Image forming apparatus

An image forming apparatus comprising:

• an image carrier on a surface of which a toner image is developed;
• a transfer device transferring the toner image from the image carrier onto paper;
• a cleaning device removing a toner remaining on the surface of the image carrier and discharging the toner from a toner exhaust port;
• a toner container of a detachable type having an opening part formed of a transparent member, receiving, through the opening part, the toner discharged from the cleaning device, and storing the toner therein;
• an optical sensor having a light emission section and a light reception section arranged at position sandwiching the opening part of the toner container from both sides when the toner container is attached;
• a shutter sliding in conjunction with the attachment and detachment of the toner container, the shutter having a top surface member opening and closing the toner exhaust port of the cleaning device and a side surface member transmitting and blocking light of the optical sensor;
• and
• a control section, based on a signal outputted from the optical sensor, performing detection of fullness of the toner stored in the toner container and detection of the attachment and detachment of the toner container,
• wherein a slit extending in a direction orthogonal to a sliding direction of the shutter is formed at the side surface member of the shutter, and
• the control section performs the detection of the attachment and detachment of the toner container based on a waveform pattern of light transmitted through the slits which pattern appears in the signal of the optical sensor.