LED Curing Light having Fresnel Lenses

• US 20070275344A1
• Filed: 02/24/2006
• Published: 11/29/2007
• Est. Priority Date: 02/26/2005
• Status: Active Grant

• Current Assignee: Yongqian Liu
• Original Assignee: Yongqian Liu
• Inventors: Liu, Yongqian
• Granted Patent: US 7,857,619 B2
• Time in Patent Office: Days
• US Class Current: 433/29
• CPC Class Codes: A61C 19/004 Hand-held apparatus, e.g. guns
• CPC Class Codes: G02B 3/08 with discontinuous faces, e.g. Fresnel lens diffractive Fresnel lenses G02B5/1876

Abstract

Disclosed is a LED curing light device for curing of photo-polymerization materials. The device comprises of a plurality of LED source and a plurality of Fresnel lenses. The said LED source is powered and controlled by a drive board and batteries providing high power curing light in the range of 300 to 500 nm and optical power in the range of 100 to 800 mW. The said Fresnel lenses couple said curing light efficiently to a focused spot on a curing object.

Claims

1. A curing light apparatus for curing light activated composite comprising:

a plurality of LED sources to emit curing light;

a lens mount consisting of a high reflectance inner surface configured adjacent to said plurality of LED sources;

Fresnel lens pair consisting of a first Fresnel lens and a second Fresnel lens adjacent and parallel to each other in cascaded series and mounted on said lens mount to deliver said curing light directly to a composite.

2. The apparatus of claim 1 further including

a mounting head wherein said plurality of LED sources are mounted;

a handpiece body wherein the mounting head is attached to;

wherein said handpiece body and mounting head are made of highly heat conductive materials comprising aluminum and copper.

3. The apparatus of claim 1, wherein said plurality of LED sources emit curing light with optical power approximately between 100 mW to 800 mW at a wavelength approximately between 300 to 500 nm.

4. The apparatus of claim 1 further comprising a lens cap with a length shorter than the focal length of said second Fresnel lens that snaps on the surface of said lens mount for shielding said curing light and protecting said Fresnel lens pair.

5. The apparatus of claim 1, wherein

said first Fresnel lens has a focal length approximately between 2 to 10 millimeters to collect and collimate the curing light from said plurality of LED sources simultaneously;

said second Fresnel lens has a focal length approximately between about 2 to about 20 millimeters to focus said curing light to said curing composite;

said lens mount consists of a high reflectance inner surface of parabolic cylindrical shape.

6. The optical apparatus of claim 1, wherein said Fresnel lens pair consists of circular cylindrical disks of Fresnel lenses formed from circular grooves of preferably constant height wherein

said first Fresnel lens has a first flat side facing said plurality of LED sources and a second groove side collimating light received from the first flat side;

said second Fresnel lens has a first groove side facing said first Fresenl lens and a second groove side focusing light received from the first groove side.

7. The optical apparatus of claim 1, wherein said first Fresnel lens and said second Fresnel lens have thickness approximately between 0.1 to 5 millimeters and F number of approximately between 0.1 and 2.

8. The apparatus of claim 5, wherein said first Fresnel lens and said second Fresnel lens are made from materials selected from the group consisting of polycarbonate, acrylic, rigid vinyl, and polyacrylic.

9. The optical apparatus of claim 5, wherein said Fresnel lens pair and said lens cap are mounted on said lens mount consisting of a parabolic cylindrical inner reflecting surface made of high reflectance materials comprising plated, coated and bonded aluminum, chromium, zinc, silver and multiplayer metal oxide thin films and polymer films wherein the reflecting surface reflects light emitted from said plurality of LED sources.

10. The apparatus of claim 2, wherein said handheld body comprising

a plurality of rechargeable battery;

a plurality of circuit boards;

means of activating said circuit boards;

wherein said means of activating said circuit board comprising mechanical switches and liquid crystal control panels.

11. (canceled)

12. (canceled)

13. (canceled)

14. A method of making a dental LED curing light apparatus comprising the step of:

supplying a plurality of LED sources to emit curing light;

supplying a lens mount consisting of a high reflectance inner surface configured adjacent to said plurality of LED sources;

supplying a Fresnel lens pair consisting of a first Fresnel lens and a second Fresnel lens adjacent and parallel to each other in cascaded series and mounted on said lens mount to collimate and focus said curing light directly to a composite.

15. The method of claim 14, wherein said plurality of LED sources emit curing light with optical power approximately between 100 mW to 800 mW at a wavelength approximately between 300 to 500 nm.

18. The method of claim 14, wherein

said first Fresnel lens has a focal length approximately between about 2 to about 10 millimeters to collect and collimate the curing light from said plurality of LED sources simultaneously;

said second Fresnel lens has a focal length approximately between about 2 to about 20 millimeters to focus curing light to said composite;

said lens mount consists of a high reflectance inner surface of parabolic cylindrical shape.

19. The method of claim 14, wherein said Fresnel lens pair are made from materials selected from the group consisting of polycarbonate, acrylic, rigid vinyl, and polyacrylic.

20. The method of claim 14, wherein said lens mount has inner surface of a parabolic reflector with reflecting surface made from high reflectance materials comprising of plated, coated and bonded aluminum, chromium, zinc, silver and multiplayer metal oxide thin films and polymer films.

16. (canceled)

17. (canceled)

21. A dental curing apparatus comprising:

a mounting head wherein a plurality of LED sources is mounted and attached inside;

a handpiece body wherein the mounting head is attached to;

a lens mount consisting of a high reflectance inner surface configured adjacent to said plurality of LED sources;

an optical lens assembly mounted on said lens mount for focusing light emitted from said plurality of LED sources comprising

a first Fresnel lens having a first end that is substantially flat and a second end comprising circular grooves, wherein the substantially flat first end is configured for receiving light from the LED source, wherein the circular grooved second end is configured for refracting the light received from the first end into a diffraction limited collimation beam;

a second Fresnel lens having a first end comprising circular grooves and a second end that is substantially flat, wherein the first circular grooved end is configured for refracting the light received from the first Fresnel lens into a focused beam and the second flat end is configured for transmitting the light received from the first end into a diffraction limited focused spot adjacent to a curing composite.

22. The apparatus of claim 21, wherein said first and second Fresnel lenses are circular cylindrical in shape comprising circular grooves of constant height and constant spacing made of transparent materials comprising polycarbonate, acrylic, silicone, rigid vinyl using processes comprising compression and injection molding.

23. The apparatus of claim 21, wherein said lens mount has an inner surface of a parabolic reflector with reflecting surface made from high reflectance materials comprising of plated, coated and bonded aluminum, chromium, zinc, silver and multiplayer metal oxide thin films and polymer films.

24. A dental curing apparatus comprising:

a mounting head wherein a plurality of LED sources is mounted and attached inside;

a handpiece body wherein the mounting head is attached to;

a lens mount consisting of a high reflectance inner surface configured adjacent to said plurality of LED sources;

a Fresnel lens mounted on said lens mount for focusing light emitted from said plurality of LED sources having a first end comprising circular grooves and a second end that is substantially flat, wherein the circular grooved first end is configured for receiving light from the LED source, wherein the substantially flat second end is configured for refracting and focusing the light received from the first end into a diffraction limited focused spot adjacent to a curing composite.