JPH03140809A - Liquid film thickness measuring apparatus - Google Patents

Abstract

PURPOSE:To achieve a simplification of the construction of the apparatus by providing a control means to stabilize a quantity of light irradiated of a projecting means according to a reception output of a photodetecting means. CONSTITUTION:A part of light emitted from a projecting section 30 is reflected on a surface 1 to be measured passing through a half mirror 41 to be converted into electricity from light with a photodiode 33 of the photodetecting means 33 and an electrical signal from the photo detecting section 311 is applied to an integration circuit 37 as light signal P through an amplifier circuit 35. With the circuit 37, the light signal P is integrated for a fixed time and a hourly mean signal Q is applied to an output section 40. Then, with the output section 40, the signal Q is linearized while the signal obtained is outputted as voltage signal or current signal corresponding to a thickness. Light which is emitted from the projecting section 30 and reflected with a mirror 47 is converted into electricity from light with a photodiode 33 of a photo detecting section 312 and an electrical signal corresponding to a quantity of light received to be outputted from the photo detecting section 312 is processed with a processing section 42. A control signal which always allows the quantity of light received of the photodetecting section 312 to be constant is applied to the projecting section 30. Thus, a thickness of a liquid on the surface 1 to be measured can be measured with ease.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid film thickness measuring device that measures the film thickness of a liquid that adheres almost uniformly to a rough surface.

[Prior Art] One of the most developed printing methods at present is offset printing (lithographic printing). This is not a physical printing method like letterpress printing or intaglio printing. In other words, a photosensitive liquid is applied onto a grained aluminum or zinc plate,
It is possible to bake a prepared plate in advance, create a plate cylinder through chemical treatment, apply ink to the pattern on the cylinder, soak water in areas other than the pattern, and print the ink on this pattern using pressure. This is a possible method.

That is, this method cleverly utilizes the repulsion between water and the fat contained in the ink to clearly distinguish the water and ink portions, thereby printing only the ink portions.

Therefore, in lithographic printing machines and the like, it is necessary to apply a liquid such as ink and dampening water almost uniformly to a plate having a rough surface that serves as a printing original plate. By applying the liquid evenly and uniformly in this manner, uniform printing can be performed. Therefore, a liquid film thickness measuring device is required to maintain a constant film thickness of the dampening water.

In measurement using this liquid film thickness measuring device, first, a light beam is irradiated onto the surface to be measured such as a printing plate from a light source provided at a predetermined angle. Furthermore, at least one optical sensor is provided at a symmetrical angle and an asymmetrical angle with respect to the optical axis of the irradiated light to receive reflected light from the surface to be measured due to the irradiated light.

Thereafter, the thickness of the adhered liquid film is measured according to the light reception output of each sensor.

However, in the above-described method, it is necessary that the intersection between the optical axis of the irradiation light and the optical axis of each optical sensor coincides with the surface to be measured. Furthermore, measurement errors will occur if the facing distance between the light source and optical sensor and the surface to be measured is not maintained accurately, so there has been a demand for a method that can easily and accurately adjust the facing distance. In order to meet this demand, we
A liquid film thickness measuring device disclosed in Japanese Patent No. 75304 was proposed. This liquid film thickness measuring device will be explained with reference to the drawings.

FIG. 9 is a diagram showing the relationship between the light source, each optical sensor, and the surface to be measured of the liquid film thickness measuring device disclosed in Japanese Patent Laid-Open No. 62-75304.

In the figure, the liquid film thickness measuring device is provided with a facing distance d from the surface 1 to be measured. In this device, a mounting member 10 having an arcuate cross section is made of a non-transparent material, and a mounting hole is provided in the outer edge of the mounting member 10 to securely mount a light source 2 and a light sensor 4.5.9. Furthermore, these optical sensors 4.5
．． A through hole 11 directed from 9 toward the center is formed in each of the holes so that each optical axis 3.6.7.8 can pass through the center of each hole. More specifically, a light source 2 is provided to project a beam of light at a predetermined angle α onto a surface to be measured 1 on a horizontal plane.

Furthermore, the first and second light beams are arranged so as to receive reflected light based on the light projected by the optical axis 3 from the surface to be measured 1 by the symmetrical angle α and the asymmetrical angle β with respect to the optical axis 3 of the light source 2. Sensors 4 and 5 are provided.

Here, optical axes 6 and 7 of each optical sensor 4 and 5
The intersection point O between this and the optical axis 3 coincides with the surface to be measured 1 . Therefore, if the surface to be measured 1 is a smooth surface, almost all of the energy of the light projected by the optical axis 3 is transferred to the optical axis 6.
Accordingly, the light receiving output of the optical sensor 4 is large and the light receiving output of the optical sensor 5 is small. On the other hand, if the surface to be measured 1 is a non-smooth surface, the projected light is scattered and reflected. arises,
Since the energy is dispersed in each direction and becomes reflected light, the light receiving output of the optical sensor 4 decreases, while the light receiving output of the optical sensor 5 increases. Here, the state of dampening water adhesion to the surface to be measured 1, such as a printing plate, will be explained.

FIG. 10 is a sectional view showing how dampening water adheres to the printing plate.

In the figure, the printing plate, which is the surface to be measured 1, has recesses 21 formed in advance, and dampening water 22 adheres to the recesses 21. To explain in detail, if the surface 1 to be measured is a printing plate, minute irregularities are formed according to the pattern. When a small amount of dampening water 22 adheres to the four parts 21, the liquid level has an arcuate shape with a lower center as shown by the solid line, and when it is large, it becomes almost flat as shown by the dotted line. Accordingly, the plate surface exhibits a reflection condition equivalent to that of a non-smooth surface or a smooth surface, and the light reception outputs of the optical sensors 4 and 5 change as described above.

Therefore, by determining the difference between the light reception outputs of the optical sensors 4 and 5, it is possible to measure the film thickness of the dampening water 22 on the plate surface.

However, if the intersection O does not coincide with the surface to be measured 1,
Even if the surface 1 to be measured is a smooth surface, reflected light in the direction of the optical axis 6 will not occur, resulting in a measurement error. Therefore,
A third optical sensor 9 is provided which receives the light reflected by the optical axis 8 in the direction perpendicular to the intersection O.
The light spot from the projected light is detected by the optical sensor 9.
It is designed to detect whether or not it is directly below the .

Therefore, as shown in FIG. 9, the apparatus supports the light source 2 and the optical sensors 4, 5, and 9 as one body according to the above-mentioned relationship, and then supports the light source 2 and the optical sensors 4, 5, and 9 as a unit against the surface to be measured 1 so that the received light output of the optical sensor 9 is maximized. By moving forward and backward and adjusting the facing distance d, the intersection point O will accurately match the surface to be measured 1, and measurement errors will not occur. At this time, by determining the difference in the light reception outputs of the optical sensors 4 and 5, the thickness of the liquid film such as water adhering to the surface to be measured 1 can be accurately measured. Therefore, by controlling the rotation speed of the motor that drives the water supply roller etc. in accordance with this measurement result, the liquid film thickness can be maintained constant.

Next, in order to perform the above-mentioned liquid film thickness measurement process, the following apparatus has also been proposed.

FIG. 11 is a block diagram of a liquid film thickness measuring device for rough surfaces disclosed in Japanese Patent Application No. 63-270550.

This device includes a function of calculating the liquid film thickness according to the light reception output of the above-mentioned light reception sensor and outputting a signal corresponding to the calculated value to the outside.

In the illustrated liquid film thickness measuring device, illustration of the member 10 and the transparent light 11 shown in FIG. 9 is omitted to simplify the explanation. Further, in the same manner as described above, dampening water 22 (not shown), for example, is applied to the surface to be measured 1, which is a rough surface having minute irregularities, in a substantially negative direction, and then the film thickness is measured. Assume that there is.

In the figure, the liquid film thickness measuring device is provided with a light projecting section 30 inclined at a predetermined angle α with respect to the surface 1 to be measured. Furthermore, the light emitted from the light projecting section 30 onto the surface to be measured 1 is reflected by the irradiated surface, and a light receiving section 31 is also provided to receive this reflected light. Furthermore, a calculation output section 32 is provided for inputting the light reception output signal from the light receiving section 31, calculating the film thickness of the dampening solution 22, and outputting a signal corresponding to the calculated film thickness value to the outside. It is assumed that this device is also installed with the facing distance d between the surfaces 1 to be measured.

FIGS. 12A to 12C are block diagrams showing examples of the configuration of the light projecting section 30. FIG.

The light projector 30 has a light source and emits a parallel light beam onto the surface to be measured 1.
It irradiates the area. For example, as shown in FIG. 12(a), an IeNe laser 401 (which emits visible light) may be used as is, or as shown in FIG. 12(b), a semiconductor laser 402 may be used as a light emitting element. The light may be focused by a focusing lens 403 and irradiated onto the surface 1 to be measured as an l'-line light beam. Also, the first
As shown in FIG. 2(C), a halogen lamp 404 is used as a light source instead of a laser, and a pinhole plate 4 having an opening in the center is used.
05 and the light 1 passing through the opening thereof may be focused by a focusing lens 403 to form a parallel light beam.

Now, the light irradiated onto the surface to be measured 1 from the light projecting section 30 configured as described above is reflected by the irradiated surface, and the reflected light enters the light receiving section 31. As shown in FIG. 11, the light receiving section 31 is provided with a first light receiving element, such as a photodiode 33, in a region that receives specularly reflected light, and a second light receiving element, such as a photodiode, is provided somewhere around it. A diode 34 is provided. These photodiodes 33 and 3
The light reception outputs obtained from each of the sections 4 and 4 are respectively given to the calculation output section 32 at the next stage.

Next, the calculation output section 32 includes amplifier circuits 35 and 36, integration circuits 37 and 38, a calculation section 39, and an output section 40.
including. The light receiving outputs obtained from the photodiodes 33 and 34 of the light receiving section 31 at the front stage are each transmitted to an amplifier circuit 35.
and 36. The amplifier circuits 35 and 36 amplify the applied signals to obtain optical signals P1 and P2, the outputs of which are applied to the integrating circuits 37 and 38. Integrating circuits 37 and 38 receive optical signals P1 and P2.
By integrating over a certain period of time, the temporal mean value signals Q1 and Q2 are obtained, and the output is sent to the calculation unit 3.
given to 9. The calculation section 39 includes integration circuits 37 and 38.
It calculates the ratio of the outputs Q1 and Q2, for example, Q2/Ql, and provides the calculated signal to the output section 40. The output unit 40 operates to linearize the calculated signal and output the obtained signal to the outside as a voltage signal of 0 to IOV or a current signal of 4 to 20 mA depending on the film thickness.

Next, the operation of the liquid film thickness measuring device shown in FIG. 11 will be explained with reference to FIGS. 11 to 14.

FIGS. 13(a) and 13(b) are schematic diagrams for explaining the relationship between the rough surface and the film thickness.

FIG. 14 is a graph showing the relationship between the film thickness and the calculation output of the calculation section 39 shown in FIG.

First, when the He--Ne laser 401 of the light projector 30 is driven, a light beam of =l'- is irradiated onto the surface to be measured 1. The angle α between this light beam and the surface to be measured 1 is kept at a small angle such that the light is totally reflected (in this case, the laser beam is reflected and given to the light receiving section 31. Here, as shown in FIG. As shown in (a), when the film thickness of the dampening water 22 is sufficiently large with respect to the unevenness on the rough surface 1a of the surface to be measured 1, the laser beam is completely reflected without being scattered, and the laser beam is reflected at the light receiving part 31. Therefore, even if the amount of light received by the light receiving section 31 is converted into electrical signals P1 and P2 via the amplifier circuits 35 and 36 and integrated by the integration circuits 37 and 38 for a predetermined time, the integration circuit 38
can only be given extremely low level signals. Therefore, if the film thickness of the dampening water 22 is sufficiently large, the calculation unit 3
The output of one will be close to zero. Now, as shown in FIG. 13(b), if the film thickness of the dampening water 22 becomes thinner and becomes approximately equal to the height of the unevenness of the rough surface 1a of the surface to be measured 1, all of the irradiated light beam will be specularly reflected. Some of the particles are scattered by the uneven parts. Therefore, the level of light received by the photodiode 33 decreases, and the level of light received by the photodiode 34 increases. Therefore, by converting these signals into electrical optical signals 1 and P2 and integrating them for a predetermined period of time, the output obtained from the calculation section 39 gradually increases. In this way, an output corresponding to the film thickness is obtained from the calculation section 39, and this relationship is shown, for example, as shown in FIG. 14. Therefore, by calibrating this output level in advance and linearizing the output using, for example, a linearizer, it is possible to obtain a linear output that corresponds to the film thickness within the range. The output section 40 may be a linearizer made of an analog circuit, or the output of the calculation section 39 is A/D converted into a digital quantity, and the output is given to, for example, a microcomputer, and the film thickness corresponding to the input is determined in advance. A correction table having values may be provided and the digital value of the film thickness may be obtained by reading the table. Also, calculation section 3
9, the film thickness signal is obtained by the ratio of the outputs of the integrating circuits 37 and 38, but the outputs Q1 and Q of both
It is also possible to obtain a film thickness signal from the difference between 2 and 5.

[Problems to be Solved by the Invention] As conventional liquid film thickness measuring devices, those shown in FIGS. 9 and 11 have been proposed. Install two receivers,
Since the liquid film pressure is determined based on the outputs of the two light receivers, there is a problem that the configuration of the device and the processing circuit become complicated.

Therefore, an object of the present invention is to provide a liquid film thickness measuring device having a single light receiving device and having a simple device configuration and processing circuit.

[Means for Solving the Problems] A liquid film thickness measuring device according to the present invention irradiates a light beam at a predetermined angle with respect to a rough surface, receives reflected light of the light beam from the rough surface, and A device for measuring liquid film pressure on a rough surface based on the amount of reflected light or the distribution of the amount of reflected light, the device comprising: a projecting means for irradiating a light beam toward the rough surface at a predetermined angle with respect to the rough surface; , comprising a light receiving means for receiving a part of the destination beam irradiated from the light projecting means, and a control means for stabilizing the amount of light irradiated by the light projecting means according to the light receiving output of the light receiving means. be done.

[Function] Since the liquid film thickness measuring device according to the present invention is configured as described above, by using the control means, the amount of light irradiated from the light projecting means can be always stabilized. Therefore, it is possible to receive the reflected light of the irradiation light beam from the rough surface with one light receiver and measure the liquid film pressure on the rough surface.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIGS. 1(a) and 1(b) are configuration diagrams of a liquid film thickness measuring apparatus according to an embodiment of the present invention, which has a function of integrating a light receiver into one and stabilizing the amount of light emitted from a light projecting section. Note that this device is an improved version of the device shown in FIG. 11 above.

In FIG. 1(a), the device is equipped with a surface to be measured 1 which is a rough plate.
a light projecting section 30 arranged at a predetermined angle α from the surface; a bar 7 that transmits a portion of the incident light and reflects a portion of the incident light; a light receiving section 311 that receives reflected light from the surface to be measured 1; a half mirror 41; It has a light receiving section 312 that receives reflected light, a processing section 42, and a calculation output section 321.

Note that the light receiving sections 311 and 312 include, for example, a photodiode 33, detect light reception by the photodiode 33, and output a signal.

Further, the calculation output section 321 includes an amplifier circuit 35, an integration circuit 3
7 and an output section 40, and outputs a signal corresponding to the measured film thickness to the outside. To explain in detail, the light-receiving signal from the light-receiving section 311 is first amplified in the amplifier circuit 35, and the amplified optical signal P is given to the integrating circuit 37. The integrating circuit 37 integrates the optical signal P for a certain period of time and provides a temporal average value signal Q to the output section 40 . The output section 40 is
While linearizing the given average value signal Q,
The obtained signal is outputted to the outside as a voltage signal or a current signal depending on the film thickness.

The photodiodes 33 of the light receiving sections 311 and 312 perform photoelectric conversion in response to the received light, and output an electric signal corresponding to the amount of received light to the next stage circuit. In particular, the light receiving section 312
The electrical signal corresponding to the amount of received light output from the processing unit 42
In response, the processing unit 42 provides the light projecting unit 30 with a control signal for driving the light projection so that the amount of light received by the light receiving unit 312 is always constant. To explain in detail, the processing unit 42
compares the constant voltage level with the voltage level of iA given from the light receiving section 312, and operates to output a control signal to the light projecting section 30 according to the comparison result. therefore,
The amount of light projected by the light projecting section 300 is adjusted so that the amount of light received by the light receiving section 312 is always constant, and as a result, the amount of light transmitted through the half mirror 41 is also adjusted to be constant. In other words,
Even if the light receiving unit 311 receives light at one point by one photodiode 33, the liquid film thickness on the surface to be measured 1 can be easily determined as 11111.

Now, in the above-mentioned FIG. 1(a), the half mirror 41
The amount of light projected is adjusted according to the amount of reflected light from the LED (Light), as shown in Figure 1(b).
It is also possible to adjust the amount of light emitted according to the amount of leaked light when the light beam 9 emitted from the light emitting element (abbreviation for Emitting Diode) enters from the end face of the optical fiber.

In FIG. 1(b), the device is equipped with a surface to be measured 1 which is a rough plate.
It includes an LED 301 that is disposed at a predetermined angle α.

Furthermore, an optical fiber 302 into which the light beam irradiated from the LED 301 is incident, a lens unit 303 which focuses the light incident from the optical fiber 302, and a lens unit 30.
3 is irradiated onto the surface to be measured 1, and includes a light receiving section 311 that receives the reflected light. Furthermore, the device includes LED301
It includes a light receiving section 312 that receives leaked light when a light beam is incident on the optical fiber 302, a processing section 42, and a calculation output section 321. Note that the configuration and operation of the calculation output section 321 are the same as those in FIG. 1(a), and the explanation thereof will be omitted. Light receiving part 3
11 and 312 include photodiodes 33 as in FIG. 1(a), perform photoelectric conversion in response to received light, and output electrical signals in accordance with the amount of received light. Further, the processing section 42 is also the same as that shown in FIG. 1(a), and drives the light emission of the LED 301 based on the light reception signal from the light reception section 312 so that the amount of light received by the light reception section 312 is always constant.

To explain in detail, when the light beam emitted from the LED 301 is incident on the end face of the optical fiber 302, not all of the light beam is incident on the optical fiber 302, and light leakage occurs. This leaked light is received by the photodiode 33 of the light receiving section 302, and an electric signal corresponding to the amount of the received light is given to the processing section 42. In response to this, the processing unit 42 gives a control signal to the LED 301 so that the amount of light received by the light receiving unit 312 is always constant.
The amount of light projected at 01 is adjusted so that the amount of light received by the light receiving section 312 is always constant. Therefore, the amount of light irradiated onto the surface to be measured 1 via the optical fiber 302 and the lens unit 303 is also always adjusted to be constant. Therefore, similarly to FIG. 1(a), the calculation output section 321
The liquid film thickness on the surface to be measured 1 can be easily measured in accordance with the light reception signal obtained by single point light reception by the photodiode 33 of [1].

Note that the optical fiber 302 has a diameter of 200 mm, for example, so that the light beam passing through it is uniform within the fiber.
It has a certain length.

As described above, the apparatus shown in FIG. 1 measures the liquid film thickness after adjusting the facing distance d with respect to the surface to be measured 1 and aligning, as in the conventional case. However, for accurate film thickness measurement, it is necessary not only to match the opposing distance d, but also to match the normal direction of the surface to be measured 1 to a predetermined angle with respect to the apparatus. This is because if the slope of the surface to be measured 1 changes, the surface to be measured 1
This is because the direction in which the light is reflected changes, and the position at which the light reaches the light receiving surface of the light receiving section 311 changes. However, in the apparatus shown in FIG. 1, it is not possible to detect a shift in the arrival position of the incident light on the light receiving section 311 due to the inclination of the surface 1 to be measured, and therefore it is not possible to accurately determine the liquid film thickness 11111. In order to solve this problem, the device is configured as follows.

For example, in the liquid film thickness measuring apparatus shown in FIG. 1 mentioned above, the light receiving section 311 is configured as follows.

FIGS. 2(a) to 2(c) are block diagrams of a liquid film thickness measuring device having a function of detecting the arrival position of reflected light from a surface to be measured on a light receiving surface according to an embodiment of the present invention. The configuration and operation of this device other than the light receiving sections 313 to 315 are the same as those shown in FIG. 1 above, and illustration and description thereof will be omitted.

Hereinafter, the shaded area in the figures indicates a virtual light-receiving surface.

In FIG. 2(a), the device is equipped with a surface to be measured 1 which is a rough plate.
It includes a light projecting section 30 which is arranged at a predetermined angle α from , and a light receiving section 313 which receives reflected light from the surface to be measured 1 . The light receiving section 313 includes comparators 61 and 62 and an LED 521.
551 to 551, and photodiodes 52, 53, 54, 55 are arranged around the photodiode 51 at the center.
including.

Note that the output signal of the photodiode 51 is output from the calculation output section 3.
Given to 21.

In the figure, when the facing distance d between the device and the surface to be measured 1 is appropriate, the reflected light from the surface to be measured 1 enters the light receiving section 313 with the photodiode 51 as the center. photodiode 54
The output signal levels of 3 and 55 in response to the reception of light become equal. However, when the position of the device shifts and the facing distance d increases, the reflected light enters the light receiving section 313 with the photodiode 53 as the center, so the output signal level of the photodiode 53 becomes higher than that of the photodiode 52. On the other hand, if the position of the device shifts and the facing distance d becomes smaller, the photodiode 53
The output signal level of the photodiode 52 becomes higher. That is, by detecting and comparing the output signal levels of the photodiodes 52 and 53, the opposing distance d
The position of the device can be adjusted so that it is appropriate.

By the way, the positional relationship between the surface to be measured and the device is determined by the facing distance d
In addition, as shown in FIGS. 3(a) and 3(b), there is a relationship with the inclination angle of the surface to be measured 1 in the left-right direction and the front-back direction.

As shown in FIG. 3(a), when the inclination angle (indicated by the solid line) of the surface to be measured 1 and the facing distance d are appropriate, the reflected light from the surface to be measured 1 is perpendicular to the virtual light-receiving surface. Therefore, in FIG. 2(a), the reflected light is centered on the photodiode 51 and passes through the light receiving section 3.
13. Therefore, the output signal levels corresponding to the amounts of light received by the photodiodes 52 and 53 are equal. However, the inclination angle of the surface to be measured 1 deviates (indicated by the dotted line), and as shown in FIG. Second
Since the output signal is shifted in the direction of the photodiode 53 in FIG. 5A, the output signal level of the photodiode 53 becomes higher than that of the photodiode 52. Furthermore, when the surface to be measured 1 moves downward toward the light projecting section 30 (backward downward) with respect to the virtual light-receiving surface, the output signal level of the photodiode 52 becomes higher than that of the photodiode 53 in the opposite direction. In other words, the photodiode 52
By detecting and comparing the output signal levels of and 53, it is possible to detect a deviation in the inclination of the surface to be measured 1 in the front-rear direction relative to the virtual light reception, and to make adjustments accordingly.

Further, adjustment is also performed in accordance with the tilt shift of the surface to be measured 1 when viewed from the rear of the light projecting section 30. As shown in FIG. 3(b), when the lower right of the surface to be measured 1 is at an angle of 25 degrees with respect to the virtual light-receiving surface, the center of incidence of the reflected light is at the photodiode 5.
Because of the shift in four directions, the output signal level of the photodiode 54 becomes higher than that of the photodiode 55. In addition, when the surface to be measured 1 is downward to the left with respect to the virtual light-receiving surface, the photodiode 5 is lower than the photodiode 54.
The output signal level of No. 5 increases. That is, by detecting and comparing the output signal levels of the photodiodes 54 and 55, it is possible to detect a deviation in the inclination angle of the surface to be measured 1 in the left-right direction with respect to the virtual light-receiving surface, and to adjust it accordingly.

As described above, in order to adjust the facing distance d and the inclination angle of the surface to be measured 1 to be appropriate, the output signal levels of the photodiodes 52 to 55 in FIG. 2(a) are detected and compared. Thereafter, this comparison result may be displayed externally as an output signal, and adjustments may be made based on this display. In other words,
As shown in FIG. 2(a), the respective output signals of the photodiodes 52 to 55 may be applied to comparators 61 and 62, and the display media of, for example, LEDs 5216 to 551 may be controlled to blink in accordance with the comparison output signals. .

That is, the adjustment of the facing distance d and the inclination angle of the surface to be measured 1 can be easily performed by checking the blinking states of the LEDs 521 to 551.

In addition, in accordance with the completion of adjustment of the facing distance d and the inclination angle of the surface to be measured 1 (the light receiving levels of the photodiodes 52 and 53 and the light receiving levels of the photodiodes 54 and 55 are in an equilibrium state, the LEDs 521 to 551 are turned on. The output signal level of the photodiode 51 that is obtained (when not being used) corresponds to the liquid film thickness to be measured.

Next, as shown in FIG. 2(b), even if the reflected light from the surface to be measured 1 is split into two directions by the half mirror 41, the opposing distance d and the inclination angle of the surface to be measured 1 can be adjusted. can be easily performed as described below.

In FIG. 2(b), similarly to FIG. 2(a) above, the device receives reflected light from the surface to be measured 1 through a light projector 30 arranged at a predetermined angle α with respect to the surface to be measured 1. However, if the mirror 41 branches into two directions, it includes a mirror 7 and light receiving sections 314 and 318. half mirror 4
1, part of the reflected light from the surface to be measured 1 is transmitted and made to enter the light receiving section 314, and a part thereof is reflected and made to enter the light receiving section 318. Further, the light receiving section 314 includes comparators 61 and 62, an AND gate 63, and an LED 521. Note that the light receiving sections 314 and 318 constitute a photodiode array with respect to the virtual light receiving surface. The light receiving section 314 has photodiodes 5] to 53 arranged, and the light receiving section 318
Arrange the photodiodes in the same way. Note that the output signal of the photodiode 52 is given to the calculation output section 321.

By the way, in the apparatus shown in FIG. 2(b), if the facing distance d and the inclination angle of the surface to be measured 1 are appropriate as in FIG. 2(a) above, the output signal level of the photodiode array is , the center photodiode 52 should be the largest. However, if the opposing distance d and the inclination angle of the surface to be measured 1 are not appropriate, the maximum output signal level of the photodiode array will shift from the center of the array to the periphery, as shown in Figure 2 (a) above. Detected in parts. That is, by detecting the output distribution of each photodiode array, it is possible to detect an error in the facing distance d and a shift in the inclination angle of the surface to be measured 1. Therefore, it is only necessary to perform an adjustment to correct the detected error in the facing distance d and the deviation in the inclination angle of the surface to be measured 1.

By the way, in order to ensure that the facing distance d and the inclination angle are appropriate, the comparison results of the output signals of the photodiodes 51 to 53 may be displayed externally, and adjustments may be made based on this display. In other words, Fig. 2(b)
As shown in the figure, the output signals of each photodiode 51 to 53 are applied to comparators 61 and 62, and the comparison results are outputted via the AND gate 63 at the next stage, and the LED 521
All you have to do is control the flashing. In other words, Figure 2 (
The LED 521 shown in b) is ((output signal level of photodiode 51) <(output signal level of photodiode 52), AND, (output signal level of photodiode 53) <(output signal level of two photodiodes 52). )) is established, the light is lit for the first time, so the output signal level of the photodiode 52 when the LED 521 is lit corresponds to the liquid film thickness to be measured.

The above has described the light receiving section 314, but the light receiving section 318
By having a similar configuration for the light receiving section 314, it is possible to adjust the light receiving section 314 in the same manner as the light receiving section 314.

In addition, as shown in FIG. 2(c), a two-dimensional PSD (Position 5 sensitive
Even if a detector (abbreviation for optical position detector) is provided, the opposing distance d and the inclination angle of the M1 constant surface 1 can be easily adjusted as described below. Note that this device obtains the liquid film thickness from the calculation output section 321 when a light receiving spot is detected within a predetermined area on the light receiving surface of the two-dimensional PSD.

In FIG. 2(C), the device receives reflected light from the surface to be measured 1 by a light projector 30 arranged at a predetermined angle α with respect to the surface to be measured 1, as in FIG. 2(a) above. Light receiving section 31
Contains 5. Furthermore, the light receiving section 3105 includes a two-dimensional PSD 69, a position calculation circuit 64, absolute value circuits 651 and 652, comparators 66 and 67, and an AND
It includes a gate 63, an LED 521, and a summation circuit 68.

Note that the output signal of the summation circuit 68 is given to the calculation output section 321.

By the way, in the apparatus shown in FIG. 2(C), if the facing distance d and the inclination angle of the surface to be measured 1 are appropriate as in the case of FIG. 2(a) above, the reflected light from the surface to be measured 1 is enters the center of the two-dimensional PSD 69 of the light receiving section 315. That is, by detecting the left and right output signal levels and the upper and lower output signal levels of the two-dimensional PSD 69, the error in the facing distance d and the deviation in the inclination angle of the surface to be measured 1 can be detected.

Therefore, according to the detected error in the facing distance d and the deviation in the inclination angle of the surface to be measured 1, adjustments are made to correct this so that the reflected light enters the center of the two-dimensional PSD 69. . At this time, if the output signal of the summation circuit 68 is given to the calculation output section 321, an appropriate film thickness can be obtained.

Incidentally, this adjustment can be easily made by observing the display of the LED 521 which is controlled to blink in response to the output signal of the AND gate 63.

Next, the detection operation of the light receiving spot position on the two-dimensional PSD 69 will be explained.

As shown in FIG. 2(c), the four output parts of terminals A to D of the two-dimensional PSD 69 are simultaneously applied to the position calculation circuit 64 and the summation circuit 68. In response, the position calculation circuit 64 calculates the light receiving spot position of the two-dimensional PSD 69 (x
, y) and given to the next absolute value circuits 651 and 652. To explain in detail, the position calculation circuit 64 calculates and outputs the position coordinate X according to the current flowing from the terminals A and B, and similarly, according to the current flowing from the terminals C and D, using a well-known technique. The position coordinate Y is calculated and output.

Therefore, by converting the position coordinates X and Y into absolute values in the absolute value circuits 651 and 652, the position coordinate (X) of the light receiving spot at this time.

Y) can be obtained as a relative position from the center (origin) of the two-dimensional PSD 69. Next, the position coordinates X and Y obtained as the relative position from the center (origin) of the two-dimensional P2 SD 69 are given to the comparators 66 and 67,
It is compared with predetermined reference values Refl and Ref2. Thereafter, by applying this comparison result to the next AND gate 63, it is possible to control the lighting of the LED 521 only when the AND operation is satisfied. In other words, the light receiving spot position is 2
The LED 521 lights up only when it is within a certain range including the center (origin) of the dimension PSD 69. Therefore, the output signal level given from the summation circuit 68 to the calculation output section 321 at this time corresponds to the liquid film thickness to be measured.

In addition, in this device, by arbitrarily setting the reference values Refl and Ref2 of the comparators 66 and 67, the area on the light-receiving surface of the two-dimensional PSD 69 where the light-receiving spot is to be detected can be arbitrarily expanded or contracted. Ru.

As described above, the device shown in FIG. 2 has the function of detecting the arrival position of the reflected light on the light-receiving surface in the light-receiving section. It is possible to simultaneously detect the deviation and perform a film thickness measurement operation that corrects the deviation.

By the way, in the above-mentioned apparatus, it is assumed that normal reflected light is always incident on the light receiving part from the surface to be measured 1, but for example, if it is assumed that the surface to be measured 1 rotates, the normal reflected light is Sometimes reflected light cannot be obtained. In other words, the fourth
As shown in the figure, when the gap E of the plate cylinder reaches the light emitting position of the light emitting section 30, the light reflected from the gap E that should not be measured enters the light receiving section 311. An erroneous output signal from the device will cause malfunctions of the liquid supply control section and the like. In order to solve this problem, the arithmetic output section 321 of the device shown in FIG. 1 is configured as shown in FIG. 5.

FIG. 5 is a configuration diagram of a liquid film thickness measuring device according to an embodiment of the present invention, which is equipped with a validity processing function of a received light signal.

In FIG. 5, the device is set at a predetermined angle α with respect to the surface to be measured 1.
It includes an arithmetic output section 322 that inputs output signals from the light projecting section 30, the light receiving section 3411, and the light receiving section 311 and processes the signals. The light receiving section 311 includes a photodiode 33 for receiving specularly reflected light from the surface to be measured 1 and photoelectrically converting the received light. The calculation output section 322 includes an amplifier circuit 35, an integration circuit 37, an S/H (abbreviation for sample and hold) circuit 398, a level determination section 39b, and an output section 40.
including. Note that the calculation output unit 322 has a S/H circuit 39a and a level determination unit 3Qb surrounded by dotted lines newly added to the calculation output unit 321 shown in FIG. Since it is similar to the calculation output section 321 shown in the figure, detailed explanation will be omitted.

In the figure, the light projected from the light projecting unit 30 is projected onto the surface to be measured 1.
When the light is irradiated onto the gap E, the reflected light at the gap E enters the photodiode 33 of the light receiving section 311 and is charged and converted. At this time, since the reflected light at the gap E contains a large amount of diffuse reflection components, the signal level of the optical signal P of the amplifier circuit 35 obtained via the photodiode 33 rapidly decreases by 5. On the other hand, the level determination section 39b constantly receives the optical signal P output from the amplifier circuit 35. Accordingly, the level determination unit 39b compares the signal level of the applied optical signal P with a predetermined level. As a result of this comparison, if it is determined that the optical signal P is above a predetermined level, a signal for controlling the sampling operation is given to the S/H circuit 39a, and if it is determined that the optical signal P is below the predetermined level, a hold operation is controlled to the S/H circuit 39a. Give a trigger signal like this. In other words,
Even if the average value signal Q of the integrating circuit 37 suddenly changes due to the reception of the reflected light at the gap E, the S/H circuit 39a holds the average value signal Q immediately before the detection of the gear E, so that the signal of the output section 40 is Does not change significantly. therefore,
It is also possible to prevent malfunctions of the liquid supply control section and the like that operate in response to the output signal of the output section 40. To explain further, the optical signal P is transmitted from the light receiving section 311 via the amplifier circuit 35.
The processing up to when this is obtained and provided to the integrating circuit 37 is carried out at extremely high speed. Therefore, before the average value signal Q at the time of gear E measurement is outputted, it is required to give a trigger signal to the S/H circuit 39a to perform a hold operation. In other words, the integrating circuit 37
If we set the time constant of to a value that satisfies this requirement, we get
The output signal of the calculation output section 322 can be easily held according to the determination result of the level determination section 39b.

As described above, according to the apparatus shown in FIG. 5, the output signal of the calculation output section 322 immediately before the detection of the gear E on the surface to be measured 1 can be held, so that malfunctions of the liquid supply control section and the like can be prevented.

Now, according to the apparatus shown in FIG. 5, the gap E, which should not be measured, is detected based on the fact that normal reflected light is not received. However, in addition to gap E, 111
Even when measuring a portion that should not be determined, that is, an image portion (portion to be coated with ink) of the surface 1 to be measured, accurate liquid film original information cannot be transmitted to the liquid supply control section. For example, according to the device shown in Figure 4 above, the liquid film thickness is measured all around the plate cylinder including the gap E, so if the printing area occupies the entire circumference of the plate cylinder, the normal reflected light 7 will be extremely unlikely to be received, and erroneous output signals will frequently be transmitted to the liquid supply control unit. In order to solve this problem, a liquid film thickness measuring device is configured as shown in FIG. 6, for example.

FIG. 6 is a configuration diagram of a liquid film thickness measuring device according to an embodiment of the present invention, which outputs a measurement signal in response to detection of a predetermined position on a surface to be measured.

In FIG. 6, a liquid film thickness measuring section 73 and a rotational position detecting section 70, which correspond to the apparatus shown in FIG. 1 above, are installed facing a plate cylinder which rotates at a constant speed to which a printing original plate is attached. Further, the detection signal of the rotational position detection section 70 is sent to the S/H circuit 39a, and the sampling operation and holding operation of the S/H circuit 39a are controlled accordingly. Note that the rotational position detection section 7
0 includes, for example, a rotary encoder, etc., and in response to detecting a predetermined rotational angular displacement of the plate cylinder, the next stage S/
It operates to provide a trigger signal for controlling the hold operation to the H circuit 39a. On the other hand, the liquid film thickness measuring device 3 performs the same measuring operation as the device shown in FIG. Therefore, according to this device, the liquid film thickness at a predetermined position on the surface 1 to be measured can be measured. Note that the rotational position detection section 70 includes, for example, a proximity switch or a photoelectric switch, and operates to provide a trigger signal for a hold operation to the next-stage S/H circuit 39a in response to the detection of the gap E. Good too.

In the figure, the mounting positions of the liquid film thickness δ-1 fixed part 73 and the rotational position detection part 70 are set so that they face the position on the plate cylinder to be measured when the rotational position detection part 70 outputs the hold trigger signal. Attach the liquid film thickness measuring section 73. The rotational position detection unit 70 activates the S/H circuit 39a at the time when the gap E is detected or when the predetermined rotational angular displacement of the plate cylinder is detected.
A sample operation instruction signal is given to the In response to this,
The S/H circuit 39a samples and holds the output signal from the liquid film thickness measuring section 73. This held signal will be held until the next sample operation instruction signal is given from the rotational position detection section 70. In other words, the S/H circuit 39a is capable of holding the output signal from the liquid film thickness measuring section 73 for a period from when the sample operation 9 instruction signal is applied until when the next sample operation instruction signal is applied. Must have a constant.

As described above, since the present device measures the liquid film thickness at a predetermined position, it is possible to avoid situations where measurement is performed at the image area or at the gap E. Also,
Even when the surface to be measured 1 moves like a plate cylinder, the analog output signal corresponding to the measured liquid film thickness does not fluctuate, so a stable control signal can be transmitted to the liquid supply control section. can.

By the way, for example, in the device shown in FIG. 1 above,
The light emitter, light receiver, processing circuit, etc. were all housed in one housing. However, when functions are added to the device, the configuration size of the device inevitably increases. In order to solve this problem, the apparatus is configured as shown in FIG.

FIG. 7 is a configuration diagram of a liquid film thickness 0 measuring device according to an embodiment of the present invention, which emits and receives light via an optical fiber and is miniaturized. Note that in the figure, the calculation output unit 321 is the same as described above, and illustration and description thereof will be omitted.

In the figure, the device includes a light emitting and processing section 304, a light receiving section 3
11, an optical fiber 302 and a head section 71. The light emitting and processing section 304, the light receiving section 311, and the head section 71 are connected by an optical fiber 302 that has strong resistance to noise, and are configured to be mutually independent. Note that the light emitting and processing unit 304 is shown in FIG. 1(b).
It includes an LED 301, a light receiving section 312, and a processing section 42 shown in FIG. Further, the head section 71 has a lens unit 303 attached to the tip of the optical fiber 302 on the surface to be measured 1 side, so as to irradiate the surface to be measured 1 with a parallel light beam. Further, the reflected light from the surface to be measured 1 is focused by the lens unit 303, and is transmitted to the head section 71 via the optical fiber 302.
The light is then sent to the light receiving unit 311 from there.

As described above, the projected light is irradiated onto the surface to be measured 1 via the head section 71 via the tip fiber 302.

1 Also, since the reflected light from the surface to be measured 1 is given to the light receiving section 311 via the head section 71 and the optical fiber 302, the influence of noise components in the transmission path of the transmitted and received light can be eliminated by using the optical fiber 302. can. In addition, the head section 7
By making the head 1 independent from the device, the device itself can be made smaller, and furthermore, by adjusting only the head portion 71, the facing distance d can be set appropriately. Further, by moving the head section 71, the liquid film thickness at any position can be measured.

By the way, in the above-mentioned apparatus, since the light emitting part and the light receiving part are exposed to the surface to be measured 1, the inside of the apparatus is easily contaminated by dust, ink, etc. Furthermore, even if the amount of light irradiated to the surface to be measured 1 and the amount of reflected light from the surface to be measured 1 that enters the light receiving section inside the device decrease due to the adhesion of dirt,
It cannot be detected with conventional equipment. Therefore, the liquid supply control section will malfunction. In order to solve this problem, the apparatus is configured as shown in FIG.

FIG. 8 is a configuration diagram of a liquid film thickness measuring two-window device having a function of preventing a decrease in the amount of transmitted and received light due to dew condensation and dirt, according to an embodiment of the present invention. FIG. 8(a) shows the transparent window 411
8(b) is a block diagram of a device configured to project and receive light through prisms 413 and 412. FIG. Note that this device is particularly an improved version of the head portion 71 shown in FIG. 7, and since the other configurations are the same as those shown in FIG. 7, illustration and description thereof will be omitted.

First, in FIG. 8(a), the device is separated from the light emitting part, the light receiving part, and the calculation output part, and the head part 7 for light emitting and receiving
Contains 2. Note that both are connected by an optical fiber 302. Furthermore, the head unit 72 has a transparent window 411 to prevent and detect a low F amount of projected and received light due to dew condensation and dirt.
and 412, light receiving parts 316 and 317 for dew condensation and dirt detection, comparators 66 and 67, and LED 561
and 571. Note that the comparator 66 has a reference value Re.
f3 is given, and the comparator 67 is given a reference value Ref4. Furthermore, the transparent windows 411 and 412 are made of a translucent material. In addition, the light receiving section 31 for detecting dew condensation and dirt
6 and 317 include photodiodes 33, which receive light, perform photoelectric conversion, and output optical signals.

In FIG. 8(a), similarly to FIG. 7 above, the light emitted from the light emitting and processing unit 304 passes through the optical fiber 302, passes through the transparent window 411, and is irradiated onto the surface 1 to be measured. Further, after being irradiated onto the surface to be measured 1, the reflected light passes through the transparent window 412 and enters the light receiving section 311 via the optical fiber 302.

Now, the amount of transmitted light incident on the transparent windows 411 and 412 at this time depends on the degree of transparency of the transparent windows 411 and 412. However, transparent windows 411 and 412
The degree of transparency may be reduced due to adhesion of ink droplets from the surface 1 to be measured or dew condensation. In such a state, the amount of light irradiated onto the surface to be measured 1 decreases, and accordingly, the amount of light reflected from the surface to be measured 1 that enters the light receiving section 311 also decreases. This is the transparent window 41 with dirt attached.
This is because the light incident on 1 and 412 is diffusely reflected.

Therefore, by detecting the amount of diffusely reflected light, it can be determined whether the transparent windows 411 and 412 are dirty or not. Regarding this discrimination operation,
This will be explained with reference to the drawings.

It is now assumed that dirt has adhered to the transparent windows 411 and 412, reducing the amount of transmitted light.

First, the light emitted from the processing unit 304 is transmitted to the transparent window 41.
When the light enters the transparent window 411, a part of the incident light is diffusely reflected due to dirt attached to the transparent window 411.

A part of this diffusely reflected light is transmitted to the light receiving section 31 for detecting dew condensation and dirt.
6, and a received light signal corresponding to the amount of incident light is given to a comparator 66. The comparator 66 compares the reference value Ref3 with the applied light reception signal, and depending on the comparison result, the LE
Controls blinking of D561.

In other words, by controlling the lighting of the LED 561 only when the light reception level of the light receiving section 316 for detecting dew condensation and dirt exceeds the reference value Ref3, the user can detect dirt adhesion on the transparent window 411 by lighting the LED 561. . On the other hand, when the reflected light from the surface to be measured 1 enters the transparent window 412, a portion of the incident light is diffusely reflected due to the dirt on the transparent window 412. A part of this diffusely reflected light is incident on the light receiving section 317 for detecting dew condensation and dirt, and a light reception signal corresponding to the amount of incident light is given to the comparator 67 accordingly. The comparator 67 compares the reference value Ref4 with the applied light reception signal, and controls the LED 571 to blink according to the comparison result. In other words, the light reception level of the light receiving section 317 for detecting dew condensation and dirt is at the reference value R.
By controlling the lighting of the LED 571 only when ef4 is exceeded, the user can detect dirt on the transparent window 412 by the lighting of the LED 571.

The above-mentioned device shown in FIG. 8(a) uses transparent windows 4]1 and 412 to detect dirt adhesion to prevent measurement malfunctions, but the device shown in FIG. 8(b) like,
Transparent windows 411 and 412 are connected to prisms 413 and 41
It may be replaced with 4.

In other words, the prisms 413 and 414 may be used to detect a decrease in the amount of received light due to the adhesion of dirt to prevent measurement errors.

As described above, the apparatus is configured such that a transparent window or prism is provided in the optical path formed between the apparatus and the surface to be measured 1, and light is emitted and received through this. Therefore, the inside of the device is not contaminated. Further, since dew condensation and dirt can be detected, malfunctions of the device can be prevented, and it is also possible to notify when to remove condensation and when to remove dirt. Also, since dirt only adheres to the head,
The maintainability of the equipment is improved.

[Effects of the Invention] As described above, according to the present invention, the number of light receivers in the light receiving section is reduced to one, and the amount of light irradiated by the light emitting section is stabilized, thereby simplifying the device configuration and processing circuit. . In addition, since the arrival position of the reflected light from the rough surface is detected on the light receiving surface, it is possible to detect the error in the facing distance and the deviation in the tilt angle of the rough surface, and the adjustment can be made according to the detection results. , equipment malfunction can be prevented. In addition, the light emitting/receiving head is provided using an optical fiber and is separated from the light emitting section, light receiving section, and processing circuit section, so the light emitting/receiving head section can be miniaturized and the light Transmission is performed using optical fibers, which avoids the effects of noise. Further, a transparent member is provided in the optical path between the device and the rough surface, and by detecting the amount of diffusely reflected light on this member, dirt, dew condensation, etc. on the light incident surface of the member is detected. Therefore, the inside of the device is not directly contaminated, and it is possible to know when to remove condensation and when to wipe off dirt. Furthermore, even if it gets dirty, it can be easily maintained. In addition, since the calculation output for film thickness calculation is held in accordance with the displacement of the light receiving output level of the light receiving section, the output signal level will not fluctuate greatly even if, for example, the gap part of the plate cylinder is measured. Therefore, stable signals can be transmitted to the next-stage control section. Furthermore, in response to detection of a predetermined measurement position, a measurement signal corresponding to the film thickness is output. Therefore, it is possible to detect the film thickness at a specific location, and there are also effects such as being able to transmit a stable output signal without fluctuations to the next stage control unit, etc.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a liquid film thickness measuring device according to an embodiment of the present invention, which has one light receiver and has a function of stabilizing the amount of light emitted from the light projecting section. FIG. 2 is a configuration diagram of a liquid film thickness measuring device having a function of detecting the arrival position of reflected light from a surface to be measured on a light receiving surface according to an embodiment of the present invention. FIG. 3 is a diagram illustrating the relationship between the inclination angle of the surface to be measured and the position at which the reflected light reaches the apparatus. FIG. 4 is a diagram for explaining the detection operation in the gap of the plate cylinder. FIG. 5 is a configuration diagram of a liquid film thickness measuring device according to an embodiment of the present invention, which is equipped with a validity processing function of a received light signal. FIG. 6 is a configuration diagram of a liquid film thickness measuring device according to an embodiment of the present invention, which outputs a measurement signal in response to detection of a predetermined position on a surface to be measured. 7th
The figure is a configuration diagram of a liquid film thickness measuring device according to an embodiment of the present invention, which emits and receives light via an optical fiber to reduce the size of the device. FIG. 8 is a configuration diagram of a liquid film thickness measuring device according to an embodiment of the present invention, which has a function of preventing a reduction in the amount of transmitted and received light due to dew condensation and dirt. Figure 9 is from Japanese Patent Application Laid-Open No. 62-753.
FIG. 9 is a diagram showing the relationship between the light source, each optical sensor, and the surface to be measured of the liquid film thickness measuring device disclosed in the No. 04 publication. FIG. 10 is a sectional view showing how dampening water adheres to the printing plate. FIG. 11 is a block diagram of a liquid film thickness measuring device for rough surfaces disclosed in Japanese Patent Application No. 63-270550. FIG. 12 is a block diagram showing an example of the configuration of the light projecting section. FIG. 13 is a schematic diagram for explaining the relationship between the rough surface and the film thickness. FIG. 14 is a graph showing the relationship between the film thickness and the calculation output of the calculation section shown in FIG. 11. In the figure, 1 is a surface to be measured, 30 is a light emitter, 33 is a photodiode, 311 to 315, 318 are light receivers,
316 and 317 are light receiving parts for dew condensation and dirt detection;
2, 321 and 322 are calculation output parts, 302 is a tip fiber, 71 and 72 are head parts, and 39a is a sample &amp;
41 is a half mirror, 171 is a rotational position detection section, 73 is a liquid film thickness measurement section, 411 and 412 are transparent windows, and 413 and 414 are prisms. In each figure, the same reference numerals indicate the same or corresponding parts. 0 68- DO\ 0 Procedural amendment Patent Application No. 280359 of 1999 2 Title of the invention Liquid film thickness measuring device 1990 1 Ming 7 6 Claims column 7 of the specification subject to amendment The scope of claims in the description of the amendment is as attached. 3. Relationship with the case of the person making the amendment Patent applicant address 10 Hanazono Tsuchido-cho, Ukyo-ku, Kyoto City Name
(294) Omron Corporation Name changed on January 29, 1990 (-) Representative Yoshio Tateishi 4, Agent address 2-1-29 Minamimorimachi, Kita-ku, Osaka Sumitomo Bank Minamimorimachi Building 2, Patent Claims (1) A light beam is irradiated onto a rough surface at a predetermined angle, the reflected light of the light beam from the rough surface is received, and the rough surface is determined based on the amount of reflected light or the distribution of the amount of reflected light. A device for measuring the liquid film thickness on a surface, the device comprising: a light projecting means for irradiating a light beam directed toward the rough surface at a predetermined angle with respect to the rough surface; and a part of the light beam irradiated from the light projecting means. A liquid film thickness measuring device comprising: a light receiving means for receiving light; and a control means for stabilizing the amount of light irradiated by the light projecting means according to the light receiving output of the light receiving means. (2) A light beam is irradiated onto the rough surface at a predetermined angle, the reflected light from the rough surface is received, and the liquid on the rough surface is determined based on the amount of reflected light or the distribution of the amount of reflected light. A device for measuring film thickness, comprising: a light projecting means for emitting a light beam directed at the rough surface at a predetermined angle with respect to the rough surface; and a light beam emitted from the light projecting means near the rough surface. a first optical fiber means for guiding the light beam from the rough surface; a light receiving means for receiving the light reflected from the rough surface of the light beam irradiated by the light projecting means; and a light receiving means for receiving the light reflected from the rough surface of the light beam in the vicinity of the rough surface. A liquid film thickness measuring device, comprising: a second optical fiber means leading to a light receiving means. (3) A light beam is irradiated onto the rough surface at a predetermined angle, the light beam reflected from the rough surface is received, and the rough surface is determined based on the amount of reflected light or the distribution of the reflection intensity. A device for measuring liquid film thickness, the device comprising: a light projecting means for projecting a light beam directed at the rough surface at a predetermined angle with respect to the rough surface; and a light beam directed from the rough surface by the light projecting means. a light receiving means for receiving reflected light; a light projecting window made of a transparent member, in which the light projecting means and the light receiving means are housed, through which the light beam from the light projecting means can pass; and a light projecting window through which the reflected light can pass. A liquid film thickness measuring device comprising: a storage means provided with a light receiving window; a detection means for detecting the amount of diffusely reflected light due to the opacity of the transparent member; and an output means for outputting a signal in response to the detection output of the detection means. . (4) A light beam is irradiated at a predetermined angle to the rough surface, the reflected light from the rough surface is received, and the liquid on the rough surface is determined based on the amount of reflected light or the distribution of the amount of reflected light. A device for determining a film thickness of 1llll, having a light receiving surface, means for detecting the arrival position on the light receiving surface of the reflected light from the rough surface of the light beam, and responding to the detection output of the detecting means. A liquid film thickness measuring device, comprising an output means for outputting a signal. (5) A light beam is irradiated at a predetermined angle to the rough surface, the reflected light from the rough surface is received, and the liquid on the rough surface is determined based on the amount of reflected light or the distribution of the amount of reflected light. A device for measuring film thickness, the device comprising: a light receiving means for receiving reflected light of the light beam from a rough surface; and a calculating means for calculating a liquid film thickness on the rough surface based on a received light output of the light receiving means. . A liquid film thickness measuring device, comprising: holding means for holding an output signal of the calculating means based on a displacement of the light receiving output of the light receiving means. (6) A light beam is irradiated onto the rough surface at a predetermined angle, the light beam reflected from the rough surface is received, and the intensity of the reflected light is determined based on the distribution of the amount of reflected light. A device for measuring liquid film thickness, comprising a measuring means for measuring the liquid film thickness based on the amount of reflected light or the distribution of the amount of reflected light, and a first detection stage for detecting the relative position between the measuring means and the rough surface. A liquid film thickness measuring device, comprising: a holding means for holding an output signal of the measuring means based on a detection position of the detecting means and a predetermined total if1 position.

Claims (6)

[Claims] (1) Irradiate a light beam at a predetermined angle to the rough surface,
A device that receives reflected light of the light beam from a rough surface and measures the liquid film thickness on the rough surface based on the amount of reflected light or the distribution of the amount of reflected light, the device being tilted at a predetermined angle with respect to the rough surface. a light projecting means for emitting a light beam directed toward a rough surface; a light receiving means for receiving a part of the light beam emitted from the light projecting means; A liquid film thickness measuring device comprising a control means for stabilizing the amount of irradiated light. (2) Irradiate a light beam at a predetermined angle to the rough surface,
A device that receives reflected light of the light beam from a rough surface and measures the liquid film thickness on the rough surface based on the amount of reflected light or the distribution of the amount of reflected light, the device being tilted at a predetermined angle with respect to the rough surface. a first optical fiber means that guides the light beam emitted from the light projecting means to the vicinity of the rough surface; and a first optical fiber means that directs the light beam emitted from the light projecting means to the vicinity of the rough surface; a liquid film thickness comprising: a light receiving means for receiving the reflected light of the light beam from the rough surface; and a second optical fiber means for guiding the reflected light of the light beam from the rough surface to the light receiving means in the vicinity of the rough surface. measuring device. (3) Irradiate a light beam at a predetermined angle to the rough surface,
A device that receives the reflected light of the light beam from the rough surface and measures the liquid film thickness on the rough surface based on the amount of the reflected light or the distribution of the reflected light, the device being tilted at a predetermined angle with respect to the rough surface. a light projecting means for emitting a light beam directed toward a rough surface; a light receiving means for receiving reflected light from the rough surface of the light beam emitted from the light projecting means; the light projecting means and The light receiving means is stored, the storage means is provided with a light projection window through which the light beam from the light projection means can pass, and a light reception window through which the reflected light can pass, and the amount of diffusely reflected light due to the opacity of the transparent member is controlled. A liquid film thickness measuring device comprising: a detection means for detecting a liquid film; and an output means for outputting a signal in response to a detection output of the detection means. (4) Irradiate a light beam at a predetermined angle to the rough surface,
An apparatus for receiving the reflected light of the light beam from the rough surface and measuring the liquid film thickness on the rough surface based on the amount of the reflected light or the distribution of the amount of the reflected light, the device having a light receiving surface, A liquid film thickness measuring device comprising means for detecting the arrival position on a light receiving surface of light reflected from a rough surface of a light beam, and output means for outputting a signal in response to a detection output of the detection means. (5) Irradiate a light beam at a predetermined angle to the rough surface;
A device that receives reflected light from the rough surface of the light beam and measures a liquid film thickness on the rough surface based on the amount of the reflected light or the distribution of the amount of reflected light, the device receiving the reflected light from the rough surface of the light beam. a light receiving means for receiving reflected light; a calculating means for calculating the liquid film thickness on the rough surface based on the light receiving output of the light receiving means; and an output signal of the calculating means based on the displacement of the light receiving output of the light receiving means. A liquid film thickness measuring device, comprising a holding means for holding a liquid film thickness. (6) Irradiate a light beam at a predetermined angle to the rough surface,
An apparatus for receiving reflected light of the light beam from a rough surface and measuring the liquid film thickness on the rough surface based on the amount of the reflected light or the distribution of the amount of the reflected light, the device comprising: the amount of the reflected light or the amount of the reflected light; a measuring means for measuring the liquid film thickness based on the distribution of the liquid film; a detecting means for detecting the relative position between the measuring means and the rough surface; based on the detection position of the detecting means and a predetermined measurement position, A liquid film thickness measuring device, comprising: holding means for holding an output signal of the measuring means.