How Buried Channel CCDs Move Data Deep Inside Silicon Chips
A foundational 1974 invention that improved how computer chips store and move electrical charges by keeping them away from messy surface defects.
Original patent title: “Buried channel charge coupled devices”
A foundational 1974 invention that improved how computer chips store and move electrical charges by keeping them away from messy surface defects. Granted to Individual in 1974 with 14 claims and 22 forward citations, and it is now in the public domain.
Key facts
Coverage
What does this patent actually cover?
This patent describes a way to move electrical charges through the middle of a semiconductor material rather than along its surface. By creating a 'buried channel'—a specific potential energy path deep inside the silicon—the device prevents charges from getting trapped by surface defects, which were a major problem in early chip designs. The device uses a series of electrode plates on the surface to pull these charges along this internal path, essentially acting like a bucket brigade for electrons. This allows for much faster and more reliable movement of data within the chip.
The gap
What does this patent NOT cover?
- Does not cover charge-coupled devices that store or transfer charge directly on the semiconductor surface.
- Does not cover memory structures that rely on traditional floating-gate transistors for long-term storage.
- Does not cover devices lacking the specific ohmic contact means required to bias the storage medium for internal depletion.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
Instead of fighting surface defects, the inventors moved the 'highway' for electrons into the bulk of the material, using an electrical bias to create a potential energy 'valley' that keeps charges safely away from the surface.
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
Digital camera image sensors
Early digital video camcorders
High-speed analog signal delay lines
Why it matters
The bigger picture
This invention was critical for the evolution of digital imaging and high-speed signal processing. By solving the charge-trapping problem, it enabled the creation of high-quality Charge-Coupled Device (CCD) sensors, which became the standard for early digital cameras and video recorders. It essentially allowed engineers to build more reliable and sensitive silicon-based sensors.
Filed
April 19, 1973
Granted
February 12, 1974
Market context
Who's building on this
Companies in this space
The technology was pioneered at Bell Labs by Willard Boyle and George Smith, who later won the Nobel Prize for this work. Today, major semiconductor manufacturers and sensor companies like Sony, Samsung, and ON Semiconductor continue to refine the underlying physics of charge transfer in CMOS and CCD image sensors.
Market impact
This patent provided the technical foundation for the digital imaging revolution. It enabled the transition from analog film to digital sensors, eventually leading to the ubiquity of cameras in every smartphone and professional imaging system worldwide.
Claim 1 — Plain English
What this patent covers
This patent describes a way to move electrical charges through the middle of a semiconductor material rather than along its surface. By creating a 'buried channel'—a specific potential energy path deep inside the silicon—the device prevents charges from getting trapped by surface defects, which were a major problem in early chip designs. The device uses a series of electrode plates on the surface to pull these charges along this internal path, essentially acting like a bucket brigade for electrons. This allows for much faster and more reliable movement of data within the chip.
The clever bit
Instead of fighting surface defects, the inventors moved the 'highway' for electrons into the bulk of the material, using an electrical bias to create a potential energy 'valley' that keeps charges safely away from the surface.
What it does not cover
- Does not cover charge-coupled devices that store or transfer charge directly on the semiconductor surface.
- Does not cover memory structures that rely on traditional floating-gate transistors for long-term storage.
- Does not cover devices lacking the specific ohmic contact means required to bias the storage medium for internal depletion.
Patent Journey
From filing to expiry
PatentBrief Score
Impact Score
Early stage
Citation count
27/40
Moderately cited
Claim breadth
9/20
Moderate scope
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
$16K – $50K
Midpoint $32K · expired or expiring · industry ×1.4
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
The original legal language
Original claims
14 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Boyle, W., & Smith, G. (1974). How Buried Channel CCDs Move Data Deep Inside Silicon Chips (U.S. Patent No. 3,792,322). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/3792322/ccd-image-sensor
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
Embed
Add this patent to your site
Drop this plain-English patent card into any blog post or article — free, no signup. It always links back to the full breakdown here.
<div data-patentlens-widget data-patent-number="US3792322"></div> <script src="https://patentbrief.org/embed.js" async></script>
Stay in the loop
Get a weekly digest of new patents.
One email per week. No spam. Unsubscribe anytime.
Keep exploring
Related patents you should know
US 4683195 · 1987
How to Make Billions of Copies of a DNA Segment
This patent describes the Polymerase Chain Reaction (PCR), a method to rapidly create many copies of a specific piece of DNA or RNA, enabling its detection and analysis.
Cetus Corp
US 8697359 · 2014
How to Edit Genes in Human Cells Using an Engineered CRISPR System
This patent describes an engineered CRISPR-Cas9 system for precisely cutting DNA in eukaryotic cells to change how genes work, opening the door for gene editing in complex organisms.
Massachusetts Institute of Technology
US 7657849 · 2010
How the iPhone's Slide-to-Unlock Gesture Works
Apple's 2010 patent describes unlocking a device by dragging a specific graphical image across the touchscreen along a predefined path, a gesture that became iconic with the original iPhone.
Apple Inc
US 4733665 · 1988
How Doctors Implant a Permanent Stent Using a Balloon
This patent describes the method for placing a permanent, expandable wire mesh tube inside a blood vessel or other body tube using a balloon-tipped catheter to widen it and keep it open.
Expandable Grafts Partnership
US 4405829 · 1983
How RSA Public-Key Encryption Keeps Digital Messages Secret
This patent describes the foundational RSA algorithm, a method for securely sending messages where anyone can encrypt a message using a public key, but only the intended recipient can decrypt it using a secret private key.
Massachusetts Institute of Technology
US 4575330 · 1986
How 3D Printers Build Objects Layer by Layer from Liquid
This patent describes the foundational method for 3D printing, where a machine builds a three-dimensional object layer by layer by hardening a liquid material with light or other energy.
UVP Inc
Semantically similar
You might also find these interesting
US 4131919 · 1978 · Eastman Kodak Co
The First Digital Camera's Core Technology
US 5471515 · 1995 · California Institute of Technology
How a Modern Camera Sensor Captures Light and Converts It to Data
US 5903495 · 1999 · Toshiba Corp
How Multi-Level Cell Memory Stores More Data in Less Space
US 3102230 · 1963 · Bell Telephone Laboratories Inc
The Invention of the Modern Field-Effect Transistor
More to explore
More in Semiconductors & Chips
US 5563422 · 1996 · Nichia Chemical Industries Ltd
How Nichia Created the First Practical Blue LED Electrodes
US 2981877 · 1961 · Fairchild Semiconductor Corp
How Robert Noyce Invented the Modern Integrated Circuit
US 2569347 · 1951 · Bell Telephone Laboratories Inc
The Invention of the Junction Transistor
US 2524035 · 1950 · Bell Telephone Laboratories Inc
The Invention of the Transistor
New to patents?
Common Questions
Frequently Asked Questions
What does How Buried Channel CCDs Move Data Deep Inside Silicon Chips cover?
A foundational 1974 invention that improved how computer chips store and move electrical charges by keeping them away from messy surface defects.
Who owns patent US 3792322?
Individual owns this patent, granted in 1974.
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 3792322 cited by?
This patent has been cited by 22 later patents that build on its ideas.
What problem does this patent solve?
This invention was critical for the evolution of digital imaging and high-speed signal processing. By solving the charge-trapping problem, it enabled the creation of high-quality Charge-Coupled Device (CCD) sensors, which became the standard for early digital cameras and video recorders. It essentially allowed engineers to build more reliable and sensitive silicon-based sensors.
What does this patent NOT cover?
Does not cover charge-coupled devices that store or transfer charge directly on the semiconductor surface.
Same assignee
More from Individual
Patent monitoring