LG RD-JT30 Service Manual page 85

Appendix D DMD Image Quality
1. SCOPE
This document specifies the image quality requirements applicable to the DLPTM .6SVGA
Component Set. The Component Set provides the DLPTM .6SVGA Projector with digital imaging
functionality based on Digital Micromirror Device (DMD) technology.
2. Definitions
2.1 Blemish
A blemish is an obstruction, reflection, or refraction of light that is visible, but out of focus in
the projected image under specified conditions of inspection (see Table 1). It is caused by a particle,
scratch, or other artifact located in the image illumination path.
2.2 Dark pixel
A single pixel or mirror that is stuck in the OFF position and is visibly darker than the
surrounding pixels.
2.3 Bright pixel
A single pixel or mirror that is stuck in the ON position and is visibly brighter than the
surrounding pixels.
2.4 Unstable pixel
A single pixel or mirror that does not operate in sequence with parameters loaded into memory.
The unstable pixel appears to be flickering asynchronously with the image.
2.5 Adjacent pixel
Two or more stuck pixels sharing a common border or common point, also referred to as a
cluster.
2.6 Streaks
Artifact resulting from localized variation in mirror tilt angle relative to surrounding mirrors.
They are similar in appearance to window scratches but appear at the mirror level. Streaks appear as
faint diagonal or arcing patterns in the image.
2.7 Reset boundary artifact
The reset boundary artifact is a single row of pixels on the reset group boundaries that are
visibly darker or lighter than the neighboring rows of pixels.
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