HP Lp2480zx User Guide

each of the three channels (that is, exactly what will be output, in terms of light, for the given values of
red, green, and blue). This may be expressed by the following diagram:
Figure A-2  Model of Standard Display Device
Here, the input RGB values are first modified by the appropriate transfer function (γR, γG, or γB); this
operation may be viewed as being performed by three look-up tables (LUTs) of the appropriate width
and depth. The modified RGB values (R′, G′, and B′) are then mapped to the...

Figure A-4  Correcting Native Display Characteristics
It can be shown that the required transform (T) may be implemented as a pair of appropriately-sized
look-up tables (LUTs), on either side of a 3 x 3 matrix multiplication. The LUT preceding the matrix
multiplication (the “pre-LUT”) implements the desired standard transfer function or gamma response
curve, such that input values are correctly mapped per that standard into a “linear light” space. The
required matrix for the color remapping (which is...

Note that since the look-up tables for the three channels (R, G, and B) are independent, differences in
the display device’s transfer function across these three, along with any minor errors in the display white
point, may be “nulled out” using the look-up tables, in addition to the operations required for the color
space emulation as described above. In the LP2480zx, these functional blocks are implemented as part
of the “front end” electronics, in addition to the usual scaler/controller functions of a...

Input usedColor encodingScan formatResult
Component, CVBS, S-Video YUV (RGB not supported) Either Color Space presets: disabled
Hue/Saturation controls:
enabled
10 bits/color LCD Module
As noted earlier, the LCD module in the LP2480zx monitor provides a 10 bits/color (30 bits/pixel) input,
with true 10-bit drivers within the LCD itself. This means that each primary (red, green, and blue) may
be controlled over 1,024 steps (input codes 0 to 1023) from the black level to the white (peak luminance
for that...

brightness settings, both its white luminance and black level compare favorably with those of traditional
CRT displays. (At the low end of this range, the monitor’s black level will typically be approximately 0.05
cd/m
2.)
As with several other parameters set in the color space presets, the programming of the backlight
controller is managed either through the LP2480zx’s on-screen display (OSD), or by using the HP
Display Assistant software.
Transfer Function (Gamma)
As noted briefly in the previous...

Figure A-7  Low Linear Region Response Curve
A generalized model for the display response curve accommodating the addition of a linear section as
shown above thus requires the specification of four parameters in addition to the “gamma” exponent
value:
For input values (I) ≤ A
0:
Y = I/A
1
For input values (I) > A0′
Y = [(I + A
2)/(1 + A3)]γ
The response of the LP2480zx is automatically set to the correct standard as part of the color-space
selection, using either the on-screen display (OSD) or using the...

Color spaceA0A1A2A3gamma (γ)
Full01002.2*
* Note that in “full gamut” mode, the color space emulation capabilities of the LP2480zx monitor are used to correct any
deviations in the LCD’s native performance from its nominal specified values. The color gamut, white point, and response curve
seen in this mode are therefore those of the LCD panel itself, but corrected to their nominal values as accurately as possible.
References:
●Adobe® RGB (1998) Color Image Encoding, Version 2005-05, May 2005, Adobe...

B Troubleshooting
Solving Common Problems
The following table lists possible problems, the possible cause of each problem, and the recommended
solutions.
ProblemPossible CauseSolution
Screen is blank.Power cord is disconnected.Connect the power cord.
Power button on front panel of the
monitor is turned off.Press the front panel power button.
NOTE:If pressing the power button has no effect, press
and hold the power button for 10 seconds to disable the
power button lockout feature.
Video cable is...

Using the Worldwide Web
For the online access to technical support information, self-solve tools, online assistance, community
forums of IT experts, broad mutlivendor knowledge base, monitoring and diagnostic tools, go to
http://www.hp.com/support
Preparing to Call Technical Support
If you cannot solve a problem using the trouble shooting tips in this section, you may need to call
technical support. Have the following information available when you call:
●The monitor
●Monitor model number
●Serial number...

C Technical Specifications
NOTE:All performance specifications are provided by the component manufacturers. Performance
specifications represent the highest specification of all HPs component manufacturers typical level
specifications for performance and actual performance may vary either higher or lower.
HP LP2480zx Model
Table C-1  HP LP2480zx Model Specifications
Display
Type61 cm
TFT LCD24 inches
Viewable Image Size61 cm diagonal24–inch diagonal
Tilt Adjustment-5 to 35°
Swivel Adjustment-45 to 45°...