Sheet Supply Device Optical Detection for Pickup Timing
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Solution Overview
Problem
Existing sheet supply devices for image forming apparatuses face challenges in reducing the number of detecting units and waiting time when replenishing sheets, leading to unnecessary delays in printing operations, especially when a large number of sheets are loaded.
Innovation Solution
A sheet supply device with a detecting unit that checks for the presence of sheets at a predetermined position above the stacking portion, allowing the delivery unit to start the delivering operation only when sheets are detected, thereby reducing unnecessary waiting time and the number of sensors required.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the delivering operation is started after waiting for a maximum waiting time regardless of sheet amount, then pickup errors are prevented, but unnecessary waiting time is caused when many sheets are loaded
Solution Approach 1:
The patent replaces the mechanical timing system with an optical detection system. A light source and light receiving unit detect the presence of sheets on the stacking portion, converting a mechanical waiting-time-based system into an optical sensing system that can determine sheet presence immediately without waiting for the stacking portion to reach a specific height.
Solution Approach 2:
The patent introduces a light source and light receiving unit as intermediary detection components. These intermediaries detect sheet presence by measuring light reflection or transmission, providing an indirect but reliable method to determine whether sheets are loaded without requiring mechanical position sensing or timing mechanisms.
2Reliability
If multiple sensors are used to detect sheet presence at different positions, then detection reliability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The light source and light receiving unit serve multiple functions: they detect both the presence of sheets and can potentially determine sheet quantity or position based on light reflection characteristics. This single detection system replaces what would otherwise require multiple separate sensors, achieving multi-functionality with a unified component.
Solution Approach 2:
The patent combines the light source and light receiving unit into a single integrated detection system. Rather than using separate sensors for different detection purposes, these components are merged to perform multiple detection tasks simultaneously, reducing overall system complexity while maintaining or improving detection reliability.
Data Source
AI summary
A sheet supply device including: a device main body; a storage cassette having a stacking portion on which a sheet is loaded; a lifting mechanism that lifts up the stacking portion by using driving power supplied from a driving source; a delivery unit that is disposed above the stacking portion and performs a delivering operation in a contact state with the sheet on the stacking portion lifted up by the lifting mechanism, thereby delivering the sheet to a downstream side in a conveying direction; a control unit that controls the delivering operation of the delivery unit; and a detecting unit that detects whether the sheet is loaded on the stacking portion at a predetermine detecting position above the stacking portion; wherein, when the detecting unit detects that the sheet is in existence, the control unit starts the delivering operation of the delivery unit.