Determining method for determining whether ink was ejected or not, computer-readable medium, and printing apparatus

A computer-readable medium for causing a printing apparatus, which includes a plurality of nozzles for ejecting ink and a sensor for emitting light toward a print medium on which a print pattern has been printed by ejecting ink from said plurality of nozzles and receiving the light that is reflected, to operate, said computer-readable medium comprising the following codes for determining whether or not ink has been ejected from said nozzles:

• a code for printing a non-ejection print pattern that is made of print blocks that can be formed for each said nozzle and in which only a print block to be determined, which is an object of determination, included within a region of said print medium that is irradiated by said light is not printed;
• a code for emitting light from said sensor toward said print medium on which said non-ejection print pattern has been printed and obtaining an output value upon non-ejection that is output from said sensor;
• a code for printing an all-ejection print pattern in which the print blocks have been printed in the entire area within said region of said print medium that is irradiated by said light;
• a code for emitting light from said sensor toward said print medium on which said all-ejection print pattern has been printed and obtaining an output value upon ejection that is output from said sensor;
• a code for setting a threshold value between said output value upon non-ejection and said output value upon ejection;
• and
• a code for comparing said threshold value with an output value that is output from said sensor based on light that is emitted toward a print medium on which said print pattern has been printed by ejecting ink from said plurality of nozzles.

A printing apparatus comprising:

• a plurality of nozzles for ejecting ink;
• a sensor for emitting light toward a print medium on which a print pattern made of print blocks that can be formed for each of said nozzles has been printed by ejecting ink from said plurality of nozzles and receiving the light that is reflected;
• and
• a determination section for determining whether or not ink has been ejected from said nozzles by comparing a predetermined threshold value with an output value that is output from said sensor based on light that is received by said sensor;
• wherein said threshold value is set between an output value upon non-ejection and an output value upon ejection, said output value upon non-ejection being output from said sensor when only a print block to be determined, which is an object of said determination, included within a region of said print medium that is irradiated by said light is not printed, and said output value upon ejection being output from said sensor when the print blocks have been printed in the entire area of said region.