CN215494475U - Projection module, three-dimensional imaging device and electronic equipment - Google Patents

Abstract

The utility model relates to a projection module, a three-dimensional imaging device and electronic equipment. The projection module comprises an emitting component and a reflecting piece; the transmitting assembly comprises a structural member with an accommodating cavity and a light outlet, and a light source and a diffractive optical element which are arranged in the accommodating cavity, wherein the diffractive optical element is arranged on the light outlet side of the light source and is positioned at the light outlet; the light reflecting pieces are arranged on one side of the light emitting surface of the diffractive optical element at intervals, the surface of the light reflecting pieces facing the diffractive optical element is a light reflecting surface, and the light reflecting surface is parallel to the light emitting surface; the light reflecting piece is used for reflecting the light beams projected by the diffractive optical element, the reflected light beams formed by reflection of the light reflecting piece comprise central light beams and peripheral light beams, the cross-sectional area of the central light beams corresponding to the position of the emitting assembly is matched with the profile of the emitting assembly, and the projection module can eliminate diffraction zero-order light spots, so that the projection pattern is closer to a target pattern.

Description

Projection module, three-dimensional imaging device and electronic equipment

Technical Field

The present invention relates to the field of three-dimensional detection, and in particular, to a projection module, a three-dimensional imaging device, and an electronic apparatus.

Background

Electronic devices based on Time of Flight (TOF) technology or structured light technology typically include a projection module in which diffractive optical elements are arranged so that light emitted by a light source is diffracted into a specific pattern to be projected onto an object to be measured. However, the current diffraction optical element projection pattern usually has zero-order light spots which are difficult to eliminate in the design and processing stages, so that the projection pattern deviates from the target pattern, thereby reducing the quality of the projection pattern and influencing the detection accuracy of the electronic device.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is necessary to provide a projection module, a three-dimensional imaging device, and an electronic apparatus, which are directed to the problem that the projection pattern of the existing diffractive optical element deviates from the target pattern.

A projection module, comprising: an emitting assembly and a reflector;

the transmitting assembly comprises a structural part with an accommodating cavity and a light outlet, and a light source and a diffractive optical element which are arranged in the accommodating cavity, wherein the diffractive optical element is arranged on the light outlet side of the light source and is positioned at the light outlet;

the light reflecting pieces are arranged on one side of the light emitting surface of the diffractive optical element at intervals, the surface of the light reflecting piece facing the diffractive optical element is a light reflecting surface, and the light reflecting surface is parallel to the light emitting surface;

the light reflecting piece is used for reflecting the light beams projected by the diffractive optical element, the reflected light beams formed by reflection of the light reflecting piece comprise central light beams and peripheral light beams surrounding the central light beams, and the cross section area of the central light beams corresponding to the position of the emitting assembly is matched with the profile of the emitting assembly.

In the projection module, the light emitted by the diffractive optical element is reflected by the reflector and then projected onto the object to be measured, in other words, the projection direction of the projection module is opposite to the emission direction of the diffractive optical element. Set up reflection of light spare and structure, after the light of diffraction optical element outgoing is reflected by the reflection of light spare, the central beam of projection light can be sheltered from to the transmission subassembly, thereby realize eliminating the effect of diffraction central beam, for example, the zero order facula that the structure can shelter from diffraction optical element outgoing light, thereby realize eliminating the effect of diffraction zero order facula, avoid zero order facula to influence the quality that diffraction optical element throws the pattern, and then make diffraction optical element throw the pattern and be closer with the target pattern, be favorable to promoting electronic equipment's detection precision.

In one embodiment, a cross-sectional area of the central beam corresponding to the location of the emitting assembly coincides with a profile of the emitting assembly. The structural part can just shield the central light beam, has good shielding effect and cannot influence the projection effect of the peripheral light beam.

In one embodiment, the projection module satisfies the following conditional expression:

arctan(A/4B)≤10°；

wherein, A is the diameter of the structural part, and B is the vertical distance between the light reflecting surface and the light emergent surface. The condition formula is met, the light with the emergent angle smaller than or equal to 10 degrees of the diffraction optical element can be shielded by the structural part, so that the zero-order light spot or the light near the zero-order light spot can be effectively shielded according to actual requirements, and the requirements of more scenes are met.

In one embodiment, the interior walls of the structure are provided with an extinction layer. The extinction layer can absorb the reflected light beams which reach the inner wall of the structural member, so that the reflected light beams entering the containing cavity are prevented from interfering with the projection of the light source and the diffraction optical element.

In one embodiment, the structure surrounds the periphery of the diffractive optical element and connects the diffractive optical element to secure the diffractive optical element; and/or the structure has a bottom wall surface facing the diffractive optical element, the light source being arranged on the bottom wall surface. The fixing structure of the light source and the diffraction optical element in the projection module is used as a structural member, so that the setting cost of the structural member can be saved.

In one embodiment, the light emitting device further comprises a driving member, wherein the driving member is used for driving the light reflecting member to move in a direction perpendicular to the light emitting surface, and/or the driving member is used for driving the emitting assembly to move in a direction perpendicular to the light emitting surface. The driving piece can drive the distance between the reflection piece and the emission assembly in the direction perpendicular to the light emitting surface, so that the perpendicular distance between the reflection surface and the light emitting surface can be adjusted, more different shielding requirements can be met, and the applicability of the projection module is improved.

In one embodiment, the reflector covers a projection area of the light emitted by the diffractive optical element corresponding to the position of the reflector. From this, the reflector can be with the complete reflection of diffraction optical element projection pattern to on the measured object of complete projection, promote the utilization ratio of light, also can make projection pattern and target pattern more close simultaneously.

In one embodiment, the reflector comprises a substrate and a reflective film layer disposed on a side of the substrate facing the diffractive optical element. The configuration of basement and reflection rete can play effectual reflection of light effect, and the cost of setting is low simultaneously.

A three-dimensional imaging device comprises a receiving module and a projection module according to any one of the embodiments, wherein the projection module can project light rays to a measured object, and the receiving module can receive the light rays reflected by the measured object. Adopt above-mentioned projection module in three-dimensional imaging device, the central light beam in the module projection light of throwing is sheltered from to the realization eliminates central facula, for example eliminates the effect of zero order facula, avoids zero order facula to influence the quality that diffraction optical element throws the pattern, and then makes diffraction optical element's the projection pattern and target pattern be closer, is favorable to promoting three-dimensional imaging device's detection accuracy.

An electronic device includes a housing and the projection module according to any of the above embodiments, wherein the projection module is disposed on the housing. The projection module is adopted in the electronic equipment, so that the projection effect of zero-order-free light spots can be realized.

Drawings

FIG. 1 is a schematic projection of a zero-order-free spot and a zero-order spot;

FIG. 2 is a schematic view of a projection module according to some embodiments;

FIG. 3 is a schematic view of a projection module according to further embodiments;

FIG. 4 is a schematic diagram of an electronic device in some embodiments.

100, a projection module; 105. a transmitting assembly; 110. a light source; 120. a collimating lens; 130. a diffractive optical element; 131. a light incident surface; 132. a light-emitting surface; 140. a light reflecting member; 141. a light-reflecting surface; 150. a structural member; 151. an accommodating cavity; 152. a bottom wall surface; 153. a light outlet; 160. a shield; 200. an electronic device; 210. a receiving module; 220. and (5) measuring the object.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the utility model and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the utility model.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

In combination with the background art, the size of the microstructure arranged on the existing diffractive optical element is mostly in the nanometer level, so that the generation of the processing error is difficult to avoid in the actual production, and the processing error on any position of the diffractive optical element can contribute to the central light intensity, thereby enhancing the zero-order light spot. Therefore, zero-order light spots of emergent light of the existing diffractive optical element are difficult to eliminate, so that the projection pattern is deviated from the target pattern, and the quality of the projection pattern is influenced. For example, referring to fig. 1, taking the positioning of the square as an example, the left side of fig. 1 shows the case of the zero-order spot without diffraction, and when the light emitted from the diffractive optical element does not have the zero-order spot, the projection pattern approaches the designed target pattern. The right side of fig. 1 shows the situation that there exists a diffraction zero-order spot, when there exists a zero-order spot in the light emitted from the diffractive optical element, the zero-order spot easily affects the projection pattern, so that the actual projection pattern deviates from the designed target pattern, and at the same time, the light intensity of the projection pattern is reduced, the quality of the projection pattern is reduced, and further when the diffractive optical element is applied to an electronic device, the zero-order spot easily causes the detection accuracy of the electronic device to be reduced.

In order to solve the problem, the application provides a throw the module, can realize eliminating the effect of zero order facula to make the actual projection pattern of diffractive optical element more close with the target pattern, promote the quality of projection pattern.

Referring to fig. 2, fig. 2 is a schematic view of a projection module 100 according to some embodiments. The projection module 100 can be applied to an electronic device, the projection module 100 can project a pattern to a measured object, and the electronic device obtains three-dimensional depth information of the measured object according to light reflected by the measured object.

Specifically, in some embodiments, the projection module 100 includes an emitting component 105 and a reflector 140, and the reflecting component 105 is used for projecting light to the reflector 140. Specifically, the emission assembly 105 includes a structure 150 having a receiving cavity 151 and a light outlet 153, and the light source 110 and the diffractive optical element 130 are disposed in the receiving cavity 151, and the light outlet 153 communicates the receiving cavity 151 with the outside of the structure 150. The diffractive optical element 130 is disposed on the light exit side of the light source 110 and located at the light exit 153, the light source 110 can emit light toward the diffractive optical element 130, the light emitted by the light source 110 enters the diffractive optical element 130 from the light entrance surface 131, and is diffracted to form a specific pattern and then emitted from the light exit surface 132. The light reflecting members 140 are disposed at an interval on one side of the light emitting surface 132 of the diffractive optical element 130, and the light reflecting members 140 are parallel to the light emitting surface 132 and disposed at an interval with the diffractive optical element 130. The surface of the light reflector 140 facing the diffractive optical element 130 is a light-reflecting surface 141, in other words, the light-reflecting surface 141 has a high reflection coefficient and a low transmission coefficient. The reflector 140 is used for reflecting the light beam projected by the diffractive optical element 130, and the reflected light beam formed by reflection of the reflector 140 includes a central light beam and a peripheral light beam surrounding the central light beam, and the cross-sectional area of the central light beam corresponding to the position of the emitting assembly 105 is matched with the profile of the emitting assembly 105. In other words, the structural member 150 can block the central light beam of the light reflected by the light reflecting surface 141, and the projection of the structural member 150 on the light reflecting surface 141 covers the range of the central light beam of the light reflected by the light reflecting surface 141.

It can be understood that, in the projection module 100, the light emitted from the diffractive optical element 130 is reflected by the reflector 140 and then projected onto the object 220 to be measured, in other words, the projection direction of the projection module 100 is opposite to the projection direction of the diffractive optical element 130, and when the projection module is applied to an electronic device, the object to be measured is located on a side of the light source 110 away from the reflector 140. The reflective member 140 and the structural member 150 are disposed, and when the light emitted from the diffractive optical element 130 is reflected by the reflective member 140, the structural member 150 can block the central light beam of the projected light, for example, the structural member 150 can block the zero-order light spot of the light emitted from the diffractive optical element 130. Therefore, the effect of eliminating the diffraction zero-order light spot is achieved, the influence of the zero-order light spot on the quality of the projection pattern of the diffraction optical element 130 is avoided, the projection pattern of the diffraction optical element 130 is closer to the target pattern, and the detection precision of the electronic equipment is favorably improved.

It should be noted that the angle range of the central light beam of the light reflected by the light reflecting surface 141 is not limited, and may be specifically selected according to the actual light beam range shielded by the structural component 150. For example, in some embodiments, the spot of the central light beam blocked by the structural component 150 is a diffracted zero-order spot formed by the diffractive optical element 130, and of course, when there is no pattern to be projected in the light beam near the zero-order spot, the spot range of the central light beam may be larger than the range of the diffracted zero-order spot, and then the structural component 150 may also block the light beam around the diffracted zero-order spot. More specifically, in some embodiments, the structure 150 is capable of blocking the beam projected by the diffractive optical element 130 at an angle less than or equal to 10 °, i.e., the angle θ shown in FIG. 2 is less than or equal to 10 °. For example, when the structural member 150 can block the light beam projected by the diffractive optical element 130 at an angle of 5 °, it can be understood that in the light beam emitted by the diffractive optical element 130, the light beam having an angle less than or equal to 5 ° with the central light beam is blocked by the structural member 150 after being reflected by the light-reflecting surface 141. The light with the projection angle within 5 ° may be the diffracted zero-order light beam, and may also include the diffracted zero-order light beam and the light beam around the diffracted zero-order light beam.

Further, in some embodiments, the cross-sectional area of the central light beam corresponding to the emitting component 105 coincides with the profile of the emitting component 105, and the central light beam is the diffracted zero-order light beam projected by the diffractive optical element 130, so that the emitting component 105 can just block the diffracted zero-order light beam, and the effect of no zero-order light spot is achieved. In some embodiments, the contour of the emitter assembly 105 may be understood as the outer contour of the structure 150.

In addition, the type of the light emitted by the light source 110 may be selected according to the detection requirement of the electronic device, for example, in some embodiments, the light emitted by the light source 110 is a near infrared band light. In some embodiments, the light source 110 is a Vertical-Cavity Surface-Emitting Laser (VCSEL). In some embodiments, the projection module 100 is further provided with a collimating lens 120, the collimating lens 120 is disposed between the light source 110 and the diffractive optical element 130, and the collimating lens 120 can collimate the light beam emitted from the light source 110, so as to improve the parallelism of the light beam, and thus improve the quality of the projection pattern of the diffractive optical element 130. The diffractive optical element 130 may be provided with an array of microstructures, and the microstructures on the diffractive optical element 130 are designed to enable the diffractive optical element 130 to diffract the light emitted from the light source 110 to form different projection patterns, so as to meet the detection requirement of the electronic device.

In some embodiments, the reflector 140 is a flat mirror, and after the light projected by the diffractive optical element 130 is reflected on the reflecting surface 141, the central light beam is blocked by the structural component 150, and the other light beams are projected on the object to be measured on the side of the light source 110 away from the reflector 140 to form the projection pattern. Of course, the light reflecting member 140 may be disposed in other ways, for example, a reflective film layer is disposed on the surface of any suitable substrate, such as plastic, metal, glass, etc., facing the diffractive optical element 130 to form the light reflecting member 140, as long as the light projected by the diffractive optical element 130 can be reflected on the light reflecting surface 141 in a planar manner. In some more specific embodiments, the reflector 140 is formed by depositing a metal coating on a glass substrate.

In some embodiments, the reflector 140 covers a projection area of the light emitted from the diffractive optical element 130 corresponding to the position of the reflector 140, in other words, the light emitted from the diffractive optical element 130 is projected onto the light-reflecting surface 141. Therefore, the reflector 140 can completely reflect the projection pattern of the diffractive optical element 130, so that a complete pattern is formed on the object 220 to be measured by projection, the utilization rate of light is improved, and the projection pattern can be closer to the target pattern.

The specific arrangement of the structural member 150 is not limited as long as the central light beam reflected by the reflecting surface 141 can be shielded. In some embodiments, the structural member 150 is disposed on a side of the diffractive optical element 130 facing away from the light reflector 140. Of course, the structure 150 may also connect the peripheral edges of the diffractive optical element 130. Further, in some embodiments, the orthographic projection of the structure 150 on the light incident surface 131 of the diffractive optical element 130 covers the light incident surface 131 of the diffractive optical element 130. Therefore, the structural member 150 can better shield the central light beam of the light reflected by the reflecting surface 141, and the elimination effect of the structural member 150 on zero-level light spots is improved. It is understood that the central light beam of the light reflected by the reflective surface 141 may be understood as a light beam formed by the light beam in the θ range projected by the diffractive optical element 130 shown in fig. 2 and reflected by the reflective surface 141.

Further, in some embodiments, the structural component 150 also plays a role of fixing and protecting the light source 110 and the diffractive optical element 130, in other words, the structural component 150 of the projection module 100 itself is used to achieve the effect of eliminating the zero-order light spot. Specifically, the structure 150 has a receiving cavity 151, and the diffractive optical element 130 and the light source 110 are received in the receiving cavity 151. The light source 110 is fixed to the bottom wall 152 of the structural member 150, and the structural member 150 surrounds the periphery of the diffractive optical element 130 and is connected to the diffractive optical element 130. Therefore, the utilization rate of the structure of the projection module 100 can be improved, and the installation cost of the structure 150 can be reduced. Of course, the structural component 150 may also be another structure disposed on a side of the diffractive optical element 130 away from the reflective component 140, as long as the structural component 150 can block the central light beam reflected by the reflective surface 141, and does not affect the light emitted from the light source 110 to the diffractive optical element 130.

The material of the structural member 150 may be any suitable light-shielding material such as metal, plastic, etc.

In some embodiments, the light-reflecting surface 141 is parallel to the light-emitting surface 132, and the projection module 100 satisfies the following conditional expression: the arctan (A/4B) is less than or equal to 10 degrees; wherein, a is a radial dimension of the structural component 150 in the diffractive optical element 130, when the cross section of the diffractive optical element 130 is overall circular, the radial dimension of the diffractive optical element 130 is a diameter of the cross section of the diffractive optical element 130, and B is a vertical distance between the light reflecting surface 141 and the light emitting surface 132. It can be understood that arctan (a/4B) ═ θ, and from the above conditional expression, the projection angle range of the central light beam blocked by the structural member 150 can be adjusted by adjusting the size a and the size B, so as to meet the blocking requirements at more different angles.

In some embodiments, the inner wall of the structure 150 is provided with a light extinction layer (not shown), and in particular, the light extinction layer may be made of a light absorption material disposed on the inner wall of the structure 150, wherein the inner wall of the structure 150 may be understood as the surface of the structure 150 and the bottom wall 152 enclosing the receiving cavity 151. It is understood that the central beam of the light reflected by the reflector 140 is blocked by the emitting assembly, and a portion of the central beam enters the receiving cavity 151 and is reflected by the inner wall of the structure 150. Therefore, the extinction layer is disposed on the inner wall of the structure 150, and can absorb the central light beam entering the accommodating cavity 151, so as to avoid interference of the central light beam entering the accommodating cavity 151 on the light emitted from the light source 110 to the diffractive optical element 130. Of course, in some embodiments, the outer wall of the structure 150 may also be provided with a light extinction layer, so as to further absorb the central light beam striking the outer wall of the structure 150 and prevent the central light beam from interfering with the operation of the projection module 100.

In some embodiments, the projection module 100 further includes a driving element (not shown), which may be a driving motor or a motor, an output end of the driving element is connected to the reflective element 140 to drive the reflective element 140 to move toward a direction close to or away from the emission assembly 105 in a direction perpendicular to the reflective surface 141, so as to increase or decrease a distance between the reflective surface 141 and the light exit surface 132, thereby changing a shielding range of the emission assembly 105 for the reflected light, meeting shielding requirements of different angle ranges, and improving applicability of the projection module 100. Of course, in other embodiments, the output end of the driving member may be connected to the emitting assembly 105, such as the structure 150, to drive the emitting assembly 105 to move toward or away from the reflector 140 in a direction perpendicular to the reflective surface 141. In still other embodiments, the output end of the driving member may simultaneously connect the reflector 140 and the emitting element 105 to drive the reflector 140 and the emitting element 105 to move toward or away from each other in a direction perpendicular to the reflecting surface 141.

Referring to fig. 3, fig. 3 is a schematic view of the projection module 100 in other embodiments. In the embodiment shown in fig. 3, the arrangement of the light source 110, the collimating lens 120 and the diffractive optical element 130 may be the same as the embodiment shown in fig. 2, except that fig. 3 is provided with a shutter 160 instead of the reflector 140. The shielding element 160 is disposed on the light exit surface 132 side of the diffractive optical element 130, and corresponds to the position of the central light beam emitted from the diffractive optical element 130, in other words, the shielding element 160 is disposed on the propagation path of the central light beam of the diffractive optical element 130, and the shielding element 160 can shield the central light beam of the light emitted from the diffractive optical element 130, in other words, the projection of the shielding element 160 on the light exit surface 132 covers the central light beam range of the light exit surface 132.

It can be understood that, in the embodiment shown in fig. 2, the central light beam of the light projected by the diffractive optical element 130 needs to be reflected by the reflective surface 141 before being blocked by the structural component 150, and thus the projection direction of the projection module 100 is opposite to the projection direction of the diffractive optical element 130. In the embodiment shown in fig. 3, the central beam of the light projected by the diffractive optical element 130 directly strikes the shielding member 160 and is shielded by the shielding member 160, and the remaining beams are projected onto the object 220 to be measured, so that the projection direction of the projection module 100 is the same as the projection direction of the diffractive optical element 130.

Above-mentioned projection module 100, set up the shielding piece 160 corresponding with the central light beam on one side of the exit surface 132 of diffractive optical element 130, shielding piece 160 can shelter from the central light beam of diffractive optical element 130 outgoing light, can shelter from the zero order facula of diffractive optical element 130 outgoing light promptly, thereby realize eliminating the effect of diffraction zero order facula, avoid zero order facula to influence the quality that diffractive optical element 130 throws the pattern, and then make diffractive optical element 130 throw the pattern and be closer with the target pattern, be favorable to promoting electronic equipment's detection precision.

Similarly, the angle range of the central light beam blocked by the blocking member 160 is not limited, and may be less than or equal to 10 °. In some embodiments, the projection of the shielding member 160 on the light emitting surface 132 is a circle, and the shape of the circle is more suitable for the shape of a general diffraction zero-order spot, so that the zero-order spot can be shielded more effectively.

In addition, in the embodiments shown in fig. 2 and 3, the two beams are illustrated with different dashed arrows for ease of understanding the central beam from the other beams. Here, the beam E may be understood as a central beam having the largest projection angle, and the beam F may be understood as other beams having a larger projection angle than the beam E. In the embodiment shown in fig. 2, the central beam E of the light projected by the diffractive optical element 130 is reflected by the reflective surface 141 and then blocked by the structural member 150, and the beam F is reflected by the reflective surface 141 and projected toward the object to be measured to form the projection pattern. In the embodiment shown in fig. 3, the central beam E of the light projected by the diffractive optical element 130 is blocked by the blocking member 160, and the other beams F having a larger projection angle than the central beam E are projected toward the object 220 to form a projection pattern.

In some embodiments, the shielding member 160 is made of any suitable opaque material such as plastic or metal, i.e., the shielding member 160 has a low transmittance, so as to prevent the diffracted zero-order light spot or light near the zero-order light spot from transmitting through the shielding member 160. Furthermore, in some embodiments, a light absorption layer (not shown) is disposed on a surface of the shielding element 160 facing the diffractive optical element 130, and the light absorption layer has a low reflection coefficient, so that when the shielding element 160 shields the central light beam of the light emitted from the diffractive optical element 130, the central light beam can be absorbed to a greater extent, and the influence of the reflection of the central light beam on the projection pattern of the projection module 100 is reduced. In particular, any suitable black light absorbing material may be used for the light absorbing layer.

In some embodiments, the shielding member 160 is parallel to the light emitting surface 132, and the projection module 100 satisfies the following conditional expression: the arctan (C/2D) is less than or equal to 10 degrees; where C is the diameter of the shutter 160 and D is the perpendicular distance between the shutter 160 and the diffractive optical element 130. It can be understood that arctan (C/2D) ═ θ, and as can be seen from the above conditional expressions, by adjusting the size C and the size D, the projection angle range of the central light beam blocked by the blocking piece 160 can also be adjusted, thereby satisfying the blocking requirements at more different angles.

It should be noted that in the embodiment shown in fig. 2, the structural component 150 is used for blocking the central light beam of the light reflected by the reflective component 140, so as to achieve the effect of indirectly blocking the central light beam of the light projected by the diffractive optical element 130, and therefore the object 220 to be measured is located on the side of the diffractive optical element 130 away from the reflective component 140. In the embodiment shown in FIG. 3, the shielding member 160 directly shields the central beam of the light projected by the diffractive optical element 130, so that the object 220 to be measured is located on the side of the shielding member 160 facing away from the diffractive optical element 130. It can be seen that the angle θ shown in fig. 2 and fig. 3 is calculated differently, and in the embodiment shown in fig. 2, the light rays within the angle θ of the light rays projected by the diffractive optical element 130 are blocked by the structural member 150, and θ is arctan (a/4B). In the embodiment shown in fig. 3, the light rays within the θ angle range of the light rays projected by the diffractive optical element 130 are blocked by the blocking member 160, and the calculation of the θ angle is less by one reflection path compared with the embodiment shown in fig. 2, so θ equals arctan (C/2D). From the two relations, when the angle ranges of the light rays to be blocked in the light rays projected by the diffractive optical element 130 are consistent, C is twice B. In other words, when the diffraction zero-order spot range to be blocked is not changed, the vertical distance between the blocking element 160 and the light-emitting surface 132 shown in fig. 3 is greater than the vertical distance between the light-reflecting element 140 and the light-emitting surface 132 shown in fig. 2. Therefore, the embodiment shown in fig. 2 is advantageous for reducing the axial dimension of the projection module 100 while achieving the effect of shielding the diffracted zero-order light spot, thereby facilitating the miniaturization design of the electronic device.

In addition, in the embodiment shown in fig. 2, the light reflecting member 140 is disposed to reflect the light, so that the path of the light projected by the diffractive optical element 130 and the path of the light reflected by the light reflecting member 140 are partially overlapped, thereby being beneficial to shortening the dimension of the projection module 100 in the direction perpendicular to the light reflecting surface 141, further being beneficial to the miniaturization design of the projection module 100, and making the projection module 100 more suitable for the electronic device with the miniaturization design.

Furthermore, since the reflector 140 covers the projection area of the light beam emitted from the diffractive optical element 130 in the embodiment shown in fig. 2, and the shielding element 160 only needs to cover the projection area of the central light beam in the light beam emitted from the diffractive optical element 130 in the embodiment shown in fig. 3, the embodiment shown in fig. 3 is advantageous for reducing the diameter of the projection module 100.

Referring to fig. 2 and 4, fig. 4 is a schematic diagram of an electronic device 200 according to some embodiments. The type of the electronic device 200 is not limited, and includes but is not limited to a smart phone, a tablet computer, an e-reader, and the like having a three-dimensional detection function, and the electronic device 200 may be based on a TOF technology or a structured light technology, that is, the electronic device 200 may be a three-dimensional imaging apparatus. The electronic device 200 includes a receiving module 210 and the projecting module 100 according to any of the above embodiments, the projecting module 100 can project light to the object 220 to be measured, the receiving module 210 is configured with an image sensor, and the receiving module 210 can receive the light reflected from the object 220 to be measured, so as to obtain three-dimensional depth information of the object 220 to be measured. For example, the receiving module 210 can obtain three-dimensional depth information of the object to be measured 220 according to the projection pattern of the projection module 100 and the pattern reflected from the object to be measured 220. Of course, in other embodiments, the electronic apparatus 200 may not include the receiving module 210, and in this case, the electronic apparatus 200 may be a projecting device for projecting a pattern.

It should be noted that, in the embodiment shown in fig. 4, the electronic device 200 adopts the projection module 100 in the embodiment shown in fig. 2, and the projection direction of the diffractive optical element 130 is opposite to the projection direction of the projection module 100 toward the object 220 to be measured. In other embodiments, the electronic device 200 employs the projection module 100 in the embodiment shown in fig. 3, and the projection direction of the diffractive optical element 130 is the same as the projection direction of the projection module 100 toward the object 220 to be measured.

Adopt above-mentioned projection module 100 in electronic equipment 200, the central beam in the module 100 projection light of throwing is sheltered from to realize eliminating the effect of zero order facula, avoid zero order facula to influence the quality that diffraction optical element 130 throws the pattern, and then make diffraction optical element 130's the projection pattern and the target pattern be closer, be favorable to promoting electronic equipment 200's detection precision.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A projection module, comprising: an emitting assembly and a reflector;

the transmitting assembly comprises a structural part with an accommodating cavity and a light outlet, and a light source and a diffractive optical element which are arranged in the accommodating cavity, wherein the diffractive optical element is arranged on the light outlet side of the light source and is positioned at the light outlet;

the light reflecting pieces are arranged on one side of the light emitting surface of the diffractive optical element at intervals, the surface of the light reflecting piece facing the diffractive optical element is a light reflecting surface, and the light reflecting surface is parallel to the light emitting surface;

the light reflecting piece is used for reflecting the light beams projected by the diffractive optical element, the reflected light beams formed by reflection of the light reflecting piece comprise central light beams and peripheral light beams surrounding the central light beams, and the cross section area of the central light beams corresponding to the position of the emitting assembly is matched with the profile of the emitting assembly.

2. The projection module of claim 1 wherein the cross-sectional area of the central beam corresponding to the location of the emitter assembly coincides with the profile of the emitter assembly.

3. The projection module of claim 1, wherein the projection module satisfies the following conditional expression:

arctan(A/4B)≤10°；

wherein, A is the diameter of the structural part, and B is the vertical distance between the light reflecting surface and the light emergent surface.

4. The projection module of claim 1 wherein the interior wall of the structure is provided with an anti-glare layer.

5. The projection module of claim 4 wherein the structure surrounds a perimeter of the diffractive optical element and connects the diffractive optical element to secure the diffractive optical element; and/or

The structure member has a bottom wall surface facing the diffractive optical element, and the light source is disposed on the bottom wall surface.

6. The projection module of claim 1, further comprising a driving member for driving the light reflecting member to move in a direction perpendicular to the light exit surface, and/or a driving member for driving the emission assembly to move in a direction perpendicular to the light exit surface.

7. The projection module of claim 1 wherein the reflector covers a projection area of the diffractive optical element where the light rays exit the reflector.

8. The projection module of claim 1 wherein the reflector comprises a substrate and a reflective film layer disposed on a side of the substrate facing the diffractive optical element.

9. A three-dimensional imaging device, comprising a receiving module and a projecting module according to any one of claims 1 to 8, wherein the projecting module is capable of projecting light toward an object to be measured, and the receiving module is capable of receiving light reflected from the object to be measured.

10. An electronic device, comprising a housing and the projection module according to any one of claims 1-8, wherein the projection module is disposed on the housing.

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