Apparatus for detecting number of remaining sheets
AssigneeMinolta Camera Kabushiki Kaisha
InventorsMasazumi Ito, Kenzo Nagata
Life of this patent
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Abstract
An improved paper feeding device, for example, for a copying machine is provided and is capable of warning a user of the status of available copy paper sheets. A movable support tray can be monitored to provide a measurement of the total initial height of the paper stack and subsequent movements of this paper stack to introduce individual copy paper sheets into a paper transport system can be correlated with the actual number of sheets that are transported. From these monitored values, it is possible to calculate the number of sheets remaining on the stack and to provide an audible, vocal or visual display of the actual number or relative condition to warn a user.
Claims15
In a paper feeder having a mechanism for holding a stack of sheets on a tray and lifting the stack to a predetermined upper limit position every time the height of the stack decreases by a specified amount due to removal of sheets from the tray, an apparatus for detecting the number of remaining sheets comprising:
- means for generating corresponding signals relative to the lifting movement of the stack;
- means for counting the number of sheets removed from the tray which corresponds to a predetermined lifting movement of the stack;
- means for detecting the signals generated with a lifting movement of the stack to obtain numerical data corresponding to the amount of the lift;
- means for obtaining numerical data corresponding to the height of the remaining stack;
- and
- means for calculating the number of remaining sheets from the data corresponding to the amount of the lift, the number of sheets used and the data corresponding to the height of the remaining stack and producing a representative signal.
In an improved copying machine for making multiple copies of an original on copy paper sheets that are moved by a paper transport system and having means for setting a desired number of copies to be produced, means for supporting a stack of sheets of copy paper, means for removing a sheet of copy paper from the stack and introducing it into the paper transport system, means for adjusting the relative position of the stack and the means for removing to ensure a continual supply of copy paper sheets to the paper transport system and means for counting the number of copy paper sheets moved by the paper transport system, the improvement comprising:
- means for providing an indication of the total initial height of the stack;
- means for measuring an increment of relative movement of the stack;
- means for correlating the number of copy paper sheets removed from the stack and counted by the means for counting with the increment of relative movement of the stack, and
- means for calculating the number of sheets of copy paper remaining on the stack from the relationship of the increment of movement, the height of the initial stack and the number of sheets counted and producing a corresponding signal of that number whereby a user can be informed of the relative storage condition of available copy paper sheets.
Dependencies are inferred from the claim text.