TLDR: A charge-coupled device (CCD) is a special kind of chip that can capture and store electrical charges. It is commonly used in digital imaging, like in cameras. CCDs have been around for a long time and have been used in professional, medical, and scientific applications. However, in recent years, they have been largely replaced by a newer technology called CMOS sensors.

CCDs work by using an array of capacitors to capture and transfer electric charges. Each capacitor can transfer its charge to a neighboring capacitor under the control of an external circuit. When light hits the CCD, it converts the photons into electric charges, which are then read out by the CCD.

CCDs have a long history, with the first one being invented in 1969 by George E. Smith and Willard Boyle. They were initially used in memory and imaging devices. Over time, CCD technology improved, and companies like Fairchild Semiconductor, RCA, and Texas Instruments started developing commercial devices.

There are different types of CCD architectures, including full-frame, frame-transfer, and interline. Each architecture has its own advantages and disadvantages. Full-frame CCDs have the entire image area active but require a mechanical shutter. Frame-transfer CCDs have a shielded area for storing the image, which eliminates the need for a mechanical shutter. Interline CCDs mask every other column of the image sensor for storage, allowing for fast shutter times.

CCDs can be sensitive to near-infrared light, making them useful for applications like night-vision devices and infrared photography. Cooling the CCD can improve its sensitivity to low light intensities. This is why professional observatories often use liquid nitrogen to cool their CCDs.

In recent years, there have been advancements in CCD technology, such as the development of intensified CCDs and electron-multiplying CCDs (EMCCDs). Intensified CCDs are optically connected to an image intensifier, while EMCCDs have a gain register that amplifies the charge. EMCCDs are particularly useful in low-light applications and have found applications in astronomy and biomedical research.

Overall, CCDs have played a significant role in digital imaging and have been instrumental in capturing high-quality images. However, with the advancement of CMOS sensor technology, CCDs have become less common in consumer and professional digital cameras.

Related Links:

• Charge-coupled device
• Digital imaging
• CMOS sensor
• Night vision devices
• Infrared photography