Optical scanner
AssigneeAvison Inc.
InventorMichael Chen
Life of this patent
Estimating the term…
Abstract
The invention relates to an optical scanner for saving power. The optical scanner comprises a scanning module for scanning a document to generate corresponding image signals, a cold cathode ray tube for supplying lights to the document when scanning the document, a power source for supplying electric power to the cold cathode ray tube, and a control circuit for controlling operations of the scanner. When the scanning module is in an idle state, the control circuit controls the active period of each of the power source's duty cycles to reduce the electric power supplied to the cold cathode ray tube so that the cold cathode ray tube can be maintained in a warm state and the startup time for warming the cold cathode ray tube to scan the document is reduced.
Claims7
An optical scanner comprising:
- a scanning module for scanning a document to generate corresponding image signals;
- a cold cathode ray tube for supplying lights to the document when scanning the document;
- a power source for supplying electric power to the cold cathode ray tube;
- a control circuit for controlling operations of the scanner;
- and
- a timing circuit for providing a timer to the control circuit;
- wherein when the scanning module is in an idle state, the control circuit controls an active period of a variable duty cycle of the power source by reducing the active period of the duty cycle as time spent in the idle state increases thereby reducing the electric power supplied to the cold cathode ray tube so that the cold cathode ray tube can be maintained in a warm state and the startup time for warming the cold cathode ray tube to scan the document is reduced.
A power controlling method used in an optical scanner which comprises a scanning module for scanning a document to generate corresponding image signals, a cold cathode ray tube for supplying light to the document when scanning the document, and a power source for supplying electric power to the cold cathode ray tube, the power controlling method comprising:
- when the scanning module is in an idle state, controlling an active period of a variable duty cycle of the power source by reducing the active period the duty cycle as time spent in the idle state increases thereby reducing the electric power supplied to the cold cathode ray tube so that the cold cathode ray tube can be maintained in a warm state and the startup time for warming the cold cathode ray tube to scan the document is reduced.
Dependencies are inferred from the claim text.