Image Sensor Working and Its Applications

The classification of sensors can be done based on the type of structure, type of chroma and type of shutter. And also these are categorized by frame rate, resolution, size of a pixel and also sensor format. By understanding these terms can assist in selecting the sensor for different applications. This article discusses an overview of the image sensor and its types. The main function of this sensor is to change the light into an electrical signal which can be analyzed and stored. The image sensor is an essential component in a vision camera machine. Day by day different kinds of sensors is available in the market by improving the size, speed, resolution & sensitivity of light.

What is an Image Sensor?

An image sensor is used to detect & transmit information for making an image. These sensors are used in both analog & digital type electronic imaging devices like digital cameras, imaging tools used in medical, camera modules, night vision tools like radar, thermal imaging devices, sonar, etc. The analog sensors which are used in the past are video camera tubes. At present, semiconductor CCDs (charge-coupled devices) is used otherwise active pixel sensors within CMOS (complementary metal-oxide-semiconductor) technologies. Analog sensors are vacuum tubes whereas digital sensors are flat-panel detectors.

Different Types

There are two types of image sensors available which include the following.

  • Charge-coupled Device (CCD)
  • Complementary Metal Oxide Semiconductor (CMOS)

A CCD image sensor includes a collection of capacitors, which carries electric charge related to the pixel’s light intensity. A control circuit in the senor will cause every capacitor to transmit its contents toward its neighbor & the last capacitor within the array of capacitors will unload its electric charge into an amplifier. The method like bucket-brigade of data transfer can be a feature of CCD sensors.


In a CMOS image sensor, it includes a CMOS transistor switch & a photodiode for every pixel, permitting the pixel signals to be improved separately. By operating these switches, the signals can be allowed straight and in sequence with high-speed compare with a CCD sensor. Including an amplifier for every pixel can also provide another benefit: it decreases the noise that arises as understanding the electrical signals which are changed from captured light.


Working Principle of Image Sensor

The image sensor in a camera system gets photon that is focused on using a lens otherwise optics. Based on the type of sensor like CCD / CMOS, the information will be transmitted to further stage like a voltage otherwise a digital signal.


The main function of the CMOS sensor is to change photons into electrons, after that to a voltage or digital value with the help of ADC (analog to digital converter).

The general components used in the camera will change based on the manufacturer. The main intention of this design is to change beam into a digital signal to examine to activate some upcoming action. Consumer cameras have extra components to store the image and for viewing whereas the machine vision cameras doesn’t have.

Thus, this is all about image sensor, types and working principle. These sensors are available in various formats & packages. The overall size of the sensor will dictate the pixel size & resolution. Understanding the arrangement of this sensor is mandatory to select a lens & optics of a camera. Each lens is designed for a particular sensor format & resolution. Here is a question for you, what are the advantages of image sensor?