Optical Scanning Casing With Dual-Space Cooling

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Solution Overview

Problem

Existing optical scanning apparatuses face challenges in maintaining high printing speed while preventing thermal deformation of components due to heat generation, leading to increased cost and size, and reduced print precision.

Innovation Solution

The optical scanning apparatus incorporates a dual-space casing design with a first space for the light deflector and a second space for cooling, utilizing airflow circulation to efficiently cool the apparatus without increasing size or cost, reducing thermal deformation and noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the polygon mirror is rotated at a higher speed to achieve higher printing speed, then productivity is improved, but temperature increases causing thermal deformation of the casing and optical elements

Engineering Contradiction:
Improveprinting speedVSAvoidtemperature of casing and optical elements
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The casing is divided into two separate spaces: a first space that accommodates the light deflector (polygon mirror) and a second space dedicated to cooling functions. This segmentation allows the cooling space to be positioned away from the optical elements, enabling effective heat dissipation without interfering with the optical path or requiring additional cooling components near the sensitive optics.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A partition wall with a communicating space is introduced as an intermediary structure between the first space (light deflector) and the second space (cooling space). This intermediary allows controlled thermal management while maintaining functional separation, enabling heat to be managed without direct contact between cooling airflow and optical elements.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If a heatsink is disposed in the optical scanning apparatus to cool the motor and board, then temperature is reduced, but cost increases

Engineering Contradiction:
Improvetemperature of motor and boardVSAvoidcost
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The casing structure itself is designed to provide cooling functionality through its dual-space configuration and natural airflow circulation. The partition wall with communicating space enables the system to self-regulate temperature without requiring additional active cooling components like heatsinks, fans, or thermal management circuits, thereby reducing cost and complexity while maintaining effective thermal management.

Inventive Principle:
Principle #25Self-service

3Temperature

If a box is disposed above the casing to cool the optical scanning apparatus, then temperature is reduced, but the size of the apparatus increases in the axial direction

Engineering Contradiction:
Improvetemperature of optical scanning apparatusVSAvoidsize in axial direction
Core Design Contradiction:
TemperatureVSLength of stationary object

Solution Approach 1:

Instead of extending the cooling function in the axial direction (adding a box above the casing), the invention utilizes the radial/directional space within the existing casing by creating a second space adjacent to the first space. The partition wall with communicating space enables three-dimensional airflow circulation within the existing footprint, achieving effective cooling without increasing the axial length of the apparatus.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 enhances cooling performance, maintains print precision, and reduces thermal deformation, thereby improving image quality without increasing costs or size.

Implementation Method 1

The optical scanning apparatus deflects a laser beam controlled in accordance with image data, and scans a photosensitive drum with the deflected laser beam

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

a motor and a board for driving the polygon mirror are cooled by using a heatsink

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4318076B1Optical scanning apparatus and image forming apparatus
Publication Date: 2025.10.08 CANON KK
  • EP4318076B1 patent drawingFigure 1
  • EP4318076B1 patent drawingFigure 2
  • EP4318076B1 patent drawingFigure 3A~3B

AI summary

An optical scanning apparatus (2) includes a light source (202), a polygon mirror (2041) being configured to be rotated around a rotary shaft (2042), and a casing (250) configured to accommodate the light source (202) and the polygon mirror (2041). The casing (250) defines a first space (2013) that accommodates the polygon mirror (2041) and a second space (2014) that is different from the first space (2013), the casing (250) including a partition wall (2050) disposed between the first space (2013) and the second space (2014). The second space (2014) is disposed further from the rotary shaft (2042) than the partition wall (2050) in a radial direction orthogonal to an axial direction (AD) of the rotary shaft (2042), and is disposed such that the second space (2014) overlaps with the first space (2013) in the axial direction (AD).