An optical beam scanning apparatus and an image forming apparatus having the optical beam scanning apparatus are provided. The interior wall tapers toward the lower end to form a choke. The system determines a separation based on a pacing algorithm and sends the second message to the recipient according to the separation. The objects placed through the particular depth range are rendered and displayed in a virtual scene based on geometric characteristics of the object itself. The example embodiment increases the overall aggregate capacity as a function of connections between the first switching shelf and the multiple second switching shelves. The notch fits over the doorknob, and the user swings the handle and thereby turns the doorknob.