JPH11314342A - Offset printing method and image forming apparatus using the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] When filling a plate with an ink composition and performing doctoring with an offset rotary press or offset proofing machine, the ink runs out poorly, the pattern engraved on the plate is not printed correctly, and the ink is further printed There was a problem of improving the utilization efficiency of the composition. SOLUTION: When doctoring ink in offset printing, one or more of a doctoring blade, ink and an intaglio are preferably used for 30 to 10 times.
An offset printing method and an image forming apparatus that improve ink depletion by heating to 0 ° C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an offset printing method and apparatus suitable for high-precision printing of components such as a printed wiring board or an image display device, and more particularly, to an improvement in ink filling means by doctoring. The present invention relates to an offset printing method and an apparatus thereof. More specifically, the present invention relates to a printing method for transferring and printing an original pattern formed on a printing plate onto a printing material with high precision, and an image display apparatus using the printed pattern formed by transfer printing.

[0002]

2. Description of the Related Art In recent years, a thin flat plate-shaped image forming apparatus has attracted attention as an image forming apparatus replacing a large and heavy cathode ray tube. Although a liquid crystal display device has been actively researched and developed as a flat plate image forming device, the liquid crystal display device still has problems such as a dark image and a narrow viewing angle. As an alternative to the liquid crystal display device, there is a self-luminous display, that is, a display using an electron-emitting device such as a plasma display, a fluorescent display tube, and a surface conduction electron-emitting device. A self-luminous display can obtain a brighter image and has a wider viewing angle than a liquid crystal display device.

On the other hand, recently, a cathode ray tube having a screen display section of 30 inches or more is also appearing, and further enlargement is desired. However, it is hard to say that a cathode ray tube is suitable for increasing the size because it takes up a large space. For such a large and bright display, a self-luminous flat display is suitable. The present applicant was disclosed by MIElinson et al., Who can emit electrons with a simple structure, among image forming apparatuses using electron-emitting devices, among self-luminous flat plate image forming apparatuses (Radio.Eng.E.
Electron Phys., 10, 1290, (1965)) pays attention to an image forming apparatus using a surface conduction electron-emitting device.

In a surface conduction electron-emitting device, electron emission occurs when a current flows through a small-area thin film formed on a substrate in parallel with the film surface. As the surface conduction electron-emitting device, SnO2 by Elinson et al. Thin film, Au thin film [G. Dittmer: Thin Solid
Films, 9,317 (1972)], In2 O3 / SnO2 thin film [M. Hartwell and CGFonstad: IEEE Tran
ED Conf., 519 (1975)], using a carbon thin film [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, p. 22 (19
83)] have been reported.

As a typical example of these surface conduction electron-emitting devices, the above-mentioned M.E. FIG. 4 schematically shows an element configuration of the Hartwell. In the figure, reference numeral 1001 denotes a substrate. 1
Reference numeral 004 denotes a conductive thin film, which is formed of a metal oxide thin film or the like formed by sputtering in an H-shaped pattern.
5 are formed. The element electrode interval L in the figure is 0.5 to
1 mm and W 'are set to 0.1 mm.

[0006] Further, the present applicant has previously disclosed in US Pat.
In 883, a surface conduction electron-emitting device in which fine particles for emitting electrons are dispersed between a pair of device electrodes was proposed. This electron-emitting device can control the electron-emitting position more precisely than the conventional surface conduction electron-emitting device. FIG. 5 shows a typical device configuration of this surface conduction electron-emitting device. FIG. 5A is a plan view of the element configuration, and FIG. 5B is a cross-sectional view of the element configuration. In this figure, 1101 is an insulating substrate, 1102 and 1103 are element electrodes for obtaining electrical connection, and 1104 is a conductive thin film made of finely divided conductive material. In this surface conduction electron-emitting device, the distance L1 between the pair of device electrodes is 0.01 μm to 100 μm.
μm, the sheet resistance of the electron-emitting portion of the conductive thin film 1104 is 1
An appropriate value is from × 10 ⁻³ Ω / □ to 1 × 10 ⁻⁹ Ω / □. Further, it is desirable that the element electrode be formed to have a thickness d of 200 nm or less in order to maintain electrical connection with the thin film made of the fine particle conductive material.

The present inventors are studying an increase in the area of an image forming apparatus in which many surface conduction electron-emitting devices are arranged on a substrate. Various methods are conceivable for producing an electron source substrate in which an electron-emitting device and a wiring are arranged on a substrate, and one of them is a method of producing all of an element electrode, a wiring, and the like by a photolithography method.

[0008] On the other hand, a method of producing the surface conduction electron-emitting device and an electron source substrate including the same by diverting a printing technique such as screen printing or offset printing is conceivable. The printing method is suitable for forming large-area patterns, and it is possible to form a large number of surface conduction electron-emitting devices on a substrate by forming the device electrodes of the surface conduction electron-emitting device by printing. Becomes It is also advantageous in terms of cost. In forming element electrodes by a printing method, an offset printing technique suitable for forming a thin film is suitable for forming element electrodes. An example in which this offset printing technique is applied to a circuit board is disclosed in JP-A-4-290295. In the substrate disclosed in this publication, the angles of a plurality of bonding electrodes connected to circuit components are changed in order to eliminate bonding defects due to variations in electrode pitch dimensions due to pattern expansion and contraction during printing. Japanese Patent Application Laid-Open No. 4-290295 describes that an electrode pattern is formed by offset printing.

Conventionally, for this kind of high-precision printing, for example, an offset rotary press or an offset calibrator has been frequently used.

A general offset printing apparatus and printing method for forming an electrode pattern, a color filter and the like will be described below.

FIG. 6 is a diagram showing a flatbed proofing machine type offset printing apparatus for performing the offset printing method. In this figure, reference numeral 101 denotes an ink kneading table on which ink 107 is spread by ink rollers 104, and reference numeral 102 denotes a plate surface plate for fixing the intaglio 105. Reference numeral 103 denotes a work 10 which is a printing material.
6 is a work surface plate for fixing the base 6 and is fixedly disposed on the main body frame 108. Two rack gears 109 and 110 are arranged on both sides of the three platens arranged in a line, and the gears 111 and 1 are mounted on the rack gears 109 and 110.
12 are arranged. The blanket 113 has its axis connected to the carriage 1 at both ends.
14 and 115, and the carriages 114 and 11
5 moves forward and backward by the crank operation of the crank arm 116 from the lower part of the main body, and the blanket 113 rotates and slides on the ink mixing table 101, the intaglio 105, and the work 106 sequentially. The surface of the blanket 113 is provided with a rubber-like blanket rubber. Reference numeral 118 denotes an alignment scope, which takes in ink pattern position information printed on the work 106 and reads the work surface plate 103 every time the work is replaced.
The alignment is performed at a predetermined position by fine adjustment.

FIGS. 7A to 7D are views showing an offset printing process. In this drawing, 101 is an ink mixing table, 105 is an intaglio, and 106 is a glass substrate serving as a work, which is arranged in series on the same plane. Reference numeral 104 denotes an ink roll which transfers the ink 107 kneaded by the ink kneading table 101 onto the intaglio 105 (FIG. 7A). Reference numeral 117 denotes a doctor blade which scrapes out the ink 107 transferred by sliding on the upper surface of the intaglio 105, except for the ink filled in the concave portions (FIG. 7).
b). Reference numeral 113 denotes a blanket, and the intaglio 105 and the upper surface of the glass substrate 106 are brought into rotational contact with each other in this order, whereby an intaglio 1 is formed.
The ink filled in the recesses 05 is received (FIG. 7C), and the ink 107 is transferred onto the glass substrate 106 in the pattern of the intaglio 105 (FIG. 7D).

Thus, the printing process is completed. The printing ink 107 can be appropriately selected depending on the function of the pattern to be manufactured. That is, an ink containing an organic Au metal mainly called Au resinate paste is used for an electrode pattern of a recording thermal head or the like, and R, G, and B color pigments are used for a color filter used in a liquid crystal display device or the like. Dispersed inks, inks containing organic dyes, and the like are used.

[0014]

However, when performing doctoring to fill the plate with ink using such conventional offset rotary presses and offset proofing machines,
There is a problem in that the ink is not sufficiently cut, and consequently the pattern engraved on the plate is not printed on the printing substrate in the pattern.

That is, since the ink is hard to be cut during doctoring, the ink once in the plate is dragged and held by the doctor blade, and the ink remaining in the plate becomes indefinite, or hardly remains depending on the ink, or The ink dragged by the doctor blade remains in another place outside the pattern, so-called scraping occurs,
It was very difficult to completely or stably fill the plate with ink. Therefore, there is a problem that it is extremely difficult to faithfully reproduce the pattern of the plate in the pattern printed by the conventional methods.

An object of the present invention is to provide a printing method and a printing apparatus which solve the above-mentioned problems, improve the cut of ink at the time of doctoring, and completely or stably fill the plate with ink. is there. It is another object of the present invention to provide an inexpensive and easy-to-handle image forming apparatus that can print a pattern shape of a printing plate three-dimensionally as faithfully as possible on an object to be printed using this.

[0017]

The above object is achieved by the present invention described below.

That is, the present invention is characterized in that, during doctoring of ink in offset printing, one or more of a doctoring blade, ink, and an intaglio are heated to improve ink depletion. In this method, the heating temperature is preferably in a temperature range of 30 to 100 ° C.

Further, according to the present invention, an element electrode of an electron-emitting device is formed on a substrate by an offset printing method in which one or more of a doctoring blade, ink, and an intaglio are heated when doctoring ink in offset printing. It is another object of the present invention to provide an image forming apparatus incorporating an electron source substrate obtained by forming a conductive thin film and a wiring on the element electrode. The heating temperature employed in this application method is preferably in the range of 30 to 100 ° C.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The contents of the present invention will be described below in detail with reference to the attached schematic diagrams.

FIG. 1 is a view schematically showing filling of a plate with ink by doctoring in offset printing. In this figure, 1 is a doctor blade, 2 is an intaglio, 3
Represents an ink, and 4 represents a heater. (A) at the start of doctoring after inking, (b) at the time of doctoring, (c)
Indicates the end of doctoring.

The doctor blade 1 used in the present invention comprises:
It is characterized in that the temperature changes during doctoring. The method of changing the temperature may be any method, for example, by heating with a heater 4 or the like in contact with the blade.

As shown in FIG. 1 (a), after ink is injected into a part of the intaglio of the intaglio plate, the plate is filled with ink by doctoring as shown in FIG. 1 (b) → FIG. 2 (c). . At this time, when the doctor blade is heated, when the ink comes into contact with the doctor blade, the ink in the contact portion is heated and the fluidity is increased, and as a result, the ink is easily cut.

The material of the doctor blade 1 is preferably made of aluminum, stainless steel or the like, but is not limited to this. The temperature can be changed, the heat conductivity is good, and heat is well transmitted to the printing ink. Any material may be used as long as such a material is used. However, it is usually appropriately selected according to the physical properties of the ink to be printed.

The intaglio 2 is formed by etching a copper to form a desired pattern and performing a chromium treatment, or a general intaglio made of aluminum, glass, or the like.

As the printing ink 3, there are used ordinary color filter materials, various wiring materials, and various ink materials selected according to the required printing use purpose. These can be used commercially as they are, or they can be diluted with a solvent or added with a thickener, and modified as those having rheological properties suitable for the printing and the method to be performed. It does not matter. Also,
If necessary, various material components may be kneaded and adjusted.

In any case, any ink may be used as long as it has a property of being easily cut by a change in temperature generated when the ink comes into contact with the doctor blade. For example, any material may be used as long as it has a property of increasing fluidity or being cleaved by heating. However, the method in which the ink runs out is not limited to this.

Any heater may be used, and the mechanism for heating the doctor blade is not limited to a so-called heater. At the time of doctoring, any method can be applied as long as the doctor blade can keep a warm state. When a heater is used, it is more preferable that the heater is equipped with a mechanism such as a thermostat for temperature control.

The work 106 to be printed is a soda lime glass, a silica glass, other various glass materials, ceramics, or other general substrates.

(Operation) The above technical problems can be solved by using the printing method and the image forming apparatus according to the present invention.

That is, when the heated doctor blade for printing passes through the scraped-off portion of the intaglio while scraping the ink, the ink in contact with the doctor blade is heated by the blade and easily cut off. The ink is faithfully scraped off by the scraping operation, and the ink is filled in the plate along the path of the blade edge of the doctor blade. Therefore, at this time,
The ink is faithfully filled into the pattern of the concave portions of the intaglio plate, and the required amount of ink can be stably filled in the plate by controlling the trajectory of the blade edge of the doctor blade during doctoring.

Next, the present invention will be described with reference to examples.

[0033]

The present invention will be further described with reference to the following examples.

Example 1 An ink 3 was inked into an intaglio 2 made of glass, and doctoring was performed using an offset printing apparatus equipped with a heater 4 on a doctor blade 1 made of stainless steel (FIG. 1). At this time, the doctor blade was adjusted so as to always maintain 55 ° C. The ink used in this example is a Pt resinate paste composed of an organic metal (MO Paste E-3100 manufactured by NE Chemcat Corporation).
It is.

When the pattern of the plate was observed with a laser microscope immediately after the doctoring, the filling rate of the ink into the concave portions of the plate was 100%. Further, when the pattern portion of the plate was observed with a microscope, no scraping residue occurred.

Example 2 Ink 3 (Pt resinate paste composed of an organic metal (MOC manufactured by NE Chemcat Co., Ltd.)
Paste E-3100) was heated to 50 ° C. while stirring in a 50 ° C. thermostat. This was inked into an intaglio plate 2 made of glass, and immediately doctored with a doctor blade 1 made of stainless steel. Immediately after that, when the pattern of the intaglio was observed with a laser microscope, it was found that the ink was completely filled in the recesses of the intaglio.

Example 3 A heater was provided below a stainless steel plate, and the surface of the intaglio pattern was controlled to maintain 50 ° C. This intaglio ink (Pt resinate paste made of organic metal (N.
E-Chemcat Co., Ltd. MO Paste E-3100)) was inked, and doctoring was performed using a polypropylene doctor blade.

Immediately after this, when the pattern of the plate was observed with a laser microscope, it was found that the ink was completely filled in the concave portions of the plate.

Embodiment 4 Hereinafter, a method of manufacturing an image forming apparatus using element electrodes of electron-emitting devices formed by offset printing will be described.

The device electrodes of the electron-emitting devices were printed on the glass substrate by the offset printing apparatus using the offset blanket described in each of the above embodiments. In this example, a Pt resinate paste made of an organic metal (MO Paste E-3100 manufactured by NE Chemcat Co., Ltd.) was used as the ink. The ink transferred onto the glass substrate is dried at about 80 ° C. and dried at about 580 ° C.
It can be used as a device electrode made of Pt by baking at a temperature of ° C. The thickness of the transferred ink on the glass substrate after printing and drying was as small as about 2 microns and uniform, and the width of the printed electrode pattern was very small. Furthermore, the thickness of the fired Pt electrode was as thin as about 400 angstroms. Here, the pattern shape of the device electrode has a device electrode interval for arranging the electron-emitting material, and its dimension is set to about 20 microns.

An electron source substrate can be manufactured by forming a thin film composed of wiring and Pd fine particles on the device electrode formed as described above. This will be described below with reference to the drawings.

In FIG. 3, reference numeral 401 denotes an electron source substrate made of soda lime glass. 402, 403, and 404 are device electrodes formed by offset printing according to the present invention. 407,
Reference numerals 408 and 409 denote printed wirings having a thickness of about 7 microns obtained by screen printing and baking of Ag paste ink. The device electrodes 402, 403, and 404 are printed wiring 40
7, 408, and 409, respectively. 405, 40
Reference numeral 6 denotes a thin film made of Pd fine particles having a thickness of about 200 angstroms obtained by coating and baking an organic metal solution. did. 410, 411, and 412 are plating wirings formed on the printed wirings 407, 408, and 409 by Cu plating having a thickness of about 50 microns and a width of 400 microns.

Reference numeral 415 denotes a glass substrate made of soda lime glass, which faces the electron source substrate 401 at a distance of 5 mm. Phosphors 416 and 417 are disposed on the substrate 415 and are formed at positions corresponding to electrode gaps formed by the element electrodes 402, 403, and 404 disposed on the electron source substrate 401 facing the phosphor. The phosphors 416 and 417 are obtained by mixing a photosensitive resin with the phosphor to form a slurry, coating and drying, and then performing patterning by photolithography. A film 418 is formed on the phosphors 416 and 417 by a filming process, and then has a thickness of about 3 by vacuum evaporation.
This is a metal back obtained by forming an Al thin film of 00 angstrom and firing it to burn off the film layer. The one in which the phosphor and the metal back are formed on the glass substrate 415 is called a face plate.

Reference numeral 419 denotes a grid electrode disposed between the element substrate and the face plate. After arranging the above in a vacuum envelope, a voltage was applied between the plating wirings 410, 411, and 412 to conduct the electric current to the thin films 405, 406, thereby obtaining electron emitting portions 413, 414. Thereafter, a metal extraction voltage of 5 kV is applied to the metal back 418 using the metal back 418 as an anode electrode.
The electron-emitting portion 41 from the device electrodes 402 and 304
When a voltage of 14 V was applied to No. 3, electrons were emitted. The emitted electrons were modulated by changing the voltage of the grid 419, and the amount of emitted electrons applied to the phosphor 418 could be adjusted. Thereby, the phosphor 416
Could be arbitrarily emitted. Similarly, the device electrode 40
When a voltage of 14 V was applied from 3, 404 to the electron emitting portion 414, electrons were emitted. The emitted electrons were modulated by changing the voltage of the grid 419, and the amount of emitted electrons applied to the phosphor 417 could be adjusted. As a result, the phosphor 417 was able to emit light arbitrarily.

Although the configuration has been described with respect to two display pixels in the drawing, the number of display pixels is not limited to this. Therefore, an arbitrary image can be displayed by a large number of display pixels by forming a wiring and a grid in a matrix and arranging and driving a large number of electron-emitting devices.

At this time, since the doctor blade for printing according to the present invention was used, no scraping or excessive scraping at the time of doctoring did not occur, so that the accuracy of the shape of the device electrode was improved and the space between the devices was uniform. As a result, no pixel defect due to a defect of the element was observed.

Comparative Example 1 Ink 3 (Pt resinate paste (M.O.M., manufactured by NE Chemcat Co., Ltd.) on glass intaglio 2
The paste E-3100)) was inked and doctored using a doctor blade 1 made of stainless steel [FIG. 2].

Observation of the pattern of the plate by a laser microscope immediately after doctoring revealed that only 30% of the ink remained in the recesses of the plate. In addition, when the pattern portion was observed, unscraped portions were found in places other than the concave portions.

[0049]

As described above, according to the offset printing method and the image forming apparatus of the present invention, the temperature of the cutting edge is adjusted to a high temperature at the time of filling the ink so that the ink is easily cut. The ink is almost completely filled in the recesses of the printing plate, so that the printing pattern can faithfully reproduce the shape of the printing plate in the subsequent reception and transfer. In addition, as a result, extremely uniform patterning including the three-dimensional shape such as film thickness is performed, and it is very useful for printing wiring materials on thin display substrates such as large-screen liquid crystal displays and color filters. It is valid.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a first embodiment showing an offset printing process of the present invention.

FIG. 2 is an explanatory diagram of Comparative Example 1 showing a conventional offset printing process.

FIG. 3 is a top view illustrating an image forming apparatus according to a fourth embodiment of the present invention.

FIG. 4 is a top view showing a surface conduction electron-emitting device.

FIG. 5 is a top view showing the surface conduction electron-emitting device.

FIG. 6 is a top view showing a conventional offset printing apparatus.

FIG. 7 is a side view showing a conventional offset printing process.

[Explanation of symbols]

 Reference Signs List 1 doctor blade 2 intaglio 3 ink 4 heater 105 intaglio 106 blue plate glass 107 ink 113 blanket 117 doctor blade 402, 403, 404 device electrode 405, 406 thin film 407, 408, 409 printing wiring 410, 411, 412 plating wiring 413, 414 electron Emitting part 415 Glass substrate 416, 417, 418 Phosphor 419 Grid 501 Device electrode 502 Lower printed wiring 503 Insulating layer 504 Opening 505 Upper printed wiring 509 Thin film 1001 Substrate 1004 Conductive thin film 1005 Electron emitting part

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Nobuyuki Nakahara 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (4)

[Claims] 1. An offset printing method characterized in that at the time of doctoring of ink in offset printing, one or more of a doctoring blade, ink, and an intaglio are heated to improve ink depletion. 2. An offset printing method, wherein a heating temperature is in a temperature range of 30 to 100 ° C. 3. An element electrode of an electron-emitting device is formed by printing on a substrate by an offset printing method of heating one or more of a doctoring blade, ink and an intaglio at the time of doctoring of ink in offset printing. An image forming apparatus incorporating an electron source substrate obtained by forming a conductive thin film and a wiring on an element electrode. 4. An image forming apparatus, wherein a heating temperature is in a temperature range of 30 to 100 ° C.