Image Forming Apparatus Shutdown Sequence Control

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Solution Overview

Problem

Existing image forming apparatuses experience delays in starting subsequent image formation when a request is received during the shutdown sequence, leading to increased downtime and reduced productivity.

Innovation Solution

The image forming apparatus is designed to control the shutdown and startup sequences by allowing the continuation of operations such as driving of photoconductors and intermediate transfer belts without stopping, enabling immediate startup when a subsequent print request is received during the shutdown sequence, thus reducing downtime.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the shutdown sequence is continued until completed even when a request for subsequent image formation is received during the shutdown sequence, then the shutdown process is completed properly preventing component abrasion and toner deterioration, but the start of subsequent image formation is delayed for the time required to perform the rest of the shutdown sequence and then the startup sequence

Engineering Contradiction:
Improvecomponent protectionVSAvoiddowntime
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system dynamically adjusts the shutdown sequence execution based on real-time detection of subsequent image formation requests. When a request is detected during the shutdown sequence, the system suspends the shutdown sequence and transitions to the image formation operation, allowing the operation state to change dynamically rather than following a fixed shutdown path

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control unit continuously monitors for incoming image formation requests during the shutdown sequence and uses this feedback information to determine whether to continue or suspend the shutdown process. This feedback mechanism enables the system to respond adaptively to changing operational conditions

Inventive Principle:
Principle #23Feedback

2Productivity

If the shutdown sequence is suspended when a request for subsequent image formation is received during the shutdown sequence, then the subsequent image formation can start immediately improving productivity, but the operations such as photoconductor rotation and charging bias application are not properly shut down leading to component abrasion and toner deterioration

Engineering Contradiction:
Improvestart-up speedVSAvoidcomponent protection
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The control unit performs preliminary detection of subsequent image formation requests during the shutdown sequence before the shutdown is fully completed. This preliminary action allows the system to prepare for immediate startup by detecting incoming requests in advance, enabling a smoother transition without full shutdown completion

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the image forming apparatus waits for the shutdown and startup sequences to complete before processing subsequent requests, then component abrasion and toner deterioration are prevented, but productivity is reduced due to increased downtime

Engineering Contradiction:
Improvecomponent protectionVSAvoidoutput efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system transitions from a static shutdown protocol to a dynamic state machine that can switch between shutdown and image formation operations based on real-time conditions. This dynamic approach allows the apparatus to optimize between component protection and productivity by adapting its operational state to incoming requests

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control unit changes the operational parameters of the shutdown sequence based on the detection of subsequent image formation requests. When requests are detected, the system modifies the shutdown parameter execution to suspend or reduce the shutdown duration, thereby changing the operational state to prioritize productivity while still maintaining adequate component protection

Inventive Principle:
Principle #35Parameter changes

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 approach reduces downtime by allowing for immediate start of subsequent image formation when a print request is received during the shutdown sequence, enhancing productivity and preventing component abrasion.

Implementation Method 1

a charger charges a surface of an image bearing member (e.g., a photoconductor)

Methodology Applied
Scientific EffectElectrostatic charging: Electrostatics

Implementation Method 2

an irradiating device emits a light beam onto the charged surface of the photoconductor to form an electrostatic latent image on the photoconductor

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 3

a developing device develops the electrostatic latent image with a developer (e.g., toner) to form a toner image on the photoconductor

Methodology Applied
Scientific EffectElectrostatic attraction: Electrostatics

Implementation Method 4

a transfer device transfers the toner image formed on the photoconductor onto a sheet

Methodology Applied
Scientific EffectElectrostatic transfer: Electrostatics

Implementation Method 5

a fixing device applies heat and pressure to the sheet bearing the toner image to fix the toner image onto the sheet

Methodology Applied
Scientific EffectThermal bonding: Heating

Data Source

PatentEP2116907B1Image forming apparatus and control method for controlling the same
Publication Date: 2020.03.18 RICOH CO LTD
  • EP2116907B1 patent drawingFigure 1
  • EP2116907B1 patent drawingFigure 2
  • EP2116907B1 patent drawingFigure 3~4

AI summary

An image forming apparatus (200) including a latent image bearing member (3) a surface of which is rotated, a charging device (5), an irradiating device (20), a developing device (7), a transfer device (40), and a control unit (140). The control unit (140) controls the image forming apparatus (200) to perform subsequent image formation in accordance with a subsequent image forming request when determining that the subsequent image forming request is present at a predetermined determination time after completion of previous image formation, and controls the image forming apparatus (200) to shut down certain predetermined operations including at least rotation of the surface of the latent image bearing member (3) and application of a charging bias from the charging device (5) and a developing bias from the developing device (7) in accordance with a predetermined shutdown sequence when determining that the subsequent image forming request is not present at the predetermined determination time, wherein the control unit (140) controls the image forming apparatus (200) to start subsequent image formation in accordance with the subsequent image forming request without stopping rotation of the surface of the latent image bearing member (3) when the subsequent image forming request is received during the time between when the control unit (140) determines that the subsequent image forming request is not present at the predetermined determination time and when a process to stop rotation of the surface of the latent image bearing member (3) is completed.