# US 7,608,992 B2 · Device for displaying images on its front and back surfaces > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,992 B2 - Document ID: US7608992B2 - Status: Granted - Kind: B2 - Application number: 10/526,007 - Filed: 2003-08-27 - Published: 2006-06-29 - Granted: 2009-10-27 - Earliest claimed: 2002-08-28 - Assignees: Kabushiki Kaisha Toshiba - Inventors: Michiya Kobayashi - Web page: https://patentgrep.com/patent/US7608992B2 ## CPC - H10K 59/128: comprising two independent displays, e.g. for emitting information from two major sides of the display - H05B 33/26: characterised by the composition or arrangement of the conductive material used as an electrode - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL ## Abstract An organic electro-luminescence display device includes first pixels formed aver an optically transparent substrate, each of the first pixels including a first organic electro-luminescence element, which includes a first optically transparent and electrically conductive layer, an organic layer including a light-emitting layer, a second optically transparent and electrically conductive layer and a first optically reflective and electrically conductive layer in order, and second pixels formed over the optically transparent substrate, each of the second pixels including a second organic electro-luminescence element which includes a second optically reflective and electrically conductive layer, the first optically transparent and electrically conductive layer, the organic layer including the light-emitting layer and the second optically transparent and electrically conductive layer in order. Accordingly, the first organic electro-luminescence element and the second organic electro-luminescence element commonly share same layers, thus minimizing the thickness of the device. ## Claims ### Claim 1 An organic electro-luminescence display device comprising: an optically transparent substrate; first pixels formed over the optically transparent substrate, each of the first pixels including a first organic electro-luminescence element which includes a first optically transparent and electrically conductive layer, an organic layer including a light-emitting layer, a second optically transparent and electrically conductive layer, and a first optically reflective and electrically conductive layer in order, the organic layer configured to transform electric energy applied between the first optically transparent and electrically conductive layer and the second optically transparent and electrically conductive layer into light, the first optically reflective and electrically conductive layer configured to reflect light, and the first pixel configured to emit light towards a first surface of the organic electro-luminescence display device; and second pixels formed over the optically transparent substrate, each of the second pixels including a second organic electro-luminescence element which includes a second optically reflective and electrically conductive layer, the first optically transparent and electrically conductive layer, the organic layer including the light-emitting layer, and the second optically transparent and electrically conductive layer in order, the second optically reflective and electrically conductive layer configured to reflect light, and the second pixel configured to emit light towards a second surface of the organic electro-luminescence display device, the second surface being opposite to the first surface. ### Claim 2 (depends on 1) The organic electro-luminescence display device according to claim 1, further comprising: a first selection switch and a first control element disposed in the first pixel, the first selection switch selecting the first pixel, and the first control element controlling electrical current supplied to the first organic electro-luminescence element; and a second selection switch and a second control element disposed in the second pixel, the second selection switch selecting the second pixel, and the second control element controlling electrical current supplied to the second organic electro-luminescence element. ### Claim 3 (depends on 2) The organic electro-luminescence display device according to claim 2, wherein each of the first selection switch, the first control element, the second selection switch and the second control element is constituted with a thin film transistor. ### Claim 4 (depends on 2) The organic electro-luminescence display device according to claim 2, further comprising: an undercoat layer formed on the optically transparent substrate, the first selection switch, the first control element, the second selection switch and the second control element being formed on the undercoat layer; a passivation layer covering the first selection switch, the first control element, the second selection switch and the second control element, and the first organic electro-luminescence element and the second organic electro-luminescence element being on the passivation layer; and a partition insulation later formed on the passivation layer, the partition insulation later isolating between the first organic electro-luminescence element and the second organic electro-luminescence element. ### Claim 5 (depends on 4) The organic electro-luminescence display device according to claim 4, wherein the undercoat layer is laminated with silicon nitride and silicon oxide in order. ### Claim 6 (depends on 4) The organic electro-luminescence display device according to claim 4, wherein the partition insulation later is laminated with a hydrophilic layer and a water repellent layer in order. ### Claim 7 (depends on 1) The organic electro-luminescence display device according to claim 1, wherein a hole injection layer is included in the organic layer and is formed between the light-emitting layer and the first optically transparent and electrically conductive layer. ### Claim 8 (depends on 7) The organic electro-luminescence display device according to claim 7, wherein a composition containing donor and acceptor constitutes the hole injection layer. ### Claim 9 (depends on 8) The organic electro-luminescence display device according to claim 8, wherein the composition containing donor and acceptor contains at least one of a polythiophene derivative such as polyethylene dioxithiophone, a polyaniline derivative such as polyaniline or a polystyrene sulfonic acid. ### Claim 10 (depends on 1) The organic electro-luminescence display device according to claim 1, wherein the light-emitting layer is constituted with at least one of a polymer compound having an alkyl or alkoxy substituent in a benzene ring of a polyvinylene styrene derivative, a polymer compound having vinylene or cyano group of a polyvinylene styrene derivative a polyvinylene styrene derivative introducing an alkyl, alkoxy or allylic derivative substituent into its benzene ring or a polyfluorene derivative such as a copolymer of dialkylfluorene and althracen. ### Claim 11 (depends on 1) Electronic equipment comprising: an organic electro-luminescence display device as set forth in claim 1; and an input manipulator to input signals to the organic electro-luminescence display device, wherein the organic electro-luminescence display device displays images in response to the input. ### Claim 12 An organic electro-luminescence display device comprising: an optically transparent substrate; first pixels formed over the optically transparent substrate, the first pixels being disposed in a first direction, each of the first pixels including a first organic electro- luminescence element, a first selection switch, and a first control element, the first selection switch selecting the first pixel, the first control element controlling electrical current supplied to the first organic electro-luminescence element; second pixels formed over the optically transparent substrate, the second pixels being disposed in the first direction, each of the second pixels including a second organic electro-luminescence element, a second selection switch and a second control element, the second selection switch selecting the second pixel, the second control element controlling electrical current supplied to the second organic electro-luminescence element; and electrode lines disposed in the first line, each of the electrode line being interposed between the first control element and the second control element, the electrode line being commonly connected to the first organic electro-luminescence element via the first control element and the second organic electro-luminescence element via the second control element; wherein the first organic electro-luminescence element includes a first optically transparent and electrically conductive layer, an organic layer including a light-emitting layer, a second optically transparent and electrically conductive layer and a first optically reflective and electrically conductive layer in order, the organic layer configured to transform electric energy applied between the first optically transparent and electrically conductive layer and the second optically transparent and electrically conductive layer into light, the first optically reflective and electrically conductive layer configured to reflect light, and the first pixel configured to emit light towards a first surface of the organic electro-luminescence display device, the second organic electro-luminescence element is laminated with a second optically reflective and electrically conductive layer, the first optically transparent and electrically conductive layer, the organic layer including the light-emitting layer and the second optically transparent and electrically conductive layer in order, and the second optically reflective and electrically conductive layer configured to reflect light, and the second pixel configured to emit light towards a second surface of the organic electro-luminescence display device, the second surface being opposite to the first surface. ### Claim 13 (depends on 12) The organic electro-luminescence display device according to claim 12, wherein the electrode line is interposed between the first organic electro-luminescence element and the second organic electro-luminescence element; and the first selection switch and the first control element are disposed in a first region being different to the first organic electro-luminescence element in plane and the second selection switch and the second control element are disposed in a second region being different to the second organic electro-luminescence element in plane. ### Claim 14 (depends on 12) The organic electro-luminescence display device according to claim 12, wherein at least one of a portion of the first selection switch, a portion of the first control element, a portion of the second selection switch or a portion of the second control element is overlapped with the second organic electro-luminescence element in plane. ### Claim 15 (depends on 12) The organic electro-luminescence display device according to claim 12, further comprising: scanning lines disposed in the first direction over the optically transparent substrate; and first video signal lines and second video signal lines disposed in the second direction over the optically transparent substrate; wherein the first selection switch supply video signals from the first video signal lines between the first optically transparent and electrically conductive layer and the second optically transparent and electrically conductive layer into light in response to scanning signals from the scanning lines, and the second selection switch supply video signals from the second video signal lines between the first optically transparent and electrically conductive layer and the second optically transparent and electrically conductive layer into light in response to scanning signals from the scanning lines. ### Claim 16 (depends on 12) Electronic equipment comprising: an organic electro-luminescence display device as set forth in claim 12; and an input manipulator to input signals to the organic electro-luminescence display device, wherein the organic electro-luminescence display device displays images in response to the input. ### Claim 17 An organic electro-luminescence display device comprising: an optically transparent substrate; first pixels formed over the optically transparent substrate, the first pixels being disposed in a first direction, each of the first pixels including a first organic electro-luminescence element, a first selection switch, a first control element and a first capacitor, the first selection switch selecting the first pixel, the first control element controlling electrical current supplied to the first organic electro-luminescence element and the first capacitor retaining gate voltage applied to the first control element; second pixels formed over the optically transparent substrate, the second pixels being disposed in the first direction, each of the second pixels including a second organic electro-luminescence element, a second selection switch, a second control element, and a second capacitor, the second selection switch selecting the second pixel, the second control element controlling electrical current supplied to the second organic electro-luminescence element and the second capacitor retaining gate voltage of the second control element; and electrode lines disposed in the second line, each of the electrode line being commonly connected to the first organic electro-luminescence element via the first control element and the second organic electro-luminescence element via the second control element; wherein the first organic electro-luminescence element includes a first optically transparent and electrically conductive layer, an organic layer including a light-emitting layer, a second optically transparent and electrically conductive layer and a first optically reflective and electrically conductive layer in order, the organic layer configured to transform electric energy applied between the first optically transparent and electrically conductive layer and the second optically transparent and electrically conductive layer into light, the first optically reflective and electrically conductive layer configured to reflect light, and the first pixel configured to emit light towards a first surface of the organic electro-luminescence display device, the second organic electro-lurninescence element includes a second optically reflective and electrically conductive layer, the first optically transparent and electrically conductive layer, the organic layer including the light-emitting layer and the second optically transparent and electrically conductive layer in order, and the second optically reflective and electrically conductive layer configured to reflect light, and the second pixel configured to emit light towards a second surface of the organic electro-luminescence display device, the second surface being opposite to the first surface. ### Claim 18 (depends on 17) The organic electro-luminescence display device according to claim 17, wherein the first selection switch and the first control element are disposed in a first region being different to the first organic electro-luminescence element in plane and the second selection switch and the second control element are disposed in a second region being different to the second organic electro-luminescence element in plane. ### Claim 19 (depends on 17) The organic electro-luminescence display device according to claim 17, wherein at least one of a portion of the first selection switch, a portion of the first control element, a portion of the second selection switch or a portion of the second control element is overlapped with the second organic electro-luminescence element in plane. ### Claim 20 (depends on 17) Electronic equipment comprising: an organic electro-luminescence display device as set forth in claim 17; and an input manipulator to input signals to the organic electro-luminescence display device, wherein the organic electro-luminescence display device displays images in response to the input.