Movable Optical Sensor for Toner Cleaning in Image Forming Apparatus
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Solution Overview
Problem
In image forming apparatuses, toner deposition on optical sensors due to scattered toner images leads to fluctuations in output, and existing solutions that move registration mark formation and detection positions outside the image formation width result in increased apparatus size and cost.
Innovation Solution
An image forming apparatus with a movable optical sensor unit that includes a cleaning member to clean the cover glass, allowing for maintenance of detection accuracy without upsizing the apparatus, by positioning the optical sensor to oppose the image bearing member with a predetermined distance and then retracting to form a cleaning space for the cleaning member to clean the cover glass.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the optical sensor is fixed close to the intermediary transfer member for accurate detection, then detection precision is improved, but toner deposits on the cover glass causing output fluctuation
Solution Approach 1:
The optical sensor is made movable between a first position (close to the intermediary transfer member for accurate detection) and a second position (spaced away for cleaning access). This dynamic positioning allows the system to switch between detection mode and cleaning mode, resolving the contradiction between maintaining detection precision and preventing toner deposition on the cover glass.
2Reliability
If registration mark detection positions are moved outside the image formation width to avoid toner deposition, then toner deposition is reduced, but apparatus size increases
Solution Approach 1:
Instead of permanently positioning the optical sensor outside the image formation width (which would increase apparatus size), the sensor is made dynamically movable. It can be positioned inside the image formation width during detection to maintain compact apparatus size, and moved outside during cleaning to prevent toner deposition, thus resolving the contradiction between reliability and apparatus size.
Solution Approach 2:
The optical sensor is extracted from its fixed position and made independently movable. This allows the cleaning operation to be performed by moving the sensor away from the detection position, rather than permanently positioning it outside the image formation width. The harmful factor (toner deposition) is avoided by temporarily removing the sensor from the contamination zone during cleaning.
3Measurement precision
If the optical sensor is positioned close to the image bearing member for accurate detection, then detection accuracy is maintained, but no space is available for cleaning the cover glass
Solution Approach 1:
The optical sensor's position is made dynamic, allowing it to be close to the image bearing member during detection for accurate measurements, and moved away during cleaning operations to provide accessibility for cleaning the cover glass. This resolves the contradiction between maintaining detection accuracy and enabling cleaning operations.
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
Maintains detection accuracy of the optical sensor while preventing upsizing of the image forming apparatus, ensuring high-quality color registration and density control without increasing the apparatus size or cost.
Implementation Method 1
an optical sensor including a light emitting portion for emitting light to a surface of the image bearing member, a light receiving portion for receiving the light reflected by the surface of the image bearing member
Data Source
AI summary
An image forming apparatus includes an image bearing member, an optical sensor including a light emitting portion, a light receiving portion and a cover member, a cleaning member, and a supporting member movable between a proximity position where the optical sensor opposes the image bearing member with a predetermined distance and a spaced position where the optical sensor is spaced from the image bearing member by a distance more than the predetermined distance to form a cleaning space between the optical sensor and the image bearing member. When the supporting member is in the proximity position, the cleaning member is in a retracted position retracted from an opposing space between the optical sensor and the image bearing member. When the supporting member is in the spaced position, the cleaning member is in a cleaning position for cleaning the cover member with the cleaning member.