CN116338976A - A Phase Modulation Moiré Imaging Device - Google Patents

Abstract

The present invention relates to a phase modulation moiré imaging device, comprising a spacer layer, which has a first surface and a second surface oppositely arranged; a transmission unit, which is arranged on the first surface, and the transmission unit includes a first micro-focus A unit, the first micro-focusing unit includes a plurality of first micro-focusing elements; a reflection unit, which is arranged on the second surface, the reflection unit includes a second micro-focusing unit, a plurality of the first micro-focusing elements The projection on the spacer layer and the projections of the plurality of second micro-focusing elements on the spacer layer have a relative offset, the surface of the second micro-focusing element is provided with a reflective layer, and the graphic information is encoded in the reflective layer. The present invention does not require precise alignment between the micro-focusing element array and the image-text array during the manufacturing process, and reduces the alignment requirements between the transmission unit and the reflection unit, thereby reducing the manufacturing difficulty and production cost. Anti-counterfeiting and other fields have application value and prospects.

Description

A Phase Modulation Moiré Imaging Device

technical field

The invention relates to the technical field of micro-optical imaging, in particular to a phase modulation moiré imaging device.

Background technique

Three-dimensional display technology uses various technical means such as optics to simulate the stereoscopic vision characteristics of the human eye, reproduces the three-dimensional information of the target object, and presents a three-dimensional image with a sense of depth. Three-dimensional display technology is mainly divided into vision-aided three-dimensional display and naked-eye three-dimensional display. Vision-aided 3D display needs to wear glasses, helmets and other auxiliary tools to see the 3D effect, which brings inconvenience to the observer. Naked-eye 3D display can achieve 3D display effect without other auxiliary equipment. Naked-eye 3D display technologies mainly include volumetric 3D display technology, holographic display technology, and light field display technology. Volumetric 3D display occupies a real 3D space, and uses the persistence of vision of the human eye to reconstruct a 3D image with real depth. However, the 3D images reproduced by 3D display are all transparent, which cannot express the occlusion relationship of objects.

In the moiré imaging device in the prior art, the micro-lens array and the micro-text array located on both sides of the transparent substrate must achieve precise alignment. In the Chinese invention patent "A Reflective Imaging Film" (authorization number: 202110983747.3), a reflective imaging film is disclosed. The micro-text array unit in the micro-text layer is projected by the virtual object through the reflective focusing unit array. Imaging is obtained. In order to reproduce virtual objects, the microtext array must be strictly aligned with the microlens array, otherwise the reproduced image will be distorted.

Contents of the invention

Therefore, the technical problem to be solved by the present invention is to overcome the deficiencies in the prior art, to provide a phase modulation moiré imaging device, which does not require accurate alignment of the projection unit and the reflection unit, and uses human eyes to recognize different grayscale images Forming a three-dimensional image reduces production difficulty and production cost, and is visible to the naked eye, and the observed image can change with the change of the viewing angle.

In order to solve the above technical problems, the present invention provides a phase modulation moiré imaging device, comprising:

A spacer layer, which has a first surface and a second surface opposite to each other, the incident light enters from the first surface, exits through the second surface, and after reflection, enters from the second surface, and then passes through the first surface shoot out

a transmission unit, which is arranged on the first surface, the transmission unit includes a first micro-focus unit, and the first micro-focus unit includes a plurality of first micro-focus elements;

A reflective unit, which is arranged on the second surface, the reflective unit includes a second micro-focusing unit, the second micro-focusing unit includes a plurality of second micro-focusing elements, and a plurality of the first micro-focusing elements are in the There is a relative offset between the projection of the spacer layer and the projections of the plurality of second micro-focusing elements on the spacer layer, the surface of the second micro-focusing element is provided with a reflective layer, and the graphic information is encoded on the plurality of said second microfocusing element;

Observing the image and text information through the transmission unit to obtain a three-dimensional object image that changes with the change of the viewing angle.

Preferably, the first micro-focusing element and the second micro-focusing element include linear micro-focusing elements, a plurality of the first micro-focusing elements are arranged in an array, and a plurality of the second micro-focusing elements are arranged in an array .

Preferably, the linear micro-focusing element includes a one-dimensional linear cylindrical lens or a one-dimensional Fresnel cylindrical lens.

Preferably, the aspect ratio of the projection of the first micro-focusing element on the spacer layer is greater than 5:1, and the aspect ratio of the projection of the second micro-focusing element on the spacer layer is greater than 5:1.

Preferably, the first micro-focusing element and the second micro-focusing element include two-dimensional micro-focusing elements, and the arrangement of a plurality of the first micro-focusing elements includes two-dimensional periodic type, non-periodic type, random type and their combination.

Preferably, the two-dimensional micro-focusing element comprises a spherical micro-lens.

Preferably, the projections of the first micro-focusing element and the second micro-focusing element on the spacer layer are circular with a diameter ratio of less than 2:1.

Preferably, the thickness of the spacer layer is within ±30% of the sum of the focal length of the first micro-focusing element and the focal length of the second reflective micro-focusing element.

Preferably, the spacer layer includes a plurality of composite layer structures, and the material of the layer structure includes PMMA and PET, PMMA, or at least two of PET, PMMA, PC, PI, PE, and glass.

Preferably, the reflective layer includes an optical thin film of metal or non-metallic material, and the thickness of the reflective layer is 20nm to 100nm.

The above technical solution of the present invention has the following advantages compared with the prior art:

A phase modulation moiré imaging device according to the present invention, by setting a spacer layer, a transmission unit and a reflection unit, the transmission unit and the reflection unit are respectively arranged on the first surface and the second surface of the spacer layer, the The transmission unit includes a first micro-focusing element unit, and the reflection unit includes a second micro-focusing element unit. It should be noted that the projection of the first micro-focusing element unit on the spacer layer is relative to the second micro-focusing element unit The projection of the unit on the spacer layer has a position offset or a phase difference, so that the graphic information on the reflective layer can be observed through the transmission unit, and a three-dimensional object image that changes with the viewing angle can be obtained. The phase modulation moiré imaging device described in the invention does not require precise alignment between the micro-focusing element array and the image-text array during the manufacturing process, and its stereoscopic effect is visible to the naked eye without wearing glasses, and can change with the change of the viewing angle. Strong, etc., compared with the traditional Moiré imaging device, the alignment requirements between the transmission unit and the reflection unit are reduced, thereby reducing the difficulty of production and production costs. The invention has a wide range of applications, such as stereoscopic imaging, visual anti-counterfeiting, etc. The field has application value and prospect.

Description of drawings

In order to make the content of the present invention more easily understood, the present invention will be described in further detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

Fig. 1 is a schematic cross-sectional structure diagram of a preferred embodiment of the present invention.

Fig. 2 is a schematic diagram of the working principle of the preferred embodiment of the present invention.

Fig. 3 is a schematic diagram of the working principle of the preferred embodiment of the present invention.

Fig. 4 is a schematic diagram of the working principle of the preferred embodiment of the present invention.

Fig. 5 is a phase modulation method of a linear phase modulation moiré imaging element in the preferred embodiment of the present invention.

Fig. 6 is a phase modulation method of a linear phase modulation moiré imaging element according to the best embodiment of the present invention.

Fig. 7 is a phase modulation method of a linear phase modulation moiré imaging element according to the best embodiment of the present invention.

Fig. 8 is a phase modulation mode of a linear phase modulation moiré imaging element according to the best embodiment of the present invention.

Fig. 9 is a moiré imaging method of embedding graphic and text information in the best embodiment of the present invention.

Fig. 10 is a phase modulation mode of a phase modulation moiré imaging element according to the best embodiment of the present invention.

Fig. 11 is a phase modulation mode of a phase modulation moiré imaging element in the best embodiment of the present invention

Fig. 12 is a schematic top view of a phase modulation mode of a phase modulation Moiré imaging element according to the best embodiment of the present invention.

Fig. 13 is a schematic top view of a phase modulation mode of a phase modulation moiré imaging element according to the best embodiment of the present invention.

Explanation of reference numerals in the specification: 1. First micro-focusing element; 2. Spacer layer; 3. Second micro-focusing element; 4. Reflective layer; 51. Reflective layer area; 52. Holographic grating unit area.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and implement it, but the examples given are not intended to limit the present invention.

Example

Referring to Figures 1 to 13, the present invention provides a phase modulation Moiré imaging device, comprising:

The spacer layer 2 has a first surface and a second surface opposite to each other, the first surface and the second surface are parallel to each other, the incident light enters from the first surface, exits through the second surface, and after reflection, incident from the second surface and emitted from said first surface;

A transmission unit, which is arranged on the first surface, the transmission unit includes a first micro-focusing unit, and the first micro-focusing unit includes a plurality of first micro-focusing elements 1;

A reflection unit, which is arranged on the second surface, the reflection unit includes a second micro-focus unit, the second micro-focus unit includes a plurality of second micro-focus elements 3, and a plurality of the first micro-focus elements 1 The projection on the spacer layer 2 has a relative offset from the projections of the plurality of second micro-focusing elements 3 on the spacer layer, specifically, the projection of the first micro-focusing unit on the spacer layer 2 There is a phase difference between the projection of the second micro-focusing unit on the spacer layer 2, the surface of the second micro-focusing element 3 is provided with a reflective layer 4, and the graphic information that needs to be displayed is encoded on the reflective layer 4 In this way, along the incident direction of the incident light, there are in turn the first micro-focusing element 1, the spacer layer 2, the second micro-focusing element 3, and the reflective layer 4. It should be noted that the spacer layer 2 and the first The micro-focusing elements 1 are closely connected without an optical interface, and the spacer layer 2 and the second micro-focusing element 3 are closely connected without an optical interface;

Observing the image and text information on the reflective layer 4 through the transmission unit can obtain a three-dimensional object image that changes with the viewing angle.

It can be known from this that a phase modulation moiré imaging device to be protected by the present invention is provided with a spacer layer, a transmission unit and a reflection unit, and the transmission unit and the reflection unit are respectively arranged on the first surface and the first surface of the spacer layer. On the second surface, the transmission unit includes a first micro-focusing element unit, and the reflection unit includes a second micro-focusing element unit. It should be noted that the projection of the first micro-focusing element unit on the spacer layer is relative to The projection of the second micro-focusing unit on the spacer layer has a position offset or a phase difference, so that the graphic information on the reflective layer can be observed through the transmission unit, and a three-dimensional image that changes with the viewing angle can be obtained. Sensitive object images, the phase modulation moiré imaging device of the present invention does not require precise alignment of the micro-focusing element array and the graphic array during the manufacturing process, and its stereoscopic visual effect is visible to the naked eye without wearing glasses, and can change with the viewing angle Compared with the traditional moiré imaging device, the requirements for the alignment between the transmission unit and the reflection unit are reduced, thereby reducing the production difficulty and production cost. The present invention has a wide range of applications. Stereoscopic imaging, visual anti-counterfeiting and other fields have application value and prospects.

It should be noted that the micro-focusing elements in the transmission unit and the reflection unit include two different types, one of which is a linear micro-focusing element, and the other is a two-dimensional micro-focusing element:

On the one hand, the first micro-focusing elements 1 and the second micro-focusing elements 3 include linear micro-focusing elements, and a plurality of the first micro-focusing elements 1 and a plurality of second micro-focusing elements 2 are arranged in an array.

Furthermore, the linear micro-focusing element includes a one-dimensional linear cylindrical lens or a one-dimensional Fresnel cylindrical lens.

Specifically, the aspect ratio of the projection of the first micro-focusing element 1 on the spacer layer 2 is greater than 5:1, and the aspect ratio of the projection of the second micro-focusing element 3 on the spacer layer 2 is greater than 5:1. 5:1.

On the other hand, the first micro-focusing element 1 and the second micro-focusing element 3 include two-dimensional micro-focusing elements, and the arrangement of multiple first micro-focusing elements 1 and multiple second micro-focusing elements includes two-dimensional Periodic, non-periodic, random and their combinations.

Further, the two-dimensional micro-focusing element includes a spherical micro-lens.

Furthermore, the projections of the first micro-focusing element 1 and the second micro-focusing element 3 on the spacer layer 2 are circular with a diameter ratio smaller than 2:1.

In detail, the thickness of the spacer layer 2 is within ±30% of the sum of the focal length of the first micro-focusing element 1 and the focal length of the second reflective micro-focusing element 3 .

Specifically, the spacer layer 2 is a transparent spacer layer, and the transparent spacer layer includes a plurality of composite layer structures, and the material of the layer structure includes PMMA and PET, PMMA, or PET, PMMA, PC, PI, At least two of PE and glass.

The reflective layer 4 includes an optical thin film of metal or non-metallic material, and the thickness of the reflective layer is 20nm to 100nm. Further, the reflective layer 4 includes a single-layer metal coating or a multi-layer metal coating. The material of the metal coating includes aluminum, nickel, silver, chromium, and their alloys. The reflective layer also includes a multi-layer film system of non-metallic materials, such as zinc oxide, silicon dioxide, magnesium fluoride and titanium dioxide.

In terms of details, there is a background area between the two adjacent second micro-focusing elements 3 on the second surface. In one embodiment, the background area does not contain any materials and structures. In another embodiment, the background region includes a scattering, absorbing or reflecting structure, such as a one-dimensional or two-dimensional Bravais lattice structure or a random structure, and its size is micron or submicron.

The working principle of the phase modulation moiré imaging device of the present invention is as follows. Referring to FIG. 2 to FIG. 4 , people observe through the first surface of the transparent spacer layer, that is, through the side of the first micro-focusing element unit. When along the vertical viewing angle, as shown in Figure 2, when the optical axis of the first micro-focus element 1 positioned on the first surface is aligned with the second micro-focus element 3 positioned on the second surface, it is reflected along the vertical direction and enters the human body. The reflection efficiency of eye is the highest, thereby has the highest brightness; As shown in Figure 3, when the optical axis that is positioned at the first micro-focus element 1 of the first surface and the second micro-focus element 3 that is positioned at the second surface has opposite along horizontal direction Offset, that is, there is a phase difference between the array formed by a plurality of first micro-focusing elements and the array formed by a plurality of second micro-focusing elements, part of the transmitted light is reflected by the second micro-focusing element unit to other directions, and cannot enter the observer The eyes, therefore present a relatively low brightness; further, as shown in Figure 4, when observed at a certain viewing angle, more transmitted light is reflected to other directions by the second micro-focusing element unit, and cannot enter the observer's eyes, Thus presenting a lower brightness.

According to the aforementioned principle, by encoding the graphic information and modulating the phase between the second micro-focusing element unit array and the corresponding first micro-focusing element unit array, object images with different brightness levels can be obtained, forming a three-dimensional and An object image whose light and shadow effects change with the viewing angle.

As shown in Figure 5, the phase modulation method of the linear phase modulation Moiré imaging device in one of the embodiments of the present invention is as follows, the first micro-focusing element unit (R ₁ , R ₂ , R ₃ ,...,R _N ) are linear and arranged periodically, and the period is denoted as D. The second micro-focusing element unit (P ₁ , P ₂ , P ₃ , ..., P _N ) of the reflection unit, wherein the micro-focusing units P ₃ -P _n are linear, and relative to the corresponding R ₃ -R The offset Δ of _n , the image and text information is coded in the reflective layer of the phase-modulated second micro-focus element unit.

As shown in Figure 6, the phase modulation method of the linear phase modulation Moiré imaging device in one of the embodiments of the present invention is as follows, the first micro-focusing element unit (R ₁ , R ₂ , R ₃ ,...,R _N ) are linear and arranged periodically, and the period is denoted as D. The second micro-focusing element unit (P ₁ , P ₂ , P ₃ , ..., P _N ) of the reflection unit, wherein the linear micro-focusing element unit is in the shape of a curve, and the image and text information is encoded in the phase-modulated second In the reflective layer of the micro-focusing element unit.

As shown in Figure 7, the phase modulation method of the linear phase modulation Moiré imaging device in one of the embodiments of the present invention is as follows, the first micro-focusing element unit (R ₁ , R ₂ , R ₃ ,…,R _N ) are curved and arranged periodically, and the period is denoted as D. The second micro-focusing element unit (P ₁ , P ₂ , P ₃ , ..., P _N ) of the reflection unit, wherein the linear micro-focusing element unit is linear, and the image and text information is encoded in the phase-modulated second In the reflective layer of the micro-focusing element unit.

As shown in Figure 8, the phase modulation method of the linear phase modulation Moiré imaging device in one of the embodiments of the present invention is as follows, the first micro-focusing element unit (R ₁ , R ₂ , R ₃ ,...,R _N ) are linear and arranged periodically, and the period is denoted as D. The second micro-focusing element units (P ₁ , P ₂ , P ₃ , ..., P _N ) of the reflection unit, wherein each second micro-focusing unit consists of a plurality of micro-focusing elements [(P ₁₁ , P ₁₂ ), (P ₂₁ , P ₂₂ ), ... (P _N1 , P _N2 )], wherein the micro-focusing unit arrays P ₃ -P _n are linear. The image and text information is coded in the reflective layer of the phase-modulated second micro-focus element unit.

As shown in FIG. 9 , a moiré imaging method of embedding graphic information in the present invention is as follows, and the lines in the figure are schematic diagrams of linear micro-focusing element units of reflective units. Fig. 9(a) shows that the second micro-focusing element unit of the reflective unit is relatively shifted along the period direction relative to the first micro-focusing element unit of the transmissive unit, forming phase modulation on the moiré image. Figure 9(b) shows that the second micro-focusing element unit of the reflective unit has an arc-shaped relative translation along the period direction with respect to the first micro-focusing element unit of the transmissive unit, forming phase modulation on the moiré image. Figure 9(c) shows that the second micro-focusing element unit of the reflective unit has a linear relative translation along the periodic direction with respect to the first micro-focusing element unit of the transmissive unit, forming phase modulation on the moiré image. The grayscale variation formed by the structure shown in Fig. 9(c) is more obvious on the moiré image.

As shown in FIG. 10 and FIG. 11 , an embodiment of a phase modulation moiré imaging device of the present invention, the first micro-focusing elements 1 of the transmission unit are arranged in a periodic square array, and the period is denoted as D. The second micro-focusing element unit (i, j) has offsets (Δ _ix , Δ _jy ) along the x and y directions respectively with respect to the first micro-focusing element unit. The magnitude of the offset, that is, the modulated phase, is determined by encoding the grayscale of the graphic information to be displayed.

As shown in Figure 12, it is a schematic top view of an embodiment of the present invention, the first micro-focusing element unit is arranged in a periodic square array, and the graphic information is encoded in the phase-modulated second micro-focusing element unit, The position of the associated second micro-focusing element unit is slightly displaced relative to the first micro-focusing element unit, forming a character "B" shape as shown in FIG. 12 .

As shown in Figure 13, it is a schematic top view of an embodiment of the present invention, the first micro-focusing element unit is arranged in a periodic square array, and the graphic information is encoded in the phase-modulated second micro-focusing element unit, The position of the associated second microfocusing element unit is slightly displaced relative to the first microfocusing element unit. In the background area of the reflective unit, there are holographic grating units with different periods and different orientations. Observing from the transmission unit, the graphic information is displayed through the phase-modulated reflective layer region 51, and the holographic grating unit region 52 is the background.

In summary, the phase modulation moiré imaging device to be protected by the present invention is provided with a spacer layer, a transmission unit and a reflection unit, and the transmission unit and the reflection unit are respectively arranged on the first surface and the second surface of the spacer layer. On the second surface, the transmission unit includes a first micro-focusing element unit, and the reflection unit includes a second micro-focusing element unit. It should be noted that the projection of the first micro-focusing element unit on the spacer layer is relative to the The projection of the second micro-focusing unit on the spacer layer has a position offset or a phase difference, so that the graphic information on the reflective layer can be observed through the transmission unit, and a three-dimensional image that changes with the viewing angle can be obtained. The object image of the phase modulation moiré imaging device of the present invention does not need the precise alignment of the micro-focusing element array and the graphic array in the manufacturing process, and its stereoscopic visual effect is visible to the naked eye without wearing glasses, and can change with the change of the viewing angle. change, strong three-dimensional effect, etc. Compared with the traditional Moiré imaging device, the requirement for the alignment between the transmission unit and the reflection unit is reduced, thereby reducing the difficulty of production and production cost. The present invention has a wide range of applications. Imaging, visual anti-counterfeiting and other fields have application value and prospects.

Apparently, the above-mentioned embodiments are only examples for clear description, and are not intended to limit the implementation. For those of ordinary skill in the art, on the basis of the above description, other changes or changes in various forms can also be made. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (10)

1. A phase modulation moiré imaging device, characterized in that: comprising, A spacer layer, which has a first surface and a second surface opposite to each other, the incident light enters from the first surface, exits through the second surface, and after reflection, enters from the second surface, and then passes through the first surface shoot out a transmission unit, which is arranged on the first surface, the transmission unit includes a first micro-focus unit, and the first micro-focus unit includes a plurality of first micro-focus elements; A reflective unit, which is arranged on the second surface, the reflective unit includes a second micro-focusing unit, the second micro-focusing unit includes a plurality of second micro-focusing elements, and a plurality of the first micro-focusing elements are in the There is a relative offset between the projection of the spacer layer and the projections of the plurality of second micro-focusing elements on the spacer layer, the surface of the second micro-focusing element is provided with a reflective layer, and the graphic information is encoded on the plurality of said second microfocusing element; Observing the image and text information through the transmission unit to obtain a three-dimensional object image that changes with the change of the viewing angle. 2. A phase modulation moiré imaging device according to claim 1, characterized in that: the first micro-focusing element and the second micro-focusing element comprise linear micro-focusing elements, and a plurality of the first micro-focusing elements The elements are arranged in an array, and a plurality of the second micro-focusing elements are arranged in an array. 3 . The phase modulation moiré imaging device according to claim 2 , wherein the linear micro-focusing element comprises a one-dimensional linear cylindrical lens or a one-dimensional Fresnel cylindrical lens. 4 . 4. A phase modulation moiré imaging device according to claim 2, characterized in that: the aspect ratio of the projection of the first micro-focusing element on the spacer layer is greater than 5:1, and the second micro-focusing element The aspect ratio of the projection of the focusing element on the spacer layer is greater than 5:1. 5. A phase modulation moiré imaging device according to claim 1, characterized in that: the first micro-focusing element and the second micro-focusing element comprise two-dimensional micro-focusing elements, and a plurality of the first micro-focusing elements The arrangement of elements includes two-dimensional periodic type, non-periodic type, random type and their combination. 6 . The phase modulation moiré imaging device according to claim 5 , wherein the two-dimensional micro-focusing element comprises a spherical micro-lens. 7 . 7. A phase modulation moiré imaging device according to claim 6, characterized in that: the projections of the first micro-focusing element and the second micro-focusing element on the spacer layer are circular with a diameter ratio of less than 2:1 . 8. A phase modulation moiré imaging device according to claim 1, characterized in that: the thickness of the spacer layer is ±30 of the sum of the focal length of the first micro-focusing element and the focal length of the second reflective micro-focusing element % within. 9. A kind of phase modulation moiré imaging device according to claim 1, characterized in that: the spacer layer comprises a plurality of composite layer structures, and the material of the layer structure comprises PMMA and PET, PMMA, or At least two of PET, PMMA, PC, PI, PE, glass. 10 . The phase modulation moiré imaging device according to claim 1 , wherein the reflective layer comprises an optical thin film of metal or non-metallic material, and the thickness of the reflective layer is 20 nm to 100 nm. 11 .

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