JP2005292395A - Low-profile display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-profile, compact and inexpensive display device having a switch. <P>SOLUTION: The display device (1) comprises a flexible substrate (30), a plurality of light emitting elements formed like a matrix on the flexible substrate (30), a power supply circuit (14), and a power supply (15). The switch (SW) consists of a first electrode (50) formed on the flexible substrate (30) and connected to either one of the power supply circuit (14) and the power supply (15) and a second electrode (52) separately opposed to the first electrode (50) and connected the other one out of the power supply circuit (14) and the power supply (15), and the first electrode (50) is arranged so as to be curved in accordance with the curve of the flexible substrate (30) and brought into contact with the second electrode (52). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display device including a power supply switch, and more particularly to a thin display device including a thin switch.

  In recent years, with the spread of sheet-like display devices such as gift cards or IC card displays, or electronic paper, thin, compact and low-cost sheet-like display devices have been demanded. For example, an organic EL (electroluminescent) display device, a liquid crystal display device, or an electrophoretic device is employed as the sheet-like display device. Even if the panel is compact, it is difficult to make the display device compact if the peripheral structure such as a drive circuit for driving the display panel, a battery, or a switch for turning on the power is large. Even if the peripheral structure is compact, it is difficult to realize a low-cost display device if its manufacturing cost is high.

Conventional sheet-like display devices include, for example, Patent Document 1 (Japanese Patent Laid-Open No. 2004-5260; title of the invention “IC media having an electroluminescent display portion and manufacturing method thereof”) and Patent Document 2 (JP 2003-255403 gazette; the title of the invention "display medium, display device, display method and display body").
JP 2004-5260 A JP 2003-255403 A

  In view of the above circumstances, an object of the present invention is to provide a thin display device having a thin, compact, and low-cost switch.

  In order to achieve the above object, the invention according to claim 1 is based on a flexible substrate, a plurality of light emitting elements formed in a matrix on the flexible substrate, and electric power supplied from a power source. A thin display device comprising: a power supply circuit that generates an operating voltage for causing each of the light emitting elements to emit light; and a switch that is interposed between the power supply circuit and the power supply to supply or cut off the power. The switch is formed on the flexible substrate and is connected to one of the power supply circuit and the power supply. The switch is spaced apart from the first electrode to face the power supply circuit and the power supply. The second electrode is connected to the other of the first and second electrodes, and the first electrode is arranged so as to be bent according to the curvature of the flexible substrate and to be in contact with the second electrode. It is characterized by.

  Examples according to the present invention will be described below.

FIG. 1 is a perspective view schematically showing an appearance of a sheet-like display device (thin display device) 1 by a passive matrix driving system according to an embodiment of the present invention, and FIG. 2 is a sheet-like display shown in FIG. 2 is a block diagram schematically showing the configuration of the device 1. FIG. The sheet-like display device 1 includes a flexible substrate 30 having light emitting elements C _{1, 1} ,..., A first drive unit 20, a second drive unit 21, a signal processing module 13, a power supply circuit 14, a battery power supply 15, and the like. It has a push button switch SW. The battery power source 15 is composed of a lithium polymer battery or a lithium ion battery, and is mounted in the housing 10 on the back side of the flexible substrate 30. The power supply circuit 14 and the signal processing module 13 are provided on a flexible wiring board (not shown) and are incorporated in the housing 10.

  The power supply circuit 14 generates an operating voltage to be supplied to the signal processing module 13 and the first and second drive units 20 and 21 based on the power supplied from the battery power supply 15. A push button switch SW is interposed between the power supply circuit 14 and the battery power supply 15. The push button switch SW has a function of turning on (supplying) or turning off (cutting off) power from the battery power supply 15 to the power supply circuit 14. Have. The user can turn on the display device 1 by pressing the push button switch SW and display an image in the display area 12. The structure of the push button switch SW will be described later.

  Referring to FIG. 2, the signal processing module 13 is a circuit group that operates when receiving power supply from the power supply circuit 14, and includes a signal processing unit 22 and a signal supply source 23. The signal supply source 23 holds image data to be displayed in the internal memory, and starts supplying the held image data, the vertical synchronization signal, and the horizontal synchronization signal to the signal processing unit 22 at the same time as the power is turned on. The signal processing unit 22 generates control signals based on the image data, the vertical synchronization signal, and the horizontal synchronization signal supplied from the signal supply source 23 and supplies them to the first drive unit 20 and the second drive unit 21, respectively. .

On the flexible substrate 30, a plurality of light emitting elements arranged in a matrix, that is, organic EL elements C _{1, 1} , C _{1, 2} ,..., C _{M, N} (M and N are positive integers of 2 or more). Is formed. Each of these light emitting elements C _{1, 1} ,..., C _{M, N} may constitute one pixel, or when a structure for color display or area gradation is adopted, the light emitting element C _{1 , 1} ,..., C _{M, N} may constitute one pixel. For example, three display cells constituting one pixel may have color filters of R (red), G (green), and B (blue), or three display cells constituting one pixel. A 2-bit area gradation may be realized by a combination of lighting and non-lighting.

The first drive unit 20 is connected to a plurality of line-shaped anode electrodes D ₁ , D ₂ ,..., D _N extending in the Y direction, and the second drive unit 21 is a plurality of extension extending in the X direction perpendicular to the Y direction. The line-shaped cathode electrodes S ₁ , S ₂ ,..., S _M are connected. The anode electrode D _1, ..., D _N and the cathode electrode S _1, ..., the intersection near the S _M, respectively, the organic EL element _{1, 1, C 1, 2} , ..., and C _{M, N} are formed The anode electrodes D ₁ ,..., _DN are electrode lines for supplying holes to the organic EL elements C _{1, 1} ,..., _{CM, N} , and cathode electrodes S ₁ ,. S _M is an electrode wire for supplying electrons to the organic EL elements C _{1, 1} ,..., C _{M, N.}

3, the organic EL element C _{1, 1,} ..., shown schematically C _M, the cross-sectional structure of _N. On the flexible substrate 30 having a thickness of about 200 μm, a moisture-proof barrier film 31 made of silicon nitride oxide (SiO _x N _y ) is formed by sputtering. Examples of the material of the flexible substrate 30 include PMMA (polyethyl methacrylate), PC (polycarbonate), PES (polyethersulfone), PAr (polyarylate), PEI (polyetherimide), and PI (polyimide). Examples include crystalline plastics.

On the barrier film 31, an anode electrode 32 (D _{1 to} D _N ), an organic functional layer 33, and a cathode electrode 34 (S _{1 to} S _M ) are sequentially formed. As a material of the anode electrode 32, a conductive material having a large work function from the viewpoint of hole injection into the organic functional layer 14, for example, ITO (indium tin oxide), IZO (zinc oxide), tin oxide, polythiophene or polyaniline. In particular, ITO is preferable. Examples of the material of the cathode electrode 34 include MgAg alloy, magnesium, aluminum, and aluminum alloy. Furthermore, a protective film (passivation film) 35 is formed so as to cover the entire organic EL element. Examples of the material of the protective film 35 include organic insulating materials such as silicon oxide, magnesium oxide, silicon nitride, silicon nitride oxide (SiO _x N _y ), and polyimide resin.

FIG. 4 is a diagram schematically illustrating an example of a cross-sectional structure of the organic functional layer 33. The organic functional layer 33 includes a hole transport layer 40, a light emitting layer 41, and an electron transport layer 42, and can be formed by an evaporation method, a spin coating method, or the like. When holes are injected into the hole transport layer 40 from the anode electrode 32 and electrons are injected into the electron transport layer 42 from the cathode electrode 34, the hole transport layer 40 and the electron transport layer 42 emit holes and electrons, respectively. Layer 41 is provided. Holes and electrons recombine in the light emitting layer 41, and the energy of recombination is emitted through the singlet excited state and the triplet excited state of the organic molecules constituting the light emitting layer 41, and fluorescence and phosphorescence are emitted. It will be. Examples of the material for the hole transport layer 40 include phthalocyanine-based materials such as copper phthalocyanine, aromatic amine compounds, or TPD (triphenylamine dimer). Examples of the material for the electron transport layer 42 include Alq _3. (Aluminum quinolinol complex). The material of the light-emitting layer 41 includes a π-conjugated polymer such as a poly (p-phenylene vinylene) derivative, tris (8-quinolinolato) aluminum (Alq), an aluminum complex, or a bis (benzoquinolinolato) beryllium complex ( BeBq) and the like.

Next, the structure of the push button switch SW will be described. FIG. 5A is a diagram schematically showing an example of a cross-sectional structure of the push button switch SW. The push button switch SW is provided in an end region where the light emitting elements C _{1, 1} ,..., _{CM, N} are not formed in the region of the flexible substrate 30, and the spacers 51 </ b> A, 51 </ b> B. An upper electrode (first electrode) 50 and a lower electrode (second electrode) 52 that are spaced apart from each other and face each other. The upper electrode 50 is formed in a planar shape on the flexible substrate 30 by a vacuum deposition method, a sputtering method, or the like, and is electrically connected to the power supply circuit 14. The lower electrode 52 is formed in a planar shape on the cover layer 53 and is electrically connected to the battery power supply 15. The spacers 51A and 51B may be formed in an annular shape, or may be provided with a plurality of members as appropriate.

  In the state shown in FIG. 5A, the lower surface 50s of the upper electrode 50 and the upper surface 52s of the lower electrode 52 are separated from each other, and the push button switch SW is in an off state (non-conductive state). When the user depresses the end (FIG. 1) of the flexible substrate 30 downward, as shown in FIG. 5 (B), the flexible substrate 30 uses the spacers 51A and 51B as fulcrums against external pressure. At the same time, the upper electrode 50 is curved and the lower surface 50 s of the upper electrode 50 is in contact with the upper surface 52 s of the lower electrode 52, so that they are electrically connected. As a result, the push button switch SW is turned on and power is supplied from the battery power supply 15 to the power supply circuit 14, so that the display device 1 displays an image or message recorded in the signal supply source 23. It becomes.

  Thereafter, when the user relaxes the pressure on the end portion of the flexible substrate 30, the push button switch SW returns to the non-conductive state shown in FIG. In this way, the user can display an image or message on the display device 1 or turn it off according to the pressure applied to the end. In order to adjust the pressure required to turn the push button switch SW from the OFF state to the ON state, a flexible film having appropriate elasticity is interposed between the upper electrode 50 and the flexible substrate 30, or the upper part What is necessary is just to adjust the film thickness of the electrode 50 suitably, or to form a notch in the edge part of the flexible substrate 30, for example.

  As described above, the push button switch SW according to the present embodiment is formed in the end region on the flexible substrate 30 and has a simple structure. Therefore, the switch SW is very thin, compact, and low cost. It is possible to provide the sheet-like display apparatus 1 which has.

In the above embodiment has been described display employing a passive matrix drive system, the structure of the switch SW, the light emitting element C ₁ formed in a _{matrix, 1,} ..., C _M, respectively active elements _N ( The present invention can also be applied to a display device using a so-called active matrix driving system including an organic TFT).

In the sheet-like display device 1, the plurality of light emitting elements C _{1, 1} ,..., C _{M, N} are formed in a matrix _, but instead of this, one or more light emitting elements are fixed patterns, for example, Segments forming numbers, letters or patterns may be configured.

1 is a perspective view schematically showing an appearance of a sheet-like display device according to an embodiment of the present invention. FIG. 2 is a block diagram schematically showing the configuration of the sheet-like display device shown in FIG. It is a figure which shows roughly the cross-section of an organic EL element. 3 is a diagram schematically showing an example of a cross-sectional structure of an organic functional layer 33. FIG. It is a figure which shows roughly the structure of the pushbutton switch which concerns on a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sheet-like display apparatus 12 Display area 13 Signal processing module 14 Power supply circuit 15 Battery power supply 20,21 Drive part 22 Signal processing part 23 Signal supply source 50 Upper electrode 51A, 51B Spacer 52 Lower electrode 53 Cover layer

Claims (8)

A flexible substrate, a plurality of light emitting elements formed on the flexible substrate, and a power supply circuit that generates an operating voltage for causing each light emitting element to emit light based on power supplied from a power source, A thin display device including a switch for supplying or cutting off the electric power interposed between the power supply circuit and the power supply;
The switch includes a first electrode formed on the flexible substrate and connected to one of the power supply circuit and the power supply, and spaced apart from the first electrode to face the power supply circuit and the power supply circuit. The second electrode is connected to the other of the power supplies, and the first electrode is arranged so as to be bent according to the curvature of the flexible substrate and to be in contact with the second electrode. A thin display device characterized by the above. 2. The thin display device according to claim 1, wherein the switch is provided in an end region where the plurality of light emitting elements are not formed in the region of the flexible substrate. Display device. 3. The thin display device according to claim 1, wherein the first electrode and the second electrode are opposed to each other via a spacer, and the flexible substrate is against an external pressure. A thin display device which is bent using the spacer as a fulcrum. 4. The thin display device according to claim 1, wherein the light emitting element is an organic EL element. 5. 5. The thin display device according to claim 1, wherein the plurality of light emitting elements are formed in a matrix. 6. 5. The thin display device according to claim 1, wherein the light emitting element forms a fixed pattern. 6. The thin display device according to claim 5, wherein the thin display device is based on a passive matrix driving method. The thin display device according to claim 5, wherein the thin display device is based on an active matrix driving method.

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