CMOS stands for complementary metal-oxide-semiconductor. It’s an image sensor that is used in today’s mobile phones. Generally, engineers called an eye of the camera phones, video cameras, and digital cameras. It looks like a computer chip that senses light on the targeted capture. It has replaced the CCD (charge-coupled device) image sensor as it delivers more quality pictures. Therefore, the CMOS image sensor test is done on most smartphones. The test is conducted to ensure that the cellphone provides high-definition images.
Let’s Read in Depth About CMOS Image Sensors!
Understanding Image Sensors
Do you know who launched the photoelectric effect for the first time? It was done by Albert Einstein in 1905. He had the idea from plank light which is quantized in small packets known as photons. He made the standard theory about the light:
- Per photon’s energy is based on the frequency of its electromagnetic wave.
- A photon with energy can strike a bound electron within a material.
- Photon’s energy will be consumed by the electron and removed from its current orbital, which is called a photoelectron.
Whether it’s a CMOS image sensor or the CCD image sensor, both use the photoelectric effect. It transforms the photons into an electric signal. The essential thing which you can learn from this is that a photon’s energy totally depends on its frequency rather than intensity. Therefore, photons with the right frequency can eject the electrons from their current orbital. Photons with increased intensity will not create a photoelectron.
Once a photoelectron is introduced, then you need to capture & quantify it. CMOS captures the photoelectron differently and recreates an image. Both the sensors are made by a matrix of pixels. When the photoelectric takes place, then the sensors treat it differently. Here the difference comes in both the sensors and CMOS sensors excel.
How is CMOS Better Than CCD?
Till now, you have an idea that both sensors make use of photons’ energy and convert them into an electrical charge. However, the process is completely different.
When coming to CCD image sensors, pixels collected light and moved across the circuit via current. The light level is recorded in the readout circuitry. Generally, the process takes a lot of time and power
On the other hand, CMOS sensors the pized have the readout circuitry, which is situated at the photosensitive site. The process is quick and eliminates any stain & mark. The pixels of CMOS allows the photosensitive electronics to be more efficient in collecting light.
Advantages of CMOS Image Sensors Vs. CCD Image Sensors
- CMOS’ latest pixel architecture is quite beneficial in lower light applications.
- It has lower dark noise that supports a higher fidelity image.
- It has improved its saturation capacity, which provides a higher dynamic range.
- CMOS automated test equipment consumes less power.
- It has smaller pixels that lower down the sensor format, decreasing the lens cost.
As mentioned above, CMOS is now mainly used by today’s smartphones. However, the supporting reasons discussed in the post are the answers to why mobile phone industries trust the CMOS image sensors over CCD image sensors.
