JP2006032069A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device achieving improvements in reliability and display quality by suppressing a deviation of an electron beam from its course. <P>SOLUTION: A first substrate 10 with a fluorescent screen formed thereon and a second substrate 12 with a plurality of electron emission sources 18 provided thereon are opposed to each other. A plurality of spacers 30 to support an atmospheric pressure load acting on the first and second substrates are arranged in a standing condition between the first and second substrates. A plurality of projections 34a, 34b for correcting the movement of electron beams emitted from the electron emission sources are provided to project from the side of the first substrate toward the second substrate, and are opposed to the second substrate with a gap in between. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a flat-type image display device that includes a pair of substrates disposed opposite to each other and a spacer disposed between the substrates.

  2. Description of the Related Art In recent years, various flat-type image display devices have attracted attention as next-generation lightweight and thin display devices that replace cathode ray tubes (hereinafter referred to as CRTs). For example, a surface conduction electron-emitting device (hereinafter referred to as SED) is being developed as a kind of field emission device (hereinafter referred to as FED) that functions as a flat display device.

  The SED includes a first substrate and a second substrate that are arranged to face each other at a predetermined interval, and these substrates form a vacuum envelope by bonding peripheral portions to each other through rectangular side walls. ing. Three color phosphor layers are formed on the inner surface of the first substrate, and on the inner surface of the second substrate, a large number of electron-emitting devices corresponding to each pixel are arranged as an electron source for exciting the phosphor. Each electron-emitting device includes an electron-emitting portion and a pair of electrodes that apply a voltage to the electron-emitting portion.

In the SED, it is important to maintain a high degree of vacuum in the space between the first substrate and the second substrate, that is, in the vacuum envelope. When the degree of vacuum is low, the lifetime of the electron-emitting device, and hence the lifetime of the device, is reduced. Further, in order to support an atmospheric pressure load acting between the first substrate and the second substrate and maintain a gap between the substrates, a large number of plate-like or columnar spacers are arranged between the two substrates (for example, Patent Document 1). In the SED, when displaying an image, an anode voltage is applied to the phosphor layer, and the phosphor emits light by accelerating the electron beam emitted from the electron-emitting device by the anode voltage and colliding with the phosphor layer. Display an image. In order to obtain practical display characteristics, it is necessary to use a phosphor similar to a normal cathode ray tube and set the anode voltage to several kV or more, preferably 5 kV or more.
JP 2001-272926 A

  In the SED having the above-described configuration, when electrons (primary electrons) emitted from the electron-emitting device and having a high acceleration voltage collide with the phosphor layer on the inner surface of the first substrate, scattered electrons including secondary electrons and reflected electrons from the first substrate. Will occur. In addition, the gap between the first substrate and the second substrate is set to a relatively small value of about 1 to 2 mm from the viewpoint of resolution, characteristics of the support member, manufacturability, and the like. Therefore, the scattered electrons generated on the first substrate side collide with the spacer disposed between the substrates, and the spacer is charged. At the acceleration voltage in the SED, the spacer is normally positively charged. In this case, the electron beam emitted from the electron-emitting device is attracted to the spacer and deviates from the original trajectory. As a result, there is a problem that electron beam mislanding occurs in the phosphor layer and the color purity of the display image is deteriorated.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an image display apparatus that suppresses an orbit shift of an electron beam and has improved display quality.

  In order to achieve the above object, an image display device according to an aspect of the present invention is provided with a first substrate on which a phosphor screen is formed, and opposed to the first substrate with a gap therebetween, and facing the phosphor screen. A second substrate provided with a plurality of electron emission sources for emitting an electron beam and exciting the phosphor screen, and the first substrate and the second substrate, respectively, standing between the first substrate and the second substrate. A plurality of spacers supporting an atmospheric pressure load acting on the first substrate, projecting from the first substrate side toward the second substrate, facing the second substrate with a gap, and emitted from the electron emission source A plurality of protrusions for correcting movement of the electron beam.

  According to the present invention, by providing a plurality of protrusions in parallel with the spacer, the orbit shift of the electron beam due to the charging of the spacer can be corrected by the protrusion, and an image display device with improved display quality can be provided. .

Hereinafter, embodiments in which the present invention is applied to an SED as a flat image display device will be described in detail with reference to the drawings.
As shown in FIGS. 1 to 3, the SED includes a first substrate 10 and a second substrate 12 each made of a rectangular glass plate, and these substrates have a gap of about 1.0 to 2.0 mm. Opposed. The 1st board | substrate 10 and the 2nd board | substrate 12 comprise the flat vacuum envelope 15 by which the peripheral parts were joined through the rectangular-frame-shaped side wall 14 which consists of glass, and the inside was maintained at the vacuum. The side wall 14 functioning as a bonding member is sealed to the peripheral edge of the first substrate 10 and the peripheral edge of the second substrate 12 by, for example, a sealing material 20 such as low-melting glass or low-melting metal. Are joined.

  A phosphor screen 16 that functions as a phosphor screen is formed on the inner surface of the first substrate 10. The phosphor screen 16 is configured by arranging phosphor layers R, G, and B that emit light in red, blue, and green, and a light shielding layer 11, and these phosphor layers are formed in stripes, dots, or rectangles. ing. On the phosphor screen 16, a metal back 17 and a getter film 19 made of aluminum or the like are sequentially formed.

  On the inner surface of the second substrate 12, a number of surface-conduction electron-emitting elements 18 that emit electron beams are provided as electron emission sources for exciting the phosphor layers R, G, and B of the phosphor screen 16. Yes. These electron-emitting devices 18 are arranged in a plurality of columns and a plurality of rows corresponding to the pixels. 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. On the inner surface of the second substrate 12, a large number of wirings 21 for supplying a potential to the electron-emitting devices 18 are provided in a matrix shape, and end portions thereof are drawn out of the vacuum envelope 15.

  As shown in FIGS. 2 to 4, the SED includes a spacer structure 22 disposed between the first substrate 10 and the second substrate 12. The spacer structure 22 includes a support substrate 24 made of a rectangular metal plate and a large number of columnar spacers 30 that are integrally provided upright on one surface of the support substrate.

  The support substrate 24 is formed in a rectangular shape having a size almost equal to that of the phosphor screen 16. The support substrate 24 has a first surface 24 a facing the inner surface of the first substrate 10 and a second surface 24 b facing the inner surface of the second substrate 12, and is arranged in parallel with these substrates. A large number of electron beam passage holes 26 are formed in the support substrate 24 by etching or the like. The electron beam passage apertures 26 are respectively arranged to face the electron emission elements 18 and transmit the electron beams emitted from the electron emission elements.

  The support substrate 24 is formed with a thickness of 0.1 to 0.25 mm using, for example, an iron-nickel metal plate, and the electron beam passage holes 26 are, for example, 0.15 to 0.25 mm × 0.15 to 0.005. It is formed in a 25 mm rectangular shape. On the surface of the support substrate 24, a high resistance film 32 is formed as an insulating layer by applying and baking an insulating material mainly composed of glass, ceramic or the like. According to the present embodiment, the first and second surfaces 24a and 24b of the support substrate 24 and the inner wall surfaces of the respective electron beam passage holes 26 have a high resistance film 32 having a thickness of about 10 μm made of Li-based alkali borosilicate glass. It is covered with. The support substrate 24 is provided in a state where the first surface 24 a is in surface contact with the inner surface of the first substrate 10 via the getter film 19, the metal back 17, and the phosphor screen 16.

  When the longitudinal direction of the first substrate 10 and the second substrate 12 is the first direction X and the width direction orthogonal to the longitudinal direction is the second direction Y, the electron beam passage hole 26 provided in the support substrate 24 is They are arranged at a predetermined first pitch P1 along the direction X, and the second direction Y is arranged at a second pitch P2 larger than the first pitch P1. The phosphor layers R, G, B of the phosphor screen 16 formed on the first substrate 10 and the electron-emitting devices 18 on the second substrate 12 pass the electron beam in the first direction X and the second direction Y, respectively. They are arranged at the same pitch as the holes 26 and face the electron beam passage holes, respectively. Thereby, each electron-emitting device 18 is opposed to the corresponding phosphor layer through the electron beam passage hole 26.

  On the second surface 24b of the support substrate 24, spacers 30 are integrally provided so as to be positioned between the electron beam passage holes 26 aligned in the Y direction. The plurality of spacers 30 are provided side by side with a predetermined pitch in the second direction Y, and are provided side by side with a pitch larger than the predetermined pitch in the first direction. The extended end of the spacer 30 is in contact with the inner surface of the second substrate 12. Each of the spacers 30 is formed in a tapered shape having a diameter that decreases from the support substrate 24 side toward the extending end. The cross section of the spacer 30 along the direction parallel to the surface of the support substrate 24 is substantially elliptical. Each of the spacers 30 is formed of a spacer forming material mainly composed of glass as an insulating substance.

  A plurality of protrusions are integrally provided on the second surface 24 b of the support substrate 24 and protrude from the first substrate 10 side toward the second substrate 12. The plurality of protrusions are provided side by side with the plurality of first protrusions 34a and the plurality of second protrusions 34b provided along with the spacer 30 along the first direction X, and with the spacer 30 along the second direction Y. The plurality of third protrusions 34c are included.

  The first protrusions 34a are arranged side by side on both sides of each spacer 30 in the first direction X, and are provided apart from the spacers by approximately one pixel, that is, by the first pitch P1. The second protrusion 34b is arranged side by side with the first protrusion 34a on the opposite side of the spacer 30 in the first direction X. That is, the first protrusion 34a and the second protrusion 34b are arranged in this order from the spacer 30 side. The first and second protrusions 34a and 34b are opposed to the inner surface of the second substrate 12 with a gap. The protrusion heights of the first and second protrusions 34 a and 34 b are formed such that the first protrusion 34 a located next to the spacer 30 is higher than the second protrusion 34 b. That is, the protrusions farther from the spacer 30 are formed lower.

In the second direction Y, the third protrusions 34 c are provided between the adjacent spacers 30 and between the adjacent electron beam passage holes 26. Further, the third protrusions 34 c are provided at equal intervals from the spacer 30 in the second direction Y. The third protrusion 34c faces the inner surface of the second substrate 12 with a gap.
Each of the first to third protrusions 34a, 34b, 34c is formed in a tapered shape having a diameter that decreases from the support substrate 24 side toward the extending end. The first to third protrusions 34 a, 34 b, 34 c are formed of a spacer forming material whose main component is glass as an insulating material, for example, like the spacer 30.

  The spacer structure 22 configured as described above acts on these substrates when the support substrate 24 comes into surface contact with the first substrate 10 and the extended end of the spacer 30 contacts the inner surface of the second substrate 12. The atmospheric pressure load is supported and the distance between the substrates is maintained at a predetermined value.

  The SED includes a voltage supply unit (not shown) that applies a voltage to the metal back 17 of the first substrate 10. When displaying an image, an anode voltage of about 10 kV is applied to the phosphor screen 16 and the metal back 17, and the electron beam emitted from the electron-emitting device 18 is accelerated by the anode voltage to collide with the phosphor screen 16. As a result, the phosphor layer of the phosphor screen 16 is excited to emit light and display an image.

  In the SED having the above configuration, when electrons having a high acceleration voltage collide with the phosphor screen 16, secondary electrons and reflected electrons are generated from the first substrate 10 and the phosphor screen. Secondary electrons and reflected electrons generated on the phosphor screen 16 collide with the spacers 30 disposed between the substrates, and as a result, the spacers are charged. At the acceleration voltage in the SED, the spacer is generally positively charged. In this case, the electron beam emitted from the electron-emitting device is attracted to the spacer.

  On the other hand, secondary electrons and reflected electrons generated in the phosphor screen 16 also collide with the first, second, and third protrusions 34a, 34b, and 34c protruding from the support substrate 24. As a result, these protrusions are also positive. Is charged. Therefore, the electron beam emitted from the electron-emitting device 18 in the vicinity of the spacer 30 is once attracted to the spacer 30 side as indicated by reference numeral B1 in FIG. 5, and then, as shown by reference numeral B2 in FIG. The orbital shift in the first direction X is corrected by being attracted to the one protrusion 34a. At the same time, the electron beam is attracted to the third protrusion 34c and the orbital deviation in the second direction Y is corrected, as indicated by reference numeral B3 in FIG. As a result, the electron beam passes through a predetermined electron beam passage hole 26 corresponding to the electron emitter 18 and reaches the target phosphor layer.

  The electron beam emitted from the electron-emitting device 18 located in the vicinity of the first and second protrusions 34a and 34b is once attracted to the first protrusion 34a and then attracted to the second protrusion 34b. The orbital deviation in the direction X is corrected. As a result, the electron beam passes through a predetermined electron beam passage hole 26 corresponding to the electron emitter 18 and reaches the target phosphor layer.

  As described above, the orbit shift of the electron beam caused by the charging of the spacer 30 is corrected by the first and second protrusions 34a and 34b in the first direction X, and is corrected by the third protrusion 34c in the second direction Y. be able to. The correction effect of the electron beam trajectory, that is, the degree to which the electron beam is attracted increases as the protrusion height of the protrusion increases. Accordingly, by adjusting the protrusion heights of the first to third protrusions 34a, 34b, and 34c and setting the correction degree to an optimum level, it is possible to suppress the orbital deviation of the electron beam and land on the target phosphor layer. it can. As a result, the SED with improved display quality can be obtained by preventing the deterioration of color purity in the display image.

  Next explained is an SED according to the second embodiment of the invention. As shown in FIGS. 6 and 7, according to the second embodiment, the spacer structure 22 includes a support substrate 24 made of a rectangular metal plate disposed between the first substrate 10 and the second substrate 12. And a large number of columnar spacers which are integrally provided upright on both sides of the support substrate.

  The support substrate 24 has a first surface 24 a that faces the inner surface of the first substrate 10 and a second surface 24 b that faces the inner surface of the second substrate 12, and is arranged in parallel with these substrates. A large number of electron beam passage holes 26 are formed in the support substrate 24 by etching or the like. The electron beam passage apertures 26 are arranged at a first pitch in the first direction X, and are arranged at a second pitch larger than the first pitch in a second direction Y orthogonal to the first direction. The electron beam passage apertures 26 are respectively arranged to face the electron emission elements 18 and transmit the electron beams emitted from the electron emission elements.

  The support substrate 24 is formed to a thickness of 0.1 to 0.3 mm by using, for example, an iron-nickel metal plate. On both surfaces of the support substrate 24, a high resistance film 32 is formed as an insulating layer by applying and baking an insulating material mainly composed of glass, ceramic, or the like. According to the present embodiment, the first and second surfaces 24a and 24b of the support substrate 24 and the inner wall surfaces of the respective electron beam passage holes 26 have a high resistance film 32 having a thickness of about 10 μm made of Li-based alkali borosilicate glass. It is covered with.

  A plurality of first spacers 30 a are integrally provided on the first surface 24 a of the support substrate 24, and are respectively positioned between the electron beam passage holes 26 aligned in the second direction Y. The plurality of first spacers 30a are provided side by side with a predetermined pitch in the second direction Y, and are provided side by side with a pitch larger than the predetermined pitch in the first direction. The tip of the first spacer 30 a is in contact with the inner surface of the first substrate 10 through the getter film 19, the metal back 17, and the light shielding layer 11 of the phosphor screen 16.

  A plurality of second spacers 30b are integrally provided on the second surface 24b of the support substrate 24, and are respectively positioned between the electron beam passage holes 26 aligned in the Y direction. The plurality of spacers 30 are provided side by side with a predetermined pitch in the second direction Y, and are provided side by side with a pitch larger than the predetermined pitch in the first direction. The tip of the second spacer 30 b is in contact with the inner surface of the second substrate 12.

  The first and second spacers 30a and 30b are aligned with each other, and are formed integrally with the support substrate 24 with the support substrate 24 sandwiched from both sides. Each of the first and second spacers 30a and 30b is formed in a tapered shape having a diameter that decreases from the support substrate 24 side toward the extended end. The first and second spacers 30a and 30b have, for example, a substantially elliptical cross-sectional shape.

  In addition, a plurality of protrusions are integrally provided on the second surface 24 b of the support substrate 24 and protrude from the first substrate 10 side toward the second substrate 12. The plurality of protrusions include a plurality of first protrusions 34a and a plurality of second protrusions 34b provided alongside the second spacer 30b along the first direction X, and a second spacer 30b along the second direction Y. And a plurality of third protrusions 34c provided side by side.

  The first protrusions 34a are arranged side by side on both sides of each second spacer 30b in the first direction X, and are provided so as to be separated from the spacer by approximately one pixel, that is, the first pitch P1. In the first direction X, the second protrusion 34b is arranged side by side with the first protrusion 34a on the side opposite to the second spacer 30b. That is, the first protrusion 34a and the second protrusion 34b are arranged in this order from the second spacer 30b side. The first and second protrusions 34a and 34b are opposed to the inner surface of the second substrate 12 with a gap. The protrusion height of the first and second protrusions 34a and 34b is such that the first protrusion 34a located adjacent to the second spacer 30b is higher than the second protrusion 34b. That is, the protrusions farther from the spacer 30 are formed lower.

In the second direction Y, the third protrusions 34 c are provided between the adjacent second spacers 30 b and between the adjacent electron beam passage holes 26. Further, the third protrusion 34c is provided in the second direction Y so as to be spaced apart from the second spacer 30b at equal intervals. The third protrusion 34c faces the inner surface of the second substrate 12 with a gap.
Each of the first to third protrusions 34a, 34b, 34c is formed in a tapered shape having a diameter that decreases from the support substrate 24 side toward the extending end. The first to third protrusions 34a, 34b, 34c are formed of a spacer forming material mainly composed of glass as an insulating material, for example, similarly to the first and second spacers 30a, 30b.

  The spacer structure 22 configured as described above is disposed between the first substrate 10 and the second substrate 12. The first and second spacers 30a and 30b are in contact with the inner surfaces of the first substrate 10 and the second substrate 12, thereby supporting the atmospheric pressure load acting on these substrates and maintaining the distance between the substrates at a predetermined value. is doing.

In the second embodiment, other configurations are the same as those of the first embodiment described above, and the same reference numerals are given to the same portions, and detailed description thereof is omitted.
According to 2nd Embodiment comprised as mentioned above, the effect similar to 1st Embodiment mentioned above can be acquired. That is, the orbit shift of the electron beam due to the charging of the first and second spacers 30a and 30b is corrected by the first and second protrusions 34a and 34b in the first direction X, and the third protrusion in the second direction Y. 34c can be corrected. The correction effect of the electron beam trajectory, that is, the degree to which the electron beam is attracted increases as the protrusion height of the protrusion increases. Accordingly, by adjusting the protrusion heights of the first to third protrusions 34a, 34b, and 34c and setting the correction degree to an optimum level, it is possible to suppress the orbital deviation of the electron beam and land on the target phosphor layer. it can. As a result, the SED with improved display quality can be obtained by preventing the deterioration of color purity in the display image.

  In the first and second embodiments described above, the number of protrusions arranged in the first direction X is not limited to the first and second protrusions, and can be increased as necessary. The number of protrusions arranged in the second direction Y is not limited to the third protrusion, and can be increased as necessary. Furthermore, although the projection is configured to be provided side by side in both the first direction and the second direction, it may be configured to be provided side by side only in one direction of the first direction and the second direction. The protrusion of the electron beam can be corrected by the protrusion. In particular, for the first direction X in which the arrangement pitch of the phosphor layers and the electron beam passage holes is small, the electron beam trajectory correction by the protrusion is effective. In the first embodiment described above, the spacer 30 and the first to third protrusions 34a, 34b, and 34c are erected on the support substrate 24. However, the support substrate is omitted, and the spacer and the protrusion are the first substrate. It is good also as a structure standing upright directly on the inner surface of 10.

  In addition, 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.

  The shape of the spacer, the size of the spacer, the shape and size of the protrusion, the size of other components, the material, and the like are not limited to the embodiment described above, and can be selected as appropriate. The present invention is not limited to one using a surface conduction electron-emitting device as an electron source, but can also be applied to an image display apparatus using another electron source such as a field emission type or a carbon nanotube.

The perspective view which shows SED which concerns on 1st Embodiment of this invention. The perspective view of said SED fractured | ruptured along line AA of FIG. Sectional drawing which expands and shows the said SED. The top view which shows the support substrate of the said SED, a spacer, and protrusion. The top view which shows roughly the orbit correction | amendment state of the electron beam in the said SED. The perspective view which partially fractures and shows SED which concerns on 2nd Embodiment of this invention. Sectional drawing which expands and shows SED which concerns on the said 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... 1st board | substrate, 12 ... 2nd board | substrate, 14 ... Side wall, 15 ... Vacuum envelope,
16 ... phosphor screen, 18 ... electron-emitting device, 22 ... spacer structure,
24 ... Support substrate, 26 ... Electron beam passage hole, 30 ... Spacer,
30a ... 1st spacer, 30b ... 2nd spacer, 34a ... 1st protrusion,
34b ... 2nd protrusion, 34c ... 3rd protrusion

Claims (8)

A first substrate on which a phosphor screen is formed;
A second substrate disposed opposite to the first substrate and provided with a plurality of electron emission sources for emitting an electron beam toward the phosphor screen and exciting the phosphor screen;
A plurality of spacers that are respectively provided between the first substrate and the second substrate and support an atmospheric pressure load acting on the first and second substrates;
A plurality of protrusions that protrude from the first substrate side toward the second substrate and face the second substrate with a gap, and correct the movement of the electron beam emitted from the electron emission source;
An image display device comprising:   The image display apparatus according to claim 1, wherein the plurality of protrusions are provided side by side with the spacer, and the protrusion height is lower as the protrusion is farther from the spacer.   The plurality of electron emission sources are arranged at a first pitch in a first direction, and are arranged in a second direction orthogonal to the first direction at a second pitch larger than the first pitch, The image display device according to claim 1, wherein the plurality of protrusions are provided side by side in the first direction between the plurality of electron emission sources.   The plurality of electron emission sources are arranged at a first pitch in a first direction, and are arranged in a second direction orthogonal to the first direction at a second pitch larger than the first pitch, 3. The image display device according to claim 1, wherein the plurality of protrusions are provided side by side in the second direction between the plurality of electron emission sources.   The plurality of electron emission sources are arranged at a first pitch in a first direction, and are arranged in a second direction orthogonal to the first direction at a second pitch larger than the first pitch, The image display device according to claim 1, wherein the plurality of protrusions are provided side by side in the first direction and the second direction between the plurality of electron emission sources. A plate-like support having a first surface in contact with the first substrate, a second surface facing the second substrate with a gap therebetween, and a plurality of electron beam passage holes each facing the electron emission source Equipped with a substrate,
6. The device according to claim 1, wherein the spacer and the plurality of protrusions are each erected on a second surface of the support substrate, and the spacer has a tip portion in contact with the second substrate. The image display device described in 1. A support substrate having a first surface facing the first substrate and a second surface facing the second substrate and disposed between the first and second substrates;
The spacers are erected on the first surface and have a plurality of first spacers each having an extended end in contact with the first substrate, and are erected on the second surface. And a plurality of second spacers having extended ends in contact with the second substrate,
The image display device according to claim 1, wherein the plurality of protrusions are erected on a second surface of the support substrate.   The image display device according to claim 1, wherein the spacer is a columnar spacer.

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