Method and apparatus for automatic image focusing

Claim 1

An apparatus for automatically focusing an image of an object onto an image plane located perpendicular to an optical axis defined by said object and said image plane which comprises: (a) a means for focusing said image of said object onto an image plane, said focusing means fixed on the optical axis; (b) movable means for detecting said image; (c) a means for determining the position of said object along said optical axis and feeding this information to a controller means for determining the location of said image plane: (d) means connected to said movable detecting means for controlling the movement of said movable detecting means substantially along said optical axis; (e) said controller means for determines the amount of movement control that will be applied to said movable detecting means by said movement controlling means in an open loop fashion.

Claim 2

An apparatus for automatically focusing an image of an object onto an image plane located perpendicular to an optical axis defined by said object and said image plane which comprises: (a) a means for focusing said image of said object onto an image plane, said focusing means fixed on the optical axis; (b) movable means for detecting said image; (c) a means for determining the position of said object along said optical axis and feeding this information to a controller means for determining the location of said image plane: (d) means connected to said movable detecting means for controlling the movement of said movable detecting means substantially along said optical axis; (e) said controller means for determines the amount of movement control that will be applied to said movable detecting means by said movement controlling means in an open loop fashion.

Claim 28

An apparatus for automatically focusing an image of an object onto an image plane located perpendicular to an optical axis defined by said object and said image plane which comprises: (a) lens assembly fixed on said optical axis; (b) an imager movably located on said optical axis; (c) an image quality detector, said detector determines the position of said image plane along said optical axis from the evaluation of the quality of the image and sends this information to a electronic controlling circuit; (d) an actuator for controllably moving said imager linearly along said optical axis; and (e) said electronically controlling circuit connected to operate said actuator to move said imager to said image plane in an open loop fashion.

Claim 29

An apparatus for automatically focusing an image of an object onto an image plane located perpendicular to an optical axis defined by said object and said image plane which comprises: (a) lens assembly fixed on said optical axis; (b) an imager movably located on said optical axis; (c) an image quality detector, said detector determines the position of said image plane along said optical axis from the evaluation of the quality of the image and sends this information to a electronic controlling circuit; (d) an actuator for controllably moving said imager linearly along said optical axis; and (e) said electronically controlling circuit connected to operate said actuator to move said imager to said image plane in an open loop fashion.

Claim 32

An apparatus for automatically focusing an image of an object onto an image plane located perpendicular to an optical axis defined by said object and said image plane which comprises: (a) lens assembly fixed on said optical axis; (b) an imager movably located on said optical axis; (c) an image quality detector, said detector determines the position of said image plane along said optical axis from the evaluation of the quality of the image and sends this information to an electronic controlling circuit; (d) an actuator for controllably moving said imager along an arc tangential to said optical axis; and (e) said electronically controlling circuit connected to operate said actuator to move said imager to said image plane in an open loop fashion.

Claim 33

An apparatus for automatically focusing an image of an object onto an image plane located perpendicular to an optical axis defined by said object and said image plane which comprises: (a) lens assembly fixed on said optical axis; (b) an imager movably located on said optical axis; (c) an image quality detector, said detector determines the position of said image plane along said optical axis from the evaluation of the quality of the image and sends this information to an electronic controlling circuit; (d) an actuator for controllably moving said imager along an arc tangential to said optical axis; and (e) said electronically controlling circuit connected to operate said actuator to move said imager to said image plane in an open loop fashion.

Claim 36

A method for automatically focusing an image of an object onto an image plane located perpendicular to an optical axis defined by said object and said image plane which comprises: (a) focusing said image of said object onto an image plane with a focusing means fixed on the optical axis; (b) detecting said image with an imager; (c) evaluating the degree of focus of the image as detected by the imager; (d) calculating the position of the image plane using empirical algorithms previously determined from measurements with the focusing means in an open loop fashion; (e) determining the position of said image plane and controllably moving said imager to this image plane along said optical axis where an image of said object is in focus.

Claim 37

A method for automatically focusing an image of an object onto an image plane located perpendicular to an optical axis defined by said object and said image plane which comprises: (a) focusing said image of said object onto an image plane with a focusing means fixed on the optical axis; (b) detecting said image with an imager; (c) evaluating the degree of focus of the image as detected by the imager; (d) calculating the position of the image plane using empirical algorithms previously determined from measurements with the focusing means in an open loop fashion; (e) determining the position of said image plane and controllably moving said imager to this image plane along said optical axis where an image of said object is in focus.

Claim 39

An apparatus for forming a focused optical image of an object on an imager, the image being focused in an image plane that intersects an optical axis, which comprises: (a) a first member with a focusing device held in a fixed position relative to the optical axis: (b) a second member, supported for pivotal movement relative to the first member and adapted to hold the imager and movable relative to the first member; and (c) an actuator attached to the second member to move the second member relative to the first member in response to a drive signal to position the imager at the image plane.

Claim 40

An apparatus for forming a focused optical image of an object on an imager, the image being focused in an image plane that intersects an optical axis, which comprises: (a) a first member with a focusing device held in a fixed position relative to the optical axis: (b) a second member, supported for pivotal movement relative to the first member and adapted to hold the imager and movable relative to the first member; and (c) an actuator attached to the second member to move the second member relative to the first member in response to a drive signal to position the imager at the image plane.

Claim 50

An apparatus for forming focused optical images of objects at varying distances from the apparatus as they pass by the apparatus along a predetermined path of travel, the apparatus comprising: (a) a first member held in a fixed position relative to the predetermined path; (b) an optical element supported by the first member in a fixed position relative to the predetermined path and producing a focused image of one of the objects in an image plane located along an optical axis intersecting the predetermined path; (c) an imager; (d) a device that determines the position of the object along the optical axis in an open loop manner and produces a drive signal based upon the location of the image plane relative to the position of the object along the optical axis; (e) a second member holding the imager and movable relative to the first member to selectively move the imager along the optical axis; and (f) an actuator attached between the first member and the second member to move the second member relative to the first member in response to said drive signal to position the imager at the image plane.

Claim 51

An apparatus for forming focused optical images of objects at varying distances from the apparatus as they pass by the apparatus along a predetermined path of travel, the apparatus comprising: (a) a first member held in a fixed position relative to the predetermined path; (b) an optical element supported by the first member in a fixed position relative to the predetermined path and producing a focused image of one of the objects in an image plane located along an optical axis intersecting the predetermined path; (c) an imager; (d) a device that determines the position of the object along the optical axis in an open loop manner and produces a drive signal based upon the location of the image plane relative to the position of the object along the optical axis; (e) a second member holding the imager and movable relative to the first member to selectively move the imager along the optical axis; and (f) an actuator attached between the first member and the second member to move the second member relative to the first member in response to said drive signal to position the imager at the image plane.

Claim 61

An apparatus for forming focused optical images of objects at varying distances from the apparatus as they pass by the apparatus along a predetermined path of travel, the apparatus comprising: (a) a first member held in a fixed position relative to the predetermined path; (b) an optical element supported by the first member in a fixed position relative to the predetermined path and producing a focused image of one of the objects in an image plane located along an optical axis intersecting the predetermined path; (c) an imager; (d) a second member holding the imager and movable relative to the first member to selectively move the imager along the optical axis; said second member being supported for pivotal movement relative to the first member; and, (e) an actuator attached between the first member and the second member to move the second member relative to the first member in response to a drive signal to position the imager at the image plane.

Claim 62

An apparatus for forming focused optical images of objects at varying distances from the apparatus as they pass by the apparatus along a predetermined path of travel, the apparatus comprising: (a) a first member held in a fixed position relative to the predetermined path; (b) an optical element supported by the first member in a fixed position relative to the predetermined path and producing a focused image of one of the objects in an image plane located along an optical axis intersecting the predetermined path; (c) an imager; (d) a second member holding the imager and movable relative to the first member to selectively move the imager along the optical axis; said second member being supported for pivotal movement relative to the first member; and, (e) an actuator attached between the first member and the second member to move the second member relative to the first member in response to a drive signal to position the imager at the image plane.

Claim 63

An apparatus for forming focused optical images of symbologies appearing on the surfaces of articles located at varying distances from the apparatus, the apparatus comprising: (a) a conveyor carrying the articles along a predetermined path; (b) a stationary first member held in a fixed position relative to the predetermined path; (c) an optical element supported by the first member in a fixed position and producing an image of the symbologies on the surface of one of the articles in an image plane along an optical axis intersecting the predetermined path as the conveyor carries the articles past the optical element; (d) an imager; (e) a device that measures the relative position of at least one of said symbologies located on the surface of said one of said articles with respect to the position of said fixed optical element along said optical axis; and, produces a drive signal based upon said relative position of said imager with respect to the position of said surface of said one of said articles along the optical axis; (f) a second member supporting the imager for travel therewith, the second member being movable relative to the first member to selectively move the imager along the optical axis; and (g) an actuator attached to move the second member relative to the first member in response to said drive signal indicative of the distance along the optical axis between the position of the imager and the position of the image plane to adjustably position the imager at the image plane.

Claim 64

An apparatus for forming focused optical images of symbologies appearing on the surfaces of articles located at varying distances from the apparatus, the apparatus comprising: (a) a conveyor carrying the articles along a predetermined path; (b) a stationary first member held in a fixed position relative to the predetermined path; (c) an optical element supported by the first member in a fixed position and producing an image of the symbologies on the surface of one of the articles in an image plane along an optical axis intersecting the predetermined path as the conveyor carries the articles past the optical element; (d) an imager; (e) a device that measures the relative position of at least one of said symbologies located on the surface of said one of said articles with respect to the position of said fixed optical element along said optical axis; and, produces a drive signal based upon said relative position of said imager with respect to the position of said surface of said one of said articles along the optical axis; (f) a second member supporting the imager for travel therewith, the second member being movable relative to the first member to selectively move the imager along the optical axis; and (g) an actuator attached to move the second member relative to the first member in response to said drive signal indicative of the distance along the optical axis between the position of the imager and the position of the image plane to adjustably position the imager at the image plane.

Claim 65

A method for forming a focused optical image of an object on an imager, the image being focused in an image plane that intersects an optical axis, comprising the steps of: (a) placing a first member supporting a stationary optical element at a fixed position relative to the optical axis; (b) providing a movable second member holding the imager; (c) measuring the distance between said object and said stationary optical element along said optical axis; and, generating a drive signal proportional to said measured distance to adjust the relative position of the imager and the image plane along the optical axis in an open loop fashion; and (d) selectively moving the second member relative to the first member in response to the drive signal to position the imager at the image plane.

Claim 66

A method for forming a focused optical image of an object on an imager, the image being focused in an image plane that intersects an optical axis, comprising the steps of: (a) placing a first member supporting a stationary optical element at a fixed position relative to the optical axis; (b) providing a movable second member holding the imager; (c) measuring the distance between said object and said stationary optical element along said optical axis; and, generating a drive signal proportional to said measured distance to adjust the relative position of the imager and the image plane along the optical axis in an open loop fashion; and (d) selectively moving the second member relative to the first member in response to the drive signal to position the imager at the image plane.

Claim 68

An apparatus for forming focused optical images of objects at varying distances from the apparatus as they pass by the apparatus along a predetermined path of travel, the apparatus comprising: (a) a first member held in a fixed position relative to the predetermined path; (b) an optical element supported by the first member in a fixed position relative to the predetermined path and producing a focused image of one of the objects in an image plane located along an optical axis intersecting the predetermined path; (c) an imager; (d) a second member holding the imager and movable relative to the first member to selectively move the imager along the optical axis; said second member including: (d)(1) a planar bed holding said imager with an imager receiving surface oriented at a predetermined angle to the plane of the bed; (d)(2) at least one first pivot arm pivotally connected to a first edge of said planar bed; (d)(3) at least one second pivot arm pivotally connected to a second opposite edge of said planar bed, said first and second pivot arms having substantially equal lengths; (d)(4) said first pivot arm connected at its end opposite the end connected to the bed to a first pivot point in a plane parallel to the bed and spaced a predetermined distance from said bed; and (d)(5) said second pivot arm connected at its end opposite the end connected to the bed to a second pivot point in said plane parallel to the bed, said distance between said first and second pivot points substantially equal to the distance between the connections of said first and second pivot arms to said bed, whereby the edge of the bed, the line between first and second pivot points, and the first and second pivot arms approximately form a parallelogram and (e) an actuator attached between the first member and the second member to move the second member relative to the first member in response to a drive signal to position the imager at the image plane.

Claim 69

An apparatus for forming focused optical images of objects at varying distances from the apparatus as they pass by the apparatus along a predetermined path of travel, the apparatus comprising: (a) a first member held in a fixed position relative to the predetermined path; (b) an optical element supported by the first member in a fixed position relative to the predetermined path and producing a focused image of one of the objects in an image plane located along an optical axis intersecting the predetermined path; (c) an imager; (d) a second member holding the imager and movable relative to the first member to selectively move the imager along the optical axis; said second member including: (d)(1) a planar bed holding said imager with an imager receiving surface oriented at a predetermined angle to the plane of the bed; (d)(2) at least one first pivot arm pivotally connected to a first edge of said planar bed; (d)(3) at least one second pivot arm pivotally connected to a second opposite edge of said planar bed, said first and second pivot arms having substantially equal lengths; (d)(4) said first pivot arm connected at its end opposite the end connected to the bed to a first pivot point in a plane parallel to the bed and spaced a predetermined distance from said bed; and (d)(5) said second pivot arm connected at its end opposite the end connected to the bed to a second pivot point in said plane parallel to the bed, said distance between said first and second pivot points substantially equal to the distance between the connections of said first and second pivot arms to said bed, whereby the edge of the bed, the line between first and second pivot points, and the first and second pivot arms approximately form a parallelogram and (e) an actuator attached between the first member and the second member to move the second member relative to the first member in response to a drive signal to position the imager at the image plane.