US 7071626

Patent Overview — US 7,071,626 B2

Title: Plasma generator
Inventor: Manabu Harada
Original/Current Assignee (per listing): Marukomu KK / Kabushiki Kaisha Marukomu
Priority date: 2003-11-10 · Filing date: 2004-01-16 · Grant/publication date: 2006-07-04
Application number: US 10/759,955 · Other version: US 2005/0099134 A1
Legal status (as listed, not a legal conclusion): Expired – Fee Related; adjusted expiration 2024-08-20

Purpose. The patent addresses a trade-off in plasma generators used for deodorizing, bactericidal and air-cleaning apparatus: discharge between electrodes produces plasma whose ions/activated species (radicals) decompose airborne harmful substances (bacteria, viruses, pollen), but inevitably generates ozone, which is harmful and is environmentally limited to at most 0.05 ppm by, e.g., the Japan Air Cleaning Association. The stated object is to reliably decompose or remove harmful substances while preventing or controlling ozone generation.

Plain-language scope. In the disclosed arrangement, band plate-like first and second electrodes sit on opposite surfaces of a flat dielectric and are relatively displaced in the dielectric's surface direction, satisfying Equations 1–3 (not reproduced in the excerpt). The displacement quantity L₁ is the offset between the first electrode's front end edge A and the second electrode's corresponding end edge B; θ₂ is the "displacement angle" formed by an imaginary plane through A and B relative to the dielectric's thickness direction; d is dielectric thickness. Preferred values mentioned: θ₂ at least 45°; L₁/d from 1 to 3; applied voltage 2.5–3.5 kV. Alternative arrangements claimed include electrodes spaced in the same plane, and dielectric-film-coated electrode surfaces, each satisfying Equation 4. The stated mechanism is that lower average electron energy in the discharge field enlarges the ozone-molecule collision cross-section, promoting ozone decomposition via low-energy electron collisions, while displacement preserves electrostatic capacity and activated-species formation efficiency.

Source: https://patents.google.com/patent/US7071626/en

What the excerpt does not establish. It does not reproduce the actual text of Equations 1–4, all claims, the full description or drawings; it does not establish enforceability, validity, ownership history, or prior-art scope; and it provides no litigation or prosecution information.