Mechanical scanning method and apparatus for ultrasonic imaging, or the like

A scanning mechanism for mechanically scanning ultrasonic transducer means, or the like, comprising

• a parallelogram linkage comprising a pair of parallel arms interconnected by a pair of parallel connecting links,
• means for attaching transducer means, or the like, to one of the connecting links,
• means for driving the parallelogram linkage opposite said one connecting link along a portion of an ellipse adjacent a focus thereof, and
• means for constraining the parallelogram linkage intermediate the one connecting link and focus to substantially straight-line movement along a portion of the major axis of the ellipse,
• said one connecting link being driven with translational movement along a straight-line path extending along the minor axis of the ellipse.

A mechanism for converting arcuate motion to straight line motion comprising,

• a parallelogram mechanism which comprises first and a second parallel arms and first and second parallel connecting links pivotally connected to said arms,
• means for supporting said parallel arms adjacent one end thereof for arcuate motion along portions of generally elliptical paths adjacent focii of ellipses,
• means for constraining the parallel arms intermediate the opposite ends thereof to movement along substantially straight line paths along the major axes of the elipses whereby the arms opposite said one end thereof are movable along substantially straight line paths along the minor axes of the ellipses,
• weight means for establishing the center of mass of said parallelogram mechanism adjacent the constraining means where the mechanism is limited to substantially straight line motion,
• a balance bar pivotally supported at a pivot axis extending adjacent the center of mass of said parallelogram, and
• means for simultaneously driving said parallelogram mechanism and balance bar at the same rate but opposite rotary direction to substantially balance reaction torques produced by the resultant movements thereof.

A mechanism for converting arcuate motion to straight line motion comprising,

• a parallelogram mechanism which comprises first and second parallel arms and first and second parallel connecting links pivotally connected to said arms,
• means for supporting said parallel arms adjacent one end thereof for arcuate motion along portions of generally elliptical paths adjacent focii of ellipses,
• means for constraining the parallel arms intermediate the opposite ends thereof to movement along substantially straight line paths along the major axes of the ellipses whereby the arms opposite said one end thereof are movable along substantially straight line paths along the minor axes of the ellipses,
• said supporting means comprising a pivotally mounted supporting link pivotally attached to said first connecting link intermediate the opposite ends thereof,
• said constraining means comprising a third connecting link pivotally connected to said arms parallel with and intermediate of said first and second connecting links,
• a pivotally mounted shaft attached to said third connecting link intermediate the opposite ends thereof, and
• said constraining means being attached to said shaft for pivotal support thereof while constraining shaft movement in a radial direction along a substantially straight line path.

A scanning mechanism for mechanically scanning ultrasonic transducer means, or the like, comprising,

• a parallelogram linkage comprising a pair of parallel arms interconnected by first and second connecting links adjacent opposite arm ends and a third connecting link intermediate thereof,
• a supporting link pivotally attached to the first connecting link intermediate the opposite ends thereof for supporting one end of the parallelogram linkage for arcuate motion along a portion of a generally elliptical path adjacent a focus of the ellipse,
• a shaft attached to said third connecting link intermediate opposite ends and extending from opposite faces thereof,
• means for pivotally mounting said shaft including means for constraining radial shaft movement to a substantially straightline path extending along the major axis of the ellipse, and
• transducer means attached to said second connecting link at the minor axis of the ellipse.