"incandescent" light and monitor solutions

[Guest]

Greetings all!

I have somehow peculiar question regarding monitor solutions:

Progressively, my eyes develloped resistance to all kind of monitors. Very quickly i'll get eye strain and even eye pain. This is most noticeable with CRT type monitors. Of course i bought LCD 21'' monitor; due to their supposedly eye friendly no flicker tech. I had some relief with lcd but still not enought.
As i was tought most LCDs use CCFL (that DO flicker and produce this unbalanced high blue-green mixture of white light).

My question is: since I am NOT bothered by an incandescent type of light (from regular light bulb) i was wondering if there exists any solutions that would use similar light (no flicker, stable and evenly distributed light spectre)? I still need to try LED backlight solutions (do the LEDS flicker?) and my other idea is to try projector as a possible solution. (what kind of light is used with projectors?)

If anyone has some constructive remarks on the subject i would appreciaite it alot. (and sorry for my bad english).

Best regards, Tom

 

[cjl]

LEDs do not flicker, and CCFLs, although they flicker, do so at a much faster speed than CRTs, which is probably why they helped. There are no incandescent backlit monitors though, so I would say LED is your best bet.

 

[jaguarskx]

Certain LCD monitors actually do flicker and I am not referring to the CCFL backlighting.

Many of the less expensive monitors use TN panel technology which cannot truly produce 16.7m colors. They actually produce 256k colors and thru dithering can create 16.2m - 16.7m (at least that what's listed in the specs).

Examples of cheap monitors using TN panels are all 22" monitors and smaller. Exceptions that I am aware of in the 20" range is the Dell 2007WFP (IPS or S- PVA panel). As for 22" monitors, the exceptions are Lenovo ThinkVision L220x and the HP LP2275W (both are S-PVA panels). In the 24" range of monitors, basically anything selling for less than $550 when not on sale uses TN panels.

There are two types of dithering methods:

Spatial Dithering - To create a color each single pixel cannot create on it's own, a "mesh" or checkerboard pattern of colors is used to estimate the desired colors. For example, let's say a pixel in a TN panel cannot create purple on it's own. The solution is to use two pxiels next to each other; one will be blue and the other will be red. From a distance it will look like the color purple is being displayed.

Temporal Dithering - This is a newer form of dithering and is sometimes referred to as FRC (Frame Rate Control). In this situation, purple is created by pixel actually flashing very, very quickly between blue and red. The flashing occurs so quickly that it seems to be solid purple to your brain.

Dithering is not required for monitors using S-PVA, P-MVA, and IPS panels since they can truly reproduce 16.7m colors.

LED monitors are relatively expensive since they are new. The less expensive monitors (meaning under $900) will likely use a TN panel. I know NEC will be releasing LED backlit monitors using an IPS panel, but it will cost in excess of $2,000.


A solution you may want to try is "Full Spectrum Florencent Lights". These light covers the entire spectrum of visible light to create white light. They are a little pricey though, at $20 - $25 per bulb. I use these bulbs to light up my livingroom.

 

[Guest]

many tnx for your answers; just a few things to make things clear:

you said that predominant tech is TN panel. as i understood there is double flicker in the game; the one caused by CCFL and the one by TN panel tech.

and that LEDs dont flicker (they'r better than CCFLs)- is this correct?

what about IPS or S- PVA and CCFL? do these panel techs eliminate the baclight flicker causd by CCFL or this is always a separate issue?

the ideal combination is then LED + IPS or S- PVA but these aren't even out yet?

 

[jaguarskx]

Apple is selling a 24" LCD monitor with LED backlighting for about $900.

http://www.engadget.com/2008/10/14/apple-finally-refreshes-cinema-displays/

There's currently a debate as to what type of panel it actually uses. You may want to go to an Apple store to look at it. I wouldn't bother asking the sales rep whether it is TN, PVA, MVA or IPS. They will have no idea.

 

[Guest]

hm, as i noticed there are monitors and laptops using led backlight. and back in 2005 nec introduced led backlight monitor on ips panel (SpectraView LCD2180 WideGamut LED) and samsung its own XL20 on A-MVA...

anyway; i'll go and check it out.


peace

 

[cjl]

IIRC, though, the new Apple displays only have a mini-displayport connector, which kind of sucks for connecting it to anything but a new macbook.

 

[neptikos]

There are no incandescent backlit monitors though

I stripped a regular CCFL LCD monitor, removed it's fluorescent bulbs, and left it transparent, with only 3 sheets for regulating light. Then I placed my desk lamp as to light from the back of the lcd panel, and voila: incandescent backlight monitor. It's not exactly even lighting, but it is still sufficient as to do Photoshop artwork. When it's sunny outside, I also like to use natural sun light. It's magical.

Alexandru Nechifor
t3ofil@yahoo.co.uk

 

[wassja]

Hi,

I think a projector wouldn't be the right choise because of the flicker and the expensive lamps that need to replaced after some time.

Having a similar problem I tried an LED LCD once, but it was about just as mean to my eyes as the CCFL LCD. I am not sure about wether all LED LCDs flicker or not. I know that under certain conditions they do flicker, like when backlight dimming is used. I remember lowering all of the menu settings in my LED, therefor I may have also dimmed the backlight while doing it. Perhaps the display would have been good for me if I had not done this, but my eyes were extremely sensitive to light at that time. At this point I doubt that LED LCDs do not flicker, but don't know for sure. If anyone knows more, please clarify this.

My display choise problem got solved when I rebuilt my CCFL LCD to work with incandescence, similar to nepticos. It is the best display in the world to me now and it would be hard for me to live without it 😍 . More on my site:

www.vasyafromukraine.webs.com

I atribute all of my health problems to flickering light, wether it's 60 Hz or 20 kHz. As long as it flickers, it is bad for the nervous system. It does not matter if we see the flicker, all that matters is that it is there and that our body uncounsciously notices it.

 

[neptikos]

Hi, Vasya! I'm really glad I found someone else dealing with this situation. I've been telling all the people I know about how the fluorescent light affects the nervous system, and I received little understanding or support, although generally, they all agree that it's not so good for the eyes. I'm Neptikos, the one who submitted the previous comment. I also placed an incandescent light behind the lcd layer on the assumption that incandescent never gave me problems in reading or any other activity. I've read your web page about LCDs, and agree to your assumptions and observations. The "interesting quotes" was especially useful, because it gives me more sources for documentation on the subject.

I want to tell you what I've read and my conclusions until now regarding this subject. I don't know if I should do it here or privately, by mail. Having this conversation here could let other people find it, with other pieces of information in this rather scientific dilemma. Or maybe we should start a blog together, and investigate in an organized, scientific way. I was even thinking of making a documentary about this, with scientific experiments, like testing people with an electroencephalogram machine in a specialized environment. I'll explain later why EEG would be needed.

I think I'll tell you here. So, from my reading, I found out that the brain emits electrical signals, which are of different types, according to the type of activity in which the brain is involved. It seems that there are two main types of activities: abstract thinking (linear reasoning and language functions) and emotional processing (perception but not cognitive analysis of physical stimuli). The first type is indicated by beta waves (between 14 and 30 Hz) and the second by alpha waves (7,6-13,9 Hz). Authours like Jerry Mander, Valdemar Setzer, Fred and Merrelyn Emery, Marshall McLuhan have written about scientifically proven shift to alpha waves in TV viewers during EEG measures. Although TV has lower flicker rate then LCDs today, I relate the two because the state that they provoke to the brain is very similar. They both provoke loss of concentration. The best way to prove this is in trying to read a serious book from the LCD. Everyone I know says that they are not able to read to much.

The thing that happens is that the flickering (pulsating) light physically puts the brain in an alpha wave state, making it really difficult for it to shift between the two, according to the activity required. The nervous system gets really tired trying, and eventually either gives up or it gets exhausted, requiring urgent rest. The eye problem is separated from the brain problem, and while Wikipedia and major visible sources do recognize the fluorescent light problem of LCDs, they only talk about the eye part of the problem.

I found scientific articles about the brain part of the problem, but I couldn't access them because they were in payed scientific libraries.
Here is a short list:

1.Measurement Of Work Load Using Brain Potentials During VDT Tasks
Akihiro Yagia and Mika Ogata, Department of Psychology, Kwansei Gakuin University, Nishinomiya, Hyogo, 662, Japan
Brain Topogr. 1990 Summer;2(4):257-67.

2. Brain Topogr. 1990 Summer;2(4):257-67.
Topographic EEG study of visual display terminal (VDT) performance with special reference to frontal midline theta waves.
Yamamoto S., Matsuoka S., Department of Management Science, Dokkyo University, Saitama, Japan.

3. International Archives of Occupational and Environmental Health, Volume 63, Number 2, 109-113, DOI: 10.1007/BF00379073
Central nervous system effects and visual fatigue in VDT workers
Katsuyuki Murata, Shunichi Araki, Norito Kawakami, Yuko Saito and Eiko Hino

From the summaries I assumed that they were in favour with my opinion expressed above.
I am willing to go further with my research.

 

[buwish]

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