Abstract: An electronic device, method, and computer program product automatically support fingerprint authentication using a fingerprint scanner on an opposite side even when the electronic device is detected as being grasped upside down. The electronic device includes front and back fingerprint scanners respectively exposed on front and back sides of a device housing. In response to determining that a requirement exists for scanning a fingerprint of a user while the electronic device is upside down, a controller of the electronic device triggers at least one of the front and the back fingerprint scanners to initiate scanning. The controller receives a fingerprint image from a corresponding one of the front and back fingerprint scanner. The controller authenticates the user in response to identifying that an upside-down version of the received fingerprint image corresponds to a fingerprint of an authorized user, based on authentication data stored in memory of the electronic device.

Abstract: An electronic device, method, and computer program product provide a predictable external finger area on a “rollable display device” for fingerprint authentication that is available at least in both a fully retracted position and fully extended position. The electronic device selectively operates a translation mechanism to slide a blade assembly relative to a device housing between the fully retracted position and the fully extended position. The blade assembly has a blade slidably coupled to a device housing and having a flexible display attached to the blade. The blade assembly has first and second fingerprint-on-display (FOD) areas that are optically transmissive, enabling light to pass through the blade assembly. While retracted, both fingerprint scanners are aligned FOD areas for use while looking at either the front or back portions of the flexible display. While extended, the front fingerprint scanner is aligned with the second FOD area while viewing the flexible display.