Abstract: An image forming apparatus has a photo-conductor drum that bears a toner image, and a transfer roller that is rotated in contact with the photo-conductor drum. The transfer roller transfers the toner image borne on the photo-conductor drum onto a recording medium conveyed between the photo-conductor drum and the transfer roller. The image forming apparatus includes a controller for applying to the transfer roller a transfer bias voltage for transferring the toner image from the photo-conductor drum onto the recording medium. The transfer bias voltage is a convolution of DC component and AC component.

Abstract: A toner supply bias voltage that is a vibrating voltage comprising an a.c. voltage and a d.c. voltage is applied to a toner supply roller. The d.c. voltage of toner supply bias voltage is changed in dependence upon a variation in the value of developing bias voltage. The lowering in the density at the leading end part of an image, the lowering in the density at the trailing end part of an image, and the uneven developing can be eliminated by satisfying the relationships100.ltoreq..vertline.VB.vertline..ltoreq..vertline.VSR.vertline.,2(.vertline.VSR-VB.vertline.+50).ltoreq..vertline.VPP.vertline..ltoreq.2.ve rtline.VSR.vertline. andf.gtoreq.v/lare satisfied, where VB is a developing bias voltage (unit: Volt), VSR is a d.c. voltage of the toner supply bias voltage (unit: Volt), VPP is a peak-to-peak value of the a.c.

Abstract: A developing apparatus includes a developing roller having a surface on which a layer of a non-magnetic single component developing agent (toner) is adapted to be formed, a toner supply roller held in contact with the developing roller so as to electrify the toner and also to supply the toner to the developing roller, and a toner regulating blade for regulating the toner on the developing roller so as to form a film of the toner thereon. The toner regulating blade is formed into a generally L-shape, and with a simple construction, the thickness of the toner layer, formed on the developing roller, can be stabilized, and also a torque of the developing roller can be reduced, and the degradation of a printed image is suppressed, thereby stabilizing the printed image.

Abstract: A nonmagnetic single component developing device comprises a developing roller having an outer surface on which a layer of a nonmagnetic single component developer composed of nonmagnetic toner is formed, a toner supply roller arranged in rear of the developing roller and made into contact therewith, for agitating and supplying the toner, a toner regulating blade arranged above the developing roller and made into press-contact therewith, for regulating a volume of the toner. The toner supply roller is electroconductive, and is applied thereto with an a.c. voltage so as to prevent lowering of the density in the leading and trailing end parts of an image so as to obtain a uniform image characteristic.

Abstract: An antenna element is composed by molding with an armor, and therefore if a slight deformation is caused by external force, the antenna characteristics are hardly changed. In particular, by the helicoid constitution of the antenna, changes of the pitch of antenna element and coil length are small, so that an antenna of excellent characteristics may be obtained. Moreover, by forming a hollow part in the armor and holding part of the helicoid part by the armor, more excellent antenna characteristics may be obtained.

Abstract: A developing apparatus has a toner reservoir for holding a non-magnetic toner, a toner supply roller including a supply surface for receiving the toner from the toner reservoir and electrifying the toner thereon, an electrostatic latent image carrier including a curved or flat latent image surface on which a latent image formed by an electrostatic voltage distribution thereon is developed by the toner transferred from the supply surface, and a toner seal surface arranged adjacent to the toner supply roller to contact a remaining part of the toner on the supply surface after the latent image development so that the remaining part of the toner is taken into the toner reservoir. The respective frictional coefficients between the toner seal surface and the toner and between the toner particles are selected to prevent a disturbance of toner condition between the toner and the toner seal surface.

Abstract: A magenta toner for electrophotography which comprises a binder resin and from 0.1 to 10 parts by weight of a colorant per 100 parts by weight of the binder resin. The colorant contain a mixture of from 40 to 60 parts by weight of a Rhodamine dye classified as C.I. Solvent Red 49 and, correspondingly, from 60 to 40 parts by weight of a pigment classified as C.I. Pigment Red 48. The toner may be mixed with a carrier to provide a two-component system. The toner has improved weatherability while keeping a good chromaticity.