Patent ID: 7722171
Filing Date: 2010-05-25
Classification: B41J

Abstract:
1. An ink refilling system for an ink jet printer, wherein ink is transferred from a main tank to an auxiliary tank of a printhead, comprising: a memory located on board of said auxiliary tank; a detecting circuit for detecting values of the level of ink in said auxiliary tank at different filling conditions; initialization means for initializing each new printhead mounted on said printer by storing in said memory predetermined reference values of the level of ink in said auxiliary tank; means for repeatedly comparing, against said reference values, the values of said level of ink in said auxiliary tank, as detected by said detecting circuit during printing of said printhead; means for activating the refilling of said auxiliary tank each time that the detected value of the level of ink in said auxiliary tank is less than a first one of said predetermined reference values corresponding to an upper limit of a refilling intervention window; means for establishing that said main tank is empty, when at least two values of said level of ink in said auxiliary tank, as detected in succession in at least two occasions, are constant and lower than a second one of said predetermined reference values corresponding to a normal reference value of said level of ink; and means for providing a message that said main tank, as being empty, has to be substituted.