Abstract: The present invention provides a method for controlling light emission of an ink cartridge, a control unit, a circuit board, an ink cartridge and an imaging device, to decrease misjudgment rate of the imaging device. The control method includes: receiving and identifying a light emitting control instruction from the imaging device main body; starting a light-on delay timing when identifying the light emitting control instruction is a light-on instruction; controlling the light emitting unit of the ink cartridge to stop emitting light when identifying the light emitting control instruction is a light-off instruction; controlling the light emitting unit to emit light when detecting a timing value of the light-on delay timing reaches a delay threshold value. The present invention avoids misjudgment problem of unable to pass position detection due to light amount inconsistent caused by manufacturing errors of the light emitting unit, when setting a light-on delay timing.

Abstract: The invention relates to an ink cartridge for an ink jet printer. The ink cartridge comprises a cartridge body and a detection mechanism for detecting the ink cartridge and residual quantity of ink, wherein the cartridge body comprises an ink tank for storing ink, an ink outlet for supplying ink to a printing head of the printer and an air inlet, the ink tank comprises a first ink chamber and a second ink chamber, a first negative pressure mechanism and a second negative pressure mechanism are arranged between the first ink chamber and the second cavity, the first negative pressure mechanism and the second negative pressure mechanism cooperatively control the ink inside the first ink chamber to be consumed preferentially than the ink inside the second ink chamber, and the second negative pressure mechanism generates negative pressure when a certain quantity of ink inside the ink tank is used for printing.