Vehicle lamp

Abstract

To provide a lighting fixture for a vehicle capable of suppressing brightness difference and unevenness in a light distribution pattern for passing each other even when the light distribution pattern for passing each other is expanded to a lower side.SOLUTION: In the vehicular lamp 10, light L from a light source 11 is made incident on a lens member 12 as parallel light from an incident part 13, reflected by a first reflection surface 17, and projected by an emission part 25 while being partially shielded by a cutoff formation part 18 to form a light distribution pattern LP for passing having a cutoff line CL. The lens member 12 has a second reflection surface 24 for reflecting the light L from the first reflection surface 17 to the vicinity of the cutoff formation part 18, and the first reflection surface 17 is a curved surface based on a paraboloid having a focus set in the vicinity of the cutoff formation part 18. The second reflecting surface 24 has a parallel reflecting surface portion 34 continuous with the cutoff formation part 18, and an inclined reflecting surface portion 35 inclined downward while being continuous with the parallel reflecting surface portion 34 on the first reflecting surface 17 side.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle lamp. [Background technology]

[0002] Some vehicle lamps form a low-passing light distribution pattern having a cutoff line by partially blocking light reflected by a reflector covering a light source with a cutoff forming portion provided on a shade and projecting the light with a projection lens (see, for example, Patent Document 1). This vehicle lamp has an auxiliary reflective surface on the light source side of the cutoff forming portion, and the auxiliary reflective surface has a parallel reflective surface portion on the cutoff forming portion side and an inclined reflective surface portion continuous with the parallel reflective surface portion. This vehicle lamp reflects light from the light source that travels toward the auxiliary reflective surface by the parallel reflective surface portion toward the upper side of the cutoff forming portion and then by the inclined reflective surface portion further upward, thereby forming a low-passing light distribution pattern that efficiently utilizes the light from the light source and expands downward. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6184150 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned vehicle lamp, the reflector has a curved surface based on an ellipse having foci both near the light source and near the cutoff forming portion, thereby concentrating light from the light source near the cutoff forming portion. Therefore, the above-mentioned vehicle lamp projects an image of the light emitting surface of the light source forward, the size of which varies depending on the distance from the light source to the reflecting point of the reflector, and the images of the light emitting surface are superimposed to form a light distribution pattern for passing vehicles. In this conventional vehicle lamp, light for which the image of the light emitting surface becomes large is reflected by the inclined reflecting surface portion and travels above the cutoff forming portion to form the lower portion of the light distribution pattern for passing vehicles, and the brightness difference and unevenness are easily noticeable, which may cause discomfort to occupants.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide a vehicle lamp that can suppress brightness differences and unevenness in a low-beam light distribution pattern even when the low-beam light distribution pattern is expanded downward. [Means for solving the problem]

[0006] The vehicle lamp of the present disclosure comprises a light source and a lens element that guides light from the light source inward and then emits it to form a light distribution pattern for passing vehicles, the lens element having an entrance portion that causes light from the light source to enter as parallel light, a first reflecting surface that reflects the light incident from the entrance portion, a cutoff forming portion that partially blocks light from the first reflecting surface to form a cutoff line in the light distribution pattern for passing vehicles, a second reflecting surface that reflects a portion of the light reflected by the first reflecting surface toward the vicinity of the cutoff forming portion, and an exit portion that emits light that has passed through the vicinity of the cutoff forming portion, the first reflecting surface being a curved surface based on a paraboloid with a focus set near the cutoff forming portion, and the second reflecting surface having a parallel reflecting surface portion that is continuous with the cutoff forming portion and an inclined reflecting surface portion that is continuous with the parallel reflecting surface portion on the first reflecting surface side relative to the parallel reflecting surface portion and is inclined downward. [Effects of the Invention]

[0007] According to the vehicle lamp of the present disclosure, even when the low-beam light distribution pattern is expanded downward, it is possible to suppress the difference in brightness and unevenness in the low-beam light distribution pattern. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an explanatory diagram showing a vehicle lamp according to a first embodiment of the present disclosure; [Figure 2] FIG. 2 is an explanatory diagram showing the vehicle lamp as viewed from diagonally below. [Figure 3] FIG. 2 is an explanatory diagram showing the vehicle lamp as viewed from the bottom and in front. [Figure 4] FIG. 4 is a cross-sectional view of the vehicle lamp taken along line II in FIG. 3. [Figure 5] 2. FIG. 3 is a cross-sectional view of the vehicle lamp taken along line II-II in FIG. [Figure 6] 6 is an explanatory diagram showing an enlarged view of the area surrounded by the dashed line in FIG. 5. FIG. [Figure 7] 3. FIG. 4 is an explanatory diagram showing how light reflected by the lower horizontal reflecting surface portion 32 travels, and corresponds to a cross section taken along line III-III in FIG. [Figure 8] 5 is an explanatory diagram showing how light reflected by the parallel reflecting surface portion 34 and the inclined reflecting surface portion 35 of the upper horizontal reflecting surface portion 31 travels, and corresponds to a cross section similar to that of FIG. [Figure 9] FIG. 10 is an explanatory diagram showing a state in which a low-beam light distribution pattern that is not expanded downward is formed on a screen where a horizontal line and a vertical line intersect at the center position on the projection optical axis. [Figure 10] FIG. 10 is an explanatory diagram showing a state in which a low-beam light distribution pattern with an expanded lower side is formed on a screen where a horizontal line and a vertical line intersect at the center position on the projection optical axis. [Figure 11] 10 is an explanatory diagram showing how light from the first reflecting surface is reflected by the upper horizontal reflecting surface portion, the lower horizontal reflecting surface portion, and the inclined reflecting surface portion in the second reflecting surface serving as a comparative example. FIG. [Figure 12]10 is an explanatory diagram showing how light from the first reflecting surface is reflected by the upper horizontal reflecting surface portion, the lower horizontal reflecting surface portion, and the inclined reflecting surface portion in the second reflecting surface according to the present disclosure. FIG. [Figure 13] 7 is an explanatory diagram similar to FIG. 6, showing another example of a second reflecting surface. DETAILED DESCRIPTION OF THE INVENTION

[0009] A vehicle lamp 10 according to one embodiment of the present disclosure will be described below with reference to the drawings. Note that hatching (diagonal lines) indicating cross sections is omitted in FIGS. 7 and 8 to facilitate understanding of the progression of each light beam. In FIGS. 7 and 8, an example of light L1 is shown as light emitted from the center of the light source 11, collimated at the incident portion 13, and incident thereon, and an example of light L2 is shown as light emitted from the end of the light source 11 and incident thereon. Also, FIG. 9 shows a passing light distribution pattern LP formed when the upper horizontal reflecting surface portion 31 of the second reflecting surface 24 does not have the inclined reflecting surface portion 35. Furthermore, FIG. 12 emphasizes the curved inclined reflecting surface portion 33 to explain the effect of the curved inclined reflecting surface portion 33. [Example]

[0010] A vehicle lamp 10 according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 12. The vehicle lamp 10 according to the first embodiment is used as a headlight device for a vehicle such as an automobile. The headlight device is configured by mounting the vehicle lamp 10 in a lamp chamber formed by a lamp housing, the open front end of which is covered by an outer lens, on each of the left and right sides of the front of the vehicle. The vehicle lamp 10 is mounted in the lamp chamber via a vertical beam axis adjustment mechanism and a horizontal beam axis adjustment mechanism, and appropriately illuminates the area ahead of the vehicle. In the following description, in the vehicle lamp 10, the direction in which the vehicle travels is defined as the longitudinal direction (referred to as Z in the drawings), the vertical direction when the longitudinal direction is aligned with a horizontal plane is defined as the vertical direction (referred to as Y in the drawings), and the direction perpendicular to the longitudinal direction and the vertical direction (horizontal direction) is defined as the width direction (referred to as X in the drawings). In the longitudinal direction, the side that projects each light beam described below is defined as the front side, and in the vertical direction, the side on which two light sources 11 described below are provided is defined as the upper side.

[0011] 1 to 4, the vehicle lamp 10 of the first embodiment includes two light sources 11 and a lens member 12. Each light source 11 and lens member 12 form a low-vehicle light distribution pattern LP (see FIG. 10) that illuminates a lower (nearby) area ahead of the vehicle.

[0012] Each of the two light sources 11 is composed of a light-emitting element such as an LED (Light Emitting Diode). The light sources 11 in the first embodiment are arranged side by side in the width direction and individually face two incident portions 13 (described later) of the lens member 12. Each of the light sources 11 is mounted on a board (not shown) and is turned on by an appropriate supply of power under the control of a lighting control circuit. This board may be common to the two light sources 11, or may be provided for each light source individually. The board may be attached to a heat sink made of an aluminum plate, aluminum die-cast, or resin having appropriate thermal conductivity, thereby dissipating heat generated by each light source 11 to the outside.

[0013] The lens member 12 is an optical lens that guides light L (see Figures 9, 10, etc.) emitted from each light source 11 inward to form a light distribution pattern. The lens member 12 is a molded product made of a transparent resin material, is elongated in the front-to-rear direction, and is configured with appropriate recesses, protrusions, etc. to form each of the sections (reference numerals 13 to 35) described below. This lens member 12 is provided with two entrance sections 13 on the rear side in the front-to-rear direction and on the upper side in the up-down direction. Both entrance sections 13 correspond individually to each light source 11 and are configured identically to each other.

[0014] Each incident portion 13 has a portion facing the corresponding light source 11 that protrudes toward the light source 11, and a center that is recessed toward the opposite side of the light source 11. As shown in FIG. 4 and other figures, the incident portion 13 has an opposing incident surface 14, an annular incident surface 15, and an annular reflecting surface 16. The opposing incident surface 14 is curved convexly toward the light source 11, and the light source 11 is positioned near a focal point (rear focal point) on the rear side (on the light source 11 side). The opposing incident surface 14 causes light emitted from the light source 11 to enter the lens member 12 as parallel light traveling approximately parallel to the axis of the incident portion 13, and the parallel light travels toward a first reflecting surface 17 (described later) (see FIG. 6). Note that this parallel light (parallel light) refers to light that has been collimated by passing through the opposing incident surface 14.

[0015] The annular incident surface 15 is provided in a truncated cone shape surrounding the opposing incident surface 14 while protruding from the opposing incident surface 14 toward the light source 11. This annular incident surface 15 allows light from the light source 11 that does not travel to the opposing incident surface 14 to enter the lens member 12. The annular reflective surface 16 is provided in a truncated cone shape surrounding the annular incident surface 15 and is positioned at a position where light that has entered the lens member 12 from the annular incident surface 15 travels, with the focal point being near the light source 11, taking into account refraction at the annular incident surface 15. The annular reflective surface 16 reflects the light that has entered the annular incident surface 15, causing it to travel as parallel light traveling approximately parallel to the axis of the incident portion 13 toward the first reflective surface 17, which will be described later (see FIGS. 7 and 8). The annular reflective surface 16 may reflect light by total internal reflection, or may reflect light by adhering aluminum, silver, or the like to the annular reflective surface 16 by vapor deposition, coating, or the like.

[0016] First reflecting surface 17 reflects light L emitted from light source 11 and incident through incident portion 13 toward the front-rear direction (see FIGS. 7 and 8). First reflecting surface 17 has an axis parallel or approximately parallel to projection optical axis Lp of lens member 12 and is a free-form surface based on a paraboloid having a focal point near cutoff forming portion 18 provided near focal point f (see FIG. 4) of exit surface 26 (described later) of lens member 12. First reflecting surface 17 reflects collimated light L incident through incident portion 13, causing light L to travel near cutoff forming portion 18 and then toward exit surface 26, i.e., the front-rear direction (see FIGS. 7 and 8). Note that first reflecting surface 17 may be configured to utilize total reflection, to be subjected to a reflection treatment, or in some other manner, as long as it reflects light as described above.

[0017] The cutoff forming portion 18 forms a cutoff line CL (see FIG. 10 , etc.). As shown in FIGS. 5 and 6 , the cutoff forming portion 18 has an upper cutoff forming portion 21 extending in the width direction (horizontal direction), a lower cutoff forming portion 22 extending in the width direction at a position lower than the upper cutoff forming portion 21 in the height direction, and an inclined cutoff forming portion 23 connecting the two horizontal edges. When viewed from above in the vertical direction, the cutoff forming portion 18 of the first embodiment has the upper cutoff forming portion 21 on the left side in the width direction (the right side when viewed from the front in FIGS. 5 and 6 ) and the lower cutoff forming portion 22 on the right side, and the inclined cutoff forming portion 23 is inclined downward from the left side to the right side. In the first embodiment, the cutoff forming portion 18 is curved so that the center in the width direction is positioned at the rearmost position and displaces forward as it moves outward in the width direction, and is shaped to approximate the shape of the focal plane Fp (see FIG. 4 ) of the curved exit surface 26, as described below.

[0018] This cutoff forming portion 18 is located near a focal point f (see FIG. 4) of an exit surface 26, which will be described later. In addition, in the lens member 12, the front side of the cutoff forming portion 18, i.e., the rear side in the front-to-rear direction, is a second reflecting surface 24, which reflects light reflected by the first reflecting surface 17 toward the upper side of the cutoff forming portion 18 (see FIGS. 7 and 8). Therefore, the cutoff forming portion 18 allows light above it to travel, while blocking light below it (toward the second reflecting surface 24). This allows the cutoff forming portion 18 to reflect its own shape in the light reflected by the first reflecting surface 17. The light reflecting the shape of this cutoff forming portion 18 is emitted from the exit portion 25.

[0019] As shown in FIGS. 1 to 5 , etc., exit portion 25 is located at the front end of lens member 12 in the front-rear direction. This exit portion 25 is located forward of cutoff forming portion 18 in the front-rear direction and projects light that reflects the shape of cutoff forming portion 18 forward of the vehicle to form a passing light distribution pattern LP (see FIG. 10 ). This exit portion 25 has exit surface 26 that is a convex surface that protrudes forward in the front-rear direction (optical axis direction). As shown in FIG. 4 , this exit surface 26 has a focal plane Fp (meridional image plane) on the object space side, inside lens member 12 and near cutoff forming portion 18. This focal plane Fp is curved so that the position of the focus f of exit surface 26 is located at the rearmost side in the front-rear direction and displaces forward in the front-rear direction as it moves away from projection optical axis Lp. The exit surface 26 (exit section 25) projects an image formed on a focal plane Fp including the focal point f, inverted vertically and horizontally, onto a screen by irradiating light that reflects the shape of the cutoff forming section 18. The screen is defined as an intersection of a horizontal line H and a vertical line V, with the center position O of irradiation (projection optical axis Lp) as the origin (see FIG. 10, etc.).

[0020] As shown in Figure 6 and other figures, the second reflecting surface 24 is continuous with the cutoff forming portion 18 and extends rearward from the cutoff forming portion 18 in the front-to-rear direction. The second reflecting surface 24 has an upper horizontal reflecting surface portion 31 continuous with the upper cutoff forming portion 21, a lower horizontal reflecting surface portion 32 continuous with the lower cutoff forming portion 22, and an inclined reflecting surface portion 33 continuous with the inclined cutoff forming portion 23. Therefore, the second reflecting surface 24 connects the upper horizontal reflecting surface portion 31 and the lower horizontal reflecting surface portion 32, which extend substantially horizontally at different heights, with the inclined reflecting surface portion 33 that is inclined toward the lower horizontal reflecting surface portion 32, i.e., inclined downward in the width direction as it approaches the lower horizontal reflecting surface portion 32.

[0021] The inclined reflecting surface portion 33 in the first embodiment is elongated and extends rearward in the front-to-rear direction from the cutoff forming portion 18 (the inclined cutoff forming portion 23), and is curved toward the lower horizontal reflecting surface portion 32 as it extends rearward in the front-to-rear direction. As a result, the upper horizontal reflecting surface portion 31 increases in width as it extends rearward in the front-to-rear direction, while the lower horizontal reflecting surface portion 32 decreases in width as it extends rearward in the front-to-rear direction. The inclined reflecting surface portion 33 gradually changes from a state inclined toward the lower horizontal reflecting surface portion 32 in the width direction to a state inclined obliquely toward both the width direction and the front side in the front-to-rear direction. Therefore, the inclined reflecting surface portion 33 has a larger width dimension than a case in which it extends in the front-to-rear direction, even if the dimension in the direction perpendicular to the extending direction (hereinafter referred to as the short dimension) is the same. Here, since the inclined reflecting surface portion 33 connects the upper horizontal reflecting surface portion 31 and the lower horizontal reflecting surface portion 32, which are located at different positions in the vertical direction, the inclination relative to both horizontal surfaces 31, 32 becomes smaller by increasing the dimension in the width direction.

[0022] 4 to 6, the upper horizontal reflective surface portion 31 of the first embodiment has a parallel reflective surface portion 34 and an inclined reflective surface portion 35. The parallel reflective surface portion 34 is located rearward of the upper cutoff forming portion 21 in the front-to-rear direction, and is a surface that is continuous with the upper cutoff forming portion 21 and parallel to the projection optical axis Lp. The inclined reflective surface portion 35 is located rearward of the parallel reflective surface portion 34 in the front-to-rear direction, and is a surface that is continuous with the parallel reflective surface portion 34 and inclined downward toward the rearward side in the front-to-rear direction. As will be described later, the inclined reflective surface portion 35 reflects light from the first reflective surface 17 to form a lower portion LPl (see FIG. 10) of the low-beam light distribution pattern LP. Therefore, the inclined reflective surface portion 35 has an inclination angle with respect to the parallel reflective surface portion 34, i.e., the projection optical axis Lp, so as to appropriately form the lower portion LPl of the low-beam light distribution pattern LP. That is, the size and the inclination angle relative to the parallel reflecting surface portion 34 (projection optical axis Lp) of the inclined reflecting surface portion 35 may be set so as to adjust the amount of light (brightness) passing above the cutoff forming portion 18 and its position according to the size and brightness required for the lower portion LPl of the low-beam light distribution pattern LP, and are not limited to the configuration of embodiment 1.

[0023] Therefore, by providing the inclined reflecting surface portion 35, the second reflecting surface 24 of the first embodiment has a smaller difference in the vertical positions between the upper horizontal reflecting surface portion 31 and the lower horizontal reflecting surface portion 32 as it moves rearward in the front-to-rear direction, and the inclination of the inclined reflecting surface portion 33 also decreases. In addition, as shown in Figure 6 and other figures, the short dimension of the inclined reflecting surface portion 33 of the first embodiment gradually increases from the cutoff forming portion 18 toward the rear in the front-to-rear direction, is largest at the intermediate position in the front-to-rear direction, and gradually decreases from the intermediate position toward the rear. For these reasons, the inclined reflecting surface portion 33 is curved toward the lower horizontal reflecting surface portion 32, and its inclination with respect to both horizontal surfaces 31 and 32 decreases as it moves rearward in the front-to-rear direction.

[0024] Next, we will explain the lighting of the vehicle lamp 10. The vehicle lamp 10 is installed in a lamp chamber in the assembled state in the above-mentioned positional relationship, and a lighting control circuit is connected to the board via a connector or the like. This vehicle lamp 10 supplies power from the lighting control circuit to both light sources 11 mounted on each board, thereby turning both light sources 11 on and off as appropriate.

[0025] As shown in FIGS. 7 and 8 , when both light sources 11 are turned on in the vehicle lamp 10, light L from each light source 11 enters the lens member 12 through the corresponding entrance portion 13. A portion of each light L enters the lens member 12 through the opposing entrance surface 14, and the remainder enters the lens member 12 through the annular entrance surface 15 and is appropriately reflected by the annular reflecting surface 16 to become parallel light and travel toward the first reflecting surface 17. The first reflecting surface 17 reflects each light L from the entrance portion 13, causing it to basically travel toward the vicinity of the cutoff forming portion 18. At this time, a portion of each light L travels toward the second reflecting surface 24, but is reflected by the second reflecting surface 24 and travels toward the vicinity of the cutoff forming portion 18.

[0026] As a result, on a focal plane Fp (see FIG. 4) set near the cutoff forming section 18, light is prevented from traveling below the cutoff forming section 18 in the vertical direction, and light travels above the cutoff forming section 18. As described above, this focal plane Fp includes the focal point f of the exit surface 26 set near the cutoff forming section 18. Therefore, by emitting each light L from the exit surface 26, the light distribution on the focal plane Fp, which has been brightened as described above, is projected forward in the front-to-back direction while slightly blurring it. On the focal plane Fp, the area near the cutoff forming section 18 is brightest, and the area becomes darker as it moves away from the cutoff forming section 18 in the vertical direction.

[0027] Therefore, as shown in FIG. 10 , the lens member 12 forms a low-beam light distribution pattern LP on a screen where a horizontal line H and a vertical line V intersect with the center position O as the origin. This low-beam light distribution pattern LP has a cutoff line CL at its upper edge. This cutoff line CL reflects the shape of the cutoff forming portion 18 and is formed by inverting that shape vertically. In particular, since the vehicular lamp 10 curves the cutoff forming portion 18 along the focal plane Fp of the emission surface 26, it is possible to brighten the vicinity of the cutoff forming portion 18 regardless of its position in the width direction, and the brightness and darkness of the cutoff line CL can be clearly defined. The cutoff line CL has a lower horizontal edge el corresponding to the upper cutoff forming portion 21, an upper horizontal edge eh corresponding to the lower cutoff forming portion 22, and an inclined edge es corresponding to the inclined cutoff forming portion 23. This cutoff line CL is designed to correspond to areas where vehicles drive on the left side, with an upper horizontal edge eh located on the left side and a lower horizontal edge el located on the right side, and these are joined by an inclined edge es. In this passing light distribution pattern LP, the area near the inclined edge es is brightest, and the area toward the cutoff line CL is brightened as a whole, gradually becoming darker as it moves downward from the cutoff line CL. For these reasons, the vehicular lamp 10 can achieve light distribution during passing by forming a passing light distribution pattern LP having a cutoff line CL by turning on each light source 11. Note that, in the first embodiment, the cutoff line CL is designed to correspond to areas where vehicles drive on the left side. However, in areas where vehicles drive on the right side, the positional relationship between the upper cutoff forming portion 21, the lower cutoff forming portion 22, and the inclined cutoff forming portion 23 in the cutoff forming portion 18 is reversed left and right, and the cutoff line is reversed left and right.

[0028] This vehicle lamp 10 is provided with a second reflecting surface 24 that is continuous with the cutoff forming portion 18 on the first reflecting surface 17 side of the cutoff forming portion 18. Therefore, as shown in FIG. 7, the vehicle lamp 10 allows light L1 and light L2 that are reflected by the first reflecting surface 17 and travel rearward beyond the cutoff forming portion 18 to be reflected by the second reflecting surface 24 (lower horizontal reflecting surface portion 32 in FIG. 7) and travel upward of the cutoff forming portion 18. This allows the vehicle lamp 10 to efficiently utilize the light from each light source 11.

[0029] Furthermore, the vehicle lamp 10 is provided with a parallel reflecting surface portion 34 and an inclined reflecting surface portion 35 on the upper horizontal reflecting surface portion 31 of the second reflecting surface 24. As shown in FIG. 8, in this vehicle lamp 10, light L1 from the first reflecting surface 17 is reflected by the parallel reflecting surface portion 34 to travel above the cutoff forming portion 18, and light L2 from the first reflecting surface 17 is reflected by the inclined reflecting surface portion 35 to travel above the light reflected by the parallel reflecting surface portion 34. Here, because the inclined reflecting surface portion 35 is inclined rearward as described above, it travels above the light L2 reflected by the non-inclined lower horizontal reflecting surface portion 32 (see FIG. 7). Therefore, the vehicle lamp 10 can illuminate the area up and down on the focal plane Fp compared to a case in which the inclined reflecting surface portion 35 is not provided (see FIG. 7). Here, when the vehicular lamp 10 does not have the inclined reflective surface portion 35, it is assumed that it can form a passing light distribution pattern LP having a cutoff line CL as shown in Fig. 9. In contrast to this, the vehicular lamp 10 can irradiate a lower portion LPl on the lower side as shown in Fig. 10 by light L2 reflected by the inclined reflective surface portion 35, and can spread the passing light distribution pattern LP downward. When this passing light distribution pattern LP is actually mounted on a vehicle and illuminates the road, the lower side becomes the front side (the side closer to the vehicle), and therefore visibility can be improved over a wide range from the cutoff line CL located far away to the front side.

[0030] Furthermore, in the vehicle lamp 10, the second reflecting surface 24 connects the upper horizontal reflecting surface portion 31 and the lower horizontal reflecting surface portion 32 with an inclined reflecting surface portion 33, and the inclined reflecting surface portion 33 curves toward the lower horizontal reflecting surface portion 32 as it moves rearward in the longitudinal direction. Furthermore, in the vehicle lamp 10, the upper horizontal reflecting surface portion 31 is provided with a parallel reflecting surface portion 34 and an inclined reflecting surface portion 35, thereby reducing the difference in vertical position between the upper horizontal reflecting surface portion 31 and the lower horizontal reflecting surface portion 32 as it moves rearward in the longitudinal direction. Additionally, in the vehicle lamp 10, the short dimension of the inclined reflecting surface portion 33 gradually changes so that it is greatest at the midpoint in the longitudinal direction. As a result, in the vehicle lamp 10, the inclination of the inclined reflecting surface portion 33 relative to both horizontal surfaces 31, 32 decreases as it moves rearward in the longitudinal direction. As a result, the vehicle lamp 10 can reduce the effect on the low-vehicle light distribution pattern LP caused by the inclined reflective surface portion 33 compared to a case in which the inclined reflective surface portion 33 is extended in the longitudinal direction without changing the short dimension and the inclined reflective surface portion 35 is not provided on the second reflective surface 24. This will be explained below with reference to FIGS.

[0031] Here, Fig. 11 shows the second reflecting surface 24' as a comparative example, and Fig. 12 shows the second reflecting surface 24 of the vehicle lamp 10 of Embodiment 1. In Fig. 11 and Fig. 12, the upper horizontal reflecting surface portions 31, 31' and the lower horizontal reflecting surface portions 32, 32' are assumed to be substantially horizontal, and only the extending direction of the inclined reflecting surface portions 33, 33' is different. In Fig. 11 and Fig. 12, of the light L from the first reflecting surface 17, the portion reflected by the upper horizontal reflecting surface portions 31, 31' and the lower horizontal reflecting surface portions 32, 32' is indicated by arrows as light La, and the portion reflected by the inclined reflecting surface portions 33, 33' is indicated by arrows as light Lb.

[0032] As shown in FIG. 11 , the second reflecting surface 24′ of the comparative example has an inclined reflecting surface portion 33′ that is provided along the front-rear direction without being bent toward the lower horizontal reflecting surface portion 32′, and extends in the front-rear direction while maintaining a tilt toward the lower horizontal reflecting surface portion 32′. On the second reflecting surface 24′, when light La from the first reflecting surface 17 travels toward the upper horizontal reflecting surface portion 31′ or the lower horizontal reflecting surface portion 32′, it is reflected without being deflected in the width direction and travels toward the front side in the front-rear direction, i.e., the exit surface 26. On the other hand, on the second reflecting surface 24′, when light Lb from the first reflecting surface 17 travels toward the inclined reflecting surface portion 33′, it is reflected so as to be deflected in the width direction toward the lower horizontal reflecting surface portion 32′ (the right side in the illustrated example), and travels toward the right of the exit surface 26. For this reason, the second reflecting surface 24′ allows light L from the first reflecting surface 17 to be reflected by the upper horizontal reflecting surface portion 31′ and the lower horizontal reflecting surface portion 32′ and then emitted from the emission surface 26, but cannot allow light L reflected by the inclined reflecting surface portion 33′ to be emitted from the emission surface 26. As a result, in the low-passing light distribution pattern LP, the light reflected by the inclined reflecting surface portion 33′ is partially lost, resulting in the formation of a dark area ds extending downward from the vicinity of the inclined edge es in the cutoff line CL, as shown by the dashed line in FIG. 10 . Here, two dark areas ds are formed downward from the vicinity of both ends of the inclined edge es in FIG. 10 , because two light sources 11 are arranged side by side in the width direction. In other words, the light from each light source 11 passes through the first reflecting surface 17 and reaches the inclined reflecting surface portion 33′ at different angles, and therefore the position where the dark area ds is formed in the low-passing light distribution pattern LP is shifted toward the horizon H. These dark areas ds only partially darken the low-vehicle light distribution pattern LP and are not particularly noticeable. However, since the dark areas ds are located near the vehicle occupants at the lower part of the low-vehicle light distribution pattern LP, i.e., on the front side when the road is illuminated, they are easily noticeable and may cause the occupants to feel uncomfortable.

[0033] In contrast, as shown in Fig. 12, the second reflecting surface 24 of the first embodiment has the inclined reflecting surface portion 33 bent toward the lower horizontal reflecting surface portion 32, gradually changing to a state inclined toward the lower horizontal reflecting surface portion 32 in the width direction and toward the front in the front-to-rear direction. Therefore, compared to the second reflecting surface 24' in Fig. 11, the second reflecting surface 24 has a larger dimension in the width direction even when the short dimension is the same, and the inclination with respect to both horizontal surfaces 31, 32 is smaller. As a result, when light Lb from the first reflecting surface 17 travels toward the inclined reflecting surface portion 33, the second reflecting surface 24 reflects the light Lb so as to be deflected toward the lower horizontal reflecting surface portion 32 in the width direction (to the right in the illustrated example), but the deflection angle can be reduced, allowing the light Lb to travel toward the exit surface 26. Furthermore, at the second reflecting surface 24, when light La from the first reflecting surface 17 travels toward the upper horizontal reflecting surface portion 31 or the lower horizontal reflecting surface portion 32, it is reflected without being deflected in the width direction, and travels toward the front side in the front-to-back direction, i.e., the exit surface 26, similar to the second reflecting surface 24' in Figure 11.

[0034] As a result, the second reflecting surface 24 emits, from the exit surface 26, light La reflected by the upper horizontal reflecting surface portion 31 and the lower horizontal reflecting surface portion 32, with respect to light L from the first reflecting surface 17, and also emits light Lb reflected by the inclined reflecting surface portion 33. Therefore, in the passing light distribution pattern LP, partial loss of light reflected by the inclined reflecting surface portion 33 is suppressed, and the formation of the dark portion ds shown in Fig. 10 can be suppressed, thereby suppressing the discomfort felt by occupants.

[0035] In particular, the second reflecting surface 24 of the first embodiment has a parallel reflecting surface portion 34 and an inclined reflecting surface portion 35 on the upper horizontal reflecting surface portion 31, and the short dimension of the inclined reflecting surface portion 33 is gradually changed so that it is greatest at the middle position in the front-to-rear direction. Therefore, the second reflecting surface 24 can further reduce the inclination of the inclined reflecting surface portion 33 with respect to both horizontal surfaces 31, 32, and can more reliably direct the light Lb reflected by the inclined reflecting surface portion 33 toward the exit surface 26, thereby more effectively suppressing the formation of dark areas ds.

[0036] Here, we will explain the technical problems of conventional vehicle lamps. Conventional vehicle lamps form a low-passing light distribution pattern having a cutoff line by partially blocking light reflected by a reflector covering a light source with a cutoff forming portion and projecting the light with a projection lens. The reflector has a curved surface based on an ellipse with foci both near the light source and near the cutoff forming portion, and collects light from the light source near the cutoff forming portion. Furthermore, conventional vehicle lamps have an auxiliary reflective surface on the light source side of the cutoff forming portion, and the auxiliary reflective surface has a parallel reflective surface portion on the cutoff forming portion side and an inclined reflective surface portion continuous with the parallel reflective surface portion. This conventional vehicle lamp reflects light from the light source that travels toward the auxiliary reflective surface by the parallel reflective surface portion toward the upper side of the cutoff forming portion and then further upward by the inclined reflective surface portion, thereby spreading the light from the light source downward and forming a low-passing light distribution pattern. Here, conventional vehicle lamps, because the reflector is configured as described above, project an image of the light-emitting surface of the light source forward. The size of this image of the light-emitting surface changes depending on the distance from the light source to the reflecting point on the reflector, with the image reflected near the lower end of the reflector being largest. In such conventional vehicle lamps, light reflected near the lower end of the reflector travels toward the inclined reflective surface portion, and the light reflected by the inclined reflective surface portion travels further upward than the light reflected by the parallel reflective surface portion to form the lower portion of the light distribution pattern for passing vehicles, i.e., the near side when illuminating the road. Therefore, in conventional vehicle lamps, the image of the light-emitting surface is formed in the lower portion with light that is largest, and the brightness difference and unevenness are easily noticeable, which may cause discomfort to occupants.

[0037] In contrast, the vehicular lamp 10 of the present disclosure causes light L from each light source 11 to enter the lens member 12 as parallel light from each incident portion 13, and reflects the light L by the first reflecting surface 17 so as to be concentrated near the cutoff forming portion 18. The first reflecting surface 17 is a free-form surface based on a paraboloid having a focal point near the cutoff forming portion 18, and reflects the parallel light from each incident portion 13 so as to be concentrated near the cutoff forming portion 18. The vehicular lamp 10 then causes the light L to basically travel directly above the cutoff forming portion 18, and also causes a portion of the light L to be reflected by the second reflecting surface 24 and then travel above the cutoff forming portion 18. The vehicular lamp 10 forms a passing light distribution pattern LP by projecting the light L from the exit surface 26. Therefore, the vehicular lamp 10 allows images of all sizes of light-emitting surfaces to travel above the cutoff forming portion 18, either directly or after being reflected by the second reflecting surface 24, regardless of the distance from each light source 11 or the first reflecting surface 17. As a result, the vehicular lamp 10 can form the entire passing light distribution pattern LP using images of all sizes of light-emitting surfaces, thereby suppressing the effects of differences in brightness and unevenness due to differences in the size of the light-emitting surface images. Therefore, even if the vehicular lamp 10 provides the parallel reflecting surface portion 34 and the inclined reflecting surface portion 35 on the upper horizontal reflecting surface portion 31 to expand the passing light distribution pattern LP downward, the vehicular lamp 10 can suppress differences in brightness and unevenness in the passing light distribution pattern LP, thereby suppressing any discomfort felt by the occupants. In particular, the vehicular lamp 10 has the first reflecting surface 17 formed as a curved surface basically formed on a paraboloid with a focus set near the cutoff forming portion 18. Therefore, even if the vehicle lighting device 10 is provided with multiple light sources 11 (two in embodiment 1), the light L from these light sources can be directed to the vicinity of the cutoff forming portion 18, thereby achieving the effect of suppressing the difference in brightness and unevenness caused by differences in the size of the image of the light-emitting surface described above.

[0038] The vehicle lamp 10, which is an example of a vehicle lamp according to the present disclosure, can achieve the following effects.

[0039] Vehicle lamp 10 causes light L from light source 11 to enter lens member 12 as parallel light from incident portion 13, reflects light L from first reflecting surface 17, and projects light L from exit portion 25 while being partially blocked by cutoff forming portion 18, thereby forming a passing light distribution pattern LP having a cutoff line CL. Lens member 12 has second reflecting surface 24 that reflects a portion of the light reflected by first reflecting surface 17 toward the vicinity of cutoff forming portion 18, and first reflecting surface 17 is a curved surface basically formed of a paraboloid with a focus set near cutoff forming portion 18. Second reflecting surface 24 has parallel reflecting surface portion 34 that is continuous with cutoff forming portion 18, and an inclined reflecting surface portion 35 that is continuous with parallel reflecting surface portion 34 on the first reflecting surface 17 side relative to parallel reflecting surface portion 34 and inclined downward. Therefore, even when the low-beam light distribution pattern LP is expanded downward, the vehicle lamp 10 can suppress the difference in brightness and unevenness in the low-beam light distribution pattern LP, thereby preventing the occupant from feeling uncomfortable.

[0040] Furthermore, the incident portion 13 of the vehicle lamp 10 has an opposing incident surface 14 facing the light source 11, an annular incident surface 15 surrounding the opposing incident surface 14, and an annular reflecting surface 16 surrounding the annular incident surface 15. Therefore, the vehicle lamp 10 can effectively utilize the light L from the light source 11 with a simple configuration and cause the light L to be incident on the lens member 12 as parallel light.

[0041] Furthermore, the cutoff forming portion 18 of the vehicle lamp 10 has an upper cutoff forming portion 21 and a lower cutoff forming portion 22 that are located at different heights, and an inclined cutoff forming portion 23 that connects them. The second reflecting surface 24 has an upper horizontal reflecting surface portion 31 that is continuous with the upper cutoff forming portion 21, an inclined reflecting surface portion 33 that is continuous with the inclined cutoff forming portion 23, and a lower horizontal reflecting surface portion 32 that is continuous with the lower cutoff forming portion 22. The inclined reflecting surface portion 33 curves toward the lower horizontal reflecting surface portion 32 with increasing distance from the cutoff forming portion 18. Therefore, the inclined reflecting surface portion 33 of the vehicle lamp 10 can be gradually changed from being inclined toward the lower horizontal reflecting surface portion 32 in the width direction to being inclined obliquely not only in the width direction but also in the front-to-rear direction with increasing distance from the cutoff forming portion 18, thereby enabling the vehicle lamp 10 to have an increased dimension in the width direction. As a result, the vehicle lamp 10 can cause light L from the first reflecting surface 17 to travel to the exit portion 25 even when reflected by the inclined reflecting surface portion 33, thereby preventing the formation of dark areas ds in the passing light distribution pattern LP and reducing the discomfort felt by occupants.

[0042] In the vehicle lamp 10, at least a portion of the inclined reflecting surface portion 33 has a shorter dimension that increases with increasing distance from the cutoff forming portion 18. Therefore, in the vehicle lamp 10, the inclination of the inclined reflecting surface portion 33 can decrease with increasing distance from the cutoff forming portion 18, and even when light L from the first reflecting surface 17 is reflected by the inclined reflecting surface portion 33, it can travel to the emission portion 25.

[0043] Therefore, the vehicle lamp 10 of the first embodiment as a vehicle lamp according to the present disclosure can suppress the difference in brightness and unevenness in the low-beam light distribution pattern LP even when the low-beam light distribution pattern LP is expanded downward.

[0044] The vehicle lamp of the present disclosure has been described above based on the first embodiment, but the specific configuration is not limited to the first embodiment, and design changes and additions are permitted as long as they do not deviate from the gist of the invention according to each claim in the scope of the claims.

[0045] In the first embodiment described above, the inclined reflective surface portion 33 is curved toward the lower horizontal reflective surface portion 32 as it extends rearward in the front-to-rear direction. However, like the second reflective surface 24A of the vehicle lamp 10A shown in FIG. 13 , the inclined reflective surface portion 33A may be configured such that its short dimension increases with increasing distance from the cutoff forming portion 18. By increasing the short dimension of the inclined reflective surface portion 33A, the inclination of the inclined reflective surface portion 33A relative to the upper horizontal reflective surface portion 31A and the lower horizontal reflective surface portion 32A can be reduced with increasing distance from the cutoff forming portion 18. Therefore, even when the light L from the first reflective surface 17 is reflected by the inclined reflective surface portion 33, the second reflective surface 24A can direct the light L toward the exit portion 25, thereby preventing the formation of a dark area ds in the low-vehicle light distribution pattern LP and reducing the discomfort felt by the occupant.

[0046] Moreover, in the above-described first embodiment, two light sources 11 are used. However, the number of light sources 11 may be set appropriately as long as the light source 11 is one that emits light L that is incident as parallel light from the incident portion 13 of the lens member 12 and that passes through the first reflecting surface 17, the cutoff forming portion 18, and the second reflecting surface 24 as appropriate, and that is projected from the exit portion 25 to form the low-beam light distribution pattern LP, and is not limited to the configuration of the first embodiment.

[0047] Furthermore, in the above-described first embodiment, the upper horizontal reflecting surface 31, 31A of the second reflecting surface 24, 24A has a parallel reflecting surface portion 34, 34A and an inclined reflecting surface portion 35, 35A, while the lower horizontal reflecting surface 32, 32A is a single flat surface. However, the lower horizontal reflecting surface 32, 32A may also have a parallel reflecting surface portion and an inclined reflecting surface portion, and the configuration is not limited to that of the first embodiment. In this case, it is desirable that the inclination angle of the inclined reflecting surface portion relative to the parallel reflecting surface portion on the lower horizontal reflecting surface 32, 32A is smaller than the inclination angle of the inclined reflecting surface portion 35, 35A relative to the parallel reflecting surface portion 34, 34A. This is because, with this configuration, the inclination of the inclined reflecting surface portion 33, 33A located between them can be made smaller with increasing distance from the cutoff formation portion 18. [Explanation of symbols]

[0048] 10, 10A Vehicle lamp 11 Light source 12, 12A Lens member 13 Incident portion 14 Opposing incident surface 15 Annular incident surface 16 Annular reflective surface 17 First reflective surface 18 Cut-off forming portion 21 Upper cut-off forming portion 22 Lower cut-off forming portion 23 Inclined cut-off forming portion 24, 24A Second reflective surface 25 Exit portion 31, 31A Upper horizontal reflective surface portion 32, 32A Lower horizontal reflective surface portion 33, 33A Inclined reflective surface portion 34, 34A Parallel reflective surface portion 35, 35A Inclined reflective surface portion CL Cut-off line LP Light distribution pattern for passing

Claims

1. A light source and a lens member that guides light from the light source inward and then emits the light to form a low-beam light distribution pattern, the lens member has an incident portion that causes light from the light source to be incident as parallel light, a first reflecting surface that reflects the light incident from the incident portion, a cutoff forming portion that partially blocks the light from the first reflecting surface to form a cutoff line in the low-beam light distribution pattern, a second reflecting surface that reflects a portion of the light reflected by the first reflecting surface to a vicinity of the cutoff forming portion, and an exit portion that causes the light that has passed through a vicinity of the cutoff forming portion to exit, the first reflecting surface is a curved surface based on a paraboloid with a focus set near the cutoff forming portion, The second reflective surface has a parallel reflective surface portion that is continuous with the cutoff forming portion, and an inclined reflective surface portion that is continuous with the parallel reflective surface portion on the first reflective surface side of the parallel reflective surface portion and slopes downward.

2. 2. The vehicle lamp according to claim 1, wherein the incident portion has an opposing incident surface facing the light source, an annular incident surface surrounding the opposing incident surface, and an annular reflective surface surrounding the annular incident surface.

3. the cutoff forming portion has an upper cutoff forming portion and a lower cutoff forming portion which are located at different heights, and an inclined cutoff forming portion which connects the upper and lower cutoff forming portions, the second reflecting surface has an upper horizontal reflecting surface portion continuous with the upper cutoff forming portion, an inclined reflecting surface portion continuous with the inclined cutoff forming portion, and a lower horizontal reflecting surface portion continuous with the lower cutoff forming portion, 3. The vehicle lamp according to claim 1, wherein the inclined reflecting surface portion curves toward the lower horizontal reflecting surface portion as it moves away from the cutoff forming portion.

4. 4. The vehicle lamp according to claim 3, wherein the inclined reflecting surface portion has a width dimension that increases with increasing distance from the cutoff forming portion.

5. the cutoff forming portion has an upper cutoff forming portion and a lower cutoff forming portion which are located at different heights, and an inclined cutoff forming portion which connects the upper and lower cutoff forming portions, the second reflecting surface has an upper horizontal reflecting surface portion continuous with the upper cutoff forming portion, an inclined reflecting surface portion continuous with the inclined cutoff forming portion, and a lower horizontal reflecting surface portion continuous with the lower cutoff forming portion, 3. The vehicle lamp according to claim 1, wherein the inclined reflecting surface portion has a width dimension that increases with increasing distance from the cutoff forming portion.

Images