Touch sensor with force-actuated switched capacitor

Abstract

This disclosure provides apparatus, systems and methods of fabricating force-sensitive switches. In some implementations, an array of force-sensitive switches and local capacitors of a combined sensor device may be used to connect the local capacitor into associated projected capacitive touch (PCT) detection circuitry. In some implementations, each capacitor may be formed with a thin dielectric layer to achieve a high capacitance increase when the force-sensitive switch is closed, e.g., by the pressing of a stylus or finger. In some implementations, the same PCT detection circuitry can be used to detect changes in mutual capacitance when touched with a finger (touch mode) and changes in sensel capacitance when the force-sensitive switch is depressed (stylus or fingerprint mode).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to U.S. Provisional Patent Application No. 61 / 394,054, entitled “COMBINATION TOUCH, HANDWRITING AND FINGERPRINT SENSOR” (Attorney Docket No. QUALP045P / 102908P1) and filed on Oct. 18, 2010, which is hereby incorporated by reference and for all purposes. This application is related to U.S. patent application Ser. No. ______, entitled “COMBINATION TOUCH, HANDWRITING AND FINGERPRINT SENSOR” (Attorney Docket No. QUALP045A / 102908U1) and filed on Oct. 11, 2011, to U.S. patent application Ser. No. ______, entitled “FABRICATION OF TOUCH, HANDWRITING AND FINGERPRINT SENSOR” (Attorney Docket No. QUALP045B / 102908U2) and filed on Oct. 11, 2011, to U.S. patent application Ser. No. ______, entitled “TOUCH, HANDWRITING AND FINGERPRINT SENSOR WITH ELASTOMERIC SPACER LAYER” (Attorney Docket No. QUALP045C / 102908U3) and filed on Oct. 11, 2011, to U.S. patent application Ser. No. ______, entitled “WRAPAROUND ASSEMBLY FOR COMBI...

AI Technical Summary

Benefits of technology

[0019]Details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Although the examples provided in this summary are primarily described in terms of MEMS-based displays, the concepts provided herein may apply to other ty

Problems solved by technology

The increased use of touch screens in handheld devices causes increased complexity and cost for modules that now include the display, the touch panel and a cover glass.

Each layer in the device adds thickness and requires costly glass-to-glass bonding solutions for attachment to the neighboring substrates.

These problems can be further exacerbated for reflective displays when a frontlight also needs to be integrated, adding to the thickness and cost of the module.

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