Image Forming Apparatus Frame Segmentation for Feeding Accuracy

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Solution Overview

Problem

The existing image forming apparatuses face accuracy issues due to deformation of the lower frame, which affects the relative positional relationship between the feed unit and the image forming unit, leading to deviations in the conveying path and reduced medium feeding accuracy.

Innovation Solution

The apparatus employs a design with upper frames of higher rigidity supporting the image forming and feed units, and lower frames of lower rigidity allowing deformation, with a recording medium cassette detachably attached between the lower frames. The cassette is positioned using contact portions that maintain relative positions with the upper and lower frames, ensuring minimal displacement and maintaining accuracy even during frame deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of stationary object

If the lower frame is designed with low rigidity to suppress twisting and distortion, then the weight of the frame structure is reduced, but the lower frame deforms under biased load due to level difference and inclination, causing displacement of the feed unit and deterioration of medium feeding accuracy

Engineering Contradiction:

Improveweight of frame structureVSAvoidmedium feeding accuracy

Core Design Contradiction:

Weight of stationary objectVSManufacturing precision

Solution Approach 1:

The frame structure is segmented into upper frame and lower frame with different rigidity characteristics. The lower frame has lower rigidity to reduce weight and suppress twisting, while the upper frame has higher rigidity to maintain positional accuracy. This segmentation allows each part to fulfill its specific function without compromising the overall system performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A positioning mechanism acts as an intermediary between the lower frame and the feed unit. This positioning mechanism compensates for the deformation of the lower frame, ensuring that the feed unit maintains its correct position relative to the image forming unit even when the lower frame deforms under load or inclination.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If the lower frame is designed with low rigidity to maintain high accuracy in relative positional relationship between image forming units, then the weight increase is suppressed, but the feed unit follows the deformation of the lower frame, significantly changing its relative position to the upper frame and deviating the conveying path

Engineering Contradiction:

Improverelative positional accuracy between image forming unitsVSAvoidconveying path accuracy

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The frame is divided into upper and lower segments with different rigidity properties. The lower frame segment absorbs deformation through its lower rigidity, while the upper frame segment maintains high positional accuracy for the image forming units. This segmentation isolates the deformation effects to specific regions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A positioning mechanism serves as an intermediary that decouples the feed unit from the deformation of the lower frame. This mechanism ensures that the conveying path from the feed unit to the image forming unit remains accurate even when the lower frame deforms, by compensating for the positional changes.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Stability of the object's composition

If the recording medium cassette is supported over the entire range between ends of the guide mechanism to prevent displacement, then the cassette is stable, but the cassette follows the deformation of the guide mechanism along with the lower frame, changing its relative position to the feed unit

Engineering Contradiction:

Improvecassette stabilityVSAvoidrelative position accuracy between cassette and feed unit

Core Design Contradiction:

Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The support function for the recording medium cassette is extracted from the guide mechanism. Instead of the guide mechanism providing continuous support along its entire length, the cassette is supported only at specific discrete positions. This extraction allows the guide mechanism to deform with the lower frame while the cassette maintains its correct position through localized support points that are decoupled from the deformation.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS8554111B2Image forming apparatus

Publication Date: 2013.10.08 BROTHER KOGYO KK

AI summary

An image forming apparatus includes: a recording medium cassette storing recording medium; an image forming unit, a feed unit; an upper frame that supports the image forming unit and the feed unit; and a lower frame in which the recording medium cassette is detachably attached, the upper frame being disposed on the lower frame, and the lower frame having rigidity lower than the rigidity of the upper frame, the lower frame including a rail for guiding the recording medium cassette to a predetermined receiving position, wherein the feed unit has a groove portion formed along a direction parallel to a horizontal direction, the recording medium cassette has a first convex portion which is fitted in the groove portion when the recording medium cassette is attached in the lower frame, the recording medium cassette having a second convex portion which is contact with a portion of the rail of the lower frame.