Abstract: A color capable electrophotographic printer remains operable for monochrome printing when one or more toner cartridges are unavailable for use. Instead of reverting to an error state when a toner cartridge is missing or unavailable, the laser printer remains operable to print monochrome images or single "spot color" images using a single color and monochrome toner.

Abstract: An image forming apparatus is provided with a photosensitive drum on whose surface a toner image is formed, and image formation is carried out by transferring the toner image onto a transfer material such as paper or OHP sheet which is caused to electrostatically adhere to a surface of a transfer drum while being guided to the photosensitive drum. Alternatively, the toner image formed on the photosensitive drum may be once transferred onto an intermediate transfer drum, then transferred from the intermediate transfer drum onto the transfer material. In the image forming apparatus, a light projecting device for projecting light onto the photosensitive drum is provided on an upstream side to a toner image transfer position and on a downstream side to a development position on the photosensitive drum. Execution and suspension of the light projecting operation of the light projecting device is controlled depending on a toner type.

Abstract: A photographic developing apparatus which visualizes a latent image formed on an image carrier is disclosed which includes:a developing powder carrier provided so as to be opposite to the image carrier;a layer forming member for forming a thin layer of developing powder over a circumferential surface of the developing powder carrier;a charge imparting member which is provided so as to be opposite to the developing powder carrier and causes an electric field between the charge imparting member and the developing powder carrier; andan electrification control member which is interposed between the charge imparting member and the developing powder carrier, and limits an ionization area caused by electric discharge in the electric field by receiving an intermediate electric potential between the electric potential of the charge imparting member and the electric potential of the developing powder carrier.

Abstract: A liquid developing material replenishment system wherein an apparatus for developing an electrostatic latent image with a liquid developing material includes a liquid developing reservoir for providing a supply of operative liquid developing material to the developing apparatus, and a liquid developing material supply is coupled to the liquid developing material reservoir for providing a supply of liquid developing concentrate to the liquid developing material reservoir for replenishing the supply of operative liquid developing material in the liquid developing reservoir. A predetermined amount of operative liquid developing material is periodically and/or systematically discharged from the liquid developing material reservoir to remove contaminated liquid developing material from the reservoir.

Abstract: A power saving method of an image forming apparatus, such as a laser beam printer, warms up the image forming apparatus when a given time period has elapsed after entering a power saving mode for reducing energy consumption, thereby reducing the amount of time in waiting for a printing operation. The power saving method of the present invention includes the steps of: determining whether the image forming apparatus is in the power saving mode, performing a timing operation while the image forming apparatus is in the power saving mode and no print data is input, and warming up the image forming apparatus when a duration of the timing operation exceeds a predetermined time period.