Toner Density Sensor Cleaning With a Retracting Brush
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Solution Overview
Problem
Existing image forming apparatuses face challenges in effectively cleaning the sensing surface of toner density sensors, which affects the accuracy of density correction in toner images.
Innovation Solution
The apparatus incorporates a cleaning portion with a brush that moves in an intersecting direction to clean the sensing surface of the sensor, controlled by a control portion to alternate between a cleaning and retracted position, ensuring proper cleaning without contacting the sensor package or substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a brush is used to clean the sensing surface of the sensor, then cleaning effectiveness is improved, but the risk of damaging the sensor package or substrate increases
Solution Approach 1:
The brush is designed to be movable relative to the sensor package, transitioning between a retracted position (when the sensor package is present) and a cleaning position (when the sensor package is removed). This dynamic positioning allows the brush to clean the substrate surface without contacting or damaging the sensor package, resolving the contradiction between cleaning effectiveness and damage risk
Solution Approach 2:
The system performs preliminary detection to determine whether the sensor package is mounted before activating the brush cleaning function. This preliminary action prevents the brush from operating when the sensor package is present, thereby avoiding potential damage while maintaining cleaning capability when appropriate
2Manufacturing precision
If the brush is positioned to contact the sensing surface for cleaning, then cleaning performance is improved, but the brush may contact and potentially damage the sensor package or substrate
Solution Approach 1:
The brush positioning system is designed to dynamically adjust the brush position based on the presence of the sensor package. When the sensor package is mounted, the brush remains retracted at a safe distance. When the sensor package is removed, the brush moves to the cleaning position to contact the substrate surface. This dynamic control achieves precise cleaning when needed while preventing contact damage when the sensor package is present
3Area of stationary object
If the brush length is increased to ensure contact with the sensing surface, then cleaning coverage is improved, but the risk of contacting the substrate or sensor package increases
Solution Approach 1:
Rather than using a longer fixed brush that would always contact the substrate or sensor package, the invention employs a brush of appropriate length combined with a movable mounting structure. This allows the brush to reach the sensing surface for effective cleaning when the sensor package is removed, while being retractable to avoid contact when the sensor package is present, thus achieving cleaning coverage without excessive contact risk
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 configuration enables favorable cleaning of the sensing surface, ensuring accurate toner density correction and miniaturization of the image forming apparatus.
Implementation Method 1
a sensor that applies light toward an outer circumferential surface of an image carrier and receives reflected light from the image carrier
Implementation Method 2
a brush that moves in an intersecting direction intersecting with the light applied by the sensor, and performs cleaning of a sensing surface of the sensor by use of the brush
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An image forming apparatus (1) includes a density sensing portion (14), a cleaning portion (40), and a control portion (8). The density sensing portion (14) includes a substrate (151) and a sensor package (17) and outputs a sensing value related to a toner density of a toner image formed on an outer circumferential surface of an image carrier (31). The control portion (8) performs control so that, when the cleaning portion (40) performs cleaning of a sensing surface (17f), a brush (43) is moved to a cleaning position where the brush (43) contacts the sensing surface (17f). The control portion (8) also performs control so that, when the cleaning portion (40) does not perform the cleaning of the sensing surface (17f), the brush (43) is moved to a retracted position where the brush (43) does not contact the sensor package (17) and the substrate (151).