JP2016039121A - Lighting fixture using light guide body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance use efficiency of light which is emitted from a light source and improve an appearance of a lighting fixture by accurately and efficiently emitting light which is emitted from the light source and guided in a light guide body in a desired direction, in the lighting fixture which uses the light guide body.SOLUTION: A light guide body 20 in which a plurality of triangular prism cuts 25 are formed, and a light source 10 are arranged in a lamp chamber 50 which is formed of a housing 40 and an outer lens 30. A face 25a located at the light source 10 side of each prism cut 25 is set so that an angle α formed of light which is emitted from the light source 10, linearly guided in the light guide body 20, and reaches the face, and a normal line N1 at the reaching point P becomes larger than a critical angle τ, and a face 25b located at a side opposite to the light source 10 is set so that an angle β formed of light which is emitted from the light source 10, linearly guided in the light guide body 20, and reaches the face, and a normal line N2 at the reaching point Q becomes smaller than the critical angle τ.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a lamp using a light guide, and more particularly to a lamp using light emitted from a light source and guided through the light guide as irradiation light.

  Conventionally, as this type of lamp, for example, a C (clearance lamp CL) / T (turn signal lamp TSL) unit configured as shown in FIGS. 6 to 8 is disclosed in Patent Document 1 (name: light illumination device and vehicle lamp). It is disclosed.

  The disclosed C / T unit is disposed in a headlamp lamp chamber composed of a lamp body and a front lens, and includes an LED of a light source, a light guide that guides light emitted from the LED, and a light guide An extension that reflects light guided in an apron region, which will be described later, and returns the light into the light guide is provided.

  As shown in FIG. 6, the specific configuration of the C / T unit 80 includes a base region 82 extending along the optical axis direction of the headlamp and a vertical direction from the front end of the base region 82. A suspended apron region 83 is integrally formed, and the base region 82 of the base region 82 is inclined downward at a minute angle toward the front end direction, and the upper surface has a plurality of taper steps extending in the left-right direction in a cross-sectional shape of a minute sawtooth. 84 is formed in the front-rear direction, and reflecting means 85 for reflecting light guided in the base region 82 toward the upper surface is disposed on the entire lower surface. A plurality of first LEDs 86 and second LEDs 87 are disposed in the vicinity of the rear end portion of the base region 82 of the light guide 81 and in the vicinity of the rear surface of the apron region 83, respectively, and an extension 88 is provided below the light guide 81. Is arranged.

  Therefore, when the clearance lamp CL is caused to function (see FIG. 7), the first LED 86 is caused to emit light. Then, almost all of the light emitted from the first LED 86 enters the light guide 81 from the rear end portion of the base region 82, and a part of the light is guided straight through the base region 82 and directly to the front end portion. Finally, the light is emitted forward as direct light, and part of the light is guided forward in the base region 82 while repeating total reflection on the upper surface and the lower surface, and emitted from the front end portion in the same manner. At the same time, a part of the light guided in the light guide 81 is reflected by the reflecting means 85 provided on the lower surface of the base region 82, and a part of the reflected light is guided in the base region 82 and the upper surface. Thus, a part of the light reaching the upper surface of the base region 82 is refracted and emitted by the stepped taper step 84 on the upper surface.

  On the other hand, when the turn signal lamp TSL is caused to function (see FIG. 8), the second LED 87 is caused to emit light. Then, almost all of the light emitted from the second LED 87 enters the apron region 83 from the rear surface of the apron region 83, and most of the incident light into the apron region 83 is guided straight through the apron region 83. Then, the light directly reaches the front surface and is refracted in the left-right direction by the cylindrical step 89 on the front surface before being emitted. A light distribution pattern that satisfies the light distribution standard in the horizontal direction is formed by the emitted light. Further, a part of the light incident on the apron region 83 is reflected by the bottom portion 90 of the extension 88 that is in close contact with the bottom surface of the apron region 83 or totally reflected by the bottom surface and front surface of the apron region 83 to be the upper part of the apron region 83. Light is guided in the light guide 81 toward the direction or the base region 82, a part of the light guided in the light guide 81 is emitted from the upper front surface of the apron region 83, and part of the light in the base region 82 Reflected by the reflecting means 85 provided on the lower surface, a part of the reflected light is guided through the base region 82 to the upper surface, and a part of the light reaching the upper surface of the base region 82 is a stepped taper on the upper surface. In step 84, the light is refracted and emitted.

  As described above, regardless of whether the first LED 86 is caused to emit light or the second LED 87 is caused to emit light, the light guided in the light guide 81 is emitted from the front surface of the apron region 83 and the upper surface of the base region 82. As a result, the entire light guide 81 emits light, and the emitted light is emitted through the front lens and used as irradiation light of the headlamp.

JP 2006-236588 A

  By the way, in the headlamp configured as described above, most of the light emitted from the upper surface of the base region 82 of the light guide 81 is guided through the light guide 81 and provided on the lower surface of the base region 82. The light is reflected by the reflecting means 85 toward different angular directions and returned into the base region 82, and the light reaches the upper surface of the base region 82 from various different directions. In addition, on the upper surface of the base region 82 where light from various different directions arrives, a large number of taper steps 84 extending in the left-right direction are formed in the front-rear direction with a cross-sectional cross-sectional shape.

  Therefore, the light emitted from the upper surface of the base region 82 of the light guide 81 is irradiated in various different directions, and it is difficult to direct it in a desired direction with good accuracy. As a result, when the required irradiation region is limited with respect to the irradiation light from the base region 82 of the light guide 81, the light irradiated to the region other than the necessary irradiation region is unnecessary and wasted light. As a result, a headlamp with low utilization efficiency of the light emitted from each of the first LED 86 and the second LED 87 of the light source is obtained.

  Therefore, the present invention was devised in view of the above problems, and an object of the present invention is to provide a desired direction of light emitted from a light source and guided through the light guide in a lamp using the light guide. Therefore, the use efficiency of light emitted from the light source is improved and the appearance of the lamp is improved.

  In order to solve the above-mentioned problem, the invention described in claim 1 of the present invention is characterized in that a long flat light guide and the light guide are provided in a lamp chamber formed of a closed space formed by a housing and an outer lens. In the vicinity of one end surface along the longitudinal direction of the body, it has a linear light source disposed along the end surface and with the emitting direction facing the end surface, and the light guide is on one flat plate surface, A plurality of convex triangular prism-shaped prism cuts extending along the longitudinal direction have a lens cut surface formed continuously in the lateral direction, and each prism cut has a surface located on the light source side The angle formed between the light emitted from the light source and guided in a straight line through the light guide and the normal line at the arrival point is set to be larger than the critical angle, opposite to the light source. The side surface is emitted from the light source and directly enters the light guide. And light arriving is guided in, the angle between the normal at the arrival point is characterized in that it is set to be smaller than the critical angle.

  According to a second aspect of the present invention, in the first aspect, the lens cut surface is formed so that the pitch of the plurality of prism cuts gradually becomes denser as the distance from the light source increases. It is characterized by this.

  Further, the invention described in claim 3 of the present invention is the light emitted from the other end surface in the first or second aspect, wherein the other end surface facing the one end surface along the longitudinal direction of the light guide body is the light emitted from the other end surface. Is provided with a lens cut configured to form a predetermined light distribution pattern.

  A lamp using a light guide according to the present invention includes a light guide formed with a plurality of triangular prism-shaped prism cuts and a light source in a lamp chamber formed of a housing and an outer lens. The surface located on the side is set so that the angle formed between the light that is emitted from the light source and is guided in a straight line through the light guide and the normal line at the reaching point is larger than the critical angle, The angle formed between the light that is emitted from the light source and is guided in a straight line through the light guide in the surface opposite to the light source, and the normal at the arrival point is smaller than the critical angle. Set.

  The light emitted from the latter surface (light emitting surface) of each prism cut is mainly composed of light emitted from the light source and traveling straight through the light guide. Therefore, by appropriately setting the direction and shape of the light exit surface, the light distribution characteristics that contribute to the improvement of appearance by directing the design of the lamp by the light emitted from the light exit surface can be efficiently performed with high accuracy. Can be realized.

It is a disassembled perspective view which concerns on the lamp of embodiment. It is a longitudinal cross-sectional view of a lamp. It is a ray tracing diagram of a lamp. Similarly, it is a ray tracing diagram of a lamp. Similarly, it is a ray tracing diagram of a lamp. It is explanatory drawing of a prior art example. Similarly, it is explanatory drawing of a prior art example. Similarly, it is explanatory drawing of a prior art example.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIG. 1 to FIG. 5 (the same parts are given 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 an exploded perspective view of an embodiment according to a “lamp using a light guide” according to the present invention.

  A lamp (hereinafter, simply referred to as “lamp”) 1 using a light guide according to the present invention includes a light source 10, a light guide 20 that guides light emitted from the light source 10, a light guide 20, An outer lens 30 that covers the light source 10 and transmits light emitted from the light guide 20 and a housing 40 that houses the light source 10 and the light guide 20 by the outer lens 30 are provided.

  Among them, the light source 10 is a linear light source from which emitted light is emitted linearly. The configuration of the linear light source is, for example, that light is introduced from one or both ends into a rod-shaped light guide (light guide rod), the light introduced into the light guide rod is guided, and the short direction of the light guide rod In addition, the light is emitted linearly. However, the configuration of the linear light source is not necessarily limited to the above configuration, and may be any configuration as long as linear output light can be obtained.

  The light guide 20 is made of a transparent member and has a long and thick plate shape. One end face (rear end face) of both end faces facing each other along the longitudinal direction is a light incident face 21, and the other The end face (front end face) is the first light exit surface 22. Also, one of the opposing surfaces extending in a direction substantially perpendicular to the thickness direction (upper surface) is the second light emitting surface 23, and the other surface (lower surface) is the light transmitting / reflecting surface 24.

  In the second light exit surface 23, a plurality of triangular prism-like prism cuts 25 extending along the longitudinal direction are continuously parallel from the edge on the first light exit surface 22 side to the middle of the edge on the light incident surface 21 side. And a flat surface 27 that extends from the end of the prism surface 26 to the edge on the light incident surface 21 side and is not subjected to lens cutting or light diffusion processing.

  The entire surface of the light transmission / reflection surface 24 is a flat surface, and the light reflection means 28 is provided in close contact with the light transmission / reflection surface 24. As the light reflecting means 28, for example, a method of directly forming a metal reflecting layer on the light transmitting / reflecting surface 24 by a vacuum deposition method or a method of attaching a metal reflecting member to the light transmitting / reflecting surface 24 by an adhesive method or the like can be considered.

  The outer lens 30 is made of a transparent member, and has a substantially rectangular thin flat plate-like second light transmission part 32 and one end side of both end parts facing each other along the longitudinal direction of the second light transmission part 32. The first light transmitting portion 31 is formed of a bent portion formed by bending the lens at a substantially right angle (downward). Note that the transparent member forming the outer lens 30 may be a colored transparent member colored, for example, red.

  The second light transmission part 32 has a plurality of triangular prisms or arc-shaped prism cuts 33 extending along the lateral direction, and the first light transmission part 31 side from the edge opposite to the first light transmission part 31. A prism portion 34 that is arranged in parallel to the middle of the edge portion, and a through portion that is not subjected to lens cutting or light diffusion processing that extends from the end portion of the prism portion 34 to the edge portion on the first light transmitting portion 31 side. 35.

  The housing 40 has a light shielding property and is formed in a predetermined shape by, for example, resin molding or metal plate processing of a metal plate. If necessary, light shielding means is applied by painting or chemical treatment.

  FIG. 2 is a longitudinal sectional view along the front-rear direction of the lamp 1 including the light source 10, the light guide 20, the outer lens 30, and the housing 40.

  In the lamp 1, a lamp chamber 50 including a closed space is formed by the outer lens 30 and the housing 40, and the light source 10 and the light guide 20 are accommodated in the lamp chamber 50.

  In the lamp chamber 50, a linear light source 10 is disposed in the vicinity of the light incident surface 21 that is an end surface along the longitudinal direction of the light guide 20, with the light emitting surface 11 facing the light incident surface 21. ing.

  The light guide 20 and the light source 10 are covered with an outer lens 30, and the first light transmission portion 31 of the outer lens 30 is positioned in front of the first light emission surface 22 of the light guide 20 in the light emission direction. In addition, the second light emitting portion 32 of the outer lens 30 is located above the second light emitting surface 23 of the light guide 20.

  At the same time, the threading portion 35 of the second light emitting portion 32 of the outer lens 30 is positioned above the prism surface 26 of the second light emitting surface 23 of the light guide 20, and the second light emitting surface 23 of the light guide 20. The prism portion 34 of the second light emitting portion 32 of the outer lens 30 is located above the flat surface 27 and the light source 10.

  As described above, the light transmitting / reflecting surface 24 formed of a flat surface of the light guide 20 is provided with the light reflecting means 28 in close contact with the light transmitting / reflecting surface 24. Similarly, as described above, the prism surface 26 of the light guide 20 has a plurality of triangular prism-shaped prism cuts 25 extending along the longitudinal direction, from the edge on the first light emitting surface 22 side to the light incident surface 21 side. Parallel to the middle of the edge of the.

  The plurality of prism cuts 25 are formed so that the pitch gradually increases from the light incident surface 21 side toward the first light emitting surface 22 side. The light guide 20 is formed so that its thickness gradually decreases from the light incident surface 21 side toward the first light emitting surface 22 side.

  In this way, the light that is emitted from the light source 10 and incident from the light incident surface 21 by gradually reducing the thickness of the light guide 20 from the light incident surface 21 side toward the first light emitting surface 22 side. However, the distance from the light incident surface 21 is sufficiently long to reach the vicinity of the first light emitting surface 22. Further, by gradually increasing the pitch of the prism cuts 25 from the light incident surface 21 side toward the first light exit surface 22 side, the light incident from the light incident surface 21 is a distance from the light incident surface 21. The amount of emitted light decreases as the distance increases, and the brightness of the emitted light from the prism surface 26 is increased and the brightness uniformity is ensured by increasing the efficiency of the emission and leveling the emitted light. Yes.

  Next, an optical system constituted by the light source 10, the light guide 20, and the outer lens 30 will be described with reference to FIG.

  The light emitted from the light exit surface 11 of the light source 10 enters the light guide 20 from the light incident surface 21 of the light guide 20, and part of the light incident on the light guide 20 enters the first light exit surface 22. Opposite, a part is directed to the prism surface 26 of the second light emitting surface 23 and a part is directed to the light transmitting / reflecting surface 24.

  Among them, the light L1 traveling toward the first light exit surface 22 travels straight through the light guide 20 and is guided to reach the first light exit surface 22 and exits from the first light exit surface 22 and is positioned forward. The light passes through the first light transmission portion 31 of the outer lens 30 and is emitted in the forward direction of the lamp 1.

  The light traveling toward the prism surface 26 of the second light exit surface 23 is a surface on the light source 10 side (hereinafter referred to as a “first prism surface”) of each triangular prism-shaped prism cut 25 that partially constitutes the prism surface 26. ) 25a and a part thereof is directed to a surface opposite to the light source 10 (hereinafter referred to as “second prism surface”) 25b.

  In this case, as shown in FIG. 4 (partially enlarged view of the ray tracing diagram), the first prism surface 25a includes the light L2a that has been guided through the light guide 20 and the arrival point thereof. The angle α formed by the normal line N1 in P is set to be larger than the critical angle τ (α> τ). In other words, the first prism surface 25a is arranged so that the incident angle α of the light guided in the light guide 20 is larger than the critical angle τ. Therefore, most of the light L2a incident from the light incident surface 21 and guided through the light guide 20 to reach the first prism surface 25a is reflected (totally reflected) by the first prism surface 25a and is guided. Return to 20.

  The light L2a returned into the light guide 20 (returning to FIG. 3) is reflected by the light transmitting / reflecting surface 24 (total reflection) or reflected by the light reflecting means 28 (specular reflection) and reflected by the first prism surface 25a ( The lamp 1 is guided toward the first light emitting surface 22 while repeating total reflection), and is transmitted through the first light transmitting portion 31 of the outer lens 30 that is emitted from the first light emitting surface 22 and positioned forward. Is emitted in the forward direction.

  On the other hand, as shown in FIG. 5 (partially enlarged view of the ray tracing diagram), the second prism surface 25b has the light L2b that has been guided through the light guide 20 and the normal line N2 at the arrival point Q. Is arranged such that the angle β is smaller than the critical angle τ (β <τ). In other words, the second prism surface 25b is set such that the incident angle β of the light guided through the light guide 20 is smaller than the critical angle τ. Therefore, most of the light L2b that is incident from the light incident surface 21 and is guided through the light guide 20 and reaches the second prism surface 25b is directly emitted from the second prism surface 25b and positioned on the upper side. The light is transmitted through the second light transmitting portion 32 of the lens 30 and emitted in the forward direction or obliquely forward direction of the lamp 1.

  Further, the light L3 traveling toward the light transmitting / reflecting surface 24 is repeatedly reflected by the light transmitting / reflecting surface 24 (total reflection) or reflected by the light reflecting means 28 (specular reflection) and reflected by the first prism surface 25a (total reflection). The light is guided toward the first light emitting surface 22, is emitted from the first light emitting surface 22, passes through the first light transmitting portion 31 of the outer lens 30 positioned forward, and is emitted in the forward direction of the lamp 1. The

  Therefore, from the first light exit surface 22 of the light guide 20, the light L1 emitted from the light source 10 and straightly guided in the light guide 20 and the light reflected in the light guide 20 is reflected more than once. Alternatively, the light L2a and L3 guided while being totally reflected are emitted.

  Outgoing lights L1, L2a, and L3 from the first light emitting surface 22 are transmitted forward through the first light transmitting portion 31 of the outer lens 30 located in the front, and emitted in the forward direction of the lamp 1, and the light distribution pattern of the lamp 1 Form. Therefore, a desired light distribution pattern is formed by appropriately setting one or both of the shape of the first light emitting surface 22 of the light guide 20 and the shape of the first light transmitting portion 31 of the outer lens 30. Can do.

  Further, the emitted light L2b from each second prism surface 25b of the prism cut 25 of the prism surface 26 passes through the through portion 35 of the second light transmission portion 32 of the outer lens 30 located above, or in the forward direction of the lamp or The light is emitted diagonally forward, and the design of the lamp 1 is produced by the emitted light, thereby improving the appearance.

  Further, the emitted light L2b from each second prism surface 25b of the prism cut 25 of the prism surface 26 is light that is emitted from the light source 10 and travels straight through the light guide 20 and is guided. Therefore, by appropriately setting the shape and direction of each second prism surface 25b, the light L2b that has reached each second prism surface 25b is accurately and efficiently directed in a predetermined direction by refraction at each second prism surface 25b. The desired light distribution pattern can be obtained by the emitted light.

  For example, by directing each second prism surface 25b in the same direction, the directivity characteristic of the light emitted from the prism surface 26 can be set to a directivity characteristic that is obtained by partially projecting the directivity characteristic of the linear light source 10 as it is. it can. Specifically, when the light emitted from the linear light source 10 has Lambertian directivity, the light emitted from the prism surface 26 also forms part of the Lambertian directivity.

  Further, for example, by appropriately setting an angle for each prism surface 25b with respect to the light L2b reaching each second prism surface 25b, the light emitted from the prism surface 26 can be made substantially parallel light.

  As described above, the lamp of the present invention efficiently takes in the light emitted from the linear light source into the light guide, and distributes the light taken into the light guide and guided through the light guide. The light is separated into light that contributes to the formation of light distribution characteristics that satisfy the optical standard and light that contributes to the provision of design, and each light is efficiently emitted from the light guide.

  In addition, light that contributes to the formation of light distribution characteristics and light that contributes to the provision of design properties are mainly guided by light emitted from the light source and entering the light guide through the light guide. Consists of light. Therefore, desired light distribution characteristics can be realized with high accuracy by appropriately setting the inclination, shape, and the like of the exit surface with respect to the light guided in the light guide.

  Further, light is emitted from the front surface and the upper surface from the light guide, and the light is emitted to the outside through the outer lens. Therefore, when the lamp is viewed from the surroundings, it is viewed as if light is emitted from the entire surface of the lamp, and a sense of unity of the lamp is produced. In particular, in a long lamp that is curved so as to wrap around along the side surface from the front surface of the vehicle, the effect of unity by light is effectively exhibited.

DESCRIPTION OF SYMBOLS 1 ... Lamp 10 ... Light source 11 ... Light emission surface 20 ... Light guide 21 ... Light incident surface 22 ... 1st light emission surface 23 ... 2nd light emission surface 24 ... Light transmission reflective surface 25 ... Prism cut 25a ... 1st prism Surface 25b ... Second prism surface 26 ... Prism surface 27 ... Flat surface 28 ... Light reflecting means 30 ... Outer lens 31 ... First light transmitting portion 32 ... Second light transmitting portion 33 ... Prism cut 34 ... Prism portion 35 ... Through portion 40 ... Housing 50 ... Light room

Claims (3)

In the lamp chamber consisting of a closed space formed by a housing and an outer lens,
In the vicinity of one end face along the longitudinal direction of the light guide, and a linear light source disposed along the end face and the emitting direction toward the end face,
The light guide has a lens cut surface in which a plurality of convex triangular prism-shaped prism cuts extending along the longitudinal direction are continuously formed in the lateral direction on one flat surface.
Each of the prism cuts has a critical angle defined by the angle formed between the light that the surface located on the light source side emits from the light source and is guided in a straight line through the light guide and the normal line at the arrival point. Is set to be larger than
The angle formed by the surface located on the opposite side of the light source and emitted from the light source and guided in a straight line through the light guide and the normal at the arrival point is smaller than the critical angle. A lamp using a light guide, which is set as described above.   2. The lamp using a light guide according to claim 1, wherein the lens cut surface is formed so that a pitch of the plurality of prism cuts is gradually increased as the distance from the light source is increased.   The other end surface facing the one end surface along the longitudinal direction of the light guide is provided with a lens cut configured such that light emitted from the other end surface forms a predetermined light distribution pattern. A lamp using a light guide according to claim 1 or 2.

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