Method and apparatus for transverse image registration on photoreceptive belts

A method for transverse registration of multiple image exposures of an image area on a longitudinally moving belt subject to lateral deviation from linear travel, the exposures being made by successive presentation of the image area to a transverse line scanning means, said method comprising the steps of:

• providing a target on the belt in a position relative to the image area;
• detecting the lateral position of the target for a first of the image exposures;
• detecting the lateral position of the target for each succeeding presentation of the image area to the transverse line scanning means;
• and
• adjusting the transverse line scanning means for each said succeeding presentation as needed to assure transverse registration of said image exposures on said belt irrespective of the lateral position of the belt during each said presentation.

Apparatus for transverse registration of an image area to be exposed on a longitudinally moving belt subject to lateral deviation from linear travel, said apparatus comprising:

• means for defining a target in a fixed position on the belt comprising a pattern of light apertures in said belt and establishing an inclined linear edge disposed at an angle to the direction of belt travel and a reference edge;
• means for detecting the lateral position of said target in relation to a spatially fixed reference point during movement of the belt;
• and
• means for adjusting the transverse location of the image area on the belt in relation to the detected lateral position of said target.

Apparatus for multiple image exposures of an image area on a longitudinally moving belt subject to lateral deviation from linear travel, said apparatus comprising:

• transverse scanning means for exposing the image area;
• means defining a target on the belt in a position relative to the image area;
• means for detecting the lateral position of said target for each of the image exposures;
• and
• means for adjusting said transverse scanning means for each of the image exposures in response to the detected lateral position of said target to assure transverse registration of said image exposures irrespective of the lateral position of the belt during each exposure.