Apple filed a patent application related to in-app purchasing in 2010, which could potentially change the dynamic of the company’s patent dispute with US licensing firm Lodsys, it has emerged.

Technology site Tom’s Guide reports that the patent was filed in April 2010, almost a year after Apple released iOS3 on the iPhone 3GS. The patent application was also filed following the granting of a Lodsys patent which Apple has since licensed for its in-app payment functionality.

The payments Apple makes to Lodsys are based on the “Customer-based product design module” patent filed by Lodsys in 2006 and granted by the US Patent and Trademark Office in November 2009. The patent enables future interaction – including purchase orders – with a customer within a service or application.

Apple’s “In Application Purchasing” patent application is for existing technology that “provides a purchasing interface within an application that allows users to purchase a product from another source without leaving the application”.

Apple’s patent concept is aimed at helping app developers sell their product, as consumers can be easily put off potential purchases if they are charged upfront. In-app purchasing means “a user, desiring to purchase the product, can provide an input effective to cause a purchasing interface to be displayed,” the patent says.

The difference between the Apple and Lodsys patent is that Apple’s is more specific, according to Tom’s Guide. However, if the Apple patent is granted, both sides could potentially challenge each other’s patents.

Lodsys have been embroiled in a patent dispute with iOS and Android developers after first serving papers to a number of iOS developers in March 2011, alleging that they infringed its in-app purchasing intellectual property.

In response to the actions of Lodsys, Apple filed a “motion to intervene”, saying that the existing relationship it has with Lodsys provides protection for its app community. Google has meanwhile requested the US Patent and Trademark Office to re-examine the Lodsys patents.

In August, Lodsys apparently targeted BlackBerry developers for the first time after serving a patent infringement notice to one-man band developer Rotton Ogre for linking to a payment channel outside an app.