Coaxial telescopic range finder with night vision function

Abstract

The invention discloses a coaxial telescopic range finder with a night vision function, which comprises a first lens cone, a second lens cone and a coaxial range finding module, and is characterized in that the coaxial range finding module is located at one side of the first lens cone and is connected with the second lens cone; the first lens cone and the enhanced image projection module form an infrared matching imaging module, and the infrared matching imaging module and the telescopic module form an image enhancement module. The invention provides the coaxial telescopic range finder with the night vision function, so that the coaxial telescopic range finder has all-weather and full-target range finding and observation capabilities and also has farther telescopic distance, clearer visual experience and a more compact overall structure, image enhancement can be carried out by using an image enhancement technical scheme during night observation or dark target observation, and the image enhancement efficiency is improved. The application scene is expanded, and the use experience is optimized.

Description

Technical Field

[0001] The invention belongs to the technical field of telescopic rangefinders, and in particular relates to a coaxial telescopic rangefinder with a night vision function. Background Art

[0002] A telescopic rangefinder is a measuring instrument that combines a laser rangefinder with a telescopic system, integrating observation and measurement. Its main application range is field distance measurement. An existing patent with application number CN202304807U discloses "a laser-illuminated night-vision telescopic rangefinder, comprising a laser receiving module for receiving light reflected from an illuminated object, the laser receiving module comprising an illumination objective lens group, a receiving lens for receiving laser light disposed on the output light path of the illumination objective lens group, and a laser receiving tube disposed on the output light path of the receiving lens." However, the telescopic range and concealment of this patent are limited by visible light itself, making it impossible to achieve long-distance observation at night and having limited application scenarios.

[0003] The existing patent application number CN1967309A discloses a "projection-type low-light-level night vision system, which includes a projection optical system, a reflector, and a spectroscope." This application is only applicable to observation during the day or at night with low light levels, and cannot achieve night observation.

[0004] The night vision function of telescope rangefinders in existing technologies is generally achieved with the help of visible light illumination, infrared camera modules or additional low-light-level night vision lenses. However, the transmission distance of visible light is limited, which will limit the telescopic distance. Laser telescope rangefinders are generally non-coaxial structures, and the mechanical finished product generally requires a binocular structure. Introducing an infrared camera module on this basis will lead to a complex optical path, reduced transmittance, and stray light affecting working performance and user experience; it will also lead to a further increase in the mechanical structure and a worse user experience. The use of low-light-level night vision lenses, on the one hand, cannot achieve night observation and target observation in dark places during the day, and on the other hand, the optical noise signal is also amplified while the image signal is amplified, resulting in large noise in the imaging and a worse observation experience. Therefore, there is currently no portable laser telescope rangefinder with full-time and full-target observation function in the existing technology.

[0005] As a dual-use factory product, night vision telescope rangefinders are increasingly used in military, hunting, exploration and other fields. Currently, their night vision is mainly achieved through visible light illumination, additional low-light night vision lenses or infrared camera modules. Their application is generally accompanied by the need for full-target, full-time observation. For example, observing targets at night or observing targets in dark places during the day also requires full-time observation to match the full-time performance of the ranging module. To this end, the present invention proposes a coaxial telescope rangefinder with night vision function. Summary of the Invention

[0006] The object of the present invention is to provide a coaxial telescopic rangefinder with night vision function to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solution: a coaxial telescopic rangefinder with night vision function, comprising a first lens barrel, a second lens barrel, and a coaxial ranging module, wherein the coaxial ranging module is located on one side of the first lens barrel and connected to the second lens barrel:

[0008] The second lens barrel includes a telephoto module and an enhanced image projection module. The first lens barrel and the enhanced image projection module form an infrared matching imaging module, and the infrared matching imaging module and the telephoto module form an image enhancement module.

[0009] Preferably, the first lens barrel includes a first lens group, a second lens group, an infrared focal plane array detector, and a micro-displacement driver for loading the infrared focal plane array detector, which are arranged in sequence.

[0010] Preferably, the telescopic module includes an objective lens, a prism group, a projection display plane and an eyepiece that are coaxially arranged in sequence, wherein the prism group consists of a prism 1, a Schmidt roof prism and a prism 2.

[0011] Preferably, the enhanced image projection module includes a projection light source, a lens 1 and a prism group arranged in sequence.

[0012] Preferably, the coaxial ranging module includes a laser diode, lens 2, a perforated reflector, an aspheric spliced lens, lens 3 and a photodiode. Along the optical path of the laser diode emitting laser, the lens 2, the perforated reflector and the aspheric spliced lens are respectively arranged in sequence. Along the optical path of the diffusely reflected echo laser, the lens 3 and the photodiode are respectively arranged in sequence.

[0013] Preferably, the first prism is a half-pentagonal prism, and the second prism is a compensating prism.

[0014] Preferably, the aspheric spliced lens is formed by splicing two aspheric lenses with different focal lengths, and the two aspheric lenses are divided into a central lens and an outer ring lens.

[0015] Preferably, the lens with a shorter focal length in the aspheric spliced lens is located in the center and is used for the laser emission optical path to collimate the laser, and the lens with a longer focal length in the aspheric spliced lens is located at the periphery and is used for the laser receiving optical path.

[0016] Preferably, the focal length of the outer ring lens of the aspheric spliced lens is greater than the focal length of the central lens.

[0017] Preferably, the micro-displacement driver includes a piezoelectric crystal or piezoelectric ceramic driver, a photoelastic modulator or a micro-electromechanical system.

[0018] Compared with the existing technology, the beneficial effects of the present invention are: the present invention provides a coaxial telescopic rangefinder with night vision function, which has all-weather, all-target ranging and observation capabilities, and at the same time has a longer telephoto distance, a clearer visual experience and a more compact overall structure. When observing at night or observing dark targets, the image enhancement technical solution can be used for image enhancement, which expands the application scenarios and optimizes the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the interior of the entire machine of the present invention;

[0020] Figure 2 is a schematic diagram of a telescopic module of the present invention;

[0021] Figure 3 is a schematic diagram of an image enhancement module of the present invention;

[0022] Figure 4 is a signal transmission route map of the present invention;

[0023] Figure 5 Schematic diagram of the coaxial ranging module of the present invention;

[0024] In the figure: 11, lens group 1; 12, lens group 2; 13, infrared focal plane array detector; 14, micro-displacement driver; 21, objective lens; 22, prism 1; 23, Schmidt roof prism; 24, projection display plane; 25, eyepiece; 26, projection light source; 27, lens 1; 28, prism 2; 31, laser diode; 32, lens 2; 33, holed reflector; 34, aspheric spliced lens; 35, lens 3; 36, photodiode. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] Example 1

[0027] See also Figures 1 to 5, which is the first embodiment of the present invention, provides a technical solution: a coaxial telescopic rangefinder with night vision function, comprising a first lens barrel, a second lens barrel, and a coaxial ranging module, wherein the coaxial ranging module is located on one side of the first lens barrel and connected to the second lens barrel; the second lens barrel comprises a telephoto module and an enhanced image projection module, the first lens barrel and the enhanced image projection module constitute an infrared matching imaging module, and the infrared matching imaging module and the telephoto module constitute an image enhancement module.

[0028] In this embodiment, the first lens barrel includes a lens group 11, a lens group 2 12, an infrared focal plane array detector 13 and a micro-displacement driver 14 for loading the infrared focal plane array detector (13). The infrared focal plane array detector 13 and the micro-displacement driver 14 are tightly fitted and assembled. Specifically, a groove corresponding to the infrared focal plane array detector 13 is opened on one side of the micro-displacement driver 14, and the infrared focal plane array detector 13 is installed in the groove to ensure the fit between the two. In this way, the infrared imaging image obtained has higher image resolution and higher image quality, which brings convenience to subsequent users.

[0029] In this embodiment, the telescope module includes an objective lens 21, a prism group, a projection display plane 24 and an eyepiece 25 that are coaxially arranged in sequence, wherein the prism group consists of prism 1 22, a Schmidt roof prism 23 and prism 28. The visible light emitted by the object passes through the objective lens 21 and the prism group, and then undergoes four total reflections in prism 1 22 and Schmidt roof prism 23, and finally forms a real image a at the location of the projection display plane so that the human eye can observe it through the eyepiece 25.

[0030] In this embodiment, the enhanced image projection module includes a projection light source 26 , a lens 1 27 and a prism group arranged in sequence, wherein the prism group is composed of a prism 1 22 , a Schmidt roof prism 23 and a prism 28 .

[0031] Among them, lens group 1 11 and lens group 2 12 can form a large-field-of-view imaging lens. The specific field of view setting of the imaging lens depends on the rangefinder specifications, ranging range, and the distance between the upper and lower lens barrels. The infrared focal plane array detector 13 and the micro-displacement driver 14 are tightly assembled together through structural design. The micro-displacement driver 14 supports high-frequency micro-displacement in four directions: up, down, left, and right. Specifically, the displacement of the micro-displacement driver 14 can be achieved by a micro-motor driving a rack. This can drive the infrared focal plane array detector 13 to acquire multiple frames of images in a short period of time, thereby combining them to obtain a high-resolution image. By using a matching curve or ranging data feedback adjustment method, the high-resolution image can be matched with the real image formed by the objective lens 21 at the projection display plane 24 in the rangefinder chip program. The matched image is displayed on the projection light source 26 in the form of an infrared grayscale image. The light emitted by the projection light source 26 in the enhanced image projection module passes through lens 1 27 and then prism 2 28. After undergoing two total internal reflections at the Schmidt roof prism 23, it finally forms a grayscale real image b at the projection display plane 24.

[0032] As an optional solution, a liquid crystal display screen can be installed at the projection display plane 24, thereby omitting the above-mentioned projection step.

[0033] Under the premise of high-resolution imaging, the device can also adjust the overlap of images b and a in the main control board with the help of matching curves or ranging data feedback adjustment means. When the overlap between the two reaches close to 100%, it can ensure a more comfortable human eye observation experience, prevent ghosting or blurring, and ensure human eye comfort. In addition, the ranging result of the coaxial ranging module is also transmitted to the projection display plane 24 by an electrical signal and then directly displayed on the projection display plane 24. Therefore, the human eye or a monocular industrial camera with an industrial lens can observe the telescopic system imaging at the position of the projection display plane 24 through the eyepiece 25 to realize the telescopic function, the superimposed image of the infrared enhanced image and the ranging data of the projection display plane 24. This signal transmission process can be referred to Figure 4 signal transmission route map.

[0034] In practical applications, the superposition of enhanced images can enhance the brightness and clarity of images observed by the human eye or a monocular camera during night observation and dark target observation, achieving the effect of observing dark targets outdoors. It can also provide image enhancement when observing targets beyond the observation range of the telescope optical path, assisting in increasing the telephoto distance, and further extending and improving the telescopic effect.

[0035] It should be noted that, in this embodiment, the first lens barrel, the second lens barrel and the coaxial ranging module are connected by a structural member, and a circuit switch for controlling the first lens barrel and the coaxial ranging module is provided on the structural member, which can control whether the two are working or not, so that the two can stop working when unnecessary, thereby extending the standby time of the instrument. The structural member between the first lens barrel and the second lens barrel is a rotating shaft, so that the first lens barrel and the second lens barrel can be rotatably connected by the rotating shaft, which is convenient for rotation and adjustment of the distance between each other during use. The coaxial ranging module is a structure integrally formed with the first lens barrel and can rotate together with the rotation of the first lens barrel, which is equivalent to being installed on the first lens barrel.

[0036] In this embodiment, the coaxial ranging module is equipped with a laser emitting system and a laser receiving system, including a laser diode 31, a second lens 32, a perforated reflector 33, an aspheric spliced lens 34, a third lens 35 and a photodiode 36. The laser diode 31 is used to emit laser light. Along the optical path of the laser diode 31 emitting laser light, the second lens 32, the perforated reflector 33 and the aspheric spliced lens 34 are respectively arranged in sequence. Along the optical path of the diffusely reflected echo laser, the third lens 35 and the photodiode 36 are respectively arranged in sequence. At the same time, the actual laser emitting and receiving optical path also includes the prism 2 28, the prism 1 22 and the objective lens 21 in the telescope module. The prism 1 22 is a semi-pentagonal prism, and the prism 2 28 is a compensating prism, which is used to realize the ranging function of the device, thereby performing real-time ranging during the telescope process, providing a reasonable basis for the user to judge the distance of distant objects.

[0037] After the main control board controlled by the button transmits an electrical signal to the coaxial ranging module, as shown in the transmitting optical path, the infrared laser emitted by the laser diode 31 is focused by the lens 2 32, passes through the small hole on the hole reflector 33 with a size close to the Airy disk, and enters the aspheric splicing lens 34 from the central circular hole of the hole reflector 33 to perform the first collimation of the light beam. The collimated laser beam passes through the prism 2 28 of the prism group, and then is reflected by the prism 1 22 and enters the objective lens 21 for secondary collimation, and is emitted as nearly parallel light to the object to be measured; the aspheric splicing lens 3 4 is composed of two aspheric lenses with different focal lengths, which are divided into a central lens and an outer ring lens. The lens with a shorter focal length in the aspheric splicing lens 34 is located in the center and is used for the laser emission optical path, which can perform the first collimation of the laser. The lens with a longer focal length in the aspheric splicing lens 34 is located on the periphery and is used for the laser receiving optical path. The aspheric splicing lens 34 and the objective lens 21 can collimate the emitted laser twice to ensure the collimation of the laser, so that the output light spot has better collimation, the energy is more concentrated, the transmission distance is longer, and the ranging range is further improved.

[0038] As shown in the receiving optical path, the laser reflected from the target object is converged at a larger receiving angle through the objective lens 21, and undergoes a total internal reflection in the prism 1 22. After being focused by the annular lens of the aspheric spliced lens 34, it is reflected on the perforated reflector 33, and then passed through the lens 3 35 to be converged into a smaller light spot. It is then received by the photodiode 36 and converted into an electrical signal, thereby completing the distance measurement of the target object.

[0039] The main control board can calculate the time interval between the emission and reception of the two electrical signals through signal processing, and use the principle of time ranging method L = 1 / 2C*▲t to measure the distance information of the target object. The ranging result is sent to the projection display plane 24 or the projection light source 26 in the telescopic optical system via the main control board for display, so that the human eye or a monocular industrial camera with an industrial lens can observe the telescopic system imaging at the position of the projection display plane 24 through the eyepiece 25, and the superimposed image of the infrared enhanced image and the ranging data of the projection display plane 24;

[0040] It should be noted that a portion of the returning light signal will pass through the central lens of the aspheric splicing lens 34, and after converging, pass through the middle hole of the reflector with a hole 33. This part of the light cannot reach the photodiode 36 along the trajectory of the designed light signal receiving optical path, resulting in a decrease in the signal-to-noise ratio of the ranging signal. The focal length of the outer ring lens of the aspheric splicing lens 34 is greater than the focal length of the central lens. At the same time, the aperture of the reflector with a hole 33 is designed to be very small, so this part of the received light accounts for a very small proportion of the total energy and generally does not affect the ranging capability of the rangefinder.

[0041] In this embodiment, preferably, the micro-displacement driver 14 is a piezoelectric crystal.

[0042] Example 2

[0043] See also Figures 1 to 5 , which is the second embodiment of the present invention, is based on the first embodiment, except that the micro-displacement driver 14 is driven by piezoelectric ceramics.

[0044] Example 3

[0045] See also Figures 1 to 5 , which is the third embodiment of the present invention, is based on the first embodiment, except that the micro-displacement driver 14 is a micro-electromechanical system.

[0046] Example 4

[0047] See also Figures 1 to 5 , which is the fourth embodiment of the present invention, is based on the first embodiment, except that the micro-displacement driver 14 is a photoelastic modulator.

[0048] Although the embodiments of the present invention have been shown and described (see the above detailed description for details), it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, and the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A coaxial telescopic rangefinder with night vision function, characterized in that: It includes a first lens barrel, a second lens barrel and a coaxial distance measurement module, wherein the coaxial distance measurement module is located on one side of the first lens barrel and connected to the second lens barrel: The second lens barrel includes a telephoto module and an enhanced image projection module. The first lens barrel and the enhanced image projection module form an infrared matching imaging module, and the infrared matching imaging module and the telephoto module form an image enhancement module.

2. The coaxial telescopic rangefinder with night vision function according to claim 1, characterized in that: The first lens barrel comprises a lens group 1 (11), a lens group 2 (12), an infrared focal plane array detector (13), and a micro-displacement driver (14) for loading the infrared focal plane array detector (13), which are arranged in sequence.

3. The coaxial telescopic rangefinder with night vision function according to claim 1, characterized in that: The telescope module comprises an objective lens (21), a prism group, a projection display plane (24) and an eyepiece (25) which are coaxially arranged in sequence, wherein the prism group consists of a prism 1 (22), a Schmidt roof prism (23) and a prism 2 (28).

4. The coaxial telescopic rangefinder with night vision function according to claim 3, characterized in that: The enhanced image projection module comprises a projection light source (26), a lens 1 (27) and a prism group which are arranged in sequence.

5. The coaxial telescopic rangefinder with night vision function according to claim 1, characterized in that: The coaxial distance measurement module comprises a laser diode (31), a second lens (32), a reflector with a hole (33), an aspheric spliced lens (34), a third lens (35) and a photodiode (36). Along the optical path of the laser emitted by the laser diode (31), the second lens (32), the reflector with a hole (33) and the aspheric spliced lens (34) are respectively arranged in sequence. Along the optical path of the diffusely reflected echo laser, the third lens (35) and the photodiode (36) are respectively arranged in sequence.

6. The coaxial telescopic rangefinder with night vision function according to claim 3, characterized in that: The first prism (22) is a half-pentagonal prism, and the second prism (28) is a compensating prism.

7. The coaxial telescopic rangefinder with night vision function according to claim 5, characterized in that: The aspheric spliced lens (34) is formed by splicing two aspheric lenses with different focal lengths, and the two aspheric lenses are divided into a central lens and an outer ring lens.

8. The coaxial telescopic rangefinder with night vision function according to claim 5, characterized in that: The lens with a shorter focal length in the aspheric splicing lens (34) is located in the center and is used for the laser emission optical path to collimate the laser. The lens with a longer focal length in the aspheric splicing lens (34) is located at the periphery and is used for the laser reception optical path.

9. The coaxial telescopic rangefinder with night vision function according to claim 5, characterized in that: The focal length of the outer ring lens of the aspheric spliced lens (34) is greater than the focal length of the central lens.

10. The coaxial telescopic rangefinder with night vision function according to claim 1, characterized in that: The micro-displacement driver (14) includes a piezoelectric crystal or piezoelectric ceramic driver, a photoelastic modulator or a micro-electromechanical system.

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