Single-cylinder laser ranging telescope and range finder

Abstract

The utility model provides a single-cylinder laser ranging telescope and a range finder. The single-cylinder laser ranging telescope comprises a casing, a first lens group, a second lens group, an external liquid crystal display screen and a main control board, the first lens group and the second lens group are arranged in the machine shell, the second lens group is arranged on one side of the first lens group, the external liquid crystal display screen is rotatably arranged on the outer side of the machine shell, and the main control board is arranged on the inner side of the machine shell; the main control board is in signal connection with the first lens group, the second lens group and the external liquid crystal display screen, micro-displacement distance measurement is performed on a target object through the second lens group, and a distance measurement result is displayed through the external liquid crystal display screen. According to the utility model, the precision of infinitesimal displacement measurement can be improved, the display functions are diversified, and the user experience effect is good.

Description

Technical Field

[0001] The utility model belongs to the technical field of ranging, and particularly relates to a single-tube laser ranging telescope and a rangefinder. Background Art

[0002] As one of the representative products of civilian laser ranging, the single-tube laser ranging telescope is more and more widely used in the fields of architecture, surveying and mapping, hunting, safety monitoring, etc. At present, the mainstream principle of its long-distance measurement is the time-of-flight method. However, the application fields of the single-tube laser ranging telescope often have the need to measure displacements below the centimeter level at a distance of hundreds of meters, such as the measurement of building deformation degree, water level monitoring, pollution source monitoring, etc.

[0003] A laser ranging telescope is provided in the related art, which includes a first lens group and a second lens group. The first lens group is provided with an eyepiece, an objective lens, a prism group, a transmitting lens, a laser transmitter, and a liquid crystal display system. The eyepiece and the objective lens are located at both ends of the first lens group. The prism group is located on the optical axis between the eyepiece and the objective lens, and the laser transmitter is located on one side of the prism group. The infrared laser emitted by the laser transmitter is focused by the transmitting lens, passes through the wedge prism, enters the semi-pentaprism, is reflected by the semi-pentaprism, and then passes through the objective lens and is emitted to the target object to realize the ranging function.

[0004] However, due to the algorithm limitations of the laser ranging technology and circuit interference in the above related technology, the time resolution of the laser ranging telescope is low, resulting in a large ranging error and inability to measure tiny displacements. For example, an error of 0.1 ns can cause an error of 1.5 cm. At the same time, when encountering requirements such as building deformation and water level monitoring, the measurement accuracy is low and the usage function is single. Summary of the Utility Model

[0005] An embodiment of the utility model provides a single-tube laser ranging telescope, aiming to solve the problems of low measurement accuracy and single usage function of the telescope in the prior art.

[0006] In a first aspect, an embodiment of the utility model provides a single-tube laser ranging telescope, including: a housing, a first lens group, a second lens group, an external liquid crystal display screen, and a main control board. The first lens group and the second lens group are arranged in the housing. The second lens group is arranged on one side of the first lens group. The external liquid crystal display screen is rotatably arranged on the outside of the housing. The main control board is arranged on the inside of the housing. The main control board is respectively in signal connection with the first lens group, the second lens group, and the external liquid crystal display screen. Tiny displacement ranging is performed on the target object through the second lens group, and the ranging result is displayed through the external liquid crystal display screen.

[0007] Further, the second lens group includes a first lens, a second lens, and a first camera arranged in sequence. The first lens is used to measure the color block displacement change of the target object, and is adjusted by the second lens. The first camera is used to collect an image, and the ranging result is sent to the external liquid crystal display screen for display through the main control board.

[0008] Further, the first lens group includes a coaxial emission and reception module, an optical ranging unit, and a projection module. The optical path of the coaxial emission and reception module is perpendicular to the optical path of the optical ranging unit. The main control board controls the coaxial emission and reception module to emit laser to the optical ranging unit. The optical ranging unit reflects the laser and the reflected laser is received by the coaxial emission and reception module, and the received image is sent to the external liquid crystal display screen for display through the main control board. The projection module projects the ranging result onto the optical ranging unit for observation.

[0009] Further, the coaxial emission and reception module includes a laser emission unit and a laser reception unit with coaxial optical paths. The laser emission unit emits laser to the target object and performs diffuse reflection. The laser reception unit receives the diffusely reflected laser for imaging.

[0010] Further, the laser emission unit includes a laser emitter, a third lens, a perforated mirror, and an aspherical spliced lens. The laser emitter emits laser that passes through the third lens, the perforated mirror, and the aspherical spliced lens in sequence to the target object.

[0011] Further, the aspherical spliced lens includes a central lens and an outer ring lens attached to the outer edge of the central lens. The focal lengths of the central lens and the outer ring lens are different. Among them, the central lens with a shorter focal length is located at the center and is used for the laser emission optical path to collimate the laser for the first time. The lens with a longer focal length is located on the periphery and is used for the laser reception optical path.

[0012] Further, the laser reception unit includes a fourth lens and a photodiode. The laser reflected by the target object passes through the aspherical spliced lens, the perforated mirror, the fourth lens, and the photodiode in sequence. The photodiode converts the color block formed by the fourth lens focusing the laser into an electrical signal. The main control board processes the electrical signal to obtain position information and sends the position information to the external liquid crystal display screen.

[0013] Further, the optical ranging unit includes an objective lens, a prism group, an LCD liquid crystal, and an eyepiece; the optical path of the objective lens passing through the target object sequentially passes through the prism group, the LCD liquid crystal, and the eyepiece, and a real image is formed at the position where the LCD liquid crystal is located through the objective lens and the prism group, and the real image is observed through the eyepiece by the human eye or a monocular industrial camera with an industrial lens.

[0014] Further, the prism group includes a compensation prism, a semi-pentagonal prism, and a Schmidt roof prism stacked in a direction perpendicular to the optical path passing through the target object; the semi-pentagonal prism is arranged between the compensation prism and the Schmidt roof prism.

[0015] Further, the projection module includes an organic light-emitting diode, a reflecting mirror, and a projection objective lens. After being reflected by the reflecting mirror, the organic light-emitting diode is projected and transmitted to the prism group through the projection objective lens. After being transmitted through multiple internal reflections in the prism group, the measurement result is projected onto the LCD liquid crystal, and the measurement result is observed through the eyepiece by the human eye or a monocular industrial camera with an industrial lens.

[0016] In a second aspect, an embodiment of the present invention provides a measurement method for a single-tube laser rangefinder telescope, and the measurement method is implemented based on the single-tube laser rangefinder telescope as described above;

[0017] The measurement method includes the following steps:

[0018] After pressing the measurement button, the coaxial laser emission and reception module and the second lens group start to be activated;

[0019] The main control board collects the ranging result of the coaxial laser emission and reception module, the micro-displacement measurement result of the second lens group, and the received image;

[0020] Send the ranging result and the micro-displacement measurement result to the projection module for display;

[0021] The received image is sent to the external liquid crystal display screen for display.

[0022] In a third aspect, an embodiment of the present invention provides a rangefinder, and the rangefinder includes a rangefinder body and an external liquid crystal display screen that is flipably arranged outside the rangefinder body.

[0023] Beneficial effects achieved by the present utility model: The present utility model provides a single-tube laser rangefinder telescope. The first lens group and the second lens group are arranged in the housing, the second lens group is arranged below the first lens group, and the external liquid crystal display screen and the main control board are respectively arranged on both sides of the housing; the main control board is respectively signal-connected to the first lens group, the second lens group and the external liquid crystal display screen. The second lens group is used for measuring the micro-displacement of the target object, and the external liquid crystal display screen is used for displaying the ranging result. The micro-displacement measurement module of the second lens group can fill the industry technical gap that single-tube laser rangefinder telescopes do not have the function of measuring micro-displacements; it can simultaneously measure distances and micro-displacements, display scenes and measurement results, optimize the use experience and avoid cumbersome operations. Description of the Drawings

[0024] Figure 1 FIG. is a schematic structural diagram of a single-tube laser rangefinder telescope provided by an embodiment of the present utility model;

[0025] Figure 2 FIG. is an equivalent schematic diagram of a single-tube laser rangefinder telescope provided by an embodiment of the present utility model;

[0026] Figure 3 FIG. is an optical path schematic diagram of a laser emission unit provided by an embodiment of the present utility model;

[0027] Figure 4 FIG. is an optical path schematic diagram of a laser receiving unit provided by an embodiment of the present utility model;

[0028] Figure 5 FIG. is an optical path schematic diagram of an optical ranging unit provided by an embodiment of the present utility model;

[0029] Figure 6 FIG. is an optical path schematic diagram of the second lens group provided by an embodiment of the present utility model;

[0030] Figure 7 FIG. is the usage state of a rangefinder provided by an embodiment of the present utility model Figure 1 ;

[0031] Figure 8 FIG. is the usage state of a rangefinder provided by an embodiment of the present utility model Figure 2 ;

[0032] Figure 9 FIG. is a flowchart of a measurement method of a single-tube laser rangefinder telescope provided by an embodiment of the present utility model;

[0033] Figure 10 FIG. is Figure 9 the flowchart of the near-distance measurement of;

[0034] Figure 11 Yes Figure 9 Flow chart of long-distance measurement

[0035] Among them, 100 is a single-tube laser rangefinder telescope; 1 is a rotating mechanism, 2 is the first lens group, 21 is a coaxial transmitting and receiving module, 211 is a laser transmitting unit, 2111 is a laser transmitter, 2112 is a third lens, 2113 is a perforated mirror, 2114 is an aspherical spliced lens, 212 is a laser receiving unit, 2121 is a fourth lens, 2122 is a photodiode, 22 is an optical ranging unit, 221 is an objective lens, 222 is a prism group, 223 is an LCD liquid crystal, 224 is an eyepiece, 225 is a monocular industrial camera, 23 is a projection module, 231 is an organic light-emitting diode, 232 is a mirror, 233 is a projection objective lens, 3 is the second lens group, 31 is a first lens, 32 is a second lens, 33 is a first camera, 4 is a housing, and 5 is an external liquid crystal display screen. Specific implementation mode

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0037] In the existing technical solutions, due to the algorithm limitations of laser ranging technology and circuit interference, the time resolution of laser rangefinder telescopes is low, resulting in large ranging errors and inability to measure micro-displacements. For example, an error of 0.1 ns can cause an error of 1.5 cm. At the same time, when encountering requirements such as building deformation and water level monitoring, the measurement accuracy is low and the use function is single.

[0038] However, the present invention can fill the industry technical gap that single-tube laser rangefinder telescopes do not have the function of measuring micro-displacements through the micro-displacement measurement module of the second lens group; it can simultaneously maintain the measurement of distance and micro-displacements, the display of scenery and measurement results, optimize the use experience and avoid cumbersome operations.

[0039] Embodiment 1

[0040] See Figures 1 - 8 as shown Figure 1 is a structural schematic diagram of a single-tube laser rangefinder telescope provided by an embodiment of the present invention; Figure 2 is an equivalent schematic diagram of a single-tube laser rangefinder telescope provided by an embodiment of the present invention; Figure 3 is an optical path schematic diagram of a laser transmitting unit provided by an embodiment of the present invention;

[0041] Figure 4 It is a schematic optical path diagram of the laser receiving unit provided by an embodiment of the present utility model; Figure 5 It is a schematic optical path diagram of the optical ranging unit provided by an embodiment of the present utility model; Figure 6 It is a schematic optical path diagram of the second mirror group provided by an embodiment of the present utility model; Figure 7 It is the usage state of a single-tube laser rangefinder telescope provided by an embodiment of the present utility model Figure 1 ; Figure 8 It is the usage state of a single-tube laser rangefinder telescope provided by an embodiment of the present utility model Figure 2 。

[0042] The present utility model provides a single-tube laser rangefinder telescope 100, including: a housing 4, a first mirror group 2, a second mirror group 3, an external liquid crystal display screen 5, and a main control board; the first mirror group 2 and the second mirror group 3 are arranged inside the housing 4, the second mirror group 3 is arranged on one side of the first mirror group 2, the external liquid crystal display screen 5 is rotatably arranged outside the housing 4, and the main control board is fixed to the housing 4; the main control board is respectively signal-connected to the first mirror group 2, the second mirror group 3, and the external liquid crystal display screen 5, the second mirror group 3 performs micro-displacement ranging on the target object, and the external liquid crystal display screen 5 displays the ranging result.

[0043] Among them, the housing 4 is used to install and fix the first mirror group 2, the second mirror group 3, the external liquid crystal display screen 5, and the main control board. The first mirror group 2 and the second mirror group 3 are arranged inside the housing 4 to protect the first mirror group 2 and the second mirror group 3. The external liquid crystal display screen 5 is arranged on one side of the housing 4 for convenient opening for observation. The main control board is convenient for operation and control to achieve the control function.

[0044] Among them, micro-displacement ranging is performed on the target object through the second mirror group 3. When performing displacement measurement or displacement monitoring through the main control board, a pre-coded archive is used for decoding to obtain the coded position corresponding to the calibration position. Algorithms such as the centroid algorithm, contour positioning, geometric center positioning, and multi-target relative position positioning can be used to obtain the relative position relationship of the color blocks as the calibration color block distribution data; when the target object moves, the above operations are repeated to obtain the target color block data. The difference between the calibration color block distribution data and the current color block distribution data is used to calculate the three-dimensional coordinate change value. The number of longitudinal color block changes in the field of view of the second mirror group 3 is the longitudinal movement amount, and the number of transverse color block changes in the field of view of the second mirror group 3 is the transverse movement amount. The longitudinal movement amount and the transverse movement amount constitute the plane movement amount, which represents the movement amount of the object to be measured in the plane where the array light source is located. Combining the magnification of the color block size, the magnification of the optical system, and the number of color blocks in the field of view, using the triangular relationship, the movement amount of the depth distance can be obtained, and the movement amount of the depth distance can be used to determine the displacement size of the target object in the optical axis direction of the second mirror group 3.

[0045] More specifically, the second lens group 3 includes a first lens 31, a second lens 32, and a first camera 33 arranged in sequence. The first lens 31 is used to measure the color block displacement change of the target object, and is adjusted by the second lens 32. The imaging is collected by the first camera 33, and the imaging result is sent to the external liquid crystal display screen 5 for display through the main control board.

[0046] Among them, in order to perform micro-displacement measurement, multiple differently colored LED light-emitting diodes are placed in front of the target object as an array light source, and a grating is placed as a diffractive optical element. The LED light source on the target object will be diffracted and imaged by the grating into color blocks arranged one by one. When the target object moves, the LED light source installed on it will also move, and the corresponding diffraction order and light intensity distribution will also change, and the corresponding arranged color blocks will also move. By analyzing the color block displacement change, the displacement change of the center of the target object can be deduced, thereby realizing ranging.

[0047] The first lens 31 and the second lens 32 in the second lens group 3 form a Gaussian imaging structure. The first lens 31 and the second lens 32 are ordinary industrial mobile phone lenses, which have a larger field of view angle compared to the telescopic optical system and can observe the color block change corresponding to the diffraction pattern. During measurement, the camera of the micro-displacement measurement module will save two pictures with different diffraction patterns before and after the displacement of the object to be measured and transmit them to the main control board for analysis, and then the micro-displacement measurement result of the object to be measured can be obtained. The main control board will send the measurement result of the micro-displacement module to the LCD liquid crystal, OLED in the optical ranging unit 22, or the external display screen on the left side of the lens group for display.

[0048] More specifically, the first lens group 2 includes a coaxial transmitting and receiving module 21, an optical ranging unit 22, and a projection module 23; the optical path of the coaxial transmitting and receiving module 21 is perpendicular to the optical path of the optical ranging unit 22; the main control board is used to send a control signal to control the coaxial transmitting and receiving module 21 to emit laser light onto the optical ranging unit 22, and the optical ranging unit 22 reflects the laser light and receives it through the coaxial transmitting and receiving module 21, and sends the received image to the external liquid crystal display screen 5 through the main control board for display; the projection module 23 is used to project the ranging result onto the optical ranging unit 22 for observation. The micro displacement measurement module of the second lens group 3 can fill the industry technical gap that single-tube laser rangefinder telescopes do not have the function of measuring micro displacement; the coaxial transmitting and receiving module 21 with a two-stage collimated optical path structure is more compact than the traditional system structure with separate laser emission and reception, and can transmit a longer distance than the general single-stage collimated optical path; the combination of the side-flipping display screen structure, internal LCD, and OLED can realize the simultaneous display of micro displacement, distance, and scenery; it has a longer ranging distance and a more compact laser emission and reception structure, and can simultaneously maintain the measurement of distance and micro displacement, the display of scenery and measurement results when measuring near or far objects, optimizing the use experience and avoiding cumbersome operations.

[0049] More specifically, the coaxial transmitting and receiving module 21 includes a laser transmitting unit 211 and a laser receiving unit 212 with coaxial optical paths; the laser transmitting unit 211 is used to emit laser light to the target object and perform diffuse reflection; the laser receiving unit 212 is used to receive the laser light emitted by the diffuse reflection for imaging.

[0050] More specifically, the laser transmitting unit 211 includes a laser emitter 2111, a third lens 2112, a perforated mirror 2113, and an aspherical splicing lens 2114; the laser emitter 2111 emits laser light that passes through the third lens 2112, the perforated mirror 2113, and the aspherical splicing lens 2114 to the target object in sequence. The infrared laser emitted by the laser emitter 2111 is focused by the third lens 2112 on the laser beam of the laser emitter 2111, so that the relatively thin beam passes through the central circular hole of the perforated mirror 2113 and is collimated by the aspherical splicing lens 2114, thereby emitting a collimated laser beam.

[0051] Among them, the laser emitter 2111 is a laser diode LD, which is used to emit infrared laser light.

[0052] More specifically, the aspheric spliced lens 2114 includes a central lens and an outer ring lens disposed along the outer edge of the central lens, and the central lens and the outer ring lens have different focal lengths. Among them, the central lens with a shorter focal length is located at the central position and is used for the laser emission optical path to collimate the laser for the first time; the outer ring lens with a longer focal length is located at the peripheral position and is used for the laser reception optical path.

[0053] Optionally, the aspheric spliced lens 2114 in the laser emission unit can be replaced by splicing two orthogonal cylindrical mirrors and an outer ring lens to achieve full calibration of the fast and slow axes of the LD laser diode.

[0054] More specifically, the laser reception unit 212 includes a fourth lens 2121 and a photodiode 2122. The laser reflected by the target sequentially passes through the aspheric spliced lens 2114, the perforated mirror 2113, the fourth lens 2121, and the photodiode 2122. The photodiode 2122 converts the color block formed by the fourth lens 2121 focusing the laser into an optical signal, and the main control board processes the optical signal to obtain the position information and sends the position information to the external liquid crystal display screen 5.

[0055] More specifically, the optical ranging unit 22 includes an objective lens 221, a prism group 222, an LCD liquid crystal 223, and an eyepiece 224. The optical path of the objective lens 221 passing through the target sequentially passes through the prism group 222, the LCD liquid crystal 223, and the eyepiece 224. A real image is formed at the position where the LCD liquid crystal 223 is located by the objective lens 221 and the prism group 222, and the real image is observed through the eyepiece 224 by the human eye or a monocular industrial camera 225 with an industrial lens.

[0056] Among them, the light emitted by the object forms a real image at the position where the LCD liquid crystal 223 is located through the objective lens 221 and the prism group 222. The human eye or a monocular industrial camera 225 with an industrial lens observes the image at the position where the LCD is located and the LCD itself through the eyepiece 224.

[0057] Specifically, after the main control board sends an electrical signal to the coaxial laser emission and reception module, the infrared laser emitted by the laser diode LD is focused by the third lens 2112 on the LD laser beam, and the thinner beam passes through the central circular hole of the perforated mirror 2113 and is collimated by the aspheric spliced lens 2114. Len6 is spliced by two aspheric lenses with different focal lengths and is divided into a central lens and an outer ring lens. Among them, the lens with a shorter focal length is located at the center and is used for the laser emission optical path to collimate the laser for the first time; the lens with a longer focal length is located at the periphery and is used for the laser reception optical path.

[0058] The collimated laser beam passes through the compensation prism in the prism group 222, and then reaches the objective lens 221 after being reflected by the semi-pentagonal prism. After the objective lens 221 collimates the laser beam for the second time, it emits a nearly parallel light with a smaller divergence angle and hits the target object at infinity. The emission color patch has a very small laser emission angle after two collimations, can transmit a farther distance compared with the traditional single collimation, and thus has a wider ranging scope.

[0059] Specifically, the infrared laser emitted by the laser emission unit 211 will undergo diffuse reflection after hitting the target object. The energy of the diffusely reflected infrared laser will be collected by the objective lens 221 with a larger receiving angle for the first light collection, and reflected in the prism group 222. After the second light collection by the outer ring lens with a longer focal length of the aspherical spliced lens 2114, the perforated mirror 2113 performs a second reflection, and finally is transmitted to the fourth lens 2121 for focusing into a smaller color patch and received by the photodiode 2122 to be converted into another electrical signal. The main control board processes the signal and calculates the time interval between the two electrical signals of emission and reception to measure the position information of the target object. The ranging result is sent by the main control board to the LCD liquid crystal 223 in the optical ranging unit 22, and is displayed on the OLED or the external display on the left side of the lens group.

[0060] At the same time, a part of the received infrared laser that passes through the central lens of the aspherical spliced lens 2114 and passes through the middle hole of the perforated mirror 2113 cannot reach the PD photodiode 2122. This part of the received light will be lost, but it accounts for a very small part of the entire received light energy and will not affect the ranging effect. The perforated mirror 2113 can make the light conduct inside the mirror, facilitating the distribution and conversion of the optical path. At the same time, the perforated mirror 2113 can also reduce the occlusion during optical imaging, realize the penetration of the optical path, so as to achieve a clearer imaging effect. Further reduce the interference of the reflected laser on ranging and improve the stability and accuracy of ranging.

[0061] The coaxial emission and reception module adopting the two-stage collimation optical path structure is more compact than the traditional system structure with separate laser emission and reception, and can transmit a farther distance than the general single collimation optical path; the combination of the side flip display screen structure, the internal LCD, and the OLED can realize the simultaneous display of minute displacement, distance, and scenery; it has a farther ranging distance and a more compact laser emission and reception structure. When measuring near or far objects, it can simultaneously maintain the measurement of distance and minute displacement, the display of scenery and measurement results, optimizing the use experience and avoiding cumbersome operations.

[0062] More specifically, the prism group 222 includes a compensation prism, a semi-pentagonal prism, and a Schmidt roof prism stacked in a direction perpendicular to the optical path passing through the target object; the semi-pentagonal prism is arranged between the compensation prism and the Schmidt roof prism.

[0063] More specifically, the projection module 23 includes an organic light-emitting diode 231, a reflecting mirror 232, and a projection objective lens 233. After being reflected by the reflecting mirror 232, the organic light-emitting diode 231 is projected and transmitted through the projection objective lens 233 to the prism group 222. After being transmitted through multiple internal reflections in the prism group 222, the measurement result is projected onto the LCD liquid crystal 223, and the measurement result is observed through the eyepiece 224 by the human eye or a monocular industrial camera 225 with an industrial lens. This facilitates the transmission and display of the projected image, and the observation effect is good.

[0064] More specifically, the single-tube laser rangefinder telescope 100 further includes a rotating mechanism 1 that can rotate on the housing 4 and is located above the eyepiece 224. The monocular industrial camera 225 with an industrial lens is fixed on the rotating mechanism 1. By twisting the rotating mechanism 1, the camera is turned to the lower side to be flush with the eyepiece 224 and buckled, so as to realize the switching function between the human eye and the camera of the optical ranging unit 22.

[0065] Among them, the external liquid crystal display screen 5 is connected to the lens group through the rotating mechanism 1. When in use, it can be straightened to be perpendicular to the user's line of sight or rotated and tilted flexibly. The monocular industrial camera 225 installed above the eyepiece 224 of the first lens group 2 can be turned to the lower side to be flush with the eyepiece 224 and buckled by twisting the rotating mechanism 1 during use, so as to realize the switching between the human eye and the camera of the optical ranging unit. Through the combination of the external liquid crystal display screen 5 on the side, the liquid crystal display LCD in the first lens group 2, and the organic light-emitting diode 231, the simultaneous display of minute displacements, distances, and scenes is realized.

[0066] Embodiment 2

[0067] See Figures 9 - 11 as shown Figure 9 is a flowchart of a measurement method of a single-tube laser rangefinder telescope provided by an embodiment of the present invention; Figure 10 is Figure 9 a flowchart of close-range measurement; Figure 11 is Figure 9 a flowchart of long-range measurement.

[0068] The embodiment of the present invention provides a measurement method of a single-tube laser rangefinder telescope, and the measurement method is implemented based on the single-tube laser rangefinder telescope 100 as described in Embodiment 1 above;

[0069] The measurement method includes the following steps:

[0070] S1. After pressing the measurement button, the coaxial laser emission and reception module and the second lens group 3 start to be activated;

[0071] S2. The main control board collects the ranging result of the coaxial laser transmitting and receiving module, the micro-displacement measurement result of the second lens group 3, and the received image.

[0072] S3. Send the ranging result and the micro-displacement measurement result to the projection module 23 for display.

[0073] S4. Send the received image to the external liquid crystal display screen 5 for display.

[0074] Specifically, when the distance of the object to be measured is relatively close, the micro-displacement measurement module can normally measure the micro-displacement of the object to be measured. The human eye can normally observe the object to be measured through the optical ranging unit 22. When the measurement button is pressed, the coaxial laser transmitting and receiving module and the micro-displacement measurement module will start to work. The main control board will collect the ranging result of the coaxial laser transmitting and receiving module and the micro-displacement measurement result of the micro-displacement measurement module, and send them to the LCD liquid crystal 223 and the organic light-emitting diode 231 for display. The main control board will also collect the image received by the micro-displacement measurement module and send it to the flip-up display screen on the left side of the lens group for display. The human eye can observe the measurement results displayed on the LCD liquid crystal 223 and the organic light-emitting diode 231 while observing the object to be measured through the optical ranging unit 22.

[0075] When the object with the micro-displacement to be measured is at a relatively far distance, the diffraction imaging observation requirement exceeds the image quality limit of the Gaussian imaging structure of the micro-displacement module. At the same time, because the human eye does not have the ability to distinguish and analyze the diffraction patterns of two objects to be measured with fine displacements, it is necessary to flip and straighten the monocular industrial camera 225 with a lens installed above the first lens group 2 to the lower part and buckle it with the eyepiece 224 of the optical ranging unit 22, replacing the observation surface of the optical ranging unit 22 from the human eye with the camera, that is, using the camera of the optical ranging unit 22 to measure the micro-displacement. As an optical module with a certain magnification and better imaging conditions, the optical ranging unit 22 has a stronger resolution ability for relatively far objects to be measured.

[0076] At this time, the main control board will collect the camera image of the optical ranging unit 22, analyze and obtain the micro-displacement measurement result, as well as the ranging result of the coaxial transmitting and receiving module 21, and send them to the external flip-up liquid crystal display screen for display for the user to obtain. The user can simultaneously obtain the image information, position and displacement information of the object to be measured.

[0077] Specifically, when obtaining the object to be measured at the current position, the current image data is obtained by collecting an image of the diffraction plane formed when the array light source emits light through a fixedly arranged camera. Image extraction processing is performed on the color blocks in the current image data to obtain the current color block distribution data. The displacement value of the object to be measured from the calibration position to the current position is determined through the preset color block position coding archive, the current color block distribution data, and the calibrated color block distribution data at the calibration position.

[0078] The array light source is attached to the surface of the object to be measured. The array light source can be displaced as the object to be measured is displaced. The array light source includes a plurality of light source units arranged in an array that are encoded. There are color block images in the diffraction plane formed when the array light source emits light. When the camera collects an image of the diffraction plane formed when the array light source emits light, the image data of the object to be measured at the current position can be obtained, and this image data is the current image data.

[0079] It should be noted that for the camera, when performing micro-displacement measurement, the optical axis direction and position remain unchanged. Therefore, the field of view range of the camera is also fixed and unchanged, making the factor that causes the change in the color block distribution data within the field of view only come from the displacement of the object to be measured.

[0080] The above-mentioned current position can be understood as the position where the object to be measured is located when displacement measurement or displacement monitoring needs to be performed.

[0081] In the array light source, the light source units are arranged in an order difference array. In the plane where the array light source is located, the distances between the light source units are not equal. It can increase in a certain direction, with the increase being an increasing distance difference or an increasing multiple difference. There is an array light source as follows:

[0082]

[0083] In the above formula, N represents that there are N light source units horizontally, M represents that there are M light source units vertically, and L i，j represents the i-th light source unit horizontally and the j-th light source unit vertically. For the horizontal order difference, among the adjacent two light source units L 1，j →L N，j ) horizontally, for the two light source units L i，j and L i-1，j , the distance d(L i，j and L i-1，j ) between the light source units L i，j and L i-1，j ) ≠ d(L i-1，j and L i-2，j ), and d(L i-1，j and L i-2，j ) is the distance between two adjacent light source units L i-1，j and L i-2，j horizontally., indicating that the distances between two adjacent segments horizontally are not equal, or there is [d(L i，j , L i-1，j ) / d(L i-1，j , L i-2，j )] ≠ [d(L i-1，j , L i-2，j ) / d(L i-2，j , L i-3，j ), indicating that the ratio between the distances of two adjacent segments horizontally is different from the ratio between the distances of another two adjacent segments. There is a common distance d(L i-1，j , L i-2，j ) between the two adjacent segments and the other two adjacent segments. Similarly, for the ordinal difference vertically, in the vertical direction (L i，1 → L i，M ), the distances between two adjacent segments are not equal, or the ratio between the distances of two adjacent segments is different from the ratio between the distances of another two adjacent segments. There is a common distance between the two adjacent segments and the other two adjacent segments.

[0084] The color block extraction algorithm can be used to perform image extraction processing on the color blocks in the current image data to obtain the current color block distribution data. It should be noted that the above current image data is the image collected by the camera within the field of view, and the above current color block distribution data represents the color block distribution data within the camera field of view.

[0085] The color block position encoding archive records the mapping relationship between the color block distribution data and the encoding position. After encoding the light source units in the array light source, the mapping relationship between the color block distribution data and the encoding position can be recorded by testing. It should be noted that during the testing process, the camera is fixedly set, the variable in the testing is the displacement change of the array light source, and the result is the color block distribution data. The color block position encoding archive includes the mapping relationship between the color block distribution data and the encoding position.

[0086] The above calibration position can be the initial position of the object to be measured or the position specified by the user. For example, it can be the position of the object to be measured during the previous displacement measurement. When the object to be measured is at the calibration position, the camera can collect an image of the diffraction surface formed when the array light source emits light, and then the image data of the object to be measured at the calibration position can be obtained. This image data is the calibration image data. By performing image extraction processing on the color blocks in the calibration image data, the calibration color block distribution data can be obtained.

[0087] Specifically, since the camera is fixedly installed, its field of view is limited and it can only capture the color patches within the field of view, unable to capture the color patches outside the field of view. There is the above-mentioned sequence difference in the settings of the light source units in the array light source. This sequence difference enables the distance between the light source units to be encoded. Within the field of view of the camera, different color patch distributions have different sequence differences. Therefore, the relationship between the color patch distribution and the sequence difference can also be encoded. And different color patch distributions are caused by the array light source at different positions. Therefore, the relationship between the position of the array light source and the color patch distribution can also be encoded. The array light source is attached to the surface of the object to be measured, and the position of the array light source can represent the position of the object to be measured. Therefore, the encoded position corresponding to the object to be measured can be found through the color patch distribution data in the color patch image. Different color patch distribution data correspond to different encoded positions. The calibration encoded position of the object to be measured at the calibration position and the current encoded position of the object to be measured at the current position can be determined using the color patch position encoding archive to obtain the encoded position difference, and the displacement value of the object to be measured from the calibration position to the current position can be calculated using the encoded position difference.

[0088] In the embodiment of the present utility model, the displacement value of the object to be measured from the calibration position to the current position can be measured using the mapping relationship between the color patch distribution data and the encoded position. Since the slight movement of the object to be measured can cause a large change in the color patch distribution formed by the array light source, the change amount of the color patch distribution can characterize the movement amount of the object to be measured, and thus sub-millimeter precision positioning over a distance of one hundred meters can be achieved.

[0089] During the process of obtaining the calibration position of the object to be measured, calibration image data is obtained by collecting images of the diffraction surface formed when the array light source emits light using a fixedly installed camera; the color patches in the calibration image data are subjected to image extraction processing to obtain calibration color patch distribution data.

[0090] When the object to be measured is at the calibration position, there are color patch images in the diffraction surface formed when the array light source emits light. The camera collects images of the diffraction surface formed when the array light source emits light, and then the image data of the object to be measured at the calibration position can be obtained. This image data is the calibration image data. In the obtained calibration image data, the color patches in the calibration image data can be subjected to image extraction processing through a color patch extraction algorithm to obtain calibration color patch distribution data. It should be noted that the above-mentioned calibration image data is the image collected by the camera within the field of view, and the above-mentioned calibration color patch distribution data represents the color patch distribution data within the field of view of the camera.

[0091] The change between the calibration color patch distribution data and the current color patch distribution data can be calculated to obtain the change in the color patch distribution within the field of view of the camera from the calibration position to the current position, and then the displacement value from the calibration position to the current position can be calculated.

[0092] Perform color patch extraction processing on the current image data to obtain the current color patch image data in the current image data; determine the current color patch distribution data at the current position in the current color patch image data.

[0093] In the embodiment of the present utility model, the color patch extraction algorithm can be used to perform color patch extraction processing on the current image data, and the color patch image data is extracted from the current image data. The above color patch image data may include data such as the number of color patches, the positions of color patches, the colors of color patches, and the sizes of color patches. The above current color patch distribution data may include at least one of the data such as the number of color patches, the positions of color patches, the colors of color patches, and the sizes of color patches. Specifically, the data items included in the above current color patch distribution data correspond to the data items in the color patch position coding archive. In this way, it is convenient to decode the current color patch distribution data through the color patch position coding archive.

[0094] It should be noted that in the step of performing image extraction processing on the color patches in the calibration image data to obtain the calibrated color patch distribution data, it can also be implemented by the step of performing image extraction processing on the color patches in the current image data to obtain the current color patch distribution data.

[0095] Based on the color patch position coding archive, the current color patch distribution data, and the calibrated color patch distribution data, determine the planar movement amount of the object to be measured at the current position relative to the calibrated position, and determine the depth movement amount of the object to be measured at the current position relative to the calibrated position; based on the planar movement amount and the depth movement amount, determine the displacement value of the object to be measured in the three-dimensional space; based on the displacement value of the object to be measured in the three-dimensional space, determine the displacement value of the object to be measured between the calibrated position and the current position.

[0096] Among them, the above planar movement amount refers to the movement amount in the horizontal and vertical directions, and the above depth movement amount refers to the movement amount in the direction of the camera optical axis. The camera optical axis is orthogonal to the plane formed by the light source unit in the horizontal and vertical directions.

[0097] The number of longitudinal color block changes within the field of view of the camera is the longitudinal movement amount, and the number of transverse color block changes within the camera's field of view is the transverse movement amount. Specifically, the longitudinal color block change amount within the camera's field of view is the longitudinal movement amount, and the transverse color block change amount within the camera's field of view is the transverse movement amount. More specifically, the longitudinal color block change amount within the field of view can be the change amount of the distance between color blocks in the longitudinal direction (i.e., the longitudinal sequence difference), and the maximum transverse color block change within the camera's field of view can be the change amount of the distance between color blocks in the transverse direction (i.e., the transverse sequence difference). When the array light source moves longitudinally, the color blocks within the camera's field of view also move longitudinally, and the longitudinal sequence of the color blocks within the camera's field of view changes, causing the longitudinal distance between the color blocks within the module's field of view to change. When the array light source moves transversely, the color blocks within the camera's field of view also move transversely, and the transverse sequence of the color blocks within the camera's field of view changes, causing the transverse distance between the color blocks within the module's field of view to change. The changes in this longitudinal movement and transverse movement and the change in the distance between the color blocks within the module's field of view are recorded in the color block position coding archive, and the longitudinal movement and transverse movement of the object to be measured can be obtained by calculating the change in the distance between the color blocks within the module's field of view.

[0098] It can be understood that the closer the array light source is to the camera, the closer the diffraction surface is to the camera, the larger the size of the color blocks within the camera's field of view, and the fewer the number of color blocks. The farther the array light source is from the camera, the farther the diffraction surface is from the camera, the smaller the size of the color blocks within the camera's field of view, and the more the number of color blocks. Within the camera's field of view, the correlation between this depth change and the change in color block size and / or the number of color blocks is also recorded in the color block position coding archive. By combining the magnification of the color block size with the optical system magnification and the number of color blocks within the field of view, and using the color block position coding archive for decoding, the movement amount of the depth distance can be obtained, and the movement amount of the object to be measured in the direction of the camera optical axis can be determined using the movement amount of the depth distance.

[0099] The current color block distribution data includes the current sequence difference data between each color block at the current position, and the calibrated color block distribution data includes the calibrated sequence difference data between each color block at the calibrated position. The color block position coding archive includes the mapping relationship between the sequence difference and the planar coding position. Using the color block position coding archive and the current sequence difference data to determine the current planar coding position corresponding to the current position; and using the color block position coding archive and the calibrated sequence difference data to determine the calibrated planar coding position corresponding to the calibrated position; based on the difference between the current planar coding position and the calibrated planar coding position, determine the planar movement amount of the object to be measured from the calibrated position to the current position.

[0100] The above-mentioned current sequence difference data can be understood as the distance difference or the distance multiple difference between consecutive color blocks. The above-mentioned current sequence difference data can include the longitudinal current sequence difference data and the transverse current sequence difference data.

[0101] It can be understood that the distribution of color blocks within the camera's field of view is affected by the position of the array light source. This is mainly because the sequence difference of color blocks within the field of view will change. Since the color blocks within the field of view are obtained by the diffraction of the array light source, the light emitted by the light source unit is diffracted and amplified, causing the slight movement of the array light source to be amplified into a change in the sequence difference of the color block distribution. This change in the sequence difference can be encoded and characterized by the distance between color blocks, forming an archived color block position encoding.

[0102] The above-mentioned planar movement amount includes the longitudinal movement amount and the transverse movement amount. The longitudinal encoding position corresponding to the current position (the encoded coordinate value y1 in the Y-axis direction, where the Y-axis direction can be the vertical direction of the plane where the array light source is located) can be determined through the archived color block position encoding and the current sequence difference data in the longitudinal direction. The transverse encoding position corresponding to the current position (the encoded coordinate value x1 in the X-axis direction, where the X-axis direction can be the horizontal direction of the plane where the array light source is located) can be determined through the archived color block position encoding and the current sequence difference data in the transverse direction. The current planar encoding position (x1, y1) can be obtained based on the longitudinal encoding position and the transverse encoding position. The longitudinal encoding position corresponding to the calibration position (the encoded coordinate value y0 in the y-axis direction) can be determined through the archived color block position encoding and the calibrated sequence difference data in the longitudinal direction. The transverse encoding position corresponding to the calibration position (the encoded coordinate value x0 in the x-axis direction) can be determined through the archived color block position encoding and the calibrated sequence difference data in the transverse direction. The calibrated planar encoding position (x0, y0) can be obtained based on the longitudinal encoding position and the transverse encoding position. Based on the difference between the current planar encoding position and the calibrated planar encoding position, the planar movement amount (△x, △y) of the object to be measured at the current position is determined as follows:

[0103] △x = |x0 - x1|;

[0104] △y = |y0 - y1|.

[0105] Using the archived color block position encoding and the current sequence difference data to determine the current planar encoding position and the calibrated planar encoding position corresponding to the current position, the planar movement amount of the object to be measured from the calibration position to the current position can be quickly calculated. By using the size, arrangement interval, beam quality, spatial position between the light source and the diffraction layer, and the parameters of the diffraction layer as the main degrees of freedom for optical system design to determine the corresponding archived color block position encoding, the mapping relationship between the encoding position and the color block distribution data can be flexibly set, and sub-millimeter precision positioning at a distance of one hundred meters can be achieved.

[0106] The current color patch distribution data includes the current color patch quantity data and / or the current color patch size data at the current position. The calibrated color patch distribution data includes the calibrated color patch quantity data and / or the calibrated color patch size data at the calibrated position. The color patch position coding archive includes the mapping relationship between the color patch quantity and / or the current color patch size and the depth coding position.

[0107] Use the color patch position coding archive and the current color patch quantity data and / or the current color patch size data to determine the current depth coding position corresponding to the current position; use the color patch position coding archive and the calibrated color patch quantity data and / or the calibrated color patch size data to determine the calibrated depth coding position corresponding to the calibrated position; based on the difference between the current depth coding position and the calibrated depth coding position, determine the depth movement amount of the object to be measured at the current position relative to the calibrated position.

[0108] The depth movement amount refers to the movement amount of the object to be measured in the direction of the camera optical axis.

[0109] It should be noted that the closer the array light source is to the camera, the closer the diffraction surface is to the camera, the larger the color patch size in the camera's field of view, and the fewer the color patch quantity. The farther the array light source is from the camera, the farther the diffraction surface is from the camera, the smaller the color patch size in the camera's field of view, and the more the color patch quantity. In the camera's field of view, the correlation between this depth change and the color patch size and / or color patch quantity change is also recorded in the color patch position coding archive. By combining the magnification factor of the color patch size with the optical system magnification factor and the color patch quantity in the field of view, and decoding using the color patch position coding archive, the movement amount of the depth distance can be obtained. Using the movement amount of the depth distance, the movement amount of the object to be measured in the direction of the camera optical axis can be determined.

[0110] The current depth coding position corresponding to the current position (the coded coordinate value z1 corresponding to the Z-axis direction, and the camera optical axis direction is the Z-axis direction) can be determined through the color patch position coding archive and the current color patch quantity data and / or the current color patch size data. The calibrated depth coding position corresponding to the calibrated position (the coded coordinate value z0 corresponding to the Z-axis direction) can be determined through the color patch position coding archive and the calibrated color patch quantity data and / or the calibrated color patch size data. Based on the difference between the current depth coding position and the calibrated depth coding position, determine the depth movement amount △z of the object to be measured at the current position, as follows:

[0111] △z = |z0 - z1|.

[0112] By using the color block position encoding archive and the current color block quantity data and / or the current color block size data, the calibrated color block quantity data and / or the calibrated color block size data to respectively determine the current depth encoding position and the calibrated depth encoding position corresponding to the current position, the depth movement amount of the object to be measured from the calibrated position to the current position can be quickly calculated. By using the size, arrangement interval, beam quality of the light source unit, the spatial position between the light source and the diffraction layer, and the parameters of the diffraction layer as the main degrees of freedom for the optical system design to determine the corresponding color block position encoding archive, the mapping relationship between the encoding position and the color block distribution data can be flexibly set, and sub-millimeter precision positioning at a distance of one hundred meters can be achieved.

[0113] Through the object-image space relationship, the displacement value of the object to be measured in the three-dimensional space is converted into the initial displacement value of the object to be measured in the real space; the initial displacement value is calibrated and compensated to obtain the displacement value of the object to be measured from the calibrated position to the current position in the real space.

[0114] The above object-image space relationship can be understood as the projection relationship between the real object and the object in the image, that is, the mapping relationship between the real space coordinate system and the camera space coordinate system. The displacement value in the above three-dimensional space is the calculated (△x, △y, △z). Through the object-image space relationship, the displacement value of the object to be measured in the three-dimensional space is converted into the initial displacement value of the object to be measured in the real space. The initial displacement value can be understood as the displacement value without post-processing.

[0115] It should be noted that due to the influence of installation and environment, there will be a certain systematic error in the process of micro-displacement measurement, and this systematic error cannot be eliminated. For example, the optical axis of the camera is offset, the beam is affected by the environment, etc. Therefore, after calculating the initial displacement value of the object to be measured in the real space, the initial displacement value can be calibrated and compensated to make the displacement value after calibration and compensation more accurate.

[0116] In a possible embodiment, multiple camera measurements can also be performed at the current position. After obtaining multiple displacement values after calibration and compensation, the average displacement value can be calculated or the median displacement value can be selected as the final displacement value.

[0117] In a third aspect, an embodiment of the present invention provides a rangefinder. Please refer to Figure 7 and Figure 8 , the above rangefinder includes a rangefinder body and an external liquid crystal display screen 5 that is flipably arranged outside the rangefinder body. The user flips the external liquid crystal display screen 5 to view the external liquid crystal display screen 5 in a better posture. The above external liquid crystal display screen 5 displays the ranging result of the micro-displacement.

[0118] It should be noted that the terms "comprising" and "having" and any variations thereof in the description, claims and drawings of the present utility model are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description, claims or drawings of the present utility model are used to distinguish different objects, rather than to describe a specific order. The mention of "embodiment" in this text means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present utility model. The appearance of this phrase at various positions in the description does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0119] The above are only the preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A monocular laser ranging telescope, characterized in that: include: A housing, a first lens group, a second lens group, an external liquid crystal display screen and a main control board; the first lens group and the second lens group are arranged in the housing, the second lens group is arranged on one side of the first lens group, the external liquid crystal display screen is rotatably arranged on the outside of the housing, and the main control board is arranged on the inside of the housing; the main control board is respectively connected to the first lens group, the second lens group and the external liquid crystal display screen by signal, a small displacement distance measurement is performed on the target object through the second lens group, and the distance measurement result is displayed through the external liquid crystal display screen.

2. The monocular laser ranging telescope according to claim 1, characterized in that: The second lens group includes a first lens, a second lens and a first camera which are arranged in sequence. The first lens is used to measure the displacement change of the color block of the target object and is adjusted by the second lens. The first camera is used to collect images and the distance measurement results are sent to the external LCD display screen for display through the main control board.

3. The monocular laser ranging telescope according to claim 1, characterized in that: The first lens group includes a coaxial transmitting and receiving module, an optical ranging unit and a projection module; the optical path of the coaxial transmitting and receiving module is perpendicular to the optical path of the optical ranging unit; the main control board controls the coaxial transmitting and receiving module to transmit laser to the optical ranging unit, the optical ranging unit reflects the laser and receives it through the coaxial transmitting and receiving module, and sends the received image to the external LCD screen through the main control board for display; the projection module projects the ranging result to the optical ranging unit for observation.

4. The monocular laser ranging telescope according to claim 3, characterized in that: The coaxial transmitting and receiving module comprises a laser transmitting unit and a laser receiving unit with coaxial optical paths; the laser transmitting unit transmits laser light to the target object for diffuse reflection; and the laser receiving unit receives the diffusely reflected laser light for imaging.

5. The monocular laser ranging telescope according to claim 4, characterized in that: The laser emitting unit comprises a laser emitter, a third lens, a reflector with a hole and an aspheric splicing lens; the laser emitter emits laser light sequentially through the third lens, the reflector with a hole and the aspheric splicing lens to the target object.

6. The monocular laser ranging telescope according to claim 5, characterized in that: The aspheric spliced ​​lens includes a central lens and an outer ring lens arranged to fit the outer edge of the central lens, and the focal lengths of the central lens and the outer ring lens are different; wherein the central lens with a shorter focal length is located at a central position and is used for the laser emission optical path to perform the first collimation of the laser; the outer ring lens with a longer focal length is located at a peripheral position and is used for the laser receiving optical path.

7. The monocular laser ranging telescope according to claim 5, characterized in that: The laser receiving unit includes a fourth lens and a photodiode. The laser reflected by the target object passes through the aspheric spliced ​​lens, the perforated reflector, the fourth lens and the photodiode in sequence. The photodiode converts the color block formed by the laser focusing by the fourth lens into a photoelectric signal. The main control board processes the photoelectric signal to obtain position information and sends the position information to the external LCD display.

8. The monocular laser ranging telescope according to claim 3, characterized in that: The optical distance measuring unit comprises an objective lens, a prism group, an LCD liquid crystal and an eyepiece; the objective lens passes through the prism group, the LCD liquid crystal and the eyepiece in sequence through the light path of the target object, and a real image is formed at the position where the LCD liquid crystal is located through the objective lens and the prism group, and the real image is observed through the eyepiece by the human eye or a monocular industrial camera with an industrial lens; The prism group includes a compensation prism, a half pentagonal prism and a Schmidt roof prism stacked in a direction perpendicular to the light path passing through the target object; the half pentagonal prism is arranged between the compensation prism and the Schmidt roof prism.

9. The monocular laser ranging telescope according to claim 8, characterized in that: The projection module includes an organic light emitting diode, a reflector and a projection objective lens. After being reflected by the reflector, the organic light emitting diode is projected and transmitted to the prism group through the projection objective lens. After multiple reflections and transmissions inside the prism group, the measurement result is projected onto the LCD liquid crystal. The measurement result is observed through the eyepiece by the human eye or a monocular industrial camera with an industrial lens.

10. A rangefinder, characterized in that: The rangefinder comprises a rangefinder body and an external liquid crystal display screen which is flippably arranged on the outside of the rangefinder body.

Images