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US 5,309,151 AGranted
Current-supplying integrated circuit
AssigneeSeiko Epson Corporation
InventorKanji Aoki
Life of this patent
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AssigneeSeiko Epson Corporation
InventorKanji Aoki
Estimating the term…
A current supplying integrated circuit which has multi-output for controlling current supply from a current source to a plurality of elements to be driven, such as LEDs, and comprises a plurality of switching devices for controllably supplying the current from the source to the corresponding elements to be driven wherein each of the switching devices has N unit switching elements arranged to be connected in parallel to each other to form a current synthesizing circuit. The unit switching elements have substantially the same current capacity. Each of the elements to be driven, such as LEDs, is supplied with a current whose intensity can be varied by N degrees by the synthesizing circuit. By varying the current intensity supplied to each of the elements, the unevenness in properties among them can be avoided or suppressed in an effective and simplified manner.
A current supplying integrated circuit having multi-output for controlling current supply from a current source to a plurality of elements to be driven, comprising a plurality of switching means for controllably supplying the current from said source to the corresponding element to be driven, each of said switching means comprising N unit switching elements arranged to be connected in parallel to each other to form a current synthesizing circuit, each of said unit switch elements being switchable from a first condition wherein no current flows therethrough to a second condition wherein a predetermined essentially constant current flows therethrough, each of said unit switching elements including at least one field effect transistor for providing essentially constant current, said at least one field effect transistor operating in the saturation region of the characteristic curve when in the second condition, said switching means supplying an essentially constant current to the associated element to be driven equal to at least the sum of the predetermined essential constant currents flowing through those of the unit switching elements thereof in said second condition.
An electronic device for controlling a plurality of elements which are controlled in their driving state by the level of electric current from a current source applied thereto, comprising a current supplying means controlled by an output data and a corrected data, said output data being relative to whether said corresponding element is driven, said corrected data being relative to said level of electric current applied, said current supplying means producing said current in response to said corrected data, said current supplying means comprising a plurality of switching means for respectively controlling the supply of said current to a corresponding element to be driven in response to said corrected data, each of said switching means comprising N unit switching elements arranged to be connected in parallel to each other to form a current synthesizing circuit, each of said switching elements being switchable from a first condition wherein no current flows therethrough to a second condition wherein a predetermined essentially constant current flows therethrough, each of said unit switching elements including at least one field effect transistor for providing essentially constant current, said at least one field effect transistor operating in the saturation region of the characteristic curve when in the second condition, said switching means supplying an essentially constant current to the associated element to be driven equal to at least the sum of the predetermined essentially constant currents flowing through those of the unit switching elements thereof in said second condition.
An electronic device for controlling a plurality of elements which are essentially aligned in a first direction and are controlled in their driving state by the level of electronic current applied thereto, comprising a current supplying means controlled by an output data and a corrected data, said output data being relative to whether said corresponding element is driven, said correcting data being relative to said level of electric current applied, said current supplying means producing said current in response to said corrected data, said current supplying means comprising a plurality of switching means for respectively supplying said current to a corresponding element to be driven, each of said switching means comprising N unit switching elements arranged to be connected in parallel to each other to form a current synthesizing circuit, said switching elements being essentially aligned in a second direction, said second direction being substantially orthogonal to said first direction.
An LED printer having an LED printer head for printing by using a plurality of LEDs, comprising:
An LED printer having an LED printer head for printing by using a plurality of LEDs, comprising:
Dependencies are inferred from the claim text.