Abstract: A photoelectronic image forming apparatus reproduces an image on the basis of an electrostatic latent image produced on a photo-sensitive body by using a developer containing a toner and a carrier, and comprises a plurality of toner density measuring units for respectively producing outputs each indicative of a toner density of the developer and a toner density determining unit responsive to the outputs for determining an actual toner density so as to precisely control the tone of the image.

Abstract: A handset device which includes a small magnet unit, is simple in construction, and yet ensures the magnetic holding of a handset and the outputting of an on-hook signal when it is hung up on a main body. The magnet unit is provided in one of a portion of the main body and a portion of the handset which face each other when the handset is hung up, while a magnetic material is provided in the other of those portions, so that a magnetic attracting force may occur between the magnet unit and the magnetic material. The magnetic material has a saturation magnetic flux density which is lower than that of the magnet unit, so that magnetic leakage may occur. A magnetic detector is provided for detecting such magnetic leakage and outputting the on-hook signal.

Abstract: A cleaner in a transfer section of a copying machine for cleaning a soil toner transferred from a photoconductive member and adhering to the surface of a transfer drum, which includes a cleaning device which electrically attracts and cleans the soil toner on the surface of the transfer drum and an electrode disposed at the interior surface of the transfer drum for weakening the electrostatic force between the soil toner and the surface of the transfer drum. The electrode disposed in the interior of the dielectric drum is movable.

Abstract: A corona charging device for charging a surface of a moving member, the device including a plurality of wire electrodes for generating corona discharge at a high voltage applied thereto, and a grid electrode located between the moving member and the wire electrodes, wherein a distance between the grid electrode and the moving member is shortest immediately below the wire electrode located most downstream in the moving direction of the moving member.

Abstract: The transporting speed of a developer transporting roller is switched over depending on the condition whether a developing unit is operated for developing process or the developing unit is not in action for developing operation, and a comparable standard value for making a decision whether toner replenishment is required or not is changed based on the toner density value detected by a magnetic sensor when the developing unit is operated or is not in action for developing operation. When the developing unit has finished a predetermined number of operations, and image forming operation is suspended, a developer stirring and transporting roller is driven for a duration of time corresponding to the number of developing operations conducted, and toner density detection and toner replenishment is carried out corresponding to the toner density detected.

Abstract: The operating key switch unit according to the present invention includes a plurality of key switch buttons exposed from the front of a waterproof case and a switch panel integrally formed therein using an elastic material and mounted with bolts between the waterproof case and a printed circuit board. Furthermore, a first contactor projecting in the key switch button operating direction annularly in a surrounding relation to the key switch buttons is provided, and a second annular contactor formed integrally with the switch panel and in contact with the first contactor throughout the overall circumference at all times is provided.

Abstract: In a telephone set, a base unit has a front recess defined by a bottom and a sloping wall including a front part and a rear part, and a rear recess, and a protrusion is provided on the front part of the sloping wall and extends rearward. A locking piece is provided to extend through an aperture formed in the rear part of the sloping wall of the front recess. The locking piece extends toward the protrusion and is pushed toward the protrusion by a spring. The spring permits the retraction of the locking piece into the enclosure of the base unit. A buffer member having a resiliency is provided in the center of the bottom of the front recess. A front dent provided on the front part of the front convex part engages the protrusion. A rear dent provided on the rear part of the front convex part engages the locking piece.

Abstract: In a self-illuminating panel switch, a key top is supported by a front panel. The key top has a rear surface on which a character area is printed with one of a dark color or a light color, and the background area is printed with the other of a dark color and a light color. Because the printing is made on the rear or inner surface of the key top, the ink is free from wear or removal.

Abstract: A heat fixing unit in an electrophotographic copying apparatus is disclosed. The heat fixing unit comprises a heat fixing roller with a heater, a pressure roller with a plurality of fibers, and driven ring components disposed on the ends of the pressure roller for adjusting the contact amount between the heat fixing roller and the pressure roller. The heat fixing unit offers a less warming up time and a better paper delivery performance, and requires less material cost.The heat fixing unit in an electrophotographic copying apparatus may employ a fixed type or a rotary type curing unit for raising the plurality of fibers.

Abstract: A polyacetal resin composition excellent in heat stability and surface processability which comprises (a) about 100 parts by weight of polyacetal resin, (b) about 2 to about 35 parts by weight of a carbonate, phosphate or acetate of a metal belonging to Group II of the Periodic Table or a mixture thereof and (c) about 0.01 to about 20 parts by weight of a polymer, a copolymer or a mixture thereof of a compound selected from the group consisting of unsaturated polyesters, alkyl esters of acrylic acid or methacrylic acid, amides of acrylic acid or methacrylic acid, triallyl cyanurate, diallyl phthalate, vinyl acetate and divinylbenzene.

Abstract: A polyacetal resin composition excellent in heat stability and surface processability which comprises (a) about 100 parts by weight of polyacetal resin, (b) about 2 to about 35 parts by weight of a carbonate, phosphate or acetate of a metal belonging to Group II of the Periodic Table or a mixture thereof and (c) about 0.01 to about 20 parts by weight of a polymer, a copolymer or a mixture thereof of a compound selected from the group consisting of unsaturated polyesters, alkyl esters of acrylic acid or methacrylic acid, amides of acrylic acid or methacrylic acid, triallyl cyanurate, diallyl phthalate, vinyl acetate and divinylbenzene.