Optical Deflector With Elastic Heat Transfer for Substrate Stability

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Solution Overview

Problem

The high-speed rotational driving of a rotary polygon mirror in image forming apparatuses leads to increased power consumption and heat generation, causing thermal expansion and deformation of components, which deteriorates optical performance and may result in the collapse of the rotation posture of the polygon mirror.

Innovation Solution

The optical deflector incorporates a housing, a rotary polygon mirror, a substrate, a heat dissipation member, and an elastic heat transfer member. The heat dissipation member is pressed against the substrate with a biasing force weaker than the fastening force, supported by the substrate, to prevent deformation and maintain the optical performance of the components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the rotary polygon mirror is driven at high speed (about 58000 rpm), then the scanning performance and productivity are improved, but power consumption and heat generation increase causing thermal expansion and deformation of components

Engineering Contradiction:

Improvescanning performanceVSAvoidheat generation

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The patent converts the harmful thermal expansion effect into a beneficial pre-compensation mechanism. By designing the support plate with predetermined curvature and the adhesive layer with specific viscosity characteristics, the thermal expansion during high-speed operation is used to maintain optimal optical alignment, transforming the harmful heat generation into a useful self-adjusting mechanism that preserves scanning performance.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Speed

If the rotary polygon mirror rotates at high speed, then the scanning speed is improved, but the adhesive undergoes creep deformation due to centrifugal force at high temperature

Engineering Contradiction:

Improverotation speedVSAvoidadhesive deformation

Core Design Contradiction:

SpeedVSStability of the object's composition

Solution Approach 1:

The patent changes the parameters of the adhesive layer by selecting materials with specific viscosity characteristics and controlling the bonding conditions. The adhesive is designed to maintain its bonding strength and dimensional stability across the temperature range experienced during high-speed rotation, preventing creep deformation while allowing the high rotation speed to maintain optimal optical alignment through thermal expansion compensation.

Inventive Principle:

Principle #35Parameter changes

3Temperature

If the substrate is fastened to the heat dissipation plate with ordinary screws, then heat dissipation is achieved, but deformation of the substrate occurs and predetermined driving force is not generated

Engineering Contradiction:

Improveheat dissipationVSAvoidsubstrate deformation

Core Design Contradiction:

TemperatureVSStrength

Solution Approach 1:

The patent introduces a support plate as an intermediary component between the substrate and the heat dissipation plate. This support plate distributes the mechanical stress from the screws across a larger area of the substrate, preventing localized deformation. The support plate also provides a stable mounting surface for the polygon motor, ensuring that the predetermined driving force is generated without substrate deformation, while still allowing effective heat dissipation from the substrate.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 configuration effectively prevents deformation of the substrate and maintains the optical performance of the optical deflector, reducing the risk of rotation collapse and ensuring stable operation of the image forming apparatus.

Implementation Method 1

a heat dissipation member that dissipates heat of the substrate to the outside

Methodology Applied

Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

a heat transfer member that includes an elastic body, is interposed between the substrate and the heat dissipation member, and transfers heat of the substrate to the heat dissipation member

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 3

transfers heat of the substrate to the heat dissipation member

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 4

elastic members that elastically presses the heat dissipation member and the heat transfer member against the substrate with a biasing force

Methodology Applied

Scientific EffectElastic force: Elasticity

Data Source

PatentUS20250291177A1Optical deflector, scanning optical device, and image forming apparatus

Publication Date: 2025.09.18 KONICA MINOLTA INC

AI summary

An optical deflector includes a housing, a rotary polygon mirror housed in the housing and having a mirror surface formed on an outer peripheral surface of the rotary polygon mirror, a substrate on which at least a part of a driving source configured to drive the rotary polygon mirror is mounted, a heat dissipation member that dissipates heat of the substrate to the outside, a heat transfer member includes an elastic body, is interposed between the substrate and the heat dissipation member, and transfer heat of the substrate to the heat dissipation member, fixing members that fix the substrate to the housing, and elastic members which elastically press the heat dissipation member and the heat transfer member against the substrate with a biasing force weaker than a fixing force of the fixing members such that the heat dissipation member and the heat transfer member are supported by the substrate.