JP2006059541A - Light guide and LED light source unit including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To illuminate illumination light in the optical axis direction by using a flat LED substrate for a lens installed in a vehicle inclined with respect to an optical axis of illumination light emitted outside a vehicle. To provide a light guide and an LED light source unit using the light guide.
A light guide 5 according to the present invention includes a lens 2 installed in a vehicle in a state inclined by an angle θ with respect to a direction perpendicular to the optical axis of illumination light projected outside the vehicle, and a plurality of light guides 5 The LED 4 is provided between the LED flat substrate 3 and the LED flat substrate 3 which is installed substantially parallel to the lens 2. The light guide 5 includes a first light guide 7 that guides illumination light emitted from the LEDs 4 in a direction (α direction) perpendicular to the LED flat substrate 3, and illumination guided by the first light guide 7. A reflecting surface 8 that reflects light in the optical axis direction (β direction) of the optical axis, and a second light guide unit 9 that guides illumination light reflected by the reflecting surface 8 in the optical axis direction (β direction). Have.
[Selection] Figure 1

Description

  The present invention relates to a light guide provided between a lens and an LED flat substrate installed substantially parallel to the lens, and an LED light source unit including the same.

2. Description of the Related Art Conventionally, many devices using LEDs as a light source of a vehicular lamp are known in order to reduce power consumption and reduce the size and thickness of a light source unit (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 2002-245813 (FIGS. 2, 3, and 4)

  By the way, from the recent trend of vehicle design, the lens is often provided inclined with respect to the optical axis of the illumination light projected outside the vehicle. On the other hand, the LED that is the illumination light source needs to be installed in the lamp such that the optical axis of the LED light source faces the same direction as the optical axis described above.

  Therefore, a method is used in which the LED flat substrate is installed so as to face the optical axis direction described above, with respect to the lens installed in the vehicle inclined with respect to the optical axis of the illumination light emitted outside the vehicle. In this method, since a space larger than usual is required between the lens and the LED flat substrate, there is a problem that the lamp itself becomes large.

  Moreover, although the method (refer patent document 1) which installs LED stepwise according to the inclination of a lens surface is also considered, in this method, it will be necessary to manufacture an LED board in step shape, and a plane board cannot be used. Therefore, there was a problem that the cost increased.

  The present invention has been made in view of the above-described problem, and a flat LED substrate is used for a lens installed in a vehicle so as to be inclined with respect to the optical axis of the illumination light projected outside the vehicle. It is an object of the present invention to provide a light guide capable of projecting in the optical axis direction and an LED light source unit using the light guide.

  In order to solve the above-described problems, a light guide according to the present invention includes a lens installed on a vehicle that is inclined with respect to an optical axis of illumination light projected outside the vehicle, and a plurality of LEDs. And a first light guide part that guides illumination light emitted from the LED in a direction perpendicular to the LED flat substrate, and the first light guide. A reflective surface that reflects the illumination light guided by the optical unit in the optical axis direction of the optical axis, and a second light guide unit that guides the illumination light reflected by the reflective surface in the optical axis direction. It is characterized by.

  In particular, it is preferable that the lens is installed with an inclination of θ with respect to a direction perpendicular to the optical axis, and the reflection surface is formed with an inclination of θ / 2 with respect to the optical axis.

  In addition, the LED light source unit according to the present invention includes a lens installed in the vehicle inclined with respect to the optical axis of the illumination light emitted outside the vehicle, and a plurality of LEDs provided and installed substantially parallel to the lens. And an LED light guide that guides illumination light emitted from the LED in the optical axis direction of the optical axis, and the light guide emits illumination light emitted from the LED. A first light guide section that guides light in a direction perpendicular to the first light guide section, a reflective surface that reflects illumination light guided by the first light guide section in the optical axis direction, and illumination light reflected by the reflective surface. And a second light guide part for guiding light in the optical axis direction.

  By using the light guide and the LED light source unit according to the present invention, even when the lens is installed in the vehicle in a state inclined with respect to the optical axis of the illumination light projected outside the vehicle, the flat LED Illumination light can be emitted in the optical axis direction using a substrate (LED flat substrate).

  Further, since the LED flat substrate can be mounted substantially parallel to the lens, the distance between the lens and the LED flat substrate can be minimized, and the lamp can be easily downsized. Furthermore, since it is not necessary to form the LED substrate in a step shape, it becomes easy to reduce the cost.

  Hereinafter, a case where the LED light source unit according to the present invention is used as a tail lamp will be described with reference to the drawings.

  As shown in FIG. 1, a tail lamp 1 that is an LED light source unit includes a lens 2, an LED flat substrate 3, a plurality of LEDs 4 arranged at equal intervals on the LED flat substrate 3, and a light guide 5. Have.

  The lens 2 is provided in the vehicle body in a state where the lens 2 is inclined by θ with respect to a direction perpendicular to the optical axis of the illumination light emitted outside the vehicle, for example, the vehicle width direction. The LED flat substrate 3 is attached to the vehicle body substantially parallel to the lens 2. For this reason, the LED flat substrate 3 is inclined by θ with respect to the vehicle width direction (direction perpendicular to the optical axis).

  A plurality of LEDs 4 are installed at equal intervals on the LED flat substrate 3 such that the optical axis of the LED 4 is directed in a direction perpendicular to the LED flat substrate 3. The light guide 5 is provided between the lens 2 and the LED flat substrate 3. Hereinafter, for convenience of explanation, the direction perpendicular to the LED plane substrate is defined as α direction, the optical axis direction of the illumination light emitted outside the vehicle, and in this embodiment, the vehicle rear direction is defined as β direction.

  FIG. 2 is an enlarged plan view showing the light guide 5, and FIG. 3 is a perspective view showing the light guide 5. The light guide 5 is made of a highly translucent material, for example, a synthetic resin such as polycarbonate. The light guide 5 includes a first light guide 7 that guides illumination light emitted from the LEDs 4 in a direction (α direction) perpendicular to the LED flat substrate 3, and illumination guided by the first light guide 7. A reflective surface 8 that reflects light rearward of the vehicle (optical axis direction: β direction) and a second light guide unit 9 that guides illumination light reflected by the reflective surface 8 rearward of the vehicle (optical axis direction: β direction). And have.

  The first light guide 7 is formed by a light guide band extending in a direction (α direction) perpendicular to the LED flat substrate 3. The light guide 5 is installed so that the LED 4 faces a substantially hemispherical recess 10 formed at the end of the first light guide 7 on the LED flat substrate 3 side. The illumination light emitted from the LED 4 is refracted or reflected by the curved surface of the curved portion 11 formed on the LED flat substrate 3 side and the inner surface of the curved convex portion 12, and is perpendicular to the LED flat substrate 3 ( Irradiated in the α direction). The illumination light whose irradiation direction is adjusted in the α direction is guided to the reflection surface 8 by the first light guide unit 7.

  The second light guide unit 9 is configured by a light guide band extending rearward of the vehicle (optical axis direction: β direction). Irradiation light passing through the second light guide unit 9 is rearward of the vehicle (optical axis). Direction: β direction). A diffusion prism surface 13 is formed in a stepped shape at the end of the second light guide 9 on the lens 2 side.

  The reflecting surface 8 is formed to be inclined by θ / 2 with respect to the front of the vehicle (the direction opposite to the optical axis of the optical axis: -β direction). The end point B of the reflecting surface 8 on the LED flat substrate 3 side is from an extension line extending in the α direction from one end point A of the curved convex portion 12 of the first light guide portion 7 and one end point F of the second light guide portion 9. The end point D on the lens 2 side of the reflecting surface 8 is located at the intersection with the extension line (two-dot chain line shown in FIG. 2) extending in the −β direction. It is located at the intersection of an extension line (two-dot chain line shown in FIG. 2) extending from the end point G in the α direction and an extension line extending from the other end point E of the second light guide portion in the −β direction. 2 is an intersection of an extension line extending from the other end point G in the α direction and an extension line extending from the end point B in the β direction (two-dot chain line shown in FIG. 2).

  That is, as shown in FIG. 2, the end point B is in the α direction from the one end point A at a predetermined distance, and the intersection C is in the α line direction from the other end point G and in the β direction of the end point B. One end point F is located in the β direction of the intersection point C, the end point D is at an angle θ / 2 with respect to the β direction from the end point B, and is located in the α direction of the intersection point C, and the other end point E is the end point It is a predetermined distance in the β direction from D. The predetermined distance between the end point B and the one end point A and the predetermined distance between the end point D and the other end point E are determined by the positional relationship between the lens 2 and the LED flat substrate 3, and the distance between the lens 2 and the LED flat substrate 3. It is shortened according to.

  As shown in FIGS. 1 and 3, the light guide 5 is in a bar state (light guide bar) configured by connecting a plurality of first light guide parts 7, second light guide parts 9, and reflecting surfaces 8. It is installed between the lens 2 and the LED flat substrate 3. A plurality of light guides 5 are used according to the size of the area of the lens 2.

  In the tail lamp (LED light source unit) 1 provided with the light guide 5 described above, when the LED 4 is turned on, the illumination light of the LED 4 is reflected / curved on the curved surface of the curved portion 11 and the inner surface of the curved convex portion 12. The light is refracted and travels through the first light guide 7 as parallel lines parallel to the α direction. The illumination light guided to the first light guide unit 7 is internally reflected by the reflection surface 8 and travels in the second light guide unit 9 while changing the traveling direction in the β direction. The illumination light guided to the second light guide unit 9 is emitted toward the rear of the vehicle while being diffused by the step-like diffusion prism surface 13 formed at the lens side end of the second light guide unit 9. The lens 2 is lit.

  By using the light guide 5 as described above, even if the lens 2 is installed inclined with respect to the optical axis direction, illumination light is emitted using a flat LED substrate (LED flat substrate 3). Can be projected in the optical axis direction.

  In addition, since the LED flat substrate 3 can be mounted substantially parallel to the lens 2, the distance between the lens 2 and the LED flat substrate 3 can be minimized, and the lamp can be easily downsized. . Furthermore, since it is not necessary to form the LED substrate in a step shape, it becomes easy to reduce the cost.

  As mentioned above, although the LED light source unit which concerns on this invention was demonstrated using drawing, the LED light source unit and light guide which concern on this invention are not limited to what was mentioned above. For example, by providing a planar state without providing a step-like diffusion prism surface formed at the lens side end of the light guide, it is possible to illuminate the rear of the vehicle without diffusing the illumination light of the LED Become.

  Further, the light guide and the LED light source unit according to the present invention are not limited to the case where the optical axis direction is used for a tail lamp whose rear side is the vehicle, and the light source unit indicates a direction other than the rear side of the vehicle, For example, it may be used for a clearance lamp or the like.

It is the top view which showed the LED light source unit which concerns on this invention. It is an enlarged plan view which shows the light guide which concerns on this invention. It is a perspective view which shows the light guide which concerns on this invention.

Explanation of symbols

1 Tail lamp (LED light source unit)
2 Lens 3 LED flat substrate 4 LED
5 Light Guide 7 First Light Guide 8 Reflecting Surface 9 Second Light Guide 13 Diffusion Prism

Claims (3)

Inclined with respect to the optical axis of the illumination light emitted outside the vehicle, provided between the lens installed in the vehicle and the LED flat substrate provided with a plurality of LEDs and installed substantially parallel to the lens,
A first light guide for guiding the illumination light emitted from the LED in a direction perpendicular to the LED planar substrate; and the illumination light guided by the first light guide in the optical axis direction of the optical axis. A light guide comprising: a reflective surface that reflects; and a second light guide that guides illumination light reflected by the reflective surface in the optical axis direction. The lens is installed with an inclination of θ with respect to a direction perpendicular to the optical axis,
The light guide according to claim 1, wherein the reflection surface is formed to be inclined by θ / 2 with respect to the optical axis. A lens installed on the vehicle inclined with respect to the optical axis of the illumination light emitted outside the vehicle, an LED flat substrate provided with a plurality of LEDs and installed substantially parallel to the lenses, and emitted from the LEDs A light guide for guiding illumination light in the optical axis direction of the optical axis,
The light guide includes a first light guide unit that guides illumination light emitted from the LEDs in a direction perpendicular to the LED flat substrate, and illumination light guided by the first light guide unit. An LED light source unit comprising: a reflective surface that reflects in an axial direction; and a second light guide unit that guides illumination light reflected by the reflective surface in the optical axis direction.

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