Proximity mask alignment using a stored video image

A method for generating a focussed image, with one microscope, of two surfaces that are disposed at different distances from a microscope objective, comprising the steps of:

• focussing the microscope on a first one of the surfaces and maintaining a first electrical record of the first focus position;
• focussing the microscope on a second one of the surfaces and maintaining a second electrical record of the second focus position;
• maintaining the microscope focussed on a selected one of the first or the second surfaces, as specified by either the first electrical record or the second electrical record;
• and, responsive to a command from a user of the microscope,
• focussing the microscope on the other one of the first or the second surfaces, as specified by the other electrical record;
• storing an image obtained by the microscope of the other one of the first or the second surfaces;
• refocussing the microscope on the selected one of the first or the second surfaces, as specified by either the first electrical record or the second electrical record;
• and
• displaying to the user of the microscope a current image obtained by the microscope of the selected one of the first or the second surfaces while simultaneously displaying, on the same display means, the stored image superimposed upon the current image.

A proximity mask alignment system, comprising:

• a splitfield microscope having a first microscope objective and a second microscope objective;
• means for use by an operator of the system for specifying a location of a first focal position and a location of a second focal position for said first microscope objective and for said second microscope objective, said specifying means outputting to said splitfield microscope, at any given time, either a specification of the location of the first focal position or a specification of the location of the second focal position;
• means, coupled to said splitfield microscope, for generating and for storing image data representing an image viewed by said splitfield microscope;
• display means, having an input coupled to an output of said generating and storing means, for displaying to the operator an image corresponding to the image viewed by said splitfield microscope;
• and control means, coupled to said specifying means and to said generating and storing means, and responsive to an input from the operator of the system, for causing said specifying means to change, for a predetermined interval of time, from specifying the location of one of said first or said second focal positions to specifying the location of the other one of said focal positions, for causing said generating and storing means to store, during the predetermined interval of time, image data generated at the location of the other one of the focal positions, and for causing said generating and storing means to superimpose, after an expiration of the predetermined interval of time, the stored image data upon image data being generated at the originally specified one of the first or the second focal positions.

An microscopy system, comprising:

• a microscope having at least one microscope objective;
• means for specifying a first focal position and a second focal position for said at least one microscope objective, said specifying means selectively outputting to said microscope either a specification of the first focal position or a specification of the second focal position, said microscope being responsive to the specification for moving said at least one objective to the specified focal position;
• means, coupled to said microscope, for generating and for storing image data representing an image viewed by said microscope through said at least one microscope objective;
• and
• control means, coupled to said specifying means and to said generating and storing means and responsive to a triggering input signal, for causing said specifying means to change, for an interval of time, from a first specification that specifies one of said first or said second focal positions to a second specification that specifies the other one of said focal positions, for causing said generating and storing means to store, during the interval of time, image data that is generated at the focal position specified by the second specification, for causing, at the expiration of the interval of time, said specifying means to change back to specifying the first specification, and for causing said generating and storing means to combine, after the expiration of the interval of time, the stored image data with image data that is generated at the focal position specified by the first specification;
• and
• display means, having an input coupled to an output of said generating and storing means, for displaying an image corresponding to the image data, where said display means is responsive to the combined image data to display an image wherein the stored image data is superimposed with the image data that is generated at the focal position specified by the first specification.