NTT DoCoMo, Japan's largest mobile operator, said that it had invested $14 million (£8.7 million) in Eye-Fi, the maker of Wi-Fi-enabled memory cards.
The Japanese carrier said it would offer services based on Eye-Fi technology, including one that would automatically send pictures taken with digital cameras to its digital photo frames, which can also display photos taken by phones on its network.
DoCoMo will also be the first to employ a new method for configuring Eye-Fi cards using only a smartphone, a process that previously required a computer.
Eye-Fi's memory cards have proven popular for their ability to automatically sync wirelessly with other devices and download photos from the digital cameras in which they are used.
But the company has competition from camera makers, which are increasingly building the feature directly into their hardware, and a major standardisation body. The SD Association has proposed a new specification for SD cards with Wi-Fi, which Eye-Fi contests, saying the move infringes on its intellectual property.
The latest investment was part of a $20 million (£12 million) round of funding for Eye-Fi. Previous investors Shasta Ventures, Opus Capital and TransLink Capital also took part.
KDDI, which runs Japan's second largest mobile network, announced a separate tie-up with Eye-Fi last year, on a service that uploads pictures taken with phones online.