Fujitsu's 2-in-1 Tablet Waterproof But Fan-cooled

Oct 9, 2013
Tomohisa Takei, Nikkei Electronics
The "Arrows Tab QH77/M" is waterproof while equipped with a cooling fan.
The "Arrows Tab QH77/M" is waterproof while equipped with a cooling fan.
[Click to enlarge image]
The main body of the QH77/M operating under water
The main body of the QH77/M operating under water
[Click to enlarge image]

Fujitsu Ltd announced 11 new Windows 8.1-based products in six series by remodeling the FMV series of personal computers and Arrows Tab series of tablet computers Oct 8, 2013.

Among them, the "Arrows Tab QH77/M" 2-in-1 computer can be used both as a clamshell notebook computer and as a tablet computer when the display unit is detached. The QH77/M is waterproof even though it is equipped with a cooling fan.

The QH77/M comes with a 12.5-inch touch-sensitive LCD panel and Intel Corp's "Core i5-4200U" microprocessor, whose thermal design power is 15W.

"Fujitsu employed the Core i5 processor to realize a high performance," said a staffer at a private view of Fujitsu's new products. "The Core i7-4600U can be selected for a model sold on the company's website."

Despite the focus on high performance, the thickness of the QH77/M's main body (without the keyboard unit) is only 11.9mm. With the thermal design power of 15W, it is not possible to cool the processor with a fan-less (airtight) structure, the staffer said. Therefore, it becomes necessary to add a mechanism to cool it by using a fan.

Internal space separated into non-waterproof, waterproof areas

The QH77/M complies with IPX5/7/8 waterproof and IP5X dustproof standards. To support the standards while using a cooling fan, Fujitsu separated the space inside the computer into two areas: a non-waterproof area and waterproof area. The cooling fan and heatsink are located in the non-waterproof area, and electrical components including the main board are contained in the waterproof area.

The non-waterproof area is used as an air way for forced air cooling. To transfer heat from the microprocessor located in the waterproof area to the heatsink located in the non-waterproof area, a heat pipe is used.

"Fujitsu came up with a structure that prevents water from remaining in the non-waterproof area," the staffer said.

The dimensions and weight of the display unit (main body) are 309.6 x 199.3 x 11.9mm and about 980g, respectively. When combined with the keyboard unit, it measures 309.6 x 212.7 x 20.0mm and weighs about 1.67kg. The display uses a 1,920 x 1,080-pixel IPS LCD panel.

As a storage, the QH77/M has a 128-Gbyte SSD. The capacity of its main memory is 4 Gbytes. With a battery capacity of 46Wh, it can be continuously run for about 16 hours on battery power when used as a tablet computer.