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

Claim 3:
4. The image forming apparatus according to claim 1,
wherein
the program instructions further cause the processor to
detect the rear edge of the mark based on a third threshold set between a brightness value of the background color of the recording medium and a brightness value of the mark, and
calculate a position of the rear edge in a width of the rear line based on a product of a ratio and a detected value difference, the ratio being a ratio between (i) a difference between a brightness value of the rear line and a brightness value of an immediately preceding rear line that is a line immediately preceding the rear line and (ii) a difference between a brightness value of the immediately preceding rear line and the third threshold, the detected value difference being a difference between (iii) a detected value output from the detector corresponding to the rear line and (iv) a detected value output from the detector corresponding to the immediately preceding rear line.