........................................................................4
Space ........................................................................................ 4
Power ........................................................................................ 6
Lifetime...................................................................................... 7
S
ECONDARY
B
ENEFITS OF
LCD
S
............................................................10
Ergonomics............................................................................... 10
Installation costs ....................................................................... 13
Removals costs/frequency ....................................................... 13
Reduced interference effect ........................................................ 14
Simpler conformance to Display Screen Regulations ....................... 14
LCD Image A Marketing Benefit ................................................ 14
O
VERALL
C
OST
I
SSUES
..........................................................................15
C
ONCLUSION
.........................................................................................15
R
EFERENCES
........................................................................................16 Comparing LCD & CRT Costs
©Meko Ltd 2002
3
Purpose
The purpose of this paper is to consider the cost savings and benefits of LCD
monitors.
TFT LCD technology has developed over nearly thirty years to become the
technology of choice for high resolution colour mobile display applications where
the low size and power consumption of TFT LCDs has made them indispensible.
Until recently, the cost premium for an LCD monitor over a traditional CRT made
LCDs a choice only for some special desk-bound applications, where the space,
power or style considerations made the technology the best choice. However,
with the dramatic reductions in price of recent years
a
, the price of LCDs is
getting much closer to that of CRTs.
Average UK Prices
17" CRT Monitor vs 15" LCD Monitor
£100
£200
£300
£400
£500
£600
£700
£800
Q1 2000 Q2 2000 Q3 2000 Q4 2000 Q1 2001 Q2 2001 Q3 2001 Q4 2001 Q1 2002 Q2 2002 Q3 2002
CRT
LCD
Although the graph shows average pricing, theres a much wider variation
among LCD monitor prices than CRT monitors. Its not difficult to find LCD
monitors from reputable suppliers at less than £300
b
For some time to come, the initial purchase price of an LCD monitor is likely to
be more expensive than CRTs. There are a wide range of advantages, some very
obvious and some not so obvious, that can come into play to reduce the total
cost of ownership (TCO) of LCDs over their lifetime. In many cases, these cost
savings can bring the TCO to below that of CRTs.
For the purposes of analysis, weve broken these benefits down into two
groups, primary and secondary. Weve defined primary benefits as those that are
directly related to the performance and features of the LCD itself, while
secondary benefits arise from the installation and use of the monitor. Comparing LCD & CRT Costs
©Meko Ltd 2002
4
Primary Cost Issues
Space
Floor/Desk Space
One of the most obvious advantages of LCD monitors over CRTs is in the
reduced space occupied on the desk compared to CRT monitors. An LCD
monitor will typically occupy a footprint around 63% smaller than an equivalent
CRT monitor
c
. The cost of floor and desk space can be calculated relatively
easily. A spin-off of this saving is that often more staff can work in a limited
area. A study by the architects Pringle Brandon in 1996
d
showed that a new
office design such as a bank trading room designed around flat screens can
allow as many as 22% more people than a room designed for CRTs.
CRT
LCD
Annual
Saving
Office
£87.44
£31.75
£55.68
Call Centre
£87.44
£31.75
£55.68
Retail
£375.19
£136.25
£238.94
Assumptions
Office space cost £460.19 sq. m
e
Retail space cost - £1,975 sq. m
f
17 CRT Monitor 0.19 sq. m footprint
g
15 LCD Monitor 0.069 sq. m footprint
h
For installations such as call centres, the savings in space can be especially
important. In some organisations, keeping staff physically close together can be
a real advantage by encouraging informal communication.
In small and medium-sized companies with existing offices, it may be possible to
delay moving to new premises or even avoid it completely in certain cases by
switching to LCDs.
Many staff are now employed at least part of the time at home, but relatively
few have the kind of ideal workstation arrangements that are possible in a
purpose-built office. The use of an LCD monitor can make home office work
more acceptable to other family members by occupying less space. There may
also be health and safety improvements in home offices with the use of LCDs,
but well look at these later in the secondary benefits section. Employers have
health and safety responsibilities for display screen users that apply to staff
employed at home or as teleworkers that are no different from those applicable
to employees in an office
i
.
More flexible office design
A fundamental disadvantage of the CRT technology is that the phosphor that
glows to create the image is also reflective. This means that performance can be
severely affected by the glare of ambient lighting reflecting on the screen. In
traditional curved screen CRTs, its difficult and expensive to eliminate this glare.
LCDs, on the other hand, can easily use separately manufactured and developed Comparing LCD & CRT Costs
©Meko Ltd 2002
5
anti-glare filters that can be very effective in eliminating reflections from the
surface of the LCD. Because LCDs dont use phosphors there is no fundamental
glare problem.
Where levels of ambient lighting are higher than would be ideal, or ambient light
is hard to control, such as in retail premises, its very difficult to increase the
brightness of CRT monitors without degrading other aspects of performance.
The main way to increase brightness in a CRT is to boost the beam current, but
with more current, the beam spreads. Because of this effect, known as
blooming, CRTs tend to lose focus as the brightness increases
j
.
With an LCD, there is no degradation in focus performance as brightness is
increased. The consequence of this is that LCDs may be usable in a wider
variety of positions within an office, relative to windows and other light sources.
The increased flexibility of monitor placement has the potential to allow cost
savings.
Less weight on desk
Since the microcomputer was invented, there has been a steady increase in the
amount of data presented on screens, and users have wanted larger and larger
image areas. It seems that over the longer term, users always want to maximise
the amount of information that is presented to them on the screen.
There are two ways to increase the amount of data available by increasing the
density of information on the screen or by increasing the size of the image itself.
New technologies are allowing the development of LCDs with high dot densities,
dramatically beyond the capability of CRT technology.
Looking at image size alone then CRTs are at a disadvantage. The nature of CRT
technology means that the depth increases as the screen diagonal increases. In
turn, the weight of the CRT also increases dramatically as a function of screen
size. Although CRT designers have tried to minimise this problem, by using wider
deflection angles, its hard to do this without reducing screen quality and
increasing the power needed for deflection of the electron beam.
Average Weights - CRT & LCD Monitors
0
5
10
15
20
25
30
35
14-15
15-16
16-17
17-18
18-19
19-20
20-21
Diagonal Size
LCD Monitor Ave
CRT Monitor Ave
Source - Meko product
database - based on
4318 CRT monitors
1799 LCD monitors Comparing LCD & CRT Costs
©Meko Ltd 2002
6
The higher weight of CRT monitors means that desks and mountings for screens
need to be more substantial than those used for LCDs. Large screens, from 19
and upwards in particular, need more robust designs.
The light weight of LCDs means that a much wider range of mounting options is
available including arm mounting which can actually remove the monitor from
the desk surface completely. Again this contributes to office design flexibility.
Less barrier in customer facing applications
The reduction in the physical size made possible by the used of LCDs can be
particularly important in customer-facing situations where a large screen might
act as a barrier between customer service staff and their customers. These retail
installations can often represent very expensive floor space or even the limit on
the amount of business that can be taken.
Where staff only occasionally need to talk to customers and at other times use
their screens privately, an LCD that can be easily moved out of the way may
represent the optimum balance between an ergonomically sound work position
for the operator and cost.
In applications such as travel agencies, where staff may wish to share
information with customers, the light weight and ease of positioning of LCD
monitors can be a major advantage.
Power
Power consumption
The power saving benefits of LCDs are both significant and relatively easy to
calculate. Because TFT LCDs use fluorescent lamps to produce light very
efficiently, they consume a third or less of the power of CRT monitors.
A typical working year in an office is around 2,000 hours (1,976 hours)
k
, but
often monitors are left on over weekends and overnight. A monitor left on
overnight is on for the equivalent of two normal working days. A