Abstract:
A touch control apparatus, a control method thereof and an electronic device having the touch control apparatus are disclosed, which belong to the technical field of touch control. The touch control apparatus comprises: a panel ( 1 ); a transmitting antenna ( 2 ) arranged on the panel ( 1 ) and configured to transmit a detection wave for detecting whether the panel ( 1 ) is being touched; at least three resonant circuits arranged on the panel and configured to sense the detection wave and generate resonant waves; and a control processing unit ( 6 ) configured to control to process the resonant waves and position information of the resonant circuits to obtain corresponding touch information comprising at least a touch pressure and a touch position. The touch control apparatus, the control method thereof and the electronic device enable touch control of the panel by a general object through utilizing the resonant circuits. The present disclosure can be advantageously implemented by simple process at low cost and have wide usage prospect in the touch control field.

Description:
This application is a National Stage Application of PCT/CN2011/072374, filed 1 Apr. 2011, which claims benefit of Serial No. 201110064952.6, filed 17 Mar. 2011 in China and which applications are incorporated herein by reference. To the extent appropriate, a claim of priority is made to each of the above disclosed applications. 
     TECHNICAL FIELD 
     The present disclosure relates to the field of touch control, and particularly, to a touch control apparatus implementing touch control by a general object, a control method thereof, and an electronic device having the touch control apparatus. 
     BACKGROUND 
     Electromagnetic touch control was once widely used in early panel-type devices due to its high positioning accuracy and high sensitivity to pressure. However, it has been gradually substituted by currently-prevalent multi-point capacitive touch control because it requires specialized electromagnetic stylus and thus is inconvenient for interaction between a user and the device. 
     With the wide application of touch control, people are realizing convenience of finger touch control and multi-point touch control. Particularly, the development of mobile phone and tablet computer encourages further exploration of new technology. 
     Multi-point capacitive touch control screen is the most popular one among various multi-point touch control technologies that are currently used. However, it has certain disadvantages. First, it has to be placed in front of a display screen, which may degrade display effect thereof. The degradation is especially significant for reflective screens. As a result, it can hardly be used in a paper-like display screen such as an electronic-ink screen. Secondly, the touch control object has to be conductive and have a relatively large area to enable the touch control. The user&#39;s finger can be used as the touch control object. However, it becomes non-conductive after wearing a glove and thus becomes ineffective as the touch control object. Also, accuracy and sensitivity of the touch control are susceptible to dirt and sweat on the finger. The interaction performance of the multi-point capacitive touch control screen is substantially compromised by these disadvantages. Contrary to the multi-point capacitive touch control screen, the electromagnetic touch control screen is typically arranged at the back side of the display screen and thus is very suitable for the reflective screens such as the electronic ink screen. 
     As described above, the multi-point capacitive touch control screen and the electromagnetic touch control screen both have certain disadvantages. The multi-point capacitive touch control screen has to be operated by the finger while the electromagnetic touch control screen has to be operated by the electromagnetic stylus. Neither of them can be conveniently operated by an arbitrary object. 
     SUMMARY 
     In view of the above disadvantages, there are provided a touch control apparatus, a control method thereof, and an electronic device having the touch control apparatus. 
     In accordance with a first aspect of the present disclosure, there is provided a touch control apparatus, comprising: a panel; a transmitting antenna arranged on the panel and configured to transmit a detection wave for detecting whether the panel is being touched; at least three resonant circuits arranged on the panel and configured to sense the detection wave so as to generate resonant waves; and a control processing unit configured to control to process the resonant waves and position information of the resonant circuits to obtain corresponding touch information comprising at least a touch pressure and a touch position. 
     A control method of the touch control apparatus in accordance with the first aspect of the present disclosure comprises: a detection wave transmission step for transmitting, by the transmitting antenna, a detection wave for detecting whether the panel is being touched; a resonant wave generation step for sensing, by the resonant circuits, the detection wave when the resonant circuits are being touched to generate resonant waves; and a touch information obtaining step for controlling, by the control processing unit, to process the resonant waves and position information of the resonant circuits to obtain corresponding touch information comprising at least a touch pressure and a touch position. 
     In accordance with a second aspect of the present disclosure, there is provided a touch control apparatus, comprising: a panel; a transmitting antenna arranged on the panel and configured to transmit a detection wave for detecting whether the panel is being touched; an electromagnetic stylus configured to sense the detection wave when it touches the panel and generate a first resonant wave; at least three first receiving antennas arranged on the panel and configured to receive the first resonant wave; at least three resonant circuits arranged on the panel and configured to sense the detection wave when the panel is being touched by a second object different from the electromagnetic stylus and generate respective second resonant waves; and a control processing unit configured to control to process the first resonant wave and position information of the first receiving antennas or to process the second resonant waves and position information of the resonant circuits to obtain corresponding touch information. 
     A control method of the touch control apparatus in accordance with the second aspect of the present disclosure comprises: a detection wave transmission step for transmitting, by the transmitting antenna, a detection wave for detecting whether the panel is being touched; a first resonant wave generation step for sensing, by the electromagnetic stylus, the detection wave when the electromagnetic stylus approaches or touches the panel to generate a first resonant wave; a first resonant wave receiving step for receiving, by the first receiving antennas, the first resonant wave; a second resonant wave generation step for sensing, by the resonant circuits, the detection wave when the resonant circuits are being touched by a second object different from the electromagnetic stylus to generate respective second resonant waves; and a touch information obtaining step for controlling, by the control processing unit, to process the first resonant wave and position information of the first receiving antennas or to process the second resonant waves and position information of the resonant circuits to obtain corresponding touch information. 
     An electronic device in accordance with the present disclosure has the above-described touch control apparatus. 
     The touch control apparatus, the control method thereof and the electronic device having the touch control apparatus enable touch control of the panel by a general object through utilizing the resonant circuits. This addresses the defect of the existing touch control screen that cannot be controlled by the general object. The touch control of the touch control screen by the general object can be implemented by obtaining touch information, e.g., touch position of the object, through detecting transient capacitance variation in the resonant circuits when the object is touching the touch control apparatus or the electronic device having the same. 
     The present disclosure can be advantageously implemented by simple process at low cost. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a touch control apparatus in accordance with an embodiment of the present disclosure. 
         FIG. 2  is a schematic view of a control processing unit of a touch control apparatus in accordance with an embodiment of the present disclosure. 
         FIG. 3  is a schematic view of a touch control apparatus in accordance with a further embodiment of the present disclosure. 
         FIG. 4  is a schematic view of a control processing unit of a touch control apparatus in accordance with a further embodiment of the present disclosure. 
         FIG. 5  is a flow chart of a control method of a touch control apparatus in accordance with an embodiment of the present disclosure. 
         FIG. 6  is a flow chart of a control method of a touch control apparatus in accordance with a further embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Next, embodiments of the present disclosure will be explained in detail with reference to the drawings. The embodiments are only exemplary and should be not construed as any limitation to the present disclosure. 
     In an embodiment of the present disclosure, as shown in  FIG. 1 , a touch control apparatus comprises a panel  1 , at least one transmitting antenna  2 , at least three resonant circuits each comprising a receiving antenna  4 ′ and at least one signal sheet  5  connected with the receiving antenna  4 ′, and a control processing unit  6 . 
     The at least one transmitting antenna  2 , the receiving antennas  4 ′ and the signal sheets  5  are all arranged on the panel  1 , for example, on its back side or lateral side, or embedded in it. 
     The at least one transmitting antenna  2  may each transmit a detection wave for detecting whether the panel  1  is touched. The detection wave may be a square wave having a base frequency f′ or a sinusoid wave having a frequency f 1 ′. The detection wave may be any other suitable signal. 
     The signal sheet  5  is a sheet-like component having a pressure-sensitive capacitance value. The capacitance value of the signal sheet  5  varies in accordance with a pressure applied thereon. The signal sheet  5  may also have an acousto-electric or electric-acoustic characteristic to improve positioning accuracy and user experience of touch control. The resonant circuit senses the square wave having the base frequency f′ or the sinusoid wave having the frequency f 1 ′ transmitted from the transmitting antenna  2  when it is touched to generate a resonant wave having the frequency f′ or f 1 ′, respectively. 
     The panel  1  may be a display screen or a transparent panel. Particularly, the panel  1  may be an electronic ink screen. 
     The numbers and positions of the transmitting antenna  2 , the receiving antennas  4 ′, and the signal sheets  5  can be properly set to implement touch control by a finger or a general object through detecting physical change induced by touch of the finger or the general object without degrading display effect. 
     The control processing unit  6  controls to process the resonant waves and position information of the resonant circuits to obtain corresponding touch information comprising a touch pressure and a touch position. 
     Particularly, the control processing unit  6  selects at least three receiving antennas  4 ′, of which the respective signal strengths have the largest variations induced by the touch. Then the control processing unit  6  uses the signal strengths and the position information of the receiving antennas  4 ′ as initial parameters of a conic curve to calculate conic approximation to obtain corresponding touch information comprising at least a touch pressure and a touch position. In particular, the conic curve is depicted by taking the position information of the receiving antennas  4 ′ as the x-axis of the conic curve and the signal strengths of the receiving antennas  4 ′ as the y-axis of the conic curve. The touch position is obtained by calculating the apex or nadir of the conic curve. The touch pressure is obtained by calculating the amplitude of the conic curve. The conic curve may be a parabolic curve, a single strand of hyperbolic curve, or any other suitable conic curve. 
     As shown in  FIG. 2 , the control processing unit  6  comprises a band-pass filter  62 ′. The band-pass filter  62 ′ passes the resonant waves. 
     The control processing unit  6  also comprises a MUX analog switch  63 . The receiving antennas  4 ′ in the resonant circuits are connected to an input of the band-pass filter  62 ′ directly or via the MUX analog switch  63 . A specific receiving antenna  4 ′ is selected by the MUX analog switch  63 . 
     The control processing unit  6  also comprises an integration circuit  66 ′, an analog-to-digital conversion (ADC) circuit  68 ′, a main control circuit  64 , a transmission circuit  69 , and a DEMUX analog switch  70 . 
     The transmission circuit  69  selects a specific transmitting antenna  2  to transmit the detection wave using the DEMUX analog switch  70  under control of the main control circuit  64 . 
     The band-pass filter  62 ′ has an output connected to an input of the integration circuit  66 ′. An output of the integration circuit  66 ′ is connected to an input of the ADC circuit  68 ′. 
     A specific receiving antenna  4 ′ is selected by the MUX analog switch  63 . The main control circuit  64  then may process the signal output from the ADC circuit  68 ′ and the position information of the at least three receiving antenna  4 ′ having the largest signal strength variations to obtain the touch information comprising at least the touch pressure and the touch position. 
     In a further embodiment of the present disclosure, as shown in  FIG. 3 , a touch control apparatus comprises a panel  1 , at least one transmitting antenna  2 , an electromagnetic stylus  7 , at least three first receiving antennas  3 , at least three resonant circuits each comprising a receiving antenna  4  and at least one signal sheet  5  connected with the receiving antenna  4 , and a control processing unit  6 . 
     The at least one transmitting antenna  2 , the first receiving antennas  3 , the receiving antennas  4  and the signal sheets  5  are all arranged on the panel  1 , for example, on its back side or lateral side, or embedded in it. 
     The at least one transmitting antenna  2  may each transmit a detection wave for detecting whether the panel  1  is touched. The detection wave may be a square wave having a base frequency f or a sinusoid wave having a frequency f 1 . The detection wave may be any other suitable signal. 
     The electromagnetic stylus senses, in the square wave having the base frequency f or the sinusoid wave having the frequency f 1 , a harmonic wave having a frequency  3   f  or a sinusoid wave having a frequency f 3 , respectively, when it touches the panel  1 , so as to generate a first resonant wave having the frequency  3   f  or f 3 , respectively. 
     The at least three first receiving antennas  3  may each receive the first resonant wave having the frequency  3   f  or f 3 . 
     The transmitting antenna may also be used as the receiving antennas by transmitting the detection wave and receiving the resonant wave in a time-divisional manner. In this way, the number of antennas can be reduced. 
     The signal sheet  5  is a sheet-like component having a pressure-sensitive capacitance value. The capacitance value of the signal sheet  5  varies in accordance with a pressure applied thereon. The signal sheet  5  may also have an acousto-electric or electric-acoustic characteristic to improve positioning accuracy and user experience of touch control. The resonant circuit senses the square wave having the base frequency f or the sinusoid wave having the frequency f 1  transmitted from the transmitting antenna  2  when it is touched by a second object different from the electromagnetic stylus to generate a second resonant wave having the frequency f or f 1 . 
     The panel  1  may be a display screen or a transparent panel. Particularly, the panel  1  may be an electronic ink screen. 
     The numbers and positions of the transmitting antenna  2 , the first receiving antennas  3 , the second receiving antennas  4 , and the signal sheets  5  can be properly set to implement touch control by a finger or a general object through detecting physical change induced by touch of the finger or the general object without degrading display effect. Also, precise writing of the electromagnetic stylus can be implemented by utilizing electromagnetic positioning technology. 
     The control processing unit  6  controls to process the first resonant wave and position information of the first receiving antennas  3  or the second resonant waves and position information of the resonant circuits to obtain corresponding touch information comprising a touch pressure and a touch position. 
     Particularly, the control processing unit  6  selects at least three first receiving antennas  3  or at least three second receiving antennas  4 , of which the respective signal strengths have the largest variations induced by the touch. Then the control processing unit  6  uses the respective signal strengths and the position information of first receiving antennas  3  or the receiving antennas  4  as initial parameters of a conic curve to calculate conic approximation to obtain corresponding touch information comprising at least a touch pressure and a touch position. In particular, the conic curve is depicted by taking the position information of the receiving antennas as the x-axis of the conic curve and the signal strengths of the receiving antennas as the y-axis of the conic curve. The touch position is obtained by calculating the apex or nadir of the conic curve. The touch pressure is obtained by calculating the amplitude of the conic curve. The conic curve may be a parabolic curve, a single strand of hyperbolic curve, or any other suitable conic curve. 
     As shown in  FIG. 4 , the control processing unit  6  comprises a first band-pass filter  61  and a second band-pass filter  62 . The first band-pass filter  61  passes the first resonant wave and the band-pass filter  62  passes the resonant waves. 
     The control processing unit  6  also comprises a MUX analog switch  63 . The first receiving antennas  3  are connected to an input of the first band-pass filter  61  directly or via the MUX analog switch  63 . The second receiving antennas  4  in the resonant circuits are connected to an input of the band-pass filter  62  directly or via the MUX analog switch  63 . A specific first receiving antenna  3  or second receiving antenna  4  is selected by the MUX analog switch  63 . 
     The control processing unit  6  also comprises a first integration circuit  65 , a second integration circuit  66 , a first analog-to-digital conversion (first ADC) circuit  67 , a second analog-to-digital conversion (second ADC) circuit  68 , a main control circuit  64 , a transmission circuit  69 , and a DEMUX analog switch  70 . 
     The transmission circuit  69  selects a specific transmitting antenna  2  to transmit the detection wave using the DEMUX analog switch  70  under control of the main control circuit  64 . 
     The first band-pass filter  61  has an output connected to an input of the first integration circuit  65 . An output of the first integration circuit  65  is connected to an input of the first ADC circuit  67 . 
     The second band-pass filter  62  has an output connected to an input of the second integration circuit  66 . An output of the second integration circuit  66  is connected to an input of the second ADC circuit  68 . 
     A specific first receiving antenna  3  or a specific second receiving antenna  4  is selected by the MUX analog switch  63 . The main control circuit  64  then may process the signal output from the first ADC circuit  67  and the position information of the at least three first receiving antenna  3  having the largest signal strength variations or the signal output from the second ADC circuit  68  and the position information of the at least three second receiving antenna  4  having the largest signal strength variations, so as to obtain the touch information comprising at least the touch pressure and the touch position. 
     An electronic device in accordance with the present disclosure may have the touch control apparatus in the above-described embodiments. Particularly, the electronic device in accordance with the present disclosure may be an electronic reader, a tablet computer, a panel display, or a mobile phone having the above-described touch control apparatus. 
     Next, a touch control method of a touch control apparatus in accordance with an embodiment will be explained with reference to a specific example. In this example, there are m transmitting antennas  2 , n first receiving antennas, and k second receiving antennas, wherein m is a natural number no less than 1, and n and k are natural numbers larger than 2, respectively. 
     In the example as shown in  FIG. 5 , the control method comprises the following steps. 
     In step S 1 , one transmitting antenna  2  transmits a square wave signal having a base frequency f. 
     In step S 2 , all of the second receiving antennas  4  receive a harmonic wave signal having a frequency f. All of the first receiving antennas  3  receive a harmonic wave signal having a frequency  3   f  in the square wave signal having the base frequency f. The control processing unit  6  obtains signal strengths of all the second receiving antennas  4  and the first receiving antennas  3  and stores the signal strengths of the second receiving antennas  4  in table  1  and the signal strengths of the first receiving antennas  3  in table  2 . 
     In step S 3 , another transmitting antenna  2  is selected and the process returns to step S 1 . The process is repeated until all transmitting antennas have been selected. 
     In step S 4 , m×n signal strengths in the table  2  are compared with an initialization table II. The process proceeds to step S 6  if there is no substantial difference, which means the signal strengths contain tolerable noise. Otherwise the process proceeds to step S 5 . The initialization table II is a table containing m×n signal strengths obtained by averaging the signal strengths from all of the first receiving antennas  3  through repeating steps S 1 ˜S 3  for multiple times without presence of any touch or electromagnetic stylus. 
     In step S 5 , two groups of first receiving antennas  3  are selected having the largest signal strength variations. As shown in  FIG. 3 , one group may comprise at least three horizontally-arranged first receiving antennas  3 , while the other group may comprise at least three perpendicularly-arranged first receiving antennas  3 . Conic approximation is calculated using the signal strengths and position information of the selected first receiving antennas  3  to obtain touch position and touch pressure of the electromagnetic stylus. Then the process returns to step S 1 . 
     In step S 6 , m×k signal strengths in the table  1  are compared with an initialization table I. The process returns to step S 1  if there is no substantial difference, which means the signal strengths contain tolerable noise. Otherwise the process proceeds to step S 7 . The initialization table I is a table containing m×k signal strengths obtained by averaging the signal strengths from all of the second receiving antennas  4  through repeating steps S 1 ˜S 3  for multiple times without presence of any touch or electromagnetic stylus. 
     In step S 7 , two groups of second receiving antennas  4  are selected having the largest signal strength variations. As shown in  FIG. 3 , one group may comprise at least three horizontally-arranged second receiving antennas  4 , while the other group may comprise at least three perpendicularly-arranged second receiving antennas  4 . Conic approximation is calculated using the signal strengths and position information of the selected second receiving antennas  4  to obtain touch position and touch pressure of the electromagnetic stylus. Then the process returns to step S 1 . 
     In steps S 5  and S 7 , the conic curve may be a parabolic curve, a single stand of hyperbolic curve or any other suitable conic curve. 
     In the example as shown in  FIG. 6 , the control method comprises the following steps. 
     In step S 1 , one transmitting antenna  2  transmits a square wave signal having a base frequency f 1  and a sinusoid wave signal having a frequency f 3  alternately. 
     In step S 2 , all of the second receiving antennas  4  receive a harmonic wave signal having the frequency f 1 . All of the first receiving antennas  3  receive a harmonic wave signal having the frequency f 3 . The control processing unit  6  obtains signal strengths of all the second receiving antennas  4  and the first receiving antennas  3  and stores the signal strengths of the second receiving antennas  4  in table  1  and the signal strengths of the first receiving antennas  3  in table  2 . 
     In step S 3 , another transmitting antenna  2  is selected and the process returns to step S 1 . The process is repeated until all transmitting antennas have been selected. 
     In step S 4 , m×n signal strengths in the table  2  are compared with an initialization table II. The process proceeds to step S 6  if there is no substantial difference, which means the signal strengths contain tolerable noise. Otherwise the process proceeds to step S 5 . The initialization table II is a table containing m×n signal strengths obtained by averaging the signal strengths from all of the first receiving antennas  3  through repeating steps S 1 ˜S 3  for multiple times without presence of any touch or electromagnetic stylus. 
     In step S 5 , two groups of first receiving antennas  3  are selected having the largest signal strength variations. As shown in  FIG. 3 , one group may comprise at least three horizontally-arranged first receiving antennas  3 , while the other group may comprise at least three perpendicularly-arranged first receiving antennas  3 . Conic approximation is calculated using the signal strengths and position information of the selected first receiving antennas  3  to obtain touch position and touch pressure of the electromagnetic stylus. Then the process returns to step S 1 . 
     In step S 6 , m×k signal strengths in the table  1  are compared with an initialization table I. The process returns to step S 1  if there is no substantial difference, which means the signal strengths contain tolerable noise. Otherwise the process proceeds to step S 7 . The initialization table I is a table containing m×k signal strengths obtained by averaging the signal strengths from all of the second receiving antennas  4  through repeating steps S 1 ˜S 3  for multiple times without presence of any touch or electromagnetic stylus. 
     In step S 7 , two groups of second receiving antennas  4  are selected having the largest signal strength variations. As shown in  FIG. 3 , one group may comprise at least three horizontally-arranged second receiving antennas  4 , while the other group may comprise at least three perpendicularly-arranged second receiving antennas  4 . Conic approximation is calculated using the signal strengths and position information of the selected second receiving antennas  4  to obtain touch position and touch pressure of the electromagnetic stylus. Then the process returns to step S 1 . 
     In steps S 5  and S 7 , the conic curve may be a parabolic curve, a single stand of hyperbolic curve or any other suitable conic curve. 
     The embodiments of the present disclosure have been described as above. Those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present disclosure. The scope of the present disclosure is defined by the attached claims and equivalents thereof.