# 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. - **Patent:** US 3792322 - **Original title:** Buried channel charge coupled devices - **Owner:** Individual - **Granted:** 1974 - **Status:** Public domain (expired) - **Times cited:** 22 - **Field:** semiconductors, consumer_electronics ## What it does 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. ## 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. ## 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. ## Real-world examples 1. Digital camera image sensors 2. Early digital video camcorders 3. High-speed analog signal delay lines ## Why it matters 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. ## 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. **Full plain-English explainer:** https://patentbrief.org/patent/us/3792322/ccd-image-sensor **Original patent:** https://patents.google.com/patent/US3792322 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [The First Digital Camera's Core Technology](https://patentbrief.org/patent/us/4131919/digital-camera-electronic-still) — Kodak's 1978 patent on the fundamental technology for capturing, processing, and storing digital images using a CCD sensor and magnetic tape. - [How a Modern Camera Sensor Captures Light and Converts It to Data](https://patentbrief.org/patent/us/5471515/cmos-active-pixel-image-sensor) — This patent describes a camera sensor technology that combines light-capturing elements with a special circuit to read out the image data quickly and efficiently, all on a single chip. - [How Multi-Level Cell Memory Stores More Data in Less Space](https://patentbrief.org/patent/us/5903495/semiconductor-device-and-memory-system) — Toshiba's 1999 patent describes a method for storing multiple bits of data in a single memory cell by precisely controlling voltage levels during programming. - [The Invention of the Modern Field-Effect Transistor](https://patentbrief.org/patent/us/3102230/mosfet-field-effect-transistor) — This 1960 patent describes the fundamental structure of the MOSFET, the tiny electronic switch that powers every modern computer processor. - [How Flash Memory Cells Use an Erase Gate to Clear Data](https://patentbrief.org/patent/us/4531203/nand-flash-memory) — This 1985 patent describes the foundational structure of flash memory, introducing an 'erase gate' that allows data to be electrically wiped from a memory cell.