Ultrapointe Corporation

Other

Timothy V Thompson

Ken K Lee

Christopher R Fairley

Christopher R Fairlay

A microscope system moves a target in a first direction relative to a low power objective lens and, during the relative motion, generates and records values of an electronic focus signal that depends on the magnitude of light reflected by the target. Then, a host workstation calculates a first estimate of position ('focus position') of the target at which the microscope system is focused, by a median point method. In the median point method, the host workstation calculates the sum of the recorded values and determines the position along the range of motion at which half of this sum was exceeded, to be a first estimate of the focus position. From the intensity values of the first pass, optimal sensor gain is set for subsequent passes. Second and third estimates of the focus position can be calculated in a similar manner if necessary and the target is moved to the most recent estimate of the focus position. In one embodiment, the microscope system uses an area scan in which the largest value of an electronic focus signal at a set of points within an area of the target is recorded at a given elevation of the target. The largest of the recorded values is then used to estimate the focus position of the brightest layer of the target. In one embodiment, the microscope system focuses on a predetermined layer using an offset from the brightest layer.

Method and apparatus for automatically focusing a microscope

Method and apparatus for automatic focusing of a confocal laser

A method for quickly performing an auto-focus operation on a confocal microscope. As a coarse Z-stage moves a target toward an objective lens, a photodetector generates an analog electronic focus signal which exceeds a threshold level during a focused condition. When a focused condition exists, a latching comparator, which is coupled to the electronic focus signal and to a signal representative of the threshold level, trips and the target is stopped. The analog nature of the electronic focus signal assures that the focused condition will be detected. As a result, the target may be moved quickly without missing a focused condition. The target is moved several times at progressively slower velocities to position the target close to the focus position. In another embodiment of the present invention, an auto focus operation is performed by positioning the target such that a focus position is within the range of motion of the target, moving the target a plurality of first steps through its range of motion, and measuring the strength of a focus signal at each first step. The target is sequentially moved a multiplicity of second steps through a second range of motion on either side of the first step at which the maximum strength was measured. The strength of the focus signal is measured at each of these second steps. The target is moved to the second step at which the maximum strength was measured.

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San Jose, CA, United States of America

Timothy V Thompson