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 allowed; in those cases, they issue a sound that alerts the driver and passengers.
Another type of very common sensor is one that is installed in the entrance door of the houses and reacts to the movement. Yes one person It approaches the sensor, it emits a signal and a lamp comes on. The use of these sensors is linked to the security , since they prevent someone from taking advantage of the darkness to hide and enter the house without being warned.
He thermometer they are also a type of sensor that takes advantage of the ability of mercury to react to the temperature and, thus, allows to detect if a person has a fever.
The sensors, in short, are artifacts that allow obtaining information of the environment and interact with it. Just as humans appeal to their sensory system for this task, machines and robots require sensors for interaction with the environment in which they find themselves.
When developing computers capable of responding to orders from voiceFor 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 can react to the stimulus as required by the user.
Digital cameras use an element known as image sensor To catch the light. It is a chip composed of millions of small parts sensitive to light called pixels (term that derives from "picture element" or "image element"), capable of capturing a photo when it is exposed.
Sensor image It is equivalent to the photographic reel of traditional cameras. Your task is to convert the light into electrical signals to store, measure and transform them into a digital representation of the light pattern you 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 photographic, and refers to the number of pixels that make up your sensor, since the minimum acceptable currently exceeds one million. While 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 pixel density (the amount of pixels per unit of measurement squared) and the size of the latter is related to quality: larger size, better results and more sensitivity.
The form is also responsible for the proportions of the photograph, which is known as the "relationship of appearance "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 the image sensors; The best known today are: CCD and SuperCCD, widely adopted in photography and video; CMOS, which requires less energy and is more economical to produce; Foveon X3, the only one mentioned in this list that does not interpolate colors (does not complete the missing information with preset algorithms) to generate the final image.