Feeder Roller Color Matching for Image Reading Show-Through
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Solution Overview
Problem
Conventional image reading apparatuses face issues with show-through due to the feeder roller and guide device, leading to irregular document feeding and reduced reading capability, particularly when dealing with thin documents, and require additional components for transmittance measurement and correction, increasing cost and complexity.
Innovation Solution
The image reading apparatus features a feeder roller and guide device with matching colors to minimize reflectance differences, and incorporates a restricting member to prevent rotational displacement of the feeder roller, ensuring consistent document feeding and improved reading accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the feeder roller and guide device are disposed with clearance to guide the document sheet, then the document sheet can be fed along the feed pathway, but light transmitted through thin document sheets is reflected by the feeder roller and guide device causing show-through stripes in the read image
Solution Approach 1:
The patent applies color matching between the feeder roller and guide device surfaces. By making the outer circumferential surface of the feeder roller and the guide surface of the guide device have substantially the same color, the reflectance characteristics are unified, preventing the formation of show-through stripes in the read image while maintaining the necessary clearance for document sheet feeding
2Productivity
If the feeder roller is made of elastic material to improve document sheet separation, then document sheets can be fed one by one, but the outer circumferential surface may rotate relative to the driving shaft causing irregularities in document feeding
Solution Approach 1:
The patent introduces a restricting member as an intermediary component between the elastic roller body and the driving shaft. This restricting member restrains rotational displacement of the outer circumferential surface of the elastic roller body relative to the driving shaft, preventing irregularities in document feeding while maintaining the elastic properties needed for effective document sheet separation
3Measurement precision
If additional components are added for transmittance measurement and show-through correction, then reading accuracy can be improved, but device complexity and cost increase
Solution Approach 1:
The patent converts the potentially harmful light reflection from the feeder roller and guide device into a beneficial uniform reflection by matching their colors. This eliminates show-through stripes without requiring additional measurement or correction components, thereby improving reading accuracy while avoiding increased device complexity
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 effectively reduces show-through and irregularities in document feeding, enhancing the reading capability and accuracy of the image reading apparatus without increasing component count, thus improving overall performance and reducing costs.
Implementation Method 1
The light emitted from the light source is reflected by a surface of the document sheet being fed over the platen glass, and incident back on the image sensor
Implementation Method 2
The image sensor converts the received light into an electrical signal
Implementation Method 3
the outer circumferential surface of the roller body rotates relative to the driving shaft of the feeder roller due to an elastic deformation of the roller body in a circumferential direction of the roller body
Data Source
AI summary
There is disclosed an image reading apparatus which comprises a document feeder, a reading unit, and a guide device. The document feeder includes a feeder roller and feeds a document sheet with an image thereon, along an outer circumferential surface of the feeder roller. The reading unit has a reading surface opposed to the outer circumferential surface of the feeder roller, and reads, at a reading position, the image on the document sheet being fed. The guide device has a guide surface, and is disposed to be opposed to the reading surface of the reading unit, so as to guide the document sheet along the guide surface to the reading position. The outer circumferential surface of the feeder roller, and at least an opposed portion of the guide surface at which the guide surface is opposed to the reading surface, have a substantially same color.