JP3479963B2 - Measuring device for sheet-like objects - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-like object measuring apparatus for measuring the basis weight, moisture content, etc. of a sheet of paper, plastic, or the like, and more particularly to an improvement for determining whether or not a sensor is present on the sheet. .

[0002]

2. Description of the Related Art In the paper manufacturing industry, a grammometer for measuring the weight per unit area of paper, a moisture meter for measuring the water content of the paper, and a unit area of the paper when the surface of the paper is coated. A coating amount meter for measuring the coating weight of the above, and an ash meter for measuring the ash weight per unit area of paper are used. Further, in the synthetic organic chemical industry, the thickness of films and sheets and the film thickness of multilayer films are measured.

Such a measuring device is disclosed, for example, in Yokogawa Giho, Vol. 24, page 107 (1980) and Vol. 33, page 193 (1989). Since paper and sheets are spread in the width direction, a sensor head equipped with a grammometer, a moisture meter, and the like reciprocally scans in the width direction for measurement. Therefore, determining whether or not the sensor head is on the sheet is information necessary for reciprocal scanning of the sensor head and measurement of the sensor. Therefore, an on-sheet signal is used as disclosed in Japanese Patent Application Laid-Open No. 7-85283 proposed by the present applicant.

[0004]

However, due to the nature of the paper manufacturing industry, the optical switch for determining the on-sheet is liable to malfunction because it is used in an environment with a lot of dust such as paper dust. That is, if the optical switch is covered with paper dust, it may be determined to be in the on-sheet state even though it is in the off-sheet state.

Then, a caliper meter for measuring the thickness of the paper or the sheet has a disadvantage that a sensor for measuring the thickness of the paper or the sheet causes a paper break. More specifically, in the contact type sensor, if the sheet is on-sheet, the sheet comes into contact with the sheet from above and below to measure, and if the sheet is off-sheet, the sensor moves away from the sheet. If the sheet is in the off-sheet state but is determined to be in the on-sheet state, the contact type sensor rushes into the sheet with a member called a target, which is in contact with the sheet, closed to cause a sheet break.

Further, the automatic calibration operation is performed without a paper so that the sensor can always measure an accurate measured value. Therefore, it was confirmed that the optical switch was in the off-seat state, and the automatic calibration operation was performed. However, if there is paper or foreign matter in the measurement center of the sensor other than the optical switch, the paper or foreign matter cannot be detected, and there is a problem that an inappropriate amount of dust is stored if the automatic calibration operation is forcibly performed. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a sheet-like object measuring apparatus capable of accurately determining the off-sheet state even when the optical switch is covered with paper dust.

[0008]

In order to achieve the above object, the sheet-like object measuring device according to claim 1 of the present invention comprises:
In a device for measuring a sheet-like object that reciprocally scans in the width direction of paper or sheet to measure the quality such as weight or thickness per unit area of the paper or sheet, is the measurement device above the paper or sheet? An optical switch 10 for determining whether or not the measurement device has a means for determining whether a measurement signal of the measuring device is in an assisting state for determining an on-seat state. When the assist determining means is in the assisting state, the optical switch is used. Along with this, the measurement signal is also used to determine whether or not the measuring device is on a paper or sheet.

According to such a configuration, when the support determining means is in the support state, the measurement signal is used together with the optical switch to determine whether or not the measuring device is on the paper or sheet. Even if the optical switch is covered with paper dust and the off-sheet state cannot be accurately determined, the off-sheet state can be accurately detected using the measurement signal.

Here, as in the second aspect, it is preferable to select, as the measurement signal of the measurement device, a measurement signal of the presence or absence of the paper or sheet that appears in the measurement signal of the measurement device. Specifically, as in claim 3, a measurement signal of a grammometer or an ash meter is preferable.

Further, in the support state of the support determining means, it is preferable that the measuring device is in an operating state and the measurement signal of the measuring device is normal. In this state, the measurement signal of the measuring device is normal, so that it can be used for on-sheet / off-sheet discrimination. Further, claim 5
As described above, the support state of the support determination means is preferably such that the optical switch displays the on-seat state. Since the optical switch regards the light-shielded state as the on-sheet state, the optical switch may be erroneously recognized as the on-sheet state by being covered with paper dust.

On the contrary, the support state of the support determining means is not applicable when the optical switch indicates the off-seat state or the measuring device is in the maintenance state. . The measurement signal of the measuring device is
This is because it is not in a state where it can be used to distinguish between on-seat and off-seat.

[0013]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, an optical switch 10 is a reflection type optical switch having a pair of a light emitting element and a light receiving element, and detects whether or not the paper or the sheet 12 is present based on the amount of reflected light.

The B accounting head 20 and the B measuring head 21 are
It is a grammometer that measures the grammage of the paper or sheet located in the gap between the two, and uses the attenuation amount of radiation such as β-rays. The mode switch 30 sends to the measurement data unit 50 a determination signal indicating whether the entire measuring device is in an operating state or a maintenance state. In the operating state, for example, paper is strained by a paper machine, or a sheet is manufactured from plastic pellets. In the maintenance state, maintenance and inspection work of the measuring device is performed.

The measurement data unit 50 has a measurement unit mode process 60, an on-sheet determination process 70, and a B meter measurement process 81. Measurement unit mode processing 6
0 indicates that the measurement signal from the measurement device is valid in the operation mode because the measurement signal from the measurement device is valid according to the mode signal from the mode switch 30, and the measurement device does not perform measurement in the maintenance mode. Stop processing.

The on-sheet determination processing 70 is performed by the optical switch 1
The measurement signal from 0 is input and it is determined whether it is in the on-seat state or the off-seat state. On-sheet status display data 71
Is turned on in the on-seat state and turned off in the off-seat state, and turns on a lamp for notifying the operator of the on-seat state, or informs the human interface device of the on-seat state.

The B meter switch 80 switches between ON and OFF for sending the measurement signals from the B accounting head 20 and the B down head 21 to the B meter processor 81. The B meter processing device 81 calculates the basis weight from the measurement signals from the B counting head 20 and the B metering head 21. The B-meter operable state data 82 stores state data indicating whether the B-counting head 20 and the B-measuring head 21 are operable, and outputs the state data according to an external access.

The B meter shutter open / closed state data 83 is the state data indicating the open / closed state of the radiation shielding shutters provided on the B counting head 20 and the B lowering head 21. It is necessary to close the shutter to secure it. B total basis weight measurement data 8
4 is the data of the basis weight measured at a constant interval in the width direction of the paper or sheet.

The operation of the thus constructed device will be described below. FIG. 2 is an explanatory diagram of the conditions of the condition items and the support function of the optical switch. Since the support function of the optical switch is on, the mode switch 30 is in an operating state, the B meter switch 80 is on, the B meter operable state data 82 is in a normal state,
It is necessary that the B meter shutter open / closed state data 83 is open, the on-sheet state display data 71 is on-sheet, and the B meter basis weight measurement data 84 is less than or equal to a predetermined value. At this time, the final determination of the on-seat state is off-seat.

The reason why the B-weight basis weight measurement data 84 is set to a predetermined value or less is that if the weight of the paper is sufficiently smaller than the current weight of the paper, it can be considered that the weight meter is out of the paper. This is because the signal of the optical switch may be corrected by the measurement value of the grammometer even when indicates the on-sheet state.

The support function of the optical switch is turned off because
The condition items are other than the above. That is, the mode switch 30 is in the operating state, the B meter switch 80 is on, the B meter operable state data 82 is normal, the B meter shutter open / close state data 83 is open, the on-seat state display data 71 is off-seat, and the B meter is If the basis weight measurement data 84 is equal to or larger than the predetermined value, the support function of the optical switch is turned off, and the on-sheet state display data 71 is used for the final determination of the on-sheet state.

If the B meter shutter open / close state data 83 is closed, the B meter cannot measure the grammage, and the on-sheet state display data 71 is meaningless. However, the mode switch 30 is in the operating state, the B meter switch 80 is on, and the B meter operable state data 82 shows the normal state. In this case, the support function of the optical switch is off, and the final determination of the on-seat state is made using the on-seat state display data 71.

In addition, when the B meter operable state data 82 indicates an abnormal state, the B meter switch 80 is off, or the mode switch 30 is in the maintenance state, the optical switch support function is off. Then, the final determination of the on-sheet state is made using the on-sheet state display data 71.

In the above embodiment, the measurement signal of the grammometer is used to support the optical switch, but an ash meter may also be used. The composition of the ash meter is similar to that of the basis weight meter. That is, the measuring device is equipped with an A counting head and an A measuring head, and the measuring data unit 50 has an A meter switch, A meter operable state data 82, A meter shutter open / close state data 83, and A meter ash. Measurement data 8
4 are provided. Then, the portion corresponding to the A total is read as the portion corresponding to the B total to support the optical switch.

[0025]

As described above, according to the first aspect of the present invention.
The sheet-like object measuring device of, the reciprocating scanning in the width direction of the paper or sheet, in the sheet-like object measuring device for measuring the quality such as weight and thickness per unit area of the paper or sheet,
An optical switch 10 for determining whether or not the measuring device is on a sheet of paper or a sheet, and means for determining whether or not a measurement signal of the measuring device is in an assisting state for determining an on-sheet state, When the means is in the support state, the measurement signal is used together with the optical switch to determine whether or not the measuring device is on the paper or sheet. Uses the measurement signal together with the optical switch to determine whether the measuring device is on the paper or sheet, so if the optical switch is covered with paper dust and the off-seat state cannot be accurately determined. However, the off-seat state can be accurately detected using the measurement signal.

[Brief description of drawings]

FIG. 1 is a configuration block diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram of conditions of condition items and an optical switch support function.

[Explanation of symbols] 10 Optical switch 20 grammometer 30 mode switch 50 measurement data units

Claims (6)

(57) [Claims] 1. A measuring device for a sheet-like object, which measures the quality such as weight and thickness per unit area of a paper or a sheet by reciprocally scanning the width of the paper or the sheet, wherein the measuring device is the paper or the sheet. An optical switch (10) for determining whether or not it is above, and means for determining whether or not the measurement signal of the measuring device is in an assisting state for determining an on-seat state, and the assist determining means is in an assisting state. In some cases, the measurement device for a sheet-like object is characterized in that the measurement signal is used together with the optical switch to determine whether or not the measurement device is on paper or a sheet. 2. The apparatus for measuring a sheet-like object according to claim 1, wherein the measurement signal of the measurement apparatus shows presence or absence of paper or a sheet in the measurement signal of the measurement apparatus. 3. The measurement signal of the measuring device is a measurement signal of a grammometer or an ash meter.
The sheet-shaped object measuring device described. 4. The measurement of a sheet-like object according to claim 1, wherein the support state of the support determining means is that the measuring device is in an operating state and the measurement signal of the measuring device is normal. apparatus. 5. The apparatus for measuring a sheet-like object according to claim 3, wherein the support state of the support determining means is such that the optical switch indicates an on-seat state. 6. The support state of the support determining means is not applicable when the optical switch is displaying an off-seat state or when the measuring device is in a maintenance state. 1. The sheet-like object measuring device according to 1.