Sheet Feed Device Stacking Tray Lift Mechanism

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Solution Overview

Problem

Conventional sheet feed devices hinder the operability of the sheet supplying operation due to the positioning of the openable member and casing, which obstructs the feeding of sheets, especially when the openable member is open or when sheets are not present on the stacking tray.

Innovation Solution

A sheet feed device with a stacking tray that can be lifted and lowered, featuring an opening/closing member that positions the sheet stacking surface higher than the openable member when open, and a notched casing to facilitate sheet supply from the side, ensuring unobstructed access and improved operability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sheet stacking surface is positioned lower than the uppermost portion of the openable member, then the openable member can cover the stacking tray when closed, but the sheet supplying operation is hindered when the openable member is open

Engineering Contradiction:

Improvecoverage of stacking tray by openable memberVSAvoidoperability of sheet supplying operation

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent makes the stacking tray movable (liftable and lowerable) rather than fixed, allowing it to change position dynamically. When the openable member is open, the stacking tray can be lowered to provide clearance for sheet supply, and when closed, it returns to its original position to be covered by the openable member, thus resolving the contradiction between coverage and operability

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent introduces vertical movement (up-down direction) as an additional dimension for the stacking tray position adjustment. By moving the stacking tray vertically, it creates sufficient clearance between the sheet stacking surface and the openable member when open, enabling smooth sheet supply from the front surface without compromising the coverage function when closed

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Ease of operation

If the sheet stacking surface is positioned higher than the uppermost portion of the openable member when open, then sheet supply is unobstructed, but the openable member cannot effectively cover the stacking tray

Engineering Contradiction:

Improveoperability of sheet supplying operationVSAvoidcoverage of stacking tray by openable member

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The stacking tray is designed to move vertically, allowing it to adjust its position dynamically. When the openable member is open during sheet supply, the stacking tray is lowered to create clearance. When the openable member is closed, the stacking tray returns to its higher position to ensure proper coverage, thus resolving the contradiction

Inventive Principle:

Principle #15Dynamics

3Reliability

If the casing has a complete front surface, then the casing provides full enclosure and protection, but sheet supply from the front surface is hindered

Engineering Contradiction:

Improveenclosure and protection by casingVSAvoidoperability of sheet supplying operation

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent segments the casing front surface by introducing a notched portion, dividing it into two parts: an upper part that maintains enclosure and a lower notched area that provides access for sheet supply. This segmentation allows the casing to simultaneously provide protection and facilitate easy sheet insertion from the front surface

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The casing is designed with different properties in different locations: the majority of the front surface maintains complete enclosure for protection, while a specific local area (the notched portion) is modified to provide open access for sheet supply, thus resolving the contradiction between full enclosure and ease of operation

Inventive Principle:

Principle #3Local quality

4Manufacturing precision

If a position restricting member is added to restrict sheet position, then sheet positioning is improved, but the openable member and position restricting member create obstruction when open

Engineering Contradiction:

Improvepositioning precision of sheetsVSAvoidoperability of sheet supplying operation

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The stacking tray's vertical movement capability allows it to dynamically adjust its position. When the openable member and position restricting member are in the open position, the stacking tray is lowered to create sufficient clearance, eliminating obstruction. When closed, the stacking tray returns to its normal position, maintaining the positioning function of the position restricting member, thus resolving the contradiction between positioning precision and operability

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS10351368B2Sheet feed device and image forming apparatus including the same

Publication Date: 2019.07.16 SHARP KK

AI summary

A sheet feed device includes: a stacking tray on which sheets are stacked in such a manner as to be capable of being lifted and lowered; and an opening/closing member. When the opening/closing member is open, a sheet stacking surface on which the sheets are stacked is positioned at a position higher, in an upper and lower direction of the sheet feed device, than an uppermost portion of the opening/closing member in the upper and lower direction.