Position indicator, position indicating device, and detection method of tilt of position indicator

Abstract

A position indicator includes a transmission signal generating circuit, a resonant circuit coupled to the transmission signal generating circuit, a first electrode connected to a first node of the resonant circuit, and a second electrode connected to a second node of the resonant circuit. The first electrode, in operation, transmits a first signal. The second electrode, in operation, transmits a second signal that is different from the first signal.

1 . A position indicator comprising:
 a transmission signal generating circuit;   a resonant circuit coupled to the transmission signal generating circuit;   a first electrode connected to a first node of the resonant circuit, wherein the first electrode, in operation, transmits a first signal; and   a second electrode connected to a second node of the resonant circuit, wherein the second electrode, in operation, transmits a second signal that is different from the first signal.   
     
     
         2 . The position indicator according to  claim 1 , wherein a phase of the second signal is opposite a phase of the first signal. 
     
     
         3 . The position indicator according to  claim 1 , wherein the resonant circuit includes a capacitor and a coil, and wherein the second node is different from the first node and is connected to either the capacitor or the coil. 
     
     
         4 . The position indicator according to  claim 1 , wherein a resonant frequency of the resonant circuit is equal to an oscillation frequency of an oscillation circuit included in the transmission signal generating circuit. 
     
     
         5 . The position indicator according to  claim 1 , further comprising a control circuit which, in operation, controls a transmission of the second signal from the position indicator. 
     
     
         6 . The position indicator according to  claim 5 , further comprising a receiving circuit which, in operation, receives an instruction signal, the control circuit being controlled based on the instruction signal received by the receiving circuit. 
     
     
         7 . The position indicator according to  claim 5 , wherein the control circuit is coupled to the resonant circuit and controls whether the resonant circuit is grounded to control the transmission of the second signal from the position indicator. 
     
     
         8 . The position indicator according to  claim 5 , wherein the resonant circuit includes a capacitor and a coil, and wherein the control circuit includes a switch circuit coupled between an end of the coil and a reference potential. 
     
     
         9 . The position indicator according to  claim 8 , wherein the second electrode is connected to a first end of the coil, and wherein the control circuit includes a switch circuit coupled between a second end of the coil and a reference potential. 
     
     
         10 . The position indicator according to  claim 1 , wherein the second electrode surrounds the first electrode. 
     
     
         11 . A method comprising:
 providing a position indicator having a transmission signal generating circuit, a resonant circuit coupled to the transmission signal generating circuit, a first electrode connected to a first node of the resonant circuit, and a second electrode connected to a second node of the resonant circuit;   transmitting a first signal from the first electrode; and   transmitting a second signal from the second electrode, the second signal being different from the first signal.   
     
     
         12 . The method according to  claim 11 , wherein a phase of the second signal is opposite a phase of the first signal. 
     
     
         13 . The method according to  claim 11 , wherein the resonant circuit includes a capacitor and a coil, and wherein the second node is different from the first node and is connected to either the capacitor or the coil. 
     
     
         14 . The method according to  claim 11 , wherein a resonant frequency of the resonant circuit is equal to an oscillation frequency of an oscillation circuit included in the transmission signal generating circuit. 
     
     
         15 . The method according to  claim 11 , further comprising a control circuit which, in operation, controls a transmission of the second signal from the position indicator. 
     
     
         16 . The method according to  claim 15 , further comprising:
 receiving an instruction signal; and   controlling the control circuit being based on the instruction signal.   
     
     
         17 . The method according to  claim 15 , wherein the control circuit is coupled to the resonant circuit and controls whether the resonant circuit is grounded to control the transmission of the second signal from the position indicator. 
     
     
         18 . The method according to  claim 15 , wherein the resonant circuit includes a capacitor and a coil, and wherein the control circuit includes a switch circuit coupled between an end of the coil and a reference potential. 
     
     
         19 . The method according to  claim 18 , wherein the second electrode is connected to a first end of the coil, and wherein the control circuit includes a switch circuit coupled between a second end of the coil and a reference potential. 
     
     
         20 . The method according to  claim 11 , wherein the second electrode surrounds the first electrode.