Printing – Stenciling – Rotary machines
Reexamination Certificate
1999-04-13
2001-12-18
Hilten, John S. (Department: 2854)
Printing
Stenciling
Rotary machines
C347S051000
Reexamination Certificate
active
06330857
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to printing devices. More concretely, the invention relates to a machine for printing different polygraphic matter, both simple and highly artistic.
2. Description of the Related Art
Printing machines are known comprising a printing form in the form of a stencil applied on a mesh, means for applying ink onto the form and means for forcing the ink through cells of the stencil to deposit the ink on the surface of the material being imprinted. In a known machine, disclosed in Japanese Application No. 55-34970, class B41M 1/12, published Mar. 11, 1980, the printing form is made in the form of a mesh covered with a layer of light-sensitive emulsion. Upon exposure of the emulsion through a photoform under the effect of UV radiation, the emulsion is hardened in the space portions of the mesh in the desired pattern. The unhardened portions of the emulsion are washed off. The hardened emulsion is subjected to setting by thermal treatment and is covered with a special composition to protect it against acids or alkalis.
In the process of printing, ink is applied to the form and is forced through the open cells of the mesh by a doctor blade to be transferred to the paper. After the printing is finished, hardened emulsion that was formed on the mesh is removed, and the mesh is again covered with a new layer of light-sensitive emulsion to prepare the next stencil.
A disadvantage of such machines is the necessity of making and setting up a printing form in order to print each run. This process is lengthy, per se. Furthermore, the trend in present-day polygraphy is characterized by small runs of publications, which causes the time necessary to prepare a machine for operation to become comparable to the time actually spent on printing. Thus, expensive equipment is used ineffectively.
In another prior art printing device, such as that disclosed in Browning et al., U.S. Pat. No. 3,798,365, ink is coated onto a printing form including a mesh having a plurality of cells. Ink is thermally ejected from selected cells onto the recording medium by sweeping a light beam across the mesh cells. The light beam heats up the entire volume of ink contained in a cell so as to evaporate the carrier liquid, whereupon the remaining ink particles are scattered onto the recording medium in a dry and heated state.
In scanning the light beam across the printing form, the disclosed apparatus controls whether or not ink is ejected from each cell by modulating the intensity of the light beam between a level capable of heating the ink carrier liquid to evaporation and a level which is not capable of such heating.
Because heat is used to release the ink from the mesh cells, the type of printing device disclosed in Browning is only capable of printing at a resolution of approximately 100 dpi, which is extremely inadequate for modern day printing applications.
SUMMARY OF THE INVENTION
The present invention provides a high resolution printing machine which, immediately after finishing printing a first publication, can begin printing a subsequent publication without replacement of the printing form.
This is achieved by providing a machine which includes a printing form made in the form of a mesh, which fills all the cells of the printing form with ink and which selectively forces the ink from selected cells by focusing to the size of a cell of the mesh and deflecting a light beam generated by a quantum generator, i.e., a laser beam, over selected cells in each row of the mesh according to a computer program executed by the machine. The laser beam produces the so called light hydraulic effect, wherein a small part of the liquid ink volume in the cell, e.g., its surface layer of 0.5-1.0 &mgr;m thickness of the liquid, develops enormous pressure when it is heated and that pressure provides an explosive shock to the remaining ink in the cell which transfers the remaining cold drop of ink out of the cell.
Operating the machine in this manner, the quantum generated light beam knocks out drops of ink from selected specified cells of the mesh onto the paper or other recording medium. Since the ink is applied to all the cells of the printing form mesh in each cycle of printing, there is no need to replace the printing form after each cycle, as is needed in the prior art.
Preferably, the machine additionally includes a beam diameter modulator in order to vary the zone of mesh cells which are simultaneously covered by the quantum generated light beam.
Such features enable the machine of the present invention to efficiently produce polygraphic matter with a wide range of color gradation.
Further, the printing machine is preferably provided with means for forcefully cleansing, from the mesh cells, ink which was not transferred onto the surface of the material being imprinted after completion of one deflection cycle of the light beam. This capability prevents the overfilling with ink of the mesh cells of the printing form which were not used in a previous printing cycle.
REFERENCES:
patent: 1668322 (1928-05-01), Kessler, Jr.
patent: 2590321 (1952-03-01), Huebner
patent: 3738266 (1973-06-01), Maeda et al.
patent: 3745586 (1973-07-01), Braudy
patent: 3798365 (1974-03-01), Browning et al.
patent: 3878519 (1975-04-01), Eaton
patent: 4210080 (1980-07-01), Gundlach
patent: 5130726 (1992-07-01), Fukushima et al.
patent: 6056388 (2000-02-01), Maximovsky
patent: 2452380 (1980-10-01), None
patent: 121802 (1958-12-01), None
patent: 1535742 (1990-01-01), None
patent: 9518020 (1995-07-01), None
Maximovsky Sergei Nikolaevich
Radutsky Grigory Avramovich
Cone Darius N.
Hilten John S.
Ostrolenk Faber Gerb & Soffen, LLP
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