Display device
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Accused Products
Abstract
The present invention is intended to suppress power consumption of an EL display. In accordance with the brightness of an image to be displayed in a pixel portion, the contrast of the image is determined whether to be inverted or not, and the number of bits of the digital video signal to be input into the pixel portion is reduced, and the magnitude of a current to flow through the EL element is allowed to be maintained at a constant level even when a temperature of an EL layer changes by providing the EL display with another EL element to be used for monitoring a temperature.
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Citations
84 Claims
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1-45. -45. (Canceled)
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46. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line, wherein the display device performs a digital driving, and wherein a brightness change of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element. - View Dependent Claims (47, 48, 49, 50, 51, 52)
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53. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line, wherein the display device performs a digital driving, and wherein a brightness change of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element.
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54. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line, wherein the display device performs a digital driving, and wherein a brightness decrease of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element.
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55. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line, wherein the display device performs a digital driving, and wherein a brightness increase of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element.
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56. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween;
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line; and
a constant current source formed over the substrate, the constant current source electrically connected to the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a brightness change of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element. - View Dependent Claims (57)
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58. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween;
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line; and
a constant current source formed over the substrate, the constant current source electrically connected to the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a brightness change of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element.
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59. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween;
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line; and
a constant current source formed over the substrate, the constant current source electrically connected to the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a brightness decrease of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element.
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60. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween;
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line; and
a constant current source formed over the substrate, the constant current source electrically connected to the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a brightness increase of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element.
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61. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element, wherein the display device performs a digital driving, and wherein a brightness change of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element.
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62. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element, wherein the display device performs a digital driving, and wherein a brightness change of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element.
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63. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element, wherein the display device performs a digital driving, and wherein a brightness decrease of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element.
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64. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element, wherein the display device performs a digital driving, and wherein a brightness increase of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element.
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65. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element through a power source line, wherein the display device performs a digital driving, and wherein a brightness change of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element.
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66. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element through a power source line, wherein the display device performs a digital driving, and wherein a brightness change of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element.
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67. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element through a power source line, wherein the display device performs a digital driving, and wherein a brightness decrease of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element.
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68. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element through a power source line, wherein the display device performs a digital driving, and wherein a brightness increase of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element.
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69. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line, wherein a brightness change of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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70. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line, wherein a brightness change of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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71. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line, wherein a brightness decrease of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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72. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line, wherein a brightness increase of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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73. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween;
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line; and
a constant current source formed over the substrate, the constant current source electrically connected to the monitoring light emitting element, wherein a brightness change of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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74. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween;
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line; and
a constant current source formed over the substrate, the constant current source electrically connected to the monitoring light emitting element, wherein a brightness change of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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75. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween;
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line; and
a constant current source formed over the substrate, the constant current source electrically connected to the monitoring light emitting element, wherein a brightness decrease of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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76. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween;
a monitoring light emitting element formed over the substrate, the monitoring light emitting element electrically connected to the at least one light emitting element through a power source line; and
a constant current source formed over the substrate, the constant current source electrically connected to the monitoring light emitting element, wherein a brightness increase of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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77. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element, wherein a brightness change of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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78. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element, wherein a brightness change of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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79. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element, wherein a brightness decrease of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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80. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element, wherein a brightness increase of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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81. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element through a power source line, wherein a brightness change of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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82. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element through a power source line, wherein a brightness change of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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83. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element through a power source line, wherein a brightness decrease of the at least one light emitting element caused by a deterioration of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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84. A display device comprising:
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a pixel portion formed over a substrate, the pixel portion having at least one light emitting element, wherein the at least one light emitting element comprises a first electrode and a second electrode with a light emitting material interposed therebetween; and
a buffer amplifier, a monitoring light emitting element, and a constant current source, each formed over the substrate, wherein the monitoring light emitting element and the constant current source are electrically connected to an input of the buffer amplifier, wherein an output of the buffer amplifier is electrically connected to the at least one light emitting element through a power source line, wherein a brightness increase of the at least one light emitting element caused by a temperature change of the light emitting material is suppressed by using the monitoring light emitting element, wherein the display device performs a digital driving, and wherein a current flowing into the monitoring light emitting element is equal to a current flowing into the at least one light emitting element.
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Specification