| Digital pathological scanner is the necessary hardware equipment,used for the microscopic research on pathological diagnosis,drug development,biological sciences,bioengineering and ecological environment supervising.At present,since commercial equipments are usually rely on the image-based passive focus principle and the servo motors as the power source,during the scanning process,the X-Y working stage and Z-axis autofocusing stage needs corresponding starts and stops to switch the field of view or change the defocusing value.And as a consequence,the consuming time and focusing accuracy can’t satisfy the scanning requirements from the modern medicine and biology.This research concentrates on a new solution which mainly combines the bevel image plane based pre-focusing and continuous linear scanning imaging technology with the macro-micro dual-drive technology.This paper dilates the system construction and the operating principle of the bevel plane based pre-focusing and scanning system in detail,and then designs the imaging light path with high resolution and wild image field and the autofocusing light path with high-resolution in wild range,then optimizes the lens parameters using Zemax.To realize the pre-autofocusing function,a image definition evaluating function combining the characters of the human vision and the wavelet decomposition method,which is demonstrated much better than traditional ones;on the other hands,it also proposes a consistency vector based multi-windows selection method,which can avoid locating the window locating in the pollution of the section.Then this research also models and identifies the macro-moving system composed of a servo motor,gear reducer and screw-nut pairs,and the BP-PID controller is used to solve the micro-moving system’s control problem,followed by a PI compensation to the macro-moving system.At the end,this paper describes the hardware design and the upper-computer software developing process. |
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