Elevator Door Position Detection Using Single Switch

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Solution Overview

Problem

Conventional elevator door control devices are costly due to the use of multiple light switches for detecting door positions, and they struggle to accurately determine whether the door is at the full open or full close position without generating the same detection signal.

Innovation Solution

A single position switch with a first and second light transmitter/receiver pair and corresponding shield plates on the door panel, where the shield plates differently shield light beams based on the door's position, allowing the control device to determine the door's position by analyzing light reception states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple light switches are used to detect door positions, then detection accuracy is improved, but device cost and complexity increase

Engineering Contradiction:
Improvedoor position detection accuracyVSAvoidnumber of light switches
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the detection function into multiple light beams (first and second light beams) within a single position switch. Each light beam is independently detected by corresponding light receivers, allowing the system to distinguish between full-open and full-close positions through differential detection of multiple beams rather than using multiple separate switches.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent combines multiple detection functions into a single position switch by integrating multiple light transmitters and light receivers. The first light transmitter/first light receiver pair and the second light transmitter/second light receiver pair work together within one switch unit to provide both full-open and full-close position detection, reducing the total number of switches needed.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If multiple light switches are used to detect full-open and full-close positions, then detection reliability is improved, but manufacturing cost increases

Engineering Contradiction:
Improveposition detection reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent segments the detection task into multiple light beams with different functions. The first light beam detects one position state while the second light beam detects another position state, allowing reliable position detection through a single switch unit rather than requiring multiple expensive light switches.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses multiple light beams as functional copies within a single position switch. Each light beam replicates the detection capability but targets different position states, providing reliable detection across multiple positions without the cost of multiple complete switch assemblies.

Inventive Principle:
Principle #26Copying

3Device complexity

If a single position switch is used, then device cost is reduced, but the ability to distinguish full-open from full-close position deteriorates

Engineering Contradiction:
Improvenumber of position switchesVSAvoidposition state discrimination capability
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The patent applies local quality by making each light beam serve a specific local function. The first light beam is configured to detect the full-open position while the second light beam is configured to detect the full-close position. This localized functional differentiation within a single switch preserves position discrimination capability while reducing overall device complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent adds a dimensional aspect to the detection system by using multiple light beams at different positions or angles within the same switch. This multi-dimensional approach allows the single switch to capture information about different door positions that would otherwise require multiple separate switches.

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

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 enables accurate determination of the door's position using a single position switch, reducing costs and device complexity while maintaining accurate door control operations.

Implementation Method 1

a first light transmitter provided on the position switch to transmit a first light beam; a first light receiver provided at a position opposed to the first light transmitter on the position switch to receive the first light beam

Methodology Applied
Scientific EffectLight transmission and reception: Light

Implementation Method 2

a second light transmitter provided on the position switch to transmit a second light beam; a second light receiver provided at a position opposed to the second light transmitter on the position switch to receive the second light beam

Methodology Applied
Scientific EffectLight transmission and reception: Light

Implementation Method 3

when the door panel lies at either one of the full open position and the full close position, the first shield plate shields one or more predetermined light beams of the first and second light beams

Methodology Applied
Scientific EffectLight shielding: Absorption (EM radiation)

Data Source

PatentEP2502870B1Elevator door control device
Publication Date: 2016.03.30 MITSUBISHI ELECTRIC CORP
  • EP2502870B1 patent drawingFigure 1
  • EP2502870B1 patent drawingFigure 2~3
  • EP2502870B1 patent drawingFigure 4~5

AI summary

There is provided an elevator door control device that makes detection so as to be capable of judging which of the full open position and the full close position is the position of a door panel by using a position switch provided in only one location along the travel direction of the door panel. For this purpose, an elevator door control device, which controls the opening/closing operation of the door panel which opens and closes an elevator entrance in the right-and-left direction, includes one position switch; first and second light transmitters and first and second light receivers, which are provided on the position switch; a first shield plate and a second shield plate, which are provided on the door panel; and a door control device body that judges, based on a signal carring information about the light receiving state of the first and second light receivers outputted from the position switch, whether or not the door panel lies at the full open position and the full close position. When the door panel is fully opened, the first shield plate shields one or more predetermine light beams of first and second light beams, and when the door panel is fully closed, the second shield plate shields one or more predetermined light beams of the first and second light beams different from the predetermined light beams shielded by the first shield plate.