Patent ID: 9134522
Filing Date: 2015-09-15
Classification: G02B

Abstract:
1. An autofocus apparatus, comprising: a light source; an optical coupler having a first port, second port and a third port; wherein a light signal in the optical coupler travels substantially only from the first port to the second port and from the second port to the third port; wherein the optic coupler couples to the light source at the first port; an optical collimator for directing a light output from the second port of the optical coupler onto a sample through a Dichroic mirror and a microscope objective, wherein the sample is placed on a substrate supported by an adjustable microscopy stage; a scanning means for focusing the light at a plurality of focal points along an axis; a photodiode detector for converting a light signal that comprises reflections off of the substrate at the plurality of focal points along the axis, into an intensity signal, wherein the light signal is captured by the microscope objective and sent to the photodiode detector through the Dichroic mirror, the optical collimator, and into the second port and out of the third port of the optic coupler; a memory device for storing a signal template; and a microprocessor for detecting a peak in the intensity signal by cross-correlating the intensity signal with the signal template; wherein the microprocessor generates a command for moving the position of the adjustable microscopy stage along the axis based on a difference between the location of the detected peak in the intensity signal and the location of a peak in a reference signal.