JP2006344559A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device capable of enhancing exhaust efficiency and preventing image failure caused by vacuum unevenness. <P>SOLUTION: A plurality of exhaust holes 30a-30f are alternately arranged in zigzag form in a first region S1 between one end 14a of a plurality of spacers 14 and a side wall 13 and in a second region S2 between the other end 14b of the spacers 14 and the side wall 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention has a flat envelope having a flat panel structure, and emits electrons from an electron-emitting device provided on a back substrate to display a color image by exciting and emitting a phosphor layer provided on the front substrate. The present invention relates to an image display device.

  In recent years, various flat-type image display devices have attracted attention as next-generation lightweight and thin image display devices that replace cathode ray tubes (hereinafter referred to as CRTs). For example, a plasma display (PDP) using phosphor emission due to a discharge phenomenon and a field emission display (hereinafter referred to as FED) mainly using electron emission by an electric field are known.

  These image display devices include, as a basic configuration, a front substrate and a rear substrate that are arranged to face each other at a predetermined interval, and these substrates constitute an envelope by joining peripheral portions to each other. In particular, the FED enables a good image display by making the space between the front substrate and the rear substrate, that is, the inside of the envelope a high degree of vacuum. In PDP, it is an important technique to keep the inert gas filling the inside of the envelope with high purity.

  In order to create a high vacuum inside the envelope, a method of sealing the periphery of the substrate in a vacuum has also been proposed, but this method requires a vacuum chamber that is maintained at a high vacuum and imposes a load on the process. large. For this reason, a method of exhausting the interior by connecting an exhaust pipe to the envelope after sealing is known (for example, see Patent Document 1).

However, in a thin envelope such as an FED or PDP, if such an exhaust method using an exhaust pipe is adopted, a large pressure difference is generated inside the envelope, and there is a possibility that exhaust cannot be performed sufficiently. In particular, as the size of the envelope increases, this tendency increases and the characteristics of the image display device deteriorate.
JP 2003-36791 A

  An object of the present invention is to provide an image display device capable of improving exhaust efficiency and preventing image defects caused by vacuum unevenness.

  In order to achieve the above object, an image display device according to the present invention includes a front substrate having a plurality of phosphor layers, a back substrate having a plurality of electron-emitting devices corresponding to the plurality of phosphor layers, the front substrate, A frame-shaped side wall in which the peripheral portions of the back substrate are sealed, and the front substrate, the back substrate, and the space between the side walls are non-contact with the side wall and stand on the inner surfaces of the front substrate and the back substrate And a plurality of strip-shaped spacers extending in parallel with each other and supporting the atmospheric pressure load applied to the front substrate and the rear substrate, and penetrated the substrate to evacuate the space A plurality of exhaust holes are provided so as to be shifted between the longitudinal ends of the plurality of spacers and the side walls at positions that do not oppose each other along the spacers.

  According to the above invention, in the two regions between both ends of the spacer and the side wall, the plurality of exhaust holes are provided by shifting to positions that do not oppose each other along the spacer. It is possible to increase the vacuum and prevent uneven vacuum inside the envelope.

  Since the image display device according to the present invention has the above-described configuration and operation, the exhaust efficiency can be increased and image defects due to vacuum unevenness can be prevented.

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

  As shown in FIGS. 1 and 2, this FED includes a front substrate 11 and a rear substrate 12 each made of a rectangular glass plate as insulating substrates, and these substrates are arranged to face each other with a gap of 1 to 2 mm. Has been. The front substrate 11 and the back substrate 12 constitute a flat rectangular vacuum envelope 10 whose peripheral portions are bonded to each other via a rectangular frame-shaped side wall 13 and the inside is maintained in a vacuum state. .

  A plurality of spacers 14 are provided inside the vacuum envelope 10 in order to support an atmospheric pressure load applied to the front substrate 11 and the rear substrate 12. Each spacer 14 is formed in the shape of an elongated band, and is in non-contact with the side wall 13 in a space surrounded by the front substrate 11, the back substrate 12, and the side wall 13, and abuts against the inner surface of each substrate 11, 12. They extend in the same direction parallel to each other.

  On the inner surface of the front substrate 11, a phosphor screen 15 having red, green, and blue phosphor layers 16 and a matrix-shaped light shielding layer 17 is formed as an image display surface. These phosphor layers 16 may be formed in stripes or dots. A metal back 20 made of an aluminum film or the like is formed on the phosphor screen 15.

  On the inner surface of the back substrate 12, a number of surface conduction electron-emitting devices 18 that emit electron beams are provided as electron sources that excite the phosphor layer 16 of the phosphor screen 15. These electron-emitting devices 18 are arranged in a plurality of columns and a plurality of rows corresponding to each pixel. 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 on the inner surface of the rear substrate 12 in a matrix shape, and end portions thereof are drawn out of the vacuum envelope 10.

  In such an FED, when an image is displayed, an anode voltage is applied to the phosphor screen 15 and the metal back 20, and the electron beam emitted from the electron-emitting device 18 is accelerated by the anode voltage to the phosphor screen 15. Collide. As a result, the phosphor layer 16 of the phosphor screen 15 is excited to emit light and display a color image.

Next, a method for exhausting the inside of the vacuum envelope 10 of the FED configured as described above will be described.
When trying to manufacture a relatively large FED, it is easy to cause exhaust unevenness in which the air pressure becomes non-uniform inside the vacuum envelope, and it is important to select an appropriate exhaust method in order to obtain good display characteristics. become. When the method of sealing the substrates 11 and 12 and the side wall 13 in a vacuum is adopted, good display characteristics can be obtained without requiring exhaust after sealing, but it is necessary to prepare a large vacuum chamber. There is a high cost. For this reason, in this embodiment, a method of sealing the substrates 11 and 12 and the side wall 13 in the atmosphere without using an expensive vacuum chamber and then evacuating the inside of the envelope is adopted.

  However, when the inside of the envelope 10 is exhausted after sealing the panel, exhaust efficiency is deteriorated and the exhaust time is prolonged unless an exhaust hole connecting an exhaust pipe (not shown) is arranged at an appropriate position. For example, when only one exhaust hole is arranged at the corner portion of the space surrounded by the side wall 13, the exhaust efficiency decreases as the distance from the exhaust hole toward the diagonal, although the exhaust hole can be efficiently exhausted, Uneven vacuum is generated inside the envelope.

  For this reason, in this embodiment, as shown in FIG. 3, six exhaust holes 30a to 30f (hereinafter sometimes collectively referred to as exhaust holes 30) penetrating the back substrate 12 are formed at the illustrated positions. The exhaust efficiency was improved. As a result, as compared with the case where only one exhaust hole is provided in the corner portion as described above, the time required for exhaustion is reduced to about 1/3. In order to maximize the exhaust efficiency, it is not necessary to simply provide six exhaust holes, and it is necessary to provide each exhaust hole at an appropriate position (position shown in the drawing).

  The exhaust holes 30a to 30f cannot be arranged in an effective plane capable of displaying an image. Therefore, it arrange | positions in the peripheral part close | similar to the inner surface of the side wall 13 in the space enclosed by the side wall 13. FIG. However, if the exhaust hole 30 is provided close to the long side of the side wall 13 extending in parallel with the spacer 14, the exhaust efficiency at the center of the panel is lowered and the exhaust time is increased. For this reason, it is effective to dispose the exhaust hole 30 between the end portion along the longitudinal direction of the spacer 14 and the short side of the side wall 13.

  Hereinafter, the positions of the six exhaust holes 30a to 30f illustrated in FIG. 3, that is, the positions of the exhaust holes 30 that can maximize the exhaust efficiency will be described with reference to the coordinate system of FIG. In FIG. 4, each component shown in FIG. 3 is indicated by a broken line, and the xy coordinate axes are indicated by a solid line.

  The first exhaust hole 30 a is a rectangular space surrounded by the upper end (one end) of the vertically elongated first region S 1 between the right end 14 a (one end) and the side wall 13 of each spacer 14, that is, the side wall 13. It is arranged at the upper right corner in the figure. The second exhaust hole 30b is shifted along the spacer 14 to a position that does not oppose the other exhaust holes, and the second region S2 between the left end 14b (the other end) of the spacer 14 and the side wall 13 in the drawing. Is formed. More specifically, as shown in FIG. 4, when the length of the short side of the rectangular space surrounded by the side wall 13 is 1, the second exhaust hole 30b has the second region S2 in the first region. The upper end (one end) of the S1 opposite to the above-described one end, that is, the space surrounded by the side wall 13, is formed so that its center is located at about 1/5 from the upper left corner in the figure.

  Similarly, in the third exhaust hole 30c, the first region S1 and the second region S2 are alternately arranged in a zigzag manner with respect to the other exhaust holes. Specifically, when the length of the first region S1 is 1, the third exhaust hole 30c is arranged so that the center of the hole is located at about 2/5 from the upper end thereof. Similarly, the fourth exhaust hole 30d is arranged at a position about 3/5 from the upper end of the second region S2, and the fifth exhaust hole 30e is about 4/5 from the upper end of the first region S1. Is arranged. The sixth exhaust hole 30f is arranged at a position diagonal to the first exhaust hole 30a, that is, at the lower end (other end) corner of the second region S2.

  In other words, the six exhaust holes 30a to 30f described above are arranged in a zigzag manner at positions that do not face each other across the spacer 14 in the first region S1 and the second region S2 that face the end of each spacer 14, The rectangular exhaust space described above is positioned at a position that is divided into five equal parts along the extending direction of the spacer 14. Note that the positions of the exhaust holes 30 a to 30 f along the left-right direction (x-axis direction) in the drawing are positions close to the inner surface of the side wall 13, and slightly change depending on the diameter of the exhaust hole 30.

  When the six exhaust holes 30a to 30f are formed as described above, the two exhaust holes 30a and 30f are arranged at diagonal positions of the rectangular space surrounded by the side wall 13, and the remaining four exhaust holes 30b to 30e are arranged. May be arranged so that all the exhaust holes 30a to 30f are alternately zigzag in the first and second regions at a position obtained by dividing the above space into five equal parts along the spacer 14. In the case of forming the exhaust holes 30, the exhaust holes 30 may be positioned as follows.

  That is, two exhaust holes may be provided at diagonal positions, and the remaining (n-2) exhaust holes may be provided in a zigzag manner at positions that equally divide the space into (n-1). More specifically, when the length along the first region S1 of the inner surface of the side wall 13 defining the first region S1 is 1, the first exhaust hole is disposed at one end of the first region S1. The center of the third exhaust hole is disposed at a position 1 / (n-1) from one end of the second region S2, and the center of the third exhaust hole is 2 / (n-1) from one end of the first region S1. ), The center of the (n-1) th exhaust hole is disposed at a position (n-2) / (n-1) from one end of the first region S1, and the nth Each exhaust hole may be positioned so that the other exhaust hole is disposed at the other end of the second region S2.

  Further, when the exhaust efficiency when the six exhaust holes 30a to 30f are formed as in the present embodiment is examined by numerical calculation, when the centers of the exhaust holes 30a to 30f are positioned at the coordinates shown below, It was found that the exhaust efficiency was the highest. Here, only the y coordinate when the length of the short side along the y axis of the rectangular space surrounded by the side wall 13 is 1 is shown. That is, as described above, the x coordinate of each exhaust hole 30 is defined as a position close to the side wall 13 because the first and second regions S1 and S2 are alternately arranged in a zigzag manner. Only the y coordinate is shown.

  That is, the y coordinate of the first exhaust hole 30a provided at the upper end of the first region S1 is (0.9 to 1.0), and the y coordinate of the second exhaust hole 30b provided in the second region S2 is (0.775 to 0.825), the y coordinate of the third exhaust hole 30c provided in the first region S1 is (0.575 to 0.625), and the fourth coordinate provided in the second region S2. The y coordinate of the exhaust hole 30d is (0.375 to 0.425), the y coordinate of the fifth exhaust hole 30e provided in the first region S1 is (0.175 to 0.225), The y coordinate of the sixth exhaust hole 30f provided at the lower end of the second region S2 was (0.0 to 0.1).

  Similarly, when the four exhaust holes are alternately zigzag formed in the first and second regions S1 and S2, the position of each exhaust hole that can maximize the exhaust efficiency is calculated by numerical calculation. The y coordinate was as follows: That is, the y coordinate of the first exhaust hole provided in the first region S1 is (0.8 to 0.85), and the y coordinate of the second exhaust hole provided in the second region S2 is (0.55). To 0.60), and the y coordinate of the third exhaust hole provided in the first region S1 is (0.35 to 0.4), and y of the fourth exhaust hole provided in the second region S2. The coordinates were (0.15 to 0.2). From this, it is understood that when four exhaust holes are provided, no exhaust holes are provided at the corners of the rectangular exhaust space described above.

  Further, the position of each exhaust hole that can maximize the exhaust efficiency in the case where two exhaust holes are formed in the first and second regions S1 and S2, respectively, is calculated by numerical calculation. The y coordinate is as follows: became. That is, the y coordinate of the first exhaust hole provided in the first region S1 is (0.7 to 0.8), and the y coordinate of the second exhaust hole provided in the second region S2 is (0.2). Thru 0.3).

  FIG. 7 shows the pressure distribution in the rectangular space when the two exhaust holes 30a and 30b are arranged at the y coordinate based on the above-described numerical calculation. From this, it can be seen that the pressure distribution in the rectangular space is uniform as compared with the case where two exhaust holes are arranged at the positions shown in FIGS.

  That is, as shown in FIG. 5, when two exhaust holes 30a and 30b are formed near two corners that form a diagonal of the rectangular space, the long side of the rectangular space along the spacer 14 (not shown). The pressure is low only in the vicinity, but the pressure near the center is not low enough. In addition, as shown in FIG. 6, when two exhaust holes 30a and 30b are opposed to each other so that the spacer is sandwiched between both ends of the central spacer, the region between the adjacent spacers close to the hole is defined at both ends of the spacer. Since exhaust is simultaneously performed from the direction, the exhaust efficiency is reduced as compared with the case where the exhaust holes are shifted in the arrangement direction of the spacers as in the present invention. For this reason, only the central part of the rectangular space has a pressure distribution in which the pressure decreases and the pressure increases toward the long side of the rectangular space.

  In this way, even when the same number of exhaust holes 30a and 30b are provided near the end of the spacer 14, the exhaust efficiency varies depending on the positions of the holes. That is, it can be seen that the exhaust efficiency can be maximized by providing the exhaust holes 30 at the optimum positions based on the numerical calculations described above. In other words, by setting the position of the exhaust holes 30 as in the present invention, the exhaust efficiency can be increased while reducing the number of exhaust holes 30, the exhaust time can be shortened, and the manufacturing cost of the FED can be reduced. .

  As described above, according to the present embodiment, an FED capable of maintaining high display performance can be obtained without using an expensive vacuum device.

  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. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  For example, in the above-described embodiment, the optimum positions of the holes when each of the six exhaust holes, four exhaust holes, and two exhaust holes are formed have been described. However, if the number of exhaust holes is two or more, There are appropriate arrangement conditions depending on the number of exhaust holes. In particular, in the case of forming six or more n exhaust holes, exhaust holes are formed near the two corners that form a diagonal of the rectangular space surrounded by the side wall 13 that needs to be exhausted, and the rest ( If n-2) exhaust holes are alternately arranged in the above-described first region S1 and second region S2 in a zigzag manner, the exhaust efficiency becomes the highest. In other words, the exhaust efficiency can be maximized by forming the exhaust holes at positions where the rectangular space is divided into (n−1) equal parts along the spacers 14.

  In the above-described embodiment, the FED has been described as an example of the image display device. However, the present invention is not limited to this, and the present invention may be applied to other image display devices such as a PDP.

1 is an external perspective view illustrating an example of an image display device according to an embodiment of the present invention. The partial expanded sectional view which expands and shows partially the cross section which cut | disconnected the image display apparatus of FIG. 1 along line II-II. The schematic plan view for demonstrating the exhaust hole provided in the back substrate of the image display apparatus of FIG. The figure which shows the coordinate system for demonstrating the position of the exhaust hole of FIG. The figure which shows the pressure distribution inside an envelope in case two exhaust holes are provided in the diagonal of the space enclosed by the side wall. The figure which shows the pressure distribution inside an envelope in case the two exhaust holes which mutually oppose are provided in the short side center of the space of FIG. The figure which shows the pressure distribution inside an envelope at the time of providing two exhaust holes in the appropriate position of the space of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Vacuum envelope, 11 ... Front substrate, 12 ... Back substrate, 13 ... Side wall, 14 ... Spacer, 15 ... Phosphor screen, 18 ... Electron emission element, 20 ... Metal back, 30a-30f ... Exhaust hole, S1 ... 1st area | region, S2 ... 2nd area | region.

Claims (6)

A front substrate having a plurality of phosphor layers; a back substrate having a plurality of electron-emitting devices corresponding to the plurality of phosphor layers; and a frame-like side wall in which peripheral portions of the front substrate and the back substrate are sealed together. The front substrate extending in parallel with each other in a non-contacting manner with the side walls in a space surrounded by the front substrate, the rear substrate, and the side walls, and in abutment with the inner surfaces of the front substrate and the rear substrate. And a plurality of strip spacers for supporting atmospheric pressure load on the back substrate,
In order to evacuate the space, a plurality of exhaust holes penetrating the substrate are provided between the longitudinal ends of the plurality of spacers and the side walls so as not to face each other along the spacers. An image display device characterized by comprising:   The plurality of exhaust holes are alternately arranged in a first region between one end of the plurality of spacers and the side wall and a second region between the other end of the plurality of spacers and the side wall. The image display device according to claim 1, wherein the image display device is arranged in a zigzag pattern. There are two exhaust holes,
When the length along the first region of the inner surface of the side wall defining the first region is 1, the center of the first exhaust hole is 0.2 to 0.3 from one end of the first region. The center of the second exhaust hole is located at a position of 0.7 to 0.8 from one end of the second region facing one end of the first region. The image display device described. There are four exhaust holes,
When the length along the first region of the inner surface of the side wall defining the first region is 1, the center of the first exhaust hole is 0.15 to 0.2 from one end of the first region. The center of the second exhaust hole is located at a position of 0.35 to 0.4 from one end of the second region facing the one end of the first region. Is located at 0.55 to 0.60 from one end of the first region, and the center of the fourth exhaust hole is located at 0.8 to 0.85 from one end of the second region. The image display device according to claim 2. There are 6 exhaust holes,
When the length along the first region of the inner surface of the side wall defining the first region is 1, the first exhaust hole is at one end of the first region and the second exhaust hole The center is at a position 0.175 to 0.225 from one end of the second region facing one end of the first region, and the center of the third exhaust hole is 0.375 to 0.35 from one end of the first region. The center of the fourth exhaust hole is at a position of 0.575 to 0.625 from one end of the second region, and the center of the fifth exhaust hole is at the position of the first region. The image display device according to claim 2, wherein the image display device is located at a position of 0.775 to 0.825 from one end, and a sixth exhaust hole is located at the other end of the second region. There are n exhaust holes,
When the length along the first region of the inner surface of the side wall defining the first region is 1, the first exhaust hole is at one end of the first region and the second exhaust hole The center is at a position 1 / (n-1) from one end of the second region opposite to one end of the first region, and the center of the third exhaust hole is 2 / (n from one end of the first region. -1), and the center of the (n-1) th exhaust hole is at a position (n-2) / (n-1) from one end of the first region, and the nth The image display device according to claim 2, wherein an exhaust hole is provided at the other end of the second region.

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