JPH047917B2 - - Google Patents

Abstract

A paper sheet or a web is printed in accordance with (e.g.) the offset printing process at 1. Subsequently a part of the print is removed at predetermined points under the influence of applied energy at 7. The intensity of the energy and its direction are controllable. The energy can be modulated laser light, visible, IR or UV light, ultrasonic energy or a combination. <IMAGE>

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for applying individual markings to printed matter by the action of energy during a printing operation.

[Conventional technology]

A printing press produces a large number of printed sheets of information with the same content. On the other hand, by means of a numbering device, it is possible, for example, to print one or several additional symbols on each sheet, which change from sheet to sheet. This creates original documents that are slightly different from each other. Numbering machines are limited by their floor space requirements, mechanical costs and slow printing speeds.
Its use is restricted.

A printing method is known from German Patent Application No. 27 25 093, in which a latent image is created on the printing substrate by the action of energy, which can be seen by a development process. The energy beam can be changed quickly and easily, thereby making it weaker or more powerful. Separate plates are therefore not required and the printing substrate selectively takes up dampening water or printing ink. The resulting originals, printed using the offset method, can be completely different from each other. This particular method requires expensive substrates, since it is costly to coat the entire surface of the substrate prior to printing.

One method is described in DE 30 38 044 A1, in which the printing paper is first coated with an electrically insulating liquid. after that,
An electrically conductive liquid is applied to the pre-coated paper, after which this liquid is removed back under the action of a network-shaped electric field. This is followed by printing using the offset method.
This coating prior to printing has proven to be very expensive and labor intensive.

German Patent Specification No. 2501793 describes a printing press in which no surface coating is applied, but the printing ink is applied to plain paper. The desired effect of having different information on each sheet of paper is possible with the inkjet method. A particular disadvantage of this method is that the ink in this case has a low viscosity and cannot be used to print on any substrate, and the ink tends to dry at the nozzle opening while the ink is not flowing. This can cause erratic driving.

Changing information using laser light is described in West German Patent Application No. 2043140 as a method for color copying onto paper.
In this method, an offset printing plate, in this case a so-called intermediate image copy (Zwischenkopietr¨a
ger), a laser light that is controlled to form an image is used to constantly change the image. Of course, if it becomes necessary to change the content of the information to be given to the printed material, the plate must be immediately replaced with a new one. The necessity of replacing intermediate image copies makes this method very expensive.

[Problem to be solved by the invention]

It is an object of the present invention to reduce the cost of individually labeling printed products inside a printing press, to avoid the expensive work of pre-coating them elsewhere, and to make it possible to read desired additional information. It is an object of the present invention to provide a method for individualizing printed matter by varying the printed sheet or web from place to place.

[Means to solve the problem]

This object is solved by claim 1.

[Effect]

Under the action of energy at predetermined locations, the printing ink is removed back from the paper surface, so that either the original white side of the paper or the underlying ink layer is exposed. This allows various information to be written extremely quickly on expensive printed matter.

Font dimensions such as height, width, and typeface can be quickly changed in this way. By using suitable peripherals, such as a computer, the energy effects can be controlled. This device can replace traditional address printing machines and expensive numbering devices. Therefore, the information stored in a retrievable manner can be transferred directly to the printed material.

Note that in order to generate an energy effect, any one of laser light, visible light, infrared rays, ultraviolet rays, and ultrasonic waves can be used.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

The printing press shown in FIG. 1 shows a final stage offset printing device 1 with an inking device 2 and a dampening device 3, as is known in the art.

The sheets are fed in register via cylinders 4 and 5 to impression cylinder 6 of this final stage offset printing device 1.

At a location 7, shown here after the location where the final printing takes place, the sheet is irradiated with laser light. For this purpose, the laser light source 8 is modulated from the memory 9. The memory 9 stores information to be written by means of a laser beam. The laser beam removes the ink layer on the paper at predetermined locations, so that the original white side of the paper or the underlying ink layer reappears.

After the information has been transferred to the already printed sheets, the sheets are fed to a delivery pile 11 by the action of a delivery chain 10.

With the offset printing device 1, it is also possible to print on an already printed sheet an information writing surface that partially or completely covers the paper surface. This type of surface coating consists of inks or similar materials particularly suited for this purpose. . Additional information is written on this predefined uniform surface of arbitrary size by means of a laser light source 8 . The size and shape of this coating surface is determined by the printing plate.

〔Effect of the invention〕

As explained above, the present invention removes printing ink from sheets or webs on which final printing has been carried out by an energy action that creates individually different images, and by attaching individual markings to the printed matter, There is an advantage that the expensive work of pre-coating at another location is not required, and various information can be written extremely quickly.

[Brief explanation of drawings]

FIG. 1 shows a printing unit in the last stage of a printing press, which is equipped with a device for energetically applying individual markings. 1... Offset printing device, 2... Inking device, 3... Dampening device, 4, 5... Cylinder, 6... Impression cylinder, 7... Individual writing location, 8... Laser light source, 9... Memory, 10... Paper ejection chain, 11
...Paper output pile.

Claims (1)

[Scope of Claims] 1. A method of applying individual markings to printed products during a printing operation by means of an energy effect, which involves applying a controllable energy effect to a printed sheet or a printed web, in order to A method of individually marking printed products, in which the printing ink is removed at a predetermined location 7 behind the location where printing takes place by means of an energetic action that produces individually distinct images. 2. The method of claim 1, wherein the energy effect is produced by modulated laser light. 3. The method of claim 1, wherein the energy action is caused by visible light, infrared light, ultraviolet light, or ultrasound.