Side-illuminated excitation optics apparatus and systems

Patent metadata

Field	Value
Publication number	US-9798134-B2
Application number	US-201414583666-A
Country	US
Kind code	B2
Filing date	Dec 27, 2014
Priority date	Dec 27, 2014
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

One or more excitation energy sources emit light in an excitation spectrum and direct the emitted light as an excitation beam to the emitting surface of a wavelength conversion element directly or via reflection. Distinct areas of the emitting surface are coated with one or more distinct fluorescent phosphors. The phosphor-coated areas receive the excitation beam and generate a sequence of fluoresced light beams at a light output, each fluoresced beam of a narrow spectrum determined by the type of phosphor and the excitation spectrum. The fluoresced beams travel parallel to an emitting axis at a non-zero angle to axes associated with the excitation beams.

First claim

What is claimed is:

1. An illumination apparatus, comprising:
an optical wavelength conversion element, at least one portion of an emitting surface of the wavelength conversion element coated with a fluorescent phosphor to receive at least one excitation beam of photons of an excitation spectrum and to generate at least one fluoresced beam of photons of a fluoresced spectrum with a predetermined periodicity during at least one predetermined period of time;
a condensing and collimation optical element group optically coupled to the optical wavelength conversion element to direct the fluoresced beam parallel to an emitting axis perpendicular to the emitting surface; and
at least one electromagnetic excitation energy source optically coupled to the optical wavelength conversion element to emit light of the excitation spectrum and to direct the emitted light as the excitation beam to the emitting surface of the wavelength conversion element directly or via reflection parallel to an excitation axis at a non-zero angle to the emitting axis;
the excitation energy source further comprising: an emitter to emit the light of the excitation spectrum; a collimator optically coupled to the emitter to receive and collimate the emitted light; and a top-hat beam shaper optically coupled to the collimator to receive the emitted light and to homogenize the emitted light by converting an area distribution of the emitted light from a substantially Gaussian distribution to a substantially top-hat distribution, the top-hat beam shaper selected from a group of optical devices consisting of an optical diffuser, an analytical aspheric lens, and a light pipe.

2. The illumination apparatus of claim 1 , the optical wavelength conversion element being a wheel capable of spinning, the emitting surface being a flat surface of the wheel, at least a portion of at least one of a plurality of radial sectors of the wheel surface coated with the fluorescent phosphor to emit the fluoresced beam of photons, the predetermined periodicity determined by an angular velocity of the phosphor-coated portion and the predetermined period of time determined by the arc length of the phosphor coated portion while illuminated by the excitation beam.

3. The illumination apparatus of claim 1 , the emitter being a laser light source.

4. The illumination apparatus of claim 1 , the excitation energy source further comprising:
a deflecting lens optically coupled to the top-hat beam shaper to re-direct the excitation beam from an axis associated with the excitation energy source to the excitation axis.

5. An illumination apparatus, comprising:
an optical wavelength conversion element, at least one portion of an emitting surface of the wavelength conversion element coated with a fluorescent phosphor to receive at least one excitation beam of photons of an excitation spectrum and to generate at least one fluoresced beam of photons of a fluoresced spectrum with a predetermined periodicity during at least one predetermined period of time;
a condensing and collimation optical element group optically coupled to the optical wavelength conversion element to direct the fluoresced beam parallel to an emitting axis perpendicular to the emitting surface; and
at least one electromagnetic excitation energy source optically coupled to the optical wavelength conversion element to emit light of the excitation spectrum and to direct the emitted light as the excitation beam to the emitting surface of the wavelength conversion element directly or via reflection parallel to an excitation axis at a non-zero angle to the emitting axis;
the optical wavelength conversion element being a wheel capable of spinning, the emitting surface being a flat surface of the wheel, at least a portion of at least one of a plurality of radial sectors of the wheel surface coated with the fluorescent phosphor to emit the fluoresced beam of photons, the predetermined periodicity determined by an angular velocity of the phosphor-coated portion, the predetermined period of time determined by the arc length of the phosphor coated portion while illuminated by the excitation beam, and at least one portion of at least one radial sector being a reflective surface to direct a portion of the excitation beam of the excitation spectrum back parallel to the emitting axis.

6. The illumination apparatus of claim 5 , the reflective portion of the radial sector fabricated with a set of microstructures selected from a group consisting of a Fresnel grating and a set of radial grooves, the set of microstructures to disperse the reflected portion of the excitation beam across a greater angle outward from the surface of the wheel than would be the angle of dispersion without the microstructures.

7. The illumination apparatus of claim 5 , light of the fluoresced spectrum corresponding to at least one of red, green, blue, cyan, magenta, and yellow.

8. The illumination apparatus of claim 5 , the at least one excitation energy source being an array of excitation energy sources positioned around the emitting axis.

9. The illumination apparatus of claim 5 , the excitation energy source further comprising:
an emitter to emit the light of the excitation spectrum and
a collimator optically coupled to the emitter to receive and collimate the emitted light.

10. The illumination apparatus of claim 5 , the reflective portion of the radial sector coated with a material reflective to light of the excitation spectrum.

11. The illumination apparatus of claim 5 , each of at least two portions of the plurality of radial sectors coated with different fluorescent phosphors, each to emit a corresponding fluoresced beam of a corresponding fluoresced spectrum.

12. The illumination apparatus of claim 5 , the light of the excitation spectrum corresponding to a color selected from a group consisting of blue and ultraviolet light.

13. The illumination apparatus of claim 5 , further comprising:
at least one reflector optically coupled to the excitation energy source to direct the excitation beam from the excitation energy source to the emitting surface parallel to the excitation axis.

14. The illumination apparatus of claim 13 , the reflector being a transmissive plate with a reflective coating along a periphery of the plate, the reflective coating to reflect light of wavelengths corresponding to the excitation spectrum.

15. An illumination apparatus, comprising:
an optical wavelength conversion element, at least one portion of an emitting surface of the wavelength conversion element coated with a fluorescent phosphor to receive at least one excitation beam of photons of an excitation spectrum and to generate at least one fluoresced beam of photons of a fluoresced spectrum with a predetermined periodicity during at least one predetermined period of time;
a condensing and collimation optical element group optically coupled to the optical wavelength conversion element to direct the fluoresced beam parallel to an emitting axis perpendicular to the emitting surface;
at least one electromagnetic excitation energy source optically coupled to the optical wavelength conversion element to emit light of the excitation spectrum and to direct the emitted light as the excitation beam to the emitting surface of the wavelength conversion element directly or via reflection parallel to an excitation axis at a non-zero angle to the emitting axis; and
at least one reflector optically coupled to the excitation energy source to direct the excitation beam from the excitation energy source to the emitting surface parallel to the excitation axis, the reflector being a transmissive plate

Assignees

• Texas Instruments Inc

Inventors

• Bhakta Vikrant R
• Davis Michael T

Classifications

• F21V7/28

  characterised by coatings · CPC title

• H04N23/88

  for colour balance, e.g. white-balance circuits or colour temperature control · CPC title

• H04N23/10

  for generating image signals from different wavelengths · CPC title

• G09G2320/0646

  Modulation of illumination source brightness and image signal correlated to each other · CPC title

• G09G3/3406

  Control of illumination source (illumination devices structurally associated with liquid crystal cells G02F1/1336) · CPC title