Patent ID: 11922716
Assignee: FINGERPRINT CARDS ANACATUM IP AB
Field: Measurement (Instruments)
Classification: CPC A  G | IPC G

Claim 0:
1. A passive terahertz biometric imaging device operative in the terahertz range of radiation and configured to be arranged under an at least partially transparent display panel and configured to capture a terahertz image of a biometric object located on an opposite side of the transparent display panel, the terahertz biometric imaging device comprising:
an image sensor comprising an antenna pixel array configured to detect radiation in a terahertz range and arranged to detect terahertz radiation produced by the biometric object, for capturing a terahertz image of the biometric object without assisting terahertz radiation that illuminates the biometric object, wherein sub-dermal layers of the biometric object are detectable in the captured terahertz image,
wherein each of the pixels comprises a power detector including an antenna structure configured to sense terahertz radiation produced by the biometric object, and at least one on-chip frequency converting element connected to the antenna structure and configured to convert the sensed terahertz radiation to a signal at a lower frequency than the frequency of the terahertz radiation, or to a DC signal, for an analogue-to-digital converter to read as input.