Sheet Feeding Device Cassette Attachment Detection

Solution Overview

Problem

The existing sheet size detecting device in image forming apparatuses is prone to errors due to variations in push timing of switches caused by structural variations and user operations, particularly when attaching a paper feed cassette, leading to incorrect sheet size detection.

Innovation Solution

A sheet feeding device with a cassette receiving section, a size detector, an attachment detector, and a controller, where the attachment detector independently detects the attachment of the cassette, reducing variations in switch settlement timing and thereby minimizing errors in sheet size detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the size detection switch uses multiple push switches to detect sheet size, then the sheet size detection capability is improved, but variations in push timing cause errors in detection accuracy

Engineering Contradiction:

Improvesheet size detection accuracyVSAvoiddetection reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The detection system is segmented into two independent functional parts: (1) the size detection switch with multiple push switches for detecting sheet size, and (2) the attachment detection switch for detecting cassette attachment. This segmentation allows the attachment detection to trigger the size detection process independently, ensuring that size detection only occurs after proper attachment and reducing timing variation errors.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The attachment detection switch performs a preliminary action by detecting cassette attachment before the size detection process is activated. This preliminary detection ensures that the cassette is properly attached and positioned, establishing a consistent starting condition for subsequent size detection and eliminating errors caused by premature or premature timing variations.

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If the detection system waits for all push switches to settle before detecting sheet size, then detection accuracy is improved, but the detection time increases

Engineering Contradiction:

Improvesheet size detection accuracyVSAvoiddetection time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The attachment detection switch performs a preliminary action by detecting cassette attachment before the size detection process is activated. This preliminary detection ensures that the cassette is properly attached and positioned, establishing a consistent starting condition for subsequent size detection and eliminating errors caused by premature or premature timing variations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the attachment detection switch to control the timing of size detection. When the attachment detection switch is activated, it provides feedback that triggers the size detection process, ensuring that detection occurs at the appropriate moment when all push switches have settled, thereby maintaining accuracy without excessive waiting time.

Inventive Principle:

Principle #23Feedback

3Device complexity

If the same switch unit detects both cassette attachment and sheet size, then device complexity is reduced, but detection accuracy deteriorates due to timing variations

Engineering Contradiction:

Improvedetection system complexityVSAvoidsheet size detection accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The detection system is segmented into two independent functional parts: (1) the size detection switch with multiple push switches for detecting sheet size, and (2) the attachment detection switch for detecting cassette attachment. This segmentation allows the attachment detection to trigger the size detection process independently, ensuring that size detection only occurs after proper attachment and reducing timing variation errors.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The attachment detection switch acts as an intermediary between cassette attachment and size detection. It mediates the detection process by first detecting attachment and then triggering the size detection, ensuring proper sequencing and timing without requiring a highly complex integrated system.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9527684B2Sheet feeding device and image forming apparatus

Publication Date: 2016.12.27 KYOCERA DOCUMENT SOLUTIONS INC

AI summary

A sheet feeding device (1) includes a cassette (10), size detector (60), and attachment detector (30). The size detector (60) detects the size of sheets in the cassette (10). The size detector (60) includes an interlocking member (61) and switch unit (81). The interlocking member (61) includes size-detection target portions (64) and slides to sliding of a regulating member (11). The switch unit (81) detects a position of the regulating member (11) based on a state of the switches (82) that detect the size-detection target portions (64). The attachment detector (30) includes an attachment-detection target member (31) and attachment detecting member (41). The attachment detecting member (41) detects the attachment-detection target member (31) in response to attachment of the cassette (10). The controller (70) detects the sheet size based on a state of the switch unit (81) in response to the attachment detector (30) detecting attachment of the cassette (10).