Apple's Patent Background

Fingerprint sensing and matching is a reliable and widely used technique for personal identification or verification. In particular, a common approach to fingerprint identification involves scanning a sample fingerprint or an image thereof and storing the image and/or unique characteristics of the fingerprint image. The characteristics of a sample fingerprint may be compared to information for reference fingerprints already in a database to determine proper identification of a person, such as for verification purposes.

A fingerprint sensor may be particularly advantageous for verification and/or authentication in an electronic device, and more particularly, a portable device, for example. Such a fingerprint sensor may be carried by the housing of a portable electronic device, for example, and may be sized to sense a fingerprint from a single-finger. For example, the AES3400 sensor from AuthenTec, Inc. of Melbourne, Fla., the assignee of the present invention, is widely used in a variety of notebooks, desktops and PC peripherals. Other fingerprint sensors from AuthenTec, is a multi-function smart sensor that expands touch-based functionality of touchscreen and QWERTY smartphones with a reduced impact on sensor performance or durability. Thus, a fingerprint sensor may be particularly advantageous for providing more convenient access to the electronic device without a password, for example, and, more particularly, without having to type the password, which is often time consuming. A fingerprint sensor may also be particularly advantageous for starting one or more applications on the electronic device.

The desire for the user's finger to be close to the array of finger sensing pixels may limit the thickness of the material that can be placed over the array of finger sensing pixels, which may increasingly restrict the use of both protective and cosmetic coatings over the array area. Mechanically integrating these sensors into their host devices typically requires that the finger sensor project through a hole in the electronic device's case, so that the array of finger sensing pixels can be located about flush with the external surface of the case.

However, a negative aspect of these mounting arrangements may include increased difficulty and cost to seal the opening for the finger sensor in the electronic device case or housing against the ingress of moisture, dust, and other contaminants. Additionally, the opening in the case or housing with the finger sensor protruding may be cosmetically unacceptable to the intended appearance of the electronic device, and mounting the finger sensor in an opening in the case may be difficult and costly in some devices.

It may be desirable to extend the range of electric field based finger sensors so that they can image fingers through significantly thicker dielectric materials such as molded plastic structures. Using an increased thickness material layer over the array of finger sensing pixels may result in increased power consumption. More particularly, an increased thickness material layer generally requires a greater drive voltage to be driven into the user's finger. The greater distance from the array of finger sensing pixels and the increased drive voltage may result in increased noise of a finger image, which may be undesirable for authentication, for example.

One of the Inventions behind Apple's Touch ID

In view of the foregoing background, it is therefore an object of Apple's invention to provide an electronic device with a reduced noise finger image from a finger positioned at a relatively large distance from the array of biometric finger sensing pixel electrodes.

This and other objects, features, and advantages in accordance with the present invention are provided by an electronic device that may include a housing and circuitry carried by the housing and having a device ground associated therewith. The electronic device may include an array of biometric finger sensing pixel electrodes, and an array shielding electrode outside the array of biometric finger sensing pixels, for example.

The electronic device may also include a finger coupling electrode outside the array shielding electrode and coupled to the device ground. The electronic device may further include drive circuitry capable of generating a drive signal for the array of biometric finger sensing pixel electrodes and a compensating drive signal for the array shielding electrode, for example. Accordingly, the electronic device may generate a reduced noise finger image from a finger positioned at a relatively large distance from the array of finger sensing pixels.

The drive circuitry may be capable of generating the compensating drive signal comprising a scaled replica of the drive signal. The electronic device may further include sense amplifier circuitry coupled to the array of biometric finger sensing pixel electrodes and having a circuit reference associated therewith different than the device ground. The drive circuitry may be capable of generating the drive signal between the device ground and the circuit reference, for example.

The array shielding electrode may include a plurality of shielding pixel electrodes, for example. The electronic device may further include a reference electrode between the array shielding electrode and the array of biometric finger sensing pixel electrodes. The electronic device may further include a dummy biometric finger sensing pixel electrode area between the array of biometric finger sensing pixel electrodes and the reference electrode, for example.

The electronic device may include a dielectric cap over the array of biometric finger sensing pixel electrodes. A semiconductor substrate may carry the array of biometric finger sensing pixel electrodes.

The circuitry may include wireless communications circuitry capable of performing at least one wireless communications function, for example. An input device may carry the array of biometric finger sensing pixel electrodes. The drive circuitry may be capable of generating the drive signal as a square wave at amplitude in a range of 10 to 20 volts and at a frequency of 1 to 5 MHz, for example.

Apple's patent FIG. 1 illustrates an iPhone (smartphone) using Touch ID fingerprint authentication within the Home Button. The biometric sensor could likewise be used in a future iPad, MacBook or iMac.

In some embodiments, the finger-operated input device may be a different type of finger-operated input device, for example, forming part of a touch screen display. Other or additional finger-operated input devices may be carried by the portable housing (# 21).

In Apple's secondary patent regarding the technology behind Touch ID, Apple's patent figure one adds a welcoming message to the display once the fingerprint scanner has been used to identify a user. The message is on the screen as "Welcome Bill," which could technically mean that Apple could likewise tie Siri into the welcoming message by verbalizing the user's name.

Apple's patent FIG. 2 is a schematic block diagram of the electronic device and biometric finger sensor of FIG. 1.

Apple's patent FIG. 3 is a top view of the biometric finger sensor of FIG. 1.

Apple's patent FIG. 3 is a more detailed schematic block diagram of a portion of the electronic device of FIG. 1 of the second patent 20130315451.

Patent Credits

In Apple's first patent 20130314105 they credit Dale Setlak and Giovanni Gozzini as the inventors. In Apple's second patent 20130315451 they credit Gordon Franza, Gregory Minteer, Jerry Dooley, Patrick Landy, Dale Setlak and Giovanni Gozzini as the inventors.

Both of Apple's patent applications on biometric fingerprinting are highly detailed covering distinctive information as noted in their respective abstracts below:

Apple's Abstract for the first patent 20130314105: An electronic device may include a housing and circuitry carried by the housing and having a device ground associated therewith. The electronic device may also include an array of biometric finger sensing pixel electrodes and an array shielding electrode outside the array of biometric finger sensing pixels. A finger coupling electrode may be outside the array shielding electrode and coupled to the device ground. The electronic device may also include drive circuitry capable of generating a drive signal for the array of biometric finger sensing pixel electrodes and a compensating drive signal for the array shielding electrode.

Apple's Abstract for the second patent 20130315451: A finger biometric sensing device may include an array of finger biometric sensing pixel electrodes and a gain stage coupled to the array of finger biometric sensing pixel electrodes. The finger biometric sensing device may also include error compensation circuitry that may include a memory capable of storing error compensation data. The error correction circuitry may also include a digital-to-analog converter (DAC) cooperating with the memory and coupled to the gain stage and capable of compensating for at least one error based upon the stored error compensation data.

For those of you interested in exploring these patents further could do so by viewing patent one and patent two.

A Note for Tech Sites covering our Report: We ask tech sites covering our report to kindly limit the use of our graphics to one image. Thanking you in advance for your cooperation. 

Patently Apple presents a detailed summary of patent applications with associated graphics for journalistic news purposes as each such patent application is revealed by the U.S. Patent & Trade Office. Readers are cautioned that the full text of any patent application should be read in its entirety for full and accurate details. Revelations found in patent applications shouldn't be interpreted as rumor or fast-tracked according to rumor timetables.

About Making Comments on our Site: Patently Apple reserves the right to post, dismiss or edit any comments.

New on Patent Bolt this Week

Google Seeks to Patent a Privacy Display for Mobile Devices

Samsung Invents Easy-to-Use Cuffless Blood Pressure Solution

Samsung Granted Interesting New Tablet Design Patents