# US 8,542,423 B2 · Stiffness compensation in opto-mechanical mechanisms

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,542,423 B2
- Document ID: US8542423B2
- Status: Granted
- Kind: B2
- Application number: 12/811,350
- Filed: 2009-01-08
- Published: 2011-02-17
- Granted: 2013-09-24
- Earliest claimed: 2008-01-08
- Assignees: ABB AB
- Applicants: Mathieu J. Demers; Jean-Thomas Landry; Henry L. Buijs
- Inventors: Mathieu J. Demers; Jean-Thomas Landry; Henry L. Buijs
- Web page: https://patentgrep.com/patent/US8542423B2

## CPC

- G02B 7/1828: {using magnetic means}
- F16C 11/12: incorporating flexible connections, e.g. leaf springs
- G01J 3/02: Details
- G01J 3/0202: {Mechanical elements; Supports for optical elements}
- G01J 3/06: Scanning arrangements {arrangements for order-selection}
- G02B 7/1821: {for rotating or oscillating mirrors}
- Y10T 29/49002: Electrical device making
- Y10T 29/5313: Means to assemble electrical device
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An optical scanning or positioning mechanism has a head on which optical components are mounted and an actuator coupled to the head to cause the head to move when the actuator is actuated. There are one or more sets of flexure bearings mounted in the mechanism. The flexure bearings have a restoring torque when moved from a rest position. The bearings are coupled to the head to allow the head to move when actuated by the actuator. One or more magnets are mounted in the mechanism in a location other than in the actuator to compensate for the flexure bearings restoring torque.

## Claims

### Claim 1

An optical scanning or positioning mechanism comprising:
a head having optical components mounted thereon;
an actuator coupled to said head to cause said head to move when said actuator is actuated;
one or more sets of flexure bearings mounted in said mechanism and coupled to said head to allow said head when actuated by said actuator to move, said one or more sets of flexure bearings each having a restoring torque when moved from a rest position by said head movement; and
one or more permanent magnets mounted in said mechanism in a location other than in said actuator to compensate for said flexure bearings restoring torque.

### Claim 2 (depends on 1)

The optical mechanism of claim 1 wherein said optical mechanism is a scanning mechanism and said actuator is a linear voice coil actuator.

### Claim 3 (depends on 2)

The optical mechanism of claim 2 wherein said one or more flexure bearings are four sets of flexure bearings.

### Claim 4 (depends on 3)

The optical mechanism of claim 3 further comprising a linkage that is connected at opposite ends to an associated one of two of said four sets of flexure bearings and said voice coil actuator comprises a magnetic assembly.

### Claim 5 (depends on 2)

The optical mechanism of claim 2 wherein said optical components is a mirror assembly mounted on said head.

### Claim 6

In an optical scanning or positioning mechanism having a head with optical components mounted thereon, an actuator coupled to said head to cause said head to move when said actuator is actuated, one or more sets of flexure bearings mounted in said mechanism and coupled to said head to allow said head when actuated by said actuator to move, said one or more sets of flexure bearings having a restoring torque when moved from a rest position by said head movement, a method for providing compensation for said restoring torque of said one or more flexure bearings comprising:
mounting one or more permanent magnets in said mechanism in a location other than in said actuator to compensate for said flexure bearings restoring torque.

### Claim 7

A method for making an optical scanning or positioning mechanism having a head having optical components mounted thereon comprising:
coupling an actuator to said head to cause said head to move when said actuator is actuated;
providing one or more sets of flexure bearings mounted in said mechanism and coupled to said head to allow said head when actuated by said actuator to move, said one or more sets of flexure bearings having a restoring torque when moved from a rest position by said head movement; and
mounting one or more permanent magnets in said mechanism in a location other than in said actuator to compensate for said flexure bearings restoring torque.

### Claim 8

In an optical scanning or positioning mechanism having a head with optical components mounted thereon, an actuator coupled to said head to cause said head to move when said actuator is actuated, one or more sets of flexure bearings mounted in said mechanism and coupled to said head to allow said head when actuated by said actuator to move, said one or more sets of flexure bearings having a restoring torque when moved from a rest position by said head movement, a method for compensating for said restoring torque of said one or more flexure bearings comprising:
using the magnetic field of one or more permanent magnets mounted in said mechanism in a location other than in said actuator to provide a force to compensate for said restoring torque of said one or more flexure bearings.