1. A digital amplifier comprising:
a PWM modulator for modulating an analog input signal with a modulation signal of generally triangular shape so as to produce at an output thereof a pulse width modulated signal,
a high power switch responsively coupled to the output of the PWM modulator for switching between high level d.c. positive and negative voltages in accordance with a logic level of the pulse width modulated signal so as to produce a high power modulated switched signal, and
a low pass filter coupled to an output of the high power switch for filtering out the high frequency components of the signal;
CHARACTERIZED IN THAT:
the PWM modulator comprises an amplifier chain including at least two fast, low-gain amplifiers connected in cascade, an integrator is provided for integrating the analog input signal and producing an integrated analog signal, and
an adder is coupled to an output of the integrator for adding the modulation signal to the integrated analog signal.
2. The digital amplifier according to claim 1, further including a feedback control loop from the output of the high power switch to the analog input signal.
3. The digital amplifier according to claim 2, wherein the feedback control loop is applied to a negative input of the integrator.
4. The digital amplifier according to claim 1, wherein the modulation signal is of generally triangular shape.
5. The digital amplifier according to claim 2, wherein the modulation signal is of generally triangular shape.
6. The digital amplifier according to claim 3, wherein the modulation signal is of generally triangular shape.
7. A digital amplifier comprising:
a PWM modulator for modulating an analog input signal with a modulation signal of generally triangular shape so as to produce at an output thereof a pulse width modulated signal,
a high power switch responsively coupled to the output of the PWM modulator for switching between high level d.c. positive and negative voltages in accordance with a logic level of the pulse width modulated signal so as to produce a high power modulated switched signal, and
a low pass filter coupled to an output of the high power switch for filtering out the high frequency components of the signal;
CHARACTERIZED IN THAT:
a feedback control loop is provided from the output of the high power switch to the analog input signal,
the modulation signal is of generally triangular shape,
an integrator is providing for integrating the analog input signal and producing an integrated analog signal, and
an adder is coupled to an output of the integrator for adding the modulation signal to the integrated analog signal.
8. The digital amplifier according to claim 7, wherein the feedback control loop is applied to a negative input of the integrator.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A light-emitting device comprising:
a first electrode formed on an insulating surface;
a first insulating layer directly covering an end portion of the first electrode and an end portion of a second electrode and comprising tapered edges, wherein the first electrode and the second electrode are co-planar electrodes;
a second insulating layer directly covering the co-planar electrodes and the first insulating layer;
an organic compound layer formed on the second insulating layer; and
a third electrode formed on the organic compound layer,
wherein the second insulating layer has a thickness that allows the co-planar electrodes and the organic compound layer to form a tunnel junction.
2. A light-emitting device according to claim 1, wherein the second insulating layer comprises at least one selected from the group consisting of silicon oxide, silicon nitride, and silicon oxynitride.
3. A light-emitting device according to claim 1, wherein the second insulating layer comprises carbon as a main component thereof.
4. A light-emitting device according to claim 1, wherein the insulating surface comprises at least one of silicon nitride and silicon oxynitride.
5. A light-emitting device according to claim 1, wherein the first insulating layer comprises at least one of polyimide and acrylic resin.
6. A light-emitting device according to claim 1, wherein the thickness of the second insulating layer is 1 nm to 10 nm.
7. A light-emitting device according to claim 1, wherein the insulating surface comprises at least one of polyimide resin and acrylic resin.
8. A light-emitting device according to claim 1, wherein the light-emitting device is incorporated in one selected from the group consisting of a computer, a digital camera, a video camera, and a mobile phone.
9. A light-emitting device comprising:
a first electrode formed on an insulating surface;
a first insulating layer directly covering an end portion of the first electrode and an end portion of a second electrode and comprising tapered edges, wherein the first electrode and the second electrode are co-planar electrodes;
a second insulating layer directly covering the co-planar electrodes and the first insulating layer;
an organic compound layer formed on the second insulating layer; and
a third electrode formed on the organic compound layer,
wherein the second insulating layer has a thickness that allows a tunnel current or a Fowler-Nordheim current to flow therethrough.
10. A light-emitting device according to claim 9, wherein the second insulating layer comprises at least one selected from the group consisting of silicon oxide, silicon nitride, and silicon oxynitride.
11. A light-emitting device according to claim 9, wherein the second insulating layer comprises carbon as a main component thereof.
12. A light-emitting device according to claim 9, wherein the insulating surface comprises at least one of silicon nitride and silicon oxynitride.
13. A light-emitting device according to claim 9, wherein the first insulating layer comprises at least one of polyimide and acrylic resin.
14. A light-emitting device according to claim 9, wherein the thickness of the second insulating layer is 1 nm to 10 nm.
15. A light-emitting device according to claim 9, wherein the insulating surface comprises at least one of polyimide resin and acrylic resin.
16. A light-emitting device according to claim 9 wherein the light-emitting device is incorporated in one selected from the group consisting of a computer, a digital camera, a video camera, and a mobile phone.
17. A light-emitting device comprising:
a thin film transistor comprising a source region and a drain region;
an interlayer insulating film over the source region and the drain region;
a drain electrode connected to the drain region through an opening formed in the interlayer insulating film;
a first electrode formed on the interlayer insulating film so as to be connected to the drain electrode;
a first insulating layer comprising an opening on the first electrode, directly covering an end portion of the first electrode and an end portion of a second electrode, and comprising tapered edges, wherein the first electrode and the second electrode are co-planar electrodes;
a second insulating layer directly covering the co-planar electrodes and the first insulating layer;
an organic compound layer formed on the second insulating layer; and
a third electrode formed on the organic compound layer,
wherein the second insulating layer has a thickness that allows the co-planar electrodes and the organic compound layer to form a tunnel junction.
18. A light-emitting device according to claim 17, wherein the second insulating layer comprises at least one selected from the group consisting of silicon oxide, silicon nitride, and silicon oxynitride.
19. A light-emitting device according to claim 17, wherein the second insulating layer comprises carbon as a main component thereof.
20. A light-emitting device according to claim 17, wherein the interlayer insulating film comprises at least one of silicon nitride and silicon oxynitride.
21. A light-emitting device according to claim 17, wherein the interlayer insulating film comprises a first layer comprising at least one of polyimide and acrylic resin and a second layer comprising at least one of silicon nitride, silicon oxynitride, carbon, and a densified film of the first layer.
22. A light-emitting device according to claim 17, wherein the first insulating layer comprises at least one of polyimide and acrylic resin.
23. A light-emitting device according to claim 17, wherein the thickness of the second insulating layer is 1 nm to 10 nm.
24. A light-emitting device according to claim 17, wherein the interlayer insulating film comprises at least one of polyimide resin and acrylic resin.
25. A light-emitting device according to claim 17, wherein the light-emitting device is incorporated in one selected from the group consisting of a computer, a digital camera, a video camera, and a mobile phone.
26. A light-emitting device comprising:
a thin film transistor comprising a source region and a drain region;
an interlayer insulating film over the source region and the drain region;
a drain electrode connected to the drain region through an opening formed in the interlayer insulating film;
a first electrode formed on the interlayer insulating film so as to be connected to the drain electrode;
a first insulating layer comprising an opening on the first electrode, directly covering an end portion of the first electrode and an end portion of a second electrode, and comprising tapered edges, wherein the first electrode and the second electrode are co-planar electrodes;
a second insulating layer directly covering the co-planar electrodes and the first insulating layer;
an organic compound layer formed on the second insulating layer; and
a third electrode formed on the organic compound layer,
wherein the second insulating layer has a thickness that allows a tunnel current or a Fowler-Nordheim current to flow therethrough.
27. A light-emitting device according to claim 26, wherein the second insulating layer comprises at least one selected from the group consisting of silicon oxide, silicon nitride, and silicon oxynitride.
28. A light-emitting device according to claim 26, wherein the second insulating layer comprises carbon as a main component thereof.
29. A light-emitting device according to claim 26, wherein the interlayer insulating film comprises at least one of silicon nitride and silicon oxynitride.
30. A light-emitting device according to claim 26, wherein the interlayer insulating film comprises a first layer comprising at least one of polyimide and acrylic resin and a second layer comprising at least one of silicon nitride, silicon oxynitride, carbon, and a densified film of the first layer.
31. A light-emitting device according to claim 26, wherein the first insulating layer comprises at least one of polyimide and acrylic resin.
32. A light-emitting device according to claim 26, wherein the thickness of the second insulating layer is 1 nm to 10 nm.
33. A light-emitting device according to claim 26, wherein the interlayer insulating film comprises at least one of polyimide resin and acrylic resin.
34. A light-emitting device according to claim 26, wherein the light-emitting device is incorporated in one selected from the group consisting of a computer, a digital camera, a video camera, and a mobile phone.