Electronic Imaging: Digital Pixel Sensors and Systems

微系统利用微级技术来提供系统级性能。数码相机是这一概念的一个很好的例子，因为图像传感器每个像素中的微小电路及其支持系统负责摄影功能。数码相机也为这项研究计划提供了动力。由于图像传感器为消费者、国防、工业和医疗应用增加了数十亿美元的价值，因此像素设计的研究进展可能会带来数百万美元的影响。 CCD和CMOS图像传感器取得了巨大的成功。波义耳和史密斯因发明CCD技术而共同获得诺贝尔奖，美国宇航局发明了CMOS有源像素传感器（APS）技术，现在每一部移动的手机都采用了这种技术。然而，这种图像传感器的暗限比人类视网膜的色觉差几个数量级，这就是为什么当人眼在没有闪光灯的情况下看得很清楚时，数码相机可能需要闪光灯。如果不是不可能的话，在不牺牲动态范围、图像质量和/或帧速率的情况下，用CCD或CMOS APS技术实现低暗限是非常困难的。因此，这项研究计划的长期目标是用新技术打破这些障碍。 传统的CCD和CMOS图像传感器使用模拟像素。由于数字技术对模拟技术固有的噪声和失真具有强大的鲁棒性，因此数字像素是游戏规则的改变者。模拟像素的主要优点是它们更小，但更广泛的趋势表明这个问题将变得不那么重要。垂直集成CMOS技术是通过NSERC合作伙伴基金开发的，能够实现两个或更多个半导体层的3D堆叠，从而在同一区域实现更复杂的集成电路。 通过资助这项发现补助金，NSERC支持创造力和创新，这是电子成像研究计划的核心。在短期内，新型数字像素传感器（DPS）技术的空间和位分辨率、功耗和色彩匹配将得到改善，同时培训高素质的人员来设计、构建和测试非常复杂的微系统，即，数码相机

Microsystems exploit micro-level technology to deliver system-level performance. Digital cameras are a good example of this concept, as tiny circuits in each pixel of an image sensor, and their support systems, are responsible for photographic capabilities. Digital cameras also provide a motivation for this research program. Because image sensors add billions of dollars in value to consumer, defence, industrial, and medical applications, research progress in pixel design could lead to a multi-million dollar impact. CCD and CMOS image sensors have enjoyed tremendous successes. Boyle and Smith shared a Nobel Prize for inventing the CCD technology and NASA invented the CMOS active pixel sensor (APS) technology that is now in every mobile phone. However, the dark limit with such image sensors is orders of magnitude worse than with the colour vision of the human retina, which is why digital cameras may need a flash when human eyes see clearly without one. If not impossible, it is very difficult to realize low dark limit with CCD or CMOS APS technology without sacrificing dynamic range, image quality, and/or frame rate. Consequently, a long-term objective of this research program is to break these barriers with new technology. Conventional CCD and CMOS image sensors use analog pixels. Because digital technology is robust to the noise and distortion that is inherent to analog technology, digital pixels are game changers. The main advantage of analog pixels is they are smaller but wider trends suggest this issue will become less significant. Vertically integrated CMOS technology, which is explored through an NSERC Partnership Grant, enables 3D stacking of two or more semiconductor tiers to achieve a more complex integrated circuit in the same area. By funding this Discovery Grant, NSERC supports the creativity and innovation that is at the heart of this research program on electronic imaging. In the short term, the spatial and bit resolution, power consumption, and colour matching of novel digital pixel sensor (DPS) technology will be improved, while training highly qualified personnel to design, build, and test microsystems of significant complexity, i.e., digital cameras.