JPS61129554A - Measuring device for scattered light - Google Patents

Abstract

PURPOSE:To eliminate the need for a large-output light source and simplify the titled measuring device by irradiating a body to be measured with parallel luminous flux, removing unscattered light on the front surface of the object body, and converging scattered light at its peripheral part efficiently and detecting its intensity. CONSTITUTION:Light from a light source 11 is collimated by a luminous flux adjusting device 12 into parallel luminous flux to irradiate the body 13 to be measured with the light, whose transmitted light is made incident on a scattered light detecting device 15. An unscattered light detecting device 19 is provided on the optical axis of the scattered light detecting device 15. Further, through holes 17a and 17b are bored at its periphery to pass the scattered light through them, and the light is made incident on a scattered light detecting device 21 through a condenser lens 17 to form an image. Thus, the through holes 17a and 17b concentric with an optical mask 17 are formed for the scattered light L4 transmitted through the object body 13 and only the scattered light which is transmitted through it is converged and detected. Therefore, the intensity of the light that the scattered light detecting device 21 receives increases to eliminate the need to use a large-output light source, thereby measuring the dispersion of pigment in a paint.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a scattered light measuring device that detects a scattered pattern of transmitted light from a measured object irradiated with a parallel light beam from a light source.

BACKGROUND ART Generally, when detecting the presence, concentration, and size of solid particles in a liquid, for example, the detection is performed using a 6L pattern, and a scattered light measuring device is used for this purpose.

A conventional scattered light measuring device will be explained below with reference to FIG. A light source 1 irradiates a transparent container 2 containing a sample t3 containing non-several 6L particles with a parallel light beam, and a photodetector 4 detects a scattered 6L pattern caused by the sample liquid 3.

However, in many cases, the 6L light is the unscattered light L1
Since it is very weak compared to the rays, a detector with a wide detection range is required for stable detection, and high detection sensitivity is also required.

In addition, a light source with 16 outputs is often required.
Furthermore, in order to detect the charging/discharging 6L pattern, it is necessary to mechanically scan the detector 4, and a highly accurate scanning mechanism is required. This has the drawback that the measuring device is complicated and expensive, and the measurement takes time.

<Object of the Invention> Therefore, the object of the present invention is to perform complicated and expensive scanning with high accuracy without using a high-output light source or a highly sensitive and expensive photodetector. Scattered light measurement that can separate scattered light and non-digital light and detect them simultaneously without the need for grooves! ! The aim is to provide a

<Structure of the Invention> In order to achieve the above object, the scattered light measuring device of the present invention includes a light source and a light flux adjustment device that converts the light from the light source into a parallel light flux and irradiates it onto a measured object having charging and discharging properties. and a non-faulty 6L light intensity detection means provided in front of the object to be measured and at the center on a plane perpendicular to the optical path of the non-number fiL light transmitted through the object to be measured; It is characterized by comprising a scattered light condensing means provided and a scattered light intensity detection means provided in front of the scattered light condensing means.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 shows a scattered light measuring device of the present invention, in which the light emitted from a light source 11 consisting of a laser, a tungsten lamp, a sequinon arc lamp, etc. is adjusted by a condenser lens, a pinhole, a collimator lens, etc. The parallel light beam is adjusted to a certain diameter by the device W112, and is irradiated onto the book 13 to be measured which has light scattering properties. A scattered light detection device 15 is installed in front of the object 13 to be measured.

The book 13 to be measured can be moved in the front and back direction by a device 114 for moving the object to be measured.

The above 6L light detection device 15 is provided in a housing 16 with a 6L light condensing lens 17 as a light condensing means, an optical mask 18 for collecting desired scattered light, and a non-scattered light intensity detection means. Therefore, the non-scattered light detector 19 and the scattered light intensity detection means are used! iL photodetector 21 and its scattered light detector 21
A position adjustment device that adjusts the position of! 22 are provided.

The diffused light condensing line X" 17 is provided on a surface perpendicular to the optical path of the non-scattered light transmitted through the measurement object 13, that is, on one surface of the housing 16, and is provided with a non-scattered light detector. 19 is provided at the center of the surface to pass through the scattered light condensing lens 17.The optical mask 18 is superimposed on the scattered light condensing lens 17, and faces the non-scattered light detector 19. A central through hole 17a and a ring-shaped through hole 17b concentric with the through hole 17a are provided, and this ring-shaped n through hole 17b is provided.
Since it is at a constant angle, fiL L4 is made to be incident.

On the other hand, the scattered light detector 21 is provided at the center of one surface of the casing 16 facing the scattered light condensing lens 17 at a constant distance, and is opposed to the non-scattered light detector 19. The position of the scattered light detector 21 is adjusted by a position adjustment device 22, and an image of the charge/discharge 6L surface of the object to be measured 13 is formed on the scattered light detector 21 by the scattered light condensing lens X"17. That's what I do.

With this arrangement, only the portion of the scattered light from the light irradiation surface of the object to be measured 13 that has passed through the optical mask, that is, the scattered light shielding mask 18, is detected by the 6L light condensing lens 17 and detected by the scattered light detector. Since the light is focused on the scattered light detector 21, the intensity of the light received by the scattered light detector 21 increases, and measurement can be performed using an inexpensive semiconductor detector or the like without using a high-output light source.

Of the light passing through the object to be measured 13, the non-number ALi
The scattered light L is detected by the non-defective 6L photodetector 19, and the scattered light is collected by the scattered light condensing lens 17 and detected by the scattered aperture photodetector 21. The measurement area of non-scattered light, hence the 6L angular range of condensing when condensing 8L light, is:
By replacing the optical mask 18, it is possible to set the desired range.

Furthermore, the position of the object to be measured 13 is determined by the object moving device 14.
At the same time, by adjusting the position of the scattered light detector 21 so that the image of the light scattering surface of the object to be measured 13 is focused by the scattered light condensing lens 17, the scattered light can be scattered over a wider range. It becomes possible to measure scattered light from different angles.

Further, the scattered light condensing lens 17 may be a normal glass lens, but in this embodiment, it is made of a plastic Fresnel lens, which has a larger diameter and a shorter focal length than a normal glass lens. It is cheap and easy to obtain, and processing such as drilling is easy.

Next, as an application example of the apparatus according to the present invention, measurement of the dispersion state of pigment particles by detecting a light scattering pattern of pigment particles in a paint liquid will be described.

In paint production, it is necessary to uniformly disperse pigments in a vehicle, and the particle size of pigment particles in a paint liquid can be measured using the "appu gauge" specified in JISK-5400.
The current situation is based on 1.

However, ``Tsubage'' detects the maximum value of the particle size distribution of pigmented spermatozoa, and furthermore, when the maximum value is less than 5μ, it has the problem that measurement is difficult. With the recent demand for high-quality paints, the dispersion of pigment particles in paint liquids is also required to be highly dispersible, making it impossible to measure pigment particle diameters using ``Tsubage''. is the current situation.

Conventionally, the particle size distribution of particles in highly concentrated suspensions such as paint liquids has been measured using sedimentation methods, microscopy methods, light scattering methods, etc., but all methods require considerable dilution of the sample.
The essential U that the dispersion state of particles changes due to dilution
In addition to this problem, it also has the problem of requiring time and effort for dilution.

In order to solve this problem, a device to which the device according to the present invention is applied, which can easily and quickly detect the state of pigment particles in a paint liquid, will be described.

Figure 2 shows an example of measuring the light intensity distribution of a few samples in front using a conventional device as shown in Figure 5, after adjusting the paint liquid to be measured to specified conditions and using a thin layer or thin film sample. The light intensity shown in Figure 2 is normalized with the center transmitted light as 1, and the sample used in this example is a quinacridone red pigment dispersed in an acrylic resin solution with 30% PVC. A thin layer with a g-thickness of 20μ is also used. In FIG. 3, A shows the forward scattered light distribution of only the resin solution, B shows the forward scattered light distribution of the well-dispersed coating liquid, and C shows the forward scattered light distribution of the poorly dispersed coating liquid.

As is clear from FIG. 2, it can be seen that the intensity of scattered light in the range of 3° to 20° L angle changes depending on the dispersion state of the pigment particles.

Figure 3 shows the degree of dispersion of pigment particles and changes in the reading of the ``Tsho Geno'' and the forward scattered light intensity. The light intensity signal (denoted as Is in FIG. 3) detected by the photodetector 21 after scattering in the apparatus of the present invention shown in FIG. The light intensity signal divided by the light intensity signal (denoted as Da in Figure 3) detected by the scattered light detector 19 is shown, and the horizontal axis shows the intensity of light obtained by using a medium-type dispersion beam using russian beads as a medium. , shows the dispersion time when a quinacridone red pigment is dispersed in an acrylic resin.

From FIG. 3, it can be seen that the degree of pigment dispersion can be detected in a region that cannot be measured with a "tup gauge".

In the embodiment shown in FIG. 1, a single Fresnel lens is used as the scattered light condensing lens 17, but a plurality of Fresnel lenses may be used.

The embodiment shown in Fig. 4 uses two types of Fresnel lenses 91 and 92 that have focal points on the same optical axis, and separately collects scattered light L111L4□ with different filter scattering angle ranges. The sensor 121 and 221 are configured to allow simultaneous detection, and it is possible to select a necessary 6L angle range depending on the purpose of measurement.

As described above, according to the present invention, several companies have been able to use the device to be measured. It is possible to efficiently collect iL light and detect it as an optical signal with high optical intensity, there is no need to increase the intensity of the light source, and it is possible to use an inexpensive photodetector such as a semiconductor. Can be done. It is also possible to weaken the light source by using a highly sensitive photodetector. Moreover, it is possible to detect the non-scattered light and the 8L light at the same time, and there is no need to scan the detector! fI
In addition, the distance between the object to be measured and the surface on which the non-scattered light detection means and the scattered light condensing means are provided can be adjusted, and By making the distance between the object and the scattered light detection means adjustable, it is possible to set the necessary angle range of the enemy 6L depending on the purpose of measurement.

[Brief explanation of the drawing]

FIG. 1 shows a Kin 8L optical measuring device according to an embodiment of the present invention.
Figure 3 shows the forward scattered light intensity distribution due to a thin layer of paint liquid, Figure 3 shows the measured values by Y-No and the ratio of the scattered light intensity to the non-scattered light intensity with respect to the pigment dispersion time, and Figure 4 shows the ratio of the scattered light intensity to the non-scattered light intensity. The figure is a cross-sectional view of another embodiment, and Figure #15 is a cross-sectional view of a conventional scattered light measuring device. 11... Light source, 12... Luminous flux iI] adjustment device, 13.
...Measurement object, 14...Measurement object moving device, 17, 9
1.92... Fresnel lens, 18... Optical mask, 19... Non-scattered light intensity detector, 21, 121, 22
1... Scattered light intensity detector, 22... position atiiiq
. Patent applicant: Nippon Paint Co., Ltd. Agent: Patent attorney: Two people: Figure 1, 1 and 2, phase angle (Hiro)

Claims (5)

[Claims] (1) A light source, a light flux adjustment device that converts the light from the light source into a parallel light beam and irradiates it to the object to be measured that has light scattering properties, and a light flux adjustment device that converts the light from the light source into a parallel beam and irradiates it to the object to be measured that has light scattering properties, and a A non-scattered light intensity detection means provided at the center on a plane perpendicular to the optical path, a scattered light condensing means provided at the periphery on the surface, and a non-scattered light condensing means provided in front of the scattered light condensing means. A scattered light measuring device comprising a scattered light intensity detection means. (2) The distance between the object to be measured and the surface on which the non-scattered light intensity detection means and the scattered light condensing means are provided is adjustable, and the distance between the surface and the scattered light intensity detection means is adjustable. 2. The scattered light measuring device according to claim 1, wherein the distance is adjustable. (3) The device according to claim 1, further comprising an optical mask provided in front of the scattered light condensing means to allow only scattered light within a certain scattering angle range to pass through. (4) The apparatus according to claim 1, wherein the scattered light condensing means has a plurality of focal points on the same optical axis. (5) The device according to claim 1, wherein the scattered light condensing means is constituted by a Fresnel lens.