Optical Sensor Covering Member for Printing Device Cutter Position Detection

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Solution Overview

Problem

Existing printing devices that detect the position of a gear using an optical sensor are prone to defects due to foreign matter like dust and paper dust entering between the light emitting and receiving portions, leading to inaccurate determination of the cutter position.

Innovation Solution

A printing device with a gear featuring a protruding member and a covering member with a passage route that allows the protruding member to pass through, equipped with an optical sensor positioned on the covering member, where the passage route's width is larger than the protruding member and equal to or less than the distance between the light emitting and receiving portions, preventing foreign matter from interfering with the sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a shielding member is provided on the gear to detect position using optical sensor, then the cutter position can be determined, but foreign matter such as dust and paper dust may enter between the light emitting portion and the light receiving portion causing sensor defects

Engineering Contradiction:

Improvecutter position detection accuracyVSAvoidforeign matter contamination of optical sensor

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The covering member acts as an intermediary structure that allows the protruding member to pass through while blocking foreign matter from reaching the optical sensor. The passage route in the covering member is specifically designed to be larger than the protruding member to prevent contact and foreign matter accumulation, thus mediating between the need for position detection and the need to protect the sensor from contamination.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The gear is segmented with a protruding member that protrudes from the gear surface, and the covering member is segmented with a passage route that accommodates this protruding member. This segmentation allows the optical detection function to be separated from the protective function, enabling the protruding member to be detected optically while the covering member protects the sensor from foreign matter.

Inventive Principle:

Principle #1Segmentation

2Ease of operation

If the passage route width is larger than the protruding member width, then the protruding member can pass through freely, but foreign matter might still enter the sensor area

Engineering Contradiction:

Improveprotruding member passageVSAvoidforeign matter entry risk

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The passage route width is precisely controlled to be larger than the protruding member width by a specific margin (0.1mm to 1mm). This parameter optimization allows the protruding member to pass through freely while the covering member's structure prevents foreign matter from entering the sensor area, thus resolving the contradiction between ease of passage and foreign matter prevention.

Inventive Principle:

Principle #35Parameter changes

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 effectively prevents defects in the optical sensor, ensuring accurate determination of the cutter position and reducing the risk of errors in the printing process.

Implementation Method 1

an optical sensor provided on the covering member and having a light emitting portion for emitting light in a direction intersecting the protruding member and a light receiving portion for receiving light

Methodology Applied

Scientific EffectOptical detection: Light

Data Source

PatentUS11148440B2Printing device

Publication Date: 2021.10.19 SEIKO EPSON CORP

AI summary

A printing device includes a first blade configured to move between an advanced position and a retracted position, a second blade for cutting recording paper together with the first blade, and a driving mechanism including a gear that drives the first blade, a protruding member that protrudes from a first surface of the gear, a covering member that covers at least a part of the protruding member and includes a passage route of the protruding member, and an optical sensor provided on the covering member and having a light emitting portion for emitting light in a direction intersecting the protruding member and a light receiving portion for receiving light, in which a width of the passage route is larger than a width of the protruding member, and is equal to or smaller than a distance between the light emitting portion and the light receiving portion.