Patent ID: 8391770

Claim:
A measuring device of a length of a recording material comprising: a rotary unit that rotates while coming into contact with the recording material when the recording material is transported on the rotary unit; a pulse signal output unit that outputs a pulse signal in response to a rotation angle of the rotary unit; a first detection unit that detects the recording material arranged on an upstream of the rotary unit in a transport direction of the recording material; a second detection unit that detects the recording material arranged on a downstream of the rotary unit in the transport direction of the recording material; and a calculation unit that calculates a length of the recording material, wherein the calculation unit calculates a piece of the length of the recording material corresponding to a time below a pulse interval of the pulse signal based on (i) a distance in the transport direction between the first detection unit and the second detection unit and (ii) a period in which one of the first detection unit and the second detection unit detects the recording material, and the calculation unit calculates the total length in the transport direction of the recording material based on (iii) the calculated length, (iv) the distance between the first detection unit and the second detection unit, and (v) the number of pulses outputted from the pulse signal output unit while both of the first detection unit and the second detection unit are detecting the recording material.