A display panel and a display device are provided. The display panel comprises a central region and peripheral regions. The peripheral regions are provided at two opposite ends of the display panel and have a first curvature; the central region is provided between the two opposite ends of the display panel and has a second curvature; and the second curvature of the central region is smaller than the first curvature of the peripheral regions.

Display panel and display device

An apparatus comprises a fingerprint sensor having a set of capacitive elements configured for capacitively coupling to a user fingerprint. The fingerprint sensor may be disposed under a control button or display element of an electronic device, for example one or more of a control button and a display component. A responsive element is responsive to proximity of the user fingerprint, for example one or both of a first circuit responsive to motion of the control button, and a second circuit responsive to a coupling between the fingerprint and a surface of the display element. The fingerprint sensor is disposed closer to the fingerprint than the responsive element. The control button or display component may include an anisotropic dielectric material, for example sapphire.

Capacitive sensor packaging

A fingerprint sensor is incorporated in a display stack in an electronic device. A single fingerprint can be captured at one time at a single pre-defined fixed location on a display. Alternatively, a single fingerprint can be acquired at one time at any location on a display. Alternatively, multiple touches on the display can be acquired substantially simultaneously where only one fingerprint is captured at a time or where all of the fingerprints are acquired at the same time. The fingerprint sensor can be implemented as an integrated circuit connected to a bottom surface of a cover sheet, near the bottom surface of the cover sheet, or connected to a top surface of a display. Alternatively, the fingerprint sensor can be implemented as a full panel fingerprint sensor.

Fingerprint sensor in an electronic device

A low cost, two-dimensional, fingerprint sensor includes a pixel array, each pixel including a switch and a pixel electrode for forming a capacitance with a fingertip. One or more active transmission electrodes are spaced from a selected row of the pixel array, and transmit a carrier signal into the finger without direct coupling into the selected pixels. Signals sensed by the pixel array are coupled to an independent integrated circuit, and connections between the IC and the pixel array are reduced by demultiplexing row select lines, and by multiplexing sensed column data. Differential sensing may be used to improve common mode noise rejection. The fingerprint sensor may be conveniently incorporated within a conventional touchpad LCD panel, and can mimic the performance of lower density touchpad pixels.

Apparatus and Method for TFT Fingerprint Sensor

Various structures and methods are disclosed for packaging a biometric sensor, such as a capacitive biometric sensor. Embodiments incorporate various placements of the biometric sensor, structure surrounding a biometric sensor, connection structures (electrical, physical, or both), and techniques for enhanced sensor imaging, sensor retention, and guiding a user's finger to a proper location above a biometric sensor. For example, A biometric sensor assembly can include an aperture formed in a trim with a cap disposed in the aperture. A biometric sensor may be positioned below the cap and a switch positioned below the biometric sensor.

Biometric sensor stack structure

A capacitive fingerprint sensor comprises a fingerprint capacitor, a reference capacitor, a first transistor, a second transistor, a comparator and a multiplexer. The fingerprint capacitor has a capacitance that is either a valley capacitance CFV or a ridge capacitance CFR, wherein CFV is smaller than CFR. One end of the reference capacitor CS is connected to the fingerprint capacitor, and the other end is connected to a trigger signal, wherein the trigger signal is initiated only during a precharge phase. The first transistor is configured to control the fingerprint capacitor during a scan line period. The second transistor is configured to precharge the fingerprint and reference capacitors. One end of the comparator is connected to the second transistor. The multiplexer is connected to another input end of the comparator for providing a first voltage VA and a threshold voltage Vth.

Kai Lan Chuang

Papers

Capacitive fingerprint sensor and the panel thereof