Ricoh Company, Ltd.

Noboru Hirano

Yuichiro Maeyama

Tatsuya Ishii

Shingo Takai

Yoshihiro Takahashi

Dai Kurabayashi

Takayuki Shibata

Yohei Sakon

An image forming apparatus includes a conveyer configured to convey a recording medium on which a mark is formed; an image reader configured to read an image formed on the recording medium while the recording medium is being conveyed; a detector configured to detected a value corresponding to a conveyance amount of the recording medium conveyed by the conveyer and output the detected value; and a processor and a memory that stores program instructions causing the processor to calculate 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 from the detector when an edge of the recording medium and the mark are read by the image reader.

Image forming apparatus and control method for controlling image forming apparatus

An image forming apparatus is configured to detect, from image data of a recording medium on which a plurality of marks are printed, positions of outer edges being edges closer to ends of the image data and positions of inner edges being inside edges not closer to the ends of the image data in both of a first direction and a second direction different from the first direction; identify, with respect to a target mark for which a reference position is to be detected and two marks adjacent to the target mark, first line segments connecting positions of inner edges and second line segments connecting positions of outer edges; and detect, as a reference position of the target mark, a midpoint of a line segment connecting an intersection of the two first line segments and an intersection of the two second line segments.

Image forming apparatus, position detection method, and computer-readable medium

An image scanner includes a conveyance path and a conveyor that conveys a medium through the conveyance path. The medium bears a detection mark that is spaced from a leading edge of the medium in a medium conveyance direction. A background member is disposed opposite the conveyance path. A luminance sensor is disposed opposite the background member via the conveyance path. The luminance sensor detects a luminance value of each of the background member and the medium. A controller controls the luminance sensor to detect the luminance value at a plurality of times while the conveyor conveys the medium so as to obtain a plurality of detected luminance values. The controller determines a ground color luminance value of a ground color area on the medium based on a determination range including a first peak luminance value among the plurality of detected luminance values.

Correcting back side image data based on positions of four corner detection marks specified using ground color luminance

A printing apparatus includes a printing device to print, on a sheet, a detection mark for acquiring an amount of deviation of an image, a detection device to read a position of the detection mark and acquire the amount of deviation of the position of the detection mark, and control circuitry to perform correction according to the amount of deviation. The circuitry prints the detection marks on both faces of the sheet in duplex printing, reads the detection marks on both faces with the detection device, calculates a first correction value from the position of the detection mark on a first face on which printing is performed first, calculates a second correction value from the position of the detection mark on a second face on which printing is performed later, and calculates a third correction value from the positions of the detection marks on the first and second faces.

Printing apparatus

An image reading device includes reading devices arranged in a main scanning direction perpendicular to a sub-scanning direction, position reference members each including a reference pattern for correcting relative positions of pixels in each of the reading devices or relative positions of the reading devices, and circuitry. The reference members move in the sub-scanning direction relative to the reading devices, and include first reference members for correcting the relative positions of the reading devices and second reference members for correcting the relative positions of the pixels in each of the reading devices. While switching between the first reference members and the second reference members, the circuitry calculates a correction value for a deviation of the pixels in each of the reading devices and a correction value for a deviation of the reading devices based on a result of reading of the reference members.

Growing community of inventors

Kanagawa, Japan

Noboru Hirano