Print Position Adjustment for Sheet Storage Humidity Stability

Solution Overview

Problem

Image forming apparatuses face challenges in maintaining accurate print position adjustments due to sheet expansion and shrinkage caused by changes in moisture content, particularly after sheet replenishment or replacement, leading to potential print position displacement.

Innovation Solution

The apparatus includes a selection unit for choosing sheet storage sections, a forming unit for adjusting image positions using specific adjustment values, a detection unit for identifying updates in sheet storage sections, and a control unit that temporarily inhibits the selection of updated sections until stability is reached, ensuring accurate print positioning by managing humidity and elapsed time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If sheet replenishment or replacement is performed, then sheet supply is restored or improved, but sheet humidity becomes unstable causing print position displacement

Engineering Contradiction:

Improvesheet supply continuityVSAvoidprint position accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The system performs preliminary detection of sheet replenishment actions and proactively sets a restriction period before allowing print position adjustment. This prevents adjustment operations from being performed on sheets whose humidity is still unstable, thereby avoiding print position displacement while maintaining continuous sheet supply capability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the selection availability of sheet storage sections based on their operational state. When sheets are replenished or replaced, the corresponding storage section is temporarily restricted from being selected for print position adjustment. This dynamic state management ensures that only sheets with stable humidity characteristics are used for adjustment operations

Inventive Principle:

Principle #15Dynamics

2Loss of time

If print position adjustment is performed immediately after sheet replenishment, then adjustment time is reduced, but print position accuracy deteriorates due to sheet expansion and shrinkage

Engineering Contradiction:

Improveadjustment timeVSAvoidprint position accuracy

Core Design Contradiction:

Loss of timeVSManufacturing precision

Solution Approach 1:

The system performs preliminary detection of sheet replenishment actions and proactively sets a restriction period before allowing print position adjustment. This prevents adjustment operations from being performed on sheets whose humidity is still unstable, thereby avoiding print position displacement while maintaining continuous sheet supply capability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the operational state of sheet storage sections and provides feedback control on their selection availability. When sheets are replenished or replaced, the corresponding storage section is temporarily restricted from being selected for print position adjustment. This dynamic state management ensures that only sheets with stable humidity characteristics are used for adjustment operations

Inventive Principle:

Principle #23Feedback

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 suppresses print position displacement by ensuring that sheets are stabilized in terms of humidity and time after updates, thereby maintaining high print accuracy and reducing waste.

Implementation Method 1

a sheet used for printing (recording sheet) expands and shrinks depending on a moisture content thereof. Particularly, immediately after sheets are replenished or replaced for a sheet storage section, the moisture content of each sheet changes, causing changes in the dimensions of each sheet, until it reaches the equilibrium state.

Methodology Applied

Scientific EffectHumidity absorption and equilibrium: Absorption (physical)

Implementation Method 2

a sheet used for printing (recording sheet) expands and shrinks depending on a moisture content thereof. Particularly, immediately after sheets are replenished or replaced for a sheet storage section, the moisture content of each sheet changes, causing changes in the dimensions of each sheet

Methodology Applied

Scientific EffectHygroscopic expansion and contraction: Absorption (physical)

Data Source

PatentUS11948027B2Image forming apparatus having function of adjusting print position

Publication Date: 2024.04.02 CANON KK

AI summary

An image forming apparatus that suppresses print position displacement. The image forming apparatus includes a plurality of sheet storage sections configured to store sheets. A sheet storage section to be used is selected out of the plurality of sheet storage sections. An image is formed on a sheet supplied from the selected sheet storage section and the image position is adjusted using adjustment values associated with the selected sheet storage section. When an update action performed by sheet replenishment or sheet replacement is detected for a sheet storage section, the sheet storage section for which the update action has been detected is controlled so as not to be selected by the selection unit until a predetermined time period elapses after detection of the update action.