Location History:
- Hitachi, JP (1987 - 2002)
- Ibaraki, JP (1999 - 2009)
Company Filing History:
11 out of 1,267 
7 out of 42,485 
3 out of 129 
Years Active: 1987-2009
Title: **Hisao Okada: A Pioneer in Electrophotographic Innovation**
Introduction
Hisao Okada, based in Ibaraki, Japan, is a notable inventor with a remarkable portfolio of 21 patents. His contributions primarily focus on advancements in electrophotographic technology, showcasing his innovative mindset and technical expertise in developing devices and apparatuses that enhance image processing.
Latest Patents
Among his latest achievements, Hisao Okada has patented developments in electrophotographic apparatuses. One of his key patents describes an electrophotographic apparatus that features a photoconductor and two developing rollers, which work in tandem to effectively supply developer material to form toner images. Notably, the developer incorporates a carrier with a volume-average particle size smaller than 70 µm and a volume resistivity exceeding 10 Ω·cm. Furthermore, the patent specifies that the volume ratio of the carrier between the photoconductor and the developing rollers should be maintained between 30% and 46%.
Another significant patent pertains to a color image forming apparatus that utilizes a developing unit where a developing bias with an AC component is applied. This innovative system adjusts the DC voltage of the bias to set the density of a solid image to a specified value. Additionally, the apparatus regulates the gradation density curve by alternating adjustments in DC voltage, radiation light amounts, and AC component amplitudes to achieve optimal results in image quality.
Career Highlights
Hisao Okada has worked with leading companies in the technology sector, including Hitachi Koki Co., Ltd. and Hitachi, Ltd. His experience and knowledge gained during his tenure at these companies have greatly influenced his inventive work, allowing him to contribute to groundbreaking solutions in the field of electrophotography.
Collaborations
Throughout his career, Hisao Okada has collaborated with esteemed colleagues such as Teruaki Mitsuya and Tsuneaki Kawanishi. These partnerships have played a vital role in nurturing innovation and advancing technology within their projects.
Conclusion
Hisao Okada's dedication to innovation in electrophotographic technology is evidenced by his numerous patents and impactful collaborations. His advancements not only showcase his exceptional skills as an inventor but also pave the way for future developments in the field.
Inventor’s Patent Attorneys refers to legal professionals with specialized expertise in representing inventors throughout the patent process. These attorneys assist inventors in navigating the complexities of patent law, including filing patent applications, conducting patent searches, and protecting intellectual property rights. They play a crucial role in helping inventors secure patents for their innovative creations.