Abstract:
The lens contains a cup-shaped body with a lens bottom and a lens member extended upward from the lens bottom and forming a 49-degree included angle with the lens bottom. The lens member contains, from bottom to top, a number of layers, each having a number of refraction portions. Each refraction portion contains a number of refraction elements arranged in a concentric manner. According to the inclination angle of the lens member, dimensions of the refraction portions, and the distribution of refraction elements, the lens could be applied to various applications with enhanced coverage range and sensory effect.

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention is generally related to lens for use with sensors, and more particularly to a lens having a layered structure where each layer has a number of concentric refraction elements. 
     DESCRIPTION OF THE PRIOR ART 
     A sensor is conventionally equipped with a lens to enhance its coverage range. However, the lens can only achieve a limited effect. 
     The reason lies in that the lens is of a specific focus length. When the sensor is deployed in an application requiring a different focus length, the sensor with a lens of inadequate focus length obviously cannot fulfill the application&#39;s requirement. 
     SUMMARY OF THE INVENTION 
     An objective of the present invention is to provide a lens having a layered structure and each layer has a number of concentric refraction elements so as to enhance sensed signal strength and to enlarge sensor coverage range. 
     To achieve the foregoing objective, the lens of the present invention contains a cup-shaped body with a lens bottom and a lens member extended upward from the lens bottom and forming an included angle with the lens bottom. The lens member contains a number of layers, each having a number of refraction portions. Each refraction portion in turn contains a bottom side, a top side parallel to the bottom side, and two lateral sides connecting the two ends of the bottom and top sides, respectively. Each refraction portion also contains a number of refraction elements arranged in a concentric manner. 
     The present inventor provides a number of embodiments of the lens having different number of layers and thereby achieving different refraction effects. As such, the lens could be applied to various applications, obviating the conventional problem of single-focus-length lens. The lens taught by the present inventor has a different inclination angle and refraction structure so that the sensor could have enhanced coverage range and sensory effect. 
     The foregoing objectives and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. 
     Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  provides the top and side views a lens according to a first embodiment of the present invention. 
         FIG. 2  shows the distribution of refraction elements of each layer&#39;s refraction portion of the lens shown in  FIG. 1 . 
         FIG. 3  is a top view diagram showing the distribution of sensed signal of the lens shown in  FIG. 1 . 
         FIG. 4  is a side view diagram showing the distribution of sensed signal of the lens shown in  FIG. 1 . 
         FIG. 5  provides the top and side views a lens according to a second embodiment of the present invention. 
         FIG. 6  shows the distribution of refraction elements of each layer&#39;s refraction portion of the lens shown in  FIG. 5 . 
         FIG. 7  is a top view diagram showing the distribution of sensed signal of the lens shown in  FIG. 5 . 
         FIG. 8  is a side view diagram showing the distribution of sensed signal of the lens shown in  FIG. 5 . 
         FIG. 9  provides the top and side views a lens according to a third embodiment of the present invention. 
         FIG. 10  shows the distribution of refraction elements of each layer&#39;s refraction portion of the lens shown in  FIG. 9 . 
         FIG. 11  is a top view diagram showing the distribution of sensed signal of the lens shown in  FIG. 9 . 
         FIG. 12  a side view diagram showing the distribution of sensed signal of the lens shown in  FIG. 9 . 
         FIG. 13  provides the top and side views a lens according to a fourth embodiment of the present invention. 
         FIG. 14  shows the distribution of refraction elements of each layer&#39;s refraction portion of the lens shown in  FIG. 13 . 
         FIG. 15  is a top view diagram showing the distribution of sensed signal of the lens shown in  FIG. 13 . 
         FIG. 16  a side view diagram showing the distribution of sensed signal of the lens shown in  FIG. 13   
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following descriptions are exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims. 
       FIG. 1  provides the top and side views a lens  100  according to a first embodiment of the present invention. The lens  100  has a body  1  of a cup shape with a lens bottom  11  and a lens member  12  extended upward from the lens bottom  11 . An included angle θ between 46 to 52 degrees is formed between the cut member  12  and the lens bottom  11 . Preferably, θ is 49 degree. 
     As further shown in  FIG. 2 , the body  1  has a layered structure having, from the lens bottom  11  upward, a first layer  13 , a second layer  14 , a third layer  15 , a fourth layer  16 , a fifth layer  17 , and a sixth layer  18 . The first layer  13  has a refraction portion  131  containing a number of refraction elements  1311 . Similarly, the second to the sixth layers  14 ,  15 ,  16 ,  17 , and  18  have respective refraction portions  141 ,  151 ,  161 ,  171 , and  181  which in turn contain a number of respective refraction elements  1411 ,  1511 ,  1611 ,  1711 , and  1811 . The refraction elements  1311 ,  1411 ,  1511 ,  1611 ,  1711 , and  1811  are arranged in a concentric manner respectively. 
     If the refraction elements  1311 ,  1411 ,  1511 ,  1611 ,  1711 , and  1811  are depicted altogether in  FIG. 1 ,  FIG. 1  would be too confusing to read. Therefore, instead, the refraction elements  1311 ,  1411 ,  1511 ,  1611 ,  1711 , and  1811  are depicted separately in  FIG. 2 . 
     As shown in  FIG. 2 , the distributions of the refraction elements  1311 ,  1411 ,  1511 ,  1611 ,  1711 , and  1811  within the respective refraction portions  131 ,  141 ,  151 ,  161 ,  171 , and  181  are different. For the fourth layer  16 , according to the refraction elements  1611 &#39;s distribution, the refraction portion  161  could be divided into refraction sections  161   a ,  161   b ,  161   c ,  161   d ,  161   e , and  161   f.    
     As to the refraction portion  131 , it has a circular shape of diameter 4.6 mm and the refraction elements  1311  are configured as concentric circles. The tolerance of the distance between neighboring refraction elements  1311  is ±0.05 mm. Similarly, the tolerance of the respective distance between neighboring refraction elements  1411 ,  1511 ,  1611 ,  1711 , or  1811  is also ±0.05 mm. 
     The refraction portion  141  has an arc-shaped bottom side  1412 , an arc-shaped top side  1413  parallel to the bottom side  1412 , and two lateral sides  1414  connecting the two ends of the bottom and top sides  1412  and  1413 , respectively. The length of the bottom side  1412  is between 3.15 to 3.35 mm, the length of the top side  1413  is between 8.06 to 8.26 mm, and the length of each lateral side  1414  is between 2.39 to 2.59 mm. 
     The refraction portion  151  has an arc-shaped bottom side  1512 , an arc-shaped top side  1513  parallel to the bottom side  1512 , and two lateral sides  1514  connecting the two ends of the bottom and top sides  1512  and  1513 , respectively. The length of the bottom side  1512  is between 4.34 to 4.54 mm, the length of the top side  1513  is between 7.55 to 7.75 mm, and the length of each lateral side  1514  is between 3.81 to 4.01 mm. 
     The refraction portion  161  has a bottom side  1612 , atop side  1613  parallel to the bottom side  1612 , and two lateral sides  1614  connecting the two ends of the bottom and top sides  1612  and  1613 , respectively. The length of the bottom side  1612  is between 3.4 to 3.6 mm, the length of the top side  1613  is between 4.9 to 5.1 mm, and the length of each lateral side  1614  is between 6.5 to 6.7 mm. 
     The refraction portion  171  has a bottom side  1712 , atop side  1713  parallel to the bottom side  1712 , and two lateral sides  1714  connecting the two ends of the bottom and top sides  1712  and  1713 , respectively. The length of the bottom side  1712  is between 3.7 to 3.9 mm, the length of the top side  1713  is between 4.7 to 4.9 mm, and the length of each lateral side  1714  is between 5.9 to 6.1 mm. 
     The refraction portion  181  has a bottom side  1812 , a top side  1813  parallel to the bottom side  1812 , and two lateral sides  1814  connecting the two ends of the bottom and top sides  1812  and  1813 , respectively. The length of the bottom side  1812  is between 4.7 to 4.9 mm, the length of the top side  1813  is between 6.4 to 6.6 mm, and the length of each lateral side  1814  is between 10.1 to 10.3 mm. 
     The inclination of the lens member  12  relative to the lens bottom  11  is for altering the refraction angle of a sensor, the refraction portions  131 ,  141 ,  151 ,  161 ,  171 , and  181  determines the strength of the sensor&#39;s power, and the refraction elements  1311 ,  1411 ,  1511 ,  1611 ,  1711 , and  1811  are for focusing. 
       FIG. 3  is a top view diagram showing the distribution of sensed signal of the lens  100  shown in  FIG. 1 .  FIG. 4  is a side view diagram showing the distribution of sensed signal of the lens  100  shown in  FIG. 1 . As illustrated, even though the lens  100  contains six refraction layers and as the first layer  13  is located at the lens bottom  11 , its sensed signal is perpendicular to the lens bottom  11  and is therefore omitted. 
       FIGS. 3 and 4  depict five sensed signals, A, B, C, D, and E, which are the signals refracted by the second, third, fourth, fifth, and sixth layers  14 ,  15 ,  16 ,  17 , and  18 , respectively. The five signals manifest a radial distribution in the top view diagram shown in  FIG. 3 . 
       FIG. 5  provides the top and side views a lens  200  according to a second embodiment of the present invention.  FIG. 6  shows the distribution of refraction elements of each layer&#39;s refraction portion of the lens  200  shown in  FIG. 5 . As illustrated, the components of the lens  200  are generally identical to those of the lens  100  of the first embodiment and therefore the same components are denoted by the same reference numbers. The lens  200  has a first layer  23 , a second layer  24 , a third layer  25 , a fourth layer  26 , a fifth layer  27 , and a sixth layer  28 . The first layer  23  has a refraction portion  231  containing a number of refraction elements  2311  arranged as concentric circles. The second layer  24  has a number of refraction portions  241 , each containing a number of refraction elements  2411  arranged as concentric circles. The third layer  25  has a number of refraction portions  251 , each containing a number of refraction elements  2511  arranged as concentric circles. The fourth layer  26  has a number of refraction portions  261 , each containing a number of refraction elements  2611  arranged as concentric circles. The fifth layer  27  has a number of refraction portions  271 , each containing a number of refraction elements  2711  arranged as concentric circles. The sixth layer  28  has a number of refraction portions  281 , each containing a number of refraction elements  2811  arranged as concentric circles. 
     Please note that the distributions of the refraction elements  2311 ,  2411 ,  2511 ,  2611 ,  2711 , and  2811  within the respective refraction portions  231 ,  241 ,  251 ,  261 ,  271 , and  281  are different from those of the first embodiment. Additionally, even though that the dimensions of the refraction portions  231 ,  241 , and  251  of the first, second, and third layers  23 ,  24 , and  25  are identical to those of the first embodiment, the dimensions of the refraction portions  261 ,  271 , and  281  of the fourth, fifth, and sixth layers  26 ,  27 , and  28  are identical to those of the first embodiment. As the dimensions of the refraction portions  231 ,  241 , and  251  of the first, second, and third layers  23 ,  24 , and  25  are identical to those of the first embodiment, their description is omitted. 
     The refraction portion  261  has a bottom side  2612  whose length is between 3.39 to 3.59 mm, a top side  2613  whose length is between 4.41 to 4.61 mm, and two lateral sides  2614  whose length is between 4.4 to 4.6 mm. 
     The refraction portion  271  has a bottom side  2712  whose length is between 3.77 to 3.97 mm, a top side  2713  whose length is between 4.65 to 4.85 mm, and two lateral sides  2714  whose length is between 4.4 to 4.6 mm. 
     The refraction portion  281  has a bottom side  2812  whose length is between 3.59 to 3.79 mm, a top side  2813  whose length is between 4.5 to 4.7 min, and two lateral sides  2814  whose length is between 5.9 to 6.1 mm. 
     Since the operation principle of the second embodiment is the same as the first embodiment, the description to the second embodiment is omitted. 
       FIG. 7  is a top view diagram showing the distribution of sensed signal of the lens  200  shown in  FIG. 5 .  FIG. 8  is a side view diagram showing the distribution of sensed signal of the lens  200  shown in  FIG. 5 . As illustrated, even though the lens  200  contains six refraction layers and as the first layer  23  is located at the lens bottom  11 , its sensed signal is perpendicular to the lens bottom  11  and is therefore omitted. 
       FIGS. 7 and 8  depict five sensed signals, A, B, C, D, and E, which are the signals refracted by the second, third, fourth, fifth, and sixth layers  24 ,  25 ,  26 ,  27 , and  28 , respectively. The five signals manifest a radial distribution in the top view diagram shown in  FIG. 7 . 
       FIG. 9  provides the top and side views a lens  300  according to a third embodiment of the present invention.  FIG. 10  shows the distribution of refraction elements of each layer&#39;s refraction portion of the lens  300  shown in  FIG. 9 . As illustrated, the components of the lens  300  are generally identical to those of the lenses  100  and  200  of the previous embodiments and therefore the same components are denoted by the same reference numbers. The lens  300  has a first layer  33 , a second layer  34 , a third layer  35 , a fourth layer  36 , and a fifth layer  37 . The first layer  33  has a refraction portion  331  containing a number of refraction elements  3311  arranged as concentric circles. The second layer  34  has a number of refraction portions  341 , each containing a number of refraction elements  3411  arranged as concentric circles. The third layer  35  has a number of refraction portions  351 , each containing a number of refraction elements  3511  arranged as concentric circles. The fourth layer  36  has a number of refraction portions  361 , each containing a number of refraction elements  3611  arranged as concentric circles. The fifth layer  37  has a number of refraction portions  371 , each containing a number of refraction elements  3711  arranged as concentric circles. 
     For the fourth layer  36 , according to the refraction elements  3611 &#39;s distribution, the refraction portion  361  could be divided into refraction sections  361   a ,  361   b ,  361   c ,  361   d ,  361   e , and  361   f.    
     The refraction portion  331  has a circular shape of diameter 8 mm. 
     The refraction portion  341  has an arc-shaped bottom side  3412  whose length is between 3.9 to 4.1 mm, an arc-shaped top side  3413  whose length is between 9.9 to 10.1 mm, and two lateral sides  3414  whose length is between 5.1 to 5.3 mm. 
     The refraction portion  351  has a bottom side  3512  whose length is between 6.88 to 7.08 mm, a top side  3513  whose length is between 10.23 to 10.43 mm, and two lateral sides  3514  whose length is between 4.9 to 5.1 mm. 
     The refraction portion  361  has a bottom side  3612  whose length is between 5.06 to 5.26 mm, a top side  3613  whose length is between 6.11 to 6.31 mm, and two lateral sides  3614  whose length is between 4.9 to 5.1 mm. 
     The refraction portion  371  has a bottom side  3712  whose length is between 4.56 to 4.76 mm, a top side  3713  whose length is between 6.44 to 6.64 mm, and two lateral sides  3714  whose length is between 11.9 to 12.1 mm. 
     Since the operation principle of the third embodiment is the same as the previous embodiments, the description to the third embodiment is omitted. 
       FIG. 11  is a top view diagram showing the distribution of sensed signal of the lens  300  shown in  FIG. 9 .  FIG. 12  a side view diagram showing the distribution of sensed signal of the lens  300  shown in  FIG. 9 . As illustrated, even though the lens  200  contains five refraction layers and as the first layer  33  is located at the lens bottom  11 , its sensed signal is perpendicular to the lens bottom  11  and is therefore omitted. 
       FIGS. 11 and 12  depict four sensed signals, A, B, C, and D, which are the signals refracted by the second, third, fourth, and fifth layers  34 ,  35 ,  36 , and  37 , respectively. The four signals manifest a radial distribution in the top view diagram shown in  FIG. 11 . 
       FIG. 13  provides the top and side views a lens  400  according to a second embodiment of the present invention.  FIG. 14  shows the distribution of refraction elements of each layer&#39;s refraction portion of the lens  400  shown in  FIG. 13 . As illustrated, the components of the lens  400  are generally identical to those of the lens of the previous embodiments and therefore the same components are denoted by the same reference numbers. The lens  400  has a first layer  43 , a second layer  44 , a third layer  45 , a fourth layer  46 , a fifth layer  47 , a sixth layer  48 , and a seventh layer  49 . 
     The first layer  43  has a refraction portion  431  containing a number of refraction elements  4311  arranged as concentric circles. The second layer  44  has a number of refraction portions  441 , each containing a number of refraction elements  4411  arranged as concentric circles. The third layer  45  has a number of refraction portions  451 , each containing a number of refraction elements  4511  arranged as concentric circles. The fourth layer  46  has a number of refraction portions  461 , each containing a number of refraction elements  4611  arranged as concentric circles. The fifth layer  47  has a number of refraction portions  471 , each containing a number of refraction elements  4711  arranged as concentric circles. The sixth layer  48  has a number of refraction portions  481 , each containing a number of refraction elements  4811  arranged as concentric circles. The seventh layer  49  has a number of refraction portions  491 , each containing a number of refraction elements  4911  arranged as concentric circles. 
     Please note that the dimensions of the refraction portions  431 ,  441 ,  451 ,  461 ,  471 , and  481  are identical to those of the second embodiment and their description is therefore omitted. The additional seventh layer  49  in the present embodiment is located next to the sixth layer  48 . 
     The refraction portion  491  has a bottom side  4912  whose length is between 4.04 to 4.24 mm, a top side  4913  whose length is between 5.13 to 5.33 mm, and two lateral sides  4914  whose length is between 8.4 to 8.6 mm. 
     Since the operation principle of the second embodiment is the same as the first embodiment, the description to the second embodiment is omitted. 
       FIG. 15  is a top view diagram showing the distribution of sensed signal of the lens  400  shown in  FIG. 13 .  FIG. 16  a side view diagram showing the distribution of sensed signal of the lens  400  shown in  FIG. 13 . As illustrated, even though the lens  400  contains seven refraction layers and as the first layer  43  is located at the lens bottom  11 , its sensed signal is perpendicular to the lens bottom  11  and is therefore omitted. 
       FIGS. 15 and 16  depict six sensed signals, A, B, C, D, E, and F which are the signals refracted by the second, third, fourth, fifth, sixth, seventh layers  34 ,  35 ,  36 ,  37 ,  38 , and  39  respectively. The six signals manifest a radial distribution in the top view diagram shown in  FIG. 15 . 
     While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.