Abstract: An image scanning device includes lighting circuits; a light source including light-emitting elements arranged in a line such that the light-emitting elements connected in series to the same lighting circuit are not positioned adjacent to each other; a reflecting part; a photoelectric conversion unit photoelectrically converting reflected light from the reflecting part; a lighting control unit selectively turning on one of the lighting circuits; a memory storing an area information table containing information on main-scanning areas of the photoelectric conversion unit in association with identification information of the lighting circuits; and a failure determining unit identifying the main-scanning areas corresponding to the identification information of the turned-on lighting circuit by referring to the area information table and comparing intensities of the reflected light entering the identified main-scanning areas with a first threshold to determine whether the light-emitting elements connected to the t

Abstract: A light projecting device includes a base board, a light guiding member, a holding member, a cover, and a positioning member. A plurality of light-emitting elements are arranged in a line on the base board in a main scan direction. The light guiding member faces a radiation surface of the light-emitting elements and guides light projected from the light-emitting elements to an irradiation region of an illuminated object. The holding member holds the base board. The cover covers the base board and the light guiding member. The positioning member positions the light guiding member on the holding member. The holding member and the cover sandwich the light guiding member positioned by the positioning member. The light projecting device includes the holding member, the light guiding member, the base board, and the cover as a single unit which is detachably mountable relative to a chassis of the light projecting device.

Abstract: A disclosed image scanning device includes a pressing unit for pressing a document; an operation detection unit for detecting an opening operation and a closing operation of the pressing unit; a movable scanning unit for scanning the document; and a control unit for moving the movable scanning unit from a standby position to a document-size detection start position when the opening operation is detected and moving the movable scanning unit from the document-size detection start position to the standby position to determine a size of the document when the closing operation is detected. The control unit is configured to continue moving the movable scanning unit from the standby position to the document-size detection start position until the arrival of the movable scanning unit at the document-size detection start position is detected even if the pressing unit is operated.

Abstract: A disclosed image scanning device includes a document table; a document pressing unit configured to press a document placed on the document table; a scanning unit including a light source for illuminating the document and configured to optically scan the document; a photoelectric conversion element; an open/close detection unit configured to detect opening and closing of the document pressing unit; and a control unit configured to turn on the light source of the scanning unit and thereby to cause the photoelectric conversion element to detect a size of the document if the closing of the document pressing unit is detected by the open/close detection unit or if a scanning start signal is detected. The control unit is configured to turn on the light source after a lighting delay period from a time when the closing of the document pressing unit is detected. The lighting delay period is changeable.

Abstract: An image scanning device includes a document table; a document pressing unit configured to press a document placed on the document table; a scanning unit including a light source for illuminating the document and configured to optically scan the document; an open/close detection unit configured to detect opening and closing of the document pressing unit; and a control unit configured to cause the scanning unit to move parallel to the document and thereby to detect a size of the document when the closing of the document pressing unit is detected by the open/close detection unit or when a scanning start signal is detected. The control unit detects the size of the document within a document size detection period that is changeable according to a speed of closing the document pressing unit, and turns on and off the light source based on the document size detection period.

Abstract: An optical unit including a lens unit including a lens and an optical element configured to receive a light beam focused by the lens, and a support member configured to support the lens unit. Cutouts are provided on joint surfaces of the lens unit and the support member, respectively, such that the cutouts on the joint surface of the lens unit match the cutouts on the joint surface of the support member. The cutouts are configured to accommodate a jig inserted thereinto and rotated to move the lens unit relative to the support member and adjust a position of the lens unit in a direction parallel to an optical axis of the lens.