USB Test Device and USB Power Reception Device

Abstract

A USB test device and method for testing a power reception device having a USB plug, the USB test device including a connector connected to the USB plug, a communication control unit that communicates with the power reception device through a communication line of the connector, a power supply control unit capable of supplying electric power to the power reception device through a power supply line of the connector, a test control unit that gives an instruction to the power supply control unit based on a power request from the power reception device obtained by the communication control unit, and examines a state of power supply to the power reception device, and a display unit that displays a result of examination by the test control unit.

What is claimed is: 
     
         1 . A USB test device for testing a power reception device having a USB plug, the USB test device comprising:
 a connector connected to the USB plug;   a communication control unit that communicates with the power reception device through a communication line of the connector;   a power supply control unit capable of supplying electric power to the power reception device through a power supply line of the connector;   a test control unit that gives an instruction to the power supply control unit based on a power request from the power reception device obtained by the communication control unit, and examines a state of power supply to the power reception device; and   a display unit that displays a result of examination by the test control unit.   
     
     
         2 . The USB test device according to  claim 1 , wherein
 the test control unit instructs the communication control unit to transmit first power supply information about a combination of electric power that can be supplied to the power reception device, and   the communication control unit receives the power request in accordance with the first power supply information from the power reception device.   
     
     
         3 . The USB test device according to  claim 2 , wherein
 the test control unit instructs the communication control unit to transmit second power supply information, which is different from the first power supply information, about a combination of electric power that can be supplied to the power reception device, and   the communication control unit receives the power request in accordance with the second power supply information from the power reception device.   
     
     
         4 . A USB test device for testing a power feed device having a USB plug, the USB test device comprising:
 a connector connected to the USB plug;   a connection unit that controls a connection between a signal line of the connector and a prescribed resistor;   a test control unit that examines a voltage supplied to a power supply line of the connector from the power feed device in accordance with a state of connection by the connection unit; and   a display unit that displays a result of examination by the test control unit,   the test control unit
 determining whether the voltage of the power supply line is set to a first state after instructing the connection unit to connect the signal line of the connector and the prescribed resistor, and 
 determining whether the voltage of the power supply line is set to a second state after instructing the connection unit to disconnect the signal line of the connector and the prescribed resistor. 
   
     
     
         5 . The USB test device according to  claim 4 , wherein
 the test control unit
 determines whether the voltage of the power supply line is set to the first state after lapse of a first period after instructing the connection unit to connect the signal line of the connector and the prescribed resistor, and 
 determines whether the voltage of the power supply line is set to the second state after lapse of a second period after instructing the connection unit to disconnect the signal line of the connector and the prescribed resistor. 
   
     
     
         6 . A USB power reception device that can be connected to a power feed device having a USB plug, the USB power reception device comprising:
 a connector connected to the USB plug;   a communication control unit that communicates with the power feed device through a communication line of the connector;   a load control unit capable of controlling a load of a power supply line of the connector receiving power supply from the power feed device; and   a test control unit that gives an instruction to the load control unit based on power supply information which was obtained by the communication control unit and which is about a combination of electric power that can be supplied from the power feed device, and examines a state of power supply to the load from the power feed device,   the test control unit issuing a power request to the power feed device through the communication control unit based on a result of examination.   
     
     
         7 . The USB power reception device according to  claim 6 , wherein
 the power supply information includes a plurality of power lists, and   the test control unit instructs the load control unit that voltages and currents indicated in all of the plurality of power lists be supplied to the load from the power feed device.   
     
     
         8 . The USB power reception device according to  claim 7 , wherein
 the test control unit
 determines whether voltages and currents indicated in all of the plurality of power lists are supplied to the load from the power feed device, and 
 when it is determined that a voltage and a current indicated in at least one of the plurality of power lists are not supplied to the load, issues a request for prescribed power to the power feed device through the communication control unit. 
   
     
     
         9 . A USB power reception device that can be connected to a power feed device having a USB plug, the USB power reception device comprising:
 a connector connected to the USB plug;   a communication control unit that communicates with the power feed device through a communication line of the connector;   a connection unit that controls a connection between a signal line of the connector and a prescribed resistor; and   a test control unit that examines a voltage supplied to a power supply line of the connector from the power feed device in accordance with a state of connection by the connection unit,   the test control unit
 determining whether the voltage of the power supply line is set to a first state after instructing the connection unit to connect the signal line of the connector and the prescribed resistor, 
 determining whether the voltage of the power supply line is set to a second state after instructing the connection unit to disconnect the signal line of the connector and the prescribed resistor, and 
 based on a result of determination, issuing a request for prescribed power to the power feed device through the communication control unit. 
   
     
     
         10 . A method of a USB (Universal Serial Bus) test device, the method comprising:
 providing, by a test control unit, an instruction based on a power supply request from a power reception device or a second instruction based on power supply information from a power feed device; and   examining, by the test control unit, a state of power supply to the power reception device or from the power feed device.   
     
     
         11 . The method according to  claim 10 , further comprising:
 communicating, by a communication control unit, with the power reception device through a communication line of a connector, the connector connected to a USB plug of the power reception device,   wherein the providing, by the test control unit, the instruction to a power supply control unit is based on the power request from the power reception device obtained by a communication control unit; and   supplying, by the power supply control unit, electric power to the power reception device through a power supply line of the connector; and   displaying on a display unit a result of the examining of the state of the power supply.   
     
     
         12 . The method according to  claim 10 , further comprising:
 communicating with the power reception device or the power feed device through a communication line of a connector, the connector connected to a USB plug of the power reception device or the power feed device; and   supplying electric power to the power reception device or receiving electric power from the power feed device through a power supply line of the connector; and   displaying a result of the examining of the state of the power supply.   
     
     
         13 . The method according to  claim 10 , wherein
 instructing, by the test control unit, the communication control unit to transmit first power supply information about a combination of electric power that can be supplied to the power reception device, and   receiving, by the communication control unit, the power request in accordance with the first power supply information from the power reception device.   
     
     
         14 . The method according to  claim 13 , further comprising:
 instructing, by the test control unit, the communication control unit to transmit second power supply information, which is different from the first power supply information, about a combination of electric power that can be supplied to the power reception device, and   receiving, by the communication control unit, the power request in accordance with the second power supply information from the power reception device.   
     
     
         15 . The method according to  claim 10 , wherein the examining by the test control unit includes examining a voltage supplied to a power supply line of a connector from the power feed device in accordance with a state of connection by a connection unit that controls a connection between a signal line of the connector and a prescribed resistor,
 wherein the examining further comprising:
 determining whether the voltage of the power supply line is set to a first state after instructing the connection unit to connect the signal line of the connector and the prescribed resistor; and 
 determining whether the voltage of the power supply line is set to a second state after instructing the connection unit to disconnect the signal line of the connector and the prescribed resistor. 
   
     
     
         16 . The method according to  claim 15 , wherein the examining further comprises:
 determining whether the voltage of the power supply line is set to the first state after lapse of a first period after instructing the connection unit to connect the signal line of the connector and the prescribed resistor; and   determining whether the voltage of the power supply line is set to the second state after lapse of a second period after instructing the connection unit to disconnect the signal line of the connector and the prescribed resistor.   
     
     
         17 . The method according to  claim 10 , further comprising:
 providing the second instruction to a load control unit based on power supply information which was obtained by the communication control unit and which is about a combination of electric power that can be supplied from the power feed device, the load control unit controls a load of a power supply line of the connector receiving power supply from the power feed device;   examining the state of power supply to the load from the power feed device; and   issuing a power request to the power feed device through the communication control unit based on a result of examination of the state of power supply to the load.   
     
     
         18 . The method according to  claim 17 , wherein
 the power supply information includes a plurality of power lists, and   further comprising of instructing, by the test control unit, the load control unit that voltages and currents indicated in all of the plurality of power lists be supplied to the load from the power feed device.   
     
     
         19 . The method according to  claim 18 , further comprising:
 determining, by the test control unit, whether voltages and currents indicated in all of the plurality of power lists are supplied to the load from the power feed device, and   when it is determined that a voltage and a current indicated in at least one of the plurality of power lists are not supplied to the load, issuing, by the test control unit, a request for prescribed power to the power feed device through the communication control unit.   
     
     
         20 . The method according to  claim 10 , further comprising:
 communicating, by a communication control unit, with the power feed device through a communication line of a connector connected to a USB plug of the USB power reception device;   controlling, by a connection unit, a connection between a signal line of the connector and a prescribed resistor; and   examining, by the test control unit, a voltage supplied to a power supply line of the connector from the power feed device in accordance with a state of connection by the connection unit, the examining further comprising:
 determining whether a voltage of the power supply line is set to a first state after instructing the connection unit to connect the signal line of the connector and the prescribed resistor, 
 determining whether the voltage of the power supply line is set to a second state after instructing the connection unit to disconnect the signal line of the connector and the prescribed resistor, and 
 based on a result of determination, issuing a request for prescribed power to the power feed device through the communication control unit.