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Introduction
Computer users are accustomed to using software control
panel solutions to setup and manage their computer’s
peripherals. The monitor is the lone exception.
This is because each display manufacturer creates a unique
On-Screen Display (OSD), often employing a user
interface that severely compromises the user experience.
Monitor adjustments and menu hierarchy are vastly
inconsistent from display to display, creating customer
support problems and user dissatisfaction. In addition, the
OSD is often unintuitive with no explanation of the
controls which exacerbates to the user’s frustration. The
new result is the user incorrectly adjusting the display and
adversely affecting the visual quality.
Control panel OSD replacements provide an elegant
alternative to the crude hardware OSD while also offering
the manufacturer the ability to promote the company’s
brand. But the ability to manage the display does not stop at
simple display adjustments and software controls of OSD
functions. The control panel should offer a superset of
features not found in the OSD.
The biggest obstacle in creating a solution for a software
managed display is implementing bi-directional
communications from the host to the peripheral. The host
must be able to send commands to the display and receive
information back in real time. In the past, this required the
addition of USB, Ethernet, Firewire, or other bi-directional
circuitry which was a cost adder to the BOM. A more
elegant solution would be to use the display’s analog or
digital cable as means to communicate bi-directionally.
The VESA DDC/CI standard does just that. The standard
defines the bi-directional pipeline to control the display
directly from the mouse or keyboard through the standard
analog or DVI cable. This solution requires that the
graphics card driver support I2C communication and that an
API is available to communicate from the host to the
display.
In addition, the display firmware must have the proper
hooks in place to accept commands written from the host.
VESA has defined a universal set of Virtual Control Panel
(VCP) codes in the Monitor Control Command Set
(MCCS) Standard. These codes, when embedded in the
firmware of the display, allow the host application to read
and write commands to control the screen settings of the
display. The cost adder for DDC/CI enabled displays is
negligible as all mainstream scalers have affordable
solutions that are currently shipping into the market.
With the upcoming release of Microsoft’s Vista, all
computer displays will be required to have basic
functionality in their firmware to take advantage of
software controls that will be integrated into the Vista
operating system. The list of Vista required VCP codes for
the display technology can be found in Microsoft’s
document titled “Windows Longhorn Logo Program
System and Device Requirements”.
Fortunately, display manufacturers do not have to wait until
the introduction of Vista to be more competitive and
feature-rich in today’s market. Features such as color
management, asset management, theft deterrence, auto
rotation, zoning, and PIP are just a few enhancements that
can be added to today’s displays for little or no cost while
positioning the displays for the next major OS release.
Color Management
Accurate Windows color reproduction on a display device
requires conformity to the sRGB standard. To achieve this
conformity the tonal response of the monitor must
generally follow a gamma 2.2 curve. CRTs in their native
state come very close to approximating this curve and
simple adjustments can bring them into very good
calibration. But LCDs typically vary a great deal from this
ideal response curve and most suffer from severe color
crossover effects as well. Software targets can be used to
correct critical points along the tone curve. User
adjustments with respect to these targets establish the
variance in the LCD’s tonal response to an ideal gamma 2.2
response curve. Based on this point data, software can
calculate the overall video signal compensation necessary
to cause the display to exhibit a gamma 2.2 behavior along
the entire tone curve. Software then uses an intelligent
agent to apply the calculated compensation at all times,
achieving the desired sRGB results.
Asset Management
In any large computing environment, the importance of
managing the client’s hardware and software (assets) is
instrumental in the Total Cost of Ownership (TCO).
Displays are viewed as an investment to the overall
computing solution, and require the same attention and
management as all other capital assets. IT managers need
the ability to view the asset and control it. Both are
imperative in successfully controlling expenses and asset
allocation.
However, traditional asset control implementations fell
short by not controlling the display remotely over the
network. Only with the introduction of bi-directional
communication did asset management software finally
provide the necessary control to track the display and
control all functions supported within the firmware. For
example, industry-standard DDC/CI bi-directional
communication allows the standard monitor cable to
communicate between the client’s computer and display
while the server can access the display directly through the
client. There no longer is any need for USB or other
proprietary cabling schemes that can introduce
complications into the network environment. Asset
management solutions not only support vertical markets
such as call centers or trading floors which have specialized
requirements, but can also be applied to horizontal markets,
where it can be used in both small and large domain
solutions. IT managers can experience a seamless
integration of mixed manufacturer’s displays into existing
network configurations without having to update cabling or
other special hardware considerations.
With remote control of the display the IT manager can send
various VCP commands to the client to control and adjust
the display. These controls can be sent to an individual
client or a work group to adjust white point, geometry,
factory default settings, or presets for display consistency.
In addition, the commands can be sequenced to be sent
during non-business hours for maintenance updates.
The need to control the power of the display is beneficial in
effectively managing the life span of the display’s lamp.
The IT manager can set the power mode for the display to
accommodate vacation time, unexpected sick leave,
schedule holidays, and non-business operation hours.
Another benefit of this remote control is being able to limit
user access to the OSD. The biggest problem with monitor
support calls is caused by “pilot error”. Remote access
allows the display to be reset and lock out the client’s
access to the OSD from future tampering. All remote
controls and actions can be sent to individual(s) or entire
group with a single point and click.
Theft Deterrence
LCDs are very susceptible to theft due to their high pricetag
and ease in “lifting” them from the host computer.
Software applications can be written to minimize theft or
unauthorized relocation of the display. Theft deterrence
does not prevent the display from being stolen, but hinders
the operation of the display once it is removed from the
“theft deterrence enabled” host.
There are two possible configurations for the theft
deterrence: enterprise and individual. For individual users,
software can be used to create a PIN that is locked to the
host computer. For enterprise configurations, PINs can be
set remotely for individual clients or work groups.
To activate theft deterrence, the user must completely shut
down the power by unplugging the power cord of the
display AND removing the video cable from either the
display or host (Note: some LCD controllers will only
require power disruption to initiate theft deterrence). The
assumption is that if there is theft or unauthorized
relocation, then all display cables must be disconnected so
the display can be removed from its current location. Once
these two conditions are met, the theft deterrence logic
residing in the display firmware is initiated the next time
the LCD is powered up and a user-definable clock value
stored in the display begins a countdown sequence. During
the countdown sequence, the user must enter a valid PIN to
over ride theft deterrence. Failure to enter a valid PIN
before the completion of the countdown places the display
into either an unfavorable or inoperable viewing mode.
Unfavorable view still provides some level of functionality
for the display. This would allow the user to move the
display to another system and still use the display after the
theft timer value reaches zero. The display’s image will be
put into a mode that is less desirable, such as inverting the
color ramps or placing the display into gray scale only.
This allows a minimal level of visual performance after
temporarily moving the display from the host.
Inoperable view makes the display unusable. Examples of
inoperable view are powering down the display or setting
the contrast to zero. Rendering the display inoperable lends
itself to electronic signage where the owner wants the
display to have no use or minimal resale value if it is stolen.
Auto Rotation
A common feature found on most flat panel displays is the
ability to rotate the display into 90°/270° portrait or 180°
presentation mode. The rotation is accomplished through a
pivoting hardware hinge in the monitor stand or a VESA
compliant arm or wall mount. The user can lift the display
and rotate it into portrait mode for full page viewing or flip
the display over to allow a viewer sitting across from the
display to see the contents. However, the contents of the
display must also be rotated, either through the graphics
driver or through Pivot® software. This software control
requires the user to send a command to rotate the contents
either through the keyboard or mouse.
With bi-directional communications, a sensor can be
designed into the display that relays the current orientation
to the firmware. The host can continuously poll the display
firmware to determine the orientation and then
automatically rotate the contents to the current operating
mode. There is no need for user intervention as the
mechanism to rotate the desktop contents is handled
transparently through software.
Zoning
Zoning is a hardware function that allows a region within
the desktop to be selected and controlled independently of
the entire desktop. Common adjustments such as
brightness, contrast, and color settings can be applied to a
user-definable zone without impacting the overall settings
of the display. The zone can be moved or resized while
maintaining its unique characteristics. Zoning allows for
application tuning, where an application’s window can
display settings that are most desirable for the content. For
example, text applications can be displayed in high
contrast/brightness ratio while video can be shown in high
color saturation. The display characteristics of the content
can be applied whenever the application is launched.
Zoning isn’t a new feature. However, trying to set the X:Y
coordinates of a window from a conventional OSD is
cumbersome and unintuitive. Using bi-directional
communication, the control and maintenance of the zoned
window can be controlled from the keyboard and mouse,
thus bypassing the need to navigate through a sequence of
OSD buttons and menus. The number of active zones
which can be displayed and controlled is dependent on the
scaler. Some scalers offer up to seven unique zones which
can be defined and controlled.
Picture-in-Picture
Multi-function displays are becoming more and more
popular. These displays allow for a separate video input
source such as S-Video, composite, component and/or USB
to be added to the display. Traditional OSD hardware
allows users to select, open and view the video source.
However, the problem with most traditional OSD hardware
is that the PIP window can be difficult to manage. In many
cases, the PIP window is confined to a certain size and to
one of four quadrants on the screen. With users accustomed
to moving and controlling a software window within the
desktop, bi-directional communication allows a software
control panel to be designed to let users bypass the limited
functionality and control of traditional OSD hardware
buttons. This software control panel would provide an
easy-to-use and intuitive way to select on/off, video source,
visual settings , and window location and size.
Conclusion
In today’s world, display hardware capabilities and end
users should not be subjected to the potential limitations of
a traditional OSD control. The display is an investment and
its visual quality paramount to the user’s computing
experience. The value proposition for software control of
both the common display adjustments, as well as new
exciting features, will assist in the user’s purchasing
decision. And with Vista on the horizon, now is the time to
design the necessary commands for tomorrow’s operating
system while adding compelling features that address
today’s markets.
References
- Video Electronics Standard Association. Display Data
Channel Command Interface (DDC/CI) Standard (Version
1). Milpitas, CA, 1998.
- Video Electronics Standard Association. VESA Display Data
Channel Command Interface — Proposed Implementation
Guide (Version 1P). Milpitas, CA, 2002.
- Video Electronics Standard Association. VESA Monitor
Control Command Set (MCCS) Standard (Version 2).
Milpitas, CA, 2003.
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