Flat Front Panels on eBook Readers: Advantages, Drawbacks, and Market Trends

In smartphones and tablets, a flat front panel has become the standard, but this wasn’t always the case. Before the iPhone, virtually no smartphone had a flush touchscreen; it was only after the first Apple mobile phone that things gradually began to change. This was sensible, mind you, because especially back then, when screens and display elements were still smaller and user-friendly interfaces were in their infancy, you often had to accept usability obstacles at the edges of the display, which could generally be eliminated with a flat design.

Even in eBook readers, this design is becoming increasingly common. The Kobo Aura was the first mainstream eReader to have a flat front panel, followed by several other devices, with Tolino Vision 1 & 2 and the Kindle Voyage being the most prominent examples apart from the Kobo device.

Indeed, the flat front panel is very popular among customers and product testers alike. A flat display design is often perceived as modern, and new releases that do without such a design are sometimes criticized for it. This was the case, for example, with the recently introduced Kobo Glo HD.

Possible Shadowing at the Edges

This is not without reason, because aside from the (subjectively) more attractive look, a flat front panel offers tangible advantages in certain lighting situations and usability. Especially when using the swipe gesture to turn pages, the flat design is more comfortable since you don’t have to run your fingers over recesses or edges.

However, the biggest criticism of the traditional recessed screen design must be the shadow formation at the edges. When an external light source shines at an angle on the display, the raised edges cause shadows to form on the display surface. This is, of course, not particularly pleasant to look at and can be quite disturbing depending on the user’s sensitivity.

The following image shows a typical infrared touchscreen recessed in the housing (on the Kobo Glo HD). Here, the shadows in unfavorable lighting conditions can sometimes be several millimeters wide (see red arrows). This applies not only to devices with infrared technology but also to those with a capacitive touchscreen that does not extend over the entire front side (e.g., Kindle Paperwhite or Pocketbook Touch Lux 3). Similar shadowing is also present in these devices if the lighting conditions are unfavorable.

Since the screen sits lower than the frame (in the image Kobo Glo HD), shadows can form (marked by the red arrows).

In contrast, if you take a look at a device with a flat front (here: Tolino Vision 2), things look quite different. Shadow formation is much smaller due to the minimal distance between the E-Ink display and the touchscreen or housing, which reduces potential irritation.

A flat front panel (pictured: Tolino Vision 2) minimizes shadowing because the screen sits higher up (marked by the red arrows).

To be fair, one must say that this disadvantage becomes significantly less relevant with the advent of built-in front lighting. Many users are likely to use the integrated light even during the day, which can prevent or at least minimize the scenario depicted above. The two following images illustrate the difference.

You can still see a narrow shadowy strip on the display edge of the Kobo Glo HD, but it is far less noticeable thanks to the activated lighting than before. On the flat Tolino Vision 2, the shadow almost completely disappears even with a similar brightness setting.

With activated lighting, the shadow becomes less conspicuous …

… or even almost invisible

Personally, I wouldn’t place too much weight on potential shadow formation (as it’s a matter of positioning relative to the external light source) when deciding on a purchase. This disadvantage can often be minimized with the built-in lighting.

The Particularities of Infrared Technology

A special case of the non-flat design involves devices with an infrared touchscreen, where there are additional potential pros and cons. One possible disadvantage is the higher susceptibility to dirt on the touchscreen.

The sensors sitting in the frame, which register the user’s touches, can be disturbed by dust accumulations at the edges. The result can be a lack of or sluggish responsiveness or incorrect inputs. However, this problem can usually be resolved easily with a quick wipe from a cloth.

Capacitive touchscreens react only to changes in surface tension and are therefore (relatively) insensitive to such problems.

A particular advantage of an infrared touchscreen, on the other hand, is the lack of a plastic coating. While capacitive technology necessarily requires a carrier film, this is not the case with an infrared touchscreen. As previously mentioned, the sensors are invisibly embedded in the device frame. This ensures that display performance is interference-free. Under a microscope, the difference is especially apparent with small display elements.

The following enlargement of the Kindle Voyage shows a slight blur, despite the same microscope focus, which arises because there are two plastic layers (the light guide film and the touchscreen) above the E-Ink display. The scattering is particularly noticeable at the edges of letters and the graininess of the background.

Kindle Voyage under the microscope

In contrast, things look a bit sharper on the Kobo Glo HD with infrared technology. The light guide film still causes some scattering, but the effect is less pronounced due to the absence of the touchscreen layer.

Kobo Glo HD under the microscope

But it’s also worth mentioning that the difference is hardly noticeable to the naked eye at normal reading distance and is more relevant for people unwilling to accept any compromises in display quality, no matter how minor they may be.

Scratch Sensitivity with a Flat Front Panel

The biggest drawback of the flat front, in my opinion, is the seemingly frequent use of relatively soft material. Unlike smartphones and tablets, they don’t use particularly scratch-resistant Gorilla Glass, but various other unnamed (plastic) materials. It’s often unclear whether any specific scratch resistance is present at all.

Only with the Kindle Voyage is it explicitly stated that a “chemically hardened glass panel” is used. All other manufacturers, to my knowledge, do not mention it. This is relevant because with the flat front, the friction contact with a case or pocket, backpack, etc., is potentially higher. Even small specks of dust can cause fine scratches.

With an eReader that has a recessed display, the risk of such micro-scratches is significantly lower as the flap of the device cover or other items in the backpack or pocket typically don’t rest directly on the screen surface.

Indeed, with my first-generation Tolino Vision, this exact problem occurred; after several months of handling, fine scratches had formed on the display surface. The following photo shows these micro-scratches in the light (with some marked by red arrows).

After several months of use, tiny scratches have formed on the display of my Tolino Vision 1.

Unfortunately, I can’t reconstruct exactly how the scratches occurred. To be fair, I should mention that I’m not particularly gentle with many of my purchased eReaders. The devices aren’t thrown around, but it often happens that items (notebooks, newspapers/magazines, and other eReaders) are simply placed on top.

That the scratches on my Vision 1 are not an isolated case is shown by a test from colleagues at Computerbase. Their Kobo Aura test device already showed signs of wear upon receipt, as mentioned in the text: “Unfortunately, this applies to the entire plastic panel, which is very sensitive – our test device already showed significant scratches.”

Indeed, the scratches on the Vision 1 are so fine that you can see them only at certain angles, but this does not mean they can’t be annoying during reading due to subtle sparkling.

Conclusion

Both designs have their pros and cons: while the flat front panel generally gives the eReader a modern look, it also increases the risk of scratches on the screen surface for many models. Aside from the Amazon Kindle Voyage, no other manufacturers explicitly mention surface scratch resistance.

The main advantage of the flat front is the significantly reduced shadowing in unfavorable external lighting conditions (see images), which can be relatively well managed in devices with recessed displays by using the built-in lighting. Compared to infrared technology, you also have to accept slight blurring with capacitive touchscreens (with flat fronts, only this technology is used).

From a practical standpoint, both design styles don’t differ all that much overall in my opinion, meaning the characteristics, aside from aesthetics, are more a matter of personal preference. The only important thing is that you’re aware of this before you make a purchase.

What do you think? Is a flat front a must for current eBook readers, or do you prefer a recessed display (with infrared technology)? Let us know in the comments!