TOKYO — In search of a new market beyond smartphones, Japan Display Inc. (JDI) unveiled a transparent glass-based capacitive fingerprint sensor.
For JDI, a Sony-Toshiba-Hitachi collaboration that has been mired in the red, sensors represent a whole new market. Although its TFT-based fingerprint sensors have certain advantages over silicon-based solutions, JDI might be arriving too late with too little, observed industry analysts.
Japan Display's executive officer Katsuhisa Yuda (photo: EE Times)
Katsuhisa Yuda, executive officer and president of JDI's Display Solutions Company, explained during a media briefing here that the new sensors were developed as an extension of the company’s LCD module, known as in-cell Pixel Eyes.
With Pixel Eyes, JDI had already integrated a basic touch function into the glass substrate of the TFT display. Pixel Eyes eliminates the need to add an external touch-panel module.
But with the new technology, “We have gone a step further,” explained Yuda. The glass substrate can now not only identify where a finger touches, but also "read" the changes in capacitance caused by the recesses and ridges of an individual fingerprints.
The end result is a capacitive fingerprint sensor on a pane of glass. JDI is hopeful that the high transparency of the glass substrate will open the door to a broad range of new applications not possible on widely available silicon-based fingerprint sensors. The goal is to go beyond smartphone displays to credit cards, door locks and elsewhere. “We can combine it with a backlight, or use it on a flexible surface,” Yuda said.
There are two approaches to TFT-based circuitry for fingerprint solutions. The first replaces the silicon but still offers a stand-alone fingerprint module. The other integrates sensor circuitry into the display’s TFT backplane for an in-display solution. What JDI is offering here is the former. The company provides a sensor module with an effective sensor measuring 8.0mm x 8.0mm. With 508 dpi pixel density, it offers 256 gradation and 160 x 160 resolution.
Japan Display's newly developed glass-based capacitive fingerprint sensor (photo: EE Times)
The winter for fingerprint sensor suppliers?
Had this innovation come a year ago, when the industry was worried about the emerging trend of removing the home button from smartphones, this might be a different story. Then, OEMs, controller IC makers and panel makers were frantic for display-based fingerprint sensors with a variable sensing area for greater flexibility, as well as multi-finger input assigned through the OS for more convenience.
IHS Markit then argued the advantages of display-based fingerprint sensors as being “invisible and not affecting the appearance of the set.” The firm also argued that display-based sensors might be cheaper than their silicon-based counterparts.
A year later, though, the market research firm’s latest “Fingerprint Sensors Overview Report," issued earlier this month, introduces a fresh plot twist.
Jamie Fox, principal analyst for LEDs and lighting at IHS Markit, wrote: “The fingerprint sensors market is facing a major disruption following the introduction of Face ID, a facial recognition system designed and developed by Apple Inc. for its iPhone X, along with the forthcoming arrival of in-display sensors and Chinese vendors winning market share from Western vendors.”
He noted, “Overall, Apple’s decision to replace Touch ID with Face ID will lead to 1.1 billion fewer fingerprint sensors produced by the end of 2021 than if Apple had maintained Touch ID in iPhones.”
During the press briefing, Yuda was asked if JDI plans to test the smartphone market with its new fingerprint sensor. He said JDI is “undecided,” an indication of its reluctance to engage an already brutally price-competitive market.
The lay of the land
Calvin Hsieh, director of touch and user interface at IHS Markit, doesn’t believe JDI has much chance in the smartphone fingerprint market. He told EE Times this week, “JDI cannot get into the smartphone fingerprint sensor market, because of the falling ASP (average selling price) trend.”
He explained that silicon- and display-based fingerprint solutions are positioned differently. With silicon, he said that capacitive type is mainstream, mostly made of silicon and mature for all product segments. Its ASP is $1.20 to 3.
In the display-based segment, he noted, “So far, CIS under-display solution is mainstream, only for AMOLED (cannot be applied to LCD), and high-level. Its ASP is $10-$12.”
Qualcomm Sense ID — ultrasonic fingerprint solution — is display-based, he said, but won’t be ready until the end of the first quarter this year. Hsieh said its ASP is not yet known. “Its advantage [over CIS] is live-body detection,” he added.
In short, with or without JDI’s glass-based capacitive sensor, the smartphone market has enough related technologies.
Next page: Silicon-based vs. TFT-based