KR20230024658A - Method for controlling near eye display optical system - Google Patents

Abstract

Disclosed is a method of controlling an optical system for a near-eye display for transmissive smart glasses having a glasses frame and a pair of lenses coupled to the glasses frame. The optical system to which the control method is applied includes an optical signal emitting unit, a video display unit and a filter unit. The optical signal emitting unit is coupled to the leg of the glasses frame and emits an optical signal for displaying a two-dimensional image toward the inner surface of a lens. The image display unit is coupled to each of the lenses, and includes an optical signal processing unit which selectively reflects only predefined wavelengths in the direction of the eyes of a wearer of the smart glasses with respect to the optical signal emitted from the optical signal emitting unit and processes the optical signal transmitted to the image display unit. The optical signal processing unit processes the optical signal based on the inner shape of the lens. The filter unit is installed integrally with the lens to which the image display unit is coupled, and blocks light passing through the lens. In the optical system control method, the filter unit is turned on/off to control light passing through the lens to pass through or to be blocked. According to the present invention, the wearer can watch the only two-dimensional image displayed on the image display unit with immersion.

Description

Control method of optical system for display {Method for controlling near eye display optical system}

The present invention relates to a wearable display device, and more particularly, to a control method for an optical system for a near eye display (NED) such as a head mounted display (HMD) or smart glasses will be.

Recently, metaverse-related technologies have been receiving widespread attention. Metaverse is a compound word of the English word meta, which means 'virtual' and 'transcendence', and universe, which means universe. Metaverse is a concept that has evolved one step further than Virtual Reality (VR), and is characterized by using avatars to not only enjoy games or virtual reality, but also to engage in social and cultural activities like real life. With the commercialization of 5G communication technology and the development of technologies that can implement VR, Augmented Reality (AR), and Mixed Reality (MR), the scope of application of the metaverse is gradually expanding in reality.

One way to implement the metaverse is to use an optical system for NED. The optical system for NED focuses image light generated at a location very close to the eye using a precise optical device to form a large virtual screen at a distance so that the user can see an enlarged virtual image. It is a video display device. Optical systems for NEDs, such as optical systems for HMDs, were originally used for military purposes. The necessity and possibility of an optical system that can be applied to an HMD device or a Glass Type Monitor (GTM) device as a wearable device according to the present study were studied.

These optical systems for NED include a double-plate binocular type that forms independent light paths for both eyes in two display elements, a single-plate binocular type that forms symmetrical light paths for both eyes using one display element, and one It is divided into a single plate monocular that provides a light path only for one eye among both eyes from the display device.

A NED device including an optical system for NED is manufactured in the form of a smart glass device including a glasses-type monitor, a head-mounted display (HMD) device, etc., and utilizes information communication technology and image processing technology, Its applications are expanding to virtual experience devices, video game machines, and virtual training systems that provide smart environments such as virtual reality (VR), augmented reality (AR), and mixed reality (MR).

These NED devices can be divided into a see-closed type and a see-through type. Since the blocking type NED device blocks the wearer's vision at around 25 mm from the pupil and sees the image in a darkened state, there are problems that cause various side effects to the human body, such as increased eye fatigue when worn for a long time, as well as mixed reality ( It is not applicable to applications that utilize MR). On the other hand, in the case of a transmissive NED device, the wearer can view not only the displayed image but also the actual external image.

Various structures have been proposed as optical systems applied to NED devices. For example, Korean Patent Publication No. 2018-0039576, “Eye-proximity display with stacked light guides” (Patent Document 1), Korean Patent Publication No. 2020-0007965, “Display device including a light guide” (Patent Document 1) 2), US 2020/0301149 A1 “Virtual and augmented reality systems and methods having improved diffractive grating structures” (Patent Document 3) each discloses an optical system for a NED device.

However, the optical systems disclosed in Patent Literature 1 to Patent Literature 3 transmit image signals using light waveguides manufactured in the form of prisms having a predetermined thickness and three-dimensional structure. As a result, the optical system is bulky and has a complicated structure. In addition, since a structure in which an optical waveguide is to be installed is required, it is difficult to apply to a glasses-type display device having a compact structure such as a smart glass.

Korean Patent Publication No. 2020-0002616, "Wearable smart optical system using a holographic optical element" (Patent Document 4) proposes one method for solving the disadvantages of such a conventional optical system. More specifically, the optical system disclosed in Patent Document 4 is for a transmissive NED device, and is recorded in a hologram optical element (HOE) to have an asymmetrical reflection that aligns only predefined wavelengths to the center of the eye in the form of a film. The HOE image display unit composed of the fabricated wavelength-selective transparent reflector expands the image represented by the incident light signal to a size as much as the predetermined reflection angle in a state arranged parallel to the eye, and displays it as a converged image so that the eye can see it. 1 shows an example of a wearable smart optical system disclosed in Patent Document 4.

According to the optical system disclosed in Patent Document 4, the optical signal emitted from the optical signal emitter is incident on the HOE image display unit, and the HOE image display unit reflects only the optical signal of a previously selected wavelength among the incident optical signals toward the eyes. Such an HOE image display unit may be manufactured in the form of a film that is laminated or adhered on an aspheric lens by recording only predefined wavelengths in the HOE to perform asymmetric reflection aligned with the center of the eye, and manufacturing the HOE image display unit in the form of a film.

However, when the optical system disclosed in Patent Document 4 is implemented as a spectacle-type device, the HOE image display unit is implemented on all or part of the aspheric curved spectacle lens or bonded to the surface thereof. In addition, it is easy to implement the optical signal emitting unit in the frame of glasses, especially in the bridge of glasses or the connection part of the lens of glasses. can only be

As a result, since the distance between the optical signal emitting unit and the HOE image display unit varies depending on the area in the HOE image display unit, the light signal emitted from the optical signal emitting unit and reflected from the HOE image display unit toward the eye, that is, the HOE video display unit The displayed 2D image optical signal may have a phenomenon in which its shape (eg, a rectangular image) is distorted.

However, the conventional optical systems described above are all transmissive NED devices, and the wearer can view not only the displayed image but also the actual external image. There are downsides to making it difficult.

Korean Patent Publication No. 2018-0039576 Korean Patent Publication No. 2020-0007965 US Patent Publication US 2020/0301149 A1 Korean Patent Publication No. 2020-0002616

One problem to be solved by the present invention is an optical system in which an optical signal emitted from an optical signal emitter is incident on an HOE image display unit, and the HOE image display unit reflects only an optical signal of a previously selected wavelength among the incident optical signals toward the eyes. A display capable of preventing external images from entering the eyes while the image is displayed on the HOE image display unit of the wearer of the smart glasses and preventing the 2D image optical signal from being distorted and displayed on the HOE image display unit having an aspherical curved shape It is to provide a control method of an optical system for use.

An embodiment of the present invention for solving the above problems is a method for controlling an optical system for a near-eye display for transmissive smart glasses having a spectacle frame and a pair of lenses coupled to the spectacle frame, the optical system comprising: It includes a signal emitting unit, an image display unit and a filter unit, wherein the optical signal emitting unit is coupled to the leg of the eyeglass frame and emits an optical signal for displaying a two-dimensional image toward the inner surface of the lens, and the image display unit It is coupled to each of the lenses, and selectively reflects only a predefined wavelength in the direction of the eyes of the wearer of the smart glasses with respect to the optical signal emitted from the optical signal emitter and transmits the optical signal incident to the image display unit. and an optical signal processing unit for processing the optical signal based on the shape of the inner surface of the lens, wherein the filter unit is integrally installed in the lens to which the image display unit is coupled, and controls light passing through the lens. By blocking, the light passing through the lens is controlled to pass or be blocked by turning on/off the filter unit.

According to one aspect of the embodiment, a wearer wearing the smart glasses can control on/off of the filter unit. In this case, the optical signal processing unit processes the optical signal so that a two-dimensional image displayed by the optical signal emitted from the optical signal emitting unit corresponds to the inner surface shape of the lens, and the lens has an aspheric curved surface shape. The image display unit is a film-type hologram optical element (HOE) recorded to reflect only the predefined wavelength, and may be coupled to an inner surface of the lens. The optical signal processing unit may process the optical signal to correspond to the shape of the inner surface of the lens at the portion to which the hologram optical element is coupled.

According to the above-described embodiment of the present invention, in the optical system for a spectacle-type near-eye display system such as smart glasses, even if the lens of the smart glasses to which the image display unit is coupled has an aspheric curved surface shape, the two displayed on the image display unit It is possible to prevent deterioration of the image quality of the dimensional image and, if necessary, to block external light passing through the lens, so that the wearer can watch only the 2D image displayed on the image display unit with an immersive degree of immersion.

1 is a diagram schematically showing an example of a wearable smart optical system according to the prior art.
2 is a perspective view showing a schematic configuration of a transmissive smart glass having an optical system for a near-eye display according to an embodiment of the present invention.
FIG. 3 is a plan view of the transmissive smart glasses of FIG. 2 .
4 is a diagram schematically showing an optical signal processing method by an optical signal processing unit.

Hereinafter, preferred embodiments and examples of the present invention will be described with reference to the drawings. However, the following embodiments and examples are merely illustrative of preferred configurations of the present invention, and the scope of the present invention is not limited to these configurations. And in the following description, the hardware configuration and software configuration of the device, processing flow, manufacturing conditions, size, material, shape, etc. are not intended to limit the scope of the present invention to these unless specifically described. .

An optical system for a near-eye display, which is a subject of the control method according to the present invention, is for transmissive smart glasses having a spectacle frame and a pair of lenses coupled to the spectacle frame. An optical system for a near eye display includes an optical signal emitter, an image display unit, and a filter unit. The optical signal emitter includes an optical signal processor for processing an optical signal incident to the image display unit. According to the present invention, the optical signal processing unit processes the optical signal based on the shape of the inner surface of the lens of the smart glasses, and the filter unit controls the passage of light from the outside through the lens.

Such an optical system for a near eye display is applied to a transmissive display device capable of acquiring an image while securing an external field of view. In addition, the optical system receives an image signal from a predetermined electronic device capable of exchanging image data with the optical signal emitter, for example, a mobile computer, a mini computer, a portable computer, a tablet PC, a smart phone, etc. as a user terminal, It is emitted as an optical signal through the emitter, but by processing and emitting an image to correspond to the inner surface of the lens, an image of clear quality can be displayed on the image display unit.

2 is a perspective view showing a schematic configuration of smart glasses having an optical system for a near-eye display according to an embodiment of the present invention. And FIG. 3 is a plan view of the smart glasses of FIG. 2 . In FIGS. 2 and 3 , it is shown that the filter unit 230 is activated only in the left eye lens 24b to block the passage of light from the outside, but this is merely for convenience of description. That is, although not shown in the figure, the filter unit 230 is also provided in the right eye lens 24a and is not activated, so it only looks transparent.

Referring to FIGS. 2 and 3 , the smart glasses 20 have an eyeglass frame 22 and a pair of lenses 24a and 24b coupled to the eyeglass frame 22 . The spectacle frame 22 has the same shape as ordinary spectacles, and has a frame body 22b into which lenses 24a and 24b can be fitted together with legs 22a. In addition, if not shown in the drawings, the glasses frame 22 includes various types of electronic device modules/optical device modules (eg, wired/wireless communication modules, camera modules, sound transmission/reception) according to the type of smart glasses 20 modules, etc.) may be installed.

An optical system for a near eye display according to an embodiment of the present invention for such smart glasses 20 includes an optical signal emitter 210, an image display unit 220, and a filter unit 230.

The optical signal emitter 210 is coupled to the leg 22a of the spectacle frame 22, and emits an optical signal for displaying a two-dimensional image on the image display unit 220 toward the inner surfaces of the lenses 24a and 24b. do. The optical signal emitter 210 emits an optical signal to the inner surfaces of the lenses 24a and 24b, that is, to the surfaces of the lenses 24a and 24b in the direction where the wearer's eye E is located. The optical signal emitter 210 may emit an optical signal to the front of the lenses 24a and 24b, or may emit an optical signal only to the area of the lenses 24a and 24b to which the image display unit 220 is coupled. do.

According to an embodiment of the present invention, the optical signal emitter 210 includes a dot image emitter 212 , a dot image scan unit 214 and an optical signal processor 216 .

In order to display an image on the image display unit 220, the dot image emitter 212 emits red (R), green (G), and blue (B) signals emitted from the laser light source as the dot image signal is applied to the laser light source. Each dot image color tone optical signal is mixed by a mixer to emit a point image color mixing optical signal.

The dot image scanning unit 214 is a two-dimensional MEMS scanner in which a scan mirror is located in the center, and a horizontal synchronization signal that synchronizes the dot image color mixing optical signal emitted from the dot image emitter 212 with the dot image signal Alternatively, the vertical synchronization signal is intermittent with the scan mirror according to time and emitted in the direction of the image display unit 220, so that the image display unit 220 displays a two-dimensional image formed by scanning the dot image color mixing optical signal.

According to a modified example of the present invention, the optical signal emitting unit 200 includes an optical signal emitting device using an organic light emitting diode (OLED) instead of the dot image emitting unit 212 and the dot image scanning unit 214. may be configured. In this case, the light signal emitting device using OLED emits light itself when an image signal is applied to emit a two-dimensional image signal.

Alternatively, the optical signal emitter 210 may be composed of a color light signal emitter, a polarization beam splitter, and a reflective silicon liquid crystal display instead of the dot image emitter 212 and the dot image scan section 214 . In this case, the color light signal emitter emits red (R), green (G), and blue (B) lights sequentially as sequential color signals are applied to the LED RGB light source to display an image on the image display unit 220. The color light signal is emitted through the light pipe, and the polarization beam splitter reflects only one polarized wave of the horizontal polarization signal and the vertical polarization signal constituting the color light signal, and transmits it to the reflective silicon liquid crystal display device. The device polarizes the horizontally polarized signal of the color light signal incident through the polarization beam splitter by 90 degrees and converts it into a vertical color light signal that passes through the polarization beam splitter and reflects it, or converts the vertically polarized signal of the color light signal incident through the polarization beam splitter. The polarized light is polarized at 90 degrees to form a horizontal color light signal that passes through the polarization beam splitter and is reflected so that a two-dimensional image is displayed on the image display unit 220.

2 and 3, the optical signal processing unit 216 is for processing the optical signal emitted from the point image scanning unit 214 and incident on the image display unit 220, and the lenses 24a and 24b The optical signal is processed based on the shape of the inner surface of More specifically, the optical signal processing unit 216 is a dot image so that the two-dimensional image emitted from the optical signal emitting unit 210 and displayed on the image display unit 220 corresponds to the shape of the inner surface of the lenses 24a and 24b. An optical signal emitted from the scan unit 214 is processed.

In general, the optical signal of the two-dimensional image displayed by the optical signals emitted by the dot image emitter 212 and the dot image scan unit 214 has a characteristic of displaying a rectangular image on a flat display surface. It consists of According to this, the size of a unit pixel of an image displayed by an optical signal is the same regardless of position.

However, the lenses 24a and 24b of the see-through type smart glasses 20 are not flat as a whole, like general glasses for correcting vision, and the outer side of the smart glasses 20 (in the direction opposite to the wearer's eye E) ), it has an aspheric curved surface shape in which the central and/or inner portion protrudes convexly. In the optical system according to an embodiment of the present invention, as will be described later, the image display unit 220 is coupled to the lens 24 . As a result, the optical signals emitted by the dot image emission unit 212 and the dot image scanning unit 214 (that is, the optical signal of the two-dimensional image corresponding to the flat display surface) are transmitted directly to the image display unit 220 (ie, When the light is incident on an aspheric curved surface such as the inner surface of the lenses 24a and 24b, the quality of the 2D image displayed on the image display unit 220 is inevitably deteriorated. For example, in the image display unit 220, the portion corresponding to the edge portion (relatively flat area) of the lens 24a or 24b has a constant unit pixel size, so there is no significant difference in image quality, but the central portion of the lens 24a or 24b The portion corresponding to the (curved surface area) increases in unit pixel size, degrading image quality.

However, according to the present invention, with respect to the optical signals emitted by the dot image emission unit 212 and the dot image scanning unit 214, the optical signal processing unit 216 provides the lenses 24a and 24b with the inner shape, more accurately By performing a predetermined process to correspond to the shape of the lens of the portion to which the image display unit 220 is coupled, a clear image is displayed on the aspherical curved image display unit 220. For example, the optical signal processing unit 216 maintains the unit pixel size of the edge portion of the optical signal emitted by the point image scanning unit 214 and reduces the unit pixel size of the central portion. By processing, the image displayed on the image display unit 220 can be made to have the same size of a unit pixel regardless of its location, whether at the center or at the edge.

FIG. 4 is a diagram schematically showing an optical signal processing method by the optical signal processing unit 216, and FIG. 4(a) shows the image display unit 220 ), and FIG. 4(b) shows pixels of the 2D image displayed on the image display unit 220 after being processed by the optical signal processing unit 216.

Referring to FIG. 4, the pixel size of the 2D image processed by the optical signal processing unit 216 does not change at the edge (w1 = w1'), but the center portion is smaller by reflecting the curved shape of the lens. (w1=w2 < w2'). However, FIG. 4 shows that the 2D image by the optical signal processed by the optical signal processing unit 216 is deformed so that the pixel size becomes smaller only in the horizontal direction at the center, but is deformed so that it is reduced in the vertical direction as well. It can be. That is, the pixel size change may occur only in either one of the horizontal direction and the vertical direction, or the pixel size may change in both directions.

According to this embodiment, there is no particular limitation on a specific method for the optical signal processing unit 216 to change the size of a pixel of a 2D image. For example, the optical signal processing unit 216 may process the optical signal by an optical method (a method using various lenses and/or mirrors or a combination thereof). However, the present embodiment is not limited thereto, and an image displayed by an optical signal may be processed using an image processing technology such as digital signal processing.

According to one aspect of the above-described embodiment of the present invention, the optical signal emitter 210 may further include a magnifying lens unit (not shown) if necessary. The magnifying lens unit removes speckle when the two-dimensional image emitted from the optical signal processing unit 216 is displayed on the image display unit 220 and adjusts the incident angle of the point image color mixing optical signal to the image display unit 220. It is preferable to be comprised of one sheet or a plurality of lenses.

The image display unit 220 is coupled to the lenses 24a and 24b, and the optical signal emitted from the optical signal emitter 210 has a predefined wavelength in the direction of the wearer's eyes E of the smart glasses 20. selectively reflect only

This image display unit 220 is produced in the form of a film that is laminated or adhered on the inner surfaces of the aspheric lenses 24a and 24b by recording only the predefined wavelengths on the hologram optical element HOE to perform asymmetric reflection matching the center of the eye. It is a wavelength-selective transparent reflector, and in a state arranged parallel to the eye, the image represented by the incident light signal is enlarged to a size as much as the predetermined reflection angle and displayed as a converged image so that the eye (E) can view it. To this end, the image display unit 220 is preferably made in the form of a thin film made of a photopolymer material and capable of displaying a full color image.

The filter unit 230 is integrally installed on the lenses 24a and 24b. More precisely, the filter unit 230 is installed on portions of the lenses 24a and 24b corresponding to the outside of the image display unit 220 (ie, the direction in which external light is incident). According to this, even if the filter unit 230 is turned on, the image displayed on the image display unit 220 is not blocked from going to the wearer's eyes.

The filter unit 230 is transparent in an off state and does not block external light from passing through the lenses 24a and 24b. On the other hand, when the filter unit 230 is turned on, light from the outside is blocked from passing through the lenses 24a and 24b. The filter unit 230 may block external light 100% or only partially. According to this embodiment, there is no particular limitation on the specific method of implementing the filter unit 230. For example, by applying a predetermined current or a potential difference, the characteristics of a material that changes from a transparent state to a state that blocks the passage of light can be changed. available. For example, the filter unit 230 has a film shape in which light transmittance is adjusted according to the intensity of a predetermined electric signal, and may be coupled or attached to the lenses 24a and 24b.

The on/off control of the filter unit 230 is automatically performed according to a preset procedure or actively controlled according to the surrounding environment or the type of image displayed on the image display unit 220 using artificial intelligence technology. may be Alternatively, depending on the embodiment, it may be arbitrarily controlled by the wearer. In this case, in order to control on/off of the filter unit 230, a specific part of the smart glasses 20, for example, the leg 22a of the glasses frame 22 ) or the filter operation switch 232 may be provided in the frame body 22b.

The optical system for a near eye display according to an embodiment of the present invention operates as follows.

As shown in FIG. 3 , the optical system for a near-eye display according to an embodiment of the present invention is a transmissive type in which a user can acquire an image while securing an external view through the retina of the eye E. In order to display an image on the image display unit 220, a dot image signal is emitted from a terminal electrically connected to the optical signal emitter 210 (eg, mobile computer, smart phone, tablet computer, personal computer, etc.) When applied to the laser light source of the unit 212, the dot image emission unit 223 mixes each of the red (R), green (G), and blue (B) dot image color light signals emitted from the laser light source with a mixer. The created dot image color mixing light signal is emitted. In this case, the dot image color mixing optical signal is emitted in the form of a single dot having a diameter of about 0.7 mm.

Subsequently, when the dot image color mixing optical signal is projected to the scan mirror located at the center of the 2D MEMS scanner of the dot image scanning unit 214, the dot image scanning unit 214 converts the dot image color mixing optical signal into the dot image signal. A two-dimensional image emitted to the image display unit 220 is generated by intermittently using a scanning mirror according to time according to a horizontal synchronizing signal or a vertical synchronizing signal to be synchronized. At this time, the central scanning mirror of the 2D scanner is preferably made of a single dot with a diameter of about 0.7 mm and has an elliptical shape with a width of 0.7 mm and a length of 1 mm to be suitable for scanning the emitted point image tone-mixing optical signal. In addition, the dot image scanning unit 214 uses a scan mirror to scan the dot image color mixing signal in the horizontal direction at a frequency determined according to the resonance operation method, for example, at a frequency of 25 kHz or higher for displaying a full HD level image, , in the vertical direction, it is preferable to scan the dot image color mixing signal by giving the amplitude change of the sawtooth wave or pulse width modulation method. It is possible to create a full HD level video viewed on a TV.

Further, the optical signal processing unit 216 converts the two-dimensional image (optical signal) generated by the dot image scanning unit 214 based on the inner surface shapes of the lenses 24a and 24b to which the image display unit 220 is coupled. perform certain processing on it. For example, when the image display unit 220 is coupled to the aspherical areas of the lenses 24a and 24b, the optical signal processing unit 216 performs a process of adjusting the pixel size of the 2D image, so that the image having a curved shape is imaged. Deterioration of the image quality of the image displayed on the display unit 220 can be prevented. In addition, the dot image color mixing optical signal scanned by the 2D MEMS scanner of the dot image scanning unit 214 and then processed by the optical signal processing unit 216 and emitted to the image display unit 220 is based on the angle at which the scanning mirror moves. is reflected and maintains a fixed angle.

In this way, when a dot image color mixing optical signal maintaining a predetermined angle is incident on the image display unit 220, the image display unit 220 enlarges the image represented by the incident optical signal to a size as much as the predetermined reflection angle and converges so that it can be viewed with the eyes. display in video The two-dimensional image displayed by the dot image color mixing optical signal projected on the image display unit 220 is formed by asymmetric reflection that matches only the predefined wavelength to the center of the eye, and can be viewed with the eyes by enlarging the size by the predetermined reflection angle. It is a converged video.

When a predetermined image is displayed on the image display unit 220, the filter unit 230 may be in an off state or an on state. As described above, the state of the filter unit 230 may be controlled automatically or manually by a wearer's manipulation. If the filter unit 230 is in an off state, the wearer can see the image displayed on the image display unit 220 as well as the surrounding environment at the same time. On the other hand, when the filter unit 230 is in an on state, all or part of light from the outside is blocked, and the wearer can focus on the image displayed on the image display unit 220 and focus on it.

As described above, the above description is only an example and should not be construed as being limited thereto. The technical idea of the present invention should be specified only by the invention described in the claims below, and all technical ideas within the equivalent range should be interpreted as being included in the scope of the present invention. Therefore, it is obvious to those skilled in the art that the above-described embodiment can be implemented in various forms.

Claims (4)

A method for controlling an optical system for a near-eye display for transmissive smart glasses having a spectacle frame and a pair of lenses coupled to the spectacle frame,
The optical system includes an optical signal emitting unit, an image display unit, and a filter unit, wherein the optical signal emitting unit is coupled to the leg of the spectacle frame and emits an optical signal for displaying a 2D image toward the inner surface of the lens. and the image display unit is coupled to each of the lenses, and selectively reflects only predefined wavelengths toward the eyes of the wearer of the smart glasses with respect to the optical signal emitted from the optical signal emitter, and to the image display unit. An optical signal processing unit for processing the incident optical signal based on an inner surface shape of the lens, wherein the filter unit is integrally installed in the lens to which the image display unit is coupled, By blocking the light passing through the lens,
The control method characterized in that for controlling to pass or block the light passing through the lens as it is by turning on/off the filter unit. According to claim 1,
A control method characterized in that a wearer wearing the smart glasses can control on/off of the filter unit. According to claim 2,
The optical signal processing unit processes the optical signal such that a two-dimensional image displayed by the optical signal emitted from the optical signal emitting unit corresponds to the shape of the inner surface of the lens;
The lens has an aspherical curved shape,
The image display unit is a film-type hologram optical element (HOE) recorded to reflect only the predefined wavelength, and is coupled to the inner surface of the lens. According to claim 3,
The control method according to claim 1 , wherein the optical signal processing unit processes the optical signal to correspond to an inner surface shape of the lens at a portion to which the hologram optical element is coupled.

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