TWI795552B - Measuring method and measuring apparatus - Google Patents

Abstract

An object is held in a condition where a surface of the object is perpendicular to a predetermined XY plane and a direction corresponding to a transfer direction while the object was manufactured is parallel to the XY plane. Further, the object is positioned in a condition where an angle between a normal of the surface of the object and the X direction becomes an initial angle (Step S11). Parallel light is irradiated with the object from X direction (Step S12). A image capturing device captures an image on a screen which is projected through the object (Step S13). Next, capturing an image by the image capturing device is repeated while changing the angle between the normal of the surface of the object and the X direction to obtain a plurality of images (Steps S13 to S15).

Description

Measuring method and measuring device

The present invention relates to a technique for obtaining an image from a sheet-shaped or plate-shaped object. The obtained image is preferably used to obtain characteristics of changes in thickness or surface shape of the object.

Conventionally, there has been known a technique for continuously producing sheet-like or plate-like members. For example, in the roll forming apparatus of JP-A-2010-46798, molten resin extruded from a die (die) is conveyed continuously while being sandwiched between rolls, and a sheet is formed.

On the other hand, various techniques for inspecting continuously produced sheets have also been proposed. For example, in the inspection method of Japanese Patent Application Laid-Open No. 2007-211092, a sheet-shaped film is arranged obliquely relative to the screen between the light source and the screen, and the screen is photographed, thereby inspecting the gentle wave shape of the film surface. Variation in film thickness due to unevenness. In the defect detection method of Japanese Patent Laid-Open No. 5-180785, the following technology is disclosed: a straight fluorescent tube is arranged obliquely with respect to the width direction of the transparent adhesive sheet, and a camera is used to detect defects along the length direction of the sheet. Shading of streaky defects.

However, when a sheet or a plate is manufactured while being continuously conveyed, variations in thickness or surface shape of convex or concave shapes extending in the width direction occur due to various factors. A change in thickness or surface shape may be evaluated as a defect or as a quality level of the product. In any case, it is desirable to obtain the characteristics of non-uniform transmission or reflection of light, so that the obtained characteristics can be used to help in the investigation of the cause of the change, the adjustment of the device to reduce the change, and whether there is room for reducing the change. Judgment etc.

The present invention is directed to an image acquisition method for acquiring an image derived from a sheet-shaped or plate-shaped object manufactured while being continuously conveyed in a conveying direction.

The image acquisition method includes the following steps: a) The surface of the object is perpendicular to a predetermined XY plane, and the conveying direction is parallel to the XY plane, and the normal line of the surface of the object is The object is arranged so that the angle formed by the X direction becomes the first angle; b) irradiating the object from the X direction with light that is parallel or convergent or divergent with respect to the Y direction; c) by obtaining An image formed by projecting light transmitted or reflected from the object onto a screen, or an image obtained by receiving light transmitted or reflected from the object; d) using the surface of the object and the The XY plane is vertical, the conveying direction is parallel to the XY plane, and the angle formed by the normal line of the surface of the object and the X direction becomes a second angle, and the object is arranged. and e) obtaining other images by performing the step c) again.

According to the present invention, it is possible to obtain an image showing unevenness in transmission or reflection of light from an object in the transport direction.

In a preferred embodiment, in the step d), the object is rotated about an axis perpendicular to the XY plane.

In a more preferable form, the above steps are repeated while changing the angle formed by the normal line of the surface of the object in the step d) and the X direction by an angle of 15 degrees or less. Step d) and step e) to obtain a plurality of images.

The present invention is also directed to a measuring method for obtaining measured values representing properties of said object from a sheet-shaped or plate-shaped object manufactured while being continuously conveyed in the conveying direction. . The measuring method includes the steps of: f) acquiring the image and the other images by the image acquiring method; and g) acquiring the map in a direction corresponding to the conveying direction. Changes in the brightness of the image and other images mentioned.

In a preferred form, in the step d), the object is rotated around an axis perpendicular to the XY plane, and the object is rotated while changing the position of the object in the step d). The angle formed by the normal line of the surface and the X direction, while repeatedly performing the step d) and the step e) to obtain a plurality of images, to obtain the image including the image and the other images a plurality of images, and in the step g), obtain brightness changes of the plurality of images in the conveying direction.

A more preferable form further includes the following step: h) Obtaining the maximum value of the respective brightness changes of the plurality of images.

The present invention is also directed to an image acquisition device that acquires an image derived from a sheet-shaped or plate-shaped object manufactured while being continuously conveyed in a conveying direction. The image acquisition device includes: a holding part, wherein the surface of the object is perpendicular to a predetermined XY plane, the conveying direction is parallel to the XY plane, and the normal line of the surface of the object is parallel to the X direction. The formed angle can be relatively changed to hold the object; the illumination unit irradiates the object from the X direction with parallel, convergent or divergent light with respect to the Y direction; and the imaging unit, by An image is obtained by projecting light transmitted or reflected from the object onto a screen, or an image is obtained by receiving light transmitted or reflected from the object.

In a preferred aspect, the holding unit rotates the object about an axis perpendicular to the XY plane.

A more preferable aspect further includes a control unit that controls the imaging unit and the holding unit. Under the control of the control unit, the imaging unit repeatedly acquires images while changing the angle formed by the normal line of the surface of the object and the X direction by the holding unit.

These and other objects, features, aspects, and advantages will be clarified by the following detailed description of the present invention with reference to the accompanying drawings.

1: Measuring device

9, 90: object

11: Image acquisition device

12: computer

13: Display

21: Keeping Department

22: Lighting department

23: screen

24: Camera department

25: Control Department

60: Image

61: Horizontal direction

62: Vertical direction

63: Image processing range

64: unit area

71: parallel light

81: Mold

82: Main roller

83: The first metal elastic roller

84: Second metal elastic roller

91: Shipping direction

92: Width direction

121: Computing department

211: frame

212: motor

221: light source

222: light emitting part

223, 241: lens

242: Sensor Department

243: Support Department

901~903: Measurement results for different objects 9

911, 912: dotted line

J1: axis

J2: optical axis

S11~S18: steps

X, Y, Z: direction

Fig. 1 is a front view of the measuring device.

Fig. 2 is a plan view of the image acquisition device.

Fig. 3 is a schematic diagram showing a state of manufacturing an object.

FIG. 4 is a diagram showing an object.

FIG. 5 is a diagram showing the flow of operations of the measuring device.

FIG. 6 is a diagram showing an example of an acquired image.

FIG. 7 is an enlarged view showing an image processing range.

FIG. 8 is a diagram showing an example of brightness change.

FIG. 9 is a diagram illustrating a relationship between a rotational position and a maximum change value of brightness.

Fig. 10 is a plan view showing another image acquisition device.

Fig. 1 is a front view showing a measuring device 1 according to a first embodiment of the present invention. The measurement device 1 includes an image acquisition device 11 , a computer 12 and a display 13 . FIG. 2 is a plan view of the image acquisition device 11 . In FIGS. 1 and 2 , for convenience of description, the X direction, the Y direction, and the Z direction are shown. The X direction, the Y direction and the Z direction are perpendicular to each other. The object 9 to be measured is a sheet-shaped or plate-shaped member manufactured while being continuously conveyed in a predetermined conveying direction. The object 9 is molded by resin, for example. The object 9 is preferably a plastic product as a substitute for glass for a touch panel, but the application of the object 9 is not limited thereto. The object 9 may also be formed of a material other than resin. In the first embodiment, the object 9 is transparent, and both main surfaces of the object 9 are substantially flat.

As shown in FIGS. 1 and 2 , image acquisition device 11 includes holding unit 21 holding object 9 , illuminating unit 22 irradiating light onto object 9 , screen 23 , imaging unit 24 , and control unit 25 . The illustration of the control unit 25 is omitted in FIG. 2 . The holding part 21 is the surface of the object 9 perpendicular to the XY plane, and the transportation of the object 9 during manufacture The object 9 is held so that the direction corresponding to the direction is parallel to the XY plane. The “surface” of the object 9 refers to the largest surface of the object 9 . The XY plane refers to a predetermined virtual one plane parallel to the X direction and the Y direction.

The holding unit 21 includes a frame 211 for holding the object 9 and a motor 212 . The motor 212 rotates the frame 211 about an axis J1 parallel to the Z direction, that is, perpendicular to the XY plane. The holding unit 21 holds the object 9 such that the angle between the normal line of the surface of the object 9 and the X direction can be relatively changed. In FIG. 2 , the frame 211 is rotated by a chain line of two dots.

The lighting unit 22 includes a light source 221 , a light emitting unit 222 and a lens 223 . In FIG. 2 , illustration of the light source 221 is omitted. The optical axis J2 of the illumination unit 22 is parallel to the X direction, that is, perpendicular to the YZ plane. In this embodiment, the light source 221 is a light-emitting diode (LED). Other devices can also be used as the light source 221 . The light generated by the light source 221 is introduced into the light emitting part 222 through an optical fiber. The light emitting part 222 emits light from a pin hole. That is, the light emitting part 222 is a point light source. The light source 221 and the light emitting part 222 can also be a unit. The light emitted from the light emitting portion 222 is converted into parallel light 71 by the lens 223 . In FIGS. 1 and 2 , illustration of constituent elements holding the light emitting portion 222 and the lens 223 is omitted.

The parallel light 71 is irradiated to the object 9 from the X direction by the illuminating part 22 . The light transmitted through the object 9 is guided to the screen 23 . Thereby, the light transmitted through the object 9 is projected onto the screen 23 . The imaging unit 24 acquires an image projected on the screen 23 . Expressed precisely, the imaging unit 24 acquires data representing an image of the object 9 projected on the screen 23 . The imaging unit 24 takes pictures from a position that does not interfere with the frame 211 of the holding unit 21. Capture screen 23. Since the imaging unit 24 captures the screen 23 from obliquely above, the acquired image is corrected to have the same shape as when it is captured from the front. In FIGS. 1 and 2 , constituent elements of the support screen 23 and the imaging unit 24 are omitted. The control unit 25 controls the motor 212 of the holding unit 21 and the imaging unit 24 .

FIG. 3 is a schematic diagram showing a state of manufacturing object 9 . FIG. 3 shows a state of being manufactured by the manufacturing method disclosed in Japanese Patent Application Laid-Open No. 2010-46798, but the manufacturing method of the object 9 is not limited to the method described above. The sheet-shaped molten resin extruded from the die 81 is first introduced into the gap between the highly rigid main roll 82 and the first metal elastic roll 83 . The resin is formed by being sandwiched between the main roll 82 and the first metal elastic roll 83 , and is conveyed onto the main roll 82 by the rotation of the main roll 82 . The resin is further introduced into the gap between the main roll 82 and the second metal elastic roll 84 , and is sandwiched between the main roll 82 and the second metal elastic roll 84 to be further shaped.

The resin is conveyed onto the second metal elastic roller 84 by the rotation of the second metal elastic roller 84 , and is conveyed as a continuous object 90 in the conveying direction indicated by reference numeral 91 . The object 9 shown in FIGS. 1 and 2 is an object obtained by cutting out a part of the object 90 .

FIG. 4 is a diagram showing an object 9 . A symbol 91 is attached to an arrow indicating a direction corresponding to the conveying direction 91 in FIG. 3 . In the following description, the direction on the object 9 corresponding to the conveyance direction 91 is also referred to as "transportation direction 91". In addition, a direction parallel to the surface of the object 9 and perpendicular to the transport direction 91 is referred to as a width direction 92 . In FIGS. 1 and 2 , the width direction 92 is perpendicular to the XY plane.

FIG. 5 is a diagram showing the flow of operations of the measurement device 1 . First, the The object 9 is mounted on the frame 211 of the holding part 21 . As described above, the surface of the object 9 is perpendicular to the XY plane, and the conveyance direction 91 is parallel to the XY plane. The control unit 25 rotates the motor 212 to arrange the object 9 at a predetermined initial rotation position. Thereby, the object 9 is arranged so that the angle formed by the normal line of the surface of the object 9 and the X direction becomes an initial first angle (step S11). The normal (accurately, the normal direction) of the surface of the object 9 is not the normal line in the strict sense of each position on the surface, but the approximate normal direction of the surface of the object 9 held by the frame 211, is a direction fixed with respect to the rotation axis of the frame 211 or the motor 212 .

The light generated by the light source 221 is emitted from the light emitting part 222, and the parallel light 71 is irradiated to the object 9 from the X direction (step S12). Of course, the order of step S11 and step S12 can also be exchanged. By irradiating light onto the object 9 , the light transmitted through the object 9 is projected onto the screen 23 to form a projected image of the object 9 . Under the control of the control unit 25, the imaging unit 24 acquires an image of the projected image (step S13). Image data is stored in the memory unit of the computer 12 via the control unit 25 .

The control unit 25 rotates the motor 212 to arrange the object 9 at the next rotational position. Thereby, the object 9 is arranged so that the angle formed by the normal line of the surface of the object 9 and the X direction becomes a 2nd angle (step S14, step S15). Furthermore, since the object 9 rotates around the axis J1, the surface of the object 9 is perpendicular to the XY plane, and the state in which the conveyance direction 91 is parallel to the XY plane is maintained. The data of the second image is stored in the memory section of the computer 12 by performing image acquisition again by the imaging section 24 (step S13 ).

By the control of the control unit 25, while changing the plane and X of the object 9 The second angle formed by the directions is repeatedly photographed by the imaging unit 24 (step S13 to step S15). Thereby, a plurality of images are obtained, and their data are stored in the computer 12 . Then, light irradiation to the object 9 by the illumination unit 22 is stopped (step S16).

The pitch of the rotation angle of the object 9 in step S15 is preferably 15 degrees or less. In addition, although the pitch of the rotation direction and the rotation angle can be changed in various ways, it is preferable that the pitch of the rotation direction and the rotation angle is constant. In addition, in the above description, the first angle formed by the normal line of the surface of the object 9 and the X direction is referred to as "first angle", and the second and subsequent angles are referred to as "second angle". , but these are expressions for convenience of explanation and do not necessarily have to be distinguished. The same applies to other embodiments described below.

FIG. 6 is a diagram showing an image 60 as an example of the acquired image. The horizontal direction 61 in FIG. 6 is a direction corresponding to the transport direction 91 on the object 9 . The longitudinal direction 62 is a direction corresponding to the width direction 92 of the object 9 . In FIG. 6 , the phenomenon that a plurality of stripes extending in the longitudinal direction 62 appear in the image 60 is represented by a plurality of dotted lines extending in the longitudinal direction 62 . These streaks are caused by changes in the thickness or surface shape of the object 9 in the transport direction 91 . Since the stripes extend in the width direction 92 of the object 9, they are called "horizontal stripes" hereinafter.

A rectangle indicated by a symbol 63 represents an area of the image 60 to be processed by the computing unit 121 of the computer 12 . Hereinafter, the area 63 is referred to as "image processing range". FIG. 7 is an enlarged view showing the image processing range 63 . The image processing range 63 is divided into a plurality of elongated unit areas 64 extending in the longitudinal direction 62 . A plurality of unit regions 64 are arranged in the lateral direction 61 . The width of one unit area 64 in the horizontal direction 61 is equal to or greater than one pixel, and in this embodiment, each unit area 64 is horizontally Four pixels are arranged in direction 61 .

The calculation unit 121 obtains the average value of the pixel values of each unit area 64 as the lightness of the unit area 64 . Actually, correction is performed to eliminate the unevenness of the intensity of the illumination light or the influence of the optical system. Specifically, the imaging unit 24 acquires an image of the screen 23 in advance in a state where the object 9 does not exist. The computing unit 121 obtains the brightness of each unit area 64 in the image as a reference brightness. Next, the lightness of each unit area 64 in the image acquired with the object 9 present is divided by the reference lightness. Thereby, corrected lightness is obtained. The corrected lightness represents the transmittance of the area on the object 9 corresponding to the unit area 64 . In the following description, the corrected lightness is simply referred to as "lightness".

The computing unit 121 performs the computing on a plurality of images obtained by repeatedly performing step S13. Thereby, changes in brightness in the horizontal direction 61 of each image, that is, in the direction corresponding to the transport direction 91 are obtained (step S17 ). FIG. 8 is a diagram showing an example of brightness change. The horizontal axis represents the number of the unit area 64, and the vertical axis represents lightness. It can be seen from Figure 8 that due to some reasons, the brightness has changed. Furthermore, it can be seen that the change in brightness has some degree of periodicity.

The calculation unit 121 obtains the maximum value of the brightness change of each image. Various values can be used as the change in brightness. In this embodiment, the difference in brightness between adjacent unit regions 64, that is, the absolute value obtained by subtracting the brightness of one of them from the brightness of the other is obtained. Value as a change in lightness. Then, the maximum value of brightness change is acquired from each image. Hereinafter, the maximum value of brightness change is called "contrast". Each image corresponds to each rotation position respectively, so by obtaining a The contrast of each image obtained by the sample can obtain the relationship between the rotation position and the contrast.

FIG. 9 is a diagram illustrating the relationship between the rotational position of the object 9 and the contrast. The information shown in FIG. 9 is displayed on the display 13 of FIG. 1 (step S18). Symbols 901 , 902 , and 903 represent measurement results for different objects 9 . However, FIG. 9 does not accurately represent the actually obtained measurement results, but instead depicts a typical relationship of contrast with respect to rotational position based on actual measurement results. The rotation position represents the angle formed by the normal line of the surface of the object 9 and the X direction, so the rotation position is also referred to as "incident angle" hereinafter. An incident angle of 0 degrees is a state where the parallel light 71 is perpendicularly incident on the object 9 .

In general, as the incident angle increases, the contrast increases. The reason for this is that as the incident angle of the illumination light toward the object 9 increases, the brightness difference between adjacent unit regions 64 increases. However, when the length of one cycle of brightness change is short, if the incident angle of the illumination light is excessively increased, the length of one cycle is included in one unit area 64 , and the change in brightness decreases instead. As a result, contrast decreases.

In the case of the example in FIG. 9 , in the line marked with reference numeral 901 , the contrast becomes maximum when the incident angle is 60 degrees. In the line marked with reference numeral 902, the contrast ratio is maximum when the incident angle is 70 degrees. In the line marked with symbol 903 , the contrast increases monotonously when the incident angle is from 0° to 80°. The change in lightness represents the change in the thickness or surface shape of the object 9 on the conveying direction 91, so it can be said that in the case of symbol 901, the object 9 has periodic thickness or surface shape changes with a short cycle length. In the case of 902, the object 9 has periodic changes in thickness or surface shape whose period length is longer than that in the case of symbol 901, and in the case of symbol 903, the object 9 has A periodic change in thickness or surface shape with a period length longer than in the case of symbol 902 . The measured value as the information shown in FIG. 9 represents the periodic characteristics of the change in the thickness or surface shape of the object 9 in the conveying direction 91 , that is, the characteristics of the horizontal stripes on the object 9 . More precisely, it represents the characteristic of uneven transmission or reflection of light due to horizontal stripes. Furthermore, the position where the contrast turns from increasing to decreasing is affected by the width of the unit area 64 in the lateral direction 61 . That is, the position where the contrast changes from increasing to decreasing depends on the pixel size of the imaging unit 24 and the number of pixels in the horizontal direction 61 of the unit area 64 .

In the measurement device 1 , by rotating the object 9 , the characteristics of the horizontal stripes can be easily digitized and graphed in two-dimensional space.

Information obtained in the manner described above can be used for various purposes. For example, in FIG. 9 , when the contrast is greater on the right side, it can be said that horizontal stripes extending in the width direction 92 and having a long period with respect to the conveyance direction 91 are generated on the object 9 . When the contrast is large on the left side, it can be said that horizontal stripes extending in the width direction 92 and having a short period with respect to the conveyance direction 91 are generated on the object 9 . Therefore, when a line indicating contrast exists on the upper left, it can be said that the object 9 has short-period horizontal stripes that are easy to be noticed. Thus, for example, when the incident angle is 70 degrees or less indicated by the dotted line 911 , if the contrast is greater than or equal to 0.2 indicated by the dotted line 912 , it can be determined that the manufactured member does not satisfy the quality standard. Since the quality can be evaluated by using the two parameters of the incident angle of the illumination light and the contrast, for example, when the object 9 is a transparent plate for a touch panel, it can be quantitatively evaluated by referring to the graph with the required viewing angle. Are the stripes obvious.

In addition, the information in FIG. 9 can also be used for adjustments at the start-up of the manufacturing equipment. The incident angle at which the contrast becomes the maximum is determined according to the poorly adjusted part of the manufacturing device. The so-called poor adjustment of the device refers to, for example, poor adjustment of the position of meshing gears, improper temperature of molten resin, improper speed difference between rolls, and poor adjustment of the distance between the mold and the roll gap. Owing to poor adjustment of these molding conditions, there may be cases where characteristic periodic horizontal stripes appear on the object 9 . Therefore, by acquiring the information shown in FIG. 9 , it is possible to quickly grasp the cause of the adjustment failure of the device. For example, from the characteristics of the horizontal stripes, it can be determined which gear the horizontal stripes appear as a gear mark (gear mark), so that the position that needs to be adjusted can be quickly determined.

The information in FIG. 9 can also be used by the operator to evaluate the operational capability of the manufacturing equipment. When there are horizontal stripes that cannot be said to be poorly adjusted, it can be judged whether there is room for further improvement of the current operator's ability by obtaining information in advance when a skilled person operates the device when it is made of the same material. In addition, it will also serve as a material for judging whether it is necessary to further learn the fine operation of which part of the device.

In the measurement device 1, processing other than the above-described calculations may also be performed. A plurality of images are obtained by the image acquisition device 11, and based on these images, the characteristics of the change in thickness or surface shape of the object 9 in the conveying direction 91 can be grasped, so that various judgments can be made. It is formed by light passing through the object 9 from multiple angles.

Fig. 10 is a plan view showing an image acquisition device 11 of a measurement device according to a second embodiment of the present invention. Parts other than the image acquisition device 11 of the measuring device are the same as those in FIG. 1 . In FIG. 10 , the light source 221 and the control unit of the lighting unit 22 are omitted. 25 illustration. In the following description, the same code|symbol is attached|subjected to the component which has the same function as 1st Embodiment. The imaging unit 24 of the image acquisition device 11 receives reflected light from the object 9 . The object 9 may be transparent or opaque. The surface of the object 9 irradiated with the illumination light is substantially flat.

The structures of the holding unit 21 and the lighting unit 22 are the same as those in FIGS. 1 and 2 . In FIG. 10 , the direction of the optical axis of the illuminating unit 22 is also defined as the X direction, the surface of the object 9 is perpendicular to the XY plane, and the transport direction 91 on the object 9 is parallel to the XY plane.

The imaging unit 24 includes a lens 241 , a sensor unit 242 and a support unit 243 . The lens 241 and the sensor part 242 are fixed on the supporting part 243 . Although not shown in the drawing, as shown by chain lines, a rotation mechanism for rotating the imaging unit 24 around the axis J1 of the holding unit 21 is further provided. Thereby, when the object 9 rotates around the axis J1 , the imaging unit 24 moves so that reflected light enters the imaging unit 24 . The reflected light incident on the imaging unit 24 is introduced into the sensor unit 242 through the lens 241 , and image data is stored in the memory unit of the computer 12 through the control unit 25 .

The operation of the measurement device 1 is the same as that of the first embodiment. As shown in FIG. 5 , first, the object 9 is arranged so that the angle formed by the normal line of the surface of the object 9 and the X direction becomes an initial first angle (step S11 ). The parallel light 71 is irradiated to the object 9 from the X direction (step S12 ), and the imaging unit 24 receives the light reflected by the object 9 to obtain an image (step S13 ). The image data is stored in the memory unit of the computer 12 via the control unit 25 .

The control unit 25 rotates the motor 212 to place the object 9 on the next Rotate position. Thereby, the object 9 is arranged so that the angle formed by the normal line of the surface of the object 9 and the X direction becomes a 2nd angle (step S14, step S15). The imaging unit 24 also moves so that reflected light enters. The data of the second image is stored in the storage unit of the computer 12 by performing image acquisition again by the imaging unit 24 (step S13 ).

Under the control of the control unit 25, while changing the second angle between the surface of the object 9 and the X direction and the position of the imaging unit 24, the imaging unit 24 repeatedly performs imaging (step S13 to step S15). Thereby, a plurality of images are obtained, and their data are stored in the computer 12 . Then, light irradiation to the object 9 by the illumination unit 22 is stopped (step S16).

The obtained image is subjected to the same processing as in the first embodiment, and the brightness (accurately, the brightness after correction) of each unit area 64 is obtained. The reference brightness used for brightness correction is obtained from an image obtained by holding the holding portion 21 on a flat reflector. The computing unit 121 performs the computation on a plurality of images. Thereby, changes in brightness in the horizontal direction 61 of each image, that is, in the direction corresponding to the transport direction 91 are obtained (step S17 ). Brightness changes periodically. The calculation unit 121 obtains the contrast which is the maximum value of the brightness change of each image by the same processing as that of the first embodiment.

When the imaging unit 24 receives reflected light, a change in brightness indicates a change in the shape of the surface of the object 9 in the transport direction 91 . By deriving the contrast from each image, the information according to FIG. 9, ie the measurement, is obtained. That is, the relationship between the incident angle and the contrast is obtained. The relationship between the incident angle and the contrast is displayed on the display 13 (step S18). The measured value represents the periodic characteristic of the change in the surface shape of the object 9 in the transport direction 91 , that is, the characteristic of the horizontal stripes on the object 9 . More precisely, it represents the characteristic of uneven reflection of light due to horizontal stripes. Furthermore, in the measurement device, by rotating the object 9, the characteristics of the horizontal stripes can be easily digitized and graphed in two-dimensional space.

As with the first embodiment, the information obtained from the second embodiment, which is a reflective measuring device, can be used for various purposes, such as judgment of good or bad of manufactured products, poor adjustment of equipment, judgment of operator's proficiency, etc. use.

In the measurement device, processing other than the above calculations may also be performed. By acquiring a plurality of images, the characteristics of the change in the surface shape of the object 9 in the conveyance direction 91 can be grasped based on these images, so that various judgments can be made. It is formed by the light reflected on the object 9 .

In the above embodiment, a plurality of images are obtained, but only two images may be obtained. That is, the iterative process performed by step S14 may be performed once. Even if only two images are acquired, the characteristics of the change in thickness or surface shape of the object 9 in the conveying direction 91 can be grasped. Of course, as described above, it is preferable to repeatedly acquire images while changing the angle formed by the normal line of the surface of the object 9 and the X direction by an angle of 15 degrees or less. This makes it possible to more reliably grasp the characteristics of changes in the thickness and surface shape of the object 9 in the conveying direction 91 . When the image acquisition time is taken into consideration, in practice, the angle of change is one degree or more.

The image acquisition device 11 and the measurement device 1 of the above-described embodiments can be modified in various ways.

In the first embodiment, the imaging unit 24 acquires the image of the object 9 projected on the screen 23, but similarly to the second embodiment, the imaging unit 24 can directly receive the light transmitted through the object 9 to obtain the image. image. Similarly, in the second embodiment, the light reflected by the object 9 may be guided to the screen, and the image projected on the screen may be acquired by the imaging unit 24 . As described above, the image acquisition device 11 can also acquire the image originating from the object 9 by various methods.

When the imaging unit 24 directly receives light from the object 9, as shown in FIG. However, when the light-receiving surface of the sensor part 242 is larger than the cross-section of the light beam from the object 9, the lens 241 can be omitted.

The light irradiated to the object 9 is not limited to parallel light. As long as they are parallel, convergent, or divergent with respect to the Y direction, they may also be scattered with respect to the Z direction. The so-called convergence or divergence with respect to the Y direction means that the width of the light beam in the Y direction gradually shrinks or gradually expands according to the distance from the light source. Of course, the illumination light can also be light that converges or diverges with respect to the Z direction. When the illumination light converges or diverges with respect to the Y direction, if the position on the object 9 in the conveying direction 91 is different, the distance between the position and the screen 23 or the imaging unit 24 will be different. The process of enlarging or shrinking each part of the image. These processes can be easily performed according to the geometrical positional relationship between the illumination unit 22 , the object 9 , and the screen 23 or the imaging unit 24 .

In the second embodiment of FIG. 10, the imaging unit 24 rotates in synchronization with the rotation of the object 9, but it is also possible to fix the direction of the object 9 and make the illumination unit 22 and the imaging unit 24 rotate around the axis J1. rotate. In the example shown in Figure 2 and Figure 10, By rotating the object 9 around the axis perpendicular to the XY plane, the incident angle of the illumination light toward the object 9 can be easily changed.

In the first embodiment shown in FIG. 2, the object 9 is not limited to being transparent. For example, when the imaging unit 24 is an infrared camera, the object 9 may be opaque as long as it transmits infrared rays. The object 9 only needs to be transparent to the illumination light.

In the above-described embodiment, multiple sets of illumination units 22 and imaging units 24 are used to perform multiple imaging, but a plurality of sets of illumination units 22 and imaging units 24 may be provided in the measurement device 1 . In this case, a plurality of images having different incident angles of illumination light can be acquired simultaneously. It is also possible to install the measuring device 1 in-line in the manufacturing apparatus of the manufacturing object 9 by installing a plurality of sets of the illuminating unit 22 and the imaging unit 24 on the measuring device 1 . Thereby, real-time product inspection or quality evaluation can be realized.

The processing of the calculation unit 121 of the computer 12 is not limited to the case described in the above-mentioned embodiment, and various calculations may be performed to obtain values representing the characteristics of the horizontal stripes of the object 9 . For example, it is also possible to obtain the average value of the values of the pixels arranged in the vertical direction corresponding to the width direction 92 of the object 9 among the plurality of obtained images, and to obtain the average value of the pixel values corresponding to the conveying direction 91. The change in the average value in the direction is subjected to Fourier transform to obtain the characteristics of the horizontal stripes. The characteristics of the horizontal stripes can also be grasped by observing and confirming multiple images with naked eyes. Multiple images obtained from light transmitted or reflected from the object 9 at multiple angles will show the unevenness of transmission or reflection of light caused by horizontal stripes. In any case, the characteristics of the horizontal stripes can be easily grasped.

The configurations in the above-described embodiments and modifications may be appropriately combined as long as they do not contradict each other.

The invention has been described and described in detail, but the description is illustrative and not restrictive. Therefore, it can be said that various modifications and forms are possible without departing from the scope of the present invention.

S11~S18: steps

Claims (6)

A measuring method in which measured values representing characteristics of a sheet-like or plate-like object are obtained by a measuring device from a sheet-like or plate-like object manufactured while being continuously conveyed in a conveying direction , the measuring method includes the following steps: a) by means of the holding part of the measuring device, the largest surface of the object is perpendicular to a predetermined XY plane, and the conveying direction is parallel to the XY plane, and Arranging the object so that the angle formed by the normal line of the largest surface of the object and the X direction becomes a predetermined angle; Either convergent or divergent light is irradiated to the object from the X direction; c) by the imaging unit of the measurement device, an image formed by projecting the light transmitted or reflected by the object onto the screen is obtained , or obtain an image by receiving the light transmitted or reflected by the object; d) obtain the lightness of the image in the direction corresponding to the conveying direction by the computing part of the measuring device The maximum value of the change; e) by the control unit of the measuring device, while maintaining the state in which the maximum surface of the object is perpendicular to the XY plane and the conveyance direction is parallel to the XY plane, Step b) to step d) are repeated while changing the angle between the normal of the largest surface of the object and the X direction, whereby the imaging unit acquires a plurality of images and the calculation unit obtains a maximum value of the brightness change of each of the plurality of images; and f) Obtaining the relationship between the angle formed by the normal of the largest surface of the object and the X direction and the maximum value of the brightness change by the calculation unit. The measuring method according to claim 1, wherein in the e) step, the object is rotated around an axis perpendicular to the XY plane. As the measurement method described in item 1 or item 2 of the scope of patent application, wherein in the e) step, the angle formed by the normal line of the largest surface of the object and the X direction is only While changing the angle of 15 degrees or less, step b) to step d) are repeated. A measuring device that acquires measured values representing properties of a sheet-like or plate-like object that is produced while being continuously conveyed in a conveying direction, the measuring The device includes: a holding unit for maintaining a state where the largest surface of the object is perpendicular to a predetermined XY plane and the conveying direction is parallel to the XY plane, so that the normal line of the largest surface of the object The object is held in such a manner that the angle formed with the X direction can be relatively changed; the illumination unit irradiates the object from the X direction with light that is parallel, convergent or divergent with respect to the Y direction; the imaging unit , by obtaining an image formed by projecting the light transmitted or reflected by the object onto a screen, or by receiving the light transmitted or reflected by the object to obtain an image; corresponding to the orientation of the image on the a maximum value of brightness change; and a control unit that controls the imaging unit and the holding unit; under the control of the control unit, the holding unit changes the normal line of the maximum surface of the object the angle formed with the X direction while the imaging unit repeatedly acquires images, thereby acquiring a plurality of images; the calculation unit acquires the maximum value of the brightness change of each of the plurality of images, And obtain the relationship between the angle formed by the normal of the largest surface of the object and the X direction and the maximum value of the brightness change. The measuring device according to claim 4, wherein the holding unit rotates the object about an axis perpendicular to the XY plane. The measuring device according to claim 4 or claim 5, wherein the angle formed by the normal line of the largest surface of the object and the X direction is controlled by the control unit. The plurality of images are obtained while changing only an angle of 15 degrees or less.

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