Dirty Screen Effect is a term and acronym that is often thrown around by TV reviewers and enthusiasts on A/V forums as if they all know what it is. And yet, very few people have ever heard of it before. But you may have seen it. In fact, if you recently bought a TV and it doesn’t look quite right, your TV may be suffering from the dirty screen effect, more commonly known as DSE.
In a way, Dirty Screen Effect is an apt term — and it’s one of those things you just can’t ignore. But it doesn’t quite look like it does sounds how it should look.
In this quick guide, we’ll cover what the dirty screen effect looks like, what’s happening on a technical level, and what, if anything, you can do to get rid of it. We’ll also touch on the concept of the so-called “panel lottery” and how it affects how clean – or dirty – your new TV screen can look.
What is the dirty screen effect?
Dirty Screen Effect (DSE) is a term used to describe an LCD panel that has inconsistent lighting performance across its surface. It can appear as random spots, uniform lines, wide bands and, in some cases, vignetting (a slight darkening towards the corners). DSE used to torment plasma TV panels as well. But since they are no longer manufactured, we will focus this explanation on LCD TVs.
As a reminder, any TV that uses an LED backlight also uses an LCD panel, so TVs sold as LED, QLED, and mini-LED are all sensitive. Because of what causes DSE on a technical level, some might argue that it only applies to LCD TVs. However, similar effects can be seen in OLED-based displays — hence the term is often applied — so we’ll include those types of TVs as well, but cover them separately.
What does the dirty screen effect look like?
While DSE can be seen in a variety of scenarios, you are most likely to see it when there are large patterns of the same color on the screen. Take, for example, an ice hockey game. Some areas of the ice will appear dirtier or darker than other areas of the ice. You could also see DSE more easily while watching golf; when large areas of grass are on the screen, some areas of the grass may appear darker or more muted in color than other areas.
Image used with permission of the copyright holder
Image used with permission of the copyright holder
Image used with permission of the copyright holder
The trick with DSE is that the problem is fixed on the screen, so as the image moves, you’ll notice that every part of the image that moves through those “dirty” areas gets a little darker. Therefore, the screen appears to be dirty.
Some DSE is strong, and some is so weak that you might not notice it unless you’re looking for it carefully. As a very clear example of what DSE looks like when exposed to test slides, we’ve included an example below.
What causes the dirty screen effect?
Image used with permission of the copyright holder
There are a number of factors derived from LCD panel manufacturing that can cause the dirty screen effect, from variation in backlight distribution to variation in TFT switching for sub-pixels, to variation in conductivity and/or capacitance of transparent electrodes. It’s super geeky though, and the actual cause is less important than the usual theme: inconsistency.
In panel manufacturing, there are numerous variables that can be introduced that would cause an LCD panel to have groups of pixels that glow less than others. This difference, unfortunately, is part of the technology that makes our TVs. And the way different manufacturers handle that variation is also … you guessed it: different.
Different levels of quality control by different manufacturers allow the passage of imperfect panels that are later used in consumer products.
The effect of a dirty screen can also be caused by damage to the panel during transport or by mishandling the TV during the setup or installation process. Generally speaking, it is recommended to avoid “pinching” or other pressure on the front of the TV screen.
How common is the dirty screen effect?
Image used with permission of the copyright holder
This is a difficult question to answer because I have no data to support an objective analysis of the prevalence of DSE in newly manufactured TVs. However, I can offer some anecdotal perspective based on my experience as a TV reviewer and the feedback I get from readers and viewers, as well as reports I see on A/V forums.
From what I’ve seen, DSE—ranging from negligible to strong—seems to be fairly common among newly manufactured LCD-based TVs, primarily due to the nature of LCD panel manufacturing. Generally speaking, the cheaper the TV, the more likely it is to show some level of DSE. More expensive TVs aren’t immune to the problem, but some manufacturers have tighter quality assurance tolerances for their high-end products so – again, very broadly speaking – DSE tends to be less prevalent among those models.
DSE as a symptom of old age is virtually impossible to track, however – again, anecdotally – I have witnessed DSE slowly creeping into the TV screen over time and getting worse with age. I’ve seen this happen on TVs I own, TVs owned by friends and family, and TVs installed in commercial environments like hotels and bars.
How can I test the dirty screen effect?
First, a warning: once you see DSE on your TV, it’s hard to “undo” it. So, if you’re happy with your TV’s performance and want to keep it that way, maybe you should subscribe to the “ignorance is bliss” theory and forego the following tests.
However, if you suspect that your new TV may have levels of DSE that you find unacceptable, you can use this YouTube video (also posted at the top of this article) to look for signs of DSE. In our video, we not only provide test slides to help detect DSE, but guide you on how to spot it.
How can I get rid of the dirty screen effect?
Unfortunately, there is no way to eliminate DSE. Some websites suggest loosening the screws on the back of the TV to reduce the load on the panel. We do not recommend this tactic as it may void your active warranty. Also, it is unlikely to succeed.
Indeed, the best way to get rid of DSE on a newly purchased TV is to catch it early and return or exchange the TV within the usual 30-day customer satisfaction period. It is rare for a manufacturer’s warranty to cover repair or replacement when the complaint relates to a defect that the said manufacturer has already deemed to be within an acceptable margin of error.
Image used with permission of the copyright holder
Most TVs offer a “game mode” which, because of its tendency to brighten everything on the screen, can help blur the DSE. But this is really just a Band-Aid. DSE is still there, but maybe less obvious. Another somewhat useful tip to reduce the appearance of DSE on LCD screens is to watch the TV from as direct an angle as possible. As you move off-axis (watching TV from an angle), DSE becomes more apparent.
In very limited cases, some cases of DSE on OLED TVs can be corrected by manually running the TV’s built-in “pixel refresh” system, usually found somewhere in the TV’s system menu.
What is a panel lottery?
The so-called “panel lottery” refers to a game that TV buyers unknowingly play when they buy a TV. Sometimes you “win the panel lottery”, which is a way of saying that the TV you got was in particularly pristine shape and has no signs of DSE. It is also a term used to simply express that there is such a difference in panel quality that it is almost impossible to win a perfect panel. In other words, everything is a matter of chance.
Categories: GAMING
Source: newstars.edu.vn