JP2015069841A - Lighting fixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting fixture capable of improving light extraction efficiency.SOLUTION: A lighting fixture includes: a light emitting diode 2; a light guide member 3 for guiding light of the light emitting diode 2; and a fixture body 1 for surrounding the light emitting diode 2 and the light guide member 3 and for being a reflector for reflecting light of the light emitting diode 2 on an inner peripheral surface. The light guide member 3 has an incident surface 31 facing the light emitting diode 2 side and an emission surface 33 facing the opposite side from the light emitting diode 2, and it guides light entered from the incident surface 31 and emits it from the emission surface 33. A space is provided between the inner peripheral surface of the fixture body 1 and an outer peripheral surface of the light guide member 3. Compared to the case where the inner peripheral surface of the fixture body 1 and the outer peripheral surface of the light guide member 3 are in close contact with each other, and the case where the fixture body 1 is omitted, improvement of light extraction efficiency of the light emitting diode 2 becomes possible.

Description

  The present invention relates to a lighting fixture. More specifically, the present invention relates to a lighting fixture that emits light of an area larger than a light emitting surface of a light emitting diode by passing light of the light emitting diode through a light guide member.

  2. Description of the Related Art Conventionally, lighting fixtures have been provided that emit light over a light emitting surface of a light emitting diode by passing light of the light emitting diode through a light guide member (see, for example, Patent Document 1). If this kind of lighting fixture is used, compared with the case where the light of a light emitting diode is directly emitted without using a light guide member, glare when the lighting fixture is viewed directly can be suppressed. Moreover, in the lighting fixture attached to a ceiling, it becomes possible to light-emit the whole part visible from the bottom by using the above light guide members.

JP2013-20716A

  However, in the above-described lighting fixture, when light from the light emitting diode leaks from a surface where light should not be emitted from the light guide member, the light extraction efficiency of the light emitting diode is reduced.

  This invention is made | formed in view of the said reason, The objective is to provide the lighting fixture which can improve the extraction efficiency of light.

  The lighting fixture of the present invention has a light emitting diode, an incident surface directed toward the light emitting diode, and an exit surface directed to the opposite side of the light emitting diode, and the light of the light emitting diode incident from the incident surface. A light guide member that guides and emits light from the exit surface, and a reflector that surrounds the light emitting diode and the light guide member so as to expose the exit surface, and reflects light of the light emitting diode on an inner peripheral surface thereof; The area of the emitting surface is larger than the light emitting area of the light emitting diode, and a gap is provided between the inner peripheral surface of the reflector and the outer peripheral surface of the light guide member. .

  In the above luminaire, it is desirable that the emission surface has fine irregularities and diffuses and emits light.

  According to the present invention, the light extraction efficiency of the light emitting diode can be improved as compared with the case where the reflector is omitted or the case where the inner peripheral surface of the reflector and the outer peripheral surface of the light guide member are in close contact with each other.

It is sectional drawing which shows embodiment of this invention. It is a disassembled perspective view which shows the same as the above. It is sectional drawing which shows the principal part of a light guide member same as the above. It is sectional drawing which shows the principal part of a comparative example.

  The present invention includes a light emitting diode 2, an incident surface 31 directed toward the light emitting diode 2, and an exit surface 33 directed toward the opposite side of the light emitting diode 2. And a light guide member 3 that guides the light from the light exit surface 33. The present invention also includes a reflector (apparatus main body 1) that surrounds the light emitting diode 2 and the light guide member 3 so as to expose the emission surface 33 and reflects the light of the light emitting diode 2 on the inner peripheral surface. A gap is provided between the inner peripheral surface of the reflector (the instrument body 1) and the outer peripheral surface of the light guide member 3.

  The exit surface 33 has fine irregularities (concave portion 331), and it is desirable to diffuse and emit light.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  The lighting fixture of this embodiment is provided with the fixture main body 1, the light emitting diode 2, the light guide member 3, and the translucent cover 4, as shown in FIG.1 and FIG.2. The instrument body 1 is made of, for example, aluminum die casting. Moreover, the light guide member 3 and the translucent cover 4 are each made of a translucent material such as acrylic resin (PMMA), polycarbonate (PC), or glass.

  The instrument main body 1 includes a main body portion 11 having a recess 10 on the lower surface, and an annular flange portion 12 that protrudes outward from the lower end of the main body portion 11 over the entire circumference. The light emitting diode 2 is fixed to the instrument body 1 on the inner bottom surface of the recess 10. The light emitting diode 2 has a flat shape in the vertical direction, and mainly emits light downward from the lower surface.

  The instrument body 1 is embedded in an embedding hole 60 provided in a ceiling material 6 that is plate-shaped and forms a ceiling surface. The embedding hole 60 is made large enough to allow the main body 11 to be inserted and small enough not to allow the collar 12 to be inserted, and the gap between the inner periphery of the embedding hole 60 and the outer periphery of the main body 11 is from below. It is covered with the buttocks 12 as seen. Further, an attachment spring 51 is attached to the outer peripheral surface of the main body portion 11 and is made of a leaf spring and sandwiches the ceiling material 6 between the flange portion 12. Further, an annular packing 52 made of a flexible material such as synthetic rubber is sandwiched between the collar portion 12 and the translucent cover 4. Furthermore, a ring 53 made of, for example, metal is sandwiched between the flange 12 and the ceiling material 6.

  The translucent cover 4 has a circular shape that covers the instrument main body 1 and the light guide member 3 when viewed from below. The translucent cover 4 is, for example, milky white, and diffuses light incident from above and emits it downward.

  The upper end surface of the light guide member 3 has a planar shape directed toward the light emitting diode 2 and is an incident surface 31 having an area covering the light emitting diode 2 when viewed from below. Most of the light from the light emitting diode 2 enters the light guide member 3 from the incident surface 31.

  In addition, a recess 32 is provided at the center of the lower surface of the light guide member 3, and light incident from the incident surface 31 is reflected by the recess 32. An annular lower end surface surrounding the recess 32 in the light guide member 3 (that is, a surface directed to the lower side opposite to the light emitting diode 2) diffuses light incident from above (in the light guide member 3). Thus, the light exit surface 33 is configured to emit downward (outside the light guide member 3). The exit surface 33 as described above can be realized by providing fine irregularities such as providing a large number of fine concave portions (dimples) 331 or fine convex portions (not shown) as shown in FIG. Can do. The arrows in FIG. 3 show examples of optical paths. The area of the emission surface 33 is larger than the light emission area of the light emitting diode 2. Thereby, the luminance of the emission surface 33 becomes lower than the luminance of the light emitting diode 2.

  In addition, the inner peripheral surface of the recess 10 of the instrument body 1, the outer peripheral surface of the light guide member 3, and the inner peripheral surface of the recess 32 have a shape that is infinitely rotationally symmetric about a common symmetry axis. That is, the concave portion 10 and the inner periphery and outer periphery of the light guide member 3 in a cross section orthogonal to the symmetry axis are concentric circles. The axis of symmetry is perpendicular to the center of the light emitting surface (lower surface) of the light emitting diode 2 and the center of the incident surface 31.

  Furthermore, the inner diameter of the recess 10 of the instrument body 1, the outer diameter of the light guide member 3, and the inner diameter of the recess 32 of the light guide member 3 are gradually increased downward. Moreover, the expansion width of the inner diameter and the outer diameter per unit dimension along the symmetry axis is gradually increased downward.

  Further, the inner peripheral surface of the recess 10 is a diffuse reflection surface that diffuses and reflects the light of the light emitting diode 2. That is, the instrument body 1 is a reflector. The diffuse reflection surface as described above may be realized by painting in white, or may be realized by providing fine irregularities (roughening). As described above, by making the inner peripheral surface of the concave portion 10 a diffuse reflection surface, it is relatively easy to make the brightness of the translucent cover 4 uniform compared to the case where the inner peripheral surface of the concave portion 10 is a mirror surface. Become.

  The light emitted from the light emitting diode 2 and incident on the incident surface 31 of the light guide member 3 is repeatedly reflected within the light guide member 3 as indicated by an arrow 71 in FIG. Then, the light is emitted downward through the vicinity of the outer periphery of the translucent cover 4.

  Further, as indicated by arrows 72 and 73 in FIG. 1, the light that is emitted from the light emitting diode 2 and does not enter the incident surface 31 of the light guide member 3 and is reflected by the inner peripheral surface of the recess 10 of the instrument body 1 is guided. The light enters the outer peripheral surface of the optical member 3, exits from the inner surface of the recess 32, and exits downward through the central portion of the translucent cover 4.

  Furthermore, in the cross section orthogonal to the symmetry axis, the outer diameter of the light guide member 3 is made smaller than the inner diameter of the instrument body 1, whereby the outer peripheral surface of the light guide member 3 and the inner peripheral surface of the recess 10. There is a gap (gap) between them all around.

  According to the said structure, compared with the case where the instrument main body 1 (reflector) does not exist or the outer peripheral surface of the light guide member 3 and the inner peripheral surface of the recessed part 10 of the instrument main body 1 mutually adhere, The light extraction efficiency can be improved.

  According to the experiment of the present inventor, the reflectance of the outer peripheral surface with respect to the light from the inside in the light guide member 3 is as follows. When they were brought into close contact with each other, the maximum could only be 97%. On the other hand, when there is a gap between the outer peripheral surface of the light guide member 3 and the inner peripheral surface of the recess 10 as shown in FIG. 1, the above reflectance could be 99%.

  Further, according to the simulation of the present inventor, when the luminous flux of the light emitting diode 2 is 1000 lm, the luminous flux emitted below the light guide member 3 (hereinafter referred to as “emitted luminous flux”) is the instrument body 1 (reflected). 480.2 lm when the body was not present. Moreover, when the outer peripheral surface of the light guide member 3 and the inner peripheral surface of the concave portion 10 of the instrument body 1 are in close contact with each other as shown in FIG. 4, the emitted light flux is 530.3 lm. On the other hand, when an air gap exists between the outer peripheral surface of the light guide member 3 and the inner peripheral surface of the recess 10 of the instrument body 1 as shown in FIG. 1, the emitted light flux is 642.5 lm.

1 Instrument body (reflector)
2 Light-emitting diode 3 Light guide member 31 Entrance surface 33 Output surface 331 Recess

Claims (2)

A light emitting diode;
An incident surface directed to the light emitting diode side and an exit surface directed to the opposite side of the light emitting diode are provided, and the light of the light emitting diode incident from the incident surface is guided and emitted from the exit surface. A light guide member;
A reflector that surrounds the light emitting diode and the light guide member in a form that exposes the emission surface and reflects light of the light emitting diode on an inner peripheral surface;
The area of the emission surface is larger than the light emitting area of the light emitting diode,
A lighting fixture, wherein a gap is provided between an inner peripheral surface of the reflector and an outer peripheral surface of the light guide member. The lighting apparatus according to claim 1, wherein the emission surface has fine irregularities and diffuses and emits light.

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