What is Overall system gain in image sensor chip development?

What is "Overall system gain"

In the development of image sensor chips, “Overall system gain” refers to the overall gain of the entire imaging system, which is the extent to which the light signal captured by the image sensor is amplified. This gain is used to adjust the brightness of the image so that we can see a clearer picture. When increasing the Overall system gain, the image becomes brighter, but noise or distortion may also be introduced. Simply put, Overall system gain is like adjusting the camera’s exposure so you can take brighter or darker photos depending on your needs. In the development of image sensors, measuring Overall system gain is to ensure image quality and performance.

Principle of measuring "Overall system gain"

The principle of measuring “Overall system gain” involves the processing and enhancement of light signals.

The operating principle is as follows:

  1. Light signal input: First, light is projected onto the image sensor, which can be from the camera lens or other light sources.
  2. Sensor conversion: The sensor consists of many tiny pixels (or photosensitive components) that can sense light intensity. When light hits the sensor, pixels start converting the light signal into an electrical signal.
  3. Gain setting: When measuring Overall system gain, we adjust a parameter called “gain”. Gain is a way of amplifying the light signal to make it brighter. This is usually implemented in electronic components such as amplifiers.
  4. Data recording: After the sensor converts the light signal, the electrical signal is recorded, usually in digital form. This data includes the brightness levels of the image.
  5. Calculating Overall system gain: To calculate Overall system gain, we compare the difference between the original light signal and the adjusted light signal. This difference is the effect of the gain, telling us how many times the light signal has been enhanced.

In summary, the principle of measuring Overall system gain involves adjusting the brightness of the light signal, then comparing the signal before and after gain to determine the effect of the gain. This is to ensure that the image sensor can correctly capture the light signal and display the image at the proper brightness.