Process Cartridge Optical Layout for Accurate Toner Amount Detection
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Solution Overview
Problem
In image forming apparatuses with a process cartridge system, the displacement of the process cartridge from its designated position can lead to inaccurate detection of toner residual amounts due to misalignment of light emitting and receiving portions, as described in Japanese Patent Application Laid-Open Publication No. H10-186822.
Innovation Solution
The image forming apparatus incorporates a light emitting portion and a light receiving portion on a side of the frame opposite the developer bearing member, perpendicular to the longitudinal direction of the developer bearing member, ensuring accurate toner detection regardless of the process cartridge's position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the light emitting portion and light receiving portion are provided on the image forming apparatus body, then the process cartridge can be attached and detached, but the position of the process cartridge may be displaced from the light emitting portion and light receiving portion, deteriorating detection accuracy
Solution Approach 1:
Instead of placing the light emitting and receiving portions on the image forming apparatus body (external to the process cartridge), the patent inverts the arrangement by integrating these optical components directly onto the process cartridge. This ensures that the optical path remains fixed relative to the developer container, eliminating detection accuracy issues caused by positional displacement during attachment and detachment operations.
2Ease of manufacture
If a gap is formed between the image forming apparatus body and the process cartridge for attachment and detachment, then the process cartridge can be easily installed and removed, but misalignment between the optical components and process cartridge may occur
Solution Approach 1:
The patent merges the optical detection components (light emitting portion and light receiving portion) with the process cartridge as an integrated assembly. This combination ensures that the optical path is inherently aligned with the developer container position, maintaining manufacturing precision while still allowing the process cartridge to be easily attached and detached from the image forming apparatus body through the gap.
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 maintains detection accuracy of toner residual amounts by aligning the light emitting and receiving portions relative to the developer container, independent of the process cartridge's alignment within the apparatus.
Implementation Method 1
a light emitting portion configured to emit light
Implementation Method 2
a light receiving portion configured to receive the light emitted from the light emitting portion and having passed through an interior of the storage portion
Data Source
AI summary
An image forming apparatus includes an apparatus body, an image bearing member, and a process unit attached to the apparatus body. The process unit includes a frame including a storage portion configured to store developer, a developer bearing member configured to supply developer to the image bearing member to develop an electrostatic latent image, and a circuit board attached to the frame. The circuit board includes a light emitting portion configured to emit light, and a light receiving portion configured to receive the light emitted from the light emitting portion and having passed through an interior of the storage portion.