IEC 61747-4:2012 describes the essential ratings and characteristics of LCD cells and passive matrix monochrome liquid crystal display modules. It does not apply to active matrix LCD cells nor to multicolour cells. This edition includes the following significant technical changes with respect to the previous edition: - 2.1 and 3.1 of IEC 61747-4:1998 were deleted because these items are defined in IEC 61747-1; - 2.7.6, in 2.7, Supplementary information, of IEC 61747-4:1998 was deleted because the scope of this standard is about passive matrix monochrome liquid crystal display modules; - The item "Gray scale: digital or analog" in 2.3.1 of IEC 61747-4:1998 was changed to "Gray scale: number" because it is more accurate; - Contrast mode: light symbol on dark background ("LOD" or "positive image") or dark symbol on light background ("DOL" or "negative image") was introduced in this part of IEC 61747 to replace the description in 2.3.1 and 3.3.1 of IEC 61747-4:1998. This publication is to be read in conjunction with IEC 61747-1:1998.