JPH0511009U - Basis weight - Google Patents

Abstract

(57) [Summary] [Purpose] It is possible to measure the basis weight of a sheet-like material having a pinpoint width. [Structure] Upper and lower detection heads (31) and a lower part which are provided facing each other with the substance to be measured (2) and the substance to be measured, which are assembled to the frame (1) movably left and right, and which are running, sandwiched therebetween. An optical thickness gauge (3), which comprises a detection head (32) for measuring the thickness profile of the substance to be measured, and is installed on the back stand side or the forward stand side of the frame, or Also comprises a radiation type thickness gauge (4) installed so as to move together with the optical thickness gauge, and the signal obtained from the optical thickness gauge is corrected by the signal from the radiation thickness gauge. It is a grammometer that is adapted to obtain an absolute value grammage signal.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a grammometer for measuring the thickness or basis weight of paper.

[0002]

[Prior Art]

 As a conventional technique of this kind, for example, radiation emitted from a radiation source using a radioisotope or the like and transmitted through a sheet-like substance is detected by a radiation detector, and the radiation attenuation amount A radiation applied measuring device for measuring the basis weight of a sheet-like substance (see Japanese Patent Application Laid-Open No. 1-153905), transmission β when a sheet-like substance as a substance to be measured is irradiated with β-rays from a β-ray source "Β-ray thickness meter" which detects a ray and detects a pulse signal having a wave height corresponding to the energy of the β-ray and performs a predetermined process to obtain the thickness (see Japanese Utility Model Laid-Open No. 61-105008). , Or a coherent light source such as a laser, irradiates a transparent sheet-like material with monochromatic light from an optical system, and the repeated reflection interference action by the monochromatic light on the back surface of the sheet-like material The thickness of the sheet-like material is measured by measuring the interference fringes generated by the CCD with an optical system. A transparent sheet-like substance thickness measuring device (see Japanese Utility Model Laid-Open No. 59-4406) is known.

[0003]

[Problems to be solved by the device]

 In all of these conventional techniques, the measuring area is large (width is about 10 to 25 mm), and at present, the advent of an apparatus capable of measuring a narrower basis weight is desired.

The present invention has been made in view of the above problems of the prior art, and its object is to make a sheet-like substance having a pinpoint width (hereinafter referred to as “paper”). ) The grammage meter which can measure the grammage of a) is provided.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention confronts the substance to be measured (2) and the frame (1) movably assembled to the left and right so as to face the substance to be measured, and to face it vertically. An optical thickness gauge (3), which is provided with an upper detection head (31) and a lower detection head (32) for measuring the thickness profile of the substance to be measured, and the back stand stand side of the frame or A radiation type thickness gauge (4), which is installed on the forward stand side or is installed so as to move together with the optical thickness gauge, and transmits the signal obtained from the optical thickness gauge. It is a grammage meter which is adapted to obtain an absolute value grammage signal by correcting with a signal of the radiation type thickness gauge.

[0006]

[Action]

 When the basis weight is large, the amount of detected light decreases. However, even if the basis weight is the same, the amount of detected light decreases if the material is easily scattered. Therefore, a combination of a radiation type thickness gauge and an optical thickness gauge (for example, a light transmission type scattering state measuring device using laser light) is used, and the signal obtained from the optical thickness gauge is measured by the radiation type thickness gauge. The absolute value basis weight signal obtained by correcting with the signal from the thickness gauge is used as the signal for basis weight measurement with a very narrow measurement width (without being affected by the paper material). Measure the absolute value) and measure the basis weight.

[0007]

【Example】

 Examples will be described with reference to the drawings. FIG. 1 is a view showing a concrete example of the grammage meter of the present invention. FIG. 2 is a top view of FIG. FIG. 3 is a diagram for explaining the optical thickness meter.

In FIGS. 1 to 3, a grammometer, for example, a frame 1, a paper 2, an upper detection head 31 equipped with a laser light source L as a light source and a detector M are mounted to transmit the paper 2. It is composed of a lower detection head 32 configured to detect incoming light and output it via an amplifier Q, and is equipped with a thin optical beam transmission thickness gauge that scans the left and right of the frame 1 left and right. An optical thickness gauge 3 of this type and a radiation thickness gauge 4 can be used to form an absolute thickness gauge.

At this time, the thickness profile of the paper 1 is measured by scanning the optical thickness meter 3 on the left and right sides of the frame 1, but once the transmitted light is measured, the thickness profile of the paper 1 is measured. When the thickness is measured, the measurement value of the optical thickness gauge is affected by the quality of the paper, that is, when the measurement is performed with light, the detection result for the basis weight decays exponentially. Therefore, the absorption coefficient changes from a different place, so it cannot be developed neatly by the formula, and it does not serve as an absolute thickness gauge. Therefore, the radiation thickness gauge 4 is installed on the B (backward) stand side of the frame 1 (it may be on the F (forward) stand side).

In such a configuration, the optical thickness meter 3 measures the same point for each scan so that the value becomes the same as the value indicated by the radiation thickness meter 4 (in other words, the radiation line Calibrate the value of the optical thickness gauge 3 by adding “+” and “-” to the signal of the radiation thickness gauge 4 so that it matches the signal of the thickness gauge 4. The radiation thickness gauge 4 has a large measurement area, but is not easily affected by the paper quality.Therefore, the thickness of the optical thickness gauge 3 is small and the response is fast. It becomes possible to measure.

The present invention is not limited to the configuration described above. For example, a light source other than a laser light source may be used as the light source of the optical thickness meter 3, and the radiation type thickness meter 4 is not fixed and is scanned with the optical thickness meter. Then, correction calculation (“+” and “−” similarly to the above) may be performed so that the average values are the same.

[0012]

[Effect of the device]

 Since the present invention is configured as described above, it has a practical effect that it enables measurement of basis weight with a very small measurement width and without being affected by paper quality.

[Brief description of drawings]

FIG. 1 is a view showing a concrete example of a grammage meter of the present invention.

FIG. 2 is a top view of FIG.

FIG. 3 is a diagram for explaining an optical thickness meter.

[Explanation of symbols]

 1 Frame 2 Paper (sheet-like substance) 3 Optical thickness meter 4 Radiation type thickness meter

Claims (1)

[Claims for utility model registration] [Claim 1] Face up and down with the substance to be measured (2) and the substance to be measured mounted on the frame (1) movably left and right, and running. An optical thickness gauge (3), which is provided with an upper detection head (31) and a lower detection head (32) for measuring the thickness profile of the substance to be measured, and the side of the frame on the back stand or It comprises a radiation type thickness gauge (4) installed on the forward stand side or so as to move together with the optical thickness gauge, and a signal obtained from the optical thickness gauge is applied to the radiation thickness gauge (4). The grammage meter is designed to obtain the absolute value grammage signal by correcting with the signal of the thickness gauge.