MICROSCOPIC IMAGE DETECTING INSTRUMENT AND AUTOMATIC FOCUSING METHOD THEREFOR

摘要

A microscopic image detecting instrument includes a microscope, a photographing device, a driver, a mark having a predetermined distance from an object, and a controller coupled to the photographing device and the driver. The microscope includes an object stage for holding the object and an objective lens for focusing on and magnifying the object. The photographing device is set above the objective lens to photograph an image presented by the objective lens. The controller controls the driver to move at least one of the object stage and the objective lens to an actual focusing position, according to an actual focal length to the object. The actual focal length to the object is calculated by the controller according to a comparison between an optical definition of a mark image taken as a preliminary target of focus against a predetermined definition calibration curve and the distance between the mark and the object.

主权项

1. A microscopic image detecting instrument comprising:
a microscope comprising an object stage configured to hold an object to be measured and an objective lens configured to focus on and magnify the object to be measured; a photographing device set above the objective lens and configured to photograph an image presented by the objective lens and output image data; a driver configured to drive at least one of the object stage and the objective lens move to a predetermined position; a mark set in a detecting area of the objective lens at a predetermined distance from the object to be measured; and a controller coupled to the photographing device and the driver and configured to process data and generate control instructions; wherein the controller receives a detect instruction, acquires initial focusing position data, and controls at least one of the object stage and the objective lens to move to an initial focusing position according to the initial focusing position data; the photographing device photographs the mark in the detecting area and outputs a data of the mark image to the controller, the controller calculates an optical definition of the mark image and compares the optical definition of the mark image with a predetermined definition calibration curve to acquire a focal compensation value, the controller calculates an actual focal length to the object to be measured according to the sum of the focal compensation value and the predetermined distance between the mark and the object to be measured, the optical definition is defined as an indicator representing edge sharpness of the mark image photographed by the photographing device having an invariable resolution, and the definition calibration curve is a curve which represents optical definitions of the images of the mark which can vary according to the photographed positions.