ams launches world’s first optical sensor module optimized for ‘Behind OLED’ operation in smartphones

News facts:

• Mounted behind an OLED display, the TMD3719 ALS/proximity/flicker sensor enables OEMs to design smartphones that have no bezel and so maximize screen-to-body ratio
• Patent-pending innovations provide for distortion-free proximity operation behind an OLED display
• The TMD3719 is a complete system for flicker sensing and includes on-chip algorithms for detection under artificial light sources to remove artifacts in camera image capture

ams (SIX: AMS), a leading worldwide supplier of high performance sensor solutions, today launches the industry’s first optical sensor which integrates ambient light sensing, proximity detection, and flicker detection sensing in a single module optimized for operation behind a smartphone’s OLED display screen.

A leading supplier of optical sensors to the smartphone industry for a decade, ams draws on its history of technology innovations and expertise in optical sensor design to develop the TMD3719. It is the first device to overcome the significant technical challenges of ambient light sensing, proximity detection, and flicker detection behind an OLED display, enabling breakthrough industrial designs.

By providing a complete solution for ‘Behind OLED’ (BOLED) optical sensing, the TMD3719 enables smartphone manufacturers to move sensors normally found in the bezel behind the OLED screen, addressing consumer demand to eliminate the bezel. Consumers can then enjoy an extended display screen that covers the entire front surface of the smartphone.

The TMD3719 is the first module for BOLED applications with the integrated functionality enabling OEMS to deliver key consumer features. This can include displaying auto-brightness control in response to the lighting environment, proximity detection for touchscreen auto-off control during a call, and flicker detection for removing banding and other artifacts when camera image capture occurs in artificial light sources.

Darrell Benke, Strategic Program Director for the Integrated Optical Sensors business line at ams, said: “ams’ unmatched technology allows ambient light sensing and proximity detection to be moved from the traditional in-bezel location to the extremely challenging environment BOLED display where both visible and infrared light transmissivity is less than 5%. Thanks to ams innovations in products such as the TMD3719, smartphone manufacturers have been able to make a high screen-to-body ratio a common feature. Responding to requirements from smartphone manufacturers and their customers, ams is realizing an expanding, multi-generation BOLED roadmap for the coming years.”

Innovations in integrated optical sensor operation

The TMD3719 from ams features new and patent-pending innovations from ams to enable ambient light sensing and proximity detection BOLED display. These include:

• Synchronization of the ambient light sensing with the display operation to extract the true light intensity and removing display emissions from the sensor’s light measurements
• Three proximity infrared VCSEL (Vertical Cavity Surface Emitting Lasers) emitters allow power-emission optimization for best detection distance while dispersing the emissions to reduce IR excitation of the display screen. This eliminates visible display distortion.

By integrating ambient light sensing, proximity detection, and flicker detection into a single device, ams simplifies the system design and reduces development effort for the smartphone manufacturer. In the TMD3719, ams has taken integration a step further than in previous optical sensors, implementing algorithms for flicker detection. On-chip flicker detection processing removes the processing overhead from the main application processor, and so reduces latency in the flicker-detection results. This enables comprehensive detection of ambient light flicker frequency to allow removal of unwanted artifacts, such as banding, from the image captured by the smartphone camera.

The TMD3719 optical sensor is in a surface-mount 6.35mm x 3.00mm x 1.00mm package. It is available for sampling now, and a demonstration board is available on request.

For sample requests or more technical information, go to https://ams.com/TMD3719.