US 2018/0018859 A1Published application

Touch sensitive device

AssigneeNVF Tech Ltd

InventorNeil HARRIS

Life of this patent

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Abstract

A method of generating a set of filters determining an initial estimate of a filter to be applied to a signal associated with each transducer; defining a model of the system; calculating the vibration of the member as an output of the model of the system; calculating the output of the model by comparing the output of the model with a measured value; determining changed parameter values of parameters of the model; recalculating the error value for the output of the model by comparing the output of the model with the changed parameter values with the measured value; comparing the recalculated error value with the reference error value; setting the recalculated error value as the reference error value, setting the changed parameter values as the model parameters, and repeating the above steps, or outputting the model parameters; generating a set of new filters each using respective output model parameters.

Claims20

Dependent claims

A method of generating a set of filters for a touch sensitive device

comprising a touch-sensitive member and a plurality of transducers mounted to the member, the method comprising:
choosing a set of frequencies for use in the filters;
determining an impulse response of a filter for each respective transducer to be applied to a signal associated with each transducer;
calculating the transfer function of each filter, wherein each filter has a transfer function with at least one pole and at least one zero, and calculating the transfer function of each said filter comprises,
determining at least one pole coefficient which determines at least one pole;
determining, using said at least one pole coefficient, a pole representation of the transfer function which filters said input signal using said at least one pole;
using said respective impulse response, calculating at least one zero coefficient which determines at least one zero;
combining said pole representation of the transfer function with said at least one zero coefficient to calculate said transfer function of said filter;
and
generating a set of filters comprising said calculated filters,
wherein each said filter is an infinite impulse response filter, and
wherein said infinite impulse response filter has a transfer function of the form:
Hz

(
z
,
d
)
:=
∑
k

(
d
k
,
0
+
d
k
,
1
·
z
-
1
+
d
k
,
2
·
z
-
2
1
+
a
k
,
0
·
z
-
1
+
a
k
,
1
·
z
-
2
)
where dk,0 dk,1 dk,2 are zero coefficients which determine the zeros, ak,0 ak,1 ak,2 are pole coefficients which determine the poles and k is the number of poles.

64 more elements

A method of generating a desired touch sensitivity in a touch sensitive device comprising a touch-sensitive member and a plurality of transducers mounted to the member, the method comprising:

choosing a set of frequencies for use in a set of filters to be generated for the touch sensitive device;
calculating a set of transfer functions of respective filters for each transducer to be applied to a signal associated with each transducer;
wherein each filter has a transfer function with at least one pole and at least one zero and calculating the transfer function of each said filter comprises,
determining at least one pole coefficient which determines said at least one pole;
determining, using said at least one pole coefficient, a pole representation of the transfer function which filters said input signal using said at least one pole;
using an eigenvector method to determine at least one zero coefficient which determines said at least one zero;
and
combining said pole representation of the transfer function with said at least one zero coefficient to determine said transfer function for said filter;
generating the set of filters comprising said calculated filters;
applying the set of filters to an output signal from each transducer to generate filtered output signals;
and
using the filtered output signals to provide the desired touch sensitivity.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/684,922Filed 23 Aug 2017
Priority: GB 1012387.523 Jul 2010
Published: 18 Jan 2018
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G08B 6/00
Tactile signalling systems
G06F 3/016
Input arrangements or combined input and output arrangements for interaction between user and computer: input arrangements with force or tactile…
G06F 3/041
Arrangements for converting the position or the displacement of a member into a coded form: digitisers, e.g. for touch screens or touch pads,…
G06F 3/0436
Using propagating acoustic waves: in which generating transducers and detecting transducers are attached to a single acoustic waves transmission…

Family

Application13/811,904Division · filed 11 Jun 2013
Application15/684,922Division
US 10,769,900 B2Related patent
US 2013/0249831 A1Published application
US 2018/0018859 A1This patent

From the US filing history. Foreign family members aren’t listed.