Abstract: An image forming apparatus includes a cassette chamber, a paper feed cassette, a sheet size sensor, a lift-up sensor, and an arithmetic control unit. The paper feed cassette can be mounted in the cassette chamber, and lifts up a recording sheet placed in the paper feed cassette upon being mounted in the cassette chamber. The arithmetic control unit is configured to decide that the paper feed cassette is mounted when the lift-up sensor detects that the recording sheet is lifted up, despite the sheet size sensor having detected that the paper feed cassette is not mounted.

Abstract: The image forming apparatus includes a cover member, a cover open/closed detection sensor, a driven unit, a drive detection sensor, and an attitude determination unit. The cover open/closed detection sensor outputs a closed signal corresponding to a closed attitude and an open signal corresponding to an open attitude. The drive detection sensor outputs a state signal corresponding to the drive state of the driven unit. The attitude determination unit determines whether the cover member is in an open attitude or is in a closed attitude based on a closed signal and a state signal input after the open signal.

Abstract: An image forming apparatus includes a cassette chamber, a paper feed cassette, a sheet size sensor, a lift-up sensor, and an arithmetic control unit. The paper feed cassette can be mounted in the cassette chamber, and lifts up a recording sheet placed in the paper feed cassette upon being mounted in the cassette chamber. The arithmetic control unit is configured to decide that the paper feed cassette is mounted when the lift-up sensor detects that the recording sheet is lifted up, despite the sheet size sensor having detected that the paper feed cassette is not mounted.

Abstract: The image forming apparatus 10 includes a cover member 25, a cover open/closed detection sensor 29, a driven unit 38, a drive detection sensor 35, and an attitude determination unit 60. The cover open/closed detection sensor 29 outputs a closed signal corresponding to an open attitude and an open signal corresponding to an open attitude. The drive detection sensor 35 outputs a state signal corresponding to the drive state of the driven unit. The attitude determination unit 60 determines whether the cover member is in an open attitude or is in a closed attitude based on a closed signal and a state signal input after the open signal.

Abstract: An image forming apparatus includes a controller on the apparatus body to control supply of developers from developer containers to the development devices. The controller includes a storage that reads and stores identification information pieces of all the development devices attached to the apparatus body. When any of the development devices is removed from the apparatus body, and thereafter attached at a position where the removal took place, the controller reads an identification information piece of the development device attached at the position, and when the read identification information piece disagrees with an identification information piece of the development device at the position stored, and agrees with an identification information piece of another one of the development devices at another position, the controller determines that the development device is mistakenly attached and prohibits the supply of the corresponding developers.

Abstract: An image forming apparatus includes a controller on the apparatus body to control supply of developers from developer containers to the development devices. The controller includes a storage that reads and stores identification information pieces of all the development devices attached to the apparatus body. When any of the development devices is removed from the apparatus body, and thereafter attached at a position where the removal took place, the controller reads an identification information piece of the development device attached at the position, and when the read identification information piece disagrees with an identification information piece of the development device at the position stored, and agrees with an identification information piece of another one of the development devices at another position, the controller determines that the development device is mistakenly attached and prohibits the supply of the corresponding developers.