Optical Disc Tray Control via Counter Electromotive Force Detection

Solution Overview

Problem

The high manufacturing cost and potential errors in tray opening/closing operations in optical disc drives due to the reliance on separate switches for controlling the tray's open/closed state.

Innovation Solution

A method that uses flags and counter electromotive force detection, in conjunction with a timer, to control the tray's movement within the optical disc drive, eliminating the need for separate switches and preventing errors in tray operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate switches (first switch and second switch) are used to detect tray open/closed state, then the tray operation control is reliable, but the manufacturing cost increases and device complexity increases

Engineering Contradiction:

Improvetray operation control reliabilityVSAvoidswitch component quantity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the tray state detection function from the mechanical switch components and implements it through software flag management and counter e.m.f detection. The controller determines tray state based on flag combinations rather than physical switch positions, eliminating the need for separate detection switches.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical switch-based detection system with an electrical/electronic system using counter e.m.f detection and software flag management. Instead of using physical switches to detect tray position, the system uses electromagnetic detection and computational logic to determine tray state.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If separate switches (first switch and second switch) are used to detect tray open/closed state, then the tray operation control is reliable, but the manufacturing cost increases

Engineering Contradiction:

Improvetray operation control reliabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts the tray state detection function from the mechanical switch components and implements it through software flag management and counter e.m.f detection. The controller determines tray state based on flag combinations rather than physical switch positions, eliminating the need for separate detection switches.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical switch-based detection system with an electrical/electronic system using counter e.m.f detection and software flag management. Instead of using physical switches to detect tray position, the system uses electromagnetic detection and computational logic to determine tray state.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If separate switches (first switch and second switch) are used to detect tray open/closed state, then the tray operation control is reliable, but errors may occur when switches fail

Engineering Contradiction:

Improvetray operation control reliabilityVSAvoiderror occurrence due to switch failure

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical switch-based detection system with an electrical/electronic system using counter e.m.f detection and software flag management. Instead of using physical switches to detect tray position, the system uses electromagnetic detection and computational logic to determine tray state.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements feedback through continuous monitoring of counter e.m.f signals and flag states. The controller constantly checks the consistency of flag combinations with the actual tray state, and can detect when switches fail by comparing expected versus actual states, allowing for error correction.

Inventive Principle:

Principle #23Feedback

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 approach reduces the fabrication cost of optical disc drives and prevents errors in tray operations by accurately controlling the tray's movement using flags and counter electromotive force detection, ensuring reliable tray opening and closing without separate switches.

Implementation Method 1

controlling a movement operation of the tray, based on values of the two flags and a time when a counter electromotive force (counter e.m.f) is generated in a motor for moving the tray

Methodology Applied

Scientific EffectCounter electromotive force: Electromagnetic Induction

Data Source

PatentUS8799934B2Method for controlling movement operation of tray in optical disc drive without physical switch

Publication Date: 2014.08.05 HITACHI LG DATA STORAGE KOREA INC

AI summary

A method for controlling a tray in an optical disc drive comprises: setting first and second flags for indicating a current state of the tray, the state of the tray including an open state, a closed state and a state in which the tray moves; and controlling a movement operation of the tray, base on values of the two flags and a time when a counter electromotive force is generated in a motor for moving the tray. If a request of performing a tray closing operation in the state in which the tray is opened is received, the tray closing operation is performed, and the value of the second flag is changed. If the counter e.m.f is detected after a first time from the time when the tray closing operation is started, the driving of the motor is stopped, and the value of the first flag is changed.