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US 4,065,803 AGranted
Electronic device for preventing undesirable effect resulting from voltage fluctuation
AssigneeCanon Kabushiki Kaisha
InventorsHiroyuki Mikada, Jyuji Kishimoto
Life of this patent
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Abstract
There is disclosed an electronic device which comprises means for detecting the occurrence of voltage fluctuation in the input or output voltage of a power source to produce an output signal, and means operative in response to the output signal for disabling a portion of the electronic device, such as a liquid crystal display element, thereby substantially elongating the lifetime of the particular portion of the electronic device.
Claims6
An electronic device comprising:
- detection means for coupling to a first voltage source to determine when a voltage applied from the source is outside of a predetermined range and for producing a corresponding detection signal;
- means coupled to said detection means for producing a cutoff signal in response to the detection signal from said detection means;
- voltage conversion means for coupling to the voltage source for supplying a second voltage for use in said device;
- and
- disable means coupled to said cutoff signal means and said voltage conversion means for disabling said conversion means in response to the occurrence of said signal, wherein said disable means has a hysteresis characteristic such that said voltage conversion means is enabled when the voltage applied to said device is greater than a selected value, and said conversion means is disabled when the source voltage decreases a predetermined amount below said selected value.
2 more elements
Dependencies are inferred from the claim text.