Abstract: A closed circuit control device for controlling carrier speed of a scanner. An optical meter is attached to the transparent glass panel of a scanner such that an image of the optical meter is formed on an optical sensor such as a charge couple device or a contact image sensor. Image of the optical meter is converted into sense signals by the optical sensor so that speed of the carrier can be accurately computed. Through the acquisition of an accurate carrier speed, scanning speed and direction can be precisely controlled.

Abstract: A stray-light attenuating device for removing stray light from a scanner. The attenuating device includes a light source, a lens, a reflecting mirror, a light sensor, a front cover plate and a back cover plate. The light source provides a beam of light for illuminating a document on the scanner. Light from the light source impinges upon the document and reflects to the reflecting mirror. The reflecting mirror deflects the reflected light to the lens. The lens focuses the reflected light onto the optical sensor to form an image. The optical sensor at least includes a plurality of connecting leads, a sensing surface and a backside. The back cover plate having an opening thereon is used for covering the backside of the optical sensor. The front cover plate having a window thereon is used for covering the sensing surface of the optical sensor.