JP3799723B2 - Cylinder inspection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for inspecting the positional relationship of images that should be relatively at the same position on the surfaces of a plurality of cylinders. For example, an image of a resist resist before etching a cylinder for gravure rotary printing (register mark) ).
[0002]
[Prior art]
Conventionally, there has been no apparatus and method for accurately checking whether images, marks, characters, etc. are relatively at the same position on the surface of a plurality of cylindrical cylinders. Therefore, as an example, a cylinder inspection in the process of producing a plate cylinder for gravure rotary printing using etching will be described.
FIG. 2 is an explanatory view showing a state where the development is completed by transferring the corrosion resistant resist 10 to the cylinder 11 for gravure rotary printing. Ordinary gravure rotary printing (for publishing) performs color printing with four plates: yellow plate, red plate, indigo plate, and black plate. If the images of each color plate are not accurately overlapped in printing, the colors will blur and become unsightly images with no sharpness, resulting in defective products. Usually, 16 pages, 24 pages, 36 pages, 48 pages, 72 pages, etc. are attached to one cylinder. Divide them into 4-page units and assign them to cylinders.
[0003]
FIG. 3 is a developed view of the peripheral surface of the cylinder 11 of FIG. Four anticorrosive resists 10 are transferred onto the cylinder peripheral surface 12 in units of four pages and developed. A register mark 13 is provided to superimpose the color plates, and if all the register marks 13 match exactly, the images match. However, until the state shown in FIG. 3, a dichromate photosensitive material made of a pigment such as gelatin and bengara is applied to a polyester base, sensitized with an aqueous solution of potassium dichromate and dried, and a positive film is baked onto the cylinder. There are many factors that cause inaccuracy, because it must be transferred in two parts, developed with warm water and dried. If this is not checked, the exposed part of the cylinder surface is covered with a corrosion-resistant varnish, etched with a corrosive solution, and printed on a printing machine following the normal process. I don't know if this is the cause of the printing or not, and after the extra loss time and defective print, the plate cylinder has been reworked and the loss is immeasurable.
[0004]
Therefore, conventionally, the register mark 13 is marked with a transparent film, and the distance between A4 and C1, B4 and D1, A3 and B2, C3 and D2, etc. that the register mark 13 is close to is visually measured. However, it was measured with a beam compass such as A2 and A3, A2 and B3, etc., but since it was a visual measurement, an error due to individual differences and the like were put into reliability.
[0005]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide an apparatus capable of accurately and objectively measuring the positional relationship between images that should be relatively at the same position on the surfaces of a plurality of cylinders having a cylindrical surface. .
[0006]
[Means for Solving the Problems]
According to the invention of claim 1, the relative positional relationship between the plurality of cylinders of each of the plurality of images that should be at the same relative position on the surfaces of the plurality of cylinders having a cylindrical surface is determined. A device for inspecting, wherein the cylinder has a center and parallelism, a means for rotatably mounting, a means for capturing the plurality of images, a position detection means in the surface length direction of the cylinder, means for storing the circumferential position detecting means of the cylinder, the each position measured measurement values of the plurality of images from a reference point set at a point on the surface of said cylinder, said plurality of cylinders Means for calculating a difference between a measured value of each position of the plurality of images on the reference cylinder and a measured value of each position of the plurality of images on another cylinder, and the calculated measurement And means for outputting a difference between a cylinder inspection apparatus characterized by comprising. With the above configuration, it is possible to objectively and accurately measure the positional relationship between images that should be at the same position on a plurality of cylinders. As a result, it can be determined whether the measurement result is within an allowable range, and the defective cylinder can be prevented from being passed to the next process or the like. Further, since the difference is output by performing a comparison operation with the cylinder based on the raw data, it is possible for the operator to easily determine whether or not it is within an allowable range. Note that the output can be done in any way such as on a CRT or printer output or both. In addition, it is possible to change the color or warn with a voice if it exceeds the allowable range.
[0007]
In the invention of claim 2, in measuring the positions of the plurality of images on the surfaces of the plurality of cylinders, the reference points of the second and subsequent cylinders are set based on the measurement points taught when measuring the first cylinder. 2. The cylinder inspection apparatus according to claim 1, further comprising means for automatically measuring the subsequent items. This is because, by setting a reference point and teaching a measurement point at the first time, the same set of cylinders can automatically measure the reference point and subsequent points.
[0008]
According to a third aspect of the present invention, in the cylinder inspection apparatus according to the first or second aspect, the image that should be at the relatively same position is a register mark used when the color plates are overlapped by printing. is there.
If there is a characteristic point in the image on the cylinder, it can be used as a measurement point, but if there is no characteristic point, a register mark (a cross mark is often used, but there are various shapes ) Is easy to measure and accuracy is improved.
[0009]
According to a fourth aspect of the present invention, in the cylinder inspection apparatus according to the second or third aspect, the display output by the output means is expressed on a developed view of a cylindrical peripheral surface of the cylinder. is there.
With the output form as described above, the operator can instantly recognize which position of the image (or the register mark) on the cylinder is shifted from the normal position and in which direction. In this case, the shift amount can be output in the shift direction, or the color of the register mark may be changed for each cylinder, and the positional relationship may be illustrated on the developed view. Of course, it may be drawn on paper or the like.
[0010]
According to a fifth aspect of the present invention, the cylinder is a cylinder for a gravure rotary printing press, and the image is formed of a corrosion-resistant resist on the surface of the cylinder. The cylinder inspection device according to any one of the above.
This is limited to a form that can be used immediately. Even if it is limited to the above-mentioned applications, the number is several thousand per month, and the effect of using the apparatus of the present invention is extremely large.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments will be described in detail with reference to the drawings.
FIG. 1 is an external explanatory view showing an embodiment of the present invention. The cylinder inspection apparatus 1 is mounted by means 14 for mounting the cylinder 11 rotatably while maintaining the center and parallelism. The means 14 for rotatably mounting is provided with a position detection means 3 in the circumferential direction of the cylinder and a position detection means 2 in the surface length direction of the cylinder. A camera 9 that moves on the surface length direction position detecting means 2 of the cylinder is provided, and the camera 9 captures an image on the cylinder 11. The movement of the camera 9 is performed by the movement handle 7 and the fine adjustment thereof is performed by the fine adjustment handle 8. The camera 9 uses a CCD camera, for example, and is set so as to face the axis center of the cylinder 11 with a laser displacement meter or the like. The focal length is also adjusted.
[0012]
The rotation mounting means 14 employs a conventionally used mechanism such as a lathe or a grindstone polishing apparatus. Set at the center of the cylinder 11 axis and adjust by adjusting the parallelism and cylindricity finely, or by using the inner race that fits the bearing of the cylinder 11 printing machine, and finely adjust the parallelism and cylindricity. There is a way to correct it.
[0013]
Although the encoder is used as the position detection means 3 in the circumferential direction of the cylinder, it is not limited to this. A linear scale or the like can be used as the surface length direction position detecting means 2 of the cylinder.
[0014]
The measured value is displayed on the digital display panel 4. The monitor 5 displays the image projected by the camera and can be confirmed visually. The measurement result is stored in a memory which is a storage means and can be displayed on the touch panel 6. If necessary, it can be output to a paper medium by a printer.
[0015]
FIG. 4 shows the measured values of the register mark 13 of the gravure cylinder having the same layout as FIG. Four cylinders were measured: yellow plate, red plate, indigo plate, and black plate. One reference point was provided for each cylinder (not necessarily at the same position), and A1 to D4 were measured as X and Y coordinates from the reference point. In the figure, B2 and subsequent parts are omitted.
[0016]
FIG. 5 shows the difference obtained by calculating the raw data of FIG. This indicates how much the register mark of the other symbol is shifted from the reference when the register mark (A1) is matched with the red plate as a reference.
Colors that are larger than a printing tolerance of about 0.08 mm (80 μm) can be changed in color or a warning mark can be added. Also, a warning by voice or the like is possible.
In the calculation formula, a reference value (for red plate) is subtracted from each measured value, and the value of A1 of each plate may be adjusted so as to be zero.
It is also possible to obtain the sum of squares of the deviation amount with reference to A1, A2, A3,..., D4 in order, and use the one with the smallest sum of squares as a reference.
[0017]
FIG. 6 shows an embodiment of display on the touch panel 6. In the drawing, a difference number is displayed on the development view in positions of four quadrants shifted in the X direction and the Y direction. In addition, yellow, red, indigo, and black can be displayed on the development with register marks.
[0018]
Although the measurement can be performed manually, it is also possible to set a reference point, teach the measurement point at the first time, and automatically perform measurement after setting the reference point for the same set.
[0019]
【Example】
Embodiments will be described below with reference to the drawings.
A cylinder inspection apparatus having a configuration as shown in FIG. 1 was produced. A linear scale is provided as a cylinder surface length direction position detection means 2 on a frame similar to a lathe, and an encoder is used as the cylinder circumferential direction position detection means 3. As a camera 9, a CCD camera is integrated with a linear scale, and the position of lateral movement can be measured. An image such as a register mark can be captured by the camera 9, and the center of the camera can be adjusted to a predetermined position of the register mark.
[0020]
The cylinder set was fixed to the inner race of the cylinder with bearings, and an encoder was attached to the rotating shaft. The image of the camera 9 was displayed on the monitor 4, and the position measurement value was displayed on the digital display panel 4. Although not shown, there are a computer and a storage device, and data storage and calculation are performed. The measured value and the display after calculation can be displayed on the touch panel 6. 4-6 is an example implemented with this apparatus.
As a result, what has been subject to individual differences by visual inspection can be objectively captured as numerical values, and quality assurance for the subsequent process can be reliably performed.
[0021]
【The invention's effect】
According to the first aspect of the present invention, it is possible to objectively and accurately measure the positional relationship between images that should be at the same position on a plurality of cylinders. As a result, it can be determined whether the measurement result is within an allowable range, and the defective cylinder can be prevented from being passed to the next process or the like. Further, since the difference is output by performing a comparison operation with the cylinder based on the raw data, it is possible for the operator to easily determine whether or not it is within an allowable range.
[0022]
According to the invention of claim 2, by setting the reference point and teaching the measurement point at the first time, the same set of cylinders can automatically measure the reference point and subsequent cylinders.
[0023]
In the invention of claim 3, if there is a characteristic point in the image on the cylinder, it may be used as a measurement point. However, even if there is no characteristic point, a register mark (a cross-shaped one is often used). , Various shapes are provided separately to make the shape easy to measure, the measurement is easy and the accuracy is improved.
[0024]
In the invention according to claim 4, when the output form is used, the operator can instantly recognize which position of the image (or the register mark) on the cylinder is deviated from the normal position in which direction. In this case, the amount of displacement can be output in the direction of displacement, or the color of the register mark can be changed for each cylinder, and the positional relationship can be shown on the development view. Of course, it may be drawn on paper or the like.
[0025]
The invention of claim 5 is limited to a form that can be used immediately. Even if it is limited to the above-mentioned applications, the number is several thousand per month, and the effect of using the apparatus of the present invention is extremely large.
[Brief description of the drawings]
FIG. 1 is an external explanatory view of a cylinder inspection apparatus showing an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing a state in which a corrosion-resistant resist is provided on a gravure cylinder.
FIG. 3 is an explanatory diagram of development of the peripheral surface of the gravure cylinder of FIG. 2;
FIG. 4 is a chart showing a measurement example of the cylinder inspection machine of the present invention.
FIG. 5 is a chart after the calculation of the chart of FIG. 5;
FIG. 6 is an output example of the measurement result of the cylinder inspection machine of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Cylinder inspection machine 2 ... Cylinder surface length direction position detection means 3 ... Cylinder circumferential direction position detection means 4 ... Digital display panel 5 ... Monitor 6 ... Touch panel 7 ... Movement handle 8 ... Fine adjustment handle 9 ... Camera 10 ... Corrosion resistant resist 11 ... Cylinder 12 ... Cylinder peripheral surface 13 ... Register mark 14 ... Means for mounting rotatably

Claims (5)

An apparatus for inspecting the relative positional relationship between a plurality of cylinders, each of a plurality of images that should be relatively at the same position on the surfaces of a plurality of cylinders having a cylindrical surface, A cylinder center of the cylinder and a means for rotatably mounting the parallelism; a means for capturing the plurality of images; a position detecting means for the surface length direction of the cylinder; and a circumferential position of the cylinder means for storing a detection means, the each of the positions determined measured values of the plurality of images from a reference point set at a point on the surface of the cylinder, cylinder as a reference among the plurality of cylinders Means for calculating a difference between a measured value at each position of the plurality of images above and a measured value at each position of the plurality of images on another cylinder; and a means for outputting the difference between the calculated measured values. Cylinder inspection apparatus characterized by the, the equipped. In measuring the positions of a plurality of images on the surfaces of the plurality of cylinders, a means for automatically measuring the reference points of the second and subsequent cylinders based on the measurement points taught during the measurement of the first cylinder. The cylinder inspection apparatus according to claim 1, further comprising: 3. The cylinder inspection apparatus according to claim 1, wherein the plurality of images that should be at the same relative position are register marks used when the color plates are overlapped by printing. The cylinder inspection apparatus according to any one of claims 1 to 3, wherein the display output by the output means is represented on a developed view of a cylindrical peripheral surface of the cylinder. 5. The cylinder according to claim 1 , wherein the cylinder is a cylinder for a gravure rotary printing press, and the plurality of images are formed of a corrosion-resistant resist on a surface of the cylinder. of the cylinder inspection equipment.

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