Abstract: The rim frame and the lens are continuously restrained to each other over a range other than the gap to stabilize holding of the lens while attachment and detachment of the lens can be facilitated by expanding a gap as consolidating the gaps in the two places into one place due to the deflection of the rim frame and movement of the lens in the left-right direction, whereby the lens can be easily attached and detached without using a tool such as a screwdriver, while can achieve holding stability when fixing the lens and ease of attachment and detachment.

Abstract: The line bow phenomenon is reduced by appropriately setting the reflective surface and/or the external shape of an optical element (e.g., a toric mirror) thereby realizing approximately linear illumination of the surface of the original document that is being read. In order to do this, optical elements can be formed so that the external shape of the reflective surface of the optical element is bow-shaped. Alternatively, the optical element can be arranged so that the optical axis of the reflective surface is parallel to the axis of the light reflected from the reflective surface.

Abstract: In order to provide an approximately straight line of light on an original document that is to be read, for example, by an image reading system, a light-supplying optical device includes a light source that produces a bow-shaped (i.e., curved) line of light in order to nullify the line bow phenomenon caused by an optical member such as, for example, a toric mirror that reflects the light towards the original document.

Abstract: An optical element that produces line bow, for example, a toric or cylindrical mirror or lens, is provided in a light-supplying optical device in addition to a first line-bow-producing optical element already present in the device so that a substantially straight line of light is formed on an original document. The light-supplying optical device also includes a light source that generates illuminating light to illuminate the original document and the first optical element that has a toric surface for collecting the illuminating light onto the original document and that is positioned so that the illuminating light shines at a certain angle relative to its toric surface. With this device, the second optical element having a toric surface is positioned in the optical path of the light source and of the original document so as to offset the curve of the illuminating light that otherwise would be generated on the original document by the first optical element.