Light-supplying optical device

A light-supplying optical device comprising:

• a light source that emits a supply of light along a first path, said supply of light extending in a primary scanning direction;
• and
• an optical element located in said first path, said optical element having a reflective surface that reflects and concentrates the supply of light onto an area of an original document, said optical element being arranged relative to said first path so that said supply of light is incident on the reflective surface at a non-zero angle relative to an optical axis of the reflective surface, said reflective surface being bow-shaped when said reflective surface is viewed along said optical axis of said reflective surface so that an angle between the incident light and the reflected light at a center of the reflective surface is the same as the angle between the incident light and the reflected light at ends of the reflective surface to compensate for a line-bow phenomenon that occurs when light extending in the primary scanning direction and incident on the reflective surface at the non-zero angle is reflected by the reflective surface.

A light-supplying optical device comprising:

• a light source that emits a supply of light along a first path, said supply of light extending in a primary scanning direction;
• and
• an optical element located in said first path, said optical element having a reflective surface that reflects and concentrates the supply of light onto an area of an original document, said optical element being arranged relative to said first path so that said supply of light is incident on the reflective surface at a non-zero angle relative to an optical axis of the reflective surface, said optical element being positioned relative to the light source so that the supply of light is reflected from the reflective surface along a reflection axis that is parallel to said optical axis of the reflective surface so that the reflective surface has an approximately linear shape when viewed from the original document to compensate for a line-bow phenomenon that occurs when light extending in the primary scanning direction and incident on the reflective surface at the non-zero angle is reflected by the reflective surface.

A method of forming a reflective surface of a light-supplying optical device, said light-supplying optical device including a light source that emits a supply of light along a first path, an optical element located in said first path, said optical element having said reflective surface, said reflective surface reflecting and concentrating the supply of light onto an area of an original document, said area extending in a primary scanning direction, said optical element being arranged relative to said first path so that said supply of light is incident on the reflective surface at a non-zero angle relative to an optical axis of the reflective surface, a holder that holds the original document illuminated by the supply of light reflected from the reflective surface to form a light image that travels along a second path, and an optical system located in said second path, said optical system focussing the light image from the original document into an image at a focus point of the optical system, said method comprising:

• reverse projecting a straight image reading line from the focus point of said optical system through said optical system to an ellipsoid of revolution;
• and
• forming said reflective surface so that said reflective surface is contained in a portion of said ellipsoid of revolution that is intersected by said reverse projected straight image reading line.