Exposure control device
OwnerNien-Hua Paiinventor
Life of this patent
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Abstract
An exposure control device is used for adjusting light amount received by a focusing device and a photoelectric conversion device of an image scanning apparatus. The exposure control device includes a control unit and a light-transmission adjusting device. The control unit asserts a control signal according to a certain condition of the image scanning apparatus. The light-transmission adjusting device is arranged in the light path to the focusing device and the photoelectric conversion device and changes an effective light-transmission area thereof in response to the control signal to adjust light amount passing therethrough.
Claims14
An exposure control device for adjusting an amount of light received by a focusing device and a photoelectric conversion device of an image scanning apparatus, the exposure control device comprising:
- a control unit configured to generate a control signal according to a certain condition of said image scanning apparatus;
- and
- a light-transmission adjusting device arranged in a light path from an object to said focusing device and said photoelectric conversion device, the light-transmission adjusting device being positioned to change an effective light-transmission area thereof in response to said control signal to adjust light amount passing therethrough, the light-transmission adjusting device comprising:
- a driving unit controlled by said control unit to generate a driving force in response to said control signal;
- a first optical grid plate arranged in the light path, the first optical grid plate having a first light-transmission area;
- and
- a second optical grid plate having a second light-transmission area smaller than the first light-transmission area and selectively driven by said driving force to be aligned with the first optical grid plate so as to reduce said effective light transmission area;
- wherein said certain condition of said image scanning apparatus is a selected resolution of said image scanning apparatus;
- and
- wherein said effective light-transmissible area under high resolution is smaller than that under low resolution.
An exposure control device for adjusting an amount of light received by a focusing device and a photoelectric conversion device of an image scanning apparatus, the exposure control device comprising:
- a control unit configured to generate a control signal according to a certain condition of said image scanning apparatus;
- a driving unit controlled by said control unit and configured to generate a driving force in response to said control signal;
- and
- an optical grid plate having an aperture, wherein rotation of the optical grid plate by said driving force changes an effective light-transmission area of the aperture by rotating the optical grid plate;
- wherein said certain condition of said image scanning apparatus is a selected resolution of said image scanning apparatus;
- and
- wherein said effective light-transmissible area under high resolution is smaller than that under low resolution.
An exposure control device, comprising:
- a control unit configured to generate a control signal;
- an optical grid plate having a region with a light-transmissible area, the light transmissible area having an elongate shape with a narrowed central portion;
- and
- means for rotating the optical grid plate to change the effective light-transmissible area of the region in response to the control signal;
- wherein the optical grid plate is perpendicular to a light path when the control signal identifies a low resolution and wherein the optical grid plate is slanted when the control signal identifies a high resolution.
Dependencies are inferred from the claim text.