Automated UV calibration, motorized optical target and automatic surface finder for optical alignment and assembly robot

{
  "publication_number": "US9766473B1",
  "country": "US",
  "kind": "B1",
  "title": "Automated UV calibration, motorized optical target and automatic surface finder for optical alignment and assembly robot",
  "abstract": "In an optical components automatic alignment robot, a motorized target moves closer or further from a digital camera being tested or assembled. A light sensor is used to automatically calibrate an ultraviolet (UV) or other light source used for curing adhesive. An automatic surface finder is used to accurately and repeatably find a surface on which adhesive is to be dispensed.",
  "claims": [
    "1. A system for actively aligning a lens to a digital camera having an optical axis, the system comprising: a target having optically contrasting features; a robot configured to grasp the lens and orient the lens intermediate the target and the digital camera, so as to image the target features onto the digital camera; a drive assembly mechanically coupled to the target to move the target along an axis parallel to the optical axis of the digital camera, thereby selectively adjusting spacing between the target and the digital camera; a motion controller configured to: cause the robot to scan the lens along a trajectory from a starting location to an ending location; and while the robot scans the lens from the starting location to the ending location, store a plurality of time spaced-apart positions of the lens; a measurement controller configured, while the robot scans the lens from the starting location to the ending location, to: acquire a plurality of time spaced-apart alignment data items, wherein each alignment data item of the plurality of time spaced-apart alignment data items: results from an optical signal, from the target features, that passed through the lens and was received by the digital camera; and contains data indicative of a degree of focus of an image of the target features on the digital camera; and an alignment processor configured to: estimate a desired alignment position, based at least in part on the plurality of time spaced-apart alignment data items and the plurality of time spaced-apart positions of the lens; and cause the robot to move the lens to the desired alignment position.",
    "2. The system according to claim 1, wherein the drive assembly comprises a hand crank.",
    "3. The system according to claim 1, wherein the drive assembly comprises a motor.",
    "4. The system according to claim 3, wherein the measurement controller is configured to control operation of the motor.",
    "5. The system according to claim 1, further comprising a linear encoder and a corresponding reader configured to encode position of the target along the axis parallel to the optical axis.",
    "6. The system according to claim 5, wherein the measurement controller is configured to receive, from the reader, information about the position of the target along the axis parallel to the optical axis.",
    "7. The system according to claim 1, further comprising a powered relay optical element disposed intermediate the target and the digital camera.",
    "8. A system for aligning a lens to a digital camera comprising: a robot configured to grasp the lens; an active alignment controller configured to: cause the robot to scan the lens along a trajectory, relative to the digital camera; acquire a plurality of time spaced-apart alignment data items along the trajectory; based on the alignment data items, estimate a desired alignment position for the lens; and cause the robot to move the lens to the desired alignment position; a light source radiating light of a wavelength selected to facilitate curing an adhesive to bond the lens to the digital camera in the desired alignment position; and a curing light calibrator comprising: a light sensor sensitive to the selected wavelength and an indexer configured to position the light sensor, in one mode, proximate the light source and, in another mode, distant from the light source; wherein: the active alignment controller is further configured to receive data from the light sensor indicating intensity of the light source.",
    "9. The system according to claim 8, wherein: the digital camera has an optical axis; and the indexer is configured to translate the light sensor along an axis parallel to the optical axis of the digital camera.",
    "10. The system according to claim 9, wherein the indexer is configured to rotate the light sensor about an axis parallel to the optical axis of the digital camera.",
    "11. A surface finder comprising: a housing having a longitudinal axis; a sensor disposed at a fixed location, relative to the housing; and an elongated probe having a longitudinal axis, wherein: the probe is disposed and configured to translate along the longitudinal axis of the housing, so as to extend at most partially from, and to retract at least partially into, the housing; a portion of the probe is detectable by the sensor; the housing and the sensor are configured such that: the probe can retract into the housing a distance sufficient to prevent detection of the portion of the probe by the sensor; and the probe can extend from the housing a distance sufficient to enable detection of the portion of the probe by the sensor.",
    "12. The surface finder according to claim 11, wherein the sensor comprises a proximity sensor.",
    "13. A method for finding a surface, the method comprising: providing a housing having a longitudinal axis and an elongated probe disposed therewithin and configured to translate along the longitudinal axis of the housing, so as to extend at most partially from, and to retract at least partially into, the housing; disposing a sensor at a fixed location, relative to the housing, the sensor being capable of two states, the sensor being in a first state of the two states when the sensor detects presence of the probe and the sensor being in a second state of the two states when the sensor detects absence of the probe, the sensor automatically outputting an electronic signal indicative of the state of the sensor; automatically extending the probe from the housing until the electronic signal indicates the sensor is in the first state; and automatically translating the housing toward the surface, until a distal end of the probe contacts the surface and subsequently the electronic signal indicates the sensor is in the second state.",
    "14. A method for repeatably locating a tool a predetermined distance from surfaces of a plurality of workpieces, the method comprising: providing a housing having a longitudinal axis and an elongated probe disposed therewithin and configured to translate along the longitudinal axis of the housing, so as to extend at most partially from, and to retract at least partially into, the housing; disposing a sensor at a fixed location, relative to the housing, the sensor being capable of exactly two states, the sensor entering a first state of the exactly two states when the sensor detects presence of the probe and the sensor entering a second state of the exactly two states when the sensor detects absence of the probe, the sensor automatically outputting an electronic signal indicative of the state of the sensor; automatically extending the probe from the housing until the electronic signal indicates the sensor is in the first state; automatically translating, relative to a surface of a first workpiece, the tool in unison with the housing until a distal end of the probe contacts the surface of the first workpiece and subsequently the electronic signal indicates the sensor is in the second state; automatically ceasing lowering the tool, in response to the electronic signal indicating the sensor is in the second state; automatically raising the tool; automatically extending the probe from the housing again until the electronic signal indicates the sensor is in the first state; automatically translating, relative to a surface of a second workpiece, the tool in unison with the housing again until the distal end of the probe contacts the surface of the second workpiece and subsequently the electronic signal indicates the sensor is in the second state; automatically ceasing lowering the tool, in response to the electronic signal indicating the sensor is in the second state."
  ],
  "description_excerpt": "The present invention relates to automatic robotic alignment of optical components during manufacture or testing and, more particularly, to apparatus and methods for automatically calibrating an ultraviolet (UV) source used for curing adhesive, a motorized optical target used for aligning optical components and an automatic surface finder used to find a surface on which adhesive is to be dispensed.\n\nRobots are used in many precision manufacturing processes. For example, robots are used to precisely align lenses before digital camera sensors, such as in the manufacture of cell phones and backup cameras for automobiles. In other examples, robots align ends of optical fibers before lasers or light sensors in the manufacture of telecommunication and computer network equipment. Many of the lenses are quite small, on the order of several millimeters in diameter, and must, therefore, be positioned with high precision, often on the order of about ±5 μm or less, relative to the sensors or lasers.\n\nTo keep costs down, less-than-precise methods are often used to manufacture optical elements for the lenses and to mount the optical elements in lens housings. Consequently, the optical elements and lenses are often not uniform, from piece to piece. That is, dimensions and symmetries of the components often vary from lens to lens or other optical components, resulting in variations in focal length and orientation of the optical axes of the components.\n\nTo compensate for such variations, several known methods are used to custom align each lens to its corresponding image sensor.",
  "cpc": [
    "G02B 27/62",
    "B25J 9/1687",
    "G01B 11/272",
    "G01B 5/14",
    "G02B 7/36",
    "G05B 19/401",
    "G05B 2219/37618",
    "G05B 2219/45064",
    "G05B 2219/49001",
    "Y10S 901/44"
  ],
  "ipc": [
    "B25J 9/16",
    "G01B 5/14",
    "G02B 27/62",
    "G05B 19/401",
    "G06F 19/00"
  ],
  "assignees": [
    "Automation Engineering Inc"
  ],
  "inventors": [
    "Dan Tamasanis",
    "Jonathan P. Berg",
    "John Alden"
  ],
  "filing_date": "2015-02-03",
  "publication_date": "2017-09-19",
  "grant_date": "2017-09-19",
  "priority_date": "2014-02-03",
  "application_number": "US-201514613171-A",
  "family_id": "59828497",
  "cited_by_count": 9,
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}