| US 7,469,191 B2 | ||
| Jitter measurement method, jitter measuring apparatus and image forming apparatus | ||
| Kyoji Shimoda, Amagasaki (Japan); and Koichi Saito, Tokyo (Japan) | ||
| Assigned to Sumitomo Precision Products Co., Ltd., Hyogo (Japan) | ||
| Filed on Aug. 01, 2005, as Appl. No. 11/195,466. | ||
| Claims priority of application No. 2004-227228 (JP), filed on Aug. 03, 2004. | ||
| Prior Publication US 2006/0031033 A1, Feb. 09, 2006 | ||
| Int. Cl. G01R 29/26 (2006.01) | ||
| U.S. Cl. 702—69 [250/235; 358/481; 347/111; 356/608] | 12 Claims |
| 1. A jitter measurement method for a galvano scanner for scanning a light beam on a surface to be scanned by periodically
turning a reflection mirror in a reciprocating manner, comprising the steps of:
mounting two detectors for receiving and detecting the light beam near both ends of a one-dimensional scan region of the light
beam;
extracting a first detection signal from each of the two detectors whenever the reflection mirror is activated for one scanning;
computing a required time for one scanning from the extracted detection signals;
measuring a variation in the required time for each scanning, based on the computed required time; and
writing an electrostatic latent image based on the variation in the required time for each scanning.
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