Optical Disc Drive Noise Reduction via Buffer-Controlled Speed

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Solution Overview

Problem

Existing optical disc drive devices produce significant noise when rotating high-capacity optical discs like UHD BD-ROMs, and conventional noise reduction methods increase costs by adding parts.

Innovation Solution

The optical disc drive device controls the rotational speed of the disc based on free space information from the buffer, adjusting the speed to reduce noise without increasing the number of parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the rotational speed of the optical disc is increased to support high-speed playback, then productivity is improved, but noise increases

Engineering Contradiction:
Improvedata transfer rateVSAvoidnoise
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies dynamics by making the rotational speed adjustable rather than fixed. The drive controller dynamically changes the rotational speed based on buffer status, transitioning between high speed (for fast data transfer) and low speed (for noise reduction when buffer is sufficient). This resolves the contradiction by allowing the system to adapt speed to actual needs rather than maintaining constant high speed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the rotational speed parameter based on buffer free space conditions. When buffer free space exceeds a threshold, the rotational speed is reduced from high-speed mode to low-speed mode, directly addressing the noise issue while maintaining data transfer capability through buffer management.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If the rotational speed is decreased to reduce noise, then harmful factors are reduced, but data transfer rate decreases

Engineering Contradiction:
ImprovenoiseVSAvoiddata transfer rate
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

The buffer serves as an intermediary between the optical disc and the signal processing device. It decouples the data transfer rate from the rotational speed by storing data temporarily. This allows the disc to rotate slowly (reducing noise) while the buffer supplies data at the required rate to the signal processing device, resolving the contradiction between noise reduction and data transfer efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system performs preliminary action by filling the buffer with data before reducing rotational speed. When buffer free space is sufficient, the system can safely lower the rotational speed because the buffer already contains enough data to maintain continuous playback without interruption.

Inventive Principle:
Principle #10Preliminary action

3Object-generated harmful factors

If additional parts are added to reduce noise, then harmful factors are reduced, but device complexity increases

Engineering Contradiction:
ImprovenoiseVSAvoidnumber of parts
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The system uses self-service by utilizing existing components (buffer and controller) to reduce noise without adding dedicated noise reduction hardware. The controller intelligently manages rotational speed based on buffer status, allowing the system to reduce noise through software/control logic rather than physical noise cancellation components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The buffer and controller serve multiple functions: data storage, data transfer management, and noise reduction through rotational speed control. This multi-functionality eliminates the need for separate noise reduction components, reducing device complexity while still achieving the noise reduction goal.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4116972B1Optical disc drive device and playback device
Publication Date: 2025.06.25 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP4116972B1 patent drawingFigure 1~2
  • EP4116972B1 patent drawingFigure 3
  • EP4116972B1 patent drawingFigure 4~6

AI summary

An optical disc drive device (20) includes a spindle motor (23) that rotates an optical disc (40), an OPU (21), a first controller (26) that causes the spindle motor (23) and the OPU (21) to read recorded data from the rotating optical disc (40), and an transmitter (27b) that transmits the read recorded data to a signal processing device (30) disposed external to the optical disc drive device (20). The recorded data transmitted by transmitter (27b) is stored in a buffer (33) provided in the signal processing device (30). The first controller (26) decreases the rotational speed of the optical disc (40) based on free space information indicating the free space of the buffer (33).