The evolution of Lenovo's Yoga Book

Lenovo announced the new Yoga Book today, a different take on the tablet idea. The Yoga Book has tablet-standard features like a 10-inch touchscreen and thin design, but it also has a unique, permanently attached panel that can be used as both a keyboard and writing surface. Not only that, you can also put a pad of paper on top of the panel and write your notes with real ink, while having them captured digitally at the same time.

The company says it spent three years working on the Yoga Book — much longer than the normal nine months it takes to develop a product — and as a result, went through a number of design iterations and concepts. We got a chance to see a handful of the design prototypes before today's announcement and they show how the company finalized and refined the design over time. What's perhaps most remarkable about the concepts and the final product is how little actually changed from the original form factor: the final Yoga Book is as thin and light as the first mock up, and roughly the same height and width.

You can see the progression of Lenovo's concepts below, and be sure to check out our deep dive into the development of the Yoga Book, as well.