Build Your Own Arcade Controls Forum
Main => Monitor/Video Forum => Topic started by: clutch on May 02, 2011, 11:03:16 pm
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Question for the monitor experts. Cabinet is a Sega Blast City. Got weird resolution thing going on on each side of the monitor. Like a semi-circle of loose and large bricks (pixels) that get tighter and smaller as you go toward the center of the screen. The speakers are on the right and left of the screen as well. Could this be the cause? They are supposed to be shielded.
Screen with uniform, dark red color:
(http://www.heycomputer.com/monitorweird.jpg)
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beam scans left to right top to bottom.
in order for the beam to hit a pixel on the far left or right sides, the beam has to be deflected. sometimes a little (as in normal "round" tubes), sometimes allot. (as in shallow and flat tubes.)
in order to isolate the pixel, the electrons have to pass through an aperture grille or a shadow mask just before it hits the phosphors.
(http://rays-place.dyndns.org:1080/Extras/PCTechGuide/images/06mask.gif) (http://h20000.www2.hp.com/bc/docs/support/SupportDocument/c00014008/c00014010.gif)
this image shows the guns and pixels in a triangle shape...just align them in a straight line "BGR" so the pixels end up RGB. kthx.
now imagine the beam having to hit the phosphors at an extreme angle on the sides... the electrons have to make some pretty knarly turns (90 to 110+ degrees in some cases) in order to be able to hit them without hitting any adjoining pixels. to do this... the phosphor dots and the open sections of the aperture grille are spread a little farther apart. in the middle it's no big deal... the beam goes straight on, no problems.
(http://1.bp.blogspot.com/-MjsSs_a6Ntk/TW1Y6OipSWI/AAAAAAAAGcg/3QlGwtom03Y/s1600/6897.jpg)
pixels don't move. only the electrons streaming out of the color guns are susceptible to magnetic fields. which is why the color changes when you get a magnet close to the screen... the electron beams are being moved to hit the wrong phosphor dots.
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Very cool. Whoever invented this stuff must have been an alien. lol! So you are saying this normal for monitors.
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Very cool. Whoever invented this stuff must have been an alien. lol! So you are saying this normal for monitors.
nothing to be worried about.
it's less pronounced in some monitors, as they have more sophisticated beam control and purity. others are just banged together to get them out the door because they need a half a million of them, so they fast track the design/engineering...use the bare minimum of components and gizmos and head straight to production.
just incase you are wondering, there isn't red green and blue light emitted from the guns or anything, they are 3 identical guns and emit identical streams of of energy. the red green and blue you see are tiny bits of red green and blue phosphors printed on the inside of the glass in the RGB pattern. the electron guns are aligned to strike the proper color
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Thanks. Very informative! I can't even take a pic of the entire screen because you wouldn't be able to see the full effect in a photo.
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off topic but...
Thanks. Very informative! I can't even take a pic of the entire screen because you wouldn't be able to see the full effect in a photo.
no problems...if you have high megapixel camera... like12MP, you can take a photo and view it up close on the computer since the pic would be somewhere around 4290 x 2800. but it's large size makes it hard to work with on the web with monitors :dunno. I've taken some photos of some stuff this winter while at Disneyworld from 100+ feet away, and can zoom/crop and have it look like i did it standing right there on top of it, and it still looks sharp as ever... love technology!