the design of the projection lens in a lamp unit in which multiple light source units, particularly multiple light source units with different configurations, are configured to correspond to one projection lens.

The vehicle lamp of the present invention includes a plurality of low beam light source units and a projection lens that projects light from the plurality of low beam light source units forward to form a required light distribution. The projection lens is integrally formed with a plurality of lens portions that project light from the plurality of low beam light source units to form different light distributions, and the front surface of the projection lens is formed of a uniform curved surface or flat surface, and at least one of the lens portions of the rear surface of the projection lens is formed of a different curved surface. For example, the front surface of the projection lens is a curved surface that is curved in both the vertical and horizontal directions. In this case, it is preferable that the vertical cross section of the front surface of the projection lens is an arc surface with the required curvature.

In a preferred embodiment of the present invention, the low beam light source unit includes a concentrating low beam light source unit that illuminates a central area including a hot zone of the low beam light distribution, and a diffuse low beam light source unit that illuminates a wider area than the central area, and the lens portion of the concentrating low beam light source unit is configured as a lens having refractive power in the vertical and horizontal directions, and the lens portion of the diffuse low beam light source unit is configured as a lens having refractive power in the vertical direction but not in the horizontal direction.

The vehicle lamp of the present invention includes a low beam light source unit, a high beam light source unit, and a projection lens that projects the light of each light source unit to form a desired light distribution. The projection lens is integrally formed with a low beam lens portion that projects the light of the low beam light source unit to form a low beam distribution, and a high beam lens portion that projects the light of the high beam light source unit to form a high beam distribution. The front surface of the projection lens is formed of a uniform curved surface or flat surface, and at least one of the lens portions of the projection lens is formed of a different curved surface.

In a preferred embodiment of the present invention, the low beam light source unit includes a concentrating low beam light source unit that illuminates a central area including a hot zone of the low beam light distribution, and a diffuse low beam light source unit that illuminates a wide area wider than the central area, the lens portion of the concentrating low beam light source unit is configured as a lens having refractive power in the vertical and horizontal directions, the lens portion of the diffuse low beam light source unit is configured as a lens having refractive power in the vertical direction but not in the horizontal direction, and the high beam lens portion is configured as a lens having refractive power in the vertical and horizontal directions.

According to the present invention, when a lamp unit is constructed with light source units of different configurations corresponding to one projection lens, the front surface of the projection lens is constructed as a uniform curved or flat surface, resulting in a vehicle lamp with improved design.

1 is a schematic perspective view of an automobile equipped with a vehicle lamp according to an embodiment, and FIG. FIG. 2 is a schematic exploded perspective view of the illumination lamp unit according to the first embodiment. FIG. 2 is a schematic plan view of the illumination lamp unit according to the first embodiment. 4 is a cross-sectional view and light distribution diagram of a concentrated Lo light source unit. 4 is a cross-sectional view and light distribution diagram of a diffused Lo light source unit. FIG. FIG. 4 is a schematic diagram illustrating the light distribution of a Hi light source unit. FIG. Schematic diagram illustrating suppression of coma aberration. Schematic diagram explaining glare caused by coma aberration. FIG. 11 is a schematic exploded perspective view of an illumination lamp unit according to a second embodiment. FIG. 11 is an enlarged perspective view of a portion of the Hi light source unit according to the second embodiment. FIG. 11 is a schematic exploded perspective view of an illumination lamp unit according to a third embodiment. FIG. 11 is a schematic plan view of an illumination lamp unit according to a third embodiment. Cross-sectional view and light distribution diagram of a Hi light source unit with Bi light distribution control.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1(a) is a schematic perspective view of an automobile CAR equipped with left and right headlamps L-HL, R-HL applied as the vehicle lamp of the present invention. The left and right headlamps L-HL, R-HL are symmetrical except for some configurations, so the following description will mainly focus on the right headlamp R-HL, but it may also be simply called headlamp HL. The right headlamp R-HL is disposed at the right front part of the body of the automobile CAR, and is configured as a composite headlamp in which an illumination lamp unit LLU and an indication lamp unit ILU are disposed within a lamp housing 100 attached to the body. In the following description, the longitudinal direction basically refers to the longitudinal direction of the automobile CAR, and the lateral direction refers to the width direction of the automobile CAR.

Figure 1(b) is a schematic perspective view of a partially exploded right headlamp R-HL. The lamp housing 100 is composed of a lamp body 101 with an opening extending from the front to the side of the vehicle, and a translucent outer cover 102 attached to cover the opening of the lamp body 101. This outer cover 102 is also called a translucent cover or outer lens, and is composed of a so-called plain lens made of colorless translucent resin or the like, and its surface is formed into a somewhat curved surface following the curved shape of the right front part of the body of the automobile CAR.

An illumination lamp unit LLU is disposed at the bottom of this lamp housing 100, and an indication lamp unit ILU is disposed above it. When viewed from the front side, the illumination lamp unit LLU has a light-emitting surface that is shaped like a horizontally long rectangle with its long side facing in the vehicle width direction. The indication lamp unit ILU has a light-emitting surface that is shaped like a long, thin strip that extends in the vehicle width direction above the illumination lamp unit 1.

The lighting lamp unit LLU has multiple embodiments, the details of which will be described later, and a low beam (hereinafter, Lo) light source unit and a high beam (hereinafter, Hi) light source unit are assembled to correspond to one projection lens. When the Lo light source unit emits light, it provides illumination with a specified Lo light distribution, and when the Hi light source unit emits light, it provides illumination with a Hi light distribution, in this case ADB (Adaptive Driving Beam)-Hi light distribution.

The indication lamp unit ILU is configured here as a lamp unit that functions as a CL (clearance lamp) or DRL (daytime running lamp) that emits white light to indicate the presence of the vehicle. This indication lamp unit ILU is not particularly relevant to the present invention, so a detailed description will be omitted, but it is equipped with a strip-shaped light guide that extends in the vehicle width direction along the upper edge of the illumination lamp unit LLU, and a white LED that emits white light. When the white LED emits light, the emitted white light passes through the light guide and is emitted to light up as the CL or DRL.

Alternatively, the indicator lamp unit ILU may be configured with a number of white LEDs arranged in the vehicle width direction and a projection lens that is elongated in the vehicle width direction and disposed in front of these LEDs. In this configuration, when the white LEDs emit light, the emitted white light passes through the projection lens and is lit as CL or DRL. Note that this indicator lamp unit ILU may further include an amber LED that emits amber light, in which case the indicator lamp unit ILU is also configured as a TSL (turn signal lamp) that has a signal lamp function.

(Embodiment 1)
Fig. 2 is a partially exploded perspective view of the first embodiment of the illumination lamp unit LLU in the right headlamp R-HL described above, and Fig. 3 is a schematic plan sectional view. This illumination lamp unit LLU is provided with two Lo light source units, i.e., a first Lo light source unit 1 and a second Lo light source unit 2, and one Hi light source unit 3, for one projection lens 4, and each of the light source units 1, 2, and 3 share the single projection lens 4 to form a projector-type lamp.

The two Lo light source units 1, 2 are arranged on the outside in the vehicle width direction, and the one Hi light source unit 3 is arranged on the inside in the vehicle width direction. As described below, the first Lo light source unit 1 is configured as a concentrated Lo light source unit that provides concentrated illumination of the central area of light distribution, i.e., the area near the intersection of the horizontal line H and the vertical line V (hereinafter referred to as the HV point), which serves as the reference for light distribution when illuminating the area in front of the vehicle. The second Lo light source unit 2 is configured as a diffuse Lo light source unit that provides illumination at a relatively low illuminance over a wide area including this concentrated area.

Referring also to the vertical cross-sectional view of FIG. 4A(a), the first Lo light source unit, i.e., the concentrated Lo light source unit 1, includes a white LED 11 as a light source and a reflector 12 that reflects the white light emitted from the white LED 11 forward. The white LED 11 is a chip-type LED that emits white light, and is mounted on a unit body 13 with its light-emitting surface facing vertically upward. The unit body 13 is configured as, for example, a heat sink, and the white LED 11 is mounted on its upper surface via a required attachment, and power for light emission is supplied through wiring (not shown).

The reflector 12 is configured as a concave reflecting mirror based on an ellipsoid of revolution, and the white LED 11 is disposed at its first focal point. In reality, the reflector 12 is shaped so that the flatness of the ellipse gradually decreases from a vertical cross section including the major axis of the ellipse to a horizontal cross section. The front edge of the upper surface of the unit body 13 is configured as a shade 14, and is a planar shape that is curved concavely toward the front.

The second Lo light source unit, i.e., the diffuse Lo light source unit 2, has the same basic configuration as the concentrated Lo light source unit 1, with reference to the longitudinal cross-sectional view of FIG. 4B(a). That is, it has a white LED 21 as a light source and a reflector 22 that reflects the white light emitted from the white LED 21 forward. The white LED 21 is a chip-type LED that emits white light, and is mounted on the unit body 23 with its light-emitting surface facing vertically upward. The reflector 22 is configured as a concave reflecting mirror based on an ellipsoid of revolution, and the white LED 21 is disposed at its first focus. The front edge of the upper surface of the unit body 23 is configured as a shade 24, and contrary to the concentrated Lo light source unit 1, the shade 24 has a planar shape that is curved convexly forward.

As shown in FIG. 3, the Hi light source unit 3 includes a plurality of white LEDs 31 as light sources and a correction lens 32 that converges the light emitted from the white LEDs to some extent. The plurality of white LEDs 31 are composed of ten chip-type LEDs, and are mounted in a line in the vehicle width direction on the front surface of a base wall 34 erected on a unit body 33 with their light-emitting surfaces facing forward. The spacing between adjacent white LEDs in the vehicle width direction of these ten white LEDs 31 gradually increases from the outer side of the vehicle width to the inner side of the vehicle width (towards the center of the vehicle width), and details of this will be described later.

The correction lens 32 is disposed in front of the 10 white LEDs 31, and is configured to receive the white light emitted from the light-emitting surface of each white LED 31. The correction lens 32 is configured as a lens with positive refractive power, a convex lens in this case, and is configured to refract the white light emitted in a divergent state from each white LED 31 in a converging direction and cause it to enter the projection lens 4. The correction lens 32 is assembled integrally with the Hi light source unit 3, but may be configured separately.

On the other hand, the projection lens 4 shown in FIG. 3 is configured as a common projection lens for forming the light distribution of the two Lo light source units 1, 2 and the one Hi light source unit 3, and is disposed across the area on the front side of the two Lo light source units 1, 2 and the one Hi light source unit 3. This projection lens 4 is also called an inner lens, and is configured as the light emitting surface of the illumination lamp unit LLU, and is formed from a translucent material into a shape close to a horizontally long rectangle with its long side facing the vehicle width direction.

Figure 5 is a perspective view of the projection lens 4 seen from the rear side, and the projection lens 4 is divided in the vehicle width direction corresponding to each of the light source units 1, 2, and 3. Hereinafter, each divided part will be referred to as a lens part for convenience. That is, the parts facing the concentrated Lo light source unit 1, the diffused Lo light source unit 2, and the Hi light source unit 3 will be referred to as the concentrated Lo lens part 41, the diffused Lo lens part 42, and the Hi lens part 43, respectively.

The front surface of the projection lens 4 is configured as a uniform curved surface over the entire area. That is, in the vertical cross section, each of the lens portions 41 to 43 is a convex arc surface with the required curvature or a curved surface close to this. On the other hand, in the horizontal cross section, it is formed as a curved surface that extends gently backward from the center of the vehicle toward the outside of the vehicle width, following the curved shape of the outer lens 102 of the lamp housing 100. Therefore, the front surface of the projection lens 4 is configured as a uniform curved surface that is curved in both the vertical and horizontal directions, and when the projection lens 4 is observed from the front side, it is observed as a smooth, continuous surface in which the division of each of the lens portions 41 to 43 cannot be distinguished, and in this respect, the design effect is enhanced.

The shapes of the lens sections 41 to 43 on the rear surface of the projection lens 4 are different. The rear surface of the focusing Lo lens section 41 is formed as a convex spherical or aspherical surface with the required curvature at least in the horizontal direction. It is also formed as a similarly convex curved surface in the vertical direction. Due to these surface shapes, the focusing Lo lens section 41 is configured as a so-called biconvex lens, and is configured as a lens section with positive refractive power that converges light in both the horizontal and vertical directions.

As shown in FIG. 4A(a), the focal point F on the optical axis Lx of the condensing Lo lens section 41 is set to a position near the second focal point of the reflector 12 of the condensing Lo light source unit 1, in other words, a position near the shade 14. Note that the rear surface of the condensing Lo lens section 41 may be a concave surface as long as it is configured as a lens section with positive refractive power in both the horizontal and vertical directions.

The rear surface of the diffusing Lo lens section 42 is formed as a flat surface or a curved surface that generates positive refractive power in the vertical direction. Here, it is formed as a curved surface with a smaller curvature than the front surface, is configured as a so-called meniscus type lens, and is formed to be thinner than the converging Lo lens section 41. On the other hand, in the horizontal direction, as shown in FIG. 3, it is formed as a curved surface parallel to the front surface, and is therefore configured to not generate refractive power as a lens in the horizontal direction. In other words, it is configured as a cylindrical lens curved in the horizontal direction.

The diffused Lo lens section 42 has a specific optical axis Lx and focal point F in the vertical direction, but is planar or linear in the horizontal direction. As shown in FIG. 4B(a), the optical axis Lx and focal point F are set near the second focal point of the reflector 22 of the diffused Lo light source unit 2, i.e., at the position of the shade 24.

The rear surface of the Hi lens section 43, like the focusing Lo lens section 41, is formed as a convex spherical or aspherical surface with the required curvature in the horizontal direction, and is also formed as a similar convex spherical or aspherical surface in the vertical direction. Due to these surface shapes, the Hi lens section 43 is configured as a lens section with positive refractive power that converges light in both the horizontal and vertical directions, and is formed to be the thickest of the three lens sections.

The optical axis Lx of the Hi lens section 43 coincides with the optical axis of the correction lens 32 described above. In addition, the vertical position of this optical axis Lx coincides with the height position of the white LED 41, and the horizontal position coincides with a predetermined position set as the horizontal center position of the white LED 41. The rear surface of this Hi lens section 43 may also be concave, so long as it is configured as a lens section with positive refractive power in both the horizontal and vertical directions.

The three light source units 1, 2, and 3 and the one projection lens 4 configured as above may be configured separately and then independently arranged in the lamp housing 100. Alternatively, the two Lo light sources 1 and 2 may be assembled together and then arranged in the lamp housing 100. Furthermore, the three light source units 1, 2, and 3 may be assembled together and then arranged in the lamp housing 100. In this case, the projection lens 4 may also be configured to be assembled together with the three light source units 1, 2, and 3.

The operation of the lighting lamp unit configured as above will be described. When the headlamp HL is turned on with the Lo beam distribution, the two Lo light source units 1 and 2 are simultaneously in the light emitting state. In the condensed Lo light source unit 1, as shown in FIG. 4A (a), the white light emitted from the white LED 11 is reflected forward by the reflector 12 and converged near the second focal point, and a part of the light is also reflected by the surface of the unit base 13. The white light that is not blocked by the shade 14 is incident on the condenser lens section 41 of the projection lens 4. As shown in FIG. 3, the condenser lens section 41 has refractive power in the vertical and horizontal directions, so the white light is irradiated forward of the vehicle by the condenser lens section 41.

The shade 14 of the light-collecting Lo light source unit 1 is formed in a horizontal step shape as described above, so that as shown in FIG. 4A(b), a cut-off line (hereinafter, CO line) is formed in the projected white light, here a step CO line COL1, and a light-collecting Lo light distribution PLo1 is obtained in which white light is irradiated to the lower area of this step CO line COLc. For example, the step CO line COL1 is lower on the oncoming lane side than on the own lane side, and on the oncoming lane side, it is at an angle position of 0.57 degrees downward with respect to the horizontal line H. In addition, in the light-collecting Lo light source unit 1, the shade 14 is formed in a concave shape toward the front, so that a sharp step CO line COL1 is obtained that eliminates or reduces the lens aberration, especially the field curvature, that occurs in the light-collecting Lo lens section 41. Furthermore, because the white light is irradiated in a concentrated state near the HV point due to the vertical and horizontal refractive power of the focusing Lo lens section 41, the focusing Lo light distribution PLo1 becomes an Lo light distribution that includes a relatively high illuminance area, the so-called hot zone.

In the diffused Lo light source unit 2, as shown in FIG. 4B(a), the white light emitted by the white LED 21 is reflected by the reflector 22 and converged near the second focal point, and the white light that is not blocked by the shade 24 is incident on the diffused Lo lens section 42 of the projection lens 4. The diffused Lo lens section 42 has refractive power in the vertical direction, but does not have refractive power in the horizontal direction, as shown in FIG. 3. In addition, the shade 24 of the diffused Lo light source unit 2 has a convex shape toward the front, which corresponds to the horizontally curved shape of the diffused Lo lens section 42, so that a horizontal CO line COL2 that is a straight line extending horizontally or a horizontal CO line close to this is formed, as shown in FIG. 4B(b). This horizontal CO line COL2 is at the same angle position as the oncoming lane side of the stepped CO line COL1 described above, that is, at an angle position of 0.57 degrees downward from the horizontal line H.

White light is then irradiated onto the area below this horizontal CO line COL2, forming a diffuse Lo light distribution PLo2. Because the diffuse Lo lens section 42 has no refractive power in the horizontal direction, the white light is diverged toward a wide angle in the horizontal direction and is irradiated onto a wide area in the left-right direction. In addition, because the white light is irradiated onto a wider area than the Lo light distribution PLo1, the light distribution has a relatively low illuminance. Note that in Figures 4A and 4B, the area illuminated with white light is indicated by dotted lines.

The Lo light distributions PLo1 and PLo2 produced by the concentrated Lo light source unit 1 and the diffused Lo light source unit 2 are combined to form a Lo light distribution PLo that illuminates a wide area in the horizontal direction below the stepped CO line COL1L and the horizontal CO line COL2L and has a hot zone of high illuminance in the straight-ahead direction of the car, i.e., near the HV point. This Lo light distribution is not shown in the figure, but it is a combination of the light distributions in Figures 4A(b) and 4B(b).

When the headlamp HL is turned on with the Hi beam light distribution, the white LED 31 of the Hi light source unit 3 emits light at the same time as the two Lo light source units 1 and 2 emit light. The white light of each emitted white LED 31 is incident on the correction lens 32, and after passing through this correction lens 32, is incident on the Hi lens portion 43 of the projection lens 4. Since the Hi lens portion 43 has refractive power in the vertical and horizontal directions, the white light of each white LED 31 is projected forward of the car while being diverged in the vertical and horizontal directions, respectively.

Figure 6 is a schematic diagram for explaining the light distribution operation in the Hi light source unit 3. The ten white LEDs 31 [31(1) to 31(10)] are arranged in the horizontal direction, and the white light of each white LED 31 is projected by the projection lens 4 to obtain a light distribution in which the projection patterns of each white light are arranged in the horizontal direction. In this embodiment 1, the ten white LEDs 31 are arranged more densely in the horizontal direction on the white LED 31(1) side closer to the optical axis Lx than the white LED 31(10) further away from the optical axis Lx. In other words, the spacing between the white LEDs 31 gradually increases as they move away from the optical axis Lx. Note that the pointillism of the illumination pattern is omitted here.

In such an arrangement of 10 white LEDs 31, the white light from the white LED 31 (10) disposed away from the optical axis Lx has a larger angle of incidence with respect to the optical axis Lx than the white light from the white LED 31 (1) closer to the optical axis Lx. The horizontal expansion width of this white light is increased by the lens aberration in the Hi lens section 43. Therefore, due to this increase in the horizontal expansion width, both sides of the projection patterns PAHi (10) of adjacent white light from the white LEDs 31 disposed away from the optical axis Lx overlap each other, as shown in FIG. 6.

As a result, as shown in FIG. 7(a), the white light of the 10 white LEDs 31 is projected as a horizontally aligned projection pattern above and including the horizontal line H. Since the projection patterns PAHi(1) to PAHi(10) of the projected white LEDs 31 overlap each other on both sides in the horizontal direction, each projection pattern is a continuous light distribution in the horizontal direction, and this light distribution is the so-called Hi-added light distribution PAHi. Although not shown and described, in the Hi light source unit of the left headlamp L-HL, a Hi-added light distribution PAHi that is symmetrical to this is formed. Therefore, the Hi light distribution PHi shown in FIG. 7(b) is formed by combining the Lo light distributions PLo1 and PLo2 with the Hi-added light distributions PAHi on the left and right above them.

In addition, in this configuration, the 10 white LEDs 31 are densely arranged in the horizontal direction on the side of the white LED 31(1) closer to the optical axis Lx, so that the illuminance of the projected Hi-added light distribution PAHi is higher on the side closer to the optical axis Lx than on the side farther horizontally from the optical axis Lx. As a result, when the Hi-added light distribution PAHi is combined with the Lo light distribution PLo, a Hi light distribution PHi is obtained in which the illuminance of the area adjacent to the hot zone of the Lo light distribution PLo is higher than the surrounding area.

As mentioned above, the Hi light source units 31 of the left and right headlamps are symmetrical, and the arrangement of the 10 white LEDs 31 in each is also symmetrical. Therefore, by combining the Hi additional light distribution PAHi from each Hi light source unit 31 of the left and right headlamps, the illuminance on the side closer to the optical axis is further increased, and at the same time, a Hi light distribution PHi is obtained that illuminates a wide area to the left and right in the horizontal direction centered on the optical axis Lx.

In this Hi light source unit 3, the 10 white LEDs 31 are selectively turned on or off during ADB light distribution control. Therefore, when some of the white LEDs are turned off during Hi light distribution, the area of the projection pattern of these white LEDs is formed as a light-blocking area. Therefore, when an oncoming vehicle or the like is present, the white LEDs 31 are selectively turned off so that the area where the oncoming vehicle is present becomes a light-blocking area, thereby realizing ADB light distribution control that prevents glare for the oncoming vehicle.

The white light from the white LED 31, which is positioned away from the optical axis Lx, is projected with a larger width of light distribution by utilizing the lens aberration, or so-called imaging blur, in the Hi lens section 43, but the undesirable effects of this lens aberration cannot be ignored. In other words, when the angle of incidence of the white light with respect to the optical axis increases, coma aberration, which is one type of lens aberration, becomes prominent, and this coma aberration causes the boundaries of the projection patterns of each white light to become unclear.

If the boundaries of the projection pattern become unclear, there is a risk that the glare prevention effect will be reduced when ADB light distribution control is executed. Figure 9 is a conceptual diagram of the glare prevention effect. When ADB control is executed, as shown in Figure 9(a), for example, the white LED in the area where an oncoming vehicle O is present is turned off, and this area becomes a light-blocking area D, and the glare prevention effect is obtained. However, if coma aberration occurs in the illumination area L adjacent to this light-blocking area D, as shown in Figure 9(b), the boundary of the adjacent illumination area L advances into the light-blocking area D, and the boundary of the light-blocking area D becomes unclear, and there is a risk that the glare prevention effect for oncoming vehicles O will be reduced.

In this embodiment 1, the Hi light source unit 3 is provided with a correction lens 32, and the positive refractive power of this correction lens 32 suppresses the divergence of the white light emitted from the white LED. That is, as shown in FIG. 8, which is a schematic diagram of an enlarged portion of the Hi light source unit 3, the light beam (beam of light) of the white light emitted in a divergent state from the white LED 31 is converged by the correction lens 32 as shown by the dashed line to the solid line in the figure, and an aperture effect is obtained. As a result, the angle of incidence of the white light that passes through the correction lens 32 and enters the Hi lens section 43 of the projection lens 4 is suppressed, and coma aberration is suppressed. In addition, in this embodiment 1, the Hi lens section 43 is a convex spherical surface whose curvature of the rear surface on which the white light enters is larger than the curvature of the front surface, so that coma aberration is also suppressed from this point of view. Therefore, the boundary of the illumination area L when ADB light distribution control is executed is suppressed from becoming unclear, and highly accurate ADB light distribution control can be realized.

As described above, the lighting lamp unit LLU of embodiment 1 is provided with a correction lens 32 in the Hi light source unit 3, which suppresses the coma aberration caused by the Hi lens section 43, sharpens the boundaries of the projection pattern using white light, and improves ADB light distribution control. In addition, the lighting lamp unit LLU of embodiment 1 has a front surface of the projection lens 4 that is uniformly curved, so that the appearance when observed through the outer lens 102 is simple, and the design of the lighting lamp unit LLU can be improved.

(Embodiment 2)
10 is an external view showing a schematic configuration of the illumination lamp unit LLU of the second embodiment, and since only the configuration of the Hi light source unit 3A is different from that of the first embodiment, the description of the other configurations will be omitted. The Hi light source unit 3A of the second embodiment is provided with a correction reflector 35 instead of a correction lens. That is, the correction reflector 35, which is open at the front, is attached to the front surface of the base wall 34 on which the ten white LEDs 31 are mounted so as to surround the white LEDs 31. Then, a part of the white light emitted from each white LED 31 is reflected by the correction reflector 35 and made to enter the Hi lens portion 43 of the projection lens 4.

As shown in the enlarged perspective view of FIG. 11(a), the correction reflector 35 is configured as a rectangular or elliptical frame wall surrounding the 10 white LEDs 31 when viewed from the front. At least the inner surfaces of the left and right frame walls 35a are configured as light reflecting surfaces. Here, the inner surfaces of the upper, lower, left and right frame walls are configured as light reflecting surfaces. Here, the inner surface of each frame wall 35a is formed as a light reflecting surface that is a plane, a paraboloid, or a concave shape similar thereto, with an inclination in the vertical and horizontal directions.

Therefore, as shown in FIG. 11(b), of the light emitted from each white LED 31, the white light emitted at a relatively large angle with respect to the optical axis Lx of the Hi lens section 43 is deflected toward the optical axis Lx by the correction reflector 35 and enters the Hi lens section 43. In particular, the light from the left and right white LEDs 31 that are farther away from the optical axis Lx is deflected toward the optical axis Lx by the left and right frame walls 35a. As a result, although the degree of improvement is lower compared to embodiment 1, the coma aberration that occurs in the Hi lens section 43 is suppressed, and the accuracy of the ADB light distribution control is improved.

(Embodiment 3)
FIG. 12 is an external view showing a schematic configuration of the illumination lamp unit LLU of the third embodiment, and FIG. 13 is a schematic plan view thereof. This illumination lamp unit LLU has the same Lo light source units 1 and 2 as the first embodiment, but has a different configuration of the Hi light source unit 3B and the projection lens 4B. The Hi light source unit 3B of the fourth embodiment does not perform ADB light distribution control, but simply projects an additional Hi light distribution formed on the upper side of the Lo light distribution, and is a light source unit used in an illumination lamp unit also called Bi (bifunction) light distribution control. In the third embodiment, it can be said that the Hi light source unit 3 (first Hi light source unit) performing the ADB light distribution control of the first embodiment is replaced with a Hi light source unit 3B (second Hi light source unit) performing Bi light distribution control with a different structure.

The basic configuration of this Hi light source unit 3B is similar to that of the Lo light source units 1 and 2, so a detailed explanation will be omitted, but as shown in the longitudinal cross-sectional structure in FIG. 14(a), it is equipped with a white LED 31 as a light source and a reflector 36 based on an ellipsoid of revolution. Furthermore, it is smaller overall than the Lo light source units 1 and 2, and is further configured differently in that it is equipped with a front mirror 38 formed integrally with the unit body 37 at the lower front side of the reflector 36. In addition, in this embodiment 3, two Hi light source units 3B having approximately the same configuration are arranged side by side in the horizontal direction.

The white LED 31 of each Hi light source unit 3B is composed of a chip-type LED that emits white light, and is mounted on the upper surface of the unit body 37 with its light-emitting surface facing vertically upward, and is supplied with power for light emission. The reflector 36 is configured as a concave reflecting mirror based on an ellipsoid of revolution, and the white LED 31 is disposed at its first focal point. The front mirror 38 is configured as a plane mirror with a light-reflecting surface tilted forward, located near the second focal point, i.e., in front of the second focal point.

The front surface of the projection lens 4 in the third embodiment is the same as in the first embodiment in that it is configured with a uniform curved surface over the entire area. The configurations of the condensing Lo lens section 41 and the diffusing Lo lens section 42 corresponding to the Lo light source units 1 and 2 are also the same as in the first embodiment. On the other hand, the Hi lens section 43B is divided into two corresponding to the two Hi light source units 3B. Each divided Hi lens section 43B is formed to a smaller size compared to the Hi lens section 43 in the first embodiment, but the structure is approximately the same, and the rear surface of the projection lens 4B is formed as a convex spherical or aspherical surface with a required curvature in the horizontal and vertical directions. The two Hi lens sections 43B are arranged side by side in the horizontal direction corresponding to the two Hi light source units 3B, but the optical axis Lx of each Hi lens section 43B is directed in a slightly different direction in the horizontal direction.

The Lo light distribution in the third embodiment is the same as that in the first embodiment. In the Hi light distribution, the two Lo light source units 1 and 2 and the two Hi light source units 3B are simultaneously emitted. As shown in FIG. 14(a), the light emitted from the white LED 31 in each Hi light source unit 3B is reflected forward by the reflector 36, converged near the second focal point, and then enters the Hi lens portion 43B of the projection lens 4. Each white light is refracted in each Hi lens portion 43B and projected as an additional Hi light distribution PAHi on the upper side of the Lo light distribution PLo shown by the dashed line, as shown in FIG. 14(b). Since the optical axes of the two Hi lens portions 43B are slightly different, the additional Hi light distribution PAHi by the two Hi light source units 3B is projected side by side in the horizontal direction. These additional Hi light distributions PAHi can be divided, for example, into the own lane side and the oncoming lane side. Therefore, it is possible to selectively emit light from the two Hi light source units 3B, or to simultaneously emit light from both, forming an additional Hi light distribution PAHi on either the own lane side or the oncoming lane side.

In addition, in this Hi light source unit 3B, a portion of the white light reflected by the reflector 36 is reflected by the front reflector 38 and is transmitted through the Hi lens portion 43B and projected upward. This forms an OHS (overhead sign) light distribution POHi above the additional Hi light distribution PAHi. Although not shown, by making the front reflector 38 a tilting structure that switches between a state in which the white light from the reflector 36 is reflected and a state in which it is not reflected, it becomes possible to form an OHS light distribution as desired.

In the third embodiment, it may be configured with one Hi light source unit 3B. In this case, the required additional Hi light distribution is formed by the one Hi light source unit 3B. In this case, the configuration of the Hi lens portion 43B of the projection lens 4B can be configured substantially similarly to that of the first embodiment, so the projection lens 4 of the first embodiment can be used as is.

In the illumination lamp unit LLU of embodiment 3, the front surface of the projection lens 4B is also configured as a uniform curved surface, so that the appearance when observed through the outer lens 102 of the headlamp HL is simple, and the design of the illumination lamp unit LLU can be improved. In addition, since the illumination lamp unit LLU of embodiment 3 has a different configuration for the Hi light source unit from embodiment 1, it is sufficient to select and apply the Hi light source unit 3 of embodiment 1 or the Hi light source unit 3B of embodiment 3 as necessary. In this case, if the Hi light source unit 3B is configured with one Hi light source unit, there is no need to change the projection lens.

In the above-described embodiments 1 to 3, the configuration and number of the Lo light source units and Hi light source units that make up the illumination lamp unit can be changed as appropriate.

Regarding the configuration of the projection lens in this invention, particularly the configuration of each lens section to obtain Hi and Lo light distributions, various modifications of the lens shape are possible as long as the refractive power required for each lens section, particularly the refractive power in the vertical and horizontal directions, is met. The front surface of the projection lens may also be flat, in which case the rear surface of the projection lens may be formed into a convex curved surface in order to obtain the required refractive power for each lens section.

1. Low beam light source unit (concentrated light source unit)
2. Low beam light source unit (diffuse Lo light source unit)
3 High beam light source unit (Hi light source unit)
3A High beam light source unit (ADB control Hi light source unit)
3B High beam light source unit (Bi control Hi light source unit)
4, 4B Projection lens 11, 21 White LED
12, 22 Reflector 14, 24 Shade 31 White LED
32 Correction lens 33, 36 Reflector 35 Correction reflector 38 Front reflector 41 Condensing Lo lens section 42 Diffusion Lo lens section 43, 43B Hi lens section 100 Lamp housing LLU Illumination lamp unit ILU Indication lamp unit

Claims (8)

A vehicle lamp comprising a plurality of low beam light source units and a projection lens that projects the light of the plurality of low beam light source units forward to form a desired light distribution, the projection lens being formed integrally with a plurality of lens sections that project the light of the plurality of low beam light source units to form different light distributions, the front surface of the projection lens being formed of a uniform curved or flat surface, and the rear surface of the projection lens being formed of at least one of the plurality of lens sections being formed of a different curved surface. The vehicle lamp according to claim 1, wherein the front surface of the projection lens is a curved surface that is curved in both the vertical and horizontal directions. The vehicle lamp according to claim 2, wherein the front surface of the projection lens has a vertical cross section that is an arcuate surface with a required curvature. The vehicle lamp according to claim 1, wherein the low beam light source unit includes a concentrated low beam light source unit that illuminates a central area including a hot zone of the low beam distribution, and a diffuse low beam light source unit that illuminates a wide area wider than the central area, the lens portion of the concentrated low beam light source unit is configured as a lens having refractive power in the vertical and horizontal directions, and the lens portion of the diffuse low beam light source unit is configured as a lens having refractive power in the vertical direction but not in the horizontal direction. A vehicle lamp comprising a low beam light source unit, a high beam light source unit, and a projection lens that projects light from each of the light source units to form a desired light distribution, the projection lens being integrally formed with a low beam lens section that projects light from the low beam light source unit to form a low beam distribution, and a high beam lens section that projects light from the high beam light source unit to form a high beam distribution, the front surface of the projection lens being formed with a uniform curved surface or flat surface, and the rear surface of the projection lens being formed with at least one of the lens sections being formed with a different curved surface. The low beam light source unit includes a concentrated low beam light source unit that illuminates a central area including a hot zone of the low beam distribution, and a diffuse low beam light source unit that illuminates a wide area wider than the central area, the lens portion of the concentrated low beam light source unit is configured as a lens having refractive power in the vertical direction and the horizontal direction, the lens portion of the diffuse low beam light source unit is configured as a lens having refractive power in the vertical direction and no refractive power in the horizontal direction, and the high beam lens portion is configured as a lens having refractive power in the vertical direction and the horizontal direction. Vehicle lamp according to claim 5. A vehicle lamp according to any one of claims 1 to 6, configured as an illumination lamp unit that functions as a headlamp of an automobile. 8. The vehicle lamp according to claim 7, wherein the illumination lamp unit is disposed within a lamp housing of the headlamp, and the projection lens is visible through a translucent outer lens disposed on a front surface of the lamp housing.

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