Comparing the shapes
Courts ask whether an ordinary observer, familiar with earlier designs, would see the accused product as substantially the same as the patented design. The comparison is with the drawings in the patent rather than the owner's commercial product, and features shown in broken lines are not part of the claimed design. Purely functional features get less weight, because design patents protect ornamental appearance. The Federal Circuit has revised how obviousness is judged for design patents, and accused infringers often challenge validity by pointing to older designs. A design patent's term is fixed and measured from grant, so an older patent may be near the end of its life, which changes what a dispute is worth.
Remedies and marketplace fights
Design patent law allows an owner to recover the infringer's total profit on the article of manufacture, and the Supreme Court has held that the relevant article can be a component rather than the whole product. Many owners start with marketplace reporting tools, and some file suits against large numbers of online sellers at once, often with requests to freeze seller accounts. Some courts have looked more closely at those mass filings. For an owner, useful evidence includes the patent, images of the accused products, listing URLs, purchase records, and dates.
If you are the accused seller
Sellers named in a lawsuit or a marketplace complaint should respond promptly, since frozen funds and court deadlines move quickly. Compare the product with the patent drawings and with older designs, which can narrow the patent's reach or undercut its validity. Keep records of where you sourced the product and when you began selling it. A design change can sometimes end the dispute going forward, though it does not erase past sales. When a design patent dispute comes in, we review the patent, the product, and the forum, and decide whether to negotiate, challenge, or redesign.
