CN213690182U - Three-dimensional imaging device based on structured light and electronic equipment - Google Patents
Three-dimensional imaging device based on structured light and electronic equipment Download PDFInfo
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- CN213690182U CN213690182U CN202022598835.5U CN202022598835U CN213690182U CN 213690182 U CN213690182 U CN 213690182U CN 202022598835 U CN202022598835 U CN 202022598835U CN 213690182 U CN213690182 U CN 213690182U
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Abstract
The application discloses three-dimensional imaging device and electronic equipment based on structured light, the device includes: a transmitting module and a receiving module; the transmitting module is used for transmitting the structured light with the preset polarization direction; the receiving module is used for receiving the ambient light and the structured light of the environment where the target object is located, and the preset polarization direction of the structured light is the same as the polarization direction of the light with the weakest light intensity in the ambient light received by the receiving module. According to the technical scheme provided by the embodiment of the application, the three-dimensional imaging device improves the imaging signal-to-noise ratio.
Description
Technical Field
The present application relates generally to the field of optics, and more particularly to a structured light-based three-dimensional imaging device and an electronic apparatus.
Background
With the intensive research on the three-dimensional imaging based on the structured light and the expansion of the application requirements, the three-dimensional imaging is widely applied to the aspects of depth detection and the like.
A conventional structured light-based three-dimensional imaging device for depth detection includes a light source, an image sensor, and a processor. The light source emits structured light to a target object; the image sensor images the structured light reflected back by the target object; the processor calculates the distance to the target object by determining the time difference between when the structured light is reflected from the object and then received by the image sensor based on imaging and other information.
As can be seen from the above, the prior art has at least the following problems: the environment of the target generally has a large amount of interference light, which can seriously affect the signal-to-noise ratio of the three-dimensional imaging device.
SUMMERY OF THE UTILITY MODEL
In view of the problem that the signal-to-noise ratio of the imaging of the existing three-dimensional imaging device based on the structured light is low, the application provides the three-dimensional imaging device based on the structured light and the electronic equipment, and the imaging signal-to-noise ratio can be improved.
In a first aspect, an embodiment of the present application provides a structured light-based three-dimensional imaging apparatus, including:
a transmitting module and a receiving module;
the transmitting module is used for transmitting the structured light with the preset polarization direction;
the receiving module is used for receiving the ambient light and the structured light of the environment where the target object is located, and the preset polarization direction of the structured light is the same as the polarization direction of the light with the weakest light intensity in the ambient light received by the receiving module.
Optionally, the receiving module includes a first infrared image sensor and a first optical analyzer, and the first optical analyzer covers a light receiving surface close to the first infrared image sensor.
Optionally, the receiving module further includes a second infrared image sensor and a second optical analyzer, the second optical analyzer covers a light receiving surface of the second infrared image sensor, and an analyzing direction of the second optical analyzer is perpendicular to an analyzing direction of the first optical analyzer.
Optionally, the transmitting module comprises a high contrast grating laser and a diffractive optical element, the diffractive optical element being arranged on a side of the high contrast grating laser emitting light.
Optionally, the high contrast grating laser is a high contrast grating vertical cavity surface emitting laser.
Optionally, the transmitting module further includes a rotating component, and the rotating component is connected to the high-contrast grating laser and configured to rotate the high-contrast grating laser to change a polarization direction of the structured light transmitted by the high-contrast grating laser.
Optionally, the emission module further includes a collimator lens disposed on a light emitting side of the high-contrast grating laser for reducing a divergence angle of light emitted by the high-contrast grating laser.
Optionally, the high-contrast grating vertical cavity surface emitting laser includes an N-electrode layer, an N-type DBR layer, an active layer, a P-type DBR layer, an HCG, and a P-electrode layer.
Optionally, the three-dimensional imaging device further includes a circuit board, and the circuit board is connected to the transmitting module and the receiving module and is configured to control the transmitting module and the receiving module.
In a second aspect, an embodiment of the present application provides an electronic device, which includes the three-dimensional imaging apparatus according to any one of the first aspect.
To sum up, the three-dimensional imaging device provided by the embodiment of the present application, through determining the polarization direction of the weakest light of light intensity in the environment, and making the transmitting module transmit the structured light with the same polarization direction as the weakest light of light intensity, thereby the receiving module reduces the influence of the ambient light on the structured light when receiving the structured light, reduces the interference information of imaging, and improves the signal-to-noise ratio.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments or the prior art are briefly introduced below, and it is apparent that the drawings are only for the purpose of illustrating a preferred implementation method and are not to be considered as limiting the present invention. It should be further noted that, for the convenience of description, only some but not all of the relevant portions of the present invention are shown in the drawings.
FIG. 1 is a schematic diagram of a structured light-based three-dimensional imaging device according to an embodiment of the present disclosure;
FIG. 2 is a schematic diagram of yet another structured-light based three-dimensional imaging apparatus according to an embodiment of the present application;
FIG. 3 is a schematic diagram of a receiving module according to an embodiment of the present application;
FIG. 4 is a schematic diagram of a receiving module according to an embodiment of the present application;
FIG. 5 is a schematic diagram illustrating yet another receiving module according to an embodiment of the present application;
FIG. 6 is a schematic diagram illustrating a transmitter module according to an embodiment of the present application;
FIG. 7 is a schematic diagram of a high contrast pair grating according to an embodiment of the present application;
FIG. 8 is a schematic diagram of a high contrast grating VCSEL shown in accordance with an embodiment of the present application;
FIG. 9 is a schematic diagram illustrating an exit light field of a high-contrast grating laser according to an embodiment of the present application;
fig. 10 is a schematic diagram illustrating an exit light field from a single aperture of a high-contrast grating laser according to an embodiment of the present application.
Detailed Description
The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings.
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.
Fig. 1 is a schematic diagram of a structured light-based three-dimensional imaging device according to an embodiment of the present application. As shown in fig. 1, the apparatus includes: a transmitting module 110 and a receiving module 120.
The emitting module 110 is used for emitting the structured light with a predetermined polarization direction.
The receiving module 120 is configured to receive the ambient light and the structured light of the environment where the target object 150 is located, and the predetermined polarization direction of the structured light is the same as the polarization direction of the light with the weakest intensity in the ambient light received by the receiving module 120.
Since the predetermined polarization direction of the structured light is the same as the polarization direction of the light with the weakest intensity in the ambient light received by the receiving module 120. Therefore, before the emission module 110 emits the structured light with a predetermined polarization direction, the polarization direction of the light with the weakest intensity in the ambient light needs to be determined in advance.
The predetermined polarization direction may be determined according to actual needs, for example, the predetermined polarization direction is determined as the polarization direction of the non-light-intensity weakest light and the non-light-intensity strongest light in the environment.
Further, the polarization direction of the light with the weakest intensity in the ambient light may be determined by the receiving module 120. Referring to fig. 3, the receiving module 120 includes a first infrared image sensor 121 and a first optical analyzer 122, and the first optical analyzer 122 covers a light receiving surface of the first infrared image sensor 121. Then the method for determining the polarization direction of the weakest light in the environment is as follows:
step 1: acquiring a first image of the environment by means of the first infrared image sensor 121 and the first optical analyzer 122;
step 2: rotating the directions of the first infrared image sensor 121 and the first optical analyzer 122 to form an included angle with the direction before rotation, and acquiring a second image of the environment;
and step 3: and determining the polarization direction of the light with the weakest light intensity in the environment according to the first image and the second image.
The included angle obtained by the rotation can be any size, such as 90 degrees. When the angle is 90 degrees, light in any polarization direction in the environment can be decomposed to two directions with an included angle of 90 degrees, and the precision of the received environment light is improved, so that the precision of the first image and the second image is improved, and the precision of the polarization direction of the light with the weakest light intensity in the determined environment is improved.
The first image and the second image may be one or more. When there are more than one, the average value can be calculated for many times to improve the accuracy of the polarization direction of the light with the weakest light intensity in the determined environment.
Wherein, step 3 may be as follows:
1. calculating the brightness difference of the two images;
2. determining the polarization analyzing directions of the two polarization analyzers;
3. calculating the light intensity and the corresponding polarization direction of each light in the ambient light according to the brightness difference and the polarization analysis direction;
4. and selecting the light with the weakest light intensity, and determining the polarization direction corresponding to the light with the weakest light intensity.
Optionally, the receiving module 120 further includes a second infrared image sensor 131 and a second optical analyzer 132, the second optical analyzer 132 covers the light receiving surface of the second infrared image sensor 131, and the second optical analyzer 132 has a different analyzing direction from the first optical analyzer 121. Optionally, the polarization directions of the two are perpendicular to each other, and compared with other different angles, the perpendicular to each other can improve the accuracy of determining the polarization direction of the light with the weakest light intensity in the environment.
Alternatively, in conjunction with fig. 2 and 5, the second infrared image sensor 131 and the second optical analyzer 132 may be disposed in the receiving module 120, or may be separately disposed in another receiving module 130.
Further, when the receiving module 120 further includes the second infrared image sensor 131 and the second optical analyzer 132, the method for determining the polarization direction of the light with the weakest light intensity in the environment is as follows:
step 1: acquiring a first image of the environment by means of the first infrared image sensor 121 and the first optical analyzer 122;
step 2: acquiring a second image of the environment by means of a second infrared image sensor 131 and a second optical analyzer 132;
and step 3: and determining the polarization direction of the light with the weakest light intensity in the environment according to the first image and the second image.
The method for determining the polarization direction of the light with the weakest light intensity in the environment is similar to the method, and is not described herein again.
In addition, it should be noted that the receiving module 120 does not necessarily include only the above two cases, and the number of TOF image sensors and optical analyzers may also be set according to actual situations, for example, a third TOF image sensor and a third optical analyzer may also be set, or more may also be set, which is not described here one by one.
After the polarization direction of the light with the weakest light intensity in the environment is determined, the polarization direction of the light with the weakest light intensity is determined as the preset polarization direction. The light source in the emitting module 110 emits structured light of a predetermined polarization direction.
Referring to fig. 6, the transmitting module 110 includes a laser 111, and the laser 111 is a structured light laser, and further may be a high-contrast grating laser. The High-Contrast grating laser comprises a High-Contrast grating (hereinafter, referred to as High-Contrast Gratings; HCG) and a laser. Referring to fig. 7, a schematic diagram of a high-contrast grating according to this embodiment is shown, where the high-contrast grating may analyze a polarization direction of light projected onto the high-contrast grating, and only light with the polarization direction the same as the analysis direction is allowed to pass through, so that the light emitting surface of the structured light laser covers the high-contrast grating with a predetermined analysis direction, and the structured light is analyzed and polarized to emit structured light with a predetermined polarization direction.
In addition, the high-contrast grating can also modulate the angle, wavelength, and the like of the structured light to emit high-quality structured light.
Alternatively, the Laser is a Vertical Cavity Surface Emitting Laser (hereinafter, referred to as VCSEL), and the high-contrast grating Laser is a high-contrast grating Vertical Cavity Surface Emitting Laser (HCG-VCSEL). The vertical cavity surface emitting laser has the advantages of small volume, high power, stable operation and the like, so that the volume of the three-dimensional imaging device can be reduced, and the imaging precision of the three-dimensional imaging device can be improved.
Optionally, the structure of the HCG-VCSEL includes an N-electrode layer, an N-type DBR layer, an active layer, a P-type DBR layer, an HCG, and a P-electrode layer.
Further, referring to fig. 8, the structure of the HCG-VCSEL includes an N electrode layer 310, a substrate layer 320, an N-type DBR layer 330, an active layer 340, an oxide layer 350, a P-type DBR layer 360, an oxide layer 370, an HCG380, and a P electrode layer 390.
Fig. 9 is a schematic diagram of polarization of the exit optical field of the HCG-VCSEL in this embodiment. The HCG-VCSEL of the present embodiment can emit structured light polarized in the same direction as compared to the conventional DBR-VCSEL.
Referring to fig. 10, a schematic diagram of polarization of an outgoing optical field of a single light exit hole of the HCG-VCSEL in this embodiment is shown. The included angle between the polarization direction and the horizontal direction is alpha, and the alpha can be any value from 0 to 180 degrees.
Further, referring to fig. 4, the emitting module 110 further includes a diffractive optical element 113, and the diffractive optical element 113 is disposed on a side where the laser 111 emits light, and is used for enlarging a view angle of the laser 111 emitting light to project a speckle pattern 160 with a large field of view.
Optionally, the transmitting module 110 may further include a rotating component, connected to the high-contrast grating laser, for rotating the high-contrast grating laser to change the polarization direction of the structured light emitted by the high-contrast grating laser.
In addition, the laser 111 can be designed to be rotated as well as to be fixed in polarization direction, wherein the rotation can also be realized by other methods, for example, the laser 111 itself can be set to be rotated.
Compared with a high-contrast grating with a preset polarization detection direction which is set in advance according to the polarization direction of the weakest light in the environment, the rotating assembly can be rotated to obtain the high-contrast grating with any preset polarization detection direction after being set, and in different environments, the rotating assembly only needs to be rotated according to the preset polarization direction, so that the high-contrast grating can be suitable for different environments, and the use convenience is improved.
Optionally, referring to fig. 6, the emission module 110 further includes a collimator mirror 112, the collimator mirror 112 being disposed between the high-contrast grating laser and the diffractive optical element 113 for reducing a divergence angle of light emitted by the high-contrast grating laser.
Since the transmitting module 110 transmits the structured light with the polarization direction the same as that of the light with the weakest light intensity in the environment, the receiving modules 120 and/or 130 receive the structured light with the polarization direction the same as that of the light with the weakest light intensity in the environment, so that the influence of the light with the polarization direction in the environment on the structured light is reduced, the noise is reduced, and the signal-to-noise ratio is improved. Further, when the signal-to-noise ratio of the structured light-based three-dimensional imaging device is improved, the accuracy of distance detection can be improved.
Further, when the three-dimensional imaging device only includes one receiving module, that is, only includes the receiving module 120, before receiving the structured light, the first optical analyzer 122 may be rotated, so that the polarization direction of the first optical analyzer 122 is the same as the polarization direction of the structured light emitted by the emitting module 110, and light of other polarization directions in the environment cannot pass through the first optical analyzer 122, thereby playing a role of filtering the ambient light, reducing the influence of the ambient light on the received structured light, reducing noise, and improving the signal-to-noise ratio.
The signal-to-noise ratio of the three-dimensional imaging device based on the structured light is high, and the three-dimensional imaging device can be used for detecting the depth of a target object. Further, the structured light is emitted from the emitting module 110, and then reflected to the receiving module 120 through the target, the receiving module 120 obtains the reflected image, obtains information such as the triangle parallax change of the structured light according to the image, and obtains the environmental depth information by resolving the information such as the triangle parallax change.
Alternatively, referring to fig. 1 or 2, the three-dimensional imaging apparatus further includes a circuit board 140, and the circuit board 140 includes a control circuit and a processor to share part of the control and data processing operations of the transmission module 110, the reception module 120, and the reception module 130.
Illustratively, the circuit board 140 is used to control the emission module 110 to be turned on so as to make the light source therein emit light. And is further configured to receive the image from the receiving module 120 or 130, and calculate the polarization direction of the light with the weakest light intensity in the environment or the depth of the target object according to the image.
To sum up, the three-dimensional imaging device based on structured light provided by the embodiment of the present application is through determining the polarization direction of the weakest light of light intensity in the environment, and makes the emission module emit the structured light with the same polarization direction of the weakest light of light intensity, thereby the receiving module reduces the influence of the ambient light on the receiving module when receiving the structured light, reduces the interference information of imaging, and improves the signal-to-noise ratio.
An electronic device shown in the embodiment of the present application includes any one of the three-dimensional imaging devices shown in the above embodiments and the drawings.
The electronic device may be a handheld terminal, a wearable terminal, a fixed terminal, or the like.
The electronic equipment provided by the embodiment of the application is through the polarization direction of the weakest light of light intensity in the definite environment to make emission module launch the structured light the same with this polarization direction of the weakest light of light intensity, thereby receiving module reduces the influence of ambient light to it when receiving structured light, reduces the interference information of formation of image, improves the signal-to-noise ratio.
The embodiments in this specification are described in a progressive manner, and similar parts between the various embodiments are referred to each other. The examples below each step focus on the specific method below that step. The above-described embodiments are merely illustrative, the specific examples are merely illustrative of the present invention, and those skilled in the art can make various modifications and enhancements without departing from the principles of the examples described herein, which should be construed as within the scope of the present invention.
The foregoing is considered as illustrative only of the preferred embodiments of the invention and illustrative only of the principles of the technology employed. It will be appreciated by those skilled in the art that the scope of the invention herein disclosed is not limited to the particular combination of features described above, but also encompasses other arrangements formed by any combination of the above features or their equivalents without departing from the spirit of the invention. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.
Claims (10)
1. A structured-light based three-dimensional imaging apparatus, the apparatus comprising:
a transmitting module and a receiving module;
the transmitting module is used for transmitting the structured light with the preset polarization direction;
the receiving module is used for receiving the ambient light of the environment where the target object is located and the structured light, and the preset polarization direction of the structured light is the same as the polarization direction of the light with the weakest intensity in the ambient light received by the receiving module.
2. The three-dimensional imaging apparatus according to claim 1, wherein the receiving module comprises a first infrared image sensor and a first optical analyzer, the first optical analyzer covering a light receiving face near the first infrared image sensor.
3. The three-dimensional imaging device according to claim 2, wherein the receiving module further comprises a second infrared image sensor and a second optical analyzer, the second optical analyzer covers a light receiving surface of the second infrared image sensor, and the second optical analyzer and the first optical analyzer have polarization directions perpendicular to each other.
4. The three-dimensional imaging apparatus according to claim 1, wherein the emission module comprises a high-contrast grating laser and a diffractive optical element disposed on a side of the high-contrast grating laser from which light is emitted.
5. The three-dimensional imaging apparatus according to claim 4, wherein the high-contrast grating laser is a high-contrast grating vertical cavity surface emitting laser.
6. The three-dimensional imaging apparatus according to claim 4 or 5, wherein the emitting module further comprises a rotating component connected to the high-contrast grating laser for rotating the high-contrast grating laser to change the polarization direction of the structured light emitted by the high-contrast grating laser.
7. The three-dimensional imaging apparatus according to claim 4 or 5, wherein the emission module further comprises a collimator mirror disposed on a side of the high-contrast grating laser emitting light for reducing a divergence angle of the light emitted by the high-contrast grating laser.
8. The three-dimensional imaging apparatus according to claim 4 or 5, wherein the high-contrast grating vertical cavity surface emitting laser includes an N electrode layer, an N-type DBR layer, an active layer, a P-type DBR layer, an HCG, and a P electrode layer.
9. The three-dimensional imaging apparatus according to claim 1, further comprising a circuit board connected with the transmitting module and the receiving module for controlling the transmitting module and the receiving module.
10. An electronic device, characterized in that it comprises a three-dimensional imaging apparatus according to any one of claims 1 to 9.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202022598835.5U CN213690182U (en) | 2020-11-11 | 2020-11-11 | Three-dimensional imaging device based on structured light and electronic equipment |
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| CN202022598835.5U CN213690182U (en) | 2020-11-11 | 2020-11-11 | Three-dimensional imaging device based on structured light and electronic equipment |
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| CN213690182U true CN213690182U (en) | 2021-07-13 |
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