While much of Japan relaxes during the Bon summer holiday period, its top semiconductor makers are keeping their factories running to meet fierce demand from China for the technology that runs smartphones.

Demand is expected to heat up even more with the launch of Apple Inc.'s next-generation iPhone, anticipated to hit the market next month.

Toshiba Corp., which makes NAND flash memory chips used for smartphone data storage, is continuing operations at its main factory in Yokkaichi, Mie Prefecture, over the holiday period, which ends Sunday.

Toshiba Representative Executive Officer Keizo Maeda said the company expects "demand to rise and sales to pick up from now on."

Sony Semiconductor Corp.'s Kikuyo plant in Kumamoto Prefecture is also forgoing the holiday to meet smartphone-driven demand for its image sensors.

The factory has upped production capacity for its CMOS image sensors this summer to 75 million units per month from 50 million this time last year, Sony Semiconductor said.

Fujitsu Semiconductor Ltd. said it will continue to make large-scale integrated circuits, which handle smartphone processing functions, at its Kuwana plant in Mie Prefecture throughout the holiday.

While the global leader in smartphones, South Korea's Samsung Electronics Co., is starting to see flagging sales, Chinese companies manufacturing and selling lower-priced models are increasing their market share.