JP2016213014A - Lighting appliance for vehicle - Google Patents

Abstract

A light guide plate that can increase the utilization efficiency of light emitted from a light source and can reduce the cost of a mold and a molding process in injection molding at a low cost, thereby reducing the manufacturing cost. The object is to provide a vehicular lamp that is miniaturized. In a vehicular lamp 1 including a light source 10 and a light guide plate 20 in which a light incident portion 30 and a light guide portion 40 are integrally formed, the light incident portion 30 has a focal point F and the focal point F. And a plurality of partial paraboloids that are arranged by cutting out a predetermined part from each of a plurality of rotary paraboloids having different focal lengths and having axes D and E as rotation axes. Are provided with internal reflection surfaces 32 and 33 each composed of a Fresnel-shaped composite paraboloid formed by connecting steps with each other. Light emitted from the light source 10 and incident into the light incident portion 30 is internally reflected by the internal reflection surfaces 32 and 33. Reflected light (total reflection) was made so that the reflected light whose optical path was controlled was directed to the light guide unit 40 side. [Selection] Figure 12

Description

  The present invention relates to a vehicular lamp, and more particularly to a vehicular lamp that uses light emitted from a light guide plate as irradiation light.

  Conventionally, a lamp having an optical system that takes in light emitted radially from a light source, controls the optical path to substantially parallel light, and guides the light through the light guide plate, is disclosed under the name of “planar illumination device” There is.

  As shown in FIG. 14 ((a) is a front view and (b) is a side view), the disclosed planar illumination device 80 is viewed from the LED light source 81 and one end face (light incident face) 82a side facing each other. The wedge-shaped light guide plate 82 whose thickness decreases toward the other end face 82b side, the light emitting surface 81a of the LED light source 81 and the light incident surface 82a of the light guide plate 82, which are located between the LED light source 81 and the light guide plate 82. And a light collector 83 having a light incident surface 83a and a light output surface 83b as surfaces facing each other.

  The light exit surface 83b of the light collector 83 extends in the thickness direction at a position corresponding to each LED light source 81, with the distance d between the light incident surface 83a and the light exit surface 83b matched to the focal length. A linear Fresnel lens 84 composed of a prism group is provided, and one surface of the light guide plate 82 facing each other serves as a light exit surface 82c, and the other surface extends substantially parallel to the longitudinal direction of the light incident surface 82a. The light reflecting surface 82d is provided with the prism 85.

  Therefore, the light S emitted from each LED light source 81 and incident on the light collector 83 from the light incident surface 83a is guided radially toward the light output surface 83b in the light collector 83, and is a linear Fresnel lens. The light is refracted and condensed in the XY plane by 84 and guided through the light guide plate 82 as parallel light S ′ in a front view. Thereby, the orientation distribution (in the XZ plane) of the emitted light from the light emitting surface 82c of the light guide plate 82 in the direction parallel to the light incident surface 82a can be narrowed and emitted with high directivity in the Y direction. It can be done.

JP 2007-73469 A

  By the way, in the planar lighting device 80 having the above-described configuration, it is necessary to provide a condensing body 83 for condensing light between the LED light source 81 and the light guide plate 82. Cost is generated, and as a result, the manufacturing cost of the planar lighting device 80 increases.

  Further, in order to increase the utilization efficiency of the light emitted radially from the LED light source 81 (specifically, the light emitted in a wide angle range with respect to the optical axis direction of the LED light source 81), the light collector 83 is used. It is necessary to increase the distance d (the length of the condenser 83) between the light incident surface 83a and the light emitting surface 83b, and as a result, the size of the planar illumination device 80 is increased.

  Further, the linear Fresnel lens 84 can be integrally formed on the light guide plate 82 to form the light incident portion 82a. In this case as well, the use efficiency of the light S emitted radially from the LED light source 81 can be increased as described above. In order to increase the distance, it is necessary to increase the distance between the LED light source 81 and the light incident surface 82a of the light guide plate 82, and the size of the planar illumination device 80 increases.

  At the same time, when the light guide plate 82 integrally formed with the linear Fresnel lens 84 is formed by injection molding, the concave and convex directions of the multiple prisms 85 provided on the light reflecting surface 82d of the light guide plate 82 and the light incident surface 82a are provided. The linear Fresnel lens 84 is arranged so that the concave and convex directions are perpendicular to each other. Therefore, in the molding die, it is not possible to mold only with two molds having molding surfaces facing each other, and the configuration of the mold becomes complicated, resulting in an increase in manufacturing cost.

  Accordingly, the present invention was devised in view of the above problems, and the object of the present invention is to increase the utilization efficiency of light emitted from the light source and to reduce the mold cost and molding processing cost in injection molding. An object of the present invention is to provide a vehicular lamp that can be reduced in size by using a light guide plate that can be reduced to a low manufacturing cost.

  In order to solve the above problems, the invention described in claim 1 of the present invention includes a light source and a light guide plate that guides light emitted from the light source and emits the light in a predetermined direction. A light incident part located on the light source side and a light guide part located on the opposite side of the light incident part from the light source part are integrally formed, and the light emitted from the light source is incident on the light incident part. A light incident surface, and an internal reflection surface that directs light incident from the light incident surface toward the light guide unit by internal reflection due to total reflection, and the internal reflection surface includes a focal position where the light source is located and A plurality of partial paraboloids arranged by cutting out a predetermined part from each of a plurality of paraboloids having different focal lengths sharing the axis passing through the focal position and having the axis as a rotation axis are connected by a step. It consists of a Fresnel-shaped compound paraboloid It is intended to.

  According to a second aspect of the present invention, in the first aspect, the axis of the complex paraboloid is inclined at a predetermined angle with respect to an optical axis of the light source, and the internal reflection is performed. The surface is located on the opposite side of the inclination direction of the axis with respect to the optical axis.

  According to a third aspect of the present invention, in the second aspect of the present invention, the shaft includes two shafts, and the respective shafts are inclined in opposite directions at a predetermined angle with respect to the optical axis. The internal reflection surface is composed of two surfaces, and each internal reflection surface is located at a position facing each other.

  The invention described in claim 4 of the present invention is the light guide unit according to any one of claims 1 to 3, wherein the light emitted from the light guide unit directly forms a light distribution characteristic. It is characterized by.

  The invention described in claim 5 of the present invention is characterized in that in any one of claims 1 to 4, the light source has a semiconductor light emitting element as a light emitting source.

  According to the present invention, in a vehicular lamp including a light source and a light guide plate in which the light incident portion and the light guide portion are integrally formed, the focal position where the light source is located at the light incident portion and the focal position. Fresnel formed by connecting a plurality of partial paraboloids arranged by cutting out a predetermined part from each of a plurality of rotary paraboloids having different focal lengths and sharing an axis passing through the axis. An internal reflection surface consisting of a compound paraboloid of shape is provided, and the light emitted from the light source and incident on the light incident part is internally reflected (total reflection) by the internal reflection surface to guide the reflected light whose optical path is controlled. I turned to the club side.

  As a result, by using the light guide plate that can increase the utilization efficiency of the light emitted from the light source, and can suppress the mold cost and the molding processing cost in the injection molding at a low cost, thereby reducing the manufacturing cost. It has become possible to provide a vehicular lamp that has been reduced in size.

It is a perspective explanatory view of the vehicular lamp of the embodiment. It is a perspective explanatory view of a light entrance part. FIG. 3 is an AA cross-sectional explanatory view of FIG. 2 for explaining one internal reflection surface. Similarly, it is a BB cross-sectional explanatory drawing of FIG. 2 explaining one internal reflection surface. Similarly, it is CC sectional explanatory drawing of FIG. 2 explaining one internal reflective surface. Similarly, it is an optical path explanatory drawing explaining one internal reflection surface. It is a perspective explanatory view of a light entrance part. It is an AA cross-sectional explanatory drawing of FIG. 7 explaining the other internal reflective surface. Similarly, it is BB sectional explanatory drawing of FIG. 7 explaining the other internal reflective surface. Similarly, it is CC sectional explanatory drawing of FIG. 7 explaining the other internal reflective surface. Similarly, it is an optical path explanatory drawing explaining the other internal reflection surface. It is explanatory drawing explaining both internal reflective surfaces. It is the elements on larger scale which concern on the light-incidence surface of a light-incidence part. It is explanatory drawing of a prior art example.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. 1 to 13 (the same parts are denoted by the same reference numerals). The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. Unless stated to the effect, the present invention is not limited to these embodiments.

  FIG. 1 is a perspective explanatory view of a vehicular lamp according to an embodiment of the present invention.

  The vehicular lamp 1 of the present invention includes a light source 10 and a light guide plate 20, and the light guide plate 20 includes a light incident portion 30 and a light guide portion 40.

  The light source 10 includes a light emitting source (for example, a semiconductor light emitting element such as an LED element) having a size that can be substantially regarded as a point light source in an optical system including the light source 10 and the light guide plate 20. A light source is used, and emits light radially with a light emitting source as a center.

  The light guide plate 20 controls the optical path of light emitted from the light source 10 in a predetermined direction by the light incident unit 30 and directs the light toward the light guide unit 40 side, and the light guide unit 40 further controls the optical path in a predetermined direction and directs the light outward. And exit.

  Next, the configuration of the light incident portion will be described in detail with reference to FIGS. 2 to 6 and FIGS. 7 to 11. FIGS. 2 and 7 are perspective explanatory views of the light incident portions obtained by cutting out the portions corresponding to the respective light sources from the light incident portions of the light guide plate corresponding to the plurality of light sources. FIGS. It is explanatory drawing of one internal reflective surface among a pair of internal reflective surfaces provided in the optical part, among which FIG. 3 is AA cross-sectional explanatory drawing of FIG. 2, FIG. 4 is BB cross-sectional explanatory drawing of FIG. 5 is a cross-sectional view taken along the line CC in FIG. 2, and FIG. 6 is an optical path explanatory view.

  8-11 is explanatory drawing of the other internal reflective surface among a pair of internal reflective surfaces provided in the light-incident part, among which FIG. 8 is AA cross-sectional explanatory drawing of FIG. 7, FIG. FIG. 10 is a sectional view taken along the line BB in FIG. 7, FIG. 10 is a sectional view taken along the line CC in FIG. 7, and FIG.

  2 and 7, the light incident portion 30 has a substantially rectangular parallelepiped shape. The light incident portion 31 includes a light incident surface 31 formed of one side surface that takes in light emitted from the light source, and the light incident from the light incident surface 31. On the other hand, an optical path is controlled by internal reflection (total reflection), and a pair of internal reflection surfaces 32 and 33 that are substantially perpendicular to the light incident surface 31 and face each other are provided.

  Each of the internal reflection surfaces 32 and 33 shares a focal point and an axis passing through the focal point, and a plurality of rotational paraboloids having different focal lengths with the axis as a rotation axis are cut out from a predetermined part and arranged. It consists of a Fresnel-shaped compound paraboloid formed by joining partial paraboloids by steps.

  Hereinafter, each of the pair of internal reflection surfaces 32 and 33 will be described.

  First, one internal reflection surface 32 (see FIGS. 2 to 5) is a compound rotary paraboloid that constitutes the internal reflection surface 32 in the vicinity of the light incident surface 31 of the light incident portion 30 of the light guide plate (not shown). The focal point F of the surface is set. The focal point F extends from the light incident surface 31 on the central axis C located on the same line as the optical axis of the light source 10 and extends in the surface direction (Y direction in the drawing) of the light incident portion 30 through the center of the light incident surface 31. It is located at a position separated by a predetermined distance.

  Then, the axis D of the compound paraboloid passing through the focal point F is inclined by a predetermined angle (α) with respect to the central axis C toward the other internal reflection surface 33 along the extending direction of the central axis C. It extends. The internal reflection surface 32 made up of a compound rotational paraboloid shares a predetermined part from each of a plurality of rotational paraboloids that share the focal point F and the axis D passing through the focal point F and have different focal lengths with the axis D as the rotational axis. It has a Fresnel shape formed by connecting a plurality of partial paraboloids arranged by cutting them out by steps.

  Specifically, in the present embodiment, the compound paraboloid is composed of 18 paraboloids having different focal lengths, that is, positions directly above the central axis C and the axis D of the internal reflection surface 32, in other words. The rotary paraboloid (D1) having the shortest focal length is arranged at the center position of the internal reflection surface 32, and the rotary paraboloids (D2 to D17) having a long focal length are arranged gradually toward the outer side, and the outermost side. The rotary paraboloid (D18) having the longest focal length is located at the position of.

  Therefore, each of the eighteen paraboloids constituting the compound paraboloid and having different focal lengths is arranged in a plane-symmetrical position with respect to the plane including the central axis C and the axis D.

  Thereby, when the light source 10 is arranged in a state where the light emission source 11 is located at the position of the focal point F, each rotary paraboloid (D1 to D18) of the internal reflection surface 32 constituted by the compound rotary paraboloid from the light source 10. The light L1 emitted radially toward the light enters the light incident portion 30 from the light incident surface 31 of the light incident portion 30 of the light guide plate 20 and is guided through the light incident portion 30 to each of the paraboloids ( D1-D18).

  The light L1 that has reached each of the paraboloids (D1 to D18) is internally reflected (totally reflected) by the respective paraboloids (D1 to D18), and the reflected light whose optical path is controlled to be parallel to each other has an axis D. The light is guided toward the light guide unit 40. Therefore, the light guide 40 is reflected by each paraboloid (D1 to D18) from the same direction as the extension direction of the axis D toward the surface on the same side as the internal reflection surface 33 facing the internal reflection surface 32. Light is introduced as parallel light (see FIG. 6).

  The other internal reflection surface 33 (see FIGS. 7 to 10) is a compound paraboloid that constitutes the internal reflection surface 32 in the vicinity of the light incident surface 31 of the light incident portion 30 of the light guide plate (not shown). The focal point F of the surface is set. The focal point F extends from the light incident surface 31 on the central axis C located on the same line as the optical axis of the light source 10 and extends in the surface direction (Y direction in the drawing) of the light incident portion 30 through the center of the light incident surface 31. It is located at a position separated by a predetermined distance.

  Then, the axis E of the compound paraboloid passing through the focal point F is inclined by a predetermined angle (α) with respect to the central axis C toward the other internal reflection surface 32 along the extending direction of the central axis C. It extends. The internal reflection surface 33 composed of a compound paraboloid has a predetermined part from each of a plurality of paraboloids sharing a focal point F and an axis E passing through the focal point F and having different focal lengths with the axis E as a rotation axis. It has a Fresnel shape formed by connecting a plurality of partial paraboloids arranged by cutting them out by steps.

  Specifically, in the present embodiment, the compound rotational paraboloid is composed of 18 rotational paraboloids having different focal lengths, in other words, the position directly above the central axis C and the axis E of the internal reflection surface 33, in other words. The rotary paraboloid (E1) having the shortest focal length is arranged at the center position of the internal reflection surface 33, and the rotary paraboloids (E2 to E17) having a long focal length are arranged gradually toward the outer side, and the outermost side. The rotational paraboloid (E18) having the longest focal length is located at the position of.

  Accordingly, each of the 18 rotational paraboloids constituting the compound paraboloid and having different focal lengths is disposed at a plane-symmetrical position with respect to the plane including the central axis C and the axis E.

  Thereby, when the light source 10 is arranged in a state where the light source 11 is located at the position of the focal point F, each rotational paraboloid (E1 to E18) of the internal reflection surface 33 constituted by the compound rotational paraboloid from the light source 10. The light L2 emitted radially toward the light enters the light incident portion 30 from the light incident surface 31 of the light incident portion 30 of the light guide plate 20 and is guided through the light incident portion 30 to each of the paraboloids ( E1-E18).

  The light L2 reaching each of the paraboloids (E1 to E18) is internally reflected (totally reflected) by the respective paraboloids (E1 to E18), and the reflected light whose optical path is controlled to be parallel to each other is converted into the axis E. The light is guided toward the light guide unit 40. Therefore, the light guide 40 is reflected by each paraboloid (E1 to E18) from the same direction as the extension direction of the axis E toward the surface on the same side as the internal reflection surface 32 facing the internal reflection surface 33. Light is introduced as parallel light (see FIG. 11).

  As described above, the mutually opposing internal reflection surfaces 32 and 33 of the light incident portion 30 of the light guide plate 20 have a plurality of rotary paraboloids D1 to D18 having an axis D inclined toward the internal reflection surface 33 and having different focal lengths. A plurality of paraboloids E1 having different focal lengths having an axis E inclined to the internal reflection surface 32 side, the compound rotation paraboloid configured by forming an internal reflection surface 32 opposite to the inclination direction of the axis D. A compound paraboloid composed of .about.E18 forms an internal reflection surface 33 on the side opposite to the inclination direction of the axis E (see FIG. 12 (an explanatory diagram of the internal reflection surface)).

  Therefore, each of the internal reflection surfaces 32 and 33 is formed at a position close to the central axis C side of the light incident portion 30, and the thickness of the light incident portion 30 can be reduced. Thereby, the vehicle lamp can be thinned.

  Moreover, each of the internal reflection surfaces 32 and 33 of the light incident part 30 which directs the light radiate | emitted radially from the light source 10 to the light guide part 40 side as parallel light, each has several rotating paraboloids (D1-D1) from which focal distance differs. D18) and (E1 to E18) are configured by Fresnel-shaped compound paraboloids obtained by connecting a plurality of partial paraboloids obtained by cutting out a predetermined part from each of (E1 to E18) by steps. Therefore, the light emitted in a wide angle range with respect to the optical axis direction of the light source 10, in other words, the light within a large solid angle of the light emitted radially from the light source 10 is sent to the light guide unit 40 as parallel light. The utilization efficiency with respect to the light emitted from the light source 10 can be increased.

  Further, light emitted radially from the light source 10 toward the internal reflection surfaces 32 and 33 of the light incident portion 30 is incident on the light incident portion 31 from the light incident surface 31 of the light incident portion 30. Until the internal reflection surfaces 32 and 33 are reached, the light incident portion 30 is guided radially. Therefore, it is not necessary for the light incident on the light incident part 30 to be irradiated over the entire surface of the light incident surface 31, and the distance between the light source 10 and the light incident surface 31 of the light incident part 30 can be shortened. This contributes to miniaturization of the vehicular lamp.

  By the way, when the light source 10 is placed at the same focal position of the internal reflection surfaces 32 and 33 formed of the compound rotary paraboloid, the light emitted from the light source 10 is refracted by the light incident surface 31 and then enters the light incident portion 30. Since the light enters the light incident portion 30 and reaches the internal reflection surfaces 32 and 33, the light that is optically emitted from a position shifted from the position of the light source 10 (focal position). The optical path is controlled as follows. Therefore, in order to perform high-accuracy optical path control, the positional relationship between the optical focal position and the internal reflection surfaces 32 and 33 formed of a compound rotary paraboloid is set in consideration of refraction by the light incident surface 31. There is a need. However, the shift of the focal position is a slight shift optically in the optical system constituted by the light source 10 and the light guide plate 20, and has little influence on the target optical path formation.

  In order to improve the positional accuracy by eliminating the displacement of the focal position, the shape of the light incident surface 31 of the light incident portion 30 is internally reflected as shown in FIG. By making the spherical surface around the position of the focal point F of the compound paraboloid forming the surfaces 32 and 33, the light L3 emitted radially from the light source 10 disposed at the focal point F position is the light incident surface 31. Go straight to reach the internal reflection surfaces 32 and 33, respectively. As a result, there is no positional shift of the focal position due to refraction.

  The light incident section 30 is provided with respective internal reflection surfaces 23 and 33 so that the light incident from the light incident surface 31 does not cause reflection loss and optical path disturbance due to repeated internal reflection in the light incident section 30. The position of the focal point F (light source position) shared by each of the compound paraboloids constituting the light source, the directions of the axes D and E, the focal length of each of the paraboloids constituting the respective compound paraboloids, and the light incident section 30. By appropriately setting the length (the length in the direction toward the light guide portion) and the like, the internal reflection in the light incident portion 30 is configured to be one time or less. In other words, the setting is made such that the reflected light that is incident from the light incident surface 31 and is reflected by one of the internal reflection surfaces of the light incident portion 30 does not reach the opposite internal reflection surface.

  In the above-described embodiment, the internal reflection surfaces composed of the compound paraboloids are provided on both surfaces of the light incident portion that are opposed to each other. However, only one surface can be a compound paraboloid. In that case, the reflecting means can be provided by sticking or applying a light reflecting member to the surface on which the composite paraboloid is not provided.

  The light guide 40 (see FIG. 1) is provided with at least a light exit surface 41 side, and, for example, concave and convex lens cuts 42 arranged in parallel with each other at a predetermined interval in a predetermined direction. Direct light by parallel light introduced from 30 and reflected light reflected in the light guide 40 are emitted in a desired direction by the lens cut 42 provided on the light emitting surface 41.

  In this case, the light reaching the light emitting surface 41 to which the lens cut 42 has been applied is controlled by the optical path because the direct light from the light incident part 30 and the reflected light reflected in the light guide part 40 are both substantially parallel light. The outgoing light, which is simple and easy and whose optical path is controlled by the lens cut 42, is emitted intensively in a predetermined direction with little diffused light, so that it is perceived as clear light by the viewer and the driver. A light distribution pattern that is bright and has good visibility is formed.

  By the way, the light guide plate 20 described above can integrally form the light incident part 30 and the light guide part 40, or can form the light incident part 30 and the light guide part 40 separately and integrate them later. You can also. In that case, the light incident part 30 and the light guide part 40 can also be formed of different transparent materials. As a transparent material used for the light guide plate 20, for example, an acrylic resin or a polycarbonate resin can be considered.

  In the light guide plate 20 constituting the vehicular lamp 1 of the present invention, the molds in the case where the light incident portion 30 and the light guide portion 40 constituting the light guide plate 20 are formed by injection molding are opposed to each other. It has a shape that can be molded with only two molds having a molding surface to be molded. Therefore, in either the individual molding of the light incident part 30 and the light guide part 40 or the integral molding of the light incident part 30 and the light guide part 40, the configuration of the mold can be simplified and the manufacturing cost can be reduced. Can do.

  The compound paraboloid does not necessarily need to be composed of 18 paraboloids as described above, and their arrangement positions are also set as appropriate.

DESCRIPTION OF SYMBOLS 1 ... Vehicle lamp 10 ... Light source 11 ... Light emission source 20 ... Light guide plate 30 ... Light incident part 31 ... Light incident surface 32 ... Internal reflection surface 33 ... Internal reflection surface 40 ... Light guide part 41 ... Light emission surface 42 ... Lens cut

Claims (5)

A light source and a light guide plate that guides light emitted from the light source and emits the light in a predetermined direction,
The light guide plate is integrally formed with a light incident part located on the light source side and a light guide part located on the light incident part opposite to the light source,
The light incident portion has a light incident surface on which light emitted from the light source is incident, and an internal reflection surface that directs light incident from the light incident surface toward the light guide portion by internal reflection due to total reflection,
The internal reflection surface shares a focal position where the light source is located and an axis passing through the focal position, and cuts a predetermined part from each of a plurality of paraboloids having different focal lengths with the axis as a rotation axis. A vehicular lamp characterized by comprising a Fresnel-shaped composite paraboloid formed by connecting a plurality of partial paraboloids arranged by steps.   The axis of the compound paraboloid surface is inclined at a predetermined angle with respect to the optical axis of the light source, and the internal reflection surface is located on the opposite side of the inclination direction of the axis with respect to the optical axis. The vehicular lamp according to claim 1, wherein the vehicular lamp is provided.   The axis is composed of two axes, and each axis is inclined in the opposite direction at a predetermined angle with respect to the optical axis, and the internal reflection surface is composed of two surfaces and the internal reflection surfaces are located at positions facing each other. The vehicular lamp according to claim 2.   The vehicular lamp according to any one of claims 1 to 3, wherein the light emitted from the light guide portion directly forms a light distribution characteristic.   The vehicular lamp according to claim 1, wherein the light source includes a semiconductor light emitting element as a light source.

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