Under-Display sensors - Page 5

This is a guest post by Dr. Guillaume Chansin, founder and principal consultant at Irimitech Consulting

New sensor technologies are being developed specifically for the integration of fingerprint scanning functionalities with OLED displays. The recent announcements indicate that the industry is moving away from capacitive sensors to focus their efforts on optical or ultrasonic detection. For display manufacturers, this could even present opportunities to innovate and offer their own solutions.

Once a premium feature, fingerprint sensors have become almost standard on smartphones. However, the latest design trend is to remove the bezels around the display, leaving no room for the fingerprint sensor. Some OEMs made the choice to move the sensor to the back of the device, which is not always convenient (for instance when mounted on a car dash).

IHS says that smartphone makers are expected to increase their adoption of under-the-display fingerprint sensors. In 2018, 9 million such smartphones will be sold, but the market will grow extremely quickly and will reach over 100 million unit in 2019. By 2022, over 300 million such phones will ship.

Under-the-display sensors are currently only applicable to OLED displays. Chinese phones makers (such as Vivo and Huawei) already started shipping the first phones to adopt this technology. IHS estimates that looking forward, the market will be led by Samsung and Chinese smartphone makers such as Vivo, Huawei and Xiaomi.

In December 2017 Synaptics unveiled a new under-the-OLED fingerprint sensor called Clear ID. Following a year-long collaboration with Synaptics, Chinese phone maker Vivo has unveiled the first device to use such a solution.

Vivo's smartphone (which does not have a model yet) has a 6" AMOLED display, and it will be released in Asia in Q2 2018. According to the report at Android Authority, the solution is very nice and works quite well, although it is slower than currently available sensors, as it takes 0.7 seconds to unlock the phone (Synaptics says that this is actually on par with regular sensors).

Synaptics unveiled a new fingerprint sensor called Clear ID that can be placed under the OLED display of a smartphone and can be used to unlock a device in under seven milliseconds - on par with regular fingerprint sensors.

The Clear ID sensor can be placed under any part of the OLED screen (which will have to direct the user to place the fingerprint in the right location). Clear ID works with both rigid and flexible OLEDs - and can even work underwater and on displays that are covered with a screen protector.

Sonavation announced a new technology that enables to embed an ultrasound fingerprint sensor behind an OLED display. Using this solution, mobile phone makers could enlarge the display area of the mobile device, as there will no no need for a separate fingerprint sensor.

Sonavation says that their "3D biometric ultrasound technology" is the only fingerprint authentication solution that offers complex-enough imaging through a full stack display.

Peratech announced an innovative new touch screen technology for OLED displays. The QTC Ultra Sensor is a pressure-based touch technology, that is applied behind the display. Regular touch layers are transparent films placed in front of displays, which reduce the light output (brightness). This new sensor is accurate, low on power and supports multi-touch and can also sense the amount of pressure.

Pertech says that the new sensor can be used for OLED and e-paper displays, as these can actually be pressed (unlike LCD panels, in which pressing them is not advisable). It doesn't have a to be a flexible OLED, it works behind glass - and a deflection of a micron or so all that is needed for QTC Ultra to sense the touch.

Update: Microsoft removed the video that shows the transparent OLED...

Transparent OLEDs are exciting (and Samsung wants to tap that market) - but a lot of people wonder what is it really good for? Microsoft is showing a nice concept: using a camera beneath a transparent OLED to create gesture-based UI. The camera "sees-through" the OLED:

Microsoft are using a Samsung-made transparent AMOLED panel.