Patent Publication Number: US-9843860-B2

Title: Electronic system denoising device, wearable display device and electronic device

Description:
RELATED APPLICATION 
     This application is a continuation application of PCT Patent Application No. PCT/CN2015/083871, entitled “ELECTRONIC SYSTEM DENOISING DEVICE, WEARABLE DISPLAY DEVICE AND ELECTRONIC DEVICE” filed on Jul. 13, 2015, which is incorporated by reference in its entirety 
    
    
     TECHNICAL FIELD 
     The present application relates to denoising technology for electronic systems, and more particularly relates to an electronic system denoising device, a wearable display device and an electronic device having the denoising device. 
     BACKGROUND 
     As the functions of electronic devices are more abundant, the electronic system for the electronic devices are becoming more complex. When a module of the electronic system produces signals leading to the ground level having noise, it will be prone to cause interference to analog small signals in the same system. 
     In view of that, the available technology provides a solution, which provides an independent power source to supply power to the modules which are prone to suffer interference, to realize isolation of the noise from the power source signals. 
     However, the above solution of the available technology needs to add more power sources, which increases the cost of the electronic device, on the other hand, also increases the weight of the electronic device. 
     SUMMARY 
     In order to solve the problems in the available technology, the present application provides a solution for noise caused by interference of ground level in a complex electronic system. 
     An embodiment of the present application provides an electronic system denoising device, including: a power source, a first signal processing unit, a second signal processing unit and an isolating transformer; wherein, 
     the power source is coupled to the first signal processing unit, and the power source is coupled to the second signal processing unit via the isolating transformer, the power source supplies power to the first signal processing unit and the second signal processing unit; 
     the first signal processing unit comprises a first signal output end and a first grounded end, the first signal output end outputting data signals to the second signal processing unit, the first grounded end coupled to a first ground wire; and 
     the second signal processing unit comprises a second grounded end coupled to a second ground wire. 
     The present application further provides a wearable display device, including a power source, a digital audio and video unit, an analog audio unit and an isolating transformer; wherein, 
     the power source is coupled to the digital audio and video unit, and the power source is coupled to the analog audio unit via the isolating transformer, the power source supplies power to the digital audio and video unit and the analog audio unit; 
     the digital audio and video unit comprises an audio output end and a first grounded end, the audio output end outputting audio signals to the analog audio unit, and the first grounded end coupled to a first ground wire; and 
     the analog audio unit comprises a second grounded end coupled to a second ground wire. 
     The present application further provides an electronic device, including the above electronic system denoising device. 
     The electronic system denoising device, the wearable display device and the electronic device having the electronic system denoising device of an embodiment of the present application, via the isolating transformer, avoid impact to the second signal processing unit from ground noise caused by return current of the first signal processing unit. Therefore the noise problem caused by interference of the ground level is resolved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following figures is used for combination with embodiments to illustrate embodiments of the present application in detail. It should be understood that, components in the figures do not represent the actual size and the proportion relationship, they are only used for clearly illustrating the embodiments, and should not be understood as limitation to the present application. 
         FIG. 1  shows a schematic structure of an electronic system denoising device in accordance with a first embodiment of the present application. 
         FIG. 2  shows a schematic structure of an electronic device in accordance with a second embodiment of the present application. 
     
    
    
     DETAILED DESCRIPTION 
     In order to more clear present application purpose, technology program and advantages of the present application, more details of the present application are further described in combination with the following embodiments and drawings. It should be understood that, the following described embodiments are only used for explaining, not limiting the present application. Furthermore, the elements showing in the drawings are only for illustration, rather than representing the actual proportional relation thereof. 
     In the description of the present application, the terms “first” and “second” are only used for description purpose, and should not be interpreted as instructions or suggests of the relative importance, or implying the number of the indicated technical characteristics. Thus, the characteristics having the “first” and “second” can express or imply to include one or more described characteristics. In the description of the invention, the meaning of “a plurality of” is two or more than two, unless being definitely expressed or specified in addition. 
     In the description of the invention, unless being definitely expressed or specified in addition, the terms of “connect” and “couple” each should have a general meaning. For example, “connect” and “couple” may mean electrical connection, mutual communication, direct connection, indirect connection via an intermedia, internal communication of two elements, or interaction of two elements. For the ordinary skilled person in the art, the specific meanings of the aforesaid terms of the present application can be comprehended according to the actual situation. 
       FIG. 1  shows a schematic structure of an electronic system denoising device of a first embodiment of the present application. As illustrated by  FIG. 1 , the electronic system denoising device  10  includes a power source  11 , a first signal processing unit  12 , a second signal processing unit  13  and an isolating transformer  14 . The power source  11  is coupled to the first signal processing unit  12 . The power source  11  is coupled to the second signal processing unit  13  via the isolating transformer  14 . The power source  11  is configured to supply power to the first signal processing unit  12  and the second signal processing unit  13 . The first signal processing unit  12  includes a first signal output end  121  and a first grounded end  122 . The first signal output end  121  is configured to output data signals to the second signal processing unit  13 , the first grounded end  122  is configured to be coupled to a first ground wire  15 . The second signal processing unit  13  includes a second grounded end  131  configured to be coupled to a second ground wire  16 . 
     Using the isolating transformer  14 , the electronic system denoising device  10  of the embodiment of the present application physically separates isoelectric potentials of the first ground wire  15  and the second ground wire  16  respectively coupled to the first signal processing unit  12  and the second signal processing unit  13 . Therefore, the current return paths of the first signal processing unit  12  and the second signal processing unit  13  are not overlapped, avoiding interference to the second signal processing unit  13  from ground noise caused by the return current of the first signal processing unit  12 . Thus, the noise problem caused by interference of the ground level is effectively resolved under the same power source  11 . 
     Preferably, the first signal processing unit  12  includes a first voltage regulator module  123 , the second signal processing unit  13  includes a second voltage regulator module  132 . An anode of the power source  11  is coupled to the first voltage regulator module  123 , and is coupled to the second voltage regulator module  132  via the isolating transformer  14 . Specifically, a primary winding of the isolating transformer  14  has a first end thereof coupled to the anode of the power source  11 , and a second end thereof coupled to the first ground wire  15 . A secondary winding has a first end thereof coupled to the second voltage regulator module  132 , and a second end thereof coupled to the second ground wire  16 . 
     Preferably, the first ground wire  15  and the second ground wire  16  are in a single point connection. For example, the first ground wire  15  are coupled to the second ground wire  16  by a 0Ω resistor. Due to the fact that a return circuit defined by the first signal processing unit  12  and the power source  11  is separated from a return circuit defined by the isolating transformer  14  and the second signal processing unit  13 , the consistency of grounding potentials of the two ground circuits and integrality of two sets audio signals are realized. Signal distortion caused by different grounding potentials of the first ground wire  15  and the second ground wire  16  is thus prevented. 
     An electronic device of a second embodiment of the present application includes the electronic system denoising device of any implementation way of the illustrated embodiment. 
     As an example, the electronic device can be a wearable display device. The wearable display device includes a display device (not shown) with display output, a headsets (not shown) with audio output, and the electronic system denoising device provided by the illustrated embodiment. In an embodiment, the display device includes a miniature display and an optical module, wherein the miniature display provides a display source, the optical module projects the display source to eyes of a user wearing the wearable display device, along a preset path, to provide near-to-eye display. The headsets is configured to provide audio output. Due to the display device and the headsets being available technical knowledge for the skilled person in the art, they are not given more descriptions here. Referring to  FIG. 2 , in this embodiment, an electronic system denoising device  20  includes a power source DC, a digital audio and video unit  22 , an analog audio unit  23  and an isolating transformer  24 . It can be understood that, the digital audio and video unit  22  in the illustrated embodiment is corresponding to the first signal processing unit  12 , the analog audio unit  23  is corresponding to the second signal processing unit  13 . The power source DC is coupled to the digital audio and video unit  22 , and is coupled to the analog audio unit  23  via the isolating transformer  14 . The power source DC is configured to supply power to the digital audio and video unit  22  and the analog audio unit  23 . The digital audio and video unit  22  includes a first grounded end DGND, a first voltage regulator module  223  and an audio output end  221 . The audio output end  221  includes a positive output terminal R-spk+ and a negative output terminal R-spk− of a right channel audio output, and a positive output terminal L-spk+ and a negative output terminal L-spk− of a left channel audio output. The first voltage regulator module  223  is coupled to an anode “+” of the power source DC, the audio output end  221  is configured to output audio signals to the analog audio unit  23 , the first grounded end DGND is configured to be coupled to a first ground wire GND 1 , in this embodiment, the first ground wire GND 1  is coupled to a cathode “−” of the power source DC. The analog audio unit  23  includes a second grounded end AGND coupled to a second ground wire GND 2 , a second voltage regulator module  232  coupled to the anode “+” of the power source DC via the isolating transformer  24 . 
     The wearable display device further includes a speaker  28  coupled to an analog audio output end  238  of the analog audio unit  23 . Specifically, the speaker  28  includes a left speaker  28  and a right speaker  28  respectively received in bodies of left and right earphones of the headsets. The analog audio output end  238  includes a positive output terminal R-spk+ and a negative output terminal R-spk− of a right channel audio output configured to output the right channel audio signals to the right speaker  28 , and a positive output terminal L-spk+ and a negative output terminal L-spk− of a left channel audio output configured to output the left channel audio signals to the left speaker  28 . 
     Specifically, the audio signals output by the audio output end  221  of the digital audio and video unit  22  may be analog audio signals separated and decoded by the digital circuit  225  according to digital and video audio signals. The analog audio unit  23 , according to the analog audio signals, amplifies the signals by an amplifying circuit  235  and provides the signals to the speaker  28  to output the audio. Analogy video signals separated and decoded from the digital audio and video signals by a digital circuit  225  are output to the miniature display of the display device, and is provided to display the display source. 
     A first end of a primary winding of the isolating transformer  24  is coupled to the anode “+” of the power source DC, a second end of the primary winding of the isolating transformer  24  is coupled to the first ground wire GND 1 , a first end of a secondary winding is coupled to the second voltage regulator module  232 , a second end of the secondary winding is coupled to the second ground wire GND 2 . In the illustrated embodiment, the power source DC is a direct current power source, the primary winding is further coupled to a DC/AC converter  27 , the DC/AC converter is configured to convert the direct current to alternating current to be provided to the second winding to produce voltage. 
     The first ground wire and the second ground wire are in a single point connection. Specifically, the first ground wire GND 1  is coupled to the second ground wire GND 2  by a 0Ω resistor. Due to that a return circuit defined by the digital audio and video unit  22  and the power source DC is separated from a return circuit defined by the isolating transformer  24  and the analog audio unit  23 , it is realized consistency of grounding potentials of the two ground circuits, and integrality of two sets audio signals, thereby preventing signal distortion because of different grounding potentials of the first ground wire GND 1  and the second ground wire GND 2   
     Using the isolating transformer  24 , the wearable display device of the illustrated embodiment of the present application physically separates isoelectric potentials of the first ground wire GND 1  and the second ground wire GND 2  respectively coupled to the digital audio and video unit  22  and the analog audio unit  23 . Therefore, current return paths of the digital audio and video unit  22  and the analog audio unit  23  are not overlapped, avoiding interference to the analog audio unit  23  from ground noise caused by return current of digital audio and video unit  22 . The noise caused by interference of the ground level to the analog audio unit  23  is resolved. 
     The above descriptions are only preferred embodiments of the present application, not limiting the present application. Any modification, equivalent replacement and improvement, etc., within the spirits and principles of the present application, shall be included in the protective scope of the present application.