JPS6255136B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a technique for producing cut masks for printing plates in the printing industry.

Conventionally, when printing flyers, etc., a basic block and multiple cut masks are created due to color separation, etc., and these blocks and cut masks are created by skilled workers or by using a knife, etc. This was done by cutting and peeling the strip film.

Recently, this type of work has been automated using automatic drafting devices. For example, it is now possible to automatically draw a printing plate using a drafting device such as the applicant's microphone sensor type interactive reading and drafting device. It is being done.

In addition, the automatic drawing mechanism is being improved to include a cutter instead of a pen to automatically perform mask cutting work. However, as shown above, the cut mask is automatically cut, and the drawing is automatically drawn on the stencil mount.
Positive films, which are produced through processes such as phototypesetting and photographing with a camera, have problems such as positional deviations and color deviations in printing due to dimensional errors.

In addition, in the actual process of printing, including monochrome printing, it is more efficient to install a large number of automatic drafting devices, rather than installing a large number of expensive automatic drafting devices with cutting functions. From this point of view, it is preferable that even if the device for automatically drawing on a mount and the device for automatically cutting are different, continuous work can be performed freely regardless of differences in drawing characteristics between the devices.

The present invention has been developed in view of the above-mentioned circumstances, and enables the production of a cut mask by automatic drawing on a base board and automatic cutting with sufficient precision for actual work and extremely efficiently.

The present invention will be explained in detail with reference to one example below.

As shown in FIG.
A document for printing is placed on the reading table 11 of the reading device 10 of a TV monitor type layout system, etc., as described in the specification of No. 139134 (Japanese Unexamined Patent Publication No. 57-63534) ``Method for printing flyers, catalogs, etc.'' 1, and operate the instruction cursor 12, keyboard 13, etc. of the reading device 10 to input position information and various function information to generate drawing data for drawing the block. ) is recorded in the drawing data file 30a in the drawing floppy disk 30.
Incidentally, the drawing data includes data related only to block drawing, such as registration mark drawing data, various hit line data, and various wire diameter data, and data related to drawing and cutting, such as circle, ellipse, rectangle, and various framework data for photo trimming. The index is composed of the following data, each with an index indicating the type of data.

In the preparation of the block, the drawing data floppy disk 30 obtained in this way is transferred to the drawing device 40.
The plotting data is read from the plotting data file 30a by input device 41a including a floppy disk drive. The plotting device 40a operates according to the X, Y coordinate values, pen up, pen down, etc. commands indicated by the plotting data, and automatically plots on the master mount 50 placed on the plotting table 42a. conduct.

On the other hand, in producing a cut mask, the drawing floppy disk 30 is moved to a floppy disk drive A (14a), and the cut floppy disk 31 is moved to a floppy disk drive B (14b).
Then, the cutting data converting means 20 reads the drawing data from the drawing data file 30a, and performs coordinate conversion processing on the cutting-related data and format conversion processing corresponding to the corresponding cutting function-equipped drawing device 40b, as will be described later. Thereafter, the obtained cutting data is recorded in the cutting data file 31a in the cutting floppy disk 31. An input device 41 including a floppy disk drive of a drawing device 40b with a cut function for cutting the cut floppy disk 31 obtained in this way.
Then, the cut data is read from the cut data file 31a. The cutting function-equipped drawing device 40b performs X,
It operates according to commands such as Y coordinate value, cutter up, cutter down, etc., and automatically cuts the strip film 60 placed on the drawing table 42b while controlling the direction of the cutter based on changes in the coordinate value. After cutting, the required portions of the strip film are peeled off to obtain a cut mask.

According to the method of the present invention, the drawing device 40a for drawing the block and the drawing device 40b with a cutting mechanism for cutting the strip film do not necessarily have to be separate devices.

By the way, in the above-mentioned series of operations using a combination of a positive film obtained from an automatically drawn block mount and an automatically cut cut mask, if the block and cut mask are drawn on the same scale, It has been found through many work examples that in many cases, the positions of those figures in the final printed matter are shifted and the respective figures do not correspond exactly. As a result of elucidating the cause of this discrepancy,
It was found that the following is true. In other words, the main reason is that the block copy is drawn on a mount, and it takes a relatively long time for the block copy to be photographed with a plate-making camera, and phototypesetting, etc. is adhered to the surface of the block mount using glue (water-based). Therefore, the stencil mount slightly expands and contracts due to moisture absorption, changes over time, etc., resulting in a change in the scale of the stencil figure.

The second reason is that after phototypesetting, etc. are adhered to this block as described above, it is imaged at the same magnification with a plate-making camera, and then a cut mask and positive film are superimposed. Spherical aberration occurs, and the scales of the block pattern and cut mask pattern do not match. (Note that since the mask figure is drawn on a strip film made of plastic film, its expansion and contraction is extremely small.) The expansion and contraction of the above-mentioned printing mount is approximately as follows.

For example, with the product name Matsut Color White (manufactured by Sanyo Kokusaku Pulp) paper with a paper weight of 220 kg, the paper size is 600 mm x 400 mm, and the maximum width in both the vertical and horizontal directions is 0.5 mm to 0.8 mm, depending on the humidity situation. There is growth. (This is a maximum of 0.2% when converted to a percentage.) Also, the expansion and contraction due to spherical aberration in the plate-making camera is
It depends on the camera model, but it is about ±5/100mm, so it is not a big problem at present, but the same quality will become stronger with the passage of time, and it will gradually become a problem.

Furthermore, assuming that the device that automatically draws the block copy and the device that automatically cuts the peel film are different for the reasons mentioned above, the relative dimensional error between them is currently about 0.2% at most, which poses a major problem. Further, the relative perpendicularity error is usually less than 0.1, which is a small value, but it becomes a problem when the plate size is large.

For these reasons, it is not possible to simply add a cutting function to a drawing device as has been done in the past.
It is unsuitable as an actual printing process for large-sized printed matter or high-quality printed matter.

Therefore, in the method of the present invention, the cutting data converting means 20 compensates for errors by performing coordinate conversion processing including scaling on the coordinate data in the drawing data file 30a. A corresponding format conversion process is performed to generate a cut data file 31a, and the cut floppy disk 31 having the cut data file 31a is used to automatically cut a strip film using a corresponding plotting device with a cutting mechanism. .

Here, coordinate transformation including enlargement/reduction is generally performed by multiplying each coordinate data by a transformation matrix, but especially when the above-mentioned perpendicular error, spherical aberration, etc. are taken into consideration, 130265
This can be easily done according to the conversion method described in the specification of Japanese Patent Application Laid-Open No. 56-53074. Further, when setting compensation parameters (expansion ratio, shear ratio, etc.) corresponding to the conversion matrix, it is sufficient to measure and evaluate errors occurring during the above-mentioned work process in advance.

Since the present invention has the above-described configuration, it is possible to automatically draw a draft by simply reading an input manuscript once with a reading device at a plate making site, and to create a sheet with a cutting mechanism different from that of the drafting device at a plate making site. The device can automatically cut the peel film,
Furthermore, in this series of steps, it is possible to obtain desirable printed matter with very little pattern deviation, color deviation, etc., even for printed matter with a large plate size, as described above.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an explanatory diagram showing the steps of the present invention. 10...Reading device, 20...Cut data conversion means, 30...Drawing floppy disk, 30a
...Drawing data file, 31...Cut floppy disk, 31a...Cut data file, 40...Drawing device, 50...Drawing mount, 6
0... Strip film.

Claims (1)

[Claims] 1 Read the original 1 using the reading device 10 to obtain the drawing data file 30a, input the drawing data to the automatic drawing device 40 to automatically draw the block, and compensate for at least the error between the positive film and the cut mask. A cutting data file 31a is obtained from the drawing data file 30a by performing a coordinate transformation process via a cutting data converting means 20 having a coordinate transformation function capable of setting error compensation parameters, and the cutting data is converted into an automatic plotting apparatus with a cutting function. 40b and performs automatic cutting to obtain a cut mask.