Synaptics Corporation

Fingerprint Cards Ab

Mark Pude

Eric Scott Bohannon

Jeffrey S Lillie

Patrick Smith

Erik Jonathon Thompson

Lynn Russell Kern

Eric Moule

Christopher A Ludden

Thomas A Mackin

Imre Knausz

Kevin Fronczak

Murat Ozbas

A hybrid capacitive and optical fingerprint sensor system includes: capacitive sensor electrodes; an optical image sensor having a plurality of image sensor pixels; light conditioning elements, configured to condition light from a sensing region of the hybrid capacitive and optical fingerprint sensor for detection by the optical image sensor; and a processing system having one or more controllers, configured to operate the capacitive sensor electrodes in a low-power mode of operation for the hybrid capacitive and optical fingerprint sensor, and to operate the optical image sensor to acquire an image from the sensing region of the hybrid capacitive and optical fingerprint sensor.

Hybrid optical and capacitive sensor

A system includes: a power supply; an adaptively biased power event detection comparator; and an adaptive bias circuit for the adaptively biased power event detection comparator. The adaptively biased power event detection comparator is configured to compare a first input corresponding to a voltage level of the power supply with a second input corresponding to a reference voltage. The adaptive bias circuit is configured to increase a bias current for the adaptively biased power event detection comparator based on the voltage level of the power supply decreasing to be closer to the reference voltage.

Adaptive bias circuit for power event detection comparator

An input device for capacitive sensing includes: a plurality of transmitter electrodes and a plurality of receiver electrodes. The input device is configured to: operate in a first mode by driving sensing signals onto each of the transmitter electrodes and receiving separate detected signals corresponding to each of the plurality of receiver electrodes; and operate in a second mode by driving a common sensing signal onto a plurality of the transmitter electrodes and receiving a common detected signal corresponding to at least one receiver electrode selected from the plurality of receiver electrodes.

Fingerprint sensor to support wake on finger and navigation

Embodiments of the invention generally provide an device that regulates a negative output voltage from a power supply using a positive representation of the negative output voltage. To convert the negative voltage to a positive voltage, the device changes the negative voltage into a current using, for example, a current generator that outputs a current corresponding to the negative voltage received from the power supply. This current is then transferred from the negative voltage domain to the positive voltage domain and is fed through a voltage generator that outputs a positive voltage corresponding to the current. By doing so, the negative voltage output is transformed into a corresponding positive voltage. This positive voltage may then be compared to a positive reference voltage to determine an error signal for adjusting the power supply.

Negative voltage feedback generator

Embodiments described herein synchronize a switching frequency of switched power supplies with timing events associated with updating a display screen or performing touch sensing. For example, a touch event may be the time needed for a touch controller to scan a plurality of sensing electrodes. Because noise is introduced each time switched power supplies switch between different stages, the touch controller may instruct a power management controller to switch between the stages (i.e., adjust the switching frequency) at the same time during each touch event. Even though the switched power supplies are permitted to introduce noise into the touch system, the noise happens at the same time during each touch event. Accordingly, the effect of the noise is the same for each touch event and is cancelled out. A similar process may be used for synchronizing the switching frequency to display events.

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Victor, NY, United States of America

Mark Pude