What Does sensor Mean
A sensor is a device that is able to detect external actions or stimuli and respond accordingly . These devices can transform physical or chemical quantities into electrical quantities.
For example: there are sensors that are installed in vehicles and that detect when the travel speed exceeds the permitted speed; in those cases, they emit a sound that alerts the driver and passengers.
Another very common type of sensor is the one that is installed in the front door of the houses and reacts to movement. If a person approaches the sensor, it emits a signal and a lamp lights up. The use of these sensors is linked to security , since they prevent someone from taking advantage of the darkness to hide and enter the house without being warned.
The thermometer is also a type of sensor that takes advantage of the ability of mercury to react to temperature and, in this way, allows to detect if a person has a fever.
The sensors, in short, are artifacts that allow obtaining information from the environment and interacting with it. Just as human beings appeal to their sensory system for this task, machines and robots require sensors to interact with the environment in which they are.
When developing computers capable of responding to voice commands , for example, they are provided with microphones, which are sensors capable of capturing sound waves and transforming them. If these sensors are connected to other circuits, the machine will be able to react to the stimulus according to what is required by the user.
Image sensor
Digital cameras use an element known as an image sensor to capture light. It is a chip made up of millions of small light- sensitive parts called pixels (a term derived from "picture element" or "picture element"), capable of capturing a photograph when exposed.
The image sensor is equivalent to the photographic film of traditional cameras. Its task is to convert light into electrical-type signals to store, measure and transform them into a digital representation of the light pattern it captured. Once this process is completed, a computer file is obtained that saves the image, which can be viewed on a monitor, or used for printing on paper.
The term megapixel is very popular when describing a camera , and refers to the number of pixels that make up its sensor, since the minimum acceptable currently exceeds one million. Although it is necessary to take other characteristics into account, it is possible to say that the number of pixels proportionally affects the quality of a photograph, since it is closely related to the sharpness, with the amount of detail that the device can capture from a scene.
In addition to the resolution of the sensor, its size also influences the result, since it affects the density of pixels (the number of pixels per unit of measurement squared) and the size of the latter is related to quality: the larger the size , better results and more sensitivity .
The shape is also responsible for the proportions of the photograph, which is known as the " aspect ratio ". The most common format is 3/2, which offers a representation quite close to the perception of the human eye.
Finally, there are several technologies used to manufacture image sensors; the best known today are: CCD and SuperCCD , widely adopted in photography and video; CMOS , which requires less power and is cheaper to produce; Foveon X3 , the only one mentioned in this list that does not interpolate the colors (does not fill in the missing information with preset algorithms) to generate the final image.