Semiconductor display device

• US 6,828,951 B2
• Filed: 07/16/2002
• Issued: 12/07/2004
• Est. Priority Date: 01/11/2000
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Koyama, Jun, Yamazaki, Shunpei
• Primary Examiner(s): Nelms, David
• Assistant Examiner(s): HO, TU TU V
• Application Number:
  US10/195,521
• Publication Number:
  US 20020180672A1
• Time in Patent Office: 875 Days
• Field of Search: 345/77, 345/76, 315/169.1, 349/69
• 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 digital image display device, comprising:

a) a substrate;

b) a light emitting display formed on the substrate, the display having an array of light emitting pixels;

c) a representative light emitting pixel formed adjacent to the array of light emitting pixels;

d) a photosensor and a transistor located in the representative light emitting pixel, with the photosensor being connected to a gate of the transistor; and

e) a correction circuit connected to the transistor.

3. The device claimed in claim 1, wherein the light emitting pixels of the display and the representative light emitting pixel are OLEDs.

4. The device claimed in claim 1, wherein the feedback control circuit is integrated on the substrate.

9. The device claimed in claim 1, wherein the photosensor comprises a photodiode.

10. The device claimed in claim 1, wherein the photosensor comprises a TFT.

11. The device claimed in claim 1, wherein the correction circuit is responsive to signals produced by the photosensor to operate the light emitting display so as to enhance the luminance of the light emitting pixels.

12. An electronic device having the digital image display device claimed in claim 1, wherein the electronic device is 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.

2. A digital image display device, comprising:

a) a substrate;

b) a light emitting display formed on the substrate, the display having an array of light emitting pixels;

c) a representative light emitting pixel formed adjacent to the array of light emitting pixels;

d) a photosensor and a transistor located on the display device, with the photosensor being optically coupled to the representative light emitting pixel and being adjacent to the transistor and connected to a gate of the transistor to produce a feedback signal;

; and

e) a correction circuit connected to the transistor.

5. The device claimed in claim 2, wherein the light emitting pixels of the display and the representative light emitting pixel are OLEDs.

6. The device claimed in claim 2, wherein the feedback control circuit is integrated on the substrate.

13. The device claimed in claim 2, wherein the photosensor comprises a photodiode.

14. The device claimed in claim 2, wherein the photosensor comprises a TFT.

15. The device claimed in claim 2, wherein the correction circuit is responsive to signals produced by the photosensor to operate the light emitting display so as to enhance the luminance of the light emitting pixels.

16. An electronic device having the digital image display device claimed in claim 2, wherein the electronic device is 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 digital image display device, comprising:

a) a substrate;

b) a display portion having an array of light emitting pixels and formed on the substrate;

c) a sensor portion having at least one light emitting pixel and formed adjacent to the display portion;

d) a photosensor and a transistor formed in the light emitting pixel of the sensor portion, with the photosensor being connected to a gate of the transistor; and

e) a correction circuit formed over substrate and connected to the transistor.

8. The device claimed in claim 7, wherein the correction circuit is integrated on the substrate.

17. The device claimed in claim 7, wherein the photosensor comprises a photodiode.

18. The device claimed in claim 7, wherein the photosensor comprises a TFT.

19. The device claimed in claim 7, wherein the correction circuit is responsive to signals produced by the photosensor to operate the display portion so as to enhance the luminance of the light emitting pixels.

20. An electronic device having the digital image display device claimed in claim 7, wherein the electronic device is 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.