Patent ID: 7595481

Claim:
A scanning optical system measuring device for making adjustment of a scanning optical system which performs scanning with a light beam, comprising: plural one-dimensional position detection devices provided at a distance from each other in a scanning direction of a light beam caused to perform scanning, each of the one-dimensional position detection devices having a predetermined length in a one-dimensional direction intersecting the scanning direction of the light beam, each of the one-dimensional position detection devices being configured to output current values from both edges of a corresponding detection device in the one-dimensional direction in response to the scanning of the light beam, a relation between the outputted current values being determined according to a light receiving position of the light beam caused to perform scanning on a corresponding detection device so that the outputted current values indicate the light receiving position; and a detection signal processing unit configured to detect scanning state of the light beam on the basis of the current values outputted from the one-dimensional position detection devices.