DEVICE FOR DETECTING REMAINING QUANTITY OF RECORDING SHEET

PURPOSE:To inform the operator of remaining quantity of recording sheets by detecting a mark marked on the recording sheet just before the terminal end of the recording sheet so as to check the remaining quantity of the sheets, by preparing and printing information message data of the remaining quantity of the recording sheets in a character output section. CONSTITUTION:A black mark is marked on a recording sheet 4 just before the terminal end thereof, and a photo-coupler 5 is arranged at a position corresponding to the position of the mark on a conveyer path therefore while a photo-coupler 6 is arranged at a position shifted from the position of the former position. When the photo-coupler 5 detects the mark in the vicinity of the terminal end of the sheet, the photo-coupler 5 is deenergized so that a detecting section 7 delivers a signal to a control section 10 and as well to a remaining quantity calculating section 13. The control section 10 energizes a motor rotational speed detecting section 12 which counts the rotational speed of the motor subsequent to the detection of the mark, and which delivers the same to the remaining quantity calculating section 13. The remaining quantity is then calculated to a character output section 9 which delivers data of the remaining quantity to line memory 2, and a recording section 3 prints the remaining quantity onto the recording sheet.