Ricoh Company, Ltd.

Toshihide Inaba

Shigeru Morinaga

Genichiro Kawamichi

Takeo Shirato

Hideharu Miki

Kohji Tokuyama

Hiroshi Andoh

Mitsuyuki Karasawa

A device for detecting a state of a liquid droplet discharged from each of nozzles placed in one or more rows, includes a light emitting element to emit a light beam to the liquid droplet from a nozzle in question, and a pair of light receiving elements disposed on both sides of a beam diameter of the light beam via an optical axis to receive scattered light occurring from the liquid droplet for detecting a state of the discharged liquid droplet on the basis of the scattered light. Either of the pair of the light receiving elements is selected for receiving the scattered light from the liquid droplet discharged from the nozzle according to a positional relation between the nozzle and the pair of light receiving elements.

Device and method for detecting state of discharged liquid droplet and image forming device incorporating such device

A moving unit causes a relative movement of a web and a mark detecting unit for detecting a ground color of the web and a mark color in a predetermined direction. A measuring unit measures a measurement value corresponding to a moving amount of the mark detecting unit with respect to the web in a time from when a detected color is switched from the ground color to the mark color till when a detected color is back to the ground color. A setting unit sets a threshold used for determining whether the color detected is the ground color or the mark color on the basis of the mark color detected by the mark detecting unit at the time when the mark detecting unit is moved in a reverse direction for a distance of half the measurement value since the color detected is back to the ground color.

Image forming apparatus and threshold setting method

Growing community of inventors

Tokyo, Japan

Toshihide Inaba