US 9,813,565 B2
Image forming apparatus
Takashi Inoue, Osaka (JP)
Assigned to Kyocera Document Solutions Inc., (JP)
Filed by KYOCERA Document Solutions Inc., Osaka (JP)
Filed on Nov. 22, 2016, as Appl. No. 15/359,455.
Claims priority of application No. 2015-233639 (JP), filed on Nov. 30, 2015.
Prior Publication US 2017/0155774 A1, Jun. 1, 2017
Int. Cl. H04N 1/00 (2006.01); G03G 15/00 (2006.01); G06K 1/00 (2006.01); G06K 9/00 (2006.01); H04N 1/60 (2006.01)
CPC H04N 1/00037 (2013.01) [G03G 15/556 (2013.01); G06K 9/00503 (2013.01); G06K 9/00543 (2013.01); H04N 1/00023 (2013.01); H04N 1/00904 (2013.01); H04N 1/00994 (2013.01); H04N 2201/0094 (2013.01)] 6 Claims
OG exemplary drawing
 
1. An image forming apparatus, comprising:
plural sensors (a) arranged respectively for plural toner colors and (b) configured to oscillate to generate and output detection signals with frequencies corresponding to toner densities using oscillator circuits;
an analog switch configured to select one detection signal among the detection signals outputted from the plural sensors;
a filter configured to decrease amplitude of the detection signal selected by the analog switch;
a first signal line configured to transmit the detection signal of which the amplitude has been decreased by the filter;
a comparator configured to compare the detection signal transmitted by the first signal line with a predetermined threshold value and output as the detection signal a signal of which a level is set as a high level or a low level in accordance with the comparison result, and thereby increase amplitude of the incoming detection signal transmitted by the first signal line; and
a receiver-side integrated circuit configured to (a) receive at a predetermined port the detection signal of which the amplitude has been increased by the comparator, (b) determine a frequency of the detection signal on the basis of levels of the received detection signal and (c) determine the toner density on the basis of the determined frequency.