Electrical computers: arithmetic processing and calculating – Electrical digital calculating computer – Having specialized input
Reexamination Certificate
2006-12-18
2010-11-02
Malzahn, David H (Department: 2193)
Electrical computers: arithmetic processing and calculating
Electrical digital calculating computer
Having specialized input
Reexamination Certificate
active
07827221
ABSTRACT:
A mathematical calculator where when a mixed fraction key is depressed, an integer part input area, a numerator input area, a denominator input area and a vinculum for a mixed fraction are displayed on a display screen. When a user depresses a “1” key of a numeric keypad, “1” is inputted and displayed to and on the integer part input area. When the user depresses a “+” operator key, a CPU prohibits the inputted “+” operator from being inputted and displayed to and on the integer part display area. When the user depresses the “+” operator key in a state in which “(1” is inputted and displayed to and on the integer part input area, the CPU allows the inputted “+” operator from being inputted and displayed to and on the integer part display area.
REFERENCES:
patent: 4064398 (1977-12-01), Kishimoto et al.
patent: 5138566 (1992-08-01), Comforti
patent: 5309380 (1994-05-01), Satoh et al.
patent: 2007/0150863 (2007-06-01), Katayama
patent: 4-252351 (1992-09-01), None
An English translation of a Chinese Office Action dated Apr. 11, 2008, issued in a counterpart Chinese Application.
Casio Computer Co. Ltd.
Holtz Holtz Goodman & Chick PC
Malzahn David H
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