Patent ID: 9162451
Filing Date: 2015-10-20
Classification: B41J

Abstract:
1. An image forming apparatus configured to read a test pattern formed by ejecting liquid droplets onto a recording medium to adjust an ejection timing of the liquid droplets, comprising: a light emitting unit configured to irradiate a light onto the recording medium; a first light receiving configured to receive diffuse reflected light and a second light receiving unit configured to receive regular reflected light from the recording medium; a processor configured to, the first correction method includes detecting a position of the test pattern from a scanning position of the light by the at least one of the first and second light receiving units while the sensor unit moves relative to the recording medium after the test pattern is formed, the second correction method includes detecting the position of the test pattern after an amplitude of an interval period of the test pattern is aligned to be generally constant, the amplitude appearing in the detection data of the reflected light received from the scanning position of the light by the at least one of the first and second light receiving units while the sensor unit moves relative to the recording medium after the test pattern is formed, the processor is configured to receive the detection data corresponding to the regular reflected light when the detection data corresponding to the diffuse reflected light is less than a first threshold value, and when the detection data corresponding to the regular reflected light received by the second light receiving unit is larger than a second threshold value and is to be used in the adjusting of the at least one of the first and second light receiving units, the processor selects neither the first correction method nor the second correction method and does not adjust the ejection timing of the liquid droplets.