IEC 61747-20-1:2015(E) gives the details of testing and provides general rules for visual inspection of the non-active and active area of monochrome liquid crystal display cells by the human eye, if necessary, through an optical microscope. Furthermore this standard includes defect definitions and the methods for visual defect inspection. This first edition cancels and replaces Clause 6 of the first edition of IEC 61747-5 published in 1998. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) The editorial modifications were done in accordance with the ISO/IEC Directives, Part 2, Ed 6.0:2011. b) The document number was changed to align with the new numbering structure of the IEC 61747 series.