IEC 61747-4:2012

Overview

IEC 61747-4:2012 is an international standard published by the International Electrotechnical Commission (IEC) that specifies the essential ratings and characteristics of liquid crystal display (LCD) modules and cells. This part of the IEC 61747 series focuses exclusively on passive matrix monochrome LCD modules and cells. It excludes active matrix and multicolour LCD cells. The standard provides detailed technical requirements regarding electrical and optical performance parameters needed to ensure quality, reliability, and consistency for manufacturers, designers, and engineers working with passive matrix monochrome LCDs.

This edition updates and refines the earlier 1998 edition by deleting elements incorporated into IEC 61747-1, refining grayscale terminology to “number” rather than “digital or analog,” and introducing contrast modes to better characterize display behavior.

Key Topics

• Scope and Applicability
  Covers passive matrix monochrome LCD modules and cells, excluding active matrix and multicolor types. It applies to devices used in a wide range of applications requiring monochrome displays.

• Operating Principles
  Describes various LCD operational modes, including optical modes such as reflective, transmissive, and transflective illumination modes, and electrical modes like static and multiplex operation.

• Essential Characteristics
  Details critical parameters including:

  • Supply voltages and input signal levels
  • Frame and oscillator frequencies
  • Operating temperature ranges
  • Backlight requirements where applicable
  • Contrast ratio definitions-specifically light symbol on dark background ("LOD" or positive image) versus dark symbol on light background ("DOL" or negative image)
  • Viewing angle and optical properties such as luminance, transmittance, and reflectance
  • Switching times (turn-on and turn-off)

• Mechanical and Connection Details
  Specifies material composition (glass, plastic, metal), module construction (including integrated backlight and bezel), connector types (flex cable, pins), dimensions, and pinout configurations.

• Supplementary Information
  Provides guidelines on contrast ratio angular dependence, switching time variation with temperature, timing and logic voltage sequences, handling and electrostatic discharge precautions, installation requirements, and safety considerations.

Applications

IEC 61747-4:2012 is widely used in industries that manufacture or utilize passive matrix monochrome LCD modules such as:

• Consumer Electronics
  Devices requiring reliable monochrome displays like calculators, digital watches, and handheld devices.

• Industrial Instrumentation
  Equipment where clear monochrome readouts are necessary, including control panels and measurement devices.

• Automotive Displays
  Instrument clusters and information displays that use monochrome LCDs for improved visibility and reliability.

• Medical Devices
  Instruments requiring straightforward visual indicators with durable monochrome LCD components.

By adhering to this standard, manufacturers ensure compatibility, improved performance consistency, and interoperability across components and systems.

Related Standards

• IEC 61747-1:1998
  This foundational document provides generic specifications essential to understanding and applying IEC 61747-4:2012. It defines many fundamental terms and ratings used throughout the series.

• Other Parts of IEC 61747 Series
  The series covers a broad range of LCD technologies, including active matrix, colour modules, and their specific characteristics and ratings.

• ISO/IEC Directives
  The standard is developed in accordance with the joint ISO/IEC directives ensuring international consensus and quality in standardization practices.

Summary

IEC 61747-4:2012 establishes critical ratings and measurement methods for passive matrix monochrome LCD modules and cells, enabling manufacturers and designers to assess and ensure display performance and reliability. The standard enhances clarity with precise definitions of contrast modes and operational characteristics, supporting improved compatibility across applications. It is a key reference for industries deploying monochrome LCD technology in both consumer and specialized electronic devices.