Toshiba POcket PC e830 Series, User Manual

Page: 11 / 230

11
Prevention of eyestrain
Viewing angle and viewing distance of LCD
When using Pocket PCs, the operator is linked to the equipment through
the eyes as well as through the hands. Viewing angle and viewing dis-
tance are two of the controllable factors which significantly affect the abil-
ity of the eyes to focus easily on the LCD.
Viewing distances of less than 16 inches can cause eyestrain and head-
aches, both in persons with normal vision and in persons who must wear
corrective glasses or contact lenses. Consequently, viewing distances of
at least 16 inches must be maintained. Closer viewing distances will cre-
ate stress both on the binocular (eye aiming) system and on the accom-
modating (eye-focusing) system.
Most persons also find it to be more restful on the eyes if the top line of
the LCD is located 20 degrees or more below eye-level, rather than
straight ahead or upward. In general, the closer the location of the LCD,
the lower it should be placed.
Always ensure that the top line of the LCD is located at least 20 degrees
below eye-level.
Always tilt the top of the LCD away from you until you have located the
position that affords maximum visibility.
Always adjust the brightness and contrast controls to maximize the char-
acter and image quality on the LCD.
Ambient lighting
Adequate lighting increases work effectiveness and reduces eyestrain.
Sources of illumination should be selected that are located outside of the
peripheral field of vision, to minimize both direct and reflected disability
glare (i.e., glare that results in a reduction of the readability of the informa-
tion displayed on the LCD), and discomfort glare (i.e., glare that produces
visual distraction).
Ambient illumination, comprised of general lighting and local (task) light-
ing, must be sufficiently bright, uniform, and free from both disability and
discomfort glare, or from flicker, to permit the use of your Toshiba Pocket
PC e830 without any noticeable visual impairment or eyestrain.
Always locate the LCD directly in front of you, at a com-
fortable viewing distance, always greater than 16 inches
both for persons with normal eyesight as well as for those
who wear corrective glasses or contact lenses.