TW201940929A - Light source module, sensing device and method for generating superposition structured patterns - Google Patents

Abstract

A light source module adapted to provide a superposition structured pattern is provided. The light source module includes a light emitting element, a light guide element, a first diffraction element and a second diffraction element. The light guide element includes a polarizing beam splitter to separate into a first light beam and a second light beam. The first and the second diffraction elements are adapted to convert into a first and a second structured light, wherein polarization types of the first and the second light beam are different. The first and the second structured light are projected onto a projection region to overlap and are imaged as a superposition structured pattern. The projection region has a plurality of sub-projection regions arranged in an array and adjacent to each other, and the pattern distribution of the superposition structured pattern in each sub-projection region is different from each other.

Description

Light source module, sensing device and method for generating superimposed structure pattern

The invention relates to an optical device and a method for generating structured light, and more particularly, to a light source module, a sensing device, and a method for generating a superimposed structure pattern.

In the current 3D sensing technology, 3D measurement is mainly divided into a triangulation method and a time delay method. At present, there are three major stereo sensing technologies such as Stereo Vision, Structured Light and Time of Flight (ToF), which have advantages in price, volume and efficiency.

Among them, the structured light technology of the three major three-dimensional sensing technologies is to project a structured light pattern onto an object to be measured, and then use an image capture device such as a camera to capture image information and measure the distance to obtain the target light. The stereo information of the measured object. Therefore, how to design a practical and high-resolution structured light is a joint effort of those skilled in the art.

The invention provides a light source module, a sensing device and a method for generating a superimposed structure pattern, which can provide structured light, and the structured light has different pattern distributions at different projection positions.

The invention provides a light source module, which is suitable for providing a superimposed structure pattern. The light source module includes a light emitting device, a light guiding element, a first diffractive element and a second diffractive element. The light emitting device is adapted to provide a light beam. The light guide element is disposed on a transmission path of the light beam. The light guiding element includes a polarizing beam splitting element to distinguish the light beam into a first light beam and a second light beam. The first diffractive element is disposed on a transmission path of the first light beam to convert the first light beam into a first structured light. The second diffractive element is disposed on the transmission path of the second light beam to convert the second light beam into a second structured light, wherein the polarization patterns of the first light beam and the second light beam are different. The first structured light and the second structured light are projected in a projection area to overlap and be imaged as a superimposed structure pattern. The projection area has a plurality of sub-projection areas arranged in an array and adjacent to each other, and the pattern distribution of the superimposed structure pattern in each sub-projection area is different from each other.

In an embodiment of the present invention, the first structured light and the second structured light are respectively imaged into a first structure pattern and a second structure pattern in the projection area, and the first structure pattern and the second structure pattern include an arrangement. Dot pattern with different periods.

In an embodiment of the present invention, the overlap ratio between the first projection area defined by the projection boundary of the first structured light and the second projection area defined by the projection boundary of the second structured light in the projection area is greater than 80%.

In an embodiment of the present invention, the divergence angle of the first structured light and the divergence angle of the second structured light are different.

In an embodiment of the present invention, the light guiding element further includes a reflecting member on a transmission path of the second light beam to reflect the second light beam to the second diffractive element.

In an embodiment of the present invention, the light source module further includes at least one birefringent element disposed on a transmission path of the light beam between the light emitting device and the light guide element.

In an embodiment of the present invention, the at least one birefringent element includes a first birefringent element and a second birefringent element, and an optical axis direction of the first birefringent element and an optical axis direction of the second birefringent element different.

In an embodiment of the present invention, the light guiding element further includes a first reflecting member and a second reflecting member. The polarizing beam splitting element is located between the first reflector and the second reflector. The first reflector is located on the transmission path of the light beam to reflect the light beam to the polarizing beam splitting element, and the second reflector is located on the transmission path of the second light beam to reflect the second light beam to the second diffractive element.

In an embodiment of the present invention, the second diffraction element is disposed on the light guide element.

In an embodiment of the present invention, the first diffractive element is a transmissive diffractive element, and the second diffractive element is a reflective diffractive element or a transmissive diffractive element.

In an embodiment of the present invention, the first diffractive element is an active diffractive element or a passive diffractive element, and the second diffractive element is an active diffractive element or a passive diffractive element.

In an embodiment of the present invention, the first diffraction element and the second diffraction element include a display device that provides a fixed dot array pattern or a variable dot array pattern.

In an embodiment of the present invention, the light source module further includes a first light beam adjusting element and a second light beam adjusting element. The first light beam adjusting element is disposed on a transmission path of the first light beam and is located between the first diffractive element and the light guiding element. The second light beam adjusting element is disposed on the transmission path of the second light beam and is located between the second diffractive element and the light guiding element.

The invention further provides a sensing device, which includes the light source module and an image capturing element. The image capturing component is used to capture an image of the projection area.

In an embodiment of the present invention, the image capturing element includes a pixel array, and the pixel array includes a plurality of first pixels and a plurality of second pixels. The first pixels are interleaved with the second pixels. And the polarization patterns of the light received by the first pixel and the second pixel are different.

In an embodiment of the present invention, the image capturing element includes a pixel array, and the pixel array includes a plurality of first pixels, a plurality of second pixels, and a plurality of third pixels. The odd rows of the pixel array (add rows) are formed by staggering part of the first pixels and part of the third pixels. The even rows of the pixel array are formed by staggering some second pixels and some third pixels. The add columns of the pixel array are formed by staggering part of the first pixels and part of the third pixels. The even columns of the pixel array are formed by staggering some second pixels and some third pixels, and the first, second, and third pixels can receive light with different polarization types. .

The invention further provides a method for generating a superimposed structure pattern, comprising the steps of providing a light beam to a light guide element, and using the light guide element to generate a first structured light and a second structured light of different polarization types. A step and a step of projecting the first structured light and the second structured light onto a projection area to overlap and image into a superimposed structure pattern, wherein the projection area has a plurality of sub-projection areas arranged in an array and adjacent to each other, and the superimposed structure pattern is The pattern distribution of each sub-projection area is different from each other.

In an embodiment of the present invention, the first structured light and the second structured light are respectively imaged into a first structure pattern and a second structure pattern in the projection area, and the first structure pattern and the second structure pattern include an arrangement. Dot pattern with different periods.

In an embodiment of the present invention, the overlap ratio between the first projection area defined by the projection boundary of the first structured light and the second projection area defined by the projection boundary of the second structured light in the projection area is greater than 80%.

In an embodiment of the present invention, the divergence angle of the first structured light and the divergence angle of the second structured light are different.

Based on the above, in the light source module, the sensing device, and the method for generating a superimposed structure pattern of the present invention, the light source module provides a light beam to the light guide element through the light emitting device, and generates different polarization types by the light guide element A first structured light and a second structured light of the state are projected in a projection area to generate an overlap and be imaged as a superimposed structure pattern. In this way, the depth information of the irradiated object can be identified by the difference in the pattern distribution in each sub-projection area and its variation.

In order to make the above features and advantages of the present invention more comprehensible, embodiments are hereinafter described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a sensing device according to an embodiment of the present invention. Please refer to FIG. 1. In this embodiment, the sensing device 50 includes a light source module 100 and an image capturing element 200, and the light source module 100 is electrically connected to the image capturing element 200. The sensing device 50 is suitable for stereoscopically sensing a target object 10, so as to identify appearance characteristics or depth information of the target object 10. The target object 10 is, for example, a street view object or a human face, and the present invention is not limited thereto.

During stereo sensing, the sensing device 50 emits a superimposed structured light LC to the target object 10 through the light source module 100, so that the superimposed structure pattern SP formed according to different depth positions of the target object 10 changes the pattern distribution. After projecting the superimposed structured light LC, the sensing device 50 performs image capture on the target object 10 through the image capturing element 200 to identify the depth value corresponding to the projection position on the target object 10 by capturing the superimposed structure pattern SP. , And then obtain the three-dimensional information of the target object 10.

FIG. 2 is a schematic diagram of a light source module according to an embodiment of the present invention. Please refer to FIGS. 1 and 2. In detail, in this embodiment, the light source module 100 includes a light emitting device 110, a light guiding element 120, a first diffractive element 130 and a second diffractive element 140. . The light emitting device 110 is adapted to provide a light beam L to the light guiding element 120. In other words, the light guide element 120 is disposed on the transmission path of the light beam L. The light-emitting device 110 is, for example, a plurality of semiconductor lasers or a plurality of light-emitting diodes arranged in an array. The semiconductor laser is, for example, a vertical-cavity surface-emitting laser (VCSEL) or a photon. Photonic crystal laser. In this embodiment, the light emitting device 110 is described using a vertical cavity surface-emission laser, but the present invention is not limited thereto. In this embodiment, a collimating lens group 105 is disposed on the light emitting device 110 to collimate the light beam L into the light guiding element 120, but the present invention is not limited thereto.

FIG. 3 is a schematic diagram of the light emitting device of FIG. 2. Please refer to FIG. 2 and FIG. 3. Specifically, in this embodiment, the light-emitting device 110 includes a light-emitting element 112, a driving circuit 114, a control substrate 116, and a thermally conductive substrate 118. The light emitting element 112 is configured to emit light toward the light guiding element 120. The light emitting element 112 can be manufactured by combining or integrating the array arrangement of the plurality of light emitting units 112_1. That is, in this embodiment, the light emitting element 112 is, for example, a vertical cavity surface emitting laser array, and the light emitting unit 112_1 is, for example, a single vertical cavity surface emitting laser, and each vertical cavity surface emitting type The laser corresponds to a light-emitting end O.

The control substrate 116 is disposed on a side of the light-emitting element 112 adjacent to the light-emitting terminal O, and is used to control the light-emitting of the light-emitting element 112 by a circuit. The control substrate 116 is, for example, a silicon substrate. The heat conductive substrate 118 is disposed on the other side of the light emitting element 112 opposite to the light output end O, and is used to guide the heat generated by the light emitting element 112 to the outside. In addition, an optical design can be integrated on the other side of the control substrate 116 opposite to the light-emitting element 112, and optical structures such as lenses, microstructures, gratings, optical waveguides, or photonic crystals can be fabricated using infrared light penetrability for modulation. Light emitting characteristics of the light emitting element 112. For example, in the present embodiment, a plurality of focusing structures 116_1 are formed on the other side of the control substrate 116 opposite to the light emitting element 112 to focus light emitted by the light emitting element 112. In other words, in this embodiment, the collimating lens group 105 in the above description is directly formed by the control substrate 116, and in some embodiments, the collimating lens group 105 may be an additional configured optical structure or optical element The present invention is not limited to this.

The driving circuit 114 is disposed between the light-emitting element 112 and the control substrate 116, and is used for electrically connecting the light-emitting element 112 and the control substrate 116, and the light output of each light-emitting unit 112_1 can be further controlled by a control signal provided from the outside. Specifically, the driving circuit 114 is formed by, for example, an array control line 114_1 and a plurality of connection pads 114_2 being connected, but the present invention is not limited thereto. It can be known from the above-mentioned configuration manner that, in this embodiment, the driving circuit 114 can be formed on the side of the light emitting element 112 having the light output end O without affecting the light emitting effect of the light emitting element 112. Therefore, in this embodiment, the light output of different light-emitting units 112_1 in the light-emitting device 110 can be further controlled by a circuit, thereby achieving the effect of point control or area control.

FIG. 4 is a schematic diagram of a light emitting device according to another embodiment of the present invention. Please refer to Figure 4. The light-emitting device 110A of this embodiment is similar to the light-emitting device 110 of FIG. 3 except that in this embodiment, a plurality of grating structures 116_2 are formed on the other side of the control substrate 116A opposite to the light-emitting element 112. In order to further regulate the light emitting characteristics of the light emitting element 112. In this way, each light-emitting unit 112_1 in the light-emitting element 112 can have a different light-emitting effect. In some embodiments, the focusing structure 116_1 (see FIG. 3) and the grating structure 116_2 may be formed at the same time, and the present invention is not limited thereto.

FIG. 5 is a schematic diagram of a light emitting device according to another embodiment of the present invention. Please refer to Figure 5. The light-emitting device 110B of this embodiment is similar to the light-emitting device 110A of FIG. 4 except that in this embodiment, the control substrate 116B further includes a plurality of light-guiding structures 116_3, which are located inside the body of the control substrate 116B. It is used to distribute a part of the light emitted by the light emitting element 112A to the adjacent grating structure 116_2 or the focusing structure 116_1 (see FIG. 3). In this embodiment, the light guide structure 116_3 is, for example, a silicon light guide or a photonic crystal, and the present invention is not limited thereto. In this way, the density of the plurality of light-emitting units 112_1 in the light-emitting element 112A can be further reduced, thereby saving costs.

The light guiding element 120 includes a polarization beam splitting element 122 to distinguish the light beam L into a first light beam L1 and a second light beam L2, and the polarization patterns of the first light beam L1 and the second light beam L2 are different. Specifically, the light beam L provided by the light emitting device 110 is unpolarized light or linearly polarized light having an oblique relationship with the incident surface. When the light beam L is transmitted to the polarization beam splitting element 122, the light beam L is divided into polarized light having a specific direction. The first light beam L1 and the second light beam L2 are polarized, and the polarization direction of the first light beam L1 and the polarization direction of the second light beam L2 are perpendicular to each other. One of the first light beam L1 and the second light beam L2 passes through the polarization beam splitting element 122 and the other one is reflected by the polarization beam splitting element 122. In this embodiment, the first light beam L1 passes through the polarization beam splitting element 122 and the second light beam L2 is reflected by the polarization beam splitting element 122. Therefore, the light source module 100 can form two light beams with different polarization types by the light guide element 120, as shown in the polarization direction shown in FIG. 2. The included angle between the extension direction of the polarizing beam splitting element 122 and the transmission direction of the light beam L is 45 degrees, but in other embodiments, other angles may be used, and the present invention is not limited thereto.

In this embodiment, the light guiding element 120 further includes a reflector 124 disposed on the transmission path of the second light beam L2 to reflect the second light beam L2. Specifically, when the polarizing beam splitting element 122 forms the first light beam L1 and the second beam L2, the first light beam L1 passes through the polarizing beam splitting element 122 and is emitted from the light exit side of the light guide element 120. The second light beam L2 is reflected by the polarizing beam splitting element 122 and transmitted to the reflecting member 124, and then is reflected by the reflecting member 124 and is emitted from the light exit side of the light guide element 120. The polarizing beam splitting element 122 and the reflector 124 are respectively formed in the light guide element 120 by a coating method, or the coating element is combined on a light transmitting element, for example, the present invention is not limited thereto.

FIG. 6A is a schematic diagram of a pattern distribution of a first structured light according to an embodiment of the present invention. FIG. 6B is a schematic diagram of a pattern distribution of a second structured light according to an embodiment of the present invention. FIG. 6C is a schematic diagram in which the first structured light of FIG. 6A and the second structured light of FIG. 6B overlap and are imaged as a superimposed structure pattern in a projection area. Please refer to FIG. 2 and FIGS. 6A to 6C simultaneously. The first diffractive element 130 and the second diffractive element 140 are respectively disposed on a transmission path of the first light beam L1 and a transmission path of the second light beam L2. The first diffractive element 130 is used to convert the first light beam L1 into a first structured light LC1, and the second diffractive element 140 is used to convert the second light beam L2 into a second structured light LC2. The first structured light LC1 and the second structured light LC2 are projected toward the target object 10 in the same transmission direction, and are projected in a projection area to overlap and be imaged as a superimposed structure pattern SP, as shown in FIG. 6C, where the projection area may be It is regarded as having a plurality of sub-projection areas AP arranged in an array and adjacent to each other.

In detail, the first diffraction element 130 and the second diffraction element 140 may be an active diffraction element or a passive diffraction element. The active diffraction element is, for example, a liquid crystal array device (Liquid Crystal Array Device), a space Optical modulator (Spatial Light Modulator, SLM) or Liquid Crystal on Silicon (LCOS), passive diffractive elements are, for example, diffractive optical elements (DOE) with different patterns or different optical structures Or raster. The first diffractive element 130 and the second diffractive element 140 use active diffractive elements, which can make the pattern distribution of the first structured light LC1 and the second structured light LC2 through the first diffractive element 130 and the second diffractive element. Element 140 is further adjusted.

The projection area is, for example, a surface of the target object 10 facing the sensing device 50. Therefore, the patterns of the first structured light LC1 and the second structured light LC2 projected on the projection area APG are different from each other. Specifically, the first structured light LC1 and the second structured light LC2 are respectively imaged into a first structure pattern SP1 and a second structure pattern SP2 in the projection area APG, and the first structure pattern SP1 and the second structure pattern SP2 include an arrangement The dot array patterns with different periods are shown in FIGS. 6A and 6B. In this embodiment, the arrangement manner and the light spot size of the first structure pattern SP1 and the second structure pattern SP2 are different, but the present invention is not limited thereto. In other embodiments, the second diffractive element 140 may be an active diffractive element, so that the pattern distribution of the second structured light LC2 can be further adjusted by the second diffractive element 140, and the present invention is not limited thereto.

Therefore, the pattern distribution of the superimposed structure pattern SP in each sub-projection area AP is made different from each other. In other words, the pattern distribution in each sub-projection area AP is unique. In this way, the change in the depth of the target object 10 corresponding to the position of the sub-projection area AP can be identified by the variation amount of the pattern distribution in each sub-projection area AP, and then the depth information of each part of the target object 10 can be obtained. In this embodiment, the overlap ratio of the first projection area defined by the projection boundary of the first structured light LC1 and the second projection area defined by the projection boundary of the second structured light LC2 in the projection area is greater than 80. %, But the invention is not limited to this.

It is worth mentioning that because the first structured light LC1 and the second structured light LC2 have different polarization directions, the refraction and reflectance of the transparent material are different. In other words, the target object 10 can be a light-transmitting material, and the sensing device 50 can further detect it by the first structured light LC1 and the second structured light LC2 with different polarization types. In some embodiments, additional processors can be used to perform back-end operations to help determine the appearance characteristics of the transparent material.

FIG. 7 is a schematic diagram of a partial superimposed structure pattern of the first structured light and the second structured light at different distances from projection regions according to an embodiment of the present invention. Please refer to FIG. 1, FIG. 2 and FIG. 7 at the same time. In this embodiment, the light source module 100 further includes a first light beam adjusting element 150_1 and a second light beam adjusting element 150_2, which are respectively disposed on the transmission path of the first light beam L1. And on the transmission path of the second light beam L2. The first light beam adjusting element 150_1 and the second light beam adjusting element 150_2 are, for example, a single optical lens or a divergent lens group. The first light beam adjustment element 150_1 is located between the first diffraction element 130 and the light guide element 120, and the second light beam adjustment element 150_2 is located between the second diffraction element 140 and the light guide element 120. Therefore, the first light beam L1 and the second light beam L2 can be uniformly irradiated to the first diffraction element 130 and the second diffraction element 140, respectively. However, in some embodiments, the light source module 100 may use only a single beam adjustment element, and the present invention is not limited thereto.

It is worth mentioning that in this embodiment, the first structured light LC1 and the second structured light LC2 can be projected toward the target object 10 at different divergence angles, that is, the divergence angle of the first structured light LC1 and the second structured light LC2 are different. The divergence angle is different. In other words, if the divergence angle of the first beam adjustment element 150_1 is different from the divergence angle of the second beam adjustment element 150_2, or the divergence angles designed by the first diffraction element 130 and the second diffraction element 140 are different, then The projection divergence angles of the first structured light LC1 and the second structured light LC2 toward the projection area are different, so that the pattern spacing or superimposition degree of the first structure pattern SP1 and the second structure pattern SP1 changes with different positions in the projection direction A. As shown in FIG. 7. In this way, the change in the depth of the target object 10 can be further identified by the change in the pattern pitch or the degree of superposition. The method for the sensing device 50 to identify depth information through different pattern distributions. The detailed steps and implementations thereof can be obtained from the general knowledge in the technical field with sufficient teaching, suggestions, and implementation descriptions, and therefore will not be described again.

FIG. 8A is a schematic diagram of a pixel array of a sensing element according to an embodiment of the invention. Please refer to FIG. 2, FIG. 6C and FIG. 8A. In this embodiment, the image capturing device 200 is, for example, a charge coupled device (CCD) or a complementary metal oxide semiconductor transistor (CMOS). ) And other photosensitive elements. In this example, the image capturing device 200 is a complementary metal-oxide semiconductor transistor. The image capturing element 200 includes a pixel array PA formed by an array of a plurality of first pixels P1 and a plurality of second pixels P2, and the first pixels P1 and the second pixels P2 are staggered. The polarization patterns of the first pixel P1 and the second pixel P2 that can receive light are different, as shown in FIG. 8A. In other words, the structured light that can be received by the first pixel P1 and the second pixel P2 on the image capturing element 200 is different. For example, the first pixel P1 receives only the first structured light LC1, and the second pixel P2 receives only the second structured light LC2. In this way, the position of each part of the target object 10 can be identified by the pattern distributions sensed by the first pixel P1 and the second pixel P2 respectively, and the sensing accuracy can be further improved.

FIG. 8B is a schematic diagram of a pixel array of a sensing element according to another embodiment of the present invention. Please refer to FIG. 2, FIG. 6C and FIG. 8B. The image capturing element 200A of this embodiment is similar to the image capturing element 200 of FIG. 8A, except that in the embodiment, the image capturing element 200A further includes A plurality of third pixels P3 of the pixel array PA are formed in an array with the plurality of first pixels P1 and the plurality of second pixels P2. The odd rows (add rows) R1 of the pixel array PA are formed by staggering part of the first pixels P1 and some third pixels P3, and the even rows R2 of the pixel array PA are made of some second pixels P2 It is staggered with some third pixels P3. The odd columns C1 of the pixel array PA are formed by staggering part of the first pixels P1 and some third pixels P3, and the even columns C2 of the pixel array PA are part of the second pixels P2 It is staggered with some third pixels P3. The first pixel P1, the second pixel P2, and the third pixel P3 can receive light with different polarization types. For example, the first pixel P1 receives only the first structured light LC1, the second pixel P2 receives only the second structured light LC2, and the third pixel P3 can receive the first structured light LC1 and the second structured light LC2. In some embodiments, the third pixel P3 may only receive other polarization types, such as circular polarization or elliptical polarization. In this way, the position of each part of the target object 10 can be identified by the pattern distributions sensed by the first pixel P1 and the second pixel P2 respectively, and all beams can be received by the third pixel P3, thereby further improving Sensing accuracy and improving sensing resolution.

FIG. 9 is a schematic diagram of a light source module according to another embodiment of the present invention. Please refer to FIG. 9, the light source module 100A of this embodiment is similar to the light source module 100 of FIG. 2, but the difference is that in this embodiment, the light source module 100A further includes a birefringent element 160 configured to emit light. The transmission path of the light beam L between the device 110 and the light guide element 120. The birefringent element 160 is, for example, a liquid crystal material or a birefringent crystal, and can cause the light beam L passing through to generate two light beams with two different polarization directions. Therefore, when the light beam L passes through the birefringent element 160, two beams with different polarization directions can be generated as shown in FIG. Divided into a first light beam L1 and a second light beam 2. In this way, the distribution density of the patterns formed by the first structured light LC1 and the second structured light LC2 in the projection area can be doubled, the effect of copying the pattern can be achieved, and the accuracy of identification can be further improved.

FIG. 10 is a schematic diagram of a light source module according to another embodiment of the present invention. Please refer to FIG. 10, the light source module 100B of this embodiment is similar to the light source module 100A of FIG. 9, except that the two differ in that in this embodiment, the light source module 100B includes a first birefringent element 162 and a first There are two birefringent elements 164, and the optical axis direction of the first birefringent element 162 and the optical axis direction of the second birefringent element 164 are different. Therefore, the polarization directions of the light beams separated after passing through the first birefringent element 162 and the second birefringent element 164 are also different. The first birefringent element 162 and the second birefringent element 164 are disposed on a transmission path of the light beam L between the light emitting device 110 and the light guide element 120. Therefore, when the light beam L passes through the first birefringent element 162, two beams with different polarization directions can be generated to the second birefringent element 164 as shown in FIG. FIG. 10 illustrates four light beams with different polarization directions. Therefore, the four light beams are further divided into a first light beam L1 and a second light beam 2 by the above-mentioned spectroscopic principle of the polarization beam splitting element 122. In this way, the distribution density of the pattern formed by the first structured light LC1 and the second structured light LC2 in the projection area can be doubled again to achieve the effect of copying the pattern and further improve the identification accuracy.

FIG. 11 is a schematic diagram of a light source module according to another embodiment of the present invention. Please refer to FIG. 11, the light source module 100C in this embodiment is similar to the light source module 100 in FIG. 2, but the difference is that in this embodiment, the light guiding element 120 of the light source module 100C includes a first reflecting member. 124_1 and the second reflector 124_2, and the polarizing beam splitting element 122 is located between the first reflector 124_1 and the second reflector 124_2. The first reflector 124_1 is located on the transmission path of the light beam L to reflect the light beam L to the polarization beam splitting element 122, and the second reflector 124_2 is located on the transmission path of the second light beam L2 to reflect the second light beam L2 to the second diffraction element 140. In this way, it can respond to the situation where a longer optical path is required on the product module side.

FIG. 12 is a schematic diagram of a light source module according to another embodiment of the present invention. Please refer to FIG. 12. The light source module 100D in this embodiment is similar to the light source module 100 in FIG. 2, but the difference is that in this embodiment, the second diffractive element 140A of the light source module 100D is disposed in the light guide. Priming element 120B. In other words, when the second light beam L2 is transmitted to the second diffractive element 140A, the second structured light LC2 can be generated. In this way, only one set of diffractive elements (ie, the first diffractive element 130) and the corresponding set of light beam adjusting elements 150 can be used on the light exit side of the light guiding element 120B, thereby achieving the effect of saving materials.

In any of the above embodiments, the first diffractive element 130 and the second diffractive element 140 may include an active diffractive device, such as a liquid crystal panel, that provides a fixed dot array pattern or a variable dot array pattern. In other words, in some embodiments, an active diffraction panel can be used as the first diffraction element 130 and the second diffraction element 140 to further project a superimposed structure pattern on the target object 10. Therefore, the active diffraction panel with different resolutions can be used for sensing with the structural fineness of the target object 10, and the present invention is not limited thereto.

FIG. 13 is a flowchart of steps for generating a superimposed structure pattern according to an embodiment of the present invention. Please refer to FIG. 1, FIG. 2, FIG. 6C, and FIG. 13. The method for generating the superimposed structure pattern in FIG. 13 can be applied to at least the light source module in any of the above embodiments. The following description will be applied to FIGS. 1 and 2 The light source module 100 is taken as an example. In this embodiment, step S300 is performed to provide the light beam L to the light guiding element 200. Then, after step S300 is completed, step S310 is performed to generate the first structured light LC1 and the second structured light LC2 with different polarization types by the light guiding element 200. Finally, after step S310 is completed, step S320 is performed to project the first structured light LC1 and the second structured light LC2 to a projection area APG to be overlapped and imaged as a superimposed structure pattern SP, wherein the projection areas APG have an array arrangement and are opposite to each other A plurality of adjacent sub-projection areas AP, and the pattern distribution of the superimposed structure pattern SP in each sub-projection area AP are different from each other. In this way, the depth value corresponding to the projection position on the target object 10 can be sensed by capturing the superimposed structure pattern SP through the image capturing step, thereby obtaining the stereoscopic information of the target object 10.

In summary, in the light source module, the sensing device, and the method for generating a superimposed structure pattern of the present invention, the light source module provides a light beam to the light guide element through the light emitting device, and generates a difference by the light guide element A first structured light and a second structured light of polarization type are projected in a projection area to generate an overlap and are imaged as a superimposed structure pattern. In this way, the depth information of the irradiated object can be identified by the difference in the pattern distribution in each sub-projection area and its variation.

Although the present invention has been disclosed as above with the examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some modifications and retouching without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be determined by the scope of the attached patent application.

10‧‧‧ Target Object

50‧‧‧ sensing device

100, 100A, 100B, 100C, 100D‧‧‧ light source modules

105‧‧‧ Collimating lens group

110, 110A‧‧‧ Light-emitting device

112, 112A‧‧‧ Light-emitting element

112_1‧‧‧Light-emitting unit

114‧‧‧Drive circuit

114_1‧‧‧Array control circuit

114_2‧‧‧Connecting pad

116, 116A, 116B‧‧‧ Control Board

116_1‧‧‧Focus Structure

116_2‧‧‧ grating structure

116_3‧‧‧Light guiding structure

118‧‧‧ Thermally Conductive Substrate

120, 120A, 120B ‧‧‧light guiding elements

122‧‧‧ Polarizing Beamsplitter

124‧‧‧Reflector

124_1‧‧‧first reflector

124_2‧‧‧Second reflector

130‧‧‧first diffractive element

140, 140A‧‧‧Second diffraction element

150‧‧‧beam adjustment element

150_1‧‧‧First beam adjustment element

150_2‧‧‧Second beam adjustment element

200, 200A‧‧‧Image capture element

A‧‧‧ Projection direction

APG‧‧‧ Projection Zone

AP‧‧‧Sub Projection Zone

C1‧‧‧odd column

C2‧‧‧even column

L‧‧‧ Beam

L1‧‧‧First Beam

L2‧‧‧Second Beam

LC‧‧‧ Superimposed Structured Light

LC1‧‧‧First Structured Light

LC2‧‧‧Second structured light

O‧‧‧light output

P1‧‧‧first pixel

P2‧‧‧Second Pixel

P3‧‧‧third pixel

PA‧‧‧Pixel Array

R1‧‧‧odd

R2‧‧‧ even series

SP‧‧‧ Overlay Structure Pattern

SP1‧‧‧First Structure Pattern

SP2‧‧‧Second Structure Pattern

S300, S310, S320 ‧‧‧ steps

FIG. 1 is a schematic diagram of a sensing device according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a light source module according to an embodiment of the present invention. FIG. 3 is a schematic diagram of the light emitting device of FIG. 2. FIG. 4 is a schematic diagram of a light emitting device according to another embodiment of the present invention. FIG. 5 is a schematic diagram of a light emitting device according to another embodiment of the present invention. FIG. 6A is a schematic diagram of a pattern distribution of a first structured light according to an embodiment of the present invention. FIG. 6B is a schematic diagram of a pattern distribution of a second structured light according to an embodiment of the present invention. FIG. 6C is a schematic diagram in which the first structured light of FIG. 6A and the second structured light of FIG. 6B overlap and are imaged as a superimposed structure pattern in a projection area. FIG. 7 is a schematic diagram of a partial superimposed structure pattern of the first structured light and the second structured light at different distances from projection regions according to an embodiment of the present invention. FIG. 8A is a schematic diagram of a pixel array of a sensing element according to an embodiment of the invention. FIG. 8B is a schematic diagram of a pixel array of a sensing element according to another embodiment of the present invention. FIG. 9 is a schematic diagram of a light source module according to another embodiment of the present invention. FIG. 10 is a schematic diagram of a light source module according to another embodiment of the present invention. FIG. 11 is a schematic diagram of a light source module according to another embodiment of the present invention. FIG. 12 is a schematic diagram of a light source module according to another embodiment of the present invention. FIG. 13 is a flowchart of steps for generating a superimposed structure pattern according to an embodiment of the present invention.

Claims (20)

A light source module is adapted to provide a superimposed structure pattern. The light source module includes: a light emitting device adapted to provide a light beam; a light guiding element configured on a transmission path of the light beam, the light guiding element including A polarizing beam splitting element to distinguish the beam into a first beam and a second beam; a first diffractive element arranged on a transmission path of the first beam to convert the first beam into a first beam Structured light; and a second diffractive element configured on the transmission path of the second light beam to convert the second light beam into a second structured light, wherein the polarization patterns of the first light beam and the second light beam are different The first structured light and the second structured light are projected in a projection area to overlap and be imaged as the superimposed structure pattern, the projection area has a plurality of sub-projection areas arranged in an array and adjacent to each other, and the superimposed structure pattern The pattern distribution in each of the sub-projection regions is different from each other. The light source module according to item 1 of the scope of patent application, wherein the first structured light and the second structured light are respectively imaged into a first structure pattern and a second structure pattern in the projection area, and the first structure The pattern and the second structure pattern include a dot array pattern in which the arrangement periods are different from each other. The light source module according to item 1 of the scope of patent application, wherein the first projection area defined by the projection boundary of the first structured light and the second projection area defined by the projection boundary of the second structured light The overlap ratio in the projection area is greater than 80%. The light source module according to item 1 of the scope of patent application, wherein the divergence angle of the first structured light is different from the divergence angle of the second structured light. The light source module according to item 1 of the patent application scope, wherein the light guiding element further comprises a reflector on the transmission path of the second light beam to reflect the second light beam to the second diffractive element. The light source module according to item 1 of the scope of patent application, further comprising: at least one birefringent element arranged on the transmission path of the light beam between the light emitting device and the light guide element. The light source module according to item 6 of the patent application, wherein the at least one birefringent element includes a first birefringent element and a second birefringent element, and an optical axis of the first birefringent element and the second birefringent element The birefringent elements have different optical axis directions. The light source module according to item 1 of the scope of patent application, wherein the light guiding element further includes a first reflecting member and a second reflecting member, and the polarizing beam splitting element is located on the first reflecting member and the second reflecting member. Between the pieces, the first reflecting member is located on the transmission path of the light beam to reflect the light beam to the polarizing beam splitting element, and the second reflecting member is located on the transmission path of the second light beam to reflect the second light beam to the The second diffractive element. The light source module according to item 1 of the scope of patent application, wherein the second diffractive element is disposed on the light guide element. The light source module according to item 1 of the scope of the patent application, wherein the first diffractive element is a transmissive diffractive element, and the second diffractive element is a reflective diffractive element or a transmissive diffractive element. The light source module according to item 1 of the scope of patent application, wherein the first diffractive element is an active diffractive element or a passive diffractive element, and the second diffractive element is an active diffractive element or a passive diffractive element. element. The light source module according to item 1 of the scope of patent application, wherein the first diffractive element and the second diffractive element include a display device that provides a fixed dot array pattern or a variable dot array pattern. The light source module according to item 1 of the scope of patent application, further comprising: a first light beam adjusting element disposed on a transmission path of the first light beam and located between the first diffraction element and the light guide element And a second light beam adjusting element disposed on the transmission path of the second light beam and located between the second diffractive element and the light guiding element. A sensing device includes: a light source module as described in any one of claims 1 to 13 of the scope of patent application; and an image capturing element for capturing an image of the projection area. The sensing device according to item 14 of the scope of patent application, wherein the image capturing element includes a pixel array, and the pixel array includes a plurality of first pixels and a plurality of second pixels. The pixels are staggered with the second pixels, and the polarization patterns of the light received by the first pixels and the second pixels are different. The sensing device according to item 14 of the application, wherein the image capturing element includes a pixel array, and the pixel array includes a plurality of first pixels, a plurality of second pixels, and a plurality of third pixels. Pixels. The odd rows of the pixel array are formed by staggering some of the first pixels and some of the third pixels. The even rows of the pixel array are partially The second pixels are staggered with some of the third pixels, and the odd columns of the pixel array are formed by staggering some of the first pixels and some of the third pixels. The even columns of the pixel array are formed by staggering part of the second pixels and part of the third pixels, and the first pixels, the second pixels, and the third pixels Pixels can receive light with different polarization patterns. A method for generating a superimposed structure pattern includes: providing a light beam to a light guiding element; using the light guiding element to generate a first structured light and a second structured light with different polarization modes; and projecting the first structured light A structured light and the second structured light are superimposed on a projection area and imaged as a superimposed structure pattern, wherein the projection area has a plurality of sub-projection areas arranged in an array and adjacent to each other, and the superimposed structure pattern is in each of the sub-areas. The pattern distribution of the projection areas is different from each other. The method for generating a superimposed structure pattern as described in item 17 of the scope of patent application, wherein the first structured light and the second structured light are respectively imaged into a first structure pattern and a second structure pattern in the projection area, and the first A structure pattern and the second structure pattern include dot array patterns with different arrangement periods. The method for generating a superimposed structure pattern as described in item 17 of the scope of the patent application, wherein a first projection area defined by a projection boundary of the first structured light and a second projection area defined by a projection boundary of the second structured light The overlap ratio of the projection area in the projection area is greater than 80%. The method for generating a superimposed structure pattern as described in item 17 of the scope of the patent application, wherein the divergence angle of the first structured light is different from the divergence angle of the second structured light.