Physics, Optics, and Electronics of Image Sensors

A 5-hour course at HPA Tech Retreat 2015

Monday, Feb. 9, approx. 13:30 – 18:30

The image sensor is the heart of a modern HD or digital cinema camera. In a modern camera, the sensor is a silicon CMOS integrated circuit: an active pixel sensor (APS). In this 5-hour course, we examine the sensor in detail. We start by describing the physics of silicon semiconductors; we explain exactly what the C, M, O, and S mean. We explain the conversion of photons to electrons, the collection of electrons, their conversion into analog voltage, conversion of the associated signal to digits through an analog to digital converter (ADC), and the conveyance of the digital signal across the chip and finally off-chip. We discuss pixel structures (3T/4T) and the functional capabilities that are associated with these structures (rolling shutter/global shutter). We examine issues of sensitivity, noise, nonuniformities (DSNU/PRNU), dynamic range, and bit depth. To make a useful camera, the image sensor must be coupled to a lens system and to a digital processing path. Familiarity with the image sensor itself enables a better understanding of lens issues and a better understanding of image signal processing algorithms (such as demosaicking and colour processing). Throughout the seminar, we will make the links between sensor technology and HD/d-cinema application requirements. We conclude by reviewing emergent technologies such as back-side illumination, active focusing, optical image stabilization, and high dynamic range (HDR).

Registration, USD 225 until 2015‑02‑02, modestly higher thereafter (not included in HPA conference registration)

Copyright © Charles Poynton 2015-01-30 18:10 EST
Charles Poynton