Image Forming Apparatus Forced Toner Consumption Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electrophotographic image forming apparatuses, impaired and insufficiently charged toner leads to background contamination and degraded image quality, especially in high-temperature, high-humidity environments, due to excessive toner circulation and charge loss, which affects toner density and charging characteristics.
Innovation Solution
An image forming apparatus with a controller that executes a forced toner consumption control to discharge insufficiently charged toner from the developing device, adjusting the developing bias to maintain target image density without excessively decreasing toner density, using a two-component developer and a transfer unit to transfer toner images onto a recording medium.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If forced toner consumption is performed to discharge insufficiently charged toner, then background contamination is prevented, but toner density in the developing device decreases
Solution Approach 1:
The system performs forced toner consumption as a preliminary action before normal image formation to discharge insufficiently charged toner from the developing device. This prevents background contamination while maintaining sufficient toner density for subsequent printing operations by proactively removing problematic toner particles.
Solution Approach 2:
The forced toner consumption is executed periodically under specific conditions (when toner has circulated for a predetermined time or in high-temperature high-humidity environments) rather than continuously. This periodic intervention maintains toner quality without excessively reducing toner density, balancing image quality prevention with resource conservation.
2Reliability
If toner density is decreased to facilitate frictional charging, then toner charging is improved, but image density may become insufficient
Solution Approach 1:
The system applies partial forced toner consumption rather than complete toner replacement. By consuming only a controlled amount of toner sufficient to improve charging characteristics without depleting the developer, the system achieves adequate frictional charging while maintaining sufficient toner density for normal image formation.
Solution Approach 2:
The system changes operational parameters by adjusting the developing bias voltage during forced toner consumption mode. This parameter change enables effective toner discharge and frictional charging while the system monitors and maintains toner density within acceptable ranges to prevent image density deficiency.
3Quantity of substance
If new toner is supplied during forced toner consumption to maintain density, then toner density is preserved, but charging characteristics worsen due to lower charge on new toner
Solution Approach 1:
The system performs forced toner consumption as a preliminary action before supplying new toner. This ensures that insufficiently charged toner is discharged first, creating space for fresh toner without mixing them. The preliminary discharge prevents charging characteristic degradation that would occur if new toner were mixed with depleted toner.
Solution Approach 2:
The system rushes through the forced toner consumption phase quickly to discharge depleted toner, then transitions to toner supply. This rapid transition minimizes the time during which charging characteristics could deteriorate, ensuring that new toner is introduced only after sufficient discharge has occurred.
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
Prevents background contamination by ensuring sufficient toner charging and maintaining desired image density, even in high-temperature, high-humidity conditions, without excessively reducing toner density in the developing device.
Implementation Method 1
The developing device contains a two-component developer including toner and carrier charged to a predetermined polarity. The developing device electrostatically attaches the toner to the latent image with a developing bias to form a toner image
Implementation Method 2
The transfer unit transfers the toner image from the surface of the latent image carrier onto a recording medium
Implementation Method 3
Forced consumption of the insufficiently charged toner decreases the toner density in the developing device and facilitates frictional charging of individual toner particles with the carrier particles. As a result, the toner is sufficiently charged
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
An image forming apparatus (100) includes a latent image carrier (2) to carry a latent image, a developing device (5) to develop the latent image with toner to form a toner image on the latent image carrier (2), a transfer unit (6) to transfer the toner image onto a recording medium, and a controller (30). The controller (30) executes an image density adjustment control of adjusting a developing bias to obtain a target image density, and further executes a forced toner consumption control of forcibly consuming the toner contained in the developing device (5) by attaching the toner to the latent image carrier (2) to form a toner pattern on the surface of the latent image carrier (2). The controller (30) executes the forced toner consumption control to forcibly consume a smaller amount of toner in response to a higher developing bias as adjusted by the image density adjustment control.