An image forming apparatus including an image forming unit which comprises a cartridge having a toner therein to form an image and a controller to control the image forming unit to increase a density of the image to be formed, if it is determined that a standard of the cartridge does not meet a usage requirement. The orientation indicator is positioned in a location on the respiratory device visible to a user during the operation of the respiratory device. The organic electroluminescent element is characterized in that at least one layer in the organic layer contains a crown ether compound and a compound having a dibenzofuran skeleton.