Electronic Device With Shared Near Field Communications and Sensor Structures

Abstract

An electronic device may have electrical components such as sensors. A sensor may have sensor circuitry that gathers sensor data using a conductive structure. The sensor may be a touch sensor that uses the conductive structure to form a capacitive touch sensor electrode or may be a fingerprint sensor that uses the conductive structure with a fingerprint electrode array to handle fingerprint sensor signals. Near field communications circuitry may be included in an electronic device. When operated in a sensor mode, the sensor circuitry may use the conductive structure to gather a fingerprint or other sensor data. When operated in near field communications mode, the near field communications circuitry can use the conductive structure to transmit and receive capacitively coupled or inductively coupled near field communications signals. A fingerprint sensor may have optical structures that communicate with external equipment.

What is claimed is: 
     
         1 . An electronic device configured to communicate with external equipment and configured to gather user input, the electronic device comprising:
 a user input sensor having an array of transmitters and receivers that communicates with a corresponding array of transmitters and receivers in the external equipment; and   control circuitry coupled to the array of transmitters and receivers in the user input sensor, wherein the control circuitry is configured to gather the user input using the receivers in the array, is configured to transmit data to the external equipment using the transmitters in the array, and is configured to receive data from the external equipment using the receivers in the array.   
     
     
         2 . The electronic device defined in  claim 1 , wherein the array of transmitters and receivers comprises an array of electrodes, and wherein each of the electrodes transmits data to the external equipment and receives data from the external equipment. 
     
     
         3 . The electronic device defined in  claim 2 , wherein each of the electrodes comprises a capacitive electrode that forms a portion of a touch sensor that gathers the user input. 
     
     
         4 . The electronic device defined in  claim 3 , the electronic device further comprising:
 a display; and   an additional array of capacitive electrodes that form an additional touch sensor that overlaps the display, wherein the touch sensor and the display do not overlap.   
     
     
         5 . The electronic device defined in  claim 4 , wherein the touch sensor comprises a fingerprint sensor. 
     
     
         6 . The electronic device defined in  claim 2 , wherein the corresponding array of transmitters and receivers in the external equipment comprises an array of mating electrodes, wherein each mating electrode forms a mating electrode pair with a corresponding one of the electrodes in the electronic device. 
     
     
         7 . The electronic device defined in  claim 6 , wherein each mating electrode pair transmits a data stream between the mating electrode and the electrode in parallel with each of the other mating electrode pairs. 
     
     
         8 . The electronic device defined in  claim 7 , further comprising:
 switching circuitry coupled to each of the electrodes in the array of electrodes in the electronic device, wherein the switching circuitry selects which of the mating electrode pairs transmit data streams.   
     
     
         9 . The electronic device defined in  claim 8 , wherein the electronic device detects a signal strength of the data stream between the mating electrode and the electrode in each of the mating electrode pairs, and wherein the switching circuitry selects whether a given mating electrode pair transmits the data stream based on the signal strength for the given pair. 
     
     
         10 . The electronic device defined in  claim 8 , wherein only a subset of the electrodes and the mating electrodes transmit data streams when the electrode and the mating electrode of at least one mating electrode pair are misaligned. 
     
     
         11 . The electronic device defined in  claim 10 , wherein the switching circuitry automatically begins transmitting a data stream between an additional electrode and an additional mating electrode when the additional electrode and the additional mating electrode become aligned. 
     
     
         12 . An electronic device that communicates wirelessly with an electronic device accessory and that gathers user touch input, the electronic device comprising:
 an array of electrodes that communicates wirelessly with a corresponding array of electrodes in the electronic device accessory;   wireless communications circuitry coupled to the array of electrodes, wherein the wireless communications circuitry transmits data to the corresponding array of electrodes in the electronic device accessory using the array of electrodes and receives data from the corresponding array of electrodes in the electronic device accessory using the array of electrodes; and   input-output circuitry coupled to the array of electrodes, wherein the input-output circuitry gathers the user touch input using the array of electrodes.   
     
     
         13 . The electronic device defined in  claim 12 , wherein the electrodes comprise capacitive electrodes that form a capacitive touch sensor, and wherein the input-output circuitry gathers the user touch input using the capacitive touch sensor. 
     
     
         14 . The electronic device defined in  claim 12 , wherein the electronic device accessory comprises an electronic device cradle having an opening that receives the electronic device, and wherein the array of electrodes in the electronic device and the corresponding array of electrodes in the electronic device accessory overlap when the electronic device is received in the opening. 
     
     
         15 . The electronic device defined in  claim 12 , wherein the electronic device uses selected electrodes in the array of electrodes to transmit a pattern of signals to the electronic device accessory. 
     
     
         16 . The electronic device defined in  claim 12 , wherein in response to receiving a pattern of signals from the electronic device accessory, the electronic device compares the received pattern of signals to a plurality of known patterns of signals. 
     
     
         17 . The electronic device defined in  claim 16  wherein the electronic device takes a predetermined action in response to the received pattern of signals matching one of the plurality of known patterns of signals. 
     
     
         18 . A method of communicating between a first device and a second device, comprising:
 receiving a predetermined spatial pattern of near field communications signals from an array of electrodes in the first device using an array of electrodes in the second device; and   in response to receiving the predetermined spatial pattern of near field communications signals using the array of electrodes in the second device, taking a corresponding action with the second device.   
     
     
         19 . The method defined in  claim 18  wherein taking the corresponding action comprises initiating a data transfer mode between the first and second devices. 
     
     
         20 . The method defined in  claim 18 , further comprising:
 detecting cross-talk between a first mating electrode pair and a second mating electrode pair, wherein each of the first and second mating electrode pairs comprises an electrode from the array of electrodes in the first electronic device and an electrode from the array of electrodes in the second electronic device; and   discontinuing near-field communications between at least one of the first and second mating electrode pairs in response to detecting the cross-talk.