Abstract:
A control method for use with a lighting system is provided. The lighting system includes a light source and an ultrasonic transceiver. The control method includes steps of: measuring the time of an ultrasonic signal emitted from the ultrasonic transceiver and reflected by the object to reach the ultrasonic sensor to obtain a time of flight; calculating a distance between the object and the ultrasonic transceiver according to the time of flight; defining at least one control region according to the distance; and moving the object to the control region, thereby performing a controlling operation corresponding to the control region and adjusting an optical characteristic.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is the 35 U.S.C. §371 national stage of PCT application PCT/CN2007/003201, filed Nov. 12, 2007, the disclosure of which is hereby incorporated by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a method of controlling a lighting system, and more particularly to a method of controlling optical characteristics of a lighting system. 
     BACKGROUND OF THE INVENTION 
     A light emitting diode (LED) is a semiconductor device capable of converting electrical energy into visible light and radiation energy when electrical current flows between the anode and the cathode due to a voltage applied on both terminals of the semiconductor device. When the current passes through the LED in the forward direction, electrons recombine with holes and the extra energy is released in the form of light. The wavelength of the emitted light corresponds to the material and the energy associated with electron-hole pair recombination. The advantages of using the LED include a low operating voltage, low power consumption, high illuminating efficiency, very short response time, pure light color, high structural firmness, high impact resistance, excellent performance reliability, light weight, cost effectiveness, long service life, and so on. Therefore, the incandescent bulbs or mercury vapor lamps used in the conventional lighting system are gradually replaced by LEDs in many applications. 
     By using three primary color LEDs, for example a combination of red (R), green (G) and blue (B) LEDs, and adjusting the brightness of the LEDs, output light beams with various emission colors can be produced. Generally, the lighting system has a user operation interface (e.g. a button or a knob) or a remote controller. By triggering the user operation interface or using the remote controller, the brightness or the color of the output light from the lighting system can be controlled accordingly. Recently, an ultrasonic transceiver has been employed in the lighting system so as to adjust the light strength or the light color. 
       FIG. 1A  is a schematic diagram illustrating a lighting system with an ultrasonic transceiver to control the light strength or the light color according to the prior art. As shown in  FIG. 1A , the lighting system comprises a light source  10  and an ultrasonic transceiver  11 . The light source  10  comprises a red (R) LED, a green (G) and a blue (B) LED. When an object  12  (e.g. a user&#39;s hand) enters the sensing range of the ultrasonic transceiver  11 , an ultrasonic signal emitted by the ultrasonic transceiver  11  is reflected by the object  12 , and the reflected ultrasonic signal (or an echo signal) is then transmitted to a receiver of the ultrasonic transceiver  11 . Upon receipt of the echo signal, the processor of the lighting system may measure the time of flight (TOF) of the ultrasonic signal. In the context, the time of the ultrasonic signal emitted from the ultrasonic sensor and reflected by the object to reach the receiver of the ultrasonic sensor is referred as the time of flight (TOF). According to the TOF, the distance R between the object  12  and the receiver of the ultrasonic transceiver  11  can be deduced. According to a change of the distance R, a control signal is generated. In response to the control signal, the light source  10  of the lighting system can produce light with adjustable optical characteristics including the light strength or the light color. 
       FIG. 1B  is a schematic diagram illustrating another lighting system disclosed in WO 2006/056814. As shown in  FIG. 1B , the lighting system principally comprises an infrared transceiver  13  and a light-emitting unit  13 . When an object  12  (e.g. a user&#39;s hand) enters the sensing range of the infrared transceiver  13 , an infrared beam  15  emitted by the infrared transceiver  13  is reflected by the object  12 , and the reflected infrared beam  16  is then transmitted to an infrared receiver  17  of the infrared transceiver  13 . Generally, the intensity of infrared light  16  reflected from the object  12  and received by the infrared transceiver  13  is dependent on the inverse square of the distance between the infrared transceiver  13  and the object  12 . By determining the movement of the object  12  away from or toward the infrared transceiver  13 , the brightness or the color of the output light from the light-emitting unit  14  of the lighting system is adjustable accordingly. 
     The above lighting systems, however, still have some drawbacks. For example, only one of the optical characteristics can be adjusted at a time. Since the light strength adjusting operation and the light color adjusting operation fail to be simultaneously done, the conventional light-adjusting methods are not user-friendly. Therefore, there is a need of providing an improved light-adjusting method to obviate the drawbacks encountered from the prior art. 
     SUMMARY OF THE INVENTION 
     In accordance with an aspect of the present invention, there is provided a control method for use with a lighting system. The lighting system includes a light source and an ultrasonic transceiver. The control method includes steps of: measuring the time of an ultrasonic signal emitted from the ultrasonic transceiver and reflected by the object to reach the ultrasonic sensor to obtain a time of flight; calculating a distance between the object and the ultrasonic transceiver according to the time of flight; defining at least one control region according to the distance; and moving the object to the control region, thereby performing a controlling operation corresponding to the control region and adjusting an optical characteristic. 
     In accordance with an aspect of the present invention, there is provided a control method for use with a lighting system. The lighting system includes an ultrasonic transceiver. The control method includes steps of: entering a wait-for-enabling mode after the lighting system is powered on; measuring the time of an ultrasonic signal emitted from the ultrasonic transceiver and reflected by the object to reach the ultrasonic sensor to obtain a time of flight; calculating a distance between the object and the ultrasonic transceiver according to the time of flight; defining at least one control region according to the distance; entering a wait mode; discriminating whether the object is moved to one specified control region within a specified time interval; entering a control mode if the object is moved to the specified control region within the specified time interval, and performing a controlling operation corresponding to the control region and adjusting an optical characteristic; and entering a standby mode if the object is not moved to the specified control region within the specified time interval 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above contents of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: 
         FIG. 1A  is a schematic diagram illustrating a lighting system with an ultrasonic transceiver to control the light strength or the light color according to the prior art; 
         FIG. 1B  is a schematic diagram illustrating another lighting system according to the prior art; 
         FIG. 2A  is a schematic diagram illustrating several regions defined by a control method for use with a lighting system according to a preferred embodiment of the present invention; 
         FIG. 2B  is a schematic diagram illustrating a standby region defined by the control method of the present invention; 
         FIG. 2C  is a schematic diagram illustrating a flowchart of controlling optical characteristics of the lighting system; 
         FIG. 3A  is a flowchart illustrating operations of the wait-for-enabling mode; 
         FIG. 3B  is a flowchart illustrating operations of the wait mode; 
         FIG. 3C  is a flowchart illustrating operations of the control mode; 
         FIG. 3D  is a flowchart illustrating operations of the standby mode; 
         FIG. 4  is a schematic diagram illustrating an example of implementing the control method of the present invention, in which the floor is deemed as the object; 
         FIG. 5A  is a schematic diagram illustrating an example of controlling the first optical characteristic according to the control method of the present invention; 
         FIG. 5B  schematically illustrates a table associated with a series of color parameters in a cyclic variation; 
         FIG. 6A  is a schematic diagram illustrating an example of controlling the second optical characteristic according to the control method of the present invention; and 
         FIG. 6B  schematically illustrates a table associated with a series of intensity parameters in a cyclic variation. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 2A  is a schematic diagram illustrating several regions defined by a control method for use with a lighting system according to a preferred embodiment of the present invention. The lighting system principally comprises a light source module and a processor (not shown). The light source module comprises a light source  140  and an ultrasonic transceiver  141 . 
     When an object  150  (e.g. a user&#39;s hand) enters the sensing range of the ultrasonic transceiver  141 , the processor is in a wait-for-enabling mode. Meanwhile, an ultrasonic signal emitted by the ultrasonic transceiver  141  is reflected by the object  150 , and the reflected ultrasonic signal is then transmitted to a receiver of the ultrasonic transceiver  141 . Upon receipt of the echo signal, the processor of the lighting system may measure the time of flight (TOF) of the ultrasonic signal. According to the TOF, the distance R 1  between the object  150  and the ultrasonic transceiver  141  can be deduced. 
     According to the distance R 1  between the object  12  and the ultrasonic transceiver  141 , the processor defines a control enable region  122 , a first control region  111 , a second control region  144  and a wait region  155 . As shown in  FIG. 2A , the distance between the upper limit of the control enable region  122  and the ultrasonic transceiver  141  is R 2 , and the distance between the lower limit of the control enable region  122  and the ultrasonic transceiver  141  is R 3 . The distance between the upper limit of the first control region  111  and the ultrasonic transceiver  141  is R 4 , and the distance between the lower limit of the first control region  111  and the ultrasonic transceiver  141  is R 5 . The distance between the upper limit of the second control region  144  and the ultrasonic transceiver  141  is R 6 , and the distance between the lower limit of the second control region  144  and the ultrasonic transceiver  141  is R 7 . The distance between the upper limit of the wait region  155  and the ultrasonic transceiver  141  is R 5 , and the distance between the lower limit of the wait region  155  and the ultrasonic transceiver  141  is R 6 . As shown in  FIG. 2A , R 4 &lt;R 5 &lt;R 2 &lt;R 1 &lt;R 3 &lt;R 6 &lt;R 7 . In this embodiment, the distance between the upper limit and the lower limit of the control enable region  122  is about 5 centimeters. The distance between the upper limit and the lower limit of the first control region  111  is ranged from about 10 to 50 centimeters. The distance between the upper limit and the lower limit of the second control region  144  is ranged from about 10 to 50 centimeters. The distance between the upper limit and the lower limit of the wait region  155  is ranged from about 10 to 30 centimeters. 
     Please refer to  FIG. 2C , which is a schematic diagram illustrating a flowchart of controlling optical characteristics of the lighting system. When the lighting system is powered on and the object  150  is positioned in the sensing range of the ultrasonic transceiver  141 , the processor will enter the wait-for-enabling mode (Step  25 ). In the wait-for-enabling mode, the processor may measure the TOF of the ultrasonic signal and calculate the distance R 1  between the object  150  and the ultrasonic transceiver  141  according to the TOF. By referring to the distance R 1 , the processor defines the control enable region  122 , the first control region  111 , the second control region  144  and the wait region  155 , as can be seen in  FIG. 2A . In a case that the object  150  has been positioned in the control enable region  122  (i.e. the region between R 2  and R 3 ) for more than a first time interval (e.g. 1 second), the processor will enter the wait mode (Step  28 ). 
     Whereas, if the object  150  has been positioned in the control enable region  122  for less than the first time interval, the processor is still in the wait-for-enabling mode and continuously calculate the distance R 1  between the object  150  and the ultrasonic transceiver  141  according to the TOF. Until the object  150  has been positioned in the control enable region  122  for more than the first time interval, the processor will enter the wait mode (Step  28 ). 
     If the object  150  is moved off the wait region  155  within a second time interval (e.g. 5 seconds) in the wait mode, the optical characteristics need to be adjusted. For example, if the object  150  is moved to the first control region  111  within the second time interval, the processor will enter a control mode (Step  31 ). Meanwhile, a first controlling operation is executed to adjust a first optical characteristic such as the light color. Whereas, if the object  150  is moved to the second control region  144  within the second time interval, the processor will also enter the control mode (Step  31 ). Meanwhile, a second controlling operation is executed to adjust a second optical characteristic such as the light strength. The first control region  111  and the second control region  144  are used for controlling different optical characteristics respectively. Whereas, if the object  150  is continuously positioned in the second control region  144  within the second time interval or the object  150  is moved off the first control region  111  and the second control region  144 , the processor will issue an erroneous signal and enter a standby mode (Step  35 ). 
     Moreover, when the processor enters the control mode to execute the first controlling operation, the first optical characteristic is subject to a cyclic variation. That is, a series of predetermined light colors are cyclically changed. At the time that when the object  150  is being moved off the first control region  111 , a desired light color is selected. On the other hand, when the processor enters the control mode to execute the second controlling operation, the second optical characteristic is subject to a cyclic variation. That is, a series of predetermined light strengths are cyclically changed. At the time that when the object  150  is being moved off the second control region  144 , a desired light strength is selected. Afterwards, the processor goes back to the wait mode (Step  28 ). Whereas, if the object  150  is continuously positioned in the first control region  111  or the second control region  144  and the time period of executing the controlling operation exceeds a third time interval (e.g. 1 minute), the processor will issue an erroneous signal and enter a standby mode (Step  35 ). 
     When the processor is in the standby mode (Step  35 ), the processor will define a standby region  166  according to the distance R 1  between the object  150  and the ultrasonic transceiver  141 . As shown in  FIG. 2B , the distance between the upper limit of the standby region  166  and the ultrasonic transceiver  141  is R 8 , and the distance between the lower limit of the standby region  166  and the ultrasonic transceiver  141  is R 9 . In an embodiment, the distance between the upper limit and the lower limit of the standby region  166  is ranged from about 10 to 20 centimeters. Next, the processor continuously discriminates whether the object  150  is still positioned in the standby region  166 . If the object  150  is still positioned in the standby region  166 , the processor is maintained in the standby mode. Whereas, if the object  150  is moved off the standby region  166 , the processor will enter the wait-for-enabling mode again (Step  25 ). The procedures of controlling optical characteristics of the lighting system will be illustrated in detail hereinafter. 
       FIG. 3A  is a flowchart illustrating operations of the wait-for-enabling mode. When the processor enters the wait-for-enabling mode (Step  25 ), the processor may measure the distance between the object (within the sensing range) and the ultrasonic transceiver (Step  251 ). According to the distance between the object and the ultrasonic transceiver, the processor defines a control enable region, a first control region, a second control region and a wait region (Step  252 ). Next, the processor will discriminate whether the object is positioned in the control enable region for more than a first time interval (Step  253 ). If the object has been positioned in the control enable region for more than a first time interval, the processor will enter the wait mode (Step  254 ). Otherwise, the Step  251  is repeatedly done. 
       FIG. 3B  is a flowchart illustrating operations of the wait mode. When the processor enters the wait mode (Step  28 ), the processor may discriminate whether the object is moved to the first control region or the second control region within a second time interval (Step  282 ). If the object is moved to the first control region or the second control region within the second time interval, the processor will enter a control mode (Step  283 ). Otherwise, the processor will enter a standby mode (Step  284 ). 
       FIG. 3C  is a flowchart illustrating operations of the control mode. When the processor enters the control mode (Step  311 ), the processor may discriminate whether the object is positioned in the first control region (Step  311 ). If the object is positioned in the first control region, the processor will execute a first controlling operation (Step  312 ). Next, the processor will discriminate whether the object is still positioned in the first control region (Step  313 ). If the object is not positioned in the first control region, the processor will enter the wait mode (Step  314 ). If the object is still positioned in the first control region, the processor will discriminate whether the object has been continuously positioned in the first control region for more than a third time interval (Step  315 ). If the object has been continuously positioned in the first control region for more than the third time interval, the processor will enter the standby mode (Step  316 ). Otherwise, the processor continuously executes the first controlling operation (Step  312 ) until the object is detected to be not positioned in the first control region. 
     In the control mode, the processor discriminates whether the object is positioned in the first control region (Step  311 ). If the object is not positioned in the first control region, the processor will execute a second controlling operation (Step  317 ). Next, the processor will discriminate whether the object is still positioned in the second control region (Step  318 ). If the object is not positioned in the second control region, the processor will enter the wait mode (Step  314 ). Whereas, if the object is still positioned in the second control region, the processor will discriminate whether the object has been continuously positioned in the second control region for more than a third time interval (Step  319 ). If the object has been continuously positioned in the second control region for more than the third time interval, the processor will enter the standby mode (Step  316 ). Otherwise, the processor continuously executes the second controlling operation (Step  317 ) until the object is detected to be not positioned in the second control region. 
     When the processor enters the control mode to execute the first controlling operation, the first optical characteristic (e.g. the light color) is subject to a cyclic variation. In an embodiment, the frequency of changing the light colors is one per second. In a case that the third time interval is 1 minute, at most 60 times of light colors are cyclically changed when the object is positioned in first control region. If the object has been positioned in the first control region for more than the third time interval, the processor will issue an erroneous signal and enter a standby mode. On the other hand, if the object is moved off the first control region within the third time interval, a desired light color is selected based on the cyclic variation of the first optical characteristic (e.g. the cyclic variation of the different light colors) and the processor enters the wait mode. 
     Similarly, when the processor enters the control mode to execute the second controlling operation, the second optical characteristic (e.g. the light strength) is subject to a cyclic variation. In an embodiment, the frequency of changing the light strengths is one per second. In a case that the third time interval is 1 minute, at most 60 times of light strengths are cyclically changed when the object is positioned in second control region. If the object has been positioned in the second control region for more than the third time interval, the processor will issue an erroneous signal and enter a standby mode. On the other hand, if the object is moved off the second control region within the third time interval, a desired light strength is selected based on the cyclic variation of the second optical characteristic (e.g. the cyclic variation of the different light strengths) and the processor enters the wait mode. 
       FIG. 3D  is a flowchart illustrating operations of the standby mode. When the processor enters the standby mode (Step  3 ), the processor may define a standby region (Step  351 ). Next, the processor may measure the distance between the object and the ultrasonic transceiver (Step  352 ). Next, the processor will discriminate whether the object is moved off the standby region (Step  353 ). If the object is not moved off the standby region, the processor will measure the distance between the object and the ultrasonic transceiver again (Step  352 ). Whereas, if the object is moved off the standby region, the processor will enter the wait-for-enabling mode (Step  354 ). 
     Hereinafter, several examples of implementing the control method of the present invention will be illustrated. In a first example, no object is moved to the sensing range after the lighting system is powered on. Since the ultrasonic signal is reflected by the floor, the floor  300  can be deemed as an “object”.  FIG. 4  is a schematic diagram illustrating a first example of implementing the control method of the present invention. When the processor discriminates that the floor  300  is positioned within the sensing range of the ultrasonic transceiver  141 , the processor will enter the wait-for-enabling mode (Step  25 ). In the wait-for-enabling mode, the processor may measure the TOF of the ultrasonic signal and calculate the distance R 1  between the object (i.e. the floor  300 ) and the ultrasonic transceiver  141  according to the TOF. By referring to the distance R 1 , the processor defines the control enable region  122  (R 2 ˜R 3 ), the first control region  111  (R 4 ˜R 5 ), the second control region  144  (R 6 ˜R 7 ) and the wait region  155  (R 5 ˜R 6 ). Since the object (i.e. the floor  300 ) has been positioned in the control enable region  122  for more than a first time interval, the processor will enter the wait mode (Step  28 ). Since the object (i.e. the floor  300 ) has been not moved off the wait region  155  for more than the second time period, the processor will enter the standby mode (Step  35 ). When the processor is in the standby mode (Step  35 ), the processor will define a standby region  166  (R 8 ˜R 9 ). Since the object (i.e. the floor  300 ) is continuously positioned in the standby region  166 , the processor is maintained in the standby mode. In other words, the light color or the light strength of the lighting system fails to be adjustable in the situation where the floor  300  is served as the object. 
     In a second example, after the lighting system is powered on, a household pet passes through the sensing range of the ultrasonic transceiver  141 . The ultrasonic signal emitted by the ultrasonic transceiver  141  is reflected by the object (i.e. the household pet) and the reflected ultrasonic signal then is received the ultrasonic transceiver  141 . When the processor discriminates that the object (i.e. the household pet) is positioned within the sensing range of the ultrasonic transceiver  141 , the processor will enter the wait-for-enabling mode (Step  25 ). In the wait-for-enabling mode, the processor may measure the TOF of the ultrasonic signal and calculate the distance R 1  between the object (i.e. the household pet) and the ultrasonic transceiver  141  according to the TOF. In the wait-for-enabling mode (Step  25 ), if the object (i.e. the household pet) is moved off the sensing range of the ultrasonic transceiver  141 , the processor will not enter the wait mode (Step  28 ). Under this circumstance, the floor is deemed as an “object” again and eventually the processor is maintained in the standby mode, as is described in the first example. In other words, the strategy of the present control method can prevent erroneous operation caused by the household pet. 
     In a third example, after the lighting system is powered on, a user&#39;s hand is positioned in the sensing range of the ultrasonic transceiver  141  for controlling the first optical characteristic.  FIG. 5A  is a schematic diagram illustrating a third example of implementing the control method of the present invention. When the object  320 A (e.g. the user&#39;s hand) enters the sensing range of the ultrasonic transceiver  141 , the processor will enter a wait-for-enabling mode (Step  25 ). In the wait-for-enabling mode, the processor may measure the TOF of the ultrasonic signal and calculate the distance R 1  between the object  320 A (e.g. the user&#39;s hand) and the ultrasonic transceiver  141  according to the TOF. By referring to the distance R 1 , the processor defines the control enable region  122  (R 2 ˜R 3 ), the first control region  111  (R 4 ˜R 5 ), the second control region  144  (R 6 ˜R 7 ) and the wait region  155  (R 5 ˜R 6 ). If the object  320 A (e.g. the user&#39;s hand) has been positioned in the control enable region  122  for more than a first time interval, the processor will enter the wait mode (Step  28 ). In the wait mode, if the object  320 B (e.g. the user&#39;s hand) is moved to the first control region  111  within the second time interval, the processor will enter a control mode (Step  31 ). Meanwhile, a first controlling operation is executed to adjust a first optical characteristic such as the light color. 
       FIG. 5B  schematically illustrates a table associated with a series of color parameters in a cyclic variation. As shown in  FIG. 5B , 12 sets of color parameters are used to adjust 12 kinds of light colors. Each set of color parameters include the proportion of brightness of red (R), green (G) and blue (B) LEDs. By using the combination of red (R), green (G) and blue (B) LEDs, output light beams with various emission colors can be produced. For example, the first set of color parameters (1st) include only red (R) color at 80% power rating, so that the proportion of brightness of red (R), green (G) and blue (B) LEDs is 1:0:0. The second set of color parameters (2nd) include red (R) color at 60% power rating and green color at 20% power rating, so that the proportion of brightness of red (R), green (G) and blue (B) LEDs is 3:1:0. The rest may be deduced by analogy. 
     In an embodiment, when the object  320 B (e.g. the user&#39;s hand) is moved to the first control region  111 , the 12 kinds of light colors as shown in  FIG. 5B  are cyclically changed in the sequence of 5th→6th→7th→8th→ . . . →12th→1st→2nd→3rd→4th→5th→6th→ . . . for example. In addition, the light colors are changed once per second. At the time that when the object  320 C (e.g. the user&#39;s hand) is being moved off the sensing range of the ultrasonic transceiver  141 , the cyclic variation is interrupted and the light with desired color parameters is selected. 
     In a fourth example, after the lighting system is powered on, a user&#39;s hand is positioned in the sensing range of the ultrasonic transceiver  141  for controlling the second optical characteristic.  FIG. 6A  is a schematic diagram illustrating a fourth example of implementing the control method of the present invention. When the object  330 A (e.g. the user&#39;s hand) enters the sensing range of the ultrasonic transceiver  141 , the processor will enter a wait-for-enabling mode (Step  25 ). In the wait-for-enabling mode, the processor may measure the TOF of the ultrasonic signal and calculate the distance R 1  between the object  330 A (e.g. the user&#39;s hand) and the ultrasonic transceiver  141  according to the TOF. By referring to the distance R 1 , the processor defines the control enable region  122  (R 2 ˜R 3 ), the first control region  111  (R 4 ˜R 5 ), the second control region  144  (R 6 ˜R 7 ) and the wait region  155  (R 5 ˜R 6 ). If the object  330 A (e.g. the user&#39;s hand) has been positioned in the control enable region  122  for more than the first time interval, the processor will enter the wait mode (Step  28 ). In the wait mode, if the object  330 B (e.g. the user&#39;s hand) is moved to the second control region  144  within the second time interval, the processor will enter a control mode (Step  31 ). Meanwhile, a second controlling operation is executed to adjust a second optical characteristic such as the light strength. 
       FIG. 6B  schematically illustrates a table associated with a series of intensity parameters in a cyclic variation. As shown in  FIG. 6B , 12 intensity parameters are used to adjust 12 kinds of light strengths. The intensity parameters of  FIG. 6B  in combination with the color parameters of  FIG. 5B  are employed to adjust the light strength. For example, if the second set of color parameters and the first intensity parameter (1st) are selected, a red light at 72% (1.2×60%=72%) power rating and a green light at 24% (1.2×20%=24%) power rating are mixed and outputted. Similarly, if the second set of color parameters and the second intensity parameter (2nd) are selected, a red light at 66% (1.1×60%=66%) power rating and a green light at 22% (1.1×20%=22%) power rating are mixed and outputted. The rest may be deduced by analogy. 
     In an embodiment, when the object  330 B (e.g. the user&#39;s hand) is moved to the second control region  144 , the 12 kinds of light strengths as shown in  FIG. 6B  are cyclically changed in the sequence of 5th→6th→7th→8th→ . . . →12th→1st→2nd→3rd→4th→5th→6th→ . . . for example. In addition, the light strengths are changed once per second. At the time that when the object  3300  (e.g. the user&#39;s hand) is being moved off the sensing range of the ultrasonic transceiver  141 , the cyclic variation is interrupted and the light with desired intensity parameters is selected. 
     From the above description, the control method of the lighting system according to the present invention uses an ultrasonic sensor to detect the position of the object within the sensing range and define several control regions. When the object is moved to different control regions, various controlling operations are executed to adjust different optical characteristics. The present invention is illustrated by referring to adjustment of the light color or the light strength. Nevertheless, the control method of the present invention can be used to control the light color temperature, the light glisten, the area of the illuminating zone, the shape of the illuminating zone, the position of the illuminating zone or the on/off statuses of the light source. 
     While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not to be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.