JP2016009545A5 - - Google Patents

Description

The figure for demonstrating the structure of the illuminating device which concerns on this invention. The figure for demonstrating the basic structure of the illuminating device of this invention. The figure for demonstrating the whole structure of the reflector which consists of a transparent member of the illuminating device of this invention. The figure for demonstrating a paraboloid and a critical angle. The figure for demonstrating an equiangular spiral reflective surface. The figure for demonstrating the Example of this invention. The figure for demonstrating the cross-section of the reflective surface of Example 1 of this invention, and a light ray state. The figure for demonstrating the change of the cross-section of Example 2 of this invention.

FIG. 4 shows a state of reflection when a parabolic surface is used as the structure of the reflecting surface 2. Reference numeral 3 represents a light emitting point. When light traveling from the inside of the reflector 4 toward the surface reaches the surface, refraction and reflection occur according to Snell's law. At this time, there is a critical angle δc determined from the following relationship.
sinδc = 1 / n
Here, n is the refractive index of the transparent member. For example, when polycarbonate (n = 1.59) is used as the transparent member,
δc = 38.97 °
It becomes. A light ray incident at an angle closer to the surface normal than the critical angle does not cause total reflection and is refracted from the reflecting surface 2. On the other hand, light incident at an angle larger than the critical angle causes total reflection at the reflecting surface 2, and 100% of the incident light beam is reflected. Thus, total reflection is an extremely efficient reflection method, but the problem is that a critical angle limit occurs. In the case of this example, the incident light beam having a smaller angle than the critical angle leaks from the reflecting surface without being reflected, and the light beam cannot be directed in a desired direction.

1 Incident surface 2 Reflecting surface 3 Light emitting point 4 Reflector (reflector)
5 Critical angle position 6 Instrument chassis 7 Emission surface 8 Emission light beam 9 Reflection surface valley portion 10 Reflection surface mountain portion 11 LED element 12 LED mounting substrate 13 Power supply 14 Sade

Claims (11)

An illumination device including a plurality of LEDs and a reflector made of a light transmissive member,
Opposing the plurality of LEDs on the LED substrate, the reflector that reflects light incident from the LEDs in a substantially right angle direction is disposed,
The illumination device according to claim 1, wherein a roof-shaped groove is formed on the outer surface of the reflector in parallel to the light emission direction so as to direct light in a right angle direction by two total reflections. The lighting device according to claim 1.
The range of existence of the roof-shaped groove is limited to a portion where the ridge line of the groove and the incident light from the LED are not more than a critical angle. The lighting device according to claim 1 or 2,
The illuminating device, wherein the reflector is disposed with an emission direction outward along an outer peripheral portion of the LED substrate on which the plurality of LEDs are placed. The lighting device according to claim 1 or 2,
The illuminating device, wherein the reflector is arranged with an emission direction inward along an inner peripheral portion of the LED substrate on which the plurality of LEDs are placed. The lighting device according to claim 1.
The lighting device according to claim 1, wherein the shape of the cross section of the groove on the outer surface of the reflector is a V-shaped groove. The lighting device according to claim 5.
An illumination device, wherein the shape of the cross section of the groove on the outer surface of the reflector is a V-shaped groove having a vertex angle of 90 degrees. The lighting device according to claim 1.
An illumination device, wherein an angle of a V-shaped surface of a cross section of a groove on an outer surface of the reflector is changed according to an angle between a ridge line and an incident light beam. The lighting device according to claim 7.
When the angle between the ridge line and the incident light beam is small, the angle of the V-shaped surface is increased, and as the angle between the ridge line and the incident light beam is increased, the angle of the V-shaped surface is decreased. A lighting device. In the illuminating device as described in any one of Claims 1-8,
An illuminating device characterized in that a curved surface or minute unevenness is provided on a reflecting surface of the reflector . In the illuminating device as described in any one of Claims 1-8,
An illumination device, wherein a light exit surface of the reflector is provided with a curved surface or minute irregularities, or a microlens array or a prism array is provided. In the illuminating device as described in any one of Claims 1-10,
A lighting device is provided with a shade so as to surround the plurality of LEDs and the reflector .