Driver circuit, as for an OLED display

• US 20050068275A1
• Filed: 08/26/2004
• Published: 03/31/2005
• Est. Priority Date: 09/29/2003
• Status: Active Grant

• Current Assignee: Transpacific Infinity LLC
• Original Assignee: Transpacific Infinity LLC
• Inventors: Kane, Michael Gillis
• Granted Patent: US 7,633,470 B2
• Time in Patent Office: Days
• US Class Current: 345/82
• CPC Class Codes: G09G 2310/0248 Precharge or discharge of column electrodes before or after applying exact column voltages
• CPC Class Codes: G09G 2320/0223 Compensation for problems related to R-C delay and attenuation in electrodes of matrix panels, e.g. in gate electrodes or on-substrate video signal electrodes
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 3/3216 using a passive matrix
• CPC Class Codes: G09G 3/3225 using an active matrix
• CPC Class Codes: G09G 3/3283 in which the data driver supplies a variable data current for setting the current through, or the voltage across, the light-emitting elements

Abstract

An electronic driver circuit for driving a load exhibiting a capacitance comprises a controllable current source for providing at an output current related to an input data signal and a capacitance coupled between the output and input of the controllable current source for providing positive feedback.

Claims

1. An electronic driver circuit for driving a load, wherein the load exhibits a capacitance, comprising:

a source of an input data signal;

a controllable current source having an input coupled for receiving the input data signal for providing at an output thereof an output current proportionally related in steady-state value to the input data signal; and

a capacitance coupled between the output of said controllable current source and the input thereof for providing positive feedback from the output to the input of said controllable current source.

2. The electronic driver circuit of claim 1 wherein the input data signal is a current and wherein said controllable current source includes a diode-connected transistor for providing an input voltage signal responsive to the input data signal current.

3. The electronic driver circuit of claim 1 wherein the input data signal is a voltage and wherein said controllable current source includes an amplifier coupled to a resistance for providing a current proportional to the input data signal voltage and the resistance.

4. The electronic driver circuit of claim 1 further comprising a resistance coupling said source to the input of said controllable current source for reacting with said capacitance for providing said positive feedback.

5. The electronic driver circuit of claim 1 wherein said controllable current source comprises:

a first transistor of a first polarity having a controllable conduction path and a control electrode for controlling the conduction of said controllable conduction path, wherein the input data signal is applied to the control electrode of said first transistor;

second and third transistors of a second polarity opposite to the first polarity, each of said second and third transistors having a controllable conduction path and a control electrode for controlling the conduction of said controllable conduction path,

wherein the control electrode of said second and third transistors are connected to each other, to one end of the controllable conduction path of said first transistor; and

to one end of the controllable conduction path of said second transistor;

wherein the steady-state output current produced at the controllable conduction path of said third transistor is proportionally related to the input data signal.

6. An electronic driver circuit for driving a load, wherein the load exhibits a capacitance, comprising:

a source of an input data signal current;

a controllable current source having an input coupled for receiving the input data signal current for providing at an output thereof an output current proportionally related in steady state value to the input data signal current; and

a capacitance coupled between the output of said controllable current source and the input thereof for providing positive feedback from the output to the input of said controllable current source.

7. The electronic driver circuit of claim 6 wherein said controllable current source includes a diode-connected transistor for providing an input voltage signal responsive to the input data signal current.

8. The electronic driver circuit of claim 6 further comprising a resistance coupling said source to the input of said controllable current source for reacting with said capacitance for providing said positive feedback.

9. The electronic driver circuit of claim 6 wherein said controllable current source comprises:

a first transistor of a first polarity having a controllable conduction path and a control electrode for controlling the conduction of said controllable conduction path, wherein the input data signal current is applied to the control electrode of said first transistor;

second and third transistors of a second polarity opposite to the first polarity, each of said second and third transistors having a controllable conduction path and a control electrode for controlling the conduction of said controllable conduction path,

wherein the control electrodes of said second and third transistors are connected to each other, to one end of the controllable conduction path of said first transistor; and

to one end of the controllable conduction path of said second transistor;

wherein the output current produced at the controllable conduction path of said third transistor is proportionally related to the input data signal current.

10. An electronic driver circuit for driving a load, wherein the load exhibits a capacitance, comprising:

a source of an input data signal voltage;

a controllable current source having an input coupled for receiving the input data signal voltage for providing at an output thereof an output current proportionally related in steady-state value to the input data signal voltage; and

a capacitance coupled between the output of said controllable current source and the input thereof for providing positive feedback from the output to the input of said controllable current source.

11. The electronic driver circuit of claim 10 wherein said controllable current source includes an amplifier coupled to a resistance for providing a current proportional to the input data signal voltage and the resistance.

12. The electronic driver circuit of claim 11 wherein said controllable current source further comprises:

a first transistor of a first polarity having a controllable conduction path and a control electrode for controlling the conduction of said controllable conduction path, wherein the control electrode of said first transistor is connected to an output of said amplifier;

second and third transistors of a second polarity opposite to the first polarity, each of said second and third transistors having a controllable conduction path and a control electrode for controlling the conduction of said controllable conduction path, wherein one end of the controllable conduction paths of said second and third transistors are connected together;

wherein the control electrodes of said second and third transistors are connected to each other, to one end of the controllable conduction path of said first transistor, and to the other end of the controllable conduction path of said second transistor;

wherein the steady-state output current produced at the controllable conduction path of said third transistor is proportionally related to the input data signal voltage.

13. The electronic driver circuit of claim 10 further comprising a resistance coupling said source to the input of said controllable current source for reacting with said capacitance for providing said positive feedback.

14. An electronic driver circuit for driving a load, wherein the load exhibits a capacitance, comprising:

a source of an input data signal current;

a diode-connected transistor of a first polarity for providing an input voltage signal responsive to the input data signal current;

a second transistor of the first polarity having a controllable conduction path and a control electrode for controlling the conduction of said controllable conduction path, wherein the input voltage signal provided by said diode-connected transistor is applied between the control electrode and one end of the controllable conduction path of said second transistor;

third and fourth transistors of a second polarity opposite to the first polarity, each of said third and fourth transistors having a controllable conduction path and a control electrode for controlling the conduction of said controllable conduction path, wherein one end of the controllable conduction paths of said third and fourth transistors are connected together;

wherein the control electrodes of said third and fourth transistors are connected to each other, and to the other end of the controllable conduction path of said second transistor;

a capacitance coupled between the other end of the controllable conduction path of said fourth transistor and the control electrode of said second transistor for providing positive feedback thereat; and

a resistance coupling said source to the control electrode of said second transistor for reacting with said capacitance for providing said positive feedback,

wherein the steady-state output current produced at the other end of the controllable conduction path of said fourth transistor is proportionally related to the input data signal current.

15. An electronic driver circuit for driving a load, wherein the load exhibits a capacitance, comprising:

a source of an input data signal voltage

an amplifier coupled to a first resistance for providing a current proportional to the input data signal voltage and the resistance;

first and second transistors of a first polarity, each of said first and second transistors having a controllable conduction path and a control electrode for controlling the conduction of said controllable conduction path, wherein one end of the controllable conduction paths of said first and second transistors are connected together;

wherein the control electrodes of said first and second transistors are connected to each other and to the other end of the controllable conduction path of said first transistor for receiving the current provided by said amplifier;

a capacitance coupled between the other end of the controllable conduction path of said second transistor and an input of said amplifier for providing positive feedback thereat; and

a second resistance coupling said source to the input of said amplifier for reacting with said capacitance for providing said positive feedback,

wherein the steady-state output current produced at the other end of the controllable conduction path of said second transistor is proportionally related to the input data signal voltage.

16. The electronic driver circuit of claim 15 further comprising a third transistor of second polarity opposite to the first polarity and having a controllable conduction path and a control electrode for controlling the conduction of said controllable conduction path, wherein the control electrode of said third transistor is connected to an output of said amplifier, one end of the controllable conduction path of said third transistor is connected to said first resistance, and the other end of the controllable conduction path thereof is connected to the control electrode of said first transistor for providing the current provided by said amplifier.