Image forming apparatus and voltage supply method

A voltage supply method for an image forming apparatus having an apparatus body, an image forming unit, a transfer part, an electric board, a first voltage supply unit, and a second voltage supply unit, wherein

• the apparatus body includes a fittable-and-removable top plate,
• the image forming unit includes:
• a plurality of image forming parts which are arranged next to each other along the fitting direction and which form developer images;
• an intermediate transfer unit which transfers the developer images to the sheet;
• and
• input terminals for receiving the voltages from the first and second voltage supply units,
• the input terminals are arranged at different positions in a widthwise direction intersecting the fitting direction,
• the image forming unit is made fittable and removable to the apparatus body along a specified fitting direction and forms a developer image,
• the transfer part transfers the developer image onto a sheet,
• the electric board is placed in the apparatus body so as to extend in the fitting direction above the image forming unit and has a plurality of electric components and an output terminal in its upper surface portion, the electric board being exposed outside the apparatus body when the top plate is removed from the apparatus body, and
• the first voltage supply unit is fitted to one side end portion of the electric board extending in the fitting direction and electrically connected to the output terminal to supply the voltage to the image forming unit from a side portion of the electric board, whereby
• the second voltage supply unit is fitted to another side end portion of the electric board extending in the fitting direction and electrically connected to the output terminal provided to another side of the electric board to supply the voltage to the image forming unit from the electric board, and
• when the image forming unit is inserted in the apparatus body,
• the input terminals of the image forming unit make electrical contact with the first or second voltage supply unit, and the voltage is supplied from the output terminal provided in the upper surface portion of the electric board, from the first and second voltage supply units, to the image forming unit placed below the electric board.