Abstract: An LED head is supplied which is able not only to reduce cost but also to improve disintegration efficiency and assembly efficiency. The LED head comprises a SLA holder with electroconductivity which has a insulating cover and supports a rod lens array with convergency; a substrate which is mounted in the SLA holder and is used for installing a LED array chip; a base with electroconductivity used for fixing the substrate at the SLA holder; and a clamp with electroconductivity which presses and contacts the base, wherein the clamp, while mounted onto the SLA holder, scrapes off contact part of the insulating cover.

Abstract: A positioning apparatus for an optical head includes a cylindrical photoconductive drum, an optical head, and at least one spacer. The cylindrical photoconductive drum extends in a direction of a longitudinal axis thereof. The optical head extends parallel to the longitudinal axis. The spacer is disposed to abut the photoconductive drum, limiting a distance between the optical head and the photoconductive drum. The photoconductive drum has a photoconductor and the spacer is in contact with the photoconductor through sliding friction. The spacer has a first surface in contact with the photoconductor. The photoconductor has a second surface in contact with the first surface. The first surface has a first curvature and the second surface has a second curvature. When the first surface is pressed against the second surface, the spacer may deform resiliently so that the first curvature becomes substantially equal to the second curvature.

Abstract: An image forming apparatus has a fixing unit. A heat roller heats a toner image on a print medium to fuse the toner image. A first temperature detector is in contact with a longitudinal end portion of the heat roller, and generates a first temperature data. A second temperature detector opposes the heat roller and is in proximity to a substantially middle portion of the heat roller. The second temperature detector generates a second temperature data. Depending on the first temperature data and the second temperature data, a controller performs temperature control either in a first mode where the heater is energized such that the first temperature data is equal to a first target value, or in a second mode where the heater is energized such that second temperature data is equal to a second target value.

Abstract: An image forming apparatus has a fixing unit. A heat roller heats a toner image on a print medium to fuse the toner image. A first temperature detector is in contact with a longitudinal end portion of the heat roller, and generates a first temperature data. A second temperature detector opposes the heat roller and is in proximity to a substantially middle portion of the heat roller. The second temperature detector generates a second temperature data. Depending on the first temperature data and the second temperature data, a controller performs temperature control either in a first mode where the heater is energized such that the first temperature data is equal to a first target value, or in a second mode where the heater is energized such that second temperature data is equal to a second target value.

Abstract: A developing roller rotates in contact with a photoreceptor drum. The developing roller controls a development thorough the formation of a toner layer 50 .mu.m or less in thickness on an outer surface. The photoreceptor drum transfers a toner image formed on the outer surface by the controlled-development onto a medium. A fixation device heat-treats and fixes the toner image transferred onto the medium. A toner for the developing treatment comprises a resin having a Tg of 75.degree. C. or more as at least part of it.

Abstract: The developing unit of an electrostatic printer is designed to avoid under-development of the bottom part of a dark latent image due to a reduction in recycled toner. This can be accomplished by providing the developing unit with one developing roller and at least two supply rollers. Alternatively, the developing unit has just one supply roller, but the rate at which toner is transferred from the supply roller to the developing roller can be switched. As another alternative, the supply roller and developing roller are designed to turn slowly enough that development of an entire page is completely developed before reaching the point where under-development would begin.