JP2020071103A - Height distribution measurement device and height distribution measurement method - Google Patents

Abstract

To provide a height distribution measurement device and a height distribution measurement method which improve resolution in a height direction by increasing an incident angle of light to an irradiation position even if members other than a measured object are arranged around the measured object.SOLUTION: A height distribution measurement device 12 includes: a light irradiation member 18 for applying light for measuring a height distribution of a surface of a measured object (measurement target roll 14); an imaging member 20 for imaging the measured object at an irradiation position LA to which the light is applied; a reflection member 22 for reflecting the light, so as to allow the light to enter the irradiation position LA at an incident angle larger than an angle at which the light directly enters the irradiation position LA from an output point of a light irradiation member 28; and a derivation device (control device 32) for deriving the height distribution from an image taken by the imaging member 20.SELECTED DRAWING: Figure 2

Description

  The present application relates to a height distribution measuring device and a height distribution measuring method.

  In Patent Document 1, line light is irradiated to the measurement object OB in order to measure the three-dimensional shape of the measurement object OB by the light cutting method, and reflected light of the line light irradiated to the measurement object OB is received. A detection device that outputs a received light signal is described. The detection device described in Patent Document 1 includes a laser irradiator that emits line light having a linear cross-sectional shape perpendicular to the traveling direction, and a light-receiving camera. Then, the line light emitted from the laser irradiator in a substantially vertical downward direction is reflected by the first mirror and changes its traveling direction to a direction perpendicular to the moving direction of the laser irradiator. The line light irradiated to the measurement target is scattered on the surface of the measurement target, a part of the reflected light of the scattered light is incident on the first mirror, and the traveling direction of the incident reflected light is the direction toward the light receiving camera. It is changed in a substantially upward direction. The reflected light whose traveling direction is changed in this way is received by the light receiving camera located above the first mirror.

  Patent Document 2 describes an in-tank welding mark inspection device that measures the shape of a welding mark on the inner surface of a tank made by welding a cylindrical object by light and inspects it. In the in-tank welding mark inspection device described in Patent Document 2, the light emitted from the semiconductor laser unit becomes a light beam having a focus on the object to be measured by the built-in lens, and enters the cylindrical lens. The light emitted from the cylindrical lens is linearly extended in only one direction. After that, the direction is changed to a direction perpendicular to the inner surface of the tank by a folding mirror, and the tank welding mark is irradiated to form a laser line. Then, the laser line irradiated to the inner surface of the tank is diffused and reflected there, and a part of the diffusely reflected light passes through the two image forming lenses through the folding mirror and forms an image on two cameras to be imaged.

JP, 2008-203091, A JP, 2008-9807, A

  When measuring the height distribution of the surface of the object to be measured from the image of the irradiated light, it is preferable to increase the incident angle of the light at the irradiation position in order to improve the resolution in the height direction. However, when a member other than the object to be measured is arranged around the irradiation position, the range in which the light source can be arranged is limited, and it may be difficult to increase the incident angle of light to the irradiation position. is there.

  In the present invention, even when a member other than the object to be measured is arranged around the object to be measured, the incident angle of light to the irradiation position is increased to improve the resolution in the height direction. Is the purpose.

  In the first aspect, a light irradiation member that irradiates light for measuring the height distribution of the surface of the measured object, an imaging member that images the measured object at an irradiation position where the light is irradiated, and the light. Is reflected by the reflection member to make the light incident on the irradiation position at an incident angle larger than the incident angle at which the light directly enters the irradiation position from the emission point of the light irradiation member. And a derivation device that derives the height distribution from the image of the measured object at the irradiation position.

  In this height distribution measuring device, the light from the light irradiation member is applied to the irradiation position of the measured object, and the imaging device images the measured object at the irradiation position. Then, the derivation device derives the height distribution of the surface of the measured object from the image of the measured object at the irradiation position imaged by the imaging member.

  The light emitted by the light emitting member is reflected by the reflecting member. Due to this reflection, the light enters the irradiation position at an angle of incidence larger than the angle of incidence directly from the emission point of the light irradiation member to the irradiation position. In this way, the resolution in the height direction can be improved by increasing the angle of incidence of light on the irradiation position.

  Moreover, in this height distribution measuring device, the incident angle of the light to the irradiation position is increased by reflecting the light with the reflection member, and the light is directly incident from the emission point of the light irradiation member to the irradiation position. Not a configuration. Since it is not necessary to increase the incident angle of the incident light directly to the irradiation position, even if members other than the object to be measured are arranged around the irradiation position, the irradiation position is not affected by these members. The angle of incidence of light on can be increased.

  In a second aspect, in the first aspect, the light is line light that spreads linearly in a direction perpendicular to the axis orthogonal to the traveling direction, and the reflecting member is a line that is a reflecting surface extending in the direction perpendicular to the axis. It reflects the entire light.

  By using the line light, it is possible to irradiate light in a wide range. Since the reflecting member reflects the entire line light by the reflecting surface, it is possible to increase the incident angle of the entire line light.

  In a third aspect, in the first or second aspect, the reflection member is a tangential plane of the surface at the irradiation position with respect to the object to be measured whose surface is convexly curved toward the imaging member. Will be placed across.

  That is, the reflection member can increase the incident angle of light to the irradiation position, as compared with the configuration in which the reflection member is disposed closer to the light irradiation member than the tangential plane. Further, since a part of the reflecting member can be arranged so as to enter the measured object side with respect to the tangential plane, the degree of freedom of arrangement is high.

  In a fourth aspect, in any one of the first to third aspects, with respect to the measured object in which two external members are arranged outside the measured object on both sides of the irradiation position. , The reflective member is arranged between two outer members.

  As described above, even if two external members are arranged outside the object to be measured with a space on both sides of the irradiation position, by arranging the reflecting member between the two external members, the light to the irradiation position is irradiated. It is possible to realize a structure for increasing the incident angle of.

  In the fifth aspect, by irradiating light for measuring the height distribution of the surface of the object to be measured and reflecting the light, the light is directly incident from the emission point to the irradiation position. The height distribution is derived from the image of the measured object at the irradiation position, in which the measured object is imaged at the irradiation position.

  In this height distribution measuring method, the light from the light irradiation member is applied to the irradiation position of the measured object, and the measured object is imaged at the irradiation position. Then, the height distribution of the surface of the measured object is derived from the imaged image of the measured object at the irradiation position.

  The light for measuring the height distribution of the surface of the measured object is reflected and applied to the irradiation position. Due to this reflection, the light enters the irradiation position at an angle of incidence larger than the angle of incidence of directly entering the irradiation position from the emission point. In this way, the resolution in the height direction can be improved by increasing the angle of incidence of light on the irradiation position.

  Moreover, in this height distribution measuring method, the incident angle of the light to the irradiation position is increased by reflecting the light, and the light does not directly enter the irradiation position from the emission point. Since it is not necessary to increase the incident angle of the incident light directly to the irradiation position, even if members other than the object to be measured are arranged around the irradiation position, the irradiation position is not affected by these members. The angle of incidence of light on can be increased.

  In the present application, even when a member other than the object to be measured is arranged around the object to be measured, it is possible to increase the incident angle of light to the irradiation position and improve the resolution in the height direction. it can.

FIG. 1 is a perspective view of the height distribution measuring device of the first embodiment. FIG. 2 is a side view of the height distribution measuring device of the first embodiment. FIG. 3 is a partially enlarged side view of the height distribution measuring device of the first embodiment. FIG. 4 is a side view of the height distribution measuring device of the first comparative example. FIG. 5 is a side view of the height distribution measuring device of the second embodiment. FIG. 6 is a side view of the height distribution measuring device of the third embodiment. FIG. 7 is a side view of the height distribution measuring device of the second comparative example.

  Hereinafter, the height distribution measuring device 12 of the first embodiment will be described with reference to the drawings.

  1 and 2, the height distribution measuring device 12 of the first embodiment is shown together with a measuring object roll 14 which is an object to be measured.

  The height distribution measuring device 12 includes a measurement target roll 14 that is a target for measuring the height distribution of the surface, and two external rolls 16A and 16B arranged in contact with the measurement target roll 14. The measurement target roll 14 and the external rolls 16A and 16B are cylindrical members. Then, the measurement target roll 14 and the two external rolls 16A and 16B are both arranged so that their respective rotation axes are parallel to the measurement target roll 14.

  On the outer circumference of the measurement target roll 14, for example, an electrode layer forming a lithium ion secondary battery is formed in a foil shape, and the height distribution of minute unevenness generated on the surface of the foil is measured by a height distribution measuring device. Measure at 12.

  The height distribution measuring device 12 has a light irradiation member 18, an imaging member 20, and a reflection member 22. The light irradiation member 18 irradiates the line light LL for measuring the height distribution of the surface of the measurement target roll 14. The line light LL reaches the irradiation position LA set on the surface of the measurement target roll 14 via the reflecting member 22. In the example shown in FIGS. 1 and 2, the light irradiation member 18 includes a light source 24 and an irradiation lens 26 that linearly spreads the light emitted from the emission point LP of the light source 24 into the line light LL. ing. The line direction (spreading direction) of the line light LL is parallel to the axial direction of the measurement target roll 14.

  The image pickup member 20 includes an image pickup camera 28 capable of picking up a moving image or a still image of the irradiation position LA, and an image pickup lens 30 for forming an image on the image pickup camera 28. As shown in FIG. 2, the imaging member 20 is connected to the control device 32 and can send the imaging data to the control device 32. In the control device 32, the height distribution at the irradiation position LA can be calculated from the image of the received imaging data by a predetermined calculation formula based on, for example, the light section method. Alternatively, the control device 32 may store a correspondence table that associates various values of the imaging data with the height of the surface of the measurement target roll 14, and may obtain the height distribution based on the correspondence table. In any of the configurations, in the present embodiment, the control device 32 also serves as a derivation device that derives the height distribution of the surface of the measurement target roll 14.

  As described above, the object to be measured in the present embodiment is the cylindrical measurement target roll 14. The surface of the measurement target roll 14 is convexly curved toward the imaging member 20.

  Further, in the present embodiment, the optical axis A-1 of the imaging member 20 (the optical path from the irradiation position LA to the imaging member 20) coincides with the direction of the normal line NL of the measurement target roll 14 at the irradiation position LA, The image pickup member 20 is in a so-called vertical arrangement. This normal line NL is a normal line on the arc surface when the slight unevenness (height distribution to be measured) on the surface of the roll 14 to be measured is leveled.

  The reflection member 22 is arranged between the two outer rolls 16A and 16B. The line light LL emitted from the light emitting member 18 is reflected by the reflecting member 22 and is emitted to the irradiation position LA (see FIG. 3). Compared with the configuration in which the line light LL from the light irradiation member 18 is directly irradiated to the light irradiation member 18 without being reflected by the reflection member 22, the line light LL is reflected by the reflection member 22 in the present embodiment. Therefore, the incident angle β of the line light LL to the irradiation position LA is large. The incident angle β is an angle formed by the normal line NL of the irradiation position LA and the incident light (line light LL).

  The reflective member 22 is not limited to a specific configuration as long as it can reflect light in this manner, and for example, a prism or a mirror can be used.

  In the present embodiment, the optical axis A-2 of the line light LL, which is irradiated by the light irradiation member 18 and is reflected by the reflection member 22, is parallel to the optical axis A-1 of the imaging member 20.

  As shown in detail in FIG. 3, the reflection member 22 of the present embodiment is arranged such that a part thereof overlaps the tangent plane TP of the measurement target roll 14 at the irradiation position LA.

  Next, the operation of this embodiment and the height distribution measuring method will be described.

  In order to measure the height distribution of the surface of the measurement target roll 14, as shown in FIG. 2, the light irradiation member 18 irradiates the line light LL. The line light LL is reflected by the reflecting member 22 and is applied to the irradiation position LA of the measurement target roll 14 at the incident angle β. The image capturing member 20 captures an image of the irradiation position LA. From the captured image, the control device 32 which also functions as a derivation device derives the height distribution of the surface.

  In the present embodiment, the line light LL irradiated by the light irradiation member 18 is reflected by the reflection member 22 and enters the irradiation position LA at a predetermined incident angle β.

  Here, as a first comparative example, as shown in FIG. 4, the height distribution measurement in which the line light is directly irradiated from the light irradiation member 18 to the irradiation position LA without being reflected by the reflection member 22. Consider device 82. In the height distribution measuring device 82 of the first comparative example, the incident angle β is small because the light path is a straight optical path from the emission point LP of the light irradiation member 18 to the irradiation position LA. On the other hand, in the present embodiment, since the light emitted by the light emitting member 18 is reflected by the reflecting member 22, the incident angle β is larger than that in the first comparative example. In the present embodiment, since the incident angle β is large in this way, the height distribution of the surface of the measurement target roll 14 can be measured with higher resolution than that in the first comparative example.

  In addition, in order to increase the incident angle β of the measurement target roll 14 to the irradiation position LA, the position of the light irradiation member 18 may be changed. However, in this embodiment, two external rolls 16A and 16B are arranged in contact with each other outside the measurement target roll 14. Therefore, for example, when the light irradiating member 18 is arranged at the position shown by the chain double-dashed line in FIG. 2 (the reflecting member 22 is not used), the optical axis A from the emission point LP of the light irradiating member 18 to the irradiation position LA is taken. The external roll 16A covers -3. That is, the irradiation position LA cannot be irradiated by the light irradiation member 18.

  On the other hand, in the present embodiment, it is not necessary to increase the incident angle of the incident light directly from the light irradiation member 18 to the irradiation position LA. Therefore, even if the external roll 16A is disposed near the irradiation position LA outside the measurement target roll 14, the incident angle can be increased without being affected by the external roll 16A.

  Moreover, the incident angle β of the line light LL to the irradiation position LA is increased by using the reflection member 22, and there are few restrictions on the relative positional relationship between the light irradiation member 18 and the imaging member 20. Therefore, it is easy to adjust the relative position between the light irradiation member 18 and the imaging member 20.

  Next, a second embodiment will be described. In the second embodiment, the same elements and members as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

  As shown in FIG. 5, in the height distribution measuring device 42 of the second embodiment, the optical axis A-1 of the imaging member 20 is at a predetermined inclination angle with respect to the normal line NL of the measurement target roll 14 at the irradiation position LA. It is inclined at α. However, as in the first embodiment, the optical axis A-2 from the emission point LP of the light irradiation member 18 to the reflection member 22 and the optical axis A-1 of the imaging member 20 are parallel to each other.

  In the structure in which the optical axis A-1 of the imaging member 20 is inclined as in the second embodiment, the side opposite to the side on which the irradiated line light LL is incident with respect to the normal NL, that is, the regular reflection direction. The irradiation position LA is imaged from a direction close to. Therefore, for example, even when the amount of light from the light irradiation member 18 is small, the irradiation position LA can be reliably imaged and the height distribution can be measured.

  In the first and second embodiments, the measurement target roll 14 is cited as an example of the measured object. Since the measurement target roll 14 has a cylindrical shape, both side portions (both side portions in the circumferential direction) of the irradiation position LA are located farther from the imaging member 20 than the tangent plane TP. Since the space GP is generated between the tangent plane TP and the roll 14 to be measured, the range in which the reflecting member 22 can be arranged is wide. For example, in the example shown in FIG. 3, the reflection member 22 is arranged so as to intersect the tangential plane TP, and a part of the reflection member 22 is arranged so as to enter the measurement target roll 14 side from the tangential plane TP. In this way, by arranging the reflection member 22 close to the surface of the measurement target roll 14, the incident angle β can be increased. Even if the reflecting member 22 is arranged on the light irradiation member 18 side with respect to the tangential plane TP without intersecting the tangential plane TP, the space GP is provided between the tangential plane TP and the measurement target roll 14. If the occurrence of the reflection occurs, it is easy to arrange the reflection member 22.

  Next, a third embodiment will be described. In the third embodiment, elements and members similar to those in the first or second embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

  As shown in FIG. 6, in the height distribution measuring device 52 of the third embodiment, the object to be measured is a flat member 54 having a flat surface. The plane member 54 is moved in a predetermined direction (for example, the arrow M1 direction) by a moving mechanism (not shown).

  Two external members 56A and 56B are arranged on both sides of the irradiation position LA of the plane member 54. As an example of the external members 56A and 56B in the third embodiment, a measuring device that measures properties and shapes other than the height distribution in the planar member 54 can be cited, but is not limited thereto.

  In the third embodiment, as in the second embodiment, the optical axis A-1 of the imaging member 20 is tilted with respect to the normal line NL at a predetermined tilt angle α (a value different from that in the second embodiment). There is.

  Also in the third embodiment having such a configuration, the line light LL emitted from the light emitting member 18 is reflected by the reflecting member 22 and is emitted to the irradiation position LA.

  Here, FIG. 7 shows a height distribution measuring device 92 of the second comparative example. In the height distribution measuring device 92 of the second comparative example, as in the height distribution measuring device 82 of the first comparative example, the line light LL is directly irradiated from the emission point LP of the light irradiation member 18 to the irradiation position LA. To be done. Since the reflecting member 22 does not reflect the line light LL, the incident angle β becomes small when the space between the external members 56A and 56B is narrow.

  On the other hand, in the height distribution measuring device 52 of the third embodiment, even if the distance between the external members 56A and 56B is narrow, the line member LL from the light irradiating member 18 is reflected by the reflecting member 22, so that the irradiation position The light can be incident on LA at a large incident angle β. Then, the height distribution of the surface of the plane member 54 can be measured with higher resolution than that of the second comparative example.

  In the above, the structure in which the optical axis A-2 of the line light LL emitted from the light emitting member 18 and the optical axis A-1 of the imaging member 20 are parallel to each other has been illustrated. Thus, when the optical axis A-2 and the optical axis A-1 are parallel to each other, for example, the light irradiation member 18 and the imaging member 20 can be arranged close to each other, which is advantageous in terms of installation space. Is. Further, the light irradiating member 18 and the imaging member 20 can be held by a holding tool so that their relative positions are constant, and handling is easy. In particular, when the light irradiation member 18 and the imaging member 20 are integrally installed, they can be installed with a small installation jig, and various operations such as adjustment during installation and replacement during maintenance are easy. Is. It should be noted that the term “parallel” as used herein, that is, “parallel” between the optical axis A-2 of the line light LL emitted from the light emitting member 18 and the optical axis A-1 of the imaging member 20 is strictly parallel. In addition to a certain structure, a structure that can be regarded as being substantially parallel is included.

  Further, as the light for measuring the height distribution of the surface of the object to be measured, the line light LL is mentioned above, but the light is not limited to the line light and may be spot light, for example. However, when the line light LL is used, it is possible to irradiate light simultaneously in a range where there is a line-shaped spread, and it is possible to perform efficient height distribution measurement. Even with the configuration using the line light LL, if the reflecting member 22 has a shape having a wide reflecting surface corresponding to the spread range of the line light LL, the entire line light LL is reflected to the irradiation position LA. It is possible to increase the incident angle β of.

  The measurement target in each of the above embodiments is not limited to the electrode layer of the lithium ion secondary battery. For example, the surface layer of an antireflection film, the adhesive layer of an adhesive tape, the surface of a solar cell (photocell), the surface of various displays, etc. can be mentioned.

12 Height distribution measuring device 14 Roll to be measured (an example of an object to be measured)
16A, 16B External roll (an example of external member)
18 Light Irradiation Member 20 Imaging Member 22 Reflecting Member 24 Light Source 26 Irradiation Lens 28 Imaging Camera 30 Imaging Lens 32 Control Device (One Example of Derivation Device)
42 Height distribution measuring device 52 Height distribution measuring device 54 Planar member (an example of an object to be measured)
56A External member

Claims (5)

A light irradiation member for irradiating light for measuring the height distribution of the surface of the measured object,
An imaging member that images the object to be measured at an irradiation position irradiated with the light,
By reflecting the light, a reflection member that is incident on the irradiation position at an incident angle larger than the incident angle at which the light is directly incident from the emission point of the light irradiation member to the irradiation position,
A deriving device that derives the height distribution from the image of the object to be measured at the irradiation position captured by the image capturing member,
A height distribution measuring device. The light is a line light that spreads linearly in a direction perpendicular to the axis orthogonal to the traveling direction,
The height distribution measuring device according to claim 1, wherein the reflecting member reflects the entire line light on a reflecting surface extending in the direction perpendicular to the axis. For the object to be measured whose surface is convexly curved toward the imaging member,
The height distribution measuring device according to claim 1, wherein the reflecting member is arranged so as to intersect a tangential plane of the surface at the irradiation position. With respect to the measured object in which two external members are arranged outside the measured object on both sides of the irradiation position,
The height distribution measuring device according to any one of claims 1 to 3, wherein the reflecting member is arranged between the two external members. Irradiate light for measuring the height distribution of the surface of the measured object,
By reflecting the light, the light is incident on the irradiation position at an incident angle larger than the incident angle at which the light directly enters the irradiation position from the emission point,
Imaging the measured object at the irradiation position,
Deriving the height distribution from the image of the measured object at the imaged irradiation position,
Height distribution measurement method.