公开(公告)号：US20210402788A1

公开(公告)日：2021-12-30

申请号：US16959383

申请日：2019-10-25

Applicant: HEWLETT-PACKARD DEVELOPMENT COMPANY. LP.

Inventor： James Michael GARDNER ,  Frank D. DERRYBERRY ,  Sirena LU

IPC: B41J2/175

Abstract: A liquid level sensor package for a replaceable print liquid reservoir, the package including a substrate, a surface layer to contact a print liquid in the print liquid reservoir, and a layer stack including a number of metal layers disposed between the substrate and the surface layer. An array of heater elements disposed in one of the metal layers of the layer stack, and an array of thermal sensors disposed in a different one of the metal layers of the layer stack, each thermal sensor corresponding to a different heater element of the array of heater elements, and each thermal sensor to provide indication of a presence or absence of print liquid based on a sensed temperature after being heated by the corresponding heater element.