CCD Sensors

The CCD sensor, or the charge-coupled device sensor, was created in the 1960s by Bell Laboratories. It was supposed to be a new type of computer memory chip, but since the device proved to be so much more than that, Bell began developing other uses that included signal processing. Since the sensor utilized silicon, it was more sensitive to light, and thus made a good imaging sensor.

Thin layers of silicon process within the unit itself. Each layer has identical layers within it that serve a separate function. Dies are cut from the layers and preserved by an outer, more durable layer to be included in other devices, such as a digital camera. You cannot just take apart your camera and find the CCD sensor, although in some cameras you can. High-end cameras can be taken apart for you to clean your sensor, but only camera professionals should attempt to do so. If you damage your sensor, you could potentially have to replace your entire digital camera, and that can become costly.

The sensor itself serves to capture an image. It is like an eye, it collects light, converts it to an electric charge and then emits the results that become a static image. Kodak developed one of the most used CCD sensors, it includes thousands of pixels situated in a linera fashion or in a matrix to capture light's intensity in an image. The process is similar to how the eye captures an image for you to constantly see the world around you.

There are several different ways CCD sensors are used. Area arrays allow picture takers to capture motion in one exposure no matter what the shutter speed. Linear arrays focus on one row of pixels to scan an image. From there, it makes three different exposures, one for each color filter, based on reds, blues and greens. This captures one-dimensional images and captures still subjects. These types of images must have a self-contained light source and can be captured in high-resolution for spectacular detail in the imagery.

Tri-linear sensors utilize three CCD layers coated with red, blue and green filters. When the picture is taken and the sensor captures it, it is processed line-by-line to capture the entire color spectrum of the image. High-end cameras use this type of CCD sensor to capture high-resolution pictures. Interline transfer sensors have several arrays for both capture and transfer. This is not the best type of sensor, and you will find it in lower-end digital cameras and camcorders.

Full frame sensors allow for a higher charge, range and reduces white noise. Kodak's full frame sensors can capture the entire color matrix instantly as opposed to having to be scanned line-by-line. There are a set of parallel CCD registers, a shift register and a output amplifier. These combine the exposure through use of a mechanical shutter. When a picture is taken, the image is projected into the parallel registers to set up the image plane. The camera then determines key elements and define the pixels in the image. From there, the rows of data are shifted to the register which then transmits the image into an output for viewing. Once all the rows are processed and transferred, your image is processed on your view screen.

From start to finish, the CCD sensor is capable of capturing and producing an image. First, the shutter opens, exposing light to the sensor. The light is then converted to a charge in the unit. This is the exposure process. During exposure, light is converted into the charge and focused into pixel points. Once the shutter closes, light is blocked and the transfer is then transmitted and converted into a single signal. This is the transfer process. Packets of pixels are spun around the silicon-based CCD sensor. Then, the signal is processed into digital data, captured into the camera's memory and then produced on your view screen. The final step is the output of the image.

Light being captured by the sensor is what produces the image. When light, through photos, is captured by the array of pixels within the CCD sensor, the shutter closes and captures that light. Energy from the photons is absorbed by the sensor's silicon-based array and an electrical reaction occurs in the sensor. Electrons are formed when the photons interact with the array and create pixels of color. Each pixel is determined by how much light is being absorbed at that single point of the array and how much exposure time was given during the capture of it.

CCD sensors are just one type of camera sensor. CMOS sensors, the other most common type, are also part of the digital camera market. Each camera and its sensor has its own pros and cons, depending on what you are looking for, a CCD sensor-based digital camera may be the way to go. Check out different cameras and look for what works for you, your photography and your lifestyle. You may find a CCD sensor-based camera is right up your alley, or you may discover that you just need something simpler to take pictures. Without doing the proper research, you will never know what camera sensor is right for you.