Display device

• US 8,144,144 B2
• Filed: 05/02/2008
• Issued: 03/27/2012
• Est. Priority Date: 10/21/2002
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Koyama, Jun
• Primary Examiner(s): Dharia, Prabodh M
• Application Number:
  US12/149,486
• Publication Number:
  US 20090009505A1
• Time in Patent Office: 1,425 Days
• Field of Search: 345 76-103, 345/204, 345/205, 345211-214, 345/691, 359/630, 315/169.3, 315/169.1, 323/282, 323/283, 363/59, 348/730
• US Class Current: 345/212
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2330/02 Details of power systems and of start or stop of display operation
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters

Abstract

A display device according to the present invention includes a switching regulator control circuit formed of TFTs. A digital switching regulator control circuit is composed of an AD converter circuit, a CPU, a pulse generation circuit or the like. An analog switching regulator control circuit is composed of an error amplifier circuit, a triangle wave generation circuit, a PWM comparator or the like. By integrally forming the switching regulator control circuit on a display device, the problem of the conventional portable information equipment as to the reduction in size and weight can be solved.

Claims

1. A display device comprising:

a pixel portion; and

a switching regulator control circuit comprising;

a nonvolatile memory;

an AD converter circuit into which an output of a switching regulator is inputted;

a CPU for outputting data corresponding to a switching duty of a switching element using data stored in the nonvolatile memory and an output of the AD converter circuit; and

a pulse generation circuit for outputting a pulse based on data outputted from the CPU into the switching element,

wherein the pixel portion and the switching regulator control circuit are formed over a same substrate.

2. A display device according to claim 1, wherein the display device is a liquid crystal display device.

3. A display device according to claim 1, wherein the display device is an EL display device.

4. A display device according to claim 1, wherein the display device is applied to electronic equipment selected from the group consisting of a digital camera, a notebook type personal computer, a PDA, a DVD player, a folding portable display device, a watch type display device and a mobile telephone.

5. A display device comprising:

a pixel portion; and

a switching regulator control circuit comprising;

a nonvolatile memory;

an AD converter circuit into which an output of a switching regulator is inputted;

a CPU into which an output of the nonvolatile memory and an output of the AD converter circuit are inputted; and

a pulse generation circuit into which an output of the CPU and a clock signal are inputted,

wherein the pixel portion and the switching regulator control circuit are formed over a same substrate.

6. A display device according to claim 5, wherein the display device is a liquid crystal display device.

7. A display device according to claim 5, wherein the display device is an EL display device.

8. A display device according to claim 5, wherein the display device is applied to electronic equipment selected from the group consisting of a digital camera, a notebook type personal computer, a PDA, a DVD player, a folding portable display device, a watch type display device and a mobile telephone.

9. A display device comprising:

a pixel portion;

a switching regulator comprising a switching element, an inductor, a diode and a smoothing capacitor; and

a switching regulator control circuit comprising;

a nonvolatile memory;

an AD converter circuit into which an output of the switching regulator is inputted;

a CPU for outputting data corresponding to a switching duty of the switching element using data stored in the nonvolatile memory and an output of the AD converter circuit; and

a pulse generation circuit for outputting a pulse based on data outputted from the CPU into the switching element,

wherein the pixel portion and the switching regulator control circuit are formed over a same substrate.

10. A display device according to claim 9, wherein the switching element is formed over the same substrate.

11. A display device according to claim 9, wherein the display device is a liquid crystal display device.

12. A display device according to claim 9, wherein the display device is an EL display device.

13. A display device according to claim 9, wherein the display device is applied to electronic equipment selected from the group consisting of a digital camera, a notebook type personal computer, a PDA, a DVD player, a folding portable display device, a watch type display device and a mobile telephone.

14. A display device comprising:

a pixel portion;

a switching regulator comprising a switching element, an inductor, a diode and a smoothing capacitor; and

a switching regulator control circuit comprising;

a nonvolatile memory;

an AD converter circuit into which an output of the switching regulator is inputted;

a CPU into which an output of the nonvolatile memory and an output of the AD converter circuit are inputted; and

a pulse generation circuit into which an output of the CPU and a clock signal are inputted,

wherein the pixel portion and the switching regulator control circuit are formed over a same substrate.

15. A display device according to claim 14, wherein the switching element is formed over the same substrate.

16. A display device according to claim 14, wherein the display device is a liquid crystal display device.

17. A display device according to claim 14, wherein the display device is an EL display device.

18. A display device according to claim 14, wherein the display device is applied to electronic equipment selected from the group consisting of a digital camera, a notebook type personal computer, a PDA, a DVD player, a folding portable display device, a watch type display device and a mobile telephone.

19. A display device comprising:

a pixel portion formed over a first substrate; and

a switching regulator control circuit comprising;

a nonvolatile memory;

an AD converter circuit into which an output of a switching regulator is inputted;

a CPU for outputting data corresponding to a switching duty of a switching element using data stored in the nonvolatile memory and an output of the AD converter circuit; and

a pulse generation circuit for outputting a pulse based on data outputted from the CPU into the switching element,

wherein the switching regulator control circuit is formed over a second substrate made of a same material as the first substrate.

20. A display device according to claim 19, wherein the display device is a liquid crystal display device.

21. A display device according to claim 19, wherein the display device is an EL display device.

22. A display device according to claim 19, wherein the display device is applied to electronic equipment selected from the group consisting of a digital camera, a notebook type personal computer, a PDA, a DVD player, a folding portable display device, a watch type display device and a mobile telephone.

23. A display device comprising:

a pixel portion formed over a first substrate; and

a switching regulator control circuit comprising;

a nonvolatile memory;

an AD converter circuit into which an output of a switching regulator is inputted;

a CPU into which an output of the nonvolatile memory and an output of the AD converter circuit are inputted; and

a pulse generation circuit into which an output of the CPU and a clock signal are inputted,

wherein the switching regulator control circuit is formed over a second substrate made of a same material as the first substrate.

24. A display device according to claim 23, wherein the display device is a liquid crystal display device.

25. A display device according to claim 23, wherein the display device is an EL display device.

26. A display device according to claim 23, wherein the display device is applied to electronic equipment selected from the group consisting of a digital camera, a notebook type personal computer, a PDA, a DVD player, a folding portable display device, a watch type display device and a mobile telephone.