(19)
(11) EP 3 708 380 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
07.04.2021 Bulletin 2021/14

(43) Date of publication A2:
16.09.2020 Bulletin 2020/38

(21) Application number: 20161550.7

(22) Date of filing: 06.03.2020
(51) International Patent Classification (IPC): 
B41J 29/393(2006.01)
B41J 25/00(2006.01)
 B41J 2/21(2006.01)
(84) Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated Extension States:
BA ME
Designated Validation States:
KH MA MD TN

(30) Priority: 14.03.2019 JP 2019047192

(71) Applicant: Ricoh Company, Ltd.
Tokyo 143-8555 (JP)

(72) Inventor:
  • MOTEGI, Akio
    Ohta-ku, Tokyo 143-8555 (JP)

(74) Representative: White, Duncan Rohan 
Marks & Clerk LLP Fletcher House Heatley Road The Oxford Science Park
Oxford OX4 4GE
Oxford OX4 4GE (GB)

   


(54) LIQUID DISCHARGING APPARATUS


(57) A liquid discharging apparatus (1) includes a liquid discharging head (220) including nozzles arranged linearly and configured to discharge liquid onto a recording medium (P) conveyed by a conveying unit (210); a scanner (231, 232) installed in such a manner that a main-scanning direction of the scanner (231, 232) is aligned with a direction in which the nozzles of the liquid discharging head (220) are arranged; a chart generating unit (101) configured to generate a defective nozzle detection chart (C) in which lines (L) in a sub-scanning direction corresponding to the respective nozzles of the liquid discharging head (220) are arranged; and a position detecting unit (102) configured to perform an interpolating process on pixel values of a plurality of pixels around a line position detected from pixel values of scanned data of the defective nozzle detection chart (C) scanned by a scanner (231, 232), and detect a position where a differential of an interpolation function derived from the interpolating process is zero, as a line position.







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