BERLIN -- Sony has revamped its entire smartphone lineup in the Z5 range, topped by the headline-grabbing Xperia Z5 Premium with the world’s first 4K display on a phone. Sony is clearly hoping the inclusion of the first ultrahigh-definition display on a smartphone will help invigorate its declining smartphone sales.

Indeed, in the last quarter Sony lost $25 on every smartphone it sold. The company has continued its twice-yearly smartphone update cycle across the entire range of its premium smartphone lineup with the launch of Xperia Z5, Xperia Z5 Compact and Xperia Z5 Premium.

The Z5 Premium will grab most of the headlines thanks to its 5.5-inch screen with a resolution of 3840 x 2160 pixels, giving it an incredible pixel density of 808 pixels per inch. When you consider the iPhone 6 Plus -- which has the same size screen -- has a pixel density of 401 ppi, then you get some idea of the level of detail available on the new Z5 Premium.

The problem for Sony, as it has seen on its 4K televisions, is of course content, but during the company's press conference at the IFA trade show here, CEO Kaz Hirai said Sony had been working with studios and content providers like Amazon to help drive the growth of 4K content.

One of the ways Sony can solve the issue is through its own camera technology. All the new phones feature updated cameras, which bring some of the expertise of Sony’s camera division — particularly its mirrorless and DSLR technologies — to its smartphone range. The all-new Exmoor camera module features a 23-megapixel sensor and a bright f/2.0 lens, and Hirai said the new module was the first completely redesigned module seen since the company’s Xperia Z1.

Another major advance on the camera side is autofocus, which Sony says can now match — and surpass — anything else on the market, focusing in faster than the blink of an eye — which is around 0.03 seconds, if you are wondering. The camera also will be able to capture video in 4K, a feature that will now be more useful on the 4K display of the Xperia Z5 Premium.

All three new phones across the range continue to use Sony’s fully flat OmniBalance design language, but the iconic circular metallic home button on the side has been replaced by a fingerprint sensor.

The Xperia Z5 continues to feature the same 5-inch full-HD screen, while the Xperia Z5 Compact comes with a 4.6-inch HD screen. All three continue to feature the Qualcomm Snapdragon 810 chip, which proved so problematic in the Xperia Z3+ earlier this year. But Sony told International Business Times ahead of the announcement that it had not seen any problems with the chip overheating in the new phones.

The Xperia Z5 and Xperia Z5 Compact will be available in October, while the 4K Xperia Z5 Premium arrives in November. Sony said the models would be priced in line with similar smartphones from other markets.