JP2001264022A - Instrument and method for measuring liquid film thickness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid film thickness measuring instrument and a liquid film thickness measuring method, capable of accurately measuring the film thickness of a liquid existing on the surface of a roller. SOLUTION: This instrument 1 for measuring liquid film thickness comprises the roller 11 with its surface coated with the liquid including a fluorescent substance for example, a light source 12 for emitting a laser beam 12a, a photographing device 15 for photographing a fluorescent image 20 from the substance, a microscope 14 disposed between a measuring area and the photographing device and magnifying the image 20 emitted from the substance to obtain a magnified fluorescent image, and an optical filter 13 disposed in front of the microscope 14 to remove light of a specific wavelength from the beam 12a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid film thickness measuring device and a liquid film thickness measuring method, and more particularly to a liquid film thickness measuring device and a liquid film thickness measuring method on a roller surface coated with a liquid.

[0002]

2. Description of the Related Art Rollers made of an elastomer material such as rubber are used to transmit driving force such as a transport mechanism such as paper or tape or a tire, because the elastomer material has flexibility or stable friction characteristics. It is used in various fields and applications such as consumer machinery, industrial machinery, precision machinery, etc. Among these various rollers, for example, in a printing unit, a copying machine, a facsimile, etc., in a printing portion or a fixing portion, ink or a fixing solution is applied to the roller surface, and the roller surface is transferred to a printed material, and the paper adheres. Oil or the like is applied to the roller surface for the purpose of prevention or the like.

[0003] It is very important to accurately grasp the film thickness distribution of the liquid such as the ink and the fixing liquid on the roller surface in order to manufacture a product of better quality.

Conventionally, the measurement of the film thickness of the liquid on the roller surface has been performed by an optical method due to the necessity of non-contact measurement. For example, sensing the change in the reflection intensity of light or measuring the film thickness from the height change (displacement) of the liquid film surface by applying the principle of triangulation, or configuring the emission part and light reception part of the slit light source A method of measuring the roller outer diameter from the length of the slit light interrupted by disposing the roller so that the rotation of the roller is orthogonal to the optical axis,
Alternatively, a method utilizing light interference has been implemented.

[0005]

However, in the above-mentioned conventional method for measuring the height displacement of the liquid film surface, accurate film thickness measurement can be achieved unless the influence of the axial eccentricity and vibration of the roller is sufficiently considered. When the liquid is colorless and transparent, the light reflection intensity on the surface of the liquid film becomes very small,
That measurement is virtually impossible. The optical interferometry can be applied only to a transparent liquid and requires light reflection on a roller surface, so that it is difficult to apply it as it is. Therefore,
Some special pretreatment such as coating treatment is required to increase the reflectivity of the roller surface, and it is difficult to use it universally for measuring the liquid film thickness on the roller surface.
In the method of measuring the outer diameter from the blocked slit light,
Each has its advantages and disadvantages, such as difficulty in capturing local changes in film thickness.

[0006] Further, the problems in these conventional methods become more apparent when applied to a roller having a generally large surface roughness, such as a rubber roller. That is, when the surface roughness of the roller and the liquid film thickness are in the same order (for example, the liquid film may be present only in the concave portion having such roughness), the measurement is practically difficult. there were. This is because both the change in the outer diameter of the liquid film surface due to the surface roughness of the roller and the change in the outer diameter due to the presence of the liquid film eventually appear in the measurement results as the same change in displacement. Furthermore, among the rollers used in the industrial field, the surface of the roller is intentionally finished in a porous (sponge) shape to increase the liquid holding capacity,
When no load is applied (outside of the contact area with the partner member, ie, the part where the roller is not functioning), the liquid is retained inside the roller surface layer, and the contact with the partner member causes the liquid to remain in the surface layer only in the functional area. Some liquids are used to transfer liquid from a liquid to a partner member. In such a case, the liquid to be measured permeates near the surface in the measurement section where no load is applied, and the outer diameter of the roller hardly changes. Could not measure.

The present invention has been made in view of the above circumstances. Accordingly, the present invention provides a liquid film thickness measuring device and a liquid film thickness measuring method for accurately measuring the film thickness of a liquid existing on a roller surface. The purpose is to provide.

[0008]

In order to achieve the above object, a liquid film thickness measuring apparatus according to the present invention comprises a roller member having a liquid containing a fluorescent substance applied to a surface thereof, and a measurement area for the liquid. A light source for irradiating the laser light, and an imaging unit for imaging a fluorescent image emitted from the fluorescent substance in the liquid in the measurement area when the laser light is irradiated, and The thickness of the liquid applied to the roller surface in the measurement area is measured.

According to the liquid film thickness measuring device of the present invention described above,
The laser light from the light source is applied to the fluorescent substance in the liquid in the area to be measured, the fluorescent substance that has absorbed the laser light emits fluorescence, and a fluorescent image is captured by the imaging unit. The liquid film thickness is measured from the fluorescence image and the relationship between the previously determined fluorescence intensity and the liquid film thickness. The above operation can be achieved irrespective of the surface roughness of the roller and the material constituting the surface, so that the liquid film thickness can be accurately measured. In addition, the above-described action is achieved by irradiating the held liquid with laser light even in a roller in which the surface of the roller is intentionally finished to be porous (sponge-like) to increase the liquid holding ability. Since it emits fluorescence, it can be measured. Further, since a laser beam having a small beam diameter and strong linearity is used to excite the fluorescent substance, an area to be measured irradiated with the laser beam is a minute area. Therefore, since a fluorescent image from the minute area is captured,
The resolution of the fluorescent image is high, and the measurement accuracy of the liquid film thickness is high.

The liquid film thickness measuring device of the present invention is preferably
The image processing apparatus further includes an optical filter that is disposed between the measurement area and the imaging unit and that removes light having a wavelength of laser light from the light source. This prevents only the fluorescence from being coupled to the imaging unit, and prevents the laser light from the light source from being coupled to the imaging unit, thereby preventing a decrease in the contrast between the laser light and the fluorescent image and reducing the liquid film thickness on the roller surface. Measurement can be performed with high accuracy.

The liquid film thickness measuring device of the present invention is preferably
The apparatus further includes a light condensing member that condenses the laser light from the light source on the measurement area. By condensing the laser light from the light source on the area to be measured, the fluorescent substance is further excited in the minute area, so that the fluorescent image obtained by imaging the fluorescent light emitted from the fluorescent substance is in the horizontal and vertical directions. A fluorescent image with high resolution is obtained.

The liquid film thickness measuring device of the present invention is preferably
The image processing apparatus further includes a first optical member that expands the laser light so that the area to be measured is linear. For example, by irradiating a laser beam so that a linear measurement area is parallel to the rotation axis of the roller and measuring the rotation, the measurement area can be scanned by rotating the roller, and the entire roller surface can be scanned. Can be measured.

The liquid film thickness measuring device of the present invention is preferably
By scanning the laser light, or by rotating the roller member about the rotation axis,
Scanning means for scanning the measurement area is further provided, and the imaging means captures the fluorescence image from each scanned measurement area. By scanning the area to be measured by the scanning means, the liquid film thickness distribution on the roller surface can be measured.

The liquid film thickness measuring device of the present invention is preferably
The image forming apparatus further includes a second optical member that guides laser light from the light source to the measurement area and couples fluorescence emitted from the fluorescent substance to the imaging unit. Thereby, the laser light from the light source is guided to the measurement area through the second optical member, and the fluorescence from the fluorescent substance in the measurement area that has absorbed the laser light is coupled to the imaging unit by the second optical member. Then, a fluorescent image is captured by the image capturing means. Therefore, the excitation of the fluorescent substance in the measurement area by the laser light and the imaging of the fluorescent image are performed by the same optical system, and the adjustment of the apparatus is easy and a liquid film thickness measuring apparatus having a simple configuration can be achieved.

Preferably, the liquid film thickness measuring apparatus of the present invention
The liquid film thickness measurement device further includes a display unit that displays an image captured by the imaging unit. Thus, the measurement position, the imaging state of the fluorescent image, and the like can be observed and confirmed, and it is possible to determine during the measurement whether adjustment of the apparatus is necessary.

The liquid film thickness measuring device of the present invention is preferably
The laser light is a laser light having a wavelength of 300 nm to 700 nm. Depending on the absorption region of the fluorescent substance to be used, the wavelength of the laser light to be used is selected, and in order to increase the horizontal resolution, a shorter wavelength is preferable, but if the wavelength is too short, a special optical design is required. This makes it difficult to design a simple liquid film thickness measuring device.

Further, in order to achieve the above object, a liquid film thickness measuring method according to the present invention is directed to a method of irradiating a laser beam to a measurement area on a roller member surface on which a liquid containing a fluorescent substance is applied. And a fluorescence imaging step of capturing a fluorescence image emitted from the fluorescent substance in the liquid in the measurement area when the laser light is irradiated, and the fluorescence image in the measurement area from the fluorescence image The liquid film thickness on the roller member surface is measured.

According to the liquid film thickness measuring method of the present invention described above,
The laser light from the light source is applied to the fluorescent substance in the liquid in the measurement area, and the fluorescent substance that has absorbed the laser light emits fluorescence, and the fluorescent image is captured. The liquid film thickness is measured from the fluorescence image and the relationship between the previously determined fluorescence intensity and the liquid film thickness. The above operation can be achieved irrespective of the surface roughness of the roller and the material constituting the surface, so that the liquid film thickness can be accurately measured. Furthermore, for excitation of fluorescent substances,
Since a laser beam having a small beam diameter and strong linearity is used, a measurement area irradiated in the laser light irradiation step is a minute area. Therefore, since the fluorescence image from the minute area is captured, the resolution of the fluorescence image is high, and the film thickness of the liquid can be accurately measured.

Preferably, the liquid film thickness measuring method of the present invention
In the laser light irradiating step, the measurement target area is irradiated with laser light while being fixed so as to have a linear shape substantially parallel to the rotation axis of the roller member, and in the fluorescence imaging step, the linear measurement target area is used. By imaging the fluorescence at, scanning the area to be measured by rotating the roller member at a predetermined angle about the rotation axis, by repeating the laser light irradiation step and the fluorescence imaging step, the surface of the roller member Image fluorescence. Thus, the area to be measured can be efficiently scanned, and the distribution of the liquid film thickness on the roller surface can be measured.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the liquid film thickness measuring device and the liquid film thickness measuring method of the present invention will be described below with reference to the drawings.

First Embodiment The liquid film thickness measuring method according to the present invention is measured by using, for example, a liquid film thickness measuring device described below. FIG. 1 is a schematic configuration diagram of a liquid film thickness measuring device according to the present embodiment. A liquid film thickness measuring device 1 according to an embodiment of the present invention includes a roller (roller member) 1 having a surface on which a liquid containing a fluorescent substance is applied, for example.
1, a light source 12 that emits a laser beam 12a, and an imaging device (imaging unit) 15 that captures a fluorescent image 20 from a fluorescent substance.
A microscope (fluorescence enlarging means) 14 arranged between the area to be measured and the imaging device 15 and enlarging a fluorescent image 20 emitted from the fluorescent substance to obtain an enlarged fluorescent image; and a laser beam arranged in front of the microscope 14 An optical filter 13 for removing light having a wavelength of 12a is provided.

The surface of the roller 11 is made of, for example, an elastomer material such as rubber, a metal material, or a porous (porous) material. When the surface of the roller 11 is made of a porous material, the liquid is absorbed and held on the surface. The roller 11 is rotatable with respect to its rotation axis.

The liquid containing a fluorescent substance (not shown) includes a paint,
It is composed of various things such as oil and fixer, and the type is not particularly limited. The fluorescent substance introduced into the liquid is laser light 1
There is no particular limitation as long as it emits sufficient fluorescence when excited by 2a. From the viewpoint of measurement sensitivity, it is preferable that the emission quantum yield be higher and that the amount dissolved in the liquid be larger. preferable.

Laser light 12a emitted from light source 12
Has a high energy density at a single wavelength and has properties suitable for exciting the fluorescent substance, and an optimal wavelength is selected according to the absorption region of the fluorescent substance in the liquid on the surface of the roller 11. In order to measure a minute area, a light having a short wavelength is preferable. However, since a light having a very short wavelength requires a special optical design, a laser light is required to constitute a simple and general-purpose liquid film thickness measuring apparatus. The wavelength of 12a is 300 nm to 70
Preferably, it is selected from the range of 0 nm. In order to measure a finer area, it is preferable to use the laser beam 12a having a small beam diameter.
Since 2a has rectilinearity, for example, a pinhole or the like is disposed in front of the light source 12 and only a part of the laser beam 12a is extracted to irradiate a smaller area.

When the image pickup device 15 picks up the fluorescent light image 20 from the fluorescent substance in the liquid, the optical filter 13 also picks up the laser light 12a from the light source 12 so that the laser light 12a and the fluorescent light image The light source 12 is made of an appropriate material for preventing a decrease in contrast with the laser light 20 and removing light having a wavelength of the laser light 12 a from the light source 12.

As the microscope 14, an optical microscope having a general-purpose objective lens is used. The imaging device 15 captures a fluorescent image 20, and is configured by, for example, an imaging tube, a CCD camera, and the like.

In the liquid film thickness measuring apparatus 1 and the liquid film thickness measuring method using the same, the laser beam 12a emitted from the light source 12 is guided to the area to be measured on the surface of the roller 11, and the fluorescent substance in the liquid is Is irradiated. The laser beam 1
Fluorescence is emitted by the fluorescent substance in the liquid that has absorbed 2a, passes through the optical filter 13, is magnified by the microscope 14, and is imaged by the imaging device 15. The above operation can scan the area to be measured by scanning the laser beam 12a or rotating the roller. In addition, since the fluorescence emitted from the fluorescent substance in the liquid is imaged, the above-described effect can be exerted even when the roller has a large surface roughness and the liquid exists only in the concave portion on the roller surface. Further, even in a roller whose surface is finished to be porous and the liquid is held inside the surface layer, the above-mentioned action can be exerted by irradiating the held liquid with laser light.

According to the liquid film thickness measuring apparatus 1 and the liquid film thickness measuring method using the same according to the embodiment of the present invention, since the fluorescent method is used, the case where the roller has a large surface roughness, Even when the surface is finished to be porous and the liquid is held inside the surface layer, the liquid film thickness on the roller surface can be accurately measured. In addition, by using the laser beam 12a as a light source, it is possible to measure the thickness of a liquid in a minute region.
The resolution of the fluorescence image 20 after the enlargement can be increased by a microscope.

Modified Example FIG. 2 is a schematic configuration example in the case where the beam spot shape of the laser beam 12a of the first embodiment onto the area to be measured is deformed using, for example, a cylindrical lens (first optical member) 19. It is. In this modification, the laser light 1 from the light source 12
2a is irradiated using the cylindrical lens 19 so that the measurement area becomes a linear shape 12b parallel to the rotation axis 11a of the roller 11. Also, instead of the cylindrical lens 19, a laser beam is mechanically scanned using a polygon mirror, a galvanometer mirror, or the like,
The area to be measured may have a linear shape.

The operation of the liquid film thickness measuring apparatus having the above-described configuration is substantially the same as that of the first embodiment, but the area to be measured is scanned by rotating the roller while the laser beam 12a is fixed. To measure the liquid film thickness distribution on the roller surface.

According to the liquid film thickness measuring method using the liquid film thickness measuring device having the above configuration, in addition to the same effects as in the first embodiment, in particular, the liquid film thickness distribution over a wide area of the roller surface is measured. In this case, it is possible to efficiently capture the fluorescent image 20 and scan the measurement area, and to measure the liquid film thickness distribution on the roller surface in a short time.

Second Embodiment A liquid film thickness measuring method can be implemented by using a liquid film thickness measuring device described below. FIG. 3 is a schematic configuration diagram of the liquid film thickness measuring device 2 according to the present embodiment. The liquid film thickness measuring device 2 according to the embodiment of the present invention includes, for example, a roller (roller member) having a surface on which a liquid containing a fluorescent substance is applied.
11, a light source 12 for emitting a laser beam 12a, a scanning unit 16 for scanning the laser beam 12a, an imaging device (imaging unit) 15 for capturing a fluorescent image 20 from a fluorescent substance, and a laser beam 12a from the light source 12 Is guided to the fluorescent substance in the liquid on the surface of the roller 11, and the fluorescent image 20 emitted from the fluorescent substance
(Second optical member) 17 that couples the laser beam to the imaging device 15, and the laser beam 12 a guided from the beam splitter 17 is focused on the measurement area on the surface of the roller 11, and the fluorescent image 20 emitted from the fluorescent substance is formed. A microscope (condensing member, fluorescence enlarging means) 14 having an objective lens 18 for enlarging and guiding to a beam splitter 17 and an optical filter (not shown) arranged in front of the imaging device 15 for removing the wavelength of the laser beam 12a Be composed.

In the liquid film thickness measuring device 2 according to the present embodiment, the roller 11, the light source 12 for emitting the laser beam 12a, the optical filter, the microscope 14, the imaging device 1
5 has substantially the same function as that used in the first embodiment, and is as described above.

The scanning means 16 scans the laser beam 12a for exciting the fluorescent substance in a plane substantially perpendicular to the axis of incidence on the beam splitter 17, and includes, for example, a combination of a mechanical stage and a motor, And a mechanical device using a galvanomirror or the like, or an electro-optic deflecting element or an acousto-optic deflecting element may be used.

Beam splitter (second optical member) 17
Is for guiding the laser beam 12a from the light source 12 to the fluorescent substance in the liquid on the surface of the roller 11, and coupling the fluorescent image 20 emitted from the fluorescent substance to the imaging device 15. Note that a dichroic mirror or the like may be used instead of the beam splitter 17. As described above, in the liquid film thickness measuring apparatus 2 according to the present embodiment, the beam splitter 17 is mounted on the microscope 14 for enlarging the fluorescent image 20, and the excitation of the fluorescent substance in the liquid by the laser beam 12a and the fluorescent image 2
The imaging of 0 is performed by the same optical system.

In the liquid film thickness measuring device 2 and the liquid film thickness measuring method using the same, the laser beam 12a emitted from the light source 12 is reflected by the beam splitter 17 to the measurement area on the roller 11 surface. The laser light 12 a is guided to the measurement area via the objective lens 18, and is irradiated on the fluorescent substance in the liquid on the surface of the roller 11. Fluorescence is emitted by the fluorescent substance in the liquid that has absorbed the laser light 12a, and the fluorescent image 20 passes through the beam splitter 17 and an optical filter (not shown), is enlarged by the microscope 14, and image-processed by the imaging device 15. You. The above operation is achieved by scanning the laser beam 12a with the scanning means 16
Scanning in a plane substantially perpendicular to the axis of incidence on the beam splitter 17 or the roller 11
, The area to be measured can be scanned. Further, even in the case where the surface roughness of the roller 11 is large, or in a roller in which the surface of the roller 11 is finished to be porous, the above-described operation can be exerted similarly to the first embodiment.

According to the liquid film thickness measuring device 2 and the liquid film thickness measuring method using the same according to the above-described embodiment of the present invention, the laser beam 12a is condensed on the area to be measured by the objective lens, so Since the liquid film thickness in the region can be measured and the resolution of the enlarged fluorescent image 20 can be increased by the microscope 14, it is particularly effective when the local liquid film thickness on the roller surface is accurately measured. It is. In addition, since the excitation of the fluorescent substance in the liquid on the surface of the roller 11 by the laser beam 12a and the imaging of the fluorescent image 20 are performed by the same optical system, the adjustment of the apparatus can be easily performed. By scanning the laser beam 12a while checking the position and the imaging state of the fluorescent image 20, etc., the liquid film thickness distribution can be accurately measured. Further, a simple and small liquid film thickness measuring device can be realized.

The liquid film thickness measuring apparatus and liquid film thickness measuring method of the present invention are not limited to the above description. For example, a measurement area can be enlarged by inserting a lens or a diffuser between the beam splitter 17 and the laser light source 12 to give a divergence angle to the laser light 12a.
Further, in the liquid film thickness measuring apparatus 2 of the second embodiment, the beam splitter 17 is disposed between the microscope 14 and the roller 11 so that the fluorescence image 20 is not focused on the area to be measured and the fluorescence image 20 is focused on the microscope 14. , And it is also possible to capture the enlarged fluorescent image. Further, the types of the roller, the imaging device, the beam splitter, and the laser light source are not limited to those described above, and various types can be applied. In addition, various changes can be made without departing from the gist of the present invention.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a liquid film thickness measuring apparatus and a liquid film thickness measuring method according to the present invention will be described below with reference to the drawings.

First Embodiment FIG. 4A shows a liquid film thickness measuring apparatus 1 according to the first embodiment.
Is a fluorescence image 20 obtained by using the above method.
In the present embodiment, a rubber seal used in a commercially available printing apparatus is used as the roller 11, and a cylindrical shaft thereof can be rotated by a motor. As the liquid, silicone oil in which coumarin 6 (fluorescent substance) was dissolved was used. Laser light 12a from light source 12
Used a laser beam having a wavelength of 427 nm and a laser beam 12a having a beam diameter of about 1 mm. In this embodiment, the roller 11 is rotated at a rotational speed of 20 in the direction of the arrow in the figure.
A fluorescent image 20 from the fluorescent substance in the liquid on the roller surface when rotating at rpm was taken. As the imaging device 15, a CCD camera was used.

FIG. 4A shows that the fluorescent image 20 from the fluorescent substance in the liquid on the roller surface can be taken with high accuracy.

FIG. 4B shows the fluorescence intensity of the fluorescence image 20 shown in FIG. 4A by three-dimensional image processing. It can be seen that the fluorescence intensity from the fluorescent substance in the liquid on the roller surface can be accurately measured.

Second Embodiment FIG. 5 shows a fluorescent image 20 when the roller 11 is rotated at various rotation speeds using the same constituent materials as in the first embodiment. The rotation speed of the roller 11 is increased from FIG. 5A to FIG. 5D. The rotation speed of the roller 11 is 10 rpm for (a), 20 rpm for (b), and (c).
Is 50 rpm, and (d) is 100 rpm. In this embodiment, the area to be measured is fixed without scanning with the laser beam 12a. According to the present embodiment, the fluorescence intensity increases from (a) to (d) due to an increase in the number of rotations of the roller 11, and the film thickness of the liquid existing on the surface of the roller 11 increases with an increase in the number of rotations. You can understand what you are doing.

FIG. 6 is a graph showing the relationship between the film thickness of the liquid used in FIG. 5 and the fluorescence intensity of the liquid used in FIG. It is a measurement result of a film thickness. In FIG. 6, the horizontal axis shows the number of rotations of the roller in logarithmic coordinates, and the vertical axis shows the oil film thickness in logarithmic coordinates. However, here, the film thickness at the rotation speed of 100 rpm is standardized as 1 and is shown as a relative value. From FIG. 6, the logarithm of the film thickness of the liquid existing on the surface of the roller 11 is proportional to the logarithm of the number of rotations of the roller. It can be understood that it is increasing functionally. This indicates that the thickness of the liquid existing on the surface of the roller 11 can be accurately measured.

[0045]

According to the liquid film thickness measuring apparatus of the present invention, the laser light can be used as a light source to measure the liquid film thickness in a minute area. Resolution can be increased. Also,
By adopting a configuration in which the excitation of the fluorescent substance in the liquid on the roller member by the laser light and the imaging of the fluorescent image are performed by the same optical system, the adjustment of the apparatus can be easily performed. By scanning the laser beam while checking the imaging state of the fluorescent image and the like, the liquid film thickness distribution can be accurately measured. Further, a simple and small liquid film thickness measuring device can be realized.

According to the liquid film thickness measuring method of the present invention, since the fluorescence method is used, the liquid film thickness on the roller surface can be accurately measured regardless of the surface roughness of the roller and the material constituting the surface. In addition, by using laser light to excite the fluorescent substance, it is possible to measure the thickness of the liquid in a minute region, so that the resolution of the fluorescent image to be measured can be increased.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a liquid film thickness measuring device according to a first embodiment of the present invention.

FIG. 2 is a view showing a modification of the laser light irradiation method in the liquid film thickness measuring device according to the first embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a liquid film thickness measuring device according to a second embodiment of the present invention.

FIG. 4 shows a first embodiment, and (a) shows
It is a captured image of a fluorescent image acquired using the liquid film thickness measuring device according to the present embodiment, and (b) is a measurement result of the fluorescent intensity from the fluorescent image of (a).

FIG. 5 shows a second embodiment, and shows fluorescent images when the roller is rotated at various rotation speeds.

FIG. 6 shows a second example, and is a measurement result of the liquid film thickness obtained from the relationship between the liquid film thickness and the fluorescence intensity obtained separately from the results of FIG. 5; .

[Explanation of symbols]

1, 2 ... liquid film thickness measuring device, 11 ... roller, 12 ... light source, 12a ... laser light, 13 ... optical film, 14 ... microscope, 15 ... imaging device, 16 ... scanning means, 17 ... beam splitter, 18 ... objective Lens, 19: cylindrical lens, 20: fluorescent image.

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 2F065 AA30 BB16 CC31 DD03 FF04 GG04 GG09 JJ03 JJ19 JJ26 LL08 LL13 LL15 LL20 LL22 LL46 LL53 LL57 MM04 MM07 MM16 PP04 PP22 PP24 QQ31 SS13 2G043 AA01 BA0101 HA02 HA09 JA03 KA09 LA03

Claims (13)

[Claims] A roller member having a surface coated with a liquid containing a fluorescent substance; a light source for irradiating the liquid with laser light in a region to be measured; and a region to be measured when the laser light is irradiated. Imaging means for imaging a fluorescent image emitted from the fluorescent substance in the liquid in the above, and a liquid film thickness for measuring a film thickness of the liquid applied to the roller surface in the measurement area from the fluorescent image Measuring device. 2. The apparatus according to claim 1, further comprising: a fluorescence enlarging means disposed between the measured area and the imaging means for enlarging the fluorescence to obtain an enlarged fluorescence image, wherein the fluorescence enlarged image is imaged by the imaging means. Item 2. A liquid film thickness measuring device according to Item 1. 3. The liquid film thickness measuring apparatus according to claim 1, further comprising an optical filter disposed between the measurement area and the imaging means, for removing light having a wavelength of laser light from the light source. 4. The liquid film thickness measuring apparatus according to claim 1, further comprising a light condensing member for condensing the laser light on the measurement area. 5. The liquid film thickness measuring apparatus according to claim 1, further comprising a first optical member that expands the laser light so that the area to be measured is linear. 6. A scanning device for scanning a region to be measured by scanning the laser beam or by rotating the roller member about the rotation axis, wherein the imaging device includes: The liquid film thickness measuring device according to claim 1, wherein the fluorescence image from each scanned region to be measured is imaged. 7. The apparatus according to claim 1, further comprising a second optical member that guides the laser light from the light source to the measurement area and couples the fluorescence emitted from the fluorescent substance to the imaging unit. The liquid film thickness measuring device according to the above. 8. The liquid film thickness measuring device according to claim 1, further comprising a display unit for displaying an image picked up by said image pickup unit. 9. The liquid film thickness measuring device according to claim 1, wherein the surface of the roller member is made of a material containing an elastomer material. 10. The liquid according to claim 1, wherein the surface of the roller member is made of a material containing a porous material, and the liquid is absorbed and held on the surface of the roller member. Film thickness measuring device. 11. The laser beam according to claim 1, wherein said laser beam is 300 nm to 700 nm.
The liquid film thickness measuring device according to any one of claims 1 to 10, which is a laser beam having a wavelength of: 12. A laser beam irradiating step of irradiating a laser beam to a measurement region on a surface of a roller member coated with a liquid containing a fluorescent substance on the surface thereof, wherein the laser beam is irradiated on the measurement region when the laser beam is irradiated. A fluorescent image capturing step of capturing a fluorescent image emitted from the fluorescent substance in the liquid, and a liquid film thickness measuring method for measuring a film thickness of the liquid on the roller member surface in the measurement area from the fluorescent image. 13. The laser beam irradiating step, wherein the area to be measured is fixed so as to have a linear shape substantially parallel to a rotation axis of the roller member, and the laser beam is radiated. By imaging the fluorescence in the measurement area of the shape, scanning the measurement area by rotating the roller member at a predetermined angle around the rotation axis, by repeating the laser light irradiation step and the fluorescence imaging step, 13. The liquid film thickness measuring method according to claim 12, wherein fluorescence of the surface of the roller member is imaged.