ELECTRONIC DEVICE AND CIRCUIT FOR PROVIDING TACTILE FEEDBACK
First Claim
1. A circuit for controlling a piezoelectric actuator comprising:
- a piezoelectric actuator drive circuit operative to generate a unidirectional voltage drive signal, comprising a charging circuit operatively responsive to a first pulse-width-modulated control signal and a pulsed current sink discharge circuit operatively responsive to a second pulse-width-modulated control signal and operative to controllably draw packets of charge from a charged piezoelectric actuator.
4 Assignments
0 Petitions
Accused Products
Abstract
A circuit (800) for controlling at least one piezoelectric actuator (142) includes a piezoelectric drive circuit (802) that generates unidirectional voltage drive signal, also referred to as Vout, at node (804). The piezoelectric actuator drive circuit (802) includes a boost switcher circuit or charging circuit (806), a buck switcher circuit or pulsed current sink discharge circuit (808) and a control signal generating circuit (810) that receives an input control signal (812) from, for example, a keyboard processor or other suitable processor (604) indicating that the device has requested generation of haptic feedback utilizing the piezoelectric actuator (142). The control signal generating circuit (810) provides at least two pulse-with-modulated control signals, one to control the charging circuit and one to control the discharging circuit to produce the unidirectional voltage drive signal, that in one example is a raised cosine drive signal (904).
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Citations
22 Claims
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1. A circuit for controlling a piezoelectric actuator comprising:
a piezoelectric actuator drive circuit operative to generate a unidirectional voltage drive signal, comprising a charging circuit operatively responsive to a first pulse-width-modulated control signal and a pulsed current sink discharge circuit operatively responsive to a second pulse-width-modulated control signal and operative to controllably draw packets of charge from a charged piezoelectric actuator. - View Dependent Claims (2, 3, 4, 5)
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6. A keypad comprising:
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a touchscreen comprising a piezoelectric actuator operative to provide tactile feedback in response to touchscreen contact by a user; and a circuit operative to control the piezoelectric actuator comprising; a piezoelectric actuator drive circuit operative to generate a unidirectional voltage drive signal comprising a charging circuit operatively responsive to a first pulse-width-modulated control signal and a pulsed current sink discharge circuit operatively responsive to a second pulse-width-modulated control signal and operative to controllably draw packets of charge from a charged piezoelectric actuator. - View Dependent Claims (7, 8, 9, 10, 11)
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12. A handheld electronic device comprising:
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wireless telephone circuitry; and a keypad operatively coupled to the wireless telephone circuitry comprising; a touchscreen comprising a piezoelectric actuator operative to provide tactile feedback in response to touchscreen contact by a user; and a circuit operative to control the piezoelectric actuator comprising; a piezoelectric actuator drive circuit operative to generate a unidirectional voltage drive signal comprising a charging circuit operatively responsive to a first pulse-width-modulated control signal and a pulsed current sink discharge circuit operatively responsive to a second pulse-width-modulated control signal and operative to controllably draw packets of charge from a charged piezoelectric actuator. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A method comprising:
controlling actuation of a piezoelectric actuator of a touchscreen by generating a first pulse-width-modulated control signal to control a charging circuit to produce a portion of a unidirectional voltage drive signal and generating a second pulse-width-modulated control signal to control a pulsed current sink discharge circuit to controllably draw packets of charge from a charged piezoelectric actuator to produce another portion of the unidirectional voltage drive signal. - View Dependent Claims (19)
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20. A circuit for controlling a piezoelectric actuator comprising:
a piezoelectric actuator drive circuit operative to generate a unidirectional voltage drive signal, comprising a charging circuit operatively responsive to a first pulse-width-modulated control signal and a switched inductance discharge circuit operatively responsive to a second pulse-width-modulated control signal and operative to controllably draw packets of charge from a charged piezoelectric actuator. - View Dependent Claims (21, 22)
Specification