HP originally accused the Taiwanese firm of infringing on five patents and demanded unspecified damages, as well as a permanent injunction preventing Acer from further infringements.
Acer has now filed a counterclaim in the US Eastern District of Texas Court over DVD Rom technology to which it holds the patents.
"This counterclaim is part of Acer's response to the 'HP versus Acer Inc and Acer America Corp' case (No. 2:07-CV-103) and includes innovations with respect to the antenna and DVD Rom head technologies," said Acer in a statement.
The firm added that it would take all necessary steps to protect and enforce its patented technologies.
Back in March, Acer responded immediately to HP's original claim by announcing its own investigation into the patent claims.
"Acer respects the intellectual properties of third parties and is currently conducting a full investigation of the allegations made by HP," a spokesman said.
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