JP2004363094A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent irregular displacements of electron beams emitted from adjacent electron-emitting devices and to suppress displacements of impinging positions of the electron beams emitted from the adjacent electron-emitting devices even with a slight displacement of an installation position of a spacer 3 which is shaped like a plate and covered with a high resistance film for the purpose of preventing the spacer 3 from being charged. <P>SOLUTION: The spacer 3 is disposed along a row directional wiring 5. The high resistance film is allowed to come into contact with a metal back 11 and the row directional wiring 5 to achieve electrical connection therebetween. Contact portions between the high resistance film of the spacer 3 and the row directional wiring 5 are provided at predetermined intervals. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus used as, for example, a display panel, and more particularly, to a first substrate having a plurality of electron-emitting devices and a wiring for driving the plurality of electron-emitting devices, A plate-like spacer whose surface is coated with a high-resistance film is provided along the wiring between the first substrate and a second substrate having an electrode defined at a higher potential than the wiring. The present invention relates to a sandwiched image forming apparatus.

  Generally, in an image forming apparatus in which a first substrate on the electron source side and a second substrate on the display surface side are arranged to face each other with an interval, the first substrate is required to obtain necessary atmospheric pressure resistance. A spacer made of an insulating material is interposed between the first substrate and the second substrate. However, there has been a problem that the spacer is charged and affects the electron trajectory in the vicinity of the spacer, thereby causing a light emitting position shift. This causes image deterioration such as a decrease in light emission luminance and color bleeding of pixels near the spacer.

  Conventionally, it is known to use a spacer coated with a high-resistance film to prevent the spacer from being charged.

  Specifically, a high-resistivity film is directly connected to a plate-like spacer covered with a high-resistance film along the wiring of the first substrate with a conductive adhesive between the wiring and an electrode of the second substrate. And the spacer electrodes provided above and below the spacer covered with this high-resistance film, and the high-resistance film is sandwiched between the wiring and the electrode via this spacer electrode. (For example, see Patent Document 1).

  In addition, a conductive intermediate layer (spacer electrode) is provided on each of the first substrate side and the second substrate side of the spacer covered with the high resistance film, and this acts as an electrode for controlling the electron beam trajectory. It has also been proposed (see, for example, Patent Document 2).

JP-A-8-180821 JP-A-10-334834

  A spacer electrode is provided above and below a spacer covered with a high-resistance film described in Patent Literature 1, and the high-resistance film is connected to the wiring of the first substrate and the electrode of the second substrate via the spacer electrode. In the image forming apparatus connected to the above, an electric field distribution is generated near the spacer electrode portion. Although this electric field distribution is almost uniform in the length direction of the spacer, it appears more strongly than the case without the spacer electrode. The arrival position of the electron beam emitted from the element is easily disturbed. In addition, it has been found that the spacer electrode causes a discharge and easily deteriorates the quality of an image. In order to prevent this, it is necessary to prevent the spacer electrode from being exposed on the side surface of the spacer or to install the spacer with high accuracy, both of which cause an increase in cost.

  In the image forming apparatus described in Patent Literature 2, the intermediate layer (spacer electrode) is exposed on the side of the spacer. Therefore, the spacer is formed in the same manner as in the case where the spacer electrode of Patent Literature 1 is exposed on the side of the spacer. Unless the alignment accuracy of the target is maintained at a high level, the intended control cannot be performed, and there is a problem that the cost cannot be avoided. In addition, for example, when the pixel pitch is reduced, the emission position of the electron beam becomes closer to the spacer. As a result, it is necessary to newly design a spacer electrode having a shape corresponding to the position, which causes an increase in cost.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional problems, and has been made in consideration of the fact that electrons emitted from an adjacent electron-emitting device are used in preventing the spacer from being charged by using a plate-like pacer coated with a high-resistance film. An object of the present invention is to prevent irregular displacement of a beam and to suppress displacement of an arrival position of an electron beam emitted from an adjacent electron-emitting device regardless of a slight displacement of a spacer installation position. And It is another object of the present invention to allow a spacer having the same configuration to be applicable to various device forms.

  According to one embodiment of the present invention, there is provided a first substrate having a plurality of electron-emitting devices and a wiring for driving the plurality of electron-emitting devices; A second substrate having a conductive member defined at a high potential, disposed between the first substrate and the second substrate along the wiring, and electrically connected to the wiring and the conductive member; In an image forming apparatus having a connected plate-shaped spacer covered with a high-resistance film, a contact portion for electrical connection between the high-resistance film of the spacer and the wiring is formed along a length direction of the wiring. And an image forming apparatus provided at predetermined intervals. Here, the term “plate-like” preferably means a shape having a sufficient length for discrete contact between the spacer and the wiring, and the sufficient length means at least an electron emission region adjacent to each other. It means a length equal to or greater than the element spacing (element pitch). As an example of the plate-shaped spacer, a rectangular spacer longer than the pitch between the elements corresponds.

  The present invention positively controls the contact position and the non-contact position between the high-resistance film of the spacer and the wiring of the first substrate, thereby preventing the occurrence of an irregular potential distribution on the spacer surface and the adjacent electron emission. This is to make it easier to control the arrival position of the electron beam emitted from the element.

  Regarding this, the operation of the present invention will be described below by comparing the case where the structure of the present invention is not provided, that is, the case where the contact position and the non-contact position between the high resistance film of the spacer and the wiring of the first substrate are not controlled. explain.

  Regarding an image forming apparatus in which a high-resistance film is directly pressed against the wiring of the first substrate and the electrode of the second substrate, the charging of the spacer is not sufficiently eliminated, and the potential distribution on the spacer surface shows an unintended distribution state. We have newly discovered that there are cases.

  The cause of the above-mentioned phenomenon largely depends on the manufacturing process of the display device, and cannot be said unconditionally. For example, unexpected distortion or the like occurs in the wiring of the first substrate or the electrode of the second substrate. Contact between the high-resistance film of the spacer and the wiring or electrode is not continuous because It has been found that this is caused by the fact that a portion that does not come into contact with the device occurs, and a sufficient electrical connection cannot be obtained. In particular, in the case of a wiring formed by an inexpensive manufacturing method, the surface shape may be partially different, and the above-described electrical connection failure is likely to occur.

  In the case described above, not only the charging of the spacer is not sufficiently solved, but also an irregular change occurs in the potential distribution on the surface of the spacer, causing a problem that the electron beam trajectory is not as designed. Further, since the electron beam is accelerated from the first substrate toward the second substrate, the change in the trajectory is more remarkable due to the deflection force on the first substrate side than on the second substrate side. .

  The deflection of the electron beam due to the potential distribution on the spacer surface on the first substrate side will be described more specifically with reference to FIG.

  FIG. 21A shows a case where the high-resistance film and the wiring come into unintended partial contact when a plate-like spacer covered with the high-resistance film is interposed along the wiring of the first substrate. FIG. 21B is a diagram showing a potential distribution on the spacer surface, and FIG. 21B is an equivalent circuit diagram of FIG. 21A.

As shown, the resistance between the point C and the point A is assumed to be R _1, the point B is a non-contact portion, resistance between the corresponding point D and point B becomes R _1, the contact portion the potential of the voltage drop by point B caused by R ₂ is a (resistance between point B and point a) the resistance between the point a is is higher than the potential of the point a. As a result, the trajectory of the electron beam emitted from the electron-emitting device near point B behaves differently from the trajectory of the electron emitted from the electron-emitting device near point A. Will be different (distorted).

  On the other hand, the present invention prevents the occurrence of an irregular potential distribution on the spacer surface by positively controlling the contact position and the non-contact position between the high resistance film of the spacer and the wiring of the first substrate, This makes it easier to control the arrival position of the electron beam emitted from the adjacent electron-emitting device.

  In the present invention, the active control of the contact position and the non-contact position between the high-resistance film of the spacer and the wiring on the first substrate means, specifically, the shape of the contact portion between the spacer and the wiring. By controlling, the contact position and the non-contact position are controlled, the potential distribution on the spacer surface is positively controlled, and an electric field distribution in which a desired electron beam arrival position is easily obtained is obtained.

  Specific modes of controlling the shape of the contact portion between the spacer and the wiring include a method of providing unevenness on the wiring side surface of the spacer and a method of providing unevenness to the wiring. For example, there is a method in which a pillow material (pedestal) made of an insulating material is provided underneath to partially protrude the wiring, and a method in which a conductive protrusion is formed on the wiring. By these methods, aggressive unevenness with a height higher than the variation of the shape (surface roughness, partial protrusions, etc.) depending on the manufacturing method is formed, and the position of the contact and non-contact areas is actively controlled. can do. In other words, according to the present invention, the contact between the spacer and the wiring is not entirely performed, but is controlled positively to make partial contact, thereby forming a controlled equipotential surface on the spacer surface. It is based on.

  A preferred form of the controlled equipotential surface is that the equipotential surface has a periodicity corresponding to the electron-emitting device. As an example of realizing this, it is possible to give periodicity to a pitch between contact portions between the high-resistance film of the spacer and the wiring. The pitch between the contact portions preferably has a periodicity such as a constant multiple of the pitch between the electron-emitting devices. However, it is not always necessary to have periodicity with respect to the pitch between individual electron-emitting devices. For example, one pixel is defined as an electron-emitting device for one pixel formed of RGB of a phosphor, and the pitch between one unit is defined as one period. It is also possible to have a periodicity. In addition, it is not necessary that the intervals between the individual contact points have periodicity, and as described above, it is important that the equipotential surface near the spacer is controlled. This is a sufficiently preferable form. As an example of such a form, there can be cited one having periodicity between one large contact area and one formed by a plurality of small contact areas in close proximity. Also, a periodicity can be obtained on the equipotential surface, which is a preferable embodiment.

  According to the present invention, a desired electron beam arrival position can be obtained by controlling the contact state between the spacer and the wiring on the rear plate side or the electrode on the face plate side. Specifically, by controlling the shape of the contact portion, a non-contact portion is positively formed on the contact side between the spacer and the wiring or the electrode, and a potential change of the non-contact portion is positively controlled, thereby achieving a desired non-contact portion. An electric field distribution near the spacer suitable for the electron beam arrival position can be obtained.

  Further, by moving the position of the electron-emitting device in accordance with the distance between the desired electron beam arrival position and the spacer, a desired electron beam arrival position is obtained. As such a configuration, for example, the shape of the wiring of the rear plate is formed into an aggressive irregular shape having a variation (surface roughness, partial protrusion, etc.) depending on the manufacturing method, and the contact portion is aggressively formed. And a configuration in which a conductive member is sandwiched at a desired position between a spacer and a wiring to positively control a contact portion. In other words, the present invention is based on a change in the idea of forming a controlled equipotential surface on the spacer surface by positively making partial contact with the wiring instead of making full contact between the spacer and the wiring. Things.

  Further, according to the present invention, regardless of the configuration of the spacer itself, by controlling the contact state between the high-resistance film of the spacer and the rear plate side wiring or the face plate side electrode, and preferably further controlling the offset of the electron-emitting device. A desired electron beam arrival position can be achieved. Specifically, one or both of (1) the contact state of the spacer on the rear plate side and (2) the contact state of the spacer on the face plate side, and preferably (3) the requirement for the offset of the electron-emitting device is controlled. By doing so, a desired electron beam arrival position can be achieved. More specifically, (1) the potential distribution of the non-contact portion of the spacer on the rear plate side is controlled; (2) the potential distribution of the non-contact portion of the spacer on the face plate side is controlled; A desired electron beam trajectory can be obtained by controlling the beam trajectory immediately after electron emission using an asymmetric electric field generated by the difference in height between the contact position on the plate side and the position of the electron-emitting portion and the offset of the electron-emitting device. .

  These parameters can be designed relatively easily by, for example, calculation of an electrostatic field determined by the shape of the panel and simple electron beam simulation.

  Furthermore, even if the electron beam trajectory shifts in the vicinity of the spacer for some reason, a desired electron beam arrival position can be achieved without giving the spacer itself a function of compensating for the electron beam trajectory shift.

  As described above, the electron beam trajectory can be designed by controlling the three independent parameters irrelevant to the spacer itself. Therefore, according to the present invention, there is an advantage that the degree of freedom in design is increased.

  As a target to be brought into contact with the high resistance film of the spacer, a member unique to the panel can be used to control the shape. Specifically, it is an intersection of a row direction wiring and a column direction wiring on the rear plate or a black conductor on the face plate. In this case, it is advantageous in terms of cost. Further, in order to control the contact position, a conductive base can be arranged on the rear plate or the face plate. In this case, since the electron beam trajectory can be arranged at any position as long as the trajectory is not hindered, there is an advantage that the degree of freedom in design is further increased.

  According to the present invention, it is possible to cope with various display device configurations with the spacer having the same configuration. For example, the pixel pitch is changed for higher definition, or the acceleration voltage is increased for higher brightness. Even in the case of a change in the display device form specification such as a frustration, a slight design change on the target side with which the spacer is brought into contact is sufficient, and the design change of the spacer is not required. In addition, the same spacer member can be used for a plurality of products. For this reason, productivity can be improved remarkably and cost can be reduced significantly.

  Hereinafter, the present invention will be specifically described with reference to the drawings.

(First example)
FIG. 1 is a partially cutaway perspective view of a display panel according to a first example of an image forming apparatus according to the present invention, FIG. 2 is a partial cross-sectional view in the length direction of a spacer, and FIG. FIG. 4 is an explanatory view of a contact portion and a non-contact portion of a film and a row direction wiring, FIG. 4 is a partial sectional view in a direction perpendicular to a spacer, FIGS. 5 and 6 are explanatory views of electron beam trajectories, respectively, and FIG. 8 is a graph showing the relationship between the distance from the spacer and the offset of the device with respect to the spacer, FIG. 8 is a graph showing the relationship between the distance from the spacer at the position where the electron beam arrives and the contact area between the spacer and the wiring, and FIG. 9 is a graph showing a relationship between an offset and a contact area between a spacer and a wiring.

  As shown in FIG. 1, the display panel of the present example has a rear plate 1 as a first substrate and a face plate 2 as a second substrate facing each other with a space therebetween, and a plate-like spacer therebetween. 3 is sandwiched, the periphery is sealed with a side wall 4, and the inside is in a vacuum atmosphere.

  On the rear plate 1, an electron source substrate 9 on which a row direction wiring 5, a column direction wiring 6, an interelectrode insulating layer 7 (see FIGS. 2 and 4) and an electron emitting element 8 are formed is fixed.

  The illustrated electron-emitting device 8 is a surface conduction electron-emitting device in which a conductive thin film having an electron-emitting portion is connected between a pair of device electrodes. The present embodiment has a multi-electron beam source in which N × M surface-conduction electron-emitting devices are arranged, and M row-directional wirings 5 and N column-directional wirings 6 formed at equal intervals are arranged in a matrix. It has become something. In this example, the row wiring 5 is located on the column wiring 6 with the inter-electrode insulating layer 7 interposed therebetween, and the scanning signal is applied to the row wiring 5 via the lead-out terminals Dx1 to Dxm. Then, a modulation signal (image signal) is applied to the column direction wiring 6 through the lead terminals Dy1 to Dyn.

  The row wirings 5 and the column wiring electrodes 6 can be formed by applying a silver paste by a screen printing method. Further, for example, it can be formed using a photolithography method.

  As a constituent material of the row-direction wiring 5 and the column-direction wiring electrode 6, various conductive materials can be applied in addition to the silver paste. For example, when forming the row-directional wiring 5 and the column-directional wiring electrode 6 using a screen printing method, a coating material in which a metal and a glass paste are mixed can be used, and the metal is deposited using a plating method. Thus, when forming the row-directional wiring 5 and the column-directional wiring electrode 6, a plating bath material can be applied.

  A fluorescent film 10 is formed on the lower surface of the face plate 2 (the surface facing the rear plate 1). Since the display panel of this example is a color display, the fluorescent film 10 is coated with phosphors of three primary colors of red, green and blue. The phosphor of each color is, for example, separately applied in a stripe shape, and a black conductor (black stripe) is provided between the stripes of the phosphor of each color. The purpose of providing the black conductor is to prevent the display color from being displaced even if the irradiation position of the electron beam is slightly displaced, and to prevent the reflection of external light to prevent the display contrast from lowering. And prevention of charge-up of the fluorescent film due to the electron beam. As the black conductor, a material containing graphite as a main component can be used, but other materials can also be used as long as the material is suitable for the above purpose. The method of applying the phosphors of the three primary colors is not limited to the above-described stripe shape, but may be, for example, a delta arrangement or another arrangement.

  On the surface of the fluorescent film 10, a metal back (acceleration electrode) 11, which is a conductive member provided on the face plate 2, is provided. The metal back 11 is for accelerating and pulling up the electrons emitted from the electron-emitting device 8. A high voltage is applied from the high-voltage terminal Hv, and the metal back 11 is regulated to a higher potential than the row-directional wiring 5. It has become something. In the case of a display panel using a surface conduction electron-emitting device as in this example, a potential difference of about 5 to 20 KV is usually formed between the row wiring 5 and the metal back 11.

  On the row wiring 5, a plate-like spacer 3 is attached in parallel with the row wiring 5. Both ends of the spacer 3 are mounted on and supported by the spacer fixing block 12 in a state where the spacer 3 is placed on the row direction wiring 5. By fixing the spacer 3 using the spacer fixing block 12, the kinetic energy of the electrons is small, and the disturbance of the electric field near the electron-emitting device 8 whose electron orbit is easily affected by the electric field can be reduced.

  A plurality of spacers 3 are usually provided at equal intervals in order to impart atmospheric pressure resistance to the display panel, and are provided with electron-emitting devices 8, row-direction wires 5 and column-direction wires 6 for driving the electron-emitting devices 8. The rear plate 1 having the electron source substrate 9 is sandwiched between the face plate 2 on which the fluorescent film 10 and the metal back 11 are provided, and the upper and lower surfaces are pressed against the metal back 11 and the row wiring 5 respectively. Further, a side wall 4 is sandwiched between peripheral portions of the rear plate 1 and the face plate 2, and a joint between the rear plate 1 and the side wall 4 and a joint between the face plate 2 and the side wall 4 are respectively sealed with frit glass or the like. Has been stopped.

  Further, the spacer 3 will be described. The spacer 3 has an insulating property enough to withstand a high voltage applied between the row wiring 5 and the column wiring 6 on the rear plate 1 side and the metal back 11 on the face plate 2 side. And has sufficient conductivity to prevent charging of the surface of the spacer 3. As shown in FIG. 4, the spacer 3 includes a base 13 made of an insulating material and a high-resistance film 14 covering the surface thereof.

  Examples of the constituent material of the base 13 of the spacer 3 include quartz glass, glass with a reduced impurity content such as Na, soda lime glass, and ceramics such as alumina. The constituent material of the base 13 preferably has the same or close thermal expansion coefficient as the constituent materials of the electron source substrate 9, the rear plate 1, the face plate 2, and the like.

A current obtained by dividing the acceleration voltage Va applied to the metal back 11 on the high potential side by the resistance value of the high-resistance film 14 flows through the high-resistance film 14 covering the surface of the spacer 3. Is prevented from being charged. For this reason, the resistance value of the high-resistance film 14 is set in a desirable range from charging and power consumption. The sheet resistance of the high-resistance film 14 is preferably 10 ¹⁴ Ω / □ or less, more preferably 10 ¹² Ω / □ or less, and most preferably 10 ¹¹ Ω / □ or less from the viewpoint of antistatic. . Although the lower limit of the sheet resistance of the high resistance film 14 depends on the shape of the spacer 3 and the voltage applied between the spacers 3, it is preferably at least 10 ⁵ Ω / □ in order to suppress power consumption. More preferably, it is ⁷ Ω / □ or more.

Although it depends on the surface energy of the material constituting the high-resistance film 14, the adhesion to the substrate 13, and the temperature of the substrate 13, a thin film having a thickness of 10 nm or less is generally formed in an island shape, and the resistance is unstable and the reproducibility is low. poor. On the other hand, when the film thickness is 1 μm or more, the film stress increases, the risk of film peeling increases, and the film formation time increases, resulting in poor productivity. Therefore, the thickness of the high resistance film 14 formed on the base 13 is preferably in the range of 10 nm to 1 μm. More preferably, the film thickness is 50 to 500 nm. The sheet resistance is ρ / t (ρ: specific resistance, t: film thickness). From the preferable range of the sheet resistance and the film thickness, the specific resistance ρ of the high-resistance film 14 is 0.1 to 10 ⁸ Ωcm. Is preferred. Further, in order to realize more preferable ranges of the sheet resistance and the film thickness, the specific resistance ρ is preferably set to 10 ² to 10 ⁶ Ωcm.

  As described above, the temperature of the spacer 3 rises when a current flows through the high resistance film 14 formed on the surface thereof or when the entire display panel generates heat during operation. If the resistance temperature coefficient of the high resistance film 14 is a large negative value, the resistance value decreases when the temperature rises, the current flowing through the high resistance film 14 increases, and the temperature further rises. And the current continues to increase until it exceeds the power supply limit. The value of the temperature coefficient of resistance at which such current runaway occurs is empirically a negative value and the absolute value is 1% or more. That is, the resistance temperature coefficient of the high-resistance film 14 is preferably a value greater than -1%.

  As a constituent material of the high resistance film 14, for example, a metal oxide can be used. Among the metal oxides, oxides of chromium, nickel, and copper are preferable. The reason is that these oxides have a relatively low secondary electron emission efficiency, and are difficult to be charged even if the electrons emitted from the electron emission element 8 hit the spacer 3. Other than these metal oxides, carbon has a low secondary electron emission efficiency and is a preferred material. In particular, since amorphous carbon has high resistance, appropriate surface resistance of the spacer 3 is easily obtained.

  As another constituent material of the high-resistance film 14, a nitride of an alloy of aluminum and a transition metal can control a resistance value in a wide range from a good conductor to an insulator by adjusting the composition of the transition metal, and display It is a suitable material because it has a small change in resistance in the panel manufacturing process and is stable. Examples of the transition metal element include Ti, Cr, and Ta.

  The alloy nitride film can be formed by a thin film forming technique such as sputtering, electron beam evaporation, ion plating, or ion-assisted evaporation using a nitrogen gas atmosphere. The metal oxide film can be formed by a thin film formation technique using an oxygen gas atmosphere. Alternatively, a metal oxide film can be formed by a CVD method or an alkoxide coating method. The carbon film is formed by a vapor deposition method, a sputtering method, a CVD method, or a plasma CVD method. In particular, an amorphous carbon film is made so that hydrogen is contained in an atmosphere during film formation or a hydrocarbon gas is used as a film formation gas. Can be obtained by using

  The spacer 3 is sandwiched between the rear plate 1 and the face plate 2 as described above, and the high resistance film 14 covering the surface thereof is connected to the wiring on the rear plate 1 side (in this example, the row direction wiring 5). ) And the conductive member (the metal back 11 in this example) on the face plate 2 side, and are electrically connected to each other. In particular, as shown in FIG. 2, the electrical connection with the row-direction wiring 5 is such that the intersection of the row-direction wiring 5 with the column-direction wiring 6 is equal to the thickness of the column-direction wiring 6 as compared with other portions. Since it protrudes to the plate 2 side, this is performed by contacting the portion with the high-resistance film 14. That is, as shown in FIG. 3, the electrical connection between the high-resistance film 14 and the row direction wiring 5 is such that the intersection of the row direction wiring 5 with the column direction wiring 6 is the contact portion 15 and the other portions are non-contact. By forming the portion 16, the operation is performed at the interval of the intersection. The equipotential lines 17 near the rear plate 1 on the surface of the spacer 3 at this time are schematically shown by thick lines in FIG.

  As can be seen from the equipotential lines 17 shown in FIG. 2 and FIG. 3, since the high-resistance film 14 also exists in the non-contact portion 16, the potential near the non-contact portion 16 rises. This is because, among the paths of the current flowing from the metal back 11 to the contact portion 15, the resistance value of the current path via the non-contact portion 16 is smaller than the current path without the non-contact portion 16 (for example, This is because the potential rises by the voltage drop due to the increased resistance value because the resistance value is larger than the resistance value of the current path from the upper portion.

  As shown in FIGS. 1 and 2, since the column-directional wires 6 are at equal intervals, the contact portions 15 and the non-contact portions 16 are formed at equal intervals. As is clear from FIG. 1, since the electron-emitting device 8 is located between the row-directional wiring 5 and the column-directional wiring 6, all the electron-emitting devices 8 adjacent to the spacer 3 are located at positions adjacent to the non-contact portion 16, All the electron beams emitted from the element 8 are equally affected by the surface potential of the spacer 3 corresponding to the non-contact portion 16.

  As schematically shown in FIG. 4, the electron-emitting device 8 in this example is provided substantially at the center between the row wirings 5 except for those adjacent to the spacer 3. The emission element 8 is provided close to the spacer 3 by a distance L. This distance L is called an offset. Also, as shown by an electron beam trajectory 18 shown by a broken line in FIG. 4, the electrons emitted from the electron-emitting device 8 fly (1) away from the spacer 3 near the electron-emitting portion of the electron-emitting device 8, (2) At the position corresponding to the vicinity of the bottom surface of the spacer 3, it flies so as to approach the spacer 3, and finally reaches the desired predetermined irradiation position 19. Here, the desired irradiation position means a position where irradiation positions of the electron beams emitted from each of the plurality of arrayed electron-emitting devices are substantially equidistant from each other. In the embodiment of FIG. The present invention is conceived of a face plate portion at a position corresponding to a substantially center between the row wirings. The reason why the electron beam reaches the predetermined irradiation position 19 will be described in detail below.

The row-direction wiring 5 and the column-direction wiring 6 near the electron-emitting portion can be regarded as having substantially the same potential (0 V) as compared with the voltage for electron beam acceleration applied to the metal back 11. Since the contact portion 15 (see FIG. 3) between the high-resistance film 14 and the row direction wiring 5 is located above the electron-emitting device 8 (on the face plate 2 side), as shown in FIG. The equipotential line 20 has a downwardly convex curve in the vicinity of the electron-emitting portion of the electron-emitting device 8. When the electron-emitting device 8 is not offset to the spacer 3 side and is almost at the center between the row wirings 5, the electron beam takes a substantially vertical trajectory due to the symmetry of the potential distribution. When approaching the spacer 3, the potential distribution becomes asymmetric and takes a trajectory away from the spacer 3.

  FIG. 5 shows an electron beam trajectory 18 in the case where the electron-emitting device 8 adjacent to the spacer 3 is provided substantially at the center between the row wirings 5 without taking an offset L. Also, when the electron-emitting device 8 is moved closer to one row-direction wiring 5 by an offset L (the distance from the center between the row-direction wirings 5 to the electron-emitting portion of the electron-emitting device 8) with the spacer 3 removed. FIG. 6 shows the electron beam trajectory 18 of FIG.

  The component moving away from the spacer 3 is a function of the offset L. In this example, the electron beam trajectory 18 moves away from the spacer 3 as the offset L increases (as the electron-emitting device 8 approaches the spacer 3). FIG. 7 shows the relationship between the offset L and the distance from the spacer 3 where the electron beam reaches.

As described with reference to FIGS. 2 and 3, the high resistance film 14 of the spacer 3 is in contact with the row direction wiring 5 at each intersection with the column direction wiring 6, as described with reference to FIGS. 2 and 3. As shown in FIG. 4, the potential of the non-contact portion 16 rises, and as shown in FIG. 4, an upwardly projecting equipotential line 20 corresponding to the vicinity of the bottom surface of the spacer 3 is generated, and the electron beam flies to approach the spacer 3.

  The component approaching the spacer 3 is a function of the area (contact area) S of the contact portion 15 (see FIG. 3) determined by the contact state between the high resistance film 14 and the row direction wiring 5, and FIG. It is. As shown in FIG. 8, as the contact area S increases, the electron beam moves away from the spacer.

  The contact state between the high resistance film 14 and the row direction wiring 5 can be represented by not only the area S but also various other parameters. For example, as a function of the peripheral length of the contact portion 15 shown in FIG. 3, the length Gy of the non-contact portion 16 in the width direction of the row wiring 5, the distance Gx between adjacent contact portions 15 in the length direction of the row wiring 5, and the like. Can also be expressed. The electron beam approaches the spacer 3 as the peripheral length of the contact portion 15 decreases and Gx and Gy increase.

  According to the above description, the arrival position of the electron beam can be controlled by the independent parameters independent of the spacer 3 itself, such as the offset L and the contact state (for example, contact area S) between the high-resistance film 14 and the row direction wiring 5. I understand.

  FIG. 9 shows a curve representing the relationship between the offset L at which the electron beam reaches the predetermined irradiation position 19 (see FIG. 4) and the contact area S, with the offset L on the vertical axis and the contact area S on the horizontal axis. It is.

  As can be seen from FIG. 9, there are a plurality of conditions under which the electron beam does not reach the predetermined irradiation position 19 without any shift. When designing under the condition of the point B where the offset L is large and the contact area S is small as compared with the condition of the point A, for example, the row-directional wiring 5 has a kamaboko sectional shape, and the upper surface of the row-directional wiring 5 is By doing so, the contact area S can be reduced.

  In an actual design, an offset L reaching the predetermined irradiation position 19 and a contact state (for example, a contact area S) are determined from, for example, electrostatic field calculation and electron beam trajectory simulation. It is also possible to determine conditions based on actual measurement data.

  As described above, according to the present invention, a desired electron beam arrival position is achieved by controlling the contact state and offset L between the high-resistance film 14 and the row direction wiring 5 irrespective of the configuration of the spacer 3 itself. be able to. Therefore, according to the present invention, it is possible to cope with various image forming apparatuses with the spacer 3 having the same configuration. For example, even in the case of a specification change based on changing the pixel pitch for higher definition or increasing the acceleration voltage for higher brightness, the same spacer 3 itself is used and the same high resistance film is used. This can be dealt with by changing the contact state of the line 14 and the row wiring 5 and the offset L. Therefore, according to the present invention, productivity can be remarkably improved and cost can be significantly reduced.

For the display panel described in this example, a PD200 manufactured by Asahi Glass Co., Ltd. was used as a base material of the spacer 3, a tungsten-germanium alloy compound (WGeN) was used as the high resistance film 14, and a tungsten target and a germanium target were nitrogen. A film was formed by simultaneous sputtering in a gas. At this time, by forming the film while rotating the base 13 of the spacer 3, the film thickness was 200 ° over the entire surface and the sheet resistance was 2.5 × 10 ¹² Ω / □.

  The total thickness of the spacers 3 is 300 μm, the total height of the spacers 3 is 2.4 mm, the distance between the column wirings 6 (the distance between the contact points) is 300 μm, the distance between the row wirings 5 is 920 μm, and the row wiring is 5 is 690 μm, the height from the electron-emitting portion of the electron-emitting device 8 to the upper surface of the row-direction wiring 5 is 75 μm, the voltage applied to the metal back 11 is 15 KV, and the distance between the row-direction wiring 5 and the column-direction wiring 6 is Table 1 shows the relationship between the area S and the offset L when the applied voltage is 14 V. Note that conditions A and B in Table 1 correspond to points A and B in FIG.

(Second example)
In the second example of the present invention, only the differences from the first example will be described.

  FIGS. 10, 11, and 13 correspond to FIGS. 2, 3, and 4 of the first example. The difference between the present example and the first example is that the row at the intersection position with the column-directional wiring 6 is different. The point is that the conductive base 21 is provided on the directional wiring 5. With such a configuration, the contact state can be stabilized, and the electron beam arrival position can be accurately controlled.

  After forming the row direction wiring 5, the conductive base 21 can be formed on the row direction wiring 5 in the same manner as the row direction wiring 5. Further, the conductive pedestal 21 may be formed collectively on all the row wirings 5, or may be formed only on the row wirings 5 with which the spacers 3 are in contact.

  The conductive base 21 is preferably formed of a material that is harder than the base 13 of the spacer 3. For example, the spacer 3 may be formed of glass as the base 13, and the conductive base 21 may be formed of a conductive ceramic having a Young's modulus smaller than that of the glass. In this case, since the deformation of the conductive pedestal 21 becomes smaller, variations in the shape and position of each contact portion 15 are reduced, and further improvement in the accuracy of the electron beam arrival position can be expected. The same effect can be obtained not only when the conductive base is provided but also when the wiring and the spacer are in direct contact with each other by making the wiring harder than the glass substrate of the spacer (by reducing the Young's modulus).

(Third example)
In the third example of the present invention, only the points different from the second example will be described.

  The disposition location of the conductive base 21 does not necessarily need to be on a portion where the row wiring 5 intersects with the column wiring 6 as in the second example. In this example, as shown in FIG. 13, the conductive pedestals 21 are arranged at a half pitch of the second example.

  As in the second example, the conductive base 21 is preferably formed of a member that is harder than the base 13 of the spacer 3. In addition, by arranging the conductive base 21 as in this example, there is an advantage that the degree of freedom in designing the contact surface is increased.

  The contact between the spacer 3 and the row-directional wiring 5 at a position other than the intersection between the column-directional wiring 6 and the row-directional wiring 5 can also be achieved by providing a base for forming contact points in a region where the column-directional wiring 6 is not formed. is there. An example is shown below.

  FIG. 14 is a partially enlarged view showing an outline of this embodiment, and FIG. 15 is a sectional view taken along line AA of FIG.

  As shown in FIGS. 14 and 15, a partial electrode 22 is provided, which is connected to the row direction wiring 5 via a contact hole 24 provided in the insulating layer 23, and connected to the partial electrode 22 and the column direction wiring 6. By connecting another element electrode 26 facing the formed element electrode 25, the contact portion between the spacer 3 (see FIG. 13) and the row direction wiring 5 is utilized by utilizing the step formed by the partial electrode 22 and the contact hole 24. Can be increased (the number of protrusions of the row wiring 5 can be increased).

  A specific manufacturing method of this configuration will be described with reference to FIGS.

  First, as shown in FIG. 16A, after forming the device electrodes 25 and 26, as shown in FIG. 16B, the partial electrode 22 and the column-directional wiring 6 are collectively formed, and as shown in FIG. As shown, after an insulating layer 23 is formed on the partial electrode 22 and a part of the column-directional wiring 6, the insulating layer 23 on the partial electrode 22 is removed in a form slightly smaller than the partial electrode 22 to form a contact hole. Then, as shown in FIG. 16D, the row wiring 5 is formed on the insulating layer 23, and is connected to the partial electrode 22 through the contact hole 24 (see FIG. 16C). By arranging the spacers 3 (see FIG. 13) on the row wirings 5 formed in this way, the spacers 3 and the row wirings 5 can be provided at the intersections between the column wirings 6 and the row wirings 5. Can be realized.

(Fourth example)
In the fourth example of the present invention, only the differences from the first example will be described.

  17 and 18 are views corresponding to FIGS. 4 and 5 for the first example. As shown, the contact surface between the spacer 3 and the row wiring 5 in this example is at a low position, and is substantially Are on the same plane as the electron-emitting portion of the electron-emitting device 8. For this reason, as shown in FIG. 17, since the equipotential line 20 does not have a very downward convex shape as shown in FIG. 4 or is very small, the relationship between the offset L and the electron beam arrival position is as follows. It shows a tendency opposite to the first example.

  That is, the electron beam approaches the spacer 3 as the electron-emitting device 8 approaches the spacer. Further, the same tendency occurs when the height of the electron-emitting portion of the electron-emitting device 8 is higher than the height of the contact surface between the spacer 3 and the row-directional wiring 5. The closer the electron-emitting device 8 is to the spacer 3, the more the electron beam is emitted. Approach.

  As shown in FIG. 17, the electron beam emitted from the electron-emitting device 8 disposed at a position separated from the spacer 3 by the offset L flies so as to approach the spacer 3 by the distorted equipotential line 20, and Obtain the electron beam arrival position. The distorted equipotential lines 20 are formed due to the partial contact between the high-resistance film 14 and the row wiring 5 as described in the first example. FIG. 18 shows an electron beam trajectory 18 when the electron-emitting device 8 is moved closer to one row-direction wiring 5 by an offset L with the spacer 3 removed.

  As described above, by applying the present invention even when the design of the display panel is largely changed, it is possible to realize an image forming apparatus having no electron beam deviation.

(Fifth example)
In the fifth example of the present invention, only the differences from the first example will be described.

  This example is an example in which the contact control of the spacer 3 is applied to the face plate 2 side.

  FIGS. 19 and 20 correspond to FIGS. 2 and 4 of the first example. In the present example, a conductive base 21 is provided on the face plate 2 side, whereby the contact portion described in FIG. 15 and the non-contact portion 16 are also formed on the face plate 2 side to control the potential distribution and achieve a desired electron beam arrival position.

  Specifically, as shown in FIG. 20, (1) the electron beam is moved away from the spacer 3 in the vicinity of the electron-emitting portion of the electron-emitting device 8, and (2) the electron beam is moved in the vicinity of the contact surface of the spacer 3 with the row-directional wiring 5. A desired electron beam trajectory 18 is obtained by approaching the spacer 3 at the height position and (3) moving the spacer 3 away from the spacer 3 near the contact surface with the metal back 11 again.

  In this example, the conductive base 21 is used. However, for example, the above-described black conductive material (black stripe) may be used as a conductive member that contacts the face plate 2 side. Also, in the contact control on the face plate 2 side, the concept of the contact control on the rear plate 1 side described in the first to third examples can be applied.

  Specifically, a component that keeps the electron beam orbit 18 away from the contact surface of the spacer 3 near the face plate 2 side is a function of the contact state between the high resistance film 14 and the conductive base 21 on the face plate 2 side, for example, the contact area S The electron beam moves away from the spacer 3 as the contact area S decreases. Further, if the conductive base 21 is harder than the base 13 of the spacer 3, it is advantageous for precise control of the position of the electron beam, and the conductive base 21 can be arranged and designed at any place.

  Further, in the above example, the high resistance film 14 of the spacer 3 is in contact with the row direction wiring 5 on the rear plate 1 side, but when the column direction wiring 6 is exposed on the surface, It can also be made to contact the directional wiring 6.

FIG. 2 is a perspective view of a display panel according to a first example of the image forming apparatus according to the present invention, with a portion cut away. FIG. 4 is a partial cross-sectional view in the length direction of a spacer in a first example. FIG. 4 is an explanatory diagram of a contact portion and a non-contact portion between a high-resistance film of a spacer and a row wiring in a first example. FIG. 4 is a partial cross-sectional view in a direction orthogonal to a spacer in a first example. FIG. 3 is an explanatory diagram of a trajectory of an electron beam in the first example. FIG. 3 is an explanatory diagram of a trajectory of an electron beam in the first example. 6 is a graph showing a relationship between an offset of an electron beam arrival position from a spacer and an offset. 5 is a graph showing a relationship between a distance of an electron beam arrival position from a spacer and a contact area. It is a graph which shows the relationship between an offset and a contact area. FIG. 7 is a partial cross-sectional view in the length direction of a spacer of an image forming apparatus according to a second example of the present invention. It is explanatory drawing of the contact part and non-contact part of the high resistance film of a spacer and a row direction wiring in the 2nd example. FIG. 9 is a partial cross-sectional view in a direction orthogonal to a spacer in a second example. FIG. 11 is a partial cross-sectional view in the length direction of a spacer of an image forming apparatus according to a third example of the present invention. FIG. 4 is a plan view of a configuration in which a base for forming contact points is provided in a region where a column-directional wiring is not formed, and a convex portion is formed in a row-directional wiring. It is AA sectional drawing of FIG. FIG. 16 is an explanatory diagram of a forming process of the configuration shown in FIGS. 14 and 15. FIG. 14 is a partial cross-sectional view in a direction perpendicular to a spacer of an image forming apparatus according to a fourth example of the present invention. It is explanatory drawing of the trajectory of the electron beam in the 4th example. FIG. 13 is a partial cross-sectional view in the length direction of a spacer of an image forming apparatus according to a fifth example of the present invention. FIG. 15 is a partial cross-sectional view in a direction orthogonal to a spacer in a fifth example. It is a figure explaining a spacer when it contacts a wiring at an irregular contact point.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Rear plate 2 Face plate 3 Spacer 4 Side wall 5 Row wiring 6 Column wiring 7 Interelectrode insulating layer 8 Electron emission element 9 Electron source substrate 10 Fluorescent film 11 Metal back 12 Spacer fixing block 13 Base 14 High resistance film 15 Contact part Reference Signs List 16 Non-contact part 17 Equipotential line 18 Electron beam orbit 19 Predetermined irradiation position 20 Equipotential line 21 Conductive base 22 Partial electrode 23 Insulating layer 24 Contact hole 25 Element electrode 26 Element electrode

Claims (8)

A first substrate having a plurality of electron-emitting devices and a wiring for driving the plurality of electron-emitting devices; and a conductive member arranged to face the first substrate and having a higher potential than the wiring. A second substrate having a higher resistance than the wiring disposed between the first substrate and the second substrate along the wiring and electrically connected to the wiring and the conductive member. An image forming apparatus having a plate-like spacer covered with a film,
An image forming apparatus, wherein contact portions for electrical connection between the high resistance film of the spacer and the wiring are provided at predetermined intervals along the length direction of the wiring.   2. The image according to claim 1, wherein the predetermined interval is an interval at which the electron beams emitted from each of the plurality of electron-emitting devices are irradiated on the second substrate at substantially equal intervals. Forming equipment.   The image forming apparatus according to claim 1, wherein the contact portions are provided at intervals in which a pitch of the contact portions has a periodicity.   The image forming apparatus according to claim 1, wherein the contact portions are provided at equal intervals.   The electron-emitting device adjacent to the spacer is provided at a position corresponding to a non-contact portion between the contact portions provided at equal intervals, and is provided with a fixed offset amount. The image forming apparatus according to any one of the preceding claims.   2. The method according to claim 1, wherein the predetermined offset amount is an offset amount at which electron beams emitted from each of the plurality of electron-emitting devices are irradiated on the second substrate at substantially equal intervals. The image forming apparatus as described in the above.   2. The image forming apparatus according to claim 1, wherein the wiring is harder than the spacer.   The image forming apparatus according to claim 7, wherein the wiring is made of a material having a Young's modulus smaller than that of the spacer.

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