An inkjet recording apparatus, comprising:
- a conveyance belt that is an endless belt and that conveys a recording medium;
- a recording head that is opposed to the conveyance belt and that includes a plurality of nozzles that perform image formation by ejecting ink onto the recording medium conveyed by the conveyance belt;
- a control portion that controls landing timing of ink ejected from the recording head onto the recording medium;
- an interval detection sensor that is disposed opposite the conveyance belt across a predetermined interval and that detects a thickness of the conveyance belt;
- a thickness detection reference member that is opposed to the interval detection sensor with the conveyance belt therebetween and that contacts a surface of the conveyance belt on an opposite side of the interval detection sensor;
- and
- a storage portion that stores the thickness of the conveyance belt detected by the interval detection sensor,
- wherein
- the conveyance belt has formed therein a detection hole that penetrates therethrough at a position overlapping with the thickness detection reference member with respect to a belt width direction perpendicular to a recording-medium conveyance direction,
- the interval detection sensor is capable of detecting a first opposition interval, which is between the interval detection sensor and the conveyance belt, and a second opposition interval, which is between the interval detection sensor and the thickness detection reference member, via the detection hole,
- the control portion is capable of executing:
- an interval detection mode in which the conveyance belt is caused to rotate and in which the first opposition interval and the second opposition interval are detected;
- a thickness calculation mode in which the thickness of the conveyance belt is calculated from a difference value between the first opposition interval and the second opposition interval detected in the interval detection mode and in which the thickness of the conveyance belt is stored in the storage portion;
- and
- a landing timing correction mode in which the landing timing is controlled corresponding to the thickness of the conveyance belt stored in the storage portion,
- in the landing timing correction mode, the control portion
- sets the landing timing to be equal to reference landing timing when the thickness of the conveyance belt stored in the storage portion is equal to a predetermined reference thickness,
- sets the landing timing to be earlier than the reference landing timing when the thickness of the conveyance belt stored in the storage portion is larger than the reference thickness, and
- sets the landing timing to be later than the reference landing timing when the thickness of the conveyance belt stored in the storage portion is smaller than the reference thickness,
- as the detection hole, a plurality of detection holes are formed in the belt width direction,
- as the detection sensor, a plurality of detection sensors are disposed at positions each individually overlapping with one of the detection holes in the belt width direction, and
- in the thickness calculation mode, the control portion is capable of calculating thickness distribution of the conveyance belt in the belt width direction based on a detection result of each of the interval detection sensors, and storing the thickness distribution in the storage portion.