# US 9,438,802 B2 · Optical image stabilization calibration > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,438,802 B2 - Document ID: US9438802B2 - Status: Granted - Kind: B2 - Application number: 14/315,240 - Filed: 2014-06-25 - Published: 2015-12-03 - Granted: 2016-09-06 - Earliest claimed: 2014-05-30 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Thomas M. Gregory; Nader W. Moussa - Web page: https://patentgrep.com/patent/US9438802B2 ## CPC - H04N 23/687: {by shifting the lens or sensor position} - G02B 27/646: {compensating for small deviations, e.g. due to vibration or shake (movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68)} - G06T 3/4053: based on super-resolution, i.e. the output image resolution being higher than the sensor resolution - H04N 23/57: Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract In some embodiments, a camera actuator module includes a linear actuator motor for moving a lens assembly, a position sensor coupled to the lens assembly, a mechanical end stop mounted in the path of motion of the lens assembly, and a non-transitory storage medium storing program instructions. In some embodiments, the program instructions are computer-executable to implement exciting, using the linear actuator motor, a mechanical resonance in the camera actuator module calculated to cause the lens assembly to move to an overload displacement by powering the linear actuator of the camera actuator module at a resonant frequency of the camera actuator module, measuring, using the position sensor, a current maximal displacement of the lens assembly during the exciting using a position sensor, and estimating a position of the mechanical end stop using at least the current maximal displacement. ## Claims ### Claim 1 A camera module, the camera actuator module comprising: a linear actuator motor for moving a lens assembly; a position sensor coupled to the lens assembly; a mechanical end stop mounted in a path of motion of the lens assembly; and a non-transitory storage medium storing program instructions, wherein the program instructions are computer-executable to implement: exciting, using the linear actuator motor, a mechanical resonance in the camera actuator module calculated to cause the lens assembly to move to an overload displacement by powering the linear actuator of the camera actuator module at a resonant frequency of the camera actuator module, measuring, using the position sensor, a current maximal displacement of the lens assembly during the exciting, and estimating a position of the mechanical end stop using at least the current maximal displacement. ### Claim 2 (depends on 1) The camera module of claim 1, wherein the non-transitory storage medium further comprises program instructions computer-executable to implement: providing optical image stabilization, wherein the program instructions computer-executable to implement the providing optical image stabilization comprise: program instructions computer-executable to implement calculating a maximum safe stabilization motion using the position of the mechanical end stop, and program instructions computer-executable to implement the camera actuator module applying the maximum safe stabilization motion. ### Claim 3 (depends on 1) The camera module of claim 1, wherein The program instructions computer-executable to implement the exciting the mechanical resonance calculated to cause the actuator module to move to the overload displacement further comprise: program instructions computer-executable to implement exciting the mechanical resonance calculated to cause the actuator module to move to a displacement beyond displacements achievable by the actuator module at a steady state. ### Claim 4 (depends on 1) The camera module of claim 1, wherein program instructions computer-executable to implement the powering the linear actuator of the camera actuator module at the resonant frequency of the camera actuator module further comprise: program instructions computer-executable to implement powering a linear actuator motor of the camera actuator module at the resonant frequency of the camera actuator module. ### Claim 5 (depends on 1) The camera module of claim 1, wherein the linear actuator comprises a voice coil motor for moving a lens assembly of the camera module. ### Claim 6 (depends on 1) The camera module of claim 1, wherein the position sensor comprises a Hall sensor for measuring a position of a component of the camera module. ### Claim 7 A method for operating a camera component, comprising: exciting a mechanical resonance in a camera actuator module calculated to cause the camera actuator module to move to an overload displacement by powering a linear actuator of the camera actuator module at a resonant frequency of the camera actuator module; measuring a current maximal displacement of the actuator module during the exciting; and estimating a position of a mechanical end stop using at least the current maximal displacement, wherein the mechanical end stop is mounted in a path of motion of the camera actuator module. ### Claim 8 (depends on 7) The method of claim 7, further comprising, characterizing the camera actuator module, wherein the characterizing the camera actuator module further comprises: measuring physical properties of the camera actuator module, and storing variables representing the physical properties of the camera actuator module in a memory associated with the camera actuator module. ### Claim 9 (depends on 7) The method of claim 7, further comprising providing optical image stabilization, wherein the providing optical image stabilization comprises: calculating a maximum safe stabilization motion using the position of the mechanical end stop, and the camera actuator module applying the maximum safe stabilization motion. ### Claim 10 (depends on 7) The method of claim 7, wherein the exciting the mechanical resonance calculated to cause the actuator module to move to the overload displacement further comprises: exciting the mechanical resonance calculated to cause the actuator module to move to a displacement beyond displacements achievable by the actuator module at a steady state. ### Claim 11 (depends on 7) The method of claim 7, wherein the estimating the position of the mechanical end stop using at least the maximal displacement further comprises: estimating an actuator-unachievable position of the mechanical end stop, wherein the actuator unachievable position of the mechanical end stop is a position beyond a position range achievable by the drive power of the linear actuator. ### Claim 12 (depends on 7) The method of claim 7, wherein the powering the linear actuator of the camera actuator module at the resonant frequency of the camera actuator module further comprises: powering a linear actuator motor of the camera actuator module at the resonant frequency of the camera actuator module. ### Claim 13 (depends on 7) The method of claim 7, wherein the powering the linear actuator of the camera actuator module at the resonant frequency of the camera actuator module further comprises: powering the linear actuator of the camera actuator module at the resonant frequency of the camera actuator module at a resonant frequency associated with one or more springs in the actuator module. ### Claim 14 (depends on 7) The method of claim 7, wherein the estimating the position of the mechanical end stop using at least the maximal displacement further comprises: estimating the position of the mechanical end stop using at least the maximal displacement using the position sensor measurements and a physical system model of the actuator module. ### Claim 15 A non-transitory computer-readable storage medium storing program instructions, wherein the program instructions are computer-executable to implement: exciting a mechanical resonance in a camera actuator module calculated to cause the camera actuator module to move to an overload displacement by powering a linear actuator of the camera actuator module at a resonant frequency of the camera actuator module; measuring a current maximal displacement of the actuator module during the exciting; and estimating a position of a mechanical end stop using at least the current maximal displacement, wherein the mechanical end stop is mounted in a path of motion of the camera actuator module. ### Claim 16 (depends on 15) The non-transitory computer-readable storage medium of claim 15, further comprising: program instructions computer-executable to implement characterizing the camera actuator module, wherein the program instructions computer-executable to implement characterizing the camera actuator module further comprise: program instructions computer-executable to implement measuring physical properties of the camera actuator module, and program instructions computer-executable to implement storing variables representing the physical properties of the camera actuator module in a memory associated with the camera actuator module. ### Claim 17 (depends on 15) The non-transitory computer-readable storage medium of claim 15, further comprising program instructions computer-executable to implement providing optical image stabilization, wherein the program instructions computer-executable to implement the providing optical image stabilization comprise: program instructions computer-executable to implement calculating a maximum safe stabilization motion using the position of the mechanical end stop, and program instructions computer-executable to implement the camera actuator module applying the maximum safe stabilization motion. ### Claim 18 (depends on 15) The non-transitory computer-readable storage medium of claim 15, wherein the program instructions computer-executable to implement exciting the mechanical resonance calculated to cause the actuator module to move to the overload displacement further comprise: program instructions computer-executable to implement exciting the mechanical resonance calculated to cause the actuator module to move to a displacement beyond displacements achievable by the actuator module at a steady state. ### Claim 19 (depends on 15) The non-transitory computer-readable storage medium of claim 15, wherein the program instructions computer-executable to implement estimating the position of the mechanical end stop using at least the maximal displacement further comprise: program instructions computer-executable to implement estimating an actuator-unachievable position of the mechanical end stop, wherein the actuator unachievable position of the mechanical end stop is a position beyond a position range achievable by the drive power of the linear actuator. ### Claim 20 (depends on 15) The non-transitory computer-readable storage medium of claim 15, wherein the program instructions computer-executable to implement powering the linear actuator of the camera actuator module at the resonant frequency of the camera actuator module further comprise: program instructions computer-executable to implement powering a linear actuator motor of the camera actuator module at the resonant frequency of the camera actuator module.