This standard will define the index of measurement for mura in FPD image quality inspection. Conventionally, inspection of FPD image quality has been sensory, mainly conducted via the human eye, and among the items detected, there has been no common standard for mura and other associated defects. For this reason, when panel makers and their users who conduct business with a fixed quality level set a mura acceptance level, limit samples are used as necessary. Operational problems with limit samples include:
- Level of mura cannot be determined without viewing the sample. Due to this, it is not possible to express the level via written documentation or telephone.
- The sample settings are subjectively decided by the setter, and lack objectivity.
- It is difficult to setup and maintain a consistent sample level at multiple locations, etc.
— Above all, in a market complicated by multiple panel makers and multiple users, where presently there is no fixed standard for expressing mura level, we have to say that it is extremely difficult to ensure a fixed level for panel quality. In this standard, using ergonomics approach, we will investigate the human eye’s sensitivity regarding mura, and by expressing the relation between mura area and contrast, propose an index to express the level of mura.

This standard is applicable to FPD (Flat Panel Displays) excluding CRT and HMD (Head Mount Displays). The display sizes targeted are typically from Type 8 (8" (20.3 cm) diagonal) to Type 30 (30" (76.2 cm) diagonal).

Referenced SEMI Standards
None.

Revision History
SEMI D31-1102 (first published)