JP3352459B2 - Printing method and apparatus - Google Patents

Description

The present invention relates generally to printing technology, and more particularly, to a photolithographic printing method and apparatus for processing a feed solution by the injection of electromagnetic radiation. In most preferred aspects of the invention,
The electromagnetic radiation is in the radio frequency range and the injection takes place through conductors in direct contact with the feed solution.

Numerous systems for treating various aqueous solutions have been proposed to improve some methods or to provide certain properties to the treated solution. Some examples of such types of processes include electromagnets, permanent magnets, ultrasound, electrostatic fields, and the like. Although some technicians are convinced of the effects of such treatments, considerable skepticism remains, and commercially available devices are not of high commercial success. The types of applications that employ such treatments are also changing widely. Some of these are described below with reference to certain prior art descriptions, which generally involve treating aqueous solutions to prevent scale buildup on boilers, cooling towers, etc. Processing of emulsions, processing of certain non-aqueous materials such as fuels to improve fuel combustion efficiency,
Includes processing of automotive radiator fluids, and various other uses.

We will now briefly describe some representative examples of such prior art processing systems, with particular attention to the Morse patent, the background art mentioned therein, and the references cited therein. Should.

One such device, called the Ion Stick,
It uses the application of an electrostatic field, as shown in a pamphlet titled "The Ion Stick." A copy of the pamphlet is attached to this specification. This device is an electrostatic water treatment device that does not use chemical treatment and that is powered by its own power pack and does not cause pollution. Another electrostatic treatment method and equipment is October 8, 1985
This is disclosed in U.S. Pat. No. 4,545,887, issued to Arnesan et al.

Other devices use fixed magnets for water treatment.
An example of such a device is the Apparatus for Magnetically Treating Fl, granted to Mitchell on February 28, 1989.
U.S. Pat.Nos. 4,808,306 and 1983
Apparatus for Carpenter granted on January 4, 2008
Magnetically Treating Liquid Flowing Through
a U.S. Pat. No. 4,673,143 entitled "A Pipe and Clamping Means Therefor".

A different magnet system for water treatment was launched on December 19, 1989 by Holc
`` Magnetic Water Treatment Devic
e "is disclosed in U.S. Pat. No. 4,888,113. In this patent, Holcomb describes the use of a plurality of rectangular magnets mounted outside the pipe. The magnets are paired and located near the pipe such that the positive poles of a pair of magnets are directed to one end of the support housing and the negative pole is directed to the other end of the housing. Another similarly configured housing is secured to the other side of the pipe, but with the opposite polarity of the magnet. Thus, the first set of positive electrodes faces the second set of negative electrodes and places them in a "suck" mode of magnetic flux processing. Applications such as scale inhibition and uses in washing machines, swimming pools, ice rinks, livestock drinking water, and coffee brewing waters have been suggested. The patent also suggests that the taste of the treated water is better than the taste of the untreated water. The patent also states that a magnetic flux field can be generated by a wound core coil coupled to a DC generator.

The assignee of the present invention is the patentee of several patents relating to electromagnetic water treatment devices. These patents include 1988 5
`` Cooling System for Magnetic Water T
U.S. Patent No. 4,746,425 to Stickler et al. for "Reating Device" and "Electromagn" on April 21, 1987.
No. 4,659,479 issued to Stickler et al. for "etic Water Treating Device". Both use a pipe core in which an electromagnet surrounds a pipe through which the fluid to be treated flows, with alternating magnetic and non-magnetic parts.

The prior art includes devices that use electromagnetic energy for water treatment. Many such devices use constant frequency electromagnetic energy. Examples of such fixed frequency devices include the "Magnetic Water Treatment Apparatus and" issued to Van Gorp on October 4, 1983.
U.S. Pat. No. 4,407,719 entitled "Method of Treating Water" and "Free Flow Non-Corrosive Water Treat granted to Brigante on September 8, 1981.
U.S. Pat.No. 4,288,323 entitled "ing Device" and 19
"Electric Dev" granted to Vermeiren on May 13, 1852
There is U.S. Pat. No. 2,596,743 entitled "ice."

Some other U.S. patents describe electromagnetic energy of varying frequency, or electromagnetic energy of mixed frequency,
Alternatively, certain methods of using both, or certain devices, or both, are disclosed. For example, Avanpoto
U.S. Pat. No. 3,511,776 issued to U.S. Pat. A method is disclosed.

U.S. Pat.No. 3,562,884 to Waltrip is a sewage treatment system that uses multiple signal generators to provide several different frequencies of audio frequencies, or several different frequencies of radio frequency energy, or both simultaneously. A method is disclosed. The frequency output of each separate signal generator is
The choice can be made based on the mineral content of the untreated sewage.

U.S. Pat. No. 4,365,975 to Williams et al. Discloses the use of radio frequency microwaves (0.1 to 105 MHz
z) discloses a method for recovering alkali metal components from coal gasification residues by irradiating electromagnetic energy in a range. Such electromagnetic radiation is intended for metal extraction.

Another processing system is disclosed in a patent wherein the assignee of the present invention is the patentee, namely, "Electromag," issued Sep. 12, 1989.
The disclosure is in U.S. Pat. No. 4,865,747 issued to "Netic Fluid Treating Device and Method." 1KHz
An electromagnetic field having a voltage operating in the range from 1000 MHz to
Added to a non-ferromagnetic conduit with a ferromagnetic core mounted inside. The core acts as a sacrificial anode and as a receiving antenna for radio frequency radiation.

Designed for use in preventing scale formation,
A device known as "Aquabel" is on sale. This device intentionally includes an electronic circuit that generates an electromagnetic signal. These electromagnetic signals are transmitted into the water through a cable that is spirally wound around a water tube. A copy of the pamphlet associated with this device was included in this specification.

Electromagnetic radiation in the form of microwave radiation was introduced on April 15, 1986
U.S. Pat. No. 4,582,629, issued to Wolfe, is discussed as a mechanism for processing emulsions.

An electromagnetic process for altering the energy content of a bipolar material is disclosed in British Patent No. 417501 issued to Johnson on December 28, 1934. According to Johnson, irradiating a colloid with electromagnetic energy having the wavelength characteristics of the colloid changes the mobility and viscosity of the colloid. Also, treating an organic substance, such as milk or meat, prevents the substance from aging. Another use is to treat living organic matter, such as bean seeds, to promote its growth.

Another method and apparatus involving the treatment of water using electromagnetic energy having a variable frequency is disclosed on August 6, 1928 in Deutsc.
German Patent No. 463844 to H. and August 6, 1948.
It is disclosed in British Patent No. 606154, issued to Brake on a date.

Yet another type of scale arrest occurred on August 19, 1930, Ne
No. 1,773,275 to eley. The U.S. patent discloses supplying an electric current to the water by applying an electromagnetic field to the water or by contacting the water with a charged surface. A process for reducing hardness using electric current is disclosed in U.S. Pat. No. 2,216,933 issued June 13, 1939 to Pierpoint et al.

Another water treatment technology was granted to D. Morse on September 12, 1989, entitled "Method and System for Variable Frequent
ncy Electromagnetic Water Treatment "is disclosed in U.S. Patent No. 4,865,748. In this patent, a conductor in direct contact with the fluid to be treated is coupled to a generator of electromagnetic radiation, preferably of radio frequency. According to that patent, radiation is injected at a frequency related to the absorption or emission profile of the particular system being processed. This patent focuses on using the device to eliminate and prevent scale growth in boiler systems and the like. The Morse patent is also owned by the patentee of the present invention. A continuation-in-part application of the Morse patent was granted on October 16, 1990 as Patent No. 4063268.

Disinfection of water using current injection on June 22, 1976, Dawson
And US Pat. No. 3,753,886, issued Aug. 21, 1973 to Myers.

The assignee of the present invention has three pending applications relating to the use of a device that are generally similar to the device described in the Morse patent. They were filed on December 3, 1990, entitled "Ice Making Water Treatment" (application number 07/621619), and filed on May 31, 1990, "Bev
erage Brewing Treatment ”(application number 07/531021) and“ Filtratio ”filed on August 8, 1990.
n Cleaning System ”(application number 07 /
564790).

Lithographic printing is a well-known printing technique used for a wide range of applications, including books, magazines, office forms, advertising materials, and the like. Lithography is a planar printing method in which a printed portion and a non-printed portion are arranged on the same plane of a metal plate. The distinction between the two parts is made chemically, the image part repels water and the non-image part receives water.

One type of lithographic printing is offset lithography, in which an image is transferred from a printing plate to an intermediate cylinder or blanket cylinder and then to the printing surface. In many cases, printing is performed simultaneously on both sides of the substrate using a technique which is itself an old technique. A typical printing press can include any one to as many as twelve units.

In lithographic printing, it is common to use a "feed solution" to keep non-image areas from receiving ink. Since printing inks are usually based on oil, the feed solution is usually based on water and furthermore various additives are used. The most common of the additives is isopropyl alcohol. Isopropyl alcohol is a volatile organic compound (VOC) and has been a problem in the printing industry in terms of air pollution and cost.
Most feed solutions contain up to 35% by volume isopropyl alcohol, but the most typical compositions range from 5-20%. Many factories have attempted to reduce the amount of alcohol by using magnetic devices, one of which is "superior water conditioners.
r)). This apparatus requires that the feed solution be magnetized and its surface tension reduced so as to require less alcohol.

Non-alcohol substitutes have been developed as substitutes for isopropyl alcohol, which reduce volatile emissions from printing presses, but are more costly and, due to the problem of chemical waste, their Use is usually avoided.

As an example to illustrate the magnitude of the isopropyl alcohol problem in the printing industry, it is estimated that a typical facility may use 1-800 tonnes of alcohol per year, depending on its type. A review of offset lithographic printing, especially offset lithographic printing related to VOC issues, was made for the United States Environmental Protection Agency on September 6, 1991, by the Draft for NAPCTAC M.
eeting-Offset Lithographic Printing Control T
echniques Guideline. " Copies of Chapters 1 through 5 of this publication are attached to this specification for reference. The remainder of this publication appears to be related to cost impact analysis and emission assessment techniques that are of little relevance to the subject matter of this specification.

SUMMARY OF THE INVENTION The present invention features a lithographic printing method and apparatus that significantly reduces the amount of isopropyl alcohol. Another feature of the present invention is that in some cases the alcohol required for the feed solution is eliminated, while maintaining the print quality previously obtained with alcohol.

Another feature of the present invention is the elimination of alcohol and other VOC materials from the feed solution and the offset lithographic printing device. This can be easily done without major modifications to existing equipment.

How these and other features are achieved will be described in the following description of the preferred embodiment with reference to the drawings. However, they are generally conventional printing systems which add a device for injecting electromagnetic radiation, preferably in the radio frequency range, into the feed solution before and / or during the application of the feed solution to the printing plate. Achieved using equipment. The injection system directs the electromagnetic radiation generator and radiation from the generator to the injection device, or, in the most preferred embodiment, to the divider, and further to the conductor in direct contact with the liquid used in the feed solution. And a cable for guiding. From reading the description of the invention, other ways of achieving the features of the invention will be apparent to those skilled in the art. They are considered to be included within the scope of the present invention, and the present invention is not to be limited by the single embodiment described, but rather by the following claims.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a portion of a typical lithographic printing apparatus.

FIG. 2 is a schematic diagram of a water treatment of a feed solution of the present invention in a modification of a printing apparatus that includes an additional roller other than the roller shown in FIG.

FIG. 3 is a front view of a frequency generator used in the embodiment of FIG.

 FIG. 4 is a schematic diagram of a PC board of the frequency generator of FIG.

Similar reference numbers are used in the various figures to indicate similar components.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before proceeding with a detailed description of the preferred embodiments, it is appropriate to describe some applications of the present invention. The present invention
Although shown in the drawings as including treatment of the feed solution in the tank of the particular printing device, the present invention is not a storage tank,
It has much broader applicability, including the treatment of liquids in feed solution pans, or liquids in conduits.

Prior to the description with reference to FIGS. 1 and 2, the printing device shown has been shown in very schematic form and the direct injection of electromagnetic radiation into the feed solution has been described in any other type of lithographic system. It is necessary to state that the desired characteristics of the present invention can be achieved by performing the above. Further, while one injector is shown in FIGS. 1 and 2, the present invention does not assume that one injector is used, but may use multiple injectors in the system. As will be explained further below, it is sometimes desirable to use a single generator leading to the divider. The divider conveys the final signal to a number of injectors.

It will also help to provide a general description of the effects of the direct injection system, as currently understood by the inventors of the present invention. This explanation is based on other explanations and supply methods (fountain
There is no conflict with other mechanisms as a result of the direct injection of electromagnetic radiation into the aqueous solution of the formula).

Tests conducted by the assignee of the present invention have shown that such direct injection results in certain fundamental changes in the physical constants of water. This has an advantageous effect on electroplating. It is believed that the aggregation properties of the water molecules are altered. In fact, it has been measured that many physical properties of water change, including boiling point, freezing point, surface tension, dielectric constant, evaporation rate, and the like. Table A below
FIG. 4 shows some properties of water and corresponding numerical values measured on a distilled water sample (“treated water”) after being processed by a system that injects electromagnetic radiation in the radio frequency range directly into the water. All tests were performed according to well-known test procedures and performed a minimum of three times to confirm numerical accuracy. In viewing Table A, it should be kept in mind that tests were performed on separated samples of a particular aqueous solution. The injector system used for the test is described in detail with reference to FIGS. Pre-testing for the results shown in Table A was performed for 60 minutes using radio frequency injection at a frequency of 43.9 MHz and a current of 425 milliamps at 50 volts p / p.

The frequency of the injected radiation is believed to play a role in changing the physical properties of the solution. This is confirmed by the fact that the NMR frequency associated with the hydrogen atom is 42.5759 MHz, a value very close to the frequency used for the test. Also, for other atomic species present in the solution, another frequency determined from the textbook can be injected into the solution. Injection of multiple frequencies using separate injectors, frequency scanning or multiplexing can provide much greater improvements than those described above. Current tests appear that the water molecule itself is most strongly affected.

In the context of the present invention, changes in surface tension properties and the ability of ions to move through solution as a result of such changes are believed to be the major contributors to the dramatic results shown in the plating data below. . By tests performed on ionic solutions of various commonly encountered compounds including calcium, magnesium and silica compounds,
A number of surprising results have been produced that may involve the above-mentioned agglomeration phenomena or may involve the energy-rich effects of ionic or colloidal species present in solution. For example, noticeable changes in the rate of evaporation of such solutions when compared to untreated solutions were noted. Changes in the freezing point and boiling point of water, changes in ion mobility, changes in dissolved oxygen properties, changes in solubility properties, and changes in antimicrobial properties were noted. In addition, the change in density at various temperatures of the water before and after treatment is also recorded.

Table A Properties H ₂ O treated water Boiling point 100.0 ℃ 101.0 ℃ Melting point 0.0 ℃ 1.5 ℃ Maximum temperature density 3.98 ℃ 8.00 ℃ Refractive index 1.336 1.349 Conductivity 81.77 85.80 Surface tension 73.7 62.50 Dipole moment 1.76 1.77 Specific heat 1.00 0.98 Magnetization moment 0.72 0.68 Ionization potential 1 × 10 ^-14 5 × 10 ^-14 Now, the description will be made with reference to FIG. The manner in which the printing device 10 includes a plate cylinder is schematically illustrated. The printing device has a feed solution application system and an ink application system. This figure does not show the additional color deposition system used for the additional colors in a multicolor printing press, or the blanket cylinder or rubber substrate typically used for such operations. For details on the construction of a typical printer, see the above description of the printing industry mentioned in the background section of this specification. The illustrated printing device 10 includes a plate cylinder 12, an inking system generally indicated as 13, and a damping system generally indicated at 14. Damping system has multiple rollers 15 ~
Including 17 Roller 15 is immersed in feed solution 20 contained in pan 22. The solution can be of a typical composition, except that in the present invention isopropyl alcohol or an alternative to isopropyl alcohol need hardly be included, if at all.

Next, reference is made to FIG. Oscillator 25 is shown connected to wall outlet by cable 27 and to injector 30 by cable 32. Injector 30
Is a feed solution tank 35 containing an amount of feed solution 37
Is schematically shown in the inside. In this figure, conduits 39 and 40 feed feed solution 37 from tank 35 to pan 42 which contains a sufficient amount of feed solution 45 to be applied to pan roller 46. One typical application technique involves the use of doctor rollers 47, oscillating rollers 48, and setting rollers 49 for applying the feed solution to plate cylinder 50.

As mentioned earlier, feed solution pan 42, or conduit, if deemed appropriate for the particular printing facility
It can flow directly into 39 or 40 or both. Further, as in the case of many printing applications, printing a single substrate can include several feed solution deposits, and one variation of the present invention is to use
It is coupled to a signal splitter 51, shown schematically in FIG. An additional cable 52 then extends to an additional feed solution bath.

It is noted that print quality has improved dramatically, as indicated by one system installed with the goal of eliminating or reducing as much alcohol or alcohol substitutes as possible. The printing press is a 26 inch 6 color printing press.
It has a Komori-Matic damping system using a Royce circulation system with six 5-gallon tanks.
The generator uses one transmitter. The transmitter is sent to a divider box where the six individual outputs are RG-
It is routed by a 59 coaxial cable through a stainless steel injector submerged in a 5 gallon tank. In this study, alcohol substitutes (Printers' Service, Newa
Alkaless Plus Tw manufactured by rk, NewJersey,
o) was cleared 100% from the system before the generator was switched on. Baseline print quality was set without any changes, and there was a 4% higher DOT gain than the baseline. Because DOT gain was undesirable, 1 ounce per gallon of alcohol substitute was added to the solution, at which point the print quality was exactly in line with the baseline. Alcohol substitute reduced from 15 oz to 5 oz. this is
That was a 67% decrease.

Additional units were installed on other printing presses. As a result, 100% alcohol was eliminated. The presses continued to run with remarkable results without alcohol or alcohol substitutes.

In our tests to date, 100% of all alcohol or alcohol substitutes could be eliminated for 60% of the test applications. In addition, additional benefits were obtained at the test site including the cleaning tank, including reduced conductivity and extended roller life, when compared to using alcohol or alcohol substitutes.

Next, the third radio frequency generator 25 is shown in detail.
Refer to the figure. This radio frequency generator 25 includes a casing 53 made of plated steel or an 11 gauge aluminum plate. The PC plate 54, the fuse 56, the transformer 58, and the terminal block 60 are mounted inside the casing 53. A power cord 27 is connected to the terminal block 60 and extends through a hole 64 on one side of the case 53. The power cord 27 terminates in a normal three leg plug 66. This plug is for plugging into a commercial 120 volt AC outlet. The cable 32 is connected to the PC board 54 and passes through the opening 70 of the case 53.
As mentioned earlier, cable 32 is coaxial and RG59 / U
Type coaxial cables are preferred. The cable 32 terminates in a spark discharge plug 72 whose tip is platinum. The casing of this plug is omitted. Other materials can be used to terminate the cable 32, for example, a stainless steel injector electrode machined to be about 1 inch long and about 1/4 inch in diameter. The length of the coaxial cable 32 is selected to be either approximately one quarter, one quarter wavelength, or one half wavelength of the RF signal injected into the bath. For example, for an RF signal having a frequency of 42.7 MHz, the length of the cable is preferably about 23 to 24 feet, which is one wavelength long. For other processing frequencies, the cable length is changed to an approximate length defined by the wavelength or its harmonics. When using a splitter, the length of cable 32 is 12 feet or approximately one-half wavelength.

In operation, the radio frequency generator 25 connects the power cord 27 to a 120 VAC power source, such as a normal household electrical outlet.
Connected via Power cord 27 terminates in terminal block 60 and 120 volts AC power is applied to transformer 5 through fuse 56.
Supplied to 6. Fuse 56 is rated at 0.5 amps and protects the circuit in PC board 54 in the event of a short circuit by opening the circuit during a temporary short circuit on the primary or secondary side of transformer 58. Transformer 58 transforms 120 volts at 60 hertz into 20 volts at 60 hertz. Transformer 58 supplies power to PC board 54. The PC board generates a typical 45-volt peak-to-peak voltage RF signal. 45 volt peak
Peak RF signal is spark-discharged via coaxial cable 32
72, where it is injected into the feed solution.

Referring now to FIG. 4, which shows a circuit diagram of the components on the PC board 54. On the PC board 54, there are three types of circuits: a power supply circuit 73, a turn-off circuit 74, and an oscillator circuit 75. The power supply circuit 73 is a power-off circuit 74 and an oscillator circuit.
Supply 75. The turn-off circuit 74 is used to stop the operation of the oscillator circuit 75, but can be omitted in another embodiment. Oscillator circuit 75 generates an RF signal that is injected into the supply solution. Power supply circuit 73 is connected to terminals IN1 and IN2
, Diode D1-D4, capacitor C1, resistors R2, R3
And a variable resistor VR1 and a voltage regulator REG1. A 20 volt RMS AC signal is provided by transformer 108 to terminals IN1, IN2. Diodes D1-D4 rectify the 20 volt RMS AC signal and the AC ripple is smoothed by capacitor C9. Rectified and smoothed 20 volt DC voltage regulator REG1
Is supplied to the input terminal I1. Output terminal of voltage regulator REG1
OUT1 and the adjustment terminal A1 are connected to a voltage dividing resistor network composed of R2, R3, and VR1 to supply a voltage of +20 volts to the output terminal OUT1 of the voltage regulator REG1. OUT1 voltage is adjusted by adjusting the resistance value of VR1. Next, +20 volts power is supplied to the turn-off circuit 74 and the oscillation circuit 75.

The turn-off circuit 74 includes an input terminal 77, a resistor R4, and a relay.
It is composed of RLY1, a diode D5, and a transistor Q1. Turn-off circuit 74 is connected to power supply circuit 73 and receives +20 volt power. A resistor R4 is attached to the bottom of Q1, and the emitter of Q1 is grounded. The collector of Q1 is connected to the parallel combination of the coil of relay RLY1 and diode D5. relay
The other ends of RLY1 and diode D5 are connected to a positive +20 volt power supply. Transistor Q1 positive to ground
When enough voltage is applied to the base of Q1 through resistor R4 and input terminal 77 to turn on the transistor,
Q1 starts conducting and trips relay RLY1. As will be explained later, this grounds the output terminal of the oscillator circuit 75, thereby actually turning off the oscillator circuit 75.

Oscillator circuit 75 is coupled to power supply circuit 73 and is powered by a +20 volt power supply. Output OUT for lighting LED
2 and output terminals TP1 and TP2 for outputting a 45-volt peak-peak RF signal. Generally, oscillator 75 includes a tank circuit 78 and an amplifier circuit 80. The frequency of the tank circuit 78 is approximately
At 42.9 MHz, it provides an RF signal with an amplitude of about 10 volts peak-to-peak. Its amplitude is controlled by the magnitude of the supply signal and is therefore selected by adjusting the resistance of VR1 in power supply circuit 73. The RF signal is provided to amplifier circuit 80, where the signal is amplified to approximately 45 volts peak-to-peak. The tank circuit 78 includes resistors R5, R6, R7, R8,
R9, capacitors C2, C3, C4, variable capacitor C5,
It includes inductors L1, L2, L3 and a high-frequency transistor T1.

Inductor L1 is provided to further smooth AC ripple in +20 volt power. Resistors R5, R6, R7 are provided to apply a DC bias to the base of transistor T1. A resistor between the emitter of the transistor and ground
A tank circuit in which R8 and a capacitor C2 are connected, and capacitors C3 and C4, a variable capacitor C5, a resistor R15, and inductors L2 and L3 oscillate at a frequency selected by adjusting the capacitance of the variable capacitor C5. Complete. Using the components with the values shown below, a tank circuit operating at about 42.9MHz is configured. Of course, as will be apparent to those skilled in the art, other component values and various oscillator circuits can be used to obtain this frequency. If one wanted a processing frequency other than 42.9 MHz, one skilled in the art would know that changing the tank circuit component value would result in a new output frequency. Further, as described above, different frequencies can be added in the processing steps by using multiple oscillators, crystal systems, frequency scans, or by multiplexing the tank circuit 78.

The output of tank circuit 78 is applied to amplifier circuit 80. The amplifier circuit 80 is composed of capacitors C6, C8, C9 and a variable capacitor
C7, resistors R9, R10, R11, R12, R13, and transistor T
2, including Q2. About 10 volts peak-to-peak AC signal is applied to transistor T2 via capacitor C6 and variable capacitor C7.
Added to the base. A DC bias set for the base of transistor T2 is provided by a voltage divider network made up of R9, R10 and R11. Variable capacitor
C7 is coupled to tank circuit 54 and is used to fine tune its output frequency with variable capacitor C3. Transistor T2 amplifies the RF signal. The RF signal is supplied to the output terminal TP2 via the capacitor C9. Output terminal TP1 is grounded so that a 45 volt peak-to-peak AC signal is seen between output terminals TP2 and TP1. When the coil of relay RLY1 is set, a short circuit occurs between TP1 and TP2,
To ground the output provided by the oscillator circuit 80,
Relay RLY1 is connected between TP1 and TP2. As described above, the RF signal between TP1 and TP2 is provided to coaxial cable 18 to process the bath.

+20 volts power is supplied to the output terminal OUT2 via the resistor R14 to turn on the external LED. This external LED is turned on when power is applied to the oscillator circuit 75.

Thus, the generator 25 of the most preferred embodiment provides a 45 volt peak-to-peak RF signal having a frequency of about 42.9 MHz and injects that signal into the feed solution. The device is powered by a conventional household power supply and supplies signals using a coaxial cable 32 terminating in a spark discharge plug 72 with a platinum tip. In order to provide maximum power, some applications require impedance matching of the coaxial cable, thus minimizing standing waves.

While the present invention has been described in relation to certain schematic and exemplary components of a lithographic printing apparatus, the present invention provides:
Applicable to other printing systems where it is desired to change the ink receiving properties of the printing surface, including water-based materials. The invention is not limited to lithography and should be limited only by the following claims.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41N 3/08 B41F 7/24 B41F 7/32

Claims (9)

(57) [Claims] 1. A fountain solution including a printing surface having a portion adapted to receive the ink and a portion adapted to repel the ink, the fountain solution being used to treat the portion receiving the ink.
A printer that generates electromagnetic radiation of a preselected frequency (2
5) and an injection system for injecting electromagnetic radiation into the dampening solution (37), having an injector (30) coupled to the generator by a cable (32) and in direct contact with the dampening solution (37). A printing device characterized by the above-mentioned. 2. The method according to claim 1, wherein the fountain solution (37) is contained in the tank (35) and the injector (30) comprises a conductor that contacts the fountain solution (37) in the tank (35). apparatus. 3. Apparatus according to claim 2, wherein the electromagnetic radiation is generated in the range from 1 KHz to 1000 MHz. 4. The device according to claim 1, wherein the length of the cable is selected depending on the frequency of the radiation. 5. The apparatus according to claim 1, wherein the surface is an impression cylinder (46), and a fountain solution (37) is applied to the cylinder from a roller pan (42). 6. A method for printing an image using a printing machine on a printing surface having a portion adapted to receive ink and a portion adapted to repel ink, the portion adapted to receive ink. Dipping water (37) into the area and applying ink to the portion intended to receive the ink; and cable (32) to the conductor in direct contact with the dampening solution (37)
Treating the dampening solution by injecting electromagnetic radiation from a signal generator (25) capable of generating electromagnetic radiation via the printing press. 7. The method of claim 6, wherein the electromagnetic radiation is generated in a range from 1 KHz to 1000 MHz. 8. The surface is a printing plate, the fountain solution (37) is applied to the plate by a roller, and the processing step is performed during the sump (3.
7. The method of claim 6, comprising treating the dampening solution in 5) and transporting the treated dampening solution to a roller pan (42). 9. A printing plate, a fountain solution (37) and a system for attaching the fountain solution to the printing plate without adding the fountain solution to the alcohol, wherein the system is in contact with the fountain solution (37). Means for injecting electromagnetic radiation into the dampening water from a generator (25) capable of generating electromagnetic radiation through the cable (32) to the injector (30) and conveying the treated dampening water to the roller system (39, 40, 42)
A system for eliminating alcohol-type additives in a fountain solution in a lithographic printing operation.