JP2006228437A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the emission luminance, linearity, luminance life, and chromaticity of a thin flat-panel display device of electron beam excitation type. <P>SOLUTION: The thin flat-panel display device of electron beam excitation type comprises: a substrate having a plurality of first electrodes parallel to each other, a plurality of second electrodes parallel to each other and orthogonal to the first electrodes, and an electron emitting element placed at an intersection point of the first and second electrodes or near the intersection point thereof; and a face plate having a fluorescent film formed thereon. The fluorescent film is made up of a blue light emitting fluorescent film formed of blue light emitting CaMgSi<SB>2</SB>O<SB>6</SB>:Eu phosphor, a green light emitting fluorescent film formed of green light emitting Y<SB>2</SB>SiO<SB>5</SB>:Tb phosphor, and a red light emitting fluorescent film formed of one or a plurality of kinds of red light emitting Y<SB>2</SB>O<SB>3</SB>:Eu and Y<SB>2</SB>O<SB>2</SB>S:Eu phosphors. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an image display device including a face plate on which a fluorescent film is formed and an electron-emitting device that irradiates the fluorescent film with an electron beam, and in particular, CaMgSi ₂ O ₆ as a phosphor constituting the fluorescent film: Image display device using Eu blue light emitting phosphor, Y ₂ SiO ₅ : Tb green light emitting phosphor, Y ₂ O ₃ : Eu red light emitting phosphor or Y ₂ O ₂ S: Eu red light emitting phosphor About.

  In video information systems, various display devices are actively researched and developed in response to various demands such as high definition, large screen, thinning, and low power consumption. In recent years, research and development of an electron beam excitation type thin flat display device as a display realizing thinning and low power consumption meeting such demands has been actively conducted.

  The electron beam excitation type thin flat display device has a structure in which an electron-emitting device corresponding to a pixel (sub-pixel) is installed on the back surface of the vacuum envelope, and a fluorescent film is installed on the inner surface of the face plate on the front surface. The phosphor film is irradiated with a low acceleration electron beam having an acceleration voltage of about 0.1 to 10 kV to emit light, and an image is displayed.

  Here, since the current density of the electron beam applied to the fluorescent film is about 10 to 1000 times that of a general cathode ray tube, it is a high current density. A low resistance characteristic that does not cause it is desired. Furthermore, a life characteristic under a high current density and a color balance after being irradiated with an electron beam for a long time are good, and a characteristic with little luminance saturation and high luminance is also required.

  There are several types of electron beam excitation type thin flat display devices depending on the electron-emitting devices used. A device using a field emission electron source such as a Spindt type electron source or a carbon nanotube type electron source as an electron emission element is called a field emission display (FED).

  In addition, display devices that use surface conduction electron sources as electron-emitting devices, thin-film electron sources that use hot electrons accelerated by an electron acceleration layer, such as MIM type, BSD type (ballistic electron surface electron source), and HEED type A display device to be used is known. Hereinafter, these electron beam excitation type thin flat display devices are collectively referred to as “FED” (in a broad sense).

Until now, various developments have been made in order to realize a fluorescent film with a long life and high linearity. In the high-pressure type FED, as described in Non-Patent Document 1 as phosphor number P22, ZnS: Ag blue light-emitting phosphor, ZnS: Cu, Al green light-emitting phosphor, Y ₂ O ₂ S: Eu red light-emitting phosphor RGB phosphor sets (both sulfide-based phosphors) are used, but contamination of sulfur emitters (electron sources), luminance lifetime and luminance saturation of blue and green light emitting phosphors (light emission luminance irradiation current amount) There is a problem that the growth of

In addition, as described in Non-Patent Document 2, a low-pressure FED uses a Y ₂ SiO ₅ : Ce blue light-emitting phosphor. However, it has low luminance and chromaticity of blue light emission due to long-time electron beam irradiation. There is a problem of chromaticity deterioration that shifts in the white direction.

On the other hand, Non-Patent Document 3 describes the result of luminance evaluation of CaMgSi ₂ O ₆ : Eu blue light-emitting phosphor as a novel blue light-emitting oxide phosphor by low acceleration voltage electron beam excitation. However, there is no description about the long life and high linearity (high growth of light emission luminance with respect to the amount of irradiation current), which is a feature of CaMgSi ₂ O ₆ : Eu blue light emitting phosphor, and what green and red light emitting phosphors are combined. There is no description on whether high-performance FED can be realized if used.

Further, although not as a FED phosphor, a CaMgSi ₂ O ₆ : Eu blue light-emitting phosphor is used as a vacuum ultraviolet excitation phosphor as described in Patent Document 1 and Non-Patent Document 4. However, the combination of the green and red light emitting phosphors used in this case is inferior in performance for electron beam excitation.

  Until now, various methods have been studied for realizing a fluorescent film with low resistance, long life and high brightness for FED. However, these conventional methods have not solved all the problems. In particular, a new method for realizing long life and high linearity is required.

JP 2002-332481 A J. Vac. Sci. Technol. A19 (4) 2001, p1083 SID04, 19.4L, p832 Extended Abstract of the Fifth Int. Conf. Of Display Phosphors 1999 p317 Asia Display / IDW'01, PHp1-7, p1115

  Accordingly, an object of the present invention is to improve the characteristics of light emission luminance, luminance life, linearity, and chromaticity of the conventional fluorescent film, and to provide an image display device having excellent luminance life characteristics. .

The object is to have a plurality of mutually parallel first electrodes, a plurality of mutually parallel second electrodes orthogonal to the first electrodes, and an intersection or vicinity of the first electrode and the second electrode. An image display device having a substrate having an electron-emitting device and a face plate on which a fluorescent film is formed, the fluorescent film being a blue-emitting fluorescent material containing a CaMgSi ₂ O ₆ : Eu blue-emitting phosphor One or more of a film, a green light emitting phosphor including a Y ₂ SiO ₅ : Tb green light emitting phosphor, and a Y ₂ O ₃ : Eu red light emitting phosphor or a Y ₂ O ₂ S: Eu red light emitting phosphor This is achieved by an image display device characterized by comprising a phosphor film of an RGB phosphor set including a red light emitting phosphor film containing the above phosphor.

Further, at least one element selected from the group consisting of a group IIa such as Sr, a group IIb such as Zn and a group IVb such as Ge may be added to the CaMgSi ₂ O ₆ : Eu blue light emitting phosphor. Further, at least one element selected from the group consisting of Group IIIa such as Sc, Dy, and Gd may be added to the Y ₂ SiO ₅ : Tb green light emitting phosphor. Luminance and chromaticity can be improved by adding appropriate amounts of these elements. The upper limit of the allowable amount when adding Sr to CaMgSi ₂ O ₆ : Eu blue light emitting phosphor is about Ca _0.65 Sr _0.35 MgSi ₂ O ₆ : Eu, Zn is CaMg _0.75 Zn _0.25 Si ₂ O ₆ : Eu Degree. In addition, the upper limit of the allowable amount when adding Sc, Dy and Gd to the Y ₂ SiO ₅ : Tb green-emitting phosphor is (Y _0.75 , Sc _0.25 ) ₂ SiO ₅ : Tb, (Y _0.75 , Dy _0.25 ) _{It is about 2} SiO ₅ : Tb and (Y _0.75 , Gd _0.25 ) ₂ SiO ₅ : Tb.

  In addition, in the method of synthesizing the phosphor using the flux in each phosphor, there may be a case where at least one trace impurity selected from the group consisting of Group Ia, Group VIIb, and rare earth is contained.

Further, the object is to provide a plurality of mutually parallel first electrodes, a plurality of mutually parallel second electrodes orthogonal to the first electrodes, and intersections of the first electrodes and the second electrodes. Alternatively, a display panel having a substrate having an electron-emitting device installed in the vicinity of the intersection and a face plate on which a fluorescent film is formed; a first driving circuit connected to the first electrode; An image display device having a connected second drive circuit and a signal processing circuit to which a video signal is input, wherein the fluorescent film has a blue light emitting fluorescent film, a green light emitting fluorescent film, and a red light emitting fluorescent film The blue phosphor film includes a CaMgSi ₂ O ₆ : Eu blue light emitting phosphor, and the signal processing circuit has a function of mixing a blue signal of the video signal multiplied by a certain coefficient with a green signal. This is achieved by the image display device. The coefficient can be changed according to the intensity of the blue signal intensity, and the coefficient is preferably in the range of 0.01 to 0.4. The coefficient may be constant regardless of the blue signal intensity.

  The image display apparatus of the present invention has good linearity and long life for all of the blue, green and red light emitting phosphors, and therefore has good luminance characteristics and chromaticity balance even after being driven for a long time. In addition, the luminance and chromaticity are improved by optimizing the video signal.

That is, the electron beam excitation type thin flat display device of the present invention includes CaMgSi ₂ O ₆ : Eu blue light emitting phosphor, Y ₂ SiO ₅ : Tb green light emitting phosphor, Y ₂ O ₂ S: Eu or Y ₂ O ₃ : Since a phosphor film formed using any one or a plurality of phosphors of Eu red light emitting phosphor is used, the linearity of the light emission luminance of the display is good, and the luminance life and chromaticity balance are good. Furthermore, by performing signal processing using a signal hybrid block for video signal processing, the effective luminous efficiency of the blue phosphor can be increased, and the blue chromaticity can be made equivalent to that of the conventional phosphor. it can.

  Here, although each characteristic, such as the brightness | luminance of a fluorescent substance used for the image display apparatus of this invention, and a brightness maintenance factor, is explained in full detail, the Example shown below shows an example which actualizes this invention, and this The invention is not bound.

Embodiments of the present invention will be specifically described below with reference to the drawings.
<Example 1>
The luminance, luminance maintenance rate, and chromaticity characteristics of each phosphor were evaluated as follows.
(1) About blue light emitting phosphor:
As for the blue light-emitting phosphor, ZnS: Ag, Cl and Y ₂ SiO ₅ : Ce blue light-emitting phosphor are used as Comparative Examples 1 and 2, and CaMgSi ₂ O ₆ : Eu is used as the blue phosphor used in Example 1A of the present invention. The emission luminance characteristics were evaluated using a blue light emitting phosphor.

For each phosphor sample, a phosphor film was formed on a Ni-plated Cu substrate by precipitation coating. The coating weight was 2-5 mg / cm ² . The prepared sample was set in a demountable device equipped with an electron gun and measured. The electron beam in the demountable device is scanned left and right and up and down at the same frequency as a general television by a deflection yoke, and a square raster (electron beam irradiation range) is drawn in a certain range on the phosphor film produced as described above. Luminance and luminous intensity (radiation energy) through the radiometric filter were measured from the reflection side using a color difference meter and Si photocell. The luminance characteristics were evaluated under the conditions of an acceleration voltage of 7 kV, an irradiation area of 6 × 6 mm, an irradiation current of ² μA, a current density of 5.6 μA / cm ² , and a sample temperature of 20 ° C. Table 1 shows the evaluation results of the luminance characteristics.

The light emission luminance of the CaMgSi ₂ O ₆ : Eu phosphor that is Example 1A of the present invention is 35.2% of the ZnS: Ag, Cl phosphor used in Comparative Example 1. Comparative Example 2 with the Y ₂ SiO _5: emission luminance of Ce phosphor ZnS: Ag, but 65.2% Cl phosphor, which CaMgSi ₂ O _6: chromaticity y value of Eu phosphor is small Y ₂ Since the chromaticity y value of the SiO ₅ : Ce phosphor is large, there is a difference in luminance as visibility.

It is appropriate to use the luminescence energy to compare the luminance characteristics of the blue phosphors. The emission energy of the CaMgSi ₂ O ₆ : Eu phosphor which is Example 1A is 52.8%, which is higher than that of the Y ₂ SiO ₅ : Ce phosphor used in Comparative Example 2 which is 28.2%. Further, the linearity is as high as 0.97 compared to the ZnS: Ag, Cl phosphor (0.85) used in Comparative Example 1, and therefore the emission energy approaches the ZnS: Ag, Cl phosphor as the current becomes higher.

FIG. 1 shows changes in the amount of irradiation current of the emission energy of each blue light emitting phosphor. The linearity of the CaMgSi ₂ O ₆ : Eu phosphor (reference numeral 1 in the figure), which is Example 1A, is the same as that of Comparative Examples 1 and 2, and the ZnS: Ag, Cl phosphor (reference numeral 2 in the figure) and Y ₂ SiO ₅ : It is better than Ce phosphor (reference numeral 3 in the figure).

Next, the luminance maintenance rate of each blue light emitting phosphor was evaluated. The sample preparation and evaluation apparatus is the same as in the luminance characteristic evaluation. The luminance maintenance rate acceleration test was performed under the conditions of an acceleration voltage of 7 kV, an irradiation area of 6 × 6 mm, an irradiation current of 100 μA, a current density of 278 μA / cm ² , a sample temperature of 200 ° C., and an electron beam irradiation time of 1 hour.

Table 2 shows the evaluation results of the luminance maintenance rate and chromaticity change. Luminance maintenance ratio of the ZnS: Ag, Cl phosphor of Comparative Example 1 (the emission energy before and after the acceleration test is 7 kV acceleration voltage, irradiation area 6 × 6 mm, irradiation current ² μA, current density 5.6 μA / cm ² , sample temperature 20 ° C. Comparison) was 80.4%, while the Y ₂ SiO ₅ : Ce phosphor of Comparative Example 2 was 92.9%, and the luminance maintenance rate of the CaMgSi ₂ O ₆ : Eu phosphor of Example 1A was 95.8%. Met. The luminance maintenance rate of Y ₂ SiO ₅ : Ce phosphor is higher than that of ZnS: Ag, Cl phosphor, but both chromaticity x and y increased after the acceleration test, and the chromaticity deterioration in which the emission color shifts in the white direction. Is seen. The chromaticity y of the CaMgSi ₂ O ₆ : Eu phosphor slightly increases after the acceleration test, but is similar to that of the ZnS: Ag, Cl phosphor.

FIG. 2 shows a luminance maintenance rate curve of each blue light emitting phosphor during the acceleration test. The CaMgSi ₂ O ₆ : Eu phosphor of Example 1A (reference numeral 1 in the figure) is lower than the luminance maintenance rate of the ZnS: Ag, Cl phosphor of comparative example 1 (reference numeral 2 in the figure). And the Y ₂ SiO ₅ : Ce phosphor (reference numeral 3 in the figure) of Comparative Example 2 maintains a luminance maintenance rate of 90% or more. In particular, the luminance maintenance rate of the CaMgSi ₂ O ₆ : Eu phosphor (reference numeral 1 in the figure) used in Example 1A of the present invention is good.

（２）緑色発光蛍光体について：
緑色発光蛍光体について、比較例３としてZnS:Cu、Al緑色発光蛍光体を用い、本発明の実施例１ＢにはY₂SiO₅:Tb緑色発光蛍光体を用いた。各緑色発光蛍光体のデマウンタブル評価結果を表３に示す。Y₂SiO₅:Tb蛍光体の発光輝度はZnS:Cu,Al蛍光体の73.1%であり、発光エネルギーは75.4%であった。また、Y₂SiO₅:Tb蛍光体の色度はZnS:Cu,Al蛍光体よりもｘ値がやや大きく、ｙ値がやや小さい。リニアリティはZnS:Cu,Al(0.79)に比べて1.00とY₂SiO₅:Tb蛍光体は良好である。

(2) About green light emitting phosphor:
For the green light emitting phosphor, ZnS: Cu, Al green light emitting phosphor was used as Comparative Example 3, and Y ₂ SiO ₅ : Tb green light emitting phosphor was used in Example 1B of the present invention. Table 3 shows the demountable evaluation results of each green-emitting phosphor. The emission brightness of the Y ₂ SiO ₅ : Tb phosphor was 73.1% of the ZnS: Cu, Al phosphor, and the emission energy was 75.4%. Further, the chromaticity of the Y ₂ SiO ₅ : Tb phosphor has a slightly larger x value and a slightly smaller y value than that of the ZnS: Cu, Al phosphor. The linearity is 1.00 compared to ZnS: Cu, Al (0.79), and the Y ₂ SiO ₅ : Tb phosphor is good.

FIG. 3 shows changes in the amount of irradiation current of the light emission luminance of each green light emitting phosphor. The linearity of the Y ₂ SiO ₅ : Tb phosphor (reference numeral 5 in the figure) which is Example 1B of the present invention is better than that of the ZnS: Cu, Al phosphor of comparative example 3 (reference numeral 4 in the figure).

Next, the luminance maintenance rate evaluation of each green light emitting phosphor was performed. Table 4 shows the evaluation results of the luminance maintenance rate and chromaticity change. The brightness maintenance rate of the ZnS: Cu, Al phosphor of Comparative Example 3 is 82.5%, whereas the brightness maintenance rate of the Y ₂ SiO ₅ : Tb phosphor of Example 1B of the present invention is 96.0%, which is good. Met. Further, the chromaticity of the ZnS: Cu, Al phosphor and the Y ₂ SiO ₅ : Tb phosphor did not change much before and after the acceleration test.

FIG. 4 shows a luminance maintenance rate curve of each green light emitting phosphor during the acceleration test. While the luminance maintenance rate of the ZnS: Cu, Al phosphor (reference numeral 4 in the figure) of Comparative Example 3 is reduced, the Y ₂ SiO ₅ : Tb phosphor (Example 1B) of the present invention is shown in FIG. The luminance maintenance ratio of the middle code 5) is good at 90% or more.

（３）赤色発光蛍光体について：
赤色発光蛍光体について、本発明の実施例１ＣとしてY₂O₂S:Eu赤色発光蛍光体及び実施例１ＤとしてY₂O₃:Eu赤色発光蛍光体を用いた。各赤色発光蛍光体のデマウンタブル評価結果を表５に示す。Y₂O₃:Eu蛍光体の発光輝度はY₂O₂S:Eu蛍光体よりも高く、色度はy値がやや大きい。リニアリティはY₂O₃:Eu蛍光体がY₂O₂S:Eu蛍光体よりもやや大きい。

(3) About red light emitting phosphor:
For the red light-emitting phosphor, Y ₂ O ₂ S: Eu red light-emitting phosphor was used as Example 1C of the present invention, and Y ₂ O ₃ : Eu red light-emitting phosphor was used as Example 1D. Table 5 shows the demountable evaluation results of each red-emitting phosphor. The emission luminance of the Y ₂ O ₃ : Eu phosphor is higher than that of the Y ₂ O ₂ S: Eu phosphor, and the chromaticity has a slightly higher y value. The linearity of the Y ₂ O ₃ : Eu phosphor is slightly larger than that of the Y ₂ O ₂ S: Eu phosphor.

FIG. 5 shows changes in the amount of irradiation current of the emission luminance of each red light emitting phosphor. The emission luminance of the Y ₂ O ₃ : Eu phosphor (symbol 6 in the figure) is slightly higher than that of the Y ₂ O ₂ S: Eu phosphor (symbol 7 in the figure), but the linearity is almost the same.

Next, the luminance maintenance rate evaluation of each red light emitting phosphor was performed. Table 6 shows the evaluation results of the luminance maintenance rate and chromaticity change. The luminance maintenance rate of the Y ₂ O ₂ S: Eu phosphor used in Example 1C was 93.8%, and the luminance maintenance rate of the Y ₂ O ₃ : Eu phosphor used in Example 1D was 100%. Further, the chromaticity of the Y ₂ O ₂ S: Eu phosphor and the Y ₂ O ₃ : Eu phosphor did not change much before and after the acceleration test.

FIG. 6 shows a luminance maintenance rate curve of each red light emitting phosphor during the acceleration test. The luminance maintenance factor curve of the Y ₂ O ₂ S: Eu phosphor (symbol 7 in the figure) that becomes Example 1C rises at the initial stage of electron beam irradiation, and this is Y ₂ O ₂ S that becomes Example 1C. : The sample temperature dependence of the emission luminance of the Eu phosphor (symbol 7 in the figure) may be large. The Y ₂ O ₂ S: Eu phosphor and the Y ₂ O ₃ : Eu phosphor have good luminance maintenance ratios of 90% or more.

以上のようにして、青色発光蛍光体としてZnS:Ag,Cl蛍光体、Y₂SiO₅:Ce蛍光体及びCaMgSi₂O₆:Eu蛍光体；緑色発光蛍光体としてZnS:Cu,Al蛍光体及びY₂SiO₅:Tb蛍光体；赤色発光蛍光体としてY₂O₂S:Eu蛍光体及びY₂O₃:Eu蛍光体の発光輝度、輝度維持率及び色度の各特性を評価した。その結果、従来用いられている（ZnS:Ag,Cl青色発光蛍光体、ZnS:Cu,Al緑色発光蛍光体、Y₂O₂S:Eu赤色発光蛍光体）のＰ２２ＲＧＢ蛍光体セットよりも、（CaMgSi₂O₆:Eu青色発光蛍光体、Y₂SiO₅:Tb緑色発光蛍光体、Y₂O₂S:EuまたはY₂O₃:Eu赤色発光蛍光体のいずれか一種または複数種の蛍光体）の組合せのＲＧＢ蛍光体セットの方がＦＥＤの長寿命・高リニアリティを実現するのに適していることが分かった。

As described above, ZnS: Ag, Cl phosphor, Y ₂ SiO ₅ : Ce phosphor and CaMgSi ₂ O ₆ : Eu phosphor as blue light emitting phosphor; ZnS: Cu, Al phosphor as green light emitting phosphor and Y ₂ SiO ₅ : Tb phosphors: Y ₂ O ₂ S: Eu phosphors and Y ₂ O ₃ : Eu phosphors as red-emitting phosphors were evaluated for light emission luminance, luminance maintenance ratio, and chromaticity. As a result, the P22RGB phosphor set (ZnS: Ag, Cl blue light-emitting phosphor, ZnS: Cu, Al green light-emitting phosphor, Y ₂ O ₂ S: Eu red light-emitting phosphor) used in the prior art ( CaMgSi ₂ O ₆ : Eu blue light emitting phosphor, Y ₂ SiO ₅ : Tb green light emitting phosphor, Y ₂ O ₂ S: Eu or Y ₂ O ₃ : Eu red light emitting phosphor It was found that the RGB phosphor set having a combination of) is more suitable for realizing the long life and high linearity of the FED.

<Example 2>
MIM type electron source display device (1):
Hereinafter, description will be given with reference to FIGS. In this embodiment, a thin film electron source is used as the electron-emitting device 301. More specifically, an MIM (Metal-Insulator-Metal: metal-insulator-metal) electron source is used.

  FIG. 7 is a plan view of a display panel used in this embodiment. 8 is a cross-sectional view taken along the line AB of FIG. As shown in FIG. 8, the cross-sectional structure of the display panel is as follows. The inside surrounded by is a vacuum. A spacer 60 is disposed in the vacuum region to resist atmospheric pressure. The shape, number and arrangement of the spacers 60 are arbitrary. On the cathode plate 601, the scanning electrode 310 is disposed in the horizontal direction, and the data electrode 311 is disposed orthogonally thereto.

  An intersection of the scan electrode 310 and the data electrode 311 corresponds to a sub pixel. Here, in the case of a color image display device, the sub-pixel corresponds to each of red, blue, and green sub-pixels. FIG. 7 shows only 12 scanning electrodes 310, but there are hundreds to thousands in an actual display. The same applies to the data electrode 311. An electron-emitting device 301 is disposed at the intersection between the scan electrode 310 and the data electrode 311. In this embodiment, a thin film electron source is used as the electron-emitting device 301.

  FIG. 9 is a cross-sectional view of a display panel used in the present embodiment and shows a detailed cross-sectional structure. There is an electron emission region in a region where the lower electrode 13 (scanning electrode 310 in FIG. 7) and the upper electrode bus line 32 (data electrode 311 in FIG. 7) intersect, and electrons are emitted from this region. 9A is a cross-sectional view taken along the line AB in FIG. 7 (however, for 3 sub-pixels), and FIG. 9B is a cross-sectional view (for 3 sub-pixels) in a direction orthogonal thereto. .

Details of the configuration of the cathode plate 601 shown in FIGS. 7 and 8 will be described with reference to FIG. A thin film electron source 301 composed of a lower electrode 13 (Al), an insulating layer 12 (Al ₂ O ₃ ), and an upper electrode 11 (Ir—Pt—Au) is formed on an insulating substrate 14 such as glass. The The upper electrode bus line 32 is electrically connected to the upper electrode 11 through the upper electrode bus line base film 33, and functions as a power supply line to the upper electrode 11. In this embodiment, the upper electrode bus line 32 functions as the data electrode 311.

  A region on the cathode plate 601 (substrate 14) where the electron-emitting devices 301 are arranged in a matrix (referred to as a cathode arrangement region 610) is covered with an interlayer insulating film 410, on which a common electrode 420 is formed. Has been. The common electrode 420 is composed of a laminated film of a common electrode film A421 and a common electrode film B422. The common electrode 420 is connected to the ground potential. The spacer 60 is in contact with the common electrode 420 and functions to flow a current flowing from the acceleration electrode 122 of the face plate 110 (the fluorescent plate 602 in FIG. 8) through the spacer 60 and to flow a charged charge to the spacer 60. In FIG. 9, the scale in the height direction is arbitrary. That is, the lower electrode 13 and the upper electrode bus line 32 have a thickness of several μm or less, but the distance between the substrate 14 and the face plate (fluorescent plate 602) 110 is about 1 to 3 mm. A method for producing the cathode plate 601 is described in Japanese Patent Application Laid-Open No. 2003-323148 of the present applicant.

Fluorescent films 114A and 114B formed of CaMgSi ₂ O ₆ : Eu blue light-emitting phosphor, Y ₂ SiO ₅ : Tb green light-emitting phosphor, and Y ₂ O ₃ : Eu red light-emitting phosphor are disposed inside the fluorescent plate 602 (face plate 110). 114C. In order to increase the definition, the black conductive material 120 is provided between the pixels. In the production of the black conductive material 120, a photoresist film is applied on the entire surface, exposed through a mask and developed to leave a photoresist film partially. Thereafter, after forming a graphite film on the entire surface, hydrogen peroxide or the like was applied to remove the photoresist film and the graphite thereon, thereby forming a black conductive material.

  A screen printing method was used for applying the fluorescent film 114. The phosphor is kneaded with a vehicle mainly composed of a cellulose resin or the like to prepare a paste. Next, a stamp is applied through a stainless mesh. The red, green, and blue phosphors were separately applied by matching the positions of the mesh holes with the positions of the respective phosphor films. Next, the phosphor film formed by printing was baked and mixed to remove the cellulose resin and the like. In this way, a phosphor pattern was formed. The acceleration electrode 122 (metal back) is formed by vacuum-depositing Al after filming the inner surface of the fluorescent film. Then, it heat-processed and produced by skipping the filming agent. In this way, the fluorescent screen 602 is completed.

  As shown in FIG. 8, an appropriate number of spacers 60 are arranged between the cathode plate 601 and the fluorescent plate 602. As shown in FIGS. 7 and 8, the cathode plate 601 and the fluorescent plate 602 are sealed with a frame member 603 interposed therebetween. Further, the space 10 (see FIG. 9) surrounded by the cathode plate 601, the fluorescent plate 602, and the frame member 603 is evacuated to a vacuum. In this way, the display panel 100 is completed.

  FIG. 10 is a block diagram illustrating a configuration of an image display apparatus using the display panel 100 described above. A scan driver circuit 705 is connected to the scan electrode 310 of the display panel 100, and a data driver circuit 704 is connected to the data electrode 311. The acceleration electrode 122 (see FIG. 9) of the display panel 100 connects the acceleration voltage circuit 720. From the acceleration voltage circuit 720, a high voltage of 1 to 12 kV is applied to the acceleration electrode 122 to accelerate the electrons emitted from the electron-emitting devices and irradiate the phosphor.

  A video signal such as a television signal is input to the signal processing block 701 to generate and output a timing signal and process the video signal described later. The video signal processed here is input to the serial / parallel conversion block 703. As a result, a signal to be input to each data electrode 311 is set in a circuit corresponding to each data electrode. This signal is converted into an appropriate pulse signal by the data driver circuit 704 and applied to the data electrode 311 of the display panel. The serial / parallel conversion block 703 and the data driver circuit 704 may be realized as an integrated circuit. On the other hand, the timing signal generated by the signal processing block 701 is also input to the scan driver 705 to generate a pulse waveform synchronized with the output of the data driver circuit 704.

  FIG. 11 shows voltage waveforms applied to the scan electrode 310 and the data electrode 311 of the image display device shown in FIG. In this figure, an example of an image display device having a pixel number of 480 rows × 640 columns (sub-pixel number of 480 × 1920) is shown. Scan pulse 750 is sequentially applied to each of scan electrodes 310S1 to S480 during one field period of the image signal. At the same time, a data pulse 751 having a voltage amplitude corresponding to the image signal is applied to each of the data electrodes 311D1 to D1920.

  The sub-pixel to which both the scanning pulse 750 and the data pulse 751 are applied is turned on. At this time, the current amount of electrons emitted from the thin film electron source 301 (see FIG. 9) is adjusted according to the voltage amplitude value of the data pulse 751. The emitted electrons are accelerated by a high voltage applied to the acceleration electrode 122 (see FIG. 9), and then irradiate the phosphor to emit light. Therefore, the light emission amount (luminance value) is also adjusted by the voltage amplitude value of the data pulse.

  In this way, a desired image can be displayed. In this way, one screen can be displayed in one field period (16.6 ms for NTSC video signals). Note that the inversion pulse 756 is applied to the scan electrode 310 once in one field period. Thus, the lifetime of the thin-film electron source can be improved by applying a voltage having a reverse polarity to that during electron emission.

The configuration of the signal processing block 701 is shown in FIG. The video signal is input to the video signal processing block 711 to extract the video signal and extract a synchronization signal such as a vertical synchronization signal. This synchronization signal is input to the timing signal generation circuit 712 to generate a timing signal. On the other hand, the video signal is extracted as a signal component (RGB signal) corresponding to red (R), green (G), and blue (B). This RGB signal is subjected to gamma reverse correction in a gamma reverse correction block 714. Thereafter, in the signal mixing block 716, the green (G) signal and the blue (B) signal are mixed at an appropriate ratio. The signal strength of each color R, G, B before mixing is I (R), I (G), I (B), respectively, and the signal strength after mixing is I '(R), I' (G), I '(B).
I '(R) = I (R)
I '(G) = I (G) + αI (B)
I '(B) = I (B)
Here, α is set to a value in the range of 0.01 to 0.4.
As an example, consider the case where blue is displayed. The input signal is
I (R) = I (G) = 0, I (B) = I0
It becomes. I0 is the blue signal intensity. The signal strength after mixing is
I '(R) = 0, I' (G) = αI0, I '(B) = I0
It becomes. Even when displaying blue in this way, the green display element emits light at an appropriate ratio. By doing in this way, the chromaticity y value obtained on the screen of an image display apparatus can be match | combined with the conventional blue fluorescent substance. Furthermore, by adding the light emission of the green display element, the luminance at the time of blue display increases, so that the blue light emission efficiency as the image display device increases. That is, it is possible to alleviate the problem that the luminous efficiency is lower than that of the conventional blue phosphor.

  The light emission luminance, linearity, luminance life and chromaticity balance according to the present invention are good, and particularly good light emission luminance characteristics are exhibited even after long-time driving.

<Example 3>
MIM type electron source display device (2):
The MIM type electron source display device of the present invention is shown in FIG. In particular, a fluorescent film formed of CaMgSi ₂ O ₆ : Eu blue light-emitting phosphor, Y ₂ SiO ₅ : Tb green light-emitting phosphor and Y ₂ O ₂ S: Eu red light-emitting phosphor is disposed inside the fluorescent plate 602 (face plate 110). There are 114A, 114B, and 114C. The formation method of the phosphor film 114, the black conductive material 120, and the metal back 122 is the same as that in the second embodiment. The light emission luminance, linearity, luminance life and chromaticity balance according to the present invention were as good as in Example 2.

<Example 4>
MIM type electron source display device (part 3):
The MIM type electron source display device of the present invention is shown in FIG. In particular, the CaMgSi ₂ O ₆ : Eu blue light-emitting phosphor, Y ₂ SiO ₅ : Tb green light-emitting phosphor, Y ₂ O ₂ S: Eu and Y ₂ O ₃ : Eu red light are emitted inside the fluorescent plate 602 (face plate 110). There are phosphor films 114A, 114B, and 114C formed by a red light emitting phosphor sample mixed with phosphors. The formation method of the phosphor film 114, the black conductive material 120, and the metal back 122 is the same as that in the second embodiment. The light emission luminance, linearity, luminance life and chromaticity balance according to the present invention were as good as in Example 2.

<Example 5>
MIM type electron source display device (part 4):
The MIM type electron source display device of the present invention is shown in FIG. In particular, the inside of the fluorescent plate 602 (face plate 110) is formed of CaSrMgSi ₂ O ₆ : Eu blue light emitting phosphor, (Y, Sc) ₂ SiO ₅ : Tb green light emitting phosphor, Y ₂ O ₃ : Eu red light emitting phosphor. Phosphor films 114A, 114B, and 114C. The formation method of the phosphor film 114, the black conductive material 120, and the metal back 122 is the same as that in the second embodiment. The light emission luminance, linearity, luminance life and chromaticity balance according to the present invention were as good as in Example 2.

In this embodiment, fluorescent blue-emitting phosphor of the body CaMgSi ₂ O ₆ Example _2: CaSrMgSi 2 O ₆ containing Sr as IIa group element instead of Eu: the Eu, The green emitting phosphor Instead of Y ₂ SiO ₅ : Tb, (Y, Sc) ₂ SiO ₅ : Tb containing Sc as a group IIIa element was used.

<Example 6>
MIM type electron source display device (part 5):
The MIM type electron source display device of the present invention is shown in FIG. In particular, CaMg (Si, Ge) ₂ O ₆ : Eu blue light emitting phosphor, (Y, Gd) ₂ SiO ₅ : Tb green light emitting phosphor, Y ₂ O ₃ : Eu red are inside the fluorescent plate 602 (face plate 110). There are fluorescent films 114A, 114B, and 114C formed of a light emitting phosphor. The formation method of the phosphor film 114, the black conductive material 120, and the metal back 122 is the same as that in the second embodiment. The light emission luminance, linearity, luminance life and chromaticity balance according to the present invention were as good as in Example 2.

In this example, CaMg (Si, Ge) ₂ O ₆ : Eu containing Ge as an IVb group element instead of the blue light emitting phosphor CaMgSi ₂ O ₆ : Eu in the phosphor of Example ₂ , Instead of the green light-emitting phosphor Y ₂ SiO ₅ : Tb, (Y, Gd) ₂ SiO ₅ : Tb containing Gd as a group IIIa element was used.

<Example 7>
MIM type electron source display device (6):
The MIM type electron source display device of the present invention is shown in FIG. In particular, the inside of the fluorescent plate 602 (face plate 110) is formed of CaMgZnSi ₂ O ₆ : Eu blue light emitting phosphor, (Y, Dy) ₂ SiO ₅ : Tb green light emitting phosphor, Y ₂ O ₃ : Eu red light emitting phosphor. Phosphor films 114A, 114B, and 114C. The formation method of the phosphor film 114, the black conductive material 120, and the metal back 122 is the same as that in the second embodiment. The light emission luminance, linearity, luminance life and chromaticity balance according to the present invention were as good as in Example 2.

In this example, CaMg Zn Si ₂ O ₆ : Eu containing Zn as a group IIb element instead of the blue light emitting phosphor CaMgSi ₂ O ₆ : Eu among the phosphors of Example 2, and green light emission Instead of the phosphor Y ₂ SiO ₅ : Tb, (Y, Dy) ₂ SiO ₅ : Tb containing Dy as a group IIIa element was used.

<Example 8>
Spindt-type electron source display device (Part 1)
A Spindt type electron source display device of the present invention is shown in FIG. The Spindt-type electron source display device 19 includes a face plate 110, a Spindt-type electron source 18, and a rear plate 14. The Spindt-type electron source 18 includes a cathode 20, a resistance film 21, an insulating film 22, a gate 23, a conical metal ( Mo etc.) 24 is formed. In particular, inside the face plate 110 is a fluorescent film 114 formed of CaMgSi ₂ O ₆ : Eu blue light-emitting phosphor, Y ₂ SiO ₅ : Tb green light-emitting phosphor and Y ₂ O ₃ : Eu red light-emitting phosphor.

  The formation method of the phosphor film 114, the black conductive material 120, and the metal back 122 (not shown) is the same as that in the second embodiment. The light emission luminance, linearity, luminance life and chromaticity balance according to the present invention were as good as in Example 2.

  The Spindt-type electron source 18 has a characteristic that the electron emission performance is greatly deteriorated when sulfur (element name: S) adheres to the surface. Therefore, as in this embodiment, the lifetime of the electron-emitting device can be extended and the stability can be improved by using a combination containing no sulfur in the phosphor.

<Example 9>
Spindt-type electron source display device (2):
A Spindt type electron source display device of the present invention is shown in FIG. In particular, inside the face plate 110 is a fluorescent film 114 formed of CaMgSi ₂ O ₆ : Eu blue light-emitting phosphor, Y ₂ SiO ₅ : Tb green light-emitting phosphor and Y ₂ O ₂ S: Eu red light-emitting phosphor. . The method for forming the fluorescent film, the black conductive material, and the metal back is the same as that in Example 2. The light emission luminance, linearity, luminance life and chromaticity balance according to the present invention were as good as in Example 2.

<Example 10>
Spindt-type electron source display device (Part 3):
A Spindt type electron source display device of the present invention is shown in FIG. In particular, CaMgSi ₂ O ₆ : Eu blue light-emitting phosphor, Y ₂ SiO ₅ : Tb green light-emitting phosphor, Y ₂ O ₂ S: Eu and Y ₂ O ₃ : Eu red light-emitting phosphor are placed inside the face plate 110. There is a phosphor film 114 formed by a mixed red-emitting phosphor sample. Further, in order to reduce the resistance of the phosphor, a conductive substance In ₂ O ₃ was mixed into the phosphor film. The formation method of the phosphor film 114, the black conductive material 120, and the metal back 122 is the same as that in the second embodiment. The light emission luminance, linearity, luminance life and chromaticity balance according to the present invention were as good as in Example 2.

<Example 11>
Carbon nanotube type electron source display device (Part 1):
The carbon nanotube type electron source display device of the present invention is shown in FIG. The carbon nanotube type electron source display device 28 includes a face plate 110, a carbon nanotube electron source 27, and a rear plate 14. The carbon nanotube type electron source 27 includes an electrode 25 and a carbon nanotube layer 26. In particular, inside the face plate 110 is a fluorescent film 114 formed of CaMgSi ₂ O ₆ : Eu blue light-emitting phosphor, Y ₂ SiO ₅ : Tb green light-emitting phosphor and Y ₂ O ₃ : Eu red light-emitting phosphor. The formation method of the phosphor film 114, the black conductive material 120, and the metal back 122 is the same as that in the second embodiment. The light emission luminance, linearity, luminance life and chromaticity balance according to the present invention were as good as in Example 2.

<Example 12>
Carbon nanotube electron source display device (2):
The carbon nanotube type electron source display device of the present invention is shown in FIG. In particular, inside the face plate 110 is a fluorescent film 114 formed of CaMgSi ₂ O ₆ : Eu blue light-emitting phosphor, Y ₂ SiO ₅ : Tb green light-emitting phosphor and Y ₂ O ₂ S: Eu red light-emitting phosphor. . The formation method of the phosphor film 114, the black conductive material 120, and the metal back 122 is the same as that in the second embodiment. The light emission luminance, linearity, luminance life and chromaticity balance according to the present invention were as good as in Example 2.

<Example 13>
Carbon nanotube electron source display device (Part 3):
The carbon nanotube type electron source display device of the present invention is shown in FIG. In particular, CaMgSi ₂ O ₆ : Eu blue light-emitting phosphor, Y ₂ SiO ₅ : Tb green light-emitting phosphor, Y ₂ O ₂ S: Eu and Y ₂ O ₃ : Eu red light-emitting phosphor are placed inside the face plate 110. There is a phosphor film 114 formed by a mixed red-emitting phosphor sample. Further, in order to reduce the resistance of the phosphor, a conductive substance In ₂ O ₃ was mixed into the phosphor film. The formation method of the phosphor film 114, the black conductive material 120, and the metal back 122 is the same as that in the second embodiment. The linearity, luminance life and chromaticity balance of the light emission luminance according to the present invention were as good as in (Example 2).

The graph which shows the light emission energy-irradiation current amount change of the fluorescent film of this invention. The graph which shows the brightness | luminance maintenance factor curve of the fluorescent film of this invention. The graph which shows the light emission luminance-irradiation current amount change of the fluorescent film of this invention. The graph which shows the brightness | luminance maintenance factor curve of the fluorescent film of this invention. The graph which shows the light emission luminance-irradiation current amount change of the fluorescent film of this invention. The graph which shows the brightness | luminance maintenance factor curve of the fluorescent film of this invention. The typical top view of the display panel in Example 2 of the present invention. The typical sectional view of the display panel in Example 2 of the present invention. The typical sectional view of the display panel in Example 2 of the present invention. The block diagram of the image display apparatus in Example 2 of this invention. The figure which shows the applied voltage waveform in Example 2 of this invention. The block diagram explaining the structure of the signal processing block in Example 2 of this invention. The schematic diagram which shows the whole structure of the Spindt type | mold electron source display apparatus of this invention. The schematic diagram which shows the whole structure of the carbon nanotube type | mold electron source display apparatus of this invention.

Explanation of symbols

11 ... Upper electrode,
12 ... Insulating layer,
13 ... lower electrode,
14 ... substrate,
18 ... Spindt type electron source,
19 ... Spindt type electron source display device,
20 ... cathode,
21 ... resistive film,
22: Insulating film,
23 ... Gate,
24 ... conical metal,
25 ... electrodes,
26 ... carbon nanotube layer,
27 ... Carbon nanotube type electron source,
28 ... Carbon nanotube type electron source display device,
32 ... Upper electrode bus line,
41. Scanning drive circuit,
42: Data drive circuit,
43 ... Accelerating electrode drive circuit,
60: spacer,
100 ... display panel,
110 ... face plate,
114 ... phosphor,
120 ... black conductive material,
122 ... Accelerating electrode,
301 ... Thin film electron source,
310 ... scanning electrodes,
311: Data electrode,
420 ... Common electrode,
601 ... cathode plate,
602 ... fluorescent screen,
603 ... a frame member,
701 ... Signal processing block,
711 ... Video signal processing block,
712 ... Timing signal generation circuit,
714 ... Gamma inverse correction block,
716 ... Signal hybrid block,
703 ... Serial to parallel conversion block,
704 ... Data driver circuit,
705 ... Scan driver,
750 ... scan pulse,
751 ... data pulse,
754 ... Inverted pulse,
756: Vertical blanking period.

Claims (9)

A plurality of parallel first electrodes, a plurality of mutually parallel second electrodes orthogonal to the first electrodes, and an intersection or the vicinity of the first electrode and the second electrode. An image display device having a substrate having an electron-emitting device and a face plate on which a fluorescent film is formed, wherein the fluorescent film is a blue light-emitting fluorescent film containing a CaMgSi ₂ O ₆ : Eu blue light-emitting phosphor, Y ₂ SiO ₅ : Tb Green light-emitting phosphor containing green light-emitting phosphor and Y ₂ O ₃ : Eu red light-emitting phosphor or Y ₂ O ₂ S: Eu red light-emitting phosphor An image display device comprising a phosphor film of an RGB phosphor set including a red light emitting phosphor film including   2. The image display device according to claim 1, wherein a blue light emitting phosphor film is used in which at least one element selected from the group consisting of Group IIa, Group IIb and Group IVb is added to the blue light emitting phosphor.   2. The image display device according to claim 1, wherein a green light emitting phosphor film is used in which at least one element selected from the group consisting of group IIIa is added to the green light emitting phosphor.   2. The image display device according to claim 1, wherein the phosphor constituting the phosphor film contains at least one trace impurity selected from the group consisting of Group Ia, Group VIIb, and rare earth. A plurality of parallel first electrodes, a plurality of mutually parallel second electrodes orthogonal to the first electrodes, and an intersection or the vicinity of the first electrode and the second electrode. A display panel having a substrate having an electron-emitting device and a face plate on which a fluorescent film is formed; a first drive circuit connected to the first electrode; and a second drive connected to the second electrode An image display device having a driving circuit and a signal processing circuit to which a video signal is input, wherein the fluorescent film includes a blue light emitting fluorescent film, a green light emitting fluorescent film, and a red light emitting fluorescent film, and the blue light emitting The fluorescent film includes a CaMgSi ₂ O ₆ : Eu blue light emitting phosphor, and the signal processing circuit has a function of mixing a blue signal of the video signal multiplied by a certain coefficient with a green signal. Display device.   The image display apparatus according to claim 5, wherein the coefficient is changed according to a magnitude of a blue signal intensity.   The image display apparatus according to claim 5, wherein the coefficient is in a range of 0.01 to 0.4.   The image display apparatus according to claim 5, wherein the coefficient is constant regardless of the blue signal intensity. Y ₂ SiO ₅ : Tb green light-emitting phosphor is used as the green phosphor film, and Y ₂ O ₃ : Eu red light-emitting phosphor or Y ₂ O ₂ S: Eu red light-emitting phosphor is used as the red phosphor film, 6. The image display device according to claim 5, wherein a plurality of types of phosphors are used.

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