Suppressing unstable electrical coupling between a bottom plate and a cable by providing a recess on the bottom plate for attachment of the cable

An image forming apparatus, comprising:

• an optical reading device for optically reading a document image;
• and
• an image forming unit for forming an image on a sheet based on the document image;
• wherein the optical reading device includes:
• a housing made of metal, including a bottom plate and having an open upper surface;
• a document platen member mounted in an opening of the housing;
• a scanning unit in which a light source is mounted and which emits light toward the document platen member while reciprocating along a predetermined scanning direction between the bottom plate and the document platen member;
• a cable including a first end which is fixed to the scanning unit, a second end which is fixed to the bottom plate and an intermediate portion which is held in surface contact with the bottom plate and curved and deformed according to a reciprocal movement of the scanning unit;
• and
• an insulating sheet interposed between the bottom plate and the intermediate portion of the cable;
• wherein:
• the housing includes a recess formed in the bottom plate and extending in the scanning direction, the recess being a shallow groove having an open upper side, a flat bottom surface and a pair of inclined portions extending obliquely up from side edges of the bottom surface;
• and
• the insulating sheet covers an opening of the recess, the upper surface thereof is in contact with the intermediate portion of the cable and a space is formed between the lower surface of the insulating sheet and the bottom surface of the recess.