Pivoting Stopper Prevents Unintentional Tray Opening

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In image forming apparatuses, as the size increases, the distance between the image reading unit and the discharge tray grows, necessitating a larger stopper to prevent unintentional opening, which raises component costs.

Innovation Solution

A compact stopper design is implemented, where the stopper is pivotally supported and biased by a spring, with a tray abutment portion that interacts with the image reading unit, allowing it to restrict the discharge tray's movement and maintain a closed state without requiring significant size or cost increases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the distance between the image reading unit and the discharge tray increases in larger image forming apparatuses, then the apparatus size increases, but the stopper size must also increase to maintain prevention of unintentional opening, leading to increased component cost

Engineering Contradiction:
Improveapparatus sizeVSAvoidcomponent cost
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The stopper is configured to pivot about a rotary axis, transitioning from a linear positioning problem to a rotational mechanism. This allows the stopper to maintain effective engagement with the discharge tray across varying distances through angular adjustment rather than requiring proportional increases in stopper dimensions, thereby controlling component cost while accommodating larger apparatus sizes.

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

Solution Approach 2:

The stopper mechanism utilizes spring biasing to dynamically adjust its position and engagement force. By changing the mechanical state through spring compression and relaxation, the stopper can maintain effective prevention of unintentional opening regardless of the distance to the image reading unit, avoiding the need to increase stopper size proportionally with apparatus size.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a stopper is provided to prevent unintentional opening of the discharge tray, then reliability improves, but device complexity increases

Engineering Contradiction:
Improveprevention of unintentional openingVSAvoidstopper mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The stopper mechanism is integrated with the existing discharge tray structure, where the stopper serves dual purposes: preventing unintentional opening during normal operation and allowing intentional opening when the image reading unit is in the open position. This merging of functions reduces overall device complexity while maintaining reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The spring-biased stopper automatically engages and disengages based on the position of the image reading unit without requiring external control mechanisms. The mechanism self-regulates its state through mechanical interaction with the discharge tray and image reading unit, simplifying the overall control system while ensuring reliable prevention of unintentional opening.

Inventive Principle:
Principle #25Self-service

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

The compact stopper effectively prevents unintentional opening of the discharge tray, reducing manufacturing costs and ensuring the image forming apparatus operates without interruptions due to accidental tray opening.

Implementation Method 1

a stopper (100, 200, 300) which is pivotally supported and has a tray abutment portion (100b, 200b, 300b) that abuts against the discharge tray (12)

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP3428736B1Image forming device
Publication Date: 2024.02.14 CANON KK
  • EP3428736B1 patent drawingFigure 1
  • EP3428736B1 patent drawingFigure 2A~2B
  • EP3428736B1 patent drawingFigure 3A~3B

AI summary

To provide an image forming apparatus where a stopper with a small size can prevent a user from opening an openable and closable door unintentionally. In an image forming apparatus A which forms an image on a sheet, the image forming apparatus A includes: an apparatus main body of the image forming apparatus; an openable and closable member 12 provided on the apparatus main body in an openable and closable manner; an image reading portion 13 configured to read an image of an original, the image reading portion 13 being supported on the apparatus main body and being movable to a first position and to a second position having a positional relationship with respect to the apparatus main body different from the first position; and a stopper member 100 provided in the apparatus main body and configured to move in conjunction with a movement of the image reading portion 13, wherein when the image reading portion 13 is moved to the first position, the stopper member 100 is moved to a restricting position in which the stopper member 100 restricts the openable and closable member 12 from being moved from a closed position to an open position, and wherein when the image reading portion 13 is moved to the second position, the stopper member 100 is moved to an allowing position in which the stopper member 100 allows the openable and closable member 12 to be moved from the closed position to the open position.