Printer Driver Sleep Resumption Logic

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Solution Overview

Problem

Image forming apparatuses face inefficiencies when resuming from a sleep state due to unnecessary initialization processing, as the printer driver cannot accurately determine if the printer unit has been powered off, leading to wasted time and reduced usability.

Innovation Solution

The image forming apparatus includes a processor that controls the printer unit to transmit instructions for transitioning between power states and resumes communication only when necessary, using a power control unit to latch the power state, allowing the printer driver to skip initialization processing if the power was not previously turned off.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the printer driver performs initialization processing upon resuming from sleep state, then communication reliability with the printer unit is ensured, but the resumption time is increased due to unnecessary processing

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidresumption time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary actions by having the system controller track and store the power state of the printer unit during sleep transition. When resuming, the printer driver receives notification about whether power was actually turned off, allowing it to prepare appropriately in advance and skip unnecessary initialization processing.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements feedback by having the system controller monitor the actual power state of the printer unit and communicate this information back to the printer driver. This feedback loop allows the printer driver to make informed decisions about whether initialization processing is necessary, based on the actual power state rather than assuming it was turned off.

Inventive Principle:

Principle #23Feedback

2Stability of the object's composition

If the printer driver always performs initialization processing upon receiving resume instruction, then communication stability is maintained, but operational efficiency is reduced due to wasted processing time

Engineering Contradiction:

Improvecommunication stabilityVSAvoidoperational efficiency

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The system applies dynamics by making the initialization processing conditional rather than static and always-executed. The printer driver dynamically adjusts its behavior based on the power state information received from the system controller, performing initialization only when necessary (when power was turned off) and skipping it when unnecessary (when power remained on).

Inventive Principle:

Principle #15Dynamics

3Use of energy by moving object

If the system controller turns off power to the printer unit during sleep transition, then power saving is achieved, but the printer driver cannot determine whether power was actually turned off leading to unnecessary initialization

Engineering Contradiction:

Improvepower consumptionVSAvoidpower state information

Core Design Contradiction:

Use of energy by moving objectVSLoss of information

Solution Approach 1:

The system controller acts as an intermediary between the power management system and the printer driver. It receives sleep transition notifications, controls the power state of the printer unit, tracks whether power was actually turned off, and communicates this power state information to the printer driver. This intermediary role solves the information loss problem by maintaining and transmitting the power state information that would otherwise be unavailable to the printer driver.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11789673B2Image forming apparatus, control method of image forming apparatus, and storage medium storing program having transition event occurring during switching process of power state

Publication Date: 2023.10.17 CANON KK

AI summary

Upon receiving a resumption notification from a system controller, a printer driver determines whether a power supply to a printer apparatus has stopped/resumed after a previous transition instruction to a sleep state was transmitted to the printer apparatus. If stop/resumption is not performed, an initialization negotiation processing performed to the printer apparatus when stop/resumption is not performed.