Optical waveguide units, arrays and flat lenses

Abstract

The present invention discloses an optical waveguide unit, comprising: at least one total reflection layer group, each total reflection layer group includes at least one type of total reflection layer, each type of total reflection layer includes at least one single total reflection layer; at least two sub-waveguides, one total reflection layer group is arranged between each two adjacent sub-waveguides. According to the optical waveguide unit of the embodiment of the present invention, by arranging a total reflection layer or a total reflection layer group between the sub-waveguides, and each type of total reflection layer corresponds to a different incident angle and optical refractive index, the light collection efficiency of the entire optical waveguide unit at the corresponding specific incident angle can be improved, and the uniformity of light intensity at the overall viewing angle is improved. The present invention also discloses an optical waveguide array having the optical waveguide unit, and a flat lens.

Description

Technical Field

[0001] The present invention relates to the field of optical display, and in particular to an optical waveguide unit, an optical waveguide array comprising the optical waveguide unit, and a flat lens comprising the optical waveguide array. Background Art

[0002] With the development of imaging display technology, the requirements for imaging characteristics are constantly increasing. On the one hand, a higher resolution is required to ensure the clarity of the observed picture while also meeting the requirements of small distortion. On the other hand, it is required to have three-dimensional stereoscopic display characteristics while meeting the requirements of naked-eye three-dimensional holographic display. On the one hand, the existing imaging technology mainly uses lens imaging, which is mainly limited by the field of view and aperture. It has optical aberrations such as spherical aberration, coma, astigmatism, field curvature, distortion, and chromatic aberration. It is greatly limited in the field of large field of view and large aperture imaging display. On the other hand, most of the existing naked-eye three-dimensional display technologies are based on adjusting the parallax of the left and right eyes to achieve three-dimensional perception, rather than actual three-dimensional display technology.

[0003] When the incident light at a certain angle θ is incident on the equivalent optical waveguide unit in the related art, there is a loss zone as shown in the schematic diagram Figure 1 As shown in the figure, b0' is the size of the loss zone. At the same time, the equivalent optical waveguide unit in the related art is more sensitive to light incident at different angles. As the angle changes, the loss zone of the optical waveguide becomes larger, resulting in serious light energy loss, and part of the lost light will cover the image plane to form ghost light, affecting the viewing effect. In addition, since the loss zone formed by light incident from different angles is of different sizes, the light intensity at each viewing angle formed by focusing through the flat lens in the related art is uneven, affecting the actual viewing effect. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an optical waveguide unit.

[0005] The invention also discloses an optical waveguide array comprising the optical waveguide unit.

[0006] The invention further discloses a flat plate lens comprising the optical waveguide array.

[0007] According to an embodiment of the first aspect of the present invention, an optical waveguide unit comprises: at least one total reflection layer group, each of the total reflection layer groups comprises at least one type of total reflection layer, each type of the total reflection layer comprises at least one single total reflection layer; and at least two sub-waveguides, one of the total reflection layer groups being arranged between every two adjacent sub-waveguides.

[0008] According to the optical waveguide unit of the embodiment of the present invention, by arranging a total reflection layer or a total reflection layer group between the sub-waveguides, and each type of total reflection layer corresponds to a different incident angle and optical refractive index, the light collection efficiency of the entire optical waveguide unit at the corresponding specific incident angle can be improved, and the uniformity of light intensity at the overall viewing angle is improved.

[0009] According to some embodiments of the present invention, in the stacking direction of the total reflection layer group and the sub-waveguide, the total height H of the optical waveguide unit satisfies 0.1 mm. <H<5mm。

[0010] According to some embodiments of the present invention, the number of the sub-waveguides is two, and the total reflection layer group disposed between the two sub-waveguides includes a type of total reflection layer.

[0011] According to some embodiments of the present invention, the number of the sub-waveguides is 4, the number of the total reflection layer groups is three, and include: a first type of total reflection layer located in the middle; two second type of total reflection layers, the refractive index of the second type of total reflection layer is different from the refractive index of the first type of total reflection layer, and in the stacking direction of the total reflection layer and the sub-waveguide, the two second type of total reflection layers are respectively located on both sides of the first type of total reflection layer.

[0012] According to some embodiments of the present invention, in the stacking direction, the heights of the four sub-waveguides are GH1, GH2, GH3, and GH4, respectively, wherein GH1=GH4=GH2+GH3, GH2=GH3, and GH1+GH2=GH3+GH4.

[0013] According to some embodiments of the present invention, the number of the sub-waveguides is 3, the number of the total reflection layer groups is two, and the refractive indexes of the two total reflection layer groups are the same or different.

[0014] According to some embodiments of the present invention, the distribution of each total reflection layer in each type of total reflection layer in the total reflection layer group satisfies the following formula:

[0015]

[0016] Where comb(x) represents the comb function;

[0017] In the stacking direction of the total reflection layer group and the sub-waveguide unit, one side surface of the optical waveguide unit is used as a reference surface, wherein

[0018] k is the total number of types of the total reflection layer;

[0019] i is the class ordinal number of the total reflection layer, and is an integer;

[0020] x is the distance from a single total reflection layer in the i-th type total reflection layer to the reference plane;

[0021] num is the layer number of the single total reflection layer in the i-th type total reflection layer;

[0022] Ti represents the position period of the i-th type total reflection layer, and the position period is the shortest distance between adjacent i-th type total reflection layers in the optical waveguide unit;

[0023] δ(x) is the impulse function.

[0024] According to some embodiments of the present invention, the position period Ti is calculated by the following formula:

[0025]

[0026] Wherein, W is the cross-sectional width of the optical waveguide unit, and the direction of the width on the cross-section is perpendicular to the stacking direction;

[0027] θi is the incident angle corresponding to the i-th type total reflection layer on the surface of the optical waveguide unit;

[0028] n is the refractive index of the sub-waveguide.

[0029] According to some embodiments of the present invention, the thickness of each layer in each type of total reflection layer is 0.04 mm. <t<0.2Ti。

[0030] According to some embodiments of the present invention, the refractive index range n of each type of total reflection layer is ei Calculated by the following formula:

[0031]

[0032] Wherein, the parameter θi is a predetermined angle selected within the observation viewing angle range, n is the optical refractive index of the sub-waveguide, and n>1.4.

[0033] According to some embodiments of the present invention, in the stacking direction of the total reflection layer group and the sub-waveguide, reflection layers are disposed on both sides of the optical waveguide unit.

[0034] The optical waveguide unit according to the embodiment of the present invention can greatly reduce the loss of light energy and improve the energy uniformity at various viewing angles.

[0035] According to an embodiment of the second aspect of the present invention, an optical waveguide array comprises a plurality of optical waveguide units according to an embodiment of the first aspect of the present invention, wherein the cross section of each optical waveguide unit is rectangular and the plurality of optical waveguide units are connected in parallel; the outer contour of the optical waveguide array is rectangular, and the extension direction of the optical waveguide unit forms an angle of 30-60 degrees with at least two sides of the outer contour of the optical waveguide array.

[0036] According to some embodiments of the present invention, an extension direction of the optical waveguide unit forms an angle of 45 degrees with at least two sides of the outer contour of the optical waveguide array.

[0037] According to some embodiments of the present invention, the plurality of optical waveguide units are bonded together by an adhesive layer, and the thickness of the adhesive layer is greater than 0.001 mm.

[0038] A flat lens according to an embodiment of a third aspect of the present invention comprises: two transparent substrates, each of the transparent substrates having two optical surfaces; and two optical waveguide arrays according to an embodiment of the second aspect of the present invention, the two optical waveguide arrays being arranged between the two transparent substrates by means of adhesive, and the optical waveguide extension directions of the two optical waveguide arrays being arranged orthogonally.

[0039] According to some embodiments of the present invention, an anti-reflection film is disposed on an optical surface of each transparent substrate away from the optical waveguide array.

[0040] According to the planar lens of the embodiment of the present invention, an array structure is formed by a single-column and multi-row optical waveguide with a rectangular cross-section, which can enable a two-dimensional or three-dimensional light source to form a real image directly in the air to realize a true holographic image, and realize a naked-eye three-dimensional stereoscopic display characteristic while having a good imaging effect.

[0041] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0043] Figure 1 It is a principle diagram of the loss region of incident light at a certain angle θ in an equivalent optical waveguide unit in the prior art;

[0044] Figure 2a is a schematic diagram of an optical waveguide array according to an embodiment of the present invention, wherein two optical waveguide arrays are arranged orthogonally;

[0045] Figure 2b yes Figure 2a The middle frame shows an enlarged view of G;

[0046] Figure 3a yes Figure 2b Schematic diagram of the two sub-waveguides being matched through an adhesive layer;

[0047] Figure 3b yes Figure 3a A cross-sectional view of any sub-waveguide in the figure, where W is the width and H is the height;

[0048] Figure 4 is a schematic diagram of light modulation in the overlapping area when two optical waveguide units are placed orthogonally according to an embodiment of the present invention;

[0049] Figure 5 is a schematic diagram of imaging principle when two optical waveguide arrays are orthogonal according to an embodiment of the present invention;

[0050] Figure 6 is a principle diagram of a light waveguide unit according to an embodiment of the present invention where a loss region exists when light is incident at an angle θ;

[0051] Figure 7 It is a principle diagram of reflection and transmission of light greater than or less than a critical angle of the total reflection layer by the total reflection layer after a total reflection layer and a sub-waveguide are arranged in an optical waveguide unit according to an embodiment of the present invention;

[0052] Figure 8 The optical waveguide unit according to the embodiment of the present invention and Figure 1 The energy uniformity at each viewing angle and the stray light comparison diagram of the equivalent optical waveguide unit shown in ;

[0053] Fig. 9 is a schematic diagram of the internal structure of an optical waveguide unit according to an embodiment of the present invention;

[0054] Fig.10 yes Fig. 9 A cross-sectional view of the optical waveguide unit shown in ;

[0055] Fig.11 is a schematic diagram of a plane lens according to an embodiment of the present invention.

[0056] Reference numerals:

[0057] Optical waveguide arrays 1000a, 1000b

[0058] Optical waveguide unit 100; total reflection layer group 1; total reflection layer 11;

[0059] Sub-waveguide 2; reflection layer 3; adhesive layer 4;

[0060] First embodiment: sub-waveguides 211, 212; total reflection layer 111;

[0061] Second embodiment:

[0062] Sub-waveguides 221, 222, 223, 224; first type total reflection layer 1121; second type total reflection layer 1122

[0063] Transparent substrate 2000; anti-reflection film 2100. DETAILED DESCRIPTION

[0064] Embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Embodiments of the present invention are described in detail below.

[0065] First refer to Figure 1-Figure 5 An optical waveguide array according to an embodiment of the present invention is described.

[0066] like Figure 1 As shown, the optical waveguide arrays 1000a and 1000b include a plurality of optical waveguide units 100, each of which has a rectangular cross section and a plurality of optical waveguide units 100 are connected in parallel. The outer contour of the optical waveguide array is rectangular, and the extension direction of the optical waveguide unit 100 is at an angle of 30-60 degrees to at least two sides of the outer contour of the optical waveguide array. Optionally, the extension direction of the optical waveguide unit 100 is at an angle of 45 degrees to at least two sides of the outer contour of the optical waveguide array. Of course, the present invention is not limited to this, and large-size requirements can be achieved by splicing multiple optical waveguide arrays when displaying on a large screen. The overall shape of the optical waveguide array is set according to the application scenario.

[0067] like Figure 1 In the example shown, the outer contours of the optical waveguide arrays 1000a and 1000b are both rectangular. Figure 2a As shown, the optical waveguide unit extending between the two diagonal corners of the rectangle has the longest length, and the optical waveguide units 100 located at the two diagonal corners are triangular and the shortest. The optical waveguide unit in the middle is a trapezoidal or parallelogram structure, and the lengths of the individual optical waveguides are not equal. In some further optional examples, the optical waveguide unit extending between the two diagonal corners of the rectangle is used as a reference, and the optical waveguide units located on both sides thereof can be symmetrically arranged.

[0068] The optical waveguides of the two optical waveguide arrays 1000a and 1000b are arranged in an orthogonal extension direction to form an equivalent negative refractive index plane lens, wherein the extension direction of each optical waveguide in the optical waveguide array 1000a is also orthogonal to the extension direction of each optical waveguide in the optical waveguide array 1000b.

[0069] like Figure 4 The figure shows the principle diagram of light modulation in the overlapping area when two optical waveguide units are placed orthogonally, where a and b represent two optical waveguide units, A and B represent odd-order reflected light beams, C represents transmitted stray light, D represents imaging light beam, O represents the object light source point, and Ox represents the imaging point on the image side. Therefore, when the two optical waveguide units are placed orthogonally, the light beam on the object image plane is mirror-symmetrical with respect to the equivalent negative refractive index flat lens, resulting in a negative refractive index phenomenon, thus realizing flat lens imaging, as shown in FIG. Figure 5 shown.

[0070] In some embodiments of the present invention, Figure 3aAs shown, the plurality of optical waveguide units 100 are connected by an adhesive layer 4, and the thickness of the adhesive layer 4 is greater than 0.001 mm. The adhesive layer 4 is, for example, a photosensitive adhesive or a heat-sensitive adhesive.

[0071] Reference below Figure 1-Figure 10 An optical waveguide unit according to an embodiment of the present invention is described.

[0072] An optical waveguide unit 100 according to an embodiment of the present invention comprises: at least one total reflection layer group 1 and at least two sub-waveguides 2, wherein a total reflection layer group 1 is disposed between each two adjacent sub-waveguides 2. Each total reflection layer group 1 comprises at least one type of total reflection layer 11, each type of total reflection layer corresponds to an incident angle and has different optical refractive indexes. Each type of total reflection layer 11 comprises at least one single total reflection layer, and the optical refractive indexes of the single total reflection layers in each type are the same.

[0073] According to the optical waveguide unit 100 of the embodiment of the present invention, by arranging a total reflection layer 11 or a total reflection layer group 1 between the sub-waveguides 2, and each type of total reflection layer corresponds to a different incident angle and optical refractive index, the light collection efficiency of the entire optical waveguide unit 11 at the corresponding specific incident angle can be improved, and the uniformity of light intensity at the overall viewing angle is improved.

[0074] Optionally, the material of the total reflection layer used in the optical waveguide unit 100 according to the embodiment of the present invention includes optical glue, optical plastic, optical glass, etc.

[0075] The specific principle of the optical waveguide unit 100 according to the embodiment of the present invention is described below.

[0076] refer to Figure 4 , the incident light from the object light source point O is divided into four beams after being reflected inside the equivalent optical waveguide unit as shown in the figure, one beam participates in imaging, and three beams form interfering stray light, namely A, B and C. In order to reduce the influence of the ghost image formed by stray light on imaging, the two groups of optical waveguide arrays are arranged along 45° and orthogonal to each other.

[0077] As mentioned above, each optical waveguide unit is prone to generate stray light, and the stray light is part of the original object light, but does not participate in imaging, which is loss light. Figure 1 As shown in the figure, when the light beam is incident on the optical waveguide array in the related art at a certain incident angle, there is a loss zone with a size of b0'. Since the object side light source is a large divergence angle light source, the incident angle changes continuously with the different light emission of the light source. The smaller the angle, the larger the loss zone and the more serious the light loss, which greatly reduces the light energy utilization rate of the flat lens composed of the optical waveguide array. In addition, different incident angles lead to different energy losses, causing uneven energy at each viewing angle, which affects the effect of the observer observing the object at different viewing angles.

[0078] In order to make full use of light energy and improve the energy uniformity at various incident angles, as Figure 6 shown, by arranging a plurality of sub-waveguides 2 and a total reflection layer group 1 or a total reflection layer 11 between the sub-waveguides 2 in the optical waveguide unit according to the embodiment of the present invention, the light energy located in the loss area b0 can be collected after being differentiated by the total reflection layer and the sub-waveguide, so that the loss area b0 of the incident light incident at the θ angle will be relatively reduced. As Figure 7 shown, the function of the total reflection layer 11 is as follows: totally reflect the light incident on the surface of the optical waveguide unit at an angle greater than the critical angle, and transmit the light incident on the surface of the optical waveguide unit at an angle less than the critical angle, so as to achieve the purpose of accurately modulating the light near the critical angle respectively. Therefore, in the present application, in order to achieve the accurate modulation of the light near multiple critical angles, multiple types of total reflection layers 11 need to be arranged in a single optical waveguide unit 100, and the single optical waveguide unit 100 is divided into multiple layers of sub-waveguides 1.

[0079] As Figure 8 shown, the left side is a normal optical waveguide unit in the related art, and the right side is an optical waveguide unit according to the embodiment of the present invention. The figure shows the energy uniformity and stray light contrast of the two at each viewing angle. It can be seen that the optical waveguide unit 100 according to the embodiment of the present invention can greatly reduce the loss of light energy and improve the energy uniformity at each viewing angle.

[0080] As Figure 3b and Fig. 9 shown, in the stacking direction of the total reflection layer group 1 and the sub-waveguide 2, the total height H of the optical waveguide unit 100 satisfies 0.1 mm < H < 5 mm. In addition, the cross-sectional width of the optical waveguide unit 100 is W, and in the cross-section, the direction of the width w is perpendicular to the stacking direction, that is, the direction of the above-mentioned height H, where W also satisfies 0.1 mm < W < 5 mm.

[0081] According to some embodiments of the present invention, as Figure 7 in the simple example of, the number of sub-waveguides 2 is two, namely sub-waveguides 21 and 22, and the total reflection layer group 1 arranged between the two sub-waveguides 2 includes one type of total reflection layer 11. Thus, the light near one of the critical angles can be accurately modulated.

[0082] According to other embodiments of the present invention, as Fig. 9 shown, there are four sub-waveguides 221, 222, 223, and 224, the number of total reflection layer groups 1 is three, and it includes a first type of total reflection layer 1121 in the middle and two second type of total reflection layers 1122. The refractive index of the second type of total reflection layer 1122 is different from that of the first type of total reflection layer 1121. In the stacking direction of the total reflection layer 11 and the sub-waveguide 2, the two second type of total reflection layers 1122 are respectively located on both sides of the first type of total reflection layer 11. As Fig.10In the optional example shown, in the stacking direction, the heights of the four sub-waveguides 2 are GH1, GH2, GH3, and GH4, respectively, wherein GH1=GH4=GH2+GH3, GH2=GH3, and GH1+GH2=GH3+GH4. In this way, most of the object-side light corresponding to the selected incident angle can be collected, greatly improving the energy utilization rate of the imaging beam and the uniformity of the beam.

[0083] In some other embodiments of the present invention, the number of sub-waveguides 2 is 3, the number of total reflection layer groups 1 is two, and the refractive indexes of the two total reflection layer groups 1 are the same or different, which is not shown in the figure.

[0084] Of course, the present invention is not limited to the above-mentioned embodiments. According to some embodiments of the present invention, the distribution of each total reflection layer 11 in each type of total reflection layer 11 in the total reflection layer group 1 satisfies the following formula:

[0085] Formula 1:

[0086] Where comb(x) represents the comb function;

[0087] In the stacking direction of the total reflection layer group 1 and the sub-waveguide 2 unit, one side surface of the optical waveguide unit 100 is used as a reference surface, wherein

[0088] k is the total number of types of the total reflection layer 11;

[0089] i is the class number of the total reflection layer 11 and is an integer;

[0090] x is the distance from a single total reflection layer 11 in the i-th type total reflection layer 11 to the reference plane;

[0091] num is the layer number of the single total reflection layer 11 in the i-th type total reflection layer 11;

[0092] Ti represents the position period of the i-th type total reflection layer 11, and the position period is the shortest distance between adjacent i-th type total reflection layers 11 in the optical waveguide unit 100;

[0093] δ(x) is the impulse function.

[0094] In a further embodiment, the position period Ti can also be calculated by the following formula:

[0095] Formula 2:

[0096] Wherein, W is the cross-sectional width of the optical waveguide unit 100 , and the width direction on the cross section is perpendicular to the stacking direction; θi is the incident angle corresponding to the i-th type total reflection layer 11 incident on the surface of the optical waveguide unit 100 ; and n is the refractive index of the sub-waveguide 2 .

[0097] For example, in Fig. 9 and Fig.10 In the example shown, there are four sub-waveguides 221, 222, 223, 224 and two types of total reflection layers 11, and the total reflection layer 11 includes a first type of total reflection layer 1121 located in the middle and two second type of total reflection layers 1122. Among them, GH1 = GH4 = T2 = GH2 + GH3, GH2 = GH3, GH1 + GH2 = T1 = GH3 + GH4, where T1 is the period of the first type of total reflection layer calculated by the above formula when the selected incident angle is θ1. T2 is the period of the second type of total reflection layer calculated by the above formula when the selected incident angle is θ2. Fig.10 As shown, T1 is the shortest distance where the first type total reflection layer 11 appears, and T2 is the shortest distance where the second type total reflection layer 11 appears.

[0098] Of course, the present invention is not limited thereto. In other embodiments, when the number of groups, classes and layers of the total reflection layer 11 is different, the above formula 2 can be used to calculate the position period of the total reflection layer of the corresponding class, and then the distribution of each total reflection layer 11 in each class of total reflection layer 11 can be calculated according to formula 1, so as to more accurately design the internal structure of the entire optical waveguide unit 100. Preferably, the height H of the cross section of the optical waveguide unit is an integer multiple of the position period Ti.

[0099] In some optional examples, the thickness of each layer in each type of total reflection layer is 0.04 mm. <t<0.2Ti。

[0100] In some embodiments of the present invention, the refractive index range n of each type of total reflection layer 11 is ei It can be calculated by the following formula:

[0101] Formula 3:

[0102] The parameter θi is a predetermined angle selected within the observation viewing angle range, n is the optical refractive index of the sub-waveguide 2, and n>1.4. According to the optical waveguide unit of the embodiment of the present invention, each type of total reflection layer corresponds to one θi, n ei The θi angle is an angle selected within the observation viewing angle range, the purpose of which is to improve the light collection efficiency at the corresponding angle and to improve the uniformity of light intensity at the overall viewing angle.

[0103] It is worth noting that in order to improve the collection effect in the loss zone, relevant personnel can appropriately increase or decrease the number of total reflection layers and the number of sub-waveguides in the optical waveguide unit 10 during the implementation process to meet the light collection requirements. When it is necessary to collect light in the loss zone at multiple incident angles at the same time, multiple types of total reflection layers are required. The embodiments of the present invention do not impose any restrictions on the number of types and layers of total reflection layers.

[0104] In a further embodiment of the present invention, in the stacking direction of the total reflection layer group 1 and the sub-waveguide 2, the reflection layer 3 is disposed on both sides of the optical waveguide unit 100, such as Fig. 9 and Fig.10 Optionally, the reflective layer 3 here is made of aluminum film, which can further reduce the light loss to a certain extent.

[0105] Reference below Fig.11 A flat lens according to an embodiment of the third aspect of the present invention is described, comprising: two transparent substrates 2000 and two optical waveguide arrays 1000a and 1000b according to the above embodiments.

[0106] Each transparent substrate 2000 has two optical surfaces, and the optical surfaces are used to protect the optical waveguide arrays 1000a and 1000b. The two optical waveguide arrays are arranged between the two transparent substrates 2000 by adhesive, and the optical waveguide extension directions of the two optical waveguide arrays are arranged orthogonally, that is, the extension directions of the optical waveguide units are perpendicular to each other, so that the light beams converge at one point, and the object image plane is ensured to be symmetrical with respect to the equivalent negative refractive index flat lens, so as to generate a negative refractive index phenomenon and realize flat lens imaging.

[0107] Optionally, the optical waveguide array and the transparent substrate 2000 are also bonded together by photosensitive adhesive or heat-sensitive adhesive.

[0108] In some embodiments of the present invention, Fig.11 As shown, an anti-reflection film 210 is disposed on the optical surface of each transparent substrate 200 away from the optical waveguide array to further improve the imaging effect.

[0109] According to the planar lens of the embodiment of the present invention, an array structure is formed by a single-column and multi-row optical waveguide with a rectangular cross-section, which can enable a two-dimensional or three-dimensional light source to form a real image directly in the air to realize a true holographic image, and realize a naked-eye three-dimensional stereoscopic display characteristic while having a good imaging effect.

[0110] In the description of the present invention, it should be understood that the terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0111] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0112] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An optical waveguide unit, characterized in that: include: At least one total reflection layer group, each of the total reflection layer groups includes at least one type of total reflection layer, and each type of the total reflection layer includes at least one single total reflection layer; At least two sub-waveguides, with one total reflection layer group being arranged between every two adjacent sub-waveguides; The cross-sectional width of the optical waveguide unit is W, wherein the cross-sectional width W satisfies 0.1 mm <W<5mm; The distribution of each total reflection layer in each type of total reflection layer in the total reflection layer group satisfies the following formula: Where comb(x) represents the comb function; In the stacking direction of the total reflection layer group and the sub-waveguide unit, one side surface of the optical waveguide unit is used as a reference plane, wherein k is the total number of the total reflection layers, i is the class number of the total reflection layer, and is an integer, x is the distance from a single total reflection layer in the i-th total reflection layer to the reference plane, num is the layer number of the single total reflection layer in the i-th total reflection layer, Ti represents the position period of the i-th total reflection layer, and the position period is the shortest distance between the adjacent i-th total reflection layers in the optical waveguide unit, δ(x) is the pulse function, and m i represents the total number of all single total reflection layers in the i-th type total reflection layer; The position period Ti is calculated by the following formula: Wherein, W is the cross-sectional width of the optical waveguide unit, and the direction of the width on the cross-section is perpendicular to the stacking direction; θi is the incident angle corresponding to the i-th type total reflection layer on the surface of the optical waveguide unit; n is the refractive index of the sub-waveguide; The refractive index range n of each type of total reflection layer ei Calculated by the following formula: ， Wherein, the parameter θi is a predetermined angle selected within the observation viewing angle range, n is the optical refractive index of the sub-waveguide, and n>1.

4.

2. The optical waveguide unit according to claim 1, characterized in that In the stacking direction of the total reflection layer group and the sub-waveguide, the total height H of the optical waveguide unit satisfies 0.1 mm <H<5mm。 3. The optical waveguide unit according to claim 1, characterized in that The number of the sub-waveguides is two, and the total reflection layer group arranged between the two sub-waveguides includes a type of total reflection layer.

4. The optical waveguide unit according to claim 1, characterized in that The number of the sub-waveguides is 4, the number of the total reflection layer groups is three, and the invention comprises: The first type of total reflection layer located in the middle; Two second-type total reflection layers, the refractive index of the second-type total reflection layer is different from the refractive index of the first-type total reflection layer, and in the stacking direction of the total reflection layer and the sub-waveguide, the two second-type total reflection layers are respectively located on both sides of the first-type total reflection layer.

5. The optical waveguide unit according to claim 4, characterized in that In the stacking direction, the heights of the four sub-waveguides are GH1, GH2, GH3, and GH4, respectively, wherein GH1=GH4=GH2+GH3, GH2=GH3, and GH1+GH2=GH3+GH4.

6. The optical waveguide unit according to claim 1, characterized in that The number of the sub-waveguides is 3, the number of the total reflection layer groups is two, and the refractive indexes of the two total reflection layer groups are the same or different.

7. The optical waveguide unit according to claim 1, characterized in that The thickness of each layer in each type of total reflection layer is 0.04 mm. <t<0.2Ti。 8. The optical waveguide unit according to claim 1, characterized in that In the stacking direction of the total reflection layer group and the sub-waveguide, reflection layers are disposed on both sides of the optical waveguide unit.

9. An optical waveguide array, characterized in that: The optical waveguide unit comprises a plurality of optical waveguide units according to any one of claims 1 to 8, each of the optical waveguide units has a rectangular cross section and the plurality of optical waveguide units are connected in parallel; The outer contour of the optical waveguide array is in a rectangular shape, and the extension direction of the optical waveguide unit forms an angle of 30-60 degrees with at least two sides of the outer contour of the optical waveguide array.

10. The optical waveguide array according to claim 9, characterized in that: The extension direction of the optical waveguide unit forms an angle of 45 degrees with at least two sides of the outer contour of the optical waveguide array.

11. The optical waveguide array according to claim 9, characterized in that: The plurality of optical waveguide units are bonded together by an adhesive layer, and the thickness of the adhesive layer is greater than 0.001 mm.

12. A flat lens, characterized in that: include: Two transparent substrates, each of which has two optical surfaces; Two optical waveguide arrays according to any one of claims 9 to 11, the two optical waveguide arrays are arranged between the two transparent substrates by adhesive, and the optical waveguide extension directions of the two optical waveguide arrays are arranged orthogonally.

13. The flat lens according to claim 12, characterized in that: An anti-reflection film is disposed on the optical surface of each transparent substrate away from the optical waveguide array.

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