Sheet Ejecting Device with Selective Strengthener and Bender

Solution Overview

Problem

Soft printed sheets often bend and interfere with stacked sheets on a tray when ejected from image forming apparatuses, leading to misalignment, and existing solutions that curve sheets to prevent interference can cause them to jump out with great force, further misaligning the stack.

Innovation Solution

A sheet ejecting device with a strengthener and bender mechanism, controlled by sensors and drivers, that selectively strengthens and then cancels the force on the sheet to ensure proper alignment without excessive force, using levers or plates that advance and retreat within the ejection route.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a spring or elastic member is used to curve the sheet in a direction perpendicular to the ejection direction, then the leading edge contact point is moved farther from the ejection rollers, but the sheet may jump out of the ejection rollers with great force and push the stack out of alignment

Engineering Contradiction:

Improvesheet interference with stackVSAvoidejection force

Core Design Contradiction:

Object-affected harmful factorsVSForce

Solution Approach 1:

The patent applies local quality by differentiating the strengthening approach between the leading edge and the body of the sheet. The leading edge is curved perpendicular to the ejection direction to prevent interference, while the body is strengthened in the ejection direction to control force. This localized differentiation resolves the contradiction by addressing each region's specific requirements rather than applying uniform strengthening.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The sheet strengthening function is segmented into two distinct mechanisms: a curving mechanism for the leading edge and a strengthening mechanism for the sheet body. This segmentation allows independent control of the curving action (to prevent interference) and the strengthening action (to control ejection force), thereby resolving the contradiction between preventing interference and controlling force.

Inventive Principle:

Principle #1Segmentation

2Object-affected harmful factors

If the sheet is strengthened evenly from leading edge to trailing edge, then the leading edge contact point is moved farther from the ejection rollers, but the sheet becomes soft again before the trailing edge comes out, eliminating tension

Engineering Contradiction:

Improvesheet interference with stackVSAvoidsheet tension

Core Design Contradiction:

Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by differentiating the strengthening approach between the leading edge and the body of the sheet. The leading edge is curved perpendicular to the ejection direction to prevent interference, while the body is strengthened in the ejection direction to control force. This localized differentiation resolves the contradiction by addressing each region's specific requirements rather than applying uniform strengthening.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The sheet strengthening function is segmented into two distinct mechanisms: a curving mechanism for the leading edge and a strengthening mechanism for the sheet body. This segmentation allows independent control of the curving action (to prevent interference) and the strengthening action (to control ejection force), thereby resolving the contradiction between preventing interference and controlling force.

Inventive Principle:

Principle #1Segmentation

3Shape

If no strengthening is applied to soft sheets, then the leading part bends downward and interferes with the stack, but applying strengthening causes the sheet to jump out with great force

Engineering Contradiction:

Improvesheet alignmentVSAvoidejection force

Core Design Contradiction:

ShapeVSForce

Solution Approach 1:

The patent applies local quality by differentiating the strengthening approach between the leading edge and the body of the sheet. The leading edge is curved perpendicular to the ejection direction to prevent interference, while the body is strengthened in the ejection direction to control force. This localized differentiation resolves the contradiction by addressing each region's specific requirements rather than applying uniform strengthening.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The sheet strengthening function is segmented into two distinct mechanisms: a curving mechanism for the leading edge and a strengthening mechanism for the sheet body. This segmentation allows independent control of the curving action (to prevent interference) and the strengthening action (to control ejection force), thereby resolving the contradiction between preventing interference and controlling force.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS8100400B2Sheet ejecting device with sheet strengthener

Publication Date: 2012.01.24 KONICA MINOLTA BUSINESS TECH INC

AI summary

A sheet ejecting device has a pair of ejection rollers, a strengthener arranged in the sheet ejection device, for strengthening a sheet, a driver for moving the strengthener to advance into and retreat from a sheet ejection route, a sheet sensor, and a tray for receiving sheets ejected via the pair of ejection rollers and holding the sheets in a stack. Based on a detection signal from the sheet sensor, the strengthener is moved to advance into and retreat from the sheet ejection route so that only a necessary part of a sheet can be strengthened.