Ultrasonic lens cleaning with travelling wave excitation
AssigneeTexas Instruments Incorporated
InventorsYunhong Li, David P. Magee, Stephen John Fedigan
Life of this patent
Estimating the term…
Abstract
Disclosed examples include ultrasonic lens cleaning systems and driver circuits to clean a lens using four or more transducer segments mechanically coupled to the lens, in which the driver circuit provides phase shifted oscillating signals to the transducer segments to generate a mechanical traveling wave rotating around the center axis of the lens to vibrate the lens for improved ultrasonic cleaning.
Claims22
An ultrasonic cleaning system, comprising:
- an integer number NS transducer segments mechanically coupled to a lens, NS being an even integer greater than or equal to 4, the individual transducer segments radially spaced from a center axis of the lens and angularly spaced from one another around a periphery of the lens;
- and
- a driver circuit to provide phase shifted oscillating signals to the transducer segments to generate a mechanical traveling wave rotating around the center axis to vibrate the lens.
An integrated circuit (IC) to drive an ultrasonic lens cleaner, comprising:
- a signal generator circuit to generate a first output signal that oscillates at a non-zero frequency;
- a phase shift circuit to generate a second output signal that oscillates at the non-zero frequency, the second output signal phase shifted from the first output signal by a non-zero angle;
- a first amplifier including an input to receive the first output signal, and a first amplifier output to generate a first amplified signal based on the first output signal;
- a second amplifier including an input to receive the second output signal, and a second amplifier output to generate a second amplified signal based on the first output signal;
- a plurality of driver signal output terminal pairs, the individual driver signal output terminal pairs including:
- a first output terminal coupleable to a first side of a corresponding one of a plurality of transducer segments mechanically coupled to a lens, and
- a second output terminal coupleable to a second side of the corresponding transducer segment;
- and
- a routing circuit to deliver the first amplified signal to a first set of the output terminals and to deliver the second amplified signal to a second set of the output terminals to generate a mechanical traveling wave to vibrate the lens.
A method to clean a lens using a plurality of transducer segments mechanically coupled to the lens, the method comprising:
- providing a first signal that oscillates at a non-zero frequency;
- providing a second signal that oscillates at the non-zero frequency, the second output signal phase shifted from the first output signal by a non-zero angle;
- amplifying the first signal to generate a first amplified signal;
- amplifying the second signal to generate a second amplified signal;
- providing the first amplified signal to a first set of the transducer segments;
- and
- providing the second amplified signal to a second set of the transducer segments to generate the mechanical traveling wave to vibrate the lens.
Dependencies are inferred from the claim text.