Turn lamp for vehicle outside mirror

While a light source is arranged on the back side of a light guide lens, light beams can be emitted from the light source with respective optical axes directed in one direction and be guided toward opposite ends of the light guide lens. A light source and a reflective surface are arranged on the back side of a light guide lens. The light source emits light beams with respective optical axes directed in one direction. One of the light beams obliquely enters the light guide lens toward one end in a long direction of the light guide lens without being reflected by the reflective surface. Another one of the light beams is reflected by the reflective surface and obliquely enters the light guide lens toward another end in the long direction of the light guide lens.

The disclosure of Japanese Patent Application No. JP2012-281171 filed on Dec. 25, 2012 including the specification, drawings, claims and abstract is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a turn lamp to be assembled to a vehicle outside mirror, which enables light beams from a light source to be emitted with respective optical axes directed in one direction and be guided toward opposite ends of a light guide lens while the light source is arranged on the back side of the light guide lens.

2. Description of the Related Art

As examples of a vehicle door mirror equipped with a turn lamp, there are ones described in Japanese Patent Laid-Open Nos. 2006-114309 and 2010-052566. The turn lamp described in Japanese Patent Laid-Open No. 2006-114309 is one with a light source arranged at an end in a long direction (in other words, long length direction or longitudinal direction, etc.) of a light guide lens. The turn lamp described in Japanese Patent Laid-Open No. 2010-052566 is one with a light source arranged on the back side of a light guide lens.

In the turn lamp described in Japanese Patent Laid-Open No. 2006-114309, a light source is arranged at an end of a light guide lens, providing an advantage of being able to guide light over an entire length of the light guide lens by emitting light beams from the light source with respective optical axes directed in one direction; however, there is a problem of an increase in entire length of the turn lamp. Meanwhile, in the turn lamp described in Japanese Patent Laid-Open No. 2010-052566, light sources are arranged on the back side of a light guide lens, providing the advantage of suppression of an entire length of the turn lamp; however, it is necessary to make light beams from the light sources be emitted in different directions: a direction toward one end of the light guide lens and a direction toward another end.

The present invention aims to solve the problems in the conventional techniques mentioned above and provide a turn lamp that enables light beams to be emitted from a light source with respective optical axes directed in one direction and be guided toward opposite ends of a light guide lens while the light source is arranged on the back side of the light guide lens.

SUMMARY OF THE INVENTION

The present invention provides a turn lamp for a vehicle outside mirror, the turn lamp including a light guide lens having an elongated shape with a shape of a front surface having a long direction (in other words, long length direction or longitudinal direction, etc.) and a short direction (in other words, short length direction or transversal direction or lateral direction, etc.), the light guide lens including a transparent material, and a light source arranged on a back side of the light guide lens, a light beam emitted from the light source entering a predetermined position on the back side of the light guide lens and being radiated from surfaces of respective parts of the light guide lens to an outside of the light guide lens while being guided inside the light guide lens, the turn lamp including a reflective surface arranged on the back side of the light guide lens, wherein the light source emits a light beam with an optical axis directed in one direction; wherein a part of the light beam emitted from the light source obliquely enters the light guide lens toward one end in the long direction of the light guide lens without being reflected by the reflective surface; and wherein another part of the light beam emitted from the light source is reflected by the reflective surface and obliquely enters the light guide lens toward another end in the long direction of the light guide lens. Consequently, while the light source is arranged on the back side of the light guide lens, a light beam can be emitted from the light source with an optical axis directed in one direction and guided toward opposite ends of the light guide lens.

In the present invention, it is possible that the position where the light beam enters the light guide lens is set at a middle portion in the long direction of the light guide lens. Consequently, as a result of the light source being arranged on the back side of the light guide lens, even if a bulge portion is generated by the light source on a back surface of the turn lamp, a position in the long direction of the light guide lens where the light source is arranged can favorably be selected. Accordingly, the bulge portion can be arranged at a position that avoids interference with structures such as a frame, a power folding unit and a mirror surface angle adjustment actuator inside a door mirror, preventing a degree of freedom in designing an internal structure of the door mirror from being impaired.

In the present invention, it is possible that: the light source includes a first LED and a second LED with respective optical axes directed in a same direction; a light beam emitted from the first LED is guided inside the light guide lens toward the one end of the light guide lens without substantially being reflected by the reflective surface; and a light beam emitted from the second LED is substantially reflected by the reflective surface and guided inside the light guide lens toward the other end of the light guide lens. Consequently, by arranging the first LED and the second LED with a proper space therebetween, a light beam entering the light guide lens off the reflective surface and a light beam entering the light guide lens after falling on the reflective surface can easily be separated from each other. In this case, it is possible that: the first LED is arranged at a position closer to the light guide lens than the second LED, and the second LED is arranged at a position further from the light guide lens than the first LED; the light beam emitted from the first LED travels in a straight line and obliquely enters the light guide lens toward the one end; and the light beam emitted from the second LED is reflected by the reflective surface and obliquely enters the light guide lens toward the other end. Consequently, the simple arrangement of the first and second LEDs enables the light beams to be divided and enter the light guide lens toward the opposite ends of the light guide lens. Also, in the aforementioned structure described in Japanese Patent Laid-Open No. 2010-052566, two LEDs are arranged outward from each other, resulting in the problem of the area between the two LEDs tending to be dark. Meanwhile, according to this aspect of the present invention, a position of entrance of the light beam directed to the one end of the light guide lens and a position of entrance of the light beam directed to the other end can be arranged to close to each other, enabling suppression of the darkening of the area between the positions of entrance.

In the present invention, it is possible that the first LED and the second LED are mounted on one substrate with the respective optical axes directed in the same direction. In the aforementioned structure described in Japanese Patent Laid-Open No. 2010-052566, it is necessary to mount two LEDs on separate substrates and arrange the LEDs with respective optical axes in directions different from each other, resulting in the problem of taking trouble in the work of mounting two LEDs in separate substrates and the work of assembling the respective substrates to a turn lamp. Meanwhile, according to this aspect of the present invention, the first LED and the second LED may be mounted on one substrate with respective optical axes directed in a same direction, facilitating the work of mounting the first and second LEDs on a substrate and the work of assembling the substrate to a turn lamp.

In the present invention, it is possible that the reflective surface is arranged on a lamp housing arranged on the back side of the light guide lens. Consequently, the reflective surface can be arranged on the lamp housing side. Also, in the present invention, it is possible that the reflective surface is arranged on the light guide lens. Consequently, the reflective surface can be arranged on the light guide lens side.

In the present invention, it is possible that: the turn lamp further including a convex lens that converts the light beam emitted from the light source into collimated light; and a part of the collimated light resulting from the conversion enters the light guide lens without being reflected by the reflective surface, and another part of the collimated light is reflected by the reflective surface and enters the light guide lens. Consequently, the light beam emitted from the light source can efficiently enter the light guide lens toward the opposite ends of the light guide lens without diffusing widely. In this case, it is possible that the convex lens is configured in such a manner that the convex lens is integrated with the light guide lens on the back side of the light guide lens using a material that is the same as that of the light guide lens. Consequently, since the light guide lens and the convex lens are integrated with each other, the work of assembling the light guide lens and the convex lens to a turn lamp is facilitated. Also, misalignment between the light guide lens and the convex lens is prevented.

In the present invention, it is possible that: the light guide lens includes a projection configured in such a manner that the projection is integrated with the light guide lens on the back side of the light guide lens using a material that is the same as that of the light guide lens; the projection includes a first surface allowing the light beam from the light source to enter at a right angle to an optical axis of the light beam, and a second surface arranged in parallel to the reflective surface on a side opposite to the first surface or arranged at a surface that is the same as the reflective surface on the side opposite to the first surface; a part of the light beam that has entered from the first surface enters the light guide lens off the second surface and is guided toward the one end of the light guide lens; and another part of the light beam that has entered from the first surface falls on the second surface, is reflected by the reflective surface, enters the light guide lens and is guided toward the other end of the light guide lens. Consequently, as a result of the light beam entering the light guide lens through the projection, the light beam can efficiently enter the light guide lens. Also, the influence of refraction when the light beam from the light source obliquely enters the light guide lens (body portion of the light guide lens not including the projection) can be reduced.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the present invention will be described below.FIG. 2illustrates a right-side door mirror10equipped with a turn lamp according to the present invention. The door mirror10includes a mirror base12fixed to a vehicle body (right door) (not illustrated), and a mirror body14pivotably attached to and supported by the mirror base12so as to be able to move between a used position and a folded position. In the mirror body14, a frame, a power folding unit and a mirror surface angle adjustment actuator both supported by the frame, a mirror holder supported by the mirror surface angle adjustment actuator in such a manner that a mirror surface angle can be adjusted, a mirror plate fixed to and held by the mirror holder (these are not illustrated), and a turn lamp18are arranged and housed inside a mirror housing16. In the mirror housing16, a cut portion20is formed from a roughly center portion in a width direction of the back side thereof (vehicle front side) to the outer side (side away from the vehicle body) as to extend in a horizontal direction, and an outer lens22of the turn lamp18is exposed from the cut portion20in a projecting manner. The outer lens22is formed as to curve in the horizontal direction (long direction) along a curved surface of the mirror housing16. Turn signal light emitted from an entire exposed surface of the turn lamp18can be viewed from all of areas from the front side to the right rear side of the vehicle.

A configuration of the turn lamp18will be described.FIG. 3is an exploded perspective view of the turn lamp18. The turn lamp18includes a lamp housing24formed of an opaque plastic material, and a light guide lens26and an outer lens22each formed of a transparent plastic material such as a PMMA resin. The lamp housing24includes a holding portion that holds the transparent light guide lens26. The transparent outer lens22provides a cover for the light guide lens26. The lamp housing24is formed in a rectangular shape in its entirety. The light guide lens26has a flat plate shape, and a shape of a front surface thereof is formed in an elongated shape having a long direction and a short direction. The outer lens22is formed in a rectangular shape having a size substantially the same as that of the lamp housing24, in its entirety. The lamp housing24and the light guide lens26are formed so as to curve in the long direction along the outer lens22. The light guide lens26is put in a recess part28at a front surface of the lamp housing24, fitted in, and fixed to the lamp housing24by, e.g. bonding, the outer lens22is put on the lamp housing24, and the lamp housing24and the outer lens22are joined to each other by, e.g., welding or bonding at respective peripheral portions in which the lamp housing24and the outer lens22come into contact with each other, whereby the lamp housing24and the outer lens22are integrated in such a manner that the light guide lens26is housed in an internal space30(FIGS. 1 and 5).

InFIG. 3, at a middle portion in the long direction on the back side of the light guide lens26, a box-shaped portion31that opens downward is configured in such a manner that the box-shaped portion31is integrated with the light guide lens26using a transparent plastic material that is the same as that of the light guide lens26. Also, on the back side of the lamp housing24, a box-shaped housing portion36is provided in such a manner that the housing portion36is integrated with the lamp housing24using an opaque plastic material that is the same as that of the lamp housing24. The housing portion36houses the box-shaped portion31and a substrate40with a light source42mounted thereon. The housing portion36includes an opening38at a side thereof, and the substrate40with the light source42mounted thereon is put in the housing portion36via the opening38and fixed to the housing portion36. On the substrate40, a plurality of LEDs42which constitute the light source42are mounted with respective optical axes directed in a same direction that is at right angle with a surface of the substrate40. In this example, the light source42includes four LEDs42a,42b,42cand42darrayed in a quadrangular shape. From among the LEDs, the LEDs42aand42bprovide first LEDs arranged at respective positions close to the light guide lens26, and the LEDs42cand42dprovide second LEDs arranged at respective positions far from the light guide lens26. Turn signal light is emitted from each of the LEDs42a,42b,42cand42d.

FIG. 4illustrates an assembled state of the turn lamp18inFIG. 3. Also,FIGS. 1 and 5illustrate a cross-section along arrow A-A inFIG. 4and a cross-section along arrow B-B inFIG. 4, respectively. Also,FIG. 6illustrates an exploded cross-section along arrow A-A inFIG. 4with the outer lens22excluded. As illustrated inFIG. 5, a recess part28that houses the light guide lens26is configured as an empty space surrounded by a light leakage prevention rib44formed at the front surface of the lamp housing24. As a result of the light guide lens26being housed in the recess part28, light leakage from upper and lower edge surfaces of the light guide lens26is prevented.

When the light guide lens26is put in the recess part28, the box-shaped portion31formed at a back surface of the light guide lens26is put in an internal space48of the housing portion36formed at a back surface of the lamp housing24via an opening46formed at the front surface of the lamp housing24. On a surface on the deep side of the housing portion36, a reflective surface50is arranged by, e.g., film formation of a metal reflective film or adhesion of a film member coated with a metal reflective film, or adhesion of a metal plate. The reflective surface50is arranged on a region that corresponds to only a part of an entire length in the long direction of the light guide lens26. Accordingly, if a light beam is projected from the back side of the light guide lens26, depending on the position where the light beam is projected, the light beam directly enters the light guide lens26(plate-shaped part excluding the box-shaped portion31including the later-described projection33) without falling on the reflective surface50or enters the light guide lens26after falling on and being reflected by the reflective surface50. The substrate40with the LEDs42mounted thereon is put and fitted in the housing portion36and fixed to the housing portion36by, e.g., bonding or screw fastening. After the substrate40is put in and fixed to the housing portion36, the opening38of the housing portion36is occluded by bonding a lamp cover52to the housing portion36. Electric wires (not illustrated) connected to the LEDs42are drawn to the outside of the turn lamp18through the lamp cover52. At a front wall of the box-shaped portion31that faces the four LEDs42(42a,42b,42cand42d), four convex lenses54(54a,54b,54cand54d) that convert light beams emitted from the LEDs42(42a,42b,42cand42d) into collimated light are formed. A rear wall of the box-shaped portion31provides a projection33having a wedge shape in a cross section. A front surface33aof the projection33is at right angle with the optical axes of the respective LEDs42and a rear surface33bof the projection33is parallel with the reflective surface50.

Light beam paths of turn signal light from the turn lamp18having the configuration described above are indicated in dashed lines La and Lb inFIG. 1. The light beam La is a light beam emitted from the first LEDs42aand42b, and the light beam Lb is a light beam emitted from the second LEDs42cand42d. The light beam La emitted from the LEDs42aand42bis converted into collimated light by the convex lenses54aand54band then obliquely enters the light guide lens26toward one end26a(end at a position far from the vehicle body) of the light guide lens26, and while the light is repeatedly subjected to internal reflection (total reflection resulting from an incident angle exceeding a critical angle at an interface with the air) inside the light guide lens26, the light is radiated little by little to the outside at each part, and finally, the light reaches the end26aand is radiated toward the right rear side of the vehicle. The light beam Lb emitted from the LEDs42cand42dis converted into collimated light by the convex lenses54cand54dand is reflected by the reflective surface50and then obliquely enters the light guide lens26toward another end26b(end at a position close to the vehicle body), and while the light is repeatedly subjected to internal reflection inside the light guide lens26until the light reaches the other end26b, the light is radiated little by little to the outside. Consequently, turn signal light is emitted from all regions in the long and short directions of the light guide lens26. The turn signal light emitted from the light guide lens26passes through the outer lens22and is radiated to the outside, and can be viewed from all of the areas from the front side to the right rear side of the vehicle.

FIG. 7is an enlarged view of a part around positions where the light beams La and Lb enter the light guide lens26inFIG. 1. The light beam La emitted from the LEDs42aand42band converted into collimated light by the convex lenses54aand54benters the projection33at right angle with the front surface33aof the projection33(that is, without refraction), travels in a straight line off the rear surface33band the reflective surface50and directly obliquely enters the light guide lens26(plate-shaped portion excluding the box-shaped portion31including the projection33) toward the end26aof the light guide lens26(with an angle a of the optical axis relative to a tangent in the long direction of the light guide lens26at the position of entrance as a sharp angle) and is guided toward the end26a. Also, the light beam Lb emitted from the LEDs42cand42dand converted into collimated light by the convex lenses54cand54denters the projection33at right angle with the front surface33aof the projection33, travels in a straight line, exits from the rear surface33b, is reflected by the reflective surface50, and enters the projection33again from the rear surface33b, and obliquely enters the light guide lens26(plate-shaped portion excluding the box-shaped portion31including the projection33) toward the other end26bof the light guide lens26(with an angle b of the optical axis relative to the tangent in the long direction of the light guide lens26at the position of entrance as a sharp angle) and is guided toward the other end26b. In this case, the reflective surface50is parallel with the rear surface33b, and thus, an angle change of the light beam Lb due to refraction when the light beam Lb exits from the rear surface33bis cancelled by an angle change of the light beam Lb due to refraction when the light beam Lb enters the projection33again from the rear surface33b. The angles a and b when the light beams La and Lb enter the light guide lens26are substantially equal to each other. As a result of the light beams La and Lb entering the light guide lens26through the projection33, the light beams La and Lb can efficiently enter the light guide lens26. Also, since the optical axes of the light beams La and Lb are at right angle with the front surface33aof the projection33and the rear surface33bof the projection33is parallel with the reflective surface50, the influence of refraction when the light beams La and Lb obliquely entering the light guide lens26can be reduced.

FIG. 8illustrates an alteration of the embodiment described above. This is one resulting from arranging a reflective surface50on a rear surface33bof a projection33by, e.g., film formation of a metal reflective film, adhesion of a film member coated with a metal reflective film or adhesion of a metal plate. The rest of the configuration is the same as that of the embodiment described above.

Although the above embodiment has been described in terms of a case where a reflective surface is arranged by, e.g., film formation of a metal reflective film, adhesion of a film member coated with a metal reflective film or adhesion of a metal plate, instead, a reflective surface can be arranged using internal reflection by a transparent member itself, which constitutes the light guide lens (for example, internal reflection by the rear surface33bof the projection33in the above embodiment). Consequently, a need to use, e.g., a metal reflective film, a film member coated with a metal reflective film or a metal plate can be eliminated. Also, although in the above embodiment, the convex lenses54are configured in such a manner that the convex lenses54are integrated with the light guide lens26, instead, convex lenses54can be configured separately from the light guide lens26and fixed to a substrate40or LEDs42. Also, although in the above embodiment, LEDs are used as a light source, instead, incandescent bulbs or other light sources can be used as a light source. Also, although in the above embodiment, a plurality of light sources is used, only one light source can be used if the light source has a sufficient luminance. In this case, the one light source can be arranged in such a manner that a part (for example, a half) of a range irradiated with a light beam emitted from the light source falls on a reflective surface and another part (for example, the remaining half) travels off the reflective surface. Also, although in the above embodiment, the optical axis of the light source42is directed toward the end26alocated at a position far from the vehicle body, as opposed to this, an optical axis of a light source42can be directed toward an end26blocated at a position close to the vehicle body. Also, a separate reflective surface can be formed on a back surface of a light guide lens26or an inner surface of a recess part28of a lamp housing24by, e.g., film formation of a metal reflective film, adhesion of a film member coated with a metal reflective film or adhesion of a metal plate to enhance the use efficiency of light beams. Also, although in the above embodiment, the box-shaped portion31including the projection33is configured in such a manner that the box-shaped portion31is integrated with the light guide lens26, instead, a box-shaped portion31including a projection33can be configured separately from a light guide lens26and joined to a back surface of the light guide lens26by, e.g., a transparent adhesive. Also, although the above embodiment has been described in terms of a case where the present invention is applied to a turn lamp for a right-side door mirror, the present invention can also be applied to any of turn lamps for various types of vehicle outside mirrors such as a left-side door mirrors and left and right-side fender mirrors.

DESCRIPTION OF SYMBOLS