Surrounding ambient light and proximity sensing measurements in smartphones is done by maximising edge-to-edge display screen size
Accurately measuring the ambient light intensity from behind an OLED screen is the TCS3701, an RGB light and IR proximity sensor IC, which supports the modern industrial design of increasing a display area by eliminating front-facing bezels, where an ambient light/proximity sensor is typically located.
By developing this ‘Behind OLED’ ambient light/proximity sensor, smartphone manufacturers can achieve the highest possible ratio of display area to body size while retaining essential touchscreen functions and automatic display brightness/colour adjustment functions, which require an RGB/infrared light sensor.
The sensor’s unique algorithms enable accurate detection of ambient light levels without knowledge of the display pixel brightness above the sensor. This means that the TCS3701’s ultra-high sensitivity to light produces accurate light measurements in all lighting conditions (whereas light transmission through an OLED screen gets limited by its opacity).
The TCS3701 is small enough to be placed behind a smartphone’s OLED screen, which gives a smartphone designer the flexibility to mount an IR emitter for proximity sensing function in the best front-facing location. Cross-talk compensation algorithms also provide for a reliable proximity sensing performance.
“The TCS3701 enables phone designers to maximise their product’s screen-to-body ratio, potentially eliminating the bezel entirely. This is possible because the TCS3701 can operate behind an OLED display, a breakthrough enabled by the outstanding sensitivity of the device and by the implementation of sophisticated measurement algorithms to compensate for the optical distortion caused by the OLED display,” said David Moon, Senior Marketing Manager at AMS.
The TCS3701 comes in a 2.0mm x 2.5mm x 0.5mm OQFN package and is available for sampling now from AMS.