Encoder Roller Positioning for Conveyance Belt Speed Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing paper conveyance apparatuses in image recording devices, such as inkjet printers, face challenges in accurately detecting the rotation speed of the conveyance belt due to instantaneous displacement of rollers, leading to variations in contact pressure and inaccurate speed detection.
Innovation Solution
A paper conveyance apparatus with an endless type conveyance belt and rollers, where the encoder rollers are positioned outside the paper passing region to maintain constant pressure and accurately detect the rotation speed, ensuring stable and precise speed detection by preventing instantaneous displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the encoder roller and encoder nip roller are positioned in the paper passing region to detect conveyance belt speed, then the detection system can be compact and integrated, but the rollers experience instantaneous displacement when paper enters or exits, causing contact pressure variation and inaccurate speed detection
Solution Approach 1:
The encoder roller and encoder nip roller are extracted from the paper passing region and repositioned to a location where paper does not pass through. This separation eliminates the interference of paper passage on roller contact pressure, allowing stable speed detection without the displacement issues that occur when paper enters or exits the roller gap.
Solution Approach 2:
The patent introduces a dedicated encoder roller system as an intermediary measurement device that indirectly detects conveyance belt speed through rotational position detection, rather than having the paper passage directly interact with the detection rollers. This intermediary system isolates the measurement function from the paper handling function.
2Device complexity
If the encoder roller contacts the conveyance belt in the paper passing region, then the structure is simplified, but the rotation speed detection becomes inaccurate due to roller displacement during paper passage
Solution Approach 1:
The encoder roller system is extracted from the paper passing region and positioned separately. This spatial separation maintains structural simplicity while eliminating the measurement errors caused by paper-induced roller displacement, achieving both simplicity and accuracy.
3Ease of operation
If the opposed roller applies biasing force to the conveyance belt for speed detection, then the detection mechanism is straightforward, but instantaneous displacement during paper passage causes contact pressure variation and detection errors
Solution Approach 1:
The speed detection function is extracted from the paper passing region by repositioning the encoder rollers to a location unaffected by paper passage. This maintains the simplicity of the biasing mechanism while eliminating the harmful effects of instantaneous displacement during paper entry and exit.
Data Source
AI summary
A paper conveyance apparatus includes an endless type conveyance belt, a driving unit, first and second rollers, a first biasing mechanism and an encoder. The endless type conveyance belt has first and second surfaces. The driving unit drives the conveyance belt. The first roller is in contact with the first surface. The second roller is in contact with the second surface. The first and second rollers nip the conveyance belt therebetween. The first biasing mechanism biases at least one of the first and second rollers so that the first and second rollers come close to each other. The encoder detects a rotation position of the first roller. At least one of the first and second rollers is in contact with at least one of the first and second surfaces in a region outside a paper passing region where a conveyed sheet of paper passes.