Abstract: Disclosed are an inkjet multifunction device having a function of attempting to correct malfunctioning nozzles. The inkjet multifunction device includes a printing unit for printing a test pattern, a scanner for scanning the printed test pattern, and a control unit for determining whether respective nozzles in the printing unit malfunction based on the scanned test pattern. The control unit controls the printing unit in order for the nozzles determined as malfunctioned to perform spitting. The determination on whether the nozzles malfunction and the purging of the nozzles are repeatedly performed by the predetermined number of times, and the test step stops if it is determined that all the nozzles normally operate after the repetition operation. Paper and ink can be saved since the purging is selectively performed only on nozzles deemed to be malfunctioning, and meaningless testing and purging operations are prevented from occurring in the case of where there is an absence of malfunctioning nozzles.

Abstract: A method for efficiently compensating for malfunctioning nozzles in a printhead. A print order is input, malfunctioning nozzles on a printhead are identified, and, in the case malfunctioning nozzles are present, compensation printing occurs to optimize print quality. The detecting of malfunctioning nozzles includes printing a test pattern, scanning the test pattern, comparing the scanned test pattern to an ideal test pattern, and then identifying the locations of malfunctioning nozzles. In the case that only one nozzle is malfunctioning, the number of nozzles used to scan a line of print is reduced by two so that compensation printing can correct two lines of print with one single swath.

Abstract: An apparatus for recognizing an establishment of speech channel in communication appliances connected in parallel to a common telephone line includes a hook switching unit for establishing a speech channel between the telephone line and a selected one of the communication appliances in accordance with a switch-on control signal, and for cutting off the established speech channel in accordance with a switch-off control signal; a detecting unit, connected to the telephone line and adapted to detect a loop current from the telephone line; a storage unit for storing a value of the loop current detected from the detecting unit as a one-channel value when the speech channel is initially established between the telephone line and the selected one of the communication appliances, and a control unit for generating the switch-on control signal to the hook switching unit in response to an incoming call, and for generating the switch-off control signal to the hook switching unit for switching a call conversation to anoth