Patent ID: 9229353
Filing Date: 2016-01-05
CPC Classification: G03G

Claim Text:
1. An image forming apparatus comprising: an endless belt rotatingly conveying toner images transferred thereon; a first image carrier rotatably supported in a state in contact with the endless belt; a second image carrier rotatably supported in a state in contact with the endless belt, in parallel with the first image carrier and downstream of the first image carrier in a rotational direction of the endless belt; a first exposure portion exposing the charged first image carrier and forming a latent image thereon; a second exposure portion exposing the charged second image carrier and forming a latent image thereon; a first developing portion developing the latent image formed on the first image carrier as one of the toner images at a first developing position by applying a developing bias; a second developing portion developing the latent image formed on the second image carrier as one of toner images at a second developing position by applying a developing bias; a transfer portion transferring the toner image transferred from the first image carrier to the endless belt at a first transfer position and the toner image transferred from the second image carrier to the endless belt at a second transfer position collectively to a recording medium conveyed thereto; and a control portion selectively executing, corresponding to a predetermined condition, a first or second test mode correcting at least one of exposure timings of the first exposure portion and the second exposure portion after transferring test toner images respectively from the first and second image carriers to the endless belt, the control portion starting the exposure of the first exposure portion after a position of the second image carrier, having been located at a second developing position when the developing bias is started to be applied to the second developing portion, arrives at the second transfer position in forming the test toner images in the first test mode, and the control portion starting the exposure of the first exposure portion before the position of the second image carrier, having been located at the second developing position when the developing bias is started to be applied to the second developing portion, arrives at the second transfer position in forming the test toner image in the second test mode.