Yoga Book: The World’s Thinnest and Lightest 2-in-1

Lenovo’s newly launched Yoga Book is a tablet made for productivity on-to-go. It’s unique among tablets in combining the zero-travel halo keyboard feature (zero travel, because your fingers don’t move when pressing the keys) with the dual-use stylus of the real pen accessory. Apart from its distinctive form factor, what makes the Yoga Book really stand out is its size and practicality as a tablet to do your work practically anywhere, even in crowded places with limited elbow or leg room. That’s because Lenovo’s new Yoga Book is the thinnest and lightest 2-in-1 in the world,[1] clocking in at just 9.6mm and 690g.

Thin and light have always been important considerations in tablet design, partly because they’re typically the first trade-offs made in the design process as more features are added over time. Lenovo was clear in the development of the Yoga Book that it would not compromise on the thinness and lightness of the design. So at each stage in its development, Lenovo’s engineers had a laser focus on driving down the weight and thickness to strike the perfect balance between size and performance. The team achieved all this through a judicious use of materials and innovative designs; magnesium-aluminum alloys to give the body the right level of tensile strength and thinness; completely new component designs, such as the hinge; and a tight stacking and strategic placing of components.

Productivity and portability

Inspired by the elegance and simplicity of physical notebooks, Yoga Book measures a mere 9.6mm thick (when closed) with a 10.1” IPS FHD screen, and packs in more functionality than devices that are much larger in size. It’s designed to be the ideal format for mobile productivity. Our research determined that 9.6mm was the right size in which users could hold the Yoga Book as comfortably as a notebook, either by laying it down flat on a surface or holding it in one hand and taking notes on it. Its light weight means it’s not difficult to hold and doesn’t feel unbalanced. Its size also offers optimum balance between giving users a thin device without it feeling fragile, while any thinner than 9.6mm would have compromised its functionality, making it too thin even for micro-USB slots.

The halo keyboard is a counterpoint to the standard approach of detachables (which bolt on a keyboard to the traditional touch tablet slate), replacing the mechanical keyboard with a zero-travel keyboard that only shows up when needed. This switch means the keyboard is 60% thinner than typical mechanical keyboards, measuring just 1.2mm in width. The halo keyboard comprises an LCD/touch panel, with touch sensors and backlight, haptic feedback and sound to touch. When not used for typing, the keyboard can switch to become a digitizing pad for sketching or note-taking, writing directly on the multi-use keyboard with the real pen accessory or over a sheet of paper or notepad, which digitizes the notes or sketches to the screen.

Lenovo’s engineers packed in a vast array of different components into a tight stack in order to be able to work the Gorilla glass, LCD panel, LGF backlighting, EMR film and various processors into a thin package measuring just 4mm. Combined, the keyboard panel of the Yoga Book measures in at a mere 5.55mm.

Multimedia minimized

The Yoga Book has one of the industry’s leading designs for its screen, measuring 2.15mm, while also using the thinnest available sidehorn speaker, delivering great sound for films, music or video calls, yet measuring only 3.15mm in thickness. The tablet also includes an industry breakthrough in the design of the full HD camera, with the thinnest front-facing camera on the market at 2.76mm. The total thickness of the screen panel is 4.05mm.

Materials and design

Driving down the thickness of the tablet also meant the hinge itself had to be completely reinvented. The watchband hinge models used across notebooks in Lenovo’s Yoga range were too large for such a thin format and wouldn’t allow the Yoga Book to close properly. Yet the hinge needed enough strength to handle the wear and tear of constant 360-degree use. So in order to slim down the size, the team reduced the hinge to three axial rods – an odd number or rods, and impossible under the current configuration, based on an even number of rods. To manage this, the engineers incorporated 130 separate mechanical parts, and as a consequence invented the first three-rod hinge in the world. The team even managed to shave 0.15mm off the diameter of each rod, down to 1.85mm from the original 2mm rods. The new design allowed for perfect fit when the tablet was closed, further reducing thickness and increasing the tensile strength of the tablet. The hinge design was also put through a continuous cycle of opening and closing the tablet 25,000 times to ensure it would survive everyday use.

At just 0.45mm thick, the cover is a technical wonder in balancing size with strength. The engineering team used a very light and strong magnesium-aluminum alloy, which kept the thickness down but ensured the tablet was rugged enough to survive being dropped or knocked around. Its structural design can withstand pressures of up to 15kg.

[1] Based on Lenovo’s internal analysis as of 8/18/16 of 10.1” or greater 2-in-1 computers (sold with keyboard) using Windows, Android, Chrome or OSX sold by major competitors shipping >1 million units worldwide annually; measured with keyboard attached in closed position.