Ink remaining amount detecting device, method for detecting ink remaining amount, and ink jet printing apparatus

摘要

According to the present invention, in the case where the amount of ink remaining in an ink tank is detected using light from a light emitting unit, whether or not the amount of remaining ink is smaller than a predetermined value can be accurately determined with a decrease in the life of the light emitting unit suppressed. Thus, the present invention determines a difference between output signals each output by the light receiving unit according to a corresponding one of at least two of a plurality of levels of light emissions from the light emitting unit. Based on the difference, whether or not the amount of remaining ink is smaller than the predetermined value is determined.

主权项

1. An ink remaining amount detecting device that determines whether or not an amount of ink remaining in an ink tank is smaller than a predetermined amount, the device comprising:
a reflector provided in the ink tank and in which an optical reflectance obtained in a case where an amount of ink remaining in the ink tank is smaller than the predetermined amount is higher than an optical reflectance obtained in a case where an amount of ink remaining in the ink tank is equal to or larger than the predetermined amount; a light emitting unit configured to generate light allowed to enter the reflector; a light receiving unit configured to receive light reflected by the reflector and outputting an output signal according to an amount of received reflected light; a control unit configured to perform light emission control that switches an emission intensity of the light emitting unit among a plurality of levels; and a determination unit configured to determine whether or not an amount of ink remaining in the ink tank has reached the predetermined amount based on an output signal output by the light receiving unit, wherein the determination unit determines whether or not a difference between output signals each output by the light receiving unit according to a corresponding each of at least two of the plurality of levels of light emissions has reached a specific value, the control unit switches an emission intensity of the light emitting unit to a higher level than the levels of the two light emissions in a case where the determination unit determines that a difference of output signals has reached the specific value, and the determination unit determines that an amount of remaining ink has reached the predetermined amount in a case where an output signal output by the light receiving unit according to light with the higher emission intensity generated by the light emitting unit has reached a preset threshold value.