Polygon Motor Standby Control for Laser Printer Exposure Alignment

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Solution Overview

Problem

Image forming apparatuses face exposure misalignment due to temperature rises within the exposure device, caused by the polygon motor, leading to color misalignment, which existing correction controls struggle to fully address.

Innovation Solution

The apparatus includes a temperature sensor to detect temperature changes and adjust the rotation duration of the polygon motor during standby operations based on user-defined execution frequencies for image quality self-checks, thereby correcting exposure misalignment by modifying the exposure timing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the polygon motor rotates continuously during standby operation to maintain image quality, then exposure misalignment is prevented, but temperature rise and heat generation increase

Engineering Contradiction:

Improveimage quality consistencyVSAvoidexposure device temperature

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent implements periodic rotation of the polygon motor during standby operation instead of continuous rotation. The control unit determines rotation timing based on elapsed time from the end of image formation, creating a periodic action pattern that maintains image quality while reducing overall heat generation by keeping the motor stationary during non-rotation periods.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent changes the operational parameters of the polygon motor from continuous rotation to intermittent rotation based on elapsed time thresholds. By adjusting the rotation duration and timing parameters dynamically, the system maintains sufficient motor operation to prevent exposure misalignment while reducing total operation time to minimize temperature rise.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If correction control is performed frequently to maintain exposure alignment, then image quality is improved, but processing time and system complexity increase

Engineering Contradiction:

Improveexposure alignment precisionVSAvoidcorrection control processing time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary correction control at predetermined intervals based on elapsed time from the end of image formation. By proactively executing correction before significant temperature-induced misalignment occurs, the system maintains exposure alignment precision while avoiding frequent reactive corrections, thus reducing overall processing time.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If the polygon motor rotation duration is extended to prevent temperature rise, then exposure misalignment is reduced, but energy consumption increases

Engineering Contradiction:

Improveexposure alignment stabilityVSAvoidpolygon motor energy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent uses periodic rotation with controlled duration based on elapsed time thresholds. The motor rotates for specific time intervals rather than continuously, maintaining exposure alignment stability through periodic motion while significantly reducing energy consumption compared to continuous operation during standby periods.

Inventive Principle:

Principle #19Periodic action

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 reduces temperature-induced expansion within the housing, preventing exposure misalignment and ensuring consistent image quality by dynamically adjusting the polygon motor's operation in response to detected temperature thresholds and elapsed times.

Implementation Method 1

the polygon motor that rotates the polygon mirror generates heat

Methodology Applied

Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

The temperature rise causes the housing to expand, and the expansion may change the positions or angles of the lens and mirror inside the housing

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS11372358B1Image forming apparatus

Publication Date: 2022.06.28 TOSHIBA TEC KK

AI summary

An image forming apparatus includes a processor. The processor is configured to emit a laser beam reflected by a polygon mirror, the polygon mirror rotated by a polygon motor, form an image based on a latent image carried on a photoconductor by the laser beam, store an execution frequency of an image quality self-check of the image formed and a rotation duration of the polygon motor during a standby operation period of image formation, accept a change in the execution frequency, change the rotation duration based on the change in the execution frequency, execute the image quality self-check based on the execution frequency, and continuously rotate the polygon motor during the standby operation period based on the rotation duration stored.