Patent Publication Number: US-11662828-B2

Title: Method for identifying object, optical sensing apparatus and system

Description:
FIELD OF THE DISCLOSURE 
     The present disclosure relates to a technology of identifying an approaching object, and more particularly to a method for identifying object, an optical sensing apparatus and a system. 
     BACKGROUND OF THE DISCLOSURE 
     Rather than a conventional button that a user&#39;s hand should press thereon in order to perform a subsequent action, e.g., switching a light on or off, a new type of contactless button allows a user to perform the subsequent action without touching the button. Further, the contactless button is advantageous to prevent the user from being exposed to the risk of virus infection due to hygienic concerns. 
     An optical proximity sensor is generally one of the solutions to implement the contactless button. The proximity sensor is able to detect an approaching object by using a light source to emit a light and sensing the intensity of the light reflected by the object. However, one major challenge of the conventional optical proximity sensor is that it may easily lead to a misjudgment since it only relies on the intensity of the light, which is emitted by only one light source, reflected by the object to determine the approaching object. It is easy to make the misjudgment due to the various intensities may be obtained while sensed from the light reflected by various unknown object with different reflectivities are not reliable. 
     For instance, a switch equipped with the conventional optical proximity sensor may be turned on or off regardless of the sensed object approaching the switch is a user&#39;s finger that is supposed to be sensed or his body. In other words, the conventional optical sensor cannot identify the size of the approaching object effectively. 
       FIG.  1    shows an example of a conventional switch  12  equipped with the conventional optical proximity sensor. In general, the optical proximity sensor is configured to provide a sensing angle θ and sense any object entering a sensing zone defined by the sensing angle θ. In the present example, when a user&#39;s hand  10  approaches the switch  12  for switching on or off a light bulb  14 , the switch  12  can be activated if the optical proximity sensor inside the switch  12  senses the user&#39;s hand  10 . However, the switch  12  may lead to a false action if an approaching object is sensed by the optical proximity sensor even if it is not intent to press the switch  12  to turn on the light bulb  14 . For example, the light bulb  14  may be turned on or off unintentionally only because the approaching object is big enough to be sensed by the optical proximity sensor. 
     SUMMARY OF THE DISCLOSURE 
     In response to the above-referenced technical inadequacies, the present disclosure provides a method for identifying an object, an optical sensing apparatus and a system thereof. The system includes one or more optical sensing apparatuses and a controller. The optical sensing apparatus includes multiple light sources that are used to emit multiple light beams with different beam angles and a light sensor used to sense intensities of the light beams reflected by an object when the multiple light beams illuminate the object. The controller drives the multiple light sources to emit the multiple light beams, controls the light sensor to sense the light beams reflected by the object, and performs the method for identifying the object. 
     In one embodiment of the present disclosure, in the method, a first light source is used to emit a first light beam with a first beam angle, and a light sensor is used to sense a first intensity of the first light beam reflected by the object; a second light source is used to emit a second light beam with a second beam angle, and the light sensor is used to sense a second intensity of the second light beam reflected by the object. The object can accordingly be identified by integrating information of the intensities obtained by the light sensor. 
     In an aspect, the first beam angle of the first light beam is different from the second beam angle of the second light beam, and intensities respectively sensed from the reflected first light beam and the reflected second light beam form the information to identify a size of the object. Further, the intensities respectively sensed from different reflected light beams can be compared with each other for determining a movement of the object. 
     In another aspect, the first beam angle of the first light beam is configured to be smaller than the second beam angle of the second light beam, and the object can be identified when the object enters both the first beam angle and the second beam angle. When the intensity sensed from the reflected first light beam is greater than the intensity sensed from the reflected second light beam and a difference between the intensities exceeds a threshold, it is determined that the object is close to the light sensor. 
     In yet another aspect, in the method, a first set of intensities can be sensed for a period of time and a second set of intensities can also be sensed for the same period of time. The first set and the second set of intensities being sensed over time are resolved to determine a movement of the object. When a first trend of changes of the first set of intensities is close to a second trend of changes of the second set of intensities for the period of time, it is determined that the object is close to or away from the light sensor. 
     Furthermore, in one further embodiment of the present disclosure, the optical sensing apparatus implements a contactless switch adapted to an electronic device. The contactless switch is configured to accept a gesture performed by a user&#39;s finger or palm, and the size of the object indicates the user&#39;s finger or palm. 16. Further, the contactless switch is configured to accept a gesture performed by a user&#39;s finger or palm, and the size of the object determined by the method of the present disclosure can be interpreted as the user&#39;s finger or palm. 
     According to one further embodiment of the present disclosure, the system includes a water meter that has a rotatable pointer and a rotatable half plate. The system includes a first proximity sensor disposed in or on the water meter. The first proximity sensor outputs a first signal when the first proximity sensor detects the rotatable half plate. The first proximity sensor outputs a second signal when the first proximity sensor does not detect the rotatable half plate. The system includes a second proximity sensor disposed in or on the water meter. The second proximity sensor outputs a third signal when the second proximity sensor detects the rotatable half plate and the second proximity sensor outputs a fourth signal when the second proximity sensor does not detect the rotatable half plate. A controller of the system receives the signals from the first proximity sensor and the second proximity sensor and determines that the water meter is rotated clockwise or counter-clockwise. 
     These and other aspects of the present disclosure will become apparent from the following description of the embodiment taken in conjunction with the following drawings and their captions, although variations and modifications therein may be affected without departing from the spirit and scope of the novel concepts of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will become more fully understood from the following detailed description and accompanying drawings. 
         FIG.  1    shows an example of a conventional switch adopting a proximity sensor; 
         FIG.  2    is a schematic diagram depicting a switch adopting an optical sensing apparatus including multiple light sources for sensing an approaching object according to one embodiment of the present disclosure; 
         FIG.  3    is a functional block diagram of an optical sensing apparatus according to one embodiment of the present disclosure; 
         FIG.  4    is another functional block diagram of a system for identifying an object with one or more optical sensing apparatuses according to another embodiment of the present disclosure; 
         FIG.  5    is a flowchart which describes a method for identifying an object according to one embodiment of the present disclosure; 
         FIGS.  6 A- 6 C  show schematic diagrams depicting an application of the system with multiple optical sensing apparatuses according to one embodiment of the present disclosure; 
         FIG.  7 A  is a schematic diagram depicting an optical sensing apparatus sensing a moving object in an exemplary example of the disclosure; 
         FIG.  7 B  is a schematic chart showing intensity distribution curves generated by the optical sensing apparatus shown in  FIG.  7 A ; 
         FIG.  8 A  is another schematic diagram depicting an optical sensing apparatus sensing an approaching object in an exemplary example of the disclosure; 
         FIG.  8 B  is another schematic chart showing intensity distribution curves generated by the optical sensing apparatus shown in  FIG.  8 A ; and 
         FIGS.  9 A- 9 D  show schematic views depicting one more application of the system with multiple optical sensing apparatuses according to one more embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     The present disclosure is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. Like numbers in the drawings indicate like components throughout the views. As used in the description herein and throughout the claims that follow, unless the context clearly dictates otherwise, the meaning of “a”, “an”, and “the” includes plural reference, and the meaning of “in” includes “in” and “on”. Titles or subtitles can be used herein for the convenience of a reader, which shall have no influence on the scope of the present disclosure. 
     The terms used herein generally have their ordinary meanings in the art. In the case of conflict, the present document, including any definitions given herein, will prevail. The same thing can be expressed in more than one way. Alternative language and synonyms can be used for any term(s) discussed herein, and no special significance is to be placed upon whether a term is elaborated or discussed herein. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms is illustrative only, and in no way limits the scope and meaning of the present disclosure or of any exemplified term. Likewise, the present disclosure is not limited to various embodiments given herein. Numbering terms such as “first”, “second” or “third” can be used to describe various components, signals or the like, which are for distinguishing one component/signal from another one only, and are not intended to, nor should be construed to impose any substantive limitations on the components, signals or the like. 
     The present disclosure is about a method for identifying an object with an optical sensing apparatus that generally includes multiple light sources used to emit multiple light beams with different beam angles, and a light sensor used to sense the lights reflected by an object when the multiple light beams illuminate the object. A system including one or more optical sensing apparatuses and a controller is also provided. The controller is electrically connected to the one or more optical sensing apparatuses. The controller drives the multiple light sources to emit the multiple light beams, controls the light sensor to sense the lights reflected by the object, and performs the method for identifying the object. 
     One of the objectives of the system and the method of the present disclosure is to reduce misjudgments when identifying the object entering coverage of the one or more optical sensing apparatuses of the system. The object can be accurately identified because the system acquires further more spatial information sensed by the light sensor from the multiple light sources that are configured to emit the multiple light beams with different beam angles. 
       FIG.  2    is a schematic diagram depicting a switch  22  adopting the optical sensing apparatus equipped with multiple light sources for sensing an approaching object according to one embodiment of the present disclosure. In an aspect of the disclosure, the optical sensing apparatus having the multiple light sources is provided to be installed in a switch  22  electrically connected to a controlled device  24  and accordingly the switch  22  is configured to sense an approaching object, e.g., a hand  20 , for determining whether or not to turn on or off the controlled device  24  when the object enters a sensing zone defined by a first beam angle θ 1  and a second beam angle θ 2 . 
     According to one embodiment of the present disclosure, the optical sensing apparatus installed in the switch  22  emits at least two light beams with two different beam angles, i.e., the first beam angle θ 1  and the second beam angle θ 2  schematically shown in the drawing, from at least two light sources. Accordingly, system including one or more optical sensing apparatuses can effectively acquire more spatial information from the two or more different beam angles that define a specific sensing zone. The optical sensing apparatus uses a light sensor to sense an intensity of a light beam reflected by an object within the first beam angle θ 1 , and another intensity of another light beams reflected by the object within the second beam angle θ 2 . The system further includes a controller that is electrically connected with the multiple light sources and the light sensor and is able to integrate the information of the different intensities for identifying any approaching object entering the sensing zone. Afterwards, the controller can switch on or off the controlled device  24  based on the information. It should be noted that the information of the different intensities indicates a ratio of or a different between the two or more intensities sensed by the light sensor from the at least two light beams. 
     Further, it should be noted that, in one further aspect of the present disclosure, the different light beams can also be emitted by a single light source when the light source emits the different light beams with different beam angles via different optical arrangements by a time-sharing method. 
     Next, reference is made to  FIG.  3   , which is a functional block diagram of an optical sensing apparatus according to one embodiment of the present disclosure. 
     In the present embodiment of the disclosure, an optical sensing apparatus  30  shown in the drawing includes a first light source  305 , a second light source  306  and a light sensor  303 . In particular, a first sensing range S 1  is defined by a first light beam with a beam angle that is emitted by the first light source  305  and reached to the light sensor  303 , and a second sensing range S 2  is defined by a second light beam with a different beam angle that is emitted by the second light source  306  and also reached to the light sensor  303 . The first sensing range S 1  is configured to be different from the second sensing range S 2 . The light sensor  303  is configured to sense the lights reflected by an object when the multiple light beams illuminate the object. The optical sensing apparatus  30  includes a controller  301  that is electrically connected to the multiple light sources (e.g., the first light source  305  and the second light source  306 ) and the light sensor  303 . In an aspect of the disclosure, the controller  301  drives the multiple light sources ( 305 ,  306 ) to emit the multiple light beams, controls the light sensor  303  to sense the lights reflected by the object, and performs a method for identifying the object. 
     In the present embodiment, the optical sensing apparatus  30  is installed in a switch  32  that is adapted to an electronic device, i.e., a controlled device  34 . The controller  301  constantly detect if any object approaches the switch  32  and identify the object by integrating information of the first intensity sensed from the first light beam within the first sensing range S 1  and the second intensity sensed from the second light beam within the second sensing range S 2 . 
     Accordingly, the information obtained from the first intensity and the second intensity is referred to for determining whether or not the switch  32  is activated to control the controlled device  34 . In an exemplary example, when the first intensity sensed from the reflected first light beam is greater than the second intensity sensed from the reflected second light, and as well a difference between the first intensity and the second intensity exceeds a threshold, it is determined that the object is close to the switch  32 , and the switch  32  is activated to switch on or off the controlled device  34 . 
       FIG.  4    is another functional block diagram of the system for identifying an object with one or more optical sensing apparatuses according to another embodiment of the present disclosure. 
     The abovementioned system can also include more than one optical sensing apparatus such as a first optical sensing apparatus  401  and a second optical sensing apparatus  402 , which are exemplarily shown in  FIGS.  6 A- 6 C . A controller  40  of the system is electrically connected with the first optical sensing apparatus  401  and the second optical sensing apparatus  402 , and is able to control these optical sensing apparatuses ( 401 ,  402 ) to sense the lights reflected by the object. After integrating the information of the intensities sensed from the multiple light beams within the different sensing ranges defined by the optical sensing apparatuses ( 401 ,  402 ) respectively, the controller  40  can effectively identify the object. In yet another aspect, the determination made by the controller  40  can be transmitted to an electronic device such as the above-mentioned controlled device; or alternatively the information obtained by the controller  40  can also be transmitted to a host  42  that performs the method for identifying the object. 
     Reference is made to  FIG.  5   , which is a flowchart which describes a method for identifying an object according to one embodiment of the present disclosure. 
     In various embodiments of the present disclosure, the sample flowchart shows steps that are arranged in a sequence to describe a process flow performed in an optical sensing apparatus or a system. In the beginning, as shown in step S 501 , a controller of the optical sensing apparatus drives a light source, e.g., a first light source, to emit a first light beam with a first beam angle, and in step S 503  utilizes a light sensor to sense a first intensity of the first light beam reflected by an object. In the same time or by a time-sharing method, in step S 505  the controller drives the light source, e.g., a second light source, to emit a second light beam with a second beam angle, and in step S 507  utilizes the light sensor to sense a second intensity of second light beam reflected by the object. 
     Afterwards, the object can be identified by integrating information of the first intensity and the second intensity. In detail, such as in step S 509 , the controller compares the intensities sensed from the reflected first light beam and the reflected second light beam respectively, and accordingly, in step S 511 , identifies a state of the object. 
     More specifically, in various exemplary examples, the first beam angle of the first light beam is different from the second beam angle of the second light, and a size of the object can be identified by comparing the first intensity and the second intensity. For example, the first beam angle (e.g., S 1  of  FIG.  3   ) is configured to be smaller than the second beam angle (e.g., S 2  of  FIG.  3   ). Further, a movement of the object can also be identified by comparing a profile of the first intensity and another profile of the second intensity when the intensities are collected within a time period. It should be noted that the profile of the intensities indicates a trend of a series of changes of the intensities sensed for a period of time, and the trend can be used to determine the movement of the object. 
       FIGS.  6 A- 6 C  show schematic diagrams depicting an application of the system with multiple optical sensing apparatuses according to one embodiment of the present disclosure. 
     The present application is related to a panel system that includes multiple buttons (i.e., the switches) provided for a user to press for performing a subsequent action. For example, the panel system is used in an elevator. The panel system of the elevator provides a panel  600  having multiple buttons  610 , as shown in  FIG.  6 A , which are provided for a passenger to push one of the buttons for requesting a destination floor. A system having one or more optical sensing apparatuses of the present disclosure is installed in the panel system according to the present embodiment of the disclosure. 
     The panel  600  includes multiple buttons  610 . When a passenger reaches out his hand  60  to press one of the buttons  610  of the panel  600  with his finger, there will not only one optical sensing apparatus installed inside one button senses the approaching hand  60  and the fingers. In an aspect, the optical sensing apparatus including at least two light sources and a light sensor installed inside every button allows the panel system to prevent a false action caused by an error judgment in deciding the button to be pressed. 
     In the optical sensing apparatus, at least two sensor sources are provided to emit at least two light beams with at least two different beam angles forming different sensing ranges. The at least two light sources accordingly provide more spatial information for the controller of the optical sensing apparatus to identify an approaching object, i.e., the hand  60  and the fingers. The optical sensing apparatus actually can identify a size of the approaching object based on the intensities sensed from the different reflected light beams, and in the present embodiment the optical sensing apparatus can identify the parts of the user&#39;s body, palm and fingers. 
       FIG.  6 B  shows an exemplary example of the panel  600  having multiple buttons  610 , and in which every button is installed with an optical sensing apparatus including a light sensor  630  and multiple light sources  620 . 
       FIG.  6 C  schematically shows a diagram depicting a circumstance that a hand  60  approaches the panel  600  having two buttons installed with a first optical sensing apparatus  61  and a second optical sensing apparatus  62  respectively. The first optical sensing apparatus  61  emits two light beams for forming two different sensing ranges (S 1 , S 2 ) and the second optical sensing apparatus  62  also emits two light beams for forming another two different sensing ranges (S 1 ′, S 2 ′). 
     In the present exemplary example, when the hand  60  approaches the panel  600  having the two buttons, i.e., the first optical sensing apparatus  61  and the second optical sensing apparatus  62 , the first optical sensing apparatus  61  senses a first portion  601  (i.e., the index finger) of the hand  60  and at the same time the second optical sensing apparatus  62  senses a second portion  602  (i.e., the palm) of the hand  60 . As discussed above, even if the hand  60  is within a very short distance from the buttons, the controller of the optical sensing apparatus can accurately identify the different portions of the hand  60 . Therefore, the optical sensing apparatus of the present disclosure can prevent the false action effectively. 
     It other words, the size of the approaching object can be identified by the optical sensing apparatus based on the intensities sensed from different sensing ranges (S 1 , S 2  or S 1 ′, S 2 ′). The right side of the figure exemplarily shows a relationship between a first intensity obtained within a first sensing range (S 1 , S 1 ′) of the first optical sensing apparatus  61  or the second optical sensing apparatus  62  and a second intensity obtained within a second sensing range (S 2 , S 2 ′). For example, referring to the right side of the figure that shows the first intensity (S 1 ) of the first optical sensing apparatus  61  is greater than the second intensity (S 2 ), if the first intensity sensed from a first light beam reflected by the object is greater than a second intensity sensed from a reflected second light beam, it is determined that the object is a small size. Specifically, as shown in  FIG.  6 C , the first optical sensing apparatus  61  can recognize that the first portion  601  is the user&#39;s finger because the intensities sensed from the two light beams reflected by the first portion  601  which is a smaller portion within the two different sensing ranges S 1  and S 2  are different and a difference there-between exceeds a threshold. 
     On the other hand, referring to the right side of the figure that shows the first intensity (S 1 ′) of the second optical sensing apparatus  62  is similar with the second intensity (S 2 ′), the second optical sensing apparatus  62  may not easily recognize the second portion  602  is the user&#39;s palm but may recognize it is not the finger because a difference between the intensities sensed from the two light beams reflected respectively by the second portion  602  which is a larger portion within the two different sensing ranges S 1 ′ and S 2 ′ does not exceed the threshold. 
     Therefore, the system including the one or more optical sensing apparatuses allows the panel system mentioned above to prevent the false action caused by the error judgment when the contactless buttons are adopted in the panel system. 
     Furthermore, in one further aspect, the optical sensing apparatus can also identify a moving object. Reference is made to  FIG.  7 A , which is a schematic diagram depicting an optical sensing apparatus  70  used to sense a moving object  74  and to instruct a controlled device  72  to perform a subsequent action in an exemplary example of the disclosure. 
     In the drawing, a switch equipped with an optical sensing apparatus  70  is shown. In the optical sensing apparatus  70 , two light sources are driven to emit two light beams for forming two sensing ranges, i.e., a first sensing range S 1  and a second sensing range S 2 , with two different beam angles. The optical sensing apparatus  70  is configured to sense a moving object  74  if the moving object  74  enters a sensing zone defined by the two sensing ranges S 1  and S 2 . As discussed above, the object can be identified based on a difference between the intensities sensed from the two light beams reflected by the object  74  respectively since the first beam angle S 1  is configured to be different from the second beam angle S 2 , for example S 1  is smaller than S 2 . 
     Furthermore, for identifying the moving object  74 , the optical sensing apparatus  70  is configured to sense the intensities from the at least two light beams reflected from the object  74  for a period of time because a trend indicated by the changes of the intensities sensed for the period of time can be referred to for determining a movement of the object  74 . In an aspect, a first set of intensities are sensed from the first light beam reflected by the object  74  for a period of time, and a second set of intensities are sensed from the second light beam reflected by the object  74  for the same period of time, and the first set and the second set of intensities over time are resolved to determine a movement of the object  74 . For example, when a first trend of the changes of the first set of intensities is close to a second trend of changes of the second set of intensities, it is determined that the object is close to or away from the optical sensing apparatus  70 . 
     The trend indicated by the changes of the intensities for a period of time is referred to for determining the movement of the object  74 . The first trend or the second trend of the intensities can be described by distribution curves, as shown in  FIG.  7 B . The trends are formed by sensing the intensities according to the sensed reflected lights over time. The above-mentioned first trend indicating the changes of the first set of intensities refers to a narrower distribution curve with an obvious peak because the intensities being sensed over time as the object passing by the smaller first sensing range S 1  will have dramatic changes. On the other hand, the second trend indicating the changes of the second set of intensities refers to a flatter distribution curve without an obvious peak because the intensities over time do not have dramatic changes when the object passes by the relatively larger second sensing range S 2 . 
     Through the above-mentioned scheme, in some embodiments for identifying the moving object, the system can eliminate the event that the object merely passes by the optical sensing apparatus without intention to approach the optical sensing apparatus; and, in other words, the system can effectively sense the event that the object intents to approach the optical sensing apparatus. 
       FIG.  8 A  is another schematic diagram depicting the optical sensing apparatus sensing an approaching object in an exemplary example of the disclosure. 
     A switch installed with an optical sensing apparatus  70  coupled to a controlled device  72  is shown in the diagram. In the optical sensing apparatus  70 , a controller drives two light sources to emit two different light beams, i.e., a first light beam and a second light beam, for forming a first sensing range S 1  and a second sensing range S 2 . By this arrangement, the intensities respectively sensed from the reflected first light beam and the reflected second light are compared for determining a movement of an approaching object  80 . In an aspect, if it is determined that the object  80  intents to approach to the optical sensing apparatus  70 , the controlled device  72  coupled with the optical sensing apparatus  70  can be activated for performing a specific action. 
     In the drawing, an object  80 , e.g., a user&#39;s hand, approaches the switch with the optical sensing apparatus  70 . Similarly, the two senor sources are driven to emit two light beams forming two different sensing ranges with two different beam angles. Therefore, the optical sensing apparatus  70  outputs two sets of intensities sensed from the two light beams reflected by the approaching object  80 . The two sets of intensities sensed by the optical sensing apparatus  70  for a period of time can be drawn by a first trend that indicates changes of a first set of intensities and a second trend that indicates changes of a second set of intensities. In the present embodiment, the first trend and the second trend can be described by the distribution curves shown in  FIG.  8 B . 
     Since the two sets of intensities are sensed from two different light beams reflected by the object  80  which enters a sensing zone defined by different sensing ranges with different beam angles, the intensity distribution curves over time can be used to determine the movement of the object  80 . 
     For example, in  FIG.  8 B , the first trend with respect to the first set of intensities sensed within the first sensing range S 1  refers to the earlier intensity distribution curve with a higher peak and the second trend with respect to the second set of intensities sensed within the second sensing range S 2  refers to the later intensity distribution curve with a lower peak. Therefore, the trends respective to the first set of intensities and the second set of intensities can be used to determine the movement of the object  80 . In the present aspect, when the first trend of changes of the first set of intensities is close to the second trend of changes of the second set of intensities for the period of time, it is determined that the object is close to or away from the light sensor. 
     The method and the system for identifying the object using the optical sensing apparatus of the present disclosure can be applied to various applications.  FIGS.  9 A- 9 D  show schematic views depicting one more application of the system with multiple optical sensing apparatuses according to one more embodiment of the present disclosure. A meter  9  (e.g., a water meter) is shown in  FIG.  9 A . The meter  9  includes several indicators  901 ,  902 ,  903 , and each of which includes a rotatable half plate  91  and a rotatable pointer  92 , and the rotatable pointer  92  and the rotatable half plate  91  are connected with each other, as shown in  FIGS.  9 B- 9 D . 
     According to one embodiment of the present disclosure, one or more optical sensing apparatuses are installed in the meter  9 . The optical sensing apparatus acts as a proximity sensor for determining if the meter  9  is rotated clockwise or counter-clockwise in order to monitor the meter  9 . For example, the optical sensing apparatus includes a first proximity sensor  911 , a second proximity sensor  912  and a controller  913 . The first proximity sensor  911  and the second proximity sensor  912  can be disposed in or on the meter  9  and driven to emit two light beams with two separate beam angles from different positions. The first proximity sensor  911  and the second proximity sensor  912  then sense the light beams reflected by the rotatable pointer  92  or the rotatable half plate  91  respectively. 
     While the optical sensing apparatus is constantly in operation, the first proximity sensor  911  outputs a first signal when it detects the rotatable half plate  91 , and the first proximity sensor  911  outputs a second signal when it does not detect the rotatable half plate  91 . Similarly, the second proximity sensor  912  outputs a third signal when it detects the rotatable half plate  91 , and the second proximity sensor  912  outputs a fourth signal when it does not detect the rotatable half plate  91 . The controller  913 , which is electrically connected to the first proximity sensor  911  and the second proximity sensor  912 , then receives the signals from the first proximity sensor  911  and the second proximity sensor  912  respectively, and determines the meter  9  is rotated clockwise or counter-clockwise. 
       FIGS.  9 B- 9 D  schematically show at least three conditions of any of the indicators  901 ,  902  and  903  of the meter  9 , and use tables to illustrate three Boolean conditions for indicating the states of the first proximity sensor  911  and the second proximity sensor  912  to the controller  913 . It should be noted that these tables are simple examples for illustrating the method of the present disclosure. 
     According to the present examples,  FIG.  9 B  shows that both the first proximity sensor (PS1)  911  and the second proximity sensor (PS2)  912  detect the rotatable half plate  91  but not the rotatable pointer  92 , and a Boolean expression on the side shows states (PS1:1, PS2:1) of the two sensors ( 911 ,  912 );  FIG.  9 C  shows that the second proximity sensor (PS2)  912  detects the rotatable half plate  91 , and the Boolean expression on the side shows states (PS1:0, PS2:1) of the two sensors ( 911 ,  912 ); and  FIG.  9 D  shows that none of the two sensors ( 911 ,  912 ) detects the rotatable half plate  91 , and the Boolean expression on the side shows states (PS1:0, PS2:0). Accordingly, the system can determine the movement of the meter  9  based on the continuous states of the two sensors ( 911 ,  912 ) transmitted from the controller  913 . For example, the system can rely on a Boolean expression, as shown in Table 1, that indicates various states of the two sensors to determine the movement, i.e., rotated clockwise or counter-clockwise, of the meter  9  over time. 
     
       
         
           
               
               
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                   
                 Clockwise 
                 Counter-Clockwise 
               
            
           
           
               
               
               
               
               
            
               
                 Time 
                 PS1 
                 PS2 
                 PS1 
                 PS2 
               
               
                   
               
               
                 1 
                 1 
                 1 
                 1 
                 1 
               
               
                 2 
                 0 
                 1 
                 1 
                 0 
               
               
                 3 
                 0 
                 0 
                 0 
                 0 
               
               
                 4 
                 1 
                 0 
                 0 
                 1 
               
               
                 5 
                 1 
                 1 
                 1 
                 1 
               
               
                   
               
            
           
         
       
     
     It should be noted that, as applying the above embodiments of the method for identifying the object of the present disclosure, the optical sensing apparatus installed in the meter  9  can effectively avoid wrong interpretation of the rotating direction of the rotatable half plate  91  or the rotatable pointer  92  because the optical sensing apparatus uses the trends of intensities sensed from at least two light beams to identify the movement of the rotatable half plate  91  or the rotatable pointer  92 . 
     The foregoing description of the exemplary embodiments of the disclosure has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching. 
     The embodiments were chosen and described in order to explain the principles of the disclosure and their practical application so as to enable others skilled in the art to utilize the disclosure and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the present disclosure pertains without departing from its spirit and scope.