JP2008226745A - Fluorescent screen with metal back, its manufacturing method, and image display surface - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a fluorescent screen having a smooth metal back layer excelling in reflectivity to improve luminance of an image display device. <P>SOLUTION: In this fluorescent screen with a metal back, voids of 1-10 μm are formed between a metal film and a phosphor layer constituting the metal back layer. The fluorescent surface with a metal back can be provided by forming a light absorption layer thicker than the phosphor layer, and forming the metal film tightly on the upper surface of the light absorption layer through a smooth resin layer. The voids can be formed by forming a resistance adjustment layer formed of heat-resistant inorganic fine particles on the light absorption layer, and forming the metal film tightly on the upper surface of the resistance adjustment layer through the smooth resin layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a phosphor screen with a metal back, a method for manufacturing the same, and an image display device having the phosphor screen with a metal back.

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

In general, an FED has a face plate (front substrate) and a rear plate (back substrate) that are arranged to face each other at a predetermined interval. These substrates are joined to each peripheral portion via a rectangular frame-like 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.

  On the inner surface of the face plate, a phosphor screen including a phosphor layer that emits red, blue, and green, respectively, and a light absorption layer (light-shielding layer) 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 in 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 a getter layer. A metal thin film such as Ba (barium), V (vanadium), Ti (titanium), or Ta (tantalum) is deposited on the metal back layer. A number of elements that emit electrons for exciting the phosphor to emit light are provided on the inner surface of the rear plate.

  In the FED, an anode voltage of several kV to 10 kV or more is applied to an image display surface including a phosphor layer and a metal back layer. Then, the electron beam emitted from the electron-emitting device is accelerated by the anode voltage and collides with the phosphor screen, whereby the phosphor emits light, and an image is displayed on the image display surface by the emission of the phosphor. In the FED configured as described above, the distance (gap) between the face plate and the rear plate can be set to about several millimeters, so that it is compared with a cathode ray tube (CRT) currently used as a display of a television or a computer. Thus, a significant reduction in weight and thickness can be achieved.

  By the way, in recent years, the spread of thin displays has increased, and the demand for higher image quality has been increasing in order to increase added value. Among the improvements in image quality, increasing brightness is an important item for improving bright room contrast.

In an FED that is a self-luminous display, luminance is improved by enhancing a metal back effect. For example, a proposal has been made to smoothen the phosphor layer surface by applying pressure while heating a phosphor layer containing a thermoplastic resin, thereby improving the film formability and adhesion of the metal back layer (Patent Document 1). reference).
JP 2002-343248 A

  However, in the method for forming a phosphor screen described in Patent Document 1, the following problems may occur when the thicknesses of the light absorption layer and the phosphor layer are different and there is a step on the upper surface of each layer. That is, when the thickness of the phosphor layer is smaller than the thickness of the light absorption layer, the upper surface of the phosphor layer is located lower than the upper surface of the light absorption layer, so that the side wall of the light absorption layer becomes an obstacle and heating is performed. -It was difficult to smooth the surface of the phosphor layer by pressurization.

  In addition, if the thickness of each pattern of the light absorption layer varies, the phosphor layer adjacent to the thick light absorption layer is smoothed when the light absorption layer is heated and pressurized together with the phosphor layer. Not only is insufficient, but also the light absorption layer having a large layer thickness may be damaged such as chipping or wrinkling.

  The present invention has been made to solve these problems, and an object of the present invention is to obtain a fluorescent screen having a metal back layer that is smooth and has good reflectivity. It is another object of the present invention to provide an image display device having such a phosphor screen with a metal back and high brightness.

  The phosphor screen with a metal back according to the first aspect of the present invention has a phosphor screen in which at least a light absorption layer and a phosphor layer are formed on the inner surface of the face plate, and is formed on the phosphor screen via a smooth resin layer. A phosphor screen with a metal back having a metal back layer made of a metal film, and a gap is provided between the metal film and the upper surface of the phosphor layer at a position lower than the metal film It is characterized by.

  According to the second aspect of the present invention, there is provided a method for manufacturing a phosphor screen with a metal back, wherein a light absorption layer having a predetermined pattern and a phosphor layer having a thinner thickness than the light absorption layer are formed on the inner surface of the face plate. A step of forming a phosphor screen, and a transfer film in which at least a release agent layer, a smooth resin layer and an adhesive layer are formed on a base film, and the smooth resin layer is interposed between the phosphor screen and the adhesive layer. The step of transferring the smooth resin layer by peeling off the base film after being bonded while being heated and pressed by a transfer roller, and the smooth transferred on the phosphor screen The method includes a step of forming a metal film on the conductive resin layer, and a step of heat-treating the face plate on which the metal film is formed to decompose and remove organic components.

  According to a third aspect of the present invention, there is provided a method for producing a phosphor screen with a metal back, on a face plate inner surface, a light absorption layer having a predetermined pattern, and a resistance adjustment layer mainly composed of heat-resistant inorganic fine particles laminated thereon. Forming a light-absorbing laminate portion, and forming a phosphor layer having a thinner layer thickness than the light-absorbing laminate portion on the inner surface of the face plate on which the light-absorbing laminate portion is formed, A step of forming a phosphor screen comprising the light-absorbing laminate, a transfer film having at least a release agent layer, a smooth resin layer and an adhesive layer formed on a base film, and the smooth resin layer being the adhesive. The layer is placed in contact with the resistance adjusting layer through a layer, and is pressed and bonded while being heated by a transfer roller, and then the base film is peeled off to transfer the smooth resin layer onto the phosphor screen. A step of forming a metal film on the smooth resin layer transferred onto the phosphor screen, and a step of heat-treating the face plate on which the metal film is formed to decompose and remove organic components. It is characterized by providing.

  An image display device of the present invention includes a face plate, a rear plate disposed to face the face plate, a number of electron-emitting devices formed on the rear plate, and the face plate facing the rear plate. And a phosphor screen that emits light from an electron beam emitted from the electron-emitting device, and the phosphor screen is the phosphor screen with the metal back according to the first aspect described above.

  According to the present invention, the metal film is formed via the smooth resin film on the upper surface of the light absorption layer or the upper surface of the resistance adjustment layer further laminated thereon, and the metal film and a position lower than the metal film are formed. Since a gap is provided between the upper surface of a certain phosphor layer, a gentle undulation with a long pitch is formed in the metal film, and irregularities corresponding to minute irregularities on the surface (upper surface) of the phosphor layer are formed. It will not be done. As a result, the diffuse reflection of the reflection surface of the metal back layer is reduced and the regular reflection component is increased. In addition, no cracks or pinholes are generated in the metal film, and the light transmittance is kept low, so that the luminance is improved. Therefore, by providing such a phosphor screen with a metal back, an image display device with high luminance can be realized.

  Hereinafter, modes for carrying out the present invention will be described.

  FIG. 1 is a cross-sectional view showing a phosphor screen with a metal back according to the first embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view showing a main part of FIG. In these drawings, reference numeral 1 denotes a glass substrate constituting the face plate. On the inner surface of the glass substrate 1, a light absorption layer 2 having a predetermined pattern (for example, a dot shape or a stripe shape) made of a black pigment such as carbon is provided. Further, between the patterns of the light absorption layer 2, there are provided the patterns of the phosphor layers 3 of three colors of red (R), green (G), and blue (B), and the phosphor layers 3 of these colors. The light absorption layer 2 forms a phosphor screen (phosphor screen). Here, the phosphor layers 3 of the respective colors are formed to have the same thickness. Further, the thickness of the phosphor layer 3 is formed to be thinner than the thickness of the light absorption layer 2.

  A metal back layer 4 made of a metal film such as an Al film is formed on the phosphor screen configured as described above. The metal film constituting the metal back layer 4 is in intimate contact with the upper surface of the light absorption layer 2, and between this metal film and the upper surface of the phosphor layer 3 at a position lower than the upper surface of the light absorption layer 2, A void 5 is formed. The dimension D in the thickness direction of the gap 5 is desirably in the range of 1 to 10 μm.

  In the phosphor screen with a metal back of the first embodiment configured as described above, a gap 5 is formed between the metal film constituting the metal back layer 4 and the upper surface of the phosphor layer 3, and the metal film is Since the surface of the phosphor layer 3 is not in close contact with the minute unevenness, the reflective surface of the metal film is formed smoothly without having the minute unevenness. Therefore, the diffuse reflection on the reflecting surface of the metal back layer 4 is reduced and the regular reflection component is increased, so that the luminance is improved.

  In addition, when the gap 5 between the phosphor layer 3 and the metal film constituting the metal back layer 4 is less than 1 μm, in the step of firing the metal film, which will be described later, The metal film can easily come into contact with the phosphor layer 3. When the metal film comes into contact with the phosphor layer 3, the metal film follows the irregularities on the surface of the phosphor layer 3 (due to the particle size of the phosphor particles), and as a result, minute irregularities are formed on the surface of the metal back layer 4. Arise. Therefore, the diffuse reflection of the metal back layer 4 is increased and the reflectivity is impaired. FIG. 3 shows a phosphor screen with a metal back in which the gap 5 between the phosphor layer 3 and the metal film constituting the metal back layer 4 is less than 1 μm (for example, 0). As shown in this figure, since the metal film constituting the metal back layer 4 is in contact with the phosphor layer 3, the irregularities on the surface of the phosphor layer 3 cause minute irregularities on the surface of the metal back layer 4 and diffuse reflection. Therefore, high brightness cannot be obtained.

  Moreover, it is preferable that the space | gap between the metal film which comprises the metal back layer 4, and the upper surface of the fluorescent substance layer 3 shall be 10 micrometers or less for the reason shown below. That is, in order to set the gap 5 between the phosphor layer 3 and the metal film to be larger than 10 μm, the thickness of the phosphor layer 3 is reduced or the thickness of the light absorption layer 2 adjacent to the phosphor layer 3 is set. It is necessary to increase the thickness. The layer thickness of the phosphor layer 3 needs to be set in the range of 7 μm to 13 μm (more preferably around 10 μm) in order to maximize the light emission luminance, and the layer thickness of the phosphor layer 3 is greatly changed from around 10 μm. For this reason, in order to set the gap 5 between the phosphor layer 3 and the metal film to exceed 10 μm, the thickness of the light absorption layer 2 adjacent to the phosphor layer 3 needs to be 20 μm or more in practice. is there. When the layer thickness of the light absorption layer 2 made of black pigment is increased to 20 μm or more, light (generally ultraviolet light) does not reach the bottom of the light absorption layer 2 and is insufficiently cured when exposed through a photomask. Inviting, it becomes difficult to form a predetermined opening.

The phosphor screen with a metal back according to the first embodiment can be manufactured as follows. That is, first, as shown in FIG. 4A, a light absorption layer 2 made of a dot-like or stripe-like black pigment is formed on the inner surface of the glass substrate 1 constituting the face plate by, for example, a photolithography method, and then, A resin paste containing phosphors of various colors such as ZnS, Y ₂ O ₃ and Y ₂ O ₂ S is printed (screen printed) using a screen plate having a predetermined pattern and dried. Thus, between the patterns of the light absorption layer 2, the patterns of the phosphor layers 3 of three colors of red (R), green (G), and blue (B) are arranged so as to be adjacent to each other, A phosphor screen is formed. At this time, the phosphor layer 3 is formed by adjusting the thickness so that the thickness of the phosphor layer 3 is 1 to 10 μm thinner than the thickness of the light absorption layer 2. The light absorption layer 2 can be formed by screen printing, and the phosphor layers 3 of the respective colors can be formed by a spray method or a photolithography method.

  Next, the smooth resin layer 6 is formed on the phosphor screen thus formed as shown in FIG. 4B. In order to easily manufacture the phosphor screen with a metal back according to the first embodiment, the smooth resin layer 6 is preferably formed by a transfer method as described below.

  The transfer film for forming the smooth resin layer 6 has a structure in which a release agent layer, a smooth resin layer, and an adhesive layer are sequentially laminated on a base film made of a polyester resin or the like.

  Here, the film thickness of the base film is desirably 5 to 50 μm in order to effectively perform heating and pressing with a transfer roller in a transfer step described later. Examples of the mold release agent include cellulose acetate, wax, fatty acid, fatty acid amide, fatty acid ester, rosin, acrylic resin, silicone, and fluorine resin. From these, it selects and uses suitably according to peelability with a base film and a smooth resin layer.

  The smooth resin layer formed on the release agent layer is preferably based on a thermosetting resin, a thermoplastic resin, a photocurable resin, and more specifically, an acrylic resin, 1 type selected from melamine resin, urea resin, acrylic-melamine copolymer resin, melamine-urea copolymer resin, polyurethane resin, polyester resin, epoxy resin, alkyd resin, polyamide resin, cellulose, vinyl resin, etc. It is composed mainly of two or more kinds of resins.

  The smooth resin layer preferably contains a softening agent. Softeners include phosphate esters, aliphatic monobasic acid esters, aliphatic dibasic acid esters, dihydric alcohol esters, oxyacid esters, butyl oleate, dibutyl adipate, chlorinated paraffin, toluene sulfone ethylamide, toluene sulfone Examples include methylamide, aminobenzenesulfonamide compound, methyl abietic acid, dinonylnaphthalene, tributyl acetylcitrate, aminotoluenesulfonamide compound, N-butylbenzenesulfonamide and the like. The content ratio of the softening agent is desirably 1 to 30% by weight with respect to the entire material constituting the smooth resin layer. When the content of the softening agent exceeds 30% by weight, transferability is deteriorated, which is not preferable.

  As the adhesive, vinyl acetate resin, ethylene-vinyl acetate copolymer, styrene-acrylic acid resin, ethylene-vinyl acetate-acrylic acid terpolymer resin, or the like is used.

  Such a transfer film is disposed so that the adhesive layer is in contact with the upper surface of the light absorption layer 2 of the phosphor screen. And after pressing with the transfer roller heating and adhere | attaching the smooth resin layer 6 on the light absorption layer 2, a base film is peeled off.

As the transfer roller, for example, a rubber roller having a coating layer such as natural rubber or silicone rubber on a metal core is used. Then, this transfer roller is heated so that the temperature of the rubber layer surface as a pressing portion becomes 70 to 240 ° C., and the surface of the transfer film is pressed on the base film surface with a pressing force of 1 to 10 kgf / cm ^2. Move at a speed of ~ 20 m / min. The conditions regarding the surface temperature and pressing speed of the transfer roller are necessary and sufficient conditions for the smooth resin layer 6 to be transferred to the phosphor screen surface. Adhesiveness with the conductive resin layer 6 is insufficient, and there is a possibility that transfer failure or cracks after baking may occur.

  That is, if the surface temperature of the transfer roller is too high or the pressing speed is too slow, the base film is heated too much and softens or melts. As a result, a smooth resin layer is not transferred / formed. On the other hand, if the surface temperature of the transfer roller is too low or the pressing speed is too high, heating of the adhesive becomes insufficient, and adhesion of the smooth resin layer 6 becomes insufficient. As a result, transfer defects such as partial transfer are not preferable.

  In addition, in such pressing by the transfer roller, in addition to a mode in which the face plate side as a pressed portion is fixed and the transfer roller is moved, a mode in which the position of the transfer roller is fixed and the face plate side is moved and traveled Can also be taken. Therefore, the pressing speed by the transfer roller means the relative moving speed of the transfer roller and the pressed part.

  Thus, after the smooth resin layer 6 is transferred onto the phosphor screen, it can be further pressed while being heated by a press roller. By performing such a press treatment and pressing the smooth resin layer 6 against the surface of the light absorption layer 2 to bring it into close contact, the adhesion between the smooth resin layer 6 and the light absorption layer 2 can be further enhanced.

As the press roller, similarly to the transfer roller, a rubber roller having a coating layer such as natural rubber or silicone rubber on a metal core can be used. And while pressing this press roller on the smooth resin layer with the pressing force of 1-10 kgf / cm < ² >, in the state heated so that the temperature of the rubber layer surface which is a press part may be 70-250 degreeC, Move at a speed of 1-20 m / min. In addition, in pressing with the press roller, in addition to a mode in which the face plate side that is a pressed portion is fixed and the press roller is moved, a mode in which the position of the press roller is fixed and the face plate side is moved and traveled is adopted. Can do.

  By using such a transfer method, the smooth resin layer 6 is brought into close contact with only the upper surface of the light absorption layer 2 of the phosphor screen, and is formed in a state in which it is stretched between the patterns of the light absorption layer 2 without slack. Can do. Therefore, a gap 5 corresponding to the difference in thickness is formed between the upper surface of the phosphor layer 3 formed to be 1 to 10 μm thinner than the light absorption layer 2 and the smooth resin layer 6.

  Next, a metal film 7 such as an Al film is formed on the smooth resin layer 6 thus transferred and formed, as shown in FIG. 4C. As a method for forming the metal film 7, a general dry metal thin film forming method such as a vacuum evaporation method or a sputtering method can be employed. From the viewpoint of the metal back effect, the thickness of the metal film 7 is preferably 80 to 150 nm. That is, when the thickness of the metal film 7 is less than 80 nm, pinholes are likely to be generated in the metal back layer and the light transmittance is increased, so that the performance of reflecting the light emitted from the phosphor layer 3 is deteriorated. Then, the luminance is lowered. On the other hand, if the thickness of the metal film 7 exceeds 150 nm, the dead voltage (the lower limit value of the electron beam acceleration voltage necessary for light emission) becomes too high, and a discharge phenomenon is likely to occur in the metal back layer. For this reason, the thickness of the metal film 7 is preferably in the range of 80 nm to 150 nm.

  Thereafter, the entire face plate on which the metal film 7 is formed is heated and baked (baked) at a temperature of about 500 ° C. to decompose and remove organic components. Since the smooth resin layer 6 is also decomposed and disappears during the baking, only the metal film 7 remains on the phosphor screen as shown in FIG. 4D. The metal film 7 is disposed in close contact with only the upper surface of the light absorption layer 2 and is stretched between the patterns of the light absorption layer 2 without slack. The metal film 7 and the upper surface of the phosphor layer 3 A gap 5 of 1 to 10 μm is held between them.

  In this way, the metal back layer 4 having no cracks, wrinkles, slack, etc. and having a substantially flat and gentle undulation is formed, and a phosphor screen with a metal back excellent in reflection characteristics can be obtained.

  Next, a second embodiment of the phosphor screen with a metal back according to the present invention will be described.

  FIG. 5 is a cross-sectional view showing a phosphor screen with a metal back according to the second embodiment of the present invention, and FIG. 6 is an enlarged cross-sectional view showing the main part of FIG. 5 and 6, the same parts as those in FIGS. 1 and 2 showing the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the second embodiment, the phosphor layer 3 is formed so as to be thicker than the light absorption layer 2. Note that the thickness of the phosphor layer 3 may be formed to be equal to the thickness of the light absorption layer 2. A resistance adjustment layer 8 for controlling the electrical resistance value of the metal back layer 4 is formed on the light absorption layer 2, and the light absorption layer 9 is configured by the light absorption layer 2 and the resistance adjustment layer 8. Yes. The thickness of the light absorption laminated portion 9 is adjusted to be thicker than the thickness of the phosphor layer 3.

The resistance adjustment layer 8 is a layer mainly composed of heat-resistant inorganic fine particles. The heat-resistant inorganic fine particles can be used without any particular limitation as long as they have electrical insulating properties and can withstand high-temperature heating such as a sealing process. For example, fine particles of metal oxides such as SiO ₂ , TiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ are exemplified, and one or more of these can be used in combination. The resistance adjustment layer 8 can be formed by a method of screen printing a resin paste containing the heat-resistant inorganic fine particles.

  A metal film such as an Al film constituting the metal back layer 4 is in intimate contact with the upper surface of the resistance adjusting layer 8 of the light absorption laminated portion 9, and the phosphor located at a position lower than the upper surface of the resistance adjusting layer 2. A gap 5 is formed between the upper surface of the layer 3 and the metal film. The dimension D in the thickness direction of the gap 5 is desirably in the range of 1 to 10 μm.

  In order to manufacture the phosphor screen with the metal back according to the second embodiment configured as described above, first, a light absorbing layer made of a black pigment in the form of dots or stripes is formed on the inner surface of the glass substrate 1 constituting the face plate. 2 is formed, and the resistance adjusting layer 8 mainly composed of heat-resistant inorganic fine particles is formed thereon to form the light-absorbing laminated portion 9, and then the three-color fluorescence is formed between the patterns of the light-absorbing laminated portion 9. A pattern of the body layer 3 is formed to form a phosphor screen. Next, a smoothing resin layer is formed on the phosphor screen by the transfer method in the same manner as in the manufacture of the first embodiment, and then a metal film is formed on the smoothing resin layer. A face plate having a metal film is heated and baked to decompose and remove organic components.

  Also in the second embodiment, a gap 5 is formed between the metal film constituting the metal back layer 4 and the upper surface of the phosphor layer 3, and the metal film has minute irregularities on the surface of the phosphor layer 3. Therefore, the reflective surface of the metal film is smooth and has no unevenness. Therefore, the diffuse reflection of the reflection surface of the metal back layer 4 is reduced and the regular reflection component is increased, so that the luminance is improved.

  Next, an FED that is a third embodiment of the present invention will be described. As shown in FIG. 7, this FED has a face plate 11 in which the above-described phosphor screen with a metal back according to the first embodiment or the second embodiment is formed on a glass substrate 1 and a matrix on the substrate 12. And a rear plate 14 having a large number of electron-emitting devices 13 arranged at a distance of 1 mm to several mm, and a high voltage of 5 to 15 kV is applied between these plates. It is configured. In the figure, reference numeral 15 denotes a phosphor screen, and 16 denotes a metal back layer. Reference numeral 17 denotes a support frame (side wall).

  In the FED of this embodiment, since a gap is provided between the metal film constituting the metal back layer 16 and the upper surface of the phosphor layer located at a lower position, there is no crack, the undulation is gentle, and almost A smooth metal back layer 16 is obtained, and the reflection characteristics are improved. That is, since the diffuse reflection of the reflection surface of the metal back layer 16 is reduced and the regular reflection component is increased, the luminance is improved. In addition, since the metal back layer 16 has no cracks or pinholes and the light transmittance is kept low, a display with high luminance and excellent reliability can be realized.

  Next, specific examples in which the present invention is applied to an FED will be described.

Example 1
A black pigment is mixed with a glass frit powder composed of Bi ₂ O ₃ , ZnO, Al ₂ O ₃ and B ₂ O ₃ , and a mixed solvent of butyl carbitol acetate and α-terpineol is mixed with a photosensitive acrylic resin. A black pigment paste was prepared. This paste is screen-printed on a glass substrate constituting the face plate, dried, and then exposed to a total amount of light of 500 mJ / cm ² (illuminance of 8 mW / cm ² ) using a photomask on which a predetermined pattern is drawn. The unexposed portion was dissolved and removed with a 0.2 wt% aqueous solution to form an opening where a phosphor layer was to be formed. Subsequently, after rinsing with pure water, the organic component was removed by heating and baking at 500 ° C. Thus, a striped light absorption layer having a thickness of 15 μm was formed.

Next, a paste containing a phosphor such as ZnS, Y ₂ O ₃ , or Y ₂ O ₂ S was used, screen-printed so as to be embedded in a predetermined portion of the pattern of the light absorption layer, and dried. In this way, phosphor layers of three colors of red (R), green (G), and blue (B) were formed adjacent to each other between the patterns of the light absorption layer, thereby producing a phosphor screen. Next, on the inner surface of the face plate, a peripheral black matrix made of a black pigment and an outer frame made of a silver paste film are sequentially formed in a non-display area around such a phosphor screen, and then heated and fired at 500 ° C. went. Thus, a phosphor layer having a layer thickness of 10 μm was formed.

Next, in the face plate having the phosphor screen thus formed, the peripheral black matrix and the outer frame portion are masked with a polyester film having a thickness of 12 μm, and then formed on a polyethylene terephthalate base film (thickness 12 μm). A release film, a smooth resin layer made of nitrocellulose resin, a transfer film in which an adhesive layer mainly composed of ethylene-vinyl acetate copolymer is laminated in order, and the adhesive layer is a light absorbing layer of the phosphor screen. It was placed in contact with the top surface. And it heated and pressurized with the silicone rubber roller from the base film. That is, a silicone rubber roller having a hardness of 80 degrees heated to a surface temperature of 150 ° C. is pressed on the base film at a speed of 2 m / min and a pressure of 2.5 kgf / cm ² , and then the base film is peeled off. Thus, the smooth resin layer was brought into close contact with the upper surface of the light absorption layer. Thus, the smooth resin layer was formed in close contact with only the upper surface of the light absorption layer and stretched in the form of a film above the phosphor layer.

Next, a silicone rubber roller having a hardness of 80 degrees heated to a surface temperature of 80 ° C. was run on the smooth resin layer at a speed of 2 m / min and a pressure of 1 kgf / cm ² . In this way, the smooth resin layer was heated and pressurized to improve the adhesion between the light absorption layer and the smooth resin layer, and the smooth resin layer was further smoothed.

  Thereafter, an Al film having a thickness of 120 nm is formed on the smoothed smooth resin layer by sputtering, and then the whole face plate is baked (baked) at a temperature of 500 ° C. to include the smooth resin layer. The minute was decomposed and removed. Thus, a phosphor screen with a metal back having the structure shown in FIGS. 1 and 2 and having a dimension D of the gap 5 between the upper surface of the phosphor layer 3 and the metal film (Al film) of 4 to 5 μm was provided. Three face plates were produced.

Example 2
A black pigment is mixed with a glass frit powder composed of Bi ₂ O ₃ , ZnO, Al ₂ O ₃ and B ₂ O ₃ , and a mixed solvent of butyl carbitol acetate and α-terpineol is mixed with a photosensitive acrylic resin. A black pigment paste was prepared. This paste was screen printed on a glass substrate constituting the face plate and dried to form a light absorption layer having a thickness of 10 μm after drying. Next, glass frit powder composed of Bi ₂ O ₃ , ZnO, Al ₂ O ₃ , and B ₂ O ₃ is mixed with metal oxide fine particles composed of rutile spherical TiO ₂ whose surface is coated with SnO ₂ and Sb conductive layers. Further, a paste prepared by mixing a mixed solvent of butyl carbitol acetate and α-terpineol and a photosensitive acrylic resin was screen-printed and dried on the light absorption layer to form a resistance adjusting layer. In addition, the resistance adjustment layer was formed so that the layer thickness of the light absorption lamination | stacking part (lamination part of a light absorption layer and a resistance adjustment layer) after drying might be set to 20 micrometers.

Next, using a photomask on which a predetermined pattern is drawn, exposure is performed with an integrated light amount of 500 mJ / cm ² (illuminance of 8 mW / cm ² ), and unexposed portions are dissolved and removed with a 0.2 wt% sodium carbonate aqueous solution. An opening for forming a body layer was formed. Subsequently, after rinsing with pure water, the organic component was removed by heating and baking at 500 ° C. In this way, a stripe-shaped light absorption laminated portion having a combined thickness of the light absorption layer and the resistance adjustment layer of 15 μm was obtained.

Next, screen printing was performed using a paste containing phosphors of various colors such as ZnS, Y ₂ O ₃ , and Y ₂ O ₂ S and dried. In this way, phosphor layers of three colors of red (R), green (G), and blue (B) were formed adjacent to each other between the light-absorbing laminated portions, thereby producing a phosphor screen. Next, on the inner surface of the face plate, a peripheral black matrix made of black pigment and an outer frame part made of silver paste film are sequentially formed in a non-display area around such a phosphor screen, and then heated and fired at 500 ° C. went. Thus, a phosphor layer having a thickness of 10 μm was formed.

Next, in the face plate having the phosphor screen thus formed, the peripheral black matrix and the outer frame portion are masked with a polyester film having a thickness of 12 μm, and then formed on a polyethylene terephthalate base film (thickness 12 μm). Release agent layer, smooth resin layer made of nitrocellulose resin, transfer film in which adhesive layer mainly composed of ethylene-vinyl acetate copolymer is laminated and formed in order, adhesive layer absorbs light of phosphor screen The laminated part (resistance adjustment layer) was placed in contact with the upper surface. Then, from the top of the base film, a silicone rubber roller having a hardness of 80 degrees heated to a surface temperature of 150 ° C. is run at a speed of 2 m / min and a pressure of 2.5 kgf / cm ² to press and press the base film. By peeling off, the smooth resin layer was brought into close contact with the upper surface of the resistance adjustment layer. Thus, in this way, the smooth resin layer was formed in close contact with only the upper surface of the resistance adjusting layer and stretched in a film shape above the phosphor layer.

Next, on the smooth resin layer, a silicone rubber roller having a hardness of 80 degrees heated to a surface temperature of 80 ° C. was run at a pressure of 1 kgf / cm ² at a speed of 2 m / min. In this way, the smoothing resin layer was heated and pressurized to improve the adhesion between the light absorption layered portion (resistance adjusting layer) and the smoothing resin layer, and the smoothing resin layer was further smoothed.

  Thereafter, an Al film having a thickness of 120 nm is formed on the smoothed smooth resin layer by sputtering, and then the entire face plate is baked (baked) at a temperature of 500 ° C. The minute was decomposed and removed. Thus, a phosphor screen with a metal back having the structure shown in FIGS. 5 and 6 and having a dimension D of the gap 5 between the upper surface of the phosphor layer 3 and the metal film (Al film) of 4 to 5 μm is thus obtained. Three face plates were prepared.

Comparative Example 1
In Example 1, the coating thickness was adjusted so that the layer thickness after firing was 10 μm, and after forming the light absorption layer, the coating thickness was adjusted so that the layer thickness after firing was also 10 μm, A phosphor layer was formed. Other than that was carried out similarly to Example 1, and produced the phosphor surface with a metal back | bag of the structure where the upper surface of the fluorescent substance layer and Al film | membrane closely_contact | adhered.

Comparative Example 2
In Example 2, the coating thickness was adjusted so that the layer thickness after firing was 10 μm, and after the laminated portion of the light absorption layer and the resistance adjustment layer was formed, the layer thickness after firing was similarly 10 μm. The phosphor layer was formed by adjusting the coating thickness. Other than that was carried out similarly to Example 2, and produced the fluorescent surface with a metal back | bag of the structure where the upper surface of the fluorescent substance layer and Al film | membrane closely_contact | adhered.

  Next, each sample (specimen) of the face plate having the phosphor screen with the metal back obtained in Examples 1 and 2 and Comparative Examples 1 and 2 was used, and an FED was manufactured according to the procedure described below. First, an electron generation source in which a number of surface conduction electron-emitting devices were formed on a substrate was fixed to a glass substrate to produce a rear plate. Next, the rear plate and the face plates obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were arranged to face each other via a support frame and a spacer, and sealed with frit glass. Thereafter, necessary processing such as sealing and exhausting was performed to complete a 10-inch color FED.

The obtained 10-inch color FED was displayed as a white raster with an electron beam acceleration voltage of 10 kV, and the brightness of the screen was measured. Then, the relative brightness of the FEDs obtained in Examples 1 and 2 was determined based on the brightness of the FEDs obtained in Comparative Examples 1 and 2. The relative luminance was calculated using the following equation. The results are shown in Table 1.
Relative brightness of Example 1 = (FED brightness of Example 1) ÷ (FED brightness of Comparative Example 1)
Relative brightness of Example 2 = (FED brightness of Example 2) / (FED brightness of Comparative Example 2)

  As is clear from Table 1, the FED having the metal-backed phosphor screen obtained in Examples 1 and 2 has a metal-backed phosphor screen having a conventional structure in which the upper surface of the phosphor layer and the metal-back layer are in close contact with each other. The brightness is increased from 22% to 27% compared to the FEDs of Comparative Examples 1 and 2 provided. Further, the FEDs of Examples 1 and 2 were subjected to a 1000 hour drive test at an electron beam acceleration voltage of 5 kV, but no discharge phenomenon occurred.

  ADVANTAGE OF THE INVENTION According to this invention, it has a metal back layer which was excellent in reflective characteristics, and the light transmittance was restrained low, and can obtain the fluorescent screen with a metal back with high brightness | luminance. Therefore, by providing such a phosphor screen with a metal back, an image display device with high luminance can be realized.

It is sectional drawing which shows the fluorescent screen with a metal back which is the 1st Embodiment of this invention. It is sectional drawing which expands and shows the principal part of FIG. It is sectional drawing which shows the fluorescent screen with a metal back which is a conventional structure and does not have a space | gap between a fluorescent substance layer and a metal back layer (metal film). It is sectional drawing which shows the process of manufacturing the fluorescent screen with a metal back of 1st Embodiment. It is sectional drawing which shows the process of manufacturing the fluorescent screen with a metal back of 1st Embodiment. It is sectional drawing which shows the process of manufacturing the fluorescent screen with a metal back of 1st Embodiment. It is sectional drawing which shows the process of manufacturing the fluorescent screen with a metal back of 1st Embodiment. It is sectional drawing which shows the fluorescent screen with a metal back which is the 2nd Embodiment of this invention. It is sectional drawing which expands and shows the principal part of FIG. It is a figure which shows typically the structure of FED which is the 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Glass substrate, 2 ... Light absorption layer, 3 ... Phosphor layer, 4,16 ... Metal back layer, 5 ... Air gap, 6 ... Smooth resin layer, 7 ... Metal film, 8 ... Resistance adjustment layer, 11 ... Face Plate, 13 ... Electron-emitting device, 14 ... Rear plate, 15 ... Phosphor screen.

Claims (12)

A fluorescence with a metal back having a phosphor screen on which at least a light absorption layer and a phosphor layer are formed on the inner surface of the face plate, and a metal back layer made of a metal film formed on the phosphor surface through a smooth resin layer Surface,
A phosphor screen with a metal back, wherein a gap is provided between the metal film and the upper surface of the phosphor layer at a position lower than the metal film.   The layer thickness of the light absorption layer is formed larger than the layer thickness of the phosphor layer, and the metal film is in close contact with the upper surface of the light absorption layer via the smoothing resin layer. The fluorescent screen with a metal back according to claim 1.   On the light absorption layer, there is a resistance adjustment layer mainly composed of heat-resistant inorganic fine particles for controlling the electric resistance value of the metal back layer, and the smooth resin layer is provided on the upper surface of the resistance adjustment layer. 2. The phosphor screen with a metal back according to claim 1, wherein the metal film is in close contact with each other, and a gap is provided between the metal film and the upper surface of the phosphor layer.   The space | gap provided between the upper surface of the said fluorescent substance layer and the said metal film exists in the range of 1-10 micrometers in the dimension of a thickness direction, The any one of Claim 1 thru | or 3 characterized by the above-mentioned. Phosphor screen with metal back. The phosphor screen with a metal back according to any one of claims 1 to 4, wherein the metal film has a thickness of 80 to 150 nm.   The smooth resin layer is acrylic resin, melamine resin, urea resin, acrylic-melamine copolymer resin, melamine-urea copolymer resin, polyurethane resin, polyester resin, epoxy resin, alkyd resin, polyamide resin, celluloses, The phosphor screen with a metal back according to any one of claims 1 to 5, comprising one or more resins selected from vinyl resins. Forming a light absorption layer having a predetermined pattern on the inner surface of the face plate and a phosphor layer having a thinner thickness than the light absorption layer, and forming a phosphor screen;
A transfer film in which at least a release agent layer, a smoothing resin layer and an adhesive layer are formed on a base film is disposed so that the smoothing resin layer is in contact with the phosphor screen via the adhesive layer, and then transferred. A step of transferring the smoothing resin layer by peeling off the base film after pressing and bonding while heating with a roller;
Forming a metal film on the smooth resin layer transferred onto the phosphor screen;
A method of manufacturing a phosphor screen with a metal back, comprising a step of heat-treating the face plate on which the metal film is formed to decompose and remove organic components. Forming a light absorption layered portion comprising a light absorption layer having a predetermined pattern and a resistance adjustment layer mainly composed of heat-resistant inorganic fine particles laminated thereon on the inner surface of the face plate;
Forming a phosphor layer having a thinner layer thickness than the light-absorbing laminate on the inner surface of the face plate on which the light-absorbing laminate is formed, and forming a phosphor screen comprising the phosphor layer and the light-absorbing laminate And a process of
A transfer film in which at least a release agent layer, a smoothing resin layer and an adhesive layer are formed on a base film is disposed so that the smoothing resin layer is in contact with the resistance adjusting layer via the adhesive layer, and then transferred. A step of transferring the smoothing resin layer onto the phosphor screen by peeling off the base film after being pressed and bonded while being heated by a roller;
Forming a metal film on the smooth resin layer transferred onto the phosphor screen;
A method of manufacturing a phosphor screen with a metal back, comprising a step of heat-treating the face plate on which the metal film is formed to decompose and remove organic components.   The smooth resin layer includes acrylic resin, melamine resin, urea resin, acrylic-melamine copolymer resin, melamine-urea copolymer resin, polyurethane resin, polyester resin, epoxy resin, alkyd resin, polyamide resin, celluloses, The method for producing a phosphor screen with a metal back according to claim 7 or 8, comprising one or two or more resins selected from vinyl resins.   The adhesive layer is made of vinyl acetate resin, ethylene-vinyl acetate copolymer, styrene-acrylic acid resin, ethylene-vinyl acetate-acrylic acid terpolymer resin, vinyl chloride-vinyl acetate copolymer resin, polybutene resin, The method for producing a phosphor screen with a metal back according to any one of claims 7 to 9, wherein the main component is one or more resins selected from polyamide resins.   The method for producing a fluorescent screen with a metal back according to any one of claims 7 to 10, wherein the metal film is formed on the transferred smooth resin layer by vapor deposition or sputtering.   A face plate; a rear plate disposed opposite to the face plate; a plurality of electron-emitting devices formed on the rear plate; and the electron-emitting device formed on the face plate so as to face the rear plate. An image display device comprising: a phosphor screen that emits light by an electron beam emitted from the phosphor screen, wherein the phosphor screen is a phosphor screen with a metal back according to claim 1.

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