Ultrasonic fingerprint sensor with a contact layer of non-uniform thickness
摘要
說(shuō)明書
The captured at least one fingerprint image is combined to generate an output fingerprint image. In one embodiment, the plurality of fingerprint images is combined into a single output fingerprint image, wherein the single output fingerprint image reduces the impact of the interference pattern caused by the non-uniform thickness of the contact layer. In one embodiment, the plurality of fingerprint images is combined into a single output fingerprint image by averaging the plurality of fingerprint images. In another embodiment, the plurality of fingerprint images is combined into a single output fingerprint image by using convolution.
In another embodiment, the plurality of portions of the fingerprint image is combined into a single output fingerprint image. In one embodiment, the plurality of transmission frequencies provide constructive interference for corresponding portions of the plurality of portions of the fingerprint image during the imaging operation. In one embodiment, the portions of the plurality of portions include a plurality of pixels. In another embodiment, the portions of the plurality of portions include single pixels.
