The Hongneung Small and Medium-Sized Enterprise Special Zone is a medical, bio, and healthcare cluster equipped with academia, industry, research, and hospitals, discovering and supporting deep-tech startups in various fields. Introducing promising deep-tech startups that are poised to make a mark on the global market from Korea.

LuminaX is a deep-tech startup leading innovation in medical imaging technology. LuminaX has developed a carbon nanotube-based cold cathode X-ray tube (hereafter referred to as cold cathode X-ray tube) that addresses the drawbacks of conventional hot cathode X-ray tubes, such as unnecessary X-ray exposure, high energy consumption, and slow response time. LuminaX has achieved a performance 20 to 30 times higher than existing cold cathode X-ray tubes by implementing a cold cathode X-ray tube with an output of 5.5kW. As a result, it can be applied not only to X-ray imaging diagnostic devices but also to security screening and non-destructive testing X-ray devices.

LuminaX is currently conducting or planning demonstration tests with five domestic X-ray imaging diagnostic device manufacturers and plans to enter overseas markets starting with participation in overseas exhibitions in the fourth quarter of this year. The company is also seeking investment for global expansion and mass production.

Meeting with the leaders of LuminaX, Cheoljin Lee and Hyunje Lee, to discuss the cold cathode X-ray tube technology.


Startup based on 30 years of research achievements

IT Donga: Hello, Mr. Cheoljin Lee and Mr. Hyunje Lee. Please introduce yourselves first.

Cheoljin Lee: Hello, I am Cheoljin Lee from LuminaX. Over the past 30 years, I have published 203 SCI papers, achieved 15,862 citations, registered 21 international patents, and 63 domestic patents through research conducted as a university professor. In 2023 and 2024, I was selected as one of the top 2% researchers worldwide by Elsevier and Stanford University. I founded LuminaX in January 2022 as a faculty startup while serving as a professor in the Department of Electrical and Electronic Engineering at Korea University and have been focusing on developing commercialization technology for cold cathode X-ray tubes since retiring in February 2024.

Hyunje Lee: Hello, I am Hyunje Lee from LuminaX, serving as a co-representative with Cheoljin Lee. I graduated from the Department of Electrical and Electronic Engineering at Korea University and obtained a Ph.D. from the Department of Electrical and Computer Engineering at Cornell University in the United States, researching next-generation semiconductor devices. During that time, I participated in research projects by DARPA, NSF, and Intel, published 12 SCI papers, and filed one international and one domestic patent.

I joined LuminaX in August 2022, right after obtaining my Ph.D. I intended to join the startup from the beginning but was slightly delayed due to completing my Ph.D. program. At LuminaX, I am responsible for overall research and development and business operations.

IT Donga: I heard you are father and son, which is impressive that you started a business together.

Cheoljin Lee: Hyunje Lee and I are father and son, as well as alumni of Korea University, mentor and mentee in the Department of Electrical and Electronic Engineering, and co-founders of LuminaX. We have similar doctoral research fields and share a common goal of commercializing university laboratory technology, which led us to co-found the company. We are currently dedicated to developing commercialization technology based on the core technology of cold cathode X-ray tubes.

In Korea, there are few cases of father-son startups compared to advanced countries, but it is not uncommon overseas. Especially in the United States, Germany, and Japan, there are many companies founded and grown by fathers and sons.


IT Donga: What was the motivation for founding LuminaX?

Cheoljin Lee: I have long focused on improving the drawbacks of conventional hot cathode X-ray tubes with cold cathode X-ray tube technology and researched the characteristics and fabrication methods of electron emitters using carbon nanotube thin films. As a result, I was able to secure the core technology for cold cathode X-ray tubes. Subsequently, I contemplated ways to develop this core technology into commercialization technology, which was not easy. Developing commercialization technology requires specialized knowledge and highly trained professionals who understand the core technology of cold cathode X-ray tubes. Therefore, we, who have a high understanding of the core technology and have secured extensive experience and technical expertise in the related field, decided to develop the commercialization technology ourselves.

Additionally, I have always felt regret that there are very few cases in Korea where core technologies secured by university laboratories are developed into commercialization technologies that contribute to human society and create high added value through technology. Therefore, I decided to take this opportunity to create a successful case of commercializing university laboratory core technology and took on the challenge. Through LuminaX, I hope to spread a startup culture for the commercialization of university laboratory core technology in Korea.

LuminaX cold cathode tube capable of replacing existing X-ray tubes

IT Donga: What kind of company is LuminaX?

Hyunje Lee: LuminaX is a deep-tech startup in the medical imaging technology field. We develop carbon nanotube-based cold cathode X-ray tubes applicable to X-ray imaging diagnostic devices based on core technologies related to nanomaterials, cold cathode electron emitters, and cold cathode X-ray tubes. For reference, LuminaX is a compound word of 'Lumina,' meaning light in Latin, and 'X,' meaning X-ray.

IT Donga: Cold cathode X-ray tubes are somewhat unfamiliar. Could you introduce the product?

Hyunje Lee: Conventional X-ray imaging diagnostic devices use hot cathode X-ray tubes. This method generates X-rays by applying about 2000 degrees of heat to a tungsten filament to emit electrons. Hot cathode X-ray tubes have drawbacks such as causing unnecessary X-ray exposure to medical staff, high energy consumption due to operation, and slow operation time.


Our cold cathode X-ray tube can improve the drawbacks of existing X-ray tubes. It emits electrons by applying a small voltage instead of heat to carbon nanotubes, reducing unnecessary X-ray exposure, operating at low energy, and generating less heat. It also allows for fast operation and free adjustment of X-ray doses.

Of course, cold cathode X-ray tubes existed before. However, they generated very low X-ray doses, limiting their application to portable oral radiography devices used in dentistry. We increased the electron emission properties of carbon nanotube materials and designed a new electron emitter structure to enhance X-ray output.

Currently, the LuminaX cold cathode X-ray tube implements a maximum operating current of 50mA, a maximum operating voltage of 120kV, and an output of 5.5kW. This is 20 to 30 times higher output than existing cold cathode tubes, allowing it to be used in a variety of medical and dental diagnostic applications similar to conventional hot cathode tubes. This means it can replace existing X-ray tubes in most medical and dental diagnostic device fields.

IT Donga: Can it be used outside the medical field?

Hyunje Lee: It can be applied to various medical areas such as dental diagnostics and veterinary X-ray imaging diagnostic devices, real-time X-ray fluoroscopy devices, and portable devices. When applied to portable imaging diagnostic devices, it can be easily used in remote areas with limited access to medical services. Additionally, it can be applied to security screening devices needed at airports and ports, non-destructive testing devices used in the semiconductor, battery, precision machinery, and defense industries, and industrial X-ray inspection devices.

Demonstration tests with five domestic companies, overseas market entry next year

IT Donga: Please tell us about the current business progress.

Cheoljin Lee: We have completed the development of a commercialized product for cold cathode X-ray tubes and are conducting or planning demonstration tests for system application with five major domestic X-ray imaging diagnostic device manufacturers. The demonstration tests are scheduled to be fully conducted by early next year, and after the demonstration tests, it is expected to be applied to X-ray imaging diagnostic devices.

In November this year, we plan to showcase the cold cathode X-ray tube at the global medical device exhibition MEDICA2025 in Germany. We will hold meetings with overseas X-ray imaging diagnostic device manufacturers and pursue cooperation on-site. Based on this, we plan to start full-scale overseas expansion from next year. Since there are no high-power cold cathode X-ray tube commercialization cases overseas, such as in the United States, Japan, and Germany, overseas expansion is expected to proceed quickly.

Additionally, we are conducting research and development projects selected for government support programs such as the Ministry of SMEs and Startups' Deep-Tech Private Investment-Led Technology Startup Support (TIPS) program and the Super Gap Startup 1000+ Project based on cold cathode X-ray tube technology. We successfully completed seed investment attraction last year and plan to proceed with pre-series A investment attraction soon. Based on this, we aim to secure global market entry, mass production technology for cold cathode X-ray tubes, and establish production facility infrastructure.


IT Donga: You are currently receiving support from the Hongneung Small and Medium-Sized Enterprise Special Zone. What kind of support have you received?

Hyunje Lee: We have received a lot of help necessary for business development through the Hongneung Small and Medium-Sized Enterprise Special Zone. We expanded our connections with investors through investment-related corporate presentations and secured networks with other startups through scale-up networking days. We were introduced to government support projects through conferences and investment consultations and received consultations on investment and product demonstration support projects.

IT Donga: Lastly, please tell us about your future plans and goals.

Hyunje Lee: We will strive to successfully complete the ongoing demonstration tests and seamlessly continue to supply commercialized products. We plan to expand our business areas to various fields such as security screening and non-destructive testing while preparing for global market entry.

We aim to establish LuminaX as a global leader in the X-ray technology and industry field by supplying LuminaX cold cathode X-ray tubes to X-ray diagnostic device manufacturers in various regions and ultimately grow into a unicorn company. Through this, we want to create a successful case of commercializing university laboratory core technology and become a model case leading the startup culture of university laboratories and research institutes in Korea.

IT Donga Reporter Han Man-hyuk (mh@itdonga.com)

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