What Are CCD Image Sensors?

You don’t need to be an electrical engineer to understand why CCD image sensors are better than CMOS when it comes to digital cameras, camcorders, and security cameras. The image sensor is a special component that converts light into electronic impulses. For traditional cameras it would be the equivalent component of the film used. The film used in a camera is a major factor on how the photographs will turn out. These days imaging equipment, such as security cameras and digital cameras, rely on CCD or CMOS image sensors. Both chips are about the size of a dime. CCD stands for Charged coupled device and are widely used in digital cameras, and surveillance cameras. CMOS, complimentary metal-oxide semiconductor, rely on a different manufacturing process and are substantially less expensive to make.

Image sensors function similar to a photovoltaic (PV) cell and are found in many other types of hardware in addition to cameras. As light hits a silicon matrix where each tiny point represents a single pixel it is converted into electrons. For CMOS chips a transistor next to each pixel reads the data. The problem here is that sometimes the light hits the transistor instead of the photodiode. On the other hand CCD sensors carry the data across the chip to a single point in a way that there is very little signal distortion. Another component then assigns a digital value to each pixel. It is not hard to see why a CCD sensor would be preferable for security cameras which may be focusing in on moving targets hundreds of feet away. Although there are a few trade-offs. CCD sensors require up to 100 times more power, which effects battery life in wireless security cameras. This makes CMOS great for camera phones with small batteries, but is also the reason most phone cams have quite low resolution. It keeps costs down as well.

Just like with film types the use of different image sensors will impact the photographic quality and characteristics of picture and video images, and can dramatically affect the color and clarity. Because the data is converted at the same point CCD image sensors offer a higher quality image with better resolution and less noise. They also have greater sensitivity to light and therefore are better for low light situations. There are different kinds of image sensors for day and night imaging equipment. Cameras record in color during the day, but will switch to black and white at night. Infrared cameras also record in black and white.


About the Author: Mike Ward is the owner and operator of Protection Depot, a leading online provider of wireless security cameras. For more information about security cameras please visit The Protection Depot.