JP2013008525A - Vehicular lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular lamp capable of making light emitted from a light-emitting element efficiently be incident to a light guide plate and sufficiently diffusing the light on a belt-shaped slender light irradiating surface as a side wall surface of the light guide plate in a width direction.SOLUTION: In a light incident surface 16B of the light guide plate 16, there are provided, from the center, a lens surface 22A, a flat inclined surface 22B, and a tapered surface 22C arranged on an outer surface of a projection section 21. The lens surface 22A makes the light from the light-emitting elements emit from the light irradiating surface 16A so as to make the light from the light-emitting elements 17 approximately be in parallel with front and back surfaces of the light guide plate 16. The flat inclined surface 22B makes the light from the light-emitting elements emit from the light irradiating surface 16A so as to repeat reflection of the light between the front and back surfaces of the light guide plate 16. The tapered surface 22C makes the light from the light-emitting elements emit from the light irradiating surface 16A so as to make the light from the light-emitting elements 17 approximately be in parallel with the front and back surfaces of the light guide plate 16 or so as to make the light from the light-emitting elements 17 approximately be in parallel with the front and back surfaces of the light guide plate 16 by making the light from the light-emitting elements 17 reflect from the front surface or the back surface of the light guide plate 16.

Description

  The present invention relates to a vehicular lamp, and more particularly to a vehicular lamp that includes a light emitting element and a light guide plate.

  As this type of vehicular lamp, there is known a configuration in which a light emitting element is disposed at one end of a light guide plate extending from one end to the other end. While the light from the light emitting element is guided into the light guide plate from the side wall surface at one end of the light guide plate, reflection is repeated between the pair of side wall surfaces arranged opposite to each other from the one end to the other end, Light is emitted from one of the pair of side wall surfaces. In this case, the one side wall surface functioning as a light irradiation surface has a strip-like elongated rectangular shape and is suitable for use as, for example, a detime lamp, a clearance lamp, or a front turn lamp.

  In addition, as a well-known technique related to the present invention, for example, a technique disclosed in the following Patent Document 1 or Patent Document 2 is known in order to make light from a light emitting element efficiently enter a light guide plate. In Patent Document 1, a light-incident surface of a light guide plate is formed with a substantially spherical lens surface that is convex on the side facing the light source, and a cylindrical protrusion that surrounds the light source around the lens surface. In which the light guide plate is attached integrally with the light guide plate. Further, in Patent Document 2, a lens surface is formed on the light incident surface of the light guide plate so as to be convex on the side facing the light source and to have a central axis in the thickness direction of the light guide plate. A lens is disclosed in which protrusions are attached to both sides of a lens surface integrally with a light guide plate.

JP 2003-63304 A JP 2009-117270 A

  Here, in the vehicular lamp that uses the strip-shaped elongated side wall surface of the light guide plate as the light irradiation surface, the light emitted from the light irradiation surface is in the width direction of the light irradiation surface (the direction corresponding to the thickness direction of the light guide plate). It is preferable to diffuse it. This is because such a configuration makes it possible to visually recognize the lighting of the vehicular lamp in a wide range.

  However, any of the vehicular lamps disclosed in Patent Document 1 or Patent Document 2 only discloses the configuration in which light from the light emitting element is efficiently incident on the light guide plate, and the width direction of the strip-shaped elongated light irradiation surface. The light is not diffused.

  Incidentally, in order to realize light diffusion in the width direction on the strip-shaped elongated light irradiation surface, for example, it can be achieved by applying a special shape or the like on the light irradiation surface of the light guide plate. The shape is easily limited, and it may be desired to realize light diffusion in the width direction of the light irradiation surface at a place other than the light irradiation surface.

  The present invention has been made in view of such circumstances, and light from a light emitting element is efficiently incident on a light guide plate, and at that time, in a strip-like elongated light irradiation surface which is a side wall surface of the light guide plate. An object of the present invention is to provide a vehicular lamp configured to sufficiently diffuse light in the width direction.

  In order to achieve such an object, the vehicular lamp according to the present invention emits light from a light emitting element to a light incident surface of a light guide plate so as to emit light substantially parallel to the front and back surfaces of the light guide plate. A reflection surface made up of a lens surface and a tapered surface that leads to the irradiation surface, and a flat inclined surface that leads to the light irradiation surface of the light guide plate by repeating reflection on each of the front and back surfaces of the light guide plate It is.

The present invention can be grasped by the following configuration.
(1) The vehicular lamp according to the present invention includes a light guide plate that is elongated from one end to the other end, and a light emitting element that allows light to be incident from a first side wall surface of the one end of the light guide plate. Is repeatedly reflected between the second side wall surface and the third side wall surface arranged opposite to each other over the other end of the light guide plate, and the second side wall surface is used as a light irradiation surface. A vehicular lamp comprising: a concave portion extending in a second direction orthogonal to the first direction, which is a thickness direction of the light guide plate, on the first side wall surface, and the second side on both sides of the concave portion. A projection formed extending in two directions, and formed on the bottom surface of the concave portion as a substantially cylindrical surface that is convex toward the light emitting element at the center of the bottom surface and has a central axis in the second direction. And a flat inclined surface formed from both sides of the lens surface to the projections. The protrusion is configured to have a tapered surface on the front and back surfaces of the light guide plate, and the lens surface allows the light from the light emitting element to be substantially parallel to the front and back surfaces of the light guide plate. The flat inclined surface emits light from the light emitting element from the light irradiation surface so that reflection is repeated between the front and back surfaces of the light guide plate, and the tapered surface emits light from the light emitting surface. The light from the element is made substantially parallel to the front and back surfaces of the light guide plate, or the light from the light emitting element is reflected on the front or back surface of the light guide plate so as to be substantially parallel to the front and back surfaces of the light guide plate. It is comprised so that it may radiate | emit from the said light irradiation surface.
(2) In the vehicular lamp according to the present invention, in the configuration of (1), the flat inclined surface is formed with an inclination so that a vertical axis direction of the flat inclined surface is directed toward the light emitting element. It is characterized by being.

  According to the vehicular lamp configured as described above, light from the light emitting element is efficiently incident on the light guide plate, and at that time, light in the width direction is formed on the strip-shaped elongated light irradiation surface which is the side wall surface of the light guide plate. It becomes possible to configure so that the diffusion is sufficiently performed.

It is sectional drawing which showed the embodiment of the vehicle lamp of this invention, and is sectional drawing in the II line | wire of FIG.3 (b). It is the front view which showed the outline of the headlight of the motor vehicle to which the vehicle lamp of this invention is applied. (A) is the whole perspective view which showed the embodiment of the vehicle lamp of this invention, (b) is the enlarged view which expanded and showed the part of the dotted-line frame of (a). It is explanatory drawing which showed the optical path from a light emitting element to a light irradiation surface in the vehicle lamp of this invention. It is explanatory drawing which shows the positional relationship of the lens surface, flat inclined surface, and taper surface which are formed in the light-guide plate of the vehicle lamp of this invention. It is explanatory drawing which shows the inclination-angle of the flat inclined surface formed in the light-guide plate of the vehicle lamp of this invention. It is explanatory drawing which shows the path | route of the light from the light emitting element which passes along the lens surface, flat inclined surface, and taper surface which are formed in the light-guide plate of the vehicle lamp of this invention.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the accompanying drawings. Note that the same number is assigned to the same element throughout the description of the embodiment.
(Embodiment 1)
FIG. 2 is a front view showing an outline of a headlamp (headlight) of, for example, an automobile in which the vehicular lamp of the present invention is provided. The headlamp is a so-called combination-type lamp provided with a plurality of vehicle lamps. The headlamp 10 shown in FIG. 2 shows what was attached to the right side, for example, when a motor vehicle is seen from the front.

  In FIG. 2, there is a lamp body 11, and the lamp body 11 includes a lamp chamber 12 having an opening at the front. In the lamp chamber 12, for example, a passing beam lamp 13, a traveling beam lamp 14, and a clearance lamp 15 are arranged.

  The low beam lamp 13 is configured, for example, by arranging a light source (not shown) in a reflector (not shown) having a spheroid surface and attaching a lens 13A to the front surface of the reflector. In the Klang-type head, for example, it is arranged at the upper position. The traveling beam lamp 14 is configured, for example, by arranging a light source 14B in a reflector 14A that extends to the left and right in the figure and whose cross section in the vertical direction and the like is formed as a paraboloid. Placed in position. The clearance lamp 15 includes a light guide plate 16 extending to the left and right in the drawing, and light emitting elements 17A and 17B made of, for example, a light emitting diode disposed on one end A of the light guide plate 16 (the other end is indicated by a symbol B in the drawing). In the lamp chamber 12, for example, at the lower position. The light guide plate 16 is arranged with its thickness direction aligned with the vertical direction in the figure, and the side wall surface directed forward of the automobile functions as the light irradiation surface 16A. After the light from the light emitting elements 17A and 17B is guided to the inside of the light guide plate 16, the clearance lamp 15 and the other side wall surface (not shown) facing the side wall surface as the light irradiation surface 16A. While being repeatedly reflected, light is emitted from the light irradiation surface 16A, so that uniform luminance can be achieved from one end A to the other end B of the light irradiation surface 16A. The clearance lamp 15 will be described in detail later.

  A front lens 18 is attached to the opening of the lamp body 11, and light from the passing beam lamp 13, the traveling beam lamp 14, and the clearance lamp 15 is emitted to the front of the automobile through the front lens 18. It has become. The opening of the lamp body 11 shown in FIG. 2 is positioned with the left end and the lower end in the figure in front of the automobile in accordance with the streamlined design of the automobile, and the right end and the upper end in the figure. Slanted to be positioned behind the car. And then. The front lens 18 also has a curved shape that matches the shape of the opening of the lamp body 11.

  FIG. 3A is a perspective view showing details of the configuration of the clearance lamp 15. As described above, the clearance lamp 15 has the two light emitting elements 17A and 17B and the light from these light emitting elements 17A and 17B incident on a part of the side wall surface and emitted from the other side wall surface. It is comprised with the light-guide plate 16 to be made. Note that the number of the light emitting elements 17A and 17B is not necessarily limited to two, and may be one, or three or more.

  The light guide plate 16 is made of a light-transmitting plate material whose front and back surfaces are substantially parallel in the vertical direction in the figure, and is formed in an elongated substantially curved shape from one end A side to the other end B side in the figure. Yes. Note that the direction α shown in the drawing is shown to coincide with the forward direction of the vehicle, and the light guide plate 16 is arranged slightly inclined with respect to the direction α. That is, according to the shape of the front lens 18 of the headlamp 10, for example, one end A side of the light guide plate 16 is positioned on the rear side of the vehicle, while the other end B side is on the front side of the vehicle. It is arranged to be positioned.

  The light guide plate 16 arranged in this way has a side wall surface (sometimes referred to as a second side wall surface) directed toward the front (direction α) of the vehicle as a light irradiation surface 16A over almost the entire area, and is on the one end A side. The side wall surface facing the light irradiation surface 16A (the side wall surface facing the light emitting elements 17A and 17B: sometimes referred to as a first side wall surface) serves as a light incident surface 16B, and the other end B side from the light incident surface 16B. A side wall surface (sometimes referred to as a third side wall surface) facing the light irradiation surface 16A is configured as a light reflecting surface 16C.

  The light incident surface 16B of the light guide plate 16 is planar as shown in FIG. 3B, which is an enlarged view of the dotted circle in FIG. 3A (the light emitting elements 17A and 17B are omitted). The trapezoidal protrusions 19A and 19B projecting from the light irradiation surface 16A side are formed on the side wall surface of the side corresponding to the upper side. Accordingly, the light guide plate 16 is configured to be wide from the light incident surface 16B to the light irradiation surface 16A side by the trapezoidal protrusions 19A and 19B, and is emitted from each of the light emitting elements 17A and 17B within a predetermined angle range. It is possible to efficiently guide most of the light to the light guide plate 16. In the case of this embodiment, two light emitting elements 17A and 17B are provided, and two protrusions 19A and 19B each having a trapezoidal shape are provided side by side corresponding to the number of the light emitting elements 17A and 17B.

  Further, the light irradiation surface 16A of the light guide plate 16 is configured to have a light emitting function and a light reflecting function from one end A side to the other end B side of the light guide plate 16. The light irradiation surface 16A having such a function is configured by, for example, a so-called kamaboko prism having a semicircular cross section provided in parallel from one end A side to the other end B side. The light incident surface 16B having the above-described configuration is formed on the side wall surface of the light guide plate 16 facing the light irradiation surface 16A having such a configuration, and from the light incident surface 16B to the light guide plate 16. A light reflecting surface 16 </ b> C having only a light reflecting function is formed on the other end B. The light reflecting surface 16C having such a function is constituted by a so-called flat prism having a triangular cross section, for example, provided in parallel from the light incident surface 16B to the other end B side.

  As shown in FIG. 4, the clearance lamp 15 configured in this way has a part of the light L1 from each of the light emitting elements 17A and 17B incident from the light incident surface 16B on the one end A side of the light guide plate 16. Light is emitted from the light irradiation surface 16A, and the remaining portion is reflected. Most of the light L2 reflected by the light irradiation surface 16A is directed and transmitted to the other end B side of the light guide plate 16. The light L2 directed to the other end B side of the light guide plate 16 is reflected by the light reflecting surface 16C, and the reflected light L3 is emitted from the light irradiation surface 16A facing the light reflecting surface 16C. . In this case, a part of the light L3 incident on the light irradiation surface 16A of the light guide plate 16 is reflected, and the reflected light L4 is further transmitted to the other end B side of the light guide plate 16, and the above-described operation is repeated. It is. As a result, the light irradiation surface 16 </ b> A of the light guide plate 16 is irradiated with light having substantially uniform luminance from one end A side to the other end B side of the light guide plate 16.

  FIG. 1 is a view showing a cross section taken along line I-I in FIG. As shown in FIG. 1, a groove-like recess 20 extending in a direction (front and back direction in the drawing) perpendicular to the thickness direction (t direction in the figure) of the light guide plate 16 is formed on the light incident surface 16B of the light guide plate 16. (See FIG. 3 (b)), and by forming the recessed portion 20, the ridge portions 21 are formed on both sides (the front surface 16P side and the back surface 16Q side of the light guide plate 16) of the recessed portion 20 in the t direction. (See FIG. 3B).

  The concave portion 20 forms a lens surface 22 </ b> A composed of a curved surface that is convex toward the opening side of the concave portion 20 on the bottom surface thereof. The highest portion of the lens surface 22A is positioned substantially at the center in the thickness direction (t direction in the figure) of the light guide plate 16 (hereinafter, the surface of the light guide plate 16 including the highest portion of the lens surface 22A). A surface parallel to 16P and the back surface 16Q may be referred to as an optical axis surface M). The lens surface 22A is configured as a semi-cylindrical surface that forms a part of a substantially cylindrical surface having a central axis parallel to the front and back direction of the paper. One focal point F of the lens constituted by the lens surface 22A is positioned on the intersection of the surface (indicated by N in the figure) connecting the tips of the respective protrusions 21 and the optical axis surface M. . The light emitting element 17A (17B) is arranged so that the light emission surface thereof is substantially coincident with the focal point F, whereby the light from the light emitting element 17A (17B) is refracted by the lens surface 22A and the light guide plate 16 The inside is transmitted substantially parallel to the optical axis plane M. That is, the light from the light emitting element 17A (17B) incident on the lens surface 22A passes through the inside of the light guide plate 16 as shown by the optical path L10 in FIG. The light is transmitted toward the light irradiation surface 16A without being reflected by 16P or the back surface 16Q, and is emitted from the light irradiation surface 16A. As described above, the lens surface 22A is constituted by a part of a substantially cylindrical surface having a central axis parallel to the paper front and back direction in the drawing, so that the light emitting elements 17A and 17B are arranged in the paper front and back direction in the drawing. Even if a slight misalignment occurs, there is an effect that no inconvenience due to the misalignment occurs.

  Returning to FIG. 1, a flat inclined surface 22 </ b> B extending from each end side in the t direction of the lens surface 22 </ b> A to the inner side surface 21 </ b> A of the protrusion 21 is formed on the bottom surface of the recessed portion 20. . The inner side surface 21A of the ridge portion 21 is formed so as to be substantially parallel to the front surface 16P or the back surface 16Q of the light guide plate 16, respectively. Then, as shown in FIG. 5 drawn corresponding to FIG. 1, the boundary S between the flat inclined surface 22B and the inner surface 21A is a recessed portion than the boundary E between the flat inclined surface 22B and the lens surface 22A. 20 is positioned on the opening side, and the boundary portion S passes through the highest portion of the lens surface 22A and is positioned substantially in a virtual vertical plane L that is arranged orthogonal to the optical axis plane M. Yes. Accordingly, the flat inclined surface 22B is formed with an inclination so that the vertical axis direction thereof is directed toward the light emitting element 17A (17B). In the first embodiment, for example, as shown in FIG. 6 drawn corresponding to FIG. 1, the inclination (light) such that the vertical axis X of the flat inclined surface 22B substantially passes the focal point F of the lens surface 22A. With respect to the axial surface M). Accordingly, the flat inclined surface 22B is formed with an inclination angle such that the vertical axis X of the flat inclined surface 22B is approximately 45 ° with respect to the optical axis surface M. The inclination angle of the flat inclined surface 22B is set in this way so that light from the light emitting element 17A (17B) can be incident on the flat inclined surface 22B from a substantially vertical direction and refracted on the flat inclined surface 22B. This is so that it can be incident without any incident. Note that the vertical axis X of the flat inclined surface 22B does not necessarily pass through the focal point F of the lens surface 22A, and may slightly deviate from the focal point F. In short, the flat inclined surface 22B only needs to have an inclination so that the vertical axis direction is directed to the light emitting element 17A (17B) side. This is because even in such a case, the effect of the present invention is achieved. In this case, the light from the light emitting element 17A (17B) incident on the flat inclined surface 22B does not refract greatly on the flat inclined surface 22B as shown by the optical path L11 in FIG. 16P or the back surface 16Q is incident and then reflected by the front surface 16P or the back surface 16Q, and further, the light guide plate is incident on the back surface 16Q or the front surface 16P and then reflected by the back surface 16Q or the front surface 16P. The light is emitted from the light irradiation surface 16A. In this case, the light from the light irradiation surface 16A is emitted in a direction in which the light is diffused relatively greatly with respect to the thickness direction of the light guide plate 16 (t direction in the figure). For this reason, the light from the light irradiation surface 16A can be recognized from a wide angle in the vertical direction of the light guide plate 16, and the lighting of the vehicular lamp can be visually recognized in a wide range.

  Returning to FIG. 1, a taper surface 22 </ b> C is formed on each of the protrusions 21 on the front surface 16 </ b> P and the back surface 16 </ b> Q of the light guide plate 16. These tapered surfaces 22 </ b> C are formed with an inclination such that the thickness from the inner side surface 21 </ b> A becomes smaller as approaching the tip of the protrusion 21. The angle between the inner side surface 21A and the tapered surface 22C is set to approximately 45 °, for example. Further, as shown in FIG. 5, the tapered surface 22C is an imaginary surface disposed orthogonal to the optical axis surface M through the highest portion of the lens surface 22A on the front surface 16P and the back surface 16Q of the light guide plate 16. It is formed in a region extending from the portion intersecting the vertical plane L to the tip of the ridge 21. In this case, as indicated by the optical path L12 in FIG. 7, the light incident on the protruding portion 21 from the light emitting element 17A (17B) through the inner side surface 21A is reflected by the tapered surface 22C and then guided. Even though it is reflected by the front surface 16P or the back surface 16Q of the optical plate 16, it is transmitted substantially parallel to the optical axis surface M and is emitted from the light irradiation surface 16A. In this case, the light from the light emitting element 17A (17B) reflected by the tapered surface 22C is not reflected by the front surface 16P or the back surface 16Q of the light guide plate 16 depending on the reflection part of the tapered surface 22C, but the optical axis surface M. In some cases, the light is emitted from the light irradiation surface 16A substantially in parallel. As a result, among the light emitted from the light emitting elements 17A and 17B, even light that is emitted with a relatively large radiation angle can be transmitted to the inside of the light guide plate 16 through the protrusions 21 without waste, and is emitted from the light irradiation surface 16A. As a result, it is possible to achieve effective use without wasting light.

  The clearance lamp 15 configured in this way can guide light from the light emitting elements 17A and 17B to the inside of the light guide plate 16 without waste, and can ensure uniform luminance throughout the light irradiation surface 16A and also in the vertical direction. An effect that the light can be sufficiently diffused to the surface can be obtained. In addition, as means for diffusing light in the vertical direction, the light incident surfaces of the light emitting elements 17A and 17B are devised, and for example, it is not necessary to apply a special shape or the like on the light irradiation surface 16A to be observed. Etc. can be produced.

  In the embodiment described above, a clearance lamp is used as an example of the vehicular lamp of the present invention. However, the present invention is not limited to this. Needless to say, the present invention can be applied to other vehicular lamps such as a detime lamp, a position lamp, a front turn lamp, and the like.

  As mentioned above, although this invention was demonstrated using embodiment, it cannot be overemphasized that the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiments. Further, it is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Head lamp, 11 ... Lamp body, 12 ... Lamp chamber, 13 ... Passing beam lamp, 13A ... Lens, 14 ... Traveling beam lamp, 14A ... Reflector, 14B ... Light source, 15 ... Clearance lamp, 16: Light guide plate, 16A: Light irradiation surface, 16B: Light incident surface, 16C: Light reflection surface, 16P: Front surface, 16Q: Back surface, 17A, 17B ... Light emitting element, 18 ... ... front lens, 19A, 19B ... trapezoidal projection, 20 ... concave, 21 ... ridge, 21A ... inner surface, 22A ... lens surface, 22B ... flat inclined surface, 22C ... tapered surface .

Claims (2)

A light guide plate extending elongated from one end to the other, and a light emitting element that allows light to enter from the first side wall surface of the one end of the light guide plate,
The light from the light emitting element is repeatedly reflected between the second side wall surface and the third side wall surface that are arranged opposite to each other across the other end of the light guide plate, and the light is transmitted through the second side wall surface. A vehicular lamp configured as an irradiation surface,
On the first side wall surface, a recessed portion extending in a second direction orthogonal to the first direction which is the thickness direction of the light guide plate, and a protruding portion extending in the second direction on both sides of the recessed portion Formed,
On the bottom surface of the recessed portion, a lens surface that is convex toward the light emitting element at the center of the bottom surface and is formed as a substantially cylindrical surface having a central axis in the second direction, and each protrusion from both sides of the lens surface A flat inclined surface formed to reach the part,
The protrusion is configured to have a tapered surface on the front and back surfaces of the light guide plate,
The lens surface emits light from the light emitting element from the light irradiation surface so as to be substantially parallel to the front and back surfaces of the light guide plate,
The flat inclined surface emits light from the light emitting element from the light irradiation surface so that reflection is repeated between the front and back surfaces of the light guide plate,
The tapered surface is formed so that light from the light emitting element is substantially parallel to the front and back surfaces of the light guide plate, or light from the light emitting element is reflected to the front or back surface of the light guide plate. A vehicular lamp characterized by being configured to emit light from the light irradiation surface so as to be substantially parallel to the back surface. The vehicular lamp according to claim 1, wherein the flat inclined surface is formed to have an inclination so that a vertical axis direction of the flat inclined surface is directed to the light emitting element side.

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