Lecture

CCD Cameras: Electronics and Charge Conversion

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Description

This lecture covers the electronics involved in CCD cameras, focusing on the output amplifiers and charge conversion processes. The instructor begins by explaining the structure of a CCD camera, highlighting the sensitive area with a matrix of CCD cells and the readout register. The discussion includes the role of output amplifiers located at the corners of the register and how they function in converting photo charges into a readout voltage. The lecture details the use of a source follower for charge conversion, emphasizing the importance of resetting the system before measurement. The instructor elaborates on the electronic capacities involved, including the output diffusion capacity and the gate capacity of the first MOSFET. The process of transferring charges and measuring voltage is explained, along with the integration of reset transistors on the chip. The charge conversion factor is introduced, illustrating the relationship between charge and capacity, and the significance of minimizing capacity to enhance measurement accuracy.

Official source

Ontological neighbourhood

Information engineering

Signal processing: Digital image processing

Related concepts (32)

Charge-coupled device

A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a major technology used in digital imaging. In a CCD , pixels are represented by p-doped metal–oxide–semiconductor (MOS) capacitors.

Active-pixel sensor

An active-pixel sensor (APS) is an , which was invented by Peter J.W. Noble in 1968, where each pixel sensor unit cell has a photodetector (typically a pinned photodiode) and one or more active transistors. In a metal–oxide–semiconductor (MOS) active-pixel sensor, MOS field-effect transistors (MOSFETs) are used as amplifiers. There are different types of APS, including the early NMOS APS and the now much more common complementary MOS (CMOS) APS, also known as the CMOS sensor.

Image sensor

An image sensor or imager is a sensor that detects and conveys information used to form an . It does so by converting the variable attenuation of light waves (as they pass through or reflect off objects) into signals, small bursts of current that convey the information. The waves can be light or other electromagnetic radiation. Image sensors are used in electronic imaging devices of both analog and digital types, which include digital cameras, camera modules, camera phones, optical mouse devices, medical imaging equipment, night vision equipment such as thermal imaging devices, radar, sonar, and others.

Digital camera

A digital camera is a camera that captures photographs in digital memory. Most cameras produced today are digital, largely replacing those that capture images on photographic film. Digital cameras are now widely incorporated into mobile devices like smartphones with the same or more capabilities and features of dedicated cameras (which are still available). High-end, high-definition dedicated cameras are still commonly used by professionals and those who desire to take higher-quality photographs.

Video camera

A video camera is an optical instrument that captures videos (as opposed to a movie camera, which records images on film). Video cameras were initially developed for the television industry but have since become widely used for a variety of other purposes. Video cameras are used primarily in two modes. The first, characteristic of much early broadcasting, is live television, where the camera feeds real time images directly to a screen for immediate observation.

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