Fresnel led lens and led assembly thereof
AssigneeLan-Yang Investment Co., Ltd.
InventorsSan-Woei Shyu, Yi-Min Chen
Life of this patent
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Abstract
A Fresnel light emitting diode (LED) Lens and a LED Assembly thereof are provided. The Fresnel LED Lens is a lens disposed with a plurality of Fresnel optical surfaces. Each Fresnel optical surface includes a zone area having a plurality of drafts with vertical shape. Each Fresnel optical surface is arranged linearly along a center of a corresponding LED, and each Fresnel optical surface can used to focus light emitted from a LED chip so as to generate a quasi-circle distribution pattern of light with uniform light intensity and satisfy special optical requirements. A LED assembled formed by the Fresnel LED lens and a corresponding LED is used as a light source applied to illumination, mobile phone flashlights or camera flashlights.
Claims5
A Fresnel light emitting diode (LED) lens covered over a plurality of LEDs arranged linearly at an equal distance, comprising:
- an object-side optical surface having a plurality of Fresnel optical surfaces, each of the Fresnel optical surfaces having a zone area having a plurality of drafts with vertical shape, the plurality of Fresnel optical surfaces corresponding to the plurality of LEDs and arranged linearly at an equal distance so that each central axis formed by a center of each LED connected with a center of each corresponding Fresnel optical surface being parallel to one another;
- and
- a source-side optical surface;
- wherein the light emitted from the plurality of LEDs passes through the zone area of each of the Fresnel optical surfaces and a quasi-circle distribution pattern of the light is formed, and the Fresnel optical surface satisfying following conditions:
- 0.7
- ≤
- f
- s
- r
- n
- ≤
- 2.2
- 0.1
- ≤
- (
- N
- d
-
-
- 2
- -
- 1
- )
-
- d
- 2
- f
- s
- ≤
- 1.25
- wherein fs is effective focal length of the Fresnel LED lens, rn is radius of a last zone of each the Fresnel optical surface, d2 is thickness of the Fresnel LED lens on the central axis, and Nd2 is refractive index of the Fresnel LED lens.
A LED assembly, comprising
- the Fresnel light emitting diode (LED) lens as claimed in any of the preceding claims,
- a circuit board, and
- a plurality of LEDs;
- the improvement comprises the plurality of LEDs are arranged linearly at an equal distance on the circuit board so that a central axis formed by a center of each LED connected with a center of each corresponding Fresnel optical surface is parallel to one another;
- the LED assembly satisfies following condition:
- 0.8
- ≤
- κ
- =
- φ
- y
- φ
- x
- ≤
- 1.25
- wherein 2φx is an angle of the place where light intensity is half of highest light intensity in the X direction of the light emitted from the Fresnel LED lens, and 2φy is an angle of the place where light intensity is half of highest light intensity in the Y direction of the light emitted from the Fresnel LED lens.
Dependencies are inferred from the claim text.