Audio signal processing circuit and a display device incorporating the same

• US 7,769,190 B2
• Filed: 04/12/2004
• Issued: 08/03/2010
• Est. Priority Date: 04/14/2003
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Miyata, Kazuhiko, Miyake, Hiroyuki, Takahashi, Kei, Koyama, Jun
• Primary Examiner(s): Chin; Vivian
• Assistant Examiner(s): Tran; Con P
• Application Number:
  US10/821,848
• Publication Number:
  US 20040201056A1
• Time in Patent Office: 2,304 Days
• Field of Search: 381/311, 381/388, 381/28, 381/120, 381/150, 381/333, 257/288, 257/581, 257/359, 345/92, 345/55, 345/30, 330/177, 330/157, 330/1.R, 330/282, 330/250, 330/278, 330/129, 330/307, 361/734, 361/748, 361/749, 438/149, 438/381, 438/384, 348/739, 715/864
• US Class Current: 381/111
• CPC Class Codes: G02F 1/13452 Conductors connecting driver circuitry and terminals of panels
• CPC Class Codes: H01C 7/006 Thin film resistors
• CPC Class Codes: H01G 4/40 Structural combinations of fixed capacitors with other electric elements, the structure mainly consisting of a capacitor, e.g. RC combinations
• CPC Class Codes: H05K 1/189 characterised by the use of a flexible or folded printed circuit H05K3/326 takes precedence
• CPC Class Codes: H05K 2201/10136 Liquid Crystal display [LCD]
• CPC Class Codes: H05K 3/361 Assembling flexible printed circuits with other printed circuits

Abstract

An audio signal processing circuit for processing an audio signal which is compact and small is provided. For the audio signal processing circuit of the invention, an input circuit, a feedback circuit, and a smoothing circuit are formed using a chip capacitor with small mounting space and a thin film resistor on an insulating substrate. Accordingly, the audio signal processing circuit that is small and further a display device incorporating the audio signal processing circuit are provided.

Claims

1. An audio signal processing circuit comprising:

an operational amplifier formed over an insulating substrate and comprising a thin film element, the operational amplifier including an input terminal and an output terminal;

a first thin film resistor formed over the insulating substrate, a first terminal of the first thin film resistor being electrically connected to the input terminal of the operational amplifier, and a second terminal of the first thin film resistor being electrically connected to the output terminal of the operational amplifier;

a second thin film resistor formed over the insulating substrate, a first terminal of the second thin film resistor being electrically connected to the input terminal of the operational amplifier and the first terminal of the first thin film resistor;

a first chip capacitor mounted over a flexible printed circuit connected to the insulating substrate, the first chip capacitor being electrically connected to a second terminal of the second thin film resistor, and

a smoothing circuit and the smoothing circuit comprises a third thin film resistor and a second chip capacitor,

wherein a first terminal of the third thin film resistor is electrically connected to the first thin film resistor, and

wherein a second terminal of the third thin film resistor is connected to the second chip capacitor.

2. The audio signal processing circuit according to claim 1, wherein P-type impurities are doped in the first thin film resistor and the second thin film resistor.

3. The audio signal processing circuit according to claim 1, wherein the first thin film resistor and the second thin film resistor have a resistance value of 80 kΩ

or more.

4. An electronic equipment comprising the audio signal processing circuit according to claim 1, wherein the electronic equipment is one selected from the group consisting of a video camera, a digital camera, a head mounted display, a game machine, a car navigation system, a personal computer and a portable information terminal.

5. The audio signal processing circuit according to claim 1, wherein the audio signal processing circuit comprises an input circuit and the input circuit comprises the second thin film resistor and the first chip capacitor.

6. A display device comprising:

a pixel portion formed over an insulating substrate; and

an audio signal processing circuit, wherein the audio signal processing circuit comprises;

an operational amplifier formed over the insulating substrate and comprising a thin film element, the operational amplifier including an input terminal and an output terminal;

a first thin film resistor formed over the insulating substrate, a first terminal of the first thin film resistor being electrically connected to the input terminal of the operational amplifier, and a second terminal of the first thin film resistor being electrically connected to the output terminal of the operational amplifier;

a second thin film resistor formed over the insulating substrate, a first terminal of the second thin film resistor being electrically connected to the input terminal of the operational amplifier and the first terminal of the first thin film resistor;

a first chip capacitor mounted around the pixel portion and over the insulating substrate, the first chip capacitor being electrically connected to a second terminal of the second thin film resistor, and

a smoothing circuit and the smoothing circuit comprises a third thin film resistor and a second chip capacitor,

wherein a first terminal of the third thin film resistor is electrically connected to the first thin film resistor, and

wherein a second terminal of the third thin film resistor is connected to the second chip capacitor.

7. The display device according to claim 6, wherein P-type impurities are doped in the first thin film resistor and the second thin film resistor.

8. The display device according to claim 6, wherein the first thin film resistor and the second thin film resistor have a resistance value of 80 kΩ

or more.

9. An electronic equipment comprising the display device according to claim 6, wherein the electronic equipment is one selected from the group consisting of a video camera, a digital camera, a head mounted display, a game machine, a car navigation system, a personal computer and a portable information terminal.

10. The display device according to claim 6, wherein the display device comprises an input circuit and the input circuit comprises the second thin film resistor and the first chip capacitor.

11. A display device comprising:

a pixel portion formed over an insulating substrate; and

an audio signal processing circuit, wherein the audio signal processing circuit comprises;

an operational amplifier formed over the insulating substrate and comprising a thin film element, the operational amplifier including an input terminal and an output terminal;

a first thin film resistor formed over the insulating substrate, a first terminal of the first thin film resistor being electrically connected to the input terminal of the operational amplifier, and a second terminal of the first thin film resistor being electrically connected to the output terminal of the operational amplifier;

a second thin film resistor formed over the insulating substrate, a first terminal of the second thin film resistor being electrically connected to the input terminal of the operational amplifier and the first terminal of the first thin film resistor;

a first chip capacitor mounted over a flexible printed circuit connected to the insulating substrate, the first chip capacitor being electrically connected to a second terminal of the second thin film resistor, and

a smoothing circuit and the smoothing circuit comprises a third thin film resistor and a second chip capacitor,

wherein a first terminal of the third thin film resistor is electrically connected to the first thin film resistor, and

wherein a second terminal of the third thin film resistor is connected to the second chip capacitor.

12. The display device according to claim 11, wherein P-type impurities are doped in the first thin film resistor and the second thin film resistor.

13. The display device according to claim 11, wherein the first thin film resistor and the second thin film resistor have a resistance value of 80 kΩ

or more.

14. An electronic equipment comprising the display device according to claim 11, wherein the electronic equipment is one selected from the group consisting of a video camera, a digital camera, a head mounted display, a game machine, a car navigation system, a personal computer and a portable information terminal.

15. The display device according to claim 11, wherein the display device comprises an input circuit and the input circuit comprises the second thin film resistor and the first chip capacitor.

16. An audio signal processing circuit comprising:

an operational amplifier formed over an insulating substrate and comprising a thin film element, the operational amplifier including an input terminal and an output terminal;

a first thin film resistor formed over the insulating substrate, a first terminal of the first thin film resistor being electrically connected to the input terminal of the operational amplifier, and a second terminal of the first thin film resistor being electrically connected to the output terminal of the operational amplifier;

a second thin film resistor formed over the insulating substrate, a first terminal of the second thin film resistor being electrically connected to the input terminal of the operational amplifier and the first terminal of the first thin film resistor;

a first chip capacitor mounted over the insulating substrate, the first chip capacitor being electrically connected to a second terminal of the second thin film resistor, and

a smoothing circuit and the smoothing circuit comprises a third thin film resistor and a second chip capacitor,

wherein a first terminal of the third thin film resistor is electrically connected to the first thin film resistor, and

wherein a second terminal of the third thin film resistor is connected to the second chip capacitor.

17. The audio signal processing circuit according to claim 16, wherein the audio signal processing circuit comprises an input circuit and the input circuit comprises the second thin film resistor and the first chip capacitor.

18. The audio signal processing circuit according to claim 16, wherein P-type impurities are doped in the first thin film resistor and the second thin film resistor.

19. The audio signal processing circuit according to claim 16, wherein the first thin film resistor and the second thin film resistor have a resistance value of 80 kΩ

or more.

20. An electronic equipment comprising the audio signal processing circuit according to claim 16, wherein the electronic equipment is one selected from the group consisting of a video camera, a digital camera, a head mounted display, a game machine, a car navigation system, a personal computer and a portable information terminal.

21. An audio signal processing circuit comprising:

an operational amplifier formed over an insulating substrate and comprising a thin film element, the operational amplifier including an input terminal and an output terminal;

a first thin film resistor formed over the insulating substrate, a first terminal of the first thin film resistor being electrically connected to the input terminal of the operational amplifier, and a second terminal of the first thin film resistor being electrically connected to the output terminal of the operational amplifier;

a second thin film resistor formed over the insulating substrate, a first terminal of the second thin film resistor being electrically connected to the input terminal of the operational amplifier and the first terminal of the first thin film resistor;

a first chip capacitor mounted over a printed circuit board electrically connected to the insulating substrate, the first chip capacitor being electrically connected to a second terminal of the second thin film resistor, and

a smoothing circuit and the smoothing circuit comprises a third thin film resistor and a second chip capacitor,

wherein a first terminal of the third thin film resistor is electrically connected to the first thin film resistor, and

wherein a second terminal of the third thin film resistor is connected to the second chip capacitor.

22. The audio signal processing circuit according to claim 21, wherein the audio signal processing circuit comprises an input circuit and the input circuit comprises the second thin film resistor and the first chip capacitor.

23. The audio signal processing circuit according to claim 21, wherein P-type impurities are doped in the first thin film resistor and the second thin film resistor.

24. The audio signal processing circuit according to claim 21, wherein the first thin film resistor and the second thin film resistor have a resistance value of 80 kΩ

or more.

25. An electronic equipment comprising the audio signal processing circuit according to claim 21, wherein the electronic equipment is one selected from the group consisting of a video camera, a digital camera, a head mounted display, a game machine, a car navigation system, a personal computer and a portable information terminal.

26. A display device comprising:

a pixel portion formed over an insulating substrate; and

an audio signal processing circuit, wherein the audio signal processing circuit comprises;

an operational amplifier formed over the insulating substrate and comprising a thin film element, the operational amplifier including an input terminal and an output terminal;

a first thin film resistor formed over the insulating substrate, a first terminal of the first thin film resistor being electrically connected to the input terminal of the operational amplifier, and a second terminal of the first thin film resistor being electrically connected to the output terminal of the operational amplifier;

a second thin film resistor formed over the insulating substrate, a first terminal of the second thin film resistor being electrically connected to the input terminal of the operational amplifier and the first terminal of the first thin film resistor;

a first chip capacitor mounted over a printed circuit board electrically connected to the insulating substrate, the first chip capacitor being electrically connected to a second terminal of the second thin film resistor, and

a smoothing circuit and the smoothing circuit comprises a third thin film resistor and a second chip capacitor,

wherein a first terminal of the third thin film resistor is electrically connected to the first thin film resistor, and

wherein a second terminal of the third thin film resistor is connected to the second chip capacitor.

27. The display device according to claim 26, wherein the display device comprises an input circuit and the input circuit comprises the second thin film resistor and the first chip capacitor.

28. The display device according to claim 26, wherein P-type impurities are doped in the first thin film resistor and the second thin film resistor.

29. The display device according to claim 26, wherein the first thin film resistor and the second thin film resistor have a resistance value of 80 kΩ

or more.

30. An electronic equipment comprising the display device according to claim 26, wherein the electronic equipment is one selected from the group consisting of a video camera, a digital camera, a head mounted display, a game machine, a car navigation system, a personal computer and a portable information terminal.