Title:
MEDIUM DETECTION DEVICE AND IMAGE FORMING APPARATUS
Document Type and Number:
Japanese Patent JP2020148837
Kind Code:
A
Abstract:
To provide a technique to improve the accuracy in detecting a position of a medium using a difference in contrast.SOLUTION: A medium detection device comprises: a first calculation unit that calculates the concentration level of a first area based on a reflected optical signal; a second calculation unit that calculates the concentration level of a second area separated from the first area in a main scanning direction based on the reflected optical signal; a threshold determination unit that determines a threshold level based on one of the concentration levels calculated by the first calculation unit and the second calculation unit, the one with a larger difference from the concentration level of a conveyance path; a third calculation unit that calculates the concentration level of every pixel in a position detection area extending in the main scanning direction across ends of a medium based on the reflected optical signal, on the downstream side of the first area and the second area on the medium in the conveyance direction; and a position specification unit that specifies, as an end position of the medium, a position of a pixel, of the plurality of pixels included in the position detection area, in which the concentration level calculated by the third calculation unit changes from one of less than the threshold level and equal to or more than the threshold level to the other.SELECTED DRAWING: Figure 10
Inventors:
KAIMA NOBUKANE
Application Number:
JP2019044241A
Publication Date:
September 17, 2020
Filing Date:
March 11, 2019
Export Citation:
Assignee:
RICOH CO LTD
International Classes:
G03G21/00; B41J3/60; B41J25/20; H04N1/04
Attorney, Agent or Firm:
Takashi Munakata