Computer desk

The monitor workplace is a common name for a job in the electronic data processing (EDP). Understood as an IT term, it is a combination of devices with which the so-called " man-machine interface " is implemented, and consists of a screen, input devices such as keyboard and pointing device and the software controlling these devices. In the wider context of work physiology and the organization are also home to the office chair, a desk, other optional storage options and other devices, such as the phone for the video workstation.

Computer workstations are available in all offices and areas of government.

Legislation

Employees who usually use as a significant part of their normal work, a visual display unit, are protected by the EC Council Directive 90/270/EEC of 29 May 1990 on the minimum requirements regarding the safety and health requirements for work with display screen equipment. In Germany, several EC directives including the EU Directive 90/270/EEC, lays down 19 Occupational Safety and Health Act by the Federal Government Regulation on Safety and Health at Work with display screen equipment ( BildscharbV ) of 4 December 1996 pursuant to the authorization according to §.

In Greece, a scheme was introduced in 1989, after which officials who sit more than five hours per day on a computer, every two months, a day's special leave ( ie six days per year) are entitled to. Minister Kyriakos Mitsotakis declared in September 2013, the scheme from being abolished.

Technical Development

The rapid development in the field of Information Technology is particularly evident at VDU workplaces: Until the introduction of personal computers ( PC) were mentioned as a video workstation only special, ' Terminal' devices are used. After that, the PCs took over using an emulation software whose function. Running on remote workstations application software can communicate with the users directly over the existing in the computer operating system interfaces. Internet applications use Web browsers for handling the user interface.

Optical- Visual factors

Vote ergonomically relevant factors require consideration optical- visual aspects, so that compatibility with the various power functions is (adaptation, accommodation and fixation, visual acuity, depth perception and time).

Arise in reverse video ( light characters on a dark background ) Stochastic and stressful adaptation processes of the eye, when switching between screen and printed information. Therefore, the positive representation is to be preferred ( dark characters on a light background ).

Bright workstations (apart from dark areas ) in terms of glare cheaper, as are reflected reflections or stray light on a light background less. Lack of sharpness in the characters lateral visual field leads to headaches, as well as watery and burning eyes. The frame rate should be higher than the flicker fusion frequency (~ 50 Hz).

The term rigid view or Office Eye Syndrome concentrated fixing the screen display and content is understood in the computer work. "Forgets" By fixing the screen, the eye almost to the blinking ( the blink unconsciously suppressed ). Regular Lidschag is of essential importance for the development of the tear film, for each blink in the protective lipid layer of the tear film is stabilized and applied again on the tear film. The lipid layer prevents evaporation or the expiration of the tear film of the eye and thus prevents the formation of dry eye ( keratoconjunctivitis sicca).

Device setting

With respect to the reflection glare matte surfaces are advantageous. Lateral daylight in the room serves to avoid glare and contrast reduction. With color screens with a maximum of 5 foreground colors should be avoided of borderline spectral like red and blue, as the eye is here the least sensitive and these colors can be seen clearly not the same, so that the accommodation is also required ( Akkomodationsdifferenzen due to chromatic aberration).

Lighting and distance

An absolute value for a good lighting can not be specified. When designing good lighting conditions following consideration should be given:

• Adequate illuminance
• Uniformity of illumination (harmonic luminance distribution )
• Limiting glare
• Contrast
• Light direction
• Shadow
• Light color
• Color rendering
• Interference

Of great importance for the assessment of lighting has the illuminance ( illuminance E = Luminous flux / area). The illumination should be higher, the more difficult the visual task. To play contrasts correctly, a very uniform illumination must prevail in the work area. In DIN 5035 required for certain visual tasks nominal illuminance levels are fixed. The nominal illuminance is defined as the recommended spatial and temporal average of the illuminance and refers to the average age of the lighting system.

For general lighting purposes, the light direction should be parallel to the viewing direction. The interior lighting with daylight occurs through windows. These are in addition to the lighting nor the important task of creating a visual connection between the workplace and the outside world. Because daylight is subject to large diurnal and seasonal variations, has introduced the so-called daylight factors for the assessment of daylight. The daylight falls, particularly in deep rooms for room depth steeply.

For the artificial lighting often on so-called screen - workplace lighting (BAP - Lights ) is resorted to. These lights have a glare rating ( UGR ) have ≤ 19 in order to be officially recognized as BAP light.

The spatial arrangement is to ensure the maximum relief of Akkomodationsapparates. The recommended distance of the screen would therefore be about 50 cm, in people aged 50 years approximately 70 - 80 cm. The spacing of the keyboard to the table edge should be half a cubit, ideally so that the heel of the hand can rest comfortably.

Flickering light sources ( also above the limit of the flicker fusion frequency ) lead to demonstrably quicker eye fatigue. So far, little attention is the fact that the combination of flickering lighting sources such as fluorescent lamps may, together with the use of flickering CRT screens to eye discomfort. Probably reinforced the superposition of different Flimmerfrequenzen eye fatigue.

It should be noted that not only CRT screens but also fluorescent lamps flicker with conventional ballasts, which also leads to faster fatigue. By using electronic ballasts can avoid this.