Developers on ThinkPad Tablet 2: Mechanical Engineering/Industrial Design

ThinkPad Tablet 2

Following on from our first article, "Developers on the Tablet 2 - Project ", we present more interviews with the developers.

In this second article we discuss mechanical engineering and industrial design. The crucial packaging aspect of the project was handled by an engineer with experience in mechanical design for portable game consoles, and a veteran lead designer around since the birth of the ThinkPad who worked on the 560, X30, and X1, as well as the original Tablet.


- The Tablet 2 is so thin, light, and stylish. First, can you tell us about the enhancements made to the packaging that came up in the last interview?

Hasegawa: Sure. Compared to the original, the Tablet 2 went from...

  • 14.5mm to 9.8mm in thickness, which is almost 5mm or over 30% thinner.
  • It also went from about 759g (with pen) to about 590g (with pen), for weight savings of almost 150g, or 23%.

As you can imagine, this kind of evolution is almost unheard of in this industry. Now our only problem is figuring out where to go from here (LOL).

The concept for the original Tablet was to create a tablet that maintained ThinkPad quality and also included a digitizer pen, which is extremely difficult from a mechanical engineering standpoint. This concept remained unchanged for the Tablet 2, but by placing emphasis on making a thinner, lighter product, we had to take on a lot of new challenges.

Looking back, my honest impression is, "I can't believe we fit everything into this body..."

Shima: The concept was also basically the same from the perspective of industrial design. But it is difficult to integrate the ThinkPad style into a product like the Tablet.

The main reason is that there are less areas to design compared with notebook PCs. It also doesn't have the classic keyboard. We had to make it feel like a ThinkPad product within these constraints. The same goes for the original Tablet, but we agonized over this quite a bit.

We stuck to the basics, and added red accents, as well as rubber coating for extra grip. In the end, I think it turned out to be a product that clearly lives up to the ThinkPad name, with a simple, luxurious appearance.

Proportions are particularly important in industrial design, and I believe it gives an even better impression due to the thinner packaging.


- We heard that your experience with a previous Android tablet was put to use in the packaging. However, the structure itself is apparently a little different. Can you go into specifics?

Hasegawa: The Android version used magnesium alloy for the inner frame and chassis. For the Tablet 2, we enclosed the magnesium alloy inner frame in a plastic chassis. In other words, the Tablet 2 has the "roll cage design" often used in ThinkPad notebook PCs.

The roll cage design uses the minimum necessary magnesium alloy internally, resulting in a lighter product. On the other hand, because the chassis itself is made of plastic that is softer than metal, robustness is a challenge. However, we knew we could give it enough robustness to compare favorably with the Android version, so we adopted this design.

The use of high-strength "Dragontrail" glass also contributes to improving the overall robustness of the product.


- I've heard a lot about Asahi Glass Co.'s "Dragontrail". Just how strong is it?

Hasegawa: It has produced excellent results in ball drop tests, in which a steel ball is dropped on the surface of the glass.

Of course, in addition to the strength of the glass, the Tablet 2 itself is very tough because the roll cage design and chassis as a whole is subject to impacts. It boasts about twice the strength of tablets from one of our most famous competitors.

It was difficult to maintain the overall strength of the Tablet 2 because it has many openings, such as the slot for the digitizer pen and the standard USB port. However, the roll cage design and all-round mechanism design were effective at improving durability.


- The digitizer pen looks really sleek now.

Hasegawa: Right. We use one with a 6.5mm diameter.

The pen in the original Tablet had a diameter of 9.5mm. It also had a battery inside. But the Tablet 2 is only 9.8mm thick, so that wouldn't work...

We were actually first told that pen manufacturers only had precision pens with diameters of 5mm or 9mm. With the Tablet 2 being 9.8mm thick, a 9mm pen wouldn't fit. And a 5mm pen creates other problems...

Shima: It is too thin, making it hard to use.

About 9mm is best for normal ball-point pens, but we knew that 7mm would not adversely impact usability too much. However, 7mm would still be difficult to fit in the chassis, and after consulting closely with the U.S. user experience team, we settled on 6.5mm.

Hasegawa: In the end, we asked a pen manufacturer to develop a new pen to meet our size specifications. The ThinkPad Helix also includes a digitizer pen with the same thickness.

Comparison of digitizer pen/chassis on original Tablet and Tablet 2

- You put a lot of effort into the pen for both the original and the Tablet 2. It this feature that important?

Shima: Tablets are really convenient if you're only reading e-mails or browsing the Internet. They're perfect for viewing content.

But PCs go beyond that, and you use them for some kind of work, right? Lots of times when you're using a tablet you'll think, "this isn't worth opening up my notebook PC, but I can't do it with just my fingers," such as when writing e-mails, editing images, or copying text on a Web page.

You really need a pen when it comes to selecting or tracing finer details.

For example, each time you select text on a Web page when using a tablet without a pen, you have to zoom in and select with your fingers, which is hardly convenient. Having a pen lets you do this much more easily. That's all you need to solve the issue.

Right now we need products that seamlessly link notebook PCs and tablets together, and we think that a pen is necessary for that.

Hasegawa: I agree with what Mr. Shima says regarding the need for a pen (LOL), but I have one other thing to add.

We also have a model without a digitizer pen, but as a developer I'd really like to see people using the model with a pen. Putting a pen into such a thin chassis was a real challenge. We practically had to jam it in there by force (LOL).

Digitizer pen holder of Tablet 2


- Are there any other things you're proud of or that you struggled with?

Hasegawa: I have some of both (grin).

The first thing I'm proud of, is that we can actually make the product 2mm thinner.

There was a design model for this. This design had an area raised 2mm around the pen, with the rest a flat 7.8mm. However, this idea reduced the battery capacity significantly, so we shelved it due to concerns about product competitiveness.

The second thing I'm proud of is how well-balanced the weight is.

Major components like the circuit board, battery, and roll cage have an almost symmetrical layout. This results in optimal balance, so the feel is no different whether it is held vertically or horizontally.

The third thing I'm proud of is the advanced keyboard folio.

Unlike the original, the tablet and keyboard folio can be docked without a soft case. It can also be fixed securely at angles, and when set up like this it looks almost identical to a notebook PC. Helix transforms from a tablet into a complete notebook PC, but the Tablet 2 keyboard folio is more compact than the one in the Helix system, so I think it offers its own unique kind of convenience.

As for what I struggled with, I'd have to say the large number of overseas business trips. I spent a total of five or six months overseas during development, and I definitely got tired of it...

Shima: I'm proud of the fact we made a product that opens up a new world of possibilities for tablets.

I don't think that any of our competitors have managed to do that. Right now it is said that tablets are for content consumption, and notebook PCs are for content creation. I believe the Tablet 2 fills the gap between these two.

Of course, I also take pride in how the industrial design exudes a high-quality feel that befits the ThinkPad series. I'm confident that we've put together a polished, convenient overall user experience for customers.

There is one other thing. As mentioned in the last interview, the keyboard folio. We've developed a concept that goes some way toward expanding usage scenarios, so in the next product I'd like to bring this to full fruition.

As for the things I struggled with...I've already forgotten (LOL).


- It seems the Tablet 2 is enjoying a great deal of popularity. I can't wait to try one out myself. Would you like to make any comments on your hopes for the future?

Hasegawa: The Tablet 2 is an edgy addition to our family of products. I'm very happy to have had the chance to work on it, but I'd honestly like to work on a notebook PC, in particular the X series.

Putting that aside... (LOL). To bring the topic back to tablets, making a thinner, lighter, and smaller product will not be enough to differentiate from our competitors. I believe we have to take on some kind of new challenge.

This may contradict what I've just said, but after using the iPad mini, I got the urge to try working on a smaller tablet. Right now I'm thinking about the mechanical engineering challenges that a small tablet would present. I'd also like to expand our line of optional extras.

Hideaki Hasegawa holding the Tablet 2


Shima: I have to admit... I often use an iPad at home. I am planning to buy a Tablet 2 soon, though (LOL).

As I've already said, something as simple as selecting text on a Web page can be frustrating when using a tablet, so I often think I might have been better off getting a notebook PC, but the Tablet 2 covers both bases.

Notebook PCs aren't the best fit when you're lying back and relaxing at home. The Tablet 2 with its digitizer lets you enjoy a little creation work casually and without stress.

I'd like to continue delivering this kind of new experience to the world.

Hisashi Shima holding ThinkPad Tablet 2