Device for detecting fluorescent printed products on line of flexo printing machine

Abstract

The utility model relates to the technical field of fluorescent printing product detection equipment, in particular to a device for detecting fluorescent printing products on line by a flexo printing machine, which comprises a rack, the fluorescence detection unit comprises an image acquisition module, an image processing module electrically connected with the image acquisition module and a light source module for providing illumination for the image acquisition module, the image acquisition module is used for performing image acquisition on passing materials and then conveying the materials to the image processing module for image comparison with samples, and defective products are screened; through the detection of the equipment, online detection can be carried out on fluorescent printed products, defective printed products are found in real time, batch production of the defective products is avoided, the product yield is improved, and the labor cost can be saved under the condition that the detection precision is improved by adopting the automatic detection equipment.

Description

Technical Field

[0001] The utility model relates to the technical field of fluorescent printed product detection equipment, in particular to a device used for online detection of fluorescent printed products by a flexographic printing press. Background Art

[0002] Flexographic printing is a printing technology widely used in packaging, labels, wallpaper and other fields. However, printing defects may occur during the flexographic printing process, such as missing printing, ghosting, uneven color, etc. These problems will seriously affect the quality of the printed products. Therefore, quality inspection of printed products is an indispensable part of the flexographic printing process.

[0003] Traditional printed product quality inspection mainly relies on manual visual inspection, which is not only inefficient but also easily affected by human factors, resulting in missed inspections or false inspections. In recent years, with the development of machine vision technology, more and more automated inspection equipment has been used in printed product quality inspection. However, existing automated inspection equipment can often only detect surface defects of printed products. Due to the particularity of fluorescent printed products, ordinary lights cannot show fluorescent patterns, and special lights such as ultraviolet lights are required to assist in the appearance of fluorescent patterns. Manual inspection under the irradiation of ultraviolet lights will cause discomfort to personnel. A Chinese patent (application number 2017104043635) discloses an online fluorescence detection device, which includes a first excitation unit, a signal detection unit and a signal analysis unit. The first excitation unit is used to excite a first microfluidic chip channel to generate fluorescence and send the fluorescence to the signal detection unit. The signal detection unit is used to convert the fluorescence into an electrical signal and then send it to the signal analysis unit. The device can be used to perform fluorescence detection on the product, but the distribution of the light source in the detection process will affect the image acquisition of the camera. If the light source is too weak, the fluorescence characteristics cannot be displayed. If the light source is too strong, it will affect the camera's shooting effect, resulting in low efficiency and accuracy of fluorescence detection. Utility Model Content

[0004] The purpose of the utility model is to overcome the deficiencies in the prior art and provide a device capable of performing fluorescence detection on flexographic printed products, and to improve the detection accuracy by improving the equipment and the distribution of the light source.

[0005] The utility model is realized by the following technical scheme: a device for online detection of fluorescent printed products of a flexographic printing machine, comprising a frame, one end of the frame is provided with a conveying roller connected to a printing device, the other end is provided with a winding roller, and the middle part of the frame is provided with a fluorescent detection unit;

[0006] The fluorescence detection unit includes an image acquisition module, an image processing module electrically connected to the image acquisition module, and a light source module providing illumination for the image acquisition module.

[0007] Furthermore, the image acquisition module includes a mounting plate located above the rack, a camera for acquiring images is arranged on the mounting plate, and a protective cover is arranged outside the camera.

[0008] Furthermore, there are multiple cameras and they are evenly distributed along the length direction of the mounting plate.

[0009] Furthermore, the light source module includes a shell located below the image acquisition module, the upper part of the shell is provided with a connection cover connected to the image acquisition module, the middle part of the connection cover is provided with a light-transmitting plate corresponding to the position of the camera, and the lower part of the shell is provided with a purple light lamp facing the material to be detected.

[0010] Furthermore, a storage chamber for installing a lighting lamp is provided at the lower portion of the shell, and two ultraviolet lamps are provided in the storage chamber and are symmetrically distributed with the center line of the light-transmitting plate as the axis.

[0011] Furthermore, the light source module also includes a supplementary light source located below the material to be detected, and the supplementary light source is coaxially arranged with the light-transmitting plate.

[0012] Furthermore, the image processing module comprises a box body, an image contrast system is arranged inside the box body, and an alarm is arranged outside the box body.

[0013] Furthermore, the image processing module further comprises a signal processing component, and the signal processing component comprises a counting roller arranged between the image acquisition module and the winding roller, and an encoder and a marking machine are arranged on the counting roller.

[0014] The beneficial effects of the utility model are as follows: 1. The device for online detection of fluorescent printed products of the flexographic printing machine comprises a frame, a fluorescence detection unit is arranged in the middle of the frame, the fluorescence detection unit comprises an image acquisition module, an image processing module electrically connected to the image acquisition module and a light source module providing lighting for the image acquisition module, the image of the passing material is acquired by the image acquisition module and then transported to the image processing module for image comparison with the sample, and defective products are screened, and the detection of the equipment can be carried out on-line for fluorescent printed products, defective printed products can be found in real time, batch production of defective products can be avoided, and product yield can be improved, and the use of automated detection equipment can save labor costs while improving detection accuracy.

[0015] 2. The light source module includes a shell located below the image acquisition module, a connection cover connected to the image acquisition module is provided on the upper part of the shell, a light-transmitting plate corresponding to the position of the camera is provided in the middle part of the connection cover, a purple light facing the material to be detected is provided at the lower part of the shell, and a supplementary light source is also provided below the material to make the fluorescent characteristics on the material appear more clearly, which facilitates image acquisition and improves the accuracy of detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0017] Figure 2 It is a cross-sectional view of the utility model.

[0018] Among them: 1-frame; 2-conveying roller; 3-winding roller; 4-mounting plate; 5-camera; 6-protective cover; 7-housing; 8-connecting cover; 9-ultraviolet light; 10-storage chamber; 11-supplementary light source; 12-box; 13-alarm; 14-counting roller; 15-encoder; 16-marking machine. DETAILED DESCRIPTION

[0019] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] The following will be combined with the drawings in the utility model embodiments to clearly and completely describe the technical solutions in the utility model embodiments. Obviously, the described embodiments are only part of the utility model embodiments, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] Example 1

[0022] like Figure 1-2 As shown, a device for online detection of fluorescent printed products of a flexographic printing machine comprises a frame 1, one end of the frame 1 is provided with a conveying roller 2 connected to a printing device for conveying materials to be detected, and the other end is provided with a winding roller 3 for providing traction for the passage of the materials to be detected, and a fluorescence detection unit is provided in the middle of the frame 1;

[0023] The fluorescence detection unit includes an image acquisition module, an image processing module electrically connected to the image acquisition module, and a light source module providing lighting for the image acquisition module. The image acquisition module acquires images of the passing materials and then transmits them to the image processing module for image comparison with the samples to screen out defective products. The detection of the equipment can be carried out on-line for fluorescent prints, and defective printed products can be discovered in real time to avoid mass production of defective products and improve product yield. The use of automated detection equipment can save labor costs while improving detection accuracy.

[0024] The image acquisition module includes a mounting plate 4 located above the rack 1, on which a camera 5 for acquiring images is provided. A protective cover 6 is provided on the outside of the camera 5. The camera 5 adopts a high-speed camera, and the model used is an industrial-grade linear array camera imported from Germany—8K pixel CameraLink color industrial linear array camera. The linear array camera is equipped with a dalsa acquisition card software CamExpert for quick start operation, which is easy to install and debug.

[0025] There are multiple cameras 5 evenly distributed along the length direction of the mounting plate 4. The specific number of cameras 5 is selected according to the size of the material to ensure that the acquisition area can cover the inspection surface of the product.

[0026] The light source module includes a shell 7 located below the image acquisition module. A connecting cover 8 connected to the image acquisition module is provided on the upper part of the shell 7. A light-transmitting plate corresponding to the position of the camera 5 is provided in the middle part of the connecting cover 8. A purple light lamp 9 facing the material to be detected is provided at the lower part of the shell 7. The connecting cover 8 can protect the lens module. The connecting cover 8 is hollow in design to avoid blocking the lens of the camera 5 during shooting. The purple light lamp 9 uses a 365nm high-intensity purple light lamp 9 to facilitate the visualization of fluorescent characteristics.

[0027] A storage chamber 10 for installing a lighting lamp is provided at the lower part of the shell 7. Two ultraviolet lamps 9 are symmetrically distributed with the center line of the light-transmitting plate as the axis in the storage chamber 10. The ultraviolet lamps 9 are installed away from the light-transmitting plate to avoid affecting the image acquisition of the camera 5 when taking pictures.

[0028] The light source module also includes a supplementary light source 11 located at the bottom of the material to be detected. The supplementary light source 11 also uses a 365nm high-intensity ultraviolet lamp 9. The supplementary light source 11 is coaxially arranged with the light-transmitting plate and is located between the two upper ultraviolet lamps 9 to provide supplementary lighting for the middle area of ​​the material.

[0029] The image processing module includes a box 12, in which an image comparison system is arranged. After acquiring the template image, the image comparison system compares it with the image acquired by the camera 5, and stores information on defective products. An alarm 13 is arranged on the outside of the box 12. When a batch of defective products appears, the alarm 13 will sound an alarm to remind manual processing. The alarm 13 is located at the upper part of the box 12 and consists of an alarm light and a buzzer.

[0030] The image processing module also includes a signal processing component, which includes a counting roller 14 arranged between the image acquisition module and the winding roller 3. An encoder 15 and a marking machine 16 are installed on the counting roller 14. The encoder 15 can count the passing materials, and the marking machine 16 can mark the defective products when they are detected, so as to facilitate the distinction of defective products in subsequent operations.

[0031] During operation, the template image is input into the information processing module, and the camera 5 is used to collect images of the passing materials under the illumination of the ultraviolet lamp 9. The collected image information is transmitted to the image processing module and compared with the template image. When a defective product is detected, a signal will be sent to the marking machine 16 to mark the defective product for easy distinction in subsequent operations. When continuous batch defective products are detected, an alarm will be issued to remind manual intervention for processing. The template image can be modified or replaced in specific operations. Modifying the template means that during the detection process, if it is found that there are still a large number of false detections or missed detections after the detection accuracy is adjusted, it is necessary to modify the relevant detection area of ​​the template according to the actual detection situation. If the image template image used in modeling is a defective image, or the current product and the template are partially different, resulting in a large number of false alarms, the template can be replaced directly without rebuilding.

[0032] In actual use, the device also has a defect shielding function, that is, when a defect is always detected at a fixed place of the product, and the defect is acceptable, if the detection accuracy is increased, it may be missed in other areas. At this time, the defect shielding function can be used. Select the defect to be shielded in the defect image display area. At this time, the defect will be highlighted with a blue frame, and then click the [Shield] button to use the defect shielding function. After shielding, the defect here will no longer be reported.

[0033] Finally, it should be noted that the above is only a preferred embodiment of the utility model. This utility model patent is not only used for online fluorescence detection of flexographic printing machines, but can also be used for other printing equipment, such as Roland printing machines, CD printing machines, gravure printing machines and other printing equipment. In addition, although the utility model is described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned embodiments, or to replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A device for online detection of fluorescent printed products of a flexographic printing press, characterized in that: It comprises a frame, one end of which is provided with a conveying roller connected to a printing device, the other end of which is provided with a winding roller, and the middle part of which is provided with a fluorescence detection unit; The fluorescence detection unit includes an image acquisition module, an image processing module electrically connected to the image acquisition module, and a light source module providing illumination for the image acquisition module.

2. The device for online detection of fluorescent printed products of a flexographic printing press according to claim 1, characterized in that: The image acquisition module comprises a mounting plate located above the rack, a camera for acquiring images is arranged on the mounting plate, and a protective cover is arranged outside the camera.

3. The device for online detection of fluorescent printed products of a flexographic printing press according to claim 2, characterized in that: The number of the cameras is multiple and they are evenly distributed along the length direction of the mounting plate.

4. The device for online detection of fluorescent printed products of a flexographic printing press according to claim 1, characterized in that: The light source module includes a shell located below the image acquisition module, a connection cover connected to the image acquisition module is arranged on the upper part of the shell, a light-transmitting plate corresponding to the position of the camera is arranged in the middle part of the connection cover, and a purple light facing the material to be detected is arranged on the lower part of the shell.

5. The device for online detection of fluorescent printed products of a flexographic printing press according to claim 4, characterized in that: A storage chamber for installing a lighting lamp is arranged at the lower part of the shell, and two ultraviolet lamps are arranged in the storage chamber and are symmetrically distributed with the center line of the light-transmitting plate as the axis.

6. The device for online detection of fluorescent printed products of a flexographic printing press according to claim 5, characterized in that: The light source module also includes a supplementary light source located at the bottom of the material to be detected, and the supplementary light source is coaxially arranged with the light-transmitting plate.

7. The device for online detection of fluorescent printed products of a flexographic printing press according to claim 1, characterized in that: The image processing module comprises a box body, an image contrast system is arranged inside the box body, and an alarm is arranged outside the box body.

8. The device for online detection of fluorescent printed products of a flexographic printing press according to claim 7, characterized in that: The image processing module further comprises a signal processing component, and the signal processing component comprises a counting roller arranged between the image acquisition module and the winding roller, and an encoder and a marking machine are arranged on the counting roller.

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