JP2963336B2 - Printing monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print monitoring apparatus used for checking the print quality of a printed material in a printing process, and more particularly, to irradiating a printed material moving at high speed with a stroboscope and using a video camera. The present invention relates to a print monitoring device that displays a captured image of a printed matter as a still image on a television monitor.

[0002]

2. Description of the Related Art Conventionally, a print monitoring apparatus in which a video camera and a stroboscope are arranged on a printed material as shown in FIG. 3 has been used. Reference numeral 1 denotes a printed matter that has just been printed, and has a long web shape, for example, and is wound around a roller (not shown) and moves at high speed in front of the video camera 2. The video camera 2 faces the optical axis 3 so that the optical axis 3 is perpendicular to the front surface of the printed matter 1. The stroboscope 4 is arranged such that the optical axis 5 is aligned with the optical axis 3 of the video camera 2 on the surface of the printed matter 1.
It is fixed to cross at an angle of 5 °. And
The stroboscope 4 emits light intermittently in synchronization with the moving speed of the printed matter 1, and the image of the printed matter 1 captured by the video camera 2 is displayed as a still image on a television monitor (not shown) to monitor the finished state of printing. is there. Note that the stroboscope 4 is centered on the optical axis 3 of the video camera 2.
Another stroboscope is mounted at a position symmetrical to the above, and the optical axis of both stroboscopes intersects the optical axis 3 of the video camera 2 at a 45 ° angle on the surface of the printed matter 1 to make the entire printed matter 1 more even. Some are illuminated with high brightness.

[0003]

In some prints, the surface of the print layer is coated with a transparent varnish or other coating material. However, the transparent film formed by coating is hardly visible by the conventional illumination method, and has a drawback that it cannot be determined whether or not the coating is correctly performed.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a printing monitoring apparatus capable of reliably monitoring the printing state of a colored printing layer and a transparent film even if the printed matter has a transparent film coated on the colored printing layer. And

[0005]

According to the present invention, a first stroboscope and a second stroboscope are arranged on both sides of a video camera, respectively, and the optical axis of the video camera and the first and second stroboscopes are arranged.
The optical axis of the second stroboscope intersects at approximately one point, and the optical axis of the first stroboscope intersects the optical axis of the video camera at an angle of approximately 45 °,
Is characterized in that the optical axes of the stroboscopes intersect at an angle of 30 ° or less. Further, according to the present invention, in the print monitoring apparatus having the same configuration, the intersection angle between the optical axis of the second stroboscope and the optical axis of the video camera is set to at least 45 °.
It is characterized by a configuration that is variable within the following range.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, portions corresponding to those of the conventional example are denoted by the same reference numerals, and an embodiment of the present invention will be described with reference to FIGS. In these figures, 1 is a video camera 2
This is the printed matter immediately after printing, which moves at high speed before. The arrow A in FIG. 2 indicates the moving direction of the printed matter 1. As shown in FIG. 2, on both sides of the video camera 2, a stroboscope 4 and a stroboscope 6 are connected and attached by an arm 8. The video camera 2 is fixed to a pedestal 9, and the pedestal 9 is movable in the width direction of the printed matter 1 by a known method. As shown in FIG. 1, the video camera 2 faces the optical axis 3 of the printed matter 1 so that the optical axis 3 is perpendicular to the surface of the printed matter 1, and the optical axis 5 of the stroboscope 4 and the optical axis 7 of the stroboscope 6 are aligned with the printed matter 1. One point on the surface intersects the optical axis 3 of the video camera 2. On the other hand, the stroboscope 4 has an optical axis 5
It is fixed so as to keep an angle of 5 °. On the other hand, the other stroboscope 6 can adjust the angle α between the optical axis 7 and the optical axis 3 of the video camera 2 within the range of 10 ° to 45 °, that is, the position and the direction of the stroboscope 6 It is attached to the video camera 2 so that it can be adjusted.
Although a mechanism for adjusting the position and the direction of the stroboscope 6 is not shown, it is preferable that the stroboscope 6 can be remotely operated using a pulse motor or the like.

Next, a method of using the print monitoring device will be described. First, in the case of the printed matter 1 not coated with a transparent film, only one of the stroboscopes 4 emits light intermittently in synchronization with the moving speed of the printed matter 1, or the optical axis 7 of the stroboscope 6 is connected to the video. The stroboscope 6 is moved to the position shown by the two-dot chain line in FIG. 1 so that the angle α formed by the optical axis 3 of the camera 2 becomes 45 °, and both stroboscopes 4 and 6 emit light simultaneously. In this case, the printed matter 1 is illuminated under the same conditions as in the related art, so that the printing state can be monitored on the television monitor as in the related art. On the other hand, when the print 1 is a print 1 in which a transparent coating is applied on a colored print layer, the angle α between the optical axis 7 of the stroboscope 6 and the optical axis 3 of the video camera 2
However, the stroboscope 6 is moved to, for example, 20 °, so that the stroboscope 4 and the stroboscope 6 emit light. Then, the light of the stroboscope 6 having different irradiation angles is applied, so that the coated transparent film comes to appear. However, in this case, the surface of the colored print layer becomes difficult to see because the surface shines, so that the printing state of the colored print layer is monitored with the stroboscope 6 turned off. As described above, by switching the stroboscopes 4 and 6 between simultaneous light emission and light emission only from the strobe scope 4 at any time, it is possible to check both the printing state of the colored printing layer and the coating state of the transparent film on a television monitor. Can be.

The angle α between the optical axis 7 of the strobe 6 and the optical axis 3 of the video camera 2 is adjusted according to the thickness of the coated transparent film. It is difficult to reduce the angle α because it is limited by the size and shape of the video camera 2 and the stroboscope 6. However, even if the angle α is smaller than 10 °, the transparent film can be confirmed. As the angle α approaches 45 °, the amount of reflected light decreases and the transparent film gradually becomes less visible. A practical range of the angle α at which the quality of the print of the transparent film can be easily determined is 30 ° or less. The stroboscope 6 may be configured so as to be fixed at one angle α selected from this range, but if it can be changed within a range of 30 ° or less, it can correspond to various coating layers, increases the degree of freedom, and is easy to use. . Further, as in the above embodiment, the angle α
Can be adjusted within a range of 45 ° or less, and even when the stroboscope 6 is moved to 45 ° even when the stroboscope 6 is also used for the uncoated printed matter 1, illumination that is uniform in the overall brightness can be advantageously achieved. It is.

[0009]

According to the present invention, even if the printed matter is coated with a transparent film, the printed state of the colored print layer and the transparent film can be easily recognized on the screen of the television monitor, and whether the coating has been performed correctly. Can be reliably determined. If the angle α between the optical axis 7 of the stroboscope 6 and the optical axis 3 of the video camera 2 can be adjusted within a range of 45 ° or less, it can be used for uncoated prints and used as in the past. There is also an effect that can be done.

[Brief description of the drawings]

FIG. 1 is a plan view showing a positional relationship of a main part of a printing monitoring apparatus according to the present invention.

FIG. 2 is a perspective view of a main part of the print monitoring apparatus.

FIG. 3 is a plan view showing a conventional configuration example.

[Explanation of symbols]

 2 Video camera 3.5.7 Optical axis 4.6 Stroboscope

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01N 21/84-21/91 B41F 33/14

Claims (2)

(57) [Claims] 1. A print monitoring apparatus for irradiating a moving printed matter with a stroboscope and displaying an image of the printed matter taken by a video camera as a still image on a television monitor,
A first stroboscope and a second stroboscope are respectively arranged on both sides of the video camera, and the optical axis of the video camera and the optical axes of the first and second stroboscopes intersect at substantially one point. For the axis,
A print monitoring device, wherein the optical axes of the first stroboscope intersect at an angle of approximately 45 ° and the optical axes of the second stroboscope intersect at an angle of 30 ° or less. 2. A print monitoring apparatus that irradiates a moving printed matter with a stroboscope and displays an image of the printed matter taken by a video camera as a still image on a television monitor.
A first stroboscope and a second stroboscope are respectively arranged on both sides of the video camera, and the optical axis of the video camera and the optical axes of the first and second stroboscopes intersect at substantially one point. Crosses the optical axis of the video camera at approximately 45 ° with the optical axis of the video camera.
A print monitoring device, wherein an intersection angle between an optical axis of a second stroboscope and an optical axis of a video camera is variable at least within a range of 45 ° or less.