Patent Publication Number: US-2016231424-A1

Title: Laser distance measure

Description:
BACKGROUND OF THE INVENTION 
     1. Fields of the Invention 
     The present invention relates to a distance measure, and more particularly, to a laser distance measure which uses laser beam to measure distance. 
     2. Descriptions of Related Art 
     The conventional way to measure a distance between two points is to use a tape measure, however, the tape measure is not suitable for measure a longer distance. 
     A laser distance measure is developed which emits a laser beam which bounces back when hit the object and the return laser beam is received by the laser distance measure. The laser distance measure transforms the information that the time required to receive the laser beam into digits to show the distance to the users. The laser distance measure is suitable for measuring a long distance because the return laser beam is parallel to the emitting laser beam so that the laser distance measure can successfully receive the return laser beam. However, when the distance is short, the return laser beam enters the laser distance measure at angle, the return laser beam reflects at least one time before being received by the light receiver in the laser distance measure. The return laser beam may not be able to reach the light receiver in the laser distance measure if the distance measured is too short. Therefore, the laser distance measure fails to provide the distance to the users. Some of the laser distance measures add a lens to increase the possibility that the return laser beam can be received by the light receiver. Nevertheless, this involves problems of high cost and complicated structure. 
     The present invention intends to provide a laser distance measure to eliminate the shortcomings mentioned above. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a laser distance measure and comprises a box with an emitting path and a receiving path defined therein. The receiving path is a tubular path and has a reflection wall therein. A light emitting unit is located in the emitting path and emits a first beam out from the box via the emitting path. The first beam is bounced back when hitting an object and enters into the receiving path to form a second beam which passes through the receiving path and is received by a light receiver in the receiving path. 
     Preferably, the light emitting unit has a circuit board and a laser chip which is electrically connected to the circuit board. The first beam is emitted by the laser chip. 
     Preferably, the box has a control unit connected thereto. The control unit is electrically connected to the light emitting unit to control the operation of the laser chip of the light emitting unit. 
     Preferably, the light receiver defines a first normal line and the reflection wall defines a second normal ling which is perpendicular to the first normal line. 
     Preferably, the light receiver defines a first normal line and the reflection wall defines a second normal ling. The angle between the first and second normal lines is larger than 90 degrees. 
     Preferably, the reflection wall is a planar surface or curved surface. 
     The primary object of the present invention is to provide a laser distance measure which is able to measure both of long and short distances. 
     The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows the operation of the laser distance measure of the present invention to measure a long distance; 
         FIG. 2  shows that the laser distance measure of the present invention measures a short distance; 
         FIG. 3  shows the first and second normal lines of the laser distance measure of the present invention; 
         FIG. 4  shows the operation of the second embodiment of the laser distance measure of the present invention to measure a long distance; 
         FIG. 5  shows that the laser distance measure in  FIG. 4  measures a short distance; 
         FIG. 6  shows the first and second normal lines of the laser distance measure of the present invention in  FIG. 4 ; 
         FIG. 7  shows that the reflection wall of the laser distance measure of the present invention is a planar surface, and 
         FIG. 8  shows that the reflection wall of the laser distance measure of the present invention is a curved surface. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1 to 3 , the laser distance measure of the present invention comprises a box  1  and a light emitting unit  2  in the box  1 . The box  1  has an emitting path  11  and a receiving path  12  defined therein. The receiving path  12  is a tubular path and has a reflection wall  13 . The light emitting unit  2  is located in the emitting path  11  and able to emit a first beam  21  out from the box  1  via the emitting path  11 . The first beam  21  is then bounced back when hitting an object and enters into the receiving path  12  to form a second beam  22  passing through the receiving path  12 . The second beam  22  is received by a light receiver  23  in the receiving path  12 . 
     When measuring a long distance, the light emitting unit  2  emits the first beam  21  out from the box  1  via the emitting path  11 . The first beam  21  is bounced back when hitting the target object. The first beam  21  disperses and enters into the receiving path  12  to form the second beam  22  passing through the receiving path  12 . The second beam  22  is received by the light receiver  23  in the receiving path  12 . The information of the receiving of the second beam  22  is then transformed into digits of the distance between the box  1  and the target object. 
     When measuring a short distance, the light emitting unit  2  emits the first beam  21  out from the box  1  via the emitting path  11 . The first beam  21  is bounced back when hitting the target object. The first beam  21  enters into the receiving path  12  to form the second beam  22  passing through the receiving path  12 . Because the distance is short, so that the second beam  22  cannot directly reach the light receiver  23 , the second beam  22  is reflected by the reflection wall  13  and then received by the light receiver  23  in the receiving path  12 . The information of the receiving of the second beam  22  is then transformed into digits of the distance between the box  1  and the target object. 
     Furthermore, the light emitting unit  2  has a circuit board  24  and a laser chip  25  which is electrically connected to the circuit board  24 . The first beam  21  is emitted by the laser chip  25 . Besides, the box  1  has a control unit  14  connected thereto. The control unit  14  is electrically connected to the light emitting unit  2  to control the operation of the laser chip  25  of the light emitting unit  2 . By operating the control unit  14 , the users can set a desired emitting way according individual task needs. 
     The light receiver  23  defines a first normal line  231  and the reflection wall  13  defines a second normal ling  131  which is perpendicular to the first normal line  231 . By the arrangement, the bounced first beam  21  can be reflected and received by the light receiver  23 . In other words, a short distance can also be measured by the present invention because the reflection wall  13  reflects the bounced first beam  21  to form the second beam  22  in the receiving path  12 . 
     As shown in  FIGS. 4 to 6 , a second embodiment is disclosed wherein the difference from the first embodiment is that the light receiver  23  defines a first normal line  231  and the reflection wall  13  defines a second normal ling  131 , wherein the angle between the first and second normal lines  231 ,  131  is larger than 90 degrees. When measuring a long distance, the operation and steps are the same as those of the first embodiment. When measuring a short distance, the different inclination of the reflection wall  13  can successfully reflect the bounced first beam  21  to form the second beam  22  in the receiving path  12 . 
     As shown in  FIGS. 7 and 8 , in order to ensure that the second beam  22  can be received by the light receiver  23 , the reflection wall  13  is a planar surface or curved surface. 
     While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.