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.That requires the electrongun to make 98 million pixel hits per second! That screen works at a very hectic pace which can sometimesresult in beam contamination.High refresh rateThe screen image appears more steady, the higher the refresh rate.You see the same in TV, wheretraditional sets have a refresh rate of only 50 Hz.Some manufacturers now produce TV sets with 100 HZrefresh rate.Some claim that they cannot notice the difference.However, once you have been used to 100MHZ refresh rate, it is uncomfortable to return to 50 HZ.Similarly with PC monitors, only here we have moreoptions.Older and inferior screens can only work at 60 HZ, which produces a low quality, flickering image which is notsuitable for Windows.The general consensus is that 70 HZ produces an acceptable image.I find 75 HZacceptable, but 80 or 85 HZ is better when you have to work many hours daily in front of the screen.Note: refresh rate is also called vertical frequency or vertical refresh rate, but I have chosen to use the termrefresh-rate.The higher the refresh rate, the better quality monitor you need.If you want both high resolution and highrefresh rate, you will need both a high quality monitor and a high quality video card.The bigger the screen,the more it must be able to produce.Screens can always run with higher refresh rates in lower resolutions.Here are three examples, showing howthe screen performance drops with resolution.Screen 800 x 600 1024 x 768 1280 x 1024 1600 x 1200Standard 15" 75 HZ 70 HZ 60 HZ -15" Trinitron 90 HZ 80 HZ 75 HZ -17" Trinitron 110 HZ 100 HZ 90 HZ 85 HZFor the screen to deliver images at the desired refresh rate, both screen and video card must be matched tofile:///E|/education/Click & Learn/module7a.htm (11 of 19) [4/15/1999 6:29:56 AM] An illustrated Guide to Monitors and the Video Systemthe correct specifications - the higher your demands are, the higher the cost will be.More about screensLet us take a closer look at the screens.If you read ads for monitors, you might see many hard to understandtechnical terms.They may mention many frequencies and dots and pitch?Note: In many ads, these terms (frequencies, etc.) can appear mixed and unclear.Therefore, be critical whenyou read monitor data.Trinitron or InvarWhen we talk about traditional screens, there are two primary types of tubes.The best use the so calledTrinitron tube.That is a technological principle, which was patented by the Sony company.Since the patenthas expired, there are now some clones (ChromaClear, SonicTron etc.).In the Trinitron screens, the light sensitive pixels on the inside of the tube are placed in a vertical grid, whiletraditional screens have round masks for the color dots.With the grid mask, you can achieve densercoverage and thus more color saturated images.Here is an attempt to illustrate the difference between thosemasks:file:///E|/education/Click & Learn/module7a.htm (12 of 19) [4/15/1999 6:29:57 AM] An illustrated Guide to Monitors and the Video SystemThe Trinitron screens are generally very high quality.Since the Trinitron tube is more expensive than thetraditional Invar tubes, manufacturers also include better control electronics in the Trinitron tubes.Thatincreases their price somewhat, but that money is well spent!The only disadvantage of the Trinitron (besides price) is the thin lines, which run across the screen.They arevisible wires, which contain a grid.In daily work, you will not notice them, but rather enjoy the pleasure of anextremely fine and sharp image.Invar for contrastThe traditional screen can provide more contrast than the Trinitron screens, which is important in sometechnical applications.But for ordinary use in home and offices, where you would typically choose 15" or17" screens the Trinitron screens are an obvious choice.Of course, they cost a little more than traditionaltypes, but there is a marked difference in the visible quality.You will experience a much better screen imagewith a Trinitron tube, no doubt about that!The horizontal scan frequencyThe most important factors are maximum resolution and refresh rate.The screen must be able to deliver animage in a suitable resolution (depending on screen size) and at a good refresh rate (75 HZ or more).Thescreen can display many different image types in various resolutions and refresh rates.The interestingpoint is the maximum refresh rate at different resolutions.These data are often reported together in a number, called the horizontal scan frequency.The number ismeasured in KHZ and it is very important [ Pobierz całość w formacie PDF ]