Masashi Nagayama

This inventor holds 42 USPTO granted patents and 9 published patent applications, plus 1 CIPO patent and 12 EPO patents, primarily in Electrophotographic Imaging. Top assignee: Ricoh Company, Ltd.. Active years: 2005-2026.

IDiyas Innovation Intelligence. (2026). Inventor Profile: Masashi Nagayama. Retrieved from https://idiyas.com/inventor/masashi-nagayama

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

USPTO Granted Patents = 42 (Patent Applications = 9)

% Patents Active = 57.1

CIPO Patents = 1

EPO Patents = 12 (Patent Applications = 8)

Average Co-Inventor Count = 5.0

ph-index = 7

Forward Citations = 146(Granted Patents)

Location History:

Numadu, JP (2008)
Numazu, JP (2006 - 2010)
Machida, JP (2011 - 2012)
Mishima, JP (2011 - 2014)
Shizuoka, JP (2005 - 2024)

Company Filing History:

42 out of 28,940

Ricoh Company, Ltd.

patents

Years Active: 2005-2026

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Areas of Expertise:

Electrophotographic

Image Forming Method

Developer

Carrier

Process Cartridge

Toner

Electrostatic

Two-Component Developer

Replenishing Developer

Image Forming Apparatus

Supplemental Developer

42 patents (USPTO):Sort by Forward CitationsExplore Patents

1. 12675063 - Carrier for electrophotographic image formation, developer for electrophotographic image formation, electrophotographic image forming method, electrophotographic image forming apparatus, and process cartridge (2026-07-07),

2. 12436479 - Carrier for forming electrophotographic image, developer for forming electrophotographic image, electrophotographic image forming method, electrophotographic image forming apparatus, and process cartridge (2025-10-07),

3. 12379678 - Carrier for forming electrophotographic image, developer, image forming method, image forming apparatus, and process cartridge (2025-08-05),

4. 12372893 - Carrier, developer, image forming method, and process cartridge (2025-07-29),

5. 12306582 - Carrier for forming electrophotographic image, developer for forming electrophotographic image, electrophotographic image forming method, electrophotographic image forming apparatus, and process cartridge (2025-05-20),

6. 12147192 - Carrier for developing electrostatic latent image, two-component developer, image forming apparatus, process cartridge, and image forming method (2024-11-19),

7. 12105472 - Carrier for forming electrophotographic image, developing agent for forming electrophotographic image, method of forming electrophotographic image, electrophotographic image forming apparatus, and process cartridge (2024-10-01),

8. 11934145 - Developing apparatus, developer for electrophotographic image formation, electrophotographic image forming method, and electrophotographic image forming apparatus (2024-03-19),

9. 11106150 - Carrier, developer, method, and apparatus for forming electrophotographic image, and process cartridge (2021-08-31),

10. 10474051 - Carrier for developer of electrostatic latent image, two-component developer, replenishing developer, image forming apparatus, and toner stored unit (2019-11-12),

11. 10444651 - Carrier, developer, supplemental developer, image forming apparatus, image forming method, and process cartridge (2019-10-15),

12. 10274856 - Toner for electrophotography, image forming method, and process cartridge (2019-04-30),

13. 10203620 - Toner, image forming method, and process cartridge (2019-02-12),

14. 10025214 - Carrier, developing agent, image forming apparatus, image forming method, replenishment toner, and process cartridge (2018-07-17),

15. 9946177 - Carrier, two-component developer, image forming apparatus, process cartridge, and image forming method (2018-04-17),

Title: **The Innovative Contributions of Masashi Nagayama**

Introduction: Masashi Nagayama, based in Shizuoka, Japan, is an esteemed inventor in the field of electrophotography. With a remarkable total of 37 patents, Nagayama has played a significant role in advancing technologies related to image formation and development. His latest contributions showcase his dedication to innovation and improvement in the imaging industry.

Latest Patents: Among Masashi Nagayama's recent patents are a series of inventions focusing on carriers for developing electrostatic latent images, two-component developers, image forming apparatuses, process cartridges, and image forming methods. One notable patent describes a carrier designed for developing an electrostatic latent image, which comprises a core particle with an internal void ratio of 0.0% to 2.0% and a coating layer containing flat chargeable particles. This innovative carrier achieves an apparent density ranging from 2.0 to 2.5 g/cm, allowing for efficiency in the imaging process.

Career Highlights: Currently, Masashi Nagayama is employed at Ricoh Company, Ltd., where he continues to push the boundaries of imaging technology. His work is characterized by a commitment to excellence and a profound understanding of electrophotography, which has led him to secure multiple patents that enhance the performance and quality of imaging systems.

Collaborations: Nagayama's collaborative efforts with fellow inventors, including Saori Yamada and Hisashi Nakajima, illustrate the teamwork and shared expertise within the field. These partnerships have undoubtedly contributed to the successful development of innovative imaging technologies and solutions.

Conclusion: Masashi Nagayama's significant contributions to the field of electrophotography through his inventive patents highlight his expertise and commitment to innovation. His work at Ricoh Company, Ltd. and collaboration with talented coworkers continue to influence the advancement of imaging technology, establishing him as a key figure in the industry.

Profile summary based on public USPTO records.