Distance measuring device

Abstract

The invention discloses a distance measuring device, and the device comprises a telescoping assembly which forms a first optical path for human eye telescoping; the display assembly comprises a light source assembly and a spatial light modulator, the light source assembly and the spatial light modulator are arranged outside the first light path, and the spatial light modulator is configured to form a set diffraction image on the first light path based on the light source assembly. In this way, the light transmittance of the telescopic light path can be improved, and the cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of medium-free display distance measurement, and in particular to a distance measurement device. Background Art

[0002] With the technological innovation in the field of distance measurement, it is generally required to display images on the telescopic optical path of the distance measurement device. The relevant technologies generally adopt the following two methods:

[0003] One is: high-transmittance screen display, which directly displays the required image on the display screen. In this way, the transmittance of the physical display screen is low. The current technology is generally around 75%. The energy loss of the scene through the telescope optical path is high, the human eye observes it darkly, and the experience is poor.

[0004] The other is projection display. This method requires the installation of reflectors, lenses, prisms, etc. Too many local coordinate axes aligned in three-dimensional space can easily cause projection position deviation, make installation and adjustment difficult, and increase manufacturing costs. Summary of the invention

[0005] The present application provides a distance measuring device, which can improve the light transmittance of a telescopic optical path and reduce costs.

[0006] On the one hand, the present application provides a ranging device, which includes: a telephoto component, which forms a first optical path for human eyes to see far away; a display component, which includes a light source component and a spatial light modulator, which are arranged outside the first optical path, and the spatial light modulator is configured to form a set diffraction image on the first optical path based on the light source component.

[0007] In one embodiment, the light source assembly includes: a laser configured to generate laser light; a collimating lens group including a focusing lens and a collimating lens; wherein the laser, the focusing lens, the collimating lens and the spatial light modulator sequentially form a second optical path through which the laser light passes.

[0008] In one embodiment, the light source assembly further includes an aperture, which is disposed on the second optical path between the laser and the collimating lens assembly.

[0009] In one embodiment, the light source assembly further comprises a binary diffractive optical element, which is disposed on the second optical path between the aperture and the collimating lens group, or the binary diffractive optical element is disposed on the second optical path between the collimating lens group and the spatial light modulator.

[0010] In one embodiment, the light source assembly further includes a reflector, and the laser, focusing lens, collimating lens and reflector form a third light path through which the laser passes. After the laser is reflected by the reflector, the reflector and the spatial light modulator form a fourth light path through which the laser passes.

[0011] In one embodiment, the reflector is configured to make the cross-sectional area of ​​the incident light of the spatial light modulator greater than or equal to the cross-sectional area of ​​the outgoing light of the collimating lens group.

[0012] In one embodiment, the spatial light modulator is a transmissive spatial light modulator, and the light source assembly and the spatial light modulator are disposed on the same side of the first light path.

[0013] In one embodiment, the distance measuring device further includes an extinction plate, the extinction plate and the spatial light modulator are respectively arranged on opposite sides of the first light path, and the extinction plate is arranged on the diffraction light path of the spatial light modulator.

[0014] In one embodiment, the spatial light modulator is a reflective spatial light modulator, and the light source assembly and the spatial light modulator are respectively disposed on opposite sides of the first light path.

[0015] In one embodiment, the telescopic assembly includes an objective lens and an eyepiece, and the spatial light modulator is configured to form a set diffraction image on a first optical path between the objective lens and the eyepiece based on a light source assembly.

[0016] The distance measuring device provided by the present application includes: a telescope component, which forms a first optical path for the human eye to telescope; a display component, which includes a light source component and a spatial light modulator, which are arranged outside the first optical path, and the spatial light modulator is configured to form a set diffraction image on the first optical path based on the light source component. Through the above method, on the one hand, since neither the light source component nor the spatial light modulator is arranged on the first optical path, the first optical path is 100% transparent, and the human eye can observe it well; on the other hand, only the light source component and the spatial light modulator need to form a simple optical path, and since the imaging position and angle of the spatial light modulator can be easily adjusted by software, there are no strict requirements for the setting of the optical components and the optical path in the light source component, which reduces the difficulty of production and reduces the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 is a structural schematic diagram of a first embodiment of a distance measuring device provided by the present application;

[0019] Figure 2 is a structural schematic diagram of a second embodiment of a distance measuring device provided by the present application;

[0020] Figure 3is a structural schematic diagram of a third embodiment of a distance measuring device provided by the present application;

[0021] Figure 4 is a structural schematic diagram of a fourth embodiment of a distance measuring device provided by the present application;

[0022] Figure 5 is a structural schematic diagram of a fifth embodiment of a distance measuring device provided by the present application;

[0023] Figure 6 It is a structural schematic diagram of the sixth embodiment of the distance measuring device provided by the present application. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0025] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0026] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0027] The use of "suitable for" or "configured to" in this application is meant to be open and inclusive language, which does not exclude devices that are suitable for or configured to perform additional tasks or steps. In addition, the use of "based on" is meant to be open and inclusive, because the process, step, calculation or other action "based on" one or more stated conditions or values ​​can be based on additional conditions or values ​​beyond the stated values ​​in practice.

[0028] In this application, the word "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described in this application as "exemplary" is not necessarily to be construed as being preferred or advantageous over other embodiments. The following description is given to enable any technician in the field to implement and use the present application. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present application can be implemented without using these specific details. In other instances, well-known structures and processes will not be elaborated in detail to avoid obscuring the description of the present application with unnecessary details. Therefore, the present application is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in the present application.

[0029] See also Figure 1 , Figure 1 1 is a schematic structural diagram of a first embodiment of a distance measuring device provided in the present application. The distance measuring device 100 includes a telescope component 10 and a display component 20 .

[0030] The telescope assembly 10 forms a first optical path for the human eye to telescope. Optionally, the telescope assembly 10 includes an objective lens 11 and an eyepiece 12, and a first optical path is formed between the objective lens 11 and the eyepiece 12. The telescope assembly 10 uses lenses as the objective lens 11 and the eyepiece 12, and focuses the light of a distant object to a focal point through the light refraction of the objective lens 11, and then magnifies it through the eyepiece 12 to form a virtual image.

[0031] The display component 20 includes a light source component 21 and a spatial light modulator 22, the light source component 21 and the spatial light modulator 22 are arranged outside the first optical path, and the spatial light modulator 22 is configured to form a set diffraction image on the first optical path based on the light source component 21.

[0032] Among them, the spatial light modulator 22 refers to a device that can modulate a certain parameter of the light field through liquid crystal molecules under active control, such as by modulating the amplitude of the light field, modulating the phase through the refractive index, modulating the polarization state through the rotation of the polarization plane, or realizing the conversion of incoherent-coherent light, so as to write certain information into the light wave and achieve the purpose of light wave modulation. It can conveniently load information into a one-dimensional or two-dimensional light field, and use the advantages of wide bandwidth of light, multi-channel parallel processing, etc. to quickly process the loaded information. It is a core component of systems such as real-time optical information processing, optical interconnection, and optical computing.

[0033] It can be understood that the spatial light modulator 22 has a holographic diffraction imaging function. Figure 1Taking the transmissive spatial light modulator as an example, the material of the transmissive spatial light modulator is liquid crystal. The orientation of the liquid crystal molecules can be controlled by voltage to obtain a special phase distribution. The phase distribution corresponds one-to-one to the holographic image and position to be imaged. When the laser beam is irradiated on the spatial light modulator, it will form any specified image at any specified position in the medium-free air imaging area.

[0034] It is worth noting that the spatial light modulator 22 is controlled by software. Therefore, the position and angle of the diffraction image can be adjusted by setting or adjusting the software, so that the diffraction image can be imaged at a desired designated position.

[0035] Alternatively, if Figure 2 As shown, Figure 2 is a structural schematic diagram of a second embodiment of a distance measuring device provided by the present application, Figure 2 Example and Figure 1 The difference between the embodiments is that the spatial light modulator 22 may be a reflective type. For a reflective spatial light modulator, the light source assembly 21 and the spatial light modulator 22 are respectively arranged on opposite sides of the first light path.

[0036] The distance measuring device provided in this embodiment includes: a telescope component, which forms a first optical path for human eyes to see far away; a display component, which includes a light source component and a spatial light modulator, which are arranged outside the first optical path, and the spatial light modulator is configured to form a set diffraction image on the first optical path based on the light source component. Through the above method, on the one hand, since neither the light source component nor the spatial light modulator is arranged on the first optical path, the first optical path is 100% transparent, and the human eye can observe it well; on the other hand, only the light source component and the spatial light modulator need to form a simple optical path, and since the imaging position and angle of the spatial light modulator can be easily adjusted by software, there are no strict requirements on the setting of the optical components and the optical path in the light source component, which reduces the difficulty of production and reduces the cost.

[0037] See also Figure 1 and Figure 2 In one embodiment, the light source assembly 21 includes a laser 211, an aperture 212, a binary diffractive optical element 213, a collimator lens group 214, and a reflector 215, which are arranged in sequence. The laser 211, the aperture 212, the binary diffractive optical element 213, the collimator lens group 214, the reflector 215, and the spatial light modulator 22 form a second optical path. It can be understood that since the reflector 215 changes the direction of the laser, the second optical path can further include a third optical path and a fourth optical path, that is, the third optical path formed by the laser 211, the aperture 212, the binary diffractive optical element 213, the collimator lens group 214, and the reflector 215, and the fourth optical path formed by the reflector 215 and the spatial light modulator 22.

[0038] The laser 211 may be a light emitting diode or a semiconductor laser, and is used to generate monochromatic or polychromatic laser light. Monochromatic laser light is visible light of a single wavelength such as red, green, and blue. Polychromatic laser light is a laser light of three wavelengths emitted by a combination of red, green, and blue lasers. The polychromatic laser has no special requirements for the combination of lasers. Both coaxial and non-coaxial structures are acceptable, as long as the three lasers emitted have sufficient overlapping area. The size of the overlapping area is determined by the area irradiated to the spatial light modulator 22. The area irradiated to the spatial light modulator 22 is greater than or equal to the area of ​​the output light beam of the collimator group 214. The diameter of the output light beam of the collimator group 214 can be calculated using the Rahe invariant, that is, nuy=n'u'y', wherein n and n' are the refractive indices of air, u is the divergence angle of the laser emitted from the binary diffractive optical element 213, u' is the divergence angle of the laser emitted from the collimator group 214, y is the diameter of the laser emitted from the last surface of the binary diffractive optical element 213, and y' is the diameter of the laser emitted from the last surface of the collimator group 214.

[0039] Among them, the aperture 212 refers to an entity that limits the light beam in the optical system. It can be the edge of a lens, a frame, or a specially set screen with holes. Its role can be divided into two aspects: limiting the light beam or limiting the size of the field of view (imaging range). The aperture that limits the light beam the most in the optical system is called the aperture aperture, and the aperture that limits the field of view (size) the most is called the field aperture. It can be understood that the lasers used in active light source diffraction imaging generally have the problem of uneven energy distribution, which can easily cause uneven brightness distribution of the displayed image and color distortion of the color image. The aperture 212 is used to select a laser beam in an appropriate range, and the range is determined by the beam shaping design of the binary diffraction optical element.

[0040] The binary diffractive optical element 213 is used to shape the energy distribution of the laser to obtain collimated laser light with uniform energy distribution. The binary diffractive optical element 213 can be located on the same side of the collimating lens group 214 as the aperture 212, or the aperture 212 and the binary diffractive optical element 213 can be located on both sides of the collimating lens group 214, respectively. That is, the binary diffractive optical element 213 is arranged on the second optical path between the aperture 212 and the collimating lens group 214, or the binary diffractive optical element 213 is arranged on the second optical path between the collimating lens group 214 and the spatial light modulator 22.

[0041] In one embodiment, the binary diffractive optical element 213 and the aperture 212 are located on the same side of the collimating lens group 214. Therefore, the laser 211, the aperture 212 and the binary diffractive optical element 213 can be packaged together, with a compact structure and easy installation and adjustment.

[0042] It can be understood that the above binary diffractive optical element 213 is a transmissive binary diffractive optical element as an example, and in other embodiments, the binary diffractive optical element 213 may also be a reflective one. Figure 3 As shown, Figure 3 It is a structural schematic diagram of the third embodiment of the distance measuring device provided by the present application. Figure 3 Example and Figure 1 The difference between the embodiments is that the binary diffractive optical element 213 is reflective, wherein the laser 211, the aperture 212 and the binary diffractive optical element 213 form a fifth optical path, and after the laser is reflected by the binary diffractive optical element 213, the binary diffractive optical element 213, the collimating lens group 214 and the reflector 215 form a sixth optical path, and the above-mentioned third optical path includes the fifth optical path and the sixth optical path.

[0043] The collimating lens group 214 includes a focusing lens and a collimating lens. The collimating lens group 214 is used to obtain a uniformly illuminated collimated laser beam and achieve the purpose of beam expansion.

[0044] The reflector 215 is used to fold the optical path. The laser beam emitted from the collimator lens group 214 is incident on the reflector 215 and then reflected to the spatial light modulator 22 .

[0045] Combination Figure 1 , Figure 1 The corresponding embodiment completes the workflow as follows: a software algorithm (such as the PB (Pancharatnam-Berry) phase design method) is used to obtain a phase distribution diagram of a specified image at a specified position in the medium-free air imaging area, and the phase distribution diagram is transmitted to the spatial light modulator for replication. Further, the laser emitted by the laser 211 is selected by the aperture 212 to form a laser beam of a certain width; the binary diffraction optical element 213 shapes the laser to obtain a laser with uniform energy distribution; the collimator lens group 214 collimates the laser and simultaneously obtains a certain degree of beam expansion; the reflector 215 reflects the laser to the transmission-type spatial light modulator 22; the spatial light modulator 22 diffracts a specified image at a specified position in the medium-free air imaging area; the human eye observes the diffracted image through the eyepiece 12. Because there are no physical optical elements in the medium-free air imaging area, there will be no obstruction to the telescopic imaging beam, and the transmittance is 100%.

[0046] See also Figure 1 and Figure 4 , Figure 4 It is a structural schematic diagram of the fourth embodiment of the distance measuring device provided by the present application. Figure 4 Example and Figure 1 The difference between the embodiments is that the distance measuring device 100 further includes a light extinction plate 30 , the light extinction plate 30 and the spatial light modulator 22 are respectively arranged on opposite sides of the first light path, and the light extinction plate 30 is arranged on the diffraction light path of the spatial light modulator 22 .

[0047] The extinction plate 30 is used to absorb unnecessary stray light. The laser light passing through the spatial light modulator 22 is not all used for diffraction imaging, and there will be scattered light, which will generate background light when observed by human eyes. The extinction plate 30 can effectively eliminate it.

[0048] It can be understood that the required collimated laser beam can be generated by the above-mentioned laser 211, aperture 212, binary diffraction optical element 213 and collimating lens group 214, and then reaches the spatial light modulator 22 through reflection by the reflector 215. The reflector 215 can play a role in reducing the space.

[0049] Optionally, in one embodiment, if Figure 5 As shown, Figure 5 It is a structural schematic diagram of the fifth embodiment of the distance measuring device provided by the present application. Figure 5 Example and Figure 1 The difference between the embodiments is that the reflector 215 may not be provided.

[0050] Specifically, the light source assembly 21 includes a laser 211, an aperture 212, a binary diffractive optical element 213 and a collimator lens group 214 arranged in sequence, and the laser 211, the aperture 212, the binary diffractive optical element 213, the collimator lens group 214 and the spatial light modulator 22 form a second optical path.

[0051] The laser 211 may be a light emitting diode or a semiconductor laser, and is used to generate monochromatic or polychromatic laser light. Monochromatic laser light is visible light of a single wavelength such as red, green, and blue. Polychromatic laser light is a laser light of three wavelengths emitted by a combination of red, green, and blue lasers. The polychromatic laser has no special requirements for the combination of lasers. Both coaxial and non-coaxial structures are acceptable, as long as the three lasers emitted have sufficient overlapping area. The size of the overlapping area is determined by the area irradiated to the spatial light modulator 22. The area irradiated to the spatial light modulator 22 is greater than or equal to the area of ​​the output light beam of the collimator group 214. The diameter of the output light beam of the collimator group 214 can be calculated using the Rahe invariant, that is, nuy=n'u'y', wherein n and n' are the refractive indices of air, u is the divergence angle of the laser emitted from the binary diffractive optical element 213, u' is the divergence angle of the laser emitted from the collimator group 214, y is the diameter of the laser emitted from the last surface of the binary diffractive optical element 213, and y' is the diameter of the laser emitted from the last surface of the collimator group 214.

[0052] Among them, the aperture 212 refers to an entity that limits the light beam in the optical system. It can be the edge of a lens, a frame, or a specially set screen with holes. Its role can be divided into two aspects: limiting the light beam or limiting the size of the field of view (imaging range). The aperture that limits the light beam the most in the optical system is called the aperture aperture, and the aperture that limits the field of view (size) the most is called the field aperture. It can be understood that the lasers used in active light source diffraction imaging generally have the problem of uneven energy distribution, which can easily cause uneven brightness distribution of the displayed image and color distortion of the color image. The aperture 212 is used to select a laser beam in an appropriate range, and the range is determined by the beam shaping design of the binary diffraction optical element.

[0053] The binary diffractive optical element 213 is used to shape the energy distribution of the laser to obtain collimated laser with uniform energy distribution.

[0054] The collimating lens group 214 includes a focusing lens and a collimating lens. The collimating lens group 214 is used to obtain a uniformly illuminated collimated laser beam and achieve the purpose of beam expansion.

[0055] Combination Figure 5 , Figure 5 The corresponding working process of the embodiment is as follows: a software algorithm (such as the PB (Pancharatnam-Berry) phase design method) is used to obtain a phase distribution diagram of a specified image at a specified position in the medium-free air imaging area, and the phase distribution diagram is transmitted to the spatial light modulator for replication. Further, the laser emitted by the laser 211 is selected by the aperture 212 to form a laser beam of a certain width; the binary diffraction optical element 213 shapes the laser to obtain a laser with uniform energy distribution; the collimator lens group 214 collimates the laser, and simultaneously obtains a certain degree of beam expansion before reaching the spatial light modulator 22; the spatial light modulator 22 diffracts the specified image at a specified position in the medium-free air imaging area; the human eye observes the diffracted image through the eyepiece 12. Because there are no physical optical elements in the medium-free air imaging area, there will be no obstruction to the telescopic imaging beam, and the transmittance is 100%.

[0056] Optionally, in one embodiment, if Figure 6 As shown, Figure 6 It is a structural schematic diagram of the sixth embodiment of the distance measuring device provided by the present application. Figure 6 Example and Figure 5 The difference between the embodiments is that the aperture 212 and the binary diffractive optical element 213 may not be provided.

[0057] Specifically, the light source assembly 21 includes a laser 211 and a collimator lens group 214 which are arranged in sequence. The laser 211, the collimator lens group 214 and the spatial light modulator 22 form a second optical path.

[0058] The laser 211 may be a light emitting diode or a semiconductor laser, and is used to generate monochromatic or polychromatic laser light. Monochromatic laser light is visible light of a single wavelength such as red, green, and blue. Polychromatic laser light is a laser light of three wavelengths emitted by a combination of red, green, and blue lasers. The polychromatic laser has no special requirements for the combination of lasers. Both coaxial and non-coaxial structures are acceptable, as long as the three lasers emitted have sufficient overlapping area. The size of the overlapping area is determined by the area irradiated to the spatial light modulator 22. The area irradiated to the spatial light modulator 22 is greater than or equal to the area of ​​the output light beam of the collimator group 214. The diameter of the output light beam of the collimator group 214 can be calculated using the Rahe invariant, that is, nuy=n'u'y', wherein n and n' are the refractive indices of air, u is the divergence angle of the laser emitted from the binary diffractive optical element 213, u' is the divergence angle of the laser emitted from the collimator group 214, y is the diameter of the laser emitted from the last surface of the binary diffractive optical element 213, and y' is the diameter of the laser emitted from the last surface of the collimator group 214.

[0059] The collimating lens group 214 includes a focusing lens and a collimating lens. The collimating lens group 214 is used to obtain a uniformly illuminated collimated laser beam and achieve the purpose of beam expansion.

[0060] Combination Figure 6 , Figure 6 The corresponding embodiment completes the workflow as follows: a software algorithm (such as the PB (Pancharatnam-Berry) phase design method) is used to obtain a phase distribution diagram of a specified image at a specified position in the medium-free air imaging area, and transmit it to the spatial light modulator for replication. Further, the laser 211 emits a laser; the collimator lens group 214 collimates the laser, and then obtains a certain degree of beam expansion and reaches the spatial light modulator 22; the spatial light modulator 22 diffracts a specified image at a specified position in the medium-free air imaging area; the human eye observes the diffracted image through the eyepiece 12. Because there are no physical optical elements in the medium-free air imaging area, there will be no obstruction of the telescopic imaging beam, and the transmittance is 100%.

[0061] It can be understood that the distance measuring device 100 in the above embodiment can be a handheld portable laser distance measuring device. The display content set by the distance measuring device is imaged in the air, and has no shielding effect on the telescopic light, and is 100% transparent. In addition, the hardware installation and adjustment requirements are low, and the required imaging information can be adjusted by adjusting the software to correct the position and angle in the three-dimensional space of the imaging area.

[0062] In addition, in addition to the above-mentioned handheld portable laser rangefinder, the distance measuring device 100 of the embodiment of the present application can also be applied to rifle scopes, binoculars, holographic helmets and glasses, etc.

[0063] The power supply control device, power supply control method and power supply system provided in the embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A distance measuring device, characterized in that: The distance measuring device comprises: A telescope assembly, wherein the telescope assembly forms a first optical path for a human eye to telescope; The display component includes a light source component and a spatial light modulator, wherein the light source component and the spatial light modulator are arranged outside the first light path, and the spatial light modulator is configured to form a set diffraction image on the first light path based on the light source component.

2. The distance measuring device according to claim 1, characterized in that: The light source assembly comprises: a laser configured to generate laser light; A collimating lens assembly, comprising a focusing lens and a collimating lens; The laser, the focusing lens, the collimating lens and the spatial light modulator sequentially form a second optical path through which the laser passes.

3. The distance measuring device according to claim 2, characterized in that: The light source assembly further comprises an aperture, and the aperture is arranged on the second light path between the laser and the collimating lens group.

4. The distance measuring device according to claim 3, characterized in that: The light source assembly further comprises a binary diffractive optical element, which is arranged on the second optical path between the aperture and the collimating lens group, or the binary diffractive optical element is arranged on the second optical path between the collimating lens group and the spatial light modulator.

5. The distance measuring device according to claim 2, characterized in that: The light source assembly also includes a reflector, and the laser, the focusing lens, the collimating lens and the reflector form a third light path through which the laser passes. After the laser is reflected by the reflector, the reflector and the spatial light modulator form a fourth light path through which the laser passes.

6. The distance measuring device according to claim 5, characterized in that: The reflector is configured to make the cross-sectional area of ​​the incident light of the spatial light modulator greater than or equal to the cross-sectional area of ​​the outgoing light of the collimating lens group.

7. The distance measuring device according to claim 1, characterized in that: The spatial light modulator is a transmissive spatial light modulator, and the light source assembly and the spatial light modulator are arranged on the same side of the first light path.

8. The distance measuring device according to claim 7, characterized in that: The distance measuring device further comprises an extinction plate, wherein the extinction plate and the spatial light modulator are respectively arranged on opposite sides of the first light path, and the extinction plate is arranged on the diffraction light path of the spatial light modulator.

9. The distance measuring device according to claim 1, characterized in that: The spatial light modulator is a reflective spatial light modulator, and the light source assembly and the spatial light modulator are respectively arranged on two opposite sides of the first light path.

10. The distance measuring device according to claim 1, characterized in that: The telephoto assembly includes an objective lens and an eyepiece, and the spatial light modulator is configured to form a set diffraction image on the first optical path between the objective lens and the eyepiece based on the light source assembly.

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