JP2006100176A - Flat surface display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flat surface display device which can settle resistance between divided areas of a metal back to a predetermined value. <P>SOLUTION: On the inner surface of a front substrate 2, a plurality of first ribs 21 extending to an X direction and a plurality of second ribs 22 extending to a Y direction are partially piled on each other and formed into a rib structures, and a metal back 14 is evaporated through the rib structure. This can lap divided areas over corresponding areas to respective color pixels, and can form the metal back into the electrical divided areas with stability. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a flat display device that displays an image by, for example, emitting electrons from an electron-emitting device provided on a back substrate and exciting and emitting a phosphor layer provided on the front substrate.

  In recent years, a field emission display (FED), a display device (SED) having a surface conduction electron-emitting device, and the like are known as a flat display device having a flat envelope having a flat panel structure.

  The FED and SED have a vacuum envelope in which the front and back substrates, which are opposed to each other with a predetermined interval through a spacer, are joined to each other by a rectangular frame-shaped side wall, and the inside is evacuated. ing.

  A phosphor layer of three colors and a metal back covering the phosphor layer are formed on the inner surface of the front substrate, and a large number of phosphor layers corresponding to each pixel of the phosphor layer as an electron emission source for exciting and emitting the phosphor layer on the inner surface of the rear substrate. An electron-emitting device is disposed. Further, in order to maintain a high vacuum inside the vacuum envelope, a getter film is formed on the inner surface of the front substrate.

  A voltage several kV higher than the electron-emitting device is applied to the phosphor layer, and the electron beam emitted from each electron-emitting device is accelerated by this electric field. Then, the accelerated electron beam is applied to the corresponding phosphor layer, and the phosphor is excited to emit light to display a color image.

  Thus, when a high voltage for accelerating the electron beam is applied between the front substrate and the rear substrate that are close to each other, a discharge problem often occurs. When a discharge occurs, a large amount of current flows through the discharge location, causing damage to the electron-emitting device at that location.

  On the other hand, the metal back covering the phosphor layer of the front substrate is electrically divided into small regions, and the current flowing when the discharge occurs is limited by reducing the resistance between the divided regions by reducing the discharge damage. Techniques are known (see, for example, Patent Document 1 and Patent Document 2). As a method of dividing the metal back, a method of chemically modifying the metal back or a method of partially evaporating the metal back with a laser can be considered.

However, when the metal back is divided into a plurality of small regions by such a conventional method, the resistance value between adjacent regions becomes unstable, causing uneven brightness or inducing discharge between regions. There was a problem. Further, in the above dividing method, it is extremely difficult to control the resistance value between regions to a desired value, and the electrical characteristics of the metal back are unstable.
Japanese Patent Laid-Open No. 10-326583 JP 2000-31642 A

  An object of the present invention is to provide a flat display device capable of stabilizing a resistance value between divided regions of a metal back to a desired value.

  In order to achieve the above object, a flat display device according to the present invention has a front substrate having a large number of phosphor layers and metal backs or getters on the inside and a back substrate having a large number of electron-emitting devices on the inner side at a predetermined interval. In addition, in a flat display device in which the inside is in a vacuum atmosphere and the phosphor layer and the metal back are at a higher potential than the electron-emitting device, the metal back or getter has a first rib protruding in the thickness direction of the front substrate, The second rib is electrically divided into a plurality of island-shaped regions by the wall surface of the second rib.

  According to the above invention, since the plurality of first and second ribs for electrically dividing the metal back into the plurality of island-shaped regions are provided inside the front substrate, the first and second ribs are interposed through the first and second ribs. By forming the metal back, the metal back can be reliably divided into a plurality of island-shaped regions. In addition, by forming the getter film via the first and second ribs, the getter film can also be electrically divided into a plurality of island-shaped regions.

  Since the flat display device of the present invention has the above-described configuration and action, the resistance value between the divided regions of the metal back can be stabilized at a desired value.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, an SED will be described as an example of a display device according to an embodiment of the present invention.

  As shown in FIGS. 1 to 3, the SED 1 includes a front substrate 2 and a rear substrate 4 each made of a glass plate having a rectangular shape of 1 to 2 mm, and these substrates are about 1.0 to 2 through spacers 8. They are placed facing each other with a gap of 0 mm. The front substrate 2 and the back substrate 4 are joined together via a rectangular frame-shaped side wall 6 to constitute a vacuum envelope 10 whose inside is a vacuum.

  A phosphor screen 12 for displaying an image is formed on the inner surface of the front substrate 2. The phosphor screen 12 has a configuration in which red, blue, and green phosphor layers R, G, and B and a light shielding layer 11 are arranged and the phosphor layer is covered with a metal back 14. The phosphor layers R, G, and B are formed in stripes or dots, and the metal back 14 is formed of a metal thin film such as aluminum.

  On the inner surface of the back substrate 4, a number of surface conduction electron-emitting devices 16 that emit an electron beam for exciting and emitting the phosphor layers R, G, and B are provided. These electron-emitting devices 16 are arranged in a plurality of columns and a plurality of rows corresponding to each pixel, and are configured by an electron-emitting unit (not shown) and a pair of device electrodes for applying a voltage to the electron-emitting unit. Further, on the inner surface of the back substrate 4, a large number of wirings 18 for applying a driving voltage to the respective electron-emitting devices 16 are provided in a matrix shape, and end portions thereof are drawn out of the vacuum envelope 10. Yes.

  The front substrate 2 and the rear substrate 4 are degassed and fired in a vacuum atmosphere, and the peripheral portions are sealed together to form a vacuum envelope 10. Prior to sealing, the front substrate 2 and the rear substrate 4 are sealed in the vacuum atmosphere. A getter film is formed on the entire inner surface to maintain a high vacuum after panel formation.

  In the SED 1, when an image is displayed, a voltage is applied between the element electrodes of the electron-emitting device 16 through the wiring 18 to emit an electron beam from an electron-emitting portion of the arbitrary electron-emitting device 16 and the phosphor screen 12. The electron beam is accelerated by the anode voltage applied to the phosphor screen 12 to irradiate the phosphor screen 12. As a result, the desired phosphor layers R, G, and B are excited to emit light and display an image.

  Here, the soft flash structure of the metal back 14 described above will be described with reference to FIG. FIG. 4 shows a structure in which the metal back 14 is divided into a plurality of island-like regions 14a for each of the phosphor layers R, G, and B (pixels). Here, in order to clarify the illustration, the sizes of the regions 14a and the pixels R, G, and B with respect to the substrate 2 are different from the actual ratio. Further, although FIG. 4 shows an example in which the metal back 14 is divided into island-shaped regions 14a covering the respective pixels, the metal back 14 may be divided into a plurality of regions covering a plurality of pixels. In any case, in the present embodiment, the metal back 14 is divided into a plurality of small regions 14a, and the plurality of regions 14a are connected by a high resistance member 14b.

  The higher the resistance of the high resistance member 14b between the regions 14a, the more the discharge current can be suppressed. On the other hand, an anode voltage drop is caused by the electron beam current for image display. The optimum resistance value of the high-resistance member 14b cannot be uniformly mentioned because the discharge current suppressing effect depends on the structure of the division and the withstand voltage characteristics between the divisions, but is generally a value of 1 kΩ to 10 MΩ. By making the metal back 14 have such a soft flash structure, even if a discharge occurs, the metal back 14 is divided into small regions 14a. Therefore, it is possible to limit the discharge current and suppress damage caused by the discharge.

  Next, a method for manufacturing the metal back 14 according to the first embodiment of the present invention will be described with reference to FIGS. In each figure, (a) shows a schematic plan view in which the inner surface of the front substrate 2 is partially enlarged, and (b) shows a partial perspective view of the front substrate 2. Here, a method of dividing the metal back 14 into a plurality of island-shaped regions 14a for each color pixel by a plurality of ribs 21 and 22 (described later) extending in the XY2 direction will be described.

  First, as shown in FIG. 5, the light shielding layer 11 is formed on the inner surface of the front substrate 2, and the high resistance layer 23 is formed on the light shielding layer 11. As will be described later, the high resistance layer 23 is provided to control the resistance between the regions 14a after the metal back 14 is divided into a plurality of island-like regions 14a.

  The light shielding layer 11 has a thickness of about 2 [μm], and has a plurality of rectangular openings 11 a that respectively define the color pixel regions R, G, and B of the phosphor layer. The plurality of openings 11a are formed using a predetermined mask pattern, for example, by photolithography. The light shielding layer 11 is made of a material whose resistivity is one digit higher than that of the high resistance layer 23.

  The high resistance layer 23 has a thickness of about 10 [μm], and uses a mask pattern substantially the same as the light shielding layer 11 having a resistivity of 10 [Ωm] (resistance between divided metal backs of 0.05 to 0.5 [MΩ]). Formed by the conventional photolithography method. That is, the high resistance layer 23 also has a plurality of openings 23 a that overlap the openings 11 a of the light shielding layer 22.

  Next, as shown in FIG. 6, phosphor layers R, G, and B are formed in the plurality of openings 11a and 23a, respectively. The phosphor layers R, G, and B are formed in the corresponding openings 11a and 23a with a thickness of about 10 [μm], respectively, by a printing method. That is, the phosphor layers R, G, and B are formed at substantially the same height as the high resistance layer 23.

  Then, as shown in FIG. 7, on the high resistance layer 23 between the adjacent phosphor layers R, G, B, a plurality of pieces extending in the X direction in the figure and having a thickness in the direction away from the front substrate 2. First ribs 21 are formed. The first rib 21 has a thickness of about 20 [μm] and is made of a material whose resistivity is one digit higher than that of the high resistance layer 23. In the present embodiment, the width of the first rib 21 is set to about 50 [μm], and the rising of the side surface with respect to the substrate 2 has an overhanging shape (not shown). Sometimes it can be divided on the side.

  Further, as shown in FIG. 8, a plurality of second ribs 22 are formed so as to intersect and partially overlap the plurality of first ribs 21. The second rib 22 is divided in the length direction so as to connect the two adjacent first ribs 21 and extends in the Y direction in the drawing and is a high resistance layer between the adjacent phosphor layers. A plurality of pieces (two in the present embodiment) are provided on 23. More specifically, the second ribs 22 in the first row and the second ribs 22 in the second row are formed so as to alternately connect the adjacent first ribs 21.

  Each of the second ribs 22 is formed of a material having a thickness of about 20 [μm] and a resistivity that is one digit higher than the resistivity of the high resistance layer 23. In the present embodiment, the width of the second rib 22 is set to about 80 [μm], and the width between the second rib 22 in the first row and the second rib 22 in the second row is also 80 [ μm]. Furthermore, the rising of the side surface of the second rib 22 with respect to the substrate 2 has an overhanging shape (not shown) so that it can be divided by the side surface during metal back or getter film formation described later.

  After the above rib structure is formed on the inner surface of the front substrate 2, the front substrate 2 is baked to remove excess components and be cured. At this time, in each structure, there is contraction of about 10 to 20%, but the above-mentioned numerical values describe the shape dimensions after firing.

  Finally, as shown in FIG. 9, a metal back 14 is formed on the inner surface of the front substrate 2 via the rib structures 21 and 22 described above. The metal back 14 is formed by applying a smooth resin film (not shown) to the entire front substrate 2 and then depositing AL and baking it to remove excess components. After this, the getter is directly deposited on the metal back 14 in the vacuum atmosphere of the paneling process. The thickness of the two is about 100 [nm].

  When the metal back 14 (or getter) is formed in this manner, the metal back (or getter) is divided at the side surfaces of the first and second ribs 21 and 22, and as a result, the metal back 14 has a plurality of island-shaped regions. It becomes the structure divided | segmented into 14a. For reference, a dividing line 25 obtained by dividing the metal back 14 by the rib side surface is shown by a broken line in the drawing. As a result, the metal back 14 is divided into island shapes on both the top and bottom surfaces of the ribs 21 and 22, and the discharge current can be suppressed and improved by about one digit compared to the conventional linear dividing structure. .

  Although the rib side surface is formed in an overhang shape for division, the metal back and getter can be divided if the uneven shape on the rib surface is also used if the inclination angle is large even if it is not overhang shape. In this case, the rising angle of the side surface with respect to the front substrate is preferably 45 degrees or more.

  As described above, according to the present embodiment, the metal back 14 can be reliably and easily divided into a plurality of island-like regions 14a, and the resistance value between the regions 14a can be made substantially as designed. For this reason, the electrical characteristics of the metal back 14 can be stabilized, damage due to discharge can be suppressed, luminance unevenness can be prevented, and a highly reliable display device can be provided.

  Next, a dividing structure of the metal back 14 according to the second embodiment of the present invention will be described with reference to FIG. FIG. 10A shows a state of the inner surface of the substrate after the rib structure of the present embodiment is formed, and FIG. 10B shows a state after the metal back 14 is formed through the rib structure. Is shown. Here, the same reference numerals are given to components that function in the same manner as in the first embodiment described above, and a detailed description thereof will be omitted.

  In the present embodiment, the high resistance layer 23 is formed so as to connect the phosphor layers R, G, and B arranged in the Y direction, and the high resistance layer 23 is formed between the phosphor layers adjacent in the X direction. The light shielding layer 11 was exposed. Then, the first rib layer 21 was formed of a resistance material, and the phosphor layers were electrically connected in the X direction. In addition, a substantially I-shaped second rib 22 is provided around each phosphor layer R, G, B, and the second rib 22 extending in the Y direction also extends in the middle of the first rib 21 that connects each pixel in the X direction. Ribs 22 are provided.

  In this configuration, the resistance connecting the divided region 14 a of the metal back 14 in the Y direction is controlled by the high resistance layer 23, and the resistance connecting each divided region 14 a in the X direction is controlled by the first rib 21. ing. With such a configuration, it is possible to change the longitudinal and lateral anisotropy with high resistance without forming an extra layer.

  As described above, in the present embodiment as well, as in the first embodiment described above, the first and second ribs 21 and 22 are partially overlapped to form the metal back 14 as shown by the dividing line 25. Can be reliably divided into a plurality of island-shaped regions 14a, and the discharge current can be sufficiently suppressed.

  Next, a dividing structure of the metal back 14 according to the third embodiment of the present invention will be described with reference to FIG. FIG. 11A shows the state of the inner surface of the substrate after the rib structure of the present embodiment is formed, and FIG. 11B shows the state after the metal back 14 is formed via the rib structure. Is shown. In this case as well, components that function in the same manner as in the first embodiment described above are assigned the same reference numerals, and detailed descriptions thereof are omitted.

  The rib structure of the present embodiment generally has a structure in which the rib structures of the first and second embodiments described above are combined. That is, among the second ribs 22 of the second embodiment described above, the number of relatively short second ribs 22 provided in the middle of the first ribs 21 connecting the phosphor layers adjacent in the X direction is increased to two. As in the first embodiment, the first ribs 21 adjacent to each other are connected by the second ribs 22 that are alternately shifted.

  Thus, as in the first embodiment, the creeping breakdown voltage along the X direction is improved by doubling the number of shielding ribs 22 between the divided regions 14a adjacent to the metal back 14 in the X direction. Can do. If this rib configuration is applied, as long as the space between the regions 14a adjacent in the X direction allows, a large number of second ribs 22 can be formed in this space, and one second rib 22 can be formed into a plurality of first ribs. By alternately laminating the ribs 21, it is possible to increase the number of shielding ribs 22 between the regions 14a where the metal back 14 is divided, thereby further improving the creeping withstand voltage characteristics.

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

  For example, in the above-described embodiment, the case where a plurality of the second ribs 22 extending in the Y direction are received in the region 14a has been described. However, the present invention is not limited thereto, and the first ribs 21 extending in the X direction are adjacent to each other. A plurality of them may be provided between the regions 14a.

1 is an external perspective view showing a vacuum envelope of an SED according to an embodiment of the present invention. FIG. 2 is a cross-sectional perspective view of the vacuum envelope of FIG. 1 cut along line II-II. The partial expanded sectional view which expands and shows the cross section of FIG. 2 partially. The schematic diagram which shows the state which divided | segmented the metal back of the phosphor screen of a front substrate inner surface into island shape. The partial enlarged plan view (a) for demonstrating the process which manufactures the cutting structure of the metal back which concerns on 1st Embodiment of this invention, and a partial enlarged perspective view. The partial enlarged plan view (a) for demonstrating the process which manufactures the cutting structure of the metal back which concerns on 1st Embodiment of this invention, and a partial enlarged perspective view. The partial enlarged plan view (a) for demonstrating the process which manufactures the cutting structure of the metal back which concerns on 1st Embodiment of this invention, and a partial enlarged perspective view. The partial enlarged plan view (a) for demonstrating the process which manufactures the cutting structure of the metal back which concerns on 1st Embodiment of this invention, and a partial enlarged perspective view. The partial enlarged plan view (a) for demonstrating the process which manufactures the cutting structure of the metal back which concerns on 1st Embodiment of this invention, and a partial enlarged perspective view. The partial enlarged plan view (a) which shows the rib structure for demonstrating the cutting structure of the metal back which concerns on 2nd Embodiment of this invention, and the partial enlarged plan view after forming a metal back (b). The partial enlarged plan view (a) which shows the rib structure for demonstrating the dividing structure of the metal back which concerns on 3rd Embodiment of this invention, and the partial enlarged plan view after forming a metal back (b).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... SED, 2 ... Front substrate, 4 ... Back substrate, 6 ... Side wall, 8 ... Spacer, 10 ... Vacuum envelope, 12 ... Phosphor screen, 14 ... Metal back, 14a ... Area | region, 14b ... High resistance member, DESCRIPTION OF SYMBOLS 16 ... Electron emission element, 18 ... Wiring, 21 ... 1st rib, 22 ... 2nd rib, 23 ... High resistance layer, 25 ... Broken line, R, G, B ... Phosphor layer.

Claims (10)

A front substrate having a large number of phosphor layers and metal backs or getters on the inside and a back substrate having a large number of electron-emitting devices on the inside face each other at a predetermined interval to form a vacuum atmosphere. In the flat display device having a higher potential than the electron-emitting device,
The flat display device, wherein the metal back or getter is electrically divided into a plurality of island-like regions by the wall surfaces of the first rib and the second rib protruding in the thickness direction of the front substrate.   2. The flat display device according to claim 1, wherein at least one of the first and second ribs is divided into a plurality of short portions in the length direction.   2. The flat display device according to claim 1, wherein the first and second ribs have portions overlapping each other.   4. The flat display device according to claim 3, wherein the rib that overlaps the first and second ribs is divided into a plurality of short portions in the length direction thereof.   2. The flat display device according to claim 1, wherein the protruding height of the first and second ribs is 10 [μm] or more.   2. The flat display device according to claim 1, wherein side surfaces of the first and second ribs rise at an angle of 45 degrees or more with respect to the front substrate.   2. The flat display device according to claim 1, wherein a plurality of at least one of the first and second ribs are provided between at least adjacent phosphor layers of the plurality of phosphor layers. .   2. The flat display device according to claim 1, wherein at least one of the first and second ribs is formed of a resistance material capable of changing an electric resistance between the plurality of phosphor layers.   2. The flat display device according to claim 1, wherein the metal back is divided into islands every integer multiple of the phosphor layer.   10. The first and second ribs according to any one of claims 1 to 9, wherein the first and second ribs electrically divide a getter layer formed on the metal back into a plurality of island-shaped regions. The flat display device according to item.

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