Power transmission controller for electronic calculators
AssigneeSharp Kabushiki Kaisha
InventorsShintaro Hashimoto, Sadakatsu Hashimoto, Isamu Washizuka
Life of this patent
Estimating the term…
Abstract
Disclosed is a power transmission controller for an electronic calculator which controls power transmission to a computation circuit and a display device included within the electronic calculator. The power transmission controller indicates a forthcoming termination of the power transmission at a first stage in unison with a first control signal derived from a timer circuit through said display device. Then the power transmission controller terminates said power transmission at the second stage in accordance with a second control signal derived from the timer circuit. A clear key for conducting a clear operation functions to initiate the power transmission to said computation circuit and said display device.
Claims10
An electronic calculator comprising:
- power source means for providing a source of energy;
- key input means having a plurality of keys disposed thereon for introducing information into said electronic calculator;
- computing circuit means energized by said energy from said power source means and responsive to actuation of said keys on said key input means for receiving said information from said key input means and for processing said information, said computing circuit means being normally disconnected from said power source means when said electronic calculator is not in use;
- and
- switching means connected in electrical series between said power source means and said computing circuit means and responsive to actuation of said keys on said key input means for connecting said power source means to said computing circuit means in response to actuation of one of said keys on said key input means and for disconnecting said power source means from said computing circuit means when a predetermined period of time has elapsed since the most recent actuation of one of said keys on said key input means,
- said switching means being continually energized at all times by said energy from said power source means including the periods of time when said power source means has been disconnected from said computing circuit means.
Dependencies are inferred from the claim text.