JP5999352B2 - Light guide member - Google Patents

Description

  The present invention relates to a light guide member that is rod-shaped and emits light incident from an end surface in a length direction from a surface along the length direction.

  Patent Document 1 discloses a lighting device including a rod-shaped light guide member. In this illuminating device, a light emitting diode as a light source is provided at a position facing the end face in the length direction of the light guide member. The light emitted from the light emitting diode is introduced into the light guide member from the end surface in the length direction of the light guide member. In this illumination device, the light introduced into the light guide member is reflected by the scattering dots formed on the bottom surface of the light guide member, and then emitted from the top surface of the light guide member.

JP-A-2005-198106

  A light guide member that introduces light emitted from a light source from a lengthwise end face, such as the light guide member of Patent Document 1, is viewed from the length direction of the light guide member. It is preferable to arrange at overlapping positions. This is because substantially all of the light emitted from the light source can be introduced into the light guide member, and the loss of light quantity can be reduced.

  However, when the light source is large or a plurality of light sources are provided, the light source may protrude from the end surface of the light guide member when viewed from the length direction of the light guide member. Further, if the size of the cross section perpendicular to the length direction of the light guide member is increased in proportion to the light source, the protrusion can be prevented, but in this case, the light guide member is increased in size.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a light guide member that can reduce a loss of light amount when a large light source or a plurality of light sources is used and can suppress an increase in size. To do.

In order to solve the above problems, the light guide member of the present invention is a rod-shaped light guide member, and is provided with a wide portion provided along the length direction, and also provided along the length direction. A cross-section perpendicular to the direction that protrudes from the wide portion in a direction perpendicular to the width direction, and has a narrow portion that is narrower than the wide portion, and the wide portion connects the side surface to the side surface of the narrow portion The end surface in the length direction of the wide portion is a light incident surface on which light emitted from a light source is incident, and the protruding end surface of the narrow portion protruding from the wide portion is the light incident surface A reflection surface that reflects light incident from the side, a surface opposite to the narrow portion of the wide portion as a light exit surface that emits light reflected by the reflection surface, and the step surface and the side surface of the wide portion. A claw portion that can be fitted and attached to another member is formed at a corner portion formed .

  Moreover, it is preferable that the said narrow part protrudes from the intermediate part of the said width direction of the said wide part, and the said wide part has the said level | step difference surface on the both sides of the said width direction.

  Further, it is preferable that a cross section perpendicular to the length direction is formed symmetrically about the center line, assuming a center line passing through the center of the width direction and orthogonal to the width direction.

  In the present invention, the light incident surface on which the light emitted from the light source is incident can be constituted by the end surface in the length direction of the wide portion wider than the narrow portion. For this reason, when a light source disposed at a position opposite to the light incident surface is large or a plurality of light sources are disposed at positions opposite to the light incident surface, light emitted from the light source is incident from the light incident surface. It becomes easy and the loss of light quantity can be suppressed. In addition, the light guide member can be reduced in size by forming the stepped surface by making the width of the narrow portion narrower than that of the wide portion.

It is sectional drawing of the light guide member of an example of this embodiment. It is explanatory drawing of the illuminating device incorporating the light guide member same as the above. It is sectional drawing of the light guide member of the other example made asymmetric. It is sectional drawing of the light guide member of the other example which provided the one level | step difference surface. It is explanatory drawing which shows the positional relationship of the light guide member and light source seen from the longitudinal direction of the light guide member. It is explanatory drawing which shows the vocabulary used for derivation | leading-out of Formulas 1-3. (A)-(c) is a figure which shows the cross-sectional shape pattern of the light guide member of this embodiment. It is explanatory drawing which shows the vocabulary used for derivation | leading-out of Formula 4 and Formula 5. It is explanatory drawing which shows the vocabulary used for derivation | leading-out of Formula 6 and Formula 7. It is sectional drawing which shows an example of the cross-sectional shape of a light guide member same as the above. It is sectional drawing which shows the other examples of the cross-sectional shape of a light guide member same as the above. It is sectional drawing which shows the further another example of the cross-sectional shape of a light guide member same as the above. It is sectional drawing of the light guide member of the other example which provided the attaching part on both sides. It is sectional drawing of the light guide member of the other example which provided the attaching part and the chamfering part. (A)-(c) is sectional drawing which shows the modification of the light guide member shown by FIG. It is sectional drawing which shows the modification of the light guide member shown by FIG.

  Hereinafter, the present invention will be described with reference to the accompanying drawings. The light guide member 1 of the present embodiment has a linear bar shape and is used by being incorporated in a lighting device or the like. FIG. 2 shows an illumination device 2 incorporating the light guide member 1. The illuminating device 2 is an edge light type in which light incident from the end surface in the length direction of the light guide member 1 is emitted from a surface along the length direction of the light guide member 1. The lighting device 2 includes a light source 20 and a control board 21 on which the light source 20 is mounted in addition to the light guide member 1 of the present embodiment.

  In the illuminating device 2 shown in FIG. 2, light sources 20 are arranged on both sides of the light guide member 1 in the length direction. Each light source 20 is disposed at a position facing the end surface of the light guide member 1 in the length direction. For example, an LED is used as the light source 20. When each light source 20 emits light, this light is introduced into the light guide member 1 from a corresponding end face in the length direction of the light guide member 1 (detailed light incident surface 132 described later). Subsequently, this light travels generally toward the end surface on the opposite side of the length direction of the light guide member 1. Then, this light is diffusely reflected by one surface along the length direction of the light guide member 1 (that is, a reflection surface 141 described later) in the process of progressing, and another surface along the length direction of the light guide member 1 (that is, The light exits from a light exit surface 133) which will be described later. The lighting device 2 may be one in which the light source 20 is disposed only on one side in the length direction of the light guide member 1. Further, a plurality of light sources 20 may be provided on both sides or one side in the length direction of the light guide member 1.

  The light guide member 1 is made of a synthetic resin, and a transparent resin such as an acrylic resin or a polycarbonate resin is used as the material thereof. In addition, as a material of the light guide member 1, it is not restricted to a synthetic resin, You may form using another material.

  The cross-sectional shape of the light guide member 1 is substantially uniform in the length direction. Note that the term “substantially uniform” as used herein includes not only completely the same, but also those that minutely change the shape of the reflecting surface 141, the light exiting surface 133, etc., for example, in order to suppress light unevenness.

  FIG. 1 shows a cross section orthogonal to the length direction of the light guide member 1. As shown in the figure, the light guide member 1 includes a wide portion 13 and a narrow portion 14. The wide portion 13 in the illustrated example has a rectangular cross section, and is wider than the narrow portion 14 and has a larger cross sectional area. The narrow portion 14 protrudes from the central portion in the width direction of the wide portion 13, and the protruding direction is parallel to the thickness direction of the light guide member 1. In addition, the thickness direction said here is a facing direction of the reflective surface 141 and the light emission surface 133, and is a direction orthogonal to the width direction in the cross section orthogonal to the length direction of the light guide member 1.

  The wide portion 13 has stepped surfaces 131 connecting the side surface 130 and the side surface 140 of the narrow portion 14 on both sides. Both end surfaces in the length direction of the light guide member 1 are constituted by an end surface in the length direction of the wide portion 13 and an end surface in the length direction of the narrow portion 14 which is flush with this surface. In addition, the light guide member 1 shown in FIG. 1 is symmetrical with respect to the center line CL, assuming a center line CL passing through the center in the width direction and orthogonal to the width direction in the cross section orthogonal to the length direction. Is formed. The light guide member 1 may be formed asymmetrically as shown in FIG. 3 and FIG. Moreover, although the light guide member 1 shown in FIG. 1 has the step surfaces 131 formed on both sides of the wide portion 13, the step surfaces 131 may be formed only on one side of the wide portion 13 as shown in FIG.

  As illustrated in FIG. 2, the light guide member 1 includes a light incident surface 132, a light output surface 133, and a reflective surface 141. The light incident surface 132 is configured by an end surface in the length direction of the wide portion 13. The light incident surface 132 is orthogonal to the length direction of the light guide member 1. When the light guide member 1 is used by being incorporated in the lighting device 2, a portion corresponding to the wide portion 13 of the light incident surface 132 is disposed to face the light source 20, and light emitted from the light source 20 is introduced from the same portion. For example, as illustrated in FIG. 5, the light source 20 is disposed only at a location overlapping the wide portion 13 when viewed from the length direction of the light guide member 1, and is disposed on the inner side of the outer edge of the wide portion 13. Note that the light source 20 may be disposed at a location overlapping the wide portion 13 and the narrow portion 14 when viewed from the length direction of the light guide member 1. As shown in FIG. 2, when the light sources 20 are arranged on both sides in the length direction of the light guide member 1, both end surfaces in the length direction of the wide portion 13 are used as the light incident surfaces 132. When the light source 20 is disposed only on one side of the light guide member 1, only one end surface in the length direction of the wide portion 13 is used as the light incident surface 132.

  As shown in FIG. 1, the protruding end surface of the narrow portion 14 is orthogonal to the thickness direction of the light guide member 1, and the reflecting surface 141 extends in the length direction of the light guide member 1 at the protruding end surface of the narrow portion 14. (Light diffusion surface) is configured. The reflective surface 141 is formed, for example, by providing a reflective material on the protruding end surface of the narrow portion 14 by printing or vapor deposition, providing fine irregularities, or providing a reflective portion by two-color molding.

  A surface of the wide portion 13 opposite to the narrow portion 14 is opposed to the reflecting surface 141, and a light exit surface 133 extending in the length direction of the light guide member 1 is configured on the same surface. The light exit surface 133 is orthogonal to the thickness direction of the light guide member 1. The light reflected by the reflecting surface 141 reaches the light emitting surface 133 and is emitted from the entire light emitting surface 133 as band-like light.

  As shown in FIG. 1, the width of the narrow portion 14 increases as it goes to the wide portion 13 side. Both side surfaces 140 in the width direction of the narrow portion 14 are curved so that the light reaching the both side surfaces of the narrow portion 14 is totally reflected toward the light exit surface 133 side after being reflected by the reflecting surface 141. The both side surfaces 140 are combined to form a curved surface having a substantially parabolic cross section.

  By the way, in order to suppress that the light guide member 1 suppresses the reduction | decrease in the quantity of the light radiate | emitted from the light emission surface 133, it is preferable that the cross-sectional shape orthogonal to a length direction is a shape which satisfy | fills the following formulas 1-3. .

λ <φ _ij ≦ π / 2 (Expression 1)
0 ≦ ψ _ij <λ (Expression 2)
0 ≦ ξ _jk <λ (Expression 3)
Here, as shown in FIG. 6, the width of the reflecting surface 141 is A, the width of the end portion of the narrow portion 14 on the wide portion 13 side is B ₁ , and the light exit surface 133 is centered in the width direction of the reflecting surface 141. The width of the part located on the left side in the figure is B ₂ , and the width of the part located on the right side in the figure is B ₃ . Further, the length from the reflective surface 141 to the wide portion 13 is H ₁ , and the length from the reflective surface 141 to the light exit surface 133 is H ₂ . In addition, an inclination angle with respect to the thickness direction at each point of the side surface 140 of the narrow portion 14 is θ _i . Further, in the case where the width direction of the center of the reflecting surface 141 to the coordinate origin O, the position coordinates _{x i} in the width direction of each point of the side surface 140 of the narrow portion 14 _{(however, -B 1/2 ≦ x i} < -A / 2, a / 2 < x i ≦ B 1/2), the position coordinates in the thickness direction _{y i} (where a _{0 <y i ≦ H 1)} . Similarly, the position coordinate in the width direction of each point of the reflection surface 141 when the center in the width direction of the reflection surface 141 is the coordinate origin O is p _j (where −A / 2 ≦ p _j ≦ A / 2). And Further, the incident angle of the light reflected at the point corresponding to the position coordinate p _j of the reflecting surface 141 with respect to the point (x _i , y _i ) of the side surface 140 of the narrow width portion 14 is φ _ij . Further, after being reflected at the point where the position coordinate p _j of the reflecting surface 141 is obtained, the light is reflected at the point (x _i , y _i ) on the side surface 140 of the narrow portion 14, and then the light exiting surface reaching the light exiting surface 133. An incident angle with respect to 133 is denoted by ψ _ij . In addition, when the center of the reflecting surface 141 in the width direction is set to the coordinate origin O, the position coordinate in the width direction of the point where the light reflected at the point that becomes the position coordinate p _j of the reflecting surface 141 on the light exit surface 133 directly reaches q. _k (provided that −B ₂ ≦ q _k ≦ B ₃ ). Further, an incident angle with respect to the light exit surface 133 of light directly reaching the light exit surface 133 after being reflected at the point where the position coordinate p _j of the reflection surface 141 is set to ξ _jk . Further, the total reflection angle of the light guide member 1 is λ. The refractive index of the light guide member 1 is n. Here, λ = sin ⁻¹ (1 / n) (* in the air), θ _i = −tan ⁻¹ {y _i / (x _i + p _j )} + φ _ij , ψ _ij = π / 2−φ _ij − θ _i , θ _i = 1/2 [π / 2−ψ _ij −tan ⁻¹ {y _i / (x _i + p _j )}], ξ _jk = tan ⁻¹ {(q _k −p _j ) / H ₂ }.

  By satisfying Equation 1, the light that is reflected at each point on the reflecting surface 141 and reaches each side surface 140 of the narrow portion 14 is totally reflected at the side surface 140. Thereby, it is possible to prevent light reflected at each point on the reflecting surface 141 from leaking from each side surface 140 of the narrow portion 14. Further, by satisfying Expression 2, after being reflected at each point on the reflecting surface 141, it is reflected at each point on the side surface 140 of the narrow portion 14, and then the light reaching the light emitting surface 133 is reflected on the light emitting surface 133. The light exits from the light exit surface 133 without being reflected. Further, by satisfying Expression 3, the light that has directly reflected the light exit surface 133 after being reflected at each point of the reflection surface 141 is not reflected by the light exit surface 133 but is emitted from the light exit surface 133.

Further, when considering a shape satisfying the above-described calculation formula, the shape is classified into the following shape patterns according to the light beam behavior in the light guide member 1. First shape pattern shown in FIG. 7 _{^{(a), tan -1 {(A / 2}} + B 1/2) / H 1} ≦ λ, (A / 2 + B 1/2) / H 1 <(A / 2 + B is the case of the _2/2) / _{H 2.} Second shape pattern shown in FIG. 7 _{^{(b), tan -1 {(A / 2}} + B 1/2) / H 1} ≦ λ, (A / 2 + B 1/2) / H 1 ≧ (A / 2 + B is the case of _3/2) / _H 2. The third shape pattern shown in FIG. 7 _{^{(c), tan -1 {(A / 2}} + B 1/2) / H 1}> λ, tan -1 {(A / 2 + B 3/2) / H 2} This is the case when ≦ λ.

  When the light guide member 1 is a 1st-3rd shape pattern, it is preferable that it is a shape which satisfy | fills the following formula | equation 4 and Formula 5 in addition to Formula 1. FIG.

λ <ζ _ijl ≦ π / 2 (Formula 4)
0 ≦ η _ijkl <λ (Expression 5)
Here, as shown in FIG. 8, when the center in the width direction of the reflecting surface 141 is the coordinate origin O, the position coordinates in the width direction of each point of each side surface 130 of the wide portion 13 are represented by x ′ _l {however, _{, B 1/2 ≦ X '} l ≦ B 3}, the position coordinates in the thickness direction _{y' l} {However, the _{H 1 ≦ y 'l ≦ H} 2}. Further, after being reflected at the point p _j on the reflecting surface 141, the light is reflected at the point (x _i , y _i ) on the side surface 140 of the narrow portion 14, and then the light reaches the side surface 130 of the wide portion 13 with respect to the side surface 130. _{Let the} incident angle be ζ _ijl . Further, after being reflected at a point where the position coordinate p _j of the reflecting surface 141 is obtained, it is reflected at a point (x _i , y _i ) on the side surface 140 of the narrow portion 14, and thereafter, a point on the side surface 130 of the wide portion 13 ( x ₁ , y ₁ ), and thereafter, the incident angle of the light reaching the light exit surface 133 with respect to the light exit surface 133 is η _ijkl . Here, ζ _ijl = tan ⁻¹ {(y ′ _l −y _i ) / (x ′ _l −x _i ), η _ijkl = π / 2−ζ _ijl .

  By satisfying Expression 4, after being reflected at each point on the reflecting surface 141, the light reflected at each point on each side surface 140 of the narrow portion 14, and then the light reaching each side surface 130 of the wide portion 13 is wide. Total reflection is performed on each side surface 130 of the portion 13. Thus, it is possible to prevent light reflected at each point on each side surface 140 of the narrow portion 14 from leaking from each side surface 130 of the wide portion 13 after being reflected at each point on the reflecting surface 141. Further, by satisfying Expression 5, after reflecting at each point of the reflecting surface 141, it is reflected at each point of each side surface 140 of the narrow portion 14, and then reflected by each side surface 130 of the wide portion 13 to be emitted. The light that reaches the surface 133 is not reflected by the light exit surface 133 but is emitted from the light exit surface 133.

  Moreover, when the light guide member 1 is a 2nd shape pattern and a 3rd shape pattern, it is preferable that it is a shape which satisfy | fills the following formulas 6 and 7.

λ <ε _jl ≦ π / 2 (Expression 6)
0 ≦ ω _jkl <λ (Expression 7)
Here, as shown in FIG. 9, the incident angle with respect to the side surface 130 of the light that is reflected at the point where the position coordinate p _j of the reflecting surface 141 is reached and reaches the side surface 130 of the wide portion 13 is ε _jl . Further, after being reflected at the point where the position coordinate p _j of the reflecting surface 141 is obtained, it is reflected at the point (x ′ _i , y ′ _i ) on the side surface 130 of the wide portion 13, and then the light exiting to the light exiting surface 133 is performed. The incident angle with respect to the surface 133 is ω _jkl . ^{_{Here, ε jl = tan -1 {y}} 'l / (x' l -p j)}, a _{ω jkl = π / 2-ε} jl.

  By satisfying Expression 6, the light that reaches each side surface 130 of the wide portion 13 after being reflected at each point of the reflecting surface 141 is totally reflected at the side surface 130. Thereby, it is possible to prevent light reflected at each point of the reflecting surface 141 from leaking from each side surface 130 of the wide portion 13. Further, by satisfying Expression 7, after being reflected at each point of the reflecting surface 141, it is reflected at each side surface 130 of the wide portion 13, and thereafter, the light reaching the light emitting surface 133 is not reflected at the light emitting surface 133. The light exits from the light exit surface 133.

  FIG. 10 shows the light guide member 1 having a cross-sectional shape that satisfies the expressions 1-3, 6, and 7. In the shape design of the light guide member 1, the cross-sectional shape of the light guide member 1 is set to be bilaterally symmetric, and the side surface 140 of the narrow portion 14 is set to be a curve specified by the function of Expression 8 below. ing.

y (x) = 1.06x ⁴ -4.23x ³ + 7.1x ² -3.9x + 0.64 (Equation 8)
That is, in FIG. 10, the side surface 140 of the narrow portion 14 is a curve obtained by continuously plotting the xy coordinate points obtained for each variable x value in Equation 8. Here, x and y are the position coordinates on the side surface 140 when the center of the reflecting surface 141 in the width direction is the coordinate origin O. Moreover, it is 0.5 <= x <= 1.7 and light guide member material refractive index n: 1.49 (air refractive index = 1). Further, the width (A) of the reflecting surface 141, the length (H ₁ ) from the reflecting surface 141 to the wide portion 13, the length (H ₂ −H ₁ ) from the narrow portion 14 to the light exit surface 133, and the wide portion 13. The widths (B ₂ + B ₃ ) are 1, 2.6, 11, and 11, respectively. From the result of the light ray analysis shown in FIG. 10, out of the light reflected by the reflecting surface 141, all the light reaching the light exit surface 133 and the light reaching the light exit surface 133 after being reflected by the side surface 130 of the wide portion 13 are emitted. You can see that

FIG. 11 shows the light guide member 1 having a cross-sectional shape satisfying the expressions 1 to 3. In the shape design of the light guide member 1, the cross-sectional shape of the light guide member 1 is set to be bilaterally symmetric, and the side surface 140 of the narrow portion 14 is set to be a curve specified by the function of Expression 8. . Here, the width (A) of the reflecting surface 141, the length (H ₁ ) from the reflecting surface 141 to the wide portion 13, the length (H ₂ −H ₁ ) from the narrow portion 14 to the light exit surface 133, and the wide portion. The width 13 (B ₂ + B ₃ ) is 1, 2.6, 5, and 12. From the light ray analysis result shown in FIG. 11, it can be seen that the light reflected by the reflecting surface 141 is emitted from the light exiting surface 133 without hitting the side surface 130 of the wide portion 13.

  The light guide member 1 which has the cross-sectional shape which satisfy | fills Formula 1-5 is shown by FIG. In the shape design of the light guide member 1, the cross-sectional shape of the light guide member 1 is set to be bilaterally symmetric, and the side surface 140 of the narrow portion 14 is set to be a curve specified by the function of Equation 9. .

y (x) = − 3.23x ⁴ + 13.9x ³ -12.2x ² + 5.06x−0.77 (formula 9)
Here, x and y are the position coordinates on the side surface 140 when the center of the reflecting surface 141 in the width direction is the coordinate origin O. In addition, 0.3 ≦ x ≦ 1.1 and the light guide member material refractive index n: 1.49 (air refractive index = 1). Further, the width (A) of the reflecting surface 141, the length (H ₁ ) from the reflecting surface 141 to the wide portion 13, the length (H ₂ −H ₁ ) from the narrow portion 14 to the light exit surface 133, and the wide portion 13. The widths (B ₂ + B ₃ ) are 0.6, 3.8, ₃ , and 4.5, respectively. From the result of the ray analysis shown in FIG. 12, the light reflected by the reflecting surface 141 does not directly reach the side surface 130 of the wide portion 13 but is reflected by the side surface 140 of the narrow portion 14 and then reaches the side surface 130 of the wide portion 13. I understand that.

The light guide member 1 of the present embodiment described above is rod-shaped and includes a wide portion 13 provided along the length direction and a narrow portion 14 provided along the length direction. . The narrow portion 14 projects from the wide portion 13 in a direction perpendicular to the width direction in a cross section perpendicular to the length direction, and is narrower than the wide portion 13. The wide portion 13 has a step surface 131 that connects the side surface 130 and the side surface 140 of the narrow portion 14. The end surface in the length direction of the wide portion 13 is a light incident surface 132 on which light emitted from the light source 20 is incident. The projecting end surface of the narrow portion 14 projecting from the wide portion 13 is a reflecting surface 141 that reflects light incident from the light incident surface 132. The surface of the wide portion 13 opposite to the narrow portion 14 is a light exit surface 133 that emits light reflected by the reflective surface 141. In this way, the light incident surface 132 on which the light emitted from the light source 20 is incident can be configured by the end surface in the length direction of the wide portion 13 wider than the narrow portion 14. For this reason, even when the light source 20 disposed at the position opposite to the light incident surface 132 is large or a plurality of light sources 20 are disposed at the position opposite to the light incident surface 132, the light emitted from the light source 20 is It becomes easy to enter from the light-incident surface 132, and the loss of light quantity can be suppressed. Further, the light guide member 1 can be reduced in size by making the width of the narrow portion 14 where the light source 20 is not opposed to be narrower than that of the wide portion 13.

  Further, in the light guide member 1 shown in FIGS. 1 and 3, the narrow portion 14 protrudes from the intermediate portion in the width direction of the wide portion 13, and the wide portion 13 has step surfaces 131 on both sides in the width direction. Yes. For this reason, the light diffused and reflected by the reflecting surface 141 of the narrow portion 14 does not easily reach the side surface 130 of the wide portion 13, and light does not easily leak from the side surface 130 of the wide portion 13.

  The light guide member 1 shown in FIG. 1 is symmetrical about the center line CL, assuming a center line CL passing through the center in the width direction and orthogonal to the width direction in the cross section orthogonal to the length direction. Is formed. For this reason, the light diffused and reflected by the reflecting surface 141 of the narrow portion 14 can reach the light emitting surface 133 of the wide portion 13 in a well-balanced manner, and light can be emitted from a wide range of the light emitting surface 133 of the wide portion 13. In addition, the light guide member 1 can be further reduced in size.

Further, the light-guiding member 1 of this embodiment, the corner portion 16 formed in the side surface 1 3 0 step surface 131 and the wide portion 13 of the light guide member 1, as shown in FIGS. 13 and 14, the other member You may form the attaching part 15 which can be attached. In the example of FIG. 13, as the attachment portion 15, claw portions 150 that can be fitted to other members are formed at the corner portions 16 on both sides of the wide portion 13. Each claw 150 protrudes from the corner 16 of the wide portion 13 in the same direction as the protruding direction of the narrow portion 14. In the example of FIG. 14, as the attachment portion 15, a claw portion 151 that can be fitted to another member is formed at one corner 16 in the width direction of the wide portion 13. The claw portion 151 protrudes outward in the width direction from the corner portion 16 of the wide portion 13.

  15A and 15B show an example in which the attachment portion 15 is formed at the corner portion 16 of the light guide member 1 shown in FIG. The attachment portion 15 shown in FIG. 15A is a claw portion 153 protruding from the step surface 131 of the wide portion 13. Moreover, the attachment part 15 shown by FIG.15 (b) is the flange part 152 which protruded from the side surface 130 of the wide part 13. As shown in FIG. This flange portion 152 is a region other than the region where the light reflected by the reflecting surface 141 on the side surface 130 of the wide portion 13 is reflected directly or after being reflected by the side surface 140 of the narrow portion 14 (indicated by the dimension line 4 in FIG. 10). Area).

By forming the side surfaces 1 3 0 a mounting portion 15 at the corner 16 formed at the stepped surface 131 and the wide portion 13 of the light guide member 1 as described above, combined with light fitting the mounting portion 15 to the other member The member 1 can be attached to another member. For this reason, the light guide member 1 can be easily fixed when incorporated in a lighting device or the like. In addition, the light reflected by the reflecting surface 141 is difficult to reach the corner 16 where the mounting portion 15 is formed, and therefore the light reflected by the reflecting surface 141 is difficult to leak from the corner 16. That is, the attachment portion 15 can be formed while suppressing the loss of light quantity. From the light analysis results shown in FIGS. 15A and 15B, it can be seen that the light reflected by the reflection surface 141 does not reach the attachment portion 15 and is emitted from the light exit surface 133.

  Moreover, you may form the corner part 16 of the light guide member 1 in the shape of a chamfer, as FIG.14 and FIG.15 (c) shows. In the example of FIG. 14, the corner 16 on the opposite side of the claw 151 is a chamfered portion 160 having a circular arc shape (R chamfered shape). In the example of FIG. 15C, the corners 16 on both sides of the light guide member 1 shown in FIG. 10 are chamfered portions 161 having a circular arc shape (R chamfered shape). Each chamfered portion 161 is formed over the entire stepped surface 131, and is a region that the light reflected by the reflecting surface 141 on the side surface 130 of the wide portion 13 reaches directly or after being reflected by the side surface 140 of the narrow portion 14. It is formed in other areas. From the result of the light ray analysis shown in FIG. 15C, it can be seen that the light reflected by the reflecting surface 141 is emitted from the light emitting surface 133 without reaching the chamfered portion 160. Moreover, the light guide member 1 can be further miniaturized by making the corner portion 16 of the light guide member 1 chamfered.

In addition, as shown in FIG. 16, the attachment portion 15 may be formed at a corner portion 17 formed by the light exit surface 133 and the side surface 10 30 of the wide portion 13. In this example, attachment portions 15 are formed at corners 17 on both sides of the light guide member 1 shown in FIG. Each attachment portion 15 is a claw portion 154 that protrudes from the side surface 130 of the wide portion 13 and has a distal end bent in the protruding direction of the narrow portion 14. From the light ray analysis result shown in FIG. 16, it can be seen that the light reflected by the reflecting surface 141 is emitted from the light emitting surface 133 without reaching the claw portion 154.

  In addition, this invention is not limited only to the said embodiment, In the range which does not deviate from a summary, it can change suitably and can implement.

CL center line 1 light guide member 13 wide portion 14 narrow portion 15 mounting portion 20 light source 130 side surface of wide portion 131 stepped surface 132 light incident surface 133 light exit surface 140 side surface of narrow portion 141 reflecting surface

Claims (3)

A rod-shaped light guide member,
A wide portion provided along the length direction;
Similarly provided along the length direction, protruding in a direction orthogonal to the width direction in a cross-section orthogonal to the length direction from the wide portion, comprising a narrow portion having a narrower width than the wide portion,
The wide portion has a stepped surface connecting the side surface thereof and the side surface of the narrow portion,
The end surface in the length direction of the wide portion is used as a light incident surface on which light emitted from a light source is incident, and the projecting end surface of the narrow portion projecting from the wide portion is reflected from the light incident surface. It is a reflective surface, and the light output surface that emits the light reflected by the reflective surface on the opposite side of the narrow portion of the wide portion ,
A light guide member, wherein a claw portion that can be fitted and attached to another member is formed at a corner portion formed by the step surface and the side surface of the wide portion .   The light guide member according to claim 1, wherein the narrow portion protrudes from an intermediate portion in the width direction of the wide portion, and the wide portion has the step surfaces on both sides in the width direction. The cross section perpendicular to the length direction is formed symmetrically about the center line, assuming a center line passing through the center of the width direction and orthogonal to the width direction. The light guide member described in 1 .

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