Extended Printer Hammer Error Detection
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2005-Mar-09
Print hammer driver circuits can be checked each option time by extending the hammer check window with a delay bit that is controlled by a delay count buffer containing the flight time delay value for each print position. Referring to Figs. 1 and 2, the control sequence for checking hammer driver circuits having variable turn-on and turn-off times is as follows: 1. Prior to a print line buffer and print band data comparison and during the time that each print position is addressed or optioned, the on-off status of the hammer driver is checked for an off condition by gating a hammer echo (HMR ECHO) signal through AND gate 10, under control of an ENABLE bit, to hammer misfire latch 11. The ENABLE bit is generated from check buffer 12 for the specific print position addressed.