US 8,134,780 B2Granted

Prism and lighting device

AssigneeBrother Kogyo Kabushiki Kaisha

InventorsHiroyuki Ominato, Takeshi Kitakata, Shunsuke Ichizawa

Life of this patent

Estimating the term…

Loading patent…

Abstract

A prism includes a light incident portion that has first and second convex portions, the first and second convex portions each are a convex portion that refracts rays of light incident to a prism body and reduces a spread angle after incidence to the prism body via the convex portion to be smaller than that before the incidence, the spread angle is an angle between a given two of the rays, a first reflecting surface, provided on the prism body, that can reflect a first ray of light that has entered the prism body via the first convex portion, a first emitting portion, provided on the prism body, that emits, to the outside, the first ray reflected by the first reflecting surface, and a second emitting portion that emits, to the outside, a second ray of light that has entered the prism body via the second convex portion.

Claims10

Dependent claims

A prism comprising:

a light incident portion that includes a first convex portion and a second convex portion, the first convex portion and the second convex portion each being a convex portion that refracts rays of light incident to a prism body and reduces a spread angle after incidence to the prism body via the convex portion to be smaller than the spread angle before the incidence, the spread angle being an angle formed between a given two of the rays, the light incident portion further including a flat incident surface on a first side of the first convex portion, the first side being opposite to a second side of the first convex portion, the second convex portion being provided on the second side;
a first reflecting surface that is provided on the prism body and that is capable of reflecting a first ray of light that has entered the prism body via the first convex portion;
a first emitting portion that is provided on the prism body and that emits, to the outside of the prism body, the first ray reflected by the first reflecting surface;
a second emitting portion that emits, to the outside of the prism body, a second ray of light that has entered the prism body via the second convex portion;
and
a second reflecting surface that is provided on the prism body and that is capable of reflecting a third ray of light that has entered the prism body via the incident surface, the second reflecting surface having a first reflecting convex portion that reduces the spread angle after reflection to be smaller than the spread angle before the reflection;
wherein the first reflecting surface reflects the third ray reflected by the second reflecting surface and the first ray that has entered the prism body via the first convex portion.

4 more elements

A prism comprising:

a light incident portion that includes a first convex portion and a second convex portion, the first convex portion and the second convex portion each being a convex portion that refracts rays of light incident to a prism body and reduces a spread angle after incidence to the prism body via the convex portion to be smaller than the spread angle before the incidence, the spread angle being an angle formed between a given two of the rays, the light incident portion further including a flat incident surface on a first side of the first convex portion, the first side being opposite to a second side, the second convex portion being provided on the second side;
a first reflecting surface that is provided on the prism body and that is capable of reflecting a first ray of light that has entered the prism body via the first convex portion;
a first emitting portion that is provided on the prism body and that emits, to the outside of the prism body, the first ray reflected by the first reflecting surface;
a second emitting portion that emits, to the outside of the prism body, a second ray of light that has entered the prism body via the second convex portion;
a fourth reflecting surface that is provided on the prism body and that is capable of reflecting a third ray of light that has entered the prism body via the incident surface, the fourth reflecting surface having a second reflecting convex portion that reduces the spread angle after reflection to be smaller than the spread angle before the reflection;
a fifth reflecting surface that is capable of reflecting the third ray reflected by the fourth reflecting surface;
and
a third emitting portion that is located between the first emitting portion and the fifth reflecting surface and that emits the third ray reflected by the fifth reflecting surface to the outside of the prism body.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/659,821Filed 23 Mar 2010
Priority: JP 2009-06956123 Mar 2009
Published: US 2010/0238666 A123 Sep 2010
Granted: 13 Mar 2012
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

G02B 19/0028
Characterised by the optical means employed: refractive and reflective surfaces, e.g. non-imaging catadioptric systems
F21V 5/02
Refractors for light sources: of prismatic shape
G02B 19/0061
For use with a light source: the light source comprising a LED
F21V 7/0091
Reflectors for light sources: using total internal reflection