Optical sensor measures ambient light behind an OLED screen

By Gina Roos, editor-in-chief

Launched at CES 2019, the new TCS3701 RGB light and IR proximity sensor from ams can measure the intensity of ambient light from behind a smartphone’s OLED screen. This maximizes the smartphone display area by eliminating front-facing bezels where an ambient light/proximity sensor is typically placed, said the company.

Housed in a 2.0 × 2.5 × 0.5-mm OQFN package, the TCS3701 can be easily placed behind a smartphone’s OLED screen, enabling designers to mount an IR emitter in support of the proximity-sensing function in the best front-facing location, said ams. Proximity-sensing performance is delivered through cross-talk compensation algorithms.

In addition to helping smartphone makers attain the highest ratio of display area to body size, the “Behind OLED” ambient light/proximity sensor also retains touchscreen disablement and automatic display brightness/color adjustment functions, which require an RGB/infrared light sensor.

Thanks to unique algorithms that enable accurate detection of ambient light levels, the TCS3701 — despite operating behind an emissive OLED display — senses ambient light passing through the display to light emitted by the display’s pixels located above the sensor. The device’s ultra-high sensitivity to light allows for accurate light measurements in all lighting conditions.

The TCS3701 is sampling now and is priced at $1.25 in quantities of 1,000 units. An evaluation kit is available.