Myths are carefully devised by many companies to project advanced breakthroughs and provide marketing departments something to crow about in interviews. It helps to create a mystique around a product or brand. In some cases I'm sure that the marketing department is sometimes in the dark as to what work their engineers are actually working on and today we're clearly able to see a contradiction in Apple's marketing versus reality.

Apple has made it clear that they never ever considered fingerprint detection on the iPhone X or OLED display. Perhaps in key circles that statement is 100% true. However, a patent granted to Apple in both the U.S. and Europe recently clearly details how a specialized OLED display was designed to read a fingerprint, clear and simple and it's actually core to the invention – there's no getting around that fact.

The patent issued to Apple relates to a next-gen integrated silicon-OLED display that could be used with an iPhone, an iPad and iPod touch and it's not about LCD displays. So while Apple publicly states that they never ever considered fingerprint ID in the display for iPhone X somewhat contradicts what their engineers actually invented. The patent application was only filed in 2015 and granted in this quarter. So it's not some ancient relic.

Of course it's possible that different teams worked on different solutions and perhaps different iDevices. But the bottom line is that Apple did in fact work on fingerprint ID technology integrated into OLED displays plain and simple.

Patent Background

In Apple's patent background they note that advantages of OLED displays over other types of displays make integrating OLED displays into portable electronic devices attractive. Integrating the OLED display and touch screen into a single device can include fabricating the OLED stack on a glass or plastic substrate, forming the touch sensors on the OLED stack, and electrically coupling the touch sensors and transistors for the OLED stack using routing traces and one or more metallization layers. Alternatively, the OLED stack and the touch screen can be fabricated separately and then adhered together using a conductive paste. However, both techniques can include high temperature or high pressure processes that can damage the OLED stack. Furthermore, stacking the touch sensors and any routing circuitry for the touch sensors on the OLED stack can lead to portable electronic devices with unacceptable thicknesses. Additionally, formation of the OLED stack on a glass or plastic substrate can lead to poor manufacturing yields, high process variations, and poor transistor/wiring performance.

Apple's Invention

Apple's invention relates to integrated Silicon-OLED display and touch sensor panel stackup configurations that can be used in portable electronic devices such as media players, mobile telephones, and tablet computing devices.

Stackup configurations can include a Silicon substrate, an array of transistors, one or more metallization layers, one or more vias, an OLED stack, color filters, touch sensors, and additional components and circuitry.

Forming the OLED stack and touch sensors on a Silicon substrate can allow for an extremely high number of pixels per inch. With a high number of pixels per inch, the OLED subpixels can be arranged side-by-side with the touch sensors leading to portable electronic devices that are thinner and lighter.

Arranging the OLED subpixels side-by-side with the touch sensors can also lead to a wider viewing angle display with a higher contrast ratio, higher brightness, and more vibrant colors without compromising touch sensitivity.

Due to the higher number of pixels per inch, the stackup configurations can also include one or more additional components such as electrostatic discharge devices, switches, near-field imagers, near-infrared emitters, and near-infrared detectors.

The additional components can improve the functionality of the device by consuming less power, enhancing touch sensitivity, and enhancing fingerprint detection capabilities.

In some examples, the integrated Silicon-OLED display and touch sensor panel can be coupled with one or more fiber optic magnifiers to achieve a portable electronic device with extended touch and display capability.

The patent made it clear early on that integrated Silicon-OLED displays could be used for the iPhone (mobile telephones), the iPad (tablet computing devices) and iPod touch, (media players). Apple's patent FIG. 7D below shows the display in context with an iPad.

In Apple's patent FIG. 9A illustrated above we're able to see a cross-sectional view of an exemplary integrated Silicon-OLED display and touch sensor panel with fingerprint detection.

Technically, device #900 can include an OLED stack #950, components #909, color filters CF 925, photodiode #908, and touch sensors #943 disposed on Silicon substrate #903. Components 909 can include, but are not limited to, an array of transistors, vias, insulating layers, ESD devices, switches, and metallization layers.

An object, such as finger #999, can touch or swipe the touch and display surface #970 of the device. The photodiodes can be used to detect a fingerprint image using near-field imaging. Near-field imaging allows for arbitrarily small details to be resolved, and can be well-suited for fingerprint detection.

Photodiodes can be any type of fingerprint reader such as, but not limited to, optical finger print readers or thermal finger print readers. The finger 999 in FIG. 9A can include ridges #998 and valleys #997 (areas between ridges 998), and the photodiode can use light to capture an image of the fingerprint. The ridges of the finger can reflect more light, and the valleys can reflect less light. In some examples, photodiodes can use the difference in index of refraction or light reflection to differentiate between the ridges and valleys (e.g., air). Photodiodes can generate a black and white image of the fingerprint.

In some examples, the device can include discrete components for the OLED subpixels to display one or more images, touch sensors to sense a touch or hover, and photodiodes to capture a fingerprint image, thereby allowing the device to operate one or more of the three functionalities simultaneously.

For example, the near-field imaging photodiode can be used in conjunction with touch sensor #943. In some examples, the photodiode can be used to read a fingerprint image when a touch panel cannot use capacitive fingerprint sensing. For example, touch panels using pixelated self-capacitance may not have enough spatial resolution to read a fingerprint. In such an example, the photodiode can be placed near or next to the pixelated self-capacitance touch pads to allow the touch panel the capability to read both a fingerprint image and detect a touch activity while displaying an image using the OLED subpixels. In some examples, the device can include a plurality of photodiodes such as photodiode #908 configured for capturing an image or scanning a document.

In respect to patent FIG. 9 noted above. Apple notes that "if the fingerprint image is a match, the device can unlock and allow the user access to the device (block #972). During one or more of the illustrated blocks, a fingerprint image can be detected by exclusively using the one or more activated photodiodes so the device can conserve power by deactivating the touch sensors. Additionally, the device can further conserve power by waiting until block #966 to activate or power on the photodiodes."

The Fiber Optic Magnifier

Another angle of this invention is covered in Patent FIGS. 11A-11B as presented below which illustrates cross-sectional views of exemplary integrated Silicon-OLED display and touch sensor panels coupled to fiber optic magnifiers.

A fiber optic magnifier such as fiber optic magnifier #1120 and fiber optic magnifier #1122 can be a magnifier formed by juxtaposing thousands of fiber optic cables, melting the cables together, and pulling the melted cables to form a taper. The fiber optic magnifier coupled to a display screen can display an enlargement of the image projected by the display.

Referring to FIG. 11A, OLED stack and touch sensors #1140 can display an image #1110. A fiber optic magnifier can be coupled to OLED stack and touch sensors to project an enlarged image #1112.

Different sizes and shapes of fiber optic magnifiers can be used. An exemplary integrated Silicon-OLED display and touch sensor panel coupled to a fiber optic magnifier is illustrated in FIG. 11B. OLED stack and touch sensors #1142 can display an image #1150.

Fiber optic magnifier can be coupled to OLED stack and touch sensors to project an enlarged image #1152. The fiber optic magnifier of FIG. 11B can be formed with a larger curvature than fiber optic magnifier #1120 of FIG. 11A. The fiber optic magnifiers #1120 and #1122 can be used to form flat and curved displays.

Apple was granted a patent for this invention in the last month both in the U.S. and Europe. It should be noted that Apple has a few patents with an OLED display that could read a fingerprint. One such patent report included the patent figures noted below. The actual patent filing revealed it related to OLED displays as well. Did the iPhone X team never ever consider a fingerprint technology for OLED displays? Hmm, Perhaps, but reality shows us that they were simultaneously working on an alternative methodology for some iDevices, if not the iPhone X.

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