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For the Inventor, By the Inventor

Kawagoe, Japan

Youichi Nakazato

This inventor holds 13 USPTO granted patents. Top assignees: Kotobuki Co., Ltd., Kotobuko & Co., Ltd.. Active years: 1990-1997.

IDiyas Innovation Intelligence. (2026). Inventor Profile: Youichi Nakazato. Retrieved from https://idiyas.com/inventor/youichi-nakazato

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

USPTO Granted Patents = 13

% Patents Active = 100.0

Average Co-Inventor Count = 3.6

ph-index = 7

Forward Citations = 107(Granted Patents)


Location History:

  • Saitama, JP (1991 - 1992)
  • Kawagoeshi, JP (1991 - 1994)
  • Kawagoe, JP (1990 - 1997)
  • Saitama-ken, JP (1997)

Company Filing History:

goldMedal12 out of 294 
 
Kotobuki Co., Ltd.
 patents
silverMedal1 out of 1 
 
Kotobuko & Co., Ltd.
 patent

Years Active: 1990-1997

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13 patents (USPTO):Explore Patents
1. 5700101 - Writing tool (1997-12-23),
2. 5683191 - Writing tool (1997-11-04),
3. 5370471 - Writing tool, with eraser dispenser (1994-12-06),
4. 5236270 - Writing tool for advancing lead with eraser dispenser (1993-08-17),
5. 5207522 - Knock type mechanical pencil with retractable eraser (1993-05-04),
6. 5090831 - Writing instrument (1992-02-25),
7. 5074694 - Latch mechanism for retractable writing instruments (1991-12-24),
8. 5062727 - Writing tool (1991-11-05),
9. 5022774 - Writing tool with eraser dispenser (1991-06-11),
10. 5018891 - Writing instrument with eraser dispenser (1991-05-28),
11. 4973179 - Clip actuated latch mechanism for retractable writing instruments (1990-11-27),
12. 4957384 - Mechanical pencil (1990-09-18),
13. 4955739 - Mechanical pencil having side push button actuated lead advance (1990-09-11),

Title: The Innovative Mind of Youichi Nakazato

Introduction

Youichi Nakazato is a prominent inventor based in Kawagoe, Japan. He has made significant contributions to the field of writing tools, holding a total of 13 patents. His innovative designs have enhanced the functionality and usability of everyday writing instruments.

Latest Patents

One of Nakazato's latest inventions is a sophisticated writing tool, which can be a mechanical pencil or a ballpoint pen. This writing tool features a writing shaft with a head member that is inserted into an outer sleeve, allowing the head member to project outward. The design includes a stair or step and a spiral groove on the inner surfaces of a tubular cap. The spiral groove's rear part has a larger inside diameter, facilitating smooth operation. A bearing part contacts a lead tank within the forward part of the tubular section, enabling axial movement while locking the outer sleeve against rotation. Additionally, the tubular body has a slit that accommodates holding pieces for a stick-shaped object holder, ensuring that the object is securely held in place.

Career Highlights

Throughout his career, Youichi Nakazato has worked with notable companies, including Kotobuki & Co., Ltd. and Kotobuko & Co., Ltd. His experience in these organizations has contributed to his expertise in developing innovative writing tools.

Collaborations

Nakazato has collaborated with talented individuals such as Yosh

Profile summary based on public USPTO records.
Data Sources: USPTO Patent Grant XML, Patent Center, EPO & CIPO • Normalized by IDiyas Innovation Graph. Methodology & provenance architecturePlease report any incorrect information to [email protected]
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