IEC 61747-20-1:2015

Overview

IEC 61747-20-1:2015 is an international standard developed by the International Electrotechnical Commission (IEC) for the visual inspection of monochrome liquid crystal display (LCD) cells, specifically excluding all active matrix LCD cells. This standard establishes the procedures, criteria, and defect definitions for visually assessing both active and non-active areas of monochrome LCD cells using the human eye, and-if necessary-supplemented with an optical microscope. It outlines general rules to ensure consistent inspection processes and reliability in quality assessment.

Key Topics

• Visual Inspection Methods: Specifies how to visually inspect monochrome LCD cells, including preparation, environmental conditions, and inspection procedures.
• Defect Definitions and Classifications: Provides clear categories for types of defects such as spots, bubbles, foreign particles, stains, scratches, cracks, and structural irregularities.
• Areas of Inspection: Covers both active (display) and non-active areas, including seal, contact pads, pins, flexible leads, and support plate edges.
• Inspection Conditions: Defines standard inspection environments, including controlled temperature, humidity, illumination, and viewing angles.
• Inspection Personnel Requirements: Stipulates that inspectors should possess normal or corrected vision and be regularly trained with reference samples.
• Procedural Records: Emphasizes proper documentation of results, including conditions and findings for traceability.

Applications

IEC 61747-20-1:2015 is primarily applied in the manufacturing and quality assurance of monochrome LCD cells used in devices where high visual quality and display reliability are essential. Typical applications include:

• Consumer Electronics: Quality control in the production of calculators, watches, medical devices, and industrial instruments using monochrome LCDs.
• Component Acceptance: Used by suppliers and purchasers to specify acceptance criteria and ensure delivered LCD cells meet established quality standards.
• Incoming and Outgoing Inspection: Applied during both incoming goods inspection (by customers) and outgoing inspection (by manufacturers) to identify and document defects.
• Process Improvement: Supports ongoing process optimization and defect reduction in display cell manufacturing.

The standard fosters consistency across different production lines and supply chains, ensuring LCD components comply with international best practices and meet end-user expectations.

Related Standards

For a comprehensive quality management approach and further technical detail, IEC 61747-20-1:2015 should be used alongside related standards, including:

• IEC 61747-1-2: Liquid crystal display devices – Part 1-2: Generic – Terminology and letter symbols
• IEC 61747-10-2: Liquid crystal display devices – Part 10-2: Environmental, endurance and mechanical test methods – Environmental and endurance
• IEC 61747-20-2: Visual inspection for monochrome matrix liquid crystal display modules (excluding active matrix)
• IEC 61747-20-3: Visual inspection for active matrix colour LCD modules
• IEC 61747-30-1: Measuring methods for transmissive type LCD modules
• ISO 9241-307: Ergonomics of human-system interaction – Analysis and compliance test methods for electronic visual displays

Practical Value

Using IEC 61747-20-1:2015 provides manufacturers, suppliers, and quality assurance professionals with a consistent, internationally recognized framework for the visual inspection of monochrome LCD cells. This ensures:

• Reduced product returns and customer complaints
• Improved consistency and reliability in LCD production
• Simplified communication of quality requirements with stakeholders
• Traceability and accountability in inspection processes

By adopting this standard, organizations strengthen their overall product quality, ensure regulatory compliance, and build customer trust for their monochrome LCD products.