JP2006093053A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device capable of improving luminance compared with conventional one and superior in luminance characteristics. <P>SOLUTION: The image display device comprises a front substrate 11 having a fluorescent screen 15 including a phosphor layer 16 and a light shielding layer 17 thinner than the phosphor layer 16; a metal back layer 20 laid on the phosphor layer 16 of the fluorescent screen 15; and a rear substrate 12 arranged in opposition to the front substrate 11, having an electron emission element 18 arranged for emitting electrons toward the fluorescent screen. A means for improving luminance is arranged between the phosphor layers 16. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image display device, and more particularly to an image display device having a structure capable of improving the improvement in luminance.

  In recent years, as a next-generation image display device, a flat-type image display device in which a large number of electron-emitting devices are arranged to face an image display surface has been developed. There are various types of electron-emitting devices, and all of them basically use electron emission by an electric field, and image display devices using these electron-emitting devices are generally field emission displays (hereinafter referred to as field emission displays). , Referred to as FED). Among such FEDs, an image display device using a surface conduction electron-emitting device is also called a surface conduction electron-emitting display (hereinafter referred to as SED), but the term FED is used as a general term including SED. Use.

In general, the FED has a front substrate and a rear substrate that are opposed to each other with a predetermined gap. These substrates are joined to each other at their peripheral parts via a rectangular frame-shaped side wall to constitute a vacuum envelope. The inside of the vacuum envelope is maintained at a high vacuum with a degree of vacuum of about 10 ⁻⁴ Pa or less. Further, in order to support an atmospheric pressure load applied to the back substrate and the front substrate, a plurality of support members are disposed between these substrates.

  On the inner surface of the front substrate, a phosphor screen including phosphor layers that respectively emit red, blue, and green is formed. In order to obtain practical display characteristics, an aluminum thin film called a metal back layer is formed on the phosphor screen. Furthermore, in order to adsorb the gas remaining inside the vacuum envelope and the gas released from each substrate (for example, hydrogen, methane, oxygen, carbon dioxide, water vapor, etc.), it has a gas adsorption characteristic called getter layer. A metal thin film such as Ba (barium), V (vanadium), Ti (titanium), and Ta (tantalum) is deposited on the metal back layer.

  A large number of electron-emitting devices that emit electrons for exciting the phosphor to emit light are provided on the inner surface of the rear substrate. A large number of scanning lines and signal lines are formed in a matrix and connected to each electron-emitting device.

  In such an FED, an anode voltage is applied to the image display surface including the phosphor layer and the metal back layer, and the electron beam emitted from the electron-emitting device is accelerated by the anode voltage and collides with the phosphor screen. The phosphor emits light. Thereby, an image is displayed on the image display surface. In this case, the anode voltage is desired to be at least several kV, preferably 10 kV or more.

  In such an FED, the gap between the front substrate and the rear substrate can be set to about 1 to 2 mm, which is significantly larger than that of a cathode ray tube (CRT) used as a display of a current television or computer. Weight reduction and thickness reduction can be achieved.

As a specific conventional image display device, for example, as shown in paragraph [0015] of FIG. 1 and FIG. 1, phosphor layers that emit red, green, and blue respectively on the inner surface of the face plate are, for example, striped or A configuration in which a black colored layer is formed on the inner surface of the face plate between the phosphor layers is known.
Japanese Patent Laid-Open No. 2002-127019

However, according to the conventional image display device, a black colored layer is formed on the inner surface of the face plate between the phosphor layers in order to maintain a necessary discharge space and to separate the discharge and each pixel of the phosphor layer. Therefore, there is a problem that sufficient luminance cannot be obtained.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an image display device capable of improving the luminance as compared with the prior art.

  An image display device according to a first aspect of the present invention includes a phosphor layer and a phosphor screen including a light-shielding layer having a thickness smaller than that of the phosphor layer, and a metal back layer provided on the phosphor layer of the phosphor layer. , And a rear substrate disposed opposite to the front substrate and disposed with an electron-emitting device that emits electrons toward the phosphor surface. Means for improving luminance is provided between body layers.

  According to the image display device of the present invention, the luminance can be improved as compared with the conventional device by providing means for improving the luminance between the phosphor layer and the phosphor layer.

  According to the present invention, it is possible to provide an image display device capable of improving the luminance as compared with the prior art.

  An image display apparatus according to an embodiment of the present invention will be described below with reference to the drawings. Here, as an image display device according to the present invention, an FED including a surface conduction electron-emitting device will be described as an example.

First, an overall view of the FED will be described with reference to FIGS.
As shown in FIGS. 1 and 2, the FED includes a front substrate 11 and a rear substrate 12 that are opposed to each other with a gap of 1 to 2 mm. Each of the front substrate 11 and the rear substrate 12 is configured by using a rectangular glass plate having a thickness of about 1 to 3 mm as an insulating substrate. The front substrate 11 and the back substrate 12 are flat rectangular vacuum envelopes whose peripheral portions are bonded to each other via a rectangular frame-shaped side wall 13 and whose inside is maintained at a high vacuum of about 10 ⁻⁴ Pa. 10 is constituted.

  The vacuum envelope 10 includes a plurality of spacers 14 provided therein for supporting an atmospheric pressure load applied to the front substrate 11 and the rear substrate 12. As the spacer 14, a plate shape or a column shape can be adopted.

  A fluorescent screen 15 is formed on the inner surface of the front substrate 11. The phosphor screen 15 includes a phosphor layer 16 that emits red, green, and blue light, respectively, and a light absorption layer (light shielding layer) 17 that is arranged in a matrix. A metal back layer 20 that functions as an anode electrode and a getter layer (not shown) are formed on the phosphor screen 15. The phosphor layer 16 is formed on, for example, dots. The metal back layer 20 is formed of an aluminum alloy film or the like. The getter layer is formed of a metal film (for example, a titanium film) having gas adsorption characteristics, and the gas remaining in the vacuum envelope 10 and the gas released from each substrate (for example, hydrogen, methane, oxygen, carbon dioxide) , Water vapor, etc.). On the light-shielding layer between the phosphor layer 16 and the phosphor layer 16, means for improving the luminance is applied as will be described in detail later.

  The back substrate 12 includes a surface conduction electron-emitting device 18 on its inner surface. The electron-emitting device 18 functions as an electron source that excites the phosphor layer 16 of the phosphor screen 15. That is, the plurality of electron-emitting devices 18 are arranged in a plurality of columns and a plurality of rows corresponding to each pixel on the back substrate 12, and each emits an electron beam toward the phosphor layer 16. Each electron-emitting device 18 includes an electron emitting portion (not shown) and a pair of device electrodes for applying a voltage to the electron emitting portion. Further, a large number of wirings 21 for supplying a potential to the electron-emitting device 18 are provided in a matrix shape on the inner surface of the rear substrate 12, and end portions thereof are drawn out of the vacuum envelope 10.

  In such an FED, an anode voltage is applied to an image display surface including the phosphor screen 15 and the metal back layer 20 during an image display operation. Then, the electron beam emitted from the electron emitter 18 is accelerated by the anode voltage and collides with the phosphor screen 15. As a result, the phosphor layer 16 on the phosphor screen 15 is excited and emits light in the corresponding colors. In this way, a color image is displayed on the image display surface.

Next, “means for improving luminance” which is the gist of the present invention will be described with reference to FIGS. The same members as those in FIGS. 1 and 2 are described with the same reference numerals.
1) When the means is a white resistive material layer disposed on the front substrate between the phosphor layer and the phosphor layer via a light shielding layer.
As shown in FIG. 3, a white resistive material layer 31 is formed on the light shielding layer 17 on the front substrate 11. Here, examples of the white resistor material layer 31 include a mixture of TiO ₂ and frit. The resistance material layer 31 is formed on the light shielding layer 17 after the light shielding layer 17 is formed on the front substrate 11 between the phosphor layer 16 and the phosphor layer 16. The resistance material layer 31 is preferably as thick as possible while ensuring the minimum thickness of the light shielding layer 17. The arrangement of the resistance material layer 31 can improve the luminance as compared with the conventional case.
The resistance material layer 31 is preferably formed in a concave shape as shown in FIG. The concave resistance material layer 31 can be formed by double exposure or halftone exposure. The presence of the resistance material layer 31 having such a shape has an advantage that the creepage distance can be increased and the breakdown voltage against discharge can be improved in addition to the improvement in luminance.

2) When the means is a light reflecting film disposed on the side wall around the phosphor layer.
Examples of the material of the light reflecting film include Al, but the material is not limited to this as long as the material reflects light. The light reflecting film can be formed by vapor-depositing a light reflecting film material on the side wall of the phosphor layer obliquely with respect to the main surface of the substrate while rotating the front substrate on which the phosphor layer or the light shielding layer is formed. . With the arrangement of the light reflecting film, the luminance can be improved as compared with the conventional case.

3) When the means is a white resistance material layer disposed on the front substrate between the phosphor layer and the phosphor layer via the light shielding layer, and a light reflecting film disposed on the side wall of the phosphor layer.
As shown in FIG. 5, a light reflecting film 32 is formed on the side wall of the phosphor layer 16, and a white resistive material layer 31 is formed on the light shielding layer 17 on the front substrate 11. Here, the material and the formation method of the light reflection film 32 and the resistance material layer 31 are the same as those described above. Here, the resistance material layer 31 is formed after the light reflecting film 32 is formed on the side wall of the phosphor layer 16. With the arrangement of the resistance material layer 31 and the light reflecting film 32, the luminance can be improved as compared with the conventional case.

Next, the structure on the front substrate side that can be applied to the FED configured as described above will be described in more detail.
(First embodiment)
That is, in the FED according to the first embodiment, as shown in FIG. 3, a light shielding layer 17 made of a black pigment and having a thickness of 5 μm is formed in a dot shape on a front substrate (glass substrate) 11 by a photolithography method. . Between the light-shielding layer 17 and the light-shielding layer 17, the phosphor layers 16 having a thickness of 10 μm and three colors of red (R), green (G), and blue (B) are adjacent to each other in a dot shape. Is formed. A metal back layer 20 made of an aluminum (Al) alloy is formed on the phosphor layer 16. Although not shown, a getter layer made of a material such as Ti is formed on the metal back layer 20. On the front substrate 11 between the phosphor layer 16 and the phosphor layer 16 adjacent to the phosphor layer 16, a white resistance material layer 31 having a thickness of 5 μm is formed via a light shielding layer 17. Here, the resistance material layer 31 is composed of a resistance material layer in which TiO ₂ and frit are mixed.

Each member mentioned above is formed as follows.
First, the light shielding layer 17 made of a black pigment is formed on the front substrate 11 in a dot shape by a photolithography method. Next, a resistance material layer 31 is formed on the light shielding layer 17 by photolithography. Subsequently, phosphor layers 16 of three colors of R, G, and B are formed in a dot shape between the light shielding layer 17 and the light shielding layer 17 so as to be adjacent to each other by a photolithography method. In this way, a fluorescent screen is formed. Subsequently, a metal back layer 20 and a getter layer (not shown) are sequentially formed on the phosphor screen.

  According to the first embodiment, since the white resistive material layer 31 is formed on the front substrate 11 between the phosphor layers 16 and the adjacent phosphor layers 16 with the light shielding layer 17 interposed therebetween, The luminance can be remarkably improved as compared with the structure having only the light shielding layer.

In the first embodiment, an Al alloy is used as the material for the metal back layer. However, the present invention is not limited to this. For example, any material of nickel (Ni) or chromium (Cr) can be used. In addition to Ti, the material of the getter layer is, for example, any one of tantalum and strontium getter materials, a laminate of these getter materials, or a layer based on the alloy state of these getter materials. Is possible. Further, the material of the resistance material layer is not limited to a material in which TiO ₂ and frit are mixed.

(Second Embodiment)
Although not shown, the second embodiment has a configuration in which a light reflecting film made of Al as means for improving luminance is formed on the side wall of the phosphor layer. The light reflecting film can be formed by vapor-depositing a light reflecting film material (Al) on the side wall of the phosphor layer obliquely with respect to the main surface of the substrate.
According to the second embodiment, the luminance can be improved as compared with the conventional case by adopting the configuration in which the light reflecting film is arranged on the side wall of the phosphor layer. The light reflecting film material is not limited to Al, and other materials may be used.

(Third embodiment)
As shown in FIG. 4, the FED according to the third embodiment is characterized in that the resistance material layer 31 is formed in a concave shape as compared with the case of FIG. The concave resistance material layer 31 can be formed by exposing twice using two types of exposure masks in sequence, but may be formed by halftone exposure.

  According to the third embodiment, the arrangement of the resistance material layer 31 can improve the brightness as compared with the conventional case, and the resistance material layer 31 has a concave shape, so that the creepage distance is increased and the breakdown voltage against discharge is improved. It has the advantage of being able to.

(Fourth embodiment)
As shown in FIG. 5, the FED according to the fourth embodiment forms a light reflecting film 32 made of Al on the side wall of the phosphor layer 16 and also on the front substrate 11 between the phosphor layer 16 and the phosphor layer 16. The white resistance material layer 31 is formed through the light shielding layer 21.

  According to the fourth embodiment, the brightness can be improved compared to the conventional case by the light reflecting film 32 on the side wall of the phosphor layer 16 and the white resistive material layer 31 in the region between the phosphor layers 16.

  As described above, according to the above-described embodiment, the image display device capable of improving the luminance by the presence of at least one of the white resistive material layer in the region between the phosphor layers and the light reflecting film on the side wall of the phosphor layer. Can be provided. Further, by forming the resistance material layer in a concave shape, it is possible to provide an image display device capable of improving the creepage distance and improving the breakdown voltage against discharge.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the components without departing from the gist of the invention in the stage of implementation. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

FIG. 1 is a perspective view schematically showing an example of an FED manufactured by a manufacturing method and a manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a diagram schematically showing a cross-sectional structure along the line AA of the FED shown in FIG. FIG. 3 is a cross-sectional view schematically showing the structure of each component on the front substrate side according to the first embodiment applicable to the FED shown in FIG. FIG. 4 is a cross-sectional view schematically showing the structure of each component of the front substrate according to the second embodiment applicable to the FED shown in FIG. FIG. 5 is a cross-sectional view schematically showing the structure of each component of the front substrate according to the third embodiment applicable to the FED shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Vacuum envelope, 11 ... Front substrate, 12 ... Back substrate, 15 ... Phosphor screen, 16 ... Phosphor layer, 17 ... Light absorption layer (light-shielding layer), 18 ... Electron emission element, 20 ... Metal back layer, 21 ... wiring, 31 ... white resistive material layer, 32 ... light reflecting film.

Claims (5)

A front substrate having a phosphor layer and a phosphor screen including a light-shielding layer thinner than the phosphor layer, and a metal back layer provided on the phosphor layer of the phosphor surface;
A rear substrate disposed opposite to the front substrate and disposed with an electron-emitting device that emits electrons toward the phosphor surface;
Means for improving luminance is applied between the phosphor layer and the phosphor layer. 2. The image according to claim 1, wherein the means for improving the brightness is a white resistive material layer disposed on the front substrate between the phosphor layer and the phosphor layer via the light shielding layer. Display device. 2. The image display apparatus according to claim 1, wherein the means for improving luminance is a light reflecting film disposed on a side wall of the phosphor layer. Means for improving the brightness include a white resistance material layer disposed on the front substrate between the phosphor layer and the phosphor layer via the light shielding layer, and a light reflection disposed on a side wall of the phosphor layer. The image display device according to claim 1, wherein the image display device is a film. The image display device according to claim 2, wherein the resistance material layer is formed in a concave shape on the light shielding layer.

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