Patent ID: 8398195

Claim:
A detection method for detecting adjustment values of a fluid ejection device having first and second heads with the first head disposed on an upstream side of the second head in a feed direction in which a medium is conveyed, the second head forming dot rows of a fluid between dot rows of the fluid formed by the first head, the detection method comprising: driving the first head and the second head with a first voltage change amount to form a first test pattern and driving the first head and the second head with a second voltage change amount to form a second test pattern; measuring a concentration of the first test pattern and a concentration of the second test pattern; adjusting the first voltage change amount for driving the first head and the second voltage change amount for driving the second head based on the concentration of the first test pattern and the concentration of the second test pattern, the adjusting of the voltage change amount for driving the first head and the voltage change amount for driving the second head including adjusting the first and second voltage change amount corresponding to a target concentration based on the concentration of the first test pattern and the concentration of the second test pattern.