Abstract: An apparatus for document processing comprises an optical sensor including a light source, a light detector and an optical element. The optical sensor is adapted so that, during operation of the apparatus, at least a first portion of light from the source that enters the optical element travels along paths in the optical element so as to be re-directed by total internal reflection toward the detector and wherein the total internal reflection is maintained when the optical element is wet. Signals form the optical sensor may be used to determine, for example, the state of a document storage cassette or the location of a document with respect to the cassette.

Abstract: Techniques include sensing electric signals from an actuator during a document stacking operation and determining whether an abnormal event has occurred based on the sensed signals. The techniques may find particular applicability, for example, to document acceptors that include piston-type stackers driven by a direct current motor.

Abstract: A method and apparatus for using electronic security coupons in connection with locking mechanisms for preventing unauthorized access to or removal of internal components of vending and gaming machines. A security coupon is received in the bill validator section of the machine, the security coupon is recognized, and the locking mechanism is unlocked. The security coupon optionally can be stored in a currency cassette.

Abstract: A vending machine bezel for attachment to the front panel of a vending machine that is durable and versatile, and that advantageously provides at least two apertures for the insertion of money. The face of the bezel fits through an industry-standard size bill validator opening in the front panel of the vending machine. In one embodiment, the bezel contains three apertures to accept banknotes, coins and cards in payment for a vend item.