Positive Polarity for Computer Screens

What else? For computer users of today screens with a bright background looking like a piece of paper is something very natural. Or has anybody ever tried to read the print on used carbon paper? At the beginning, manufacturer were happy with monitors displaying green characters on dirty gray background. When we first discussed the issue of positive polarity, all computer manufacturers of the world unanimously stated that this was unnecessary because readability did not differ in either polarity. And introducing bright backgrounds would cause very high costs that would lead to a decline of computer technology! They have continued submitting expert reports, conference papers et al. until the middle of the 1990s claiming that negative polarity had many virtues. Interestingly, in the middle of 1980s a number of research reports from IBM ergonomic laboratories had been published validating what had been written a decade ago.

The importance of the positive polarity for computer monitors was demonstrated by Dr. Çakir in the year 1976 with the following rationale:

• A bright background improves the performance of the human eye.
• Reflections on the screen, almost unavoidable in normal environments cause less impairments for vision and well-being if the background is bright.
• People like to work in bright environments. Work equipment should not be much darker than the environment.
• Monitors should offer the optical quality of good print.

Unfortunately, during those times, monitors of the required quality did exist in theory or in laboratories. The monitor technology became somewhat mature in 1983, still flickering. The first computers employing monitors with bright background emerged in 1981 (Xerox Star) and 1984 (Apple Macintosh), with more or less flickering images, though. The major breakthrough came with Windows 3.1 in the year 1991. Monitors with a crisp sharp and flicker free image have become everyday products in the 21st century. For the emergence of computer monitor resembling the optical quality of good print for everyone, we need to wait some more years. For the happy few, 4K-monitors seem to offer a visual quality like print, but on a much bigger area.

This important achievement people owe German health and safety organizations (Berufsgenossenschaften) who have introduced safety rules in 1980 requiring positive polarity for all workers, well knowing that during this year not a single product would pass the test. The secret of the success was the introduction of a lengthy transition period of five years and tolerating some deviations from the rules under the condition that the product offers some benefits for the users.
back to: Goals achieved