Patent Publication Number: US-2022229181-A1

Title: Laser rangefinder

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a laser rangefinder. 
     Description of the Prior Art 
     The laser rangefinder is a very convenient instrument for measuring distance. Its principle is to project laser light to the object to be ranged and calculate the time when it receives the reflected light from the object to be ranged, and thus the distance between the laser rangefinder and the object is obtained. However, the conventional rangefinder can only perform distance-measuring at a fixed angle at a time, and the rangefinder should be manually adjusted to perform distance-measuring at various angles, which is time-consuming and inconvenient. 
     The present invention is, therefore, arisen to obviate or at least mitigate the above-mentioned disadvantages. 
     SUMMARY OF THE INVENTION 
     The main object of the present invention is to provide a laser rangefinder which is simple and compact in structure. 
     To achieve the above and other objects, the present invention provides a laser rangefinder, including: a housing; a first rotational mechanism, mounted to the housing, including a first shaft and a first driving device which are movable with each other, the first driving device driving the first shaft to rotate about a first axial direction relative to the housing; a reflector, connected with the first shaft; a laser rangefinding module, mounted within the housing, including a transmitting module and a receiving module, laser light from the transmitting module being projected to the reflector and reflected to an outside of the housing, the receiving module configured to receive reflection of the laser light from the outside of the housing which is reflected from the reflector; a second rotational mechanism, mounted to the housing, including a second shaft and a second driving device, the second driving device driving the second shaft to rotate about a second axial direction, the first axial direction and the second axial direction being non-parallel; wherein the first shaft is configured to drive the reflector to rotate on a scan plane, the first rotational mechanism, the laser rangefinding module and the second rotational mechanism are located at a same side of the scan plane. 
     The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment(s) in accordance with the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a stereogram of a preferable embodiment of the present invention; 
         FIG. 2  is a partial perspective view of a preferable embodiment of the present invention; 
         FIG. 3  is a cross-sectional view of a preferable embodiment of the present invention; 
         FIG. 4  is a side view of  FIG. 2 ; 
         FIG. 5  is a cross-sectional view of  FIG. 4 ; 
         FIG. 6  is a partial view of  FIG. 5 , showing the paths of laser light during rangefinding; and 
         FIG. 7  is a partial cross-sectional view of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to  FIGS. 1 to 7  for a preferable embodiment of the present invention. A laser rangefinder of the present invention includes a housing  1 , a first rotational mechanism  2 , a reflector  3 , a laser rangefinding module  4  and a second rotational mechanism  5 . 
     The first rotational mechanism  2  is mounted to the housing  1 , the first rotational mechanism  2  includes a first shaft  21  and a first driving device  22  which are movable with each other, and the first driving device  22  drives the first shaft  21  to rotate about a first axial direction relative to the housing  1 . 
     The reflector  3  is connected with the first shaft  21 . 
     The laser rangefinding module  4  is mounted within the housing  1 , and the laser rangefinding module  4  includes a transmitting module  41  and a receiving module  42 . Laser light from the transmitting module  41  is projected to the reflector  3  and reflected to an outside of the housing  1 . The receiving module  42  is configured to receive reflection of the laser light from the outside of the housing  1  which is reflected from the reflector  3 , for distance-calculating. In this embodiment, a focusing lens  63  is disposed in the housing  1  and located between the reflector  3  and the receiving module  42 , for focusing the laser light to the receiving module  42  ( FIG. 6 ). 
     The second rotational mechanism  5  is mounted to the housing  1 , and the second rotational mechanism  5  includes a second shaft  51  and a second driving device  52 . The second driving device  52  drives the second shaft  51  to rotate about a second axial direction, and the first axial direction and the second axial direction are non-parallel. 
     The first shaft  21  is configured to drive the reflector  3  to rotate on a scan plane  7  so that the reflector  3  is rotatable on the scan plane  7  for 360 degrees. The first rotational mechanism  2 , the laser rangefinding module  4  and the second rotational mechanism  5  are located at a same side of the scan plane  7 , and the laser rangefinder is therefore simple and compact in structure. 
     Since the first axial direction and the second axial direction are parallel, the first driving device  22  and the second driving device  52  can operate to make the laser light to be reflected from the reflector  3  at any angles. 
     Preferably, the first axial direction and the second axial direction are perpendicular to each other, and the reflector  3  is exposed to the outside of the housing  1  in the first axial direction. Preferably, the second axial direction is in parallel to a vertical direction which is perpendicular to the ground. The second shaft  51  includes a support  511 , and the support  511  is disposed through the housing  1  and exposed to the outside of the housing  1  for abutting on a datum plane (such the ground). When the second shaft  51  rotates relative to the housing  1 , the housing  1  rotates relative to datum plane. 
     Specifically, the second driving device  52  includes a motor  53 , and the motor  53  is connected and movable with the second shaft  51 . The second shaft  51  is connected and movable with a first gear  54 , the motor  53  is connected and movable with a second gear  55 , the first gear  54  and the second gear  55  are engaged with each other, and the first gear  54  has a diametric dimension larger than a diametric dimension of the second gear  55  so as to reduce the rotational speed of the second shaft  51 . 
     Specifically, the first shaft  21  is rotatably inserted to the housing  1 , and the first driving device  22  includes an electromagnetic assembly  23  and a magnetic assembly  24 . One of the first shaft  21  and the housing  1  includes the electromagnetic assembly  23 , and the other of the first shaft  21  and the housing  1  includes the magnetic assembly  24 , wherein a magnetic field is produced by the electromagnetic assembly  23  to force the magnetic assembly  24  so that the first shaft  21  rotates relative to the housing  1 , which reduces noise, is stable, avoids the shake of the housing  1 , and provides good accuracy. 
     In this embodiment, the magnetic assembly  24  is an annular magnetic member which is disposed around and movable with the first shaft  21 . The electromagnetic assembly  23  includes a plurality of inductances  231  fixedly mounted to the housing  1 , and the plurality of inductances  231  are diametrically arranged relative to the annular magnetic member. As the plurality of inductances  231  are supplied with power, the plurality of inductances  231  produce magnetic force to rotate the annular magnetic member. 
     The housing  1  includes a through hole  11  surrounded by an annular wall  12  extending in the first axial direction, and the first shaft  21  is rotatably inserted in the through hole  11 . The reflector  3  is disposed on an end of the first shaft  21  remote from the housing  1 , a bearing  13  is disposed on an end of the annular wall  12 , and an end of the first shaft  21  is inserted in the bearing  13  so that the first shaft  21  is stably rotatable. The plurality of inductances  231  is disposed on the annular wall  12 . 
     A board  61  is disposed in the housing  1 , the transmitting module  41  and the receiving module  42  are disposed on the board  61 , and the first shaft  21  is a hollow tube for the laser light to pass therethrough. Preferably, the board  61  includes a prism  64 , the prism  64  is located at a side of the focusing lens  63  opposite to the reflector  3 , and the prism  64  is configured to reflect the laser light which passes through the focusing lens  63 , to the receiving module  42 . 
     Preferably, a calibration member  62  is mounted on a bottom of the housing  1  and extends in the first axial direction, and the calibration member  62  corresponds to the reflector  3  in vertical direction. Specifically, a distance between the laser rangefinder and the calibration member  62  is firstly obtained, and as the relative positions of the laser rangefinder and the calibration member  62  is not equal to a predetermined distance, the laser rangefinder should be calibrated. 
     Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.