CN218327902U

CN218327902U - Projection system

Info

Publication number: CN218327902U
Application number: CN202223007049.9U
Authority: CN
Inventors: 杨佳; 潘红响; 郎海涛; 张恩鑫; 张鹤腾; 綦可
Original assignee: Ningbo Sunny Automotive Optech Co Ltd
Current assignee: Ningbo Sunny Automotive Optech Co Ltd
Priority date: 2021-11-11
Filing date: 2022-11-11
Publication date: 2023-01-17
Anticipated expiration: 2032-11-11
Also published as: CN113777862A

Abstract

The application discloses a projection system, which comprises a light source module and at least two projection sub-modules, wherein the light source module is used for emitting light beams, the at least two projection sub-modules are distributed in the cross section of the light beams, each projection sub-module comprises an image unit and at least one micro lens, and the image unit is used for enabling part of the light beams to pass through and enabling the passing sub-light beams to carry image information; at least one microlens is located on a side of the image unit facing away from the light source module and is used for projecting a sub-beam carrying image information.

Description

Projection system

Technical Field

The present application relates to the field of optical devices, and more particularly, to a projection system.

Background

With the development of projection technology, the application of the projection technology in the field of automobiles is more and more extensive, for example, a welcome lamp technology, wherein the welcome lamp is assembled on an automobile, different marks can be projected on corresponding ground areas around the automobile, and the effect of the welcome lamp is particularly obvious in dim weather or at night.

The projection system adopted by the existing welcome lamp comprises an illuminating element, an image element and a projection element, wherein the illuminating element emits light rays, the image element enables the light rays emitted by the illuminating element to carry image information, and the light rays carrying the image information form patterns on an imaging surface through the projection element. The brightness of light rays in existing projection systems at the image element is not uniform, making the projected pattern on the imaging plane non-uniform. In order to cooperate with an image element, the conventional projection element generally uses a large number of lenses, so that the projection system has a large volume, a long total length of an optical system, and is difficult to adapt to a narrow installation space, and is also not favorable for system assembly. The existing projection element has weaker control capability on light, so that the light is easy to generate stray light on an imaging surface under the condition of not collimating at a higher standard, thereby influencing the definition of a projection pattern.

SUMMERY OF THE UTILITY MODEL

The present application provides a projection system that solves, at least in part, at least one or other problems in the art.

One aspect of the present application provides a projection system, which includes a light source module and at least two projection sub-modules, where the light source module is configured to emit a light beam, the at least two projection sub-modules are distributed in a cross-section of the light beam, each projection sub-module includes an image unit and at least one microlens, the image unit is configured to allow a part of the light beam to pass through, and allow the passing sub-light beam to carry image information; at least one microlens is located on a side of the image unit facing away from the light source module and is used to project a sub-beam carrying image information.

According to an exemplary embodiment of the present application, a radius of curvature Ra of the light incident surface of the microlens and a radius of curvature Rb of the light emitting surface of the microlens satisfy: the absolute Rb/Ra is more than or equal to 0 and less than or equal to 10.

According to an exemplary embodiment of the application, the projection submodule further comprises a diaphragm for confining the sub-beams.

According to an exemplary embodiment of the present application, the diaphragm is integrally attached to at least one of the at least one microlens.

According to an exemplary embodiment of the present application, the abutting surface of the diaphragm includes at least one of a flat surface and a curved surface.

According to an exemplary embodiment of the application, the field angle FOV of the projection submodule satisfies: the FOV is more than or equal to 20 degrees and less than or equal to 120 degrees.

According to an exemplary embodiment of the present application, the ratio FNO of the total effective focal length to the entrance pupil diameter of the projection sub-module satisfies: FNO is less than or equal to 5.

According to an exemplary embodiment of the present application, the total optical system length TOTL of the projection sub-module satisfies: TOTL is more than or equal to 0.5mm and less than or equal to 40mm.

According to an exemplary embodiment of the present application, a distance U between the image unit and the light incident surface of the microlens closest to the image unit in the projection sub-module and a total effective focal length F of the projection sub-module satisfy: U/F is more than or equal to 0 and less than or equal to 10.

According to an exemplary embodiment of the present application, the total optical system length TOTL of the projection sub-module and the total effective focal length F of the projection sub-module satisfy: TOTL/F is more than or equal to 0.2 and less than or equal to 50.

According to an exemplary embodiment of the present application, the image unit is attached to the light source module as one body, or the image unit is attached to the microlens as one body.

According to an exemplary embodiment of the present application, the attaching surface of the image unit includes at least one of a flat surface and a curved surface.

According to an exemplary embodiment of the present application, a light source module includes a light source and a light receiving element for receiving light emitted from the light source and collecting the light to form a light beam.

According to an exemplary embodiment of the present application, the light receiving element comprises at least one of a TIR lens, a plano-convex lens or a light pipe.

According to an exemplary embodiment of the present application, the projection system further comprises an illumination microlens array element, the illumination microlens array element comprising a plurality of illumination microlenses, each illumination microlens being located between a light source module and a corresponding image cell and being for adjusting a light beam irradiated to the corresponding image cell; the thickness t of the lighting micro-lens, the back focus f of the lighting micro-lens on the side away from the light source module, the diagonal length L of the lighting micro-lens, the length h of the effective light-passing area of the image unit in the diagonal direction of the lighting micro-lens and the distance d between the image unit and the light-emitting surface of the lighting micro-lens satisfy the following conditions: (t × h + L × d)/(L-h) is less than or equal to f.

According to an exemplary embodiment of the present application, the light incident surface of the illumination microlens is a convex surface, and the light emitting surface is a plane surface.

According to an exemplary embodiment of the present application, the light incident surface of the illumination microlens is a plane, and the light emitting surface is a convex surface.

According to an exemplary embodiment of the present application, the illumination microlens array element is provided separately from the light source module.

According to an exemplary embodiment of the present application, the illumination microlens array element is disposed on the light exit surface of the light receiving element.

According to an exemplary embodiment of the present application, the image unit includes a blocking portion defining a light passing area for passing the sub-beam.

According to an exemplary embodiment of the present application, the projection submodule includes at least two microlenses sequentially arranged in a direction of the sub-beam; the at least two micro lenses comprise a first micro lens and a second micro lens, the light incident surface of the first micro lens is a plane, a convex surface or a concave surface, and the light emergent surface of the first micro lens is a convex surface; the second micro lens is positioned on the light-emitting side of the first micro lens, the light-in surface of the second micro lens is a plane, a convex surface or a concave surface, and the light-out surface of the second micro lens is a convex surface.

According to an exemplary embodiment of the application, the at least two projection submodules are distributed in an array within the cross-section of the light beam.

According to an exemplary embodiment of the application, the projection submodule comprises a first microlens, the first microlens is spaced from the image unit by air in the exit path of the light beam, and the diaphragm is located on the side of the first microlens facing away from the image unit.

According to an exemplary embodiment of the application, the first microlenses of all projection submodules constitute first microlens array elements, the diaphragms of all projection submodules constitute diaphragm array elements, and the first microlens array elements and the diaphragm array elements are detachably connected.

According to an exemplary embodiment of the present application, an end portion of the diaphragm array element is provided with a first connecting member for connecting the diaphragm array element and the first microlens array element.

According to an exemplary embodiment of the application, the image units of all projection submodules constitute an image generating element, which is provided with a second connection, which is detachably connected with the first connection.

According to an exemplary embodiment of the application, the projection sub-module comprises first microlenses, wherein the first microlenses of all the projection sub-modules constitute first microlens array elements, and the first microlens array elements and the light receiving elements are detachably connected.

According to one or more of the above embodiments of the present application, the projection sub-module has a strong control capability on the light passing through it by providing at least one microlens in the projection sub-module. The projection submodule of the projection system has strong control force on light, so that light crosstalk between different projection submodules is weak, parasitic light is less, the projection system can project patterns with high definition, and the projection range of the projection system is large. Further, when at least two microlenses are arranged, the control force of each projection submodule on light is stronger, stray light is less, and the definition of a projected pattern is high.

In addition, at least two projection sub-modules of the projection system can project the patterns in an overlapping manner, so that the brightness of the projected patterns is uniform.

Drawings

Other features, objects, and advantages involved in the embodiments of the present application will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings. Wherein:

fig. 1 is a schematic structural diagram of a projection system according to a first embodiment of the present application;

FIG. 2 is a schematic configuration of a projection system of a comparative embodiment;

fig. 3 is a schematic configuration diagram of a projection system according to a second embodiment of the present application;

fig. 4 is a schematic configuration diagram of a projection system according to a third embodiment of the present application;

fig. 5 is a schematic configuration diagram of a diaphragm array element according to a third embodiment of the present application;

fig. 6 is a schematic configuration diagram of a projection submodule according to a third embodiment of the present application;

fig. 7 is a schematic view of a projection state of a projection submodule according to a third embodiment of the present application;

fig. 8 is a schematic configuration diagram of a projection system according to a fourth embodiment of the present application;

fig. 9 is a schematic configuration diagram of a projection submodule according to a fourth embodiment of the present application;

fig. 10 is a schematic configuration diagram of a projection sub-module according to a fifth embodiment of the present application;

fig. 11 is a schematic configuration diagram of a projection submodule according to a sixth embodiment of the present application;

fig. 12 is a schematic configuration diagram of a projection system according to a seventh embodiment of the present application;

fig. 13 is a schematic configuration diagram of a projection system according to an eighth embodiment of the present application;

fig. 14 is a structural relationship diagram of an image unit according to an eighth embodiment of the present application;

fig. 15 is a schematic structural view of a projection system according to a ninth embodiment of the present application;

fig. 16 is a schematic structural view of a projection system according to a tenth embodiment of the present application;

fig. 17 is a schematic configuration diagram of a projection system according to an eleventh embodiment of the present application;

fig. 18 is a schematic structural view of a projection system according to a twelfth embodiment of the present application; and

fig. 19 is a schematic diagram of an imaging principle of a projection system according to an embodiment of the present application.

[ description of embodiments of the present application ] with reference numerals

1: a light source module; 11: a light source;

12: a light receiving element; 2: a projection module;

20: a projection sub-module; 21: an image generating element;

211: an image unit; 2111: an effective light-transmitting region;

22: a first microlens array element; 221: a first microlens;

23: a diaphragm array element; 231: a diaphragm;

232: a light-blocking area; 24: a second microlens array element;

241: a second microlens; 251: a third microlens;

3: an illuminating microlens array element; 31: an illuminating microlens;

4: a first connecting member; 5: a second connecting member;

6: a third connecting member; s1: a light incident surface of the first microlens;

s2: a light-emitting surface of the first microlens; s3: a light incident surface of the second microlens;

s4: a light-emitting surface of the second micro lens; s5: a light incident surface of the third microlens;

s6: a light-emitting surface of the third microlens; s7: a light-emitting surface of the illumination microlens;

s8: an image plane.

[ COMPARATIVE EMBODIMENT REFERENCE-SPECIFIC EMBODIMENT ] A METHOD FOR MANUFACTURING THE SAME

100: a projection system; 101: a contrast image unit;

102: a front lens; 103: a rear lens.

Detailed Description

For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that the detailed description is merely illustrative of exemplary embodiments of the present application and does not limit the scope of the present application in any way. Like reference numerals refer to like elements throughout the specification.

It should be noted that in the present specification, expressions such as first, second, etc. are used only for distinguishing one feature from another feature, and do not indicate any limitation on the features. Thus, the first microlenses discussed below may be referred to as second microlenses, and the second microlenses may also be referred to as first microlenses, without departing from the teachings of the present application.

In the drawings, the thickness, size and shape of the components have been slightly adjusted for convenience of explanation. The figures are purely diagrammatic and not drawn to scale. For example, the thickness of the first microlens and the diagonal length of the first microlens are not in proportion in actual production. As used herein, the terms "approximately," "about," and the like are used as table approximation terms, not as table degree terms, and are intended to account for inherent deviations in measured or calculated values that would be recognized by one of ordinary skill in the art.

It will be further understood that the terms "comprises," "comprising," "has," "having," and/or "configured with," when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Additionally, the use of "exemplary" is intended to mean exemplary or illustrative.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In addition, the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

The embodiment of the application provides a projection system, which comprises a light source module and a projection module. The light source module is used for emitting light beams. The projection module comprises at least two projection sub-modules distributed in the cross-section of the light beam, each projection sub-module comprising an image element and a set of microlenses. The light beam emitted by the light source module can cover the image units of the projection sub-modules.

These image elements are distributed in the cross-section of the light beam. Specifically, these image cells are arranged in an array. These image cells may be formed as a unitary image-generating element. The image units may also exemplarily be single elements, the image units being adapted to pass the light beams, in particular each image unit being adapted to pass a portion of the light beam. In other embodiments, a pattern may also be directly embossed on the light emitting surface of the light receiving element when the light receiving element of the light source module is manufactured, that is, the image unit and the light receiving element are integrated into a same component.

Each group of micro lenses is positioned on one side of the corresponding image unit, which is far away from the light source module. An image unit and a group of micro lenses can form a projection sub-module, and particularly, the micro lenses for projection in the projection sub-module are positioned on the side, opposite to the light source module, of the image unit. Each set of microlenses may include at least one microlens having an optical power. The light incident surface of the micro lens can be a plane, a convex surface or a concave surface, and the light emergent surface can be a convex surface.

Further, each set of microlenses may include first microlenses, the first microlenses of all projection sub-modules being distributed, e.g. arrayed, within the cross-section of the beam. These first microlenses may be formed as integral first microlens array elements. The array mode of the plurality of image units in the cross section of the light beam is the same as the array mode of the plurality of first micro lenses, so that all projection sub-modules are also distributed in an array mode in the cross section of the light beam.

Further, each group of microlenses may include at least a first microlens and a second microlens, the second microlens being disposed on a side of the first microlens facing away from the image unit. For example, the first microlenses of all the projection sub-modules may be formed as a unitary first microlens array element, and the second microlenses of all the projection sub-modules may be formed as a unitary second microlens array element. The array mode of the plurality of image units in the cross section of the light beam, the array mode of the plurality of first micro lenses and the array mode of the plurality of second micro lenses are the same, so that all the projection sub-modules are also distributed in an array mode in the cross section of the light beam.

When the projection system provided by the application is used, the light source module emits light beams. The beams are directed to respective projection sub-modules. Each sub-beam passing through an image cell carries the image information provided by that image cell. And a group of micro lenses in the projection sub-module are used for projecting the sub-beams carrying the image information.

The projection system provided by the application has a compact structure and is suitable for being installed in equipment with limited installation space, such as automobiles and the like. When the projection system is used as an on-vehicle welcome lamp, the projection system can be arranged below a vehicle door, for example, and projects a pattern to the ground. The pattern projected by the projection system is clear. Illustratively, each projection sub-module is configured to project the same pattern and the patterns are projected at the plane of projection in an overlapping manner. The overlapped projection patterns have high and uniform brightness.

In an exemplary embodiment, the image unit includes a blocking portion defining a light-passing area for passing the sub-beam. For example, the blocking portions of at least two image cells may be different from each other. When the brightness of the overlapped projection pattern is not uniform, a shielding portion may be added to the partial image unit to shield the light transmission region, and the added shielding portion is located in a region of the projection pattern with higher brightness. And the brightness of this area in the image information carried by the sub-beams passing at this image unit decreases, and the light intensity of these sub-beams also becomes smaller. By adjusting the light-passing area of the partial image unit, the illuminance of the overlapped projection patterns at the projection surface can be adjusted so that the illuminance of the projection patterns is uniform.

In an exemplary embodiment, the present application provides a projection sub-module having a field angle FOV satisfying: the FOV is more than or equal to 20 degrees and less than or equal to 120 degrees. The field angle of the projection sub-module is in the range, the included micro-lens has high degree of freedom, and the large-angle light rays can be controlled more easily. The size of the pattern projected by the projection submodule is large.

In an exemplary embodiment, the present application provides a projection sub-module having a ratio FNO of total effective focal length to entrance pupil diameter that satisfies: FNO is less than or equal to 5. The projection submodule has the f-number within the range, the projected light effect is high, and then the projected pattern is bright.

In an exemplary embodiment, the total optical system length TOTL of the projection sub-module provided herein satisfies: TOTL is more than or equal to 0.5mm and less than or equal to 40mm. In an example, TOTL is 0.5mm ≦ 2.3mm. As shown in fig. 6, the second microlens 241 of the projection sub-module is the microlens farthest from the image unit 211, and the total optical system length of the projection sub-module 20 is the distance between the light incident surface of the image unit 211 and the light emitting surface S4 of the second microlens on the optical axis of the projection sub-module 20. Since the thickness of the image unit is very thin, the total length of the optical system is acceptable as measured from the light-emitting surface thereof. By controlling the overall optical system length of the projection sub-module, the projection system provided by the present application can be miniaturized and facilitates the assembly of individual microlens array elements.

In an exemplary embodiment, the total optical system length TOTL of the projection sub-module in the projection system provided by the present application and the total effective focal length F thereof satisfy: TOTL/F is more than or equal to 0.2 and less than or equal to 50. In an example, 1.84 ≦ TOTL/F ≦ 50. The projection submodule meets the conditional expression, the total length of an optical system of the projection submodule can be controlled within a certain range, and therefore the miniaturization of the projection system is guaranteed.

When TOTL/F is less than 1.84, the volume of the projection system is small, which can meet the development requirement of miniaturization of the industry, but the arrangement among the elements of the projection system is compact. The light is greatly bent, the system sensitivity is high, the processing requirement on the optical lens is high, the yield of the produced product is low, and the production of the system is not facilitated. And because the system size is small, the image generating element is close to the micro lens array lens, and the heat of the image generating element is high at the moment, so that the micro lens array lens is easy to damage, and the system performance is reduced.

When TOTL/F is more than 50, the light trend of the projection system is very smooth, the processing precision requirement is low, but the system is large in size, the development requirement of miniaturization is not met, and the applicability is low.

According to the projection system, the TOTL/F is more than or equal to 1.84 and less than or equal to 50, the requirement of miniaturization can be met, the system precision requirement is low, the processing performance is good, the production yield is high, and the heat dissipation is good.

In an exemplary embodiment, the distance U between the image unit and the light incident surface of the microlens closest to the image unit in the projection submodule, and the total effective focal length F of the projection submodule satisfy: U/F is more than or equal to 0 and less than or equal to 10. In the example, 0 ≦ U/F ≦ 5. And if the projection sub-module satisfies that U/F is more than or equal to 0 and less than or equal to 10, the image unit is positioned at the effective focal plane of the projection sub-module or in the vicinity of the effective focal plane and can be directly projected onto a target surface, so that the projection pattern of the projection sub-module is clear.

Further, the distance U between the image unit and the light incident surface of the microlens closest to the image unit in the projection submodule and the total effective focal length F of the projection submodule satisfy: U/F is more than or equal to 0.2 and less than or equal to 10. When the focal length of projection submodule is the definite value, can adjust the demand that the size of the projection position and the projection pattern of difference are satisfied to the size of the distance U between image element and the adjacent microlens to it is clear to realize the projection pattern of projection submodule, promptly, image element and microlens set up separately, when one set of projection system switches over the use between different application scenes, only need to change image element readjustment U value can realize the switching of different patterns, can satisfy diversified application demand better.

Based on the principle of lens imaging, under the condition of a certain focal length, the smaller U is, the larger the magnification is, the larger U is, the smaller the magnification is, so that an object is placed at different positions near the focal length, and the optimal imaging surface and the imaging size are different. As shown in fig. 19, when the object is placed at the position U1, the optimal imaging surface position is L1, and the imaging size of the projection pattern is H1; when the object is placed at the position U2, the optimal imaging plane of the projection is L2, and the imaging size at this time is H2. The smaller the visible object distance U is, the longer the projection pattern distance is, and the larger the projection pattern size is; the larger the object distance U, the closer the projected pattern distance, and the smaller the projected pattern size. Under the application scenes of different projection pattern sizes and projection distances, if the projection system is unchanged, the object distance U can be changed to meet the requirements of different application scenes, and the system has high universality and adjustability.

When U/F is less than 0.2, the more the focal plane is close to the micro-lens array, the less the number of the micro-lens arrays used for imaging is, so that the large image height cannot be obtained, and when the forced control system is large, the optical path difference between the central light and the edge light is large, so that the imaging effect of the system is poor. When the imaging quality of the system is high, the system image height is small, so that only a small amount of light is incident to the imaging end from the illumination end, the illumination on the target surface is low, and the system efficiency loss is high.

When the U/F is larger than 10, the farther the focal plane is from the micro-lens array, the longer the focal plane is, the longer the projection system becomes a long back focal system, the volume of the system is greatly increased, and the optical path of the system is enlarged, so that large-angle light at an illumination end cannot enter the system, the light crosstalk is serious, stray light on a target surface is large, and the contrast of a projection pattern is low.

According to the projection system, the U/F is not less than 0.2 and not more than 10, so that the projection effect and the light effect can be better considered by the projection system, the contrast of the projection pattern is high, and the efficiency is also high.

In an exemplary embodiment, the radius of curvature Ra of the light incident surface of the microlens of the embodiment of the present application and the light emitting surface Rb thereof satisfy | Rb/Ra | ≦ 10. The micro-lens can better control the large-angle light rays when meeting the conditional expression. And the projection submodule containing the micro lens has higher imaging capability and larger field of view, and the pattern projected by the projection submodule is clear and has a large range.

In an exemplary embodiment, each projection sub-module further comprises a diaphragm for confining the sub-beams. Whether to be equipped with a diaphragm can be selected based on the collimation degree of the light beam emitted by the light source module. When the collimation degree of the emergent light of the light source module is very low, the diaphragm can be used for directly eliminating stray light in the system; when the collimation degree of the emergent light of the light source module is very high, the diaphragm also can not be used. The diaphragms of all the projection submodules form diaphragm array elements by painting, printing, photoetching or other processing methods on a flat plate, or by die casting a metal piece, injection molding a grinding tool and other processing methods.

Furthermore, each group of micro lenses corresponds to a diaphragm, and due to the existence of the diaphragm, the emergent light of each group of micro lenses can be emitted to a target surface only through an effective light-transmitting area on the diaphragm, namely the diaphragm can limit the incident angle of the emergent light. The diaphragm can limit the light crosstalk between the adjacent groups of micro-lens light rays while limiting the incident angle of the light rays, so that the system stray light is effectively reduced, the pattern on the target projection surface has no stray light, and the clear projection effect can be realized.

The embodiments provided in the present application are described in detail below with reference to fig. 1 to 18.

Implementation mode one

Fig. 1 is a schematic configuration diagram of a projection system according to a first embodiment. Referring to fig. 1, the projection system provided by the present embodiment includes: a light source module 1 and a projection module 2.

The light source module 1 includes a light source 11 and a light receiving element 12. The light source 11 may be an LED light source. The light receiving element 12 may be a collimating lens, such as a Total Internal Reflection (TIR) collimating lens. Optionally, the light receiving element 12 may further comprise a plano-convex lens and/or a light pipe. The light emitted from the light source 11 to the right, the light in the middle portion propagates to the right approximately, and the light in the outer portion propagates to the right after being totally reflected by the sidewall of the total reflection type collimating lens. The light receiving element 12 emits a light beam to the right, and specifically, may be collimated light.

The projection module 2 receives the light beam and emits it. In particular, the projection module 2 may include a plurality of projection sub-modules 20. The plurality of projection sub-modules 20 are distributed, for example in an array, in a cross-section of the propagation direction of the light beam. The cross-section of the light beam may be defined as a plurality of channels in one-to-one correspondence with the projection sub-modules 20. The beam may be defined as a plurality of sub-beams, one projection sub-module 20 for each sub-beam.

For example, the structures of the plurality of projection sub-modules 20 may be the same, and then the corresponding same portions of the plurality of projection sub-modules 20 may be distributed in an array at the same cross-section of the light beam. In other words, the projection module 2 may include: an image generating element 21 and a first microlens array element 22.

The image generating element 21 comprises a plurality of image cells. The plurality of image elements are arranged in a cross section of the propagation direction of the light beam, for example, arranged in an array in one piece. The cross-section of the light beam is divided into different channels according to the arrangement positions of the image units. The image generating element 21 may be provided as a film. The image generating element 21 may be attached to the light emitting surface of the light receiving element 12, and the attachment surface of the image generating element 21 may be a plane. Illustratively, the image generating element 21 may also be attached to the light incident surface of the first microlens array element 22. The faying surface of the image generating element 21 may include at least one of a flat surface and a curved surface.

The first microlens array element 22 is disposed on the light exit side of the image generating element 21, and projects a light beam carrying image information. Specifically, the first microlens array element 22 includes a plurality of first microlenses. The first micro lenses correspond to the image units one by one. The first micro lens is used for projecting the light carrying the image information transmitted by the image unit. The light projected by these first microlenses may overlap in the projection plane.

According to the present embodiment, at least one microlens in the projection sub-module 20 for projecting an image is located on the light exit side of the image cell. The distance between the image unit and the nearest microlens (i.e. the first microlens) can have a large adjustment space, and the arrangement position of the image unit has a high degree of freedom. In addition, when more micro lenses are arranged, the requirements on the position, the surface shape and other parameters of the micro lenses are very loose, a very free design space is provided, the structural design can be simpler, and the projection system can be more flexibly adapted to different use requirements.

Fig. 2 shows a schematic block diagram of a projection system 100 of a comparative embodiment. The projection system 100 comprises a contrast image unit 101, a front lens 102 and a rear lens 103. When the front lens 102 is arranged, it is necessary to ensure that its focal point falls at the rear lens 103. When the contrast image unit 101 is provided, it is necessary to dispose the contrast image unit 101 between the front lens 102 and the rear lens 103 and to ensure that the contrast image unit 101 is located near the front focal point of the rear lens 103. The comparative embodiment builds the structure of the front lens 102 and the rear lens 103, and realizes the projection of the comparative image unit 101 by utilizing the principle of Kohler illumination.

In the comparative embodiment, the front lens 102 must be arranged before the comparative image unit 101 to focus the light passing through the comparative image unit 101 to the rear lens 103, so as to realize the projection function. In addition, the structures of the front lens 102 and the rear lens 103 are too strict for precision, and are fixed compared with the setting position of the image unit 101 and sensitive to the setting position precision.

In the embodiment of the application, at least one microlens for projection is arranged on the light emergent side of the image unit, and a front lens for projection is not arranged, so that the structure of the projection sub-module 20 is simpler, and the arrangement position of each optical element in the projection sub-module 20 is more free. The projection sub-module 20 according to the embodiment of the present invention has greater design flexibility, the numerical aperture of the microlens is not particularly limited, and the focal position of each microlens is not particularly limited when a plurality of microlenses are provided.

Second embodiment

Fig. 3 is a schematic configuration diagram of a projection system according to a second embodiment. Referring to fig. 3, the projection system provided by the present embodiment includes: a light source module 1 and a projection module 2.

In contrast to the first embodiment, the projection module 2 of the second embodiment further includes a diaphragm array element 23. Illustratively, the diaphragm array element 23 is disposed on the light incident side of the first microlens array element 22, and includes a plurality of diaphragms. The plurality of diaphragms correspond to the image units and the microlenses one to one. The diaphragm is used for restricting the angle of the passed sub-beams, so that the projected pattern is free from stray light. By arranging the diaphragm array element 23, the requirement on the collimation degree of emergent light of the light source module 1 can be reduced, so that the projection system of the embodiment is easier to manufacture and assemble.

Third embodiment

Fig. 4 is a schematic configuration diagram of a projection system according to a third embodiment. Referring to fig. 4, the projection system provided by the present embodiment includes: a light source module 1 and a projection module 2.

The light source module 1 includes a light source 11 and a light receiving element 12. The light source 11 may be an LED light source. The light collecting element 12 may be a collimating lens. The light emitted from the light source 11 to the right is collected by the light collecting element 12 and then emitted to the right.

The projection module 2 receives the light beam and emits it. In particular, the projection module 2 may include a plurality of projection sub-modules 20. The plurality of projection sub-modules 20 are distributed, for example in an array, in a cross-section of the propagation direction of the light beam. The cross-section of the light beam may be defined as a plurality of channels in one-to-one correspondence with the projection sub-modules 20. The beam may be defined as a plurality of sub-beams, one for each projection sub-module 20.

For example, the plurality of projection sub-modules 20 may have the same structure, and then corresponding identical portions of the plurality of projection sub-modules 20 may be distributed in an array at the same cross-section of the light beam.

Referring to fig. 4, 5 and 6, the projection module 2 may include: an image generating element 21, a first microlens array element 22, a diaphragm array element 23, and a second microlens array element 24.

The image generating element 21 comprises a plurality of image cells 211. The plurality of image cells 211 are arranged in a cross section of the propagation direction of the light beam, for example, arranged integrally in an array. The cross-section of the light beam is divided into different channels according to the positions where these picture elements 211 are arranged. The image generating element 21 may be provided as a film.

The first microlens array element 22 is disposed on the light exit side of the image generating element 21. The second microlens array element 24 is disposed on the light exit side of the first microlens array element 22. Illustratively, a plurality of microlens array elements for projecting light beams carrying image information are sequentially disposed on the light exit side of the image generating element 21.

The first microlens array element 22 includes a plurality of first microlenses 221. The plurality of first microlenses 221 correspond one-to-one to the plurality of image cells 211. The second microlens array elements 24 are similar. As shown in fig. 6, the first microlenses 221 and their corresponding second microlenses 241 are used to project light carrying image information transmitted through the image unit 211.

Illustratively, the diaphragm array element 23 is disposed between the first microlens array element 22 and the second microlens array element 24, and includes at least two diaphragms 231. The diaphragm array elements 23 may also be arranged at other positions, especially when the projection module 2 comprises more microlens array elements. The plurality of diaphragms 231 correspond one-to-one to the plurality of image cells 211. The aperture 231 is used to constrain the angle of the beamlets passing through it so that the projected pattern is free of veiling glare. The projection system of the example has low requirement on the collimation degree of emergent light of the light source module 1, and is convenient to assemble.

As shown in fig. 5, the aperture 231 of the aperture array element 23 is disposed in the opaque area 232 by being pierced. Uniform illumination can be achieved by controlling the size of the aperture 231. The arrangement of the diaphragms 231 may be rectangular, hexagonal, and other suitable shapes. The image unit 211, the first microlenses 221, and the second microlenses 241 are arranged in the same manner. The shape of the diaphragm 231 may be a rectangular shape, a circular shape, or other adaptive shape. Illustratively, the image unit 211, the first microlens 221, and the second microlens 241 may have a rectangular shape of 1mm × 1mm, and the aperture 231 may have a circular shape and be arranged in a matrix of 10 × 10, respectively.

As shown in fig. 6, the image unit 211, the first microlens 221, the diaphragm 231, and the second microlens 241 are used to constitute the projection sub-module 20. The optical parameters of the projection sub-module 20 are specified below.

The radius of curvature | R1| = + ∞ at the paraxial region of the light incident surface S1 of the first microlens, and the radius of curvature | R2| =0.65mm at the paraxial region of the light emitting surface S2 of the first microlens. The radius of curvature | R3| = + ∞ at the paraxial region of the light incident surface S3 of the second microlens, and the radius of curvature | R4| =1.32mm at the paraxial region of the light emitting surface S4 of the second microlens. Illustratively, the light incident surface S1 of the first microlens and the light incident surface S3 of the second microlens include planes, and the light emitting surface S2 of the first microlens and the light emitting surface S4 of the second microlens include curved surfaces, such as convex surfaces.

In an exemplary embodiment, the radius of curvature Ra of the light incident surface of the first microlens 221 and/or the second microlens 241 of the embodiments of the present application and the radius of curvature Rb of the light emitting surface thereof satisfy 0 ≦ Rb/Ra ≦ 10. Satisfying the conditional expressions, the first microlenses 221 and/or the second microlenses 241 can better control high-angle light rays. And the projection submodule has high imaging capability and large field of view, and the pattern projected by the projection submodule is clear and has a large range. In this embodiment, ra can be configured as R1, R3, where R1 is the radius of curvature of the light incident surface S1 of the first microlens, and R3 is the radius of curvature of the light incident surface S3 of the second microlens. Rb can be configured as R2 and R4, where R2 is the light emitting surface S2 of the first microlens, and R4 is the radius of curvature of the light emitting surface S4 of the second microlens.

Further, the field angle FOV of the projection submodule 20 is 40 °, the total effective focal length F is 1.15mm, the ratio FNO of the total effective focal length to the entrance pupil diameter is 2.8, and the total optical system length TOTL is 2.3mm.

Exemplarily, the distance U from the light incident surface S1 of the first microlens to the image unit 211 on the optical axis is 0.3mm.

As shown in fig. 7, the projection sub-module 20 forms a single projection channel, the sub-beams carrying the image information of the image unit 211 are projected in an enlarged manner, and each projection channel can project the image information of each image unit in an enlarged manner and then superimpose the image information to form a projection pattern on the imaging surface S8.

Embodiment IV

Fig. 8 is a schematic configuration diagram of a projection system according to a fourth embodiment. Referring to fig. 8, the projection system provided by the present embodiment includes: a light source module 1 and a projection module 2. The light source module 1 includes a light source 11 and a light receiving element 12, wherein the light source 11 is an LED light source, and the light receiving element 12 can be a collimating lens and has a plane light emitting surface.

The light emitted from the light source 11 to the right can emit collimated light to the right after being received by the light receiving element 12, and the projection module 2 receives the collimated light and emits the collimated light. The projection module 2 comprises a plurality of structurally identical projection submodules 20, which are distributed in an array in the cross section of the collimated light. The cross-section of the collimated light covers the projection sub-module 20.

Specifically, the projection module 2 includes: an image generating element 21, a first microlens array element 22, a diaphragm array element 23, and a second microlens array element 24. Illustratively, the light incident surface and the light exiting surface of the image generating element 21 are both planes, and the light incident surface of the first microlens array element 22 is a plane. Illustratively, the light incident surface of the image generating element 21 is bonded to the light emergent surface of the light receiving element 12, and the light emergent surface of the image generating element 21 is bonded to the light incident surface of the first microlens array element 22, so that the image generating element 21, the light receiving element 12 and the first microlens array element 22 are bonded to form a single element. In other embodiments, the image generating element 21 may be formed on the light receiving element 12 by injection molding or stamping, i.e. the image unit and the light source module 1 are integrally formed.

After the image generating element 21 receives the collimated light, the light beam carrying the image information is subjected to enlarged projection of an image via the first microlens array element 22, the diaphragm array element 23, and the second microlens array element 24 in this order.

As shown in fig. 9, the projection sub-module 20 includes: the image unit 211, the first microlens 221, the diaphragm 231 and the second microlens 241 are arranged in a one-to-one centered manner in the sub-beam direction.

The image cells 211 of the plurality of projection sub-modules 20 are arranged in an array to form the integral image generating element 21, and the image cells 211 can be attached to the first microlenses 221. The first microlenses 221 of the plurality of projection sub-modules 20 are arranged in an array to form an integral first microlens array element 22, the diaphragms 231 of the plurality of projection sub-modules 20 are arranged in an array to form an integral diaphragm array element 23, and the second microlenses 241 of the plurality of projection sub-modules 20 are arranged in an array to form an integral second microlens array element 24.

Illustratively, the field angle FOV of the projection submodule 20 is 40 °, the total effective focal length F of the projection submodule 20 is 1.25mm, the FNO of the projection submodule 20 is 2.8, and the total optical system length TOTL of the projection submodule 20 is 2.12mm.

The radius of curvature | R1| = + ∞ at the paraxial region of the light incident surface S1 of the first microlens, and the radius of curvature | R2| =0.689mm at the paraxial region of the light emitting surface S2 of the first microlens. A radius of curvature | R3| = + ∞ at the paraxial region of the light incident surface S3 of the second microlens, and a radius of curvature | R4| =0.81mm at the paraxial region of the light emitting surface S4 of the second microlens. The light incident surface S1 of the first microlens and the light incident surface S3 of the second microlens are both flat. In the present embodiment, ra may be structured as R1, R3, and Rb may be structured as R2, R4.

In this embodiment, the image generating device 21, the light receiving device 12 and the first microlens array 22 are bonded to form a single device, so that the system adjustment precision is reduced, and the adjustment time is saved.

Fifth embodiment

Fig. 10 is a schematic configuration diagram of a projection submodule according to the fifth embodiment. Referring to fig. 10, the projection sub-module 20 of the projection system provided in the present embodiment includes: the image unit 211, the first microlens 221, the diaphragm 231 and the second microlens 241 are sequentially and concentrically arranged one by one in the projection direction of the sub-beams. The overall structure of the light source module and the projection module of the projection system is the same as that of the third embodiment, wherein the optical parameters of the projection submodule 20 of the third embodiment are as follows:

the FOV of the projection submodule 20 is 44 °, the total effective focal length F of the projection submodule 20 is 1.25mm, and the FNO of the projection submodule 20 is 2.8.

The radius of curvature | R1| = + ∞ at the paraxial region of the light incident surface S1 of the first microlens, and the radius of curvature | R2| =0.659mm at the paraxial region of the light emitting surface S2 of the first microlens. The radius of curvature | R3| =1.04mm at the paraxial region of the light incident surface S3 of the second microlens, and the radius of curvature | R4| =0.75mm at the paraxial region of the light emitting surface S4 of the second microlens. In the present embodiment, ra may be structured as R1, R3, and Rb may be structured as R2, R4. Specifically, the light incident surface S1 of the first microlens is a plane, the light emitting surface S2 of the first microlens is a convex surface, the light incident surface S3 of the second microlens is a concave surface, and the light emitting surface S4 of the second microlens is a convex surface.

The projection system provided by the embodiment has strong capability of controlling light rays, and can be better adapted to the light source module.

Sixth embodiment

Fig. 11 is a schematic configuration diagram of a projection sub-module according to a sixth embodiment; referring to fig. 11, the projection sub-module 20 of the projection system provided in the present embodiment includes: the image unit 211, the first microlens 221, the second microlens 241, the diaphragm 231 and the third microlens 251 are sequentially and concentrically arranged one by one in the projection direction of the sub-beams. The light source module of the projection system provided in this embodiment may be the same as that of the third embodiment, wherein the optical parameters of the projection sub-module 20 of this embodiment are as follows:

the FOV of the projection submodule 20 is 50 °, the total effective focal length F of the projection submodule 20 is 1.2mm, and the FNO of the projection submodule 20 is 2.7.

Further, a radius of curvature | R1| = + ∞ at a paraxial region of the light incident surface S1 of the first microlens, and a radius of curvature | R2| =1.52mm at a paraxial region of the light emitting surface S2 of the first microlens. The radius of curvature | R3| =3.45mm at the paraxial region of the light incident surface S3 of the second microlens, and the radius of curvature | R4| =1.75mm at the paraxial region of the light emitting surface S4 of the second microlens. The radius of curvature | R5| =1.48mm at the paraxial region of the light incident surface S5 of the third microlens, and the radius of curvature | R6| =1.18mm at the paraxial region of the light emergent surface S6 of the third microlens.

In the present embodiment, ra may be configured as R1, R3, and R5, and Rb may be configured as R2, R4, and R6. Specifically, the light incident surface S1 of the first microlens is a plane, the light emitting surface S2 of the first microlens is a convex surface, the light incident surface S3 of the second microlens is a convex surface, the light emitting surface S4 of the second microlens is a convex surface, the light incident surface S5 of the third microlens is a convex surface, and the light emitting surface S6 of the third microlens is a concave surface.

Seventh embodiment mode

Fig. 12 is a schematic configuration diagram of a projection system according to a seventh embodiment of the present application; referring to fig. 12, the projection system provided in the present embodiment includes a light source module 1 and a projection module 2. The projection module 2 may be the same as the projection module of the third embodiment.

In the present embodiment, the light source module 1 includes a light source 11 and a light receiving element 12. The light source 11 is an LED light source. The light receiving element 12 is a plano-convex collimating lens. The light source 11 is located on the convex side of the plano-convex collimating lens, near the center of the convex surface. The projection module 2 is located on the plane side of the plano-convex collimating lens.

Embodiment eight

Fig. 13 is a schematic structural view of a projection system according to an eighth embodiment of the present application; referring to fig. 13, the projection system provided by the present embodiment includes: a light source module 1, a projection module 2 and an illumination microlens array element 3.

The light source module 1 includes a light source 11 and a light receiving element 12. The light source 11 may be an LED light source. The light emitted from the light source 11 to the right propagates substantially to the right in the middle, and the light in the outer peripheral portion is totally reflected by the side wall of the light receiving element 12 and propagates to the right. The light-receiving element 12 emits a parallel light beam to the right.

The illumination microlens array element 3 is located on the light exit side of the light source module 1 and serves to adjust light irradiated toward the corresponding projection module 2. Referring to fig. 14, the light incident surface of the illumination microlens 31 is a plane, and the light emitting surface S7 of the illumination microlens is a convex surface. And the light incident surface of the illumination microlens array element 3 is a plane. For example, the light emitting surface of the light receiving element 12 may be attached to the illumination microlens array element 3 to improve the system efficiency.

Referring to fig. 13 and 14, the illumination microlens array element 3 includes at least one illumination microlens 31, and the illumination microlens 31 corresponds one-to-one to the projection sub-module 20. The parallel light beams emitted from the light collecting element 12 pass through the illumination microlens array element 3 and then converge on the right side of the image generating element 21, so that the light beams completely irradiate the image on the image unit 211 and further completely project the pattern. In other embodiments, the illuminating microlens array element 3 comprises at least one illuminating microlens 31. Some of the projection sub-modules 20 may have corresponding illumination microlenses 31, while another portion of the projection sub-modules 20 may have no corresponding illumination microlenses.

The projection module 2 receives the light beam and emits it. In particular, the projection module 2 may include a plurality of projection sub-modules 20. The plurality of projection sub-modules 20 are distributed, for example, arrayed, within the cross-section of the light beam, and the illumination microlenses 31 are correspondingly arrayed in an array. The cross-section of the light beam may be defined as a plurality of channels in one-to-one correspondence with the projection sub-modules 20. The beam may be defined as a plurality of sub-beams, one projection sub-module 20 for each sub-beam.

For example, the structures of the plurality of projection sub-modules 20 may be the same, and then the corresponding same portions of the plurality of projection sub-modules 20 may be distributed in an array at the same cross-section of the light beam. The projection module 2 may include: an image generating element 21, a first microlens array element 22, a diaphragm array element 23, and a second microlens array element 24. The image generating element 21 is used to make the passing light beam carry image information. The first microlens array element 22 and the second microlens array element 24 are sequentially disposed on a side of the image generating element 21 facing away from the light source module 1 in a direction of the light beam for projecting the light beam carrying the image information, and for example, the image information carried by the plurality of sub-light beams may be projected in a pattern in an overlapping manner. The diaphragm array element 23 is disposed between the first microlens array element 22 and the second microlens array element 24 for restricting the angle of the light beam passing therethrough.

In an exemplary embodiment, as shown in fig. 14, one sub-beam of the light beam passes through the illumination microlens 31 and the image unit 211 in order. The central distance from the light incident surface of the illumination microlens 31 to the light emitting surface S7 of the illumination microlens, that is, the thickness of the illumination microlens 31 on the optical axis thereof, is t, the back focus of the illumination microlens 31 on the side away from the light source module 1 is f, and the diagonal length of the illumination microlens 31 is L. The back focus of the illumination microlens 31 refers to the distance from the light exit surface S7 of the illumination microlens to the focal plane of the illumination microlens 31. Specifically, the diagonal length of the illumination microlens 31 refers to the maximum connecting line length of the shape of the illumination microlens 31 in the perpendicular direction to the optical axis thereof. For example, when the illumination microlens 31 has a rectangular shape in a perpendicular plane to its optical axis, the maximum connecting line length is the diagonal length of the rectangle; when the illumination microlens 31 has a circular shape in a perpendicular plane to its optical axis, the maximum connecting line length is the diameter of the circle. The length of the effective light-passing region 2111 of the image unit 211 in the direction of the diagonal line of the illumination microlens 31 is h, the distance between the image unit 211 and the light-emitting surface of the illumination microlens 31 is d, and the above parameters satisfy the following relationship: f is not less than (t x h + L x d)/(L-h). The projection system of the present embodiment satisfies the conditional expression, and can restrict the effective light-transmitting region 2111 of the image unit 211 to be completely located in the optical path of the corresponding illumination microlens 31, so that the light beam can completely cover the effective light-transmitting region 2111 on the image unit 211. Light in the light beam passes more through the effective light passing region 2111 and is blocked less by the non-effective light passing region irradiated onto the image unit 211. Thereby making the intensity of the light passing through the image unit 211 higher and the light efficiency of the projection system high.

Illustratively, the optical parameters of the projection sub-module 20 are the same as those of the projection sub-module of the fourth embodiment.

Example nine

Fig. 15 is a schematic structural view of a projection system according to a ninth embodiment of the present application; referring to fig. 15, the projection system provided by the present embodiment includes: a light source module 1, a projection module 2 and an illumination microlens array element 3.

The light source module 1 and the projection module 2 of the present embodiment may be the same as those of the eighth embodiment.

Illustratively, in the present embodiment, the illumination microlens array element 3 includes at least two illumination microlenses 31. The effective light transmission area of the illumination microlens 31 of the illumination microlens array element 3 and the image unit of the image generating element 21 also satisfy the relation: f is not less than (t x h + L x d)/(L-h).

In the present embodiment, the light incident surface of the illumination micro-lenses 31 may be a convex surface, and the light emitting surface may be a plane surface. The light emitting surface of the illumination microlens array 3 may be a plane. Illustratively, the light-emitting surface of the illumination microlens array element 3 is attached to the image generating element 21. Further, the illumination microlens array element 3, the image generating element 21, and the first microlens array element 22 are integrally attached.

Detailed description of the preferred embodiment

Fig. 16 is a schematic structural view of a projection system according to a tenth embodiment of the present application; referring to fig. 16, the projection system provided by the present embodiment includes: a light source module 1, a projection module 2 and an illumination microlens array element 3. The light source module 1 and the illumination microlens array element 3 of the present embodiment may be the same as those of embodiment eight.

The projection module 2 receives the light beam and emits it. In particular, the projection module 2 may include a plurality of projection sub-modules 20. The plurality of projection sub-modules 20 are distributed, for example, arrayed, in the cross section of the light beam emitted from the light source module 1. The illumination microlens array element 3 includes a plurality of illumination microlenses 31, and the plurality of illumination microlenses 31 are arrayed in correspondence with the plurality of projection sub-modules 20. The cross-section of the light beam may be defined as a plurality of channels in one-to-one correspondence with the projection sub-modules 20. The beam may be defined as a plurality of sub-beams, one for each projection sub-module 20.

For example, the plurality of projection sub-modules 20 may have the same structure, and then corresponding identical portions of the plurality of projection sub-modules 20 may be distributed in an array at the same cross-section of the light beam. The projection module 2 may include: an image generating element 21, a first microlens array element 22, and a diaphragm array element 23. The image generating element 21 is used to make the passing light beam carry image information. The first microlens array element 22 is disposed on a side of the image generating element 21 facing away from the light source module 1 in the direction of the light beam for projecting the light beam carrying the image information, and illustratively, the image information carried by the plurality of sub-light beams may be projected in a pattern in an overlapping manner. The diaphragm array element 23 is disposed on a side of the first microlens array element 22 facing away from the image generating element 21, for restricting an angle of the light beam passing therethrough.

Description of the invention

Fig. 17 is a schematic configuration diagram of a projection system according to an eleventh embodiment of the present application; referring to fig. 17, the projection system provided by the present embodiment includes: a light source module 1, a projection module 2 and an illumination microlens array element 3. The light source module 1, the projection module 2, and the illumination microlens array element 3 of the present embodiment may be the same as those of the tenth embodiment. The optical parameters of the projection submodule 20 of the present embodiment are as follows:

the FOV of the projection sub-module 20 is 40 °, the total effective focal length F of the projection sub-module 20 is 1.3mm, and the FNO of the projection sub-module 20 is 2.2.

Further, a curvature radius | R1| =1.1mm at a paraxial region of the light incident surface S1 of the first microlens, and a curvature radius | R2| =1.2mm at a paraxial region of the light emergent surface S2 of the first microlens.

For example, the first microlens is disposed separately from the image unit on the exit path of the light beam, that is, there is an air gap between the first microlens and the image unit on the exit path of the light beam. The illumination microlens array element is provided separately from the light source module.

Illustratively, the first microlens array element 22 and the diaphragm array element 23 are detachably connected. Specifically, two end portions of the diaphragm array element 23 are provided with one first connecting member 4, respectively, and the first connecting member 4 is used to connect the diaphragm array element 23 and the first microlens array element 22. The first connecting member 4 is provided with a groove matched with the first microlens array element 22, and two end portions of the first microlens array element 22 are respectively embedded into the corresponding grooves to be connected with the diaphragm array element 23. The first connecting member 4 is a metal member.

Illustratively, the image generating element 21 is provided with a second connecting member 5, and the second connecting member 4 is detachably connected with the first connecting member 4, so that the image generating element 21 is connected with the diaphragm array element 23 and the first microlens array element 22. The second connecting piece 5 is a metal piece.

EXAMPLE twelve

Fig. 18 is a schematic structural view of a projection system according to a twelfth embodiment of the present application; referring to fig. 18, the projection system provided by the present embodiment includes: a light source module 1, a projection module 2 and an illumination microlens array element 3. The light source module 1, the projection module 2, and the illumination microlens array element 3 of the present embodiment may be the same as those of the tenth embodiment. The optical parameters of the projection submodule 20 of the present embodiment are as follows:

The first microlens is disposed separately from the image unit on the exit path of the light beam, that is, there is an air space between the first microlens and the image unit on the exit path of the light beam.

Illustratively, the illumination microlens array element 3 is disposed on the light emitting surface of the light receiving element 12. The first microlens array element 22 and the light receiving element 12 are detachably connected. Specifically, the two end portions of the first microlens array element 22 are respectively provided with a third connector 6, and the third connector 6 is used for connecting the first microlens array element 22 and the light receiving element 12. The third connecting piece 6 is in snap connection with the hour light element 12.

The foregoing is only an exemplary embodiment of the present application, and it should be noted that, for those skilled in the art, several modifications and substitutions can be made without departing from the technical principle of the present application, and these modifications and substitutions should also be regarded as the protection scope of the present application.

Claims

1. A projection system, comprising: the light source module is used for emitting light beams; and at least two projection sub-modules distributed within a cross-section of the beam, wherein each of the projection sub-modules comprises:

an image unit for passing a portion of the light beam and causing the passed sub-light beam to carry image information;

at least one micro lens is arranged on one side of the image unit, which is far away from the light source module, and is used for projecting the sub-beams carrying image information.

2. The projection system of claim 1, wherein the radius of curvature Ra of the light incident surface of the micro lens and the radius of curvature Rb of the light emitting surface of the micro lens satisfy: the absolute Rb/Ra is more than or equal to 0 and less than or equal to 10.

3. The projection system of claim 1, wherein the projection sub-module further comprises a diaphragm for constraining the sub-beams.

4. The projection system of claim 3, wherein the stop is integrally attached to at least one of the at least one microlens.

5. The projection system of claim 4, wherein the abutting surface of the diaphragm comprises at least one of a flat surface and a curved surface.

6. The projection system of claim 1, wherein the field angle FOV of the projection sub-module satisfies: the FOV is more than or equal to 20 degrees and less than or equal to 120 degrees.

7. The projection system of claim 1, wherein a ratio FNO of a total effective focal length to an entrance pupil diameter of the projection sub-modules satisfies: FNO is less than or equal to 5.

8. The projection system of claim 1, wherein the total optical system length TOTL of the projection sub-module satisfies: TOTL is more than or equal to 0.5mm and less than or equal to 40mm.

9. The projection system of claim 1, wherein a distance U between the image unit and the input surface of the microlens in the projection sub-module closest to the image unit and a total effective focal length F of the projection sub-module satisfy: U/F is more than or equal to 0 and less than or equal to 10.

10. The projection system of claim 1, wherein the total optical system length TOTL of the projection sub-module and the total effective focal length F of the projection sub-module satisfy: TOTL/F is more than or equal to 0.2 and less than or equal to 50.

11. The projection system of claim 1, wherein the image unit is attached to the light source module or the microlens.

12. The projection system of claim 11, wherein the abutting surface of the image unit comprises at least one of a flat surface and a curved surface.

13. The projection system of claim 1, wherein the light source module comprises:

a light source; and

and the light receiving element is used for receiving the light emitted by the light source and receiving the light to form the light beam.

14. The projection system of claim 13, wherein the light harvesting element comprises at least one of a TIR lens, a plano-convex lens, or a light pipe.

15. The projection system of claim 13, further comprising:

an illumination microlens array element including a plurality of illumination microlenses, each of the illumination microlenses being located between the light source module and a corresponding one of the image cells and being for adjusting the light beam irradiated to the corresponding one of the image cells; and

the thickness t of the illumination micro-lens, the back focus f of the illumination micro-lens on the side away from the light source module, the diagonal length L of the illumination micro-lens, the length h of the effective light-passing area of the image unit in the diagonal direction of the illumination micro-lens and the distance d between the image unit and the light-emitting surface of the illumination micro-lens satisfy the following conditions: (t × h + L × d)/(L-h) is less than or equal to f.

16. The projection system of claim 15, wherein the light incident surface of the illumination microlens is convex and the light exiting surface is planar.

17. The projection system of claim 15, wherein the light incident surface of the illumination microlens is a plane surface and the light exiting surface is a convex surface.

18. The projection system of claim 15, wherein the illumination microlens array element is disposed separately from the light source module.

19. The projection system of claim 15, wherein the illumination microlens array element is disposed on a light-emitting surface of the light-receiving element.

20. The projection system of claim 1, wherein the image unit comprises a mask defining a pass region for passing the sub-beams.

21. The projection system of claim 1, wherein the projection sub-module comprises at least two micro-lenses arranged in sequence in the direction of the sub-beams; and

wherein the at least two microlenses include:

the light incident surface of the first micro lens is a plane, a convex surface or a concave surface, and the light emergent surface of the first micro lens is a convex surface; and

the second micro lens is positioned on the light emitting side of the first micro lens, the light incident surface of the second micro lens is a plane, a convex surface or a concave surface, and the light emitting surface of the second micro lens is a convex surface.

22. The projection system of claim 1, wherein the at least two projection sub-modules are distributed in an array within the cross-section of the light beam.

23. The projection system of claim 3, wherein the projection sub-module comprises a first microlens spaced from the image unit by air in the exit path of the light beam, and the stop is located on a side of the first microlens facing away from the image unit.

24. The projection system of claim 23, wherein the first microlenses of all projection sub-modules form first microlens array elements, the diaphragms of all projection sub-modules form diaphragm array elements, and the first microlens array elements and the diaphragm array elements are detachably connected.

25. The projection system of claim 24, wherein the ends of the diaphragm array elements are provided with first connectors for connecting the diaphragm array elements and the first microlens array elements.

26. The projection system of claim 25, wherein the image units of all projection sub-modules constitute an image-generating element, the image-generating element being provided with a second connector, the second connector being detachably connectable to the first connector.

27. The projection system of claim 13, wherein the projection sub-module comprises first microlenses, wherein the first microlenses of all the projection sub-modules form a first microlens array element, and wherein the first microlens array element and the light collecting element are detachably connected.