JP5418759B2 - Vehicle lighting - Google Patents

Description

  The present invention relates to a vehicular lamp using a light guide plate, and more particularly, to a vehicular lamp using a projection lens including a cylindrical lens portion and a light guide plate in which no illusion light appears (or hardly appears) above a horizontal line. .

  Conventionally, a vehicular lamp using a light guide plate instead of a reflector used in a general projector-type headlamp is known (see, for example, Patent Document 1).

  FIG. 24 is a diagram for explaining the vehicular lamp 200 described in Patent Literature 1. FIG.

  As shown in FIG. 24A, the vehicular lamp 200 described in Patent Document 1 includes a light guide plate 210, a light source 220, and a projection lens 230. A luminance control element (not shown) is formed on the back surface 211 of the light guide plate 210 opposite to the projection lens 230, and an exit surface 212 is formed on the light guide plate 210 side of the projection lens 230. .

  In the vehicular lamp described in Patent Document 1, the light beam from the light source 220 that is incident and guided into the light guide plate 210 and reaches the luminance control element is reflected toward the emission surface 212 by the luminance control element, Through the emission surface 212, a luminance distribution as shown in FIG. 24B is formed over almost the entire area of the emission surface 212. This luminance distribution is inverted and enlarged and projected by the projection lens 230, whereby a predetermined light distribution pattern is formed.

JP 2008-140729 A

  However, in the vehicular lamp 200 described in Patent Document 1, when a projection lens including a cylindrical lens unit is employed as the projection lens 230, the light distribution pattern formed by the vehicular lamp 200 includes, for example, FIG. There is a problem that illusion light P1 (also referred to as glare light) appears above the horizontal line H as shown in FIG.

  In the vehicular lamp 200 described in Patent Document 1, the light guide plate 210 is a flat light guide plate and the light source 220 faces the end surface of the light guide plate 210 as shown in FIG. Since the light from the light source 220 cannot be collected near the line L corresponding to the horizontal line on the emission surface 212, the current brightness of the LED light source assumed as the light source 220 in Patent Document 1 Now, there is a problem that a luminance distribution including a high luminance portion corresponding to a light distribution pattern including the maximum luminous intensity required for the headlamp cannot be formed.

  Furthermore, Patent Document 1 discloses an example in which the light guide plate 210 is disposed in an inclined state. However, since the light guide plate 210 is a flat light guide plate, the depth dimension of the vehicular lamp 200 is further increased. There is also a problem that it cannot be shortened.

  The present invention has been made in view of such circumstances, and a vehicular lamp using a projection lens including a cylindrical lens portion and a light guide plate in which no illusion light appears (or hardly appears) above the horizon. It is a first problem to provide the above.

  Another object of the present invention is to provide a vehicular lamp using a light guide plate capable of forming a light distribution pattern including the maximum luminous intensity required for a headlamp. Another object of the present invention is to provide a vehicular lamp using a light guide plate that can make the depth dimension of the vehicular lamp shorter than before.

  In order to solve the above-described problem, the invention according to claim 1 is directed to a vehicular lamp including a light guide plate made of a transparent material in a visible light region, a light source, and a projection lens. A light guide plate body bent toward the projection lens in the vicinity of the focal point of the projection lens and a reflection surface with respect to the base end, and the base end includes the incident surface, the first emission surface, and vice versa. The light guide plate main body includes a second emission surface, a second back surface on the opposite side, and a prism surface, and the incident surface is a light beam emitted from the light source. Is a light incident surface for making the light incident on the inside of the light guide plate, the first emission surface and the second emission surface are formed on the projection lens side, and the first back surface and the second back surface are the projections. Formed on the opposite side of the lens, the reflective surface The prism surface is formed between the first back surface and the second back surface or on the first back surface, and the prism surface enters the light guide plate from the incident surface and is guided to reach the prism surface. A light beam from the light source is reflected toward the first and second emission surfaces so that the incident angle with respect to the first and second emission surfaces is within a critical angle, and the first and second emission surfaces are reflected. 2 is a lens cut surface for forming a luminance distribution on the emission surface, and the reflection surface is guided from the incident surface into the light guide plate and reaches the reflection surface. Is reflected toward the vicinity of the focal point of the projection lens so that the incident angles with respect to the first and second emission surfaces are within a critical angle, and the surrounding luminance on the first and second emission surfaces is reflected. A reflective surface for forming a higher brightness portion than the projection surface. The lens is a lens for reversing and enlarging the luminance distribution formed on the first emission surface and the second emission surface to form a predetermined light distribution pattern, and includes at least a cylindrical lens portion. Furthermore, it is a light-shielding member disposed between the light guide plate and the projection lens, and emits light from the light source that is irradiated from the first emission surface and the second emission surface and spreads in the left-right direction. A light-shielding shade for shielding light so as not to be incident on the lower half of the optical axis.

  According to the first aspect of the present invention, since the auxiliary shade is disposed between the light guide plate and the projection lens, the light beam irradiated from the first emission surface and the second emission surface and spreading in the left-right direction is the auxiliary shade. Is shielded from light. For this reason, it becomes possible to prevent the light beam spreading in the left-right direction from entering the lower half of the optical axis of the cylindrical lens portion. For this reason, it becomes possible to prevent the dazzling light resulting from the light rays spreading in the left-right direction entering the lower half of the optical axis of the cylindrical lens portion. That is, according to the first aspect of the present invention, it is possible to provide a vehicular lamp that can obtain a light distribution pattern suitable for a headlamp without causing illusion light above the horizontal line.

  According to the first aspect of the present invention, the light guide plate body is bent toward the projection lens in the vicinity of the focal point of the projection lens with respect to the base end portion, and between the first back surface and the second back surface (or The first back surface is formed with a reflecting surface. For this reason, the light from the light source that is incident on the light guide plate from the incident surface and guided and reaches the reflecting surface has an incident angle with respect to the first emitting surface and the second emitting surface within the critical angle by the reflecting surface. In this way, the light is reflected toward the vicinity of the focal point of the projection lens and is emitted from the first emission surface and the second emission surface. Thereby, the luminance distribution including the high luminance part higher than the surrounding luminance on the first emission surface and the second emission surface (the luminance including the high luminance part corresponding to the light distribution pattern including the maximum luminous intensity required for the headlamp). Distribution) is formed. The luminance distribution including the high luminance part is inverted and enlarged and projected by the projection lens. Thereby, it is possible to form a light distribution pattern including the maximum luminous intensity required for the headlamp.

  According to the first aspect of the present invention, the light guide plate body is bent toward the projection lens near the focal point of the projection lens with respect to the base end. For this reason, it is possible to shorten the dimension of the light guide plate body in the optical axis direction. For this reason, it becomes possible to make the depth dimension of a vehicle lamp shorter than before.

  According to a second aspect of the present invention, in the first aspect of the present invention, the light-shielding shade reflects light rays from the light source irradiated from the first emission surface and the second emission surface toward the projection lens. And a reflective surface for illuminating the road sign.

  According to the invention described in claim 2, since the light-shielding shade includes a reflection surface for illuminating the road sign, it is possible to illuminate the road sign using a light ray shielded by the light-shielding shade (reflection surface). It becomes. That is, according to the invention described in claim 2, it is possible to improve the light utilization efficiency.

  According to a third aspect of the present invention, there is provided a vehicular lamp including a light guide plate made of a transparent material in a visible light region, a plurality of light sources, and a projection lens. The light guide plate has a base end portion and a base end portion. A light guide plate body bent toward the projection lens in the vicinity of the focal point of the projection lens, and a reflection surface, and the base end portion includes an incident surface, a first emission surface, and a first back surface on the opposite side. The light guide plate main body includes a second emission surface, a second back surface opposite to the second emission surface, and a prism surface, and the incident surface guides light emitted from the plurality of light sources. A light incident surface for entering the inside of the optical plate, wherein the first light exit surface and the second light exit surface are formed on the projection lens side, and the first back surface and the second back surface are defined as the projection lens. The reflective surface is formed on the opposite side, and the first back surface and The prism surface is formed between the two back surfaces or the first back surface, and the prism surface is guided from the incident surface into the light guide plate and reaches the prism surface from the plurality of light sources. A light beam is reflected toward the first emission surface and the second emission surface so that an incident angle with respect to the first emission surface and the second emission surface is within a critical angle, and the first emission surface and the second emission surface are reflected. It is a lens cut surface for forming a luminance distribution above, and the reflection surface is guided by being incident on the inside of the light guide plate from the incident surface, and receives light beams from the plurality of light sources that have reached the reflection surface. Reflecting toward the vicinity of the focal point of the projection lens so that the incident angles with respect to the first and second emission surfaces are within a critical angle, and from the surrounding luminance on the first and second emission surfaces. Is a reflective surface for forming a high-brightness portion. The lens is a lens for reversing and enlarging the luminance distribution formed on the first emission surface and the second emission surface to form a predetermined light distribution pattern, and includes at least a cylindrical lens portion. Furthermore, the auxiliary | assistant reflective surface arrange | positioned corresponding to each of these light sources between the said light-guide plate and the said projection lens is provided, The said auxiliary | assistant reflective surface is from said 1st output surface and 2nd output surface. A light beam from the corresponding light source that is irradiated and spreads in the left-right direction is converted into a light beam parallel to a vertical plane including the optical axis of the cylindrical lens unit, and the lower half of the optical axis of the cylindrical lens unit It is a reflective surface for reflecting toward the surface.

  According to the third aspect of the present invention, the auxiliary reflection surface is disposed between the light guide plate and the projection lens, so that the light beam irradiated from the first emission surface and the second emission surface and spreading in the left-right direction is auxiliary reflection. It is converted into parallel rays by the surface. For this reason, it becomes possible to prevent (or reduce) the light beam spreading in the left-right direction from directly entering the lower half of the optical axis of the cylindrical lens portion. For this reason, it becomes possible to prevent (or reduce) the illusion light caused by the light beam spreading in the left-right direction directly entering the lower half of the optical axis of the cylindrical lens portion. That is, according to the third aspect of the present invention, it is possible to provide a vehicular lamp that can obtain a light distribution pattern suitable for a headlamp with almost no illusion light appearing above the horizontal line. .

  According to the third aspect of the present invention, the light guide plate body is bent toward the projection lens in the vicinity of the focal point of the projection lens with respect to the base end portion, and between the first back surface and the second back surface (or The first back surface is formed with a reflecting surface. For this reason, the light from the light source that is incident on the light guide plate from the incident surface and guided and reaches the reflecting surface has an incident angle with respect to the first emitting surface and the second emitting surface within the critical angle by the reflecting surface. In this way, the light is reflected toward the vicinity of the focal point of the projection lens and is emitted from the first emission surface and the second emission surface. Thereby, the luminance distribution including the high luminance part higher than the surrounding luminance on the first emission surface and the second emission surface (the luminance including the high luminance part corresponding to the light distribution pattern including the maximum luminous intensity required for the headlamp). Distribution) is formed. The luminance distribution including the high luminance part is inverted and enlarged and projected by the projection lens. Thereby, it is possible to form a light distribution pattern including the maximum luminous intensity required for the headlamp.

  According to the third aspect of the present invention, the light guide plate body is bent toward the projection lens near the focal point of the projection lens with respect to the base end. For this reason, it is possible to shorten the dimension of the light guide plate body in the optical axis direction. For this reason, it becomes possible to make the depth dimension of a vehicle lamp shorter than before.

  The invention according to claim 4 is the invention according to claim 3, wherein the light guide plate is divided into a number corresponding to the number of the plurality of light sources, and the light guide plate main body of each of the divided light guide plates. Is characterized in that it is formed in a substantially trapezoidal shape in which the width of the base end edge is shorter than that of the front end edge, and the distance between both side surfaces increases from the base end edge toward the front end edge.

  According to the invention described in claim 4, the light guide plate is divided into a number corresponding to the number of the plurality of light sources, and the light guide plate main body of each of the divided light guide plates is compared with its front end edge. The width of the base end edge is short, and it is formed in a substantially trapezoidal shape in which the distance between both side surfaces increases from the base end edge toward the front end edge. For this reason, the light beam from the specific light source that is guided to the light guide plate and reaches the both side surfaces is totally reflected without going to the auxiliary reflection surface provided corresponding to the adjacent light source, and the specific light source It irradiates toward the auxiliary reflecting surface provided corresponding to the light source. For this reason, according to the invention of Claim 4, it becomes possible to prevent the dazzling light which originates in the light ray from an adjacent light source injecting into a specific auxiliary | assistant reflective surface.

  The invention described in claim 5 is the invention described in claim 4, wherein the both side surfaces are formed in a shape substantially along a parabola or an ellipse.

  According to the fifth aspect of the present invention, similarly to the fourth aspect, it is possible to prevent the illusion light caused by the incidence of the light beam from the adjacent light source on the specific auxiliary reflection surface.

  A sixth aspect of the present invention is the prism according to any one of the third to fifth aspects, wherein the prism is disposed between the light guide plate and the projection lens. It is further characterized by further comprising a prism for refracting light rays irradiated from the emission surface and incident on the lower half of the cylindrical lens portion from the optical axis.

  According to the sixth aspect of the present invention, the prism for refracting the light beam irradiated from the first emission surface and the second emission surface is disposed between the projection lens and the auxiliary reflection surface. In addition, it becomes possible to control the light distribution from the auxiliary reflection surface to a level below the horizontal line, and it is possible to form a light distribution pattern more suitable for the headlamp.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the vehicle lamp using the projection lens containing a cylindrical lens part and a light-guide plate in which a dazzling light does not appear above a horizontal line (or hardly appears).

(A) is a top view of the vehicular lamp according to the first embodiment of the present invention, (b) is a front view of the vehicular lamp according to the first embodiment of the present invention, and (c) is a view of the present invention. It is a side view of the vehicular lamp which is 1st Embodiment. (A) is a top view of a light guide plate unit used in the vehicular lamp according to the first embodiment of the present invention, and (b) is a light guide plate unit used in the vehicular lamp according to the first embodiment of the present invention. (C) is a side view of the light-guide plate unit used for the vehicle lamp which is 1st Embodiment of this invention. It is a side view of the vehicle lamp which is 1st Embodiment of this invention. It is sectional drawing for demonstrating the light-guide plate main body 11b (prism surface 11b3). It is a graph showing the directivity characteristic (up-down direction) for every prism angle (alpha) of the light beam irradiated from the 2nd output surface 11b1 of the light-guide plate main body 11b. This is an example in which the light guide plate body 11b is arranged in a posture inclined about 45 ° toward the projection lens 20 in the vicinity of the focal point F3 of the projection lens 20 with respect to the base end portion 11a. It is sectional drawing for demonstrating the reflective surface 11c (ellipsoidal reflective surface). It is a figure for demonstrating the virtual image F0 of the light source 12. FIG. It is a figure for demonstrating the motion of the horizontal direction of the light ray from each light source 12 light-guided by the light-guide plate main body 11b. It is the graph which plotted the luminous flux divergence curve (simulation value) of the vertical cross section of the 1st and 2nd output surfaces 11a2 and 11b1, and the measurement light intensity distribution (measurement value) of the conventional general projector type headlamp. It is an example of the light distribution pattern formed with the vehicle lamp 100 (without the auxiliary shade 30) of 1st Embodiment. (A) is a top view of the vehicular lamp 100 using the auxiliary shade 30 of the first embodiment, (b) is a front view of the vehicular lamp 100 using the auxiliary shade 30 of the first embodiment, (c) ) Is a side view of the vehicular lamp 100 using the auxiliary shade 30 of the first embodiment, and (d) is a bottom view of the vehicular lamp 100 using the auxiliary shade 30 of the first embodiment. It is an example of the light distribution pattern formed with the vehicle lamp 100 using the auxiliary shade 30 of 1st Embodiment. It is a figure for demonstrating the modification of the vehicle lamp 100 using the auxiliary | assistant shade 30 of 1st Embodiment. (A) is a top view of the vehicular lamp 100 using the main shade 40 which is a modification of the first embodiment, and (b) is for a vehicle using the main shade 40 which is a modification of the second embodiment. The front view of the lamp 100, (c) is a side view of the vehicular lamp 100 using the main shade 40 which is a modification of the second embodiment, and (d) is the main shade which is a modification of the second embodiment. 4 is a bottom view of a vehicular lamp 100 using 40. FIG. It is a figure for demonstrating the focal line FL. (A) is a front view of the vehicular lamp 100 using the auxiliary reflecting surface 50 of the second embodiment, (b) is a bottom view of the vehicular lamp 100 using the auxiliary reflecting surface 50 of the second embodiment, (C) is a side view of the vehicular lamp 100 using the auxiliary reflecting surface 50 of the second embodiment. It is a perspective view of the auxiliary | assistant reflective surface 50 used for the vehicle lamp 100 of 2nd Embodiment. It is an example of the light distribution pattern formed with the vehicle lamp 100 using the auxiliary | assistant reflective surface 50 of 2nd Embodiment. (A) is a top view of the vehicular lamp 100 using the divided individual light guide plate units 10 according to the third embodiment, and (b) is a divided individual light guide plate unit according to the third embodiment. 10 is a front view of the vehicular lamp 100 using FIG. 10, (c) is a side view of the vehicular lamp 100 using the divided light guide plate units 10 according to the third embodiment, and (d) is a third view. It is a bottom view of the vehicle lamp 100 using the divided | segmented each light-guide plate unit 10 which is embodiment. It is a ray tracing diagram in one divided light guide plate unit 10 (light guide plate body 11b). It is an example of the light distribution pattern formed with the vehicle lamp 100 using the auxiliary | assistant reflective surface 50 of 3rd Embodiment. It is a side view for demonstrating the modification of the vehicle lamp 100 of 2nd and 3rd embodiment. It is a figure for demonstrating the vehicle lamp using the conventional light-guide plate.

  Hereinafter, a vehicular lamp that is an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1A is a top view of a vehicular lamp according to the first embodiment of the present invention, FIG. 1B is a front view of the vehicular lamp according to the first embodiment of the present invention, and FIG. FIG. 2 is a side view of the vehicular lamp according to the first embodiment of the present invention. 2A is a top view of a light guide plate unit used in the vehicular lamp according to the first embodiment of the present invention, and FIG. 1B is used in the vehicular lamp according to the first embodiment of the present invention. FIG. 1C is a side view of the light guide plate unit used in the vehicular lamp according to the first embodiment of the present invention. FIG. 3 is a side view of the vehicular lamp according to the first embodiment of the present invention.

  The vehicular lamp 100 according to this embodiment is applied to a headlamp and a fog lamp, and includes a light guide plate unit 10 and a projection lens 20 as shown in FIGS. In the vehicular lamp 100 of the present embodiment, the luminance distribution (light flux divergence distribution) formed on the projection lens 20 side surface (first and second emission surfaces 11a2 and 11b1) of the light guide plate unit 10 (light guide plate 11). ) Is inverted and enlarged and projected by the projection lens 20, so that a predetermined light distribution pattern is formed. Hereinafter, an example in which the vehicular lamp 100 of the present embodiment is applied to a so-called projector-type headlamp will be specifically described.

  First, the light guide plate unit 10 will be described.

  As shown in FIGS. 2 and 3, the light guide plate unit 10 includes a light guide plate 11, a plurality of light sources 12, reflection sheets 13 and 14, and the like.

  As shown in FIG. 3, the light guide plate 11 includes a base end portion 11a, a light guide plate body 11b bent toward the projection lens 20 in the vicinity of the focal point F3 of the projection lens 20, and a reflection surface 11c with respect to the base end portion 11a. It is integrally formed by injection molding a transparent material (transparent or translucent resin such as acrylic or polycarbonate) in the visible light region. Thus, since the light guide plate body 11b is bent toward the projection lens 20 in the vicinity of the focal point F3 of the projection lens 20 with respect to the base end portion 11a, the size of the light guide plate body in the optical axis direction can be shortened. It becomes possible. For this reason, the depth dimension of the vehicular lamp 100 can be made shorter than before.

  The base end portion 11a includes an incident surface 11a1, a first exit surface 11a2, a first back surface 11a3 on the opposite side, and the like.

  The incident surface 11a1 is a light incident surface for causing the light irradiated from the light source 12 (also referred to as a light beam or a light beam) to enter the light guide plate 11. For example, the cross-sectional shape 11a1 illustrated in FIG. It is formed in the lower end of the base end part 11a as a horizontal surface extended in the direction orthogonal to the paper surface (left and right direction in FIG. 2A).

  The first emission surface 11a2 is, for example, a projection of the base end portion 11a as a vertical surface in which the cross-sectional shape 11a2 shown in FIG. 3 extends in the longitudinal direction (the direction perpendicular to the paper surface in FIG. 3; the left-right direction in FIG. 2A). It is formed on the lens 20 side. The first back surface 11a3 is, for example, a projection lens of the base end portion 11a as a vertical surface in which the cross-sectional shape 11a3 shown in FIG. 3 extends in the longitudinal direction (a direction perpendicular to the paper surface in FIG. 3; the left-right direction in FIG. 2A). 20 is formed on the opposite side. As shown in FIGS. 2 and 3, a part of the first emission surface 11 a 2 is covered with the front-side reflection sheet 13, and the first back surface 11 a 3 is covered with the back-side reflection sheet 14.

  2, 3, and 9, a plurality of light sources 12 (indicated by 12 a to 12 d in FIG. 9) face the optical axis upward, and the light emitting surface 12 a faces the light guide plate 11. It arrange | positions along the longitudinal direction in the state contacted to the entrance plane 11a1, and is fixed to the entrance plane 11a1 with a transparent resin or the like, for example.

  The light source 12 is, for example, an LED light source (or a cold cathode fluorescent lamp (CCFL)) such as an LED package in which one (or plural) LED chips of white (or RGB three colors) are packaged.

  In the present embodiment, in order to obtain the maximum luminous intensity, as shown in FIG. 9, the vertical section including the one rotation axis AX (optical axis) and the other rotation axis AX (optical axis) of the projection lens 20. On the top, light sources 12a and 12b are arranged, respectively. Further, in order to form a diffused light distribution pattern, light sources 12c and 12d are arranged at positions shifted inward from one rotation axis AX and the other rotation axis AX.

  As shown in FIG. 3, the light guide plate body 11b is a flat light guide plate including a second emission surface 11b1, a second back surface 11b2 on the opposite side, a plurality of prism surfaces 11b3 (sawtooth-shaped prism array), and the like. The base end portion 11a is disposed in a posture inclined toward the projection lens 20 in the vicinity of the focal point F3 of the projection lens 20. In order to emit all the light rays incident on the light guide plate main body 11b, the cross-sectional shape of the light guide plate main body 11b becomes tapered as approaching the tip as shown in FIG.

  The second emission surface 11b1 is a projection lens 20 of the light guide plate body 11b as an inclined surface in which the cross-sectional shape 11b1 shown in FIG. 3 extends in the longitudinal direction (a direction perpendicular to the paper surface in FIG. 3; the left-right direction in FIG. 2A). Formed on the side. The second back surface 11b2 has a cross-sectional shape 11b2 shown in FIG. 3 as an inclined surface extending in the longitudinal direction (a direction orthogonal to the paper surface in FIG. 3; the left-right direction in FIG. 2A) and the projection lens 20 of the light guide plate body 11b. Is formed on the opposite side.

  As shown in FIG. 4, the plurality of prism surfaces 11b3 are guided by being incident on the light guide plate 11 from the incident surface 11a1, and the light beams from the light source 12 reaching the plurality of prism surfaces 11b3 are converted into the first and first light beams. The light is reflected toward the first and second emission surfaces 11a2 and 11b1 so that the incident angle with respect to the two emission surfaces 11a2 and 11b1 is within the critical angle, and a luminance distribution is formed on the first and second emission surfaces 11a2 and 11b1. It is a lens cut surface for forming. The plurality of prism surfaces 11b3 is, for example, a second lens cut surface having a planar shape in which the cross-sectional shape 11b3 shown in FIG. 4 extends in the longitudinal direction (a direction orthogonal to the paper surface in FIG. 4; the left-right direction in FIG. 2A). The back surface 11b2 is formed in parallel in the vertical direction.

  Next, the operation of the prism surface 11b3 will be described.

  As shown in FIG. 4, the light beam from each light source 12 guided to the light guide plate body 11b repeats total reflection on each prism surface 11b3 and the second emission surface 11b1. The incident angle of this light ray with respect to the second exit surface 11b1 becomes smaller every time it is totally reflected by each prism surface 11b3. For this reason, the light beam from each light source 12 guided to the light guide plate body 11b eventually reaches the critical angle, and is emitted from the first and second emission surfaces 11a2 and 11b1 at that time. As a result, a luminance distribution (light flux divergence distribution) is formed over substantially the entire area of the first and second emission surfaces 11a2 and 11b1.

  The amount of light emitted from the first and second emission surfaces 11a2 and 11b1 increases as the prism angle α (vertical angle; see FIG. 4) of the prism surface 11b3 increases. FIG. 5 illustrates this. Therefore, by adjusting the prism angle α of the prism surface 11b3, it is possible to form a luminance distribution (light flux divergence distribution) suitable for the headlamp over almost the entire area of the first and second emission surfaces 11a2 and 11b1. Become. For example, it is possible to form a luminance distribution that naturally changes from high luminance to low luminance by gradually changing the prism angle α as the distance from the reflecting surface 11c increases. Further, by adjusting the prism angle α of the prism surface 11b3, a luminance distribution (light flux divergence distribution) suitable for, for example, a fog lamp other than the headlamp is formed over almost the entire area of the first and second emission surfaces 11a2 and 11b1. Is also possible.

  Next, the technical significance of inclining the light guide plate body 11b with respect to the base end portion 11a will be described.

  FIG. 5 is a graph showing the directivity (vertical direction) for each prism angle α of the light beam emitted from the second exit surface 11b1 of the light guide plate body 11b. The prism angle α (= small, small, medium, slightly large). , Large, and very large).

  In the present embodiment, in order to maximize the amount of light incident on the projection lens 20, the prism 11d having a prism angle α = “slightly large” as compared with other prism angles is employed, and FIG. As shown in FIG. 6, the light guide plate main body 11 b is disposed in a posture inclined about 45 ° toward the projection lens 20 near the focal point F3 of the projection lens 20 with respect to the base end portion 11 a.

  Next, the technical significance of the reflecting surface 11c will be described.

  The reflection surface 11c is formed between the second back surface 11b2 and the first back surface 11a3 as shown in FIG.

  As shown in FIG. 7, the reflection surface 11c is incident on the light guide plate 11 from the incident surface 11a1 and is guided, and the light from the light source 12 reaching the reflection surface 11c is converted into the first and second emission surfaces 11a2. , 11b1 is reflected toward the vicinity of the focal point F3 of the projection lens 20 so that the incident angle is within the critical angle, and high brightness portions higher than the surrounding brightness are formed on the first and second emission surfaces 11a2 and 11b1. It is a reflective surface for. The reflecting surface 11c is formed in a predetermined range including the optical axis of the light source 12, for example, in order to obtain max luminous intensity. In the reflecting surface 11c, for example, the first focal point F1 is set near the light source 12 (for example, near the center of the virtual image F0 of the light source 12 shown in FIG. 8), and the second focal point F2 is set near the focal point F3 of the projection lens 20. It is formed as an elliptical reflecting surface (see FIGS. 3 and 7).

  As shown in FIG. 8, the light beam emitted from the light source 12 (light emitting surface 12a) is refracted inward by the incident surface 11a1. This refracted light beam can be regarded as being irradiated from the virtual image F0 shown in FIG. The first focus F1 is set near the center of the virtual image F0 of the light source 12. Thus, by setting the first focus F1 in the vicinity of the center of the virtual image F0, the light condensing property to the second focus F2 is improved, and the emission surface near F2 has higher luminance, so that a high maximum luminous intensity is obtained. Thus, a light distribution pattern suitable for a headlamp can be formed. Note that the position, size, and focus of the virtual image F0 are determined by the shape of the incident surface 11a1, the size of the second exit surface 11b1, and the like. When the light emitting surface 12a is a flat surface, the image is relatively blurred.

  As shown in FIG. 7, the light beam from the light source 12 that is incident on the light guide plate 11 and guided and reaches the reflection surface 11c is directed toward the first and second emission surfaces 11a2 and 11b1 by the reflection surface 11c. The light is reflected, passes through the first and second emission surfaces 11a2 and 11b1, and is condensed near the focal point F3 (second focal point F2) of the projection lens 20. As a result, high brightness portions higher than the surrounding brightness are formed on the first and second emission surfaces 11a2 and 11b1.

  For example, as shown in FIGS. 3 and 7, when the second focal point F2 is set slightly above the focal point F3 of the projection lens 20 (for example, a position 1 mm above), the first and second emission surfaces 11a2 are used. , 11b1 is formed at a portion about 1 ° above the line L corresponding to the horizontal line, which is higher in luminance than the surrounding luminance (see FIG. 10). The luminance distribution (light flux divergence distribution) including this high luminance portion is inverted and enlarged and projected by the projection lens 20. As a result, a light distribution pattern suitable for a low beam whose luminous intensity is lower in the lower part than the horizontal line (for example, in a range corresponding to about 1 ° on the lower side) than the surrounding luminous intensity is formed.

  Further, for example, when the second focal point F2 is set to the focal point F3 of the projection lens 20, the portion corresponding to the intersection of the horizontal line and the vertical line of the first and second emission surfaces 11a2 and 11b1 is more than the surrounding luminance. A high high-luminance part is formed. The luminance distribution (light flux divergence distribution) including this high luminance portion is inverted and enlarged and projected by the projection lens 20. Thereby, a light distribution pattern suitable for a traveling beam in which the light intensity in the vicinity of the intersection of the horizontal line and the vertical line is higher than the surrounding light intensity is formed. In addition, when forming the light distribution pattern suitable for a traveling beam, it is preferable to omit the front side reflection sheet 13.

  The front-side reflection sheet 13 is a reflection sheet for reflecting the light beam from the light source 12 that has been transmitted to the outside from the first emission surface 11a2 and entering the light guide plate 11 again. As shown in FIGS. The lower side is covered rather than the line L corresponding to the horizontal line of 1 emission surface 11a2. The back-side reflection sheet 14 is a reflection sheet for reflecting the light beam from the light source 12 that has been transmitted to the outside from the first back surface 11a3 and the second back surface 11b2 and again entering the light guide plate body 11b. 2 The back surface 11b2 is covered. For this reason, since the light rays from the light source 12 transmitted to the outside from the first back surface 11a3 and the second back surface 11b2 are returned to the inside of the light guide plate 11 by the reflection sheets 13 and 14, the light use efficiency can be improved. It becomes possible. Each of the reflection sheets 13 and 14 is, for example, a high reflectance sheet such as a metal deposition sheet such as silver or aluminum, or a foamed resin sheet. In addition, it is preferable to arrange | position each reflection sheet 13 and 14 in parallel with respect to each surface 11a3.

  As shown in FIGS. 2 and 3, the front-side reflection sheet 13 is a shade that shields a part of light rays emitted from the first and second emission surfaces 11 b 1 and 11 a 2 toward the projection lens 20 and forms a cut-off line. It also serves as a role. In order to give the front-side reflection sheet 13 the role of a shade, the upper edge 13a of the front-side reflection sheet 13 extends in the horizontal direction along the line L corresponding to the horizontal line, as shown in FIG. A Z-shaped step portion is formed in the vicinity of the focal point F3 of the projection lens 20. Thus, since the 1st output surface 11a2 is covered with the front side reflection sheet 13 which has the upper end edge 13a extended along the line L corresponding to a horizontal line, the light distribution which has a clear cut-off line suitable for a passing beam A pattern can be formed.

  As shown in FIG. 1 and the like, in the projection lens 20 having two rotation axes (optical axes), in the case of left-hand traffic, only the portion corresponding to the left rotation axis AX (optical axis) when viewed from the front of the vehicle is Z. What is necessary is just to form in the level | step-difference part of a type | mold (refer FIG.2 (b)). In this way, since the light beam irradiated from the vicinity of the line L corresponding to the horizontal line on the light guide plate 11 shown in FIG. 2B does not enter the projection lens 20, the light beam is irradiated upward from the horizontal line of the opposite lane. It is possible to prevent this.

  Next, the projection lens 20 will be described.

  The projection lens 20 is a lens for inverting and enlarging the luminance distribution formed on the first and second emission surfaces 11a2 and 11b1 to form a predetermined light distribution pattern. For example, as shown in FIG. 1 is a solid lens body extending in the longitudinal direction (left-right direction in FIG. 1A) including the exit surface 21 and the entrance surface 22 on the opposite side. The projection lens 20 is integrally formed by injection molding of a resin transparent in the visible light region (for example, a transparent or translucent material such as acrylic or polycarbonate) or glass.

  The exit surface 21 is a lens surface including a cylindrical lens surface 21a, a right lens surface 21b, and a left lens surface 21c, and the entrance surface 22 is formed as a flat surface. Hereinafter, the lens portion between the cylindrical lens surface 21a and the incident surface 22 on the opposite side may be referred to as a cylindrical lens portion 21a. In addition, the lens portion between the right lens surface 21b (left lens surface 21c) and the incident surface 22 on the opposite side may be referred to as the right lens portion 21b (left lens portion 21c).

The cylindrical lens surface 21a is a cylindrical lens surface extending in the longitudinal direction (left-right direction in FIG. 1A), and a right lens surface 21b and a left lens surface 21c are formed on both left and right ends, respectively. The lens surface 21c is a hemispherical aspherical lens surface cut along a plane including the optical axis, and is formed as a lens surface in which the respective cut surfaces are flush with each other at the left and right ends of the cylindrical lens surface 21a. ing.

  According to the vehicular lamp 100 having the above-described configuration, as shown in FIGS. 4 and 7, the light beams from the respective light sources 12 incident from the base end portion 11 a are allowed to travel along the run-up section of the base end portion 11 a (the first emission surface 11 a 2 and the first output surface). The luminance unevenness is reduced by passing through the base end portion 11a) between the 1 back surface 11a3, and then guided to the light guide plate body 11b (or reaches the reflection surface 11c).

  As shown in FIG. 4, the light from each light source 12 guided to the light guide plate body 11b repeats total reflection at each prism 11d and the second exit surface 11b1. The incident angle of this light ray with respect to the second exit surface 11b1 becomes smaller every time it is totally reflected by each prism surface 11b3. For this reason, the light beam from each light source 12 introduced into the light guide plate body 11b eventually reaches the critical angle, and is emitted from the first and second emission surfaces 11a2 and 11b1 at that time. As a result, a luminance distribution (light flux divergence distribution) is formed over substantially the entire area of the first and second emission surfaces 11a2 and 11b1.

  On the other hand, as shown in FIG. 7, the light beam from each light source 12 that has reached the reflecting surface 11c is reflected by the reflecting surface 11c toward the first and second emitting surfaces 11a2 and 11b1, and the first and second light beams are reflected. The light passes through the emission surfaces 11a2 and 11b1, and is condensed near the focal point F3 (second focal point F2) of the projection lens 20. Thereby, the brightness | luminance part higher than the surrounding brightness | luminance is formed in 1st and 2nd output surface 11a2, 11b1.

  As described above, a luminance distribution (light flux divergence distribution) including a high luminance portion is formed on the first and second emission surfaces 11a2 and 11b1.

  In addition, as shown in FIG. 4, the light rays transmitted to the outside from the first emission surface 11a2 of the base end portion 11a and the second back surface 11b2 of the first back surface 11a3 and the light guide plate body 11b are reflected on the back side reflection sheet 14 (front side). Since the light is again returned to the inside of the light guide plate 11 by the reflection sheet 13) and emitted from the first and second emission surfaces 11a2 and 11b1, it is possible to improve the light utilization efficiency.

  Next, the horizontal movement of the light beam from each light source 12 guided to the light guide plate body 11b will be described. FIG. 9 is a diagram for explaining the horizontal movement of the light beam from each light source 12 guided to the light guide plate body 11b.

  As shown in FIG. 9, the light from each light source 12 that is guided and guided into the light guide plate 11 is partially shielded by the front-side reflection sheet 13, then passes through the projection lens 20, and the left and right lens surfaces 21b. , 21c is irradiated as condensed light condensed on the rotation axis AX side, and the light transmitted through the cylindrical lens portion 21a is irradiated as diffused light diffused in the left-right direction.

  For this reason, the light distribution pattern formed by reversing and enlarging the luminance distribution of the first and second emission surfaces 11a2 and 11b1 by the projection lens 20 is wide in the left-right direction having a clear cut-off line, and Thus, a light distribution pattern suitable for a headlamp in which the luminous intensity in the vicinity of the horizon is higher than the luminous intensity in the surroundings is obtained. Since the diffusion angle is substantially the same as the incident angle to the cylindrical lens portion, it is possible to obtain a light distribution that diffuses in the left-right direction by making the cylindrical lens portion longer in the longitudinal direction.

  The inventors of the present application performed a simulation using a predetermined program. As a result, in the vertical direction, as shown in FIG. 10, it was confirmed that the light distribution pattern formed by the vehicular lamp 100 having the above configuration is a light distribution pattern suitable for the headlamp. FIG. 10 is a graph plotting luminous flux divergence curves (simulated values) of vertical sections of the first and second exit surfaces 11a2 and 11b1, and measured light intensity distributions (measured values) of a conventional general projector type headlamp. It is.

  Referring to FIG. 10, the luminous flux divergence curves (simulation values) of the vertical sections of the first and second emission surfaces 11a2 and 11b1 are substantially the same as the actual luminous intensity distribution (measured values) of a conventional general projector type headlamp. That is, it can be confirmed that the light distribution pattern formed by the vehicular lamp 100 of the present embodiment is a light distribution pattern suitable for a headlamp in the vertical direction.

  On the other hand, the inventors of the present application performed a simulation using a predetermined program and observed a light distribution pattern (see FIG. 11) formed by the vehicular lamp 100 having the above configuration. As a result, in the horizontal direction, it has been found that the light distribution pattern includes the illusion light P1 (also referred to as glare light) above the horizontal line H. FIG. 11A is an example of a light distribution pattern formed by the vehicular lamp 100 according to the first embodiment. FIG. 11B is an illustration of the cylindrical lens portion 21a of the vehicular lamp 100 according to the first embodiment. This is a light distribution pattern in which only the light emitted from the lower half of the optical axis AX is extracted, and shows that the illusion light P1 appears above the horizontal line H in the vicinity of 35 degrees on both the left and right sides. From these figures, it became clear that the light from which the source of the illusion light P1 is incident on the lower half of the optical axis AX of the cylindrical lens portion 21a generates the illusion light P1.

  The inventors of the present application diligently studied the cause of the appearance of the illusion light P1. As a result, first, since the prism surface 11b3 has a linear shape extending in the left-right direction (see FIG. 4 and the like), the light rays from the light sources 12a to 12b (also referred to as point light sources) are transmitted inside the light guide plate body 11b. Even after being irradiated from the light guide plate main body 11b (first and second emission surfaces 11a2 and 11b1), the light sources 12a to 12d spread radially (see FIG. 9). Of light beams spreading in the right and left direction (hereinafter simply referred to as light beams spreading in the left and right direction) are incident on the lower half of the optical axis AX of the cylindrical lens portion 21a (the region indicated by the oblique lines in FIG. 1). Third, the light beam spreading in the left-right direction is incident on the lower half of the optical axis AX of the cylindrical lens portion 21a, so that the light beam from the cylindrical lens portion 21a. Is irradiated obliquely upward, found glare P1 appears that above the horizontal line H.

  As a result of further investigation based on the above findings, the inventors of the present application have arranged the auxiliary shade 30 between the light guide plate unit 10 and the projection lens 20, and the light rays spread in the left-right direction (see FIG. 9). Can be prevented from entering the lower half of the optical axis AX of the cylindrical lens portion 21a, so that the light beam spreading in the left-right direction can be prevented from the optical axis AX of the cylindrical lens portion 21a. The idea is that it is possible to prevent the illusion light P1 resulting from the incidence on the lower half.

  In the present embodiment, the auxiliary shade 30 is disposed between the light guide plate unit 10 and the projection lens 20 as shown in FIG.

  The auxiliary shade 30 is a light shielding member for shielding light rays spreading in the horizontal direction (see FIG. 9). For example, as shown in FIG. 12, the auxiliary shade 30 has a rectangular parallelepiped shape extending in the longitudinal direction (left and right direction in FIG. 12B). And it is formed in a size that fits in the space between the light guide plate unit 10 and the projection lens 20 (the lower half of the optical axis AX).

  On the upper surface (horizontal plane) of the auxiliary shade 30, in order to illuminate a road sign or the like, a light beam that is irradiated from the light guide plate unit 10 (first and second emission surfaces 11a2 and 11b1) and spreads in the horizontal direction is applied to the projection lens 20. A reflecting surface 31 for reflecting toward the surface is formed. The reflection surface 31 is formed as a diffuse reflection surface having a reflectance required for illuminating a road sign, for example.

  According to the vehicular lamp 100 of the first embodiment, the auxiliary shade 30 having the above-described configuration is arranged between the light guide plate unit 10 and the projection lens 20 so that the light beam spreading in the left-right direction (see FIG. 9) is supplemented. Light is shielded by the shade 30 (reflection surface 31). For this reason, it becomes possible to prevent the light beam spreading in the left-right direction from entering the lower half of the optical axis AX of the cylindrical lens portion 21a. For this reason, it becomes possible to prevent the illusion light P1 caused by the light beam spreading in the left-right direction entering the lower half of the optical axis AX of the cylindrical lens portion 21a (see FIG. 13). That is, according to the vehicular lamp 100 using the auxiliary shade 30 of the first embodiment, the dazzling light P1 does not appear above the horizon H, and a vehicle capable of obtaining a light distribution pattern suitable for a headlamp. It becomes possible to provide a lighting fixture. FIG. 13 is an example of a light distribution pattern formed by the vehicular lamp 100 using the auxiliary shade 30 of the first embodiment. Referring to FIG. 13, the light distribution pattern formed by the vehicular lamp 100 using the auxiliary shade 30 does not show the illusion light P1 above the horizontal line H, and a light distribution pattern suitable for the headlamp is obtained. I understand that.

  Further, according to the vehicular lamp 100 of the first embodiment, since the auxiliary shade 30 includes the reflective surface 31 for illuminating the road sign, a light beam shielded by the auxiliary shade 30 (reflecting surface 31) is used. The road sign can be illuminated. That is, according to the vehicular lamp 100 of the first embodiment, the light use efficiency can be improved.

  If it is not necessary to illuminate a road sign or the like, the upper surface of the auxiliary shade 30 is not formed with the reflective surface 31, and the upper surface may be painted or textured with black having a low reflectance. Good.

  Further, when the side close to the light guide plate unit 10 on the upper surface (reflecting surface 31) of the auxiliary shade 30 becomes too bright (for example, when the upper surface of the auxiliary shade 30 is subjected to graining or the like and the upper surface is used as a diffuse reflecting surface) A) The upper surface (reflective surface 31) of the auxiliary shade 30 is inclined so as to have brightness suitable for the headlamp (see FIG. 14), and the upper surface (reflective surface 31) of the auxiliary shade 30 is closer to the light guide plate unit 10 It is desirable to keep the distance from the light guide plate unit 10. In this way, by adjusting the inclination angle of the upper surface (reflection surface 31) of the auxiliary shade 30, it becomes possible to form a light distribution pattern more suitable for the headlamp.

  When a clear cut-off line is formed, as shown in FIG. 15, the main shade having upper end edges 41 extending along the focal lines FL of the left and right lens portions 21b and 21c at the left and right ends of the auxiliary shade 30, respectively. 40 is desirable. For example, as shown in FIG. 16, the focal line FL is included in a horizontal plane (or a horizontal plane parallel to the horizontal plane) including the optical axis AX (rotation axis) of the left and right lens portions 21b and 21c, and the optical axis. A plurality of parallel rays having different inclination angles with respect to AX (rotation axis) (FIG. 16 illustrates a plurality of parallel rays L1 to L4) are incident on the left and right lens portions 21b and 21c from the exit surface side of the left and right lens portions 21b and 21c. And a focal point group formed when the light is emitted from the incident surface 22 side. By disposing the main shade 40 with the upper end edge 41 along the focal line FL, it is possible to form a light distribution pattern having a clear cut-off line.

  Further, according to the vehicular lamp 100 of the present embodiment, as shown in FIG. 3 and the like, the light guide plate body 11b is bent toward the projection lens 20 in the vicinity of the focal point F3 of the projection lens 20 with respect to the base end portion 11a. A reflection surface 11c as an elliptical reflection surface is formed between the first back surface 11a3 and the second back surface 11b2. For this reason, as shown in FIG. 7, the light from the light source 12 that is incident on the light guide plate 11 from the incident surface 11a1 and guided therethrough and reaches the reflecting surface 11c is reflected by the reflecting surface 11c to the first emitting surface 11a2. In addition, the light is reflected toward the vicinity of the focal point F3 (second focal point F2) of the projection lens 20 so that the incident angle with respect to the second outgoing surface 11b1 (mainly the first outgoing surface 11a2) is within the critical angle, and the first outgoing surface 11a2. And it radiates | emits from the 2nd output surface 11b1. Thereby, on the first emission surface 11a2 and the second emission surface 11b1, a luminance distribution including a high luminance part higher than the surrounding luminance (a high luminance part corresponding to a light distribution pattern including the maximum luminous intensity required for the headlamp is obtained. Brightness distribution). The luminance distribution including the high luminance part is inverted and enlarged and projected by the projection lens 20. Thereby, it is possible to form a light distribution pattern including the maximum luminous intensity required for the headlamp.

  Further, according to the vehicular lamp 100 of the present embodiment, as shown in FIG. 3 and the like, the light guide plate main body 11b is bent toward the projection lens 20 in the vicinity of the focal point of the projection lens 20 with respect to the base end portion 11a. Yes. For this reason, it becomes possible to shorten the dimension of the optical axis AX direction of the light-guide plate main body 11b. For this reason, the depth dimension of the vehicular lamp 100 can be made shorter than before.

  Next, a second embodiment will be described.

  The inventors of this application arrange | position the auxiliary | assistant reflective surface 50 between the light-guide plate unit 10 and the projection lens 20, and the light ray (refer FIG. 9) which spreads in the left-right direction is parallel to the vertical plane containing the optical axis AX. Also by converting to the light beam, the light beam spreading in the left-right direction can be prevented from entering the lower half (the region indicated by the oblique line in FIG. 1) of the optical axis AX of the cylindrical lens portion 21a. The idea is that it is possible to prevent the illusion light P <b> 1 resulting from the incident light rays extending to the lower half of the optical axis AX of the cylindrical lens portion 21 a.

  In the present embodiment, based on the above knowledge and idea, as shown in FIG. 17, auxiliary reflection surfaces 50 are arranged between the light guide plate unit 10 and the projection lens 20 so as to correspond to the plurality of light sources 12 a to 12 d, respectively. ing. Since other configurations are the same as those in the first embodiment, the same reference numerals are used, and descriptions thereof are omitted.

  The auxiliary reflection surface 50 is a reflection surface arranged corresponding to each of the light sources 12 a to 12 d between the light guide plate unit 10 and the projection lens 20, and the light source 12 arranged corresponding to the auxiliary reflection surface 50. From the light beam (light beam spreading in the left-right direction, see FIG. 9) is converted into a light beam parallel to the vertical plane including the optical axis AX, and is converted into the lower half of the cylindrical lens portion 21a (the region indicated by the oblique lines in FIG. 1). It is a reflective surface for reflecting toward.

  For example, as shown in FIG. 17 and FIG. 18, the auxiliary reflecting surface 50 is a parabolic column surface obtained by extending a parabola whose focal point is set in the vicinity of the light sources 12 a to 12 d in the vertical direction (or the first focal point is each light source). An elliptical cylinder surface set in the vicinity and having the second focal point set in front of the optical axis AX) and formed in a size that fits in a space between the light guide plate unit 10 and the projection lens 20 (lower half). ing.

  According to the vehicular lamp 100 of the second embodiment, the auxiliary reflection surface 50 having the above-described configuration is disposed between the light guide plate unit 10 and the projection lens 20, so that the light beam spreading in the left-right direction (see FIG. 9) The auxiliary reflection surface 50 converts the light into a light ray parallel to a vertical plane including the optical axis AX (see FIG. 17). For this reason, it becomes possible to prevent (or reduce) the light beam spreading in the left-right direction from directly entering the lower half of the optical axis AX of the cylindrical lens portion 21a. For this reason, it becomes possible to prevent (or reduce) the illusion light P1 caused by the light beam spreading in the left-right direction directly entering the lower half of the optical axis AX of the cylindrical lens portion 21a (see FIG. 19). ). That is, according to the vehicular lamp 100 of the second embodiment, there is provided a vehicular lamp capable of obtaining a light distribution pattern suitable for a headlamp with almost no illusion light P1 appearing above the horizon H. It becomes possible.

  FIG. 19 is an example of a light distribution pattern formed by the vehicular lamp 100 using the auxiliary reflecting surface 50 of the second embodiment, and the illusion light P1 that is 6 degrees UP or more (see FIG. 11B). Represents a decrease to about 2 degrees UP. Referring to FIG. 19, in the light distribution pattern formed by the vehicular lamp 100 using the auxiliary reflecting surface 50 of the second embodiment, the illusion light P1 hardly appears above the horizontal line H, which is suitable for a headlamp. It can be seen that a light distribution pattern is obtained.

  Further, according to the vehicular lamp 100 of the second embodiment, the reflected light from the auxiliary reflecting surface 50 is condensed in the direction of the optical axis AX (see FIG. 17), and thus is formed by the vehicular lamp 100. It is possible to improve the max luminous intensity of the light distribution pattern.

  In addition, as shown in FIG. 23, it is preferable to arrange | position the prism 60 for refracting the light ray irradiated from the light-guide plate unit 10 downward between the projection lens 20 and the auxiliary | assistant reflective surface 50. As shown in FIG. In this way, it is possible to control the light distribution from the auxiliary reflecting surface 50 to the horizontal line H or less, and it is possible to form a light distribution pattern more suitable for the headlamp.

  Next, a third embodiment will be described.

  In the second embodiment, the illusion light P1 caused by the light rays (see FIG. 9) spreading in the left-right direction entering the lower half of the optical axis AX of the cylindrical lens portion 21a hardly appears above the horizontal line H. However, the illusion light P2 appears up to about 2 degrees above the horizontal line H (see FIG. 19).

  The inventors of the present application diligently studied the cause of the appearance of the illusion light P2. As a result, first, since the light guide plate unit 10 (first and second emission surfaces 11a2 and 11b1) has a shape extending in the left-right direction, a light beam from the adjacent light source 12 is incident on a specific auxiliary reflection surface 50. Secondly, it is found that the illusion light P2 appears up to about 2 degrees above the horizontal line H due to the incident of the light beam from the adjacent light source 12 on the specific auxiliary reflecting surface 50. It was.

  As a result of further investigation based on the above knowledge, the inventors of the present application have determined that if the light guide plate unit 10 is divided in accordance with the number of light sources 12, for example, the light source 12 adjacent to the specific auxiliary reflection surface 50. Therefore, it is possible to prevent the illusion light P2 caused by the incidence of the light beam from the adjacent light source 12 on the specific auxiliary reflection surface 50. I got the idea.

  In the present embodiment, based on the above knowledge and idea, as shown in FIG. 20, the light guide plate unit 10 is divided into four corresponding to the number of light sources 12 a to 12 d, and the divided individual light guide plate units 10. Are distributed at four locations so that the irradiation light is incident only on the auxiliary reflecting surface 50 provided corresponding to each light source 12. Since other configurations are the same as those of the second embodiment, the same reference numerals are used, and descriptions thereof are omitted.

  As shown in FIGS. 20 and 21, the light guide plate main body 11b has a width of the base end edge 11b7 that is shorter than the front end edge 11b6, and the distance between the side surfaces 11b5 increases from the base end edge 11b7 toward the front end edge 11b6. It is formed in a broad trapezoidal shape.

  According to the vehicular lamp 100 of the third embodiment, the light guide plate unit 10 (light guide plate body 11b and the like) is divided into a number corresponding to the number of the light sources 12a to 12d, and the divided individual light guide plates. The light guide plate main body 11b of the unit 10 is formed in a substantially trapezoidal shape in which the width of the base end edge 11b7 is shorter than that of the front end edge 11b6 and the distance between both side surfaces 11b5 increases from the base end edge 11b7 toward the front end edge 11b6. Has been. For this reason, the light from the specific light source 12 (for example, the light source 12a) that is guided to the light guide plate body 11b and reaches the both side surfaces 11b5 is provided corresponding to the adjacent light source 12 (for example, the light source 12b). All of the light is totally reflected without going to the auxiliary reflection surface 50 (see FIG. 21), and is irradiated toward the auxiliary reflection surface 50 provided corresponding to the specific light source 12 (for example, the light source 12a). For this reason, according to the vehicular lamp 100 of the third embodiment, it is possible to prevent the dazzling light P2 caused by the light rays from the adjacent light source 12 entering the specific auxiliary reflecting surface 50 ( (See FIG. 22). FIG. 22 is an example of a light distribution pattern formed by the vehicular lamp 100 using the individual light guide plate units 10 divided into four according to the third embodiment. Referring to FIG. 22, the light distribution pattern formed by the vehicular lamp 100 using the individual light guide plate units 10 divided into the four parts of the third embodiment includes illusion light P <b> 1 above the horizontal line H, It can be seen that P2 does not appear and a light distribution pattern more suitable for the headlamp can be obtained.

  In the third embodiment, it has been described that the distance between both side surfaces 11b5 increases from the base edge 11b7 toward the front edge 11b6 (see FIGS. 20 and 21), but the present invention is limited to this. Not. For example, each side surface 11b5 may be a surface parallel to the optical axis AX. In addition, as shown by the wavy lines in FIG. 21, the side surfaces 11b5 are parabolas whose focal points are set in the vicinity of the light source 12 (or in the vicinity of the light incident position) (or the first focal points in the vicinity of the light source 12 or in the vicinity of the light incident position) It may be a surface made up of an ellipse).

  It should be noted that by arranging a light shielding plate (not shown) between the divided light guide plate units 10, the illusion light P <b> 2 resulting from the incidence of the light from the adjacent light source 12 on the specific auxiliary reflection surface 50. Can be almost completely prevented.

  In addition, as shown in FIG. 23, it is preferable to arrange | position the prism 60 for refracting the light ray irradiated from the light-guide plate unit 10 downward between the projection lens 20 and the auxiliary | assistant reflective surface 50. As shown in FIG. In this way, it is possible to control the light distribution from the auxiliary reflecting surface 50 to the horizontal line H or less, and it is possible to form a light distribution pattern more suitable for the headlamp.

  The above embodiment is merely an example in all respects. The present invention is not construed as being limited to these descriptions. The present invention can be implemented in various other forms without departing from the spirit or main features thereof.

  DESCRIPTION OF SYMBOLS 100 ... Vehicle lamp, 10 ... Light guide plate unit, 11 ... Light guide plate, 11a ... Base end part, 11a1 ... Incident surface (light-incidence surface), 11a2 ... Output surface, 11a3 ... Back surface, 11b ... Light guide plate main body, 11b1 ... Output surface, 11b2 ... back surface, 11b light guide plate body, 11b3 ... prism surface, 11b4 ... prism surface, 11c ... reflection surface, 11d ... prism, 12 ... light source, 12a ... light emitting surface, 13 ... front side reflection sheet, 13a ... top edge , 14 ... back side reflection sheet, 20 ... projection lens, 21 ... exit surface, 21a ... cylindrical lens surface, 21b ... right lens surface, 21c ... left lens surface, 22 ... entrance surface, 30 ... auxiliary shade (light-shielding shade), 31 ... reflecting surface, 40 ... main shade, 41 ... upper edge, 50 ... auxiliary reflecting surface, 60 ... prism

Claims (6)

In a vehicle lamp provided with a light guide plate made of a transparent material in the visible light region, a light source and a projection lens,
The light guide plate includes a base end portion, a light guide plate main body bent toward the projection lens in the vicinity of the focus of the projection lens with respect to the base end portion, and a reflective surface.
The base end includes an incident surface, a first exit surface, and a first back surface on the opposite side.
The light guide plate main body includes a second emission surface, a second back surface on the opposite side, and a prism surface,
The incident surface is a light incident surface for allowing light rays emitted from the light source to enter the light guide plate;
The first emission surface and the second emission surface are formed on the projection lens side,
The first back surface and the second back surface are formed on the side opposite to the projection lens,
The reflecting surface is formed between the first back surface and the second back surface or on the first back surface, and the prism surface is incident on the light guide plate from the incident surface and guided. The light from the light source that has reached the prism surface is reflected toward the first emission surface and the second emission surface so that the incident angle with respect to the first emission surface and the second emission surface is within a critical angle, A lens cut surface for forming a luminance distribution on the first emission surface and the second emission surface;
The reflection surface is incident and guided from the incident surface into the light guide plate, and a light beam from the light source that has reached the reflection surface is incident at a critical angle with respect to the first and second emission surfaces. A reflection surface for reflecting toward the focal point of the projection lens so as to be inside, and forming a high-luminance portion higher than the surrounding luminance on the first emission surface and the second emission surface,
The projection lens is a lens for reversing and enlarging the luminance distribution formed on the first emission surface and the second emission surface to form a predetermined light distribution pattern, and includes at least a cylindrical lens portion. And
further,
A light-shielding member disposed between the light guide plate and the projection lens, which emits light from the light source that is irradiated from the first emission surface and the second emission surface and spreads in the left-right direction of the cylindrical lens unit. A light-shielding shade for shielding light so as not to enter the lower half of the optical axis;
A vehicular lamp characterized by comprising:   The shading shade includes a reflecting surface for reflecting a light beam from the light source irradiated from the first emitting surface and the second emitting surface toward the projection lens and illuminating a road sign. The vehicular lamp according to claim 1. In a vehicle lamp provided with a light guide plate made of a transparent material in the visible light region, a plurality of light sources and a projection lens,
The light guide plate includes a base end portion, a light guide plate main body bent toward the projection lens in the vicinity of the focus of the projection lens with respect to the base end portion, and a reflective surface.
The base end includes an incident surface, a first exit surface, and a first back surface on the opposite side.
The light guide plate main body includes a second emission surface, a second back surface on the opposite side, and a prism surface,
The incident surface is a light incident surface for causing light beams emitted from the plurality of light sources to enter the light guide plate;
The first emission surface and the second emission surface are formed on the projection lens side,
The first back surface and the second back surface are formed on the side opposite to the projection lens,
The reflective surface is formed between the first back surface and the second back surface or on the first back surface,
The prism surface is guided by being incident on the light guide plate from the incident surface, and the light beams from the plurality of light sources that have reached the prism surface have an incident angle with respect to the first emission surface and the second emission surface. A lens cut surface for reflecting toward the first exit surface and the second exit surface so as to be within a critical angle and forming a luminance distribution on the first exit surface and the second exit surface;
The reflection surface is incident and guided from the incident surface into the light guide plate. Light rays from the plurality of light sources that have reached the reflection surface are incident on the first emission surface and the second emission surface. A reflection surface for reflecting toward the focal point of the projection lens so as to be within a critical angle, and forming a high-luminance portion higher than the surrounding luminance on the first emission surface and the second emission surface,
The projection lens is a lens for reversing and enlarging the luminance distribution formed on the first emission surface and the second emission surface to form a predetermined light distribution pattern, and includes at least a cylindrical lens portion. And
further,
Wherein and a is an auxiliary reflecting surface arranged corresponding to the plurality of light sources between the light guide plate and said projection lens,
The auxiliary reflecting surface is irradiated from the first emitting surface and the second emitting surface and parallels a light beam from the light source arranged correspondingly extending in the left-right direction to a vertical surface including the optical axis of the cylindrical lens unit. An auxiliary reflection surface for converting to a light beam and reflecting toward the lower half from the optical axis of the cylindrical lens portion,
A vehicular lamp characterized by comprising: The light guide plate is divided into a number corresponding to the number of the plurality of light sources,
The light guide plate body of each of the divided light guide plates is formed in a substantially trapezoidal shape in which the width of the base end edge is shorter than the front end edge and the interval between both side surfaces increases from the base end edge toward the front end edge. The vehicular lamp according to claim 3, wherein the vehicular lamp is provided.   The vehicular lamp according to claim 4, wherein the both side surfaces are formed in a shape substantially along a parabola or an ellipse.   A prism disposed between the light guide plate and the projection lens, and a light beam that is irradiated from the first emission surface and the second emission surface and incident on the lower half of the optical axis of the cylindrical lens unit, The vehicular lamp according to any one of claims 3 to 5, further comprising a prism for refracting downward.