Light emitting module and method of driving the same, and optical sensor

• US 20060132401A1
• Filed: 12/27/2005
• Published: 06/22/2006
• Est. Priority Date: 06/12/2000
• 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 7,515,125 B2
• Time in Patent Office: Days
• US Class Current: 345/81
• CPC Class Codes: G01J 1/4204 with determination of ambient light solar light G01J2001/4266
• CPC Class Codes: G01J 1/44 Electric circuits for command of an exposure part G03B7/02
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0852 being a dynamic memory with more than one capacitor
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• 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 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 3/3275 Details of drivers for data electrodes
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• 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 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/1288 employing particular masking sequences or specially adapted masks, e.g. half-tone mask
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H10K 50/86 : Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/13 : comprising photosensors that control luminance
• CPC Class Codes: H10K 59/8791 : Arrangements for improving contrast, e.g. preventing reflection of ambient light

Abstract

The object of the present invention is to provide a light emitting module which is excellent in visibility and can reduce power consumption.

The light emitting module includes a light emitting device containing at least a pixel section 101 and a sensor section 104, which are formed on the same insulating body, and further includes means for sensing illuminance of a use environment with the sensor section 104 and for adjusting luminance of a light emitting element according to the illuminance to keep a ratio of the luminance to the illuminance of the use environment at a constant value.

Claims

1-46. -46. (canceled)

47. An electronic device comprising:

a light emitting module comprising;

a pixel section comprising a current control TFT and a light emitting element over and electrically connected to the current control TFT; and

a sensor section comprising a reset TFT and a photodiode over and electrically connected to the reset TFT;

a correction circuit and a driver circuit mounted in a printed wiring board, electrically connected to the pixel section and the sensor section through wirings;

wherein the correction circuit adjusts luminance of the light emitting element according to environmental illuminance sensed by the sensor section and for keeping a ratio of the luminance to the environmental illuminance at a constant value by the correction circuit,

wherein the sensor section is disposed outside the pixel section.

48. An electronic device according to claim 47, wherein the sensor section includes a thin film photodiode.

53. An electronic device according to claim 47, wherein the correction circuit comprises an arithmetic circuit for calculating the luminance of the light emitting element based on a signal transmitted from the sensor section.

57. An electronic device according to claim 48, wherein the light emitting element and the thin film diode are electrically connected to a transistor.

61. An electronic device according to claim 57, wherein the transistor is a bottom gate type thin film transistor.

65. An electronic device according to claim 47, wherein the light emitting element is an EL element.

69. An electronic device according to claim 47, wherein the electronic device is a device selected from the group consisting of a portable telephone, a video camera, a digital camera, a computer, and a portable telephone.

73. An electronic device according to claim 47, wherein said sensor section comprises at least one optical sensor comprising a photodiode, a first reset TFT, a buffer TFT, a load capacitance, and a second reset TFT.

77. An electronic device according to claim 47, wherein said sensor section comprises at least one optical sensor comprising a photodiode, a reset TFT, a buffer TFT, and a load resistance or a load capacitance.

49. An electronic device comprising:

a light emitting module comprising;

a pixel section comprising a current control TFT and a thin film light emitting element over and electrically connected to the current control TFT;

a sensor section sensing environmental illuminance, comprising a reset TFT and a thin film photodiode over and electrically connected to the reset TFT,

a correction circuit and a driver circuit mounted on a printed wiring board, electrically connected to the pixel section and the sensor section through wirings;

wherein the sensor section is disposed outside said pixel section.

54. An electronic device according to claim 49, wherein the correction circuit comprises an arithmetic circuit for calculating the luminance of the light emitting element based on a signal transmitted from the sensor section.

58. An electronic device according to claim 49, wherein the light emitting element and the thin film photodiode are electrically connected to a transistor.

62. An electronic device according to claim 58, wherein the transistor is a bottom gate type thin film transistor.

66. An electronic device according to claim 49, wherein the light emitting element is an EL element.

70. An electronic device according to claim 49, wherein the electronic device is a device selected from the group consisting of a portable telephone, a video camera, a digital camera, a computer, and a portable telephone.

74. An electronic device according to claim 49, wherein said sensor section comprises at least one optical sensor comprising a photodiode, a first reset TFT, a buffer TFT, a load capacitance, and a second reset TFT.

78. An electronic device according to claim 49, wherein said sensor section comprises at least one optical sensor comprising a photodiode, a reset TFT, a buffer TFT, and a load resistance or a load capacitance.

50. An electronic device comprising:

a light emitting module comprising;

a pixel section comprising a current control TFT and a light emitting element over and electrically connected to the current control TFT;

a driver circuit comprising a CMOS circuit comprising an n-channel type TFT and a p-channel type TFT;

a sensor section comprising a reset TFT and a photodiode over and electrically connected to the reset TFT;

a control section comprising a correction circuit, and a memory section mounted in a printed wiring board, electrically connected to the pixel section, the driver circuit and the sensor section through wirings;

wherein the correction circuit adjusts luminance of the light emitting element according to environmental illuminance sensed by the sensor section and for keeping a ratio of the luminance to the environmental illuminance at a constant value by the correction circuit,

wherein the sensor section is disposed outside the pixel section.

51. An electronic device according to claim 50, wherein the sensor section includes a thin film photodiode.

55. An electronic device according to claim 50, wherein the correction circuit comprises an arithmetic circuit for calculating the luminance of the light emitting element based on a signal transmitted from the sensor section.

59. An electronic device according to claim 50, wherein the light emitting element and the thin film photodiode are electrically connected to a transistor.

63. An electronic device according to claim 59, wherein the transistor is a bottom gate type thin film transistor.

67. An electronic device according to claim 50, wherein the light emitting element is an EL element.

71. An electronic device according to claim 50, wherein the electronic device is a device selected from the group consisting of a portable telephone, a video camera, a digital camera, a computer, and a portable telephone.

75. An electronic device according to claim 50, wherein said sensor section comprises at least one optical sensor comprising a photodiode, a first reset TFT, a buffer TFT, a load capacitance, and a second reset TFT.

79. An electronic device according to claim 50, wherein said sensor section comprises at least one optical sensor comprising a photodiode, a reset TFT, a buffer TFT, and a load resistance or a load capacitance.

52. An electronic device comprising:

a light emitting module comprising;

a pixel section comprising a current control TFT and a thin film light emitting element over and electrically connected to the current control TFT;

a driver circuit comprising a CMOS circuit comprising an n-channel type TFT and a p-channel type TFT;

a sensor section sensing environmental illuminance, comprising a reset TFT and a thin film photodiode over and electrically connected to the reset TFT,

a control section comprising a correction circuit, and a memory section mounted on a printed wiring board, electrically connected to the pixel section, the driver circuit and the sensor section through wirings;

wherein the sensor section is disposed outside said pixel section.

56. An electronic device according to claim 52, wherein the correction circuit comprises an arithmetic circuit for calculating the luminance of the light emitting element based on a signal transmitted from the sensor section.

60. An electronic device according to claim 52, wherein the light emitting element and the thin film photodiode are electrically connected to a transistor.

64. An electronic device according to claim 60, wherein the transistor is a bottom gate type thin film transistor.

68. An electronic device according to claim 52, wherein the light emitting element is an EL element.

72. An electronic device according to claim 52, wherein the electronic device is a device selected from the group consisting of a portable telephone, a video camera, a digital camera, a computer, and a portable telephone.

76. An electronic device according to claim 52, wherein said sensor section comprises at least one optical sensor comprising a photodiode, a first reset TFT, a buffer TFT, a load capacitance, and a second reset TFT.

80. An electronic device according to claim 52, wherein said sensor section comprises at least one optical sensor comprising a photodiode, a reset TFT, a buffer TFT, and a load resistance or a load capacitance.