Image Forming Apparatus Toner Density Control via Sensor Timing
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Solution Overview
Problem
Existing image forming apparatuses face challenges in conducting regular image forming and adjustment operations simultaneously due to issues with toner scattering, incorrect detection, and ozone production, leading to downtime and adverse effects on image quality.
Innovation Solution
An image forming apparatus that controls the timing of image adjustment patterns by ignoring output values during the separation of the secondary transfer member from the intermediate transfer member, using optical sensors to detect toner amounts and adjust toner density, and includes a determination unit to assess the impact of separation on image forming conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical sensors are disposed at a downstream side of the secondary transfer portion to detect image adjustment patterns, then detection capability is improved, but toner scattering occurs and incorrect detection results are obtained
Solution Approach 1:
The secondary transfer member is separated from the intermediate transfer member before the image adjustment patterns reach the secondary transfer portion. This preliminary separation action prevents toner scattering and ensures accurate detection by optical sensors, as the patterns are detected on the intermediate transfer member before any potential contamination occurs during the transfer process.
2Reliability
If the secondary transfer member is separated from the intermediate transfer member during image adjustment operations, then toner scattering is reduced, but mechanical impacts affect image quality
Solution Approach 1:
The control unit monitors the separation state of the secondary transfer member and uses feedback control to determine when to ignore optical sensor output values. When separation is detected, the system selectively ignores detection data that would be affected by mechanical impacts, allowing the separation action to proceed without compromising image quality through corrupted detection results.
3Measurement precision
If image adjustment operations are conducted separately from regular image forming operations, then detection accuracy is improved, but downtime increases
Solution Approach 1:
The system merges image adjustment operations with regular image forming operations by conducting both processes simultaneously on the intermediate transfer member. The optical sensors detect image adjustment patterns during the same transfer cycle that regular images are being formed, eliminating the need for separate operational phases and reducing downtime while maintaining detection accuracy through the separation of the secondary transfer member.
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 approach reduces downtime, minimizes ozone production, and maintains image quality by allowing simultaneous regular image forming and adjustment operations while optimizing toner density and reducing mechanical impacts.
Implementation Method 1
at least one optical sensor disposed at a downstream side of the transfer portion in a travel direction of the intermediate transfer member, and configured to detect respective amounts of toner adhered to the plurality of image adjustment patterns
Implementation Method 2
The overlaid toner image is electrically attracted by a secondary transfer member at a secondary transfer portion and transferred onto a recording medium, such as a transfer sheet
Implementation Method 3
The visible toner image on each of the plurality of image forming devices is primarily transferred onto an intermediate transfer member into a full color toner image in an overlaying manner
Implementation Method 4
The overlaid toner image on the recording medium is fixed by a fixing unit and discharged to a sheet discharging tray
Data Source
AI summary
An image forming apparatus includes at least one image bearing member, an intermediate transfer member, a secondary transfer member, and at least one optical sensor. In the image forming apparatus, it is determined that output values of the respective amounts of toner detected by the at least one optical sensor are affected by an impact caused due to a separation of the secondary transfer member from the intermediate transfer member and the output values are ignored as image adjustment input information, when the secondary transfer member separates from the intermediate transfer member during any of writing, developing, and transferring the plurality of image adjustment patterns, if the output values fall outside a given range and an interval between the output values of adjacent image bearing members is substantially equal to a distance between the two adjacent image bearing members for the primary transfer.