LED OPTICAL LENS AND ILLUMINATION DEVICE THEREOF

• US 20100149801A1
• Filed: 07/24/2009
• Published: 06/17/2010
• Est. Priority Date: 12/15/2008
• Status: Abandoned Application

• Current Assignee: Create Electronic Optical Co., Ltd.
• Original Assignee: Create Electronic Optical Co., Ltd.
• Inventors: Chu, I-Lin, LO, Chih-Wei
• Application Number:
  US12/509,282
• Publication Number:
  US 20100149801A1
• Time in Patent Office: Days
• US Class Current: 362/235
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21W 2131/103 of streets or roads
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 19/0014 at least one surface having optical power
• CPC Class Codes: G02B 19/0061 the light source comprising a LED semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission H01L33/00
• CPC Class Codes: G02B 27/0955 Lenses lenses per se G02B3/00

Abstract

A LED optical lens and an illumination device thereof are revealed. The optical lens includes a light-source side surface and an image side surface of the LED optical lens that both are designed respectively according to mathematical expressions of freeform surfaces such as Anamorphic formula and Toric formula Thus the optical lens has different curvatures along different axes. After light from LED emitting into the optical lens at a fixed incident angle, emergent light with different divergence angles along different axes is generated. For example, the divergence angle along the long axis is larger than that along the short axis. Therefore a uniform and near rectangular distribution pattern is formed on the target area Moreover, a plurality of optical lenses aligned along the same axes is arranged at a holder to form a lens array. The lens array is used together with a LED array so as to form a LED illumination device.

Claims

1. A light-emitting diode (LED) optical lens that is a transparent lens and is used in combination with a LED light source comprising a light-source side surface and an image side surface, wherein

the light-source side surface is defined by mathematical expressions of freeform surfaces and is facing at least one LED light source so that light from the at least one LED light source emits into the optical lens through the light-source side surface;

the image side surface is facing a target area and is defined by mathematical expressions of freeform surfaces while light from the LED light source passes through the light-source side surface, into the optical lens and out of the image side surface to be projected into the target area;

wherein light from the LED light source is refracted by the optical lens to generate a near rectangular light distribution pattern on the target area due to the light-source side surface and the image side surface defined by mathematical expressions of freeform surfaces and there is a ratio of a length along a long axis to a width along a short axis of the near rectangular light distribution pattern.

2. The device as claimed in claim 1, wherein the light-source side surface is defined by following Anamorphic formula:

$Z=\frac{\left(\mathrm{Cx}\right)<br><br>X^2+\left(\mathrm{Cy}\right)<br><br>Y^2}{1+\sqrt{1-\left(1+\mathrm{Kx}\right)<br><br>{\left(\mathrm{Cx}\right)}^2<br><br>X^2-\left(1+\mathrm{Ky}\right)<br><br>{\left(\mathrm{Cy}\right)}^2<br><br>Y^2}}+\underset{i=1}{\overset{20}{\sum <br><br>}}<br><br>A_{2<br><br>i}<br><br>{\left\{\left(1-B_{2<br><br>i}\right)<br><br>X^2+\left(1+B_{2<br><br>i}\right)<br><br>Y^2\right\}}^i$

and the light-source side surface forms an axial symmetry that is concaved inward along a long axis thereof.

3. The device as claimed in claim 1, wherein the image side surface is defined by following Toric formula:

$\mathrm{Zx}=\frac{\left(\mathrm{Cx}\right)<br><br>X^2}{1+\sqrt{1-\left(1+\mathrm{Kx}\right)<br><br>{\left(\mathrm{Cx}\right)}^2<br><br>X^2}}+\underset{i=1}{\overset{20}{\sum <br><br>}}<br><br>A_i<br><br>X^i,<br><br>\mathrm{Cyx}=\frac{1}{\left(1<br><br>\text{/}<br><br>\mathrm{Cy}\right)-\mathrm{Zx}}$ $Z=\mathrm{Zx}+\frac{\left(\mathrm{Cyx}\right)<br><br>Y^2}{1+\sqrt{1-{\left(\mathrm{Cyx}\right)}^2<br><br>Y^2}}$

and the image side surface forms an axial symmetry with two concave parts on two sides and one concave area in a middle part thereof, like a M-shape.

4. The device as claimed in claim 1, wherein optical parameters of the mathematical expressions of freeform surfaces are modified and are simulated using computer software so as to design the ratio of the length along the long axis to the width along the short axis of the near rectangular light distribution pattern.

5. The device as claimed in claim 1, wherein the ratio of the length along the long axis to the width along the short axis of the near rectangular light distribution pattern generated on the target area by the optical lens is 3:

1.

6. The device as claimed in claim 1, wherein the optical lens further includes an outer part disposed around the light-source side surface and around the image side surface.

7. A light-emitting diode (LED) illumination device comprising at least one optical lens, at least one LED light source and a holder, wherein

the optical lens having at least one light-source side surface and at least one image side surface is a transparent lens and is mounted in a hole disposed on the holder correspondingly;

the light-source side surface and the image side surface are designed by mathematical expressions of freeform surfaces;

the LED light source faces the light-source side surface of the optical lens;

the holder is disposed with at least one hole that is mounted with an optical lens;

wherein light emitted from the LED light sources emits into the optical lens through the light-source side surface of the optical lens and out of the image side surface to be projected into a target area;

by the light-source side surface and the image side surface designed according to mathematical expressions of freeform surfaces, a near rectangular light distribution pattern is generated on the target area and there is a ratio of a length along a long axis to a width along a short axis of the near rectangular light distribution pattern.

8. The device as claimed in claim 7, wherein the optical lens further includes an outer part that is designed according to the hole disposed on the holder so that the optical lens is mounted into and integrated with the hole correspondingly.

9. The device as claimed in claim 7, wherein the holder is disposed with a plurality of holes that forms a hole array.