摘要:
An image forming apparatus including a heating rotating body (first body) and a pressurizing rotating body (second body) disposed in a pressure contact state, and commencing image forming when a temperature of the first body reaches a predetermined temperature lower than a fixing temperature. The apparatus acquires a value indicating a temperature of the second body upon commencement of warm-up, and when the value is below a threshold value, heats the first body until the temperature thereof reaches the fixing temperature while rotating the two bodies at a first speed, and when the value equals or exceeds the threshold value, heats the first body until the temperature thereof reaches the predetermined temperature while rotating the two bodies at a second speed slower than the first speed and further heats the first body until the temperature thereof reaches the fixing temperature while rotating the two bodies at the first speed.
摘要:
An image forming apparatus including a heating rotating body (first body) and a pressurizing rotating body (second body) disposed in a pressure contact state, and commencing image forming when a temperature of the first body reaches a predetermined temperature lower than a fixing temperature. The apparatus acquires a value indicating a temperature of the second body upon commencement of warm-up, and when the value is below a threshold value, heats the first body until the temperature thereof reaches the fixing temperature while rotating the two bodies at a first speed, and when the value equals or exceeds the threshold value, heats the first body until the temperature thereof reaches the predetermined temperature while rotating the two bodies at a second speed slower than the first speed and further heats the first body until the temperature thereof reaches the fixing temperature while rotating the two bodies at the first speed.
摘要:
A cleaning device for cleaning a belt member, includes a cleaning blade; a removing member coming in contact with the surface of the belt member so as to remove foreign matter adhering on the surface of the belt member; and a contact pressure changing section to change a contact pressure between the removing member to the belt member, wherein, when the contact pressure between the removing member and a region of the belt member corresponding in position to a toner image to be not transferred to a paper sheet is made P1, and the contact pressure between the removing member and a region of the belt member corresponding in position to a toner image to be transferred to a paper sheet is made P2, the contact pressure changing section changes the contact pressure to satisfy the conditional formula: (P1
摘要:
An image forming apparatus having an image carrier for forming an electrostatic latent image and a developing unit for developing the electrostatic latent image with a two-component developing agent, the developing unit includes: a developing agent carrier for developing the electrostatic latent image to form a visible image, having inside thereof a development main magnetic pole for forming a bristle of a magnetic brush; and a plurality of magnetic poles for conveying the developing agent, wherein the developing unit performs a counter type contact developing method, and wherein, the development area is formed so that, a contact width of the bristle of the magnetic brush is 70% or less with respect to a development width, and a center position of the contact width is positioned on an upstream side with respect to a center position of the development width in a rotation direction of said image carrier.
摘要:
An image forming apparatus incorporating: an image forming body; and a developing unit having a developer carrier, a magnetic field generator, a developer restriction member, a first conveyer, and a second conveyer, wherein the magnetic field generator has: a main magnetic pole; pickup magnetic pole; and a strip-off magnetic pole, wherein the developing unit satisfies following conditions: (a) the second conveyer is a screw conveyer having an outer diameter within 24 mm-30 mm, rotating speed of 300-500 rpm, (b) the pickup magnetic pole is arranged at an angle of 25°-60° downstream with a line connecting a rotation centers of the developer carrier and the second conveyer, (c) the strip-off magnetic pole is arranged at 60°-80° upward with the line,(d) a transporting capability of the first conveyer is larger than that of the second conveyer.
摘要:
An image forming apparatus includes a fog controller to control a fogging level of a toner image carrier by adjusting a fog control parameter on the basis of the fogging level detected by a fogging level detection section and the target fogging level stored in a memory section. While varying a value of the fog control parameter, the fog controller makes a detection pattern forming section to form a series of detection patterns between toner images for each page on the toner image carrier, makes the fogging level detection section to detect each of fogging levels of the series of detection patterns, determines a target fog control parameter value on the basis of each fogging level of the series of detection patterns detected and the target fogging level stored, and adjusts the fog control parameter on the basis of the target fog control parameter value.
摘要:
An image forming apparatus includes: a moving speed ratio change section which changes a circumferential speed ratio between a surface of a developer bearing member and a surface of an image carrier; and a memory section which stores a target value of fog toner. After the circumferential speed ratio has been changed by the moving speed ratio change section, a controller determines a fog control parameter based on comparing the value detected by the fog toner detection section with the target value stored in the memory section. After then, and the controller controls the moving speed ratio change section to return the circumferential speed ratio to the circumferential speed ratio prior to the change.
摘要:
High quality images are provided by controlling development conditions based on the proportion of the toner layer potential difference, which a difference between the toner layer potential and electrostatic latent image potential, to the development contrast potential difference, which is a difference between the development bias potential and electrostatic latent image potential. The control section for controlling a development power supply controls the voltage supplied by the development power supply, based on the toner layer potential difference and development contrast potential difference in the development section. This arrangement ensures formation of high-quality images free from concentration of toner.
摘要:
This invention relates to an image forming apparatus including a developing unit which develops an electrostatic latent image formed on an image carrier by using a two-component developing agent containing polymerized toner. The developing unit includes a supply/convey member which conveys the two-component developing agent in the axial direction while agitating it and a toner density sensor which detects the toner density of the two-component developing agent. The toner density sensor is placed to be in a non-contact state with respect to the supply/convey member and oppose it with a gap of 0.8 mm or less. The diameter of the supply/convey member is set to 23 mm or more.