Ricoh Company, Ltd.

Kenta Sasaki

Nobuyuki Satoh

Suguru Yokozawa

Takayuki Ito

Kohta Aoyagi

Masaya Kawarada

Kohtaroh Ikegami

A liquid discharge apparatus includes a liquid discharge head having at least one nozzle array including a plurality of nozzles lined in a nozzle array direction; a two-dimensional image sensor to capture an image formed by the liquid discharge head; and circuitry. The circuitry is configured to divide the nozzles into a plurality of nozzle units; form a pattern including a plurality of unit patterns with liquid discharged from the nozzle units, respectively; and detect a defective nozzle based on a captured image of each of the unit patterns. The unit patterns are arranged in a staggered manner. Each unit pattern is smaller in size than an image capture range of the two-dimensional image sensor. Each unit pattern includes a number of columns of lines extending in a direction perpendicular to the nozzle array direction, and the number of columns is not smaller than twice the number of nozzle arrays.

Liquid discharge apparatus, defective nozzle detection method, and recording medium

An imaging device includes an imaging unit to obtain a captured image of a test pattern and a reference mark to locate the test pattern and at least one processor. The test pattern includes a pair of first marks and a second mark. The processor includes a position detector configured to detect the reference mark in the captured image and locate the pair of first marks and the second mark in the captured image, and a ratio calculator configured to calculate one of a first ratio between a distance between the pair of first marks in the captured image and a deviation of the second mark in the captured image, and a second ratio between the distance between the pair of first marks in the captured image and a distance from one of the pair of first marks to the second mark in the captured image.

Imaging device, image forming apparatus, and method for detecting deviation of landing position

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Kanagawa, Japan

Kenta Sasaki