Apple supplier AMS designs and manufactures high-performance sensor solutions for applications requiring the highest level of miniaturization, integration, accuracy, sensitivity and lower power. More specifically, AMS provides Apple with optical sensors for 3D facial recognition features on its newest iPhones. On Monday AMS announced that new behind-the-display technology could deliver a bezeless smartphone as our cover graphic presents. While companies like Samsung and Huawei have introduced Punch Hole style displays to avoid the nasty notch trend, Apple may be able to deliver a totally full screen iPhone in the future, dropping their large camera notch.

AMD stated yesterday that their new TCS3701 RGB light and IR proximity  sensor IC enables front-facing ambient light and proximity sensing measurements in smartphones – maximizing edge-to-edge display screen size – with sensor operation under OLED display.

This capability supports today’s industrial design trend to maximize smartphone 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, ams enables smartphone manufacturers to achieve the highest possible ratio of display area to body size while retaining crucial touchscreen disablement and automatic display brightness/color adjustment functions, which require an RGB/infrared light sensor.

Despite the constraint of operating behind an emissive OLED display screen, the TCS3701 senses the addition of the ambient light passing through the display to light emitted by the display’s pixels located just above the sensor. ams has developed unique algorithms which enable accurate detection of ambient light levels without knowledge of the display pixel brightness above the sensor.

Light transmission through an OLED screen is limited by its opacity, but the TCS3701’s ultra-high sensitivity to light means that it can still produce accurate light measurements in all lighting conditions.

The TCS3701’s 2.0mm x 2.5mm x 0.5mm OQFN package is small enough to be placed behind a smartphone’s OLED screen. It gives a smartphone designer the flexibility to mount an IR emitter to support the proximity sensing function in the best front-facing location. Cross-talk compensation algorithms provide for reliable proximity sensing performance.

“Smartphone OEMs today are striving to maximize their products’ screen-to-body ratio, reducing the bezel area as much as possible on the display’s face,” said David Moon, Senior Marketing Manager at ams. “The TCS3701 enables phone designers to take this trend to a new level, potentially eliminating the bezel entirely. This is only 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.”

Benefits

• Enables maximum design flexibility for operation behind Organic LED displays or dark inked glass
• Enables dark room to sunlight operation
• Reduces power consumption
• When combined with a VCSEL emitter enables operation behind OLED
• Enables ambient light measurement during display blanking periods

About AMS