JP2014009983A - Posture adjustment method of line sensor camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate posture adjustment of a line sensor camera regarding an inspection device for imaging a straight line parallel to an axis of an inspection roll by a plurality of line sensor cameras.SOLUTION: The posture adjustment method of a line sensor camera used for conveying a sheet by using a carrier roll and inspecting the sheet surface on the carrier roll winds a posture adjustment sheet having a plurality of posture adjustment patterns having parallel opposite sides, arrayed on a straight line in a direction vertical to the opposite sides, and set as graphics where a plurality of straight lines intersect one another at one point so that the opposite sides are matched with the carrier roll circumference, and adjusts a posture by using the posture adjustment patterns having intersection points arrayed on the straight line in the direction vertical to the opposite sides.

Description

  The present invention relates to a method for adjusting the posture of each camera to the correct orientation even when the number of line sensor cameras is large in sheet appearance inspection using a line sensor camera.

  Automatic appearance inspection is widely introduced due to features such as labor saving, stability of inspection, and total inspection (full width and full length). As an example, there are an inspection for confirming that a circuit pattern on a printed wiring board is formed as designed, and an inspection for confirming an attachment state of an electronic component mounted on the circuit board. A method of performing an inspection on a stage is known (for example, Patent Document 1).

  What is to be inspected is not limited to a single-wafer such as a substrate, but thin, wide and long products represented by films and paper are also subject to inspection. Here, thin and wide sheets are collectively referred to as a long sheet.

  In the automatic visual inspection of a long sheet, a line sensor camera in which a large number of image sensors are arranged in a straight line is widely used due to the characteristics of a long sheet manufactured continuously for a long time. The function of the line sensor camera is to acquire an image obtained by cutting a sheet continuously flowing in one imaging operation into a strip shape in the width direction by aligning the direction in which the image sensors are arranged with the width direction of the sheet. By repeating such imaging and arranging the belt-like images, the entire image can be obtained. The length in the width direction of the image obtained by one imaging is (the length in the width direction on the sheet (μm / element) captured by one imaging element) × (the number of imaging elements of one line sensor camera (element / Unit)) × (number of line sensor cameras (unit)), and the length in the sheet conveyance direction is determined by (imaging cycle (seconds)) × (sheet conveyance speed (m / second)).

  As the monitor for personal computers and thin-screen TVs become higher in definition and space-saving, the disadvantages that become a problem in optical films and electronic component films are becoming smaller, and high-resolution inspection is required. In order to achieve a high-resolution inspection, the above (range in which one image sensor captures an image on the sheet) must be reduced. If the number of imaging elements of one line sensor camera is the same, this means that the imaging range of one line sensor camera is narrowed, and in order to secure the same imaging range, it is necessary to increase the number of pixels of the line sensor camera. However, the number of image sensors of one line sensor camera is limited. On the other hand, as the screen becomes larger, the sheet has become wider. To inspect the entire width of the sheet, it is not enough to increase the number of pixels of the line sensor camera, and a larger number of cameras are required. It is coming.

  In order to make one inspection device with multiple line sensor cameras, adjust the posture of multiple cameras, that is, all the image sensors of multiple line sensor cameras are on a single straight line defined by the device design. Imaging is an important item for guaranteeing inspection accuracy. The position of the inspection target determined in the apparatus design is called an inspection position, and the position where the line sensor camera is imaging is called an imaging position. Adjusting the posture of the line sensor camera means that the imaging positions of all the line sensor cameras are matched with the inspection position.

  As a light source for sheet appearance inspection, a linear light source such as a fluorescent lamp is generally used instead of one point light source. This is because if one point light source is used for a wide range of inspection objects, the light received by the inspection object in the width direction is not uniform.

  FIG. 1 shows a camera 1 (displayed by a solid line) adjusted to a correct posture and a camera 2 (displayed by a broken line) whose posture is shifted from the correct position. The incident angle (FIG. 1 N2) and the reflection angle (FIG. 1 H2) at the imaging position of the camera 2 differ from the incident angle (FIG. 1 N1) and the reflection angle (FIG. 1 H1) of the camera 1 due to the deviation of the posture. As a result, light from a bright part of the light source cannot be received. It can be seen that the amount of received light decreases as the displacement of the camera 2 increases, and that the light from the light source cannot be received when the camera 2 further increases.

  Product forms called long sheets typified by paper, cloth, and film are flexible forms that can be folded, and long sheet manufacturing apparatuses usually have a large number of rolls to convey the long sheets. . Due to the tension applied to the long sheet, the position of the long sheet in contact with the roll is regulated on the roll surface, and the inspection position is stabilized. Such a roll to be inspected thereon is hereinafter referred to as an inspection roll. The position on the inspection roll imaged by each image sensor of the line sensor camera needs to be on a straight line parallel to the axis of the inspection roll and the axis of the light source on the surface of the inspection roll. When the adjustment is performed without being on one parallel straight line, the incident angle and the reflection angle are different in the width direction of the inspection roll, and the inspection cannot be performed correctly. In the case of the inspection on the inspection roll, the long sheet to be inspected is curved as shown in FIG. 2, so that the deviation of the incident angle and the reflection angle is larger than that in the case of a flat surface (FIG. 1). Highly accurate posture adjustment is required.

  The axis of the light source here refers to the central axis of a cylinder in a cylindrical light emitter such as a fluorescent lamp or rod illumination. Further, when a plurality of light sources are arranged on a straight line, the straight line is indicated.

  As an invention for adjusting the postures of a plurality of line sensor cameras, Patent Document 1 discloses a technique using a chart in which a plane figure having a dark part and a bright part is drawn. Although the same document discloses an invention for adjusting the postures of a plurality of line sensor cameras by arranging this chart at a specific position, it is intended for inspection using reflected light on a substrate, It was not intended for inspection using reflected or transmitted light on a curved surface.

JP 2008-298491 A

  The present invention relates to an inspection apparatus used in a long sheet manufacturing apparatus, in particular, an inspection apparatus in which a plurality of line sensor cameras image a straight line parallel to the axis of the inspection roll. An attitude adjustment method that makes it easy to adjust the attitude of a line sensor camera so as to capture an image on the same straight line parallel to the axis.

  The line sensor camera attitude adjustment method of the present invention is an attitude of a single or a plurality of line sensor cameras for observing the surface of a long sheet conveyed by a conveying roll on the conveying roll or between two conveying rolls. An adjustment method comprising: a plurality of patterns in which a plurality of straight lines that are not orthogonal to the opposite sides intersect at one point on a sheet of sheets having parallel opposite sides, and the intersection points are perpendicular to the opposite sides , And the posture of the sheet is adjusted by temporarily imaging the intersection of the patterns on the sheet with a line sensor camera. This is a method for adjusting the attitude of a line sensor camera.

  Preferably, at least one straight line parallel to the opposite side is drawn on a sheet of sheets having parallel opposite sides and fixed so that the straight lines overlap when the sheet is wound around the peripheral surface of the transport roll. This is a method for adjusting the attitude of a line sensor camera.

  According to the present invention, when adjustment is performed so that a plurality of line sensor cameras capture images on a straight line parallel to the axis of the inspection roll in the sheet inspection, even if the length (axis length) of the inspection roll is large, The license camera's attitude can be adjusted correctly.

It is a figure which shows the relationship between a line sensor camera attitude | position when a test object is a plane, and an imaging position. It is a figure which shows the relationship between a line sensor camera attitude | position when a test object is a cylindrical surface, and an imaging position. It is a figure which shows an example of the sheet | seat for line sensor camera attitude | position adjustment. It is a figure which shows the optical system in the case of using the line sensor camera attitude | position adjustment sheet | seat in this invention for reflected light inspection on an inspection roll. It is a figure which shows the optical system in the case of using the line sensor camera attitude | position adjustment sheet | seat in this invention in a reflected light test | inspection in the position which is not on an inspection roll. It is a figure which shows another example of the sheet | seat for line sensor camera attitude | position adjustment in this invention. It is a figure which shows the method of fixing the sheet | seat for line sensor camera attitude | position adjustment in this invention on an inspection roll. It is a figure which shows the relationship between the imaging position of a line sensor camera, and the imaging result of the pattern for attitude | position adjustment. It is a figure which shows the difference in the imaging result when the line | wire width of an attitude | position adjustment pattern differs. It is a figure which shows the optical system in the case of using the line sensor camera attitude | position adjustment sheet | seat in this invention for a regular transmission light test | inspection. It is a figure which shows an example of the sheet | seat for line sensor camera attitude | position adjustment in this invention which has multiple types of attitude | position adjustment patterns. It is a figure which shows the attitude | position adjustment method of a line sensor camera. It is a figure which shows the change of the imaging position by the attitude | position change of a line sensor camera.

  A line sensor camera posture adjusting sheet for achieving the object of the present invention is a pattern having parallel opposite sides (straight line 5 in FIG. 3) and a plurality of straight lines that are not orthogonal to the opposite sides (hereinafter, postures). The sheet has a plurality of adjustment patterns (referred to as 6 in FIG. 3), and the intersections are aligned on a straight line in a direction perpendicular to the opposite side.

  The sheet in the present invention is used by being wound so that there is no gap between the sheet and a single roll (FIG. 4). Or it winds and uses so that a clearance gap may not be made between this roll over two conveyance rolls (FIG. 5). In that case, it is necessary to wind so that the parallel opposite sides of the sheet | seat in this invention may correspond, respectively. In this way, when the sheet according to the present invention is wound, the posture adjusting pattern aligned on the straight line on the sheet according to the present invention can be made parallel to the inspection roll axis.

  In the case where the inspection roll is long, the appearance inspection width is large, the number of line sensor cameras is large, etc., the posture adjustment pattern aligned on the straight line on the sheet in the present invention is more accurately parallel to the axis of the inspection roll. For this purpose, as shown in FIG. 6, a straight line 12 parallel to the parallel opposite side 5 of the sheet of the present invention is drawn on the sheet of the present invention, and the straight line is drawn to the end of the sheet of the present invention. preferable. By being drawn up to the end, straight lines can be overlapped at the end when wound around the inspection roll. In FIG. 7A, a straight line 12 parallel to the opposite side reaches the end of the sheet in the present invention. Wind this A so that it overlaps the straight line 12.

  In the vertical direction, the angle between two straight lines is in the range of (90 ± 0.1) °, and in the parallel direction, the angle between the two straight lines is 0.1 ° or less. This means that the posture adjustment pattern that is linearly aligned on the sheet of the present invention, which is the reference for posture adjustment of the line sensor camera, is made parallel to the inspection roll axis, and the effect of the present invention is exhibited. It is a necessary item to make it happen. By fixing the sheet of the present invention to the inspection roll by the method described so far, a straight line connecting the intersections of the posture adjustment patterns becomes parallel to the axis of the inspection roll. Further, the inspection roll is fixed so that the straight line connecting the intersections of the posture adjustment patterns is the inspection position.

  The posture adjustment pattern of the present invention uses a figure in which a plurality of straight lines intersect at one point, but more preferably, the plurality of straight lines do not intersect with the conveyance direction and the plurality of straight lines intersect at one point. Use. It is composed of a plurality of straight lines that intersect at one point, and the intersection is located at the inspection position. Therefore, when the inspection position is imaged, the imaging result becomes one point, and a position away from the inspection position is imaged. If there are, the imaging result becomes a plurality of points. If the imaging results of the posture adjustment patterns for all the line sensor cameras become one point, the imaging position of all the line sensor cameras is adjusted to the inspection position.

  FIG. 8 explains the relationship between the posture adjustment pattern and the imaging position of the line sensor camera. The camera 1 is in the correct posture, and the intersection of a plurality of straight lines constituting the posture adjustment pattern at the inspection position is shown. The case where it imaged is shown. Since the camera 2 is deviated from the correct posture, the camera 2 shows a case where an image is taken away from the intersection of a plurality of straight lines constituting the posture adjustment pattern. The imaging result of the camera 1 has one dark part (13 in FIG. 8), but the imaging result of the camera 2 has two dark parts (14 in FIG. 8).

  The image sensor of the line sensor camera has a function of generating a charge approximately proportional to the amount of received light, and the voltage of the signal output from the image sensor is proportional to this charge. As one method of knowing the imaging result of the line sensor camera in real time, there is a method in which an output signal from each imaging device is taken into a computer and displayed on a monitor screen. Currently, in the line sensor camera widely used, the number of one image sensor exceeds 10,000, and all image sensors of the line sensor camera are displayed on a monitor screen of a computer having about 2000 pixels in the monitor screen width direction. When the image pickup result is displayed, either the image pickup device is thinned to see the whole state, or a part of the image pickup device is seen without thinning.

  The finer the drawing of the posture adjustment pattern, the higher the adjustment accuracy. However, when the image sensor is thinned out with the thin line, it becomes difficult to determine the posture adjustment pattern. The case where two types of posture adjustment patterns with different line widths are imaged will be described with reference to FIG. The vertical direction of the paper is the sheet conveying direction, and the horizontal direction of the paper is the sheet width direction. In the imaging result 15 of the posture adjustment pattern with a large line width and the imaging result 18 of the posture adjustment pattern with a thin line width, the line width of the imaging result 15 is thicker, and the line sensor camera uses the posture adjustment pattern with a large line width. Whereas an image is captured with 5 pixels, an attitude adjustment pattern with a narrow line width is captured with 2 pixels. In order to monitor a wide range of imaging results in the sheet width direction, when one image sensor is thinned out, the imaging result 18 is 2 pixels in the sheet width direction in the posture adjustment pattern with a narrow line width. The posture adjustment pattern may not be displayed on the monitor when the imaging position in the sheet conveyance direction is slightly shifted in the sheet conveyance direction. However, in the posture adjustment pattern with a large line width, the imaging result is 5 pixels or more in the sheet width direction. Therefore, even when one image sensor is thinned out, the posture adjustment pattern is displayed on the monitor. On the other hand, in order to accurately align the imaging position of the line sensor camera with the inspection position, a posture adjustment pattern with a narrow line width is preferable to a posture adjustment pattern with a large line width. The portions indicated by 16 and 19 in FIG. 9 are imaging positions when the line sensor camera is correctly adjusted. At this time, the case where the positions shifted by the same distance in the sheet conveying direction are imaged (17 and 20 in FIG. 9) is compared. In the posture adjustment pattern with a narrow line width, it can be seen that there are two black portions in the imaging result, but in the posture adjustment pattern with a large line width, the black imaging result is in one location, and there is a deviation from the inspection position. It becomes difficult to understand.

  More precise by using multiple posture adjustment patterns, roughly adjusting posture using thickly drawn posture adjustment patterns, and then finely adjusting posture adjustment patterns drawn with thin lines The posture can be adjusted.

  In the sheet manufacturing apparatus, a path through which the sheet passes is hereinafter referred to as a pass line.

  The posture adjustment pass line referred to in the present invention is determined as follows in each of the three cases.

  (1) When a sheet on a roll is inspected by reflected light (FIG. 4).

  In this case, the sheet according to the present invention is fixed in such a manner that the parallel opposite sides of the sheet according to the present invention are aligned on the inspection roll.

  (2) When inspecting with reflected light, the sheet is inspected at a location slightly lifted from the roll (FIG. 5). One end of the sheet in the present invention is fixed to the upstream roll 10 in the sheet conveyance direction from the imaging position, and the sheet in the present invention is transferred from the imaging position to the downstream roll 11 in the sheet conveyance direction, and then on the upstream roll 10. Then, the parallel opposite sides of the sheet in the present invention are matched to fix the sheet in the present invention.

  (3) In the case of inspection with regular transmitted light (FIG. 10). The inspection using the regular transmitted light is an inspection used for inspecting pinholes, fish eyes on a transparent sheet, and black foreign matters, and the light source, the imaging position, and the imaging element are arranged in a straight line in this order. The angle formed by the straight line and the sheet is not particularly limited, but vertical is preferably used. One end of the sheet in the present invention is temporarily fastened to the first upstream roll 10 in the sheet conveyance direction from the imaging position, and the upstream side after passing the sheet in the present invention from the imaging position to the first downstream roll 11 in the sheet conveyance direction. On the first roll 10, the parallel opposite sides of the sheet of the present invention are made to coincide with each other to fix the sheet of the present invention.

  In the case of (2) and (3), at least two rolls need to be covered with the sheet according to the present invention. At this time, if the location to be inspected is the same as the pass line in the sheet manufacturing process, the other portions need not be the same as the pass line in the manufacturing process, and a new posture adjustment pass line may be set. Furthermore, if the fixing of the sheet is ensured, a part of the sheet according to the present invention can be cut out. For example, when the portion that does not contribute to the posture adjustment blocks the optical path from the inspection location to the light source or the camera, the posture adjustment work can be performed by removing the blocking portion (21 in FIG. 10).

  From the principle of inspection for discriminating defects based on the difference in intensity of light incident on the image sensor, the drawing on the sheet and the sheet according to the present invention are preferably combined as follows. In the case of reflection inspection, a combination having a large difference in reflectance, for example, a line with a dark color with low reflectance and parallel to the sheet conveying direction on the surface of a metal thin film provided by a processing method such as vapor deposition, sputtering, or plating on a plastic film, An adjustment pattern drawn can be used. Since this combination has both the flexibility of the plastic film and the reflectance of the metal, it can be preferably used for adjustment of appearance inspection using reflected light. In the case of transmission inspection, a combination having a large difference in light transmittance, for example, a pattern in which an adjustment pattern or the like is drawn in a dark color with low light transmittance on the inspection side surface of a colorless and transparent plastic film can be used. In addition, an opaque sheet having a transparent portion provided as an adjustment pattern can be used.

  The thickness of the sheet according to the present invention can be determined within a range that does not reduce the effect of the present invention. When the thickness of the sheet according to the present invention is the same as the thickness of the appearance inspection object, it is preferable because the posture can be adjusted without adjusting the focus of the line sensor camera. Since both the thinning direction and the thickening direction move away from the original inspection position, the difference between the thickness of the sheet and the thickness of the visual inspection object related to the present invention falls within the allowable range for focus deviation or After adjusting the focus at the position of the sheet of the invention and adjusting the posture, the focus is adjusted again at the original inspection position.

  If it is thin, the sheet is likely to be creased or wrinkled when attached to the inspection roll, which is not preferable. When it is thick, the sheet becomes stiff, and when the inspection roll is thin, the sheet cannot be wound around the inspection roll and a gap is easily formed between the inspection roll and this is not preferable. Although depending on the elastic modulus of the sheet, a sheet having a thickness of 30 μm to 200 μm is preferably used.

The material of the sheet is not particularly limited, but a material having a low elongation elastic modulus is not preferable because the sheet is stretched by the tension at the time of mounting on the roll and the drawing is deformed. Further, a material having a high flexural modulus is not preferable because it is difficult to wind the material around the roll. The following plastic films are preferably used in that they have an appropriate elastic modulus and high flatness. Polyethylene terephthalate, polyethylene-2,6-naphthalate, polypropylene, polyamide, polyimide. The plastic film may contain these copolymers and other organic polymers. Known additives such as lubricants and plasticizers may be added to these plastic films.
FIG. 11 shows a plurality of types of adjustment patterns in the sheet according to the present invention. There are two types of adjustment patterns 22 and 23 on a straight line perpendicular to the opposite side 5 of the sheet of the present invention.

  If the length of the line sensor camera posture adjusting sheet is set slightly longer than the circumferential length of the inspection roll, a surplus is generated when the sheet is wound around the inspection roll. When this surplus is overlaid on the sheet, it is attached so that the parallel opposite sides 5 overlap each other and the sheet does not float on the roll. The line sensor camera posture adjustment sheet attached in this way is used for reflected light inspection on the inspection roll. In FIG. 4 (light source 3, line sensor camera 1) showing the optical system in the case of the reflected light inspection, the intersection of a plurality of straight lines constituting the adjustment pattern is placed at the inspection position 9. In FIG. 5 showing the optical system in which the specular reflection light inspection is performed at a position where the long sheet slightly floats from the roll, the upstream side roll 10 in the sheet transport direction as viewed from the inspection position 9 and the downstream side in the sheet transport direction. The sheet according to the present invention is attached so as to cover the two rolls 11.

Even in the regular transmitted light inspection, the sheet according to the present invention is passed between two rolls, but the inspection position 9 is between the light source 3 and the line sensor camera 1 as shown in FIG. In many cases, another sheet for adjusting the posture of the line sensor camera is inserted between the sensor cameras. In such a case, after fixing the line sensor camera posture adjusting sheet to the rolls 10 and 11, the broken line portion 21 of the line sensor camera posture adjusting sheet 7 having no adjustment pattern is removed.
When the line sensor camera posture adjustment sheet is fixed, the adjustment pattern is imaged and the posture adjustment of the line sensor camera is started. The appearance is adjusted by an elevation angle 24 of the line sensor camera and a rotation angle 26 around the lens axis 25 of the camera shown in FIG. When the elevation angle 24 of the line sensor camera is changed, the imaging position of the line sensor moves on the inspection roll in the circumferential rotation direction of the inspection roll. In FIG. 13, the imaging position moves from 27B to 27A or 27A to 27B. When the rotation angle around the lens axis of the camera is changed, the imaging position of the line sensor also rotates on the inspection roll. In FIG. 13, the imaging position moves from 27C to 27A or 27A to 27C.

  By adjusting the elevation angle 24 of the line sensor camera and the rotation angle 26 around the lens axis 25 of the camera, the imaging position of the line sensor camera is set to the inspection position (27A).

Example 6 line sensor cameras (NDH7450HS1 manufactured by Nagase Sangyo Co., Ltd.) with 7450 effective pixels were used, and the resolution was 13 μm on an inspection roll having a roll diameter of 100 mm and a roll length of 650 mm. The maximum width of 540 mm is inspected on the inspection roll to be measured, and a monitor with 1000 pixels in the width direction is used. In an inspection machine in which the incident angle and reflection angle at the inspection position are both 30 °, the line sensor camera Posture adjustment was performed using the following posture adjustment sheet.

  The posture adjusting sheet is made of an ink jet receiving film (thickness 190 μm, a white polyester film base material provided with an ink receiving layer), and the shape is a rectangle of 560 mm × 320 mm, and the following (1) to (3) Is drawn in black. (1) A straight line drawn from one end to the other end of a sheet with a line width of 0.70 mm at 10 mm from both sheet edges at two straight lines parallel to the short side. (2) Adjustment pattern A: A pattern having a line width of 1.30 mm and a length of 30 mm that form an angle of 45 ° with the short side of the sheet and perpendicular to each other at the midpoint (3) Adjustment pattern B: the short side of the sheet A pattern perpendicular to each other at the midpoint between two straight lines having a line width of 0.35 mm and a length of 10 mm forming an angle of 45 °. The intersection of pattern A and pattern B is located on a straight line perpendicular to the short side of the sheet, and the position is 55 mm, 145 mm, 235 mm, 325 mm, 415 mm, and 505 mm from one end of the sheet. Pattern B was 30 mm, 80 mm, 120 mm, 170 mm, 210 mm, 260 mm, 300 mm, 350 mm, 390 mm, 440 mm, 480 mm, and 530 mm. One camera has a pattern A and two patterns B have a viewing width of one camera. The posture adjusting sheet was wound around the inspection roll, and the posture adjusting sheet was fixed on the inspection roll so that the straight lines (1) overlapped at two sheet end portions.

  While monitoring the outputs of the six cameras, the line sensor camera adjusts the elevation angle of the line sensor camera so as to capture the intersection of the pattern A using one pattern A in each camera field of view. Since one pattern A is arranged in each camera field of view, it can be adjusted by the elevation angle of the line sensor camera.

  While monitoring the output of one camera, fine adjustment of the camera's elevation angle, rotation angle around the camera's lens axis, and elevation angle is performed so that the camera captures the intersection of two patterns B in the field of view of each camera. It was.

DESCRIPTION OF SYMBOLS 1, 2 Line sensor camera 3 Light source 4 Sheet 5 Parallel opposite side of attitude | position adjustment sheet | seat 6 Attitude adjustment pattern 7 Attitude adjustment sheet 8 Inspection roll
9 Inspection position 10 Conveying roll 11 on the upstream side in the sheet conveying direction 12 Conveying roll 12 on the downstream side in the sheet conveying direction 12 Straight line 13 parallel to the opposite side of the posture adjusting sheet 13 Imaging position 14 of the line sensor camera 1 Imaging of the line sensor camera 2 Position 15 Imaging result of posture adjustment pattern with narrow line width 16 Imaging result when adjusted to inspection position 17 Imaging result at position shifted from inspection position in sheet conveyance direction 18 Imaging of posture adjustment pattern with wide line width Result 19 Imaging result when adjusted to inspection position 20 Imaging result at a position shifted from the inspection position in the sheet conveying direction 21 Part removed during posture adjustment
22 posture adjustment pattern 23 with narrow line width posture adjustment pattern 24 with wide line width elevation angle 25 camera lens axis 26 rotation angle 27A, 27B, 27C imaging position of line sensor camera

Claims (2)

A method of adjusting the attitude of a single or a plurality of line sensor cameras for observing the surface of a long sheet conveyed by a conveying roll on the conveying roll or between two conveying rolls, and having a parallel opposite side A sheet having a plurality of patterns in which a plurality of straight lines that are not orthogonal to the opposite side intersect at one point on the sheet and the intersecting points are arranged on a straight line in a direction perpendicular to the opposite side is disposed on the circumferential surface of the conveying roll. An attitude adjustment method for a line sensor camera, wherein the attitude adjustment is performed by winding and fixing the opposite sides so as to overlap each other and imaging the intersection of the pattern on the sheet with the line sensor camera at a time. At least one straight line parallel to the opposite side is drawn on a sheet of sheets having parallel opposite sides, and is fixed so that the straight lines overlap when the sheet is wound around the peripheral surface of the transport roll. The line sensor camera attitude adjustment method according to claim 1, wherein the line sensor camera is an attitude adjustment method.

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