Integrated fingerprint and force sensor
An integrated sensing device comprising a force sensor and fingerprint sensor disposed on different portions of a flexible circuit. The fingerprint sensor is disposed on a first side of a first portion of the flexible circuit and the force sensor is disposed on a second portion of the flexible circuit. The flexible circuit is configured such that the first portion is over the second portion. The fingerprint sensor includes fingerprint sensor electrodes disposed on the first side of the first portion. The force sensor comprises a compressible layer disposed between a second side of the first portion and a first side of the second portion, and one or more one force electrodes.
1. A force sensing device comprising:
a flexible circuit comprising:
a first portion disposed over a second portion;
a fingerprint sensor disposed on a first side of the first portion and over the second portion, wherein the fingerprint sensor comprises a sensor package comprising:
an integrated circuit; and
fingerprint sensor electrodes communicatively coupled to the integrated circuit, and disposed on the first side of the first portion; and
a force sensor comprising:
a compressible layer disposed between a second side of the first portion and a first side of the second portion; and
one or more force electrodes.
2. The force sensing device of claim 1 , wherein the flexible circuit further comprises:
a connector configured to be coupled to an external computing device, and wherein the first portion is between the second portion and the connector.
3. The force sensing device of claim 1 , wherein the compressible layer comprises a solid material.
4. The force sensing device of claim 1 , wherein the one or more force electrodes comprises:
a first force electrode disposed on the first side of the second portion; and
a second force electrode disposed on the second side of the first portion, and wherein the compressible layer is disposed between the first force electrode and the second force electrode.
5. The force sensing device of claim 1 , wherein the one or more force electrodes comprises a first force electrode and a second force electrode disposed on the first side of the second portion, and the compressible layer is disposed between the first portion and the first and second force electrodes disposed on the second portion.
6. The force sensing device of claim 5 , wherein the one or more force electrodes further comprises a third force electrode disposed on the second side of the first portion.
7. The force sensing device of claim 1 , wherein the one or more force electrodes are communicatively coupled with the integrated circuit, and wherein the integrated circuit is configured to:
receive first resulting signals by driving the one or more force electrodes;
determine force information based on the first resulting signals;
receive second resulting signals by driving the fingerprint sensor electrodes; and
determine fingerprint information based on the second resulting signals.
8. The force sensing device of claim 1 , wherein the flexible circuit further comprises:
an electrode of a capacitive button disposed on the flexible circuit.
9. An input device comprising:
a flexible circuit comprising:
a first portion disposed over a second portion;
a force sensor comprising:
a compressible layer disposed between a first side of the second portion and a second side of the first portion; and
one or more force electrodes; and
a fingerprint sensor disposed on the first side of the first portion, wherein the first portion opposes the second portion, and the fingerprint sensor comprises a sensor package comprising:
fingerprint sensor electrodes disposed on the first side of the first portion; and
an integrated circuit communicatively coupled to the one or more force electrodes and the fingerprint sensor electrodes, wherein the integrated circuit is configured to:
receive first resulting signals by driving the one or more force electrodes;
determine force information based on the first resulting signals;
receive second resulting signals by driving the fingerprint sensor electrodes; and
determine fingerprint information based on the second resulting signals.
10. The input device of claim 9 , wherein the flexible circuit further comprises:
a connector configured to be coupled to an external computing device, and wherein the first portion is between the second portion and the connector.
11. The input device of claim 9 , wherein the compressible layer comprises a solid material.
12. The input device of claim 9 , wherein the one or more force electrodes comprises:
a first force electrode disposed on the second side of the first portion; and
a second force electrode disposed on the first side of the second portion, and wherein the compressible layer is disposed between the first force electrode and the second force electrode.
13. The input device of claim 9 , wherein the one or more force electrodes comprises:
a first force electrode and a second force electrode disposed on the first side of the second portion, and the compressible layer is disposed between the second side of the first portion and the first side of the second portion.
14. The input device of claim 13 , wherein the one or more force electrodes further comprises a third force electrode disposed on the second side of the first portion.
15. The input device of claim 9 , wherein the integrated circuit comprises:
an amplifier; and
a switching mechanism having at least first and second modes, and connected to the amplifier, the switching mechanism is configured to couple a first fingerprint electrode of the fingerprint sensor electrodes to the amplifier when in the first mode, and couple a force electrode of the one or more force electrodes to the amplifier when in the second mode.
16. The input device of claim 9 , wherein the flexible circuit further comprises:
a capacitive button disposed on the flexible circuit.
17. The input device of claim 9 , wherein receiving the first resulting signals by driving the one or more force electrodes comprises driving a first one of the one or more force electrodes with an absolute capacitive sensing signal and receiving the first resulting signals with the first one of the one or more force electrodes.
18. The input device of claim 9 , wherein receiving the first resulting signals by driving the one or more force electrodes comprises driving transmitter signals on a first one of the one or more force electrodes, and receiving the first resulting signals with a second one of the one or more force electrodes.
19. A processing system for an input device, the processing system comprises:
an integrated circuit disposed on a first side of a first portion of a flexible circuit, wherein the first portion of the flexible circuit is disposed over a second portion of the flexible circuit, wherein the integrated circuit is configured to:
receive first resulting signals by driving one or more force electrodes of a force sensor, wherein the force sensor comprises a compressible material disposed between a second side of the first portion and a first side of the second portion;
determine force information based on the first resulting signals;
receive second resulting signals by driving fingerprint sensor electrodes of a fingerprint sensor, wherein the fingerprint sensor electrodes are disposed on the first side of the first portion; and
determine fingerprint information based on the second resulting signals.
20. The processing system of claim 19 , wherein the integrated circuit comprises:
an amplifier; and
a switching mechanism having at least first and second modes, and connected to the amplifier, the switching mechanism is configured to couple a first fingerprint electrode of the fingerprint sensor electrodes to the amplifier when in the first mode, and couple a first force electrode of the one or more force electrodes to the amplifier when in the second mode.