Display system and electrical appliance

• US 8,743,028 B2
• Filed: 08/17/2012
• Issued: 06/03/2014
• Est. Priority Date: 01/17/2000
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Koyama, Jun, Shibata, Noriko
• Primary Examiner(s): FARAGALLA, MICHAEL A
• Application Number:
  US13/587,968
• Publication Number:
  US 20120306832A1
• Time in Patent Office: 655 Days
• Field of Search: 345/76, 345/77, 345/74.1, 345/82, 345/207, 345/690, 345/173, 345/178
• 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:

a light-emitting device, the light-emitting device comprising;

a first insulating film over a substrate;

a transistor over the first insulating film, the transistor comprising;

a source region and a drain region over the first insulating film;

a channel forming region between the source region and the drain region; and

a drain wiring over the drain region,

a second insulating film over the transistor, the second insulating film having a contact hole over the drain wiring;

an EL element over the second insulating film, the EL element comprising;

a first electrode over the second insulating film;

an EL layer over the first electrode; and

a second electrode over the EL layer, and

a film over the EL element,

a sensor obtaining an information signal of an environment; and

a CPU controlling a luminance of the EL element based on the information signal,

wherein the first electrode is in contact with the drain wiring through the contact hole.

2. The electrical appliance according to claim 1, wherein the first insulating film is any of a silicon oxide film, silicon nitride film, and silicon oxynitride film.

3. The electrical appliance according to claim 1, wherein the sensor is any of a photo diode, a cadmium sulfide photoconductive cell, a charge-coupled device, and a CMOS sensor.

4. The electrical appliance according to claim 1, wherein the drain wiring and the contact hole are overlapped with the drain region.

5. The electrical appliance according to claim 1, wherein the film is a silicon nitride film.

6. The electrical appliance according to claim 1, wherein the sensor and the CPU are formed over the substrate.

7. The electrical appliance according to claim 1, wherein the second electrode is an MgAg electrode.

8. The electrical appliance according to claim 1, further comprising an EL driving power source and a voltage changer,

wherein the CPU converts the information signal into a correction signal,

wherein the voltage changer receives the correction signal and an output of the EL driving power source,

wherein the voltage changer is configured to produce an output potential that varies based on the correction signal,

wherein the output potential of the voltage changer is applied to the second electrode via a switch, and

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

9. The electrical appliance according to claim 1, wherein the 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 comprising:

a light-emitting device, the light-emitting device comprising;

a first insulating film over a substrate;

a transistor over the first insulating film, the transistor comprising;

a source region and a drain region over the first insulating film;

a channel forming region between the source region and the drain region; and

a drain wiring over the drain region,

a second insulating film over the transistor;

an interlayer insulating film over the second insulating film, the second insulating film and the interlayer insulating film have a contact hole;

an EL element over the interlayer insulating film, the EL element comprising;

a first electrode over the interlayer insulating film;

an EL layer over the first electrode; and

a second electrode over the EL layer, and

a contact hole protective portion between the first electrode and the EL layer,

a sensor obtaining an information signal of an environment; and

a CPU controlling a luminance of the EL element based on the information signal,

wherein the first electrode is in contact with the drain wiring through the contact hole, and

wherein the contact hole protective portion fills the contact hole.

11. The electrical appliance according to claim 10, wherein the first insulating film is any of a silicon oxide film, silicon nitride film, and silicon oxynitride film.

12. The electrical appliance according to claim 10, wherein the sensor is any of a photo diode, a cadmium sulfide photoconductive cell, a charge-coupled device, and a CMOS sensor.

13. The electrical appliance according to claim 10, wherein the sensor and the CPU are formed over the substrate.

14. The electrical appliance according to claim 10, wherein the second electrode is an MgAg electrode.

15. The electrical appliance according to claim 10, wherein the interlayer insulating film comprises any of polyimide, polyamide, and acrylic.

16. The electrical appliance according to claim 10, wherein the contact hole protective portion comprises any of polyimide, polyamide, and acrylic.

17. The electrical appliance according to claim 10, further comprising an EL driving power source and a voltage changer,

wherein the CPU converts the information signal into a correction signal,

wherein the voltage changer receives the correction signal and an output of the EL driving power source,

wherein the voltage changer is configured to produce an output potential that varies based on the correction signal,

wherein the output potential of the voltage changer is applied to the second electrode via a switch, and

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

18. The electrical appliance according to claim 10, wherein the 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.