초록 ▼

The present invention is directed to a flexible scanning beam imaging system. In specific embodiments, the scanning beam imaging system comprises a mask, and an objective lens having an objective lens focal point disposed between the mask and the objective lens. A field lens device is disposed befor

The present invention is directed to a flexible scanning beam imaging system. In specific embodiments, the scanning beam imaging system comprises a mask, and an objective lens having an objective lens focal point disposed between the mask and the objective lens. A field lens device is disposed before the mask to direct a light beam through the mask and focus the light beam at a field lens focal point. The field lens focal point is located between the field lens and the objective lens. One or more scanning mirrors are disposed at or near the objective lens focal point. As a result, the beam will be directed to different locations across the objective lens by the scanning mirror(s), and will travel from the objective lens substantially collimated and parallel toward a surface illuminated by the beam. This substantially collimated and parallel beam provides a large depth of field of the ablation pattern.

대표청구항 ▼

What is claimed is: 1. A system for scanning a light beam over a target, the system comprising: a first lens element disposed along a path of the light beam, the first lens element forming a converging light beam along the path, the converging beam forming a beam focal point beyond which the light

What is claimed is: 1. A system for scanning a light beam over a target, the system comprising: a first lens element disposed along a path of the light beam, the first lens element forming a converging light beam along the path, the converging beam forming a beam focal point beyond which the light beam becomes a diverging light beam; a second lens element disposed along the path of the light beam, the second lens substantially collimating the diverging light beam, the beam focal point being disposed between the first lens element and the second lens element, the second lens having a focal point disposed between the beam focal point and the first lens element; and a first movable mirror for scanning the path of the light beam from a first position on the target to a second position on the target, the mirror having a surface intersecting the beam at a position along the beam path between the first lens element and the second lens element, the path of the collimated light beam from the second lens element in the first position on the target being substantially parallel to the path of the collimated light beam from the second lens element in the second position on the target to within about 30 milliradians or less. 2. The system of claim 1 wherein a position of the beam focal point is separated from the position of the surface of the mirror. 3. The system of claim 2 wherein a dimension across the surface of the mirror intersecting the beam is greater than about 10% of a width of the beam at the second lens element. 4. The system of claim 2 wherein a full angle of the substantially collimated light beam is less than about 15 milliradians and the path of the beam in the first position on the target is parallel to the path of the beam in the second position on the target to within about 15 milliradians. 5. The system of claim 2 further comprising an aperture disposed along the path of the beam, the second lens element forming an image of the aperture near the target. 6. The system of claim 5 wherein the lens elements are selected from the group consisting of reflecting, refracting and diffracting lens elements. 7. The system of claim 5 wherein the first lens element comprises a field lens device comprising a plurality of lenses. 8. The system of claim 7 wherein the plurality of lenses are movable to adjust at least one of the size and the intensity of the beam without substantially moving the beam focal point. 9. The system of claim 7 wherein the field lens device comprises a Galilean telescope. 10. The system of claim 5 wherein the second lens element comprises an objective lens having an objective lens focal point disposed along the beam path. 11. The system of claim 10 further comprising a second movable mirror to scan the light beam from the first position on the surface to the second position on the surface with a movement of the second mirror, the second mirror being disposed along the beam path between the field lens and the objective lens. 12. The system of claim 11 wherein the first mirror and the second mirror are disposed on opposite sides of the objective lens focal point along the beam path. 13. The system of claim 12 wherein a distance between the first mirror and the second mirror is less than a focal length of the objective lens. 14. The system of claim 13 wherein the distance between the mirrors is less than about 20% of the focal length of the objective lens. 15. The system of claim 14 wherein the distance between the mirrors is less than about 10% of the focal length of the objective lens. 16. The system of claim 1, wherein the beam focal point is disposed along the beam path between the first lens element and the mirror. 17. The system of claim 1, wherein the beam focal point is disposed along the beam path between the mirror and the second lens element. 18. The system of claim 1, wherein the substantially collimated light beam is collimated to within about 30 milliradians or less for the full width of the beam. 19. The system of claim 1, wherein the position of the second lens element is adjustable along the path of the light beam between the mirror and the target such that the distance between the second lens element and the beam focal point is greater than, less than, or equal to a second lens element focal length. 20. A system for ablating a surface of a material with a light beam to form a predetermined shape in the material, the system comprising: a light source for making a beam of an ablative light energy, the beam traveling along a path; a first lens element disposed along the beam path to form a converging beam along the path, the converging beam forming a beam focal point beyond which the light beam becomes a diverging light beam; a second lens element disposed along the beam path to receive the diverging light beam and form a substantially collimated light beam along the beam path near the, surface, the focal point being disposed between the first lens element and the second lens element; a first mirror to scan the path of the light beam from a first position on the surface to a second position on the surface with a movement of the first mirror, the first mirror having a surface intersecting the beam at a position along the beam path between the first lens element and second lens element; a second movable mirror to scan the light beam from the first position on the surface to the second position on the surface with a movement of the second mirror, the second mirror being disposed along the beam path between the first lens element and the second lens element, the path of the collimated light beam from the second lens element in the first position on the surface being substantially parallel to the path of the collimated light beam from the second lens element in the second position on the surface to within about 30 milliradians or less; and a processor coupled to the first and second mirrors and the light source, the processor comprising a set of machine readable instructions adapted to ablate the material with the beam to form the predetermined shape in the material; wherein the second lens element has a focal point disposed between the first mirror and the second mirror. 21. The system of claim 20 wherein a position of the beam focal point is separated from the position of the surface of the mirror. 22. The system of claim 20 wherein a full angle of the substantially collimated beam is less than about 20 milliradians and the path of the beam in the first position on the surface is parallel to a path of the beam in the second position on the surface to within about 15 milliradians. 23. The system of claim 22 wherein a dimension across the surface of the mirror intersecting the beam is greater than about 10% of a width of the beam at the second lens element. 24. The system of claim 20 further comprising an aperture disposed along the path of the beam, the second lens element forming an image of the aperture near the surface. 25. The system of claim 24 wherein the lens elements are selected from the group consisting of reflecting, refracting and diffracting lens elements. 26. The system of claim 24 wherein the first lens element comprises a field lens device comprising a plurality of lenses. 27. The system of claim 26 wherein the plurality of lenses are movable to adjust at least one of the size and the intensity of the beam without substantially moving the beam focal point. 28. The system of claim 26 wherein the field lens device comprises a Galilean telescope. 29. The system of claim 24 wherein the second lens element comprises an objective lens having an objective lens focal point disposed along the beam path. 30. The system of claim 29 wherein the light source is a pulsed ultraviolet laser having a wavelength between about 185 and 215 nm and the material is corneal material. 31. The system of claim 20 wherein a distance between the first mirror and the second mirror is less than a focal length of the second lens element. 32. The system of claim 31 wherein the distance between the mirrors is less than about 20% of the focal length of the second lens element. 33. The system of claim 31 wherein the distance between the mirrors is less than about 10% of the focal length of the second lens element. 34. The system of claim 20 wherein the focused beam, as focused by the first lens element, is directed to the second lens element. 35. A method for delivering a light beam to a target, the method comprising: directing the light beam along a path to a first lens element to form a converging beam along the path, the converging beam forming a beam focal point beyond which the light beam becomes a diverging light beam; directing the diverging light beam to a second lens element to form a substantially collimated light beam along the beam path near the target, the beam focal point being disposed between the first lens element and the second lens element, the second lens element having a focal point disposed between the beam focal point and the first lens element; and scanning the path of the light beam from a first position on the target to a second position on the target by moving a first mirror, the mirror having a surface at a position along the beam path between the first lens element and second lens element, the path of the collimated light beam from the second lens element in the first position on the target being substantially parallel to the path of the collimated light beam from the second lens element in the second position on the target to within about 30 milliradians or less. 36. The method of claim 35 wherein a position of the beam focal point is different from the position of the surface of the mirror. 37. The method of claim 36 wherein a dimension across the surface of the mirror intersecting the beam is greater than about 10% of a width of the beam at the second lens element. 38. The method of claim 35 wherein a full angle of the substantially collimated beam is less than about 15 milliradians and the path of the beam in the first position is parallel to a path of the beam in the second position to within about 15 milliradians. 39. The method of claim 35 further comprising passing the light beam through an aperture and forming an image of the aperture near the target. 40. The system of claim 39 wherein the lens elements are selected from the group consisting of reflecting, refracting and diffracting lens elements. 41. The method of claim 39 wherein the second lens element comprises an objective lens having an objective lens focal point disposed along the beam path. 42. The method of claim 41 wherein the step of scanning of the light beam includes moving a second mirror, the second mirror being disposed along the beam path between the first lens element and the second lens element. 43. The method of claim 42 wherein the first mirror and second mirror are disposed on opposite sides of the objective lens focal point along the beam path. 44. The method of claim 43 wherein a distance between the first mirror and second mirror is less than a focal length of the objective lens. 45. The method of claim 44 wherein the distance between the mirrors is less than about 20% of the focal length of the objective lens. 46. The method of claim 45 wherein the distance between the mirrors is less than about 10% of the focal length of the objective lens. 47. A method of ablating a surface of a material with a light beam to form a predetermined shape in the material, the method comprising: generating a beam of an ablative light energy, the beam traveling along a path; directing the beam to a first lens element to form a converging beam along the path, the converging beam forming at a beam focal point beyond which the light beam becomes a diverging light beam; directing the diverging light beam to a second lens element to form a substantially collimated light beam along the beam path near the surface, the beam focal point being disposed between the first lens element and the second lens element; scanning the path of the light beam from a first position on the surface to a second position on the surface by moving a first mirror and a second mirror, the first mirror having a surface at a position along the beam path between the first lens element and second lens element, the second mirror having a surface at a position along the beam path between the first lens element and second lens element, the path of the collimated light beam from the second lens element in the first position on the surface being substantially parallel to the path of the collimated light beam from the second lens element in the second position on the surface to within about 30 milliradians or less; and ablating the material with the beam to form the predetermined shape in the material; wherein the second lens element has a focal point disposed between the first mirror and the second mirror. 48. The method of claim 47 wherein a position of the beam focal point is different from the position of the surface of the mirror. 49. The method of claim 47 wherein a full angle of the substantially collimated beam is less than about 15 milliradians and the path of the beam in the first position on the surface is parallel to a path of the beam in the second position on the surface to within about 15 milliradians. 50. The method of claim 49 wherein a dimension across the surface of the mirror intersecting the beam is greater than about 10% of a width of the beam at the second lens element. 51. The method of claim 47 further comprising passing the light beam through an aperture and forming an image of the aperture near the surface. 52. The system of claim 51 wherein the lens elements are selected from the group consisting of reflecting, refracting and diffracting lens elements. 53. The method of claim 51 wherein the second lens element comprises an objective lens having an objective lens focal point disposed along the beam path. 54. The method of claim 53 wherein the ablative light energy has a wavelength between about 185 and 215 nm and the material is a corneal material. 55. The method of claim 47 wherein a distance between the first mirror and the second mirror is less than a focal length of the objective lens. 56. The method of claim 55 wherein the distance between the mirrors is less than about 20% of the focal length of the objective lens. 57. The method of claim 56 wherein the distance between the mirrors is less than about 10% of the focal length of the objective lens. 58. A system for scanning a light beam over a target, the system comprising: a first lens element disposed along a path of the light beam, the first lens element converging the light beam to a waist beyond which the light beam becomes a diverging light beam; a second lens element disposed along the path of the diverging light beam, the second lens substantially collimating the light beam to within about 30 milliradians or less for the full width of the beam, the beam waist disposed between the first lens element and the second lens element, and which is also disposed between the first lens element and a focal point of the second lens element; and a first movable mirror for scanning the path of the light beam from a first position on the target to a second position on the target, the mirror disposed along the beam path between the first lens element and the second lens element, the path from the second lens element in the first position being substantially parallel to the path from the second lens element in the second position. 59. The system of claim 58, wherein a position of the beam waist is separated from the position of the surface of the mirror. 60. The system of claim 59, wherein a dimension across the surface of the mirror intersecting the beam is greater than about 10% of a width of the beam at the second lens element. 61. The system of claim 59, wherein a full angle of the substantially collimated light beam is less than about 15 milliradians and the path of the beam in the first position on the target is parallel to the path of the beam in the second position on the target to within about 15 milliradians.