Abstract: A display unit that moves an indicia carrier and displays changing advertisements through a window is disclosed. The drive system positively drives the indicia carrier through its cycles and the dwell time as the direction reverses twice in each cycle is reduced. The speed of the indicia carrier increases after it makes a direction reverse. In the preferred embodiment the speed between direction reverses is kept as constant as possible. The indicia carrier can cycle in either a horizontal or a vertical direction. The indicia carrier can also be held against the window as it moves.

Abstract: A bar-coding system employs a unique bar code pattern which includes a code represented by a series of dark and light stripes that may be easily decoded by a very inexpensive reader with greater reliability. The bar-coding system generates binary data from the pattern which may be described in parts as follows: long light fields at each left and right end; a start bar at each end; right and left data fields; and a three-bit asymmetric pattern (light, dark, light) in the center that indicates the direction in which the pattern is moving past the read head. The coding sequence of the data fields is arranged from either end toward the middle of the pattern where the coding method reverses; therefore, a coupon or card passed through the reader in either direction will yield the same output. Only two widths of the light and dark stripes are used, and the stripes are read as pairs in succession.

Abstract: A battery-operated rotating sign employs a mechanically efficient speed-reducing mechanism and a power controller to reduce power consumption and, hence, increase battery life. The device is particularly suited to a ceiling-mounted, vertically-suspended rotating sign. A resilient power transmission strand extends from the vertical shaft of the motor to the sign which hangs from the bottom end of the strand. The power controller includes electrical circuitry having a timer which cycles between "on" and "off" periods. During the "on" period, the rapidly turning motor shaft winds up the resilient strand; and during the "off" period, the energy stored in the strand is released to the sign which turns slowly at the opposite end of the strand. Additional energy savings are provided by a photodetector circuit which disconnects the battery at night when operation of the sign is not desired.