Cambridge Touch Technologies Ltd.

Jiahao Li

Michael Robert Astley

Xiang Cheng

Arokia Nathan

Babak Bastani

Riccardo Micci

Constantinos Tsangarides

Paridhi Sharma

Paul Richard Routley

Antonio Afonso Bras Ferreira Marques

Mojtaba Bagheri

An apparatus () is described which includes a touch panel (). The touch panel () includes a layer of piezoelectric material () disposed between a number of sensing electrodes () and at least one counter electrode (). The apparatus () also includes a touch controller () connected to the touch panel (). The touch controller () is configured to determine, in response to receiving piezoelectric signals () from one or more of the sensing electrodes (), a location () and an applied force () corresponding to a user interaction () with the touch panel (). The touch controller () is configured to determine a capacitance value () of one or more of the sensing electrodes (). The touch controller is configured to operate in a force-based mode, a capacitance-based mode or a mixed force-capacitance mode depending on the type of input received.

Force sensing touch panel

An apparatus () for processing signals from a touch panel () is described. The touch panel () includes a layer of piezoelectric material () disposed between a number of sensing electrodes () and at least one common electrode (). The apparatus () includes a capacitive touch controller () for connection to the sensing electrodes (). The apparatus () also includes a switch network () including a number of inputs for connection to some or all of the sensing electrodes (), and an output connected to system ground or a common mode voltage (V). The apparatus () also includes a second circuit () for connection to the at least one common electrode () and configured to generate, based on signals received from the at least one common electrode, a second pressure signal () indicative of a total pressure applied to the touch panel (). The apparatus () also includes a controller () configured to control the switch network () to couple any connected sensing electrodes () to system ground or the common mode voltage (V) during a pressure measurement period, and to determine an estimate of the total pressure based on the second pressure signal during the pressure measurement period.

Pressure sensing apparatus and method

A force-sensing touch panel () is described which includes a layer structure stacked in a thickness direction between first and second surfaces. The layer structure includes from first surface to second surface, a number of first electrodes () and a number of second electrodes (), a layer of piezoelectric material (), and a number of third electrodes (). The first and second electrodes () are configured to define a coordinate system for sensing a location of a force applied to the touch panel in a plane perpendicular to the thickness direction. The third electrodes () are configured such that signals received from the first, second and third electrodes () enable determining unique locations corresponding to two or more forces applied to the touch panel () concurrently.

A device () includes a body () and a touch panel () supported by, integrated with, or underlying the body (). The touch panel () includes a layer of piezoelectric material () disposed between a plurality of first electrodes () and at least one second electrode (). The device () also includes at least one second piezoelectric input region () supported by, integrated with, or underlying a portion of the body () which does not correspond to the touch panel (). The device () is configured to receive user input using the touch panel () and/or at least one piezoelectric input region ().

Buttonless device

A touch sensor () for combined capacitive touch and force sensing is described. The touch sensor () includes number plurality of first electrodes () and a number of second electrodes (). The second electrodes () are insulated from the first electrodes (). The first and second electrodes () form a grid for capacitive touch sensing. The touch sensor () also includes a transparent cover (). The touch sensor () also includes a transparent piezoelectric film () arranged between the transparent cover () and the first and second electrodes (). The touch sensor () also includes a patterned counter electrode () disposed between the transparent piezoelectric film () and the transparent cover (). The patterned counter electrode () is a conductive grid formed from the union of plurality of counter electrode line elements (). A pitch of the counter electrode line elements () is larger than a pitch of the first electrodes () and/or second electrodes ().

Touch panel

An apparatus for processing signals from a touch panel. The touch panel includes a layer of piezoelectric material disposed between a number of sensing electrodes and one or more common electrodes. The apparatus includes a capacitive touch controller for connection to the sensing electrodes and a switch network including inputs for connection to the sensing electrodes and an output connected to system ground or a common mode voltage. The apparatus includes a circuit for connection to the common electrodes and to generate, for each common electrode, a corresponding pressure signal indicative of a pressure applied to the touch panel proximate to that common electrode. The apparatus includes a controller to control the switch network to couple any connected sensing electrodes to system ground or the common mode voltage during a pressure measurement period, and to sample the one or more second pressure signals during the pressure measurement period.

Touch panel system with piezoelectric pressure sensing

An apparatus () for processing signals from a touch panel () is described. The touch panel () includes a layer of piezoelectric material () disposed between a plurality of sensing electrodes () and at least one common electrode (). The apparatus () includes a first circuit () for connection to the plurality of sensing electrodes (). The first circuit () is configured to generate one or more first pressure signals (). Each first pressure signal () corresponds to one or more sensing electrodes () and is indicative of a pressure acting on the touch panel () proximate to the corresponding one or more sensing electrodes (). The apparatus also includes a second circuit () for connection to the at least one common electrode (). The second circuit () is configured to generate a second pressure signal () indicative of a total pressure applied to the touch panel (). The apparatus also includes a controller () configured to determine an estimate of the total pressure based on a weighted difference of the second pressure signal () and a sum over the one or more first pressure signals ().

A device () for processing signals from a projected capacitance touch panel () is described. The projected capacitance touch panel () includes a layer of piezoelectric material () disposed between a number of sensing electrodes () and at least one counter electrode (). The device () includes a capacitive touch controller () having a number of measurement ports (). The device () also includes a number of charge amplifiers (). The device () also includes a number of terminals (C, . . . , C, D, . . . , D) for connection to the sensing electrodes () of the projected capacitance touch panel (). Each terminal (C, . . . , C, D, . . . , D) is connected to one of the measurement ports (). Each terminal (C, . . . , C, D, . . . , D) is also connected to an input of one of the charge amplifiers () via a corresponding switch (SW) of a number of switches (). The device () also includes a controller () configured to synchronise the capacitive touch controller () and the number of switches (SW,) so that during a first portion ([t, t]) of a cycle the capacitive touch controller () outputs a capacitance measurement signal () to one or more of the terminals (C, . . . , C, D, . . . , D), and the plurality of charge amplifiers () are disconnected from the terminals (C, . . . , C, D, . . . , D) by the respective switches (SW,). The controller () is also configured to synchronise the capacitive touch controller () and the number of switches (SW,) so that during a second portion ([t, t]) of the cycle the capacitive touch controller () does not output the capacitance measurement signal (), and one or more of the charge amplifiers () are connected to the corresponding terminals (C, . . . , C, D, . . . , D) by the respective switches (SW,).

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Cambridge, United Kingdom

Jiahao Li