Abstract:
A remote sensing system includes a first light source, a second light source, two image capturing devices and a processing unit. The first light source is configured for emitting infrared light of a first central wavelength. The second light source is configured for emitting infrared light of a second central wavelength. The two image capturing devices is configured for capturing images of the first and second light sources. The image capturing devices each includes an infrared sensitive image sensor and an infrared pass filter having two passbands for respectively allowing the infrared light of the first and second central wavelengths to pass therethrough. The processing unit is configured for analyzing the images captured by the image capturing devices thereby determining positions of the light sources relative to the image capturing devices.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present invention relates generally to electronic products, and more particularly, to a remote sensing system and an electronic apparatus having the same. 
         [0003]    2. Description of the related art 
         [0004]    Computer games, especially simulation games, are more and more popular in the modern society. A system emulating a game console generally includes a host in communication with a display device, for displaying images; and a game console in communication with the host, for performing various playing operations. 
         [0005]    For example, the game console includes a light emitting diode (hereinafter “LED”). Three linear image pickup elements each having a linear image sensor are positioned in the vicinity of the display device. Each of the linear image pickup elements takes images of the LED and obtains one light spot on the linear image sensor. Then the images are transmitted to an image processing unit. The image processing unit calculates the coordinate of the console based on positions of the light spots on the linear image sensors. Thus, the host can detect linear movements of the console in a three-dimensional space. However, the rotation of the console around a central axis of the LED cannot be detected, because the position of the LED is not changed. 
         [0006]    Therefore, a remote sensing system and an electronic apparatus having the same are needed to overcome the above shortcomings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0007]    The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. 
           [0008]      FIG. 1  is a schematic view of a remote sensing system in accordance with a first exemplary embodiment. 
           [0009]      FIG. 2  shows a graph of light output spectrum of a first light source and a second light source of the remote sensing system in  FIG. 1 . 
           [0010]      FIG. 3  shows a transmittance spectrum of a dual-pass-band infrared pass filter in  FIG. 1 . 
           [0011]      FIG. 4  is an electronic apparatus using the remote sensing system in  FIG. 1  in accordance with a second exemplary embodiment. 
           [0012]      FIG. 5  is an electronic apparatus using the remote sensing system in  FIG. 1  in accordance with a third exemplary embodiment. 
       
    
    
       [0013]    Corresponding reference characters indicate corresponding parts. The exemplifications set out herein illustrate at least one embodiment of the present display device having a brightness enhancement panel, in one form, and such exemplifications are not to be construed as limiting the scope of the disclosure in any manner. 
       DETAILED DESCRIPTION 
       [0014]    Reference will now be made to the drawings to describe embodiments of the present remote sensing system and the electronic apparatus using the same. 
         [0015]    Referring to  FIG. 1 , a remote sensing system  100  in accordance with a first exemplary embodiment includes a first light source  10 , a second light source  20 , a first image capturing device  30  and a second image capturing device  40 . 
         [0016]    Each of the first and second light sources  10  and  20  can be a point light source, such as an LED. The two light sources  10  and  20  are spaced from each other. The first light source  10  is configured for emitting infrared light with a certain wavelength band. The second light source  20  is configured for emitting infrared light with a different wavelength band from the first light source  10 . 
         [0017]    Referring to  FIG. 2 , an example of wavelength-intensity curves of light emitted from the first and second light sources  10  and  20  are shown. For easily comparing the first light source  10  with the second light source  20 , the wavelength-intensity curve corresponding to the first light source  10  and the wavelength-intensity curve corresponding to the second light source  20  are shown in a same figure, i.e.  FIG. 2 . A curve C 1  in a dashed rectangle R 1  shows a wavelength-intensity curve of the light emitted from the first light source  10 . It is seen from  FIG. 2  that the light with a wavelength λ 1  has a highest intensity in the light emitted from the first light source  10 . A curve C 2  in a dashed rectangle R 2  shows a wavelength-intensity curve of the light emitted from the first light source  20 . It is seen from  FIG. 2  that the light with a wavelength λ 2  has a highest intensity in the light emitted from the second light source  20 . The wavelengths λ 1  and λ 2  meet the following: 700 nanometers (nm for short)&lt;λ 1 &lt;λ 2 &lt;1000 nm. 
         [0018]    The first image capturing device  30  includes a lens barrel  320 , an optical lens  322 , an infrared pass filter  34  and an image sensor  36 . The optical lens  322  and the infrared pass filter  34  are mounted in the lens barrel  320  and aligned with each other. The image sensor  36  is positioned at one end of the lens barrel  320  and aligned with the optical lens  322  and the infrared pass filter  34 . In this embodiment, the image sensor  36  is infrared sensitive. The image sensor  36  includes a plurality of pixels arranged in an m by n (m×n) array, such as in a 1280×1024 array. The letters “m” and “n” denotes integers larger than one. The image sensor  36  is installed on a circuit board  360 . The optical lens  322  is configured for focusing light emitted from the first and second light sources  10  and  520  on the image sensor  36 . 
         [0019]    The infrared pass filter  34  blocks all visible light letting only infrared light with certain wavelengths pass. As shown in  FIG. 3 , a curve C 3  of transmissivity-wavelength relationship of the infrared pass filter  34  is illustrated. The curve C 3  has two peak values, which correspond to λ 1  and λ 2 , also shown in  FIG. 2 . It is to understand that most of the light emitted from the first light sources  10  and  20  can pass through the infrared pass filter  34 . In other words, most of the light emitted from the first and second light sources  10  and  20  can be captured by the first image capturing device  30 . It is seen from  FIG. 3  that, most of the interferential light can be blocked or received by the infrared bankpass filter  34 . 
         [0020]    In this embodiment, the second image capturing device  40  is identical with the first image capturing device  30 . It is understood that the second image capturing device  40  can be different from the first image capturing device  30 , as long as the second image capturing device  40  includes an infrared pass filter  44  and an infrared sensitive image sensor  46 . 
         [0021]    The remote sensing system  100  further includes a processing unit  50 . The processing unit  50  is electrically connected with the image sensor  36  and the image sensor  46 . The processing unit  50  is configured for receiving the image signals from the image sensors  36  and  46  and processing the image signals to calculate the position of the first and second light sources  10  and  20 . 
         [0022]    In use, each of the first and second image capturing devices  30  and  40  takes an image of the light emitted from the first light source  10  and generates an image signal. The image signals are transmitted to the processing unit  50 . Because the light emitted from the first light source  10  and second light source  20  has different wavelength, the images of the first light sources  10  and  20  can be distinguished. It is easy to understand that a first angle of the first light source  10  with respect to the center axis of the first image capturing device  30  and a second angle of the first light source  10  with respect to the center axis of the second image capturing device  40  can be calculated. The processing unit  50  calculates a position of the first light source  10  relative to the first and second image capturing devices  30  and  40  based on the first and second angles. Simultaneously, the processing unit  50  calculates a position of the second light source  20  relative to the first and second image capturing devices  30  and  40  in a same manner. 
         [0023]    When the first and second light sources  10  and  20  move a distance relative to the first and second image capturing devices  30  and  40 , the processing unit  50  calculates another position of each of the first and second light sources  10  and  20  in the above manner. 
         [0024]    Referring to  FIG. 4 , an electronic apparatus  200  in accordance with a second exemplary embodiment includes a display device  60  and a remote control unit  70 . The electronic apparatus  200  can be a game player. The display device  60  includes a display screen  602 . The first and second light sources  10  and  20  are installed on/in the display device  60  and adjacent to the display screen  602 . The first and second light sources  10  and  20  are spaced from each other. The remote control unit  70  includes a housing  72 , the first and second image capturing devices  30  and  40 , and the processing unit  50 . The first image capturing device  30 , the second image capturing devices  40  and the processing unit  50  are installed in the housing  72 . The first and second image capturing devices  30  and  40  are exposed to the exterior such that the image capturing devices  30  and  40  can pickup images of the first and second light sources  10  and  20 . The remote control unit  70  is configured for controlling a function of the electronic apparatus  200 , such as on and off, or remote-controlling a motion of an object showing on the display screen  602 . 
         [0025]    The electronic apparatus  200  applies the remote sensing system  100  to perform a remote controlling function. A linear movement of the remote control unit  70  can be detected through sensing each one of the first and second light sources  10  and  20  by the first and second image capturing devices  30  and  40 . When rotating the remote control unit  70 , at least one of the first and second image capturing devices  30  and  40  will move relative to the two light sources  10  and  20 . Therefore, the rotation of the remote control unit  70  can also be detected. 
         [0026]    Referring to  FIG. 5 , an electronic apparatus  300  in accordance with a third exemplary embodiment is provided. The electronic apparatus  300  is similar to the electronic apparatus  200 . The distinguishing features are that in the electronic apparatus  300 , the first and second light sources  10  and  20  are installed in/on the housing  72  to form a remote control unit  80 , and the first image capturing device  30 , the second image capturing device  40  and the processing unit  50  are installed in/on the display device  60  and adjacent to the display screen  602 . In a similar manner to the electronic apparatus  200 , the linear movement and the rotation of the remote control unit  80  can be detected. 
         [0027]    It is to be understood that the number of the light source and/or the image capturing device in the remote sensing system can be more than two such that the position of the console can be detected more accurately. 
         [0028]    It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the present invention.