Laser beam translation system and method

• US 6,896,384 B2
• Filed: 06/17/2003
• Issued: 05/24/2005
• Est. Priority Date: 06/17/2003
• Status: Expired due to Fees

• Current Assignee: Alcon Incorporated
• Original Assignee: Alcon RefractiveHorizons, LLC (Novartis Ag)
• Inventors: McWhirter, John E., Thair, David, Eskew, David
• Primary Examiner(s): Robinson, Mark A.
• Application Number:
  US10/463,839
• Publication Number:
  US 20040264012A1
• Time in Patent Office: 707 Days
• Field of Search: 359/198, 359/811, 359/819, 359/822, 359/871, 359/872, 359/877, 248/476, 248/479, 248/486, 403/24, 403/291
• US Class Current: 359/872
• CPC Class Codes: A61F 2009/00846 Eyetracking
• CPC Class Codes: A61F 2009/00872 Cornea
• CPC Class Codes: A61F 2009/00897 Scanning mechanisms or algorithms
• CPC Class Codes: A61F 9/008 using laser
• CPC Class Codes: A61F 9/00802 for photoablation
• CPC Class Codes: Y10T 403/54 Flexible member is joint component

Abstract

A light-translation system includes a fixed base and translatable mirror mount having mirror-supporting brackets. A first and second arm are pivotally attached in parallel, spaced-apart relation adjacent first ends to the base and adjacent second ends to the mirror mount to form a parallelogram-shaped attachment with the base and mirror mount. The pivotal attachments are formed using flexural pivots, each having a thick portion oriented for achieving minimal angular deviation of the mirror. A first bracket has three pads for supporting one side of the mirror. A second bracket has two surfaces shaped to support an edge of the mirror, each surface positioned opposite a pad. A washer dimensioned to admit a mounting screw is positionable opposite a third pad against an outside wall of the mirror mount to removably retain the mirror without imposing appreciable bending stress thereon.

Claims

1. A light beam translation system comprising:

a fixed base;

a translatable mirror mount having means for affixing a mirror thereto;

a first and a second arm assembly pivotally attached at lower ends to the base and pivotally attached at upper ends to the mirror mount, each arm assembly comprising a pair of generally upwardly extending arms connected in generally parallel, spaced-apart relation, a front arm attached adjacent a front edge of the base and the mirror mount and a rear arm attached adjacent a rear edge of the base and the mirror mount, the first and the second arm assemblies thereby forming a front and a rear parallelogram-shaped attachment element at a front and a rear of the base and mirror mount, respectively;

a first set of eight flexural pivots for providing the pivotal attachments, each flexural pivot having a thick portion oriented for achieving optimal stability, a first and a second flexural pivot positioned at a junction between the lower ends of the front arms and the base so that the thick portions of a front section thereof are oriented along an outer arc of the pivot, a third and a fourth flexural pivot positioned at a junction between the upper ends of the front arms and the mirror mount so that the thick portions of a front section thereof are oriented along a top arc of the pivot, a fifth and a sixth flexural pivot positioned at a junction between the lower ends of the rear arms and the base so that the thick portions of a front section thereof are oriented along an outer arc of the pivot, and a seventh and an eighth flexural pivot positioned at a junction between the upper ends of the rear arms and the mirror mount so that the thick portions of a front section thereof are oriented along a top arc of the pivot; and

means for translating the mirror mount in a generally horizontal plane.

2. The translation system recited in claim 1, wherein the translating means comprises a single-phase motor and a linear actuator driven by the motor, the actuator affixed in movement-producing relation to the mirror mount.

3. The translation system recited in claim 1, wherein the mirror mount affixing means comprises a bracket for positioning a mirror having a generally planar reflective surface so that the reflective surface is in a generally vertical plane, for translating incoming light in a horizontal plane.

4. The translation system recited in claim 1, wherein the mirror mount affixing means comprises a bracket for positioning a mirror having a generally planar reflective surface so that the reflective surface is in a plane at an angle of approximately 45 degrees to a vertical plane, for translating incoming light in a vertical plane.

5. The translation system recited in claim 1, wherein the mirror mount comprises means for retaining a mirror having a planar reflective surface in a desired orientation without imposing bending stress on the mirror sufficient to cause the reflective surface to substantially depart from planarity.

6. The translation system recited in claim 5, wherein the mirror retaining means comprises:

a mirror mount base;

a first bracket affixed to the mirror mount base having three generally coplanar pads thereon for supporting the reflective side of the mirror thereagainst;

a second bracket affixed to the mirror mount having two surfaces shaped to support an edge of the mirror thereagainst opposed to the reflective side, each of the two surfaces generally opposite a respective one of the pads; and

a removable mounting screw extending through the mirror mount; and

a washer dimensioned to admit the mounting screw and positionable generally opposite a third pad against an outside wall of the mirror mount, the washer positioned to retain the mirror in contact with the pads and the surfaces in a predetermined orientation, the pads, the surfaces, and the washer operable to removably retain the mirror within the mirror mount without imposing bending stress on the mirror sufficient to cause the reflective surface to substantially depart from planarity.

7. The translation system recited in claim 6, wherein the first and the second bracket cooperate to retain the mirror in spaced relation from the mirror mount base.

8. The translation system recited in claim 7, wherein the second bracket is shaped to support a nonreflective edge of the mirror, the nonreflective edge meeting the reflective surface at an angle of approximately 45 degrees.

9. The translation system recited in claim 8, wherein the surfaces each comprise a concave, substantially cylindrical section.

10. The translation system recited in claim 8, wherein:

the first mirror mount affixing means comprises a bracket for positioning a first mirror having a generally planar reflective surface so that the reflective surface is in a generally vertical plane;

the second mirror mount affixing means comprises a bracket for positioning a second mirror having a generally planar reflective surface so that the reflective surface is in a generally vertical plane; and

the third and the fourth mirror mount affixing means each comprise a bracket for positioning a third and a fourth mirror having generally planar reflective surfaces so that the reflective surfaces are parallel to each other and off-axis from the vertical plane, movement of the fourth mirror for translating light reflected from the third mirror in a vertical plane.

11. The translation system recited in claim 10, wherein:

the first and the second mirror mount bracket are adapted to orient the first and the second mirror reflective surfaces at an angle of approximately 45 degrees to the plate; and

the third mirror mount bracket is adapted to orient the third mirror reflective surface approximately normal to the plate and at an angle of approximately 45 degrees to the second mirror reflective surface and the fourth mirror mount bracket is adapted to orient the fourth mirror reflective surface approximately parallel to the third mirror reflective surface.

12. The translation system recited in claim 1, wherein:

the base comprises a first base, and further comprising an upwardly extending plate having a hole therethrough from a front face through to a rear face opposed to the front face, the plate front face adjacent a rear edge of the first base, and a second base having a front edge adjacent the plate rear face;

wherein;

the mirror mount comprises a first mirror mount positioned to permit the first mirror to receive incoming light from a direction generally perpendicular to a longitudinal axis of the hole and to reflect a light beam generally horizontally through the hole, and further comprising;

a second fixed mirror mount and a third fixed mirror mount affixed to the second base and having means for affixing a second and a third mirror thereto, respectively, the second mirror mount positioned to permit the second mirror to receive light reflected generally horizontally from the first mirror through the hole in the plate and to reflect light generally horizontally, the third mirror mount positioned to permit the third mirror to receive light generally horizontally from the second mirror and to reflect light generally downward;

a fourth translatable mirror mount having means for affixing a fourth mirror thereto, the fourth mirror mount positioned to permit the fourth mirror to receive downwardly reflected light from the third mirror and to reflect light generally horizontally in a direction generally parallel to the incoming light;

a third and a fourth arm assembly pivotally attached at upper ends to the second base and pivotally attached at lower ends to the fourth mirror mount, each of the third and the fourth arm assembly comprising a pair of generally upwardly extending arms connected in generally parallel, spaced-apart relation, a rear arm attached adjacent a rear edge of the second base and of the fourth mirror mount, and a front arm attached adjacent a front edge of the second base and of the fourth mirror mount, the first and the second arm assemblies thereby forming a front and a rear parallelogram-shaped attachment element at a front and a rear of the second base and the fourth mirror mount, respectively;

a second set of eight flexural pivots for providing the pivotal attachments, each flexural pivot having a thick portion oriented for achieving optimal precision, a first and a second flexural pivot positioned at a junction between the lower ends of the rear arms of the third and the fourth arm assemblies and the second base so that the thick portions of a rear section thereof are oriented along an lower arc of the pivot, a third and a fourth flexural pivot positioned at a junction between the upper ends of the rear arms of the third and the fourth arm assemblies and the fourth mirror mount so that the thick portions of a rear section thereof are oriented along an outer arc of the pivot, a fifth and a sixth flexural pivot positioned at a junction between the lower ends of the front arms and the second base so that the thick portions of a front section thereof are oriented along a lower arc of the pivot, and a seventh and an eighth flexural pivot positioned at a junction between the upper ends of the front arms of the third and the fourth arm assemblies and the fourth mirror mount so that the thick portions of a front section thereof are oriented along an outer arc of the pivot; and

means for translating the fourth mirror mount in a generally horizontal plane.