Pivoting Mount for Optical Reflective Registration Sensor
Publication Date: 2005-Dec-15
The IP.com Prior Art Database
It is proposed to use a pivoting mount for an optical reflective registration sensor. A pivot arm contacting the paper enables the sensor to remain in alignment perpendicular to the paper even when the paper buckles in the registration zone.
Optical flag sensors are traditionally used in paper paths because they are capable of sensing any form of media moving through the path. Customer demands on printers/copiers/multi-function devices require faster and smaller machines. As the paper transport speeds increases and the Inter-Document Gap (IDG) become smaller to maximize performance, the reaction time of the flag becomes a significant portion of the paper path timing latitude window.
A reflective optical sensor eliminates the actuation time of the mechanical flag. However, the reflective sensor is sensitive to the amount of IR radiation reflected back to the sensor. Reflective sensors are designed to be mounted perpendicular to the paper path. The sensor sensitivity is dependent on the reflectivity of the media and angle of incidence between the sensor and media. All reflective sensors have a +/- angular misalignment tolerance which decreases as the media becomes less reflective. Hence, the sensors have the smallest angular misalignment tolerance for transparencies.
Mounting the optical sensor on a pivoting bracket that contacts the media as it buckles at the registration nip is a solution. The bracket and sensor pivot up with the media and maintain a perpendicular relationship and consistent focal length relative to the media. The pivoting bracket maintains the sensor’s detection window regardless of paper attitude within the paper...