The catalog

Patent invalidity dossiers.

7,163 patents in the database, sorted by number of on-file litigation cases. Of these, 2,988 have at least one tracked case across 6,606 litigations.

Demand letter analyzer

You got a patent demand letter. Now what?

Paste the letter — we extract the asserted patents, identify the asserter, characterize their litigation history, flag validity vulnerabilities, and draft a sample response letter your attorney can review. Free, private, ~2-3 minutes.

Analyze a letter →

Analyze a patent

Drop a US patent number — we’ll verify it on Google Patents and generate the full invalidity dossier.

By industry

Software Technology & Computing Systems (T)(1343)Medical (M)(713)High-Tech (T)(550)Wireless Technologies(508)Semiconductor (T)(386)Automotive (A)(298)Industrial Manufacturing (IM)(295)Media & Broadcasting (T)(189)Biotechnology(153)Energy (E)(147)Optical Technology(144)Financial Technology (FT)(132)Sporting Goods (S)(84)Other (O)(73)Audio Technology(66)Consumer Durables(56)Home Appliance (HA)(48)Lighting (L)(47)Footwear(37)Agriculture (AG)(36)Firearms (F)(36)Gaming (G)(36)Food (FD)(35)Railroad(33)Home Security(31)Optical Communication(22)Audience Measurement(19)Plumbing(16)Baby Products(12)Printing Technology(10)Fire Safety (FS)(6)Retail Security(6)Telecommunications(5)Tech (T)(4)Aerospace(3)Aerospace (AS)(3)Printing Technology (P)(3)Aerospace (A)(2)Construction (C)(2)Printing (P)(2)Retail Technology (RT)(2)Telecommunications (T)(2)Telecommunications (TC)(2)Toys(2)Advertising (AD)(1)Aerospace (Ae)(1)Aviation(1)Aviation (AV)(1)Building & Construction(1)Building Construction (BC)(1)Building Materials(1)Chemical (C)(1)Chemical Sensing(1)Cosmetics (C)(1)Data Communication(1)Document Security(1)Electrical Components(1)Environmental Monitoring (EM)(1)Fencing(1)Fire Safety(1)Furniture (F)(1)High-Tech(1)Logistics (L)(1)Logistics & Shipping(1)Marine (M)(1)Maritime Logistics(1)Musical Instruments (MI)(1)Networking (N)(1)Office Equipment(1)Office Equipment (OE)(1)Paints & Coatings(1)Pet Products(1)Printing(1)Printing Technology (PT)(1)Retail Technology(1)Retail Technology (R)(1)Software Technology (T)(1)Textiles(1)Textiles (TX)(1)Tobacco (TB)(1)Vaping (V)(1)Video Surveillance(1)Video Technology(1)Water Treatment(1)

US4827888
0 cases1/8 sections
Patent Overview — US 4,827,888 ("Nozzle") Title: Nozzle Patent number / application: US 4,827,888 A; application US07/184,334. (The source also lists related prior patent US4,798,190, from which priority is claimed.) Assignee: Nitrous…
View full analysis →added 9/21/2026
US4828888
0 cases1/8 sections
Patent Overview: US4828888A — "Liquid crystalline polymer composites" Bibliographic data (as supplied) - Patent number: US4828888A - Title: Liquid crystalline polymer composites - Application number: US07/015,758 - Inventors: Alan Buckley…
View full analysis →added 9/21/2026
US4857379
0 cases1/8 sections
Patent Overview — US 4,857,379 A Title: Sheetlike structure of fibers, especially as a reinforcement for plastics components Patent number: US4857379A Assignee: Verseidag Industrietextilien GmbH (original and current assignee per the…
View full analysis →added 9/21/2026
US4862197
0 cases1/8 sections
Patent Overview — US 4,862,197 A Title: Process for manufacturing thermal ink jet printhead and integrated circuit (IC) structures produced thereby Inventor: John L. Stoffel. Original assignee: Hewlett-Packard Co. (current assignee listed…
View full analysis →added 9/23/2026
US4872097
0 cases1/8 sections
Patent Overview — US 4,872,097 Title: Miniature low-voltage lighting fixture Patent number: US 4,872,097 A (application US07/279,961) Inventor: Jack V. Miller Assignee: None listed — original assignee and current assignee are both…
View full analysis →added 9/23/2026
US4873316
0 cases1/8 sections
Patent Overview: US4873316A Title: Isolation of exogenous recombinant proteins from the milk of transgenic mammals Patent number: US4873316A Application number: US07/065,994 Inventors: Harry Meade; Nils Lonberg Original assignee: Biogen…
View full analysis →added 9/23/2026
US4885799
0 cases1/8 sections
Patent Overview — US 4,885,799 Title: Load pull isolation switch for a fast locking synthesizer Patent number: US4885799A | Application: US07/069,796 | Inventor: Mark I. Van Horn | Original assignee: Motorola, Inc. (Schaumburg, Illinois, a…
View full analysis →added 9/21/2026
US4897771
0 cases1/8 sections
Patent Overview — US4897771A Title: Reflector and light system Patent number: US4897771A Application number: US07/125,323 Inventor: Jeffrey R. Parker Original assignee: Lumitex Inc. Priority/filing date: 1987-11-24 Publication (grant)…
View full analysis →added 9/23/2026
US4906070
0 cases1/8 sections
Patent Overview: US4906070A Title: Totally internally reflecting thin, flexible film Patent number: US4906070A Application number: US07/218,087 Inventor: Sanford Cobb, Jr. Original assignee: Minnesota Mining and Manufacturing Co Current…
View full analysis →added 9/23/2026
US4917929
0 cases1/8 sections
Patent Overview — US 4,917,929 Title: One piece adhesive bandage and package unit Patent number: US 4,917,929 A Inventor: Steven B. Heinecke Original assignee: Minnesota Mining and Manufacturing Co. (current assignee listed as 3M Co.)…
View full analysis →added 9/23/2026
US4921794
0 cases1/8 sections
Patent Overview — US 4921794 A Title: T7 DNA polymerase Patent number: US 4,921,794 A Assignee: Harvard University (original assignee; the source notes listed assignees "may be inaccurate" and that Google has not analyzed or warranted the…
View full analysis →added 9/23/2026
US4936862
0 cases1/8 sections
Patent Overview — US4936862A Title: Method of designing and manufacturing a human joint prosthesis. Inventors/Assignee: Peter S. Walker and Frederick C. Ewald; current assignee listed as Zimmer Technology Inc. (original assignee…
View full analysis →added 9/24/2026
US4938219
0 cases1/8 sections
Patent Overview — US 4938219 Title: Electrocardiographic electrode Patent number: US 4,938,219 A Inventors: Hiroyoshi Ishii; Kenzo Suzuki; Misao Kaneko; Hiroshi Kawamoto; Chuji Shimizu; Yasuaki Onodera Assignees (original and current)…
View full analysis →added 9/23/2026
US4940116
0 cases1/8 sections
US4940116A — Unattended Checkout System and Method Title: Unattended checkout system and method Inventors: David F. O'Connor; Wesley Dickover; Steven J. Tilidetzke Original assignee: Checkrobot Inc. Current assignee listing (per source)…
View full analysis →added 9/24/2026
US4956288
0 cases1/8 sections
US4956288A — Concise Overview Title: "Method for producing cells containing stably integrated foreign DNA at a high copy number, the cells produced by this method, and the use of these cells to produce the polypeptides coded for by the…
View full analysis →added 9/23/2026
US4956388
0 cases1/8 sections
Patent Overview: US4956388A Title: 3-aryloxy-3-substituted propanamines Patent number: US4956388A Application number: US07/462,925 Filing date: 1990-01-12 Publication/grant date: 1990-09-11 Priority date (assumed): 1986-12-22 Inventor(s)…
View full analysis →added 9/21/2026
US4965822
0 cases1/8 sections
US4965822A — Full Duplex Speakerphone: Overview Title: Full duplex speakerphone Patent number: US4965822A Application number: US07/335,239 Inventor: Errol R. Williams Original assignee: VideoTelecom Corp (later recorded as VTEL…
View full analysis →added 9/23/2026
US496977
0 cases1/8 sections
Patent Overview: US 496,977 — "Injector" Title: Injector Patent number: US 496,977 A Inventor: Ernst Körting, of Hanover, Germany (a subject of the Emperor of Germany) Assignee: Louis Schütte, of Philadelphia, Pennsylvania Application…
View full analysis →added 9/23/2026
US4975808
0 cases1/8 sections
Patent Overview: US4975808A — "Backlighting Apparatus" Identification. US4975808A (application US07/415,741), filed and granted priority on 1989-10-02, published 1990-12-04. Inventors: David L. Bond and Kevin D. Kaschke. Original assignee…
View full analysis →added 9/23/2026
US4977594
0 cases1/8 sections
Patent Overview: US4977594A — Database usage metering and protection system and method Title: Database usage metering and protection system and method Inventor: Victor H. Shear Original/Current Assignee (as listed): Electronic Publishing…
View full analysis →added 9/23/2026