Classifications

• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
  • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
  • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B33/00—Electroluminescent light sources
  • H05B33/12—Light sources with substantially two-dimensional radiating surfaces
  • H05B33/14—Light sources with substantially two-dimensional radiating surfaces characterised by the chemical or physical composition or the arrangement of the electroluminescent material, or by the simultaneous addition of the electroluminescent material in or onto the light source
  • H05B33/145—Arrangements of the electroluminescent material
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
  • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
  • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
  • G09F9/33—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements being semiconductor devices, e.g. diodes
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B33/00—Electroluminescent light sources
  • H05B33/10—Apparatus or processes specially adapted to the manufacture of electroluminescent light sources
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B33/00—Electroluminescent light sources
  • H05B33/12—Light sources with substantially two-dimensional radiating surfaces
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B33/00—Electroluminescent light sources
  • H05B33/12—Light sources with substantially two-dimensional radiating surfaces
  • H05B33/22—Light sources with substantially two-dimensional radiating surfaces characterised by the chemical or physical composition or the arrangement of auxiliary dielectric or reflective layers

Definitions

• the present invention relates to a color display device, and more particularly to a color display device in which an EL panel and a color filter are integrated. Background technology
• a full-color flat display device used in a conventional pocket television has liquid crystal cells arranged in a matrix.
• the shutter means 100 thus obtained, a light source 10 disposed at the rear of the shutter means, and a red transmission filter corresponding to the liquid crystal cell, A green transmission filter G and a blue transmission filter B are arranged, and the filter means 102 is provided in front of the shutter means.
• the filter means 102 is provided in front of the shutter means.
• the light emitting layer is composed of a transparent thin film and has no granularity, light incident from the outside and light emitted inside the light emitting layer are scattered and cause a halation or bleeding. Because of its sharpness and high contrast, it is in the spotlight as a display device or a lighting device.
• the basic structure of the thin film EL element on a transparent substrate, a transparent electrode made of acid tin (S n 0 2) layer or the like, the consist pentoxide data pointer Le (T a 2 0 5) layer, etc. ⁇ ⁇ a dielectric layer, a light-emitting layer composed of a thin film of zinc sulfide (ZnS) containing manganese (M ⁇ ), etc., a second dielectric layer composed of a tantalum pentoxide layer, etc., and aluminum. It has a double dielectric structure in which a back electrode composed of a Ni (A i) layer and the like is laminated in an orderly manner.
• the process of light emission is as shown below J.
• a voltage is applied between the transparent electrode and the back electrode, the electrons trapped at the interface state by the electric field induced in the light emitting layer are drawn out, accelerated, and sufficiently accelerated. Energy, and this electron is an orbital electron of M ⁇ (emission center) And excites it.
• the thin-film EL device having such a structure is transparent except for the back electrode, and the incident light from the outside is reflected on the back electrode, and the reflected light is emitted from the light emitting layer. Therefore, there is a problem that a sufficient contrast ratio cannot be obtained and only a display having a low display quality can be obtained.
• An object of the present invention is to provide a thin color display device having a high trajectory and a wide viewing angle.
• Another object of the present invention is to increase the breakdown voltage of the thin film EL element of the color display device.
• Still another object of the present invention is to improve the contrast of the thin film EL device.
• FIGS. 1 (a) and (b) are a cross-sectional view and a plan view, respectively, showing a color display device according to an embodiment of the present invention
• FIGS. 2 (a) and (b) are light-emitting layers of the device, respectively.
• Diagram showing the principle of light emission a diagram showing the spectrum from the light-emitting device
• FIG. 3 shows the contrast ratio of the device
• FIG. 4 shows the contrast ratio of the device and the conventional example.
• FIG. 5 is a view showing a light emitting spectrum of a light emitting layer according to another example of the present invention
• FIG. 6 is a view showing a structure of a thin film EL device according to a second example of the present invention.
• FIG. 7 is a diagram showing a light-emitting spectrum of the same thin-film E7 device
• FIG. 8 is a diagram showing a thin-film EL device of a third embodiment of the present invention
• FIG. The figure shows the transmittance of the second dielectric layer used in the device
• FIG. 50 shows the thin film EL device using the insulating film of the third embodiment of the present invention and the conventional example.
• Trust ratio FIG. 11 is a diagram showing a thin-film EL device having a different structure using a dielectric film used in the device of the third embodiment (a modification of the third embodiment).
• Fig. 2 shows oxygen during the formation of the insulating film of this example.
• FIG. 13 is a diagram showing the relationship between partial pressure and permeation rate
• FIG. 13 is a diagram showing a thin film EL device of a fourth embodiment of the present invention
• FIG. 14 (a) and FIG. 14 (b) FIG. 15 is a curve showing the relationship between the oxygen content and the permeability and resistivity at the time of forming a tantalum oxide film, respectively.
• FIG. 15 is a graph showing the relationship between the thin film EL device of the fourth embodiment of the present invention and the conventional example.
• FIG. 16 is a diagram showing a modification of the fourth embodiment
• FIG. 17 is a diagram showing a variation of the thin film EL device shown in FIG.
• Fig. 18 is a graph showing a control curve of luminance with respect to the illuminance (horizontal axis) before and after maintaining the input unit within a certain range.
• Fig. 19 is a diagram showing a light emission spectrum of a conventional thin-film EL device emitting white light.
• a color display device is constituted by an EL panel in which thin-film EL elements that emit white light are arranged, and a color filter.
• cells composed of EL elements are arranged in a matrix on a glass substrate, and the red light-transmitting elements are arranged on the light-emitting surface side of the EL element in order corresponding to each cell.
• a color filter including a green filter, a green color filter, and a blue color filter, and controlling a voltage applied to each cell according to image information, the color filter is formed. Emits light with the desired brightness and chromaticity through the filter One — to do so.
• an EL element which emits white light including three primary colors is used as a light source and a light amount adjusting means, so that contrast and visual field are not used.
• the angle can be increased.
• the thickness can be reduced.
• nitrogen is contained as a light-emitting layer of the thin-film EL element.
• Zinc sulfide is used.
• the luminescent layer is formed by forming a sub-sulfurized sub-sintered thin film, and further ion-implanting a nitrogen ion into the sub-sulfurized sub-sintered thin film.
• an electron orbital energy level of a nitrogen atom and a molecule is generated in the zinc sulfide, and a plurality of defect levels are generated in the zinc sulfide.
• the second dielectric layer of the above-described thin film EL element is continuously changed from a black tantalum oxide film to a far-clear tantalum oxide film.
• the second dielectric layer may be made of tantalum pentoxide (T205) as a target and argon (A "> +
• T205 tantalum pentoxide
• argon A "> +
• a film is formed by the sputtering method while flowing a mixed gas of oxygen ⁇ 02>
• the oxygen partial pressure in the reaction chamber is gradually increased.
• the second color changed continuously from a black tantalum oxide film (Ta0X: X ⁇ 2.5) to a transparent tantalum oxide film (Ta205).
• a dielectric layer is obtained.
• the second dielectric layer of the above-mentioned thin film EL device is formed by reducing the stoichiometric composition ratio of oxygen or nitrogen in the insulating oxide or nitride. It may be composed of a single layer of black.
• the crude composition ratio of oxygen or nitrogen is reduced chemically, a defect occurs in a portion from which oxygen or nitrogen is lost, and light is absorbed by the defect level. It is considered to be black.
• pentoxide data te le (T a 2 0 5) is when is a transparent insulating film for small Ku
• T a O x (X ⁇ 2.5)
• FIG. 1 (a) and 1 (b) are diagrams showing a thin color display device according to an embodiment of the present invention.
• Fig. 1 (a) is a sectional view taken along the line AA in Fig. I (b).
• the color display device includes an EL element section in which a number of thin-film EL element cells G each corresponding to a pixel are arranged in a matrix, and an integral surface of the EL element section. And a color filter section disposed in the cell, and light from each cell is output through the color filter section.
• the EL element section 1 is formed of indium oxide (ITO) provided on the glass substrate 3 so as to form a plurality of first strip lines ⁇ ⁇ -n at predetermined intervals.
• a layer or we made clear Kaminarikyoku 4 the first dielectric layer 5 made of pentoxide data te le (T a 2 05) layer, and the tree um (T m "zinc sulfide (Z n S) Blue light-emitting layer 6a having a thickness of 0.5 containing 1% each of fluorine (F) and a film thickness containing approximately 1% each of erbium (E "> and fluorine in zinc sulfide.
• a three-layer structure of a green light-emitting layer 6b with a thickness of 0.2% and a red light-emitting layer 6c with a film thickness of about 0.2 made by adding about 1% each of samarium (Sm) and fluorine to zinc sulfate.
• a light emitting element a second dielectric layer 7 made of a tantalum pentoxide layer, and the second stripe layer ⁇ 1
• a back electrode 8 composed of an aluminum (A ⁇ ) layer composed of a second strip line V 1... V n arranged so as to be orthogonal to one n
• a voltage corresponding to the image information is applied between each stripe line of the transparent electrode 4 and each stripe line of the back electrode 8, and a voltage corresponding to the image information is applied to each of the stripe lines.
• the light emitting layer 6 located at the intersection is configured to emit light. The principle of this light emission is as shown in FIG. 2 (a), and light of each wavelength is emitted in this way.
• FIG. 2 (b) shows a light emission spectrum of light from the light emitting layer. That is, in this case, the intersection forms one cell.
• color filter section £ corresponds to each cell c
• the red transmission filters R are disposed on the glass substrate side of the EL element section.
• a green transmission filter G and a blue transmission filter B are sequentially arranged.
• Figure 3 shows the contrast characteristics of this color display device. As is clear from this figure, the value is about 100 at or below 1 O O O i x, which is extremely good. In addition, it is significantly improved compared to ⁇ ⁇ : 10 of the conventional one.
• FIG. 4 shows the viewing angle dependence of luminance.
• the color display device of the present invention is shown by a solid line, and the luminance has hardly decreased to 60 degrees or more. Also indicated by the dotted line It can be seen that the viewing angle is much higher than that of the conventional color display device.
• this display device does not require a client and has a very small thickness of about 1 mil even including a glass substrate.
• each cell is integrally formed.
• each layer including the light emitting layer may be separately arranged for each cell. The same applies to electrodes.
• the structure of the light emitting layer itself does not need to be a three-layer structure.
• Fig. 5 shows the emission spectrum of S "S containing Ge, Eu, and K.
• the content of the impurity serving as the emission center of each light emitting layer is not limited to ⁇ %, but can be changed appropriately within a range of 0.1 to 5%. It can be appropriately changed.
• a color filter formed separately is adhered. It can be changed as appropriate.
• Example 2 In addition, a protective film or the like can be appropriately added.
• Example 2
• This thin-film EL device uses a light-emitting layer capable of emitting light in one layer.
• the light-emitting layer 11 of the double-dielectric thin-film EL device is made of zinc sulfide. It is composed of a 5000A thin film layer containing nitrogen in it.
• a transparent electrode 13 made of a tin oxide layer (Sn02) or the like, a first dielectric layer 14, and a zinc oxide containing nitrogen as described above are formed on a translucent glass substrate 12.
• a light emitting layer 11 composed of layers, a second dielectric layer 15, and a back electrode 16 composed of an aluminum (A) thin film are sequentially laminated.
• a method is used in which zinc sulfide is formed by a sputtering method, and then nitrogen is injected into the zinc sulfide layer by an ion implantation method.
• the emission spectrum when an alternating electric field is applied to this thin-film EL element to emit light is as shown in Fig. 7, indicating that it has a wide range of emission wavelengths including the three primary colors. I have.
• a method of injecting nitrogen ions after the formation of zinc sulfide was adopted.
• the method is not limited to this, and sputtering is performed in a nitrogen atmosphere.
• a method of forming by a tiling step or a GVD step may be adopted, and can be appropriately selected as needed.
• this thin-film EL element is composed of a transparent electrode 22 made of a tin oxide layer (Sn 02) on a translucent glass substrate 21 and a first dielectric layer 2.
• ZnS light-emitting layer 24 composed of Mn
• black dielectric layer 25 composed of tantalum oxide (TaO x ( ⁇ 2.5)
• back surface composed of aluminum (A ⁇ ) thin film
• the electrodes 26 are sequentially laminated to form a double dielectric layer structure.
• the thin-film EL device of the present invention requires only 200 cd / ⁇ , and the contrast is low. You can see that it has improved significantly.
• this black tantalum oxide film is used for forming a translucent tantalum pentoxide layer, which has been conventionally used, for example, in the sputtering method. It can be easily obtained only by changing one part condition, such as reducing the pressure only, and the manufacturing workability is high.
• a black tantalum oxide film was used in place of the conventional translucent tantalum pentoxide film.
• the layer may be composed of a composite film 25 ′ of a black tantalum oxide film 25a and another dielectric layer 25b.
• the present invention can be applied to other oxides and nitrides such as tritium oxide, silicon oxide, and silicon nitride.
• constituent materials of the light emitting layer, the transparent electrode, and the back electrode are not limited to those in the embodiments, and may be effective for other materials.
• the tantalum oxide film may be appropriately selected from those having a transmittance in the visible region of 30% or less. 3 0 One one
• the contrast ratio decreases.
• T a 2 O s as a target Bok, but such changing the oxygen partial pressure in al RF spatter (RF spatter) method by Ri glass substrate to form a T a O x film.
• the composition ratio of oxygen or nitrogen in the insulating oxide or nitride is made stoichiometrically small. Therefore, the manufacturing process is also changed almost completely. Therefore, a black insulating film can be provided extremely easily.
• FIG. 3 is a diagram showing a thin-film EL device according to an example of the present invention.
• This thin film ⁇ L element consists of a transparent electrode 32 composed of a tin oxide (SnO 2 ) layer or the like on a translucent glass substrate 31, and a thin layer of yttrium oxide (Y 203)
• First dielectric layer 33 composed of employment, zinc sulfide (ZnS): light emitting layer 34 composed of manganese (M ⁇ ) employment, continuously composed from black to transparent
• ZnS zinc sulfide
• M ⁇ manganese
• the second dielectric layer starts with a transparent tantalum oxide film (TaOx: X ⁇ 2.5>) having a thickness of 300 A and is transparent pentoxide.
• the stoichiometric composition ratio changes continuously to the tantalum film (T2205), and the total thickness is 50.00 A.
• the wavelength when the amount of oxygen is changed is:
• the relationship between the transmittance (%) and the resistivity ( ⁇ ⁇ ) for 600 nm light is shown in FIGS. 14 (a) and 14 ⁇ (b).
• the permeability decreases, but the resistivity also decreases.
• the resistivity increases.
• the luminance-voltage characteristics of the thin film EL element thus formed are shown by a curve a in FIG.
• the second dielectric layer was composed of a (black) tantalum oxide film (Ta0X: X ⁇ 2.5) with a thickness of 500 A, and the others were implemented.
• Thin film EL element with the same structure as the example, and thickness of 400
• a and b are almost the same, and c is slightly lower.
• the vertical axis represents the luminance and the horizontal axis represents the applied voltage.
• the voltage that can withstand over a long period of time (withstand voltage: a is 16 V, b is 125 V) , c are set to 150 V, which indicates that the withstand voltage of the thin-film EL device of the present invention in which the second dielectric material is continuously changed is greatly improved.
• the thin film EL device of the embodiment of the present invention has a high contrast and a high withstand voltage.
• the ratio of the thickness of the black layer, the continuous layer, and the transparent layer in the second dielectric layer is not limited to the examples, and can be changed as appropriate.
• this thin-film EL element can be used as a light source for recording, reading, and erasing a signal from the optical recording medium for illumination other than the display device.
• a photo sensor 37 is provided, and based on a signal from the photo sensor, the voltage applied to the thin-film EL element is controlled so that the luminance is reduced. By changing it, the contrast can be kept constant, and the effect can be further enhanced.
• the control of the applied voltage is performed by changing the applied voltage stepwise when the signal from the photo sensor exceeds a predetermined value, as shown in FIG. It is easy to keep the rust within a certain range ⁇ a-b)
• the luminance when the surrounding illuminance that is, the detection value by the photo sensor 7 becomes about 000 lux
• the applied voltage is increased so that A becomes B, and when the illuminance further rises and reaches about 500,000 lux, the brightness is changed to C.
• the brightness is changed to A, B, C, D. ... And change step by step.
• the contrast can be kept within a substantially constant range without being affected by the surrounding illuminance.
• the applied voltage may be changed continuously based on the detection value of the photo sensor.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Electroluminescent Light Sources (AREA)
• Devices For Indicating Variable Information By Combining Individual Elements (AREA)

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Citations (6)

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• 1987
  • 1987-06-30 JP JP62163477A patent/JP2531686B2/ja not_active Expired - Lifetime
  • 1987-07-03 DE DE3750038T patent/DE3750038T2/de not_active Expired - Fee Related
  • 1987-07-03 KR KR1019880700197A patent/KR950014429B1/ko not_active IP Right Cessation
  • 1987-07-03 EP EP19920203321 patent/EP0537864A3/en not_active Withdrawn
  • 1987-07-03 WO PCT/JP1987/000469 patent/WO1988000382A1/ja active IP Right Grant
  • 1987-07-03 EP EP87904321A patent/EP0313656B1/en not_active Expired - Lifetime
• 1989
  • 1989-01-02 FI FI890007A patent/FI890007A0/fi not_active IP Right Cessation

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