Patent ID: 6876831

Claim:
An image forming apparatus, comprising: a photosensitive belt being carried by a driver device, for forming a toner image thereon; an internal transcription belt for transcribing the toner image thereon, which is formed on said photosensitive belt; and a transcription portion for transcribing the toner image, which is transcribed on said internal transcription belt, onto a recording medium, further comprising: a transcription side roller, being suspended with said internal transcription belt thereon, and disposed on a side of a photosensitive belt side roller, which is disposed on a side of said photosensitive belt, the transcription side roller being disposed on a side of said transcription portion; means for detecting a first cycle of said internal transcription belt; and means for detecting a second cycle, which starts measurement delaying by ½ cycle of said photosensitive belt side roller from the first cycle measurement start; a controller means for conducting speed compensation of said photosensitive belt by referring to said first cycle and said second cycle, wherein, said internal transcription belt is in contact with said photosensitive belt, so that it is carried following thereafter.