Range-variable laser projector, depth camera and intelligent equipment

Abstract

The utility model discloses a range-variable laser projector, a depth camera and intelligent equipment, and the range-variable laser projector comprises a light-emitting source which is used for generating laser; the liquid crystal glass is positioned on a light path of the laser and is used for changing the form of the laser into structured light or floodlight; the liquid lens is located on a light path of the laser and used for changing the emitting direction of the laser; the controller is connected with the luminous source, the liquid crystal glass and the liquid lens and is configured to control the luminous source, the liquid crystal glass and the liquid lens; the liquid lens comprises a first electrode and a second electrode. At least one of the first electrode and the second electrode comprises a plurality of independent electrodes. Rapid deformation of the lens can be realized through an electric signal, so that the direction of a light field is changed.

Description

Technical Field

[0001] The utility model relates to the technical field of depth cameras, and in particular to a laser projector with a variable range, a depth camera and an intelligent device. Background Art

[0002] The projector in the depth camera is a key component used in depth imaging technology. It is responsible for projecting laser light onto the surface of the object being measured in order to obtain depth information.

[0003] Structured light technology is a technology currently widely used in the field of 3D vision. It uses a projector to actively emit infrared light patterns (such as sinusoidal stripes, binary codes, etc.) that are invisible to the human eye onto an object, and then uses a camera to capture the deformation of these patterns. Based on the principle of triangulation, the system can calculate detailed depth information on the surface of an object and ultimately achieve three-dimensional reconstruction.

[0004] In the application of depth cameras, projectors usually work with cameras. The projectors emit light in a specific pattern, and the cameras capture the reflected pattern. By analyzing the changes in these patterns, the spatial position and depth information of the object surface can be determined. This technology not only provides richer data than traditional two-dimensional images, but also works effectively in low-light environments, especially for close-range and high-precision measurement scenes.

[0005] TOF technology is another widely used technology that emits flood light to achieve illumination over a wider range and uses a time-of-flight algorithm to calculate the surface depth of the object being measured.

[0006] In general, the projector in the depth camera is an important component for realizing three-dimensional perception capabilities, which enables the depth camera to accurately obtain the three-dimensional coordinate information of objects in various environments.

[0007] However, the variable range laser projector in the prior art can only change the focal length of the laser, and cannot automatically adjust the projection direction of the light according to the position of the object being measured. For the optical system, the light field is in a fixed state, and it is difficult to overcome the large field of view and uneven distribution of light field energy, resulting in severe shading of the obtained image and reduced edge image quality.

[0008] The disclosure of the above background technology content is only used to assist in understanding the inventive concept and technical solution of the utility model. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above content has been disclosed on the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of the present application. Utility Model Content

[0009] Therefore, the present invention proposes a laser projector with a variable range to solve the problems in the prior art.

[0010] In a first aspect, the utility model provides a variable range laser projector, characterized by comprising:

[0011] A light source for generating laser light;

[0012] Liquid crystal glass, located on the optical path of the laser, used to change the form of the laser into structured light or flood light;

[0013] A liquid lens, located on the optical path of the laser, and used to change the emission direction of the laser;

[0014] A controller connected to the light source, the liquid crystal glass and the liquid lens, and configured to control the light source, the liquid crystal glass and the liquid lens;

[0015] The liquid lens comprises: a first electrode and a second electrode;

[0016] At least one of the first electrode and the second electrode includes a plurality of independent electrodes.

[0017] Optionally, the variable-range laser projector is characterized in that the laser passes through the liquid crystal glass and the liquid lens in sequence.

[0018] Optionally, the variable-range laser projector is characterized in that the first electrode includes a third electrode and a fourth electrode; and the voltages of the third electrode and the fourth electrode are different.

[0019] Optionally, the variable-range laser projector is characterized in that the second electrode includes a fifth electrode and a sixth electrode; and the voltages of the fifth electrode and the sixth electrode are different.

[0020] Optionally, the variable-range laser projector is characterized in that the controller changes the direction of the optical axis of the emission direction by controlling the voltage of the first electrode and the second electrode.

[0021] Optionally, the variable-range laser projector is characterized in that the controller changes the projection area of ​​the laser by controlling the voltage of the first electrode and the second electrode.

[0022] Optionally, the variable-range laser projector is characterized in that the liquid lens also includes an optically active substance; the optically active substance changes the propagation path of the laser according to the voltage change between the first electrode and the second electrode.

[0023] Optionally, the variable-range laser projector is characterized in that the controller controls the liquid crystal glass to display a preset pattern so that only a partial area is transparent to the laser, and changes the irradiation area and light intensity of the structured light by changing the shape of the preset pattern.

[0024] In a second aspect, the utility model provides a depth camera, characterized by comprising a variable-range laser projector as described in any one of the above items.

[0025] In a third aspect, the utility model provides an intelligent device, characterized in that it includes a variable-range laser projector as described in any one of the aforementioned items.

[0026] Compared with the prior art, the utility model has the following beneficial effects:

[0027] The utility model adopts a liquid lens, and the liquid lens includes a first electrode and a second electrode, and at least one of the first electrode and the second electrode includes a plurality of independent electrodes, so that the plurality of electrodes can be controlled individually, so that the shape of the liquid lens can be more finely controlled, and the emission direction and focal length of the laser can be changed.

[0028] The utility model adopts liquid crystal glass to change the laser shape, thereby making the laser shape more changeable, and combined with the liquid lens, the laser shape and irradiation range can be arbitrarily adjusted; at the same time, since both the liquid crystal glass and the liquid lens are voltage controlled, rapid response and adjustment can be achieved through the controller, which can meet the needs of various application scenarios, especially complex application scenarios.

[0029] The utility model can realize the change of the emission direction and focal length of the laser, and realize the focusing of the laser from a large range to any object to be measured within a smaller range in the field of view, so that the intensity of the laser projected on the object to be measured is increased, especially for the scene where the object to be measured is far away, more accurate information about the object to be measured can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without creative work. By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, purposes and advantages of the utility model will become more obvious:

[0031] Figure 1 This is a schematic diagram of the structure of a laser projector with a variable range in an embodiment of the utility model;

[0032] Figure 2 This is a schematic diagram of a light-transmitting area of ​​a liquid crystal glass in an embodiment of the utility model;

[0033] Figure 3 This is a schematic diagram of the structure of a liquid lens in an embodiment of the utility model;

[0034] Figure 4 This is a schematic diagram of the structure of an electrode distribution in an embodiment of the utility model;

[0035] Figure 5 This is a schematic diagram of the optical path of a liquid lens in an embodiment of the utility model;

[0036] Figure 6 It is a schematic diagram of the structure of a depth camera in an embodiment of the utility model.

[0037] 1- Light source;

[0038] 2-Liquid lens;

[0039] 3- Controller;

[0040] 4- first electrode;

[0041] 5- second electrode;

[0042] 6- Receiver;

[0043] 7-Liquid crystal glass; DETAILED DESCRIPTION

[0044] The utility model is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the utility model, but do not limit the utility model in any form. It should be pointed out that for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the utility model. These all fall within the scope of protection of the utility model.

[0045] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the utility model described here, for example, can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0046] The embodiment of the utility model provides a laser projector with a variable range, aiming to solve the problems existing in the prior art.

[0047] The following specific embodiments are used to describe in detail the technical solution of the utility model and how the technical solution of the present application solves the above technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the utility model will be described below in conjunction with the accompanying drawings.

[0048] Figure 1 FIG. 1 is a schematic diagram of a variable range laser projector in an embodiment of the present utility model. Figure 1 As shown, a variable range laser projector in an embodiment of the utility model includes:

[0049] The light source 1 is used to generate laser.

[0050] Specifically, the light source 1 may be a solid laser, a gas laser, a semiconductor laser, etc., depending on the required laser wavelength, power, and application scenario. The laser generated by the light source 1 may be flood light, structured light, or any other type of light. When the light source projects flood light, the variable-range laser projector projects flood light. When the light source projects structured light, the variable-range laser projector projects structured light or flood light after being processed by a liquid lens.

[0051] The liquid crystal glass 7 is located on the optical path of the laser and is used to change the shape of the laser into structured light or flood light.

[0052] Specifically, liquid crystal glass, also known as liquid crystal display (LCD), is a display technology that uses the photoelectric effect of liquid crystal to control the transmission of light. Its working principle is mainly based on the characteristics of the arrangement change of liquid crystal molecules under the action of electric field. When there is no electric field, the liquid crystal molecules are randomly arranged, causing light to scatter, and the liquid crystal glass is opaque. When an electric field is applied, the liquid crystal molecules will be arranged in a certain order according to the direction of the electric field, allowing light to pass through in a straight line, so that the liquid crystal glass becomes transparent. Liquid crystal glass contains two glass substrates with liquid crystal material in between. By changing the arrangement of liquid crystal molecules, it is possible to control whether light can pass through, thereby realizing the display or hiding of images. Liquid crystal glass is used to change the form of laser. It can convert laser from one form to another, such as converting a laser point into a specific pattern (structured light) or diffusing it into flood light. Liquid crystal glass adjusts the phase of the light passing through it by changing its molecular arrangement, thereby changing the propagation characteristics of the laser.

[0053] The liquid lens 2 is located on the optical path of the laser and is used to change the emission direction of the laser.

[0054] Specifically, liquid lens is a new type of optical element that uses the gradient refractive index of liquid to achieve optical zoom, with the advantages of high efficiency, flexibility, and thinness. The working principle of liquid lens is mainly to adjust the focal length by changing the refractive index of the liquid. This change can be achieved in a variety of ways, such as using an electric field (electric wetting effect) or by changing the shape of the liquid (filling effect). Liquid lenses can provide optical adjustment without mechanical moving parts in different application scenarios, which makes them have advantages in volume, response speed and durability. The main types of liquid lenses include liquid lenses based on different working principles, such as electric wetting effect lenses, thermal effect lenses, etc. Each type has its specific application scenarios and advantages and disadvantages, but the common feature is that they can achieve changes in optical parameters through external control. The liquid lens is located in the optical path of the laser, which can not only change the focus of the laser, but also change the exit direction of the laser, so that the area irradiated by the laser changes.

[0055] The controller 3 is connected to the light source, the liquid crystal glass and the liquid lens, and is configured to control the light source, the liquid crystal glass and the liquid lens.

[0056] Specifically, the controller is connected to the light source, liquid crystal glass and liquid lens, and is responsible for controlling the working status of these three components. The controller can be a microprocessor or other form of electronic control unit, which adjusts the intensity and frequency of the laser and the refractive index of the liquid lens according to a preset program or user input, thereby achieving precise control of the laser emission direction. The controller includes the switch, power regulation, modulation, etc. of the light source, and can achieve voltage control and shape adjustment of the liquid lens.

[0057] The liquid lens 2 includes: a first electrode 4 and a second electrode 5; at least one of the first electrode 4 and the second electrode 5 includes a plurality of independent electrodes.

[0058] Specifically, a conductive transparent liquid (such as an electrolyte) is filled between the first electrode and the second electrode. When a voltage is applied between the first electrode and the second electrode, the charge in the liquid is redistributed, resulting in a change in the shape or refractive index of the liquid, thereby changing the propagation path of the laser. By independently controlling the voltage on each electrode, the shape change of the liquid lens can be more accurately controlled, thereby achieving more precise beam control. One of the first electrode 4 and the second electrode 5 may include multiple independent electrodes, or both may include multiple independent electrodes. The independent electrodes can be powered and controlled separately, thereby achieving more precise control of the transparent liquid.

[0059] The laser passes through the liquid crystal glass and the liquid lens in sequence, so that the laser can be emitted onto the object to be measured after being processed by the liquid crystal glass and the liquid lens.

[0060] For light source 1, the emitted light field is a light field with a fixed FOV and constant light intensity. At this time, the energy density on the surface of the target object will be inversely proportional to the square of the distance. As the target object moves away from the light source, the surface brightness will drop rapidly. At this time, to meet the imaging brightness of the target object, the current needs to be increased, or a small FOV light source needs to be selected, which is very unfriendly to scenes with large FOV requirements.

[0061] This embodiment uses a light source 1 and a front liquid lens 2. By controlling the curvature of the liquid lens, the diffusion and convergence of the light source 1 can be achieved. At the same time, the liquid lens is controlled by applying a gradient voltage to the electrode, so that the liquid lens can achieve aspheric deformation, and the direction of the emitted light can be controlled to converge at the center and to Figure 5 Rapid changes between directions c and e are achieved.

[0062] In some embodiments, the controller controls the liquid crystal glass to display a preset pattern so that only a portion of the area is transparent to the laser, and changes the irradiation area and light intensity of the structured light by changing the shape of the preset pattern. Figure 2 As shown, a and b are different patterns, that is, the liquid crystal glass can display different preset patterns, so that the emitted laser presents different coding structures. Different preset patterns can have different densities, different spot sizes, etc. When the spot is small, the power of the light source can be increased at the same time, and the power of the light source can be increased, so that the power of each spot remains relatively stable, thereby ensuring the intensity of the laser.

[0063] like Figure 3As shown, the first electrode 4 and the second electrode 5 are arranged opposite to each other. The first electrode and the second electrode are arranged on both sides of the transparent liquid. When the voltages of different first electrodes or second electrodes are different, the shape or refractive index of the corresponding transparent liquid will change, so that the propagation path of the laser will change to varying degrees. The electrodes are made of transparent materials to allow the laser to pass through.

[0064] In some embodiments, the first electrode includes a third electrode and a fourth electrode; the voltages of the third electrode and the fourth electrode are different. The number of the third electrode and the fourth electrode can be multiple. Figure 4 A cross-sectional schematic diagram of electrode distribution is shown. The electrodes can be evenly distributed on the surface of the liquid lens or unevenly distributed on the surface of the liquid lens. Figure 4 As shown in a, multiple electrodes are evenly distributed on the surface of the liquid lens, which is a symmetrical distribution, and can achieve uniform adjustment of the liquid lens. Figure 4 As shown in b, multiple electrodes are unevenly distributed on the surface of the liquid lens, with more on one side and less on the other side, so that focused monitoring of a specific area can be achieved. The voltages of the third electrode and the fourth electrode can be controlled separately, so that one of the third electrode and the fourth electrode is positive and the other is negative compared to the second electrode. Figure 5 As shown, when the third electrode is a positive electrode and the fourth electrode is a negative electrode, the interface of the liquid lens will be caused to move laterally, so that the projection direction of the laser will change on the z-axis. Figure 5 The light path directions of c, d, and e are all different.

[0065] In some embodiments, the second electrode includes a fifth electrode and a sixth electrode; the voltages of the fifth electrode and the sixth electrode are different. Similar to the first electrode, when the second electrode includes the fifth electrode and the sixth electrode, it will also have the characteristics and advantages described above. Therefore, the focus here is on the case where the first electrode includes the third electrode and the fourth electrode, and the second electrode includes the fifth electrode and the sixth electrode. Take the third electrode and the fifth electrode as an example, and the fourth electrode and the sixth electrode as an example. Since the voltages of the third electrode, the fourth electrode, the fifth electrode and the sixth electrode can be controlled separately, the third electrode and the fifth electrode, the fourth electrode and the sixth electrode respectively form different electrode pairs, which can form different voltage directions and different voltage differences, so that the transparent liquid presents various regular and irregular shapes with a higher degree of freedom.

[0066] In some embodiments, the controller changes the direction of the optical axis of the emission direction by controlling the voltage of the first electrode and the second electrode. The optical axis refers to the virtual line at the center of the path of light propagation, which defines the direction of light propagation. The liquid lens in the prior art can only change the focal length but cannot change the direction of the optical axis. However, this embodiment can change the movement of the optical axis in various directions such as up and down, left and right, etc. through fine control of the electrodes, so that the irradiation direction changes. Combined with the adjustment of the focal length, the irradiation area of ​​the variable range laser projector changes, and the center point of irradiation also changes.

[0067] In some embodiments, the controller changes the projection area of ​​the laser by controlling the voltage of the first electrode and the second electrode. The change of the projection area will change the laser density within the projection area, thereby playing a role in adjusting the light intensity per unit area, and after identifying the object to be detected, the object to be detected can be detected in a targeted and detailed manner to obtain a more accurate detection result.

[0068] In some embodiments, the liquid lens further comprises an optically active substance; the optically active substance changes the propagation path of the laser according to the voltage change between the first electrode and the second electrode. Optically active substances refer to substances that have the ability to rotate the vibration plane of polarized light passing through them. This ability is not limited to molecules containing chiral carbon atoms, even some molecules without chiral carbon atoms may also exhibit optical activity. For example:

[0069] Hexahelicene: This is a molecule that can show optical activity even without chiral atoms. Its optical activity is generated by the interaction of the benzene ring within the molecule.

[0070] Benzophenone: This is another compound that does not contain chiral atoms but is optically active due to its molecular structure.

[0071] In addition, optical activity is also related to the different degrees of refraction or absorption of left-handed circularly polarized light and right-handed circularly polarized light by a substance. This phenomenon was first discovered by Pasteur when he was studying tartaric acid. He observed that the two crystalline forms of tartaric acid caused light to rotate in opposite directions.

[0072] In general, the properties of these optically active substances make them important in scientific research and technological applications, especially in areas such as liquid lenses, where they can be used to change the propagation path of light to achieve different optical effects.

[0073] In some embodiments, the liquid lens is asymmetric along the emission direction. The liquid lens in this embodiment has an asymmetric shape, so that the emitted laser is also asymmetric, so that the uneven distribution of the light spot or light irradiation intensity can be achieved, and while detecting the key area, information can also be obtained from other areas.

[0074] Figure 6 FIG. 2 shows a schematic diagram of the structure of a depth camera in an embodiment of the present utility model. Figure 6 As shown, a depth camera in an embodiment of the present invention includes a laser projector with a variable range and a receiver 6 .

[0075] The variable-range laser projector is the variable-range laser projector of any of the preceding embodiments.

[0076] The receiver 6 is used to receive the reflected signal of the laser and generate a depth image.

[0077] The type of the receiver 6 is selected according to the type of the variable range laser projector. The receiver can be a structured light receiver or a TOF receiver.

[0078] In this embodiment, an RGB or IR camera is used to capture the size of the target object's location, so that the range of required irradiation can be identified and fed back to the controller 3. The FOV required for irradiation is calculated according to the number of pixels and focal length of the target object in the image. At the same time, the angle of the target object deviating from the optical axis of the depth camera can be calculated by the position of the center of the object in the image.

[0079] FOV = atand (number of pixels * pixel size / f)

[0080] The light source and the liquid lens correspond to different gradient changes, and a one-to-one correspondence is established with the focusing direction and the convergence angle for calibration. In this way, after the FOV and angle θ of the target object are known, a table lookup method can be used to quickly correspond to a set of gradient change voltages to control the changes on the surface of the liquid lens and achieve rapid focusing at different angles and different FOVs.

[0081] This embodiment can automatically track the target object, and at the same time, the method of controlling the light angle can effectively increase the FOV of the light source, while avoiding the edge shading problem caused by too large FOV. The light energy density irradiated to the surface of the object can always be maintained at a sufficiently strong level, effectively utilizing the light power of the depth camera, reducing power consumption,

[0082] The utility model can realize the rapid deformation of the lens through electrical signals, so that the direction of the light field changes. With the help of algorithms to quickly locate the target object, the target area can be illuminated uniformly and the light energy density can be increased. While realizing arbitrary changes in the light field, the field of view of the depth camera can be expanded, the surface uniformity of the target object can be improved, shading can be reduced, and image quality can be improved.

[0083] The embodiment of the utility model further provides a smart device, which includes the variable range laser projector provided by any of the above embodiments, and the smart device can be a mobile phone, a tablet computer, a payment device, a drone, a robot, a digital camera, etc. The variable range laser projector of this embodiment adopts a liquid lens, and the liquid lens includes a first electrode and a second electrode, and at least one of the first electrode and the second electrode includes a plurality of independent electrodes, so that the plurality of electrodes can be controlled individually, so that the shape of the liquid lens can be more finely controlled, so that the laser can be switched between structured light and flood light, so that the emission direction and focal length of the laser can be changed.

[0084] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other. The above description of the disclosed embodiments enables professionals and technicians in this field to implement or use the utility model. Various modifications to these embodiments will be obvious to professionals and technicians in this field, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the utility model. Therefore, the utility model will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features disclosed herein.

[0085] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various modifications or variations within the scope of the claims, which does not affect the essence of the present invention.

Claims

1. A variable range laser projector, characterized in that: include: A light source for generating laser light; Liquid crystal glass, located on the optical path of the laser, used to change the form of the laser into structured light or flood light; A liquid lens, located on the optical path of the laser, and used to change the emission direction of the laser; A controller connected to the light source, the liquid crystal glass and the liquid lens, and configured to control the light source, the liquid crystal glass and the liquid lens; The liquid lens comprises: a first electrode and a second electrode; At least one of the first electrode and the second electrode includes a plurality of independent electrodes.

2. A variable range laser projector according to claim 1, characterized in that: The laser passes through the liquid crystal glass and the liquid lens in sequence.

3. A variable range laser projector according to claim 1, characterized in that: The first electrode includes a third electrode and a fourth electrode; the third electrode and the fourth electrode have different voltages.

4. A variable range laser projector according to claim 1, characterized in that: The second electrode includes a fifth electrode and a sixth electrode; the fifth electrode and the sixth electrode have different voltages.

5. A variable range laser projector according to claim 1, characterized in that: The controller changes the optical axis direction of the emission direction by controlling the voltages of the first electrode and the second electrode.

6. A variable range laser projector according to claim 1, characterized in that: The controller changes the projection area of ​​the laser by controlling the voltages of the first electrode and the second electrode.

7. A variable range laser projector according to claim 1, characterized in that: The liquid lens further includes an optically active substance; the optically active substance changes the propagation path of the laser according to a voltage change between the first electrode and the second electrode.

8. A variable range laser projector according to claim 1, characterized in that: The controller controls the liquid crystal glass to display a preset pattern so that only a partial area is transparent to the laser, and changes the irradiation area and light intensity of the structured light by changing the shape of the preset pattern.

9. A depth camera, characterized in that: A variable-range laser projector comprising the step of:

10. A smart device, characterized in that: A variable-range laser projector comprising the step of:

Images