I think Rolls pioneered the wide chord fan. Not sure about the swept shape though.
https://www.rolls-royce.com/about/ou...logy/fans.aspx
Fans
The fan in a gas turbine draws air into the engine, compressing the bypass stream to produce 80 per cent of the engine's thrust, and feeding air to the gas turbine core.
The hollow, titanium wide-chord fan blade, pioneered by Rolls-Royce and introduced into airline service in the 1980s, set new standards in aerodynamic efficiency and resistance to foreign object damage. Since that time we have continued to innovate and improve on our design of wide-chord fan blades. Designed specifically for high-bypass turbofans, the breadth of these blades sets them apart from the narrow and less efficient earlier equivalents.
Fan efficiency
Fan efficiency is an increasingly important contributor to overall improvements in engine efficiencies.
The biggest improvements in fan efficiency have resulted from the analytical techniques that have evolved as a result of the revolution in computing power.
Hollow fan blades
Rolls-Royce has designed wide-chord fan blades to be hollow in order to save weight. This employs a unique manufacturing process.
Hollow design allows significant weight savings to be made in the fan blade, especially at larger sizes, and a follow-on weight saving in the fan disc, structure and containment features.
New fan technologies
New concepts and technology in fans are constantly being considered as the benefits can be very powerful. Examples of new fan concepts include fan blades made from composite material, where the move to ever larger and slower fans together with advances in manufacturing technology could provide significant benefits for some engine designs.
Open rotor concepts can offer a step change in efficiency. The larger diameter unducted fans improve propulsive efficiency, resulting in a potential to reduce fuel burn by up to 30 per cent.