LetinAR's metaverse technology- patents of optical system of AR glasses

LetinAR is a privately held company that participated in the development of optical and display modules of Maxst, a KOSDAQ-listed company. I will try to briefly explain an AR glasses technology and related patents in an easy-to-understand manner.

As of the time of posting, LetinAR has 34 AR glasses-related patents to protect a pinMR technology from various ways. You will be able to understand without taking a long time to understand LetinAR's technology that would affect the stock price if it is listed in the future. Let's find out together what LetinAR is developing from patent point of view

1. LetinAR with the technology of AR glasses optics

LetinAR, established in October 2016, is a company that develops optical systems for AR glasses to lead the popularization of augmented reality. LetinAR received the PRISM AWARDS from SPIE, the highest optical society in the United States, and recently won the CES 2022 Innovation Award for its ultra-light binocular plastic AR optics, recognized worldwide for its technological prowess. Based on this technological prowess, LetinAR is a promising company that has invested more than 15 billion won by domestic representative companies such as Naver, Kakao, and KB Investment.

LetinAR recently developed an optical display module for smart glasses from 'Maxst', a company that provides an AR development platform. Maxst is a consortium organizer of the XR metaverse project contest being promoted by the Ministry of Science and ICT and the Korea Radio Promotion Association as part of the digital new deal project.

2. AR Glasses that implements Augmented Reality(AR) contents

The AR Glasses is a wearable electronic device in the form of glasses that implements Augmented Reality contents on a transparent lens. A virtual image in the Augmented Reality contents  is implemented on the display built into the AR glasses, making it appear as if it were actually there.

LetinAR's T Glasses_from: LetinAR's official website

The AR glasses technology, essential for realizing Augmented Reality, is a technology that global giants such as Samsung Electronics, Qualcomm, Google, Xiaomi, Apple, Microsoft, Facebook, and Amazon are making large-scale investments and development as the next-generation industry. The demand for the AR glasses in the future will expand tremendously to the extent that it is predicted that the next stage of the smartphone will be the AR glasses.

Currently, the AR glasses has various problems for commercialization. First of all, there is a limit to making the form factor small in the form of glasses due to complex optical system structure applied to display Augmented Reality content. If the form factor is not miniaturized, there is a problem that it is difficult for users to use the AR glasses as a normal glasses in daily life, and it is difficult to wear them for a long time due to its weight. In addition, there are problems such as narrow field of view, out of focus between real and virtual objects, color bleeding, complex product structure, weight, and heat. Numerous global leaders developing AR glasses have tried to implement Augmented Reality using Half-Mirror Combiner, Diffractive/Holographic Waveguide or Geometrical Waveguide, but it has not been enough to commercialize AR Glasses. The reasons are mainly due to the bulky form factor, narrow viewing angle, poor color representation, high price, high manufacturing cost, and complex manufacturing process due to the complex structure of the optical system. In order to commercialize AR glasses, these problems must be solved. As will be explained below, LetinAR's pin-mirror(pinMR) technology seems to be a breakthrough technology that has solved the above problems.

3. LetinAR's AR glasses that uses the pinhole effect to solve the problems of existing AR glasses

The pin-mirror (PinMR) technology invented by LetinAR was inspired by the pinhole effect. The pinhole effect is the effect that when a person observes an object in front through a small pinhole placed in front of him, the object is clearly visible. LetinAR's core technology, pinMR lens, is a technology that shows a virtual image by putting a mirror smaller than 1 mm between two thin lenses. Its originality and excellence have already been recognized by global companies and academia. AR glasses with pin-mirror lenses are smaller than the optical systems of AR glasses being developed by other companies, have a wider viewing angle, and have clear colors.

optical system applied LetinARs pinMR technology_field of view, sharpness and color representation_from: LetinAR's official website

4. Summary of patents related to LetinAR's AR glasses - micro-sized pinMR using the pinhole effect

Let's analyze the registered patents in the order in which they were registered. four patents below are all patented technologies for pinMR applying the pinhole effect. Among the contents of the patented technologies, only the core of the technical idea is summarized.

(1) Augmented Reality Implementation Device (Korean Registration Patent No. 10-1660519)

This patent can be viewed as the original patent of pinMR. The characteristic of this patent is to have a mirror with a circular shape of 2 mm or less as the core of the technical idea. In general, the pinhole effect may appear when the size is 5 mm or less, but in the present invention, when the size of the mirror is 2 mm or less, a deep depth of field can be formed.

Figure from: Korean Registration Patent No. 10-1660519

Here, depth of field refers to the area in which focus is clearly captured. Therefore, the formation of a deep depth of field means a wider range of focus, which means that the augmented reality of AR glasses with pinMR can be seen more clearly than other products.

(2) Augmented reality realization device with depth control function (Korean Registration Patent No. 10-830364)

This patent can be regarded as an improved invention of the patent described above. In order to secure high sharpness, the pinMR size should not be just less than 2 mm, but should be as small as 50 to 700 micrometers. In addition, if the pinMR becomes smaller, the user can see only the real world and virtual reality contents neatly without seeing the pinMR in the field of view even when wearing AR glasses.

real world + augmented reality from: Korean Registration Patent No. 10-830364

This patent has been applied for in the United States and China and is currently registered in the United States, and China is under examination.

<Note>

In accordance with the principle of territoriality, if a patent is filed in Korea, the effect of the patent extends only to Korea. Since the procedure to obtain a patent registration abroad is very costly, a patent that are considered important usually go through the procedure to be registered as a patent abroad.

(3) Reflective lens module (Korean Registration Patent No. 10-1894555)

The above patents have a category of 'augmented reality device' (ie, AR glasses), but this patent is an invention with a different category as a 'reflecting lens module' (ie, pinMR). Although pinMR is implemented in AR glasses, it is an optical system that can be extended to various fields as well as AR glasses.

Figure from: Korean Registration Patent No. 10-1894555

(4) Optical device (Korean Registration Patent No. 10-1894556)

The core of this patent is the arrangement of a refractive optical element, a diffractive optical element, or a reflective optical element between pinMR and a display device that projects an image on the pinMR in AR glasses.

This patent places a refractive optical element, a diffractive optical element, or a reflective optical element on the optical path between the display device and pinMR, so that the path of the image from the display device can be adjusted. Therefore, the light path can be adjusted no matter where the display device is placed, so it has the advantage of placing the display device in an optimized position on the AR glasses. In the drawing below, the display device is the part marked with reference number 100.

Optical path(left) on which refractive optical element is arranged and optical path(right) on which reflective optical element is arranged from Korean Registration Patent No. 10-1894556

This patent has been registered not only in Korea, but also in the United States, China and Japan, and appears to be one of Letinal's core patents.

(5) summary

Let's take a look at the four early patents of LetinAR. In summary, the four patents can be considered as patents to protect the configuration of i) pinMR having a size that can cause pinhole effect and ii) optical elements to diversify the path that transmits images to pinMR. pinMR will become an essential technology to implement the metaverse of Augmented Reality in the future.