CN117518522A - Optical imaging module, array imaging module, suspension display device and multilayer display equipment - Google Patents

Abstract

The invention relates to an optical imaging module, an array imaging module, a floating display device and a multi-layer display device. The optical imaging module includes: the deflection optical group at least comprises a first light deflection unit and a second light deflection unit which are arranged in parallel with each other, and the deflection optical group modulates light in a first direction only; and a first conjugate imaging element located between the first light deflecting unit and the second light deflecting unit on the optical path, an optical path between the first conjugate imaging element and the first light deflecting unit being substantially equal to an optical path between the first conjugate imaging element and the second light deflecting unit, wherein the optical imaging module is configured to converge the light beam from the point on the object plane on the first image plane in the first direction.

Description

Optical imaging module, array imaging module, suspension display device and multilayer display equipment

Technical Field

Embodiments described herein relate generally to light field three-dimensional display technology, and more particularly, to an optical imaging module, an array imaging module, a floating display device, and a multi-layer display apparatus for floating display.

Background

Among the many display technologies, the in-air display technology has received attention from many researchers because of its ability to present images in the air, giving viewers a strong visual impact and also a truly spurious sensory experience.

The existing suspension display technology proposes to enlarge the divergence angle of the vertical observation direction by using a scattering screen, and the scheme is characterized in that a larger visual angle range is formed, and the defect is that light rays emitted by a display module are converged on two different planes in the horizontal direction and the vertical direction and are far apart, so that imaging quality is low and larger space depth display cannot be realized. Meanwhile, the floating image formed by the floating display technical scheme has only horizontal parallax and no vertical parallax, the space position of the floating image in the vertical direction is not fixed, and the floating image moves along with the movement of the position of an observer in the vertical direction, so that some scene applications requiring accurate interaction are affected. Furthermore, the required size of the hover image varies for different scene requirements. In the prior art, although various floating display technologies exist, the size of a floating image displayed by a floating display device is generally limited in the design stage of manufacturers, and cannot be adjusted when in use. As such, when a user desires to present different sizes of floating images according to different application scenes, it is generally necessary to purchase different sizes of floating display devices. For manufacturers of floating display devices, different floating display devices (especially, different optical systems are designed to adapt to different sizes of image display units) need to be designed according to different user requirements, and the floating display devices are adapted one by one, so that great manpower and material resources are consumed.

Disclosure of Invention

It is an aim of exemplary embodiments of the present invention to overcome the above and/or other problems of the prior art, and in particular to provide an optical imaging module comprising: the deflection optical group at least comprises a first light deflection unit and a second light deflection unit which are arranged in parallel, and the deflection optical group modulates light in a first direction only; and a first conjugate imaging element located between the first light deflecting unit and the second light deflecting unit on an optical path, an optical path length between the first conjugate imaging element and the first light deflecting unit being substantially equal to an optical path length between the first conjugate imaging element and the second light deflecting unit, wherein the optical imaging module is configured to converge a light beam from a point on an object plane on a first image plane in the first direction.

Optionally, the first light ray deflection unit is an aperture stop of the optical imaging module in the first direction.

Optionally, the first light ray deflection unit and the second light ray deflection unit are configured such that an image height of the optical imaging module in the first direction is equal to an object height in the first direction.

Optionally, the first light deflection unit and the second light deflection unit are the same lens.

Optionally, the first light deflection unit is a lens, and f# is greater than or equal to 1.5 and less than or equal to 6.

Optionally, the aperture of the light deflection unit is D, and the distance between the second light deflection unit and the first light deflection unit is greater than or equal to 2D.

Optionally, along the optical path, a distance between the first conjugate imaging element and the first light deflecting unit is less than or equal to a focal length of the first light deflecting unit.

Optionally, the first conjugate imaging element is a one-dimensional conjugate imaging element, and the first light ray deflecting unit, the second light ray deflecting unit and the first conjugate imaging element cooperate to converge the light beam from the point on the object plane on a first image plane in the first direction.

Optionally, the optical imaging module further comprises a second conjugate imaging element for converging the light beam from the point on the object plane in a second direction on a second image plane different from the first image plane, the first direction and the second direction being orthogonal to the main optical axis of the optical imaging module, respectively.

Optionally, the first conjugated imaging element and the second conjugated imaging element are one-dimensional reflective retroreflectors, wherein the microstructure units of the first conjugated imaging element and the microstructure units of the second conjugated imaging element are orthogonally arranged.

Optionally, the first conjugated imaging element and the second conjugated imaging element are arranged in parallel, and optical axes of the first conjugated imaging element and the second conjugated imaging element are perpendicular to optical axes of the first light beam deflection unit and the second light beam deflection unit.

Optionally, the optical imaging module further includes a light splitting element, the light beam from the object plane is deflected by the first light deflecting unit, then enters the first conjugate imaging element after being reflected by the light splitting element, then enters the second conjugate imaging element after being reflected by the first conjugate imaging element, then enters the second light deflecting unit after being reflected by the second conjugate imaging element, and then enters the second light deflecting unit after being deflected by the second light deflecting unit, and propagates towards the first image plane and the second image plane after being deflected by the second light deflecting unit.

Optionally, the light splitting element is obliquely disposed between the first conjugate imaging element and the second conjugate imaging element and between the first light deflecting unit and the second light deflecting unit.

Optionally, the light splitting element includes: a polarizing beam splitter; a first phase retardation film disposed between the first conjugate imaging element and the polarizing beam splitter; and a second phase retardation film disposed between the second conjugate imaging element and the polarizing beam splitter.

Optionally, the first conjugate imaging element is a two-dimensional conjugate imaging element, the first light ray deflection unit, the second light ray deflection unit and the first conjugate imaging element cooperate to converge the light beam from the point on the object plane on the first image plane in the first direction, and the first conjugate imaging element is configured to converge the light beam from the point on the object plane on the first image plane in a second direction, the first direction and the second direction being orthogonal to the main optical axis of the optical imaging module, respectively.

Optionally, the first conjugate imaging element is a two-dimensional reflective retroreflector, the optical imaging module further includes a light splitting element and a reflector, the light beam from the object plane is deflected by the first light deflecting unit and then enters the light splitting element, the light beam is reflected by the light splitting element to the reflector, reflected by the reflector and then transmitted by the light splitting element to enter the first conjugate imaging element, reflected by the first conjugate imaging element and then reflected by the light splitting element to enter the second light deflecting unit, deflected by the second light deflecting unit and then transmitted toward the first image plane.

Optionally, the light splitting element is obliquely disposed between the mirror and the first conjugate imaging element and between the first light deflecting unit and the second light deflecting unit, and optical axes of the mirror and the first conjugate imaging element are perpendicular to optical axes of the first light deflecting unit and the second light deflecting unit.

Optionally, the light splitting element includes: a polarizing beam splitter; the first phase delay film is arranged between the reflecting mirror and the polarization beam splitter; and a second bit-phase retardation film disposed between the first conjugate imaging element and the polarizing beam splitter.

Optionally, the first conjugate imaging element is a two-dimensional transmission type retroreflector, the optical imaging module further includes a reflector, the light beam from the object plane is deflected by the first light beam deflecting unit and then enters the two-dimensional transmission type retroreflector, the light beam is transmitted to the reflector through the two-dimensional transmission type retroreflector, reflected by the reflector and then reflected by the two-dimensional transmission type retroreflector, enters the second light beam deflecting unit, deflected by the second light beam deflecting unit and then propagates towards the first image plane.

Optionally, the first conjugated imaging element is a one-dimensional transmissive retroreflector, and the second conjugated imaging element is a one-dimensional reflective retroreflector, wherein the first conjugated imaging element is obliquely disposed between the first light deflecting unit and the second light deflecting unit, and an optical axis of the second conjugated imaging element is perpendicular to optical axes of the first light deflecting unit and the second light deflecting unit.

Optionally, the optical imaging module further includes: a reflective polarizing film disposed between the first and second conjugate imaging elements and between the first and second conjugate imaging elements; and a phase retardation film disposed between the reflective polarizing film and the second conjugate imaging element, wherein a light beam from the object plane is deflected by the first light deflecting unit and then enters the one-dimensional transmissive retroreflector, is transmitted to the one-dimensional reflective retroreflector by the one-dimensional transmissive retroreflector, is reflected by the one-dimensional reflective retroreflector, is reflected by the reflective polarizing film and then enters the second light deflecting unit, is deflected by the second light deflecting unit and then propagates toward the first image plane and the second image plane.

The invention also provides an array imaging module, which comprises: a plurality of optical imaging modules as described above are arranged in an array along the first direction.

Optionally, a distance between the first light ray deflection units of adjacent optical imaging modules is smaller than a preset threshold.

Optionally, adjacent optical imaging modules have a common optical element.

Optionally, the array imaging module further comprises a grating plate disposed between the optical imaging module and the image plane, wherein the grating plate has equidistant light shielding strips.

Optionally, the components in the optical imaging module are filled with a medium, and the refractive index of the medium is greater than 1.

The invention also provides a suspension display device, comprising: a display module configured to emit display light constituting a target image; an array imaging module as described above; wherein the display light emitted from the display module forms a floating image at the first image plane and/or the second image plane through the array imaging module.

Optionally, the display module is a three-dimensional display.

The present invention also provides a multi-layered display apparatus comprising: a floating display device as described above; and a transparent display device disposed optically downstream of the floating display device, wherein a display surface of the transparent display device is located at a different position than the floating image.

Optionally, the transparent display device comprises a transparent display or is realized by projecting an image onto a transparent film.

Drawings

The invention may be better understood by describing exemplary embodiments thereof in conjunction with the accompanying drawings, in which:

fig. 1A and 1B illustrate light propagation diagrams of an optical imaging module according to an exemplary embodiment of the present invention.

Fig. 2A shows a schematic diagram of half-aperture, focal length and image height of the first light ray deflection unit.

Fig. 2B shows a schematic diagram of an optical imaging module including a foldback structure.

Fig. 3-4 show light propagation diagrams of an optical imaging module according to another exemplary embodiment of the invention.

Fig. 5A and 5B show examples of two-dimensional reflective retroreflectors.

Fig. 6 shows an example of a two-dimensional transmissive retroreflector.

Fig. 7 shows an example of a one-dimensional reflective retroreflector.

Fig. 8 shows an example of a one-dimensional transmissive retroreflector.

Fig. 9 shows a schematic diagram of an arrayed imaging module according to a first example of the invention.

Fig. 10 shows a schematic diagram of an array imaging module using polarization splitting.

Fig. 11 shows a schematic diagram of an arrayed imaging module according to a second example of the present invention.

Fig. 12 shows a schematic diagram of an array imaging module using polarization beam splitting.

Fig. 13A shows a schematic view of the optical path of stitched imaging of an object point through multiple optical imaging modules.

Fig. 13B shows a schematic view of the optical path of different object points through a single optical imaging module in an arrayed imaging module.

Fig. 14 shows a schematic diagram of an array imaging module according to a third example of the present invention.

Fig. 15A shows a schematic view of an optical imaging module according to a fourth example of the invention.

Fig. 15B shows a light ray propagation schematic of an optical imaging module according to a fourth example of the invention.

Fig. 16 shows a schematic diagram of an arrayed imaging module according to a fifth example of the present invention.

Fig. 17A shows a schematic diagram of an array imaging module comprising a grating plate.

Fig. 17B shows a schematic view of a grating plate.

Fig. 18 shows a schematic block diagram of a floating display device according to an embodiment of the present invention.

Fig. 19 shows a schematic diagram of a multi-layer display device according to an embodiment of the present invention.

FIG. 20 shows a schematic view of a transparent display device implemented by micro-projection;

FIG. 21 shows a schematic diagram of a multi-layer display device implementing naked eye 3D display; and

fig. 22A-22C show illustrative diagrams of display modules employing three-dimensional displays.

Detailed Description

In the following, specific embodiments of the present invention will be described, and it should be noted that in the course of the detailed description of these embodiments, it is not possible in the present specification to describe all features of an actual embodiment in detail for the sake of brevity. It should be appreciated that in the actual implementation of any of the implementations, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that while such a development effort might be complex and lengthy, it would nevertheless be a routine undertaking of design, fabrication, or manufacture for those of ordinary skill having the benefit of this disclosure, and thus should not be construed as having the benefit of this disclosure.

Unless defined otherwise, technical or scientific terms used in the claims and specification should be given the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The terms "first," "second," and the like in the description and in the claims, are not used for any order, quantity, or importance, but are used for distinguishing between different elements. The terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" or "comprises", and the like, is intended to mean that elements or items that are immediately preceding the word "comprising" or "comprising", are included in the word "comprising" or "comprising", and equivalents thereof, without excluding other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, nor to direct or indirect connections. The phrase "a is substantially equal to B" is intended to take into account tolerances in the process manufacturing, i.e., the values of a and B may be within ±10% of each other.

For ease of description, light may be considered to propagate along an optical path in a light beam from an optical "upstream" position to an optical "downstream" position. Thus, the relative position of an optical element in the optical path can also be described in terms of these two terms.

A floating display device generally includes an image display unit and an optical system, wherein the image display unit presents an original image on an object plane of the optical system by means of direct display or indirect projection, and image light is then passed through the optical system to form a floating image in the air. If a large-sized floating display is to be realized, a larger optical element needs to be processed, which leads to a rapid increase in processing cost and a decrease in accuracy of the optical element. There is thus proposed an optical imaging module comprising: the deflection optical group at least comprises a first light deflection unit and a second light deflection unit which are arranged in parallel, and the deflection optical group modulates light in a first direction only; and a first conjugate imaging element located between the first light deflecting unit and the second light deflecting unit on an optical path, an optical path length between the first conjugate imaging element and the first light deflecting unit being substantially equal to an optical path length between the first conjugate imaging element and the second light deflecting unit, wherein the optical imaging module is configured to converge a light beam from a point on an object plane on a first image plane in the first direction. The optical imaging module of the present disclosure may be used as the optical system described above to form a floating image, which facilitates seamless stitching of the floating image while having lower manufacturing costs and making the floating display device more compact.

Fig. 1A and 1B illustrate light propagation diagrams of an optical imaging module 100 according to an exemplary embodiment of the present invention, wherein fig. 1A illustrates a schematic diagram of light propagation of the optical imaging module 100 in a horizontal direction, and fig. 1B illustrates a schematic diagram of light propagation of the optical imaging module 100 in a vertical direction.

The optical imaging module 100 may include a first light ray deflecting unit 101, a second light ray deflecting unit 102, and a first conjugate imaging element 103. The first light deflecting unit 101 and the second light deflecting unit 102 may be disposed parallel to each other and form a deflecting optical group. As shown in fig. 1A, the light emitted from the object point O may not be modulated by the polarized light group in the x direction.

The first conjugate imaging element 103 may be located between the first light deflecting unit 101 and the second light deflecting unit 102 in the optical path, and the optical path length between the first conjugate imaging element 103 and the first light deflecting unit 101 is substantially equal to the optical path length between the first conjugate imaging element 103 and the second light deflecting unit 102.

Referring to fig. 1B, the first light ray deflecting unit 101, the second light ray deflecting unit 102 and the first conjugate imaging element 103 may cooperate to converge the light beam from the point O on the object plane 10 at the point O' on the first image plane 20 in the y-direction. The x-direction and the y-direction are orthogonal to the main optical axis of the optical imaging module 100, respectively. The conjugated imaging element may have a microstructure element for imaging in at least one direction such that the light beam from a point on the object plane 10 is converged on the first image plane 20 in the at least one direction. The conjugated imaging element may be transmissive or may be reflective. By way of example, the conjugated imaging element may be a retroreflector, a grid transmissive array, a holographic grating, or the like. The benefits of using such conjugated imaging elements are: the positional relationship (object and image) is conjugate, the image is not amplified, and no aberration exists.

The deflection optics may be used to modulate the image height in the y-direction and may be configured to modulate light only in the y-direction. The deflection optical group is used for controlling the height of the light passing through the deflection unit to be less than or equal to the physical dimension of the deflection unit in the y direction. In some embodiments of the present disclosure, the first light ray deflection unit 101 may be an aperture stop of the optical imaging module 100 in the y-direction for limiting the height of light rays passing through the optical imaging module 100 in the y-direction.

Due to the above-described characteristics of the conjugated imaging elements, the image height of the first conjugated imaging element 103 in the y-direction may be equal to the object height in the y-direction. Therefore, the image height of the optical imaging module 100 in the y-direction can be adjusted by the light deflection group (the first light deflection unit 101 and the second light deflection unit 102). In some embodiments of the present disclosure, the first light ray deflection unit 101 and the second light ray deflection unit 102 may be configured such that the image height of the optical imaging module 100 in the y-direction (on the second image plane 20) is equal to the object height in the y-direction (on the object plane 10). As shown in fig. 1B, the light beam from the point O on the object plane 10 converges at a point O 'on the first image plane 20 in the y direction, the point O being equal in height to the point O' in the y direction. In some embodiments of the present disclosure, the first light deflecting unit 101 and the second light deflecting unit 102 may be the same lens. It will be appreciated that lenses typically introduce aberrations in the optical system, so that the benefit of using the same lenses for the first and second light-redirecting units 101, 102 is that one lens can be used to counteract the aberrations of the other lens and achieve a complete mirror image of the image point O' and the object point O. Thus, in some embodiments, the first light deflecting unit 101 and the second light deflecting unit 102 may be mirror symmetrical in the optical path with respect to the first conjugate imaging element 103, and the first light deflecting unit 101 and the second light deflecting unit 102 may have the same wavefront modulation. As an example, the light ray deflection unit may include a hologram lens, a superlens, a graded index plate, or the like.

In some embodiments of the present disclosure, the first light deflecting unit 101 and the second light deflecting unit 102 may be lenses. Alternatively, f# of the lens may be greater than or equal to 1.5, which helps ensure that there is sufficient physical space between the first light deflecting unit 101 and the second light deflecting unit 102 to set the foldback structure described below. Alternatively, the f# of the lens may be less than or equal to 6, which helps ensure that the field angle in the y-direction is greater than 10 degrees.

In some embodiments of the present disclosure, a distance d1 between the first conjugate imaging element 103 and the first light deflecting unit 101 along the main optical axis is less than or equal to a focal length f1 of the first light deflecting unit 101. As shown in fig. 2A, the maximum light angle entering the first light beam deflection unit 101 is emitted from the object point O, so as to realize that all the light beams passing through the first light beam deflection unit 101 are modulated by the optical module and then exit and image through the light beam deflection unit 102, and the heights of all the light beams between the light beam deflection unit 101 and the first conjugate imaging element 103 are less than or equal to the half-caliber d of the first light beam deflection unit 101. For the optical system in which the first light beam deflection unit 101 is a lens, the distance from the object point to the lens is far greater than the focal length of the lens, so that the imaging plane of the object point O is substantially near the focal plane, as can be seen from fig. 2A, only at a position smaller than the focal length f, it can be ensured that the light beam height l of the light beam passing through the upper edge of the light beam deflection unit 101 is smaller than the half-caliber d of the light beam deflection unit.

In some embodiments of the present disclosure, the aperture of the light deflecting unit 101 is D, and the distance between the second light deflecting unit 102 and the first light deflecting unit 101 is greater than or equal to 2D. As shown in fig. 2B, the optical imaging module 100 may include a 45-degree beam splitting element 105 to form a folded structure, where the aperture of the light beam deflecting unit 101/102 is D, the shortest optical path of the first conjugate imaging element 103 from the second light beam deflecting unit 102 is 2D, and because the first light beam deflecting unit 101 and the second light beam deflecting unit 102 may be symmetrically disposed in the optical path relative to the first conjugate imaging element 103, the distance a between the first light beam deflecting unit 101 and the folded structure is greater than or equal to D, and thus the distance between the first light beam deflecting unit 101 and the second light beam deflecting unit 103 is greater than or equal to 2D. In order to achieve a larger angle of view in the y-direction, the distance between the first light deflecting unit 101 and the second light deflecting unit 103 is desirably as short as possible, and thus the distance between the second light deflecting unit 102 and the first light deflecting unit 101 may be equal to or greater than 2D, preferably equal to 2D.

In some embodiments of the present disclosure, the first conjugated imaging element 103 may be a two-dimensional conjugated imaging element configured to image in the x-direction and the y-direction. In this case, as shown in fig. 1A, the first conjugate imaging element 103 may cause the light beam from the point O on the object plane 10 to be converged on the first image plane 20 also in the x-direction. As examples, two-dimensional conjugated imaging elements include, but are not limited to, two-dimensional reflective retroreflectors and two-dimensional transmissive retroreflectors. The two-dimensional reflective retroreflector may have an array of microstructure elements, each of which may be a corner cube element having three mutually perpendicular adjacent surfaces, as shown in fig. 5A or 5B. The two-dimensional transmissive retroreflector may be a structure in which two glass arrays are stacked, wherein each glass flat array is formed by gluing a plurality of glass flat sheets, and both sides of each glass flat sheet are plated with metal reflective layers. The glass flat sheet directions of the two layers of glass arrays are orthogonally arranged. The light is thus reflected by the transmissive retroreflector once on each of the two glass plate arrays, respectively, to achieve a light retroreflection effect in space, as shown in fig. 6.

Fig. 3-4 illustrate a light propagation diagram of an optical imaging module 200 according to another exemplary embodiment of the present invention, wherein fig. 3 illustrates a schematic diagram of light propagation of the optical imaging module 200 in a horizontal direction, and fig. 4 illustrates a schematic diagram of light propagation of the optical imaging module 200 in a vertical direction. Several details of the optical imaging module 200 are the same as the optical imaging module 100 described above with respect to fig. 1-2 and are not described in detail herein. The differences of the optical imaging module 200 are mainly described below.

The first conjugate imaging element 103 may be a conjugate imaging element having a one-dimensional grating structure for converging light in the y-direction. The optical imaging module 200 may also include a second conjugated imaging element 104 for converging light rays in the x-direction. The microstructure elements of the first conjugated imaging element 103 and the microstructure elements of the second conjugated imaging element 104 may be arranged orthogonally. In this manner, the second conjugate imaging element 104 may converge the light beam from the point O on the object plane 10 in the x-direction on a second image plane 30 different from the first image plane 20, the x-direction and the y-direction being orthogonal to the main optical axis of the optical imaging module 200, respectively. The conjugated imaging element with a one-dimensional grating structure may be a one-dimensional reflective retroreflector, a one-dimensional transmissive retroreflector, a one-dimensional holographic grating, or the like. An example of a one-dimensional reflective retroreflector is shown in fig. 7, in which a light ray that is arbitrarily irradiated to the one-dimensional retroreflective screen surface is reflected in one direction (for example, the X direction shown in fig. 7) at an original angle. An example of a one-dimensional transmissive retroreflector is shown in fig. 8, which may be formed by laminating a plurality of parallel glass plates, wherein the lamination surface is coated with a metal reflective film, wherein an object point o is optically conjugated with an image point o', and the object plane and the image plane of the structure are equal in size and free from aberration. The advantage of using such a conjugated imaging element is that the positional relationship (object to image) is conjugated, the image is not magnified, and no aberration occurs.

The optical imaging module 100/200 according to the exemplary embodiment of the present invention is described above. The optical imaging module 100/200 may be used to form a floating image at the image plane 20 and/or the image plane 30. Although the floating image formed by this scheme also has a certain astigmatism, the distance between the first conjugate imaging element 103 and the second conjugate imaging element 104 is very small, typically less than 20mm, compared with a scheme in which the scattering screen is used to make the display light have a larger divergence angle, so that the imaging quality of the floating image is improved, while a larger spatial depth display can be realized, because the output screen depth of the floating image of the floating scheme using the scattering screen is determined by the distance between the two one-dimensional retro-reflective screens, the larger the distance is, the larger the floating depth is, but the larger the astigmatism is, and the worse the imaging quality is. The floating display depth of the scheme is determined by the distance between the object plane and the conjugated imaging element, and the distance between the two one-dimensional conjugated imaging elements can be set to be very small, so that astigmatism is guaranteed not to be increased along with the increase of the floating image depth, and the quality of the floating image is guaranteed while the display depth is increased.

According to further exemplary embodiments of the present disclosure, an arrayed imaging module is also provided. As shown in fig. 1B or 4, the arrayed imaging module may include a plurality of the optical imaging modules 100/200 as described above, the optical imaging modules 100/200 being arranged in an array along the y-direction, and the optical axes of the first light deflecting unit 101 and the second light deflecting unit 102 of each optical imaging module being disposed in parallel with each other, whereby the stitching of the y-direction field angle can be achieved. It should be noted that although three optical imaging modules 100/200 are shown in the drawings, the present invention is not limited thereto. An appropriate number of optical imaging modules 100/200 may be selected depending on the desired size of the suspended image. Such an array imaging module significantly reduces costs for implementing different size floating displays because there is no need to design different optical imaging modules for a particular size floating image, only a suitable number of optical imaging modules need be selected according to the size of the floating image required, and small size optical elements are easier to process than large size optical elements.

Hereinafter, several examples of the optical imaging module and the array imaging module according to the embodiment of the present invention will be described.

First example

Fig. 9 shows a schematic diagram of an array imaging module 900 according to a first example of the invention. Several details of the optical imaging modules in the array imaging module 900 according to the first example are the same as the optical imaging modules 100/200 described above with respect to fig. 1-8 and are not repeated here. The following mainly describes the features of the array imaging module 900 of the first example.

The array imaging module 900 includes a plurality of optical imaging modules arranged in the y-direction. Each optical imaging module comprises a first light ray deflecting unit 901, a second light ray deflecting unit 902 and a first conjugate imaging element 903 as described hereinabove. For simplicity, reference numerals for elements of only one of the optical imaging modules are labeled in fig. 9. The first conjugate imaging element 903 may be a two-dimensional reflective retroreflector. Each optical imaging module of the array imaging module 900 may also include a light splitting element 905 and a mirror 906. The light splitting element 905 may be a semi-reflective and semi-transmissive element, i.e., transmitting a portion of the incident light and reflecting another portion of the incident light.

The light splitting element 905 may be disposed obliquely between the reflecting mirror 906 and the first conjugate imaging element 903 and between the first light deflecting unit 901 and the second light deflecting unit 902. The optical axis a of the mirror 906 and the first conjugate imaging element 903 may be perpendicular to the optical axis B of the first light deflecting unit and the second light deflecting unit.

In the first example, a light beam from an object plane is deflected by the first light deflecting unit 901, then enters the light splitting element 905, is reflected by the light splitting element 905 to the reflecting mirror 906, is reflected by the reflecting mirror 906, then is transmitted by the light splitting element 905 to enter the first conjugate imaging element 903, is reflected by the first conjugate imaging element 903, then is reflected by the light splitting element 905 to enter the second light deflecting unit 902, is deflected by the second light deflecting unit 902, and propagates toward the first image plane 20. As shown in fig. 9, the light beam from the object point O is converged at a point O' on the first image plane 20 in both the x-direction and the y-direction via the array imaging module 900.

It will be appreciated that since the light splitting element 905 transmits a portion of the incident light and reflects another portion of the incident light, this may cause a portion of the non-imaging light to reach the first image plane 20, affecting the imaging quality. In an alternative embodiment, the light splitting element may include a polarizing beam splitter 915, a quarter wave plate 925, and a quarter wave plate 935, as shown in FIG. 10. For example, the polarization beam splitter 915 may reflect S light and transmit P light. A quarter wave plate 925 may be disposed between the mirror 906 and the polarizing beamsplitter 915. A quarter waveplate 935 may be disposed between the first conjugated imaging element and the polarizing beam splitter 915.

The polarization state of the light beam from the object plane may be configured as S polarization (the invention is not limited thereto, and the light emitted from the object plane may be natural light), the S light is reflected by the polarization beam splitter 915, the light is reflected by the reflecting mirror after being directed to the reflecting mirror 906, and the principal axis direction passing through the 1/4 wave plate 925,1/4 wave plate twice is set at 45 degrees to the z axis in the xz plane, and the light is converted into P polarized light. The P light is transmitted through the polarization beam splitter 915 and then directed to the conjugate imaging element 903, the conjugate imaging element is a two-dimensional retroreflective screen, the light is reflected by the conjugate imaging element (retroreflective screen) 903, the principal axis direction of the light passing through the 1/4 wave plate 935,1/4 wave plate twice forms 45 ° with the z axis in the xz plane, the polarization state of the light is converted from P polarized light to S polarized light, and after being reflected by the polarization beam splitter plate 915, the S polarized light is converged at a point O' on the first image plane 20 in both the x direction and the y direction via the array imaging module 900.

In this way, the imaging quality can be improved by polarization beam splitting, and non-imaging light reaching the first image plane 20 is eliminated. It should be noted that, in some embodiments, the polarization beam splitter 915 may also transmit S light and reflect P light; in this case, the polarization state of the light beam from the object plane may be configured as P-polarization.

Second example

Fig. 11 shows a schematic diagram of an arrayed imaging module 1100 according to a second example of the invention. Several details of the optical imaging modules in the arrayed imaging module 1100 according to the second example are the same as the optical imaging modules 100/200 described above with respect to fig. 1-8 and are not described in detail herein. The following mainly describes the features of the arrayed imaging module 1100 of the first example.

The array imaging module 1100 includes a plurality of optical imaging modules arranged along the y-direction. Each optical imaging module includes a first light ray deflecting unit 1101, a second light ray deflecting unit 1102, a first conjugated imaging element 1103, and a second conjugated imaging element 1104 as described hereinabove. For simplicity, reference numerals for elements of only one of the optical imaging modules are labeled in fig. 11. The first conjugated imaging element 1103 and the second conjugated imaging element 1104 may each be one-dimensional reflective retroreflectors. The microstructure elements of the first conjugated imaging element 1103 may be disposed orthogonally to the microstructure elements of the second conjugated imaging element 1104.

Each optical imaging module of the array imaging module 1100 may also include a light splitting element 1105. The light splitting element 1105 may be a semi-reflective and semi-transmissive element, i.e., transmit a portion of the incident light and reflect another portion of the incident light.

The spectroscopic element 1105 may be disposed obliquely between the first conjugated imaging element 1103 and the second conjugated imaging element 1104 and between the first light deflecting unit 1101 and the second light deflecting unit 1102. The first conjugated imaging element 1103 and the second conjugated imaging element 1104 may be disposed in relative parallel. The optical axes a of the first conjugated imaging element 1103 and the second conjugated imaging element 1104 may be perpendicular to the optical axes B of the first light ray deflecting unit 1101 and the second light ray deflecting unit 1102.

In the second example, the light beam from the object plane is deflected by the first light deflecting unit 1101, enters the light splitting element 1105, is reflected by the light splitting element 1105, enters the first conjugated imaging element 1103, is reflected by the first conjugated imaging element 1103, is transmitted by the light splitting element 1105, enters the second conjugated imaging element 1104, is reflected by the light splitting element 1105, enters the second light deflecting unit 1102, is deflected by the second light deflecting unit 1102, and propagates toward the first image plane 20 and the second image plane 30. As shown in fig. 11, the light beams from the point O on the object plane are converged at a point O' on the first image plane 20 in the y direction and at a point o″ on the second image plane 30 in the x direction via the array imaging module 1100.

In an alternative embodiment, the spectroscopic element may include a polarization beam splitter 1115, a first phase retardation film 1125, and a second phase retardation film 1135, as shown in fig. 12. For example, the polarization beam splitter 1115 may reflect S light and transmit P light. The first phase retardation film 1125 may be disposed between the first conjugated imaging element 1103 and the polarizing beam splitter 1115. The second phase retardation film 1135 may be disposed between the second conjugated imaging element 1104 and the polarization beam splitter 1115.

The polarization state of the light beam from the object plane may be configured to be S-polarized (the invention is not limited thereto, the light emitted from the object plane may be natural light), the S-light is reflected by the polarization beam splitter 1115, the light beam is reflected by the reflecting mirror after being directed to the first conjugate imaging element 1103, and passes through the first phase retardation film 1125 twice, the first phase retardation film 1125 is a 1/2 wave plate, the main axis direction of the wave plate is set at 22.5 ° or 67.5 ° with respect to the z-axis in the xz-plane, and the light beam is converted into P-polarized light. The P-light is transmitted through the polarization beam splitter 1115 and then directed to the second conjugate imaging element 1104, the light is reflected by the second conjugate imaging element 1104, passes through the second bit phase retardation film 1135 twice, the second bit phase retardation film 1135 is a 1/2 wave plate, the main axis direction of the wave plate is set at 22.5 ° or 67.5 ° with respect to the z-axis in the xz-plane, the polarization state of the light is converted from P-polarized light to S-polarized light, the S-polarized light is reflected by the polarization beam splitter plate 1115, and then is converged at a point O' on the first image plane 20 in the y-direction and converged at a point o″ on the second image plane 30 in the x-direction via the array imaging module 1100.

Thus, the imaging quality can be improved by polarization beam splitting. It should be noted that, in some embodiments, the polarization beam splitter 1115 may also transmit S light and reflect P light; in this case, the polarization state of the light beam from the object plane may be configured as P-polarization.

Referring to fig. 13A and 13B, fig. 13A shows a schematic view of an optical path of the object point O through the plurality of optical imaging modules in the array imaging module 1100, and fig. 13B shows a schematic view of an optical path of the different object points (a, B, c, d, e, f, g, h, i) through the single optical imaging module 1110 in the array imaging module 1100.

Third example

Fig. 14 shows a schematic diagram of an arrayed imaging module 1400 according to a third example of the invention. Several details of the optical imaging modules in the arrayed imaging module 1400 according to the third example are the same as the optical imaging modules 100/200 described above with respect to fig. 1-8 and are not described in detail herein. The following mainly describes the features of the arrayed imaging module 1400 of the third example.

The array imaging module 1400 includes a plurality of optical imaging modules arranged along the y-direction. Each optical imaging module comprises a first light ray deflecting unit 1401, a second light ray deflecting unit 1402 and a first conjugate imaging element 1403 as described hereinabove. For simplicity, reference numerals for elements of only one of the optical imaging modules are labeled in fig. 14. The first conjugate imaging element 1403 may be a two-dimensional transmissive retroreflector. Each optical imaging module of the array imaging module 1400 may also include a mirror 1405.

In the third example, the two-dimensional transmissive retroreflector surface is coated with a half-reflection half-transmission film, and a light beam from the object plane is deflected by the first light deflecting unit 1401, then enters the two-dimensional transmissive retroreflector 1403, is transmitted to the reflector 1405 by the two-dimensional transmissive retroreflector 1403, is reflected by the reflector 1405, is reflected by the two-dimensional transmissive retroreflector 1403, enters the second light deflecting unit 1402, is deflected by the second light deflecting unit 1402, and propagates toward the first image plane 20. As shown in fig. 14, the light beam from the object point O is converged at a point O' on the first image plane 20 in both the x-direction and the y-direction via the arrayed imaging module 1400.

Fourth example

Fig. 15A shows a schematic diagram of an optical imaging module 1510 according to a fourth example of the invention. Several details of the optical imaging module 1510 according to the fourth example are the same as the optical imaging modules 100/200 described above with respect to fig. 1-8 and are not repeated here. The following mainly describes the features of the optical imaging module 1510 of the fourth example.

The optical imaging module 1510 may include a first light ray deflecting unit 1501, a second light ray deflecting unit 1502, a first conjugated imaging element 1503, and a second conjugated imaging element 1504 as described above. The first conjugate imaging element 1503 may be a one-dimensional transmissive retroreflector and the second conjugate imaging element 1504 may be a one-dimensional reflective retroreflector. The first conjugate imaging element 1503 may be disposed obliquely between the first light-deflecting unit 1501 and the second light-deflecting unit 1502. The optical axis a of the second conjugate imaging element 1504 may be perpendicular to the optical axes B of the first light ray deflecting unit 1501 and the second light ray deflecting unit 1502.

The optical imaging module 1510 may also include a reflective polarizing film 1505 and a half-wave plate 1506. A reflective polarizing film 1505 may be disposed between the first conjugated imaging element 1503 and the second light deflecting unit 1502 and between the first conjugated imaging element 1503 and the second conjugated imaging element 1504. The half-wave plate 1506 may be disposed between the reflective polarizing film 1505 and the second conjugated imaging element 1504.

In the fourth example, the light beam from the object plane is deflected by the first light deflecting unit 1501, then enters the one-dimensional transmissive retroreflector 1505, is transmitted to the one-dimensional reflective retroreflector 1504 through the one-dimensional transmissive retroreflector 1503 and the reflective polarizing film 1506, is reflected by the one-dimensional reflective retroreflector 1504, then enters the second light deflecting unit 1502, is deflected by the second light deflecting unit 1502, and propagates toward the first image plane and the second image plane. As shown in fig. 15A, the polarization state of the light beam from the object plane may be configured as P polarization (the light emitted from the object plane may be natural light, without being limited thereto, the P light is converged in the y direction by the one-dimensional transmission type retroreflector 1503, transmitted by the reflective polarizing film 1506 and irradiated to the one-dimensional reflection type retroreflector 1504, and the P light is twice converted into S light by the half wave plate 1506, reflected by the reflective polarizing film 1506, converged in the y direction at a point O on the first image plane and converged in the x direction at a point O' on the second image plane via the array imaging module, as shown in fig. 15B.

It should be noted that although the example array imaging module described above includes a plurality of identical optical imaging modules, the present invention is not limited thereto. The array imaging module may also include a plurality of different optical imaging modules. In some embodiments of the invention, the arrayed imaging module may include at least two of the plurality of different optical imaging modules described above (e.g., the optical imaging modules in the first, second, third, and fourth examples).

Fifth example

Fig. 16 shows a schematic diagram of an arrayed imaging module 1600 according to a fifth example of the invention. Several details of the optical imaging modules in the arrayed imaging module 1600 according to the fifth example are the same as the optical imaging modules 100/200 described above with respect to fig. 1-8 and are not described in detail herein. The following mainly describes the features of the array imaging module 1500 of the fifth example.

The array imaging module 1500 may include a first optical imaging module 1610, a second optical imaging module 1620, and a third optical imaging module 1630 arranged along the y-direction. Adjacent optical imaging modules may share the same optical element. For example, the optical imaging module 1610 may be the optical imaging module (using a two-dimensional transmissive retroreflector) in the third example described above, and the optical imaging module 1620 and the optical imaging module 1630 may be the optical imaging module (using a two-dimensional reflective retroreflector) in the first example described above. As shown in fig. 16, the optical imaging module 1610 and the optical imaging module 1620 may share the same mirror 1612, while the optical imaging module 1620 and the optical imaging module 1630 may share the same two-dimensional reflective retroreflector 1623. In this way, sharing of optical elements may be achieved, which may facilitate a reduction in the number of optical devices required for the arrayed imaging module 1600, thereby further reducing costs.

If there is a space between adjacent ones of the array imaging modules, then there will be gaps in the floating image formed on the first image plane 20 when viewed at certain angles of view. If it is desired to have as small a gap in the floating image as possible, the spacing between adjacent optical imaging modules in the array imaging module needs to be set as small as possible. In some embodiments of the present invention, the distance between the first light ray deflection units of adjacent ones of the array imaging modules described above is less than a preset threshold, which is advantageous for reducing the slit width in the floating image of the first image plane 20. Preferably, the distance between the first light deflection units of adjacent optical imaging modules may be equal to the caliber of the first light deflection units, i.e. the first light deflection units of adjacent optical imaging modules are in close contact with each other, which is advantageous for achieving a seamless suspended image.

It will be appreciated that, in view of process tolerances, adjacent optical imaging modules will inevitably present small gaps in actual production. In an alternative embodiment of the present invention, the array imaging module may further comprise a grating plate 170 disposed between the optical imaging module and the image plane, as shown in fig. 17A. The grating plate 170 may have equally spaced light shielding bars. In this way, the visual effect of the suspended image can be made to appear seamless. As shown in fig. 17B, the grating plate can screen-print uniform black stripes, which is beneficial to eliminating gaps of the suspended image when the pitch of the black stripes is relatively small (e.g., about 200 um) and uniformly arranged. The grating strips can also be directly silk-screened on the light deflection unit array, and the light deflection unit array is integrated with the light deflection unit array.

In some embodiments of the invention, the elements in any of the optical imaging modules described above may be filled with a medium having a refractive index greater than 1. Generally, the conjugated imaging element, the polarization beam splitting element, the reflecting film layer and the like are all made of a certain dielectric material by processing a functional microstructure or the film layer, so that physical positioning in space can be realized. For example, it is necessary to attach a polarizing beam-splitting film to a glass/plastic substrate, and a reflective grating is necessary to form a reflective microstructure on a glass/plastic plate. The presence of these dielectric materials inevitably creates a gap that impedes the transmission of light in these dielectric spaces, resulting in gaps in the display of the array imaging module. In order to realize seamless suspension display, glue with the same or similar refractive index as the substrate materials can be used for filling all components in the whole array optical module, and the glue becomes solid after UV or heat curing, so that the whole array optical module is formed into a flat plate structure with the consistent and uniform refractive index, and functional film layers or microstructures are distributed at specific positions in the flat plate. Thus, seamless suspension display can be realized, and the array optical assembly is formed into an integrated flat structure, so that the assembly of the display module is facilitated.

The invention also provides a suspension display device. Fig. 18 shows a schematic block diagram of a floating display device 1800 according to an embodiment of the invention.

The floating display device 1800 may include an array imaging module 1810 and a display module 1820. The display module 1820 has a display surface of an image and emits display light constituting an initial image from the display surface. The display module 1820 may employ a direct-light display mode or may employ an indirect projection mode to display or project an image on a display surface. In some embodiments, display module 1820 may include one or more displays. The array imaging module 1810 is arranged optically downstream of the display module 1820 to receive display light and has an object plane 10 and an image plane 20/30. The array imaging module 1810 may be any of the variety of array imaging modules described above. The object plane 10 may be arranged at the display surface of the display module 1820 to receive raw light at the object plane that constitutes an initial image, which is then modulated via the array imaging module 1810 to form a floating image (which may also be referred to as an aerial image) at the aerial image plane 20/30. Alternatively, it is contemplated that one or more relay optics may also be present between the display module 1820 and the array imaging module 1810, which relay optics may image the display face of the display module 1820 at the object face of the array imaging module 1810; in this case, the object plane of the array imaging module 1810 may be located at the image plane of the display module 1820 imaged by one or more relay optical systems.

According to another exemplary embodiment of the present invention, there is also provided a multi-layered display apparatus.

Fig. 19 shows a schematic diagram of a multi-layer display device 1900 according to an embodiment of the invention.

The multi-layer display device 1900 may include the floating display 1800 described previously and the transparent display 1910. The transparent display 1910 may be disposed on the light exit side (optically downstream) of the floating display 1800. The display surface of the transparent display device 1910 is located at a different position than the floating image surface 20/30 of the floating display device 1800, specifically between the floating image surface 20/30 and the floating display device 1800. The transparent display part 200 may have a high transmittance such as a transparent OLED/LED/LCD display or film (slide show). Transparent display 1910 may also be obtained from a micro-projected image by providing a transparent film (film haze less than < 5%) in front of floating display 1800, as shown in fig. 20. Alternatively, the transparent film may be angularly selective to light, diffuse for high angle light (projection images), and directly transmit for low angle light (hover images).

The above describes the multi-layer display device 1900 according to an exemplary embodiment of the present invention. The multilayer display 1900 has a display surface 1 and a display surface 2, a floating display device 1800 may form a floating image at the display surface 1 (image surface 20/30), and a transparent display device 1910 may display different information at the display surface 2. In this way, the secondary information can be displayed on the display surface 2, and the important information is presented at the display surface 1, so that the efficiency and experience of people for acquiring the information are improved. Alternatively, images with the same size may be displayed on the display surface 1 and the display surface 2, and the difference in shade and color between the distance between the object and the viewer may be utilized to further overlap the front and rear object images together, so that the viewer may generate a stereoscopic impression, and thus naked eye 3D display may be implemented, as shown in fig. 21.

Alternatively, the display module 1820 may be an open-eye three-dimensional display, which may be a multi-view autostereoscopic display or a light field display. As shown in fig. 22A, a typical naked-eye three-dimensional display is composed of a flat panel display and a micro-optical unit, which may be a microlens or a slit grating. The flat panel display generates parallax images, which are respectively sent to the left eye and the right eye of an observer after passing through the micro-optical unit, and a stereoscopic impression is generated by utilizing the binocular parallax effect of human eyes. As shown in fig. 22B, the point a1 on the display module 1820 enters the right eye, the point a2 enters the left eye, and the point seen by the human eye due to the binocular parallax principle is the point a, which is in front of the screen. The point b1 on the display screen enters the right eye, the point b2 enters the left eye, and the point seen by the human eye due to the binocular parallax principle is the point b, which is at the rear of the screen. The left and right eyes commonly see the c point on the screen, and thus the position of the c point is perceived on the screen. Thus, the 3D image presented by the conventional naked eye three-dimensional display is a 3D image with the screen as a depth center and within a certain depth range from front to back. Because human eyes focus on a physical screen of the three-dimensional display during watching, three-dimensional images floating in space cannot be perceived, and experience is affected.

The display module 1820 in the present invention may adopt a multi-viewpoint light field display, which can well solve the problem, the screen surface of the multi-viewpoint/light field display is projected into the space through the optical imaging module 120 of the present invention to form a floating image surface, and by displaying parallax images on the multi-viewpoint/light field display, a 3D image with the floating image surface as the depth center and within a certain range can be formed in the space. As shown in fig. 22C, on the floating image plane, the point a is on the front depth plane, the point b is on the rear depth plane, and the point C is on the floating image plane of the display device, so that the formed 3D image is completely floating in the air, and better 3D effect experience is achieved.

The display module 1820 in the present invention may also be a two-dimensional light field display, and the existing floating scheme of the diffuser screen cannot match the two-dimensional light field display to realize the 3D display with full parallax in space because of no vertical parallax. The array optical assembly 1810 of the invention can realize full parallax suspension display in the horizontal and vertical directions, and can display the central depth plane of the two-dimensional light field display module 1820 at a position far away from the whole optical module by matching with the two-dimensional light field display module 1820, thereby increasing the screen output sense of three-dimensional display of the light field, suspending the whole 3D image in the air for display, having more shocking stereoscopic effect, and realizing full searchable interaction of 3D content.

The optical imaging module, the array imaging module, the floating display device, and the multi-layer display apparatus according to the exemplary embodiments of the present invention are described above in detail. The invention has the advantages that: 1) The optical imaging module has no aberration or only small astigmatism; 2) The optical imaging module has simple structure, the required optical element has smaller size, is easy to process, and can effectively reduce the cost; 3) The suspension display with different sizes can be realized by adopting the display modules with specific sizes and the optical imaging modules with specific numbers according to the requirements, which is beneficial to realizing the suspension display with large sizes; 4) The optical imaging modules are designed at one time, and the corresponding number of optical imaging modules are used for seamless splicing of the floating images according to the required floating image size, so that different optical imaging modules are not required to be designed for different floating image sizes; 5) The thickness of the suspension display device is smaller, so that the suspension display device is light and thin; 6) Compared with the scheme of adopting a scattering screen, the full parallax suspension display in the horizontal and vertical directions is realized, the imaging quality is improved, and the display of larger space depth can be realized. The suspension display device is adopted to realize light field reconstruction of the display module in the air, and is a light field three-dimensional display technology.

It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with one another. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the various embodiments of the invention without departing from the scope thereof. While the dimensions and types of materials described herein are intended to define the parameters of the various embodiments of the invention, the various embodiments are not meant to be limiting and are exemplary embodiments. Many other embodiments will be apparent to those of skill in the art upon reading the above description. The scope of the various embodiments of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims (20)

1. An optical imaging module, the optical imaging module comprising:

the deflection optical group at least comprises a first light deflection unit and a second light deflection unit which are arranged in parallel, and the deflection optical group modulates light in a first direction only; and

a first conjugate imaging element located in the optical path between the first light deflecting unit and the second light deflecting unit, the optical path between the first conjugate imaging element and the first light deflecting unit being substantially equal to the optical path between the first conjugate imaging element and the second light deflecting unit,

Wherein the optical imaging module is configured to converge the light beam from the point on the object plane on the first image plane in the first direction.

2. The optical imaging module of claim 1, wherein the first light ray deflection unit is an aperture stop of the optical imaging module in the first direction.

3. The optical imaging module of claim 1, wherein the first light ray deflection unit and the second light ray deflection unit are configured such that an image height of the optical imaging module in the first direction is equal to an object height in the first direction.

4. The optical imaging module of claim 1, wherein the first light redirecting unit and the second light redirecting unit are the same lens.

5. The optical imaging module of claim 1, wherein the first light ray deflection unit is a lens having f# greater than or equal to 1.5 and less than or equal to 6.

6. The optical imaging module according to claim 1, wherein the aperture of the light deflecting unit is D, and the distance between the second light deflecting unit and the first light deflecting unit is greater than or equal to 2D.

7. The optical imaging module of claim 1, wherein a distance between the first conjugate imaging element and the first light redirecting unit along the optical path is less than or equal to a focal length of the first light redirecting unit.

8. The optical imaging module of claim 1, wherein the first conjugate imaging element is a one-dimensional conjugate imaging element, and the first light ray deflecting unit, the second light ray deflecting unit, and the first conjugate imaging element cooperate to converge light beams from points on the object plane on a first image plane in the first direction.

9. The optical imaging module of claim 8, further comprising a second conjugate imaging element for converging a light beam from a point on the object plane in a second direction on a second image plane different from the first image plane, the first and second directions being orthogonal to a primary optical axis of the optical imaging module, respectively.

10. The optical imaging module of claim 9, wherein the first conjugated imaging element and the second conjugated imaging element are one-dimensional reflective retroreflectors, wherein the microstructure elements of the first conjugated imaging element are disposed orthogonally to the microstructure elements of the second conjugated imaging element.

11. The optical imaging module of claim 10, wherein the first conjugated imaging element and the second conjugated imaging element are disposed in a relatively parallel arrangement, and wherein the optical axes of the first conjugated imaging element and the second conjugated imaging element are perpendicular to the optical axes of the first light ray deflection unit and the second light ray deflection unit.

12. The optical imaging module of claim 10, further comprising a beam splitting element, wherein the light beam from the object plane is deflected by the first light deflection unit and enters the beam splitting element, reflected by the beam splitting element and enters the first conjugate imaging element, reflected by the first conjugate imaging element and transmitted by the beam splitting element and enters the second conjugate imaging element, reflected by the second conjugate imaging element and reflected by the beam splitting element and enters the second light deflection unit, deflected by the second light deflection unit and propagated toward the first image plane and the second image plane.

13. The optical imaging module of claim 1, wherein the first conjugate imaging element is a two-dimensional conjugate imaging element, the first light ray deflection unit, the second light ray deflection unit, and the first conjugate imaging element cooperate to converge light beams from points on an object plane on the first image plane in the first direction, and the first conjugate imaging element is configured to converge light beams from points on the object plane on the first image plane in a second direction, the first direction and the second direction being orthogonal to a primary optical axis of the optical imaging module, respectively.

14. An arrayed imaging module, comprising:

a plurality of optical imaging modules of any of claims 1-13, arranged in an array along the first direction.

15. The arrayed imaging module of claim 14, wherein the distance between the first light deflecting units of adjacent ones of the optical imaging modules is less than a predetermined threshold.

16. The arrayed imaging module of claim 14, wherein adjacent ones of the optical imaging modules have common optical elements.

17. The arrayed imaging module of claim 14, further comprising a grating plate disposed between the optical imaging module and the image plane, wherein the grating plate has equally spaced light shielding strips.

18. The arrayed imaging module of claim 14, wherein the optical imaging modules comprise dielectric medium between each element, the dielectric medium having a refractive index greater than 1.

19. A floating display device, comprising:

a display module configured to emit display light constituting a target image; and

arrayed imaging modules of any one of claims 14-18;

wherein the display light emitted from the display module forms a floating image at the first image plane and/or the second image plane through the array imaging module.

20. A multi-layer display device comprising:

the floating display device of claim 19; and

and a transparent display device disposed optically downstream of the floating display device, wherein a display surface of the transparent display device is located at a different position from the floating image.