Power converters and e-paper devices using the same

Abstract

A display device including an e-paper device and a power converter is provided. The e-paper device displays information. The power converter generates a plurality of output voltages respectively at a plurality of output terminals and provides the plurality of output voltages to the e-paper device. The power converter includes a transformer and a plurality of diodes. The transformer has a primary winding and a plurality of secondary windings. The diodes are electrically connected between the secondary windings and the output terminals for generating the output voltages, respectively.

1 . A display device comprising:
 an e-paper device for displaying information; and   a power converter for generating a plurality of output voltages respectively at
 a plurality of output terminals and providing the output voltages to the 
 e-paper device, wherein the power converter comprises: 
 a transformer having a primary winding and a plurality of secondary windings; and 
 a plurality of diodes electrically connected between the secondary windings and the output terminals for generating the output voltages, respectively. 
   
     
     
         2 . The display device as claimed in  claim 1 , wherein the power converter further comprises:
 a power source electrically connected between a first terminal of the primary winding and a ground terminal;   a control unit for detecting at least one output voltage and providing a control signal according to the at least one output voltage; and   a switch electrically connected between a second terminal of the primary winding and the ground terminal and controlled by the control signal.   
     
     
         3 . The display device as claimed in  claim 2 , wherein the control signal is a pulse width modulation (PWM) signal. 
     
     
         4 . The display device as claimed in  claim 1 , wherein each of the secondary windings has a first terminal respectively electrically connected to one of the output terminals through the corresponding diode and a second terminal. 
     
     
         5 . The display device as claimed in  claim 4 , wherein the second terminal of at least one of the secondary windings is electrically connected to a ground terminal. 
     
     
         6 . The display device as claimed in  claim 4 , wherein the second terminal of at least one of the secondary windings is electrically connected to the first terminal of at least one of the other secondary windings. 
     
     
         7 . The display device as claimed in  claim 4 , wherein the second terminal of at least one of the secondary windings is electrically connected to the output terminal corresponding to at least one of the other secondary windings. 
     
     
         8 . The display device as claimed in  claim 1 , wherein the power converter further comprises at least one regulation unit electrically connected between one of the diode and the corresponding output terminal for regulating the corresponding output voltage. 
     
     
         9 . A display device comprising:
 an e-paper device for displaying information; and   a power converter for generating a plurality of output voltages respectively at
 a plurality of output terminals and providing the output voltages to the 
 e-paper device, wherein the power converter comprises: 
 a transformer having a primary winding and at least one secondary winding; 
 at least one first diode electrically connected between the primary winding and one of the output terminals for generating the corresponding output voltage; and 
 at least one second diode electrically connected between the at least one secondary winding and one of the output terminals for generating the corresponding output voltage. 
   
     
     
         10 . The display device as claimed in  claim 9 , wherein the power converter further comprises:
 a power source electrically connected between a first terminal of the primary winding and a ground terminal;   control unit for detecting at least one output voltage and providing a control signal according to the at least one output voltage; and   a switch electrically connected between a second terminal of the primary winding and the ground terminal and controlled by the control signal.   
     
     
         11 . The display device as claimed in  claim 10 , wherein the control signal is a pulse width modulation (PWM) signal. 
     
     
         12 . The display device as claimed in  claim 9 , wherein the at least one secondary winding has a first terminal electrically connected to one of the output terminals through the corresponding second diode and a second terminal. 
     
     
         13 . The display device as claimed in  claim 12 , wherein the second terminal of the at least one secondary winding is electrically connected to a ground terminal. 
     
     
         14 . The display device as claimed in  claim 12 , wherein the transformer has a first secondary winding and a second secondary winding, and the second terminal of the first secondary winding is electrically connected to the first terminal of the second secondary winding. 
     
     
         15 . The display device as claimed in  claim 12 , wherein the transformer has a first secondary winding and a second secondary winding, and the second terminal of the first secondary winding is electrically connected to the output terminal corresponding to the second secondary winding. 
     
     
         16 . The display device as claimed in  claim 8 , wherein the power converter further comprises at least one regulation unit electrically connected between the at least one second diode and the corresponding output terminal for regulating the corresponding output voltage. 
     
     
         17 . A power converter for generating a plurality of output voltages comprising:
 a plurality of output terminals for respectively providing the output voltages;   transformer having a primary winding and at least one secondary winding;   at least one first diode electrically connected between the primary winding and one of the output terminals for generating the corresponding output voltage; and   at least one second diode electrically connected between the at least one secondary winding and one of the output terminals for generating the corresponding output voltage.   
     
     
         18 . The power converter as claimed in  claim 17  further comprising:
 a power source electrically connected between a first terminal of the primary winding and a ground terminal; 
 a control unit for detecting at least one output voltage and providing a control signal according to the at least one output voltage; and 
 a switch electrically connected between a second terminal of the primary winding and the ground terminal and controlled by the control signal. 
 
     
     
         19 . The power converter as claimed in  claim 17 , wherein the control signal is a pulse width modulation (PWM) signal. 
     
     
         20 . The power converter as claimed in  claim 17 , wherein the at least one secondary windings has a first terminal electrically connected to one of the output terminals through the corresponding second diode and a second terminal. 
     
     
         21 . The power converter as claimed in  claim 20 , wherein the second terminal of the at least one secondary winding is electrically connected to a ground terminal. 
     
     
         22 . The power converter as claimed in  claim 20 , wherein the transformer has a first secondary winding and a second secondary winding, and the second terminal of the first secondary winding is electrically connected to the first terminal of the second secondary winding. 
     
     
         23 . The power converter as claimed in  claim 20 , wherein the transformer has a first secondary winding and a second secondary winding, and the second terminal of first secondary winding is electrically connected to the output terminal corresponding to the second secondary winding. 
     
     
         24 . The power converter as claimed in  claim 17  further comprising at least one regulation unit electrically connected between the at least one second diode and the corresponding output terminal for regulating the corresponding output voltage. 
     
     
         25 . A display device comprising:
 an e-paper device for displaying information; and   a power converter for generating a plurality of output voltages respectively at
 a plurality of output terminals and providing the output voltages to the 
 e-paper device, wherein the power converter comprises: 
 a coupled-inductor having a first winding and a second winding, wherein the first winding and the second winding are electrically connected in series between a first node and a second node; 
 a first diode electrically connected between a joint of the first winding and the second winding and one of the output terminals for generating the corresponding output voltage; and 
 a second diode electrically connected between the second node and one of the output terminals for generating the corresponding output voltage. 
   
     
     
         26 . The display device as claimed in  claim 25  further comprising:
 a power source electrically connected between a first node and a ground terminal; 
 a control unit for detecting at least one output voltage and providing a control signal according to the at least one output voltage; and 
 a switch electrically connected between the join and the ground and controlled by the control signal.