Laser range finder

Abstract

The invention relates to a laser range finder which comprises a visual system, a transmitting system and a receiving system. The visual system comprises an objective lens, a first prism and an eyepiece which are sequentially arranged from the object side to the image side; the transmitting system comprises a laser, a first cemented lens, the first prism and the objective lens; the laser device and the first cemented mirror are located on one side of a visual system, and laser emitted from the laser device is reflected to the first prism through the first cemented mirror, and is emitted to a target object from the objective lens after being reflected by the first prism; by means of the mode, independent parts can be reduced, integration can be achieved, the assembling and adjusting steps can be simplified, assembling and adjusting errors can be reduced, a reflector is not needed to fold a light path, and cost reduction is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of laser ranging, and in particular to a laser rangefinder. Background Art

[0002] Handheld laser rangefinders are small in size and light in weight, and can even be placed in a pocket, so they can be easily carried anywhere for measurement. In scenarios such as outdoors and construction sites where frequent measurements are required, handheld laser rangefinders are very practical tools. However, the existing handheld laser rangefinders have a complex structure, and the internal optical parts are usually independently and dispersedly arranged, resulting in many assembly and adjustment steps and large assembly and adjustment errors. In order to shorten the length of the instrument, a reflecting mirror is usually used to fold the optical path in the emission system, and the cost of the reflecting mirror is relatively high, which is not conducive to cost reduction. Summary of the Invention

[0003] Based on this, in view of the above technical problems, it is necessary to provide a laser rangefinder that can reduce independent parts and achieve integration, thereby simplifying the assembly and adjustment steps, reducing the assembly and adjustment errors, and without using a reflecting mirror to fold the optical path, which is conducive to cost reduction.

[0004] In a first aspect, the present invention provides a laser rangefinder, including a visual system, an emission system, and a reception system;

[0005] The visual system includes an objective lens, a first prism, and an eyepiece sequentially arranged from the object side to the image side;

[0006] The emission system includes a laser, a first cemented lens, the first prism, and the objective lens; the first cemented lens and the first prism are fixed, the laser and the first cemented lens are located on one side of the visual system, and the laser emitted from the laser passes through the first cemented lens and is reflected to the first prism, and after being reflected by the first prism, it is emitted from the objective lens to the target object;

[0007] The reception system is used to receive the laser reflected back from the target object.

[0008] Further, the first cemented lens includes a lens A and a prism A that are cemented and fixed, and the laser emitted from the laser passes through the lens A and then enters the prism A, and is reflected to the first prism via the prism A.

[0009] Further, the first cemented lens is located on one side of the first prism, and the prism A and the first prism are cemented and fixed, so that the first cemented lens and the first prism form a cemented lens group.

[0010] Further, the reception system includes a second cemented lens and a detector, the detector is located on one side of the second cemented lens, and the laser reflected back from the target object enters the second cemented lens and is reflected to the detector via the second cemented lens.

[0011] Further, the second cemented lens includes a lens B and a prism B that are cemented and fixed. The laser reflected from the target object passes through the lens B and then enters the prism B, and is reflected by the prism B onto the detector.

[0012] Further, the detector is fixed on the prism B.

[0013] Further, the receiving system further includes a first lens. The first lens is located on the side of the lens B facing away from the prism B. The laser reflected from the target object passes through the first lens and then enters the lens B.

[0014] Further, the first lens is cemented and fixed to the lens B.

[0015] Further, a display screen is further provided between the first prism and the eyepiece. The display screen is located at the object-side focal point of the eyepiece.

[0016] Further, the first prism is an image-rotating prism.

[0017] The above introduces a laser rangefinder, including a visual system, a transmitting system, and a receiving system; the visual system includes an objective lens, a first prism, and an eyepiece arranged in sequence from the object side to the image side; the transmitting system includes a laser, a first cemented lens, the first prism, and the objective lens; the laser and the first cemented lens are located on one side of the visual system. The laser emitted from the laser is reflected by the first cemented lens to the first prism, and after being reflected by the first prism, it is emitted from the objective lens to the target object; the receiving system is used to receive the laser reflected from the target object. Therefore, in this solution, by using the first cemented lens to reflect the emitted laser to the first prism, the folding of the optical path is realized, which is beneficial to shortening the length of the instrument and reducing the cost compared with a reflector; at the same time, compared with the method of independent parts, the cemented lens can achieve integration, reduce the number of independent parts, thereby reducing the alignment components, simplifying the alignment steps, and reducing the alignment error. Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of a laser rangefinder provided by the present invention;

[0019] Figure 2 It is a schematic structural diagram of the first prism provided by the present invention. Detailed Embodiments

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. The components of the embodiments of the present invention usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0022] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0023] In the description of the embodiments of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship when the product of this application is normally placed, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0024] The laser rangefinder provided in the embodiments of the present invention can be a handheld laser rangefinder, or can be applied to devices such as gun sights, binoculars, holographic helmets, and glasses.

[0025] Referring to Figure 1 , in the laser rangefinder 100 provided in the embodiments of the present invention, the laser rangefinder 100 includes a visual system 11, a transmitting system 12, and a receiving system 13.

[0026] Among them, the visual system 11 includes an objective lens 111, a first prism 112, and an eyepiece 113 arranged in sequence from the object side to the image side. The objective lens 111, the first prism 112, and the eyepiece 113 form a telescope for observing a target object. External ambient light enters through the objective lens 111, then passes through the first prism 112 and the eyepiece 113, and the observer observes through the eyepiece 113. Further, a display screen 114 is also arranged between the first prism 112 and the eyepiece 113. The display screen 114 is located at the object-side focal point of the eyepiece 113 and is used to display measurement data and other electronic information, such as remaining battery power, etc. The display screen 114 can be an organic light-emitting diode (OLED), a liquid crystal display screen, or other types of display screens, and there is no limitation in this regard. Among them, the objective lens 111, the first prism 112, the display screen 114, and the eyepiece 113 are coaxially arranged. The eyepiece 113 can be a transparent resin lens or an optical glass lens.

[0027] The emission system 12 includes a laser 121, a first cemented lens 122, the aforementioned first prism 112, and the objective lens 111. The first cemented lens 122 and the first prism 112 are fixed. The laser 121 and the first cemented lens 122 are located on one side of the visual system 11. For example, Figure 1 based on the view, the laser 121 and the first cemented lens 122 are located on the lower side of the eyepiece system 11. The laser emitted from the laser 121 is reflected upward by the first cemented lens 122 to the first prism 112, and after being reflected by the first prism 112, it is emitted from the objective lens 111 to the target object.

[0028] The receiving system 13 is used to receive the laser reflected back from the target object to achieve distance measurement.

[0029] Therefore, in the present invention, by using the first cemented lens 122 to reflect the emitted laser to the first prism 112, the folding of the optical path is realized, which is beneficial to shortening the instrument length and reducing the cost compared with a mirror; at the same time, the first cemented lens 122 is a cemented lens structure. A cemented lens refers to an optical device formed by bonding two or more different glass or crystal sheets together with glue to form an integral body. Compared with the method of independent parts, the first cemented lens 122 can achieve integration, reduce the number of independent parts, thereby being able to reduce the alignment elements, simplify the alignment steps, and reduce the alignment error.

[0030] Among them, the first prism 112 can be a relay prism with a beam-splitting function. The relay prism can convert an inverted image into an upright image, so that the observer can directly see an upright image without adjusting the viewing angle. Further, as Figure 2As shown, a reflective film F1 that reflects laser light and transmits visible light is plated inside the first prism 112. The ambient light is visible light, and the wavelength bands of visible light and laser light are different. Therefore, the reflective film F1 can be set according to the wavelength bands of visible light and laser light, so that the reflective film F1 can reflect laser light and transmit visible light, enabling the first prism 112 to have a beam splitting function. Therefore, when the first prism 112 is a component structure of the visual system 11, it can transmit external ambient light, and when it is a component structure of the emission system 12, it can reflect the laser light outwards.

[0031] The laser 121 can be a semiconductor laser. A semiconductor laser is a device that converts electrical energy into laser light energy. The laser emitted by a semiconductor laser not only has a narrow spectrum and high frequency stability, but also has high power and a long lifespan. Semiconductor lasers mainly include diode lasers and vertical cavity surface emitting lasers. In other embodiments, the laser 121 can also be other types of lasers, such as solid-state lasers or fiber lasers, etc. Among them, a solid-state laser is a laser that uses a solid material as the resonant cavity. It has excellent optical performance, a large tunable range, good beam quality, high power, and strong stability and reliability; a fiber laser is a laser that uses an optical fiber as the working medium and has characteristics such as high output power, good beam quality, and stable frequency.

[0032] Furthermore, the first cemented lens 122 includes a lens A1221 and a prism A1222 that are cemented and fixed. The lens A1221 and the prism A1222 can be adhesively fixed by UV (Ultra Violet) glue or AB glue (i.e., two-component epoxy resin ab glue adhesive). The lens A1221 is located between the laser 121 and the prism A1222. As Figure 1 shown, the lens A1221 can be a plano-convex lens. The side facing the laser 121 is a convex surface, and the side cemented to the prism A1222 is a flat surface. Of course, in other embodiments, the lens A1221 can also be other types of lenses. The prism A1222 functions to reflect the optical path. The laser emitted by the laser 121 passes through the lens A1221 and then enters the prism A1222, is reflected upwards by the prism A1222 to the first prism 112, and then is reflected by the first prism 112 to the objective lens 111 and exits from the objective lens 111.

[0033] Optionally, the first cemented lens 122 is located on one side of the first prism 112, such as on the lower side of the first prism 112. The prism A 1222 and the first prism 112 are cemented and fixed, and the two can be bonded and fixed by UV glue or AB glue. The first cemented lens 122 and the objective lens 111 form a laser collimation lens group, and the first cemented lens 122 and the first prism 112 form a cemented lens group. The laser 121 emits laser light, which is collimated and emitted after passing through this cemented lens group and the objective lens 111. Thus, the emission system 12 does not need to use a plane mirror to fold the optical path, which is beneficial to cost reduction and can further achieve an integrated design.

[0034] Among them, the receiving system 13 includes a second cemented lens 131 and a detector 132. The detector 132 is located on one side of the second cemented lens 131. For example, based on the Figure 1 view, the detector 132 is located on the lower side of the second cemented lens 131. The laser light reflected from the target object enters the second cemented lens 131 and is reflected downward by the second cemented lens 131 onto the detector 132. The detector 132 receives the reflected laser light through the second cemented lens 131 and converts it into an electrical signal. The detector 132 can be a photodiode, such as an avalanche photodiode (APD). An avalanche photodiode is a p-n junction type photodetector diode in which the avalanche multiplication effect of carriers is utilized to amplify the optical signal to improve the detection sensitivity. After applying a reverse bias voltage to the P-N junction of a photodiode made of silicon or germanium, the incident laser light is absorbed by the P-N junction to form a photocurrent, and increasing the reverse bias voltage will cause an "avalanche" (i.e., the photocurrent surges exponentially).

[0035] The laser rangefinder 100 further includes a ranging module and a power supply module. The power supply module provides power for devices such as the ranging module, the display screen 114, the laser 121, and the detector 132. Among them, the power supply module can include a rechargeable battery, and the rechargeable battery is connected to an external power supply through a charging port, so that the rechargeable battery can be charged. The ranging module calculates the distance between the target object and the laser rangefinder 100 based on the time from the emission to the reception of the laser, combined with the speed of light. The ranging module is also connected to the display screen 114 and is used to send the measurement data to the display screen 114 for display.

[0036] Optionally, the laser rangefinder 100 may further include a voice broadcast module. The ranging module is connected to the voice broadcast module. After the ranging module calculates the distance between the target object and the laser rangefinder 100, the voice broadcast module plays the voice information of the measurement data, so as to broadcast the measurement data in a voice manner for the convenience of the observer. In addition, a volume button may be provided to adjust the voice volume. Further, the laser rangefinder 100 may also include a temperature and humidity sensor for collecting the ambient temperature and humidity and sending the collected data to the display screen 114 for display or sending it to the voice broadcast module for voice playback, so that when the user performs measurement work outdoors, the temperature and humidity of the surrounding environment can be understood.

[0037] Further, the second cemented lens 131 includes a lens B1311 and a prism B1312 that are cemented and fixed. The laser reflected from the target object passes through the lens B1311 and then enters the prism B1312, and is reflected by the prism B1312 to the detector 132. Therefore, the prism B1312 reflects the received laser and plays a role in folding the optical path. The lens B1311 may be a plano-convex lens or other types of lenses. When the lens B1311 is a plano-convex lens, the surface of the lens B1311 that fits with the prism B1312 is a plane, and the other surface where the laser is incident is a convex surface.

[0038] Among them, the prism B1312 is a beam splitting prism, and a reflective film (the diagonal line inside the prism B1312) is plated inside it. This reflective film can reflect the laser and transmit the ambient light, so that the laser reflected from the target object can be reflected to the detector 132.

[0039] Optionally, the detector 132 is fixed to the prism B1312. For example, the surface of the detector 132 is attached to the prism B1312 by means of pasting or the like.

[0040] Optionally, the receiving system 13 further includes a first lens 133. The first lens 133 is located on the side of the lens B1311 facing away from the prism B1312. The laser reflected from the target object passes through the first lens 133 and then enters the lens B1311. Among them, the first lens 133 may be cemented and fixed to the lens B1311. The echo laser passes through the first lens 133 and the second cemented lens 131 and is focused on the photosensitive surface of the detector 132.

[0041] Thus, without using a reflector, the receiving system 13 of the present invention realizes the design of folding the optical path for the limited length requirement, and greatly improves the performance of the receiving system.

[0042] In the present invention, without the need to use a reflector, the first cemented lens 122 is utilized to fold the emission optical path, and the second cemented lens 131 is utilized to fold the reception optical path. Thereby, the length can be shortened, the cost can be reduced, and by fixedly cementing the first cemented lens 122 to the first prism 112 and fixing the second cemented lens 131 to the detector 132, the number of independent parts can be reduced, further realizing integration, simplifying the assembly process, and reducing the assembly error.

[0043] Optionally, the laser rangefinder 100 may further include a communication module. The ranging module can communicate with a terminal device through this communication module, so as to send the measurement data to the terminal device for an observer to view. This communication module can be a wireless communication module or a USB or Type-C communication module, that is, the ranging module can be wirelessly connected to the terminal device through the wireless communication module, or can be wired to the terminal device through a USB data cable or a Type-C data cable. Among them, the wireless communication module can be, for example, a Bluetooth module, a WIFI module, or an NFC module, etc. The terminal device can be, for example, a tablet, a mobile phone, or a computer, etc.

[0044] Optionally, the laser rangefinder 100 may further include a lighting lamp. By setting a lighting switch to control the turning on and off of the lighting lamp, the flashlight function can be realized, which is convenient for lighting in the dark or a dim environment.

[0045] The above introduces a laser rangefinder, which includes a visual system, an emission system, and a reception system; the visual system includes an objective lens, a first prism, and an eyepiece arranged in sequence from the object side to the image side; the emission system includes a laser, a first cemented lens, the first prism, and the objective lens; the laser and the first cemented lens are located on one side of the visual system, and the laser emitted from the laser is reflected to the first prism via the first cemented lens, and after being reflected by the first prism, it is emitted from the objective lens to the target object; the reception system is used to receive the laser reflected back from the target object. Therefore, in this solution, by using the first cemented lens to reflect the emitted laser to the first prism, the folding of the optical path is realized, which is beneficial to shortening the length of the instrument and is beneficial to reducing the cost compared with a reflector; at the same time, compared with the way of independent parts, the cemented lens can achieve integration, reduce the number of independent parts, thereby being able to reduce the alignment components, simplify the alignment steps, and reduce the alignment error.

[0046] The technical features of the above embodiments can be combined arbitrarily. For the sake of brief description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not conflict, it should be considered as the scope recorded in this specification.

[0047] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent for the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the appended claims.

Claims

1. A laser rangefinder, characterized in that: Includes visual system, transmitting system and receiving system; The visual system comprises an objective lens, a first prism and an eyepiece which are arranged in sequence from the object side to the image side; The emission system includes a laser, a first glued lens, the first prism and the objective lens; the first glued lens and the first prism are fixed, the laser and the first glued lens are located on one side of the visual system, and the laser emitted from the laser is reflected to the first prism via the first glued lens, and then emitted from the objective lens to the target object after being reflected by the first prism; The receiving system is used to receive the laser reflected from the target object.

2. The laser rangefinder according to claim 1, characterized in that: The first glued lens includes a lens A and a prism A that are glued and fixed. The laser emitted by the laser passes through the lens A and enters the prism A, and is reflected by the prism A to the first prism.

3. The laser rangefinder according to claim 2, characterized in that: The first glued mirror is located at one side of the first prism, and the prism A and the first prism are glued and fixed, so that the first glued mirror and the first prism form a glued mirror group.

4. The laser rangefinder according to claim 1, characterized in that: The receiving system includes a second glued mirror and a detector. The detector is located on one side of the second glued mirror. The laser reflected from the target object enters the second glued mirror and is reflected to the detector via the second glued mirror.

5. The laser rangefinder according to claim 4, characterized in that: The second glued lens includes a lens B and a prism B that are glued and fixed. The laser reflected from the target passes through the lens B and enters the prism B, and is reflected by the prism B to the detector.

6. The laser rangefinder according to claim 5, characterized in that: The detector is fixed on prism B.

7. The laser rangefinder according to claim 4, characterized in that: The receiving system further includes a first lens, which is located on a side of lens B facing away from prism B. The laser reflected from the target object passes through the first lens and enters lens B.

8. The laser rangefinder according to claim 7, characterized in that: The first lens is glued and fixed to the lens B.

9. The laser rangefinder according to claim 1, characterized in that: A display screen is also provided between the first prism and the eyepiece, and the display screen is located at the object focus of the eyepiece.

10. The laser rangefinder according to claim 1, characterized in that: The first prism is an image-transmitting prism.

Images