You can freely build on How Polaroid's Instant Film Pods Work
This patent expired in 1968. Every claim — 1 independent, 0 dependent — is now unenforceable. Anyone can use, reproduce, manufacture, sell, or offer for sale this technology without a license.
Original assignee
Polaroid Corp
Patent granted
1951
Expired
1968
Forward citations
119
What this patent covers
This patent describes a self-contained photographic system where a rupturable container (a small pod) holds a liquid processing chemical. When the user passes the film through rollers, the container breaks, and the liquid is squeezed out onto a photosensitive sheet. The liquid contains a thickening agent to ensure it spreads evenly across the image area. This chemical bath then reacts with the exposed film to develop the image immediately on the spot.
What is now free to use
All 1 claims of US 2543181 are in the public domain. Specifically:
Claim 79: A PHOTOGRAPHIC PRODUCT — 1 specific element
The 0 dependent claims add narrowing limitations and are also free.
What is NOT covered
Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.
Does not cover digital image sensors or electronic image processing.
Does not cover film development processes that require external chemical baths or darkroom tanks.
Does not cover non-rupturable liquid storage methods like cartridges with pumps.
Who is building on this today
Polaroid and Fujifilm are the primary entities that built their businesses on this technology. While digital photography dominates, these companies continue to refine the chemistry and physical delivery systems for modern instant film products.
Products built on expired version of this technology
Original Polaroid Land Camera film packs
Polaroid 600 series instant film
Modern Fujifilm Instax film
How to cite this patent in your documentation
Polaroid Corp. US Patent 2543181. Photographic product comprising a rupturable container carrying a photographic processing liquid. Granted 1951, expired 1968. Now in the public domain.
Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.
PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.