Display system and electrical appliance

• US 8,253,662 B2
• Filed: 11/16/2009
• Issued: 08/28/2012
• Est. Priority Date: 01/17/2000
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Koyama, Jun, Shibata, Noriko
• Primary Examiner(s): Kumar, Srilakshmi K
• Application Number:
  US12/618,926
• Publication Number:
  US 20100060620A1
• Time in Patent Office: 1,016 Days
• Field of Search: 257/763, 345 30-111, 315/169.3, 340FOR 281-FOR 282
• 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 2300/0842 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. An electrical appliance comprising:

an EL (electro-luminescent) element having a first electrode and a second electrode;

a sensor for obtaining an information signal of an environment;

a CPU (central processing unit) for converting said information signal of the environment supplied from said sensor into a correction signal;

an EL driving power source; and

a voltage changer connected to receive the correction signal and an output of the EL driving power source, and configured to produce an output potential that varies based on the correction signal,

wherein the output potential of the voltage changer is electrically connected to the second electrode of the EL element via a switch,

wherein the first electrode of the EL element is electrically connected to a power supply line.

2. An electrical appliance according to claim 1, wherein said information signal comprises a user'"'"'s living-body information.

3. An electrical appliance according to claim 1, wherein said EL (electro-luminescent) element, said sensor, said CPU and said voltage changer are formed on a same substrate.

4. An electrical appliance according to claim 1, wherein said EL (electro-luminescent) element comprises an organic material or an inorganic material.

5. An electrical appliance according to claim 1, wherein said electrical appliance 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, an image reproduction apparatus, a car audio equipment, and a personal computer.

6. An electrical appliance according to claim 1, wherein the sensor comprises a CCD (charge-coupled device) or a photo-diode.

7. An electrical appliance comprising:

at least an EL (electro-luminescent) element having two electrodes with an EL layer interposed therebetween;

an EL driving power source; and

a voltage changer connected to receive an information signal of an environment and an output of the EL driving power source, and to produce an output potential electrically connected to the other of said two electrodes of said EL element via a switch, wherein the voltage changer is configured to vary the output potential based on the information signal.

8. An electrical appliance according to claim 7, wherein said information signal comprises a user'"'"'s living-body information.

9. An electrical appliance according to claim 7, wherein said electrical appliance 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, an image reproduction apparatus, a car audio equipment, and a personal computer.

10. An electrical appliance according to claim 7, wherein the EL (electro-luminescent) element comprises an organic material or an inorganic material.

11. An electrical appliance comprising:

a sensor for obtaining an information signal of an environment;

a voltage changer connected to receive an output of an EL driving power source and a corrected potential generated by converting the information signal, and to generate an output potential that varies based on the corrected potential; and

an EL (electro-luminescent) 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 a power supply line,

wherein the output potential of the voltage changer is electrically connected to the other of the anode and the cathode of said EL element via a switch.

12. An electrical appliance according to claim 11, wherein said EL (electro-luminescent) element and said sensor are formed over a same substrate.

13. An electrical appliance according to claim 11, wherein said sensor comprises a CCD (charge-coupled device) or a photo-diode.

14. An electrical appliance according to claim 11, wherein said information signal comprises a user'"'"'s living-body information.

15. An electrical appliance according to claim 11, wherein said electrical appliance is incorporated in at least one selected from the group consisting of a video camera, a digital camera, a head-mount display, a car navigation system, a portable telephone, an image reproduction apparatus, a car audio equipment, and a personal computer.

16. An electrical appliance according to claim 11, wherein the EL (electro-luminescent) element comprises an organic material or an inorganic material.

17. An electrical appliance comprising:

a sensor for obtaining an information signal of an environment;

a voltage changer connected to receive the information signal and an output of an EL driving power source, and to generate an output potential that varies based on the information signal; and

an EL (electro-luminescent) element comprising at least an EL layer between an anode and a cathode, one of said anode and said cathode being electrically connected to a power supply line,

wherein the output potential of the voltage changer is electrically connected to the other of the anode and the cathode of said EL element via a switch.

18. An electrical appliance according to claim 17, wherein said EL (electro-luminescent) element and said sensor are formed over a same substrate.

19. An electrical appliance according to claim 17, wherein said sensor comprises a CCD (charge-coupled device) or a photo-diode.

20. An electrical appliance according to claim 17, wherein said information signal comprises a user'"'"'s living-body information.

21. An electrical appliance according to claim 17, wherein said electrical appliance is incorporated in at least one selected from the group consisting of a video camera, a digital camera, a head-mount display, a car navigation system, a portable telephone, an image reproduction apparatus, a car audio equipment, and a personal computer.

22. An electrical appliance according to claim 17, wherein the EL (electro-luminescent) element comprises an organic material or an inorganic material.

23. An electrical appliance comprising:

a sensor for obtaining an information signal of an environment;

a CPU (central processing unit) for converting said information signal to a corrected signal;

a voltage changer connected to receive the corrected signal and an output of an EL driving power source, and configured to produce an output potential that varies based on the corrected signal; and

an EL (electro-luminescent) element comprising at least an EL layer between an anode and a cathode, one of said anode and said cathode being electrically connected to a power supply line,

wherein the output potential of the voltage changer is electrically connected to the other of the anode and the cathode of said EL element via a switch.

24. An electrical appliance according to claim 23, wherein said EL (electro-luminescent) element, said sensor, said CPU, and said voltage changer are formed over a same substrate.

25. An electrical appliance according to claim 23, further comprising an A/D (analog-to-digital) converter interposed between said sensor and said CPU, and a D/A (digital-to-analog) converter interposed between said CPU and said voltage changer.

26. An electrical appliance according to claim 23, wherein said sensor comprises a CCD (charge-coupled device) or a photo-diode.

27. An electrical appliance according to claim 23, wherein said information signal comprises a user'"'"'s living-body information.

28. An electrical appliance according to claim 23, wherein said electrical appliance is incorporated in at least one selected from the group consisting of a video camera, a digital camera, a head-mount display, a car navigation system, a portable telephone, an image reproduction apparatus, a car audio equipment, and a personal computer.

29. An electrical appliance according to claim 23, wherein the EL (electro-luminescent) element comprises an organic material or an inorganic material.