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US 7,804,244 B2Granted
Display device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsTetsuji Ishitani, Yuji Egi, Takeshi Nishi
Life of this patent
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Abstract
It is an object to provide a display device having an electroluminescent element in which a contrast ratio is increased. In a display device having an electroluminescent element between a pair of light transmitting substrates, a circularly polarizing plate having stacked polarizing plates arranged on outer sides thereof is provided. At this time, opposed polarizing plates are arranged to be in a crossed nicol state or in a parallel nicol state. As a result, a display device with a high contrast ratio can be provided.
Claims21
A display device comprising:
- a first light transmitting substrate;
- a second light transmitting substrate opposed to the first light transmitting substrate;
- a light emitting element provided between the first light transmitting substrate and the second light transmitting substrate;
- a first circularly polarizing plate having stacked first linearly polarizing plates arranged on an outer side of the first light transmitting substrate;
- and
- a second circularly polarizing plate having stacked second linearly polarizing plates arranged on an outer side of the second light transmitting substrate,
- wherein the light emitting element emits light in both directions of the first light transmitting substrate and the second light transmitting substrate, and
- wherein each of the stacked first linearly polarizing plates and each of the stacked second linearly polarizing plates comprises an adhesive surface and a mixed layer of polyvinyl alcohol and iodine.
5 more elements
A display device comprising:
- a first light transmitting substrate;
- a second light transmitting substrate opposed to the first light transmitting substrate;
- a light emitting element provided between the first light transmitting substrate and the second light transmitting substrate;
- a first circularly polarizing plate having stacked first linearly polarizing plates arranged on an outer side of the first light transmitting substrate;
- and
- a second circularly polarizing plate having stacked second linearly polarizing plates arranged on an outer side of the second light transmitting substrate,
- wherein the light emitting element emits light in both directions of the first light transmitting substrate and the second light transmitting substrate,
- wherein transmission axes of the stacked first linearly polarizing plates are arranged to be in a parallel nicol state, transmission axes of the stacked second linearly polarizing plates are arranged to be in a parallel nicol state,
- wherein the transmission axes of the stacked first linearly polarizing plates and the transmission axes of the stacked second linearly polarizing plates are arranged to be in a parallel nicol state, and
- wherein each of the stacked first linearly polarizing plates and each of the stacked second linearly polarizing plates comprises an adhesive surface and a mixed layer of polyvinyl alcohol and iodine.
7 more elements
A display device comprising:
- a first light transmitting substrate;
- a second light transmitting substrate opposed to the first light transmitting substrate;
- a light emitting element provided between the first light transmitting substrate and the second light transmitting substrate;
- stacked first linearly polarizing plates arranged on an outer side of the first light transmitting substrate;
- stacked second linearly polarizing plates arranged on an outer side of the second light transmitting substrate;
- a first retardation film provided between the first light transmitting substrate and the stacked first linearly polarizing plates;
- and
- a second retardation film provided between the second light transmitting substrate and the stacked second linearly polarizing plates,
- wherein the light emitting element emits light in both directions of the first light transmitting substrate and the second light transmitting substrate,
- wherein transmission axes of the stacked first linearly polarizing plates are arranged to be in a parallel nicol state, transmission axes of the stacked second linearly polarizing plates are arranged to be in a parallel nicol state,
- wherein the transmission axes of the stacked first linearly polarizing plates and the transmission axes of the stacked second linearly polarizing plates are arranged to be in a parallel nicol state,
- wherein a slow axis of the first retardation film is arranged to be at 45° with respect to the transmission axes of the stacked first linearly polarizing plates, and a slow axis of the second retardation film is arranged to be at 45° with respect to the transmission axes of the stacked second linearly polarizing plates, and
- wherein each of the stacked first linearly polarizing plates and each of the stacked second linearly polarizing plates comprises an adhesive surface and a mixed layer of polyvinyl alcohol and iodine.
10 more elements
A display device comprising:
- a first light transmitting substrate;
- a second light transmitting substrate opposed to the first light transmitting substrate;
- a light emitting element provided between the first light transmitting substrate and the second light transmitting substrate;
- stacked first linearly polarizing plates arranged on an outer side of the first light transmitting substrate;
- a second linearly polarizing plate arranged on an outer side of the second light transmitting substrate;
- a first retardation film provided between the first light transmitting substrate and the stacked first linearly polarizing plates;
- and
- a second retardation film provided between the second light transmitting substrate and the second linearly polarizing plate,
- wherein the light emitting element emits light in both directions of the first light transmitting substrate and the second light transmitting substrate,
- wherein transmission axes of the stacked first linearly polarizing plates are arranged to be in a parallel nicol state,
- wherein the transmission axes of the stacked first linearly polarizing plates and a transmission axis of the second linearly polarizing plate are arranged to be in a parallel nicol state,
- wherein a slow axis of the first retardation film is arranged to be at 45° with respect to the transmission axis of the stacked first linearly polarizing plates, and a slow axis of the second retardation film is arranged to be at 45° with respect to the transmission axis of the second linearly polarizing plate, and
- wherein each of the stacked first linearly polarizing plates and the stacked second linearly polarizing plate comprises an adhesive surface and a mixed layer of polyvinyl alcohol and iodine.
10 more elements
A display device comprising:
- a first light transmitting substrate;
- a second light transmitting substrate opposed to the first light transmitting substrate;
- a light emitting element provided between the first light transmitting substrate and the second light transmitting substrate;
- a first circularly polarizing plate having stacked first linearly polarizing plates arranged on an outer side of the first light transmitting substrate;
- and
- a second circularly polarizing plate having stacked second linearly polarizing plates arranged on an outer side of the second light transmitting substrate,
- wherein the light emitting element emits light in both directions of the first light transmitting substrate and the second light transmitting substrate,
- wherein transmission axes of the stacked first linearly polarizing plates are arranged to be in a parallel nicol state, transmission axes of the stacked second linearly polarizing plates are arranged to be in a parallel nicol state,
- wherein the transmission axes of the stacked first linearly polarizing plates and the transmission axes of the stacked second linearly polarizing plates are arranged to be in a crossed nicol state, and
- wherein each of the stacked first linearly polarizing plates and each of the stacked second linearly polarizing plates comprises an adhesive surface and a mixed layer of polyvinyl alcohol and iodine.
7 more elements
A display device comprising:
- a first light transmitting substrate;
- a second light transmitting substrate;
- a light emitting element provided between the first light transmitting substrate and the second light transmitting substrate;
- stacked first linearly polarizing plates arranged on an outer side of the first light transmitting substrate;
- stacked second linearly polarizing plates arranged on an outer side of the second light transmitting substrate;
- a first retardation film provided between the first light transmitting substrate and the stacked first linearly polarizing plates;
- and
- a second retardation film provided between the second light transmitting substrate and the stacked second linearly polarizing plates,
- wherein the light emitting element emits light in both directions of the first light transmitting substrate and the second light transmitting substrate,
- wherein transmission axes of the stacked first linearly polarizing plates are arranged to be in a parallel nicol state, transmission axes of the stacked second linearly polarizing plates are arranged to be in a parallel nicol state,
- wherein the transmission axes of the stacked first linearly polarizing plates and the transmission axes of the stacked second linearly polarizing plates are arranged to be in a crossed nicol state,
- wherein a slow axis of the first retardation film is arranged to be at 45° with respect to the transmission axes of the stacked first linearly polarizing plates, and a slow axis of the second retardation film is arranged to be at 45° with respect to the transmission axes of the stacked second linearly polarizing plates, and
- wherein each of the stacked first linearly polarizing plates and each of the stacked second linearly polarizing plates comprises an adhesive surface and a mixed layer of polyvinyl alcohol and iodine.
10 more elements
A display device comprising:
- a first light transmitting substrate;
- a second light transmitting substrate opposed to the first light transmitting substrate;
- a light emitting element provided between the first light transmitting substrate and the second light transmitting substrate;
- stacked first linearly polarizing plates arranged on an outer side of the first light transmitting substrate;
- a second linearly polarizing plate arranged on an outer side of the second light transmitting substrate;
- a first retardation film provided between the first light transmitting substrate and the stacked first linearly polarizing plates;
- and
- a second retardation film provided between the second light transmitting substrate and the second linearly polarizing plate,
- wherein the light emitting element emits light in both directions of the first light transmitting substrate and the second light transmitting substrate,
- wherein transmission axes of the stacked first linearly polarizing plates are arranged to be in a parallel nicol state, the transmission axes of the stacked first linearly polarizing plates and a transmission axis of the second linearly polarizing plate are arranged to be in a crossed nicol state,
- wherein a slow axis of the first retardation film is arranged to be at 45° with respect to the transmission axis of the stacked first linearly polarizing plates, and a slow axis of the second retardation film is arranged to be at 45° with respect to the transmission axis of the second linearly polarizing plate, and
- wherein each of the stacked first linearly polarizing plates and the second linearly polarizing plate comprises an adhesive surface and a mixed layer of polyvinyl alcohol and iodine.
9 more elements
Dependencies are inferred from the claim text.