Patent ID: 11956392
Assignee: RICOH COMPANY, LTD.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H  B | IPC B  H

Claim 8:
9. A control method for controlling an image forming apparatus that includes a processor and a memory that stores program instructions causing the processor to execute the control method, the control method comprising:
conveying a recording medium on which a mark is formed;
reading an image formed on the recording medium while the recording medium is being conveyed;
detecting a value corresponding to a conveyance amount of the recording medium conveyed and outputting the detected value; and
calculating a position of the mark on the recording medium with respect to a conveyance direction of the recording medium based on respective detected values output when an edge of the recording medium and the mark are read,
wherein
the reading comprises reading the image on a per line basis with respect to a line extending along a direction perpendicular to the conveyance direction of the recording medium,
a length of the mark with respect to the conveyance direction is greater than twice a width of each line with respect to the conveyance direction,
wherein the control method further comprises
detecting, based on a brightness value of each line read, the edge of the recording medium, a front edge of the mark, and a rear edge of the mark, and
calculating a position of the mark on the recording medium with respect to the conveyance direction based on a difference between (i) an intermediate value between a detected value corresponding to a front line at which the front edge of the mark is detected and a detected value corresponding to a rear line at which the rear edge of the mark is detected, and (ii) a detected value corresponding to an edge line at which the edge of the recording medium is detected.