E-bike Headlight Control Circuit Delay to Prevent Sensor Blockage

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Solution Overview

Problem

The existing electrically power assisted bicycles face issues with the headlight being inadvertently lit up due to the finger blocking light from reaching the optical sensor when the power button and optical sensor are located adjacent to each other on the operation panel, leading to unnecessary headlight activation.

Innovation Solution

Implementing a control circuit that delays the activation of the headlight by a predetermined time period after the power button is pressed, allowing the finger to move away from the optical sensor, thereby preventing light blockage and ensuring appropriate timing for headlight control based on the optical sensor's signal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the power button and optical sensor are located adjacent to each other on the operation panel, then the operation panel can be made compact and buttons are easily accessible, but the rider's finger may block light from reaching the optical sensor causing the headlight to be inadvertently lit up

Engineering Contradiction:
Improvebutton accessibilityVSAvoidheadlight activation accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The control circuit is configured to activate the headlight control function only after a predetermined time period has elapsed since the power button was pressed. This preliminary time delay allows the rider's finger to move away from the optical sensor area before the headlight activation begins, preventing false activation while maintaining compact button layout.

Inventive Principle:
Principle #10Preliminary action

2Loss of information

If a large liquid crystal panel is used to display more information, then information display capability is improved, but the operation panel housing becomes larger and protrudes more from the handle

Engineering Contradiction:
Improveinformation display capacityVSAvoidoperation panel housing length
Core Design Contradiction:
Loss of informationVSLength of stationary object

Solution Approach 1:

The patent integrates the optical sensor into the same plane as the power button on the operation panel, utilizing the lateral dimension rather than increasing the housing length in the protrusion direction. This allows the sensor to be positioned adjacent to the button without increasing the overall housing length, maintaining a compact profile while enabling the delayed activation function.

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 solution effectively suppresses unnecessary headlight activation by ensuring the finger has time to move away from the optical sensor, improving the reliability of headlight operation and reducing accidental lighting.

Implementation Method 1

an optical sensor 63 configured to output a signal in accordance with received light

Methodology Applied
Scientific EffectOptical sensor light detection: Photoelectric Effect

Data Source

PatentEP3296187B1Electrically power assisted bicycle and method for controlling an electrically power assisted bicycle
Publication Date: 2020.11.04 YAMAHA MOTOR CO LTD
  • EP3296187B1 patent drawingFigure 1
  • EP3296187B1 patent drawingFigure 2
  • EP3296187B1 patent drawingFigure 3

AI summary

An electrically power assisted bicycle 1 includes an electric motor 33 to generate an assist force assisting human power of a rider; a detachable battery 36 to supply electric power to the electric motor; a headlight 2; and an operation panel 60 including a display device 72 to display information, a power button 70 usable to turn on or off the electrically power assisted bicycle 1, an illuminance sensor 63 to output a signal in accordance with received light, and a microcontroller 62 to control the headlight 2 to be on or off. The power button 70 and the illuminance sensor 63 are located adjacent to each other on or in the operation panel 60. After a predetermined time period passes after the microcontroller 62 is activated by the power button 70 being pressed by the rider, the control circuit 62 starts controlling the headlight 2 to be on or off in accordance with the signal output by the illuminance sensor 63.