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Important lcd parameters – BenQ FP781 User Manual

Page 21

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Benq LCD Color Monitor User's Guide

English 50

C. Comparison of standard and super TFT display

Important LCD parameters

A. Viewing angle

The viewing angle is the display's visible field. If one were to imagine a vertical line in the centre of
the image and to pivot up and down and to the right and to the left from that point, then that is the
viewing angle.†Working ergonomically requires a viewing angle of at least 60

°

/60

°

(right/left) hori-

zontally and 45

°

/45

°

vertically (up/down). If only two values are specified for horizontal and vertical,

the values for right and left, and for horizontal and vertical are added together. If this were the case
then this would provide a viewing angle of 120

°

horizontally and 90

°

vertically.

B. Contrast

Contrast is the ratio between the light intensity of the brightest and the darkest point of an image.
High contrast values improve readability and ergonomics.

A display should in all instances attain contrast values of 100:1. This is a point on which LCD mon-
itors are clearly superior to monitors.

C. Response time

The response time is the time, which a TFT cell requires to switch on and switch off. †For standard
applications a response time of a maximum of 70 ms (milliseconds) is sufficient. If a more rapid
image build-up is required (e.g. the multimedia field), then values of a maximum of 30 ms are
required.

D. Brightness

Brightness is the emitted luminous power over a specified area. Brightness is another point, on
which LCD monitors are superior to CRT devices. Traditional monitors create approx. 80 to 100
cd/m² (candela per meter square). In the case of LC displays, values below 150 cm/m² are not
acceptable.

Standard

Super

h good gray level resolution

hF satisfactory viewing angle

h very good viewing angle

hsatisfactory gray level resolution

Field of applications:

hImage processing

hmedical field

hStandard workstation

hBanks (confidential area)

Field of applications:

his several people are working at one

screen.

hStandard workstation

hPresentation tasks

hBanks (public area)