CURRENT DRIVING DEVICE

• US 20080143429A1
• Filed: 12/12/2007
• Published: 06/19/2008
• Est. Priority Date: 12/13/2006
• Status: Active Grant

• Current Assignee: Bishop Display Tech LLC (IP Edge LLC)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: MIZUKI, Makoto, Kojima, Hiroshi, Kojima, Tomokazu, Nishi, Kazuyoshi, Ohmori, Tetsuro
• Granted Patent: US 7,995,047 B2
• Time in Patent Office: Days
• US Class Current: 327/541
• CPC Class Codes: G05F 3/26 Current mirrors

Abstract

A current driving device comprises: a voltage supply part; a current supply part; and a plurality of current output parts, each comprising a current-voltage converting function, a voltage-current converting function, and a voltage holding capacitance element. The current output part takes three operation modes. Under a voltage supply mode, the current output part receives a voltage from the voltage supply part and holds the voltage in the voltage holding capacitance element. Under a current supply mode, the current output part receives the current from the current supply part, generates a second voltage by the current-voltage converting function and holds the voltage in the voltage holding capacitance element. Under a current output part, the current output part outputs an output current according to the voltage held in the voltage holding capacitance element by the voltage-current converting function. By charging the current output part with the reference voltage before the calibration performed by using the reference current, calibration of the current output part is performed at a high speed.

Claims

1. A current driving device, comprising:

a first voltage supply part for supplying a first voltage;

a first current supply part for supplying a first electric current;

a plurality of output terminals; and

a plurality of current output parts for outputting an electric current in accordance with said first electric current, each of said current output parts comprising a current-voltage converting function, a voltage-current converting function, a voltage holding part, and at least one current output terminal, wherein

said current output part takes three operation modes, i.e. a voltage supply mode, a current supply mode, and a current output mode,

under said voltage supply mode, said current output part receives said first voltage from said first voltage supply part and holds said voltage in said voltage holding part,

under said current supply mode, said current output part receives said first current from said first current supply part, and generates a second voltage by said current-voltage converting function and holds said voltage in said voltage holding part, and

under said current output mode, said current output part outputs an output current according to said voltage held in said voltage holding part by said voltage-current converting function.

2. The current driving device according to claim 1, wherein each of said output terminals is connected to said current output terminals provided to said plurality of said current output parts, and each of said plurality of current output parts is connected in parallel to said first current supply part and said first voltage supply part used in common.

3. The current driving device according to claim 1, wherein each of said current output parts actuates said current-voltage converting function under said voltage supply mode.

4. The current driving device according to claim 1, wherein each of said current output parts comprises a function of stopping said current-voltage converting function under said voltage supply mode.

5. The current driving device according to claims 1, further comprising

a second current supply part for supplying a second electric current that is proportional to said first electric current, and

a current-voltage converting part for generating said first voltage by receiving said second electric current, wherein

said first voltage supply part controls supplies of said first voltage generated by said current-voltage converting part to said current output parts.

6. The current driving device according to claim 5, wherein said current-voltage converting part comprises a switching part for short-circuiting a node at which said first voltage emerges to a reference voltage node.

7. The current driving device according to claims 1, further comprising a second voltage supply part with a larger voltage supply capacity than that of said first voltage supply part, wherein

the use of said first voltage supply part and the use of said second voltage supply part are switched in accordance with the number of said current output parts that take said voltage supply mode among said plurality of current output parts.

8. The current driving device according to claims 1, wherein

said first voltage supply part is constituted to be capable of changing its voltage supply capacity in accordance with the number of said current output parts that take said voltage supply mode among said plurality of current output parts.

9. A current-driving-type display device, comprising said current driving device according to claims 1 mounted thereon so as to be driven by said current driving device.

10. A current driving device, comprising:

a current input switch for controlling connection/disconnection states with respect to a current supply part;

a voltage holding part for holding a reference voltage, which is charged by a flown current;

a calibration switch interposed between said current input switch and said voltage holding part;

a plurality of voltage-current converting elements for generating an electric current in accordance with said reference voltage held in said voltage holding part;

a plurality of signal response switches that are on/off controlled in accordance with inputted signals, said response switches being connected in series to each of said voltage-current converting elements, and each of which being connected in parallel to said calibration switch;

a plurality of current output switches, each being interposed between a connection node, which is provided between said current input switch and said calibration switch, and said plurality of current output terminals; and

a high-speeding switch for controlling connection/disconnection states of said voltage supply part with respect to said voltage holding part.