JP3744978B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a display device and a recording device to which an electron source is applied, and relates to a heat dissipation device for a thin image forming apparatus.
[0002]
[Prior art]
Conventionally, two types of electron-emitting devices are known: a thermionic source and a cold cathode electron source. Cold cathode electron sources include field emission type (hereinafter abbreviated as FE type), metal / insulating layer / metal type (hereinafter abbreviated as MIM type), surface conduction electron-emitting devices, and the like. As an example of the FE type, W.W. P. Dyke & W. W. Dolan, “Field emission”, Advance in Electro Physics, 889 (1956) or C.I. A. Spindt, “Physical Properties of Thin-Film Field Emissions with Mollybdenium”, J. Am. Appl. Phys. 47 5248 (1976).
Examples of the MIM type include C.I. A. Mead, “The tunnel-emission amplifier, J. Appl. Phys., 32 646 (1961), etc. are known.
Examples of the surface conduction electron-emitting device type include M.I. I. Elinson, RadioEng. Electron Phys. 10 (1965). The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current flows through a small-area thin film formed on a substrate in parallel to the film surface. As this surface conduction electron-emitting device, SnOl by Erinson et al. ₂ Thin film, Au thin film [G. Dittmer: “Thin Solid Films”, 9 317 (1972)], In ₂ O _Three / SnO ₂ By thin film [M. Hartwell and C.H. G. Fonstad: “IEEE Trans. ED Conf.”, 519 (1975)], carbon thin film [Hisa Araki et al .: Vacuum, Vol. 26, No. 1, pp. 22 (1983)] and the like have been reported.
As a typical device configuration of these surface conduction electron-emitting devices, the above-described M.P. A conventional Hartwell device configuration is shown in FIG. In the figure, reference numeral 181 denotes a substrate. 184 is a conductive thin film made of a metal oxide thin film formed by sputtering in an H-shaped pattern, and an electron emission portion 185 is formed by an energization process called energization forming described later. The element electrode interval L in the figure is set to 0.5 to 1 mm, and W ′ is set to 0.1 mm. Since the position and shape of the electron emission portion 185 are unknown, it is represented as a schematic diagram.
[0003]
Conventionally, in these surface conduction electron-emitting devices, it has been common to form the electron-emitting portion 185 in advance by conducting a process called energization forming on the conductive thin film 184 before electron emission. In other words, energization forming means applying a DC voltage or a very slow rising voltage, for example, about 1 V / min, to both ends of the conductive thin film 184 to locally destroy, deform or alter the conductive thin film, In other words, the electron emission portion 185 is formed in a highly resistive state. In the electron emission portion 185, a crack is generated in a part of the conductive thin film 184, and electrons are emitted from the vicinity of the crack. The surface conduction electron-emitting device subjected to the energization forming process emits electrons from the electron-emitting portion 185 by applying a voltage to the conductive thin film 184 and passing a current through the device.
Since the surface conduction electron-emitting device described above has a simple structure and is easy to manufacture, there is an advantage that a large number of devices can be arranged over a large area. Various applications that take advantage of this feature are being studied. For example, display devices such as a charged beam source and an image display device can be used.
[0004]
As an image display device using such an electron-emitting device, a rear plate on which an electron-emitting portion is mounted, a face plate on which an image forming member is mounted, and a device in which both are vacuum-sealed through a support frame are known. Yes.
[0005]
Such an image forming apparatus generally includes a face plate on which an image forming member is mounted, a rear plate on which an electron source substrate is mounted, and a support frame member formed by cutting and processing a blue plate glass with a frit glass adhesive member. The temperature is raised to a temperature at which the frit glass is melted and solidified, and then cooled, and the members are bonded and manufactured. At this time, in the thermal process, since it is difficult to perform uniform temperature rise and temperature management over the entire apparatus, the entire apparatus may be curved nonlinearly.
[0006]
Further, a thin and large-area image forming apparatus can be manufactured using a conventional electron-emitting device, but it is difficult to maintain plane accuracy over a large area for the face plate, rear plate, and support frame member to be formed. The forming device may have warping and undulation.
[0007]
Further, when the image forming apparatus is driven and displayed, the temperature difference between the face plate, the rear plate, and the support frame is generated due to the heat generated by the electron emission portion on the rear plate and the heat generated by the image forming member on the face plate. Due to the difference, the image forming apparatus may be warped and the entire apparatus may be curved.
[0008]
As a result, color misregistration, luminance reduction, and screen distortion occur, and there is a risk of vacuum leaks or damage to the device if driven for a long time.
[0009]
Therefore, there is a need for a uniform heat dissipation unit that stably supports the warp and undulation of the image forming apparatus and suppresses the warp that occurs during driving.
[0010]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a high-definition image forming apparatus that safely supports a flat and large-sized image forming apparatus that solves the above-described problems of the prior art and that is free from color misregistration due to uniform heat dissipation.
[0011]
[Means for Solving the Problems]
The above object is achieved by the following means. That is, the present invention provides a face on which a rear plate on which an electron-emitting device is mounted, and an image forming member that is disposed opposite to the rear plate and on which an image is formed by irradiation of an electron beam emitted from the electron-emitting device. A display panel formed with a plate and having an internal vacuum atmosphere, and disposed outside the display panel and on the rear plate side, Frame-shaped In an image forming apparatus including a heat radiating member, a support member that has thermal conductivity and elasticity and supports the display panel according to the shape of the display panel is disposed between the display panel and the heat radiating member. And Adhering and fixing the outer frame integrally formed with the support member and the frame-shaped heat dissipation member with a conductive adhesive, The present invention proposes an image forming apparatus characterized in that the heat dissipating member and the supporting member are outside the vacuum atmosphere, and the electron-emitting device mounted on the rear plate of the display panel is a surface conduction electron-emitting device. Including.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of an essential part of an image forming apparatus showing an example of the present invention, and FIG. 13 is a schematic configuration diagram showing an example of an image forming apparatus of the present invention.
In FIG. 1, 11 is a display panel, 12 is a heat conducting member, 13 is a spring member which is a support member having a telescopic function, and 14 is a heat radiating member.
As shown in FIG. 13, the display panel 11 includes a rear plate 131 on which a pair of device electrodes of an electron-emitting device are connected by an X-direction wiring 122 and a Y-direction wiring 123 and an electron source substrate 121 manufactured on the substrate is mounted on the rear plate 131. A face plate 136 mounted with an image forming member that is disposed opposite to the plate 131 and forms an image by irradiation of an electron beam emitted from the electron-emitting device, and a support frame 132 disposed between the plates 131 and 136. ing.
The image forming member mounted on the face plate 136 is configured by sequentially laminating a fluorescent film 134 and a metal back 135 on a glass substrate 133.
The image forming apparatus of the present invention is an image forming apparatus having the display panel as described above, and has a heat conductive member 12 and a stretchable spring member between the display panel 11 and the heat dissipation member 14 as shown in FIG. 13 and a plurality of support members A composed of 13. The heat conducting member 12 and the spring member 13 may be made of the same material or different materials. It is particularly important that the support member A is attached so that it can expand and contract in accordance with the change in the shape of the display panel 11, so that the heat conducting member 12 of the support member A has an interval of about 1 to 100 mm. It is preferable to provide it.
With the above configuration, even if nonlinear warping occurs in the display panel 11, the spring member 13 can self-adjust the distance between the heat radiating member 14 and the display panel 11 by the expansion and contraction of the spring member 13, so that the display panel 11 is warped. The display panel 11 can be supported very stably without any problem. Further, since heat generated by driving the display panel 11 is conducted through the heat conducting member 12 and the spring member 13 and finally dissipated by the heat radiating member 14, it is possible to prevent expansion of the warp of the display panel 11. In this case, it is preferable that the spring member 13 is made of a heat conductive material because heat conduction is performed more smoothly.
Examples of the heat conductive member 12 include plate materials such as aluminum, copper, and heat conductive rubber.
Examples of the spring member 13 include elastic materials such as stainless steel and steel, and the shape can be selected from any known shape that can exhibit a spring effect such as a spiral shape or a cantilever shape.
The fixing means between the display panel 11 and the heat conducting member 12, the fixing means between the heat conducting member 12 and the spring member 13, and the fixing means between the heat dissipating member 14 and the spring member 13 are welded, heated in consideration of the combination of both materials. It can be appropriately selected from known means such as adhesion using a conductive tape and adhesion using a conductive adhesive.
FIG. 3 shows another example of the image forming apparatus according to the present invention. In this example, the support member A is formed by connecting the end portions of the heat conducting member 12 in series via the spring member 13. Yes. The heat conducting member 12 of the support member A is fixedly attached to the back surface of the display panel 11 as shown in FIG. 3, and the display panel 11 closes the opening of the heat radiating member 14 formed in a shallow box shape. The display panel 11 to which the support member A is fixed is attached to the heat dissipation member 14 via the spring members 13 at both ends of the support member A.
Even if the display panel 11 is warped by the above configuration, it is self-adjusted by the expansion and contraction of the spring member 13 and is supported extremely stably. Further, even if the display panel 11 is driven in this state, the heat generated by the driving is conducted through the heat conducting member 12 and the spring member 13, and the warp of the display panel 11 of the heat radiating member 14 is not eventually expanded.
FIG. 5 is a cross-sectional view showing another example of the present invention. In this example, a heat conduction support member 51 formed of a sealed bag in which a heat conduction fluid such as water is sealed is provided between the display panel 11 and the heat radiation member 14. It consists of a sandwiched structure.
By adopting the above-described configuration, the same effects as those of the examples of FIGS. 1 and 3 can be obtained.
[0013]
The cold cathode electron source used in the present invention is preferably a surface conduction electron-emitting device that has a simple configuration and is easy to manufacture.
There are basically two types of surface conduction electron-emitting devices that can be used in the present invention: planar surface conduction electron-emitting devices and vertical surface conduction electron-emitting devices.
FIG. 7 is a schematic plan view and a cross-sectional view showing a configuration of a basic surface conduction electron-emitting device.
In FIG. 7, 71 is a substrate, 72 and 73 are element electrodes, 74 is a conductive thin film, and 75 is an electron emission portion.
As the substrate 71, quartz glass, glass with low impurity content such as Na, blue plate glass, SiO 2 ₂ A glass substrate formed on the surface and a ceramic substrate such as alumina are used.
As a material for the device electrodes 72 and 73, a general conductor is used. For example, a metal or alloy such as Ni, Cr, Au, Mo, W, Pt, Ti, Al, Cu, Pd, and Pd, Ag, Au, RuO ₂ , Printed conductors composed of metals such as Pd-Ag or metal oxides and glass, In ₂ O _Three -SnO ₂ It is appropriately selected from transparent conductors such as, and semiconductor materials such as polysilicon.
The element electrode interval L is preferably several hundreds of angstroms to several hundreds of micrometers. In addition, it is desirable that the voltage applied between the element electrodes is low, and it is required that the voltage be generated with good reproducibility. Therefore, a particularly preferable element electrode interval is several micrometers to several tens of micrometers.
The element electrode length W is several hundred micrometers to several hundred micrometers from the resistance value and electron emission characteristic of the electrode, and the film thickness of the element electrodes 72 and 73 is preferably several micrometers to several hundred angstroms.
[0014]
In addition to the configuration in FIG. 7, a configuration in which the conductive thin film 74 and the element electrodes 72 and 73 are sequentially formed on the substrate 71 may be employed.
The conductive thin film 74 is particularly preferably a fine particle film composed of fine particles in order to obtain good electron emission characteristics, and the film thickness is the step coverage to the device electrodes 72 and 73, the resistance value between the device electrodes 72 and 73, and a later-described film thickness. Although it is set as appropriate depending on the energization forming conditions to be performed, it is preferably several angstroms to several thousand angstroms, and particularly preferably 10 angstroms to 500 angstroms. The sheet resistance value is 10 3 to 10 7 ohm / □.
The material constituting the conductive thin film 74 is Pd, Pt, Ru, Ag, Au, Ti, In, Cu, Cr, Fe, Zn, Sn, Ta, W, Pb and other metals, PdO, SnO. ₂ , In ₂ O _Three , PbO, Sb ₂ O _Three Oxides such as HfB ₂ , ZrB ₂ , LaB ₆ , CeB ₆ , YB _Four , GdB _Four And borides such as TiC, ZrC, HfC, TaC, SiC, and WC, nitrides such as TiN, ZrN, and HfN, semiconductors such as Si and Ge, and carbon.
The fine particle film described here is a film in which a plurality of fine particles are aggregated, and the fine structure is not limited to the state in which the fine particles are individually dispersed and arranged, but also the state in which the fine particles are adjacent to each other or overlap (including island shapes). The particle size of the fine particles is from several angstroms to several thousand angstroms, preferably from 10 angstroms to 200 angstroms.
The electron emission portion 75 is a high-resistance crack formed in a part of the conductive thin film 74 and is formed by energization forming or the like. The crack may have conductive fine particles having a particle diameter of several angstroms to several hundred angstroms. The conductive fine particles contain at least a part of the elements constituting the conductive thin film 74.
Moreover, the electron emission part 75 and the electroconductive thin film 74 of the vicinity may have carbon and a carbon compound.
[0015]
FIG. 8 is a schematic diagram showing the configuration of a basic vertical surface conduction electron-emitting device.
In FIG. 8, the same members as those in FIG. Reference numeral 80 denotes a step forming portion.
The substrate 71, the device electrodes 72 and 73, the conductive thin film 74, and the electron emission portion 75 can be made of the same material as the above-described planar surface conduction electron emission device, and the step forming portion 80 is made of an insulating material. The film thickness of the step forming portion 80 corresponds to the element electrode interval L of the planar surface conduction electron-emitting device described above. The distance is several hundred angstroms to several tens of micrometers. The distance can be controlled by the manufacturing method of the step forming portion and the voltage applied between the device electrodes, but is preferably several hundred angstroms to several micrometers.
Since the conductive thin film 74 is formed after the device electrodes 72 and 73 and the step forming portion 80 are formed, the conductive thin film 74 is laminated on the device electrodes 72 and 73. In FIG. 8, the electron emission portion 75 is shown to be formed in a straight line on the step forming portion 80. However, depending on the creation conditions, energization forming conditions, etc., the shape and position are not limited to this. Absent.
Various methods are conceivable as a method for manufacturing the above-described surface conduction electron-emitting device, and an example is shown in FIG.
Hereinafter, a method for manufacturing the electron source substrate will be described with reference to FIGS. In addition, the same code | symbol is provided about the member same as FIG.
[0016]
1) The substrate is sufficiently washed with a detergent, pure water and an organic solvent, and then an element electrode material is deposited by a vacuum vapor deposition method, a sputtering method or the like. Thereafter, device electrodes 72 and 73 are formed on the substrate by a photolithography technique (FIG. 9A).
[0017]
2) An organometallic thin film is formed by applying an organometallic solution to the substrate 71 provided with the device electrodes 72 and 73 and leaving it to stand. The organometallic solution here is a solution of an organometallic compound whose main element is the metal that forms the conductive film 74 described above. Thereafter, the organic metal thin film is heated and baked and patterned by lift-off, etching, or the like to form the conductive thin film 74 (FIG. 9B). In addition, although it demonstrated by the coating method of the organometallic solution here, it is not restricted to this, When forming by a vacuum evaporation method, a sputtering method, a chemical vapor deposition method, a dispersion coating method, a dipping method, a spinner method, etc. There is also.
[0018]
3) Subsequently, an energization process called energization forming is performed. In the energization forming, the element electrodes 72 and 73 are energized from a power source (not shown), and the conductive thin film 74 is locally broken, deformed, or altered to form a site whose structure is changed. The region where the structure is locally changed is called an electron emission portion 75 (FIG. 9C). An example of the voltage waveform of energization forming is shown in FIG.
The voltage waveform is particularly preferably a pulse waveform, and there are a case where a voltage pulse having a constant pulse peak value is applied continuously (FIG. 10a) and a case where a voltage pulse is applied while increasing the pulse peak value (FIG. 10b). . First, the case where the pulse peak value is a constant voltage (FIG. 10a) will be described.
In FIG. 10a, T1 and T2 are the pulse width and pulse interval of the voltage waveform, T1 is 1 microsecond to 10 milliseconds, T2 is 10 microseconds to 100 milliseconds, and the peak value of the triangular wave (peak voltage during energization forming) ) Is appropriately selected according to the form of the surface conduction electron-emitting device, and is applied for several seconds to several tens of minutes in a suitable vacuum degree, for example, in a vacuum atmosphere of about 10 −5 torr. The waveform applied between the electrodes of the element is not limited to a triangular wave, and a desired waveform such as a rectangular wave may be used.
T1 and T2 in FIG. 10b are the same as in FIG. 10a, and the peak value of the triangular wave (peak voltage at the time of energization forming) is increased by, for example, about 0.1 V step and applied in an appropriate vacuum atmosphere.
[0019]
In this case, in the energization forming process, the element current is measured at a voltage that does not locally destroy or deform the conductive thin film 74 during the pulse interval T2, for example, a voltage of about 0.1 V, and the resistance value is obtained. For example, the energization forming is ended when a resistance of 1 M ohm or more is shown.
[0020]
4) Next, it is desirable to perform a process called an activation process on the element that has undergone energization forming.
The activation step is, for example, a process of repeatedly applying a voltage pulse having a constant pulse peak value at a degree of vacuum of about 10 −4 to 10 −5 torr, as with energization forming. In this process, carbon and a carbon compound resulting from the organic substance present in the substrate are deposited on the conductive thin film to significantly change the device current If and the emission current Ie. The activation process ends when, for example, the emission current Ie is saturated while measuring the device current If and the emission current Ie. Moreover, it is preferable that the voltage pulse to be applied is an operation driving voltage.
[0021]
Here, carbon or a carbon compound is graphite (refers to both single and polycrystalline) and amorphous carbon (refers to a mixture of amorphous carbon and polycrystalline graphite), and its film thickness is 500 angstroms or less. Preferably, it is 300 angstroms or less.
[0022]
5) It is preferable to operate the electron-emitting device thus produced by placing it in an atmosphere having a higher degree of vacuum than the degree of vacuum in the energization forming process and the activation process. In addition, it is desirable to operate after heating at 80 ° C. to 150 ° C. in an atmosphere with a higher degree of vacuum.
The degree of vacuum higher than the energization forming step and the activated vacuum degree is, for example, a vacuum degree of about 10 −6 or more, more preferably an ultra-high vacuum system, and a new carbon and carbon compound. Is a degree of vacuum that hardly deposits on the conductive thin film. By doing so, the device current If and the emission current Ie can be stabilized. FIG. 11 is a schematic configuration diagram of a measurement evaluation apparatus for measuring the electron emission characteristics of the device having the configuration shown in FIG. 11, the same reference numerals as those in FIG. 7 denote the same components. Reference numeral 111 denotes a power source for applying the device voltage Vf to the electron-emitting device, 110 denotes an ammeter for measuring the device current If flowing in the conductive thin film 74 between the device electrodes 2 and 3, and 114 denotes the device. An anode electrode for capturing the emission current Ie emitted from the electron emission portion, 113 is a high voltage power source for applying a voltage to the anode electrode 114, and 112 is an emission current Ie emitted from the electron emission portion 75 of the device. , 115 is a vacuum device, and 116 is an exhaust pump.
Next, the image forming apparatus of the present invention will be described.
The electron source substrate used in the image forming apparatus is formed by arranging a plurality of surface conduction electron-emitting devices on the substrate.
In the arrangement method of the surface conduction electron-emitting devices, a surface-conduction electron-emitting device is arranged in parallel, and a ladder-type arrangement in which both ends of each element are connected by wiring (hereinafter referred to as a ladder-type arrangement electron source substrate), A simple matrix arrangement (hereinafter referred to as a matrix-type arrangement electron source substrate) in which an X-direction wiring and a Y-direction wiring are connected to a pair of element electrodes of a surface conduction electron-emitting device, respectively. Note that an image forming apparatus having a ladder-type arrangement electron source substrate requires a control electrode (grid electrode) that is an electrode for controlling the flight of electrons from the electron-emitting device.
Hereinafter, the configuration of the electron source configured based on this principle will be described with reference to FIG. 121 is an electron source substrate, 122 is an X-direction wiring, 123 is a Y-direction wiring, 124 is a surface conduction electron-emitting device, and 125 is a connection. The surface conduction electron-emitting device 124 may be either the above-described planar type or vertical type.
In the figure, the substrate used for the electron source substrate 121 is the above-described glass substrate or the like, and the shape is appropriately set according to the application.
The m X-direction wirings 122 are composed of Dx1, Dx2,... Dxm, and the Y-direction wiring 123 is composed of n wirings of Dy1, Dy2,.
The material, film thickness, and wiring width are appropriately set so that a substantially uniform voltage is supplied to a large number of surface conduction elements. The m X-direction wirings 122 and the n Y-direction wirings 123 are electrically separated by an interlayer insulating layer (not shown) to form a matrix wiring. (M and n are both positive integers)
An interlayer insulating layer (not shown) is formed in a desired region on the entire surface or a part of the substrate 121 on which the X direction wiring 122 is formed. The X-direction wiring 122 and the Y-direction wiring 123 are each drawn out via an external terminal.
Furthermore, element electrodes (not shown) of the surface conduction electron-emitting device 124 are electrically connected by m pieces of X-direction wirings 122, n pieces of Y-direction wirings 123, and connections 125.
The surface conduction electron-emitting device may be formed on the substrate or an interlayer insulating layer (not shown).
As will be described in detail later, a scanning signal generating means (not shown) for applying a scanning signal for scanning a row of surface conduction type emitting elements 124 arranged in the X direction to the X direction wiring 122 according to an input signal. And are electrically connected.
On the other hand, the Y-direction wiring 123 includes modulation signal generating means (not shown) for applying a modulation signal for modulating each column of the surface conduction electron-emitting devices 124 arranged in the Y direction according to an input signal. Electrically connected.
Further, the driving voltage applied to each element of the surface conduction electron-emitting device is supplied as a differential voltage between the scanning signal and the modulation signal applied to the element.
In the above configuration, individual elements can be selected and driven independently by simple matrix wiring.
Next, an image forming apparatus using the matrix type arranged electron source substrate prepared as described above will be described with reference to FIGS. FIG. 13 is a basic configuration diagram of an image forming apparatus, FIG. 14 is a fluorescent film, FIG. 15 is a block diagram of a drive circuit for displaying in accordance with an NTSC television signal, and image formation including the drive circuit is shown. Represents a device.
In FIG. 13, reference numeral 121 denotes an electron source substrate on which an electron-emitting device is formed, 131 denotes a rear plate on which the electron source substrate 121 is fixed, 136 denotes a fluorescent film 134, a metal back 135, and the like formed on the inner surface of the glass substrate 133. A face plate, 132 is a support frame, and 131 is a rear plate, and an envelope 138 is constituted by these members.
In FIG. 13, reference numeral 124 corresponds to the electron emission portion in FIG. Reference numerals 122 and 123 denote X-direction wirings and Y-direction wirings connected to a pair of device electrodes of the surface conduction electron-emitting device.
As described above, the envelope 138 includes the face plate 136, the support frame 132, and the rear plate 131. However, the rear plate 131 is provided mainly for the purpose of reinforcing the strength of the electron source substrate 121. When the electron source substrate 121 itself has sufficient strength, the separate rear plate 131 is not necessary, and the support frame 132 is directly provided on the electron source substrate 121, and the face plate 136, the support frame 132, and the electron source substrate 121 are provided. The envelope 138 may be configured.
In FIG. 14, reference numeral 142 denotes a phosphor. In the case of monochrome, the phosphor 142 is composed of only a phosphor. In the case of a color phosphor film, the phosphor 142 includes a black conductive material 141 called a black stripe or a black matrix and the phosphor 142 depending on the arrangement of the phosphors. The purpose of providing the black stripe and the black matrix is to make the mixed colors and the like inconspicuous by making the divided portions between the respective phosphors 142 of the necessary three primary color phosphors black in the case of color display, and the external light in the phosphor film 134 It is to suppress a decrease in contrast due to reflection. The material of the black stripe is not limited to the material which is not only a material mainly composed of graphite, which is usually used well, but also a material having conductivity and low light transmission and reflection.
As a method of applying the phosphor on the glass substrate 133, a precipitation method or a printing method is used regardless of monochrome or color.
A metal back 135 (FIG. 13) is usually provided on the inner surface side of the fluorescent film 134 (FIG. 13). The purpose of the metal back is to improve the luminance by specularly reflecting the light emitted from the phosphor toward the inner surface toward the face plate 136, to act as an electrode for applying an electron beam acceleration voltage, For example, the phosphor is protected from damage caused by the collision of negative ions generated in the chamber. The metal back can be produced by performing a smoothing process (usually called filming) on the inner surface of the phosphor film after the phosphor film is produced, and then depositing Al by vacuum evaporation or the like.
The face plate 136 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 134 in order to further increase the conductivity of the fluorescent film 134.
The envelope 138 passes through an exhaust pipe (not shown) and 10 ^-7 The degree of vacuum is about torr and sealing is performed. In addition, a getter process may be performed in order to maintain the degree of vacuum after the envelope 138 is sealed. This is because vapor deposition is performed by heating a getter disposed at a predetermined position (not shown) in the envelope 138 by a heating method such as resistance heating or high frequency heating immediately before or after sealing the envelope 138. This is a process for forming a film. The getter is usually composed mainly of Ba or the like, and, for example, 1 × 10 6 by the adsorption action of the deposited film. ^-Five torr or 1 × 10 ^-7 The degree of vacuum of torr is maintained. Note that the steps after forming the surface conduction electron-emitting device are appropriately set.
Next, a schematic configuration of a drive circuit for performing television display based on an NTSC television signal in an image forming apparatus constructed using a matrix type electron source substrate will be described with reference to the block diagram of FIG. 151 is the display panel, 152 is a scanning circuit, 153 is a control circuit, 154 is a shift register, 155 is a line memory, 156 is a synchronizing signal separation circuit, 157 is a modulation signal generator, and Vx and Va are DC voltage sources. It is.
[0023]
Hereinafter, the function of each part will be described. First, the display panel 151 is connected to an external electric circuit via the terminals Dox1 to Doxm, the terminals Doy1 to Doyn, and the high voltage terminal Hv. Among these, the terminals Dox1 to Doxm sequentially drive the electron source provided in the image forming apparatus, that is, a group of surface conduction electron-emitting devices arranged in a matrix of M rows and N columns in a row (N elements). Then, a scanning signal for applying is applied.
On the other hand, a modulation signal for controlling the output electron beam of each element of the surface conduction electron-emitting elements in one row selected by the scanning signal is applied to the terminals Dy1 to Dyn. The high voltage terminal Hv is supplied with a DC voltage of, for example, 10 [kV] from the DC voltage source Va. This is sufficient to excite the phosphor with the electron beam output from the surface conduction electron-emitting device. This is the acceleration voltage for applying energy.
Next, the scanning circuit 152 will be described. The circuit includes M switching elements (schematically indicated by S1 to Sm in the figure), and each switching element is an output voltage of a DC voltage source Vx or 0 [V] (ground level). Is selected and electrically connected to terminals Dx1 to Dxm of the display panel 151. Each of the switching elements S1 to Sm operates based on the control signal Tscan output from the control circuit 153, but in actuality, it can be configured by combining switching elements such as FETs.
The DC voltage source Vx is such that the driving voltage applied to the element not scanned based on the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting element is lower than the electron emission threshold voltage. It is set to output a constant voltage.
The control circuit 153 has a function of matching the operation of each unit so that appropriate display is performed based on an image signal input from the outside. Based on a synchronization signal Tsync sent from a synchronization signal separation circuit 156 described below, control signals Tscan, Tsft, and Tmry are generated for each unit.
The synchronization signal separation circuit 156 is a circuit for separating a synchronization signal component and a luminance signal component from an NTSC television signal input from the outside, and can be configured by using a frequency separation (filter) circuit. As is well known, the synchronization signal separated by the synchronization signal separation circuit 156 includes a vertical synchronization signal and a horizontal synchronization signal, but is illustrated here as a Tsync signal for convenience of explanation. On the other hand, the luminance signal component of the image separated from the television signal is represented as a DATA signal for convenience, but the signal is input to the shift register 154.
The shift register 154 is for serial / parallel conversion of the DATA signal serially input in time series for each line of the image, and operates based on the control signal Tsft sent from the control circuit 153. (In other words, the control signal Tsft may be rephrased as a shift clock of the shift register 154.) The data for one line of the serial / parallel converted image (corresponding to the drive data for N electron-emitting devices) is Id1. To Idn are output from the shift register 154 as N parallel signals.
The line memory 155 is a storage device for storing data for one image line for a necessary time, and appropriately stores the contents of Id1 to Idn according to the control signal Tmry sent from the control circuit 153. The stored contents are output as Idl to Idn and input to the modulation signal generator 157.
The modulation signal generator 157 is a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of the image data Id1 to Idn, and an output signal thereof is stored in the display panel 151 through terminals Doy1 to Doyn. Applied to the surface conduction electron-emitting device.
The electron-emitting device according to the present invention has the following basic characteristics with respect to the emission current Ie. That is, there is a clear threshold voltage Vth for electron emission, and electron emission occurs only when a voltage equal to or higher than Vth is applied.
[0024]
In addition, for a voltage higher than the electron emission threshold, the emission current also changes according to the change in the voltage applied to the device. Note that the value of the electron emission threshold voltage Vth and the degree of change of the emission current with respect to the applied voltage may change by changing the material, configuration, and manufacturing method of the electron-emitting device. I can say that.
That is, when a pulsed voltage is applied to the device, for example, no electron emission occurs even when a voltage lower than the electron emission threshold is applied, but an electron beam is output when a voltage higher than the electron emission threshold is applied. . At this time, first, it is possible to control the intensity of the output electron beam by changing the pulse peak value Vm. Second, it is possible to control the total amount of charges of the electron beam that is output by changing the pulse width Pw.
Therefore, as a method of modulating the electron-emitting device according to the input signal, there are a voltage modulation method, a pulse width modulation method, and the like. To implement the voltage modulation method, the modulation signal generator 157 has a certain length. Although a voltage pulse is generated, a voltage modulation circuit that appropriately modulates the peak value of the pulse according to input data is used.
In order to implement the pulse width modulation method, the modulation signal generator 157 generates a voltage pulse having a constant peak value, but appropriately modulates the width of the voltage pulse according to the input data. This circuit is used.
Through the series of operations described above, the image forming apparatus of the present invention can perform television display using the display panel 151. Although not specifically described in the above description, the shift register 154 and the line memory 155 may be either digital signal type or analog signal type, and in short, serial / parallel conversion and storage of image signals are performed at a predetermined speed. It only has to be done.
In the case of using a digital signal system, it is necessary to convert the output signal DATA of the synchronization signal separation circuit 156 into a digital signal. Further, the circuit used for the modulation signal generator 157 is slightly different depending on whether the output signal of the line memory 155 is a digital signal or an analog signal.
[0025]
First, the case of a digital signal will be described. In the voltage modulation method, for example, a well-known D / A conversion circuit may be used as the modulation signal generator 157, and an amplifier circuit or the like may be added as necessary.
In the case of the pulse width modulation method, the modulation signal generator 157 includes, for example, a high-speed oscillator and a counter that counts the wave number output from the oscillator, and a comparator that compares the output value of the counter with the output value of the memory. It can be configured by using a circuit combining (comparator). If necessary, an amplifier for amplifying the pulse-width modulated signal output from the comparator to the driving voltage of the surface conduction electron-emitting device may be added.
[0026]
Next, the case of an analog signal will be described. In the voltage modulation system, for example, an amplification circuit using a well-known operational amplifier or the like may be used as the modulation signal generator 157, and a level shift circuit or the like may be added if necessary. In the case of the pulse width modulation method, for example, a well-known voltage controlled oscillation circuit (VCO) may be used, and an amplifier for amplifying the voltage to the driving voltage of the surface conduction electron-emitting device is added if necessary. May be.
In the image forming apparatus completed as described above, each electron-emitting device is caused to emit electrons by applying a voltage through the container outer terminals Dox1 to Doxm, Doy1 to Doyn, and through the high voltage terminal Hv, the metal back 135, Alternatively, an image can be displayed by applying a high voltage to a transparent electrode (not shown), accelerating the electron beam, causing it to collide with the fluorescent film 134, and exciting and emitting light.
The above-described configuration is a schematic configuration necessary for producing a suitable image forming apparatus used for display or the like. For example, detailed portions such as materials of each member are not limited to the above-described contents, and image formation is performed. It selects suitably so that it may suit the use of an apparatus. Further, although the NTSC system has been exemplified as an input signal example, the present invention is not limited to this, and various systems such as the PAL and SECAM systems may be used, and more than this, a TV signal (for example, MUSE) composed of a large number of scanning lines. A high-definition TV system such as a system may be used.
[0027]
Next, the ladder-type arranged electron source substrate and the image forming apparatus using the same will be described with reference to FIGS.
In FIG. 16, 160 is an electron source substrate, 161 is an electron-emitting device, and Dx1 to Dx10 of 162 are common wirings connected to the electron-emitting device. A plurality of electron-emitting devices 161 are arranged on the substrate 160 in parallel in the X direction. (This is called an element row). A plurality of these element rows are arranged on a substrate to form a ladder type electron source substrate. By appropriately applying a driving voltage between the common wirings of each element row, each element row can be driven independently. That is, a voltage equal to or higher than the electron emission threshold may be applied to an element row that emits an electron beam, and a voltage equal to or lower than an electron emission threshold may be applied to an element row that does not emit an electron beam. Further, the common wirings Dx2 to Dx9 between the element rows may be configured such that, for example, Dx2 and Dx3 are the same wiring.
FIG. 17 is a view showing the structure of an image forming apparatus provided with an electron source arranged in a ladder shape. Reference numeral 170 denotes a grid electrode, reference numeral 171 denotes a hole through which electrons pass, reference numeral 172 denotes an external container terminal made of Dox1, Dox2,... Doxm, and reference numeral 173 denotes G1, G2,. The container outer terminal 160 is an electron source substrate in which the common wiring between the element rows is the same as described above. In addition, the same code | symbol as FIG. 13, FIG. 16 shows the same member. The difference from the image forming apparatus (FIG. 13) having the simple matrix arrangement described above is that a grid electrode 170 is provided between the electron source substrate 160 and the face plate 136.
A grid electrode 170 is provided between the substrate 160 and the face plate 136. The grid electrode 170 can modulate the electron beam emitted from the surface conduction electron-emitting device, and allows the electron beam to pass through a striped electrode provided perpendicular to the element row of the ladder-type arrangement. One circular hole 171 is provided corresponding to each element. The shape and installation position of the grid do not necessarily have to be as shown in FIG. 17, and a large number of mesh openings may be provided as openings, and may be provided, for example, around or near the surface conduction electron-emitting device. .
The container outer terminal 172 and the grid container outer terminal 173 are electrically connected to a control circuit (not shown).
[0028]
In this image forming apparatus, a modulation signal for one image line is simultaneously applied to the grid electrode columns in synchronization with the sequential driving (scanning) of the element rows one column at a time. Irradiation can be controlled and images can be displayed line by line. Further, according to the present invention, it is possible to provide an image forming apparatus suitable not only for a television broadcast display device but also for a display device such as a video conference system or a computer. Furthermore, it can also be used as an image forming apparatus as an optical printer composed of a photosensitive drum or the like.
[0029]
The electron-emitting device can be applied not only to a surface conduction electron-emitting device, but also to a cold cathode electron source such as an MIM-type electron-emitting device or a field-emission type electron-emitting device. Can also be applied.
[0030]
Specific examples that best illustrate the features of the present invention are set forth below. The above-described surface conduction electron-emitting device was used as the electron-emitting device in the examples.
[0031]
[ Reference example 1] Specific below Reference example Will be described with reference to FIG.
[0032]
An image forming apparatus was formed using the matrix type arrangement electronic substrate (FIG. 12) 121 having the surface conduction electron-emitting device obtained as described above. In the figure, a panel 11 is a frit glass adhesive member made of a face plate on which an image forming member is mounted, a rear plate on which an electron source substrate 121 is mounted, and a support frame member formed by cutting blue glass. Each member was bonded and manufactured by raising the temperature to a temperature at which the glass melted and solidified and cooling. The face plate and the rear plate were used by cutting a glass material. As a result, the parallelism between the heat dissipation member 14 and the panel 11 was not maintained. In this state, the heat conduction member 12 formed of an aluminum plate material was spread on the back surface of the display panel 11 at intervals of 10 mm. Fixing was performed using a heat conductive tape (not shown). Here, since the face plate and the rear plate used as the panel components described above are made of glass material and have a size of 1 m or more, it is difficult to obtain uniform flatness over the entire surface, and warpage and undulation are caused. It was. Furthermore, the display panel 11 was nonlinearly curved as shown in the figure due to the accompanying thermal process (temperature increase / cooling cycle) in the manufacturing process. This is because it is difficult to perform uniform temperature rise and temperature control over the entire display panel 11 in the thermal process. Next, at least one spiral spring formed by using a stainless material was weld-fixed to at least the number of the heat conductive members 12 spread. Further, the other of the aluminum plate having the same size or larger than the panel and the spring member 13 was fixed by welding.
[0033]
With this configuration, even when the display panel 11 undergoes non-linear warping, the spring member 13 can self-adjust the distance between the heat radiating member 14 and the display panel 11 (by expansion and contraction of the spring), and thus can be supported stably. Moreover, in this structure, since it was supported with the spring, it also confirmed that there was an anti-vibration effect with respect to external vibration.
[0034]
Further, in this state, an electron-emitting device (not shown) formed on the display panel 11 was driven by the above method. By this driving, the display panel 11 generates heat from the electron emission portion on the rear plate and heat from the image forming member on the face plate. Due to this heat, the display panel 11 has a temperature difference between the face plate, the rear plate, and the support frame and tends to warp due to a difference in thermal expansion. The heat conduction (moving from the high temperature part to the low temperature part) occurs through the heat conducting member 12 and the spring member 13, and finally most of the heat is sent to the heat radiating member 14 where it is radiated into the air. The Part of the heat is also radiated from the heat conducting member 12 and the spring member 13. As a result, even when the display panel 11 is driven, uniform heat dissipation is performed, so that the display panel 11 can maintain an initial shape and display a stable image.
[0035]
In the above configuration and process,
(1) It can be supported without affecting the warp of the panel.
(2) Stable drive display can be achieved even when the panel is driven.
(3) It is safe and has a long life without any vacuum leak or device destruction caused by driving the panel.
We were able to present an image forming apparatus with the advantages of
[0036]
The fixing means is not limited to the above tape. Although a spiral spring is used for the spring member 13, it is not limited to this.
[ Reference example 2] The structure of the spring member will be described with reference to FIG. 21 is an elastic member in which a thin metal plate is formed in a matrix shape in a cantilever structure using a well-known wet etching technique so as to have a spring characteristic, and 22 is a heat dissipation member having a heat dissipation material such as an aluminum plate. The thin plate on which the elastic member 21 is formed is fixed to the surface using a conductive adhesive (a place other than the cantilever portions arranged in the matrix in the figure). Further, in consideration of the warping of the display panel 11, the step portion 23 is configured by bending a part of the cantilever (broken line portion). The display panel 11 was fixed using a conductive tape at a place excluding the step portion of the elastic member 21.
[0037]
Book Reference example With this configuration, even when the display panel 11 is warped, the elastic member 21 can absorb the warp amount, so that the display panel 11 can be uniformly supported over the entire surface. Further, even if the panel is driven in this state, the heat generated by the driving is conducted through the elastic member 21 and is finally radiated by the heat radiating member 22, so that the warp of the display panel 11 is not enlarged. .
[0038]
Book Reference example Thus, since the spring portion is thin and a simple structure can be formed, the overall width of the image forming apparatus is not increased, and an advantageous configuration in terms of cost can be presented.
[ Reference example 3] FIG. 3 shows an example in which the heat conducting member 12 installed on the back surface of the display panel 11 is connected to the spring member 13 in the lateral direction (the main plane direction of the display panel 11). The display panel 11 and the heat conducting member 12 were fixed by providing a member (not shown) to which an external force is applied in the X direction on the paper surface. The connection between the heat conducting member 12 and the spring member 13 is Reference example It was performed by welding in the same manner as in 1. Furthermore, the structure of the spring member 13 is Reference example A spiral spring member was used as in No. 1, and the material was stainless steel.
[0039]
In the state where the display panel 11 is formed, the spring member 13 can be self-adjusted (by expansion and contraction) even if nonlinear warping occurs as shown in the figure, so that the heat conducting member 12 has a shape that follows the display panel 11. Arranged. Further, even if the panel is driven in this state, the heat generated by the driving is conducted through the heat conducting member 12 and the spring member 13 and finally dissipated by the heat radiating member 14, so that the warp of the display panel 11 is enlarged. It never happened.
[ Example The heat conductive member 41, the spring member 42, and the outer frame 45 were left on the thin metal plate by using a well-known wet etching technique as shown in FIG. Stainless steel was used as the material for the metal plate. Reference numeral 44 denotes an etching portion, which was removed by etching. In this configuration, the heat conducting members 41 are arranged in a matrix, and the individual heat conducting members 41 are connected to the spring members 42 that are formed by thinly removing them by etching. The spring member 42 utilizes the ductility (elasticity) of metal, and due to the shape effect, a structure having a spring property was achieved rather than a single continuous plate. Next, it fixes using one side of the outer frame 45 of the produced etching board, the thermal radiation part 43, and a conductive adhesive. The display panel 11 was fixed using one of the heat conductive members 41 and a conductive tape.
[0040]
With the configuration of this example, even when the display panel 11 is warped, the spring member 42 can absorb the amount of warpage, so that the display panel 11 can be uniformly supported over the entire surface. Further, even if the panel is driven in this state, the heat generated by the driving is conducted through the heat conducting member 41, the spring member 42, and the outer frame 45, and finally radiated by the heat radiating member 43. The warp was not enlarged.
[0041]
In addition, there is no limitation at all in the manufacturing method of the spring member presented in the present embodiment, the number of springs, and the like.
[ Reference example 4] No. 4 Reference examples In this case, a support bag in which a heat transfer fluid is contained in a sealed bag whose shape can be freely changed is used. (51 in FIG. 5) Water was used for the fluid, and carbon-based vinyl was used for the bag. The heat conduction support member 51 is sandwiched between the back surface of the display panel 11 and the heat radiating plate member 14, and an external pressure 52 is applied so that a desired pressure is applied to the heat conduction support member 51.
[0042]
Book Reference example With this configuration, even if the display panel 11 is warped, the heat conduction support member 51 can be changed into an arbitrary shape with respect to the warp, so that the display panel 11 can be supported uniformly over the entire surface. Further, even if the panel is driven in this state, the heat generated by the driving is conducted through the heat conduction support member 51 and is finally radiated by the heat radiating member 14, so that the warp of the display panel 11 is expanded. There wasn't.
[0043]
Book Reference example There is no limitation on the material configuration of the heat conducting member 51 presented in the above.
[0044]
Book Reference example With this configuration, it is possible to closely follow local warping and undulation of the panel, enabling more stable support and uniform heat dissipation. Furthermore, in this support member, compatibility between support and heat conduction could be achieved, leading to simplification of the member.
[ Reference Example 5 No. 5 Reference examples So first Reference example And second 4 Reference examples It is a support method that combines. The configuration is shown in FIG. A heat conduction support member 61 composed of water and a carbon-based plastic bag was disposed at the center between the panel 11 and the heat dissipation member 63. Furthermore, the heat conduction member 62 and the spring member 64 were comprised in the peripheral part between them.
[0045]
Mentioned above Reference example As well as the book Reference example With this configuration, even when the display panel 11 is warped, the heat conduction support member 61 and the spring member 64 can be changed to any shape with respect to the warp, so that the display panel 11 can be supported uniformly over the entire surface. Further, even if the panel is driven in this state, the heat generated by the driving is conducted through the heat conduction support member 61, the heat conduction member 62, and the spring member 64, and is finally radiated by the heat radiation member 63. Eleven warpages were not magnified.
[0046]
Book Reference example This configuration was effective when the panel was greatly warped at the periphery.
[0047]
【The invention's effect】
In the image forming apparatus of the present invention, stable support corresponding to the warping and undulation of the panel and uniform heat dissipation have been achieved, so that a safe and precise and high-definition image forming apparatus free from color shift and destruction can be obtained. Could be provided.
[Brief description of the drawings]
FIG. 1 shows an image forming apparatus according to the present invention. reference It is sectional drawing which shows an example.
FIG. 2 shows an image forming apparatus according to the present invention. reference It is a perspective view of an example.
FIG. 3 shows another image forming apparatus according to the present invention. reference It is sectional drawing which shows an example.
FIG. 4 shows an image forming apparatus according to the present invention. Example FIG.
FIG. 5 shows an image forming apparatus according to the present invention. Other references It is sectional drawing which shows an example.
FIG. 6 shows an image forming apparatus according to the present invention. Still other reference examples FIG.
FIG. 7 is a schematic plan view showing a configuration example of a basic surface conduction electron-emitting device used in the present invention.
FIG. 8 is a schematic side view showing a configuration of a basic vertical surface conduction electron-emitting device used in the present invention.
FIGS. 9A, 9B, and 9C are process diagrams showing an example of a method for manufacturing a surface conduction electron-emitting device used in the present invention.
FIGS. 10A and 10B are graphs showing examples of voltage waveforms of energization forming, respectively.
FIG. 11 is a schematic configuration diagram of a measurement evaluation apparatus for measuring electron emission characteristics.
FIG. 12 is an explanatory diagram showing a configuration of an electron source having a simple matrix arrangement.
FIG. 13 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention.
FIGS. 14A and 14B are explanatory views showing the structure of the fluorescent film, respectively.
FIG. 15 is a block diagram illustrating an example of an image forming apparatus in which a driving circuit for performing display in accordance with an NTSC television signal is incorporated.
FIG. 16 is a plan view showing an example of the configuration of an electron source with a ladder arrangement used in the present invention.
FIG. 17 is a schematic configuration perspective view showing an example of the image forming apparatus of the present invention.
FIG. 18 is an explanatory view showing a configuration example of a conventional surface conduction electron-emitting device.
[Explanation of symbols]
11 Display panel
12, 41, 62 Heat conduction member
13, 42, 64 Spring member
14, 43, 63 Heat dissipation member
A Support member
21 Elastic member
22 Heat dissipation member
23 steps
24, 44 Etching part
25, 45 outer frame
51, 61 Heat conduction support member
71 substrate
72, 73 Device electrode
74 Conductive thin film
75 Electron emission part
80 Step forming part
110 Ammeter
111 power supply
112 Ammeter
113 High voltage power supply
114 Anode electrode
115 Vacuum equipment
116 exhaust pump
121 Electron source substrate
122 X direction wiring
123 Y-direction wiring
124 surface conduction electron-emitting device
125 connection
131 Rear plate
132 Support frame
133 Glass substrate
134 Fluorescent membrane
135 metal back
136 Face plate
137 High voltage terminal
138 Envelope
141 Black conductive material
142 phosphor
151 Display panel
152 Scanning Circuit
153 Control circuit
154 Shift register
155 line memory
156 Sync signal separation circuit
157 Modulation signal generator
Vx and Va DC voltage source
160 Electron source substrate
161 Electron emitting device
162 Common wiring
170 Grid electrode
171 Holes for electrons to pass through
172 External terminal
173 External terminal

Claims (2)

A rear plate on which an electron-emitting device is mounted, and a face plate on which an image forming member on which an image is formed by irradiation of an electron beam emitted from the electron-emitting device while being opposed to the rear plate is mounted. In an image forming apparatus comprising: a display panel having a vacuum atmosphere inside; and a frame-shaped heat dissipation member disposed outside the display panel and disposed on the rear plate side.
Between the display panel and the heat radiating member, a support member that has thermal conductivity and elasticity and supports the display panel according to the shape of the display panel is disposed, and the support member is integrated. An image forming apparatus , wherein the outer frame and the frame-shaped heat radiation member are bonded and fixed by a conductive adhesive, and the heat radiation member and the support member are outside a vacuum atmosphere.   The image forming apparatus according to claim 1, wherein the electron-emitting device mounted on the rear plate of the display panel is a surface conduction electron-emitting device.

Images