Firms such as Konica, Fuji Photo, Nikon, Matsushita and Tamron are investing more in this field as they expect its popularity to continue to rise.

Konica Corp. plans to spend about 2.2 billion yen (18 million dollars) this financial year to March on stepping up its manufacturing capability for glass and plastic lenses used in digital cameras.

"The demand for digital cameras at home and abroad is going up... which is why we are funding new investments," said company spokesman Katsuyuki Sakai.

Konica, which aims to merge with counterpart Minolta in August, will raise monthly output of glass lenses by 50 percent in June from 2.7 million units at present by expanding a plant in Dalian, China.

The firm will further boost production to four million units by next spring.

As for plastic lenses, Konica will more than double output to 2.2 million units this financial year to March and to four million units next year.

Keen to keep up with the competition, rival Fuji Photo Film Co. Ltd. plans to install more equipment at a subsidiary's factory in Tochigi Prefecture, about 100 kilometres (63 miles) north of Tokyo, to boost production of lenses there to three million units by as early as July, from two million.

"We are lifting production as demand for digital cameras grows," said company spokesman Ken Sugiyama.

Fuji Photo will also increase monthly output of plastic lenses for camera-equipped mobile phones to 50 million units from 45 million.

Total investment for the expansion will amount to 2.7 billion yen.

Major camera maker Nikon Corp. will invest 1.3 billion yen in a Thai subsidiary to increase monthly output of small lenses for digital cameras to 1.7 million units by next spring, compared with the current 1.2 million.

"Lenses are a vital part of digital cameras, which is why we are boosting production," said company spokeswoman Chiaki Kumeino.

The firm will also begin making up to 500,000 units a month of a highly value-added aspheric lens.

Consumer electronics giant Matsushita Electric Industrial Co. Ltd., better known for its Panasonic and National brands, will increase monthly output of glass lenses at a plant in Yamagata Prefecture, northern Japan, by 25 percent to 2.5 million units.

"Digital cameras and mobile phones are selling really well so the demand for lenses is also going up," said company spokesman Akira Kadoga.

Not wanting to be left behind, leading lens manufacturer Tamron Co. Ltd. has begun operating a new plant in Guandong province, China.

The firm plans to boost shipments of lenses for digital cameras to almost nine million units this year, compared with just more than six million last year, said spokesman Takahiro Yamaguchi.

"(Customers) such as Sony... are expanding production of digital cameras," he said, explaining the decision to increase lens production.

SPACE.WIRE