BELLEVUE, Wash.  Nathan Myhrvold wants to shake up the marketplace for ideas. His mission and the activities of the company he heads, Intellectual Ventures, a secretive $5 billion investment firm that has scooped up 30,000 patents, inspire admiration and angst.

Admirers of Mr. Myhrvold, the scientist who led Microsoft’s technology development in the 1990s, see an innovator seeking to elevate the economic role and financial rewards for inventors whose patented ideas are often used without compensation by big technology companies. His detractors see a cynical operator deploying his bulging patent trove as a powerful bargaining chip, along with the implied threat of costly litigation, to prod high-tech companies to pay him lucrative fees. They call his company “Intellectual Vultures.”

White hat or black hat, Intellectual Ventures is growing rapidly and becoming a major force in the marketplace for intellectual capital. Its rise comes as Congress is considering legislation, championed by large technology companies, that would make it more difficult for patent holders to win large damage awards in court  changes that Mr. Myhrvold has opposed in Congressional testimony and that his company has lobbied against.

Intellectual Ventures spent more than $1 million on lobbying last year, according to public filings compiled by OpenSecrets.org. In the three most recent election cycles  2006, 2008 and 2010  Intellectual Ventures executives, led by Mr. Myhrvold, have contributed more than $1 million to Democratic and Republican candidates and committees.