Extensions

Patent Term and Status

Based on the provided documentation and an analysis of U.S. patent law, here are the details regarding the term of US Patent 5,841,978.

Application and Priority Dates

• Application Number: 08/508,083
• Filing Date: July 27, 1995
• Earliest Priority Date Claimed: November 18, 1993

Projected Expiration
For patents filed before June 8, 1995, the term is the later of 17 years from the issue date or 20 years from the earliest non-provisional filing date. For patents filed after that date, the term is 20 years from the earliest non-provisional filing date. As this patent was filed on July 27, 1995, its term is calculated as 20 years from its earliest claimed priority date.

• Calculation: November 18, 1993 + 20 years = November 18, 2013.

The patent is now expired, which is consistent with the "Expired - Lifetime" status provided by patent databases.

Patent Term Adjustments (PTA) and Extensions (PTE)

• Patent Term Adjustment (PTA): The provisions for PTA to compensate for certain prosecution delays by the USPTO apply to applications filed on or after May 29, 2000. Since the application for the '978 patent was filed in 1995, it was not eligible for Patent Term Adjustment.
• Patent Term Extension (PTE): PTE under 35 U.S.C. § 156 is typically granted to compensate for delays caused by regulatory review, most commonly by the Food and Drug Administration (FDA) for pharmaceutical products. This type of extension is not applicable to the subject matter of the '978 patent.

Application and Family Data

The prosecution history of US Patent 5,841,978 reveals a complex web of related applications, indicating a broad strategy to protect the core technology.

Continuations and Divisional Applications
The application for US 5,841,978 (Ser. No. 08/508,083) is a continuation-in-part of several earlier applications:

• Ser. No. 08/436,134 (filed May 8, 1995), now U.S. Patent 5,748,763
• Ser. No. 08/327,426 (filed October 21, 1994), now U.S. Patent 5,768,426
• Ser. No. 08/215,289 (filed March 17, 1994), which is abandoned.
• Ser. No. 08/154,866 (filed November 18, 1993), which is abandoned.

This chain of "continuation-in-part" applications establishes the earliest priority date of November 18, 1993, which is critical for determining both the patent's term and the scope of prior art.

Patent Family
US Patent 5,841,978 is part of a large family of related patents and applications filed in the United States and internationally. The provided documentation lists numerous related U.S. patents that claim priority from this lineage, demonstrating an extensive and long-term patenting effort by the assignee, Digimarc Corp., to build on this foundational technology. These related filings cover various refinements and different aspects of digital watermarking technology.

The patent also served as a priority document for numerous international applications, including in Europe (EP), Japan (JP), Germany (DE), Canada (CA), and Australia (AU), through the Patent Cooperation Treaty (PCT) application PCT/US1996/006618. This indicates the commercial importance of the invention and the assignee's intent to secure intellectual property rights globally.