JP2006242823A - Optical measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical measuring device that has a simple constitution and allows accurate measurement. <P>SOLUTION: The optical measuring device projects light of a light source to a measured object and measures properties, such as material, thickness, components, and moisture of a measured object. A slit, having an opening shape corresponding to the shape of the measured object, is disposed on an optical filter of a rotating sector, and is arranged at an image-forming position of the light from the light source. Thus, the space for the slit is not required, the component exclusive for slit installation is not required, by sharing it with the installation components for the rotating sector, and a simple device constitution is obtained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an optical measuring apparatus for measuring properties such as a material to be measured, a thickness, a component, and moisture.

There is known an optical measuring device that projects light of a predetermined wavelength from a light source onto a measurement target and measures properties such as material, thickness, component, and moisture from the reflected light and transmitted light. For example, there is an infrared component meter that utilizes the fact that water has an absorption wavelength of 1.2 μm, 1.43 μm, 1.94 μm, etc. in the near infrared region. Infrared light having this wavelength is projected onto the object to be measured. The transmitted light is measured for a thin sheet-like object, but the reflected light is measured for a granular material or the like. The light hitting the object partially penetrates into the object, and is repeatedly absorbed and reflected inside the object and comes out as diffuse reflected light. Therefore, since the diffuse reflected light is attenuated by the moisture inside the object, the amount of moisture of the object can be measured by measuring this intensity. However, in the measurement of only the absorption wavelength of water, it is difficult to perform stable moisture measurement due to the influence of the measurement distance to the substance, the surface state, the particle size, the color, and the like. Therefore, a comparative wavelength is provided near the absorption wavelength of water, and the moisture value is calculated from the ratio between the absorption wavelength and the comparative wavelength.

FIG. 4 shows a configuration example of a mirror type infrared component meter. The light L emitted from the light source 1 is collected by the lens 1A and then passes through the rotating sector 2 rotated by the motor M. A plurality of optical filters 31 to 3N are attached to the rotating sector 2 and allow near infrared rays having a predetermined wavelength to pass therethrough. These lights are projected onto the measurement object 8 through the mirror 6 from an optical body 71 including a projection window or a projection lens. The light reflected or transmitted from the measurement object 8 is collected by the concave mirror 91 through the optical body 72 made of a light receiving window or light receiving lens, reflected by the convex mirror 92, and incident on the detection element 10.

The analog output signal detected by the detection element 10 is separated for each wavelength by a synchronization detector (not shown) and input to a processing means 11 such as a μCPU incorporating an AD converter or the like. Further, the output of the temperature detector 20 for detecting the ambient temperature T and the setting signal data such as the calibration curve data set by the setting means 12 such as a key switch with reference to the display means 13 such as an LCD display, etc. Other necessary signals are input to the processing means 11. The value obtained with the moisture meter is based on other moisture measurements such as the dry weight method in which the sample is heated and dried to measure the amount of water loss, and the Karl Fischer method is used to titrate the Karl Fischer reagent to measure the moisture content of the sample. There is a certain relationship with the method. This relational expression is a calibration curve, and shows different characteristics for each measurement object.

The processing means 11 converts an analog signal into a digital signal with a built-in AD converter, performs predetermined arithmetic processing using setting data or the like, and obtains a property signal such as a desired moisture content and thickness of the measurement target. it can. For example, the moisture content and the like can be measured by taking the ratio of the light signal in the water absorption wavelength band and the light signal in the non-absorption wavelength band.

For example, when the measurement target is an area including a sheet portion to which the coating paste is not applied when the absorption wavelength range of the coating paste and the component of the sheet to which the coating paste is applied overlaps, the sheet is measured. The measurement accuracy decreases due to the influence of the part property signal.

For the purpose of improving the measurement accuracy of such an optical measuring device, as shown in FIG. 4, an opening of an arbitrary shape corresponding to the application shape of the application glue, for example, is applied to the imaging position of light from the light source. Japanese Patent Application Laid-Open No. 2001-296242 by the present applicant in which a fixed slit 5 for restricting the luminous flux is provided. In the case of a measurement object that moves in a strip shape, the fixed slit is an opening that is long in the moving direction, a concave shape corresponding to the shape of the measurement object, or a double round shape. As a result, more light is obtained in the flow direction at each point of the measurement target, and the accuracy of measurement distribution along the flow direction is improved. Or, in the case of a double round shape or the like, a projection pattern corresponding to the shape of the measurement object is formed by using a slit that regulates the light beam having a shape matched to this, so that there is no waste from the necessary part of the measurement object. Measurement light quantity is obtained to improve measurement accuracy.
JP 2001-296242 A

However, in Patent Document 1, there is a problem in that a space for a fixed slit, parts for installing the fixed slit, and the like are required, the configuration of the apparatus becomes complicated, and the degree of freedom in design is reduced.

In view of the above points, an object of the present invention is to provide an optical measuring device capable of performing highly accurate measurement with a simple configuration.

In order to achieve the above object, the present invention provides an optical measuring device that projects the light of a light source onto a measurement object to measure the property of the measurement object, and includes a slit having an opening shape corresponding to the shape of the measurement object. It is provided on the optical filter of the rotating sector, and the position of the slit is an image formation position of light from the light source.

The present invention relates to an optical measuring apparatus that projects light of a light source onto a measurement target and measures the property of the measurement target. A slit having an opening corresponding to the shape of the measurement target is provided on the optical filter of the rotating sector. An optical measuring device is provided, wherein the slit is disposed at an imaging position of light from the light source. This eliminates the need for a space for a fixed slit, and eliminates the need for a dedicated part for installing the fixed slit by sharing the rotating sector installation parts, resulting in a simple device configuration.

In addition, by using a slit with an opening that matches the pattern to be measured, and a projection pattern that corresponds to the shape of the measurement object, a large amount of measurement light can be obtained from the necessary part of the measurement object, and measurement accuracy can be obtained. Can be improved.

FIG. 1 is an explanatory view of the configuration of a mirror type optical measuring apparatus showing an embodiment of the present invention. The same components as those in FIG. 4 are denoted by the same reference numerals. In FIG. 1, light L emitted from a light source 1 such as a floodlight is projected onto a rotating sector 2 that is rotated by a motor M via a lens 1A. The rotating sector 2 has a plurality of optical filters 31 to 3N arranged on a disk, which constitutes spectroscopic means, and the light L from the light source 1 is one of the optical filters 31 to 3N at the time of measurement. Transmit sequentially.

In this rotating sector, a slit 41 having an aperture of an arbitrary shape at the light condensing / imaging position of the light source 1 is provided on each of the optical filters 31 to 3N, and light having a predetermined wavelength transmitted through the optical filter passes through the mirror 6. The light is projected onto the measurement object 8 as light having a pattern corresponding to the opening of the arbitrary shape of the slit 41 from the optical body 71 including a light projection window or a light projection lens.

The light reflected or transmitted from the measurement object 8 is collected by the concave mirror 91 through the optical body 72 made of a light receiving window or light receiving lens, reflected by the convex mirror 92, and incident on the detection element 10.

Similar to the infrared component meter shown in FIG. 4, the analog output signal detected by the detection element 10 is separated for each wavelength by a synchronous detector (not shown) and input to a processing means 11 such as a μCPU incorporating an AD converter. Is done. Further, the output of the temperature detector 20 for detecting the ambient temperature T and the setting signal data such as the calibration curve data set by the setting means 12 such as a key switch with reference to the display means 13 such as an LCD display, etc. Other necessary signals are input to the processing means 11. The processing means 11 converts an analog signal into a digital signal with a built-in AD converter, performs predetermined arithmetic processing using setting data or the like, and obtains a property signal such as a desired moisture content and thickness of the measurement target. it can.

FIG. 2A shows a plan view of the rotating sector. FIG. 2B is a cross-sectional view taken along line AA in FIG. The rotating sector rotates around the mounting hole 22 of the motor M at a speed of, for example, about 30 rotations per second. In this example, four optical filters are provided on the concentric circles, but the number of optical filters according to the measurement conditions can be arranged.

On each optical filter 31, 32, 33, 34 (3N), there is provided a slit 41 comprising a light shielding portion (shaded portion) and a light transmitting portion which is an opening corresponding to the shape of the measurement object, and rotates together with the optical filter. To do.

For example, the optical filter 31 transmits light having an absorption wavelength for moisture measurement, and the optical filter 32 transmits light having a comparative wavelength for moisture measurement. The optical filters 31 and 32 are provided with slits 41 having the same opening shape. Similarly, the optical filter 33 is a combination of an absorption wavelength for polymer measurement, the optical filter 34 is a combination of a comparison wavelength for polymer measurement, and a slit 41 having the same opening shape is disposed. Moisture and polymer components are measured from the ratio of the absorption wavelength signal of moisture and the comparison wavelength signal of moisture, or the ratio of the absorption wavelength signal of polymer and the comparison wavelength signal of polymer. In this example, four optical filters are provided on concentric circles, but the number of optical filters corresponding to the measurement conditions can be arranged as long as the installation space permits.

3A to 3D show an example of the slit 41, and the hatched portion in the figure is a light shielding portion. The slit 41 includes a light shielding part and a light transmission part that is an opening corresponding to the shape of the measurement target.

It should be noted that the opening shape of the slit 41 described above may be any shape, and may be an optimum shape according to the measurement object.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration explanatory view showing an embodiment of an optical measuring device according to the present invention. It is the top view and sectional drawing of a rotation sector. It is a figure which shows the example of a slit. It is composition explanatory drawing which shows an example of the conventional optical measuring device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Rotating sectors 31-3N Optical filter 41 Slit 6 Mirror 71, 72 Optical body 8 Measuring object 91 Concave mirror 92 Convex mirror 10 Detection element 11 Processing means 12 Setting means 13 Display means 20 Temperature detector

Claims (1)

In an optical measurement device that projects the light of a light source onto a measurement object and measures the property of the measurement object, a slit having an opening shape corresponding to the shape of the measurement object is provided on the optical filter of the rotating sector, The position is an image formation position of light from the light source.

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