JP5082162B2 - Screen plate making visual inspection device - Google Patents

Description

  The present invention relates to a screen plate appearance inspection device, and more particularly to a screen plate appearance inspection device capable of detecting clogging of a screen plate pattern.

FIG. 8 shows a manufacturing process of the screen plate making 1. The screen plate making 1 is generally manufactured through the following steps.
(1) Creeping step: The screen mesh (crease) 2 is pulled with an appropriate tension and fixed to the aluminum frame 3 with an adhesive or the like (FIG. 8A). The screen mesh 2 is made of stainless steel mesh for electronic parts and synthetic fiber mesh for posters.
(2) Pretreatment step: The plate with the screen mesh 2 stretched on the frame 3 is washed with clean water.
(3) Coating step: The photosensitive emulsion 4 (photosensitive resin) is uniformly applied to the front and back surfaces of the screen mesh 2 in the frame 3 (FIG. 8B).
(4) Baking process: A pattern original plate 5 (positive film, glass dry plate photomask, etc.) is brought into intimate contact with the screen mesh 2 coated with the photosensitive emulsion 4, and is exposed with an exposure machine, and the pattern is printed on the screen mesh. (FIG. 8C).
(5) Development / finishing step: The plate on which the pattern has been baked is developed by immersing in water, and the unexposed portion of the photosensitive emulsion is washed and removed (each after the unexposed portion of the photosensitive emulsion is removed). The holes become the pattern holes 6) and are dried. Check the state of the pattern again, fill the pinhole, apply tape, and reinforce. Thereby, the screen plate making 1 is completed (FIG. 8D).

The completed screen plate making 1 is shipped after inspection. FIG. 9 shows the principle of screen printing using screen plate making. The squeegee 7 is slid from the plate making 1 to fill each hole (pattern hole) 6 of the pattern of the screen mesh 2, and then the ink 8 is discharged from each hole 6 to lower the substrate 9. The screen printing is performed by transferring the image onto the screen.

  As a method for inspecting screen plate making, for example, a method for inspecting pinholes and pattern defects is known (see Patent Document 1).

JP 2003-200550 A

  In the above method, pinholes in the screen plate making and defects in the pattern can be found, but if there is clogging made of a photosensitive resin or the like in the pattern, it is difficult to find the clogging. FIG. 10 shows a state in which clogging A is present in a part of each pattern hole 6 of the screen plate making 1. Each pattern hole 6 forms a pattern 6A. In a conventional general appearance inspection apparatus, a screen plate is set on a table, light is applied from a lower light source (such as a halogen lamp), and a silhouette of the pattern by the light transmitted through the screen plate is read by an upper CCD camera or the like. The image is enlarged and visually inspected for pattern appearance.

  However, the conventional general appearance inspection apparatus transmits light from below when there is clogging in the screen plate making pattern (most of which is photosensitive resin), especially when clogging is a transparent resin. Therefore, it was difficult to determine whether there was clogging, and it was very difficult to find it.

  The present invention has been made in view of the above problems, and can easily detect clogging in a screen plate making pattern regardless of whether the clogging in the screen plate making pattern is opaque or transparent. An object of the present invention is to provide a screen plate appearance inspection device that can be used.

In order to solve the above-mentioned problems, an appearance inspection apparatus according to claim 1 of the present invention is set in a screen plate making on a table from a light source arranged on one side of the screen plate making on the table. In the screen plate appearance inspection apparatus, the light is transmitted to the other side of the screen, the light image of the screen plate making by the transmitted light is received by the image receiving unit, and the appearance of the screen plate making on the table is inspected from the received image.
A first polarizing filter is disposed between the light source and the screen plate on the table, and a second polarizing filter is disposed between the image receiving unit and the screen plate on the table.

  Of the light incident on the screen plate on the table, light of a specific polarization component, for example, reflected light from the table or screen plate making, is arranged by the first polarizing filter disposed between the light source and the screen plate on the table. Incident can be eliminated. Thereby, the influence of those reflected light, disturbance light, etc. at the time of inspecting the external appearance of screen platemaking can be excluded.

  Further, the second polarizing filter disposed between the image receiving unit and the screen plate making on the table allows diffusion of light having a specific polarization component out of light incident on the image receiving unit, for example, clogging of the screen plate making. The incidence of reflected light in the light can be eliminated. Thereby, the influence of those reflected light, disturbance light, etc. at the time of inspecting the external appearance of screen platemaking can be excluded.

  For example, when there is a transparent (including translucent) resin (hereinafter referred to as a transparent resin) as a clogging in the pattern hole at the inspection site of the screen plate making, the light irradiated from the light source is first reflected by the first polarizing filter. Light of a specific polarization component such as light is excluded and enters the transparent resin in the pattern hole. The light incident on the transparent resin is diffused in the transparent resin, and diffused light is emitted from the transparent resin. The diffused light emitted from the transparent resin is incident on the image receiving unit after the light of a specific polarization component such as reflected light is removed by the second polarizing filter. The image of the transparent resin obtained in the image receiving portion is darker than the bright image of the pattern hole without the transparent resin, and clogging can be easily detected. Note that the pattern hole without the transparent resin has a bright image because the light incident on the pattern hole is not diffused and is transmitted through the second polarizing filter and incident on the image receiving unit.

  When the clogging is opaque resin, the opaque resin hardly transmits the incident light from the light source, resulting in a darker image than the bright image of the surrounding pattern holes without clogging. In this case, clogging is easily detected. it can.

  As described above, even if the clogging in the screen plate making pattern is transparent or opaque, the clogging in the screen plate making pattern can be easily detected.

  The screen plate appearance inspection apparatus according to claim 2 of the present invention is characterized in that the first and second polarizing filters are rotatable relative to each other around an optical axis.

  By rotating the second polarizing filter relative to the first polarizing filter around the optical axis, the second polarizing filter is applied to the polarization plane of the reflected light out of the light diffused by clogging in the screen plate making pattern. The angle can be easily adjusted. Accordingly, the amount of light incident on the image receiving unit can be easily adjusted to the optimum amount for detecting clogging.

  According to a third aspect of the present invention, the light source is offset from the center line connecting the image receiving portion and the inspection portion of the screen plate on the table.

  Since the light source is offset from the center line connecting the image receiving part and the screen plate inspection area on the table, the light from the light source toward the inspection area of the screen plate making on the table becomes oblique light. When the pattern hole of the part is not clogged, the oblique light from the light source passes through the pattern hole as it is, and goes straight obliquely off the optical path between the inspection part and the image receiving part. For this reason, the image of the pattern hole without clogging obtained in the image receiving unit is a dark image because light does not enter.

  On the other hand, when the transparent resin is clogged in the pattern hole, the incident light to the pattern hole diffuses in the transparent resin in the pattern hole, and a part of the diffused light passes through the second polarizing filter. Since the light is transmitted and incident on the image receiving portion, the image of the clogged pattern hole obtained in the image receiving portion is a relatively bright image compared to the surrounding image of the clogged pattern hole, and the difference in brightness and darkness thereof. Thus, clogging of the screen plate-making pattern can be easily detected.

  According to a fourth aspect of the present invention, there is provided a screen plate appearance inspection apparatus according to the present invention, wherein the light source is disposed on a center line connecting the image receiving portion and the screen plate inspection portion on the table. It is characterized by being combined with a second light source arranged in a ring shape around.

  By combining the light source from a first light source disposed on the center line connecting the image receiving portion and the inspection site of screen plate making on the table, and a second light source disposed in a ring shape around the first light source. Further, the accuracy of the appearance inspection of the screen plate making can be further improved.

  That is, if the clogging of the pattern hole at the inspection site is a transparent resin, the oblique light from the second light source is applied to the pattern hole at the inspection site, and clogging is easily detected by the difference in brightness from the image of the surrounding pattern hole. it can. Further, if the clogging of the pattern hole at the inspection site is an opaque resin, the light from the first light source located at the center is applied to the pattern hole at the inspection site, and the pattern hole is caused by a difference in brightness from the image of the surrounding pattern hole. Can be easily detected. By combining the inspection with the first light source and the inspection with the second light source for the same pattern hole, the detection of the clogging can be ensured regardless of whether the clogging of the pattern hole is transparent or opaque.

  Furthermore, according to the screen plate appearance inspection apparatus according to claim 4 of the present invention, the light from the central first light source and the oblique light from the ring-shaped second light source are simultaneously applied to the pattern hole of the inspection site. By applying, it is possible to determine whether the detected clogging of the pattern hole is a transparent resin or an opaque resin.

  That is, when only oblique light from the ring-shaped second light source is applied to the pattern hole of the inspection site, the screen platemaking appears dark, and when the pattern hole is clogged with a transparent resin, the portion is brightened by the diffused light. It is reflected and can be easily detected. However, an opaque resin cannot be detected because it is as dark as the surroundings. Therefore, the first light source and the second light source are simultaneously applied to the pattern hole of the inspection site, and the overall brightness of the screen plate making is darker than the brightness of the transparent resin that can be detected when only the second light source is applied. Adjust the amount of light so that it becomes brighter.

  At this time, in the first light source, as described above, both the transparent resin and the opaque resin are darker than the overall brightness of the screen plate making and can be detected. Further, the transparent resin becomes brighter than the overall brightness of the screen platemaking by the oblique light of the second light source. For this reason, the brightness of the transparent resin is higher than the brightness of the entire screen plate making, the brightness of the opaque resin is low, and it is possible to determine whether the detected defective substance is a transparent resin or an opaque resin. It becomes possible.

  As described above, according to the screen plate appearance inspection device according to the present invention, clogging in the screen plate pattern can be easily detected with a simple structure and mechanism, including a transparent resin that has been difficult to detect in the past. There is an excellent effect of being able to.

  This eliminates the burden of screen plate appearance inspection by trial printing at the shipping destination that has been performed in the past and the problem of screen plate remanufacturing due to poor appearance, leading to a reduction in screen plate making costs. There is an effect.

  A first embodiment for carrying out the present invention will be described with reference to FIGS. In FIG. 1, reference numeral 1 denotes a screen plate making, and reference numeral 10 denotes a screen plate making appearance inspection apparatus. In addition, the same code | symbol is attached | subjected to the same member as the member shown in FIG. 8, and the description is abbreviate | omitted.

  As shown in FIGS. 1 and 2, a screen plate appearance inspection apparatus (hereinafter referred to as an “appearance inspection apparatus”) 10 places an inspection target screen plate making 1 on the upper surface of a base 11 supported on a floor G. A table 12 to be placed is placed via an auxiliary frame 13, and a monitor / operation unit unit 14 is placed at the rear of the upper surface of the base 11 so as to straddle the table 12. The table 12 can be moved horizontally in the front-rear direction (X direction) and the left-right direction (Y direction) by the guide mechanism 15 including the LM guide 15A extending in the front-rear direction and the LM guide 15B extending in the left-right direction. Has been.

  The monitor / operation unit unit 14 is provided with a monitor 16 such as a liquid crystal and an operation panel 17 in the upper front portion, and a CCD camera 19 (image receiving portion) that can move horizontally in the left-right direction via a support portion 18 in the lower front portion. And a microscope 20 is provided.

  A predetermined distance H is formed between the upper surface of the base 11 and the table 12. A first light source (first light source) 21 located on a center line L connecting the CCD camera 19 and the inspection site of the screen plate making 1 on the table 12 is provided at a substantially central position on the upper surface of the base 11 below the table 12. A ring-shaped second light source (second light source) 22 is installed around the first light source 21 so as to surround the first light source 21. A visible light source such as a halogen lamp or a xenon lamp is used as the first light source, and a visible light source such as an annular fluorescent lamp is used as the ring-shaped second light source. A non-reflective sheet (not shown) that does not reflect light from each light source is disposed on the back surface of the first light source 21 and the second light source 22.

  A first polarizing filter 23 located between the first light source 21 and the screen plate making 1 on the table 12 is attached to the lower surface of the table 12. As shown in FIG. 3, the first polarizing filter 23 removes specific polarization components (reflected light, disturbance light, etc.) from the light incident on the screen plate making 1 on the table 12, and transmits other light. It is to be transmitted. The lens unit 19A of the CCD camera 19 has the same principle as that of the first polarizing filter 23. Of the light incident on the CCD camera 19, light of a specific polarization component (reflected light based on diffused light of transparent resin, disturbance) The second polarizing filter 24 that removes light and transmits other light is rotatably attached.

  In FIG. 1, reference numeral 25 denotes a mount with casters that can fix and move the base 11 on the floor G, and reference numeral 26 denotes a second operation portion.

  Next, a method for inspecting the appearance of the screen platemaking 1 using the appearance inspection apparatus 10 configured as described above will be described below.

  FIG. 4 shows a method for detecting clogging A in the pattern hole 6 of the screen plate making 1 as shown in FIG. 10 using the first light source 21.

  The screen plate making 1 is set on the table 12 shown in FIG. 1, the first light source 21 immediately below is turned on, and the light quantity is maximized. The light emitted from the first light source 21 is excluded by the first polarizing filter 23 from the light having a specific polarization component such as reflected light (reflected light from the back surface of the screen plate making 1, the inner surface of the table 12, etc.). Into the pattern hole 6 of the screen plate making 1.

  At this time, if there is clogging (transparent resin) A in any of the pattern holes 6, as shown in FIG. 4A, the light incident on the transparent resin is diffused in the transparent resin, Diffuse light emerges from the transparent resin. The diffused light emitted from the transparent resin is removed by the second polarizing filter 24 from the light of a specific polarization component such as reflected light (reflected light based on the diffused light), and enters the lens 19A of the CCD camera 19.

  The image of the pattern hole 6 with the clog A received by the CCD camera 19 can be visually confirmed by the monitor 16 in the form of an enlarged image. The image of the pattern hole 6 with the clog A is It looks darker than the image of the pattern hole 6 without surrounding clogging. As shown in FIG. 4B, the image of the pattern hole 6 without clogging passes through the second polarizing filter 24 without the light transmitted through the first polarizing filter 23 being diffused by the transparent resin. Since it is incident on the camera 19, it looks brighter than the image of the clogged pattern hole 6. Thereby, clogging can be easily detected by the difference in brightness of the image.

The amount of light incident on the CCD camera 19 can be finely adjusted by rotating the second polarizing filter 24 relative to the first polarizing filter 23 about the optical axis L ′. Specifically, as shown in FIG. 5 (A), with respect to the reference position P ₀ of the rotational direction of the first polarizing filter 23, the combined rotational direction setting position P ₁ of the second polarizing filter 24, the angle of the filters Are matched, the amount of light transmitted through the second polarizing filter 24 is maximized, and the image received by the CCD camera 19 appears brightest. On the other hand, as shown in FIG. 5B, when the second polarizing filter 24 is rotated 90 degrees around the optical axis L ′, the amount of light transmitted through the second polarizing filter 24 is minimized, and the image is received by the CCD camera 19. The image looks darkest. Therefore, as shown in FIG. 5 (C), the second polarizing filter 24, between 90 degrees, brightness is adjusted to a position P ₂ where the silhouette of the pattern holes 6 is most clearly at best, to the position The angle of the second polarizing filter 24 is fixed. Angle can be selected between to 75 degrees to 15 degrees from the reference position P _0. Each optical axis L ′ of each of the first and second polarizing filters 23 and 24 coincides with a center line L connecting the CCD camera 19 and the inspection site of the screen plate making 1 on the table 12.

  Next, a method for detecting clogging of the pattern hole 6 of the screen plate making 1 using the ring-shaped second light source 22 will be described below with reference to FIG.

  The screen plate making 1 is set on the table 12 shown in FIG. 1, and the ring-shaped second light source 22 is turned on to maximize the amount of light. As shown in FIG. 6A, the light from the second light source 22 is obliquely applied to the inspection site of the screen plate making 1 on the table 12 and enters the pattern hole 6.

  At this time, if any of the pattern holes 6 has clogging (transparent resin) A, as shown in FIG. 6 (A), the light incident on the transparent resin diffuses in the transparent resin, Diffuse light emerges from the transparent resin. The diffused light emitted from the transparent resin is removed by the second polarizing filter 24 from the light of a specific polarization component such as reflected light (reflected light based on the diffused light), and enters the lens 19A of the CCD camera 19.

At this time, the second polarizing filter 24, the setting position P ₁ in the case of the first light source 21, as shown in FIG. 5 (D), the amount of light appear brighter to increase position (e.g., from the reference position P ₀ 15 Return to the position P ₃ ) and fix it. Thereby, the image of the pattern hole 6 with clogging (transparent resin) received by the CCD camera 19 looks relatively brighter than the dark image of the surrounding pattern hole 6 without clogging. As shown in FIG. 6B, the pattern hole 6 without surrounding clogging is not received due to the oblique light from the ring-shaped second light source 22 and is not received from the center line L of the CCD camera 19. Become. In this way, clogging can be easily detected by the difference in brightness of the image.

  Thus, according to the screen plate appearance inspection apparatus of the present invention, either the first light source 21 or the ring-shaped second light source 22 is selected, and the first polarizing filter 23 and the second polarizing filter 24 are used on the table 12. By adjusting the amount of light incident on each pattern hole 6 at the inspection site of the screen plate making 1 and the light transmitted through the pattern hole 6 at the inspection site of the screen plate making 1 and incident on the CCD camera 19, respectively, the screen is made. Clogging of the plate making 1 can be easily detected.

  As shown in FIG. 7, in the case of the ring-shaped second light source 22, clogging (transparent resin) of the screen platemaking 1 can be detected without the first polarizing filter 23 and the second polarizing filter 24. . That is, as shown in FIG. 7A, in the pattern hole 6 with clogging (transparent resin), the incident light to the clogging shines brightly to obtain a bright image, as shown in FIG. 7B. In the pattern hole 6 without clogging, the oblique light passes through the pattern hole 6 as it is, deviates from the center line L connecting the CCD camera 19 and the inspection site of the screen plate making 1 on the table 12, and does not enter, so a dark image Is obtained. Since the first and second polarizing filters 23 and 24 are not required, the structure can be further simplified.

  The appearance inspection apparatus according to the present invention can be used as an appearance inspection apparatus capable of detecting clogging of a screen plate-making pattern.

The front view which shows 1st Embodiment and shows the external appearance inspection apparatus of the screen platemaking which concerns on this invention, FIG. 1 is a side view of the appearance inspection apparatus shown in FIG. Explanatory drawing which shows the effect | action of a 1st polarizing filter, Explanatory drawing which shows the method to test | inspect clogging of the pattern hole of a screen plate making using a 1st light source using the external appearance inspection apparatus of this invention, Explanatory drawing which shows a mode that the 2nd polarizing filter is rotated relatively with respect to a 1st polarizing filter, and the light quantity which injects into a CCD camera is finely adjusted. Explanatory drawing which shows the method to test | inspect clogging of the pattern hole of a screen plate making using a ring-shaped 2nd light source using the external appearance inspection apparatus of this invention, Explanatory drawing which shows another method to test | inspect clogging of the pattern hole of screen plate making using a ring-shaped 2nd light source, (A) thru | or (D) is explanatory drawing which shows the manufacture procedure of screen plate-making, Explanatory drawing showing the principle of screen printing by screen plate making, It is an enlarged view of the pattern hole in the inspection site | part of screen platemaking.

Explanation of symbols

1 Screen making 2 Screen mesh (メ ッ シ ュ)
3 Frame 4 Photosensitive emulsion (photosensitive resin)
5 Pattern Master 6 Pattern Hole 7 Squeegee 8 Ink 9 Substrate 10 Appearance Inspection Device 11 Base 12 Table 13 Auxiliary Frame 14 Monitor / Operation Unit Unit 15 Guide Mechanism 15A, 15B LM Guide 16 Monitor
17 Operation panel 18 Support member 19 CCD camera (image receiver)
19A Lens unit 20 Microscope 21 First light source (first light source)
22 Ring-shaped second light source (second light source)
23 First polarizing filter (first polarizing filter)
24 Second polarizing filter (second polarizing filter)
25 Mount 26 with casters 2nd operation part A Clogging G Floor surface H Distance between base upper surface and table L Center line L ′ connecting CCD camera and inspection site Optical axis P _{0 of} first and second polarizing filters Rotational direction reference position P of the _first polarizing filter ₁ Rotational direction setting position P of the second polarizing filter P ₂ Position where the brightness is optimal and the silhouette of the pattern hole is most clear P ₃ Position rotated 15 degrees from the reference position

Claims (4)

The screen plate making is set on the table, light is transmitted from the light source arranged on one side of the screen plate making on the table to the other side of the screen plate making on the table, and the light image of the screen making by the transmitted light is received by the image receiving unit. In the screen plate appearance inspection apparatus for inspecting the appearance of the screen plate making on the table from the received image,
A screen plate making, wherein a first polarizing filter is disposed between the light source and the screen plate making on the table, and a second polarizing filter is disposed between the image receiving unit and the screen plate making on the table. Visual inspection equipment.   The screen plate appearance inspection apparatus according to claim 1, wherein the first and second polarizing filters are rotatable relative to each other around an optical axis.   3. The screen plate appearance inspection apparatus according to claim 1, wherein the light source is offset from a center line connecting the image receiving portion and the screen plate inspection portion on the table.   The light source is a combination of a first light source disposed on the center line connecting the image receiving portion and the screen plate inspection portion on the table, and a second light source disposed in a ring shape around the first light source. The appearance inspection apparatus for screen plate making according to any one of claims 1 to 3, characterized in that:

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