US 9,811,023 B2
Developing device, image forming apparatus, and toner detection method
Akinori Yamaguchi, Osaka (JP); and Naoki Nakatake, Hyogo (JP)
Assigned to RICOH COMPANY, LTD., Tokyo (JP)
Filed by Akinori Yamaguchi, Osaka (JP); and Naoki Nakatake, Hyogo (JP)
Filed on Nov. 3, 2014, as Appl. No. 14/531,049.
Claims priority of application No. 2013-230720 (JP), filed on Nov. 6, 2013; and application No. 2014-197382 (JP), filed on Sep. 26, 2014.
Prior Publication US 2015/0125167 A1, May 7, 2015
Int. Cl. G03G 15/08 (2006.01)
CPC G03G 15/0831 (2013.01) [G03G 15/0889 (2013.01); G03G 15/086 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A developing device comprising:
a toner container disposed in the developing device;
a toner detection unit to detect whether there is toner that is stored;
a light emitting element provided in the toner detection unit to emit light for detecting presence or absence of the toner in the toner detection unit;
a light receiving element provided in the toner detection unit to receive the light emitted from the light emitting element;
a stirring unit that stirs toner in the toner container; a calculation unit that calculates an output duty by comparing an output voltage of the toner detection unit obtained based on output of the light receiving element, representing whether there is toner after stirring, with a predetermined voltage value;
a flowability determining unit that determines level of toner flowability based on factor of variation of toner flowability;
a storage unit that stores a table including plural sub-tables corresponding to plural respective levels of flowability, each sub-table amongst the plural sub-tables representing, for a corresponding level of flowability, a correspondence relationship that is previously set, between sensor duty and an amount of remaining toner at the corresponding level of flowability; and
a remaining amount detection unit that detects an amount of remaining toner at the output duty by referring to (i) a selected sub-table, amongst the plural sub-tables, which corresponds to (ii) the level of toner flowability determined by the flowability determining unit, at the output duty calculated by the calculation unit based on a current output of the light receiving element.