Image sensors have been used in imaging devices, for example, video cameras. Image sensors mainly support image capturing for visual ray light (400 nm-700 nm). These image sensors have color filters on chip. There are various Color Filter Array (CFA) patterns suited to each purpose. The most popular CFA pattern was invented by Mr. Bayer, and it is famous for a Bayer pattern or Bayer color filter. But recently, other CFA patterns have been proposed for sensing purpose.
To capture both Red Green Blue (RGB) image and Infrared (IR) image simultaneously, an RGB-IR image sensor is proposed. The RGB-IR image sensor is generally used for both taking photos and sensing. An RGB image is a photograph to be recorded, to be shared, to be appreciated and to be sensed by applications. So image quality of the RGB image is important. But an IR image is only for sensing iris recognition, Face Recognition and other sensing purpose. Therefore, an RGB-IR camera is usually used for taking photos and sensing something, and period of taking photos is not so long, but period of sensing may be very long.
Usually sensors of 8 megapixels or 13 megapixels consume from 200 mW to 300 mW. This power consumption is large to take IR images for sensing, which reduces battery life of a camera (or a camera phone).
Therefore, it is advantageous to provide an RGB-IR image sensor which can reduce the power consumption of the image sensor.