When the third major revision of Sony's PlayStation Portable, chiefly the PSP-3000 "Brite", was released in 2008 as a successor of the PSP-2000 "Lite", many upgraders quickly noticed a quirk of its upgraded display: noticeable artifacts between lines.
Probably due to confusion with another innovation of the 3000 series (the ability to display games and applications on an interlaced external display, whereas the 2000 series only supported interlaced output for media files played via the XMB), the misconception that the console uses an interlaced LCD quickly hit discussion avenues and still circulates to date, despite pictures like the above one quickly circulating and suggesting other factors like the subpixels having been rotated horizontally.
It was only as of yesterday that Reddit user "niinono" embarked on a scientific approach of identifying the panels and comparing their datasheets, coming up with some other revelations (such as the 2000 and E1000/Street models being potentially brighter than the 3000 and N1000/Go models, despite the latter having superior contrast ratios and better response time), but perhaps equally as interestingly, he formulated (with the help of a post on the System11 gaming forums) a plausible hypothesis on the issue:
As many people who serviced Nintendo handhelds with a color display know, there is an adjustment for each screen's bias voltage (officially termed "flicker" and popularly but incorrectly called "contrast" or "scanlines", located next or under the battery until the 3DS which switched it to being a software adjustment), which if misadjusted produces a similiarly distorted image and may increase stress on the panel's electronics; and every model of PSP exhibits this issue due to the lack of this setting (using instead a fixed default value), which the increased performance and horizontal subpixels (less ideal than vertical ones for most Latin alphabet characters) of the 3000 and N1000 models can only exacerbate.
Picture credit: Xythen of Wikipedia