Inspection device and inkjet printer provided with the same

Abstract

To enable accurate inspection by suppressing noise caused by reflection light by a conveyance roller.SOLUTION: An inspection part 43 is configured so that a black tape for absorbing light from an upper reflection light source 51b, a lower reflection light source 51c and a transmission light source 53 is wound around an outer peripheral surface of conveyance rollers 45 and 47. Accordingly, reflection of the emitted light by a lower side outer peripheral surface of the conveyance roller 45 and an upper side outer peripheral surface of the conveyance roller 47 is suppressed. As a result, noise in a photographing part 51 caused by reflection light by the conveyance rollers 45 and 47 can be suppressed. Therefore, accurate inspection in the inspection part 43 can be performed. Cost can be reduced by configuration of the black tape. The configuration that only the black tape is wound can be also easily applied to an existing device.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an inspection device that reads an image on a transparent print medium being transported by a transport roller to inspect the print condition, and an inkjet printing device equipped with the same. [Background technology]

[0002] Inkjet printing devices that print images on print media by ejecting ink droplets are susceptible to various defects, such as defects caused by ejection such as nozzle chipping, lateral jumping of ink droplets, ejection of ink at times other than the designated timing (so-called dripping), defects caused by transportation such as skewing, meandering, and wrinkles of the print medium, ink flow defects caused by poor drying of ink droplets, and contamination due to re-adhesion caused by contamination of the rollers due to ink flow, etc. For this reason, inspection devices are used to inspect printed images.

[0003] Conventionally, this type of device includes a light source and a reading sensor (see, for example, Patent Document 1). The light source and the reading sensor are arranged on the same surface of the print medium. Light emitted from the light source is reflected by the print medium and enters the reading sensor.

[0004] In this configuration, if the print medium is transparent, the reflected light passes through the transparent parts, making it difficult to distinguish between the image parts printed in black ink and the transparent parts. As a result, there is a problem that accurate inspection is not possible when the print medium is transparent.

[0005] Therefore, there is a device that includes an imaging unit, a first irradiation unit, and a second irradiation unit (see, for example, Patent Document 2). The first irradiation unit is disposed facing the imaging unit with the print medium in between. The second irradiation unit is disposed on the same side as the imaging unit. This allows transmitted light from the first irradiation unit to be incident on the imaging unit. Reflected light from the second irradiation unit to be incident on the imaging unit. Therefore, accurate inspection is possible even if the print medium is transparent. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6010980 (Figure 1) [Patent Document 2] JP 2019-142007 A (Fig. 5) Summary of the Invention [Problem to be solved by the invention]

[0007] However, the conventional example having such a configuration has the following problems. That is, in the conventional device, conveying rollers are arranged on the upstream side and downstream side of the photographing unit. Therefore, strong reflection occurs at the conveying roller, especially when the outer circumferential surface of the conveying roller is silver. Therefore, noise due to the reflected light at the conveying roller occurs in the photographing unit, which may hinder accurate inspection. This problem may occur even in a configuration that does not include a second irradiation unit that is a light source of reflected light.

[0008] The present invention has been made in consideration of the above circumstances, and aims to provide an inspection device and an inkjet printing device equipped with the same that can perform accurate inspection by suppressing noise caused by light reflected by the conveying roller. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention has the following configuration. That is, the present invention provides an inspection device that reads a printed image printed on a transparent printing medium and inspects the printing condition, comprising a first transport roller that transports the transparent printing medium, a second transport roller that is spaced apart from the first transport roller and arranged downstream in the transport direction and transports the transparent printing medium, a photographing unit that is arranged between the first transport roller and the second transport roller and is arranged on one side of the transparent printing medium and photographs a printed image located in an inspection area set between the first transport roller and the second transport roller, and a light irradiation unit that irradiates light to photograph the printed image located in the inspection area by the photographing unit, and is characterized in that the outer surfaces of the first transport roller and the second transport roller are made of a light absorbing material that absorbs light from the light irradiation unit.

[0010] [Actions and Effects] According to the present invention, the outer circumferential surfaces of the first and second conveying rollers are made of a light absorbing material that absorbs light from the light irradiating unit. Therefore, the light irradiated from the light irradiating unit is prevented from being reflected by the first and second conveying rollers. As a result, noise caused by the reflected light from the first and second conveying rollers can be suppressed. Therefore, accurate inspection can be performed.

[0011] In the present invention, the light absorbing member is preferably a black tape that has been subjected to an anti-reflection treatment.

[0012] The outer circumferential surfaces of the first and second conveying rollers are made of black tape that has been treated for anti-reflection (e.g., matte finish). This allows for cost reduction. In addition, since the process only requires wrapping the black tape, it can be easily applied to existing devices.

[0013] In the present invention, it is preferable that the light absorbing member has a needle-like structure with a large number of recesses and a large number of protrusions, and is a black coating.

[0014] The first and second conveyor rollers have a needle-like structure with many recesses and many protrusions, and the outer circumferential surfaces of the rollers are made of a black coating, which provides good durability and allows the rollers to maintain their effectiveness for a long period of time.

[0015] The present invention also provides an inspection device that reads a printed image printed on a transparent printing medium and inspects the printing condition, the inspection device comprising: a first transport roller that transports the transparent printing medium; a second transport roller that is spaced apart from the first transport roller and arranged downstream in the transport direction and transports the transparent printing medium; a photographing unit that is arranged between the first transport roller and the second transport roller and arranged on one side of the transparent printing medium and photographs a printed image located in an inspection area set between the first transport roller and the second transport roller; a light irradiation unit that irradiates light to photograph the printed image located in the inspection area by the photographing unit; and a light irradiation control unit that controls the irradiation of light from the light irradiation unit onto the first transport roller and the second transport roller.

[0016] [Functions and Effects] According to the present invention, the light irradiation regulating unit regulates the light from the light irradiating unit from being irradiated onto the first and second conveying rollers. Therefore, noise caused by the reflected light from the first and second conveying rollers can be prevented. Therefore, accurate inspection can be performed.

[0017] In the present invention, it is preferable that the light irradiation regulating section is configured by the light irradiating section that irradiates light onto a range including the inspection area excluding the first transport roller and the second transport roller.

[0018] The light irradiation unit is a light irradiation regulating unit that irradiates light onto an area including the inspection area excluding the first and second transport rollers. This makes it possible to solve problems caused by reflected light from the first and second transport rollers by devising only the light irradiation unit.

[0019] In the present invention, it is preferable that the light irradiation regulating section includes a hood that prevents the light from the light irradiating section from being irradiated onto the first transport roller and the second transport roller.

[0020] The light irradiation regulating unit is provided with a hood that prevents the light from the light irradiating unit from being irradiated onto the first transport roller and the second transport roller. This makes it possible to solve problems caused by reflected light from the first transport roller and the second transport roller simply by providing a hood on the light irradiating unit. Therefore, it can be easily applied to existing devices.

[0021] In the present invention, it is preferable that the light irradiation regulating section is configured such that the distance between the first conveying roller and the second conveying roller in the conveying direction is set outside the range of light irradiation by the light irradiating section.

[0022] The light irradiation regulating unit is configured such that the distance between the first transport roller and the second transport roller in the transport direction is set to be outside the range of light irradiation by the light irradiating unit, and therefore the problem caused by the reflected light at the first transport roller and the second transport roller can be solved without adding a new configuration.

[0023] In addition, in the present invention, it is preferable that the light irradiation regulating unit is configured such that the photographing unit is positioned between the first conveying roller and the second conveying roller, on the side where the first conveying roller and the second conveying roller are located, based on the transparent printing medium transported between the first conveying roller and the second conveying roller.

[0024] The light irradiation regulating unit is configured by arranging the photographing unit at a position between the first and second transport rollers, on the side where the first and second transport rollers are arranged, based on the transparent print medium transported between the first and second transport rollers. Therefore, it is possible to prevent light reflected by the outer peripheral surface between the first and second transport rollers from entering the photographing unit. Therefore, problems caused by reflected light from the first and second transport rollers can be solved simply by changing the position of the photographing unit.

[0025] The invention described in claim 1 is an inspection device that reads a printed image printed on a transparent printing medium and inspects the printing condition, comprising: a first transport roller that transports the transparent printing medium; a second transport roller that is spaced apart from the first transport roller and arranged downstream in the transport direction and transports the transparent printing medium; a photographing unit that is arranged between the first transport roller and the second transport roller and arranged on one side of the transparent printing medium and photographs a printed image located in an inspection area set between the first transport roller and the second transport roller; and a light irradiation unit that irradiates light to photograph the printed image located in the inspection area by the photographing unit, wherein the photographing unit is provided with a moving mechanism that, during operation, is fixed in position with respect to the inspection area and, during maintenance, can move away from the inspection area and in a direction away from the surface of the transparent printing medium.

[0026] The moving mechanism allows the photographing unit to be moved away from the surface of the transparent print medium during maintenance. This makes it easy to remove powder and other particles that have detached from the transparent print medium from the photographing unit. This allows accurate inspection to be performed for a long period of time.

[0027] Furthermore, in the present invention, it is preferable that the device frame is provided on which the first conveying roller and the second conveying roller are rotatably mounted, and the moving mechanism has a long axis in the width direction of the transparent printing medium, and when the photographing unit is attached, the device frame is provided with a photographing unit frame, and a swing axis is arranged so that its axis is parallel to the surface of the transparent printing medium and is provided on one end side of the photographing unit frame (Claim 2).

[0028] The photographing unit frame has a swing shaft on one end side. The swing shaft is arranged so that its axis is parallel to the surface of the transparent print medium. Therefore, the photographing unit frame can swing around one end side with respect to the surface of the transparent print medium. Therefore, maintenance can be performed simply by swinging the photographing unit frame away from the surface of the transparent print medium.

[0029] In addition, in the present invention, it is preferable that the device frame is provided with a frame positioning pin that regulates the position of the other end of the shooting unit frame so that the shooting unit is in focus on the printed image on the transparent printing medium (Claim 3).

[0030] The frame positioning pin regulates the position of the other end of the photographing unit frame so that the photographing unit is in focus. Therefore, even if the photographing unit frame is swung and then returned to its original position, photographing by the photographing unit can be performed appropriately.

[0031] Furthermore, in the present invention, it is preferable that the shooting unit frame is provided with rails arranged on both ends of the shooting unit in the width direction of the transparent printing medium and configured so that the shooting unit can move relative to the transparent printing medium at both ends, and a shooting unit positioning pin that regulates the position of the shooting unit on the rails so that the shooting unit is in focus at a focusing position on the printed image of the transparent printing medium (Claim 4).

[0032] The photographing unit frame is provided with rails and a photographing unit positioning pin. Therefore, the photographing unit can move along the rails relative to the transparent print medium, but can be easily fixed at the in-focus position by the photographing unit positioning pin. Therefore, even if the photographing unit is moved during maintenance, the photographing unit can be easily set at the in-focus position.

[0033] In addition, in the present invention, it is preferable to include the above-mentioned inspection device and a print head upstream of the inspection device that ejects ink droplets onto the transparent printing medium to print the print image, and to inspect the print image printed by the print head using the inspection device.

[0034] The print image on the transparent print medium printed by the print head is inspected by an inspection device. In the inspection device, the light irradiated from the light irradiation unit is prevented from being reflected by the first transport roller and the second transport roller. As a result, noise caused by the light reflected by the first transport roller and the second transport roller can be suppressed. The print image printed by the inkjet printing device can be accurately inspected.

[0035] This specification also discloses an invention relating to an inspection device as follows.

[0036] In the conventional device, when the printing medium is a film and the ink for forming an image is an aqueous ink, a primer layer (also called a pretreatment layer, an ink permeation layer, etc.) is generally formed before printing so that the aqueous ink will be fixed. Therefore, powder from the primer layer may adhere to the imaging section, which may interfere with accurate inspection. Also, when the printing medium is paper, paper powder may adhere to the imaging section, which may cause a similar problem. Therefore, it is necessary to periodically clean the light transmitting surface of the imaging section. However, when the imaging element of the imaging section is a CIS (contact image sensor), the depth of field is shallow. Therefore, the distance between the light transmitting surface of the imaging section and the printing medium is narrow. Therefore, there is a problem that maintenance of the imaging section is difficult.

[0037] (1) An inspection device that reads a print image printed on a print medium and inspects the print condition, a first transport roller for transporting the print medium; a second transport roller that is spaced apart from the first transport roller and is disposed downstream in a transport direction and transports the print medium; an image capturing unit that is disposed between the first conveying roller and the second conveying roller, that is disposed on one side of the print medium, and that captures an image of a print image located in an inspection area that is set between the first conveying roller and the second conveying roller; a light irradiation unit that irradiates light for photographing a print image located in the inspection area by the photographing unit; Equipped with An inspection device characterized in that the photographing unit is fixed in position relative to the inspection area during operation, and is equipped with a moving mechanism that enables it to move away from the inspection area and in a direction away from the surface of the printing medium during maintenance.

[0038] According to the invention described in (1) above, the moving mechanism can move the photographing unit away from the surface of the print medium during maintenance. Therefore, powder and other particles that have fallen off the print medium can be easily removed from the photographing unit. This allows accurate inspection to be performed for a long period of time.

[0039] (2) In the inspection device according to (1), a device frame to which the first conveying roller and the second conveying roller are rotatably attached, the moving mechanism has a long axis in a width direction of the print medium, and an imaging unit frame attached to the device frame with the imaging unit attached; a swing shaft disposed on one end side of the photographing unit frame so that the axis of the swing shaft is parallel to the surface of the print medium; An inspection device comprising:

[0040] According to the invention described in (2) above, the photographing unit frame is provided with a swing shaft on one end side. The swing shaft is arranged so that its axis is parallel to the surface of the print medium. Therefore, the photographing unit frame can swing around one end side with respect to the surface of the print medium at the other end side. Therefore, maintenance can be performed simply by swinging the photographing unit frame away from the surface of the print medium.

[0041] (3) In the inspection device according to (1), An inspection device characterized in that the device frame is provided with a frame positioning pin that regulates the position of the other end of the photographing unit frame so that the photographing unit is focused on a printed image on the transparent printing medium.

[0042] According to the invention described in (3) above, the position of the other end of the photographing unit frame is regulated by the frame positioning pin so that the photographing unit is in the in-focus position. Therefore, even if the photographing unit frame is swung and then returned to its original position, the photographing unit can appropriately photograph.

[0043] (4) In the inspection device according to (1), An inspection device characterized in that the shooting unit frame is arranged on both ends of the shooting unit in the width direction of the transparent printing medium, and is configured so that the shooting unit can move relative to the transparent printing medium at both ends, and the shooting unit positioning pin regulates the position of the shooting unit on the rail so that the shooting unit is in focus on the printed image of the transparent printing medium.

[0044] According to the invention described in (4) above, the photographing unit frame is provided with a rail and a photographing unit positioning pin. Therefore, the photographing unit can move along the rail relative to the print medium, but can be easily fixed at the in-focus position by the photographing unit positioning pin. Therefore, even if the photographing unit is moved during maintenance, the photographing unit can properly photograph.

[0045] (5) In the inspection device according to (1) to (4), a print head that ejects ink droplets onto the print medium and prints the print image, the print head being disposed upstream of the inspection device; Equipped with An inkjet printing apparatus, comprising: an inspection device that inspects the printed image printed by the print head.

[0046] According to the invention described in (5) above, the print image on the print medium printed by the print head is inspected by an inspection device. In the inspection device, the light irradiated from the light irradiation unit is prevented from being reflected by the first transport roller and the second transport roller. As a result, noise caused by the light reflected by the first transport roller and the second transport roller can be suppressed. The print image printed by the inkjet printing device can be accurately inspected. Effect of the Invention

[0047] According to the inspection device of the present invention, the outer circumferential surfaces of the first and second conveying rollers are made of a light absorbing material that absorbs light from the light irradiating unit. Therefore, the light irradiated from the light irradiating unit is prevented from being reflected by the first and second conveying rollers. As a result, noise caused by the reflected light from the first and second conveying rollers can be suppressed. Therefore, accurate inspection can be performed. [Brief description of the drawings]

[0048] [Figure 1] 1 is a schematic diagram illustrating the overall configuration of an inkjet printing apparatus according to an embodiment. [Diagram 2] FIG. 4 is a side view showing a main part of the inspection unit. [Diagram 3] FIG. 2 is a perspective view showing a configuration of a conveying roller in the first embodiment. [Figure 4] 13 is a partially enlarged vertical cross-sectional view showing the configuration of a transport roller in a modified example. FIG. [Diagram 5] FIG. 11 is a side view showing a main part of an inspection unit in the second embodiment. [Figure 6] FIG. 11 is a side view showing a main part of an inspection unit in the third embodiment. [Figure 7] FIG. 13 is a side view showing a main part of an inspection unit in the fourth embodiment. [Figure 8] FIG. 13 is a side view showing a main part of an inspection unit in the fifth embodiment. [Figure 9] FIG. 4 is a side view of a moving mechanism in the inspection unit. [Figure 10] FIG. 4 is a plan view of a moving mechanism in the inspection unit. [Figure 11] FIG. 4 is a front view of an imaging unit moving mechanism in the examination unit. [Figure 12] FIG. 4 is a plan view of an imaging unit moving mechanism in the inspection unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] Various embodiments of an inkjet printing apparatus incorporating an inspection device according to the present invention will now be described. EXAMPLES

[0050] A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing the overall configuration of an inkjet printing apparatus according to an embodiment.

[0051] The inkjet printing device 1 includes a paper feed section 3, a coating section 5, a printing section 7, a main drying section 9, and a paper discharge section 11. The left-right direction in FIG. 1 is the transport direction X. The left direction of the transport direction X is the downstream side, and the right direction is the upstream side. In some cases, the left direction is indicated as the +X direction and the right direction is indicated as the -X direction based on a certain position. The direction toward the back of the paper surface in FIG. 1 is the width direction Y. The up-down direction in FIG. 1 is the height direction Z. The paper feed section 3, coating section 5, printing section 7, main drying section 9, and paper discharge section 11 are arranged in that order toward the downstream side in the transport direction X.

[0052] The paper feed section 3 supplies the flexible packaging film WF to be printed to the coating section 5. In this embodiment, the flexible packaging film WF is, for example, a transparent film. The paper feed section 3 holds the rolled flexible packaging film WF rotatably around a horizontal axis. The paper feed section 3 unrolls the flexible packaging film WF with the printing surface facing upward relative to the coating section 5. The material of the flexible packaging film WF is, for example, a hydrophobic base material, which has low absorbency of aqueous ink. Examples of the flexible packaging film WF include plastic films such as polypropylene resin, vinyl chloride resin, and polyimide resin.

[0053] The flexible packaging film WF corresponds to the "transparent printing medium" in the present invention.

[0054] The coating unit 5 applies a primer to the flexible packaging film WF to form a primer layer. The primer layer is also called a pretreatment layer, an ink permeation layer, or an ink receiving layer. The primer is a coating liquid, and is also called an undercoat liquid or a base adjustment liquid. Specifically, the coating unit 5 includes a pan 13, a gravure roller 15, and a conveying unit 17. The pan 13 stores the primer. The gravure roller 15 has a lower portion partially immersed in the primer stored in the pan 13, and as it rotates, its upper portion supplies the primer to the printing surface of the flexible packaging film WF. The conveying unit 17 unwinds the flexible packaging film WF from the paper feed unit 3 and conveys the flexible packaging film WF to the gravure roller 15. In the area where the primer is supplied by the gravure roller 15, the conveying direction of the flexible packaging film WF and the rotating direction of the circumferential surface of the gravure roller 15 are opposite. The primer is applied to the flexible packaging film WF by a so-called reverse kiss method. The conveying section 17 conveys the flexible packaging film WF from the coating section 5 to the printing section 7 in a position in which the print surface of the flexible packaging film WF coated with the primer faces upward.

[0055] Examples of the primer include those containing a resin, a polyvalent metal salt, an alcohol, a surface tension adjuster, and pure water. Examples of the resin include shellac, examples of the polyvalent metal salt include calcium lactate, examples of the alcohol include ethanol, and examples of the surface tension adjuster include SY Glystar.

[0056] The printing section 7 includes a color printing section 19, a pre-drying section 21, a white printing section 25, an upper drying section 27, and a conveying section 29. The color printing section 19 prints a color image on the printing surface of the flexible packaging film WF on which a primer layer has been applied, for example, by ejecting multi-colored inks. The pre-drying section 21 pre-dries the printing surface of the flexible packaging film WF on which color printing has been performed. The white printing section 25 ejects white ink onto the printing surface of the flexible packaging film WF on which color printing has been performed, to print a white image. The upper drying section 27 dries the printing surface of the flexible packaging film WF on which the white image has been printed. The conveying section 29 conveys the flexible packaging film WF from the above-mentioned color printing section 19 to the upper drying section 27.

[0057] The main drying section 9 dries both the printed surface and the opposite surface of the flexible packaging film WF printed in the printing section 7. Specifically, the main drying section 9 includes a first drying section 31, a second drying section 33, a third drying section 35, a first conveying section 37, a second conveying section 39, and a third conveying section 41. The first drying section 31 dries the printed surface of the flexible packaging film WF conveyed downstream in the conveying direction X by the first conveying section 37. The second drying section 33 dries both sides of the flexible packaging film WF conveyed upstream in the conveying direction X by the second conveying section 39. The third drying section 35 dries both sides of the flexible packaging film WF conveyed downstream in the conveying direction X by the third conveying section 41. The first drying section 31, the second drying section 33, and the third drying section 35 discharge gas heated to a predetermined temperature onto the flexible packaging film WF. This dries the image printed on the printing surface of the flexible packaging film WF. The main drying section 9 discharges gas at, for example, 80 to 90°C at a wind speed of 27 to 30 m / s.

[0058] In this embodiment, an inspection section 43 is provided at the most downstream of the main drying section 9. A detailed configuration of the inspection section 43 will be described later. The inspection section 43 corresponds to the "inspection device" in the present invention.

[0059] The paper discharge section 11 winds up the flexible packaging film WF that has been dried by the main drying section 9 around a horizontal axis.

[0060] The inspection unit 43 will now be described with reference to Fig. 2 and Fig. 3. Fig. 2 is a side view showing a main part of the inspection unit. Fig. 3 is a perspective view showing a configuration of a transport roller in the first embodiment.

[0061] The inspection section 43 includes a transport roller 45 , a transport roller 47 , a frame 49 , an imaging section 51 , and a transmission light source section 53 .

[0062] The conveying rollers 45 and 47 convey the flexible packaging film WF. Specifically, the conveying roller 45 feeds in from the left in the conveying direction X, changes direction to the lower side in the height direction Z, and sends out the flexible packaging film WF. The conveying roller 47 is disposed below the conveying roller 45 in the height direction Z. The conveying roller 47 is disposed with a distance L1 between its rotation center and the rotation center of the conveying roller 45. The distance L1 is, for example, 100 mm. The conveying roller 47 feeds out the flexible packaging film WF from the upper side, changing direction to the left in the conveying direction X.

[0063] The frame 49 is disposed between the conveying rollers 45, 47 in the height direction Z, on the opposite side (-X direction) of the conveying rollers 45, 47 with the soft packaging film WF sandwiched therebetween. In detail, the frame 49 is disposed to the right of the conveying roller 47 in the conveying direction X. The frame 49 is attached to an apparatus frame (not shown) that rotatably holds the conveying rollers 45, 47, etc. The frame 49 is formed, for example, of a cylindrical member. The frame 49 is formed long in the width direction Y. The photographing unit 51 is attached to the upper surface of the frame 49. The photographing unit 51 is formed long in the width direction Y, similar to the frame 49.

[0064] The photographing unit 51 has an imaging element 51a in the center. The photographing unit 51 has an upper reflection light source 51b above the imaging element 51a in the height direction Z. The photographing unit 51 has a lower reflection light source 51c below the imaging element 51 in the height direction Z. The imaging element 51a is, for example, a CIS (contact image sensor). The upper reflection light source 51b and the lower reflection light source 51c irradiate light from the photographing unit 51 side toward the left in the conveying direction X, that is, toward the opposite side toward the printing surface of the soft packaging film WF side conveyed by the conveying rollers 45, 47. The upper reflection light source 51b and the lower reflection light source 51c are, for example, composed of light-emitting diodes. The transmission light source 53 is disposed on the opposite side of the photographing unit 51 in the conveying direction X across the soft packaging film WF. The transmission light source 53 is, for example, composed of a light-emitting diode. The above-mentioned upper reflective light source 51b, lower reflective light source 51c, and transmitted light source 53 mainly irradiate light onto the flexible packaging film WF. However, the light from the upper reflective light source 51b and transmitted light source 53 is also irradiated onto the lower outer peripheral surface of the conveying roller 45. In addition, the light from the lower reflective light source 51b and transmitted light source 53 is also irradiated onto the upper outer peripheral surface of the conveying roller 47.

[0065] The photographing unit 51 photographs the area between the conveying rollers 45 and 47. Specifically, the photographing unit 51 photographs the inspection area IA. The inspection area IA is located between the conveying rollers 45 and 47 and is set at approximately the center of the distance L1. The photographing unit 51 detects reflected light and transmitted light from the inspection area IA with the image sensor 51a, thereby reading the printed image printed on the printing surface of the soft packaging film WF.

[0066] The above-mentioned conveying rollers 45 and 47 are made of a metal that has been conventionally used. For example, the outer peripheral surfaces of the conveying rollers 45 and 47 are silver-colored. In this embodiment, the outer peripheral surfaces of the conveying rollers 45 and 47 are treated.

[0067] Specifically, it is as shown in FIG.

[0068] The transport rollers 45, 47 have a narrow black tape 55 wound around their outer circumferential surfaces in a spiral shape around the long axis of the transport rollers 45, 47. The surface of the black tape is anti-reflective. For example, the anti-reflective treatment may be a matte finish. Alternatively, the surface of the black tape may be coated with an anti-reflective film. Alternatively, the black tape 55 may have a width that matches the length of the transport rollers 45, 47 in the width direction Y and be wound around the outer circumferential surface only once.

[0069] The above-mentioned conveying roller 45 corresponds to the "first conveying roller" in the present invention, and the conveying roller 47 corresponds to the "second conveying roller" in the present invention. The upper reflective light source 51b, the lower reflective light source 51c, and the transmitted light source 53 correspond to the "light irradiating section" in the present invention. The black tape 55 corresponds to the "light absorbing member" in the present invention.

[0070] The inspection unit 43 in this embodiment is configured by wrapping black tape 55 around the outer circumferential surfaces of the transport rollers 45 and 47, which absorbs light from the upper reflective light source 51b, the lower reflective light source 51c, and the transmitted light source 53. This prevents the irradiated light from being reflected by the lower outer circumferential surface of the transport roller 45 and the upper outer circumferential surface of the transport roller 57. As a result, noise in the photographing unit 51 caused by the reflected light from the transport rollers 45 and 47 can be suppressed. This allows accurate inspection to be performed in the inspection unit 43. In addition, since the inspection unit 43 is configured with black tape 55, costs can be reduced. In addition, since the inspection unit 43 can be easily applied to existing devices, it only requires wrapping black tape 55.

[0071] The present invention is not limited to the above-described embodiment, and can be modified as follows. Reference is now made to Fig. 4. Fig. 4 is a vertical cross-sectional view showing the configuration of a transport roller in a modified embodiment, with a portion enlarged.

[0072] In this modified example, the outer circumferential surface of the conveying roller 45, 47 is configured with a needle-like structure 57. Specifically, the needle-like structure 57 is formed with a large number of recesses 57a and a large number of protrusions 57b. In addition, the surface is configured with a black coating. With this configuration, the outer circumferential surface of the conveying roller 45, 57 is configured with a light absorbing material. Specifically, it is preferable that the aspect ratio of the recesses 57a and the protrusions 57b in the needle-like structure 57 on the outer circumferential surface of the conveying roller 45, 57 is 2 or more and 30 or less. With such a structure, the light irradiated to the needle-like structure 57 is absorbed by the needle-like structure, so that reflection can be suppressed. In addition, it is preferable that the black coating is a conductive metal. By using a conductive metal, it is possible to improve the infiltration of powder into the conveying roller 45, 47 due to static electricity. Therefore, it is possible to prevent the powder from entering the recesses and the light absorption performance from decreasing. Therefore, it is possible to maintain performance for a long period of time.

[0073] As described above, the outer circumferential surface of the conveying rollers 45, 47 is formed of the needle-like structure 57 having a large number of recesses 57a and a large number of protrusions 57b, and is also formed of a black coating. Therefore, durability is improved, and the effect can be maintained for a long period of time. EXAMPLES

[0074] Second Embodiment Next, a second embodiment of the present invention will be described with reference to the drawings. Fig. 5 is a side view showing a main part of an inspection unit in the second embodiment.

[0075] The inspection unit 43A according to the second embodiment is configured as follows.

[0076] The inspection unit 43A differs from the inspection unit 43 in the configuration of the upper reflection light source 51b1, the lower reflection light source 51c1, and the transmission light source 53a described above. Specifically, the upper reflection light source 51b1 and the lower reflection light source 51c1 irradiate the flexible packaging film WF with light from the right in the conveying direction X. However, the upper reflection light source 51b1 and the lower reflection light source 51c1 narrow the light irradiation direction. In other words, the upper reflection light source 51b1 and the lower reflection light source 51c1 have directivity. The directivity restricts the light from being irradiated to the lower outer peripheral surface of the conveying roller 45 in the height direction Z, and restricts the light from being irradiated to the upper outer peripheral surface of the conveying roller 47. However, the above-mentioned directivity is such that the light is irradiated to the inspection area IA. The transmission light source 53a also has the same directivity. Such directivity can be realized, for example, by devising the lens shape of the light source.

[0077] The upper reflective light source 51b1, the lower reflective light source 51c1, and the transmitted light source 53a correspond to the "light irradiation regulating portion" of the present invention.

[0078] According to this embodiment, the problem caused by the reflected light from the transport rollers 45 and 47 can be solved simply by modifying the light irradiation configuration. EXAMPLES

[0079] Third embodiment of the present invention will now be described with reference to the drawings. Fig. 6 is a side view showing a main part of an inspection unit in the third embodiment.

[0080] The inspection unit 43B according to the third embodiment is configured as follows.

[0081] In the inspection section 43B, the photographing section 51 includes a hood 55, and the transmissive light source section 53 includes a hood 57. Specifically, the hood 55 is attached to the upper part of the upper reflective light source 51b and the lower part of the lower reflective light source 51c. The hoods 57 are attached to the upper and lower parts of the transmissive light source 53. The hoods 55 and 57 allow irradiation of the inspection area IA. On the other hand, the hoods 55 and 57 restrict light from being irradiated onto the lower outer peripheral surface of the conveying roller 45 and restrict light from being irradiated onto the upper outer peripheral surface of the conveying roller 47 in the height direction Z.

[0082] The above-mentioned hoods 55 and 57 correspond to the "light irradiation regulating portion" in the present invention.

[0083] According to this embodiment, hoods 55, 57 are provided to prevent light from being irradiated onto the transport rollers 45, 47. Thus, problems caused by reflected light at the transport rollers 45, 47 can be solved simply by providing the hoods 55 for the upper reflective light source 51b and the lower reflective light source 51c and the hood 57 for the transmitted light source 53. Therefore, this embodiment can be easily applied to existing devices.

[0084] The present invention is not limited to the embodiment in which the hood 55 is attached to the imaging unit 51 and the hood 57 is attached to the transmitted light source 53 as described above. In other words, it is sufficient that the shielding member is disposed at a position where the light from the light source does not reach the outer circumferential surfaces of the conveying rollers 45 and 47, and the positions of the hoods 55 and 57 are not limited to the above positions. EXAMPLES

[0085] Next, a fourth embodiment of the present invention will be described with reference to the drawings. Fig. 7 is a side view showing a main part of an inspection unit in the fourth embodiment.

[0086] The inspection unit 43C according to the fourth embodiment is configured as follows.

[0087] The inspection unit 43C is disposed such that the conveying roller 45 and the conveying roller 47 are spaced apart from each other by a distance L2 in the height direction Z. This distance L2 is longer than the distance L1 of the inspection unit 43 in the first embodiment. The distance L2 is a length that does not irradiate the lower outer peripheral surface of the conveying roller 45 and the upper outer peripheral surface of the conveying roller 47 with light from the upper reflective light source 51b, the lower reflective light source 51c, and the transmitted light source 53. In other words, the conveying rollers 45 and 47 are disposed such that the lower outer peripheral surface of the conveying roller 45 and the upper outer peripheral surface of the conveying roller 47 are positioned outside the irradiation range of the light from the upper reflective light source 51b, the lower reflective light source 51c, and the transmitted light source 53.

[0088] The transport rollers 45 and 47 arranged in the height direction Z at an interval of the distance L2 correspond to the "light irradiation regulating portion" of the present invention.

[0089] According to this embodiment, the distance L2 between the conveying rollers 45 and 47 sandwiching the inspection area IA, through which the flexible packaging film WF is conveyed, is set to be outside the range of light irradiation by the upper reflective light source 51b, the lower reflective light source 51c, and the transmitted light source 53. Therefore, the problem caused by the reflected light at the conveying rollers 45 and 47 can be solved without adding a new configuration. EXAMPLES

[0090] Second Embodiment Next, a second embodiment of the present invention will be described with reference to the drawings. Fig. 8 is a side view showing a main part of an inspection unit in a second embodiment.

[0091] The inspection unit 43D according to the fifth embodiment is configured as follows. The inspection unit 43D has the same configuration as the inspection unit 43 in the first embodiment. However, the position of the inspection unit 43D relative to the transport rollers 45 and 57 is different.

[0092] First, in the configuration of the present embodiment, the arrangement of the photographing unit 51 and the equivalent plate 53 is reversed with respect to the inspection unit 43 in the first embodiment, sandwiching the flexible packaging film WF transported by the transport rollers 45 and 47. Specifically, in the inspection unit 43D, the photographing unit 51 is disposed on the left side of the transport direction X, sandwiching the flexible packaging film WF. In the inspection unit 43D, the transmitted light source 53 is disposed on the right side of the transport direction X, sandwiching the flexible packaging film WF.

[0093] Also, the position of the photographing unit 51 in the conveying direction X is different from that of the inspection unit 43 in the first embodiment. The photographing unit 51 in the present embodiment is disposed on the side where the conveying rollers 45, 47 are disposed (on the X-direction side of the soft packaging film WF) with respect to the soft packaging film WF conveyed between the conveying rollers 45 and 47, and is disposed at a position between the conveying rollers 45 and 47. More preferably, the light entrance surface of the imaging element 51a is disposed closer to the center line CL connecting the rotation centers of the conveying rollers 45 and 47 than the tangents to the left outer peripheral surfaces of both the conveying rollers 45 and 47.

[0094] This causes the photographing unit 51 to enter between the transport rollers 45, 57. This makes it possible to prevent light reflected on the outer circumferential surface between the transport rollers 45, 57 from entering the photographing unit 51. Therefore, by simply changing the position of the photographing unit 51, the problem caused by the reflected light on the transport rollers 45, 47 can be solved.

[0095] <Movement mechanism> Here, reference will be made to Figures 9 and 10. Figure 9 is a side view of the movement mechanism in the inspection unit, and Figure 10 is a plan view of the movement mechanism in the inspection unit.

[0096] In each of the above-mentioned Examples 1 to 5, a primer layer is formed in the coating unit 5 before printing so that the ink discharged from the printing unit 7 is fixed. Therefore, powder from the primer layer may adhere to the photographing unit 51 (especially the light-receiving surface), which may interfere with accurate inspection. Also, when the print medium is paper rather than the flexible packaging film WF, paper powder may adhere to the photographing unit 51, which may cause a similar problem. Therefore, it is necessary to periodically clean the surface of the photographing unit 51 on which the print medium is conveyed. However, when the imaging element 51a of the imaging unit 51 is a CIS (contact image sensor), the depth of field is shallow. Therefore, the distance between the light-transmitting surface of the imaging unit 51 and the print medium is narrow. Therefore, there is a problem that maintenance of the imaging unit 51 is difficult. It is preferable to have a moving mechanism 61 as follows.

[0097] The moving mechanism 61 fixes the position of the photographing unit 51 relative to the inspection area IA during operation of the inkjet printing device 1. On the other hand, during maintenance, the moving mechanism 61 moves the photographing unit 51 away from the inspection area IA and makes it movable in a direction away from the surface of the flexible packaging film WF.

[0098] Specifically, the moving mechanism 61 includes a device frame 63 and a swing pin 65. The conveying roller 45 and the conveying roller 47 are rotatably attached to the device frame 63. In detail, the conveying rollers 45 and 47 are rotatably attached to the device frame 63 at both ends with their rotation axes facing the width direction Y. The swing pin 65 is inserted into one end of the frame 49 on which the photographing unit 51 is mounted. The swing pin 65 is arranged so that its axis is parallel to the surface of the soft packaging film WF. The device frame 63 at one end of the frame 49 has a support plate 67 erected thereon. The support plate 67 has a pin fixing plate 69 attached to its upper portion. The swing pin 65 protruding downward from the frame 49 has its lower portion inserted into the pin fixing plate 69. 10, the frame 49 can swing about the swing axis P1 of the swing pin 65 along the upper surface of the support plate 67 along a plane defined by the transport direction X and the width direction Y. In other words, the photographing unit 51 can swing together with the frame 49 along a plane defined by the transport direction X and the width direction Y.

[0099] The above-mentioned frame 49 corresponds to the "photographing unit frame" in the present invention.

[0100] The device frame 63 is provided with a frame positioning pin 71 that regulates the position of the other end of the frame 49 so that the photographing unit 51 is in focus on the flexible packaging film WF. Specifically, the device frame 63 has a support plate 67 attached to the opposite side of the swing pin 65 in the width direction Y. The frame positioning pin 71 is attached to the upper part of the support plate 67. The lower part of the frame positioning pin 71 is embedded in the support plate 67, and the upper part protrudes in the height direction Z from the upper surface of the support plate 67. In addition, an L-shaped plate 73 is attached to the side surface of the other end of the frame 49. As shown in FIG. 10, the L-shaped plate 73 has an L shape in a plan view. The horizontal part of the L-shaped plate 73 in the width direction Y abuts against the frame positioning pin 71. In addition, with the L-shaped plate 73 abutting against the frame positioning pin 71, the L-shaped plate 73 is fixed to the support plate 67 by a screw 75, and the position of the frame 49 is fixed.

[0101] By providing the moving mechanism 61, the photographing unit 51 can be moved away from the surface of the flexible packaging film WF during maintenance. Therefore, powder and the like that has detached from the flexible packaging film WF can be easily removed from the photographing unit 51. This allows accurate inspection to be performed for a long period of time. Furthermore, the frame positioning pin 71 restricts the position of the other end of the frame 49 so that the photographing unit 51 is in the in-focus position. Therefore, even if the frame 49 is swung for maintenance of the photographing unit 51 and then returned to its original position, the photographing unit 51 can properly photograph the image.

[0102] Moreover, it is preferable that the frame 49 is configured as shown in Fig. 10 to Fig. 12. Fig. 10 is a plan view of the moving mechanism in the inspection section. Fig. 11 is a front view of the imaging unit moving mechanism in the inspection section. Fig. 12 is a plan view of the imaging unit moving mechanism in the inspection section.

[0103] That is, the frame 49 preferably includes an imaging unit moving mechanism 81 that enables the position of the imaging unit 51 in the transport direction X relative to the inspection area IA to be moved.

[0104] The photographing unit moving mechanism 81 includes a mounting plate 83 , a rail 85 , a photographing unit positioning pin 87 , a restricting piece 89 , and a screw 91 .

[0105] The mounting plate 83 is attached to both ends of the photographing unit 51 in the width direction Y. The mounting plate 83 has an L-shape. A rail 85 is attached to the frame 49 below the mounting plate 83. The rail 85 has a groove in the center when viewed from the conveying direction X. The rail 85 has a groove formed along the conveying direction X. The photographing unit positioning pin 87 is attached to the lower surface of the mounting plate 83 so as to protrude downward. The restricting piece 89 is fixed to the groove of the rail 85. The restricting piece 89 is fixed to the soft packaging film WF side in the conveying direction X. When the photographing unit 51 is moved along the conveying direction X with the photographing unit positioning pin 87 inserted into the groove of the rail 85, the photographing unit positioning pin 87 abuts against the restricting piece 89 to restrict the movement. This position is set so that the photographing unit 51 becomes a focusing position where the photographing unit 51 focuses on the printed image in the inspection area IA of the soft packaging film WF. The screw 91 is attached in a state in which the photographing unit positioning pin 87 abuts against the restricting piece 89 and is restricted in movement, whereby the photographing unit 51 is fixed to the frame 49 at the focusing position.

[0106] By providing the photographing section moving mechanism 81 in this manner, even if the photographing section 51 is moved during maintenance, it can be easily set to the in-focus position.

[0107] The present invention is not limited to the above-described embodiment, but can be modified as follows.

[0108] (1) In the above-described embodiments, the printing medium is a transparent flexible packaging film WF. However, the present invention is not limited to such a printing medium. For example, the present invention can be applied to a translucent film or a translucent paper medium.

[0109] (2) In each of the above-described embodiments, the inkjet printing apparatus 1 forms the primer layer by including the coating unit 5. However, when the printing unit 7 ejects an oil-based ink, it is not necessary to include the coating unit 5.

[0110] (3) In each of the above-described embodiments, the inspection unit 43, 43A to 43D includes the upper reflective light source 51 (51b1) and the lower reflective light source 51c (51c1). However, the present invention does not necessarily have to include two reflective light sources.

[0111] (4) In each of the above-described embodiments, the inspection unit 43, 43A to 43D includes the transmissive light source 53. However, the present invention does not require the transmissive light source 53. That is, even if only the reflective light source is provided, such as the upper reflective light source 51b and the lower reflective light source 51c, the present invention can be applied because it is possible to suppress the adverse effect of reflection from the conveying rollers 45, 57 caused by the reflective light source. Also, the present invention can be applied even if only the transmissive light source 53 is provided. [Industrial Applicability]

[0112] INDUSTRIAL APPLICABILITY As described above, the present invention is suitable for an inspection device that reads an image on a transparent print medium and inspects the print condition, and an inkjet printing device equipped with the same. [Explanation of symbols]

[0113] 1 … Inkjet printing device 3 … Paper feed section 5 … Application section 7 … Printing department 9 … Main drying section 11 ... Paper ejection section WF: Flexible packaging film 19 … Color Printing Department 25 … White printing section 43(43A~43D) … Inspection Department 45,47 … Transport roller 49 … Frame 51 … Photography Department 51a ... Image sensor 51b, 51b1 … Upper reflective light source 51c, 51c1 … Bottom reflective light source 53, 53a … Transmitted light source L1,L2 … distance IA: Inspection area 55 ... Black tape 57 … needle-like structure 55,57 … Food CL … Center line 61 … Movement mechanism 63 ... Equipment frame 65 ... Swing pin P1 … Swing axis 81 ... Imaging unit movement mechanism 85 ... Rail 87 ... Shooting unit positioning pin

Claims

1. An inspection device that reads a print image printed on a transparent print medium and inspects the print condition, a first transport roller for transporting the transparent print medium; a second transport roller disposed downstream in a transport direction away from the first transport roller, the second transport roller transporting the transparent print medium; an image capturing unit that is disposed between the first transport roller and the second transport roller, that is disposed on one side of the transparent print medium, and that captures an image of a print image located in an inspection area that is set between the first transport roller and the second transport roller; a light irradiation unit that irradiates light for photographing a print image located in the inspection area by the photographing unit; Equipped with An inspection device characterized in that the photographing unit is fixed in position relative to the inspection area during operation, and is equipped with a moving mechanism that can move it away from the inspection area and away from the surface of the transparent printing medium during maintenance.

2. 2. The inspection device according to claim 1, a device frame to which the first transport roller and the second transport roller are rotatably attached, the moving mechanism has a long axis in a width direction of the transparent print medium, and an imaging unit frame attached to the device frame with the imaging unit attached; A swing shaft is disposed so that its axis is parallel to the surface of the transparent print medium and is provided on one end side of the photographing unit frame; An inspection device comprising:

3. 3. The inspection device according to claim 2, An inspection device characterized in that the device frame is provided with a frame positioning pin that regulates the position of the other end of the photographing unit frame so that the photographing unit is focused on a printed image on the transparent printing medium.

4. In the inspection device according to claim 2 or 3, An inspection device characterized in that the shooting unit frame is arranged on both ends of the shooting unit in the width direction of the transparent printing medium, and is configured so that the shooting unit can move relative to the transparent printing medium at both ends, and the shooting unit positioning pin regulates the position of the shooting unit on the rail so that the shooting unit is in focus on the printed image of the transparent printing medium.

Images