JP2018037314A - Light-emitting device - Google Patents

Abstract

In a light-emitting device that emits light in a bar-like or belt-like region extending in a predetermined direction, the brightness of light traveling in a necessary direction is increased while the width of the light-emitting region is increased as much as possible. A light guide that receives light from a light source, propagates the light along a predetermined direction, and emits the light from a bar-shaped or belt-shaped region extending in the same direction, and the light emitted from the light guide are substantially parallel to each other. A collimating lens surface for converting into light, and the collimating lens surface is divided into a plurality of sections along the predetermined direction, and two adjacent sections along the same direction. A light emitting device having different collimating lens surface shapes was constructed. [Selection] Figure 4

Description

  The present invention relates to a light emitting device that emits light in a bar-like or strip-like region extending in a predetermined direction.

  A light guide (light guide rod or light guide plate) that makes light incident from a light source arranged on the end face, propagates the light along a predetermined direction, and illuminates a bar-shaped or strip-shaped region extending in the same direction with substantially uniform brightness For example, see the following patent document). The light guide is mainly composed of a dense resin rod-shaped material. On the side surface of the rod-shaped material, fine irregularities for inducing diffuse reflection are formed, or a reflective film or microprism for inducing specular reflection, etc. It is produced by providing. Recently, this type of light guide is being used for a vehicle headlamp (headlight), taillight (taillight), and the like.

Japanese Patent Laid-Open No. 06-150704

  There is a limit to increasing the diameter of the light guide. If an attempt is made to construct a vehicular lamp with the light guide alone, the width of the light emitting region becomes very narrow, and the design is also lowered.

  To increase the width of the light emitting area, place a transparent or translucent cover made of acrylic or other resin in front of the light guide, and diffuse the light emitted from the light guide on the inner or outer surface of the cover. It is conceivable to form a shape that acts as a lens to be moved. However, as the light diffuses, the brightness of the light, that is, the amount of light flux per unit area, decreases, and a high-performance illumination light source must be used to ensure the required brightness. This leads to an increase in cost and an increase in power consumption in the vehicle.

  The present invention, which has been made paying attention to the above problems, is intended to increase the luminance of light in a necessary direction while widening the width of the light emitting region as much as possible in a light emitting device that emits light in a rod-like or band-like region. The purpose.

  In the present invention, a light guide that receives light from a light source and propagates the light along a predetermined direction and radiates it from a rod-like or belt-like region that extends in the same direction, and light emitted from the light guide are substantially parallel. A lens body including a collimating lens surface for converting to light, and the collimating lens surface is divided into a plurality of sections along the predetermined direction, and two adjacent sections along the same direction. A light emitting device having different collimating lens surface shapes was constructed.

  ADVANTAGE OF THE INVENTION According to this invention, in the light-emitting device which light-emits a rod-shaped or strip | belt-shaped area | region, the brightness | luminance of the light which goes to a required direction can be raised, expanding the width | variety of the light-emitting area as much as possible.

The photograph which shows the vehicle lamp which uses the light-emitting device of this embodiment. FIG. 3 is a side cross-sectional view showing the light emitting device of the present embodiment. FIG. 3 is a plan sectional view showing the light emitting device according to the embodiment. The principal part perspective view which shows the collimating lens surface formed in the inner surface of the lens body of the light-emitting device of the embodiment.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a vehicular lamp that is a usage example of the light-emitting device 1 of the present embodiment. This is a tail lamp installed at the rear of the vehicle body. FIG. 1 (A) is turned off and FIG. 1 (B) is turned on. The light emitting device 1 of the present embodiment emits light in a bar-like or belt-like region that is extended so as to form an L shape.

  2 and 3 show the structure of the light emitting device 1 of the present embodiment. In addition, a part of light beam of the light 5 which this light-emitting device 1 outputs is represented with the broken line in the figure. The light emitting device 1 includes a light guide 2 that receives light 5 from a light source 4 and emits light so as to emit light while propagating the incident light 5, and a front of the light guide 2 (based on the front and rear of the vehicle). And a lens body 3 including a collimating lens surface 30 for converting the light 5 emitted from the light guide 2 into substantially parallel light.

  The light guide 2 extends in the vertical direction and has a shape curved at the lower end thereof toward the inside of the vehicle. The light guide 2 itself has the same properties as the existing one. That is, the light guide 2 is mainly composed of a dense and transparent resin rod-shaped material, and fine irregularities for causing diffuse reflection on the rear surface of the rod-shaped material (front surface with respect to the front and rear of the vehicle). 21 or a reflective film or a microprism for causing specular reflection is provided.

  Light 5 output from the light source 4 of the light emitting device 1, for example, a light emitting diode, enters the light guide 2 from the end face 20 on the upper end side of the light guide 2. The incident light 5 propagates in the light guide 2 along the direction in which the light guide 2 extends. Meanwhile, the light 5 is diffusely reflected by the fine unevenness 21 on the rear surface side of the light guide 2 or specularly reflected by a reflective film, a microprism or the like, and emitted from the light guide 2 toward the front of the light guide 2. Then, the front surface of the light guide 2 is surface-emitted with substantially uniform luminance.

  The lens body 3 is a cover that covers the front of the light guide 2. The lens body 3 is mainly composed of a transparent or translucent resin-made plate-like body, and the light guide is disposed on the inner surface (front surface when the front and rear of the vehicle are used as a reference) of the plate-like body. 2 forms a collimating lens surface 30 through which the light 5 emitted from 2 passes. As shown in FIG. 3, the collimating lens surface 30 has a so-called Fresnel lens or a cross-sectional shape close thereto, and converts the light 5 emitted forward from the light guide 2 that is the line light source 4 into substantially parallel light. Operates to act. However, it does not produce perfect parallel rays, but diffuses the light 5 to some extent.

  Thus, in the present embodiment, as shown in FIGS. 2 and 4, the collimating lens surface 30 in the lens body 3 is divided into multiple sections 31 and 32 along the extending direction of the light guide 2. The cross-sectional shapes of the collimating lens surfaces 30 of the odd-numbered steps 31 aligned along the extending direction of the light guide 2 are equal to or substantially equal to each other. The cross-sectional shapes of the even-numbered collimating lens surfaces 30 arranged along the extending direction of the light guide 2 are also equal to or substantially equal to each other. On the other hand, each part of the Fresnel lens that serves as the collimating lens surface 30 of the even-numbered stage 32 (acts as a refractive surface of the light 5) is compared with each part of the Fresnel lens that serves as the collimating lens surface 30 of the odd-numbered stage 31. The position is shifted along the direction orthogonal to the extending direction of the light guide 2. Accordingly, the cross-sectional shapes of the collimating lens surfaces 30 of the two sections 31 and 32 adjacent to each other along the extending direction of the light guide 2 are different.

  Further, as shown in FIG. 2, the longitudinal cross-sectional shape of the collimating lens surface 30 of each step 31, 32 aligned along the extending direction of the light guide 2 passes through the collimating lens surface 30 and the lens body 3. It is shaped so that the optical axis of the light 5 emitted forward is directed horizontally or obliquely upward.

  In the present embodiment, a light guide 2 that receives light 5 from a light source 4 and propagates the light 5 along a predetermined direction and radiates it from a rod-like or belt-like region that extends in the same direction, and radiates from the light guide 2. And a lens body 3 including a collimating lens surface 30 for converting the light 5 to be substantially parallel light, and the collimating lens surface 30 is divided into a plurality of sections 31 and 32 along the predetermined direction. Thus, the light emitting device 1 in which the shapes of the collimating lens surfaces 30 of the two sections 31 and 32 adjacent in the same direction are different is configured.

  According to the present embodiment, the light 5 emitted from the light guide 2 is shaped by the lens body 3 having the collimating lens surface 30, thereby expanding the width of the light-emitting rod-like or band-like region and the necessary direction. The brightness of the light 5 traveling toward can be increased. Therefore, it is freed from the need to use a high-luminance and high-performance light source 4, which can contribute to cost reduction and reduction of power consumption in the vehicle.

  In addition, since the collimating lens surface 30 of the lens body 3 is divided into a plurality of sections 31 and 32 along the extension direction of the light guide 2, it is continuously continuous along the extension direction of the light guide 2. Compared with the case of forming a collimating lens (Fresnel lens) surface having an equal cross-sectional shape, there is no problem that the stripes along the extending direction are conspicuous in the lens body 3, and a rod-shaped light is passed through the lens body 3. It is also suppressed that the guide 2 is conspicuous through the blatant. That is, it looks good when the light source 4 is turned off and the light emitting device 1 is not emitting light. Furthermore, even when the light source 4 is turned on to cause the light emitting device 1 to emit light, the presence of the collimating lens surface 30 divided into fine segments makes it possible for a number of segments to emit light uniformly like a reflector. The design will be improved.

  The lens body 3 absorbs unevenness in light emission of the light guide 2 itself, that is, the amount of light emitted from the light guide 2 and a deviation in the direction thereof, and improves the uniformity of light emission as the light emitting device 1. The light guide 2 does not need to have a complicated shape, and the weight of the light guide 2 can be reduced.

  The present invention is not limited to the embodiment described in detail above. For example, the application target of the present invention is not limited to a tail lamp of a vehicle.

  In addition, the specific configuration of each part can be variously modified without departing from the spirit of the present invention.

  The present invention can be applied to a vehicular lamp or the like.

DESCRIPTION OF SYMBOLS 1 ... Light-emitting device 2 ... Light guide 3 ... Lens body 30 ... Collimating lens surface 31, 32 ... Multi-stage division 4 ... Light source 5 ... Light

Claims (1)

A light guide that receives light from a light source, propagates the light along a predetermined direction, and radiates from a rod-shaped or belt-shaped region that extends in the same direction;
A lens body including a collimating lens surface for converting light emitted from the light guide into substantially parallel light;
The light-emitting device in which the collimating lens surface is divided into a plurality of sections along the predetermined direction, and the shapes of the collimating lens surfaces of two sections adjacent along the same direction are different.