| 摘要 |
PROBLEM TO BE SOLVED: To provide an image formation device and a voltage setting method capable of suppressing the occurrence of a ground fogging even when an object gets out of focus in an exposure device. ! SOLUTION: An image formation device 1 forms a highlight patch image and a shadow patch image on a photoreceptor drum 413 while changing a charging voltage to a plurality of different values, and acquires a detected concentration value of the highlight patch image and shadow patch image from a patch concentration detection unit 416. A charging voltage value in a case where the concentration of the highlight patch image equals a prescribed concentration (for example, 3.8 V) is specified, and, when a charging voltage of the charging voltage value is applied, an out-of-focus amount of an exposure device 411 is estimated on the basis of the concentration of the shadow patch image formed on the photoreceptor drum 413 and detected by the patch concentration detection unit 416. A set value of the charging vol |
