Patent ID: 12222078

DESCRIPTION OF EMBODIMENTS

Next, embodiments of the present disclosure will be described with reference to the drawings.FIG.1is a front view showing an automobile including a head lamp configured as a vehicle lamp according to the present disclosure. Left and right sides of a front portion of a body of the automobile CAR are provided with a left head lamp L-HL and a right head lamp R-HL that are referred to as head lamps HL. The left and right head lamps L-HL and R-HL are each configured as a composite head lamp including a plurality of lamp units and are bilaterally symmetrical.

FIG.2is a front perspective view showing the left head lamp L-HL shown inFIG.1cut in part. The left head lamp L-HL includes a lamp housing100. The lamp housing100includes: a lamp body101; and a translucent cover102installed to cover a front side of the lamp body101. The lamp housing100includes a bend100aextending from a front side of the automobile CAR toward an outer (right inFIG.2) side in a vehicle width direction. A front surface of the translucent cover102inclines rearward correspondingly to a curved shape of the front portion of the vehicle body of the automobile CAR.

A plurality of lamp units are housed in the lamp housing100. Specifically, a low-beam lamp unit LoU and a high-beam lamp unit HiU as head lamps; an edge lamp unit EgU and a rod lamp unit RoU as auxiliary lamps; and a side lamp unit SiU as a signal lamp are housed in the lamp housing100. The low-beam lamp unit LoU and the high-beam lamp unit HiU are configured as reflector-type lamp units. The edge lamp unit EgU and the rod lamp unit RoU are configured as light-guide-type lamp units. The side lamp unit SiU is configured as a lens-type lamp unit.

An extension103configured to function as a pseudo-reflector is in the lamp housing100such that the extension103does not overlap with the lamp units. The extension103prevents the interior of the lamp housing100except the lamp units from being exposed through the translucent cover102. In the following, unless otherwise specified, a front-rear direction refers to a front-rear direction of the automobile CAR and the left head lamp L-HL, and a left-right direction is based onFIGS.1and2. Therefore, the outer side of the automobile CAR in the vehicle width direction is the right side.

The lamp units will be described briefly. InFIG.2, the low-beam lamp unit LoU and the high-beam lamp unit HiU are integrally formed such that they are aligned in a left-right or horizontal direction with the low-beam lamp unit LoU placed on the right side, that is, on the outer side in the vehicle width direction. The low-beam lamp unit LoU and the high-beam lamp unit HiU each includes: a first light source; a second light source; and a reflector configured to reflect light from the first light source or the second light source ahead of the automobile in a predetermined light distribution pattern.

The edge lamp unit EgU is on the outer side of the low-beam lamp unit LoU in the vehicle width direction. The edge lamp unit EgU includes: a third light source; and an edge light guide configured with a light-guiding (translucent) plate. The edge lamp unit EgU is configured to guide light from the third light source with the edge light guide to emit the light ahead of the automobile from an edge which is a front end surface of the edge light guide.

The rod lamp unit RoU extends in the left-right or horizontal direction along upper edges of the low-beam lamp unit LoU and the high-beam lamp unit HiU. The rod lamp unit RoU includes: a fourth light source; and a rod light guide configured with a rod-shaped (translucent) light guide. The rod lamp unit RoU is configured to guide light from the fourth light source in a lengthwise direction with the rod light guide to emit the light ahead of the automobile from a circumferential surface extending in the lengthwise direction of the rod light guide.

In this embodiment, the edge lamp unit EgU and the rod lamp unit RoU is configured to function as a clearance lamp or a daytime running lamp with lighting of the edge lamp unit EgU and the rod lamp unit RoU controlled. That is, when the edge lamp unit EgU and the rod lamp unit RoU are simultaneously turned on with predetermined brightness, they function as a clearance lamp in a body. When the edge lamp unit EgU and the rod lamp unit RoU are turned on with brightness higher than the predetermined brightness described above, they function as a daytime running lamp.

The side lamp unit SiU includes: a fifth light source; and a lens configured to emit light from the fifth light source toward a desired lateral region of the automobile. The side lamp unit SiU is on the outer side of the edge lamp unit EgU in the vehicle width direction, in particular, in the bend100aof the lamp housing100.

FIG.3is a block configuration diagram showing an electrical system of the lamp units LoU, HiU, EgU, RoU, and SiU. The lamp units LoU, HiU, EgU, RoU, and SiU are connected to a lamp electronic control unit (ECU)5and are powered by electricity from an in-vehicle battery (not shown). The lamp ECU is an example of a lighting controller. InFIGS.3, L1to L5refer to the first to fifth light sources in the lamp units LoU, HiU, EgU, RoU, and SiU.

The lamp ECU5includes a lighting controller51. The lighting controller51is configured to control lighting of the first light source L1to the fifth light source L5, which are light sources of the lamp units, to control lighting of the lamp units LoU, HiU, EgU, RoU, and SiU. The lamp ECU5includes a lighting adjuster52configured to adjust brightness of the edge lamp unit EgU and the rod lamp unit RoU, that is, a light-emission intensity of the third light source L3and the fourth light source L4.

A lamp on/off switch SW1, a beam switch SW2, a function switch SW3, and a turn-signal switch SW4are connected to the lamp ECU5and are operable by a driver. The edge lamp unit EgU and the rod lamp unit RoU are turned on as the lamp on/off switch SW1is turned on. Brightness of the edge lamp unit EgU and the rod lamp unit RoU is switched by the function switch SW3. The low-beam lamp unit and the high-beam lamp unit are turned on or off as the beam switch SW2is switched. The side lamp unit SiU blinks as a turn signal lamp as the turn-signal switch SW4is turned on.

Next, the lamp units LoU, HiU, EgU, RoU, and SiU will be described detailed.

Low-beam Lamp Unit LoU and High-beam Lamp Unit HiU

FIG.4is an exploded perspective view schematically showing the low-beam lamp unit LoU and the high-beam lamp unit HiU. The low-beam lamp unit LoU includes: the first light source L1; and a reflector11. The high-beam lamp unit HiU includes: the second light source L2; and a reflector12. The reflector11and the reflector12are examples of an optical system.

The first light source L1and the second light source L2each include a plurality of (in this embodiment, three) white LEDs10configured to emit white light. These six white LEDs10are mounted on a lower surface of an A-substrate1A supported in a horizontal direction on upper portions of the reflectors11and12such that their light-emitting surfaces face downward and they are placed at a desired interval in the left-right direction. The A-substrate1A is on upper surfaces of the reflectors11and12. The white LEDs10are in cut windows111and121respectively provided in upper portions of the reflectors11and12of the low-beam lamp unit LoU and the high beam lamp unit HiU. The A-substrate1A is electrically connected to the lamp ECU5via a connector114.

In this example, the reflectors11and12are integrally formed such that three reflection surfaces112and122are aligned in the left-right direction. The reflection surfaces112and122have parabolic or similar shapes, but the high-beam lamp unit and the low-beam lamp unit are configured differently in part. The reflection surfaces112and122are configured to reflect light from the corresponding white LEDs10via the translucent cover102ahead of the automobile. The reflectors11and12are attached to the lamp body101with fixing pieces113and123on the reflectors11and12.

Accordingly, in the low-beam lamp unit LoU, the first light source L1emits light as the lamp on/off switch SW1is turned on and the beam switch SW2is switched to a low beam. As shown in the schematic cross-sectional view ofFIG.5, the light from the white LEDs10as the first light source L1is reflected by the reflection surface112of the reflector11ahead of the automobile, thereby forming a low-beam light distribution. As the beam switch SW2is switched, the second light source L2emits light. Although not shown, the light reflected by the reflection surface122of the reflector12is added to the low-beam light distribution, thereby forming a high-beam light distribution.

Edge Lamp Unit EgU

FIG.6is an exploded perspective view schematically showing a configuration of the edge lamp unit, andFIG.7is a cross-sectional view showing the edge lamp unit in the lamp housing100. The side lamp unit SiU is additionally shown inFIG.7. As shown inFIGS.6and7, the edge lamp unit EgU includes: the third light source L3; and an edge light guide21. The edge light guide21is an example of a light guide and an optical system.

The edge light guide21is configured with a light-guiding plate that has a substantially plate shape and is made of a translucent resin material. The edge light guide21is supported by the lamp body101as will be described later. The edge light guide21extends along the front-rear direction of the left head lamp L-HL such that plate surfaces on both sides of the edge light guide21are vertical surfaces that are substantially opposite to each other in the left-right direction. In the following, an outer plate surface in the vehicle width direction is referred to as an outer surface, and the opposite or inner plate surface in the vehicle width direction is referred to as an inner surface. A direction in which the edge light guide21extends is referred to as an optical axis direction.

The third light source L3includes white LEDs20mounted on a B-substrate1B placed adjacent to the edge light guide21along the outer surface of the edge light guide21. The B-substrate1B is integrally coupled to the edge light guide21along the outer surface of the edge light guide21. In this embodiment, a snap210is integrally formed with the edge light guide21, and the snap210is configured to engaged with a connection hole220on the B-substrate1B. Preferably, the B-substrate1B covers the outer surface of the edge light guide21widely as long as that does not interfere in placement of the edge light guide21in order to improve light-blocking properties to be described later.

The white LEDs20as the third light source L3are mounted on a surface of the B-substrate1B on which the B-substrate1B faces the outer surface of the edge light guide21. In this embodiment, three white LEDs20are placed at a predetermined interval in the vertical direction such that they are slightly shifted in the front-rear direction. The white LEDs20are configured to cause light to be incident on the outer surface of the edge light guide21. The B-substrate1B is electrically connected to the lamp ECU5via a connector222.

A part of the outer surface of the edge light guide21on which the light from the third light source L3is incident is configured as an incident surface211. On the inner surface of the edge light guide21opposite to the outer surface, reflection surface212configured to reflect the incident light internally is placed. A front end surface of the edge light guide21facing a front side is configured as an emission surface213configured to emit light internally reflected by the reflection surface212. The emission surface213inclines rearward in the vertical direction along a front surface of the translucent cover102and inclines in a horizontal direction outwardly in the vehicle width direction.

A rear end portion of the outer surface of the edge light guide21that faces the white LEDs20as the third light source L3is slightly thicker than a portion anterior to the rear end portion. The rear end portion is configured as the incident surface211. Light from the third light source L3travels onto the incident surface211.

As shown inFIG.6, the reflection surface212of the edge light guide21is on an inner surface opposite to the incident surface211. The reflection surface212includes three reflection surface sections arranged in the vertical direction correspondingly to the three white LEDs20as the third light source L3. In this embodiment, since the three white LEDs20are sequentially shifted forward from the top to the bottom, the three reflection surface sections are also sequentially shifted forward from the top to the bottom in a terraced manner corresponding to the three white LEDs20. In the following, the reflection surface212may be referred to as one or all of the reflection surface sections generically.

Since the three reflection surface sections are similar to each other, only one of them will be described.FIG.8Ais a cross-sectional view showing the edge light guide21in the reflection surface212. A virtual focal point of the inner surface of the edge light guide21as the incident surface211is basically in the vicinity of the corresponding white LED20. The inner surface of the edge light guide21is formed by a part of a paraboloid whose central axis is a virtual line that passes through the virtual focal point and extends in the front-rear direction. Accordingly, light incident on the incident surface211from the white LEDs20is internally reflected by the reflection surface212and is guided in the optical axis direction to the front end surface configured as the emission surface213.

Light satisfying a condition of a critical angle determined based on a refractive index of translucent resin of the edge light guide21out of light projected onto an inner surface of the reflection surface212is totally reflected on the inner surface and is guided to the emission surface213. On the other hand, since light projected onto a rear end portion of the reflection surface212of the edge light guide21is incident on the inner surface at a small angle such that the condition is not satisfied, the light leaks outside the edge light guide212from the reflection surface212as shown by a chain line without total reflection.

Therefore, the reflection surface212that satisfies the condition has a shape of the paraboloid as a single-reflection surface212mon which light is reflected once. On the other hand, the reflection surface that does not satisfy the condition is configured as a multiple-reflection surface212p.FIG.8Bis a perspective view showing the exterior of the multiple-reflection surface212p. The multiple-reflection surface212phas mountain (ridge) lines y and valley lines t extending from the virtual focal point to form a fan shape. A cross-sectional view of the multiple-reflection surface212pin the circumferential direction is shaped like a triangle wave. The mountain lines y extend along paraboloids, and the valley lines t extend along paraboloids whose parameters are different from that of the mountain lines y. Therefore, slopes r choppily arranged in the fan shape are configured such that the paraboloids incline alternately in the circumferential direction.

On the slopes r of the multiple-reflection surface212p, surface angles in the circumferential direction with respect to the incident surface211increase. Since an incident angle in the circumferential direction of incident light reaching each slope r increases, the incident light satisfies the condition and is internally reflected (primary internal reflection). The internally reflected light reaching an adjacent or distant slope r is internally reflected (secondary internal reflection) since the condition is satisfied again. Since slopes r incline along the parabola in the optical axis direction, light internally reflected through the primary, secondary, and so forth internal reflection faces approximately in the optical axis direction.

Therefore, in the edge light guide21, some light reaching the incident surface211is guided toward the emission surface213through the primary internal reflection on the single-reflection surface212m. The rest of the light is guided toward the emission surface213through multiple reflections such as the primary and secondary internal reflections on the multiple-reflection surface212p. Consequently, it is possible to prevent light from leaking outside the edge light guide21from the reflection surface212, thereby increasing reflection efficiency of light on the reflection surface212.

In the edge light guide21, light from the white LEDs20corresponding to the three reflection surface sections is internally reflected to the optical axis direction and is emitted from the emission surface213.FIG.9Ais a perspective view schematically showing the emission surface213. Refraction steps215configured to refract light diffusely are formed on a front end of the emission surface213. In this embodiment, a large number of minute spherical steps are arranged as the refraction steps215. Since the refraction steps215are provided, light reflected by one of the three reflection surface sections to the optical axis direction is refracted by the refraction steps215and is emitted diffusely toward a desired wide region ahead of the automobile, as shown in the cross-sectional view ofFIG.9B.

Further, in the edge light guide21according to this embodiment, a lateral emission step216protruding inward in the vehicle width direction is provided in a front end side of the inner surface of the edge light guide21, which is along one edge portion of the emission surface213, as shown inFIG.9A. A horizontal cross section of the lateral emission step216has trapezoidal shape protruding from the inner surface, and a wedge-shaped portion216aon a lower base positioned at a front side in the optical axis direction protrudes forward from the emission surface213. The lateral emission step216extends along the emission surface213of the edge light guide21substantially over the entire length in the vertical direction.

Accordingly, most light reflected by the reflection surface212faces in the optical axis direction of the edge light guide21, but some of the light inclines from the optical axis direction and is not emitted from the emission surface213suitably, as shown inFIG.9B. When such light is guided to the lateral emission step216, the light is reflected by an upper base of the lateral emission step216and/or front or rear inclined surface thereof and is emitted from the wedge-shaped portion216a, which protrudes forward from the emission surface213. In the wedge-shaped portion216a, light is reflected by an inner surface of the wedge-shaped portion216aand is emitted toward the left side of the left head lamp L-HL in a direction inclined toward the outer side in the vehicle width direction from the optical axis direction of the edge light guide21. In this way, the lateral emission step216is configured to reflect light guided to an edge of the edge light guide21in a thickness direction of the edge light guide21and to emit the light in the thickness direction of the edge light guide21. The emission surface213inclines in the thickness direction of the edge light guide21from one edge of the edge light guide21in which the lateral emission step216is provided to the other edge.

Since light widely emitted from the refraction steps215of the emission surface213and light emitted outwardly in the vehicle width direction from the lateral emission step216are combined, the edge lamp unit EgU can emit light extremely widely.

As described above, the three reflection surface sections are arranged in a terraced manner along the inclination direction of the emission surface213. That is, as schematically shown in a vertical cross-sectional view of a structure of the edge light guide21inFIG.10A, the three reflection surface sections are sequentially shifted forward from the top to the bottom. Therefore, boundary surfaces217extending along the optical axis direction are formed between the reflection surface sections. In other words, the boundary surfaces217extending in a direction intersecting the inclination direction of the reflections surface212are formed. Some light that is not internally reflected in the optical axis direction by each of the reflection surface sections is incident on the boundary surfaces217.

If the boundary surfaces217were flat, such light is specularly internally reflected on the boundary surfaces217as shown by chain lines.FIG.10Ashows an example of reflection on the upper boundary surface217. The internally reflected light is guided upward at a desired angle from the optical axis direction and is emitted from the emission surface213. Since the light is superposed on light reflected by each reflection surface212toward the optical axis direction, brightness of the emission surface is high in such a region. On the other hand, the brightness of the emission surface is relatively low outside the region. Such uneven brightness of the emission surface deteriorates the exterior of the lamp when turned on.

In the present disclosure, the boundary surfaces217are provided with reflection steps218configured to reflect light diffusely as schematically shown in a perspective view ofFIG.1nthis embodiment, the reflection steps218are configured with semicylindrical optical step whose cross-sectional view in an axial direction protrudes downward in a semicircular shape and that extends in the thickness direction of the edge light guide21.

Since the reflection steps218are provided, light projected onto an inner surface of the boundary surfaces217is diffusely reflected by the reflection steps218relatively widely to the optical axis direction and is guided in the edge light guide21. An example of reflection on the lower boundary surface217is shown by solid lines inFIG.10A. The light guided to the emission surface213is superposed on light guided from the reflection surface212. Consequently, light is equalized over a desired region in an upper-lower direction of the emission surface213to avert uneven brightness of the emission surface213, thereby improving the exterior when the edge lamp unit EgU is turned.

Since the boundary surfaces217are provided with the reflection steps218, it is possible to reduce light that passes through the boundary surfaces217and leaks from the edge light guide21, thereby realizing efficient use of light from the white LEDs20(the third light source L3). The reflection steps218may be optical steps, for example, having a knurled structure as long as they are configured to emit light divergently or diffusely.

The edge light guide21is supported by the lamp body101as described above. For this support, the edge light guide21includes a supporting piece214extending further rearward from a rear end surface of the edge light guide21. In other words, the supporting piece214extends from the reflection surface212of the edge light guide21in a direction opposite to the emission surface213. The supporting piece214is formed into a thin plate whose thickness corresponds approximately to that of the incident surface211, which makes the edge light guide21thicker. The supporting piece214is bent inwardly at a desired angle, for example, about 120°, with respect to the optical axis direction. In other words, the supporting piece214is bent in the thickness direction of the edge light guide21. A threaded hole214ain the thickness direction is opened in the supporting piece214.

A part of the lamp body101that supports the edge light guide21is configured as a fixing portion101afor contact with the supporting piece214. As shown inFIG.7, when the edge light guide21is supported, the fixing portion101aof the lamp body101is fastened with a screw S inserted into the threaded hole214ausing a tool T such as a screwdriver.

Since the supporting piece214inclines from the optical axis direction, the screwdriver T can be inserted through a cut in the B-substrate1B, thereby enabling easy fastening of the screw S. If a corner angled similarly to the supporting piece214is provided in the fixing portion101a, the supporting piece214can touch the fixing portion101ato fix the edge light guide21stably.

Since the supporting piece214is thinner, light incident on the incident surface211is prevented from being guided toward the supporting piece214, and most of the incident light is guided toward the reflection surface212. Even if light is guided toward the supporting piece214, the light is reflected forward on a bent of the supporting piece214toward the emission surface213. Consequently, efficient use of light from the third light source L3in the edge lamp unit EgU can be realized.

Rod Lamp Unit RoU

FIG.11Ais a perspective view schematically showing a configuration of the rod lamp unit RoU, andFIG.11Bis a cross-sectional view taken along a line b-b shown inFIG.11A. The rod lamp unit RoU includes: the fourth light source L4; and a rod light guide31. The rod light guide31is configured as a cylindrical light-guiding rod made of a translucent resin material and extends in the left-right direction curvedly along upper edges of the low-beam lamp unit LoU and the high-beam lamp unit HiU. In other words, the rod lamp unit RoU and the edge lamp unit EgU are parallel to a circumferential direction of the low-beam lamp unit LoU and the high-beam lamp unit HiU and are placed around the low-beam lamp unit LoU and the high-beam lamp unit HiU. In this embodiment, a groove103athat is opened forwardly and is extends in the left-right direction is formed on a front surface of the extension103. The rod light guide31is accommodated in and supported by the groove103afor the most part. The rod light guide31is an example of an optical system.

FIG.12Ais a perspective view schematically showing one end portion of the rod light guide31in the lengthwise direction. The rod light guide31extends to the reverse side through a hole103bprovided in the extension103. A C-substrate1C is supported by a holder321at one end of the rod light guide31. The fourth light source L4is supported by the C-substrate1C. The holder321is configured to hold the rod light guide31with a holding piece322provided in the holder321. The holder321is fixed to the lamp body101by a screw or the like (not shown) inserted through a threaded hole323, thereby the rod light guide31also supported by the lamp body101.

The C-substrate1C is supported by the holder321such that the C-substrate1C and a white LED30as the fourth light source L4mounted on the C-substrate1C face an end surface of one end of the rod light guide31. The C-substrate1C is electrically connected to the lamp ECU5via a connector324. The white LED30is configured to emit light to be incident on the end surface of the rod light guide31.

The end surface of the rod light guide31is configured as an incident surface311on which the light from the white LED30as the fourth light source L4is incident. A circumferential surface region facing a rear side of the rod light guide31, that is, a region extending in the lengthwise direction of the rod light guide along an inner bottom surface of the groove103ais configured as a reflection surface312is configured to reflect the light incident on the rod light guide31internally. On the other hand, a circumferential surface region on a front side of the rod light guide31facing the reflection surface312, that is, a circumferential surface region exposed from the opening of the groove103ais configured as an emission surface313configured to emit the light reflected by the reflection surface312.

In the rod lamp unit RoU, when the white LED30as the fourth light source L4emits light, the light from the white LED30is incident on the incident surface311of the rod light guide31. The incident light is guided in the lengthwise direction of the rod light guide31through repeated internal reflections inside the rod light guide31and is internally reflected forward sequentially by the reflection surface312.

The reflection surface312is configured with a plurality of reflecting elements placed at a desired interval along the lengthwise direction of the rod light guide31, as schematically shown in a partial cross-sectional view inFIG.12B. That is, a plurality of V-shaped grooves314are placed at a desired interval from a circumferential surface on a rear side of the rod light guide31to the front, and a trapezoidal reflection step315is formed between V-shaped grooves314adjacent in the lengthwise direction. In this embodiment, a circumferential surface region on the rear side of the rod light guide31is formed into a flat surface extending in a tangential direction, in which the reflection steps315are provided by forming the V-shaped grooves314.

Light that is incident on the rod light guide31from the incident surface311and is projected onto an inner surface of the reflection surface312is reflected by an upper bottom surface of the trapezoidal reflection steps315or inclined surfaces adjacent thereto. The reflected light is incident on the emission surface313in a circumferential region on the front side of the rod light guide31and is emitted forward therefrom for the most part. Some light reflected by the reflection surface312travels toward a circumferential region on an upper or lower side of the rod light guide31and is internally reflected in the circumferential region to be emitted from the emission surface313.

Although some light may leak from the rod light guide31to the outside as shown inFIG.11B, such light is reflected by an inner surface of the groove103aof the extension103and is incident on the rod light guide31again. Consequently, the light is emitted from the emission surface313. Alternatively, such light is reflected by the inner surface of the groove103aand is simply emitted forward. Therefore, light guided through the rod light guide31is emitted forward for the most part, thereby realizing efficient use of light from the fourth light source L4.

If an angle of the V-shaped grooves314is set appropriately, an incident angle of light reflected on the upper bottom surfaces or the inclined surfaces of the trapezoidal reflection steps315can be large, especially larger than the critical angle. Consequently, it is possible to reduce light leaking from the rod light guide31through the reflection surface312to the outside, thereby increasing reflection efficiency of light on the reflection surface312and realizing efficient use of light from the emission surface313. Furthermore, since guiding efficiency of light in the lengthwise direction of the rod light guide31increases, light can be emitted widely in the lengthwise direction of the rod light guide31uniformly.

In the rod lamp unit RoU and the edge lamp unit EgU, which was described previously, when the lamp on/off switch SW1is turned on, the third light source L3and the fourth light source L4are basically controlled to emit light simultaneously. The edge lamp unit EgU is turned on as a lamp having the same function, that is, as an auxiliary lamp such that the emission surface213of the edge light guide21and the emission surface313of the rod light guide31are combined to from an upside-down-L-shaped light-emitting surface.

If the function switch SW3is switched to a clearance lamp, white light with desired brightness is emitted from the emission surface of the edge light guide21and the emission surface of the rod light guide31to turn on the lamp units RoU and EgU as schematically shown inFIG.13A. InFIGS.13A to13C, depth of shades represents brightness for the sake of convenience. Therefore, the edge lamp unit EgU and the rod lamp unit RoU are turned on as a clearance lamp such that the emission surface213of the edge light guide21and the emission surface313of the rod light guide31are combined to form the upside-down-L-shaped light-emitting surface as viewed from a front side of the head lamp HL (L-HL).

That is, a light-emitting surface of the edge lamp unit EgU that has a relatively large width and extends in the upper-lower direction and a light-emitting surface of the rod lamp unit RoU that has a relatively small width and extends in the left-right direction are combined. Therefore, the light-emitting surface has a complex shape for good design as compared to a lamp in which only edge lamp units or rod lamp units are combined.

If the function switch SW3is switched to the daytime running lamp, brightness of the third light source L3and the fourth light source L4gets higher. Consequently, the edge lamp unit21and the rod lamp unit31are turned on as the daytime running lamp more brightly than as the clearance lamp.

In this mode, it is preferable that brightness of the light-emitting surface of the edge lamp unit EgU be equal to brightness of the light-emitting surface of the rod lamp unit RoU. In this case, for example, the edge light guide21and the rod light guide31are designed such that quantities of emitted light per unit area of the emission surfaces213and313are equal to each other. In this embodiment, the third light source L3of the edge lamp unit EgU includes three white LEDs20, and the fourth light source L4of the rod lamp unit RoU includes one white LED30. Light quantity from the white LEDs20can be equal to light quantity from the white LED30if the emission surface213of the edge light guide21is designed to be three times larger than the emission surface313of the rod light guide31.

As shown inFIG.3, since the lamp ECU5includes the lighting adjuster52configured to adjust brightness of the third light source L3and the fourth light source L4, the brightness of the light sources L3and L4may be adjusted by checking brightness of light-emitting surfaces of the lamp units EgU and RoU when the edge lamp unit EgU and the rod lamp unit RoU are turned on and changing currents supplied to the light sources L3and L4by the lighting adjuster52.

For example, when the function switch SW3is switched and the edge lamp unit EgU and the rod lamp unit RoU are turned on as a clearance lamp, the third light source L3may emit light with a predetermined brightness and the fourth light source L4with lower brightness than the predetermined brightness, as shown inFIG.13B. In this case, the edge lamp unit EgU is turned on brightly, and the rod lamp unit RoU is turned on less brightly than the edge lamp unit EgU. When the edge lamp unit EgU and the rod lamp unit RoU are turned on as a daytime running lamp, the third light source L3and the fourth light source L4may emit light with the same brightness to turn on the edge lamp unit EgU and the rod lamp unit RoU with the same brightness.

On the contrary, when the clearance lamp is turned on, the fourth light source L4emits light with the predetermined brightness, and the brightness of the third light source L3may be reduced as shown inFIG.13Csuch that the brightness of the rod lamp unit RoU when the rod lamp unit RoU is turned on gets higher than that of the edge lamp unit EgU. In this case, when the daytime running lamp is turned on, the third light source L3and the fourth light source L4emit light with the same brightness to turn on the edge lamp unit EgU and the rod lamp unit RoU with the same brightness.

Alternatively, depending on the circumstances, one of the edge lamp unit EgU or the rod lamp unit RoU (for example, only the rod lamp unit RoU) may be turned on as the clearance lamp and the other one (for example, only the edge lamp unit EgU) as the daytime running lamp, or vice versa.

If the edge lamp unit EgU and the rod lamp unit RoU are selectively turned on as described above, the lighting adjuster52may adjust brightness of the edge lamp unit EgU to be equal to rod lamp unit RoU or may adjust brightness of the edge lamp unit EgU and the rod lamp unit RoU to be higher than the predetermined brightness. That is, the lamp unit are adjusted such that each lamp unit alone emits light with brightness required for the clearance lamp or the daytime running lamp.

Since light guided in the rod light guide31from the incident surface311to an opposite end (an inner end in the vehicle width direction, in this embodiment) is gradually attenuated, brightness may be uneven in the lengthwise direction. This may be resolved by, for example, reflection steps315increasing in size as they are placed from the incident surface to the opposite end. That is, reflection efficiency can be increased toward the opposite end of the rod light guide31to compensate for attenuation by gradually increasing intervals in the lengthwise direction between the V-shaped grooves314.

Alternatively, an end surface of the opposite end of the rod light guide31may be configured as an incident surface. In this case, another fourth light source is provided such that it faces the opposite incident surface, and light is incident on both ends of the right guide. Since light incident from one end of the rod light guide is superposed on light incident from the other end of the rod light guide to be reflected and emitted, it is possible to equalize brightness in the lengthwise direction.

If the rod lamp unit RoU is housed in the lamp housing100and the incident surface311of the rod light guide31is placed close to the B-substrate1B, the incident surface311may be placed such that the incident surface311faces the B-substrate1B on which the white LED as the fourth light source L4mounted. In this case, the C-substrate1C described above can be omitted. Alternatively, the incident surface311may be placed such that the incident surface311faces the A-substrate1A on which the white LED30as the fourth light source L4mounted.

Positions of the edge lamp unit EgU and the rod lamp unit RoU can interchange as appropriate. Although the edge lamp unit EgU and the rod lamp unit RoU are placed over side and upper regions around the low-beam lamp unit LoU and the high-beam lamp unit HiU in the present embodiment, the present invention is not limited thereto. Light-emitting surfaces of the lamp units EgU and RoU, that is, the light guides21and31may be combinedly arranged in the circumferential direction.

The configuration of the edge lamp unit EgU and/or the rod lamp unit RoU may be modified as appropriate. For example, at least one of the lamp units may include a plurality of lamp units. The number of light guides in each lamp unit may be changed. For example, the rod lamp unit RoU may be configured as a lamp unit in which a plurality of rod light guides31are arranged in parallel or in series.

Accordingly, since the edge lamp unit EgU and the rod lamp unit RoU are placed in the composite head lamp HL and these lamp units EgU and RoU are turned on as lamps having the same or different functions, design effect when the lamps are turned on is improved as compared to a lamp in which only edge lamp units or rod lamp units are combined.

Side Lamp Unit SiU

FIG.14is an exploded perspective view showing the side lamp unit SiU. A horizontal cross-sectional view of the configuration of the side lamp unit SiU is shown inFIG.7. The side lamp unit SiU is configured as a side marker lamp unit or a turn signal lamp unit. In this embodiment, the side lamp unit SiU is configured as a turn signal lamp. The turn signal lamp unit includes: the fifth light source L5; and a lens41.

The fifth light source L5is mounted on an outer surface in the vehicle width direction of the B-substrate1B, on which the third light source L3of the edge lamp unit EgU is mounted. That is, the fifth light source L5is mounted on a surface opposite to a surface on which the third light source L3is mounted. The fifth light source L5includes an LED40configured to emit white or amber light. In this embodiment, the fifth light source L5is configured with a white LED40. Lighting of the fifth light source L5is controlled independently of the third light source L3. The fifth light source L5emits white light outwardly in the vehicle width direction when turned on.

The white LED40as the fifth light source L5is mounted on the B-substrate1B in a position different from a position in which the white LEDs20as the third light source L3is mounted. That is, the white LED40and the white LEDs20are not placed back to back. It is preferable that the white LED40be far away from the white LEDs20. It is further preferable that the white LEDs40and20be as far away from the incident surface211and the reflection surface212of the edge light guide21as possible. Consequently, concentration of heat in a region on the B-substrate1B in which the white LED40and the white LEDs20are placed when the white LED40and the white LEDs20emit light simultaneously is averted, and reliability of the light sources is improved. It is possible to prevent heat when the white LED as the fifth light source L5emits light from affecting the edge light guide21.

The lens41includes a translucent portion411that is made of amber translucent resin and has a curved shape protruding forward. On an edge of the translucent portion411, frame412made of opaque resin, such as black resin, is integrally formed. The translucent portion411and the frame412are made from, for example, two-color injection molding. The lens41extends along an inner surface of the translucent cover102outwardly in the vehicle width direction from a front side of the automobile. Although not shown in the drawings, the frame412of the lens41is supported by the lamp body101. The opaque frame412conceals the B-substrate1B from view through the translucent cover102. The frame412is provided with visor414protruding inwardly along the edge of the translucent portion411.

The lens41is placed such that at least the translucent portion411faces the white LED40as the fifth light source L5. Light from the white LED40is emitted toward a front or left side of the automobile through the translucent portion411. A desired optical step413is formed on an inner surface of the translucent portion411. White light through the translucent portion411is refracted by the optical step413. The white light is emitted toward the desired region as amber light. When the turn-signal switch SW4shown inFIG.3is operated, the white LED40blinks. Consequently, blinking amber light is emitted from the translucent portion411toward the front or left side of the automobile, and the side lamp unit SiU functions as a turn signal lamp.

Since the B-substrate1B extends along a side surface of the edge lamp unit EgU, which is placed adjacently to the B-substrate1B, light from the white LED40as the fifth light source L5is shielded by the B-substrate1B and is prevented from leaking into the edge light guide21. In addition, light reflected by the translucent portion411from the white LED40and external light through the translucent portion411is shielded by the visor414, which is formed on the frame412, and is prevented from leaking into the edge light guide21. Consequently, pretended lighting of the edge lamp unit EgU is averted.

Accordingly, the white LED40as the fifth light source L5is mounted on the B-substrate1B, on which the third light source L3is mounted, and the B-substrate1B is shared by the third light source L3and the fifth light source L5. Consequently, a separate substrate at least for the fifth light source L5is not required, and reduction in the number of components of the side lamp unit SiU and downsizing of the side lamp unit SiU can be realized, which leads to reduction in the number of components of the head lamp HL and downsizing of the head lamp HL.

That is, the edge lamp unit EgU is configured as a light-guide-type lamp unit including the light guide21, and a light source can be considerably freely placed in the light-guide-type lamp unit if a shape of the light guide21is designed appropriately. Therefore, even when the side lamp unit SiU placed adjacently to the edge lamp unit EgU is configured as a lens-type lamp unit, a light source can be easily placed in the side lamp unit SiU appropriately. Consequently, the third light source L3of the edge lamp unit EgU and the fifth light source L5of the side lamp unit SiU can be mounted on the single B-substrate1B.

The side lamp unit SiU configured as a lens-type lamp unit has an optical system different from an optical system of the edge lamp unit EgU configured as a light-guide-type lamp unit. With this configuration, a light source of the edge lamp unit EgU and a light source of the side lamp unit SiU can be mounted on the single substrate.

If the B-substrate1B includes drive circuit for the third light source L3, the fifth light source L5can be caused to emit light using this circuit. In this case, a part of the drive circuit for the third light source L3may function as a drive circuit for the fifth light source L5. Since the connector222for connecting the third light source to the lamp ECU5is connected to the B-substrate, the fifth light source L5can be connected to the lamp ECU5using the connector222and a separate connector is not required.

As for assembly of the head lamp HL, when the edge lamp unit EgU is installed in the lamp housing100, the fifth light source L5of the side lamp unit SiU is installed, too. Since installation of the side lamp unit SiU is completed as only the lens41is installed to the lamp body101, the head lamp HL can be assembled simply and quickly.

The B-substrate1B is supported substantially in parallel along the outer surface of the edge light guide21. The optical axis of the edge light guide21is in the front-rear direction of the head lamp HL. Therefore, each of the white LEDs20and40of the third light source L3and the fifth light source L5is configured with a chip-type LED flip-chip mounted on the B-substrate1B, a light-emitting surface of each chip-type LED faces inwardly or outwardly in the vehicle width direction. Since light from the fifth light source L5is emitted laterally in the vehicle width direction, the optical step413for forming a light distribution of the turn signal lamp to emit light through the lens41can be easily designed.

Since the B-substrate1B is integrally supported by the edge light guide21, heat when the white LEDs20and40of the third light source L3and the fifth light source L4emits light can escape through the B substrate1B to the lamp body101, which supports the edge light guide21. Consequently, efficient and reliable lighting of the white LEDs20and40can be realized.

The side lamp unit SiU is placed in a bend in the head lamp HL, and the lens41is not present anterior to the emission surface213of the edge light guide21. That is, the lens41is not present in at least front and lateral regions of the emission surface213, which inclines outwardly in the vehicle width direction. Therefore, light emitted from the emission surface213of the edge light guide21toward the front or lateral region is not shielded by the side lamp unit SiU, nor by the lens41. Light emitted from the lateral emission step216of the edge light guide21toward the lateral region is not shielded, and a light distribution of the edge lamp unit EgU is not hindered.

The side lamp unit SiU may be configured as a reflector-type lamp unit. The side lamp unit SiU configured as a reflector-type lamp unit is an example of a lamp unit whose optical system is different from that of the edge lamp unit EgU configured as a light-guide-type lamp unit. In this case, a reflector may be placed in the vicinity of the B-substrate1B to reflect light from the fifth light source L5in a desired light distribution. The fifth light source L5may be configured with an LED configured to emit light in a predetermined color. Even if the side lamp unit SiU is configured as a reflector-type lamp unit in this way, the fifth light source L5can be mounted on the B-substrate1B, on which the third light source L3of the edge lamp unit EgU is mounted, too.

The present disclosure is not limited to the embodiments described above, and various modifications can be made. For example, in the low-beam lamp unit and the high-beam lamp unit, the number of the white LEDs as the first light source or the second light source or the configuration of the reflector can be changed as appropriate. The low-beam lamp unit and the high-beam lamp unit may be configured as a lens-, especially, projector-type lamp unit.

In the edge lamp unit, the configuration of the edge lamp guide can be changed as appropriate. In particular, the number of the white LEDs as the third light source and the number of the reflecting surface sections, which are provided in the edge light guide correspondingly to the white LEDs, can be changed as appropriate. The auxiliary reflection steps formed on the boundary surface between the adjacent reflecting surface sections is not limited to knurled-structured one as long as they are configured to reflect light divergently or diffusedly.

In the rod lamp unit, the cross-sectional shape and the front shape of the rod light guide can be changed as appropriate. The reflection surface may be configured differently depending on the shape or size of the rod light guide. For example, a light-reflecting film may be provided on the reflection surface.

Although the edge lamp unit and the rod lamp unit are configured as a clearance lamp and a daytime running lamp, respectively, in the embodiment described above, they may be configured as an auxiliary lamp other than a clearance lamp or a daytime running lamp or a signal lamp. Although the side lamp unit is configured as a turn signal lamp, the side lamp unit may be configured as a side marker lamp, a signal lamp other than turn signal lamp or a side marker lamp, or an auxiliary lamp.

The present application is based on: Japanese Patent Application No. 2019-224321, filed on Dec. 12, 2019; Japanese Patent Application No. 2019-224322, filed on Dec. 12, 2019; and Japanese Patent Application No. 2019-224323, filed on Dec. 12, 2019, the contents of which are incorporated herein by reference.