Sony continued to show signs of financial improvement in the first quarter of this fiscal year, although once again it was nothing to do with its PlayStation business.

Sony's video game business is still proving detrimental to the company, as operating losses for its Game division have increased year-over-year, due in part to research and development expenses for its upcoming PS4 console.

Sony says that its video game results are significantly lower than its original forecast in May, due to a decrease in unit sales for its PS3, PSP and PS2 hardware. The negative impact of the depreciation of the yen against the U.S. dollar is also cited, as the company warns that operating results are "expected to deteriorate significantly year-on-year."

The company estimated back in May that it will sell 5 million PS Vitas and PSPs combined, and 10 million PS3 and PS2s during the fiscal year. For this first quarter, Sony managed sales of 600,000 PS Vitas and PSPs combined, and 1.1 million PS3 and PS2s combined -- and it says it is still on target to meet those original forecasts.

Looking to the rest of the year, Sony says that it is preparing to turn its video game business around with the launch of the PS4 this holiday season. The PS Vita is not mentioned in its forward-looking plans.

It was, in fact, Sony's Mobile Products division that made the real difference to the company's full quarter results, swinging from notable losses last year to operating profits this year.

For the quarter ended June 30, 2013, Sony's Game division recorded revenues of 117.9 billion yen ($1.2 billion), essentially flat year-over-year, and operating losses of 14.8 billion yen ($150.5 million), down further compared to operating losses of 3.5 billion yen ($35.6 million) year-over-year.

Overall, Sony posted revenues of 1.7 trillion yen ($17.4 billion), up 13 percent year-over-year, and profits of 3.5 billion yen ($35.6 million), a swing to profits from last year's losses of 24.6 billion yen ($250.0 million).