Method and apparatus for generating piezoelectric transducer excitation waveforms using a boost converter
First Claim
1. A method of deforming a material comprising:
- dynamically adjusting a peak charging current to adjust an energy transfer rate of a DC-to-DC step up converter;
applying according to a predetermined pattern a controlled charge to the deformable material; and
providing an increasing energy transfer rate to reduce a voltage step size so as to adjust a waveform according to the predetermined pattern.
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Abstract
Transducers formed as part of a touchscreen system emulate the motion of a pushbutton or other mechanical elements. A touchscreen system positions a transducer adjacent to an icon displayed on the touchscreen surface. When a user touches the icon, the transducer senses the touch and is then deformed in a pattern that emulates a mechanical motion, giving the user the sensation of touching a mechanical button. An excitation signal applied to the transducer is compared to a target excitation signal that, when applied to the transducer, causes the transducer to emulate the desired motion. When any differences between the two signals are detected, the excitation signal is adjusted so that the motion is corrected. The target excitation signal, or time and voltage segments defining it, are stored in memory and retrieved for comparison. The excitation signal is also selected to reduce any acoustic artifacts that can cause the transducer to generate audible clicks.
66 Citations
14 Claims
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1. A method of deforming a material comprising:
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dynamically adjusting a peak charging current to adjust an energy transfer rate of a DC-to-DC step up converter; applying according to a predetermined pattern a controlled charge to the deformable material; and providing an increasing energy transfer rate to reduce a voltage step size so as to adjust a waveform according to the predetermined pattern. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification