SEMICONDUCTOR DISPLAY DEVICE

• US 20020180672A1
• Filed: 07/16/2002
• Published: 12/05/2002
• Est. Priority Date: 01/11/2000
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Koyama, Jun, Yamazaki, Shunpei
• Granted Patent: US 6,828,951 B2
• Time in Patent Office: Days
• US Class Current: 345/77
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• CPC Class Codes: G09G 2310/027 Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2320/045 Compensation of drifts in the characteristics of light emitting or modulating elements
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/142 the light being detected by light detection means within each pixel
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 2360/148 the light being detected by light detection means within each pixel
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3258 with pixel circuitry controlling the voltage across the light-emitting element
• CPC Class Codes: G09G 3/3275 Details of drivers for data electrodes
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/14678 : Contact-type imagers
• CPC Class Codes: H01L 29/4908 : for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/78624 : the source and the drain regions being asymmetrical
• CPC Class Codes: H10K 2102/3026 : Top emission
• CPC Class Codes: H10K 50/856 : comprising reflective means
• CPC Class Codes: H10K 59/122 : Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/13 : comprising photosensors that control luminance
• CPC Class Codes: H10K 59/35 : comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/878 : comprising reflective means

Abstract

To provide a semiconductor display device capable of displaying an image having clarity and a desired color, even when the speed of deterioration of an EL layer is influenced by its environment. Display pixels and sensor pixels of an EL display each have an EL element, and the sensor pixels each have a diode. The luminance of the EL elements of each in the display pixels is controlled in accordance with the amount of electric current flowing in each of the diodes.

Claims

1. A semiconductor display device having a display portion and a sensor portion, wherein:

said display portion includes a plurality of display pixels;

said sensor portion includes at least one sensor pixel;

each of said plurality of display pixels and said sensor pixel has an EL element;

said sensor pixel has a light receiving diode; and

a luminance of each of the EL elements in said plurality of display pixels is controlled by the amount of a current flowing in said light receiving diode.

2. A semiconductor display device according to claim 1, wherein said EL element emits the color red, green, or blue.

3. A semiconductor display device according to claim 1, wherein said EL element comprises an anode, a cathode, and an EL layer sandwiched therebetween, and wherein said EL layer comprises a low molecular organic material or a polymer organic material.

4. A semiconductor display device according to claim 3, wherein said low molecular organic material is made of Alq₃ (tris-8-quinolilite-aluminum) or TPD (triphenylamine derivative).

5. A semiconductor display device according to claim 3, wherein said polymer organic material is made of PPV (polyphenylene vinylene), PVK (polyvinyl carbazole), or polycarbonate.

6. A semiconductor display device according to claim 1, wherein said semiconductor display device is incorporated into an electronic device selected from the group consisting of a video camera, a digital camera, a goggle type display, a car navigation system, an audio reproducing system, a notebook personal computer, a game equipment, a portable information terminal and an image playback device.

7. A semiconductor display device having a display portion and a sensor portion, wherein:

said display portion includes a plurality of display pixels;

said sensor portion includes at least one sensor pixel;

each of said plurality of display pixels and said sensor pixel has a switching TFT, an EL driving TFT, and an EL element;

said sensor pixel has a reset TFT, a buffer TFT, and a light receiving diode;

a drive of said EL driving TFT is controlled by said switching TFT;

a luminescence of said EL element is controlled by said EL driving TFT;

said buffer TFT has a gate electrode, a source region connected to a constant-current power source, and a drain region held at a fixed electric potential;

an electric potential of said gate electrode and an electric potential of said drain region become equivalent when said reset TFT is ON; and

a luminance of each of the EL elements in said plurality of display pixels is controlled by a change in an electric potential of said gate electrode in response to a current flowing in said light receiving diode when said reset TFT is OFF.

8. A semiconductor display device according to claim 7, wherein said EL element emits the color red, green, or blue.

9. A semiconductor display device according to claim 7, wherein said reset TFT is an n-channel TFT and said buffer TFT is a p-channel TFT.

10. A semiconductor display device according to claim 7, wherein said reset TFT is a p-channel TFT and said buffer TFT is an n-channel TFT.

11. A semiconductor display device according to claim 7, wherein said EL element comprises an anode, a cathode, and an EL layer sandwiched therebetween, and wherein said EL layer comprises a low molecular organic material or a polymer organic material.

12. A semiconductor display device according to claim 11, wherein said low molecular organic material is made of Alq₃ (tris-8-quinolilite-aluminum) or TPD (triphenylamine derivative).

13. A semiconductor display device according to claim 11, wherein said polymer organic material is made of PPV (polyphenylene vinylene), PVK (polyvinyl carbazole), or polycarbonate.

14. A semiconductor display device according to claim 7, wherein said semiconductor display device is incorporated into an electronic device selected from the group consisting of a video camera, a digital camera, a goggle type display, a car navigation system, an audio reproducing system, a notebook personal computer, a game equipment, a portable information terminal and an image playback device.

16. A semiconductor display device according to claim 15, wherein said EL element emits the color red, green, or blue.

17. A semiconductor display device according to claim 15, wherein said reset TFT is an n-channel TFT and said buffer TFT is a p-channel TFT.

18. A semiconductor display device according to claim 15, wherein said reset TFT is a p-channel TFT and said buffer TFT is an n-channel TFT.

19. A semiconductor display device according to claim 15, wherein said EL element comprises an anode, a cathode, and an EL layer sandwiched therebetween, and wherein said EL layer comprises a low molecular organic material or a polymer organic material.

20. A semiconductor display device according to claim 19, wherein said low molecular organic material is made of Alq₃ (tris-8-quinolilite-aluminum) or TPD (triphenylamine derivative).

21. A semiconductor display device according to claim 19, wherein said polymer organic material is made of PPV (polyphenylene vinylene), PVK (polyvinyl carbazole), or polycarbonate.

22. A semiconductor display device according to claim 15, wherein said semiconductor display device is incorporated into an electronic device selected from the group consisting of a video camera, a digital camera, a goggle type display, a car navigation system, an audio reproducing system, a notebook personal computer, a game equipment, a portable information terminal and an image playback device.

24. A semiconductor display device according to claim 23, wherein said EL element emits the color red, green, or blue.

25. A semiconductor display device according to claim 23, wherein said reset TFT is an n-channel TFT, said buffer TFT is a p-channel TFT, and said sensor TFT is a p-channel TFT.

26. A semiconductor display device according to claim 23, wherein said reset TFT is a p-channel TFT, said buffer TFT is an n-channel TFT, and said sensor TFT is an n-channel TFT.

27. A semiconductor display device according to claim 23, wherein said EL element comprises an anode, a cathode, and an EL layer sandwiched therebetween, and wherein said EL layer comprises a low molecular organic material or a polymer organic material.

28. A semiconductor display device according to claim 27, wherein said low molecular organic material is made of Alq₃ (tris-8-quinolilite-aluminum) or TPD (triphenylamine derivative).

29. A semiconductor display device according to claim 27, wherein said polymer organic material is made of PPV (polyphenylene vinylene), PVK (polyvinyl carbazole), or polycarbonate.

30. A semiconductor display device according to claim 23, wherein said semiconductor display device is incorporated into an electronic device selected from the group consisting of a video camera, a digital camera, a goggle type display, a car navigation system, an audio reproducing system, a notebook personal computer, a game equipment, a portable information terminal and an image playback device.

15. A semiconductor display device having a display portion, a sensor portion, a source signal line driver circuit, and a gate signal line driver circuit, wherein:

said display portion includes a plurality of display pixels;

said sensor portion includes at least one sensor pixel;

each of said plurality of display pixels and said sensor pixel has a switching TFT, an EL driving TFT, and an EL element;

said sensor pixel has a reset TFT, a buffer TFT, and a light receiving diode;

a drive of said switching TFT is controlled by a signal that is fed to a gate electrode of said switching TFT from said gate signal line driver circuit;

a drive of said EL driving TFT is controlled by a signal that is fed to a gate electrode of said EL driving TFT via said switching TFT from said source signal line driver circuit;

a luminescence of said EL element is controlled by said EL driving TFT;

said buffer TFT has a gate electrode, a source region connected to a constant-current power source, and a drain region held at a fixed electric potential;

an electric potential of said gate electrode and an electric potential of said drain region become equivalent when said reset TFT is ON; and

a luminance of each of the EL elements in said plurality of display pixels is controlled by a change in an electric potential of said gate electrode in response to a current flowing in said light receiving diode when said reset TFT is OFF.

23. A semiconductor display device having a display portion and a sensor portion, wherein:

said display portion includes a plurality of display pixels;

said sensor portion includes at least one sensor pixel;

each of said plurality of display pixels and sensor pixel has a switching TFT, an EL driving TFT, and an EL element;

said sensor pixel has a reset TFT, a buffer TFT, and a sensor TFT;

a drive of said EL driving TFT is controlled by said switching TFT;

a luminescence of said EL element is controlled by said EL driving TFT;

said sensor TFT is constantly OFF;

said buffer TFT has a gate electrode, a source region that is connected to a constant-current source, and a drain region that is held at a fixed electric potential;

an electric potential of said gate electrode and an electric potential of said drain region become equivalent when said reset TFT is ON; and

a luminance of each of the EL elements in said plurality of display pixels is controlled by a change in an electric potential of said gate electrode in response to an off current flowing in said sensor TFT when said reset TFT is OFF.

31. A semiconductor display device having a display portion, a sensor portion, a source signal line driver circuit, and a gate signal line driver circuit, wherein:

said display portion includes a plurality of display pixels;

said sensor portion includes at least one sensor pixel;

each of said plurality of display pixels and said sensor pixel has a switching TFT, an EL driving TFT, and an EL element;

said sensor pixel has a reset TFT, a buffer TFT, and a sensor TFT;

said switching TFT is driven by a signal that is fed to a gate electrode of said switching TFT from said gate signal line driver circuit;

a drive of said EL driving TFT is controlled by a signal that is fed to a gate electrode of said EL driving TFT via said switching TFT from said source signal line driver circuit;

a luminescence of said EL element is controlled by said EL driving TFT;

said sensor TFT is constantly OFF;

said buffer TFT has a gate electrode, a source region that is connected to a constant-current power source, and a drain region that is held at a fixed electric potential;

an electric potential of said gate electrode and an electric potential of said drain region become equivalent when said reset TFT is ON; and

a luminance of each of the EL elements in said plurality of display pixels is controlled by a change in an electric potential of said gate electrode in response to an off current flowing in said sensor TFT when said reset TFT is OFF.

32. A semiconductor display device according to claim 31, wherein said EL element emits the color red, green, or blue.

33. A semiconductor display device according to claim 31, wherein said reset TFT is an n-channel TFT, said buffer TFT is a p-channel TFT, and said sensor TFT is a p-channel TFT.

34. A semiconductor display device according to claim 31, wherein said reset TFT is a p-channel TFT, said buffer TFT is an n-channel TFT, and said sensor TFT is an n-channel TFT.

35. A semiconductor display device according to claim 31, wherein said EL element comprises an anode, a cathode, and an EL layer sandwiched therebetween, and wherein said EL layer comprises a low molecular organic material or a polymer organic material.

36. A semiconductor display device according to claim 35, wherein said low molecular organic material is made of Alq₃ (tris-8-quinolilite-aluminum) or TPD (triphenylamine derivative).

37. A semiconductor display device according to claim 35, wherein said polymer organic material is made of PPV (polyphenylene vinylene), PVK (polyvinyl carbazole), or polycarbonate.

38. A semiconductor display device according to claim 31, wherein said semiconductor display device is incorporated into an electronic device selected from the group consisting of a video camera, a digital camera, a goggle type display, a car navigation system, an audio reproducing system, a notebook personal computer, a game equipment, a portable information terminal and an image playback device.