A laser rangefinder riflescope and method of use

Abstract

The application relates to a laser ranging scope and a use method thereof, which comprises, coaxially and sequentially, an objective lens, a transmitting beam splitter, a small objective lens, a half-pentaprism, a beam splitter prism, a roof prism, a graticule, an ocular group, a laser transmitting unit and a laser receiving unit; after light is split by the half-pentaprism, one route of white light is emitted out of the ocular group for human eye observation and aiming, and the other route of white light is used for image acquisition; the laser transmitting unit comprises a laser transmitter, a laser beam emitted by the laser transmitter is transmitted into the edge light transmission area of the objective lens through the transmitting beam splitter, is collimated through the objective lens and is shot towards a target to be measured, the reflected laser echo is reversely transmitted, is split by the beam splitter prism and is incident to the laser receiving unit, distance measurement operation is completed by a photoelectric sensor and a signal processing circuit integrated in the laser receiving unit, and the obtained distance measurement information is displayed through a liquid crystal screen. The application builds a white light imaging light path and a laser transmitting and receiving light path by means of existing optical components, the overall layout is reasonable and compact, and aiming and rapid distance measurement can be considered.

Description

Technical Field

[0001] This invention relates to the field of optical aiming technology, and in particular to a laser rangefinder aiming scope and its method of use. Background Technology

[0002] Optical sights with integrated laser rangefinding capabilities have been widely used in outdoor observation, hunting, law enforcement, and military applications. Existing laser rangefinding sights typically incorporate independent beam-splitting elements in the white light imaging optical path to achieve coaxial operation of laser emission, reception, and white light aiming.

[0003] Existing mainstream technical solutions such as Figure 1 As shown, the objective lens 10, beam splitter 20, lens group 30, reticle 40, and eyepiece group 50 are arranged coaxially in sequence. Specifically, a separate and relatively large beam splitter 20 is inserted between the objective lens 10 and the lens group 30 to construct the laser optical path. The first beam splitter prism 21 deflects the emitted laser towards the center of the objective lens 10 and projects it outwards, while the second beam splitter prism 22 separates the returning laser from the white light imaging optical path to the receiving sensor. The above scheme has the following shortcomings:

[0004] 1) The second beam splitter 22 of the two independent beam splitters is complex to manufacture and has a very large volume. The laser travels a long distance in the second beam splitter 22, which causes the laser to be greatly attenuated. This not only causes a decrease in the illuminance of the white light image plane and a decrease in laser energy, but also easily produces ghosting and stray light, interfering with imaging and ranging signals.

[0005] 2) The entire scope has a complex structure, is difficult to assemble and adjust, and is costly;

[0006] 3) Additional optical components require more internal space, resulting in larger size and weight, which is not conducive to the miniaturization and weight reduction of the equipment;

[0007] 4) The light loss and stray light generated will shorten the maximum effective distance of laser ranging and reduce the measurement accuracy under low light conditions.

[0008] Therefore, how to provide a laser rangefinder sight with a simple structure, coaxial stability, and high light energy utilization, and its usage method, is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0009] This invention provides a laser rangefinder sight and its method of use to solve the above-mentioned technical problems.

[0010] To solve the above-mentioned technical problems, the present invention provides a laser rangefinder aiming scope, comprising an objective lens, a beam splitter, a small objective lens, a semi-pentagonal prism, a beam splitter, a roof prism, a reticle, and an eyepiece assembly arranged coaxially in sequence, and further comprising a laser emitting unit and a laser receiving unit;

[0011] The objective lens, the emitting beam splitter, the small objective lens, the semi-pentagonal prism, the beam splitter, the roof prism, the reticle and the eyepiece group constitute the white light imaging optical path. After the light is split by the semi-pentagonal prism, one path of white light is emitted through the reticle and the eyepiece group in sequence for human eye observation and aiming, and the other path of white light is incident on the receiving image sensor to complete image acquisition.

[0012] The laser emitting unit includes a laser emitter, which is disposed above the emitting beam splitter. The laser beam emitted by the laser emitter enters the upper inclined surface of the emitting beam splitter and is reflected to the lower inclined surface and then reflected to the edge light-transmitting area of ​​the objective lens. After being collimated by the objective lens, it is directed toward the target under test. The laser echo reflected by the target under test is transmitted in the reverse direction along the white light imaging optical path, and after being split by the beam splitter prism, it is incident on the laser receiving unit.

[0013] The laser receiving unit includes a receiving board and an LCD screen. The receiving board integrates a photoelectric sensor and a signal processing circuit. The photoelectric sensor receives the laser echo after beam splitting and completes photoelectric conversion. The resulting electrical signal is processed by the signal processing circuit to complete the ranging calculation. The obtained ranging information is displayed on the LCD screen.

[0014] Preferably, the objective lens, the emitting beam splitter, the small objective lens, the semi-pentagonal prism, the beam splitter, the roof prism, the reticle, the eyepiece group, the laser emitting unit, and the laser receiving unit are integrated and fixed on the same rigid mechanism support to form an integrated mechanism structure.

[0015] Preferably, the integrated mechanism structure is adjustable by swinging relative to the entire eyepiece assembly with a pivot point in the optical axis direction.

[0016] Preferably, the beam-splitting prism is cemented to the beam-splitting surface of the semi-pentagonal prism.

[0017] Preferably, the laser emitting unit further includes a beam expander disposed between the laser emitter and the emitting beam splitter.

[0018] Preferably, the laser receiving unit further includes a reflector, which is disposed between the beam splitter and the receiving plate.

[0019] Preferably, the laser beam, after passing through the objective lens, remains parallel to the white light optical axis or intersects at an infinity point.

[0020] Preferably, the signal processing circuit is configured to execute a digital correlation detection algorithm to extract the laser echo signal from the output signal of the photoelectric sensor and perform distance calculation.

[0021] Preferably, the digital correlation detection algorithm is as follows: using the modulation code sequence driving the laser emitter as a reference signal, performing cross-correlation calculation with the signal output by the photoelectric sensor, and determining the laser propagation duration by detecting the peak value of the cross-correlation function.

[0022] The present invention also provides a method for using the laser rangefinder sight as described above, comprising the following steps:

[0023] Step 1: The laser emitter generates a modulated laser beam, which passes through the beam splitter and enters the light-transmitting area at the edge of the objective lens. After being collimated by the objective lens, the laser beam is directed toward the target to be measured.

[0024] Step 2: The laser echo reflected by the target to be tested returns along the central optical axis of the original white light imaging optical path, passes sequentially through the objective lens, the emitting beam splitter, the small objective lens, and the semi-pentagonal prism, and is then incident on the photoelectric sensor after being split by the beam splitter.

[0025] Step 3: The photoelectric sensor receives the laser echo, completes the photoelectric conversion and outputs an electrical signal. The signal processing circuit processes the electrical signal and calculates the laser propagation time.

[0026] Step 4: Calculate the distance to the target based on the laser propagation time, and output the ranging information.

[0027] Compared with the prior art, the laser rangefinder sight and its usage method provided by the present invention have the following advantages:

[0028] 1. This invention eliminates the largest receiving beam splitter among the two independent beam splitters used for laser light guiding in the traditional solution, which greatly simplifies the overall structure of the optical system, effectively reduces the processing cost of parts, and reduces the difficulty of assembling and adjusting the optical path of the whole machine, resulting in higher assembly efficiency.

[0029] 2. This invention reduces redundant optical transmission and reflection interfaces, significantly reducing the light energy loss of the white light imaging optical path and the laser optical path; the transmission path is simple and concentrated, and can also effectively suppress the generation of stray light, which not only improves the imaging effect, but also increases the effective range of laser ranging, and improves the ranging accuracy and working reliability in weak signal environments.

[0030] 3. In this invention, the laser emission and receiving optical paths and the white light imaging optical path share the same rear optical path of the objective lens. Combined with the integrated mechanism structure design, it can achieve three-axis synchronous linkage adjustment, ensuring long-term coaxial accuracy of the three axes from a structural perspective, and effectively avoiding the problems of optical path offset and three-axis misalignment that are prone to occur in separate adjustment.

[0031] 4. The overall optical layout of this invention is compact, and it occupies less internal space, leaving ample space for the miniaturization and lightweight structural design of the entire scope, making it easier to carry and use in various scenarios. Attached Figure Description

[0032] Figure 1 This is a schematic diagram illustrating the principle of a laser rangefinder sight in the prior art.

[0033] Figure 2 This is a schematic diagram of the optical path structure of the laser rangefinder sight in Embodiment 1 of the present invention;

[0034] Figure 3a This is a schematic diagram of the laser emission optical path in Embodiment 1 of the present invention;

[0035] Figure 3b This is a schematic diagram of the laser receiving optical path in Embodiment 1 of the present invention;

[0036] Figure 4 This is a schematic diagram of the optical path of the laser emission optical path incident on the light-transmitting area at the edge of the objective lens in Embodiment 1 of the present invention;

[0037] Figure 5 This is a schematic diagram of the integrated movement structure in Embodiment 1 of the present invention;

[0038] Figure 6 This is a schematic diagram of the mechanical integration and synchronous adjustment of the integrated movement structure in Embodiment 1 of the present invention;

[0039] Figure 7 for Figure 6 AA cross-section view;

[0040] Figure 8 This is a schematic diagram of the optical path structure of the laser rangefinder aiming scope in Embodiment 2 of the present invention.

[0041] Figure 1 In the middle: 10-objective lens, 20-beam splitter assembly, 21-first beam splitter prism, 22-second beam splitter prism, 30-lens group, 40-reticle, 50-eyepiece group;

[0042] Figure 2-8 In the middle: 110-Objective lens, 213-Emitting beam splitter, 120-Small objective lens, 130-Half pentaprism, 131-Roof prism, 140-Beam splitter, 150-Reticle, 160-Eyepiece group, 210-Laser emitting unit, 211-Laser emitter, 212-Beam expander, 220-Laser receiving unit, 221-Receiver plate, 222-LCD screen, 223-Reflector, 300-Integrated mechanism structure, 301-Main mirror body, 302-First stroke adjustment handwheel, 303-Second stroke adjustment handwheel. Detailed Implementation

[0043] To illustrate the technical solutions of the invention in more detail, specific embodiments are listed below to demonstrate the technical effects; it should be emphasized that these embodiments are used to illustrate the invention and not to limit the scope of the invention.

[0044] Example 1

[0045] The laser rangefinder sight provided by this invention, such as Figure 2 As shown, the system includes an objective lens 110, a beam splitter 213, a small objective lens 120, a semi-pentagonal prism 130, a beam splitter 140, a roof prism 131, a reticle 150, and an eyepiece group 160 arranged coaxially in sequence. It also includes a laser emitting unit 210 and a laser receiving unit 220, wherein:

[0046] The objective lens 110 (in this embodiment, it has a focal length of f=109mm, an aperture of D=24mm, and is made of H-K9L material), the emitting beam splitter 213, the small objective lens 120, the semi-pentaprism 130, the beam splitter 140, the roof prism 131, the reticle 150, and the eyepiece group 160 constitute a complete white light imaging optical path. Ambient light is transmitted smoothly along the coaxial optical path. After the light is split by the semi-pentaprism 130, the optical path is split. One path of white light is emitted sequentially through the reticle 150 and the eyepiece group 160, allowing the human eye to clearly observe and aim at the target. The roof prism 131 works with the semi-pentaprism 130 to complete the optical path image correction, optimize the white light imaging field of view, and ensure that the image observed at the eyepiece end is upright and without distortion, further improving the user experience of visual aiming. The other path of white light is incident on the receiving image sensor (not shown) to complete the real-scene image acquisition operation. This structure relies on the original white light optical path to complete the beam splitting design, abandoning the traditional approach of adding an additional independent beam splitting element, effectively simplifying the internal optical structure, reducing the number of optical interfaces, and reducing light energy loss from the source.

[0047] Please combine Figure 3a , Figure 3b and Figure 4The laser emitting unit 210 includes a laser emitter 211, which is a 905nm wavelength pulsed semiconductor laser. The laser emitter 211 is positioned above and behind the emitting beam splitter 213. When the laser emitter 211 is working, it emits a modulated ranging laser beam. This laser beam (initial divergence angle ≤ 7mrad) is precisely incident on the inclined surface above the emitting beam splitter 213 at a horizontal angle (error ± 3°), then reflected to the inclined surface below the emitting beam splitter 213 before exiting, and finally incident on the... The light-transmitting area at the edge of the objective lens 110, after being collimated and shaped by the objective lens 110, is stably directed towards the target. After passing through the objective lens 110, the laser beam is parallel to or coincides with the white light aiming optical axis of the objective lens 110. The laser echo reflected from the target is transmitted back along the original white light imaging optical path, sharing the white light aiming optical path between the objective lens 110 and the beam splitter 140. After precise beam splitting by the beam splitter 140, the laser beam is stably incident on the laser receiving unit 220 for signal acquisition. The laser exits from the edge area of ​​the objective lens, without occupying the central main imaging optical path, achieving independent aiming and imaging with laser emission, significantly improving the overall functional compatibility of the device.

[0048] Please continue to combine Figure 3b The laser receiving unit 220 includes a receiving board 221 and an LCD screen 222. The receiving board 221 integrates photoelectric sensors (such as avalanche photodiodes APD) and signal processing circuits (FPGA). The photoelectric sensors are used to receive the laser echo signal separated by the beam splitter 140 and quickly complete the photoelectric signal conversion. The converted electrical signal is filtered, processed, and accurately calculated by the built-in signal processing circuit. The final accurate distance measurement information is displayed clearly and intuitively on the LCD screen 222 in real time, which is convenient for operators to read and view quickly and makes human-computer interaction convenient.

[0049] In some embodiments, please refer to Figure 2 The beam splitter 140 is glued and fixed to the beam splitting surface of the semi-pentagonal prism 130, and the two form an integrated optical component. No additional support is required for fixation, which further simplifies the structure and reduces the space occupied. At the same time, it reduces the air interface between optical elements, reduces light reflection and scattering loss, and suppresses the generation of stray light.

[0050] In some embodiments, please refer to Figure 2 The laser emitting unit 210 further includes a beam expander 212 mounted between the laser emitter 211 and the beam splitter 213. The beam expander 212 shapes the laser beam emitted by the laser emitter 211, making it a collimated laser beam after passing through the objective lens 110. Its beam expansion ratio is designed based on the initial divergence angle of the laser emitter 211 and the required exit divergence angle. The beam expander 212 allows for flexible adjustment of the laser exit spot size and divergence angle, adapting to different ranging scenarios.

[0051] In some embodiments, please refer to Figure 2 The laser receiving unit 220 also includes a reflector 223, which is disposed between the beam splitter prism 140 and the receiving plate 221. In this embodiment, when the overall length of the optical system, structural space is limited, and the installation position of the laser emitter 211 is inconvenient, the reflector 223 can be flexibly bent and the laser emission direction can be adjusted to adapt to the small and complex internal installation space, further optimizing the internal space layout of the whole machine and adapting to more portable installation scenarios.

[0052] In some embodiments, please refer to Figure 2 After passing through the objective lens 110, the laser beam remains parallel to the white light optical axis or intersects at an infinity point. Specifically, the angle range between the laser beam exiting the beam splitter 213 and the incident objective lens 110 and the central optical axis of the white light can be optimized and determined by optical design software (such as Zemax or Code V) to ensure the wavefront quality of the laser inside the objective lens 110 and after exiting, and to avoid mechanical interference with the lens barrel.

[0053] In some embodiments, the signal processing circuit is configured to execute a digital correlation detection algorithm to accurately extract the effective laser echo signal from the cluttered signal output by the photoelectric sensor and perform accurate distance calculation. This algorithm possesses excellent anti-interference capabilities, effectively shielding ambient natural light, stray light, and circuit electromagnetic interference, significantly improving the stability of ranging operations in complex environments. In this embodiment, the digital correlation detection algorithm uses the modulation code sequence driving the laser emitter 211 as a reference signal, performs cross-correlation calculations between it and the signal output by the photoelectric sensor, and determines the laser propagation duration by detecting the peak value of the cross-correlation function. Specifically, please refer to... Figure 3b The laser emitter 211, driven by a driver, emits light pulses modulated by a 1023-bit m-sequence pseudo-random code. The FPGA simultaneously generates the same local m-sequence as a reference signal. The weak current signal output by the APD is amplified and filtered before being fed into the FPGA for real-time sliding cross-correlation with the local reference signal. A phase detection algorithm accurately analyzes stray light and the desired laser ranging signal, then shields the stray light. The microcontroller unit (MCU) in the signal processing circuit performs precise calculations only on the ranging signal. By peak detection of the cross-correlation results, the echo delay can be accurately determined, and the distance calculated. This algorithm effectively suppresses background light noise and fixed-pattern stray light introduced by the edge of the objective lens 110.

[0054] In some embodiments, please refer to the following: Figures 5 to 7The objective lens 110, emitting beam splitter 213, small objective lens 120, semi-pentagonal prism 130, beam splitter prism 140, roof prism 131, reticle 150, eyepiece group 160, laser emitting unit 210, and laser receiving unit 220 are all integrated and fixedly mounted on the same rigid mechanism support (such as a lens barrel or mounting bracket), forming an integrated mechanism structure 300. The integrated mechanism structure 300 relies on the main lens body 301 for overall load-bearing assembly. This integrated assembly method greatly simplifies the overall assembly process, reduces the difficulty of manual adjustment, and ensures that the relative positions of all optical and electrical components are fixed for a long time, avoiding optical path misalignment problems during long-term use.

[0055] In some embodiments, please refer to Figures 5 to 7 The integrated mechanism structure 300, when used with the first stroke adjustment handwheel 302 (height and low handwheel) and the second stroke adjustment handwheel 303 (direction handwheel), can complete the overall swing adjustment relative to the eyepiece group 160 with the fulcrum in the optical axis direction. This enables the three-axis synchronous calibration of the white light path, the laser emission path, and the laser receiving path. The three-axis coaxial matching can be completed in one adjustment. Compared with the traditional separate adjustment method, the adjustment efficiency is higher and the three-axis coaxial accuracy can be maintained for a long time, eliminating the three-axis misalignment fault caused by separate adjustment.

[0056] The present invention also provides a method for using the laser rangefinder sight as described above, comprising the following steps:

[0057] Step 1: The laser emitter 211 stably generates a modulated laser beam. After being reflected from the beam splitter 213 by the beam expander 212, the laser beam enters the edge light-transmitting area of ​​the objective lens 110 at a parallel or set tilt angle. After being collimated and shaped by the objective lens 110, the beam is directed toward the target to be measured.

[0058] Step 2: The surface of the target to be tested reflects a laser echo, which is transmitted in reverse along the central optical axis of the original white light imaging optical path. It passes through the objective lens 110, the emitting beam splitter 213, the small objective lens 120, and the semi-pentagonal prism 130 in sequence. After the laser signal is split by the beam splitter prism 140, it is accurately incident on the photoelectric sensor.

[0059] Step 3: The photoelectric sensor receives the laser echo signal in real time, completes the photoelectric conversion and outputs a standard electrical signal. The signal processing circuit performs noise reduction processing on the collected standard electrical signal, extracts the effective laser echo signal from the noisy signal, and accurately calculates the overall laser propagation time.

[0060] Step 4: Quickly calculate the actual distance to the target based on the laser propagation time, and simultaneously output and display the ranging information to complete the overall aiming and ranging operation.

[0061] Example 2

[0062] The difference between this embodiment and Embodiment 1 is as follows: Please refer to the following carefully. Figure 8 The reflector 223 can be removed from the laser optical path according to the actual optical path of the receiving optical path, so as to reduce cost and assembly difficulty.

[0063] In summary, the laser rangefinder sight and its usage method provided by this invention rely on a semi-pentaprism 130 integrated beam-splitting structure to replace the traditional independent receiving beam-splitting prism, simplifying the optical system structure and effectively reducing manufacturing costs and assembly and debugging difficulties. Simultaneously, it reduces redundant optical transmission and reflection interfaces, significantly reducing light energy loss during white light imaging and laser transmission, suppressing stray light generation, and effectively improving the maximum laser ranging range and ranging accuracy in low-light environments. Combined with an integrated 300-degree synchronous adjustment mechanism, it ensures long-term coaxial stability of white light, laser emission, and laser reception. The overall optical path layout is compact and reasonable, facilitating miniaturization and lightweight manufacturing. It combines multiple functions including aiming observation, image acquisition, and precise ranging, exhibiting excellent overall performance and broad market application prospects.

[0064] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A laser rangefinder sight, characterized in that, It includes an objective lens, a beam splitter, a small objective lens, a semi-pentagonal prism, a beam splitter, a roof prism, a reticle, and an eyepiece assembly arranged coaxially in sequence, as well as a laser emitting unit and a laser receiving unit; The objective lens, the emitting beam splitter, the small objective lens, the semi-pentagonal prism, the beam splitter, the roof prism, the reticle and the eyepiece group constitute the white light imaging optical path. After the light is split by the semi-pentagonal prism, one path of white light is emitted through the reticle and the eyepiece group in sequence for human eye observation and aiming, and the other path of white light is incident on the receiving image sensor to complete image acquisition. The laser emitting unit includes a laser emitter, which is disposed above the emitting beam splitter. The laser beam emitted by the laser emitter enters the upper inclined surface of the emitting beam splitter and is reflected to the lower inclined surface and then reflected to the edge light-transmitting area of ​​the objective lens. After being collimated by the objective lens, it is directed toward the target under test. The laser echo reflected by the target under test is transmitted in the reverse direction along the white light imaging optical path, and after being split by the beam splitter prism, it is incident on the laser receiving unit. The laser receiving unit includes a receiving board and an LCD screen. The receiving board integrates a photoelectric sensor and a signal processing circuit. The photoelectric sensor receives the laser echo after beam splitting and completes photoelectric conversion. The resulting electrical signal is processed by the signal processing circuit to complete the ranging calculation. The obtained ranging information is displayed on the LCD screen.

2. The laser rangefinder sight as described in claim 1, characterized in that, The objective lens, emitting beam splitter, small objective lens, semi-pentagonal prism, beam splitter prism, roof prism, reticle, eyepiece group, laser emitting unit, and laser receiving unit are integrated and fixed on the same rigid mechanism support to form an integrated mechanism structure.

3. The laser rangefinder sight as described in claim 2, characterized in that, The integrated mechanism structure can be adjusted by swinging relative to the entire eyepiece assembly with a pivot point in the optical axis direction.

4. The laser rangefinder sight as described in claim 1, characterized in that, The beam-splitting prism is glued to the beam-splitting surface of the semi-pentagonal prism.

5. The laser rangefinder sight as described in claim 1, characterized in that, The laser emitting unit also includes a beam expander disposed between the laser emitter and the emitting beam splitter.

6. The laser rangefinder sight as described in claim 1, characterized in that, The laser receiving unit also includes a reflector, which is disposed between the beam splitter and the receiving plate.

7. The laser rangefinder sight as described in claim 1, characterized in that, After passing through the objective lens, the laser beam remains parallel to the white light axis or intersects at an infinity point.

8. The laser rangefinder sight as described in claim 1, characterized in that, The signal processing circuit is configured to execute a digital correlation detection algorithm to extract the laser echo signal from the output signal of the photoelectric sensor and perform distance calculation.

9. The laser rangefinder sight as described in claim 8, characterized in that, The digital correlation detection algorithm is as follows: using the modulation code sequence driving the laser emitter as a reference signal, cross-correlation is performed with the signal output by the photoelectric sensor, and the laser propagation duration is determined by detecting the peak value of the cross-correlation function.

10. A method of using a laser rangefinder sight as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Step 1: The laser emitter generates a modulated laser beam, which passes through the beam splitter and enters the light-transmitting area at the edge of the objective lens. After being collimated by the objective lens, the laser beam is directed toward the target to be measured. Step 2: The laser echo reflected by the target to be tested returns along the central optical axis of the original white light imaging optical path, passes sequentially through the objective lens, the emitting beam splitter, the small objective lens, and the semi-pentagonal prism, and is then incident on the photoelectric sensor after being split by the beam splitter. Step 3: The photoelectric sensor receives the laser echo, completes the photoelectric conversion and outputs an electrical signal. The signal processing circuit processes the electrical signal and calculates the laser propagation time. Step 4: Calculate the distance to the target based on the laser propagation time, and output the ranging information.

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