Display system and electrical appliance

• US 20010020922A1
• Filed: 01/03/2001
• Published: 09/13/2001
• Est. Priority Date: 01/17/2000
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Koyama, Jun, Yamazaki, Shunpei, Shibata, Noriko
• Granted Patent: US 7,688,290 B2
• Time in Patent Office: Days
• US Class Current: 345/45
• 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 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• 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 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2330/028 Generation of voltages supplied to electrode drivers in a matrix display other than LCD
• CPC Class Codes: G09G 2354/00 Aspects of interface with display user
• CPC Class Codes: G09G 2360/14 Detecting light within display terminals, e.g. using a single or a plurality of photosensors
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/30 using electroluminescent panels
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 5/10 Intensity circuits

Abstract

A display system in which the luminance of light-emitting elements in a light-emitting device is adjusted based on information on an environment. A sensor obtains information on an environment as an electrical signal. A CPU converts, based on comparison data set in advance, the information signal into a correction signal for correcting the luminance of EL elements. Upon receiving this correction signal, a voltage changer applies a predetermined corrected potential to the EL elements. Thus, this display system enables control of the luminance of the EL elements.

Claims

1. A display system comprising:

a light-emitting device,

wherein a luminance of said light-emitting device is controlled by obtaining an information signal of an environment.

2. A display system according to

claim 1

, wherein said information signal comprises a user'"'"'s living-body information.

3. A display system according to

claim 1

, wherein said light-emitting device is an EL display device.

4. A display system according to

claim 1

, wherein said display system is incorporated in one selected from the group consisting of a video camera, a digital camera, a head-mount display, a car navigation system, a portable telephone, and a personal computer.

5. A display system comprising:

a light-emitting device;

a sensor for obtaining an information signal of an environment;

a CPU for converting an electrical signal supplied from said sensor into a correction signal; and

a voltage changer for controlling a corrected potential based on said correction signal.

6. A display system according to

claim 5

, wherein said information signal comprises a user'"'"'s living-body information.

7. A display system according to

claim 5

, wherein said light-emitting device, said sensor, said CPU and said voltage changer are formed on a same substrate.

8. A display system according to

claim 5

, wherein said light-emitting device is an EL display device.

9. A display system according to

claim 5

, wherein said display system is incorporated in one selected from the group consisting of a video camera, a digital camera, a head-mount display, a car navigation system, a portable telephone, and a personal computer.

10. A display system comprising:

an EL element having two electrodes with an EL layer interposed therebetween; and

a current control TFT electrically connected to one of said two electrodes of said EL element,

wherein a potential applied to other of said two electrodes of said EL element is controlled based on an information signal of an environment.

11. A display system according to

claim 10

, wherein said information signal comprises a user'"'"'s living-body information.

12. A display system according to

claim 10

, wherein said display system is incorporated in one selected from the group consisting of a video camera, a digital camera, a head-mount display, a car navigation system, a portable telephone, and a personal computer.

13. An active matrix display device comprising:

at least one pixel thin film transistor over a substrate, said thin film transistor comprising at least an active layer, and a gate electrode adjacent to said active layer with a gate insulating film interposed therebetween;

an EL element comprising at least an EL layer between an anode and a cathode, one of said anode and said cathode being electrically connected to said active layer; and

a sensor for obtaining an information signal of an environment,

wherein a potential applied to another one of said anode and said cathode is controlled based on an information signal of an environment by converting said information signal to a corrected potential.

14. An active matrix display device according to

claim 13

, wherein said display device and said sensor are formed over a same substrate.

15. An active matrix display device according to

claim 13

, wherein said sensor comprises a CCD or a photo-diode.

16. An active matrix display device according to

claim 13

, wherein said information signal comprises a user'"'"'s living-body information.

17. An active matrix display device according to

claim 13

, wherein said display device is one selected from the group consisting of a video camera, a digital camera, a head-mount display, a car navigation system, a portable telephone, and a personal computer.

18. An active matrix display device comprising:

at least one pixel thin film transistor over a substrate, said thin film transistor comprising at least an active layer, and a gate electrode adjacent to said active layer with a gate insulating film interposed therebetween;

an EL element comprising at least an EL layer between an anode and a cathode, one of said anode and said cathode being electrically connected to said active layer; and

a sensor for obtaining an information signal of an environment,

wherein said information signal is converted to a corrected potential and said corrected potential is applied to another one of said anode and said cathode.

19. An active matrix display device according to

claim 18

, wherein said display device and said sensor are formed over a same substrate.

20. An active matrix display device according to

claim 18

, wherein said sensor comprises a CCD or a photo-diode.

21. An active matrix display device according to

claim 18

, wherein said information signal comprises a user'"'"'s living-body information.

22. An active matrix display device according to

claim 18

, wherein said display device is one selected from the group consisting of a video camera, a digital camera, a head-mount display, a car navigation system, a portable telephone, and a personal computer.

23. An active matrix display device comprising:

at least one pixel thin film transistor over a substrate, said thin film transistor comprising at least an active layer, and a gate electrode adjacent to said active layer with a gate insulating film interposed therebetween;

an EL element comprising at least an EL layer between an anode and a cathode, one of said anode and said cathode being electrically connected to said active layer; and

a sensor for obtaining an information signal of an environment,

a CPU for converting said information signal to a corrected signal;

a voltage changer for converting said corrected signal to a corrected potential,

wherein said corrected potential is applied to another one of said anode and said cathode.

24. An active matrix display device according to

claim 23

, wherein said display device, said sensor, said CPU, and said voltage changer are formed over a same substrate.

25. An active matrix display device according to

claim 23

, further comprising an A/D converter interposed between said sensor and said CPU, and a D/A converter interposed between said CPU and said voltage changer.

26. An active matrix display device according to

claim 23

, wherein said sensor comprises a CCD or a photo-diode.

27. An active matrix display device according to

claim 23

, wherein said information signal comprises a user'"'"'s living-body information.

28. An active matrix display device according to

claim 23

, wherein said display device is one selected from the group consisting of a video camera, a digital camera, a head-mount display, a car navigation system, a portable telephone, and a personal computer.

29. An active matrix display device comprising:

at least one pixel thin film transistor over a substrate, said thin film transistor comprising at least an active layer, and a gate electrode adjacent to said active layer with a gate insulating film interposed therebetween;

an EL element comprising at least an EL layer between an anode and a cathode, one of said anode and said cathode being electrically connected to said active layer; and

a sensor for obtaining an information signal of an environment,

wherein a potential of another one of said anode and said cathode is controlled by a corrected potential converted from said information signal.

30. An active matrix display device according to

claim 29

, wherein said display device and said sensor are formed over a same substrate.

31. An active matrix display device according to

claim 29

, wherein said sensor comprises a CCD or a photo-diode.

32. An active matrix display device according to

claim 29

, wherein said information signal comprises a user'"'"'s living-body information.

33. An active matrix display device according to

claim 29

, wherein said display device is one selected from the group consisting of a video camera, a digital camera, a head-mount display, a car navigation system, a portable telephone, and a personal computer.

34. An active matrix display device comprising:

at least one pixel thin film transistor over a substrate, said thin film transistor comprising at least an active layer, and a gate electrode adjacent to said active layer with a gate insulating film interposed therebetween;

an EL element comprising at least an EL layer between an anode and a cathode, one of said anode and said cathode being electrically connected to said active layer; and

a sensor for obtaining an information signal of an environment,

a CPU for converting said information signal to a corrected signal;

a voltage changer for converting said corrected signal to a corrected potential,

wherein a potential of another one of said anode and said cathode is controlled by said corrected potential.

35. An active matrix display device according to

claim 34

, wherein said display device, said sensor, said CPU, and said voltage changer are formed over a same substrate.

36. An active matrix display device according to

claim 34

, further comprising an A/D converter interposed between said sensor and said CPU, and a D/A converter interposed between said CPU and said voltage changer.

37. An active matrix display device according to

claim 34

, wherein said sensor comprises a CCD or a photo-diode.

38. An active matrix display device according to

claim 34

, wherein said information signal comprises a user'"'"'s living-body information.

39. An active matrix display device according to

claim 34

, wherein said display device is one selected from the group consisting of a video camera, a digital camera, a head-mount display, a car navigation system, a portable telephone, and a personal computer.