Tray Light-Shielding Member for Optical Detection
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Solution Overview
Problem
Existing image recording apparatuses face errors in determining whether a recording medium is loaded in a tray due to the likelihood of sebum or dust adhering to the tray surfaces, causing incorrect light reflection and detection.
Innovation Solution
The apparatus includes a tray with distinct openings for light emission and reception, allowing the sensor to determine the presence of a recording medium by comparing output values based on light reflection from the tray and the medium, reducing errors by minimizing user contact and external handling impacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the tray surface is colored black to suppress light reflection, then light reflection from the tray is reduced, but light reflection from sebum or dust on the tray surface increases, causing detection errors
Solution Approach 1:
The patent introduces a light-shielding member as an intermediary element between the light emitting/receiving portions and the tray surface. This member blocks the light path to prevent detection of spurious reflections from sebum or dust, thereby resolving the contradiction between suppressing tray reflection and maintaining detection reliability.
Solution Approach 2:
The patent divides the detection system into separate light emitting portions and light receiving portions positioned at different locations on the tray. By segmenting the detection function across multiple points, the system can distinguish between reflections from the tray surface and reflections from the recording medium, improving detection accuracy despite the presence of contaminants.
2Measurement precision
If the tray is made highly reflective to enhance light detection, then detection sensitivity is improved, but errors increase due to sebum or dust adhering to the tray surface
Solution Approach 1:
The light-shielding member acts as a mediator that allows the system to maintain high detection sensitivity through reflective tray surfaces while preventing contaminants from interfering with the detection process. The shielding member blocks the light path to areas where sebum or dust would otherwise cause false reflections.
Solution Approach 2:
The patent applies different optical properties to different regions of the tray. The tray surface is made highly reflective for detection sensitivity, while the light-shielding member creates localized non-reflective zones that prevent contamination from affecting the detection system.
3Measurement precision
If the light emitting portion and light receiving portion are positioned to detect reflections from the recording medium, then medium detection is improved, but the system becomes vulnerable to tray surface contaminants
Solution Approach 1:
The light-shielding member is positioned between the light emitting/receiving portions and the tray surface to block spurious light paths. This intermediary element allows the sensor system to maintain simple positioning while achieving reliable medium detection by preventing contamination from interfering with the optical path.
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 solution provides reliable detection of the recording medium's presence, reducing errors caused by sebum or dust adherence and ensuring accurate determination of medium loading.
Implementation Method 1
The light emitting portion emits light toward a region of a surface of the tray... The light emitted from the light emitting portion is reflected by the surface of the tray and reaches the light receiving portion
Data Source
AI summary
An image recording apparatus includes a tray including a loading portion for holding a recording medium. The tray has first and second openings. A recording portion is positioned in spaced relation to a platen supporting member having a platen and defining a transportation path therebetween. A transportation portion transports the tray along the transportation path to a position between the platen and the recording portion. A sensor is part of the recording portion and opposes the platen. The sensor outputting a signal based on a detection result obtained using a light emitting portion and a light receiving portion. A control section controls the transportation portion and the sensor to perform detection using the light emitting and light receiving portions. A determination section that determines whether the recording medium is loaded in the loading portion of the tray in accordance with a first output value, and a second output value.