本篇論文目的是設計且實現一個具自動對焦功能的手持式數位顯微鏡系統用來觀察以及紀錄微小的影像。本系統是由LED、CMOS影像感測器、標準規格的鏡頭、數位相機晶片、高性能單晶片微處理器以及直流馬達所構成，並以高斯定理為基礎提出一個新的方法，使新穎的數位顯微鏡與傳統顯微鏡相比，大幅縮小體積，系統的體積可縮小為40 mm × 35 mm × 105 mm，達到能手持的便利性，並且使用單一焦距的凸透鏡，即可有多段的放大倍率，放大倍率可從32×到128×。為了增加使用上的穩定性與便利性，使用離散餘弦轉換理論以及MATLAB軟體，實現自動對焦的功能，使系統單次自動對焦的時間只需花費4秒。
而本文另一部分則根據上述的架構與理論，透過改變影像感測器位置，進而提升放大倍率且實現一個高放大倍率的可攜式數位顯微鏡，期望可取代傳統顯微鏡。此系統具有以下優點：(1)根據不同的觀測物，可以更換不同放大倍率的物鏡；(2)當使用10倍放大倍率的物鏡時，系統最大的放大倍率可以接近1000倍；(3)影像經過數位化後，可以達到Full HD的影像品質並且透過High-Definition Multimedia Interface (HDMI)介面傳輸到螢幕上，因此本篇論文所研製的數位顯微鏡系統,除了具有上述的優點外，在未來也有很大的發展空間，例如結合X-Y軸平台和透射光源，希望可以取代傳統顯微鏡並且應用於醫學、科學與工業領域上。

The purpose of this paper is to realize a hand-held, auto-focus digital microscope system in order to observe and record microscopic images. Based on the Gauss Optical Theorem, designed is a novel algorithm and implemented into the proposed digital microscope system that includes a Light-Emitting Diode (LED), Complementary metal–oxide–semiconductor (CMOS) image sensor, standard lens, digital camera chip, high-performance single-chip microprocessor and DC (Direct Current) motor. Comparing with conventional optical microscopes, the proposed digital microscope significantly reduces the volume to 40 mm × 35 mm × 105 mm, and achieves the hand-held convenience. Using a single focal-length lens, the system has multiple segments magnification. In order to increase the stability and convenience of the usage, the Discrete Cosine Transform (DCT) method and MATLAB (MathWorks, USA) is applied to realize automatic focus function.
Furthermore, the enhancement of the magnification can achieve a high magnification portable digital microscope by moving the location of CMOS image sensor along the principle axis. It has the following advantages: (1) According to different observation, the varieties of magnification objective lenses on a microscope can be replaceable; (2) Applying advanced electronic technology, the system maximum magnification is close to 1000× by use 10× magnification power of objective lens; (3) After digitization of images, Full HD image quality can be achieved and transmitted through to High-Definition Multimedia Interface (HDMI) interface to the screen. Therefore, in addition to the advantages described above, the proposed novel system has much room for development such as combining the X-Y axis platform and transmitted light, it is hoped that this novel device can replace the tradition optical microscope for the applications in biomedical, scientific and industrial fields in the future.

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