Retinal projection device

Abstract

This invention provides a retinal projection device for reducing chromatic aberration. The retinal projection device is mounted on a near-eye wearable device and includes: a light source that emits laser light; a movable mirror that performs laser-based scanning; and a reflector that reflects the laser light after passing through the movable mirror, irradiating the reflected light onto the retina of a user wearing the near-eye wearable device, thereby projecting an image onto the retina. The reflector includes: a reflective layer that reflects the laser light at a reflection angle varying according to the wavelength of the laser light, emitting the laser light as reflected light; and a phase correction layer that corrects chromatic aberration in the reflected light.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Japanese Patent Application No. 2024-231824, filed with the Japan Patent Office on December 27, 2024, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure relates to retinal projection devices. Background Technology

[0004] Near-eye wearable devices such as smart glasses are known. For example, U.S. Patent Application Publication No. 2018 / 0113310 discloses a near-eye display assembly that includes an image source and a combiner comprising a nanostructured surface optically coupled to the image source, thereby transmitting image information into the user's field of vision by forming image information on the nanostructured surface of the combiner. Summary of the Invention

[0005] In the near-eye display assembly described in U.S. Patent Application Publication No. 2018 / 0113310, nanostructured surfaces function as reflective surfaces. In such reflectors, such as mirrors (super-optical mirrors) and diffracting mirrors, which are composed of nanostructures, the angle of light reflection sometimes varies depending on the wavelength of the light. Therefore, chromatic aberration may occur when projecting an image onto the user's retina.

[0006] This disclosure describes a retinal projection device that can reduce chromatic aberration.

[0007] One aspect of this disclosure is a retinal projection device mounted on a near-eye wearable device. The retinal projection device includes: a light source that emits laser light; a movable mirror that performs laser-based scanning; and a reflector that reflects the laser light passed through the movable mirror, irradiating the reflected light onto the retina of a user wearing the near-eye wearable device, thereby projecting an image onto the retina. The reflector includes: a reflective layer that reflects the laser light at a reflection angle varying according to the wavelength of the laser light, emitting the laser light as reflected light; and a phase correction layer that corrects chromatic aberration of the reflected light.

[0008] In this retinal projection device, the laser light is reflected at the reflective layer at a reflection angle that varies according to the wavelength of the laser, and the chromatic aberration of the reflected light is corrected using a phase correction layer. Therefore, chromatic aberration can be reduced.

[0009] In some embodiments, the phase correction layer may be a superlens comprising a plurality of pillars that are transmissive to visible light. In this case, as visible light passes through the pillars, a phase retardation of the visible light is generated according to the size of the pillars. Therefore, by appropriately adjusting the amount of phase retardation generated at each pillar, chromatic aberration can be reduced.

[0010] In some embodiments, the phase correction layer may be composed of a compound selected from the group consisting of silicon oxide, titanium oxide, tantalum oxide, and silicon nitride. These compounds are transparent in the visible light domain, thus enabling the visible light transmittance of the phase correction layer.

[0011] In some embodiments, the size of the plurality of pillars can be set such that the phase of red light at the location where the pillars are set is the same as the phase of blue light. The maximum wavelength of the operating band in a retinal projection device is the wavelength of red light, and the minimum wavelength of the operating band is the wavelength of blue light. Therefore, by making the phase of red light the same as the phase of blue light, the maximum phase lag generated in the operating band can be eliminated. Thus, chromatic aberration can be reduced.

[0012] In some embodiments, the reflective layer may be a supermirror comprising multiple nanostructures disposed along the surface of the lens of a near-eye wearable device that faces the user's eyeball. Each of the multiple nanostructures may comprise a metal layer, a dielectric layer, and a metal body sequentially stacked in a direction intersecting the aforementioned surface. In this case, the reflective layer can function as a mirror through electromagnetic resonance between the metal layer and the metal body.

[0013] In some embodiments, the reflective layer may be a supermirror comprising multiple nanostructures disposed along the surface of the lens of a near-eye wearable device facing the user's eyeball. Each of the multiple nanostructures may comprise a first transparent conductive layer, a dielectric layer, and a second transparent conductive layer sequentially stacked in a direction intersecting the aforementioned surface. In this case, the reflective layer can function as a mirror through electromagnetic resonance between the first and second transparent conductive layers. Furthermore, by using the transparent conductive layer, the possibility of visual field obstruction can be reduced.

[0014] In some embodiments, the first and second transparent conductive layers may be made of ITO. ITO has excellent conductivity and high transparency in the visible light range, making it suitable as a transparent conductive layer.

[0015] In some embodiments, the reflective layer can be configured to achieve a predetermined reflection angle relative to a reference wavelength. Since the reflection angle at the reflective layer varies with wavelength, the length of the metal body along the aforementioned surface can be determined by using a reference wavelength.

[0016] In some embodiments, the reference wavelength can be the wavelength of the red light contained in the laser. In this case, the length of the metal body along the aforementioned surface can be larger, which facilitates the manufacture of the reflector.

[0017] In some embodiments, the reflector may further include a dielectric spacer layer disposed between the reflective layer and the phase correction layer. In this case, by providing the dielectric spacer layer, surface planarization processes such as CMP can be performed to planarize the surface of the dielectric spacer layer.

[0018] In some embodiments, the dielectric spacer layer may be composed of a compound selected from the group consisting of silicon oxide, titanium oxide, tantalum oxide, and silicon nitride. In this case, a material having a refractive index that is the same as or close to that of the phase correction layer can be used, thus suppressing unwanted interface reflections.

[0019] According to various aspects and embodiments of this disclosure, chromatic aberration can be reduced. Attached Figure Description

[0020] Figure 1 This is a perspective view showing the appearance of a near-eye wearable device including a retinal projection device according to one embodiment.

[0021] Figure 2 It is a general representation Figure 1 The diagram shows the structure of the retinal projection device.

[0022] Figure 3 It is an enlarged representation Figure 2 A diagram of the reflector shown.

[0023] Figure 4 It is along Figure 3 A cross-sectional view along line IV-IV.

[0024] Figure 5 It means Figure 3 A three-dimensional diagram of the reflective layer contained in a unit area.

[0025] Figure 6 It is a schematic representation Figure 2 A diagram of the reflector shown.

[0026] Figure 7 (a) is a diagram used to illustrate the reflected light at position (-r).

[0027] Figure 7 (b) is a diagram used to illustrate the reflected light at position (+r).

[0028] Figure 8 It is a graph showing the relationship between the position of the reflector along the X-axis and the maximum phase delay.

[0029] Figure 9 It is a graph showing the relationship between the diameter of the column and the phase delay.

[0030] Figure 10It is a diagram showing the diameter of the columnar body at various positions along the X-axis of the reflector.

[0031] Figure 11 This diagram illustrates the formation of the reflective layer.

[0032] Figure 12 It is a diagram used to illustrate the formation of the dielectric layer.

[0033] Figure 13 It is a diagram used to illustrate the planarization of the dielectric layer.

[0034] Figure 14 It is a diagram used to illustrate the formation of the light-transmitting layer. Detailed Implementation

[0035] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, in the description of the drawings, the same reference numerals are used to denote the same elements, and repeated descriptions are omitted. In the figures, an XYZ coordinate system is sometimes shown. The Y-axis direction is the direction that intersects (e.g., is orthogonal) the X-axis and Z-axis directions. The Z-axis direction is the direction that intersects (e.g., is orthogonal) the X-axis and Y-axis directions.

[0036] Reference Figure 1 The description includes a near-eye wearable device for a retinal projection device according to one embodiment. Figure 1 This is a perspective view showing the appearance of a near-eye wearable device including a retinal projection device according to one embodiment. Figure 1 The near-eye wearable device 1 shown is a device that superimposes an image onto the field of view of the real world. The near-eye wearable device 1 is, for example, a head-mounted device (headwear), and can take the form of glasses, goggles, hats, and helmets. Examples of near-eye wearable devices 1 include smart glasses such as AR (Augmented Reality) glasses and MR (Mixed Reality) glasses. The near-eye wearable device 1 includes a frame 2, lenses 3, and a retinal projection device 10.

[0037] Frame 2 includes a pair of eyeglass frames 2a, a nose bridge 2b, and a pair of temples 2c. The eyeglass frames 2a hold the lenses 3. The nose bridge 2b connects the pair of eyeglass frames 2a. The temples 2c extend from the eyeglass frames 2a and hang on the user's ears. Frame 2 can also be a frameless frame. The lenses 3 are aligned with the eyeball E of the user wearing the near-eye wearable device 1 (see reference). Figure 2 The inner surfaces 3a facing each other (refer to) Figure 2 ).

[0038] In this embodiment, the retinal projection device 10 projects onto the retina RE (refer to) of the user wearing the near-eye wearable device 1. Figure 2The image is directly projected (drawn). The retinal projection device 10 is mounted on the near-eye wearable device 1. In this embodiment, in order to project images to the left and right retina REs, the near-eye wearable device 1 includes two retinal projection devices 10, but it may also include only one retinal projection device 10.

[0039] Next, refer to Figure 2 Detailed description of the retinal projection device 10. Figure 2 It is a general representation Figure 1 The diagram shows the structure of a retinal projection device. Figure 2 As shown, the retinal projection device 10 includes a light source unit 11 (light source), a collimating lens 12, a movable mirror 13, and a reflector 14.

[0040] Light source unit 11 emits laser light. For example, a panchromatic laser module is used as light source unit 11. Light source unit 11 includes a red laser diode, a green laser diode, a blue laser diode, and a combiner for combining the laser light emitted from each laser diode. Light source unit 11 emits the combined laser light. The combined laser light includes a wavelength λ having a red color. red The light (red light Lr) has a green wavelength λ. green The light (green light lg) and the wavelength λ with blue color. blue At least one component of the light (blue light Lb). In the following description, red light Lr, green light Lg and blue light Lb are sometimes referred to as "visible light", and red light Lr, green light Lg and blue light Lb are sometimes collectively referred to as "laser Ls". The light source unit 11 emits laser light having a color and intensity corresponding to the pixels of the image projected onto the retina RE.

[0041] The collimating lens 12 is an optical component that converts the laser emitted from the light source unit 11 into parallel light. The collimating lens 12 is disposed between the light source unit 11 and the movable mirror 13.

[0042] The movable mirror 13 is an optical component used for laser-based scanning (Ls). The movable mirror 13 is positioned in the emission direction of the laser light after it has been converted into parallel light by the collimating lens 12. The movable mirror 13 is configured, for example, to be able to swing about an axis extending laterally (X-axis direction) along the lens 3 and about an axis extending longitudinally (Y-axis direction) along the lens 3, thereby reflecting the laser light at varying angles in the X-axis and Y-axis directions. For example, a MEMS (Micro ElectroMechanical Systems) mirror can be used as the movable mirror 13.

[0043] Reflector 14 is an optical component that reflects the laser Ls after it has passed through the movable mirror 13, and projects the reflected light Lref onto the retina RE of the user wearing the near-eye wearable device 1, thereby projecting an image onto the retina RE. No image is displayed on reflector 14. Reflector 14 is disposed on the inner surface 3a of lens 3. Details of reflector 14 will be described later.

[0044] In addition, although the illustration is omitted, the retinal projection device 10 also includes a laser driver for driving the light source unit 11, a mirror driver for driving the movable mirror 13, and a controller for controlling the laser driver and the mirror driver.

[0045] Next, refer to Figures 3-5 Explain the structure of reflector 14. Figure 3 It is an enlarged representation Figure 2 A diagram of the reflector shown. Figure 4 It is along Figure 3 A cross-sectional view along line IV-IV. Figure 5 It means Figure 3 A three-dimensional diagram of the reflective layer contained in a unit area.

[0046] like Figure 3 As shown, the reflector 14 is divided into multiple unit regions 40. The multiple unit regions 40 are arranged along the inner surface 3a of the lens 3. The multiple unit regions 40 are arranged in a two-dimensional array in the transverse (X-axis direction) and longitudinal (Y-axis direction) directions of the lens 3.

[0047] like Figure 4 As shown, each unit region 40 is configured such that when laser Ls is incident on the unit region 40, it reflects light at a reflection angle θ corresponding to the position where the unit region 40 is located. r Reflected laser Ls. Reflection angle θ of 40° in each unit area. r So that the laser Ls (reflected light Lref) reflected by each unit area 40 passes through the pupil PP (reference). Figure 2 The center of the incident angle θ is set in a certain way. i and reflection angle θ r The location of the unit region 40 is determined by the position of the unit region 40. The unit region 40 is configured to obtain an incident angle θ corresponding to the position of the unit region 40. i and reflection angle θ r .

[0048] Here, the angle of incidence θ i It is the angle between the normal to the surface illuminated by the laser Ls and the incident direction of the laser Ls. Reflection angle θ rThe reflection angle θ is the angle between the normal to the surface illuminated by the laser Ls and the emission direction of the reflected light Lref. In a plane containing both the laser Ls and the reflected light Lref, when the reflected light Lref is emitted towards the side opposite to the incident light (laser Ls) with the normal as the boundary, the reflection angle θ is... r A positive value indicates that when the reflected light Lref is emitted towards the side that is the same as the incident light (laser Ls) as the normal, the reflection angle θ is... r It is represented by a negative value.

[0049] like Figure 4 and Figure 5 As shown, the reflector 14 includes a reflective layer 15, a dielectric spacer layer 16, and a phase correction layer 17 stacked sequentially in a direction intersecting (e.g., orthogonal) with the inner surface 3a (Z-axis direction).

[0050] The reflective layer 15 is a super-reflective mirror comprising multiple nanostructures disposed along its inner surface 3a. A super-reflective mirror is also referred to as a super-optical mirror. The reflective layer 15 has a reflection angle θ that varies according to the wavelength of the laser Ls. r The laser Ls is reflected and emitted as the reflected light Lref. The reflective layer 15 is configured to reflect at a angle θ corresponding to the incident position of the laser Ls. r Reflecting laser Ls. The reflective layer 15 includes a metal layer 51, a dielectric layer 52, a metal layer 53, and a protective layer 54 sequentially stacked in a direction intersecting (e.g., orthogonal) with the inner surface 3a (Z-axis direction).

[0051] Metal layer 51 is a substrate layer. Metal layer 51 is disposed on the inner surface 3a of lens 3. Metal layer 51 is made of a metal with high reflectivity in the visible light field. For example, metal layer 51 is made of a metal containing at least one element selected from the group consisting of gold (Au), copper (Cu), silver (Ag), and aluminum (Al). The length of metal layer 51 in the Z-axis direction is only required to allow resonant current to flow and to reflect light, for example, from 10 nm to 1000 nm. Hereinafter, the length in the Z-axis direction is sometimes referred to as "thickness".

[0052] The dielectric layer 52 functions as a spacer. It is disposed between the metal layer 51 and the metal layer 53 along the Z-axis. The dielectric layer 52 has a main surface 52a on which the metal layer 53 is disposed. The dielectric layer 52 has a dielectric constant sufficient to not impede the electromagnetic interaction between the metal layers 51 and 53. The dielectric layer 52 is made of a material that is transparent in the visible light range. To achieve higher reflectivity, the dielectric layer 52 may also be made of a material with a higher dielectric constant. For example, the dielectric layer 52 is made of a compound selected from the group consisting of silicon oxides (e.g., SiO2), titanium oxides (e.g., TiO2), magnesium oxides (e.g., MgO), and aluminum oxides (e.g., Al2O3). The thickness of the dielectric layer 52 is, for example, 10 nm to 100 nm.

[0053] Metal layer 53 is a layer that, together with metal layer 51, generates electromagnetic resonance. Metal layer 51 and metal layer 53 are stacked in the Z-axis direction, separated by dielectric layer 52. In this embodiment, metal layer 53 is disposed on the main surface 52a of dielectric layer 52. Metal layer 53 is made of a metal with high reflectivity in the visible light field. For example, metal layer 53 is made of a metal containing at least one element selected from the group consisting of silver (Ag), aluminum (Al), and copper (Cu).

[0054] The metal layer 53 includes a plurality of metal bodies 55. Each metal body 55 is disposed in a plurality of unit regions 40. Each metal body 55 is configured such that, as it moves from one end 40a to the other end 40b along the X-axis direction of the unit region 40 in which the metal body 55 is disposed, the phase change φ of the reflected light Lref achieved by the metal body 55 changes linearly. Furthermore, each metal body 55 is configured such that the phase change φ of the reflected light Lref substantially changes by 360° (2π radians) from one end 40a to the other end 40b. The phase change φ of the reflected light Lref refers to the amount of phase change of the reflected light Lref when the length of the metal body 55 along the Y-axis direction changes, with the phase of the reflected light Lref at a certain length along the Y-axis direction as a reference. Hereinafter, the length along the Y-axis direction is sometimes referred to as the "width".

[0055] In this embodiment, each metal body 55 is a trapezoidal shape when viewed from the Z-axis direction. The thickness of each metal body 55 is, for example, 10 nm to 100 nm. The length of each metal body 55 in the X-axis direction is the same as or slightly shorter than the length Lx in the X-axis direction of the unit region 40. The length of each metal body 55 in the X-axis direction is, for example, 500 nm to 2500 nm.

[0056] The length (width W1) of the short side of each metal body 55 is, for example, set near the resolution of the exposure apparatus used to form the metal body 55. Width W1 is, for example, 10 nm to 200 nm. The length (width W2) of the long side of each metal body 55 is greater than width W1, and is set to a length that substantially results in a 360° (2π radian) phase difference relative to the reflected light Lref at width W1. Width W2 is, for example, 100 nm to 500 nm. Each metal body 55 is, for example, formed using photolithography.

[0057] The protective layer 54 protects the metal layer 53 (metal body 55). The protective layer 54 is disposed on and covers the surface 55a of each metal body 55. Surface 55a is the side of the metal layer 53 opposite to the dielectric layer 52. The protective layer 54 is made of a metal that is less prone to oxidation and sulfidation and has higher corrosion resistance than the metal layer 53. In other words, the protective layer 54 is made of a metal having a higher standard electrode potential than the metal constituting the metal layer 53. For example, the protective layer 54 is made of a metal containing at least one element selected from the group consisting of gold (Au), ruthenium (Ru), and iridium (Ir). In combinations of these metals with the metal constituting the metal layer 53 (e.g., silver), near-field light attenuation is less.

[0058] In this embodiment, the protective layer 54 includes a plurality of metal bodies that have the same shape as the metal body 55 when viewed from the Z-axis direction. The thickness of the protective layer 54 (metal body) is less than 20% of the sum of the thickness of the metal body 55 and the thickness of the protective layer 54, for example, 2.5 nm to 25 nm.

[0059] The dielectric spacer layer 16 is a layer used to ensure flatness before the formation of the phase correction layer 17 and to absorb the refractive index difference between the reflective layer 15 and the phase correction layer 17. The dielectric spacer layer 16 is disposed between the reflective layer 15 and the phase correction layer 17. The dielectric spacer layer 16 is made of a material that is transparent in the visible light domain. The dielectric spacer layer 16 is made of a compound selected from the group consisting of silicon oxide (SiO2), titanium oxide (TiO), tantalum oxide (Ta2O5), and silicon nitride (SiN). The thickness of the dielectric spacer layer 16 is, for example, 50 nm or less. From the viewpoint of reducing the impact on the reflection efficiency of the reflector 14, the thickness of the dielectric spacer layer 16 can also be 10 nm or less.

[0060] Phase correction layer 17 is a layer used to correct chromatic aberration in reflected light Lref. Phase correction layer 17 is disposed on dielectric spacer layer 16. Phase correction layer 17 is made of a material that is transparent in the visible light domain.

[0061] The phase correction layer 17 is a superlens comprising a plurality of pillars 17a. Each pillar 17a is a pillar-shaped component that is transparent to visible light. That is, each pillar 17a is a pillar-shaped component that is transparent in the visible light field. As the constituent material of the pillars 17a, a material that is transparent to visible light and has a refractive index greater than 1 is used. Examples of such constituent materials include silicon oxide (SiO2), titanium oxide (TiO), tantalum oxide (Ta2O5), and silicon nitride (SiN). In other words, the phase correction layer 17 is composed of a compound selected from the group consisting of silicon oxide (SiO2), titanium oxide (TiO), tantalum oxide (Ta2O5), and silicon nitride (SiN).

[0062] In this embodiment, each columnar body 17a has a cylindrical shape. The shape of each columnar body 17a is not limited to a cylinder; it can also be a prism, or a frustum or truncated pyramid shape with a tapered tip. Each columnar body 17a is disposed upright on the dielectric spacer layer 16. That is, each columnar body 17a extends from the dielectric spacer layer 16 in the emission direction of the reflected light Lref. The height (length in the Z-axis direction) of each columnar body 17a is, for example, 500 nm or more and 2000 nm or less.

[0063] The size of each column 17a is set such that the phase of the red light Lr at the location where the column 17a is set is the same as the phase of the blue light Lb. The method for determining the size of the column 17a will then be described.

[0064] In addition, such as Figure 4 As shown, an adhesive layer 56 can also be provided between the inner surface 3a of the lens 3 and the metal layer 51. An adhesive layer 57 can also be provided between the metal layer 51 and the dielectric layer 52. An adhesive layer 58 can also be provided between the dielectric layer 52 and the metal layer 53. Adhesive layers 56 to 58 are layers used to improve the adhesion between the two layers. Adhesive layers 56 to 58 are, for example, made of chromium (Cr). The length (film thickness) of each adhesive layer 56 to 58 in the Z-axis direction is approximately 3 nm. Figure 5 The illustrations of the sealing layers 56-58 are omitted in the text.

[0065] Next, refer to Figure 4 and Figure 5 Explain the reflection principle of reflective layer 15.

[0066] As described above, the width of the metal body 55 increases from width W1 to width W2 as it moves from one end 40a to the other end 40b. The phase change φ at each position in the X-axis direction of the metal body 55 is substantially the same as the phase change φ of a square metal body with sides of the same length as the width at that position when viewed from above. The larger the area of ​​the square metal body when viewed from above, the larger the phase change φ (phase retardation) at that position. Therefore, the laser Ls is reflected with a phase change φ that varies depending on the position in the X-axis direction, thereby forming a wavefront by utilizing the interference between the reflected light. That is, a plane wave is generated with a slope of φ(x), a function representing the relationship between the position x in the X-axis direction and the phase change φ, as the wavenumber vector Φ.

[0067] Here, as Figure 4 As shown, Snell's law, after generalization, uses the wavenumber vector k0 of the laser Ls and the incident angle θ. i Reflection angle θ r The wavenumber vector Φ is represented by equation (1).

[0068] [Mathematical Formula 1]

[0069]

[0070] The wavenumber vector k0 uses the wavelength λ of the laser Ls, which is represented by 2π / λ. The wavelength λ represents any wavelength contained within the band used. The band used is the range of wavelengths (bands) used in the retinal projection device 10. The wavenumber vector Φ uses the length Lx of the unit region 40 in the X-axis direction, which is represented by 2π / Lx. By using these relationships, equation (1) is transformed to obtain equation (2).

[0071] [Mathematical Formula 2]

[0072]

[0073] By using the wavelength λ of laser Ls and the incident angle θ of laser Ls corresponding to the location where the unit region 40 is set... i and reflection angle θ r Substituting into equation (2), the length Lx of the unit region 40 is thus obtained. Here, the reference wavelength λ is used. ref The length Lx is determined by the wavelength λ. In other words, the reflective layer 15 is configured relative to the reference wavelength λ. ref Able to obtain the predetermined reflection angle θ r Here, λ is used as the reference wavelength. ref The wavelength λ of the red component (red light Lr) contained in the laser Ls is used. red As the reference wavelength λ ref Alternatively, the wavelength λ of the blue component (blue light Lb) contained in the laser Ls can be used. blue.

[0074] When the length Lx is positive, the shape of the metal body 55 is set to a trapezoidal shape in which the width of the metal body 55 increases as it moves from one end 40a to the other end 40b. When the length Lx is negative, the shape of the metal body 55 is set to a trapezoidal shape in which the width of the metal body 55 decreases as it moves from one end 40a to the other end 40b.

[0075] As described above, the length Lx of each unit region 40 is determined according to the reference wavelength λ. ref And the incident angle θ corresponding to the location where the unit area 40 is set. i and reflection angle θ r The length of the metal body 55 in the X-axis direction is the same as or slightly shorter than the length Lx in the X-axis direction of the unit region 40. Therefore, the length of the metal body 55 in the X-axis direction is determined according to the reference wavelength λ. ref and the incident angle θ corresponding to the position of the unit region 40 where the metal body 55 is located. i and reflection angle θ r To determine. As shown in equation (2), the reflection angle θ r It varies depending on the wavelength of the light component contained in the laser Ls.

[0076] Furthermore, the length Ly in the Y-axis direction of each unit region 40 is a predetermined fixed value. The length Ly is slightly larger than the width W2. The length Ly can also be the length obtained by adding the resolution of the exposure device used to form the metal body 55 (e.g., 100 nm) to the width W2, for example, set to 600 nm. The widths W1 and W2 of each metal body 55 are predetermined fixed values. As described above, the width W1 is set near the resolution of the exposure device used to form the metal body 55 (e.g., 100 nm). The width W2 is set to a length (e.g., 350 nm) that results in a phase difference of substantially 360° (2π radians) relative to the phase of the reflected light Lref at the width W1.

[0077] Next, refer to Figures 6-10 Explain the method for determining the size of columnar body 17a. Figure 6 It is a schematic representation Figure 2 A diagram of the reflector shown. Figure 7 (a) is a diagram used to illustrate the reflected light at position (-r). Figure 7 (b) is a diagram used to illustrate the reflected light at position (+r). Figure 8 It is a graph showing the relationship between the position of the reflector along the X-axis and the maximum phase delay. Figure 9 It is a graph showing the relationship between the diameter of the column and the phase delay. Figure 10 It is a diagram showing the diameter of the columnar body at various positions along the X-axis of the reflector.

[0078] like Figure 6 As shown, the position x of the center of the reflector 14 in the X-axis direction is set to 0, the position x of the end of the reflector 14 closest to the movable mirror 13 in the X-axis direction is set to +r, and the position x of the end farther away from the movable mirror 13 is set to -r.

[0079] Here, the phase quantity φ of the reflected light Lref at position x after wavefront adjustment. m (x) is approximated by equation (3) using wavelength λ and optical path length difference l(x). The optical path length difference l(x) is the difference in optical path length between two adjacent metal bodies 55 in the X-axis direction. That is, equation (3) means that by restoring the phase amount corresponding to the optical path length difference between two adjacent metal bodies 55, the phase of the laser reflected by the two metal bodies 55 is made consistent.

[0080] [Mathematical Formula 3]

[0081]

[0082] By using the maximum wavelength λ in the band max Equation (3) is transformed to obtain equation (4).

[0083] [Mathematical Formula 4]

[0084]

[0085] Here, wavelength λ is represented by angular frequency ω and speed of light c by equation (5).

[0086] [Mathematical Formula 5]

[0087]

[0088] Equation (4) is transformed by using equation (5) to obtain equation (6).

[0089] [Mathematical Formula 6]

[0090]

[0091] The optical path length difference l(x) is represented by equation (7), and the angular frequency ω is represented by wave number k and speed of light c by equation (8).

[0092] [Mathematical Expression 7]

[0093]

[0094] [Mathematical Formula 8]

[0095]

[0096] Equation (6) is transformed by using equations (7) and (8) to obtain equation (9).

[0097] [Mathematical Expression 9]

[0098]

[0099] By using the maximum wavenumber k max and minimum wavenumber k min Equation (9) is transformed to obtain equation (10).

[0100] [Mathematical Formula 10]

[0101]

[0102] The first term on the right side of equation (10) is determined by the reflection angle θ. r The difference in optical path length is determined by the geometry of reflective layer 15. Therefore, the first term on the right is a fixed value at a certain position x. The second term on the right of equation (10) varies according to the wavenumber (wavelength), and is therefore equivalent to the phase correction amount of phase correction layer 17. The maximum wavenumber k is taken as the wavenumber k. max Based on the previous case, the size of column 17a is determined to be equivalent to the phase correction amount. The following explanation uses a specific example. The maximum wavelength λ of the band used... max It is the wavelength λ of red light Lr red The minimum wavelength λ of the band is used. min It is the wavelength λ of blue light Lb blue .

[0103] exist Figure 7 In the example shown in (a), as indicated by equation (11), at position (-r), by the reflection angle θ from the red light r_red Subtract the reflection angle θ of blue light r_blue The resulting angle difference is -23°. Furthermore, the maximum wavelength λ... max (wavelength λ) red Using 630nm as the minimum wavelength λmin (wavelength λ) blue The length Lx at position (-r) is 450nm.

[0104] [Mathematical Formula 11]

[0105]

[0106] At position (-r), with an incident angle θ of laser Ls. i 60°, reflection angle θ r_red The reflective layer 15 is designed for a -15° angle. At this point, according to equation (11), the reflection angle θ...r_blue The angle is +8°. The difference in the optical path length of red light, l(-r), is 116 nm (=Lx×cos(90°-|θ)). r_red The optical path length difference l(-r) of blue light is 70nm (=Lx×cos(90°-|θ)). r_blue Therefore, the phase change φ(k) is equivalent to the difference in the optical path length l(-r) of the red light. min The optical path length difference (-r) is 1.16 radians (=2π×optical path length difference l(-r) / λ). max ), which is equivalent to the phase change φ(k) of the optical path length difference l(-r) of blue light. max The value of 0.87 radians (-r) is (=2π×optical path length difference l(-r) / r) min Therefore, the maximum phase difference (maximum phase delay) in the band used at position (-r) is 0.29 radians.

[0107] exist Figure 7 In the example shown in (b), as indicated by equation (12), at position (+r), the reflection angle θ from the red light... r_red Subtract the reflection angle θ of blue light r_blue The resulting angle difference is -9°. The length Lx at position (+r) is 1150nm.

[0108] [Mathematical Formula 12]

[0109]

[0110] At position (+r), with an incident angle θ of laser Ls i 45°, reflection angle θ r_red The reflective layer 15 is designed for a +15° angle. At this point, according to equation (12), the reflection angle θ... r_blue The angle is +24°. The optical path length difference l(+r) for red light is 298 nm, and for blue light it is 468 nm. Therefore, the phase change φ(k) corresponding to the optical path length difference l(+r) for red light is... min The phase change φ(k) of the blue light path length difference l(+r) is 2.97 radians. max The phase difference (maximum phase delay) at position (+r) is 6.53 radians. The maximum phase difference (maximum phase delay) in the band used at position (+r) is -3.56 radians.

[0111] If we assume that the distance from position (+r) to position (-r) will be expressed as a linear function of position x using the maximum phase difference (maximum phase delay) in the band, then we obtain the following: Figure 8 The relationship between position x and the maximum phase delay is shown. Figure 8 The horizontal axis represents the position x (unit: mm). Figure 8 The vertical axis represents the maximum phase delay (in radians). In this example, the position (+r) is 3.8 mm and the position (-r) is -3.8 mm.

[0112] At each position x, we can obtain Figure 8 The size of the column 17a is determined by the method of determining the maximum phase delay. In this embodiment, to facilitate the manufacture of the reflector 14, all the columns 17a included in the phase correction layer 17 are cylindrical, made of the same material, and have the same height. In this case, the diameter of the column 17a becomes the parameter that determines the phase delay.

[0113] like Figure 9 As shown, when the constituent materials and height of the column 17a are the same, the amount of phase delay achieved by the column 17a varies depending on the diameter of the column 17a. Figure 9 The horizontal axis represents the diameter of columnar body 17a (unit: μm). Figure 9 The vertical axis represents the phase delay (unit: radians). Figure 9 The properties shown are pre-calculated using numerical calculations. Property C1 is the property of a cylindrical column composed of tantalum pentoxide (Ta₂O₅) with a height of 500 nm, and with aluminum oxide (Al₂O₃) columnar columns with a height of 200 Å at both ends. Property C2 is the property of a cylindrical column composed of silicon nitride (SiN) with a height of 500 nm. Property C3 is the property of a cylindrical column composed of silicon dioxide (SiO₂) with a height of 2 μm.

[0114] according to Figure 9 The characteristics shown are used to obtain Figure 8 The method by which the maximum phase delay is shown determines the diameter of each column 17a. Thus, as... Figure 10 As shown, the diameter of columnar body 17a at each position x is determined. Figure 10 The horizontal axis represents the position x (unit: mm). Figure 10 The vertical axis represents the diameter (in nm) of columnar body 17a. Figure 10 In China, targeting Figure 9 The diagram shows the diameter of the columnar body 17a at each position x for each constituent material. Curve PS1 represents the diameter of the columnar body 17a at each position x when the constituent material shown in property C1 is used. Curve PS2 represents the diameter of the columnar body 17a at each position x when the constituent material shown in property C2 is used. Curve PS3 represents the diameter of the columnar body 17a at each position x when the constituent material shown in property C3 is used.

[0115] Figure 8 The maximum phase delay shown is 0 radians at a position x of -3.2 mm. Therefore, at positions x below -3.2 mm, in Figure 9 In the characteristics shown, the diameter of the column 17a at each position x is determined based on the diameter at 2π radians. Furthermore, if there is no diameter that can yield the maximum phase delay at a certain position, the column 17a may not be provided at that position. Alternatively, a column 17a may be provided with a diameter that yields a phase delay closest to the maximum phase delay.

[0116] Next, refer to Figures 11-14 The manufacturing method of reflector 14 is explained. Figure 11 This diagram illustrates the formation of the reflective layer. Figure 12 It is a diagram used to illustrate the formation of the dielectric layer. Figure 13 It is a diagram used to illustrate the planarization of the dielectric layer. Figure 14 It is a diagram used to illustrate the formation of the light-transmitting layer.

[0117] First, a substrate 50 is prepared and placed in a vacuum film deposition apparatus. Then, a metal layer 51 is formed on a desired area on the surface 50a of the substrate 50. Specifically, the metal layer 51 is formed using a method such as DC (Direct Current) sputtering, by vacuum film deposition. The metal layer 51 is formed using a metallic material composed of any one of the metals selected from the group consisting of gold (Au), copper (Cu), silver (Ag), and aluminum (Al), or a metal alloy containing at least one element selected from the group above.

[0118] Furthermore, to improve the adhesion between the surface 50a of the substrate 50 and the metal layer 51, an adhesion layer 56 may be formed on the surface 50a, and the metal layer 51 may be formed on the adhesion layer 56. The adhesion layer 56 may be formed, for example, by sputtering or vapor deposition. The adhesion layer 56 may be formed, for example, using chromium (Cr). The length (film thickness) of the adhesion layer 56 in the Z-axis direction may be, for example, 3 nm.

[0119] Next, a dielectric layer 52 is formed on the metal layer 51. Specifically, the dielectric layer 52 is formed by vacuum deposition using methods such as RF (Radio Frequency) sputtering. The dielectric layer 52 is formed using dielectric materials such as silicon dioxide (SiO2), titanium dioxide (TiO2), magnesium oxide (MgO), or aluminum oxide (Al2O3) that can be formed using semiconductor processes.

[0120] Furthermore, to improve the adhesion between the metal layer 51 and the dielectric layer 52, an adhesion layer 57 may be formed on the metal layer 51, and the dielectric layer 52 may be formed on the adhesion layer 57. The method for forming the adhesion layer 57 is the same as that for forming the adhesion layer 56, therefore detailed description is omitted. For example, chromium (Cr) may be used to form the adhesion layer 57.

[0121] Next, a metal layer that serves as the source of metal layer 53 is formed on dielectric layer 52. The method for forming the metal layer that serves as the source of metal layer 53 is the same as the method for forming metal layer 51, so detailed description is omitted. Furthermore, the metal layer that serves as the source of metal layer 53 is formed using a metallic material composed of any one of the metals selected from the group consisting of copper (Cu), silver (Ag), and aluminum (Al), or a metallic alloy containing at least one element selected from the group above.

[0122] Furthermore, to improve the adhesion between the dielectric layer 52 and the metal layer that serves as the source of the metal layer 53, an adhesive layer that serves as the source of the adhesive layer 58 can be formed on the dielectric layer 52, and a metal layer that serves as the source of the metal layer 53 can be formed on the adhesive layer. The method for forming the adhesive layer is the same as the method for forming the adhesive layer 56, so detailed description is omitted. Chromium (Cr) is used, for example, to form the adhesive layer.

[0123] Next, a metal layer (hereinafter sometimes referred to as the "outermost metal layer") that serves as the source of the protective layer 54 is formed on the metal layer that serves as the source of the metal layer 53. The method for forming the outermost metal layer is the same as the method for forming the metal layer 51, so detailed description is omitted. Furthermore, the outermost metal layer is formed using a metallic material composed of any one of the metals selected from the group consisting of gold (Au), ruthenium (Ru), and iridium (Ir), or a metallic alloy containing at least one element selected from the group above.

[0124] Next, a metal layer 53 (multiple metal bodies 55) and a protective layer 54 are formed using photolithography and etching processes. Specifically, a liquid resist is applied to the outermost metal layer using a spin coater or similar equipment, and the applied liquid resist is dried to form a resist film (photoresist). Then, an exposure device such as a KrF exposure machine and an electron beam lithography apparatus is used to transfer a pattern corresponding to the metal bodies 55 onto the resist film.

[0125] Then, the pattern transferred to the resist film is developed using a developing machine. Next, the portions of the metal layer that form the source of metal layer 53 and the outermost metal layer not covered by the pattern are removed using ion polishing. Afterward, the resist film is removed using an organic solvent (NMP). Thus, metal layer 53 and protective layer 54 are formed. Through the above, as... Figure 11 As shown, a reflective layer 15 is formed on the substrate 50.

[0126] Next, as Figure 12 As shown, a dielectric layer 61, which serves as the source of the dielectric spacer layer 16, is formed on the reflective layer 15. The method for forming the dielectric layer 61 is the same as that for forming the dielectric layer 52, therefore detailed description is omitted. The film thickness of the dielectric layer 61 is, for example, 80 nm.

[0127] Next, as Figure 13 As shown, the dielectric layer 61 is planarized using a CMP (Chemical Mechanical Polishing) process. Ideally, the dielectric layer 61 on the protective layer 54 would be completely removed, but planarization of the dielectric layer 61 is sufficient. This forms a dielectric spacer layer 16. The distance from the upper surface of the protective layer 54 to the upper surface of the dielectric spacer layer 16, i.e., the film thickness of the dielectric spacer layer 16 on the metal body 55, is 0 nm to 50 nm.

[0128] Next, as Figure 14 As shown, a light-transmitting layer 71, which serves as the source of the phase correction layer 17, is formed on the dielectric spacer layer 16. The light-transmitting layer 71 is a layer made of a material that transmits visible light. The thickness of the light-transmitting layer 71 is substantially equal to the height of the columnar body 17a.

[0129] Next, a phase correction layer 17 is formed using photolithography and etching processes. Specifically, a metal layer is formed using vacuum deposition methods such as DC (Direct Current) sputtering. Then, a liquid resist is applied to the metal layer using a spin coater or similar equipment, and the applied liquid resist is dried to form a resist film (photoresist). Then, a resist pattern corresponding to the columnar bodies 17a is transferred onto the resist film using an exposure apparatus such as a KrF exposure machine and an electron beam lithography device.

[0130] Then, the resist pattern transferred to the resist film is developed using a developing machine. Next, the portions of the metal layer not covered by the resist pattern are removed using an etching process, and then the resist pattern is removed. This forms a metal mask on the transparent layer 71. Then, the portions of the transparent layer 71 not covered by the metal mask are etched away to a depth equivalent to the height of the column 17a using an etching process. Then, the metal mask is removed. This forms the phase correction layer 17.

[0131] Through the above, a reflector 14 is formed on surface 50a of substrate 50 (see reference). Figure 4 ).

[0132] Using the method described above, a plurality of reflectors 14 are formed on a substrate 50. Therefore, a portion including one reflector 14 is obtained by cutting the substrate 50. Then, this portion of the substrate 50 is adhered to a predetermined area on the inner surface 3a of the lens 3, thereby forming a reflector 14 on the inner surface 3a of the lens 3.

[0133] The reflector 14 can also be formed directly on the inner surface 3a of the lens 3. The method of forming the reflector 14 on the inner surface 3a of the lens 3 is the same as the method of forming the reflector 14 on the surface 50a of the substrate 50. In this case, the reflector 14 is formed in the desired area on the inner surface 3a.

[0134] In the retinal projection device 10 described above, a reflection angle θ at the reflective layer 15 varies according to the wavelength of the laser Ls. r The reflected laser Ls is used as the reflected light Lref, and the chromatic aberration of the reflected light Lref is corrected using the phase correction layer 17. Therefore, chromatic aberration can be reduced.

[0135] To correct chromatic aberration, a correction lens is considered to be placed in the optical path of the laser Ls. In this case, the number of components in the retinal projection device increases. In contrast, in the retinal projection device 10, the reflective layer 15 and the phase correction layer 17 are integrally formed, so no additional external components are required.

[0136] The phase correction layer 17 is a superlens comprising a plurality of pillars 17a that are transmissive to visible light. According to this structure, as visible light passes through each pillar 17a, a phase delay is generated based on the size of the pillar 17a. Therefore, by appropriately adjusting the amount of phase delay generated at each pillar 17a, chromatic aberration can be reduced.

[0137] The phase correction layer 17 can be composed of a compound selected from the group consisting of silicon oxide, titanium oxide, tantalum oxide, and silicon nitride. These compounds are transparent in the visible light domain, thus enabling visible light transmittance of the phase correction layer 17. Since the absorption of visible light in the phase correction layer 17 can be suppressed, the reflectivity of visible light can be improved.

[0138] The size of each column 17a is set such that the phase of the red light Lr at the location where the column 17a is set is the same as the phase of the blue light Lb. The maximum wavelength λ of the band used in the retinal projection device 10... max It is the wavelength λ of red light Lr red The minimum wavelength λ of the band is used. min It is the wavelength λ of blue light blueTherefore, by making the phase of the red light Lr the same as the phase of the blue light Lb, the maximum phase delay generated in the operating band can be eliminated. This reduces chromatic aberration.

[0139] The reflective layer 15 is a superreflective mirror comprising multiple nanostructures (unit region 40) disposed along the inner surface 3a of the lens 3. Each nanostructure comprises a metal layer 51, a dielectric layer 52, and a metal body 55 sequentially stacked in a direction intersecting (or orthogonal) with the inner surface 3a. According to this structure, the reflective layer 15 can function as a reflective mirror through electromagnetic resonance between the metal layer 51 and the metal body 55.

[0140] The reflective layer 15 is configured relative to the reference wavelength λ ref Able to obtain the predetermined reflection angle θ r The reflection angle θ at point 15 of the reflective layer. r It varies depending on the wavelength λ, therefore, by using a reference wavelength λ ref It can set the length Lx (the length of the metal body 55 in the X-axis direction).

[0141] Reference wavelength λ ref It could be the wavelength λ of red light Lr. red In this case, the length Lx (the length of the metal body 55 in the X-axis direction) can be made longer, which makes the manufacture of the reflector 14 easier.

[0142] The reflector 14 includes a dielectric spacer layer 16 disposed between the reflective layer 15 and the phase correction layer 17. In this case, by providing the dielectric spacer layer 16, surface planarization processes such as CMP can be performed to planarize the surface of the dielectric spacer layer 16.

[0143] The dielectric spacer layer 16 can be made of a compound selected from the group consisting of silicon oxide, titanium oxide, tantalum oxide, and silicon nitride. In this case, by using a material having a refractive index that is the same as or close to that of the phase correction layer 17, unwanted interface reflections can be suppressed.

[0144] Furthermore, the retinal projection device disclosed herein is not limited to the embodiments described above.

[0145] The method for determining the length Lx is not limited to the method described in the above embodiments. For example, the length Lx of the unit regions 40 at both ends in the X-axis direction of the reflector 14 may be determined using the above method, and the length Lx of the unit regions 40 in between may be determined in such a way that the length Lx of the unit regions 40 at one end in the X-axis direction of the reflector 14 gradually changes to the length Lx of the unit regions 40 at the other end.

[0146] The metal body 55 is not limited to a single metal body in a trapezoidal shape; for example, it can also consist of multiple metal bodies arranged in the X-axis direction.

[0147] Metal layer 51 and metal body 55 can be made of transparent conductors. In other words, the nanostructures of reflective layer 15 can replace metal layer 51 and metal body 55, and include a first transparent conductor layer and a second transparent conductor layer. Each transparent conductor layer has excellent conductivity and high transparency in the visible light field. Examples of materials constituting the transparent conductor layer include transparent conductive oxide (TCO). Examples of TCOs include ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), FTO (Fluorine-doped Tin Oxide), and AZO (Aluminum-doped Zinc Oxide). In this case, similar to the case of metal layer 51 and metal body 55, reflective layer 15 can function as a reflector through electromagnetic resonance between the first and second transparent conductor layers. Furthermore, by using transparent conductor layers, the possibility of field of view being obstructed can be reduced, thereby improving visibility.

[0148] (Postscript)

[0149] [Project 1]

[0150] A retinal projection device, mounted on a wearable near-eye device, wherein,

[0151] This retinal projection device has the following features:

[0152] A light source that emits laser light;

[0153] A movable mirror that performs laser-based scanning; and

[0154] A reflector, which reflects the laser light through the movable mirror, illuminates the reflected light onto the retina of the user wearing the near-eye wearable device, thereby projecting an image onto the retina.

[0155] The reflector includes:

[0156] A reflective layer that reflects the laser at a reflection angle varying according to the wavelength of the laser, and emits the laser as the reflected light; and

[0157] A phase correction layer that corrects the chromatic aberration of the reflected light.

[0158] [Project 2]

[0159] According to the retinal projection device described in Project 1, wherein...

[0160] The phase correction layer is a superlens comprising multiple columnar elements that are transmissive to visible light.

[0161] [Project 3]

[0162] According to the retinal projection device described in Project 2, wherein...

[0163] The phase correction layer is composed of a compound selected from the group consisting of silicon oxide, titanium oxide, tantalum oxide, and silicon nitride.

[0164] [Project 4]

[0165] According to the retinal projection device described in Project 2 or Project 3, wherein...

[0166] The size of the plurality of columns is set in such a way that the phase of the red light at the location where the column is set is the same as the phase of the blue light.

[0167] [Project 5]

[0168] The retinal projection device according to any one of items 1 to 4, wherein...

[0169] The reflective layer is a super-reflective mirror comprising multiple nanostructures disposed along the surface of the lens of the near-eye wearable device that faces the user's eyeball.

[0170] Each of the plurality of nanostructures comprises a metal layer, a dielectric layer, and a metal body stacked sequentially in a direction intersecting the surface.

[0171] [Project 6]

[0172] The retinal projection device according to any one of items 1 to 4, wherein...

[0173] The reflective layer is a super-reflective mirror comprising multiple nanostructures disposed along the surface of the lens of the near-eye wearable device that faces the user's eyeball.

[0174] Each of the plurality of nanostructures comprises a first transparent conductive layer, a dielectric layer, and a second transparent conductive layer, which are sequentially stacked in a direction intersecting the surface.

[0175] [Project 7]

[0176] According to the retinal projection device described in Project 6, wherein...

[0177] The first transparent conductive layer and the second transparent conductive layer are made of ITO.

[0178] [Project 8]

[0179] The retinal projection device according to any one of items 5 to 7, wherein...

[0180] The reflective layer is configured to achieve a predetermined reflection angle relative to a reference wavelength.

[0181] [Project 9]

[0182] According to the retinal projection device described in Project 8, wherein...

[0183] The reference wavelength is the wavelength of the red light contained in the laser.

[0184] [Project 10]

[0185] The retinal projection device according to any one of items 1 to 9, wherein...

[0186] The reflector further includes a dielectric spacer layer disposed between the reflective layer and the phase correction layer.

[0187] [Project 11]

[0188] According to the retinal projection device described in Project 10, wherein...

[0189] The dielectric spacer layer is composed of a compound selected from the group consisting of silicon oxide, titanium oxide, tantalum oxide, and silicon nitride.

Claims

1. A retinal projection device mounted on a near-eye wearable device, wherein, This retinal projection device has the following features: A light source that emits laser light; A movable mirror that performs laser-based scanning; and A reflector, which reflects the laser light through the movable mirror, illuminates the reflected light onto the retina of the user wearing the near-eye wearable device, thereby projecting an image onto the retina. The reflector includes: A reflective layer that reflects the laser at a reflection angle varying according to the wavelength of the laser, and emits the laser as the reflected light; and A phase correction layer that corrects the chromatic aberration of the reflected light.

2. The retinal projection device according to claim 1, wherein, The phase correction layer is a superlens comprising multiple columnar elements that are transmissive to visible light.

3. The retinal projection device according to claim 2, wherein, The phase correction layer is composed of a compound selected from the group consisting of silicon oxide, titanium oxide, tantalum oxide, and silicon nitride.

4. The retinal projection device according to claim 2 or 3, wherein, The size of the plurality of columns is set in such a way that the phase of the red light at the location where the column is set is the same as the phase of the blue light.

5. The retinal projection device according to any one of claims 1 to 4, wherein, The reflective layer is a super-reflective mirror comprising multiple nanostructures disposed along the surface of the lens of the near-eye wearable device that faces the user's eyeball. Each of the plurality of nanostructures comprises a metal layer, a dielectric layer, and a metal body stacked sequentially in a direction intersecting the surface.

6. The retinal projection device according to any one of claims 1 to 4, wherein, The reflective layer is a super-reflective mirror comprising multiple nanostructures disposed along the surface of the lens of the near-eye wearable device that faces the user's eyeball. Each of the plurality of nanostructures comprises a first transparent conductive layer, a dielectric layer, and a second transparent conductive layer, which are sequentially stacked in a direction intersecting the surface.

7. The retinal projection device according to claim 6, wherein, The first transparent conductive layer and the second transparent conductive layer are made of ITO.

8. The retinal projection device according to any one of claims 5 to 7, wherein, The reflective layer is configured to achieve a predetermined reflection angle relative to a reference wavelength.

9. The retinal projection device according to claim 8, wherein, The reference wavelength is the wavelength of the red light contained in the laser.

10. The retinal projection device according to any one of claims 1 to 9, wherein, The reflector further includes a dielectric spacer layer disposed between the reflective layer and the phase correction layer.

11. The retinal projection device according to claim 10, wherein, The dielectric spacer layer is composed of a compound selected from the group consisting of silicon oxide, titanium oxide, tantalum oxide, and silicon nitride.

Images