Print head check method and image forming apparatus

An image forming apparatus that performs printing by ejecting print recording liquid onto a print medium, the image forming apparatus comprising:

• a print head having a plurality of nozzles that eject the print recording liquid;
• a voltage application circuit that generates a potential difference between an electrode provided in the print head and an electrode provided in a predetermined check area;
• a print head check module that performs an ejection check based on electrical change in the electrode provided in the print head or in the check area when the print recording liquid has been ejected from the print head onto the check area, to confirm whether or not each of the plurality of nozzles of the print head actually ejects the print recording liquid when the print head is driven so that the print recording liquid is ejected from the nozzles onto the check area;
• an image forming process module that executes predetermined image forming-related process that is required for printing, the predetermined image forming-related process is a process of ejecting a print medium that has completed printing and supplying a print medium for a subsequent printing;
• and
• a control module that switches on the voltage application circuit to generate the potential difference, controls the print head check module and the image forming process module to perform at least a portion of the ejection check at same time as at least a portion of the image forming-related process, and switches off the voltage application circuit at the end of the ejection check,
• wherein the print head check module performs the ejection check in parallel with, or in a partially overlapping manner with, any one process selected from a reception process of receiving a printing instruction from a user, a data conversion process of converting data for which printing is instructed into print data, a supply process of supplying the print medium to a position at which the print head ejects the print recording liquid, and an edge detection process of detecting an edge of the print medium supplied to the position at which the print head ejects the print recording liquid during printing on a first page, and, when any subsequent page to be printed exists, performs the ejection check in parallel with or in a partially overlapping manner with a print medium ejection process of ejecting the print medium for which the printing is completed.