The Face Of Your Laptop
By Sri Peruvemba, CEO, Marketer International Inc.
Laptops have always been a big part of our working life, in the past year they have become even more so. We used our laptops for the most part, at our desk, sometimes during meetings but rarely did they accompany us all through the day, all of this changed recently, our habits changed and adapted to a new normal. Today, we start the day in front of our laptop screen, we not only compute, compose, read, we use our laptops as a gateway, it’s our virtual office, its our conference room, its our way to social outings, its our new entertainment center, our children and our grandparents are in front of a screen today, more than ever before. Most of us today, spend more time staring at a laptop screen than anything else.
Laptops, and notebooks have come a long way and today’s laptop displays are increasingly complex I/O devices with a staggering array of options. Choosing the right display can increase your productivity, prevent health-related problems of extended viewing, and raise your overall satisfaction in working and playing on your laptop or tablet.
Resolution: It’s all about Pixels
One of the first choices users consider when choosing a display for their needs is resolution, which is the number of pixels on a display or screen. Here’s a breakdown of the various displays resolutions currently available:
HD—The original HD TVs used this resolution, which is 1280 x 720 pixels. Your basic 5-inch phone with a 720p display has roughly one million pixels.
Full HD—These displays employ roughly two million pixels or 1,920 x 1,080 pixels and are often called just 1080p. Many of today’s TVs and smartphones are Full HD.
QHD—At quadruple the standard HD resolution, QHD uses 2,560 x 1,440 pixels and called 1440p. QHD is essentially a 1080p display but with a significantly wider aspect ratio (16:9).
UHD—Delivering higher resolutions (more pixels), UHD offers 4K (3,840 x 2,160 pixels) resolution. It’s no surprise that UHD delivers a higher-quality, higher-resolution image than Full HD.
Aspect Ratio: Going Wide
Aspect Ratio in a display describes the correlation between the Width (X) and Height (Y) of the display. Older movies and TV had a box like format 4:3; the format is still in use. Today, your options for watching anything on a display vary greatly, thanks to changes in aspect ratio, which is the ratio between the width and height of the screen. Check out these aspect ratios available with your laptop:
- 16:9 aspect ratio: probably the most popular
- 16:10 aspect ratio: the newer laptops have them
- 4:3 aspect ratio: this would be older laptops
The newest aspect ratio—16:10–provides an extra 5% more room on top for a toolbar or some menu, which makes a big difference to some users. Most laptops use 16:9 widescreen, which is also used for most monitors and TV. The 16:9 aspect ratio is versatile as it readily displays both 4:3 content.
Anti-Reflective and Anti-Glare: Easy on the Eyes
If you spend hours working or gaming on your laptop, screen glare can give you a major headache. Your eyes inadvertently jump from the screen to the light or image being reflected from behind you. Worse yet, that glare from the light source can be brighter than what is on your display and you can’t see your content. It’s gotten so bad that many businesses have opted to use matte screens to save their employees from hours of eyestrain. But matte screens are not ideal for watching or editing movies or doing graphics work.
The terms anti-reflective and anti-glare have created a lot of confusion in the display industry. Both technologies can improve the readability of images and characters. Better readability allows users to clearly, quickly, and comfortably view written material with minimal eyestrain. But anti-glare and anti-reflective displays employ different techniques to achieve the intended result.
Anti-Reflective (AR) coatings prevent reflections by suppressing visible light. Several varieties of AR coatings are available. Film coatings of varying thicknesses are applied to the display surface. This reduces reflections by canceling out specific light wavelengths. Users won’t see their reflection on the screen but rather, a brighter and clearer display. Anti-reflective coatings are available on glass, and plastic substrates.
Anti-glare addresses the externalsources of reflection–sunlight or bright ambient light. Here, diffusion is usedto break up the reflected light by reducing the coherence of the reflected image. The distracting images appear unfocused and thus reduce their interference with the information being displayed. The downside of some anti-glare coatings is that they also reduce image brightness and color.
Viewing Angle: Seeing More Off Center
The viewing angle technology used in today’s displays can be boiled down to In-Plane Switching (IPS), Twisted Nematic (TN), or Vertical Alignment (VA)—with IPS being far superior to the latter two methods. Gamers, graphic designers, and office workers all have different usage requirements and preferences.
IPS monitors utilize parallel-aligned liquid crystals to produce rich colors. The liquid crystal’s ability to shift horizontally makes for better, wider viewing angles. The expansive viewing angles deliver superior color accuracy without ‘color shift’ when viewed from different angles. IPS monitors also support professional color space technologies—such as Adobe RGB—because they offer more displayable colors. FFS (Fringe Field Switching) technology, which is incorrectly labeled as a form of IPS, is vastly superior and quite popular in most LCD products.
The oldest LCD technology, TN uses the twisted nematic effect, which changes the alignment of liquid crystals when a voltage is applied. Not the best choice for wider viewing angles, higher contrast ratios, or better color accuracy, TN monitors suffer from color shifting when viewed at an angle. TN panels are faster, with color distortion and contrast shifting at the screen’s edges. The drop in color performance becomes even more apparent with bigger screen sizes, even when viewing from slightly off-center.
VA (Vertical Alignment) LCD technologies and SVA (Super vertical alignment) panels provide better viewing angles when viewed from the side, above, below, or in sunny or bright environments. They provide better viewing angle performance by laying its liquid crystals in varying directions, allowing viewers to see the same color at wide angles.
Contrast Ratio: Almost Limitless Now
In a nutshell, the contrast ratio defines how well a display can show bright and nuanced dark images. Listed as a numeric ratio—like 1000:1—it compares the brightest pixel to the darkest. In making this comparison, peak brightness is typically expressed in candela per square meter (cd/m2), or nits; black levels are expressed by the amount of light emitted from the darkest areas of an image, ideally zero.
Unfortunately, the contrast ratio perceived by the user is often not what the spec says. This is because measurement methods and other variables, like ambient lighting, screen reflectivity, and viewing angles come into the picture. For emissive displays like LCD (with emissive backlight), OLED and LED, the contrast ratio is usually measured in a dark room whereas that measurement does not work for reflective displays which are invisible in a dark room but shine in bright light.
OLED and LED (Mini and MicroLED) offer contrast ratios that are an order of magnitude better than the best LCD but LCD is still the workhorse of the laptop industry due to other features described in this article.
Brightness: We like bright, shiny objects
Measured in candela/meter squared (cd/m2) and also referred to as nits, a display’s brightness is its perceived luminance. One candela is equal to the brightness measured from a single candle. Most laptops have less than 500 cd/m2, which is quite bright for indoors. A 500 nit laptop has the light power of 500 candles lighting a square meter of space.
Brightness is a result of the backlight performance in a LCD; whereas in a MicroLED or OLED display it’s the brightness derived from light emitting pixels (think phosphorescence). Higher brightness display can combat high ambient lighting and even attempt to beat the sun, but it comes at a cost of high power draw, which is a problem for laptops where users want the battery to last forever.
Color Gamut: Richer Palette
Defined as the range of colors a display can depict, the color gamut is usually shown by the area constructed using the three primary colors—red, green, and blue—in the form of a triangle. A display’s color is defined by luminance, hue (color wavelength perceived by the eye), and saturation. The popular color gamut standards are:
- sRGB. The older common standard, sRGB displays conform to a smaller color gamut.
- Adobe RGB. Offering a broader color gamut, Adobe RBG depicts colors more realistically. Used in professional monitors and televisions.
- DCI-P3. Introduced bythe Society of Motion Pictures and Television Engineers (SMPTE), DCI-P3 (Digital Cinema Initiatives-P3) produces a color gamut that’s almost 25% wider than its sRGB counterpart.
- NTSC. Created by the National Television Standards Committee, the NTSC standard differs slightly in its production of red and blue colors. NTSC is used primarily in professional-level video and photographic editing.
- Rec. 2020. The designated color space for ultra-high-definition TV (UHDTV) in both 4K and 8K, Rec. 2020 represents the full range of specifications under UHDTV. Ultimately designed for television, Rec. 2020 reproduces colors found in nature—colors that even Adobe RGB and DCI-P3 do not fully cover. It may be a bit of overkill since a 90% gamut may be more than enough for most apps. Besides, people perceive colors differently. What may appear great to one person may not please another.
Response Time: The Need for Speed
Usually expressed in milliseconds, response time is how long it takes a display’s pixel to turn from ON to OFF back to ON. When a pixel is turned ON, an electrical signal is converted to light and this light rises in luminance until it’s fully ON. Similarly, when the pixel is switched off, it takes time to go from ON to completely OFF. A typical LCD response time is in milliseconds; the older laptop has few tens of milliseconds response whereas the newer ones are less than ten milliseconds. Lower response times cut down on image problems like blurring or ‘ghosting.’ For most office applications, response times aren’t that critical. For gamers, on the other hand, every millisecond counts and they can tell. Twisted Nematic (TN) displays have the fastest response times but generally have a poorer color gamut.
Response time of the LCD is not to be confused with the refresh rate. Response time is based on the LCD technology and panel module. Refresh time is the number of times the screen is refreshed each second. This is measured in Hertz (Hz) and faster refresh is not always good since high refresh rates with a low response time LCD might render poor images. Typical response rates are between 60Hz and 120Hz, there are devices with 144Hz response times usually used in gaming.
Health & Wellness: Kind Displays
*Research suggests that the, blue light common to most computer displays can result in eyestrain and interfere with your natural sleeping patterns. Studies have also shown that blue light in the 415 to 455 nm spectra can damage the cells in the retina, and result in myopia. Prolonged exposure can include headaches, dry-eye syndrome, blurry vision, and difficulty focusing.
There are multiple ways to solve this ranging from aftermarket blue filters, software apps that chop off the blue emission peak from the backlight or move the color point in the backlight, each of these comes with some tradeoffs where the image quality deteriorates. A newer method involving two sets of LEDs with different emission spectra in the backlight can reduce the blue peak while preserving much of the color gamut and brightness. This is an area that continues to see research and emphasis due to extended use of laptops as well as growing use of laptops by children both for education and entertainment.
Laptop Form Factor: Fitting Device to User
Laptops are becoming more ergonomic to dovetail with the way we use them for work and play. Things to consider include overall weight and portability and keyboard spacing and depth for comfortable typing. In addition to traditional “clamshell” laptops, you can go with versatile 2-in-1 laptops, which combine a laptop’s power with tablet portability in one lightweight device.
Many of today’s laptops havenarrow border panels. Ever since flat-panel LCD screens appeared, bezels have grown narrower to increase display area. Increasing the screen-to-body ratio and makes laptops more compact and lightweight. It also lets users enjoy games, movies, TV shows, and be more productive.
Speaking of lightweight, laptops are getting a lot lighter. Laptops are also becoming more durable. Some can withstand falls, knocks, being left in the sun or cold, and even tolerate a little water. A few laptops come with protective cover glass so they can survive drops from up to 1.6 meters onto a hard, rough surface.
ePrivacy: Protection from Prying Eyes
You’re working on your laptop on an airplane, train, or station and can’t help but feel the person sitting next to you is glancing at your screen. Usually, it’s annoying but sometimes the person may be a hacker or someone working for your competitor. Fortunately, today’s laptops offer several integrated ePrivacy panel options. For example, after market privacy screen inserts keeps displayed information private. The removable thin filter features a satin-like matte finish and also reduces blue light transmission from the display. The newest designs feature an On/Off privacy switch that instantly toggles between wide viewing and narrow viewing modes. So any ‘off-center’ viewers see only a black screen. Apart from filters, there are also birefringence films that can be activated within the display to achieve this effect; the more effective way to achieve privacy is by widening or narrowing the beam of light from the backlight.
Battery Runtime: Saving ‘Juice’
Several devices in a notebook or laptop tend to gobble up energy, including WiFi and Bluetooth, the LCD panel, and the processor and graphics chip–especially on a high-end notebook or laptop. The display alone consumes 25% to 40% of a laptop’s power. To conserve power, try the following:
- Disable wireless communications when not in use.
- Minimize screen brightness.
- Use the low power app in your laptop.
- Avoid video editing or playing 3D games, on battery power.
By a combination of better materials, batteries, power management, more transmissive touch screens, designers are creating better and better displays for laptops.
Choosing the right display in a laptop for your particular needs can be time-consuming but worth the effort. Fortunately, today’s devices come with an incredible array of options to fit your exact needs, come work or play.
*Bullough JD, Peana S. Investigating blue-light exposure from lighting and displays. Information Display. 2020;36(1):17-20
Sri Peruvemba is CEO of Marketer International Inc., in California. Peruvemba was previously Chief Marketing Officer for E Ink Holdings, where he played a major role in transforming the startup to a $1B+ global company. With over 30 years of experience in the technology industry, Peruvemba has been an influential advocate in the advancement of electronic hardware technologies. He is an acknowledged expert on sensors, electronic displays, haptics, touch screens, electronic materials and related technologies; and consults, writes, and presents on those subjects globally. Peruvemba has also held senior level positions at Sharp Corp, Cambrios, Novasentis, TFS Inc., Planar Systems, and Suntronic Technology. Based in Silicon Valley, Peruvemba advises high tech firms in the U.S., Canada, and Europe as well as serves on the boards of Omniply, Noctiluca, Summit Wireless, and Visionect. He has BS and MBA degrees and a post-graduate diploma in management. Peruvemba is also a right arm off-spinner for a cricket team he co-founded in Silicon Valley. The 58th International Display Week Symposium and Seminar, presented by the Society for Information Display (SID), will be an all-virtual event, May 17-21 that features cutting-edge laptop displays and more. Click here to register.