應用於高靈敏低照明之新型低電壓對數-線性-對數影像感測器

A Novel Low-voltage CMOS Image Sensor with Log-lin-log Response and High Sensitivity to Low Illumination

李佳澤(Chia-Tse Lee)

指導教授 ： 吳紹懋

元智大學/電機通訊學院/電機工程學系/碩士(2012年)

摘要

此論文提出一種新型低電壓對數線性對數形輸出CMOS影像感測器。這種感測器再低亮度時擁有對數的輸出響應，在中間擁有線性的輸出響應，最後在高照度時又會回到對數型態的輸出響應。與傳統的感測器相比較，此設計的感測器可以改良動態範圍與輸出擺幅電壓的限制。這種架構對低亮度時的靈敏度會特別的高，同時擁有0.7伏特的輸出擺幅與120dB的動態範圍。此外相關兩次取樣電路一可應用在此電路中以減少固定影像雜訊與製程變異。並製作讀出電路的模組，將讀出電路設計在最佳化。在理論的推導及模擬中，可證明此新型感測器有對數線性對數響應、高照明範圍、高輸出擺幅、減少內在像素固定雜訊及低製程變異。設計一操作在1.8伏特感測電路與讀出電路之影像感測器於台灣積體電路公司1層多晶矽6金屬互補式金屬氧化物半導體0.18微米標準製程中實現。

關鍵字

對數-線性-對數影像感測器

並列摘要

In this thesis, a novel low-voltage CMOS image sensor with log-lin-log response is presented. The new pixel cell has logarithmic response in very low illumination intensity, linear response in low and medium illumination intensity and logarithmic response in high illumination. In contrast to the conventional pixels, the dynamic range limit and output swing can be improved. In this scheme, the sensor is highly sensitive to very low light, while still owning the properties of high voltage swing of 0.7V (from 1.8V supply) and high dynamic range of 120dB. Furthermore, this pixel has CDS technique can be applied to the sensor array to reduce the fixed pattern noise and process variation. We make readout circuit modules, and design readout circuit in optimization. By theoretical analysis and simulation, we demonstrate that this new CMOS image sensor pixel owns log-lin-log characteristics with high illumination range, high output swing, pixel fixed pattern noise reduction and low process variation. For the purpose of demonstration, a prototyped image sensor with readout circuit and CDS is designed and realized from 1.8V supply in the TSMC 0.18μm CMOS 1P6M standard process.

並列關鍵字

Log-lin-log Response Image Sensor

參考文獻

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