Holographic aiming system and observation equipment

Abstract

The invention relates to the technical field of optics, and provides a holographic aiming system and observation equipment, the holographic aiming system comprises a hologram, a laser module, a light conversion module and a diffractive optical element, the hologram and the diffractive optical element are arranged side by side, and the optical axes of the hologram and the diffractive optical element are parallel; the hologram diffracts laser emitted by the laser module to form aiming point light which is parallel to first visible light penetrating through the hologram and the diffractive optical element and is consistent with the first visible light in direction; the diffractive optical element diffracts invisible light from the same scene with the first visible light and diffracts the invisible light to the light conversion module, and the light conversion module converts the diffracted invisible light into second visible light and projects the second visible light to the diffractive optical element at a predetermined incident angle. The diffractive optical element diffracts the second visible light at a predetermined incident angle, so that the diffracted second visible light is parallel to the first visible light and is consistent in direction. According to the invention, the specific target in the object image can be quickly aimed at in a low-light environment.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to a holographic aiming system and observation equipment. Background Art

[0002] A holographic aiming system is an optical aiming system that uses holographic technology to display an aiming point. The core of this system is a hologram that records an aiming point (such as a red dot or reticle). When a laser of a specific wavelength is illuminated at a specific angle, the hologram diffracts light to reconstruct an image of the aiming point, which is then superimposed on the aiming system's viewing window.

[0003] However, existing holographic aiming systems can only be used in visible light environments, which greatly limits their application range. For example, at night, in low-light environments, or in complex environments such as dense forests with obstructions and camouflage (resulting in light obstruction), heavy rain, and snow, relying solely on visible light for aiming cannot provide sufficient image clarity and cannot quickly target a specific target. Summary of the Invention

[0004] The present invention provides a holographic aiming system and an observation device, which are used to solve the problem that the holographic aiming system in the prior art cannot aim quickly and accurately in low light or complex environments.

[0005] The present invention provides a holographic aiming system, comprising: a hologram, a laser module, a light conversion module and a diffractive optical element, wherein the hologram and the diffractive optical element are arranged side by side, and the optical axis of the hologram is parallel to the optical axis of the diffractive optical element; The hologram is used to diffract the laser light emitted by the laser module to form an aiming point light that is parallel to and has the same direction as the first visible light passing through the hologram and the diffractive optical element; The diffraction optical element is used to diffract invisible light from the same scene as the first visible light, and diffract the invisible light to the light conversion module. The light conversion module is used to convert the diffracted invisible light into second visible light, and project the second visible light onto the diffraction optical element at a predetermined incident angle, where the predetermined incident angle is different from the incident angle of the first visible light. The diffraction optical element is also used to diffract the second visible light at the predetermined incident angle, so that the diffracted second visible diffracted light is parallel to the first visible light and has the same direction.

[0006] According to a holographic aiming system provided by the present invention, the light conversion module includes: a photoelectric conversion module, a signal processing module and a second visible light conversion module; The photoelectric conversion module is used to convert the diffracted invisible light into an electrical signal; The signal processing module is used to modulate the electrical signal and output the modulated electrical signal to the second visible light conversion module; The second visible light conversion module is used to convert the modulated electrical signal into the second visible light, and project the second visible light onto the diffractive optical element at a predetermined incident angle.

[0007] According to a holographic aiming system provided by the present invention, the photoelectric conversion module includes: an invisible light focusing module and a detector, and the detector is connected to the signal processing module; The invisible light focusing module is used to focus the diffracted invisible light onto the detector; The detector is used to convert the diffracted invisible light into an electrical signal, and transmit the converted electrical signal to the signal processing module.

[0008] According to a holographic aiming system provided by the present invention, the invisible light is infrared light and the detector is an infrared detector, or the invisible light is ultraviolet light and the detector is an ultraviolet detector, or the invisible light is millimeter wave and the detector is a millimeter wave detector.

[0009] According to a holographic aiming system provided by the present invention, the second visible light conversion module includes: a display screen and a visible light collimation module, and the display screen is connected to the signal processing module; The display screen is used to receive the electrical signal modulated by the signal processing module and display a corresponding image under the drive of the electrical signal; The visible light collimating module is used to collimate the image light displayed on the display screen to generate the second visible light, and project the second visible light onto the diffractive optical element at a predetermined incident angle.

[0010] According to a holographic aiming system provided by the present invention, the photoelectric conversion module and the second visible light conversion module are both located on the same side of the diffractive optical element; or, the photoelectric conversion module and the second visible light conversion module are respectively located on different sides of the diffractive optical element.

[0011] According to a holographic aiming system provided by the present invention, the diffraction optical element includes: a first diffraction optical sub-element and a second diffraction optical sub-element, the first diffraction optical sub-element and the second diffraction optical sub-element are arranged side by side, and their respective optical axes are parallel, the first diffraction optical sub-element is used to diffract the invisible light and directly transmit the first visible light and the second visible light, and the second diffraction optical sub-element is used to diffract the second visible light with a predetermined incident angle and directly transmit the first visible light and the invisible light.

[0012] According to a holographic aiming system provided by the present invention, the optical axis of the hologram coincides with the optical axis of the diffractive optical element.

[0013] A holographic aiming system provided according to the present invention further includes: a control switch connected to the light conversion module and used to control the light conversion module to be turned on or off.

[0014] The present invention also provides an observation device, comprising: the holographic aiming system described in any one of the above items.

[0015] The holographic aiming system and observation equipment provided by the present invention utilizes a diffractive optical element to diffract invisible light from the same scene as the first visible light. A light conversion module converts the diffracted invisible light into a second visible light, which is then projected onto the diffractive optical element at a predetermined angle of incidence. The diffractive optical element then diffracts the second visible light at the predetermined angle of incidence, so that the diffracted second visible light is parallel to and oriented in the same direction as the first visible light. The second visible light converted from the invisible light is then diffracted by the diffractive optical element and superimposed with the first visible light that directly passes through the hologram and the diffractive optical element, thereby increasing the image information entering the human eye and enhancing the human eye's ability to observe and resolve external objects. Furthermore, the aiming point light formed by the hologram diffraction laser is parallel to and oriented in the same direction as the first visible light, enabling the human eye to observe clear images even in low light and complex environments, thereby enabling rapid aiming at specific targets within the image. Moreover, the first visible light and the invisible light come from the same scene, that is, the invisible light image and the visible light image in the external scene come from the same field of view. The complete image fusion effect can be achieved relatively easily through direct physical superposition. There is no need for complex image fusion algorithms and stitching algorithms to perform overlap and fine-tune the two images, so that the human eye can see clearer images, and the aiming system has lower latency and faster response. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is one of the structural diagrams of the holographic aiming system provided by the present invention.

[0018] Figure 2 This is the second structural diagram of the holographic aiming system provided by the present invention.

[0019] Figure 3 yes Figure 2Schematic diagram of the diffraction of invisible light and second visible light by the diffraction optical element in the holographic aiming system.

[0020] Figure 4 This is the third structural diagram of the holographic aiming system provided by the present invention.

[0021] Figure 5 yes Figure 4 Schematic diagram of the diffraction of invisible light by the diffractive optical element in the holographic aiming system.

[0022] Figure 6 yes Figure 4 Schematic diagram of the diffraction of the second visible light by the diffraction optical element in the holographic aiming system. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0024] The holographic aiming system of the embodiment of the present invention is as follows: Figure 1 As shown, it includes: a hologram 112, a laser module, a light conversion module and a diffractive optical element 100. The hologram 112 and the diffractive optical element 100 are arranged side by side, and the optical axis of the hologram 112 is parallel to the optical axis of the diffractive optical element 100 to ensure that the focal plane of the external object image is parallel to the hologram 112, so that the object image is parallel to the image of the aiming point on the hologram 112 without an angle difference, so as to achieve precise aiming.

[0025] The hologram 112 is used to diffract the laser light emitted by the laser module to form an aiming point light 222 that is parallel to and has the same direction as the first visible light 230 passing through the hologram 112 and the diffractive optical element 100 , ie, the light emitted by the aiming point image.

[0026] The diffractive optical element 100 is used to diffract (reflective diffraction) the invisible light 200 from the same scene as the first visible light 230, and diffract the invisible light 200 to the light conversion module. The light conversion module is used to convert the diffracted invisible light into second visible light 211, and project the second visible light 211 onto the diffractive optical element 100 at a predetermined incident angle, which is different from the incident angle of the first visible light 230. Specifically, Figure 1In the embodiment, the diffractive optical element 100 diffracts the invisible light 200 into the invisible diffracted light 201, and the light conversion module converts the invisible diffracted light 201 into the second visible light 211. Exemplarily, the first visible light 230 is incident parallel to the optical axis of the diffractive optical element 100. To ensure that the human eye can see the target scene, there must be no obstacles on the incident light path of the first visible light 230. Therefore, the light conversion module must project the second visible light 211 onto the diffractive optical element 100 from one side of the optical axis of the diffractive optical element 100, that is, the second visible light 211 is incident on the diffractive optical element 100 at a predetermined incident angle.

[0027] The diffractive optical element 100 is also used to diffract (transmission-type diffraction) the second visible light 211 at a predetermined incident angle, causing the diffracted second visible diffracted light 212 to be parallel and aligned with the first visible light 230. This allows the second visible diffracted light 212, the first visible light 230, and the aiming point light 222 to superimpose and enter the human eye. The superposition of invisible and visible light increases the image information entering the human eye, enabling the human eye to observe clear images even in low-light environments. Combined with the superposition of aiming point light 222, this enables fast and accurate aiming in low-light environments. Furthermore, the first visible light 230 and the invisible light 200 originate from the same scene. That is, the invisible and visible light images of the external scene originate from the same field of view. Through direct physical superposition, complete image fusion can be achieved relatively easily, eliminating the need for complex image fusion and stitching algorithms to fine-tune the overlap of the two images. This results in a clearer image for the human eye and reduced latency and faster response for the aiming system.

[0028] It should be noted that the diffractive optical element 100 has microstructures on the order of wavelengths or even smaller than wavelengths. These structures can cause phase or amplitude changes in the light beam, enabling it to exhibit specific optical functions on a macroscopic scale for light beams within a specific range of incident angles and wavelengths. For example, when the second visible light 211 meets a preset incident angle and / or wavelength, the visible light is diffracted to a position parallel to the optical axis of the diffractive optical element 100 or at a small angle (e.g., within 5°) to the optical axis, and then transmits out of the diffractive optical element 100. The invisible light 200 is also diffracted, while beams of other wavelengths or visible light at other angles (the first visible light 230 and the parallel laser beam 221) do not produce specific macroscopic optical functions but instead directly transmit out of the diffractive optical element 100. This means that the diffraction is selective with respect to the angle and wavelength of the incident light beam.

[0029] In this embodiment, the laser module may include a laser 110 and a laser optical module 111. Laser light 220 generated by laser 110 is modulated by laser optical module 111 and converted into a parallel laser beam 221. Laser optical module 111 then projects parallel laser beam 221 toward hologram 112. Hologram 112 then diffracts the received parallel laser beam 221 into a visible aiming point light 222.

[0030] In the holographic aiming system of this embodiment, the diffractive optical element 100 diffracts the invisible light 200 from the same scene as the first visible light 230. The light conversion module converts the diffracted invisible light, i.e., the invisible diffracted light 201, into second visible light 211, and projects the second visible light 211 onto the diffractive optical element 100 at a predetermined incident angle. The diffractive optical element 100 diffracts the second visible light 211 at the predetermined incident angle so that the diffracted second visible diffracted light 212 is parallel to the first visible light 230 and has the same direction. The second visible light 211, converted from the invisible light 200, is diffracted by the diffractive optical element 100 and then superimposed with the first visible light 230 that directly passes through the hologram 112 and the diffractive optical element 100. This increases the image information entering the human eye, thereby enhancing the human eye's ability to observe and resolve external objects. Combined with the aiming point light 222 formed by the laser diffracted by the hologram 112, which is parallel to and oriented in the same direction as the first visible light 230, the human eye can observe clear images even in low light and complex environments, allowing it to quickly aim at specific targets within the images. Furthermore, the invisible light 200 and the first visible light 230 originate from the same scene, meaning that the invisible and visible light images of the external scene originate from the same field of view. Through direct physical superposition, complete image fusion can be achieved relatively easily, eliminating the need for complex image fusion and stitching algorithms to fine-tune the overlap of the two images. This allows the human eye to see clearer images, while also reducing latency and responsiveness of the aiming system. In addition, the invisible light 200 and the first visible light 230 come from the same scene, and only an object observation window with a smaller diameter is required, which is more convenient for aiming and observation, especially in complex environments, such as when aiming through a narrow slit.

[0031] In some embodiments, the light conversion module includes: a photoelectric conversion module, a signal processing module 103 and a second visible light conversion module.

[0032] The photoelectric conversion module is used to convert the diffracted invisible light 200 into an electrical signal, that is, to convert the invisible diffracted light 201 into an electrical signal.

[0033] The signal processing module 103 is used to modulate the electrical signal and output the modulated electrical signal to the second visible light conversion module. Specifically, the signal processing module 103 can be a chip with a signal modulation function, such as a microprocessor (MCU).

[0034] The second visible light conversion module is configured to convert the modulated electrical signal into second visible light 211 , and project the second visible light 211 onto the diffractive optical element 100 at a predetermined incident angle.

[0035] In this embodiment, the invisible light 200 is converted into an electrical signal, the electrical signal is modulated, and the modulated electrical signal is converted into the second visible light 211 , thereby achieving conversion from invisible light to visible light.

[0036] In some embodiments, the photoelectric conversion module includes: an invisible light focusing module 101 and a detector 102 , and the detector 102 is connected to a signal processing module 103 .

[0037] The invisible light focusing module 101 is used to focus the invisible diffracted light 201 onto the detector 102. Specifically, the invisible light focusing module 101 converges the invisible diffracted light 201 to form a converged light 202, and focuses the invisible light 200 at the same angle or direction into a single point. That is, the converged light 202 of the invisible diffracted light 201 at the same angle or direction converges to the focal point of the invisible light focusing module 101. The invisible light focusing module 101 can have a single lens structure or a structure composed of multiple lenses.

[0038] Detector 102 is used to convert invisible light into electrical signals and transmit the converted electrical signals to signal processing module 103. Detector 102 is located at the focal plane of invisible light focusing module 101 so that invisible diffracted light 201 can be focused onto detector 102. Detector 102 can be a device that senses invisible diffracted light 201, such as an indium gallium arsenide detector or a mercury cadmium telluride detector.

[0039] In some embodiments, the second visible light conversion module includes: a display screen 104 and a visible light collimating module 105 , and the display screen 104 is connected to the signal processing module 103 .

[0040] The display screen 104 is used to receive the electrical signal modulated by the signal processing module 103, and display the corresponding image under the drive of the electrical signal, that is, the display screen 104 displays the image corresponding to the invisible light 200, and the image light 210 emitted by the image on the display screen 104 belongs to visible light, thereby converting the invisible light 200 representing the external object image into visible image light 210.

[0041] The visible light collimating module 105 is used to collimate the image light 210 displayed on the display screen 104 to generate second visible light 211, and project the second visible light 211 onto the diffractive optical element 100 at a predetermined angle of incidence. Because the image light 210 for each pixel on the display screen 104 is divergent, the visible light collimating module 105 is required to convert the divergent light into parallel light to form the second visible light 211.

[0042] The visible light collimating module 105 may be a single lens structure or a structure composed of multiple lenses.

[0043] In some embodiments, the photoelectric conversion module and the second visible light conversion module are both located on the same side of the diffractive optical element.

[0044] For example, Figure 1 As shown, the photoelectric conversion module (invisible light focusing module 101 and detector 102) and the second visible light conversion module (display screen 104 and visible light collimation module 105) are both located on the incident side of the diffractive optical element 100 where the first visible light 230 is incident. The diffractive optical element 100 can be designed to reflectively diffract the invisible light 200 and transmissively diffract visible light (e.g., second visible light 211) that meets a threshold range of incident angles. Exemplarily, the laser module is located on the incident side of the diffractive optical element 100 where the first visible light 230 is incident, and is closer to the transmissive diffractive optical element 100 than the second visible light conversion module, so that the incident angle of the parallel laser beam 221 generated by the laser module is greater than the incident angles of the second visible light 211 converted by the second visible light conversion module and the incident angles of the first visible light 230. The transmissive diffractive optical element 100 is designed such that, for visible light, its first incident angle threshold range is smaller than the incident angle of the parallel laser beam 221 and larger than the incident angle of the first visible light 230. When the incident angle of the visible light (e.g., the predetermined incident angle of the second visible light 211) is within the first incident angle threshold range, the visible light is transmissively diffracted by the diffractive optical element 100 and then transmits out of the diffractive optical element 100 parallel to the optical axis of the diffractive optical element 100 or at a small angle (e.g., within 5°) with the optical axis. This results in the second visible light 211 being substantially parallel to the first visible light 230, which is parallel to the optical axis. When the incident angle of the visible light (e.g., the parallel laser beam 221 and the first visible light 230) is outside the first incident angle threshold range, the visible light is not diffracted and can directly transmit out of the diffractive optical element 100.

[0045] In some embodiments, the photoelectric conversion module and the second visible light conversion module are located on different sides of the diffractive optical element 100 .

[0046] For example, Figure 2 and 3As shown, the photoelectric conversion module (invisible light focusing module 101 and detector 102) is located on the incident side of the diffractive optical element 100 where the first visible light 230 is incident, and the second visible light conversion module (display screen 104 and visible light collimating module 105) is located on the exit side of the diffractive optical element 100 where the first visible light 230 is emitted. The diffractive optical element 100 is designed so that a second incident angle threshold range on the exit side of the diffractive optical element 100 where the first visible light 230 is emitted is greater than 0°. When visible light (such as a predetermined incident angle of the second visible light 211) is incident within the second incident angle threshold range, the visible light is reflectively diffracted by the diffractive optical element 100 and then reflected from the diffractive optical element 100 at an angle parallel to the optical axis of the diffractive optical element 100 or at a small angle (e.g., within 5°) with the optical axis, thereby causing the second visible light 211 to be substantially parallel to the first visible light 230, which is parallel to the optical axis. When visible light (such as the parallel laser beam 221 and the first visible light 230 ) is incident on the diffractive optical element 100 from the incident side of the first visible light 230 , the visible light is not diffracted and can directly pass through the diffractive optical element 100 .

[0047] It should be noted that: Figure 1 and Figure 2 There are two optical path structures in the holographic aiming system. The appropriate optical path structure can be selected according to the internal design structure and space size of the holographic aiming system.

[0048] In some embodiments, as Figure 4 As shown, the diffractive optical element 100 includes: a first diffractive optical sub-element 1001 and a second diffractive optical sub-element 1002, the first diffractive optical sub-element 1001 and the second diffractive optical sub-element 1002 are arranged side by side, and the arrangement order of the first diffractive optical sub-element 1001, the second diffractive optical sub-element 1002 and the hologram 112 in the incident direction of the first visible light 230 is not limited, as long as the optical axes of the three are parallel. Figure 4 and Figure 5 As shown, the first diffractive optical sub-element 1001 is used to diffract the invisible light 200 to obtain the invisible diffracted light 201, and directly transmit the first visible light 230 and the second visible light 211. Figure 4 and Figure 6 As shown, the second diffractive optical sub-element 1002 is used to diffract the second visible light 211 of a predetermined incident angle to obtain the second visible diffracted light 212 , and directly transmit the first visible light 230 and the invisible light 200 .

[0049] In this embodiment, the first diffractive optical sub-element 1001 and the second diffractive optical sub-element 1002 are designed and manufactured to diffract the invisible light 200 and the second visible light 211 respectively. Figure 1A single diffractive optical element 100 of the optical path is easier to manufacture and has a lower manufacturing cost.

[0050] In some embodiments, the optical axis of the hologram 112 coincides with the optical axis of the diffractive optical element 100. The spatial overlap area between the diffracted light of the hologram 112 and the diffractive optical element 100 is maximized, which means that the effective observation range of the human eye can be maximized, expanding the human eye's observation field.

[0051] In some embodiments, the diffractive optical element 100 includes at least one of a holographic optical element, a binary optical element, a relief grating, a metasurface element, and a micro-nano optical device. The diffractive optical element 100 may be composed of one of the holographic optical element, the binary optical element, the relief grating, the metasurface element, and the micro-nano optical device. Alternatively, the diffractive optical element 100 may be composed of multiple elements stacked side by side.

[0052] In some embodiments, the invisible light 200 may be infrared light, and the detector 102 may be an infrared detector, thereby converting the infrared light into the second visible light 211. Alternatively, the invisible light 200 may be ultraviolet light, and the detector 102 may be an ultraviolet detector, thereby converting the ultraviolet light into the second visible light 211. Alternatively, the invisible light 200 may be millimeter waves, and the detector 102 may be a millimeter wave detector, thereby converting the millimeter waves into the second visible light 211.

[0053] When the invisible light 200 is infrared light, the image of the thermal imaging image, ie, the second visible diffracted light 212 , can be observed simultaneously during aiming.

[0054] When the invisible light 200 is ultraviolet light, the second visible diffracted light 212 corresponding to the ultraviolet light can be observed simultaneously during aiming, and is used to track body fluids on the ground (such as wiped blood) and footprints covered by snow in the snow (the snow is more compacted where the feet have stepped on it).

[0055] When the invisible light 200 is a millimeter wave, the second visible diffracted light 212 corresponding to the millimeter wave can be observed simultaneously during aiming. Millimeter waves can penetrate clothing but not skin, so it is possible to observe whether the person being aimed at is carrying any dangerous items.

[0056] In some embodiments, the holographic aiming system further includes a control switch (not shown) connected to the light conversion module for controlling the light conversion module's on and off. The control switch can be controlled by the aimer. When the aimer observes through the observation window of the holographic aiming system, if the illumination is low and the image is unclear, the control switch activates the light conversion module to increase the image information entering the eye. If the illumination is high, the light conversion module does not need to be activated to save energy.

[0057] Specifically, if Figure 1 and 2As shown, the control switch may be an electric switch that controls at least one of the detector 102 , the signal processing module 103 and the display screen 104 , or a light shield that controls blocking or opening the invisible light path.

[0058] An embodiment of the present invention further provides an observation device, which includes: a holographic aiming system according to any of the above-mentioned embodiments. The observation device may be a head-mounted display device, binoculars, a sight, or other devices. Since the observation device includes the holographic aiming system according to any of the above-mentioned embodiments, when the observation device is used to aim at or observe a target in low light or complex environments, the human eye can also observe a clear image, and then quickly aim at or locate a specific target in the image. Moreover, the first visible light and the invisible light come from the same scene, that is, the invisible light image and the visible light image in the external scene come from the same field of view. By directly physically superimposing the image, it is relatively easy to achieve a complete image fusion effect, without the need for complex image fusion algorithms and stitching algorithms to perform overlap fine-tuning processing on the two images, so that the human eye can see a clearer image, and the aiming system has lower latency and faster response.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A holographic aiming system, characterized in that: include: A hologram, a laser module, a light conversion module and a diffractive optical element, wherein the hologram and the diffractive optical element are arranged side by side, and the optical axis of the hologram is parallel to the optical axis of the diffractive optical element; The hologram is used to diffract the laser light emitted by the laser module to form an aiming point light that is parallel to and has the same direction as the first visible light passing through the hologram and the diffractive optical element; The diffraction optical element is used to diffract invisible light from the same scene as the first visible light, and diffract the invisible light to the light conversion module. The light conversion module is used to convert the diffracted invisible light into second visible light, and project the second visible light onto the diffraction optical element at a predetermined incident angle, where the predetermined incident angle is different from the incident angle of the first visible light. The diffraction optical element is also used to diffract the second visible light at the predetermined incident angle, so that the diffracted second visible diffracted light is parallel to the first visible light and has the same direction.

2. The holographic aiming system according to claim 1, characterized in that: The light conversion module includes: a photoelectric conversion module, a signal processing module and a second visible light conversion module; The photoelectric conversion module is used to convert the diffracted invisible light into an electrical signal; The signal processing module is used to modulate the electrical signal and output the modulated electrical signal to the second visible light conversion module; The second visible light conversion module is used to convert the modulated electrical signal into the second visible light, and project the second visible light onto the diffractive optical element at a predetermined incident angle.

3. The holographic aiming system according to claim 2, characterized in that: The photoelectric conversion module includes: an invisible light focusing module and a detector, and the detector is connected to the signal processing module; The invisible light focusing module is used to focus the diffracted invisible light onto the detector; The detector is used to convert the diffracted invisible light into an electrical signal, and transmit the converted electrical signal to the signal processing module.

4. The holographic aiming system according to claim 3, characterized in that: The invisible light is infrared light, and the detector is an infrared detector; or the invisible light is ultraviolet light, and the detector is an ultraviolet detector; or the invisible light is millimeter wave, and the detector is a millimeter wave detector.

5. The holographic aiming system according to claim 2, characterized in that: The second visible light conversion module includes: a display screen and a visible light collimation module, and the display screen is connected to the signal processing module; The display screen is used to receive the electrical signal modulated by the signal processing module and display a corresponding image under the drive of the electrical signal; The visible light collimating module is used to collimate the image light displayed on the display screen to generate the second visible light, and project the second visible light onto the diffractive optical element at a predetermined incident angle.

6. The holographic aiming system according to claim 2, characterized in that: The photoelectric conversion module and the second visible light conversion module are both located on the same side of the diffractive optical element; or, the photoelectric conversion module and the second visible light conversion module are respectively located on different sides of the diffractive optical element.

7. The holographic aiming system according to claim 1, characterized in that: The diffraction optical element includes: a first diffraction optical sub-element and a second diffraction optical sub-element, the first diffraction optical sub-element and the second diffraction optical sub-element are arranged side by side, and their respective optical axes are parallel, the first diffraction optical sub-element is used to diffract the invisible light and directly transmit the first visible light and the second visible light, and the second diffraction optical sub-element is used to diffract the second visible light with a predetermined incident angle and directly transmit the first visible light and the invisible light.

8. The holographic aiming system according to any one of claims 1 to 7, characterized in that: The optical axis of the hologram coincides with the optical axis of the diffractive optical element.

9. The holographic aiming system according to any one of claims 1 to 7, characterized in that: Also includes: A control switch is connected to the light conversion module and is used to control the light conversion module to be turned on or off.

10. An observation device, characterized in that: include: The holographic aiming system according to any one of claims 1 to 9.

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