Developer Cartridge Light Transmission Toner Level Detection
Solution Overview
Problem
Existing image forming apparatuses, such as laser printers, face challenges in accurately detecting whether a developer cartridge is attached and in determining the remaining toner level, as the states of a detached cartridge and a new cartridge are indistinguishable using existing light-based detection methods.
Innovation Solution
The implementation of a light sensor system with a light emitting device and a light receiving device positioned on opposite sides of the developer cartridge, utilizing light transmitting tubes with deflecting portions to guide light through the cartridge, allowing detection of toner levels and cartridge attachment status by varying light paths based on toner presence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If light guides are installed on the top and bottom of the toner container to detect toner level, then toner level detection is enabled, but the state of detached cartridge cannot be distinguished from full cartridge state
Solution Approach 1:
The detection function is segmented into two independent detection paths: one for detecting cartridge attachment status (using light reflection from the cartridge body) and another for detecting toner level (using light transmission through the toner). This segmentation allows the system to distinguish between different states without interference between detection functions.
Solution Approach 2:
A light reflector is introduced as an intermediary component on the cartridge body to enable attachment status detection. The reflector mediates the light interaction between the LED and the detection circuit, creating a distinguishable signal when the cartridge is attached versus detached, while not interfering with the toner level detection path.
2Quantity of substance
If light from LED is blocked by toner to indicate full container, then toner level detection is achieved, but detached state cannot be detected
Solution Approach 1:
Instead of relying solely on light blockage by toner to detect full status, the system inverts the approach by using light reflection from the cartridge body to detect attachment status. This inversion creates a complementary detection mechanism that works independently of toner presence, solving the ambiguity between detached and full states.
Solution Approach 2:
Different detection mechanisms are applied to different local functions: light reflection is used locally for attachment status detection (using the cartridge body as the detection target), while light transmission through the toner is used locally for toner level detection. This local differentiation of detection quality allows both functions to operate simultaneously without interference.
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
Enables accurate detection of toner levels and cartridge attachment, preventing unnecessary replacements and ensuring sufficient toner is available, while allowing for flexible design and operation of the developer cartridge.
Implementation Method 1
Light emitted from an LED travels inside the toner container through the first light guide, and then travels through the second light guide to be received by the phototransistor
Implementation Method 2
The light from the LED is deflected by about 90° by the first light guide to travel through the toner container from the bottom to the top. The traveling light is deflected by about 90° by the second light guide
Implementation Method 3
Light emitted from an LED travels inside the toner container through the first light guide, and then travels through the second light guide to be received by the phototransistor
Data Source
AI summary
A light emitting device and light receiving device are positioned to face each other to sandwich the developer cartridge. A pair of light transmitting tubes is installed in the casing of a developer cartridge. Light emitted from the light emitting device travels inside the casing via the light transmitting tubes and is received by the light receiving device. The direction of light traveling through light transmitting tubes changes along the light path to the light receiving device. When a developer cartridge is attached to the housing, toner blocks light from traveling through the toner chamber to the light receiving device. When the toner is consumed and the developer cartridge is ready to be replaced, light passes through the toner chamber and is received by the light receiving device, prompting exchange of the developer cartridge.