JP2007024559A - Lens unit, shape detector, shape detection method, and sheet manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens unit for detecting minute irregularity on a surface of a body under detection accurately, over a wide area, and at a high speed, and also to provide a shape detector using this lens unit, a shape detection method, and a sheet manufacturing method. <P>SOLUTION: A linearly polarized beam is caused to enter a light separation means to generate two linearly polarized beams, with their optical paths paralleling each other, being in positions shifted in the first direction orthogonal to their traveling direction, and having vibration directions orthogonal to each other. The surface of the body under detection is illuminated with the beams to mix their reflected beams with each other thereby obtaining one beam of light. A linearly polarized beam is generated from this beam of light by means of an analyzer and received by a line sensor camera to detect the shape of the surface of the body under detection. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lens unit, a shape detection device, a shape detection method, and a sheet manufacturing method.

  A differential interference microscope is known as means for observing minute irregularities on the surface of metal or glass. A differential interference microscope is an optical microscope incorporating an interference device. A normal optical microscope obtains contrast by the difference in brightness of light, but a differential interference microscope expresses an optical path difference of light as a difference in interference color, and a contrast different from that of a normal optical microscope is obtained. The principle of the differential interference microscope will be described with reference to FIGS.

  FIG. 3 is a schematic sectional view of a conventional differential interference lens unit 110. When the incident light 20 emitted from the light source 40 is collected by the condenser lens 10 and passed through the polarizer 11 formed of a polarizing element, linearly polarized light 21 is obtained. The linearly polarized light 21 changes its traveling direction by the half mirror 12 and enters the birefringent medium 13 (light separating means). The linearly polarized light 21 that has passed through the birefringent medium 13 (light separation means) has two vibration lines that are perpendicular to each other and displaced in the first direction (left-right direction in FIG. 3) by a certain amount of deviation 16. Polarized light 22a and 22b are obtained. When the two linearly polarized lights 22a and 22b are passed through the objective lens 14 having a rear focal point at the point where they intersect, the two linearly polarized lights that are coherent with each other and whose vibration directions are perpendicular to each other are incident on the subject surface 2. it can. When these are reflected by the subject surface 2 and enter the birefringent medium 13 (light combining means), the reflected light generally becomes elliptically polarized light 23. When this elliptically polarized light 23 is passed through an analyzer 15 composed of a polarizing element, linearly polarized light can be obtained from the elliptically polarized light 23. Since the vibration direction of the elliptically polarized light 23 changes in accordance with the optical path difference between the two linearly polarized lights 22a and 22b, that is, the distance twice the step 17 on the subject surface, that is, the phase difference, the light passing through the analyzer 15 The intensity of the light varies depending on the level difference 17 on the subject surface. Therefore, the differential interference microscope can obtain an image based on the light intensity distribution according to the shape of the subject surface 2.

  FIG. 2 is an enlarged view of the cross section of the subject surface 2 in FIG. The subject surface 2 is inclined along the first direction (optical path deviation direction) as shown in FIG. 3, and the heights of the two incident positions of the two linearly polarized light 22a and 22b are different. It is assumed that there is a step 17 on the subject surface. At this time, when the incident light 20 is white light, an interference color corresponding to the optical path difference between the two linearly polarized lights 22a and 22b, that is, the distance twice the step 17 on the subject surface is obtained. That is, the fine structure gradient of the subject surface 2 that has not been seen so far is expressed by the color contrast and becomes visible.

  The lens system of the above optical system may be called a differential interference lens unit.

  As described above, by using the principle of the differential interference microscope, it is possible to observe minute irregularities on the subject surface 2 with good contrast. As an inspection method using this principle, there is a method described in Patent Document 1. This method detects a defect of a subject based on a change in the amount of light through a two-dimensional CCD camera using a mechanism for irradiating the subject surface with an inspection beam and reflected light from the subject surface based on the inspection light beam. In a surface defect inspection apparatus having a mechanism that performs this, a differential interference lens unit having a magnification of 5 to 400 times is attached in front of a two-dimensional CCD camera that captures reflected light from a subject.

  According to this method, it is possible to detect minute irregularities in nm units that could not be detected by the irregularity inspection using a conventional two-dimensional CCD camera.

  As a method for inspecting a wide range using the principle of differential interference, there is a method described in Patent Document 2.

  In this method, light from a light source is converted into two parallel linearly polarized beams having mutually orthogonal vibration directions using a polarizing element and the optical axes are shifted from each other. The surface unevenness of the subject is detected by the return light including the interference light from the subject.

According to this method, since the light beam is scanned one-dimensionally, a wide range of inspection is possible, and it can also be applied when the subject travels at high speed.
JP-A-5-296941 JP-A-8-327562

  However, according to the knowledge of the present inventors, when a two-dimensional CCD camera is used as described in Patent Document 1, uniform unevenness detection sensitivity may not be obtained over the entire visual field. This will be described below with reference to FIGS.

FIG. 8 is a conceptual diagram showing where in the birefringent medium 13 linearly polarized light passes when the arrow OA present on the surface of the subject is detected by a two-dimensional CCD camera. The horizontal direction in the figure is the direction of deviation between two linearly polarized light (not shown), that is, the first direction. The linearly polarized light emitted from the point O passes through the objective lens, then passes through the W ₂ portion of the birefringent medium 13 and gathers at the point O ′, and the linearly polarized light emitted from the point A passes through the objective lens, It passes through the W ₁ portion of the birefringent medium 13 and gathers at the point A ′. That is, the arrow OA forms an image at the position of the arrow O′A ′. Of the subject surface, light emitted from points at different positions in the first direction in the same field of view will pass through different locations W ₁ and W ₂ in the _first direction of the birefringent medium.

A problem that arises when the birefringent medium passes through is that the sensitivity varies depending on the amount of deviation. FIG. 9 shows a conceptual diagram thereof. The linearly polarized light incident on the birefringent medium is separated into normal light O wave and extraordinary ray E wave according to Snell's law. At this time, if the conditions such as the incident angle are the same, the two light beams travel through the birefringent medium 13 while maintaining a certain angle θ, and are refracted again at a certain angle at the joint surface of the birefringent medium. At this time, the light is emitted with the shift amounts D ₁ and D ₂ corresponding to the place where the light enters the birefringent medium. If the amount of deviation is different, different contrast images can be obtained even if the inclination at the step 17 on the subject surface is the same.

  Therefore, when a two-dimensional CCD camera is used, sensitivity may not be obtained uniformly in the first direction within the same field of view.

  Further, according to the knowledge of the present inventors, the method of Patent Document 2 requires a mechanism for scanning a light beam, which increases the device cost. Furthermore, since the spot diameter of the light beam becomes the measurement resolution, there is a problem that the detection accuracy is reduced for the unevenness having an area smaller than the spot diameter of the light beam.

  Therefore, an object of the present invention is to obtain a uniform image over the entire field of view, and to accurately detect fine irregularities on the surface of the subject over a wide range at high speed, and a shape detection device using the lens unit. Another object is to provide a shape detection method and a sheet manufacturing method.

In order to solve the above-described problems, according to the present invention, when linearly polarized light is incident, vibration directions orthogonal to each other are set such that the optical paths are parallel to each other and shifted to a first direction orthogonal to the traveling direction. A light separating unit that generates two linearly polarized light, an irradiation optical system that irradiates the surface of the subject with the two linearly polarized light generated by the light separating unit, and a reflected light from the surface of the subject into one light beam. A light combining means for combining; an analyzer that generates linearly polarized light from the light beam combined by the light combining means; and the linearly polarized light generated by the analyzer that receives the linearly polarized light; There is provided a lens unit including a camera mounting portion to which a line sensor camera having a line sensor extending in a second direction that forms the following corner is attached.

  Further, according to a preferred aspect of the present invention, there is provided a lens unit in which the light separating means also serves as the light synthesizing means.

  In addition, a lens unit including an adjusting unit that adjusts the position of the light separating unit in the first direction is provided.

  Further, according to another aspect of the present invention, the vibration directions are orthogonal to each other from the linearly polarized light using the light separating means, and the optical paths are parallel to each other and shifted to a first direction orthogonal to the traveling direction. Two linearly polarized lights are generated, the two linearly polarized lights are irradiated on the subject surface, the reflected light from the subject surface of the two linearly polarized lights is synthesized into one light beam using a light combining means, The synthesized light beam is passed through an analyzer and imaged on a line sensor extending in the second direction that forms an angle of 60 degrees or more and 90 degrees or less with respect to the first direction, and is output to the line sensor. There is provided a method for detecting the shape of the subject surface based on the shape information of the subject surface.

  According to another aspect of the present invention, when a light source that generates linearly polarized light and the linearly polarized light generated by the light source are incident, the optical paths are shifted in a first direction that is parallel to each other and orthogonal to the traveling direction. A light separating means for generating two linearly polarized light having mutually orthogonal vibration directions at a position, an irradiation optical system for irradiating the surface of the object with the two linearly polarized light generated by the light separating means, and the subject A light combining means for combining reflected light from the surface into one light beam; an analyzer for generating linearly polarized light from the light combined by the light combining means; and the first direction for receiving the linearly polarized light that has passed through the analyzer. An object surface shape detection apparatus is provided, comprising: a line sensor extending in the second direction that forms an angle of 60 degrees or more and 90 degrees or less.

  Further, according to a preferred embodiment of the present invention, there is provided an object surface shape detection apparatus, wherein the light separation means has adjustment means for adjusting a position in the first direction.

  Further, according to a preferred embodiment of the present invention, there is provided a method for detecting the shape of the surface of an object on a sheet that continuously travels in a direction in which the object forms an angle of not less than 30 degrees and not more than 60 degrees with respect to the second direction. Is done.

  Moreover, according to the preferable form of this invention, the manufacturing method of the sheet | seat which test | inspects the shape of the said sheet | seat using a shape detection method is provided.

  In the present invention, the line sensor refers to a sensor in which light receiving elements that simultaneously form an effective field of view are arranged one-dimensionally. The two-dimensional sensor when operating in the TDI mode (time delay integration mode) also corresponds to the line sensor here because the effective visual field takes a one-dimensional form at the same time.

  In the present invention, it is preferable to use monochromatic light or white light as the light source. When monochromatic light is used, the level difference on the surface of the subject becomes bright and dark contrast and is imaged by the line sensor camera. When white light is used, a step on the surface of the subject is imaged with a line sensor camera as a colored contrast. Here, white light refers to a light source that emits light over a continuous wavelength range of 100 nm or more.

  In the present invention, the line sensor camera may be monochrome or color. It is preferable to use a color camera when white light is used as the incident light and the surface of the subject is inspected with interference colors. The number of pixels of the line sensor camera can be 1000, 2000, 5000, 7500, etc., but it is possible to detect fine defects as the number of pixels increases.

  In the present invention, the light separating means refers to an optical element that separates and emits incident linearly polarized light into normal light O wave and extraordinary light E wave. The light combining means is an optical element that generally generates elliptically polarized light by combining normal light O-wave and extraordinary light E-wave when they are incident simultaneously. Any of them can be composed of a Nomarski prism, a Savart plate, a Wollaston prism, or the like. A Nomarski prism is a prism made by cutting and bonding uniaxial crystals such as quartz and calcite at an appropriate angle and bonding them together. To separate. The light separating means and the light synthesizing means may be realized by a single element similarly to the single birefringent medium 13 of FIG. In this case, since one light beam is divided or combined by one element, it is resistant to mechanical and thermal disturbances.

  Further, as the means for adjusting the position of the light separating means, those utilizing micrometers are preferably used.

  According to the present invention, as will be described below, a differential interferometer can be provided to the line sensor camera, so that minute irregularities on the surface of a sheet such as a continuously running film can be accurately and rapidly spread over a wide range. Can be detected.

  Hereinafter, a case where the example of the best embodiment of the present invention is applied to a film surface inspection apparatus will be described as an example with reference to the drawings. In addition, the same code | symbol is attached | subjected about the member which is common in the conventional differential interference lens unit 110 described in FIG. 3, and description may be abbreviate | omitted.

  FIG. 1 is a schematic cross-sectional view of a film surface inspection apparatus including a lens unit 100 and a line sensor 30 according to the present embodiment.

  As shown in FIG. 1, the lens unit 100 of this embodiment is obtained by attaching the camera attachment portion 19 and the position adjusting means 33 to the conventional differential interference lens unit 110 shown in FIG. The camera mounting portion 19 includes a line sensor 30 including a line sensor 30 extending in a second direction (view width direction, a direction perpendicular to the paper surface in FIG. 1) perpendicular to the first direction (optical path deviation direction). A camera 31 is attached. The subject is a direction that is orthogonal to the second direction (field width direction) and the direction of the optical axis of the two linearly polarized light 22a and 22b (the left-right direction on the paper surface. In the present embodiment, the first direction. The plastic sheet 300 running continuously is placed.

  The positional relationship between the optical axes of the two linearly polarized lights 22a and 22b of the lens unit 100 of the present embodiment, the field of view of the line sensor 30, and the traveling direction of the sheet 300 will be described below with reference to FIGS. .

  4 and 5 are conceptual diagrams showing the positional relationship between the positions of the optical axes of the two linearly polarized lights 22a and 22b and the field of view of the line sensor 30, and are viewed from a direction parallel to these optical axes. .

  As shown in FIG. 4, the traveling direction of the sheet 300 is a direction orthogonal to the second direction, that is, the visual field width direction of the line sensor 30. FIG. 4 shows that the angle formed between the two linearly polarized light 22a and 22b that are shifted in the first direction (optical path shift direction) and the visual field width direction of the line sensor 30 extending in the second direction is 90 degrees. Shows the case.

  Consider a case in which there is a long scratch 3 on the sheet 300 in a direction orthogonal to the traveling direction of the sheet 300, that is, in a direction orthogonal to the optical path deviation direction.

  FIG. 6 is a perspective view showing a state of light irradiation on the subject surface when the lens unit 100 of the present embodiment is used. In this situation, the scratch 3 formed on the sheet 300 moves from the left side to the right side of the sheet. As shown in FIG. 6, when the scratch 3 reaches the two linearly polarized lights 22a and 22b, the linearly polarized light 22b is reflected in a place deeper than 22a, and the linearly polarized lights 22b and 22a have a difference in depth. That is, an optical path difference is generated by a distance twice as large as the step, so that interference different from other parts occurs when the birefringent medium 13 is combined. Increasing the amount of deviation 16 between the linearly polarized light 22a and 22b increases the optical path difference between the two linearly polarized lights and increases the optical path difference at the scratched part, further improving the detection accuracy of the irregularities on the subject surface 2. become.

  Since the optical path difference between the reflected lights of the linearly polarized light 22b and 22a is the longest, the scratch 3 on the subject surface 2 is most accurate when extending in a direction orthogonal to the first direction (optical path deviation direction). Highly detectable. Even if the angle between the longitudinal direction of the scratch 3 on the subject surface 2 and the first direction (the optical path deviation direction) is away from 90 degrees, the optical path of the reflected light of the linearly polarized light 22b and 22a is the same shape as the distance increases. Since the difference becomes shorter, the detection accuracy becomes lower.

  When there are scratches or foreign objects having a longitudinal direction in the direction close to parallel to the first direction (optical path deviation direction) on the subject surface 2, the optical path difference between the reflected lights of the linearly polarized light 22b and 22a is shortened. For this reason, the detection accuracy is lowered. In this case, in order to increase the detection accuracy, the optical path difference between the linearly polarized light 22b and 22a is lengthened, that is, the first direction (optical path deviation direction) is aligned so as to be orthogonal to the direction of scratches or long foreign matter. Conceivable. In this case, in order to keep the detection accuracy high, the sheet is formed in a state in which the angle formed by the first direction (optical path deviation direction) and the second direction (view width direction) is maintained at 60 degrees or more and 90 degrees or less. It is preferable to adjust the viewing width direction with respect to the traveling direction of 300.

  When it is desired to detect a scratch having a longitudinal direction in a direction parallel to the traveling direction of the sheet 300 and a scratch in a direction orthogonal thereto, the first direction (light path deviation direction) and the traveling direction of the sheet as shown in FIG. It is preferable that the angle formed by is between 30 degrees and 60 degrees. This is because when the angle is 30 degrees or less and 60 degrees or more, the detection sensitivity of a scratch having a longitudinal direction in either direction is lowered, and it becomes difficult to achieve a balance.

  In this case as well, in order to keep the detection accuracy high, the direction in which the angle formed by the first direction (optical path deviation direction) and the second direction (view width direction) is maintained at 60 degrees or more and 90 degrees or less. It is good to adjust.

  Further, by adjusting the position of the birefringent medium 13 in the first direction (optical path deviation direction) by the position adjusting means 33, the optical path difference between the linearly polarized light 22b and 22a changes according to the principle explained in FIG. The phase difference of the linearly polarized light of the book changes. Even if the optical path difference is constant, if the phase difference is changed, the intensity of interference can be changed. Therefore, the detection accuracy of the object surface irregularities can be changed by the phase difference.

  Incidentally, as described above, in the case of a two-dimensional CCD camera, if the birefringent medium 13 is installed so that the two linearly polarized lights 22a and 22b are shifted in the vertical direction of the field of view (left and right direction in FIG. 8), the birefringence medium 13 is positioned at the upper and lower ends of the field of view. Since the incident locations of the light rays incident on the refractive medium 13 are different, the deviation amounts of the linearly polarized light 22a and 22b are different at the upper and lower ends of the visual field. If the amount of deviation is different, images with different contrasts can be obtained even if the step 17 on the subject surface is the same, and uniform unevenness detection sensitivity cannot be obtained at the upper and lower ends of the field of view.

  On the other hand, in the case of a line sensor camera in which the field width direction extends in a direction orthogonal to the first direction, the pixels are in one direction, here the second direction (the field width direction, in FIG. 8, the direction perpendicular to the paper surface). Therefore, when the birefringent medium 13 is installed so that the two linearly polarized lights 22a and 22b are shifted in the vertical direction of the visual field, the pixels of the line sensor camera are incident on the birefringent medium 13 at predetermined positions. Since only the light rays are collected, uniform unevenness detection sensitivity can be obtained in the visual field width direction.

  In the above embodiment, the magnification of the objective lens 14 is preferably 1 or more. When the magnification is increased, the inspection range is narrowed. Therefore, when the inspection range is widened, the number of cameras increases and the apparatus cost increases. Therefore, 10 times or less is good. Here, the magnification of the objective lens is (size of the object to be measured on the imaging plane) / (actual size of the object to be measured).

  In the above embodiment, the size of the birefringent medium 13 (light separating means, light synthesizing means) is set such that the two linearly polarized lights 22 a and 22 b are received by the entire light receiving portion of the line sensor 30.

  FIG. 7 is a schematic diagram showing the overall configuration of a film surface inspection apparatus using the lens unit 100 of the present embodiment.

  In the case of an inspection using the lens unit 100 of the present embodiment, the light received by the line sensor 30 is converted into an electrical signal corresponding to the amount of received light for each light receiving element as shown in FIG. Is done. The defect detection means 32 determines the presence / absence of a defect and the level of the defect based on the input electric signal.

  The result of inspecting the micro scratch on the film surface by the inspection apparatus using the above lens unit will be described.

  A metal halide lamp was used as the light source 40 for the incident light 20. The magnification of the objective lens 14 was set to 1. The line sensor 30 was a monochrome type having a light receiving element size of 7 μm × 7 μm, a number of light receiving elements of 5000. The pitch of the light receiving elements is 7 μm, and the visual field width of the line sensor 30 is 35 mm. The drive clock of the line sensor 30 is 40 MHz. The film was transparent and had a thickness of 6 μm, and was imaged while traveling at 5 m / min in the direction of the visual field width of the line sensor 30 and the direction perpendicular to the longitudinal direction of the slit 18.

  The lens unit 100 is attached to the line sensor camera 31 so that the direction of deviation of the optical axes of the two linearly polarized lights 22 a and 22 b is orthogonal to the visual field width direction of the line sensor 30. The deviation amount of the two linearly polarized light was 5 μm. The sensitivity was adjusted by moving the birefringent medium 13 of the lens in the direction in which the two linearly polarized lights deviated, and the lens was fixed at a position where irregularities of 0.1 μm could be detected.

  As a result of inspecting the film with this apparatus, scratches with a depth of 0.1 μm could be detected.

  The result of inspecting the unevenness of the copper foil film surface by the inspection apparatus having the same configuration as that of Example 1 will be described.

  The copper foil was run at 1 m / min.

  As a result, a protrusion having a diameter of 30 μm and a height of 2 μm could be detected.

  In addition, the conventional method of irradiating light from a shallow angle to the copper foil film surface and receiving scattered light from the projection on the film surface cannot determine the height or area of the projection even if the presence or absence of the projection can be determined. However, in the method of the present invention, the area of the protrusion could be measured with high accuracy. Further, since the slope of the protrusion is received as a contrast between black and white, the height of the protrusion can be determined.

  The present invention can be applied not only to a film surface inspection device but also to a metal plate surface inspection device, a glass plate surface inspection device, and the like, but the application range is not limited thereto.

It is a schematic sectional drawing of the film surface sensor apparatus of preferable embodiment of this invention. FIG. 4 is an enlarged view of a cross section of a subject surface in FIG. 3. It is a schematic sectional drawing of the conventional differential interference lens unit. 3 is a conceptual diagram showing a positional relationship between the positions of the optical axes of two linearly polarized lights 22a and 22b and the field of view of the line sensor 30 in the first embodiment. FIG. 3 is a conceptual diagram showing a positional relationship between the positions of the optical axes of two linearly polarized lights 22a and 22b and the field of view of the line sensor 30 in the first embodiment. FIG. FIG. 2 is a perspective view showing a state of light irradiation on a subject surface when the lens unit of the embodiment of FIG. 1 is used. It is the schematic which shows the whole structure of the film surface inspection apparatus which concerns on the lens unit of embodiment of FIG. FIG. 4 is a conceptual diagram showing where a linearly polarized light in FIG. 3 passes through a birefringent medium. It is a conceptual diagram of the difference in deviation | shift amount when the passage places of a birefringent medium differ.

Explanation of symbols

2 Subject surface 3 Scratch 10 Condensing lens 11 Polarizer 12 Half mirror 13 Birefringent medium (light separation means, light synthesis means)
DESCRIPTION OF SYMBOLS 14 Objective lens 15 Analyzer 16 Deviation amount 17 Level of object surface 19 Camera mounting part 20 Incident light 21 Linearly polarized light 22a Linearly polarized light (normal light O wave)
22b Linearly polarized light (abnormal light E wave)
30 Line sensor 31 Line sensor camera 32 Defect detection means 33 Position adjustment means 40 Light source 100 Lens unit 110 Conventional differential interference lens unit 300 Sheet

Claims (8)

Light separating means for generating two linearly polarized light beams having vibration directions orthogonal to each other at a position where the optical paths are parallel to each other and shifted in a first direction orthogonal to the traveling direction when the linearly polarized light is incident; An irradiation optical system for irradiating the surface of the subject with the two linearly polarized light generated by the light separation means, a light synthesis means for synthesizing the reflected light from the subject surface into one light beam, and the light beam synthesized by the light synthesis means An analyzer that generates linearly polarized light from the light source, and a line sensor that receives the linearly polarized light generated by the analyzer and extends in a second direction that forms an angle of 60 degrees to 90 degrees with respect to the first direction. A lens unit including a camera mounting portion for mounting the line sensor camera. The lens unit according to claim 1, wherein the light separating unit also serves as the light combining unit. The lens unit according to claim 1, further comprising an adjusting unit that adjusts a position of the light separating unit in the first direction. Using the light separating means, the linearly polarized light generates two linearly polarized light in a position where the vibration directions are orthogonal to each other, the optical paths are parallel to each other and shifted to a first direction orthogonal to the traveling direction, and the two Irradiate the surface of the subject with linearly polarized light, synthesize the reflected light from the surface of the subject of the two linearly polarized light into one light beam using light combining means, pass the combined light beam through the analyzer, An image is formed on a line sensor extending in the second direction that forms an angle of 60 degrees or more and 90 degrees or less with respect to the first direction, and shape information of the subject surface is detected based on the output of the line sensor. A method for detecting the shape of the surface of an object. When a light source that generates linearly polarized light and linearly polarized light generated by the light source are incident, the light paths are parallel to each other and have two vibration directions orthogonal to each other in a first direction perpendicular to the traveling direction. Light separating means for generating two linearly polarized lights, an irradiation optical system for irradiating the subject surface with the two linearly polarized lights generated by the light separating means, and the reflected light from the subject surface is combined into one light beam. An angle of 60 degrees or more and 90 degrees or less is formed with respect to the light combining means, an analyzer that generates linearly polarized light from the light combined by the light combining means, and the first direction that receives the linearly polarized light that has passed through the analyzer. An object surface shape detection apparatus comprising: a line sensor extending in the second direction. The shape detection apparatus for a subject surface according to claim 5, wherein the light separation means includes adjustment means for adjusting a position in the first direction. 5. The method for detecting the shape of the surface of an object according to claim 4, wherein the object is a sheet that continuously travels in a direction that forms an angle of not less than 30 degrees and not more than 60 degrees with respect to the second direction. A method for manufacturing a sheet, wherein the shape of the sheet is inspected using the shape detection method according to claim 7.

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