Description of selected functions of the QHD
Input Detect Mode
The Display supports both Single-Link DVI (SL) and Dual-Link DVI (DL). Whereas
in SL mode each source cable provides the image for one Full HD quarter of
the display, in DL mode a 1920x2160 image is transferred over a single cable
providing the image for one half of the display. In auto mode the display
detects and displays the input mode itself. In force mode a scheme can be
chosen from the Input Presets that determines where single and dual link
sources are connected.
Genlock
In a non-genlock mode the input source and the output to the screen are run
in so-called free-buffer mode, i.e. the clock for input and output are not forced
to run synchronously. For example input frame frequency and the panel frame
frequency may differ. This can lead to artefacts like frame losses. If the sources
themselves share a common vertical sync (the signal used to indicate a new
frame) this synchronized input can also be used to control the clock to the
panel side. Thus there is always a fixed phase of one frame between input and
output and thus input and output are run synchronously. The display measure
whether the input signals are suitable and allows activation only in this case.
An active genlock is disabled automatically if the prerequisites are no longer
met (e.g. because one input source is disconnected). It will be automatically
enabled if the genlock input source prerequisites are met again.
Framelock
If genlock is enabled with 4 single link DVI sources it is possible to delay the
output on the lower part of the display by one frame using the framelock
function. This can be used to avoid tearing effects with video sources: Since
the native operation mode of the display is stripe mode (i.e. the image is
displays the 2160 vertical pixels successively) for a smooth video image it must
be assured the content of the upper and the lower quarters have a one frame
phase shift.
Colour Settings
The display disposes of an integrated colour matrix that allows adjusting the
colour weight. In user mode the base colours can be modified directly. For
more advanced adjustments the external mode can be used. Please refer to the
description given in the serial protocol.
Gamma Curve
A gamma curve is used to compensate for nonlinear effects in both a display
device and the human eye. It transforms the input using an exponential
function to obtain a linearly perceived image. For special applications user
mode can be controlled by serial commands.
EYE-LCD-8400-QHD-LE
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Version 1.2 | June 2014
