How Laszlo Biro Invented the Modern Ballpoint Pen
This 1945 patent describes the original ballpoint pen mechanism that uses a rotating sphere to distribute thick, quick-drying ink onto paper.
Original patent title: “Writing instrument”
This 1945 patent describes the original ballpoint pen mechanism that uses a rotating sphere to distribute thick, quick-drying ink onto paper. Granted to Individual in 1945 with 30 forward citations, and it is now in the public domain.
Key facts
Coverage
What does this patent actually cover?
The patent describes a writing instrument featuring a small, freely rotating ball held in a socket at the tip of a reservoir. As the pen moves across paper, the ball rolls, picking up viscous ink from the reservoir and depositing it onto the writing surface. This design solved the problem of ink leakage and smearing common in fountain pens of the era, as the ball acts as a seal when the pen is not in use.
The gap
What does this patent NOT cover?
- Does not cover pens that use felt or porous fiber tips.
- Does not cover fountain pens that rely on capillary action through a nib.
- Does not cover pressurized ink delivery systems used in specialized space pens.
- Does not cover gel-based ink formulations developed decades later.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The innovation lies in the combination of a high-viscosity ink and a precision-fitted socket that allows the ball to rotate freely while preventing the ink from drying out or leaking excessively.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Bic Cristal pens
Standard office ballpoint pens
Disposable promotional pens
Why it matters
The bigger picture
This invention fundamentally changed how the world writes by replacing the messy, fragile fountain pen with a reliable, mass-producible tool. It enabled the rapid adoption of affordable writing instruments in schools, offices, and military operations during the mid-20th century.
Filed
June 17, 1943
Granted
December 11, 1945
Market context
Who's building on this
Companies in this space
Companies like Bic, Parker, and Pentel continue to refine the ballpoint mechanism, focusing on ink chemistry and ergonomic housing designs. The core mechanical principle remains the standard for the vast majority of pens sold globally today.
Market impact
The patent effectively launched the modern stationery industry, allowing for the mass production of cheap, reliable pens. It rendered the fountain pen a luxury or niche item for everyday writing and established the ballpoint as the dominant global standard for handwriting.
Claim 1 — Plain English
What this patent covers
The patent describes a writing instrument featuring a small, freely rotating ball held in a socket at the tip of a reservoir. As the pen moves across paper, the ball rolls, picking up viscous ink from the reservoir and depositing it onto the writing surface. This design solved the problem of ink leakage and smearing common in fountain pens of the era, as the ball acts as a seal when the pen is not in use.
The clever bit
The innovation lies in the combination of a high-viscosity ink and a precision-fitted socket that allows the ball to rotate freely while preventing the ink from drying out or leaking excessively.
What it does not cover
- Does not cover pens that use felt or porous fiber tips.
- Does not cover fountain pens that rely on capillary action through a nib.
- Does not cover pressurized ink delivery systems used in specialized space pens.
- Does not cover gel-based ink formulations developed decades later.
Patent Journey
From filing to expiry
PatentBrief Score
Impact Score
Early stage
Citation count
30/40
Moderately cited
Claim breadth
0/20
Narrow claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$8K – $26K
Midpoint $16K · expired or expiring · industry ×0.9
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Concepts involved
Citations
Patent lineage
Cite this patent
Jozsef, B. L. (1945). How Laszlo Biro Invented the Modern Ballpoint Pen (U.S. Patent No. 2,390,636). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/2390636/ballpoint-pen-biro
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How Laszlo Biro Invented the Modern Ballpoint Pen cover?
This 1945 patent describes the original ballpoint pen mechanism that uses a rotating sphere to distribute thick, quick-drying ink onto paper.
Who owns patent US 2390636?
Individual owns this patent, granted in 1945.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 2390636 cited by?
This patent has been cited by 30 later patents that build on its ideas.
What problem does this patent solve?
This invention fundamentally changed how the world writes by replacing the messy, fragile fountain pen with a reliable, mass-producible tool. It enabled the rapid adoption of affordable writing instruments in schools, offices, and military operations during the mid-20th century.
What does this patent NOT cover?
Does not cover pens that use felt or porous fiber tips.
Same assignee
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