Abstract: A device and method for blocking light from a laser light beam assembly in a printer, copier, or facsimile machine. Light is blocked from contact with the nonprint region of the photoreceptor drum in a toner cartridge to prevent toner spotting on the output paper and toner leakage in the cartridge and machine. A nontransparent piece of plastic material preferably rectangular in shape is sized to block a part of the light access slot on the toner cartridge cover corresponding to the nonprint region of the drum. The device is secured to the underside of the cover. A method for accurately positioning the nontransparent piece of material to block the required part of the access slot uses a long, flat tool of set length. One end of the tool is placed adjacent to a side wall on the right side of the underside of the cover and the tool is layed over the access slot.

Abstract: A developer roller contact device that provides a more reliable and longer lasting electrical connection between a bias voltage source and a developer roller of a toner cartridge assembly used in printers, copiers and facsimile machines. In the first embodiment, an improved contact device has been developed that has a conductive cylindrical member with a rim on one end. The cylindrical member is sized to fit snugly within the developer roller to contact the inner wall of the roller. The rim abuts against the end of the developer roller to hold the contact device in position. A contact surface provided inside the cylindrical member presses against the electrical contact mounted on the cartridge assembly. A second embodiment of the contact device is for a different type of cartridge assembly. The cylindrical member is divided into a large diameter portion for snugly fitting within the developer roller and a small diameter portion for fitting within an alignment piece on the cartridge assembly.