Image Forming Control for Toner Slip During Feed Switching
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Solution Overview
Problem
In image forming apparatuses using the intermediary transfer type, the phenomenon of toner slipping through the cleaning blade occurs during automatic feeding portion switching, leading to image defects due to untransferred toner images being transferred onto subsequent recording materials.
Innovation Solution
The image forming apparatus controls the resumption of image formation by adjusting the timing of the leading end of the untransferred toner image on the intermediary transfer member to pass through the cleaning position and primary transfer portion after the feeding source is switched, ensuring that the post-resumption image leading end reaches the primary transfer portion at a specific timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If automatic feeding portion switching is performed when recording material runs out, then continuous image formation can be maintained, but untransferred toner images may slip through the cleaning blade and cause image defects
Solution Approach 1:
The cleaning blade performs cleaning action in advance before the untransferred toner image reaches the secondary transfer portion. By positioning the cleaning blade upstream of the secondary transfer portion and activating it when sheet absence is detected, the system prevents toner from slipping through and causing image defects on subsequent recording materials.
Solution Approach 2:
The cleaning blade acts as an intermediary component between the untransferred toner image and the secondary transfer portion. It intercepts and removes the untransferred toner before it can be transferred to the recording material, thereby preventing image defects while allowing automatic feeding portion switching to maintain productivity.
2Productivity
If image formation is resumed immediately after cleaning the secondary transfer member, then productivity is improved, but untransferred toner may be transferred onto subsequent recording materials
Solution Approach 1:
The cleaning blade is positioned and activated in advance to remove untransferred toner before the image formation is resumed. This preliminary cleaning action ensures that when recording material is fed from the switched feeding portion, no untransferred toner remains to cause slipping-through images.
Solution Approach 2:
The cleaning blade applies a counter-action to the harmful effect of untransferred toner by removing it before it can slip through and create image defects. This preliminary anti-action prevents the slipping-through phenomenon while allowing rapid resumption of image formation.
3Quantity of substance
If the cleaning blade contacts the intermediary transfer belt to remove toner, then toner removal is effective, but high flowability toner may slip through the cleaning blade
Solution Approach 1:
The cleaning blade removes the bulk of untransferred toner in advance before the toner reaches the secondary transfer portion. By performing this preliminary removal action upstream, the system handles high flowability toner effectively and prevents it from slipping through later in the process.
Solution Approach 2:
The cleaning blade serves as an intermediary that intercepts untransferred toner with high flowability before it can slip through to the secondary transfer portion. Its strategic positioning allows it to capture and remove these problematic toner particles, preventing image defects on subsequent recording materials.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This control mechanism effectively prevents toner slipping through the cleaning blade, thereby reducing image defects caused by untransferred toner images during automatic feeding portion switching.
Implementation Method 1
a belt cleaning device of a belt cleaning type provided with a cleaning blade constituted by a plate-like elastic member as a cleaning member is used in many cases. The cleaning blade is constituted by a rubber material such as an urethane rubber and is contacted to a surface of the intermediary transfer belt
Implementation Method 2
The cleaning blade is constituted by a rubber material such as an urethane rubber and is contacted to a surface of the intermediary transfer belt so that a direction thereof becomes a counter direction to a movement direction of the surface of the intermediary transfer belt
Implementation Method 3
a toner image formed on an image bearing member is recording material transferred onto an intermediary transfer member in a primary transfer portion, and this toner is secondarily transferred onto a recording material such as paper in a secondary transfer portion
Implementation Method 4
image formation (specifically formation of an electrostatic latent image on a photosensitive drum by exposure to light)
Data Source
AI summary
An image forming apparatus includes an image forming portion, an intermediary transfer member, a secondary transfer member, a cleaning blade, first and second feeding portions, and a controller. In the case where a recording material feeding source is changed from the first feeding portion to the second feeding portion, when a position of a leading end of an untransferred toner image is an untransferred toner image leading end, and a position of a leading end of an image forming region in which a first toner image after resumption of image formation is formable is a post-resumption image leading end, the controller controls the image forming portion to carry out control in which the image formation is resumed so that the untransferred toner image leading end first passes through a primary transfer portion and then the post-resumption image leading end first reaches the primary transfer portion.