Velocity detecting apparatus and liquid ejecting apparatus

摘要

A controller performs: correcting a pre-correction pulse signal and outputting the corrected pre-correction pulse signal as a post-correction pulse signal that switches between third and fourth levels, the correcting including: switching the post-correction pulse signal from the third to fourth level when first or second condition is satisfied, the first condition being that the pre-correction pulse signal switches from the first to second level, the second condition being that duration of the third level exceeds a first reference period; and switching the post-correction pulse signal from the fourth to third level when both of third and fourth conditions are satisfied, the third condition being that duration of the fourth level exceeds a second reference period, the fourth condition being that the pre-correction pulse signal is on the first level; and calculating a relative moving velocity of the moving device based on temporal changes between the third and fourth levels.

主权项

1. A velocity detecting apparatus comprising:
a region formation member having a first region and a second region that are arranged cyclically in a particular direction, the first region and the second region having different optical characteristics from each other; an optical sensor configured to emit light to the region formation member and to output a pre-correction pulse signal that is on a first level when facing the first region and that is on a second level when facing the second region, the second level being different from the first level, the optical characteristics of the first region and the second region being such that the optical sensor receives a larger amount of light from the second region than from the first region; a moving device configured to move the optical sensor and the region formation member relative to each other in the particular direction; and a controller configured to control the optical sensor and the moving device, the controller being configured to perform:
correcting the pre-correction pulse signal outputted from the optical sensor and outputting the corrected pre-correction pulse signal as a post-correction pulse signal that switches between a third level and a fourth level different from each other, the correcting comprising:
switching the post-correction pulse signal from the third level to the fourth level when at least one of a first condition and a second condition is satisfied, the first condition being that the pre-correction pulse signal switches from the first level to the second level, the second condition being that duration of a section in which the post-correction pulse signal is on the third level exceeds a first reference period; andswitching the post-correction pulse signal from the fourth level to the third level when both of a third condition and a fourth condition are satisfied, the third condition being that duration of a section in which the post-correction pulse signal is on the fourth level exceeds a second reference period, the fourth condition being that the pre-correction pulse signal is on the first level; andcalculating a relative moving velocity of the moving device based on temporal changes between the third level and the fourth level of the post-correction pulse signal.