JP2000510992A - Rare earth metal-manganese oxide layer for field emission display - Google Patents

Abstract

(57) Abstract: A conductive, light absorbing base plate for a field emission display is disclosed. The inner surface of the base plate is coated with a rare earth metal-manganese oxide layer having a resistance not exceeding 1 × 10 ⁵ Ωcm. Also disclosed is a field emission display including a conductive, light absorbing base plate for a field emission display. At the same time, a method for producing the baseplate and field emission display and the conductive, light absorbing rare earth metal-manganese oxide material used to coat the baseplate is disclosed.

Description

DETAILED DESCRIPTION OF THE INVENTION                 Rare earth metal-manganese oxide layer for field emission display 1. Technical field   The present invention relates generally to field emission displays, and more particularly, to emitting surface charges.   On the surface of the base plate in a field emission display to absorb stray electrons   It relates to the provided conductivity, light absorption and rare earth metal-manganese oxide layer. 2. Background of the Invention   Many devices, such as computers and televisions, require the use of displays And Usually, a cathode ray tube (CRT) is used to perform this function.   CRTs consist of a scanning electron gun directed at a phosphor-coated screen. Electron gun It emits a stream of electrons impinging on individual phosphorus pixels or pixels on the lean. When an electron hits the pixel, it increases the phosphorus energy. Energy level The pixel emits photons when is reduced from this excited state. These photons are light Pass through the screen so that the viewer can see it as a point. CRT, but many Has the disadvantage of CRT screen to scan the entire width of the screen Must be relatively far from the electron gun. For this reason, the entire unit is large. It becomes bulky. CRTs also require significant power to operate.   More modern devices, such as laptop computers, are lightweight and portable It needs to be. Currently, such screens are either electroluminescent or liquid crystal displays. Uses play technology. It is expected to change to such a screen One such technique is a field emission display. Field emission display (FED) on CRT Cold cathode emitter chip as an electron source instead of the scanning electron gun used Use the base plate of the pump.   When placed in electrolysis, these emitter tips are The electron flow in the direction of the face plate.   Instead of a single gun firing electron at the pixel, the array of FED energy chips It is equipped with. Each emitter tip is individually addressable, one or more The emitter tip corresponds to a single phosphor pixel on the faceplate.   One of the problems associated with FED is that every photon emitted from a pixel is a point of light. Does not pass through the faceplate seen by the viewer .   Rather, almost half of the photons are almost in the direction of the base plate and the emitter in the FED Colliding with the chip and / or circuit. This results in unwanted photoelectric effects Fruit is generated, and the reflected light from the base plate reduces the contrast of the FED. A further problem is that all of the electrons emitted from the emitter tip actually It does not actually excite the get pixel. That generation Instead, some of these electrons reflect internally and are not targeted Exciting the pixel.   Therefore, minimize the photoelectric effect and minimize problems related to internally reflected electrons There is a technical need for field emission displays. The present invention addresses this need. And can provide other related advantages. Summary of the Invention   In summary, the invention generally has a coating on the inner surface of a FED baseplate.   It relates to electrical properties, light absorption, and rare earth metal-manganese oxide layers. Rare earth metal-man   The gun oxide layer provides the photoelectric effect and loss associated with backscattered electrons from the faceplate.   Reduces scratches and reduces the amount of ambient light and / or   Display image and contrast by absorbing photons emitted in the direction of the source plate   To improve.     In one embodiment, a conductive and light absorbing base for a field emission display. A base plate is disclosed. At least part of the inner surface of the base plate ( For example, the opposite surface of the face plate) is 1 × 10^FiveΩcm, preferably 1 × 10^FourΩcm, more preferably 1 × 10^ThreeConductivity with resistance not exceeding Ωcm , Light absorption, coated with a rare earth metal-manganese oxide layer.   This rare earth metal-manganese oxide layer has a thickness in the range of 1,000 to 15,000. At a wavelength of 500 nm at least at a wavelength of 500 nm. Also 1 × 10^Fivecm^-1Has a light absorption coefficient of   In a related embodiment, a conductive light absorbing base plate according to the present invention is provided. FED is disclosed. This display can be used on laptop computer screens. Used under high ambient light conditions, including but not limited to lean It is particularly suitable for use in manufactured products.   In yet another embodiment, a method of manufacturing a conductive light absorbing base plate is provided. It has been disclosed.   In this method, the inner surface of the base plate is 1 × 10^FiveHas resistance not exceeding Ωcm Coating with a rare earth metal-manganese oxide layer. Preferred coating technique   The technique involves (but is not limited to) forming a layer by RF sputtering.   Contains.     In yet another embodiment, a conductive, light absorbing rare earth metal-manganese oxide   A method of making a material is disclosed. This method uses rare earth metal-manganate   Rare earth at a temperature of 1200-1500 ° C. for a time sufficient to allow the   The method includes heating a mixture of a metal-like compound and a manganese compound.     The rare earth metal compound is Pr₆O₁₁And the manganese compound is MnO_Twoas well as   Mn (CO_Three)_TwoIs selected from In addition, rare earth metal-manganese oxide materials The ratio of rare earth metal to manganese compound in   After forming the same layer) 1 × 10^FiveΩcm   ing.   These and other features of the present invention will be described with reference to the accompanying figures and detailed description.   It will be clearer. Description of the drawings   FIG. 1 is a cross-sectional view of a field emission display screen according to the prior art;   Emitted and photons and back-emitted light, with internally reflected electrons   Illustrates both children,   FIG. 2 is a sectional view of an example of the field emission display according to the present invention. Description of the embodiment   As mentioned above, the present invention relates to conductive, light absorbing rare earth metals used in FEDs. It relates to a manganese oxide layer. This layer removes the surface charge associated with stray electrons in the FED. As well as at least part of the inner surface of the base plate ( For example, the opposite surface of the face plate) is 1 × 10^FiveΩcm, preferably 1 × 10^FourΩcm, more preferably 1 × 10^ThreeWith resistance not exceeding Ωcm There must be. In addition, the rare earth metal-manganese oxide layer also   (Eg, photons emitted from the faceplate in the direction of the baseplate)   It plays the role of absorbing. Due to its extremely dark color, rare earth metal-manganese   The oxide layer can easily emit light (for example, the light absorption coefficient of a rare earth metal-manganese oxide layer is   1 × 10^Fivecm^-1This is an order of magnitude), which has many advantages for FEDs.   give. One of these advantages is that the floating photons impinge on the base plate of the FED.   The purpose is to minimize the photoelectric effect in the unit side circuit. A further advantageous property is the release   Giving good contrast between the emitted light and the background reflection from the cathode surface   That is to say.     The problem related to the current FED screen is shown in FIG.   This will be described with reference to FIG. In particular, FIG. 1 shows the base plate 3 and the face plate 4   FIG. 2 is a cross-sectional view of an FED screen 2 composed of: The face plate 4 has a conductive layer 9   It contains an array of touching pixels 6. Base plate 3 is a silicon substrate   An array of emitter tips 10 protruding from 12 is provided. The conductive layer 14   Address scheme for selectively connecting each emitter chip to a power supply (not shown)   (Not shown) with the emitter tip. The insulating layer 16 is used for each emitter. -Surrounds the chip 10. The conductive gate 18 also takes the emitter tip   And is separated from the conductive layer 14 and the substrate 12 by the insulating layer 16.   The conductive layer 18 may have a similar addressing scheme (shown in FIG.   ) Is connected to the positive terminal of the power supply. The emitter tip 11 of FIG.   When a particular emitter tip is addressed, as in   And between the emitter tip and the emitter tip. This electric field is generated by the emitter tip 1   1 toward pixel 7 located on faceplate 4 (arrows 17 and   Emits a stream of electrons (indicated by.     For clarity, FIG. 1 shows a single pixel corresponding to each emitter tip   Is shown. But one or more emitter tips work with a single pixel   Recognize that you may. Furthermore, face plate 4 and base play   3 can be fixed using a suitable support member (not shown). The base plate 4 and the base plate 3 are sealed at these ends, and a high vacuum ( 1 × 10^-Five~ 1 × 10^-8Thor) is maintained.   When an electron hits phosphor pixel 7 (indicated by arrow 19 in FIG. 1), the phosphor is in an excited state. And emits photons 8 when it returns to the ground (non-excited) state. I However, as shown by photon 15, the photon also travels to base plate 3. Can be released in the opposite direction. In this case, the photons 15 It can generate photoelectric effects that lead to unwanted electrons and holes in the components.   FIG. 1 illustrates a further problem of working with current FED screens. Photon's Rather than excite phosphorous pixels that cause release, to target pixels Electrons are reflected, dispersed, and absorbed by the pixel. Indicated by arrow 13 in FIG. Bases) generated from some and / or secondary emission of these reflected electrons There is a possibility of returning to the direction of the plate 3, and the base plate 3 This leads to generation of undesirable electrons and holes.   The present invention relates to a base plate (such as an opposite surface of a face plate). A base plate with a layer of rare earth metal-manganese oxide on the internal surface of This solves the above problem. As shown in FIG. FED screen 20 has a face plate 4 and a base plate 3 . The rare earth metal-manganese oxide layer 22 is in contact with the conductive gate 18 and this gate Port 18 is in contact with conductive layer 14 and insulating layer 16 on substrate 12. Emitter -Chip 10 and face plate 4 (pixel 6, conductive layer 9 and transparent material 5) Is the same as described above for FIG.   The photon is a rare earth metal-manganese oxide layer (as indicated by arrow 15 in FIG. 2). When it hits 22, it is absorbed, which reduces the photoelectric effect and reduces FED contrast To improve Toward the base plate 3 (as indicated by the arrow 13 in FIG. 2) The reflected electrons also impact the rare earth metal-manganese oxide layer. Rare Since the earth metal-manganese oxide layer 22 is conductive, the captured electrons are When the gate 18 is positively biased, Released. Also, if the rare earth metal-manganese oxide layer 22 is, for example, an intermediate When electrically insulating from the conductive gate 18 by an insulating layer (not shown), In this case, the rare earth metal-manganese oxide layer 22 may be grounded. In any case , The rare earth metal-manganese oxide layer has the number of electrons corresponding to the components of the base plate 3. Rapidly, thereby eliminating internal unwanted electron holes .   Therefore, in one embodiment of the present invention, the inside of the FED base plate Rare earth metal-manganese oxide materials suitable for being provided on a surface are disclosed. The rare earth metal-manganese oxide material has the formula Pr: Mn: O_Three(Here, manga The molar ratio of the rare earth metal to the phosphorus compound is from about 0.1: 1 to 1: 0.1 and is preferably Or 0.5: 1 to 1: 0.5. ).   This molar ratio provides the desired conductivity of the resulting rare earth metal-manganese oxide layer. Is found out. In addition, the amount of manganese compounds for rare earth metals By increasing, the conductivity increases (ie, the resistance decreases).   Rare earth metal-manganese oxide material is Pr₆O₁₁And MnO_Two(Or Mn (CO_Three )_Two) Is mixed in a mill jar and contains particles having an average diameter of about 2 μm. It is manufactured by kneading to powder. This powder is then over a period of about 4 hours Heated to a temperature in the range 1200-1500 ° C, preferably 1250-1430 ° C. It is. The resulting material after heating has a dark color and is almost matte black It is. The heated material is then crushed again and pulverized to an average diameter of about 2 μm. To produce a powder containing particles.   As noted above, the ratio of Pr to Mn is the resulting rare earth metal-manganese. Affects the conductivity of the oxide layer. The ratio is Pr₆O₁₁And MnO_Two(Or Mn ( CO_Three)_Two) Can be controlled by the relative amounts of the components. Like this, this These components are mixed in amounts sufficient to generate the Pr: Mn ratio disclosed above. The rare earth metal-manganese oxide material has a thickness in the range of 1000-15,000 Can be deposited on the inner surface of the base plate by any technique.   Such deposition techniques are known to those skilled in the art and are (limited) Radio frequency (RF) sputtering, laser ablation, Includes plasma deposition, chemical vapor deposition (CVD) and e-beam elaboration.   For example, in the case of RF sputtering, the rare earth metal-manganese oxide material is flat. It is compressed into a planar target and then a suitable support plate for RF sputtering. Attached to the board. Thereafter, sputtering is performed at a substrate temperature of 200 to 350 ° C. And about 6 × 10^-3From 3 × 10^-2At the sputtering pressure of Torr, argon or This is performed in an RF sputter using argon and oxygen gas.   In the case of CVD, for example, Pr acetate, Pr oxalate or P r (Thd) and Mn acetate, Mn carbonyl, Mn methoxide, and A precursor compound of an organometallic compound for Pr and Mn such as Mn oxalate is used. Can be used.   The resistance of the rare earth metal-manganese oxide material is, for example, (internal table of the base plate) After forming one layer on the surface) like hydrogen and / or carbon monoxide Flame the material in a mild reducing atmosphere. This processing is performed in the practice of the present invention. It serves to increase conductivity (reduce resistance) to a level suitable for use. Ma In addition, additional components, such as conductive ions and / or metals, It can also be loaded to increase.   The rare earth metal-manganese oxide layer formed on the inner surface of the base plate is as described above. As such, the underlying circuit is shielded from photons and stray electrons. Rare earth metal-manga The oxide layer is also very dark in color, providing high contrast to FED Is generated. In addition, the FED used in the present invention has high readability under ambient light conditions. Especially as televisions, portable computer screens and Display for outdoor use such as avionics and cars Particularly suitable for rays.   The following examples are for illustrative purposes and are intended to be limiting. There is no.   Example   Example 1   Formation of rare earth metal-manganese oxide materials     Pr₆O₁₁And MnO_TwoAnd commercially available (Cerac, La Puente , CA) purchased from sources. And it was used without further raising the purity. both Ingredients (510.72 grams of Pr₆O₁₁And about 86 grams of MnO_Two) Mill Put in a jar, add 500 ml of isopropyl alcohol and get the result The slurry was kneaded at 100 rpm for 24 hours. This slurry is heated in a nitrogen atmosphere. Dried by bun. Flame dry material at 1350 ° C for 4 hours, then cool Was. The cooled material is pulverized into small particles (average particle size of about 2 μm) using suitable grinding technology. Crushed.   Example 2   Deposition of rare earth metal-manganese oxide material on base plate     The powdery material obtained in Example 1 was deposited on a base plate by an arbitrary technique. Let For example, in the case of RF sputtering, a powdery material is sintered to form a flat spa. To form a target target. Sputtering is performed at a substrate temperature of 200 to 350 ° C. And about 6 × 10^-3From 3 × 10^-2At the sputtering pressure of Torr, argon or Is performed in an RF sputter using argon and oxygen gas. Example 3   Manufacture of FED screen The base plate of Example 2 is used for manufacturing an FED screen using a known technique. Can be The resulting FED has many advantages over existing products. this Benefits include reduced photoelectric effect and the formation of a base plate from a face plate. Reduce the damage caused by backscattered electrons to the Absorption of ambient light and / or radiation by the faceplate in the direction of the baseplate Provides enhanced display image and contrast due to the absorption of any selected photons To be included.   From the foregoing, while specific embodiments of the present invention have been described for purposes of illustration, many modifications have been made. Understand that positive can be made without departing from the spirit and scope of the invention.   Will be done.     Accordingly, the invention is not limited except as by the appended claims. Absent.

────────────────────────────────────────────────── ─── Continuation of front page    (31) Priority claim number 08 / 840,084 (32) Priority Date April 9, 1997 (4.9.1997) (33) Priority country United States (US) (81) Designated countries EP (AT, BE, CH, DE, DK, ES, FI, FR, GB, GR, IE, IT, L U, MC, NL, PT, SE), OA (BF, BJ, CF) , CG, CI, CM, GA, GN, ML, MR, NE, SN, TD, TG), AP (GH, KE, LS, MW, S D, SZ, UG), EA (AM, AZ, BY, KG, KZ , MD, RU, TJ, TM), AL, AM, AT, AU , BA, BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, G E, GH, HU, IL, IS, JP, KE, KG, KP , KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, N Z, PL, PT, RO, RU, SD, SE, SG, SI , SK, TJ, TM, TR, TT, UA, UG, UZ, VN, YU (72) Inventor Rasmussen Robert Tee             United States Idaho 83706 Bo             Chair Lot 12 Sub 1 Wilderness               Lunch (no address)

Claims (1)

Claims: 1. A conductive and light-absorbing base plate for a field emission display having a base plate with an inner surface in the field emission display, wherein at least a portion of the inner surface does not exceed 1 × 10 ⁵ Ωcm. A conductive and light-absorbing base plate for a field emission display, which is covered with a rare earth metal-manganese oxide layer having resistance. 2. The base plate according to claim 1, wherein said rare earth metal-manganese oxide layer has a resistance not exceeding 1 × 10 ⁴ Ωcm. 3. 2. The base plate according to claim 1, wherein the rare earth metal-manganese oxide layer has a resistance not exceeding 1 * 10 < ³ > [Omega] cm. 4. The base plate according to claim 1, wherein the thickness of the rare earth metal-manganese oxide layer is in the range of 1000 to 15,000. 5. The rare earth metal - baseplate according to claim 1, the manganese oxide layer is characterized by having a light absorption coefficient of at least 1 × 10 ⁵ cm ^-1 at a wavelength of 500 nm. 6. In a field emission display having a conductive and light-absorbing base plate, the base plate has an inner surface of the field emission display, and at least a part of the inner surface exceeds 1 × 10 ⁵ Ωcm. A field emission display characterized by being coated with a rare earth element-manganese oxide layer having no resistance. 7. 7. The field emission display according to claim 6, wherein the rare earth metal-manganese oxide layer has a resistance not exceeding 1 × 10 ⁴ Ωcm. 8. The field emission display according to claim 1, wherein the rare earth metal-manganese oxide layer has a resistance not exceeding 1 × 10 ³ Ωcm. 9. 2. The field emission display of claim 1, wherein the rare earth metal-manganese oxide layer has a thickness in the range of 1000-15000 [deg.]. Ten. The rare earth metal - a field emission display of claim 1, the manganese oxide layer is characterized by having a light absorption coefficient of at least 1 × 10 ⁵ cm ^-1 at a wavelength of 500 nm. 11． A method of manufacturing a conductive and light-absorbing base plate for a field emission display, comprising a step of coating an inner surface of a base plate with a layer containing a rare earth metal-manganese oxide, wherein the layer has a thickness exceeding 1 × 10 ⁵ Ωcm. A method characterized by having no resistance. 12． The rare earth metal - The method of claim 11, the manganese oxide layer and wherein Rukoto to have a resistance not exceeding 1 × 10 ⁴ Ωcm. 13. The method according to claim 11, wherein the rare earth metal-manganese oxide layer has a resistance not exceeding 1 × 10 ³ Ωcm. 14. The method of claim 11, wherein the rare earth metal-manganese oxide layer has a thickness in the range of 1000-15000 °. 15． The method of claim 11, characterized in that it has a light absorption coefficient of at least 1 × 10 ⁵ cm ^-1 manganese oxide layer at a wavelength of 500 nm - the rare earth metals. 16． The method according to claim 11, wherein the layer is coated on the inner surface of the base plate by high frequency sputtering, laser ablation, plasma deposition, chemical vapor deposition or electron beam elaboration. 17． The method according to claim 11, wherein the layer is coated on the inner surface of the base plate by high frequency sputtering. 18． The method of claim 17, Pr ₆ O ₁₁ and a manganese source selected from MnO ₂ and MnCO ₃ is characterized by forming a sputtering target for the high-frequency sputtering. 19. The method according to claim 11, wherein the layer is coated on the inner surface of the base plate by chemical vapor deposition. 20. 20. The method according to claim 19, wherein a rare earth metal source selected from rare earth metal acetate, rare earth metal-manganese oxide layer oxalate, and Pr (Thd) ₃ is used to form the layer. twenty one. The method of claim 19, wherein the layer is formed using a manganese source selected from manganese acetate, manganese carbonyl, manganese methoxide, and manganese oxalate. twenty two. 20. The method according to claim 19, further comprising, after the coating step, a step of applying a flame to the layer in a reducing atmosphere to reduce the resistance so that the layer does not exceed 1 × 10 ⁵ Ωcm. Method. twenty three. 23. The method of claim 22, wherein said reducing atmosphere is formed from hydrogen, carbon monoxide, or a mixture thereof. twenty four. The method of claim 11, wherein the layer further comprises conductive ions. twenty five. The method of claim 11, wherein the layer further comprises a metal. 26. The method of claim 11 wherein said layer is comprised primarily of a rare earth metal-manganese oxide. 27. The method of claim 11, wherein the layer is formed from particles having an average particle size of about 2 microns. 28. The method of claim 11, wherein the layer is in contact with a conductive gate. 29. The method of claim 11, wherein the layer is in contact with an insulating layer. 30. The method of claim 11, wherein the layer has a rare earth metal to manganese molar ratio in the range of 0.1: 1 to 1: 0.1. 31. The method of claim 11, wherein the molar ratio of the layers ranges from 0.5: 1 to 1: 0.5. 32. Method person according to claim 11, wherein the layer contains a PrMnO _3. 33. The method of claim 11, further comprising assembling a field emission display using a conductive and light absorbing base plate. 34. Heating the mixture of the rare earth metal compound and the manganese compound at a temperature in the range of about 1200-1500 ° C. for a time sufficient to produce the rare earth metal-manganese oxide material; In the method for producing a metal-manganese oxide layer, the molar ratio of the rare earth metal compound to the manganese compound in the mixture before the heating may be such that the rare earth metal-manganese oxide material is 1 × 10 ⁵ Ωcm after the heating step. Characterized in that it is set to have a resistance not exceeding. 35. The method according to claim 34, wherein the resistance does not exceed 1 × 10 ⁴ Ωcm. 36. The method of claim 34, wherein the resistance does not exceed 1 × 10 ³ Ωcm. 37. 35. The method of claim 34, wherein prior to said heating step, the mixture of rare earth metal compound and manganese compound is powdered to an average particle size of about 2 [mu] m. 38. 35. The method of claim 34, wherein after the heating step, the rare earth metal-manganese oxide material is powdered to an average particle size of about 2 [mu] m. 39. The method of claim 34, wherein the rare earth metal compound, characterized in that it is a Pr ₆ O _11. 40. The method according to claim 34, wherein the manganese compound is MnO ₂ or MnCO ₃ . 41. The method according to claim 34, wherein the molar ratio ranges from 0.1: 1 to 1: 0.1. 42. 35. The method of claim 34, wherein said molar ratio ranges from 0.5: 1 to 1: 0.5. 43. The method of claim 34, manganese oxide material and feature that it contains a PrMnO ₃ - the rare earth metals. 44. A method of operating a FED having a faceplate and a baseplate, comprising absorbing photons to a layer comprising a rare earth metal-manganese oxide disposed between the faceplate and the baseplate. 45. The method of claim 44, wherein photons are emitted from the face plate in the direction of the base plate. 46. The method of claim 4 4, characterized in that it has a resistance which the layer does not exceed 1 × 10 ⁵ Ωcm. 47. The method of claim 44, wherein said layer is a coating on an interior surface of said base plate. 48. 48. The method of claim 47, wherein the layer is coated on the interior surface of the base plate by RF sputtering, laser ablation, plasma deposition, chemical vapor deposition, or e-beam elaboration. 49. The method of claim 44, wherein the layer further comprises conductive ions. 50. The method of claim 44, wherein said layer further comprises a metal. 51. The method of claim 44, wherein said layer is comprised primarily of a rare earth metal-manganese oxide. 52. The method of claim 44, wherein the layer has a rare earth metal to manganese molar ratio in the range of 0.1: 1 to 1: 0.1. 53. Method person of claim 44, wherein the layer contains a PrMnO _3.