JPS6189044A - Method and device for forming picture and article formed through said method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image forming method and apparatus for forming an image on a substrate having a changeable coating using a relatively small current discharge, and an article produced thereby. .

In particular, it relates to a method and apparatus for electronically imaging commonly available diazo-type lithographic printing plates at relatively high resolution at low cost. Printing plates imaged with this method and apparatus can be used in conventional lithographic printing without photosetting.

[Technical background of the invention and its problems] In most lithographic printing systems used today, the image quality of the lithographic plate is formed by photographic technology. In this case, a positive or negative transparent film of the desired image is first prepared by photographic technology, and then the image of the film is placed on the photosensitive surface of the plate, or the film is brought into contact with this photosensitive surface. Although some systems may allow the plate to be exposed directly to the original without the intervention of a transparent film, such systems still require a so-called "photographic original".

Image stamping from information stored or created electronically.

That is, various attempts have been made to directly print the image-formed I-Graph printing plate, thereby eliminating the need for producing original images and copies for various photographic processes. Such systems, for example, use laser beams, electrical sparks or arcs, or other energy sources to illuminate the surface of the photosensitive plate to remove one or more sheets of material from the surface of the lithographic type. Alternatively, these systems use electrostatic charges to form the desired image.

This type of lithographic imaging system has several major drawbacks, chief among them being that the equipment required to implement the system is relatively unreliable, expensive, and unreliable.
The custom unimaged lithographic plates typically required for use with this system are expensive and the quality of the printed images obtained from the imaged force λ produced by this system is poor.

Methods of invention by others are known. This includes special plate coating, phototypesetting, and the production of "original images for photographic contrast." 1 For example, high-quality images are formed on a conventional specification relatively inexpensive diazonium resin 1 nodogura 7 plate without the need for various photographic processing. Effective and cheap! ! 'Ii. This method was developed by F. S. Love on June 17, 1983.
U.S. Patent Application No. 502,520, filed on April 25, 1984, and U.S. Patent No. 603,5, filed on April 25, 1984.
It is described in No. 86. According to this method, a relatively small electric current is used to conduct a chemical reaction in the material (a photosensitive resin plate or a plate of other materials may be used, but a diazonium plate is generally preferred) on the surface of the plate. changes in the relative solubility of the discharged portion of the coating, without the bulk removal of coating material normally done in systems using electrical sparks, and in laser systems, which typically occur under the action of light. To form a latent image that can be developed by conventional methods without relying on processing.

This known method has a processing limit, and the width and diameter are approximately 4 m.
Only good quality images of lines and dots of less than 1lb to 5m1I1 can be formed. In other words, if Lau's method is used, the formation of high-quality images is limited to a resolution of about 200 lines/inch (sadly). It is possible to form images up to inch resolution, but this is accompanied by a significant reduction in image quality, resulting in uneven line widths and edges, broken lines, misalignment of image dots individually or all at once, and other inconveniences. The reimaging device (i.e., the speed at which the needle moves over the production surface of the plate) is relatively slow in Lau's method, which severely limits many commercial applications.

[Object of the Invention] The present invention has been made in view of the above points, and provides an image forming method, an apparatus, and a product produced thereby, which eliminates the I11 effective printing resolution and improves the image forming speed at the same time. The purpose is to provide.

[Summary of the Invention] In one embodiment of the present invention, a thin,
It involves applying a small current concentrated discharge in a relatively inert gas stream to an unimaged printing plate.

It will be well understood by reading the following description that by using the technique of the present invention, a latent image is formed on many diazonium plates and other printing plates, and the latent image is wide. , direct (about ¥1
mm line, including dots, so the line/
Enables printing of lithographic images with an effective printing capacity of inches. It has been found that the method and apparatus of the present invention achieves less concentrated small current discharges than Lau's. It is thought that this concentration of the market greatly improved the strength of the discharge to the discharge area of the printing plate. Therefore, the plate surface discharge sweep speed can be increased without significant deterioration in image quality. It is believed that the discharge sweep speed on the plate can be improved by a factor of ten or more compared to the relative linear speed possible when using Lau's technique.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure schematically illustrates a method, 菰δ, as applied to a commonly used printing plate in conventional offset lithography printing. Roller 1G acts as a support for a known lithographic plate 20. During the image formation described below, the plate 20 is fixed to the roller 1 by the fixing means 12.14. These means 12.14
Any conventional lithographic plate may be used as long as it can be attached and fixed to the roller surface. For example, many glues are manufactured by manufacturers with a series of holes at both ends.
Means using a series of tapered pins used to secure the graph plate may also be used. It is preferable that the printing plate itself has at least a certain degree of electrical conductivity and that it can be electrically conductive during image formation. In order to facilitate grounding, the means 12.14 may be installed by electrically grounding the plate 20 or ejB ground, for example by electrically grounding the roller 10.
．． 14 and roller 10. It may be designed to ensure electrical connection with both conductive materials. Other structures may be used to electrically ground the plate 20.

In order to facilitate the transfer of a desired latent image onto the roller 10, the roller 10 is rotated by a motor 5 and a belt 7. An angular displacement sensor 16 is provided in conjunction with roller 10. This sensor 16 is used to detect the positive (il['= rotational position) of the roller 10, and is particularly preferable when a figure is automatically transferred to the plate 20 by electronic means as described below. .

Opposite the roller 10 and the plate 20, an electrical image forming unit 1 is provided, indicated by reference numeral 30. Figure 1 to Figure 4
In the illustrated embodiment, the unit 30 is an electrode.

That is, a needle 31 for achieving a discharge in the discharge area 1 between this electrode and the opposing surface of the plate 20, a gas supply path 48 for supplying gas to the discharge area in the manner described below, and a needle The ionization promoting means 55 is provided toward the inside of the discharge region between the tip of the tube 31 and the opposing surface of the tube 20. Image forming unit 3
The first effect of 0 is that the figure supplied from the outside is generated in the discharge area between the surface of the plate 20 and the first contact of the needle 31, which can form an image 'a' on the surface of the plate 20 in the following manner. It is the generation, interruption, and adjustment of specific types of concentrated discharges according to information. The image forming unit 30 will be described in detail below.

The needle 31 is a thin hollow shaft with a diameter of approximately 0.001 mm.
inch (approximately 0.025 mm) to approximately o, ooa inch (
It has a hole of about 0.203 mm. An inert gas passes through this hole at a speed of about 0.05 mm. The tip of the needle was found to be 0.002 inch (approximately 0.051 mm) to approximately = o, ooa inch (approximately 0.102 = +; n). The needle 31 may be made of any suitable material, including a material with a suitable consistency.6 As shown in Figs. 2 to 4, the needle 31 may be made of any suitable material. , a disposable steel needle 32 used to pass a hypodermic syringe, with an appropriately sized tube inserted tightly into the needle (32). Attach this tube (by gluing, soldering, brazing, welding, etc.). After shrinking, the wire is pulled out and formed.ヱ＋
] is partially inserted into the insulating protective block indicated by reference numeral 35 in FIGS. 2 and 4. The needle 31 is thereby electrically insulated, , ; +1's?'', +7 :j', 7 F>4th becomes easy.

As shown in FIGS. 2 and 4 (J), the above block 40
1, the cross section is circular C, the center of the block, ';;S +]
, :The extending passage 44 is followed by a. This live LSI),
/, 4 is the sword 42 for &132 with 1 momemaya (this 4 and 1 p has a closing dimension; the left is + 4. It is necessary to use the above block 4G, acrylic plus - 1 tsuku and others 7I; may be removed from over 20 I translation parts of the I charge.The inspiratory connection between the needle 31 and a suitable power source is described below using the screw 38 and via the C-hole 139. to achieve.

As is clear from the figure, a portion of the passageway 44 is connected to the needle 31.
and its accessory parts. The other end of the passage 44 is connected to a gas supply source (not shown) by a connecting member 46. The gas source supplies a relatively inert, ionizable gas to the plate surface when there is no radiation at a pressure greater than atmospheric pressure. Commercially available p for spark chamber
Relatively inert gases with a high temperature are particularly suitable. The main components of such gases are helium and neon. The presence of cords in the discharge gap inhibits the image forming method of the present invention. Generally speaking, the ionized gas flow is directed through the needle 31 from about 0.05 to about 0.0
A relatively uniform pressure sufficient to occur at speeds in the range of 4.5 or higher is desirable.

It is contemplated that gas flow rates up to about 0.9 or higher may be acceptable.

It is preferable to position the tip of the needle 31 perpendicularly to the surface of the plate 2G, but the micrometer stand 50 is used to position the tip of the needle 31 perpendicularly to the surface of the plate 2G.
inch (approximately 0.025ff!m) to 0. Q1Q inch (approximately 0.254 mm) plate surface, '〕1 blunt C5; 2
It is preferable to Note that it is known that there is a separation distance in this range. Hereinafter, the proximal area between the tip of the needle 31 and the opposing surface of the bevel 20 will be referred to as a "radial cap." The needle is attached to a translation table 52 that is controlled to be precisely positioned along the axis of rotation of the roller 10 so that the plate 20 can be easily attached to the plate 34. The information specifying the relative position of the table 52 is made available to the graphic information processing device 75, and the needles 3 on the surface of the plate 20 are made available.
It is preferable to facilitate the relative positioning of the needles, appropriately synchronize the supply of graphic information to the needles, and accurately reproduce the image on the surface of the plate.

The ionization (decomposition) promoting means 55 may be of any kind as long as it can efficiently promote the decomposition of the intoxicants in the discharge gap.

This means 55 serves as a source 9 for generating free electrons and negative ions that initiate secondary ionization that causes decomposition and ultimately produces an avalanche phenomenon, thereby minimizing the time delay associated with the discharge. Further, by using the above-mentioned means 55, the time lag between applying the required voltage between the needle and the plate and starting the specific discharge used in the invention can be significantly shortened. Note that the voltage required to initiate the decomposition described above is reduced by the action of the means 55 described above. In one embodiment of the invention, said means 55 comprises a semi-cylindrical electrically grounded tungsten wire placed within a shield commonly used as a charging source for electrophotographic plates in electrostatic copying machines. ] Rotron outfit is fine. or reference numeral 5 in Figures 2 and 4.
A relatively inert violet radiation source directed at the discharge region may be used, as shown at 5. In some cases, it is not necessary to use ionization (decomposition) promoting means.

The radial phenomenon utilized in the present invention is distinguished from the arc or spark radial phenomenon commonly described by the intersection λ. Sentence: fJ: Most of the discharge phenomenon is described as a relatively large positive (hega) or a relatively large negative ((lambda) placed at a considerable distance from It is determined that the first shot is made with low pressure: i'<L/'(
There is.

However, in the present invention, the pressure can be generated at or near atmospheric pressure, and the pressure can be as small as 0.001 inch (about 0.025 mm) to 0.010 inch (about 0.25
1ii; n) narrow $1- and 1'1 with gaps C
8 This is something that occurs between a flat plate. Typical mean heart flow values range from 2x 10'A to 2x 10'A. However, a current above this range and below the spark discharge current range is also preferable under certain conditions. In the case of commonly available diazonium resin plates, approximately 2x10-5A no fi, 2xl
A time-averaged current in the range of 0-3 A is preferred.
fc is praised. Therefore, it is not possible to relate some of the physical parameter values presented herein with those described in the literature. However, the electric discharge technique! Electrical arcing, which is well understood in the 4j field (it should be clear that it does not involve much of a single-stage heavy arc centering here), has a relatively low time-averaged current such as Approximately 1A
People who are involved in lightning currents are classified as having a greater magnitude. (Refer to "Gas Mind Soil Science" Daiichi 1 Tani, edited by Burge and Oskan, Nos. 2940 to 295 m. . -Ichihiro of Shi No's d11, A-'
Due to the electric discharge that occurs when the cap width and gas introduction technique are adopted, when observed with a microscope, it appears approximately outward (as shown in Figure 5A).
A needle with a cross section extending perpendicular to the central axis of the needle
A brightly glowing area forms within the heart gap. This glowing area touches a much larger area of the plate than the cross-sectional area of the needle;
It looks somewhat expanded. Roughly speaking, the voltage value between the point P in FIG. 1 and the ground measured by an oscilloscope during discharge appears to have an oscillating component that gives the observed waveform a sawtooth shape. This sawtooth component ranges from about 20KH7 to about 200K
It has a frequency in the range of H2 and a width of one arrow below IOV. This type of discharge can be described as visually spreading and electrically pulsating.

Employing the method disclosed herein, i.e. Ike's process parameters, introducing gas through the hole in the vertically positioned hollow needle 31 produces a change in the eminence used in the lav;
When viewed under a microscope, the brightness, or cross-sectional area, of the bright region within the discharge gap appears to decrease sharply and greatly, resulting in a unique bright and spreading light emanating from the tip and hole of the needle 31, as shown in Figure 5B. It was discovered that a very concentrated "core" can be obtained. This bright region appears to maintain approximately the same diameter along the direction toward the printing plate. Therefore, the part of the printing plate that receives the electric discharge is also +)yi and +♂j of the hole of the needle 31.
is approximately equal to In addition, neither a pulsating component nor a sawtooth component is observed in the pressure between point P8 (FIG. 1) and ground [14] measured with an oscilloscope during this discharge. This concentrated discharge is
This is significantly different from the 11-eight scattering discharge obtained using Love's technique. As shown in Figure 5A, Love's radiant center uses a coaxial gas supply, but it spreads outward from the tip of the needle toward the printing plate, and the shining ``core'' in the center also spreads outward. As a result, a "footprint" is created on the plate that is considerably larger than the cross section of the hole of the needle 31. This difference is due to the fact that the image formation on the plate using Tochu Kinshin is different from the image formation on the plate using Love's technique, as described above.
It is possible to form an image with a resolution far exceeding that of T, and it is possible to form an image at a relative speed of transfer between the needle and the printing plate (i.e., to form a latent image) which is considerably higher than that possible with the diffusion-intensive technology disclosed herein. Therefore, image formation is possible because less discharge crystal light time is required to bring about a change in the plate surface.

The sixth diagram from FIG. 6A7'''J is a graph schematically showing the different discharge effects obtained with the apparatus not shown in FIG.

These graphs show the voltage measured from point P (Figure 1) and ground, and the internal diameter of 0.002 inch (approximately 0.051 inch).
The relationship between the gap width and the gap width obtained when helium gas is supplied at the flow rate shown in the figure using a hollow needle is shown. As can be seen from the figure, when a voltage below a certain minimum equivalent value is applied, no discharge of any kind is observed regardless of the gap width (
area engineering). When the voltage is increased, a diffused discharge occurs, and when the gap width is increased, the gap voltage generally increases and the discharge is maintained (region ■). Furthermore, when the voltage is increased from the second open voltage while keeping the gap width small, the discharge suddenly changes from a diffused type to a concentrated type (region ■).

The relative voltage values rAJ and f'BJ shown in FIG. 6A are figures formed on the printing plate using the speed of this rapid change.

That is, it represents the operating point used to adjust the image.

First, the roller rotation speed is selected to be low enough to allow a concentrated discharge to provide the necessary insolubilizing effect on the plate, and high enough to completely negate the diffuse discharge during imaging of the plate. The Ci'lir phase is then changed to a non-image-forming diffuse discharge, except during the image-forming period by rapidly changing the diffuse discharge to the concentrated one, using a voltage pulse to the level It may be set to a value such that it always occurs.

The narrow gas flow supply 131 into the discharge area and onto the plate surface does not have to be coaxial with the needle, i.e. the electrode, but is preferably coaxial in this embodiment. As a general rule, even if the gas flow path does not follow the line indicating the shortest distance between the needle tip and the plate, the M-electron 1. j.

It preferentially follows the gas flow. This is due to the fact that the ionizing capacity in the gas stream is significantly lower than the ionizing capacity in the space surrounding the gas stream, and it is said that the ionizing force in the gas stream is small. ζ1 small ゛(゛) may consist of a separate body 114 placed close to the lik electric gear 17 independent of the means for supplying the chain and the turtle (Hj; perpendicular to (
When high resolution is desired, it is important to minimize the cross-sectional area of the gas flow when it comes into contact with the plate. Therefore, h
It is usually desirable that the means for supplying the k-core region gas have a suitably small cross-sectional area and be capable of forming a narrow gas stream of the required velocity, ie, a velocity of about 0.05 or more, preferably less than the speed of sound. Generally, the inner diameter of the needle hole is approximately 0.00
Preferably, it is within the range of 2-1' inches (about 0.051 mm) to about 0.004 inches (about 0.102 m111). Within this range, a correspondingly narrow gas stream can be generated. However, a diameter outside this range may be used as long as a gas flow velocity of at least approximately Matsuha O, OS can be achieved.

The discharge used in the present invention is not very strong so that the discharge does not remove significant rows of plate coating. Physical changes in the surface of the printing plate that occur in the lower layers are not affected. The mechanism of the chemical reaction caused by electric discharge has not yet been elucidated. It is also unclear to what extent the chemical reactions that occur in the image forming process of the present invention are similar to those that occur in conventional image forming processes (such as photography). The properties of the final latent image after processing are as follows: The properties of the imaged plate after processing rj!
'I do C, Lpo is the same C? (11r from [shi(
It's not too late. Most importantly, the two do not always match. The ions are thought to flow towards the membrane due to the electrical discharge. Also, the flow of ions is focused or concentrated due to the action of the rapidly flowing gas, so it is similar to the flow of ions taught by Love. The interaction of these ions with the chemical compounds of the coating causes chemical changes in the coating that change its relative solubility.

The term "insolubility effect", where C means a chemical (or other) effect produced on the plate by the discharge treatment,
It is because of this effect that the plate can be developed and used in a manner similar to conventional plates, which are exposed and developed in a conventional manner (such as photolithography).

Current 11] Limiting resistor 60 can be used to prevent excess current between needle 31 and the surface of plate 20. When an excess current occurs, the discharge phenomenon between the needle 31 and the plate 20 changes from the small current discharge used in the present invention to the arc discharge described in the cited document. Change. Moreover, a considerable portion of the coating on the surface of the plate 2o is removed or rearranged due to the excessive current. I don't like these phenomena. By using a current limiting resistor, it is possible to prevent the value of the discharge current from approaching the value at which arc-type discharge occurs. As the time-averaged current in the discharge gap increases, the line thickness in the image also tends to increase (see Example IV), so by varying the value of the current limiting resistor the line thickness appearing on the plate can be adjusted. Can be adjusted. The thickness of the line can also be adjusted, if necessary, by varying the cross-sectional area of the gas flow, the speed of the plate relative to the needle, etc.

Blocks with reference numbers 70, 75, 80 and 85 form a latent image on the surface of the plate 2o in a timely and prompt manner based on electronically stored, generated or transmitted graphical information. It is an electronic circuit that allows Block 80ha, approximately 2X1
Figure 2 schematically represents a power supply that provides a voltage in the range of about 200V to about 2000V at a current level of about 0 A to about 2xlO-3A to (7) fJ (7) K times. Block 85 represents a high speed switch that changes the voltage generated by power supply 80 at the frequency necessary to obtain the desired resolution or print gauge. The necessary switching frequency is determined by the speed at which the needle 31 moves or scans the surface of the plate 20;
It is a function of factors such as the desired resolution and the time interval between application of the required voltage and initiation of the desired discharge. The rotation speed of the circumference of the roller is approximately 72 inches (approximately 1.82911
1>/sec and print gauge approximately 1,00
Set to 0 lines/inch and use a small lithographic plate (for example, 10 x 15 inches (approximately 25.4 cm x 38.1 cm)
) To form an image on >, approximately 0KH2 to approximately 72K
It has been found that a switching frequency in the Hz range is required.

FIG. 7 schematically shows an example of the circuit C' used in the present invention. This circuit operates as follows. The data manually input to contacts A and B by a series of +5V pulses is the voltage water (contacts C and D with XL shifter 100).
The ground voltage reference is changed from the ground voltage reference between the two. Next, the l-10s FET Q2 increases the output of the Shinnok 100 according to the bias degree cardiac pressure, so that the +5V data pulse becomes a +40V level signal, D, and the +250V bias voltage. becomes the standard. )10
The sFE driver Q2 functions as a voltage follower and reduces the coupling between the output of the FE driver Q1 and the discharge gap and load resistor R4. Voltage 1. was laid down,
The amplified and modified high speed switch 85 output data is shown. The 650V power supply is divided between the gap formed between the tip of the needle and the printing plate and the current limiting resistor R1.

The circuit shown in FIG. 7 may be any circuit as long as it applies a logic signal of a moderate voltage (for example, 5V) generated by the figure generation means to a relatively high voltage DC bias (for example, 300V>). .

For example, an optical coupler such as model TIL 111, available from Texas Instruments, Dallas, Texas, may be used. In a structure using such a bias, the stage shown in FIG.
At the voltage across the output transistor of v (relative to ground voltage)
Approximately 900 V switching can be performed.

The graphic information processing device shown by block 75 is a single stage which sends the graphic information from block 7G to the 1B speed switch 35, and transmits the desired graphic information to the surface 1 of the plate 20. In addition to rotating the C needle to an appropriate relative position, when moving the part of the plate where the figure is to be held, avoid matching the latent image previously formed on the surface of the plate 200. It is an appropriate shift of the mind from the diffused mode to the focused mode disclosed herein, or vice versa.

What kind of means can be used to generate or recover such an instruction?
It is preferred that the graphical information and switching commands be generated or recovered electronically using analog or digital data storage means such as T, RA gate, or EPRD block memory. The data generated by the sensor 16 is input to the processing device 75, and the graphic information is converted into a series of commands for switching the switch means 85 and the moving means 5.
The work of converting to the movement command in step 2 is facilitated. As a result, T types of discharges occur continuously at accurate times between the needle 31 and the surface of the plate 20 that moves relative to each other.

In addition to generating a series of "on-off" switching commands that digitally repeat the execution and stop of the discharge according to the graphical information, it also adjusts the discharge current at a value within the discharge current envelope described here. It is also intended to regulate the discharge. The range of values may be a predetermined series of discontinuous levels, or it may be a somewhat continuous value within predetermined limits. In any case, it is only necessary to change the effective area on the surface of the plate 20 where the chemical changes that form the latent image occur on the portion traced by the needle. A chemical change that forms a latent image occurs.1
If the effective area changes, the resolution or the effective cylinder gauge of the imaging process will change. Generally speaking, the lower the time average market value, the thinner the lines formed on the printing plate will be. By using this means of discontinuously or continuously adjusting the current for performing or sustaining a small current discharge, it is possible to form a latent image neatly including lines of various thicknesses and points of various diameters. I can do it. For example, by using the concentrated discharge shown here (see Example R), it is possible to form uniform and sharp dots with a diameter of approximately 1 mil (approximately 0.025 ml) on an ordinary diazonium resin plate. , it is possible to form 10 or more points of any diameter within the range of the system.
There is no need to create large-diameter points by gathering or combining uniform small-diameter points, as is done in other systems. In other words, the present invention is very advantageous when creating precise graphs and half-tone graphs.

1 slope used in this invention is 1 adventure lotus 1 banquet source and 1 kotsu J
As used in the present invention, the light produced by an EK energy discharge (' means that 1 llir image cannot be formed) is used in the conventional photosensitive image forming means (1 lithograph 1 modified), and as used in the present invention. It is generally believed that the dramatic attenuation of light generated by the discharge used in this process, IJi:
The actual diameter of the visible center can be compared to the thickness of the line formed by the discharge.The part where no image is formed There is no need to provide a mask to prevent exposure to the light generated by the discharge.The line drawn by the discharge and the surface immediately adjacent to this line that receives the light of the discharge but does not receive the discharge itself. A sharp microscopic boundary layer is observed between the two.The discharge itself is the essential or main factor behind the insolubility effect of ordinary diazonium resin plates, but the radiation This is not an essential or major factor in the effect, as shown in the experiments described in Example V.

In accordance with the operation of one embodiment of the present invention, graphical information stored in or generated by graphical information source 70 is provided to graphical information processing device 75 . The graphic information processing device 75 receives this command together with the data regarding the rotational position of the roller 10 sent from the angular displacement sensor 16, and generates two kinds of commands. A first command is provided to translation stage 52 to move the imaging needle to a precise position along the axis of roller 10. Second
This command is applied to a high speed switch 85 which generates a series of electrical pulses necessary to produce the desired graphical information (and thus the image on the plate).

The upstream output from switch 85 passes through a load resistor R1- which limits the direct current supplied to needle 31 by 111. The needle is held at a precise distance from the surface of plate 20 by a micrometer unit 50 or other flat stage.

Here (ζ When forming an image on the disclosed method 0 version, the needle 3
The sound pressure applied to the plate is normally electrically positive with respect to the plate, but it may be preferable to be negative.

By the image forming unit 304 and the moving stage 52; W
It crosses the plane of 2O. This is because the flow d of a relatively inert gas such as helium or a mixture of helium and neon from the needle hole 33 toward the discharge gap, that is, the air gap between the needle 31 and the surface of the plate 20 is not controlled. li'l be mistaken. The direction of this radiation is toward the plate 20, and the velocity is about 0.05 or more. The ionization aid means 55 extend towards the area 1 between the needle 31 and the surface of the plate 20 for the reasons mentioned above. The morph 5 rotates the roller 10 at a constant rate via the belt 7.

The needle 31 thereby scans the entire surface of the form 20 which is temporarily fixed firmly around the roller 10. Therefore,
The electric current of the needle 31 passes through the entire figure surface on the printing plate.

Under these conditions, for example, by implementing and controlling the necessary electrical discharge in the graphical or image areas of the diazonium resin plate, the portions of the printing plate corresponding to these areas are converted into the developing material used to image the printing plate. Becomes resistant (relatively insoluble). By carefully adjusting the voltage and gap size and proper gas flow in accordance with the teachings herein, the focused discharge of the present invention can be applied to the plate.
,oo.

Images with line-per-inch resolution can be formed. The discharge imaged plate of the present invention is then developed using conventional developing techniques.

The electric discharge used in the present invention is capable of forming a fine latent image with no shading under a clear printing strip ζ 1 on a commercially available 1 to 6'l plate. . Printing conditions are determined by one example shown below. It should be noted that the following examples are in no way limiting to the invention. Additive color plates have been found to be suitable for use in the present invention.

Example: The equipment shown schematically in Figure 1: δ and 43) 8 stones with the following details and operating parameter values.

Plate: A metal plate with a conductive plate and a conductive roller attached to it and grounded hypocardially to the C conductor through a conventional conductive fixing pin, located at St., Minnesota. Negative polarity additive color photosensitive plate 1-3 Mr Rj sold by 3M Corporation of Ball.

Needle: The inner diameter is 0.002 inch (approximately 0.051 old),
The tip (the radius of the part is approximately 0.002 inch (approximately 0.051 inch)
+v, co) hollow steel tube. a+5id le 1
: The section is approximately o, oois inch (approximately 0,03
3ml/l) Curly. The protruding part of r(' is inserted into the hole like a hypodermic needle.

As shown in FIGS. 2 and 4, passages are provided for supplying gas to the discharge region through the bore of the tube.

Gas: Helium fed at a rate of 31 CIII/min via the structure shown in FIGS. 2 and 4.

Decomposition promoting means: Ultraviolet lamp model 223C-35
(Ultra Violet Products Inc., 9177B, San Gabriel.

California) is provided at the tip of the needle and immediately adjacent to the printing plate (approximately 0.75 inches (approximately 19.05H)).
(See Figures 2 and 4).

Current limiting resistance (R1): 5.00MΩ, 0.5
W0 High Speed Switch: Similar to the one shown in Figure 7.

Graphical source: PI)P containing appropriate conventional electronic components
11/40 Computer (Distributed by Digital Equipment Corporation, Mayland, Mass.) 6 In the apparatus described above, the plate rotates with the rollers at a roller and surface speed of about 71 inches per second.

Ambient light adjacent to the device is attenuated to avoid cluttering the photosensitive plate. The discharge voltage during the image forming period is 900 V, and a concentrated discharge is performed, and the discharge pressure during the non-image forming period is suppressed to 300 V, and a diffused discharge is performed. The polarity of the needle voltage is always positive with respect to the grounded plate roller. The needle automatically moves slowly along the axis of rotation of the roller at a rate of approximately 0.2 inches per minute. This causes the needle to follow a close helical path on the printing plate. A preferred shape is a printed test shape that requires a minimum point approximately 0.025 nm in diameter. The maximum switching frequency break is approximately 72KHz.

After a latent image of the desired shape was formed on the coated surface of the plate by contact with the concentrated electrical discharge, the plate was removed from the roller and submerged in low oil. That is, the plates were made using a process rubber (R Process Rubber, a product of 3M Corporation of Ball, Sen., Minn.) and then in a lacquer developer for image enhancement. Processed using Reliable Red Lacquer Developer sold by Anker/Riskmeco, then 50:50 (by weight) of gum arabic and distilled water.
was treated using a mixture of The above development process,
Areas touched by concentrated discharges, similarly shown on similar plates, are imaged on the Hongtong, whereas areas touched by diffused discharges are rarely as if they were not exposed. , photographically imaged by actinic radiation. The resulting developed IC plate is
Shows details that are visually noticeable. The plate was then placed on a sheet fed into a conventional design offset lithographic ink copier. The ink chosen was 0/S Washfast, sold by Sinclair & Wallentine of Charlotte, North Carolina.
It was black NC23424. The dampening solution was diluted as directed (1:15 ratio depending on volume).
It was a 3M copier Fountain Q condensate that was sold to 3M Corporation of St. Paul, Minnesota. The selected paper was sold by International Paper Company and weighed 20 lbs.
Ordinary why 1~・ with violent level d of 08K(] )
It was business paper. The resulting imprinted sheet bore a very clear and detailed image corresponding to the area of the plate contacted by the focused discharge without any unwanted back spots.

Example ■ The plate used was a 6 mil thick LK brushed grained "wipe-on" type plate, with LKK 6110 sensitizer base and LKi (sensitizer powder or Same as Example T, except that the negative j′d1 resistor used was 2.5Ω and 1Ω,
It is U. Here, the above LKK brushing sand grain\7'
"Ci Wipe On" type version, LKK 6110 enhanced (delta agent base and LKK sensitizer powder were all sold by Anchor/Riskmeco of Rheinburg, New York. As in the case above, The image obtained on the plate had excellent contrast and resolution.

Example ■ Similar to the example except that the plate used was a 3M Type "E" plate sold by 3M Corporation of St. Ball, Minnesota. The plate was imaged using the invention disclosed therein and developed in the same manner as in the example. The image obtained on the plate had excellent contrast and resolution.

Example I■ The above gas flow d is 25 cm3/min, and the speed of the roller circumference is 20-L? - (approximately 18.29 m>/min,
Moreover, the resistance value of the current limiting resistor R4 was the same as the example, except that it changed beyond the range that allowed monitoring of the current in the discharge region. The combined linewidth of the adjacent lines (which is based on the reproduction of a series of parallel lines whose spacings were determined) was given as follows:

R, (MΩ) Current (μA) Line width (am) 9
64.5 2.27 &3.9
2.45 116.1 2.7
3 200 3゜0 2 296.7 3.41 5
8(), 5 4.1 The image quality in all cases is
I/-A was bald.

Example V A small section of "Mirror" brand polyester plastic film having a thickness of 5 mils and having a conductive coating on one side was
The needle was inserted between the needle and the surface of the plate that covered the conductive coating opposite the needle. The above plastic film is manufactured by Sherasin, Sylmar, California, under the trade name "Indrex". Sold by Corporation.

The plastic film as used was partially transparent to visible light, the transmission of which was measured above the visible region of the spectrum and amounted to approximately 50% on average. The gas flow rate was 25 cm3/min, and the relative velocity between the needle and the film surface was 0.1 in.
m>/sec, and the needle is approximately 0° from the film surface.
．． Exemplary conditions were used to establish a discharge between the needle and the conductive surface of the film, except that the position was set at >0.002 inches (approximately 0.0508 mm). Considering the transmittance of a fraction of It was grounded to the roller that carried it.

Characteristics of various discharges between the needle and the conductive film surface ↑1,
In particular, the shape of the discharge and the visibility are virtually the same as those obtained in the example process! W'? It was done.

After exposure as described above, the film was removed from the entrance face of the plate and the plate was developed as in the factory.

Many types of undeveloped imageables were observed.

It appeared that visible light alone, such as that produced by the discharge of the present invention, was not bright enough to form a latent image on this plate. This is because the light intensity to which the plate was exposed in this example, due to the limited thickness of the film, the transmission of the film, and the increased discharge from the plate surface. '14 above)
This is because the degree of degree is calculated to be 10 (@). Therefore, in the practice of this invention as illustrated in the previous small example work to IV, -C', the collision of ions on the surface is ten machine f
It is concluded that the incident product 1J1 of the light coupled to the discharge of this invention does not play a significant role.

1. To ensure that if strong enough, light from a normal light source can produce a latent image after passing through the partially transparent film used above. It was partially covered with either the same plate as used in or a small section of film as used above and then roughened against a normal light source. After exposure, the film section was removed and the plate was developed as described above. Both of the above areas are directly exposed to light and therefore those directly beneath the developed film to the same extent that the film absorbs at least some of those wavelengths of light such that the plate surface is photosensitive. It was observed that it was established that it could be carried.

[Effects of the Invention] As described above, the present invention provides an image forming method, an apparatus, and a product formed thereby, which can eliminate the constraints on printing resolution and improve the image forming speed at the same time. can be provided.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an apparatus used for forming an image on a printing plate according to the present invention, and FIG. 2 is a detailed cross-section 1 of the needle structure taken along the line ■-■ of the apparatus shown in FIG. Fig. 3 is an enlarged view of the tip of the needle shown in Fig. 2; Diagram A
[Fig. 3 shows +A, t-S, 1 item (1 item, 5; Figure, Figure 5B and figure 3M show $ digits.
This is a schematic drawing of the first side of the main part, and the intensive, non-1
i, 1 is a schematic diagram of a switching circuit that may be used. 10... Roller, 20... Plate, 30... Hypochondrial image forming unit, 31... Needle, 33... Needle hole, 48
... Gas supply path, 55 ... Ionization promotion means, 60
...Current 1111 limiting resistance, 7G...Graphic information source, 7
5...Graphic information processing l! p″fξ stone, 80...power supply,
85...High speed switch, 100...Electric water! 1ll
L shifter. Applicant's agent Patent attorney Suzue Kihiko Figure 5A Figure 5B Gear lens width - Figure 6A Figure 6B Gear 77'' width - Figure 6C Procedural amendment (method) Showa 60 ξ 10.2Q n Mochi, Director General of the License Agency, Uga Michibe 1, Indication of the case, Patent Application No. 142368/1988 3, Relationship with the Nagisa case to be amended Patent applicant Milliken!J Sury Corporation 4, Agent Showa September 24, 1960, 7, Contents of the amendment (11 Added one line between the 1st and 2nd lines on page 7 of the specification 3 and added the detailed description of the invention. (2) Engraving of drawings (no changes to content).

Claims (18)

[Claims] (1) insoluble when acted upon by a small current non-pulsating discharge to form a latent image that can later be developed for use in a printing process by a common lithographic type development process; A method for forming a desired latent image on an unimaged, electrically conductive substrate surface bearing an unimaged material that can be applied to the surface of the substrate, wherein said image is formed with a small current focused discharge. contacting an area of the material on the surface corresponding to the electrical discharge, the electrical discharge rendering the material insoluble with respect to a common lithographic type developer material only in the area contacted by the electrical discharge. An image forming method characterized by using an energy intensity suitable for. (2) The electrical discharge is substantially coaxial with a relatively inert gas flow directed onto the substrate surface at a subsonic velocity of at least approximately Mach 0.05. The image forming method according to item 1. (3) A method for forming a latent image on an unimaged printing plate having an unimaged coating in which the insoluble effect is induced by a small current focused discharge, comprising: (a) a coating of said plate; (b) placing an electrode in close proximity to a surface, thereby forming a discharge gap; (c) causing a small current concentrated discharge between the electrode and the plate surface in the gas flow; and (d) applying an inert gas to the coating contacted by the discharge. maintaining a time-averaged current in the discharge at a value sufficient to induce an insolubility effect. (4) The value of the time-averaged current in the discharge gap is between approximately 2 x 10^-^6 and approximately 2 x 10^-^3 A. The image forming method described. (5) The image forming method according to claim 3, wherein the voltage across the gap is a non-pulsating voltage. (6) The gas flow has a minimum cross-sectional area of less than or equal to approximately 2 x 10^-^5 square inches (approximately 50.8 x 10^-^5 mm^2). Third
The image forming method described in Section. (7) produced by the imaging method of claim 6, wherein the resulting latent image has a minimum uniform dot diameter of approximately 0.004 inches (approximately 0.102 mm) or less; Things to do. (8) The method of claim 3, wherein the gas stream is blown from a device coupled to the electrode. (9) The image forming method according to claim 3, wherein the electrode is a tube, and the gas flow is blown from a hole in the tube. (10) The current is limited to a maximum value that is insufficient to displace the coating so as to substantially expose the plate underneath the coating.
Both image forming methods described in section. (11) the electrode is scanned over the plate surface by a relative movement between the electrode and the plate, and the concentrated discharge is such that the electrode faces the plate surface where the insoluble effect is desired; 4. The image forming method according to claim 3, wherein the image forming method is maintained only while the image is in the area where the image is formed. (12) When the concentrated discharge is not maintained, a diffused discharge is maintained.
The image forming method according to item 1. (13) The image forming method according to claim 3, wherein the discharge current is adjusted according to graphic information. (14) An apparatus for forming a latent image on an unimaged printing plate having an unimaged coating in which the insoluble effect is induced by a small current focused discharge, comprising: (a) a coating of said plate; (b) means for locating an electrode in close proximity to a surface, thereby forming a discharge gap; (c) means for causing a small current concentrated discharge in the gas stream between the electrode and the plate surface; (d)
means for maintaining a time-averaged current in said discharge at a value sufficient to induce an insolubility effect in said coating contacted by said discharge. (15) An apparatus for forming a latent image on an unimaged printing plate having an unimaged coating in which the insoluble effect is induced by a small current concentrated discharge, comprising: (a) (b) means for locating an electrode in close proximity to the coating surface, thereby forming a discharge gap; (c) means for causing a small current concentrated discharge in the gas stream between the electrode and the plate surface; (d)
(e) means for maintaining a time-averaged current in said discharge at a value sufficient to induce an insoluble effect in said coating contacted by said discharge; and (e) a time-averaged current in said discharge area in accordance with graphical information. An image forming apparatus comprising: means for changing. (16) The image forming apparatus according to claim 14, wherein the means for arranging the electrodes is controlled according to graphic information. (17) Claim 14, wherein the electrode includes a hollow needle having a longitudinal hole, and the means for blowing the gas into the gap includes the needle hole.
The image forming apparatus described in . (18) The needle hole is approximately 0.004 inch (approximately 0.10 inch)
18. The image forming apparatus according to claim 17, wherein the image forming apparatus has a maximum diameter of 16 mm.