IPS Glow - Why?

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Maybe it's because monitors use a different tech to what you find in a TV, but why are many TVs advertised as IPS, yet they don't come with the same kind of issues that you find on your average PC IPS monitor?

I've tested several IPS monitors that have all had issues of one sort or another, specifically glow and BLB. On the other hand, I've got a cheap (for its size) LG 70" TV hanging from my wall with no visible imperfections in the screen and certainly no sign of glow.

Is the tech different or is it down to something else?
 
I've long suspected it's due to PC users getting the crappy leftovers from failed TVs because the manufacturers don't get as much profit from us.

I would buy an OLED TV today to use as a monitor if they offered one at a reasonable size for my desk.
 
There's indeed fix for IPS glow.
Use of different type polarizer would prevent black value rising when viewed from "half cardinal point" angles.
http://nec2490.blogspot.com/
https://youtu.be/PM4H6xZeq9w?t=1m13s

But instead of A-TW IPS pnael being that standard for all decent monitors, that hasn't been used in monitors in long time.
I mean why make good products when you can leech money for Twisted Nematics garbage etc.
 
Glow is inherent to the tech, its a result of the manufacturing process. Called LC pre-tilt angle.

Structure of liquid crystals, viewed from a different angle you see a different part of the Liquid crystal which alters what you see.

Viewing angle effect which causes distortion.

Cause is manufacture and the issues of accurately aligning one material placed on top of another.

Physics/ math issue, it needs to pinpoint the unknown event that causes this dynamic between two surfaces.
 
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efish said:
Glow is inherent to the tech, its a result of the manufacturing process. Called LC pre-tilt angle.
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The point I was mostly trying to make is that my TV is IPS and displays none of these characteristics - also its blacks are much deeper and this isn't an expensive model. When I go into a shop selling TVs, I see no IPS glow on any of them. What's so good about TVs that they don't have awful uniformity and half of the screen looking like someone's shining a torch on it?
 
Different priorities between TV and Monitors basically. A lot of TV panels are actually VA since it offers better contrast (i.e. Deeper blacks) than IPS. Also, there currently isn't a large demand for TVs to be 100Hz+ so they don't have to worry about ghosting issues. A lot of TV panels are also gloss finish versus (semi) matt on monitors. The gloss finish can hide a lot of issues due to the image typically being more vibrant.

All of this plays into cost. With a cost and ultimate price target the manufacturer has to play with priorities. Just look at all the people that complain that a "slighter" better panel costs so much more.
 
mulpsmebeauty said:
The point I was mostly trying to make is that my TV is IPS and displays none of these characteristics - also its blacks are much deeper and this isn't an expensive model. When I go into a shop selling TVs, I see no IPS glow on any of them. What's so good about TVs that they don't have awful uniformity and half of the screen looking like someone's shining a torch on it?
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Can rule out panel production as the cause. Was the point.

My I.P.S t.v. has some glow, I view it from a distance so its not perceptible. Contrast and blacks are better, I presume that down to processing but that is a guess.

Uniformity of the 144 h.z I.P.S panels does seem particularly poor. Never had an issue with a 60 h.z I.P.S panel generally go with Dell and the ultra sharp series here bought a few for both myself and friends and relatives (one today for my dad). Never had a major issue here at least with Dell so far. Not the cheapest option but q.c so far has been ggood and warranty is excellent.

I went with t.n for 144 h.z as just did not want to run the lottery here, particularly given the price.

No idea why 144 h.z I.P.S monitors are so bad but they do seem to have an issue here.
 
I don't work in the field, so I'm just conveying what I've picked up over time.

A monitor panel is built from a number of layers (polarizing filters, glass substrates, LCD layer, quantum dot layer, etc). Ideally, the pixel structures on each layer are perfectly aligned with the pixel structures on the layers above and blow it. Production tolerances make this impossible to achieve in practice however. After bonding, there will always be a few microns difference in pixel positioning between layers. Maintaining good alignment becomes increasingly difficult as panel sizes increase and/or curvature radii decrease.

The effect of imperfect pixel alignment is compounded by pixel density. Monitor panels typically have higher pixel densities than TV panels, meaning the pixels and the space between them are smaller. If the space between two adjacent pixels is 10 microns, then a misalignment of 1 micron between two pixel layers represents an error of 10%. If the space between two adjacent pixels is 100 microns, then a misalignment of 1 micron represents an error of only 1%.

A higher relative error leads to more pixel cross-talk and/or imperfect blocking of light. I suspect that is at least part of the difference you are observing between television and monitor panels.

All panels suffer from this, but it's particularly pronounced for IPS panels where the light emitted by each pixel is comparatively diffuse to begin with. The combined effect is what we call IPS glow. Even when it's not directly visible, it still contributes to overall lower contrast compared to other panel technologies. The upside is improved viewing angles.
 
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a5cent said:
I don't work in the field, so I'm just conveying what I've picked up over time.

A monitor panel is built from a number of layers (polarizing filters, glass substrates, LCD layer, quantum dot layer, etc). Ideally, the pixel structures on each layer are perfectly aligned with the pixel structures on the layers above and blow it. Production tolerances make this impossible to achieve in practice however. After bonding, there will always be a few microns difference in pixel positioning between layers. Maintaining good alignment becomes increasingly difficult as panel sizes increase and/or curvature radii decrease.

The effect of imperfect pixel alignment is compounded by pixel density. Monitor panels typically have higher pixel densities than TV panels, meaning the pixels and the space between them are smaller. If the space between two adjacent pixels is 10 microns, then a misalignment of 1 micron between two pixel layers represents an error of 10%. If the space between two adjacent pixels is 100 microns, then a misalignment of 1 micron represents an error of only 1%.

A higher relative error leads to more pixel cross-talk and/or imperfect blocking of light. I suspect that is at least part of the difference you are observing between television and monitor panels.

All panels suffer from this, but it's particularly pronounced for IPS panels where the light emitted by each pixel is comparatively diffuse to begin with. The combined effect is what we call IPS glow. Even when it's not directly visible, it still contributes to overall lower contrast compared to other panel technologies. The upside is improved viewing angles.
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Or as I prefer to say: "Bugger, I got a crap screen".
 
mulpsmebeauty said:
This seems like a logical explanation, so thanks for taking the time to write it. I'm still sure that these problems could (and should) be overcome, given the price of the product.
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Given the price of the product, yeah, one would think so. Unfortunately, these issues are inherent to TFT technology itself, meaning they can't be overcome simply by throwing more money at the problem.

The only solution is to build monitors using different/better display technologies. As @AStaley mentioned, OLED is one such technology. Micro LED technology is another option. Both are emissive rather than transmissive like TFT.

Personally I don't think OLED will ever become mainstream for monitors, but would gladly be proven wrong.
 
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