Control of light uniformity using fresnel field placement of optical elements
AssigneeLumenFlow Corp.
InventorHarold W. Brunt, Jr.
Life of this patent
Estimating the term…
Abstract
An optical emitter providing improved light uniformity. The optical emitter includes a light source and a lens element spaced apart from the light source such that no additional lens elements are positioned therebetween. The lens element includes an inner light-receiving surface within the Fresnel field of the light source. In some embodiments, the light source includes an LED array and the lens element includes a lens array. The optical emitter provides the ability to adjust focus or spot size while not degrading the uniformity of the light intensity.
Claims20
An optical emitter comprising:
- an LED array including a plurality of LEDs defining a diameter D and a primary emission wavelength W between 390 nm and 700 nm, inclusive;
- a lens array including a first plurality of lens elements that are positioned opposite the plurality of LEDs to define an uninterrupted light path therebetween, the first plurality of lens elements each defining an inner light-receiving surface;
- and
- a stabilizing ring including a second plurality of lens elements that are positioned opposite the lens array to define an adjustable light path therebetween;
- wherein the inner light-receiving surface of the first plurality of lens elements are within the Fresnel field of the plurality of LEDs such that the intensity of light distributed across an illuminated area is substantially uniform, the Fresnel field including a lower limit R1 of
- 0.62
- ×
- D
- 3
- W
- and including an upper limit R2 of
- 2
- ×
- D
- 2
- W
- .
An optical emitter comprising:
- a light emitting element defining a diameter D and operable to emit light having primary emission wavelength W;
- and
- an optical element spaced apart from the light emitting element such that no additional optical elements exist therebetween, the optical element including a light-receiving surface,
- wherein the light-receiving surfaces of the optical element is within the Fresnel field of the light emitting device such that the intensity of light distributed across the optical element is substantially uniform, the Fresnel field including a lower limit R1 of
- 0.62
- ×
- D
- 3
- W
- and including an upper limit R2 of
- 2
- ×
- D
- 2
- W
- .
An optical emitter comprising:
- an LED array including a plurality of co-planar LEDs each defining a diameter D and a primary emission wavelength W between 390 nm and 700 nm, inclusive;
- a lens array including a first plurality of lens elements that are positioned opposite the plurality of LEDs to define an uninterrupted light path therebetween, the first plurality of lens elements each defining an inner light-receiving surface;
- and
- a stabilizing ring including a second plurality of lens elements that are positioned opposite the lens array to define an adjustable light path therebetween, the stabilizing ring being movable in a direction orthogonal to a plane defined by the co-planar LEDs to control the focus of the LED array;
- wherein the inner light-receiving surface of the first plurality of lens elements are within the Fresnel field of the plurality of LEDs such that the intensity of light distributed across an illuminated area is substantially uniform irrespective of the distance of the stabilizing ring relative to the LED array, the Fresnel field including a lower limit R1 of
- 0.62
- ×
- D
- 3
- W
- and including an upper limit R2 of
- 2
- ×
- D
- 2
- W
- .
Dependencies are inferred from the claim text.