Remaining ink detecting device and ink jet head cartridge

摘要

A device for detecting a quantity of remaining ink includes first and second electrodes provided in an ink supply passage which connects an ink tank for storing an ink to a recording head for emitting the ink, and a detection means for detecting a resistance between the first and second electrodes. The second electrode is provided in the ink supply passage in an area relatively close to the recording head, whereas the first electrode is provided in the ink supply passage in an area relatively far from the recording head with the second electrode therebetween. The second electrode is maintained at the same potential as that of a substrate which constitutes the recording head and on which emission energy generating elements driven to emit the ink are disposed, whereas the first electrode is maintained at a potential different from that of the second electrode. Consequently, the amount of remaining ink can be detected by measuring changes in the resistance between the first and second electrodes.