Image-Forming Transfer Unit Terminal Interlock for Electric Shock Prevention

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Solution Overview

Problem

Existing image forming apparatuses lack an effective mechanism to prevent electric shocks when a movable unit supporting a transfer member is separated from an image-carrying member, exposing the transfer voltage terminals and posing a safety risk.

Innovation Solution

An electric shock preventing mechanism that includes a movable unit, a first and second terminal, a blocking member, and a latch mechanism, which ensures the second terminal contacts the first terminal only when the movable unit is in a standard position, blocking access to the first terminal when separated, thereby preventing contact and electric shock.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the movable unit is separated from the image-carrying member for maintenance or replacement, then accessibility and ease of operation are improved, but the risk of electric shock increases due to exposed high-voltage terminals

Engineering Contradiction:
ImproveAccessibility of movable unitVSAvoidElectric shock risk
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The latch mechanism is triggered in advance when the movable unit begins to move away from the image-carrying member. It automatically latches the blocking member to cover the first terminal before the movable unit is fully separated, preventing electric shock exposure while maintaining ease of operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The blocking member acts as an intermediary element between the high-voltage first terminal and the external environment. When latched by the latch mechanism, it physically blocks access to the first terminal, thereby mediating the safety risk without interfering with the normal operation or maintenance of the movable unit.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If a blocking mechanism is added to prevent electric shock, then safety is improved, but device complexity increases

Engineering Contradiction:
ImproveElectric shock preventionVSAvoidMechanism complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The blocking member and latch mechanism are merged with the existing movable unit structure. The blocking member is integrated into or adjacent to the movable unit, and the latch mechanism utilizes the movement of the movable unit itself as the triggering force, eliminating the need for separate control systems or additional power sources.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The latch mechanism is a self-activating mechanism that automatically latches the blocking member when the movable unit moves to the separated position. The kinetic energy from the movable unit's movement directly drives the latching action, requiring no external control signals, motors, or additional energy input.

Inventive Principle:
Principle #25Self-service

3Object-affected harmful factors

If the blocking member is always in position to block access to the first terminal, then safety is improved, but the ability to perform maintenance and replace components is reduced

Engineering Contradiction:
ImproveTerminal protectionVSAvoidMaintenance accessibility
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The blocking member transitions from a static always-blocked state to a dynamic state that adapts based on the movable unit's position. When the movable unit is in the standard position (operational state), the blocking member is unlatched and does not obstruct access. When the movable unit moves to the separated position (maintenance state), the blocking member automatically latches to protect the terminal.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The blocking member alternates between blocked and unblocked states in periodic response to the movable unit's movement. Each time the movable unit is inserted or removed, the blocking member cycles through unlatched (accessible) and latched (protected) positions, providing safety only when needed while maintaining operational accessibility.

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

The mechanism effectively prevents electric shocks by ensuring the second terminal is isolated from the first terminal when the movable unit is separated, maintaining safety without a complex power disconnection process.

Implementation Method 1

The transfer member causes the toner image to transition from the image-carrying member to the sheet by using an electric field caused by the transfer voltage.

Methodology Applied
Scientific EffectElectric field: Electric Field

Implementation Method 2

the latch mechanism latches the blocking member at the blocking position when the movable unit is located at the separated position

Methodology Applied
Scientific EffectMechanical fastening: Mechanical Fastener

Data Source

PatentEP4641310A1Image forming apparatus
Publication Date: 2025.10.29 KYOCERA DOCUMENT SOLUTIONS INC
  • EP4641310A1 patent drawingFigure 1
  • EP4641310A1 patent drawingFigure 2~3
  • EP4641310A1 patent drawingFigure 4~5

AI summary

A transfer member (443) is supported by a movable unit (6). A blocking member (73) is movable between a blocking position at which an access path to a first terminal (71) is blocked and an opening position at which the access path is opened. A second terminal (72) is supported by the movable unit (6). Following movement of the movable unit (6), a latch mechanism (70) latches the blocking member (73) at the blocking position when the movable unit (6) is located at a separated position and unlatches the blocking member (73) when the movable unit (6) moves from the separated position to a standard position. When the movable unit (6) moves from the separated position to the standard position, the second terminal (72) moves to a position at which the second terminal (72) comes into contact with the first terminal (71) through the access path.