JP2016178046A - Light guide body and line lighting display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light guide body capable of achieving a decorative display in addition to a line display.SOLUTION: This line lighting display device is constituted by a light guide body 1 and a light source 2. By first reflection parts 6, 7 formed on two side surfaces 4, 5 of the light guide body 1 and a groove part 10 formed on an upper surface 3 of the light guide body 1, not only line display for emitting line-shaped light uniform in the longitudinal direction X from the upper surface 3 of the light guide 1, but also by making different the inclination of emission light 19 reflected to the upper surface 3 by a second reflection part 9 formed on a bottom surface 8 of the light guide body 1 according to the position of the longitudinal direction X by a lens 13 formed on the upper surface 3 in the longitudinal direction X at an interval, a bright spot 25 appears to be moving so as to flow in the longitudinal direction X depending on an angle of viewing the light guide body 1 from the upper surface 3. Thus, freedom of a decorative display can be enlarged.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a line illumination display device for performing illumination display for decoration of automobiles and houses.

  Some conventional line illumination display devices perform line illumination display using an LED (light emitting diode) as a light source and a light guide as disclosed in Patent Document 1, for example. 17 and 18 show a line illumination display device described in Patent Document 1. FIG.

  17 is a cross-sectional view of the overall view of the line illumination display device, and FIG. 18 is an enlarged view of a portion E in FIG. 31 is a light source, and 32 is a light guide. 33 is a front cover, and 34 is a reflector. The light emitted from the light source 31 becomes a light beam 35 that is incident from the end face of the light guide 32 and propagates while totally reflecting inside the light guide 32. The light beam 35 becomes a light beam 37 incident on the prism 36 formed on the light guide 32, reflected, and emitted from the light guide 32. The light beam 37 is emitted from the upper surface of the light guide 32, that is, the surface opposite to the bottom surface of the light guide 32 on which the prism 36 is formed. The prism 36 is formed in the light propagation direction of the light guide 32, and line-shaped light is formed by the light emitted from the prism 36.

JP 2011-216279 A

  In this conventional configuration, light can be emitted in a line shape by the prism 36, but there is a problem that it is difficult to change the appearance as a decorative illumination display because the change is not sufficient only by the line light emission. Yes.

  An object of this invention is to provide the light guide which can perform a decorative display in addition to a line display, and a line illumination display apparatus.

  In order to achieve the above object, the light guide of the present invention propagates light incident from one end to the inside in the longitudinal direction toward the other end, and intersects the longitudinal direction in the middle of light propagation in the inside. A light guide that emits light in a direction, the cross-sectional shape in a direction intersecting with the longitudinal direction has two side surfaces that reflect the parabola connected to each other at the bottom with the opening surface inside, and the two The upper surface from which the light exits is formed between the upper portions of the side surfaces, and the two side surfaces are formed by a paraboloid that is the position of the bottom portion of the side surface at which the focal point of the opening is opposed. A first reflecting portion for reflecting the light propagating light to the opposite side surface is formed, and a second reflecting portion for reflecting the light propagating light to the upper surface side is opposed to the upper surface. The bottom surface is formed with an interval in the longitudinal direction. The center of the width direction intersecting with the longitudinal direction is formed by a groove part that is lower than both sides, and in the groove part, a lens that changes the inclination of the reflected light from the second reflecting part and makes the emitted light, It is characterized by being formed at intervals in the longitudinal direction.

  In addition, a line illumination display device of the present invention includes the light guide described above and a light source that causes light to enter the light guide.

  According to this configuration, the cross-sectional shape of the light guide is formed by two side surfaces and an upper surface between the upper portions of the two side surfaces, and light is incident from the end surface of the light guide, The first reflecting portion formed on the side surface and the side surface can emit light from a groove portion in which the center in the width direction intersecting the longitudinal direction is formed on the upper surface lower than both sides, thereby realizing uniform line emission.

  Further, the light reflected by the second reflecting part formed on the bottom surface of the light guide is guided by emitting light having high directivity only in a specific direction through a lens disposed in the groove part. In addition to performing line-shaped illumination display with a uniform amount of light in the longitudinal direction of the body, it is possible to realize decorative line illumination display in which the luminous pattern of the bright spot changes depending on the angle at which the light guide is viewed.

(A) XY sectional drawing which cut | disconnected the light guide of the light source and the light guide in the longitudinal direction in the line illumination display apparatus of embodiment of this invention, and (b) The light guide of the direction which cross | intersects the longitudinal direction YZ cross section of (A) Front view and (b) Side view of line illumination display device of embodiment of this invention 2A is a top view of the light guide in the line illumination display device according to the embodiment of the present invention as viewed from II in FIG. 2, and FIG. 2B is a bottom view of the light guide as viewed from II-II in FIG. BB expanded sectional view of FIG. Enlarged view of FIG. YZ sectional view showing the relationship between the focal point G of the parabolic side 4 and the side prism 6 formed on the parabolic side 5 opposite to the side 4 The figure which shows the positional relationship of a bottom prism and a lens in XY cross section. The figure which shows the light ray from the side prism and bottom prism in a YZ cross section The figure which shows the light ray which reflects by the bottom prism in a YZ cross section, and goes to an upper surface (A) Longitudinal sectional view and (b) A diagram showing a bright spot state according to the line-of-sight direction Enlarged sectional view showing another shape of side prism Enlarged sectional view showing another shape of side prism Sectional drawing which shows another example of correspondence between a lens and a bottom prism Sectional drawing which shows another example of correspondence between a lens and a bottom prism Explanatory drawing of another Example of the line illumination display apparatus which has arrange | positioned the light source to the both sides to a light guide, respectively (A) Front view showing another example of the line illumination display device according to the embodiment of the present invention, (b) a side view thereof, and (c) the light guide 1 in FIG. 15 is arranged as a gentle curve on the XY plane. Front view of the case Sectional drawing of the line illumination display apparatus described in patent document 1 Enlarged view of part E in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In addition, the same code | symbol is attached | subjected about the same component and the description is abbreviate | omitted.
Fig.2 (a) shows the front view of the line illumination display apparatus which uses the light guide 1 of embodiment of this invention. FIG. 2B shows a side view thereof. The light guide 1 is formed of a transparent material having a refractive index n of greater than 1.41, such as acrylic, polycarbonate, or glass. The refractive index n of acrylic is n≈1.49.

  Here, the right-hand direction of the paper is the X-axis direction, the upper direction of the paper is the Y-axis direction, and the depth direction of the paper is the Z-axis direction. The light guide 1 is arranged in the longitudinal direction so as to propagate light in the X-axis direction, and the end face of the light guide 1 facing the light source 2 is a plane parallel to the YZ plane.

  The line illumination display device is configured by arranging a light source 2 such as an LED that emits diffused light at one end in the longitudinal direction: X of the light guide 1. The light guide 1 propagates the incident light from the light source 2 toward the other end of the light guide 1 by total reflection inside the light guide 1, and transmits light from the upper surface 3 of the light guide 1 to the outside. Is emitted.

  The light emitting surface of the light source 2 is sufficiently smaller than at least the surface of the light guide 1 facing the light source 2. The light emitted from the light source 2 is arranged so that the center direction of the spread is the X-axis direction. The longitudinal direction of the light guide 1: the cross-sectional shape in the direction intersecting with X has two side surfaces 4, 5 that are parabolic shapes that are connected to each other at the bottom with the opening surface inside, and two side surfaces 4, 4. 5 and the upper surface 3 between the upper portions of 5. The side surfaces 4 and 5 are total reflection surfaces on the side surface of the light guide 1, and the surface normal is orthogonal to the X axis in the YZ cross section.

3A and 3B show a top view and a bottom view of the light guide 1.
In the vicinity of the bottom of the side surfaces 4 and 5 of the light guide 1, side prisms 6 and 7 are formed along the longitudinal direction: X as first reflecting portions that reflect the light propagating light to the opposite side surfaces. ing. At a position facing the top surface 3 of the bottom surface 8 of the light guide 1, a bottom prism 9 as a second reflecting portion that reflects the light propagating inside the light guide 1 toward the top surface 3 is provided in the longitudinal direction. : It is formed with an interval in X.

  On the upper surface 3 of the light guide body 1, a V-groove 10 as a groove portion having a longitudinal direction: a width direction intersecting with X: a center of Z lower than both sides is constituted by slopes 11 and 12. In the V groove 10, lenses 13 that change the inclination of the reflected light from the bottom prism 9 are formed at intervals in the longitudinal direction: X. The lens 13 of this embodiment is a cylindrical lens having a cylindrical axis in the Z-axis direction.

Fig.1 (a) shows XY sectional drawing of the AA cross section of FIG.2 (b). FIG. 1B shows a YZ sectional view intersecting with the longitudinal direction X of the light guide 1.
The slope 11 is a slope in the positive direction of the Z axis, the slope 12 is a slope in the negative direction of the Z axis, and the surface normals of the slope 11 and the slope 12 are orthogonal to the X axis.

  The side prisms 6 are formed on the side surface 5 in the vicinity of the bottom surface 8 in the X-axis direction, and the slopes of the side prisms 6 are formed in parallel along the side surface 5 in the YZ section. The side prisms 7 are formed on the side surface 4 in the vicinity of the bottom surface 8 in the X-axis direction, and the slopes of the side prisms 7 are formed in parallel along the side surface 4 in the YZ section.

The bottom prisms 9 are disposed between the side prisms 6 and 7 and are arranged on the bottom surface 8 in the X-axis direction.
4 is an enlarged view of the side prism 6 formed on the side surface 5 in the BB cross section in FIG. FIG. 5 is an enlarged view of one of the side prisms 6.

As shown in FIG. 5, the side prism 6 is a prism in which a concave shape is formed by an air layer inside the light guide 1, and a cross section is formed by a curved portion 14 and a straight portion 15. As shown in FIG. 4, the depth U of the side prism 6 is constant, and the pitch of the side prism 6 is arranged so that the brightness of the line display illumination becomes constant by decreasing the distance as the distance from the light source 2 increases. Is done. That is, when the interval between the i-th and i + 1-th side prisms 6 counted from the light source 2 side is p (i),
p (i)> p (i + 1)
The side prism 6 is arranged so that The side prisms 7 are also arranged with the same shape and interval as the side prisms 6.

  FIG. 6 is a cross-sectional view of the light guide 1 taken along the YZ plane, showing the same cross section as FIG. The side prism 6 has a width W, and is formed so that the focal point G of the paraboloid of the opposite side surface 4 comes near the center of the width of the side prism 6. The side prism 7 provided on the side surface 5 is the same, and is formed so that the focal point G of the paraboloid of the opposite side surface 5 comes near the center of the width of the side prism 7.

The refractive index of the light guide 1 is n, the region width of the non-light emitting portion including the bottom surface of the light guide 1 is 2 · S, the slope 11 in the center of the light guide 1 from the non-light emitting portion near the bottom surface 8 and If the distance to the slope 12 is H,
tan (α) = S / H
n × sin (β0−α) = sinβ0
With respect to β0 that satisfies the above, if the inclination angle from the Z axis in the horizontal plane of the slope 11 and the slope 12, that is, the XZ plane is β, the inclination angle β is set so that β> β0.

Β0 is the minimum value of the inclination angle β from the Z axis of the inclined surfaces 11 and 12 so that no dark line is generated at the center of the light guide when the light guide 1 is viewed from the front.
If α is sufficiently small and approximated,
tan (β0) ≈n × S / (H × (n−1))
It is.

By setting β> β0, the non-light-emitting portion including the bottom surface of the light guide 1 is hidden when the light guide 1 is viewed from the front, that is, from the Y-axis direction, and a dark line is prevented from being generated at the center.
FIG. 7 is a cross-sectional view of the light guide 1 taken along the XY plane, showing the same cross section as FIG.

  The bottom prism 9 formed on the bottom surface 8 is a prism in which a concave shape is formed inside the light guide 1 with an air layer. The bottom prism 9 has slopes 16 and 17 parallel to the Z axis. φ1 is an inclination angle with the bottom surface 8 of the inclined surface 17 closer to the light source 2 (X-axis negative direction side). φ2 is an inclination angle with the bottom surface 8 of the inclined surface 17 farther from the light source 2 (X-axis positive direction side), and is not emitted in the front direction by the return light from the X-axis positive direction of the light guide 1, that is, in the Y-axis direction. Therefore, a small angle, for example, φ2 = 1 ° to 15 ° is set.

A line extending from the center of the slope 17 in the Y-axis direction is defined as a vertical axis 18, and an optical axis 19 is defined as the direction of the angle θ from the vertical axis 18 to the light source side, that is, the X-axis negative direction. The lens 13 is formed such that the center of the lens 13 is disposed on the optical axis 19 and the focal point of the lens 13 is at the center of the inclined surface of the inclined surface 17. The inclination angle φ1 of the inclined surface 17 with respect to the bottom surface 8 is φ1≈50 °. Since the center of the spread of the reflected light on the inclined surface 17 is approximately the Y-axis direction, the reflected light of the inclined surface 17 is emitted in the direction of the lens 13. like
φ1 ≒ 50 + θ / 2
It is formed at an angle such that

  In order to reduce the divergence angle of light exiting the lens 13 from the bottom prism 9 in the XY section, the width d of the inclined surface 17 viewed from the lens 13 in the XY section is formed to be sufficiently small.

Operations of the line illumination display device and the light guide configured as described above will be described.
In FIG. 1A, a light beam 20 emitted from the light source 2 is incident from the end surface in the X-axis negative direction of the light guide 1 and is reflected in the X-axis positive direction while totally reflecting inside the light guide 1. Propagate. The maximum angle Ω with respect to the X axis of the light beam 20 incident on the light guide 1 is the same as the critical angle,
Ω = arcsin (1 / n)
It is. When the refractive index n of the light guide 1 is n> 1.41, Ω <45 °, and the surfaces excluding both end surfaces in the X-axis direction forming the light guide 1, that is, the side surface 4, the side surface 5, and the bottom surface 8. Since the surface normals of the upper slope 11 and the upper slope 12 are orthogonal to the X axis, the maximum incident angle ξ on each surface is (90 ° -Ω). When Ω <45 °, the maximum incident angle ξ> 45 °. Therefore, the angle is larger than the critical angle of the surface excluding both end surfaces in the X-axis direction forming the light guide 1, and total reflection occurs. For example, when the refractive index n of the light guide 1 is n = 1.49, it is about 42.2 °, and a light beam having a relatively wide spread propagates inside the light guide 1.

First, light emission in the XY plane of the light guide 1 by the side prism 6 will be described.
In FIG. 4, a part of the light beam 20 propagating inside the light guide 1 is reflected by the side prism 6 to become a light beam 21. As shown in FIG. 5, the side prism 6 is disposed on the side surface 5, and the slope of the side prism 6 is formed by a straight portion 15 and a curved portion 14. Since the inclination angle of the straight line portion 15 is larger than the inclination angle of the curved portion 14 with respect to the side surface 5, the light beam reflected by the straight portion 15 having a large inclination angle is reflected by the curved portion 14. It becomes the light source 2 side, that is, the light beam in the X-axis negative direction from the light beam. The light reflected by the curved portion 14 having a small inclination angle becomes a light beam that spreads in the opposite direction to the light source 2, that is, in the positive X-axis direction, and spreads around the direction perpendicular to the X-axis as the entire reflected light of the side prism 6. The light beam 21 becomes.

  In FIG. 1A and FIG. 1B, the light beam reflected by the side prism 6 is totally reflected by the opposing side surface 4 and is emitted from the inclined surface 12 on the upper surface of the light guide 1 in the positive Y-axis direction. Since the light beam 21 is a light beam that spreads in the X-axis direction, even when the light guide 1 is viewed from an oblique direction in the XY plane from the Y-axis direction, it appears as uniform line emission.

  The light emitted from the light guide 1 is emitted by the side prism 6, so that the amount of light propagating through the light guide 1 gradually decreases, but the distance between the side prisms 6 increases as the distance from the light source 2 increases. Since the interval between the side prisms 6 becomes narrower, the amount of light emitted from the light guide 1 in the X-axis direction is substantially constant. The same applies to the side prism 7.

The light emission in the YZ plane of the light guide 1 by the side prism 6 will be described in more detail.
FIG. 8 is a cross-sectional view of the YZ plane of the light guide 1, which is the same cross section as FIG. FIG. 9 is a cross-sectional view of the YZ plane of the light guide 1, which is the same cross section as FIG.

  In FIG. 8, since the focal point G of the paraboloid of the side surface 4 is arranged near the center of the side prism 6, the light emitted from the focal point G near the center of the side prism 6 reflects in the Y axis direction when reflected by the side surface 4. The light beam is close to parallel light at an angle α. The light beam reflected by the side surface 4 is refracted by the slope 12 and becomes a light beam substantially parallel to the Y axis. The side prism 6 has a width W in the YZ plane, and light rays deviated from the focal point G of the side surface 4 paraboloid other than the vicinity of the center of the side surface prism 6 are reflected by the side surface 4 and have an angle α from the Y axis direction. The light beam has an angle shifted from the center, and the light beam has an angle α at the center of the spread. The inclined surface 12 has an inclination of β with respect to the Z axis, and refracts light incident at an angle α with respect to the Y axis in a direction parallel to the Y axis. It becomes a light beam with a spread.

  In the YZ plane, the reflected light of the side surface 4 is inclined by an angle α with respect to the Y axis, so that the bottom surface 8 of the light guide 1 cannot be seen when viewed from the Y axis direction. The central portion of the light guide 1 does not become a dark portion, and the entire light guide 1 can emit light uniformly. Further, since the bottom prism 9 formed on the bottom surface 8 cannot be seen in the region where the lens 13 is not formed, it acts to block unnecessary light from the bottom prism 9.

Next, bright spot light emission by the bottom prism 9 formed on the bottom surface 8 will be described.
In the XY plane of FIG. 7, a part of the light beam 20 propagating through the light guide 1 is incident on the bottom prism 9 formed on the bottom surface 8, reflected by the inclined surface 17 of the bottom surface prism 9, and from the Y-axis direction. The light beam is centered on the angle θ. A lens 13 is formed in the direction of the angle θ from the center of the slope 17. Since the focal point of the lens 13 is arranged in the vicinity of the center of the inclined surface 17, the light emitted from the inclined surface 17 is made almost parallel by the lens 13, and is a light beam having high directivity in the θ direction from the Y axis. Ejected from.

  In the YZ plane of FIG. 9, since the cylindrical axis of the lens 13 is parallel to the Z axis, the lens 13 does not have a curvature in the YZ plane, and the ray incident on the lens 13 out of the emitted ray 22 from the bottom prism 9 is almost angled. The light beam 23 is emitted in the Y-axis direction without changing.

  On the other hand, out of the light rays 22 emitted from the bottom prism 9, the light rays that are incident on the slopes 11 and 12 without being incident on the lens 13 have a large angle with respect to the Y-axis direction due to refraction at the slopes 11 and 12. Light beam 24. For this reason, when viewed from the Y-axis direction, the light from the bottom prism 9 only shines in a certain region of the lens 13 and other regions, that is, the slopes 11 and 12 do not shine. Therefore, on the XY plane of FIG. 7, bright spots are generated by the bottom prism 9 only in the direction of the optical axis 19 inclined by θ from the Y axis, and no bright spots are seen at other angles. The direction in which the bright spot can be seen is determined by the direction of the optical axis 19, that is, the positional relationship between the lens 13 and the bottom prism 9. Therefore, the direction can be set freely. Light that has spread to a certain extent is emitted from the inclined surface 17 of the bottom prism 9, but light that is greatly inclined in the Z-axis direction from the Y-axis direction to the Z-axis direction in the YZ plane except for the region of the lens 13. The divergence angle of can be made extremely narrow, and a bright spot with good appearance can be formed.

In FIG. 7, the distance from the center of the slope 17 to the lens 13 is f, and the width of the slope 17 when viewed from the lens 13 is d. Since the focal point of the lens 13 is near the center of the slope 17, the light emitted from the slope 17 is converted into parallel light by the lens 13. Due to the size of the light emitting surface when viewed from the lens 13, that is, the size of the inclined surface 17, the light emitted from the lens 13 has a spread in the XY plane, and the spread angle ε of the light emitted from the lens 13 is approximately
ε = 2 × arctan (d / (2 × f))
It becomes. Where arctan is an arctangent function. For example, if d = 0.3 mm and f = 6 mm, ε = 2.9 °, and a very narrow spread angle can be obtained.

  On the other hand, since the inclination angle φ2 between the inclined surface 16 on the opposite side of the light source 2 of the bottom prism 9 and the bottom surface 8 is small, the reflected light on the end surface of the light guide 1 in the positive direction of the X-axis, etc. Even if light enters, light hardly leaks in the Y-axis direction from the upper surface of the light guide 1, that is, the surface in the positive Y-axis direction.

  FIG. 10A and FIG. 10B are diagrams showing that the light emission state of the bright spot 25 changes depending on the direction in which the light guide 1 is viewed. FIG. 10A shows an XY cross section in the same manner as FIG. FIG. 10B is an E arrow view when FIG. 10A is viewed at an angle η from the Y axis in the light source direction. A shaded portion 26 in FIG. 10B indicates a linear range in which the amount of light is uniform in the longitudinal direction: X.

10A, the lens 13 has a longitudinal direction of the bottom prism 9 formed on the bottom surface 8 such that the optical axis direction θ with respect to the bottom prism 9 is θ1, θ2, θ3, θ4 from the light source 2 side: X And the arrangement interval of X in the longitudinal direction of the lens 13 formed on the upper surface 3 are different from each other. When the spread angle of the light emitted from the lens 13 is ε,
| Θi−θj |> ε
However, i ≠ j, i = 1, 2, 3, 4, j = 1, 2, 3, 4
If the angle of the line-of-sight direction on the XY plane with respect to the Y axis is η, when η = θ1, only the light from the lens 13 whose optical axis is inclined at θ1 can be seen, and the other lenses of θ2, θ3, and θ4 The light from 13 is not visible. The same applies to the angles η = θ2, η = θ3, and η = θ4. For example,
θ1 <θ2 <θ3 <θ4
When the angle is gradually increased by making the arrangement interval of the lenses 13 smaller than the arrangement interval of the bottom prism 9 so that the bright spot 25 moves when the viewing angle η is changed. appear. That is, when the light guide 1 moves and the viewpoint (viewer) is fixed, the bright spot 25 moves so as to flow in the longitudinal direction of the light guide 1.

  In FIG. 10, four lenses 13 and bottom prisms 9 are shown, but the number is not limited to four. Further, the order may be reversed as θ1> θ2> θ3> θ4. In addition, | θi−θj |> ε is set so that only one bright spot can be seen depending on the angle at which the light guide 1 is viewed, but a plurality of bright spots are included under the condition that | θi−θj | <ε. May be visible at the same time.

  The side prism 6 of each of the above embodiments is formed in a cross-sectional shape in which one curved portion 14 is disposed between the two straight portions 15 on the surface side of the side surface 5. As shown, it can also be formed in a cross-sectional shape in which one linear portion 15 is disposed between the two curved portions 14 on the surface side of the side surface 5. Further, the curved portion 14 in FIG. 11 has a convex shape curved in a direction approaching the surface side of the side surface 5, but is configured by a concave shape curved in a direction away from the surface side of the side surface 5 as shown in FIG. 12. You can also The case of the side prism 7 is the same as that of the side prism 6.

  Although the slope 17 of the bottom prism 9 and the lens 13 in each of the above-described embodiments are in a one-to-one relationship, a plurality of slopes 17 and 17 are provided for one lens 13 as shown in FIG. The bottom prism 9 may be arranged so as to correspond. Alternatively, since light that has spread to some extent is emitted from the inclined surface 17 of one bottom prism 9, a plurality of lenses 13 may be arranged on the inclined surface 17 of one bottom prism 9, as shown in FIG. . By arranging in this way, it is possible to create a state in which light blinks with a slight change in viewing angle.

  In addition, although the light source 2 of each said embodiment was arrange | positioned only at the one end of the light guide 1, as shown in FIG. 15, in each edge part of the light guide 1, it is the light source 2a or the light source 2b. May be arranged. In this case, the direction of the inclined surface 17 in the light guide 1 is different between the bottom prism 9 belonging to the light source 2a and the bottom prism 9 belonging to the light source 2b. In other words, the bottom prism 9 belonging to the light source 2 a is arranged so that the slope 17, which is the light emitting surface of the slopes 16, 17, is closer to the light source 2 a than the slope 16. The bottom prism 9 belonging to the light source 2b is arranged so that the slope 17 which is a light emitting surface of the slopes 16 and 17 is closer to the light source 2b than the slope 16 is.

  In addition, although the light guide 1 of each said embodiment was made into the straight line parallel to the X-axis direction, it is good also as a gentle curve in the range in which the light which propagates the light guide 1 does not leak. For example, as shown in FIG. 16A, the light guide 1 may be formed in a curved shape and disposed on a front grill of an automobile. The line illumination display device of FIG. 16A is composed of two light guides 1 and 1 and two light sources 2 and 2. FIG. 16B is a view as viewed in the direction of arrow D in FIG. 16A, and the light guide 1 may be a three-dimensional curve. Alternatively, as shown in FIG. 16C, in the configuration in which the light sources 2 are arranged on both sides, the light guide 1 may be formed in a gently curved shape.

In each of the above embodiments, the distribution in the X-axis direction of the emitted light from the light guide 1 by the side prisms 6 and 7 is made uniform, but a pattern of brightness intensity may be formed.
The tilt angle φ2 of the bottom prism 9 in each of the above embodiments is about 1 ° to 15 °, but the return light from the X-axis positive direction of the light guide 1 is sufficiently small, The inclination angle φ2 of the slope 16 of the prism 9 may be a large angle of 15 ° or more. By increasing the angle of the inclined surface 16, the length of the bottom prism 9 in the X-axis direction can be shortened.

  In each of the above embodiments, the light propagated to the end portion of the light guide 1 in the positive direction of the X axis is emitted from the end portion to the outside of the light guide 1 and returns to the inside of the light guide 1. Although there was nothing, a reflector is disposed at the end of the light guide 1 in the positive direction of the X-axis, and the light emitted from the end to the outside of the light guide 1 is reflected by the reflector and the light guide By returning to the inside of 1, the light utilization efficiency can be increased.

  In addition, the light guide body 1 of each of the above-described embodiments further forms a shallow cylindrical surface parallel to the X-axis direction on the side surface 4 and the side surface 5 to diffuse the light, thereby spreading the light in the YZ plane. You can spread it.

  The lens 13 in each of the above embodiments is a cylindrical lens having a cylindrical axis in the Z-axis direction. However, the lens 13 is a spherical lens or an anamorphic lens having different curvatures in the Z-axis direction and the X-axis direction. The line may be an oval shape.

In addition, although the slopes 11 and 12 formed on the upper surface of the light guide 1 in each of the above embodiments are flat surfaces, they may be gently curved surfaces.
In addition, although the inclination angles of the slopes 11 and 12 in each of the above embodiments are the same, they may be different from each other.

Note that the focal lengths of the side surfaces 4 and 5 in each of the above embodiments are the same, but may be different focal lengths. That is, the YZ plane may not have a symmetrical shape.
In addition, although the side surfaces 4 and 5 of each of the above embodiments are parabolas, higher-order aspherical components may be added to the paraboloid to finely adjust how the light spreads.

In each of the above embodiments, the side surfaces 4 and 5 are curved paraboloids, but may be paraboloids approximated by straight lines or broken lines.
Note that the slope of the side prism 6 in each of the above embodiments may be curved along the side surface 5 in the YZ cross section, or may be approximated by a straight line or a broken line due to shape formation restrictions. . The same applies to the side prism 7.

  Note that the LEDs of the light sources 2, 2 a, 2 b in the above embodiments may be single colors such as red, blue, green, and white, or may have a plurality of emission colors. Or you may use LED which added the lens.

  The present invention can perform decorative line illumination display that emits a uniform line shape and has a bright spot whose light emission state changes depending on the viewing angle, and can be used for an automobile front grill or DRL (daytime light (daytime)). running lights)), and can be applied to a wide range of applications such as lighting display for home decoration.

DESCRIPTION OF SYMBOLS 1 Light guide 2, 2a, 2b Light source X Longitudinal direction Z The width direction which cross | intersects the longitudinal direction X 3 Upper surface 4,5 Side surface 6,7 Side prism (1st reflection part)
8 Bottom 9 Bottom prism (second reflector)
10 V-groove (groove)
11 and 12 Slopes constituting the V-groove 10 13 Lens 20 Light rays emitted from the light source 2 21 Light rays reflected by the side prism 6 22 Light rays emitted from the bottom prism 9 23 Light rays emitted in the Y-axis direction 25 Bright spots 26 Longitudinal direction A line-shaped range with a uniform amount of light in X

Claims (4)

A light guide that propagates light incident on the inside from one end in the longitudinal direction toward the other end, and emits light in a direction intersecting the longitudinal direction during light propagation in the interior;
The cross-sectional shape in the direction intersecting the longitudinal direction is a reflecting two side surfaces that form a parabola connected to each other at the bottom with the opening surface inside, and an upper surface from which light is emitted between the upper portions of the two side surfaces. Formed,
The two side surfaces are formed by a paraboloid surface that is a position of a bottom portion of the side surface at which the focal point of the opening faces, and the light propagating light is reflected by the focal point on the opposite side surface. A first reflecting portion is formed;
A second reflecting portion for reflecting the light propagating light to the upper surface side is formed on the bottom surface facing the upper surface with an interval in the longitudinal direction;
The upper surface is formed by a groove portion whose center in the width direction intersecting the longitudinal direction is lower than both sides,
In the groove part, lenses that change the inclination of the reflected light from the second reflecting part to form the emitted light are formed at intervals in the longitudinal direction.
Light guide. The angle of the optical axis of the emitted light that is reflected by the second reflecting portion and passes through the lens is varied depending on the positional relationship in the longitudinal direction to form a pattern of bright spots.
The light guide according to claim 1. The arrangement interval in the longitudinal direction of the second reflecting portion formed on the bottom surface is different from the arrangement interval in the longitudinal direction with respect to the lens formed on the top surface,
The light guide according to claim 2. A light guide according to any one of claims 1 to 3 and a light source for making light incident on the light guide.
Line lighting display device.