JPS6353406A - Film thickness measuring apparatus - Google Patents

Abstract

PURPOSE:To achieve highly accurate measurement of thickness, by providing two detection heads each housing an optical system, one fixed for measuring a reference value while the other is set to automatically scan along the axis of a rotary roller. CONSTITUTION:A detection head 1a is fixed above a rotary roller 4 in the vicinity of a sheet 9 to be measured to measure and count a gap A and when the resulting value differs from a reference value stored at an arithmetic processing section, the difference obtained is used as correction data to be added to a measured value of a gap B. A detection head 1b is stopped at a desired position while being shifted horizontally over the sheet 9 with a device 7 to measure and count a gap B and a correction value as obtained with the head 1a is added to a memory data corresponding to the stop position among data stored by measurement without the sheet 9. A difference is computed between the resulting value and actual counts and translated to a thickness of the sheet to be displayed. The position of the head 1b is moved sequentially to perform a measurement thereby achieving an online measurement of and thickness of the sheet 9 across the total width continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a film thickness measuring device for measuring the film thickness of a coating film applied, for example, in a manufacturing line for magnetic tapes and the like.

[Conventional technology]

Figure 9 shows the applicant's application (Patent Application 1986-/7'/-60
9) is shown, and in the figure, a light shielding plate (5) is placed close to a rotating shaft (da) that feeds a sheet to be measured fql. Seventh, second laser light source (/
1) A scanning mechanism that deflects the light beam by changing the angle of the reflection mirror on which the laser light from (y2) enters (
The reflected light from /3) passes through condensing lenses (/da) to (/7) and enters the light receiver (7g) (/9').

The output of the receiver (/l) (/9) is calculated by the counter (koo) (
2/), is input to the display device (,!3) via the arithmetic unit (22). , ``Also, Figure S shows the gap formed by the rotating shaft (11) and the light shielding plate (hl) as seen from the scanning mechanism (/3) side.

With the above configuration, the rotation axis (ri) is the sheet to be measured (?)
The sheet to be measured (9) is rotating at the same speed as the sheet to be measured (9). The light shielding plate (j+) is installed at a predetermined distance from the surface of the rotating shaft (Hiroshi).The first laser light source (//) and the second laser light source (/) are at a predetermined angle with each other. The emitted laser beams are both incident on the reflecting mirror surface of the scanning mechanism (/J) and scanned at the same angular velocity.These laser beams are each emitted by a lens (itl'r( /!r) and is focused,
The gap (Al) formed by the light shielding plate (rl) and the rotating axis m or the sheet to be measured (t) is such that the beam diameter is minimum at the position of Bl and the velocity is constant in the direction perpendicular to the rotating axis (ri). is scanned.

At this time, there is a gap in the receiver (/r) (/9)! AI
The laser beam is incident only while it is passing through fBl, and the third
In the figure, while the laser beam is on the upper side and is shielded by the light shielding plate (tl), and while the laser beam is on the lower side and is shielded by the rotating shaft (or the sheet to be measured (?)),
No light reaches the light receiver (1g) (/9). Therefore, the output signal of the photoreceiver (/r') (/9) is the gap fA
This becomes a pulse waveform with a width proportional to the dimension of IfBl, and this is pulse-counted by a counter (,20)(2/) to obtain a count number that is equal to the pulse width. Arithmetic unit (2,
2) has the function of calculating the thickness from these counts, and calculates the count number for the light receiver (1g) corresponding to the light that has passed through the gear cap on the side where there is no sheet to be measured (9).
1. If the number of counts for the light receiver (/9) corresponding to the light passing through the gap FB+ on the side of the sheet to be measured (9) is b, then the sheet thickness is also -cbtz=to(/--)
(1) is obtained, and this is inputted on the display (2J).

Here, to is the dimension of the gap fA). By subtracting the thickness of only the sheet to be measured (9) from the total thickness of the sheet to be measured (9) thus obtained, the coating film thickness can be determined.

[Apex while the invention is trying to solve]

With the conventional film thickness measuring device as described above, even when measuring the thickness of a wide sheet, only 7 points are measured, and the V
- Since the distance between point A and point B through which the light passes is fixed, the measurement point is at one end of the sheet width, and there is a problem that the thickness of the entire sheet width cannot be measured.

This invention was made to solve the above-mentioned problems, and it is possible to move the measurement point to any position on the sheet width surface and measure the sheet thickness at any position in real time. The purpose is to obtain a measuring device.

[Failure to solve the problem]

The film thickness measuring device according to the present invention is equipped with two detection heads each equipped with an optical system, seven of which are fixed for use in measuring a reference value, and the other seven are fixed on rotating rollers according to the sheet width. The sheet thickness can be measured at any position by moving the sheet in the axial direction.

[For production]

In this invention, seven of the two detection heads are automatically moved and scanned in the axial direction of the rotating roller in accordance with the sheet width, and the correction value stored in advance at an arbitrary position and the measurement at that position are measured. Perform arithmetic processing using the value,
Display correct film thickness.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. In FIG. 1, (/a) and (/b) indicate the first lens which houses the optical system shown in FIG. The second detection head is movable along the guide Is)K. The guide (d) is supported by the frame (,71) together with the rotating roller body.A light shielding plate (ra) (sb) is attached to the 71st detection head (/a) (/b), respectively. The first and second distance detectors (ba) and (bb) fixed to the frame (J) are located at the 1st and second detection heads (/
a) (/b) Measure each moving distance from the reference point. The moving device (7) is for moving and scanning the second detection head (/b). Figure 2 shows the relationship between the measuring point and the 6!11 constant sheet in the measurement state, and the gear ring at the side position of the sheet to be measured (9) is
q) and the light shielding plate (!; a') attached to the first detection radar (ya), a laser beam scans in a direction perpendicular to the axial direction of the rotating roller (41) and vertically. . The gap fB1 at the position where the sheet to be measured (?) is interposed is the same as the gap (support), where the laser beam scans between the sheet to be measured (91 on the rotating cola (41) and the light shielding plate (tb)).

FIG. 3 shows the optical system and electric circuit. The optical system has the same configuration as the conventional one, and the seventh and second laser light sources
), a first and second scanning mechanism (73B-) (13b) that reflects and scans the laser beam, and a condensing V lens group (/l1) (/
! r) (/6) (/ri), 11th second receiver (/l)
It consists of (/q). The electrical circuit is the first. Second counter (2θ) (2y), arithmetic processing unit (2), display (
=3). For the detection head (ya).

first laser light source (//) seventh scanning mechanism (/ja),
The optical system of the condensing lens (/1I) (/6) and the light receiver (7g) are housed, and the detection head (/b) has a second laser light source (7, 2) and a second scanning The optical system of the mechanism (/3b), condensing lens (is) (/7), and light receiver (/te) is housed.

Next, the operation will be explained. 7th detection head (ya)
is movable to any position in the axial direction of the rotating roller fIIl by a guide 2), forming a gap (a sword),
Gap (in AI, rotation o- by scanning mechanism (/Ja)
It scans between the light shielding plate (4I) and the light shielding plate (4I), and the seventh light receiver (/l) detects the first counter (,
20), the time is counted and output to the arithmetic processing m (, 22). Further, the set position of the first detection head (ya) is determined by the seventh distance detector (6a).
l Measure the distance from the left end and output it to the arithmetic processing section (here). Although not shown, an instruction circuit causes the second detection head C/b) to be moved by the rotating roller (4) by the moving device 1W.
It is movable left and right in the axial direction of Il, and forms a gap (Bl) similarly to the gear mechanism.Also, a synchronization circuit (not shown) connects the second scanning mechanism (/3b) and the first scanning mechanism (/, The laser beam scans between the rotating roller (4(l) and the light shielding plate), and the second light receiver (/9) synchronizes with the first detection head (ya) K, output to the arithmetic processing unit (2).Second calibration head (2)
The measurement position b) is determined by measuring the distance from the left end of the rotating roller (≠) using the second distance detector (6b), and
2=). The arithmetic processing unit (2, 2) has a storage circuit, and is a circuit capable of storing the input data.

As in the conventional case, the trap for measuring the thickness of the sheet is the gap (support) at the position where there is no sheet to be measured (91) and the position at the position where there is the sheet to be measured (9), as shown in Figure 2. The moss points in the gap (B) are measured and counted, the difference between them is calculated, and the value converted to sheet thickness is displayed on the display section (23).

To measure the entire width of the sheet to be measured, when the second detection head (/b) is moved, the rotating roller (4)
The dimension of the gap (Bl) changes depending on the eccentricity of the roller (1) or the parallelism of the rotating roller (21) and the guide (21). In the state without the sheet to be measured (9), the first and second detection heads C/a)C/b
) to the right with the left i of the rotating roller gravel as a reference, calculate each position [gear section at each position] and the total of fBl'! l'l is counted and stored in the arithmetic processing unit (2, 2) in correspondence with the positional dimensions determined by the first and second distance detectors (ha) (6b). By setting the rotating roller [+l] to be equal to or greater than /rotation during the measurement time at each position, the eccentricity of the rotating roller at that position becomes averaged data. In addition, the position j of the calculation trace is set to an arbitrary position, and the values calculated in between are calculated using a linear approximation formula.

To measure floating stones on the sheet to be measured (9), as shown in FIG.
is fixed at a position on the rotating roller tut near the gap fB, and the gap fB is measured and counted. If a difference with the above memorized data occurs, this difference is used as a correction value to set the gap fB.
Let this be the data to be added to the measured value of j.

The second detection head (/b) moves from side to side over the sheet to be measured (9) by a moving device [71, stops at any position, performs measurement and counting, and performs measurement without the sheet to be measured. From the above stored data, the correction value by the first detection head (ya) is added to the stored data of the measurement count corresponding to the stop position, and the difference between that value and the actual measured force Kund value is calculated. , converted to the thickness of the thread and displayed on the display (C3). By sequentially moving the position of the second detection head (lb) and measuring as described above, the thickness of the entire width of the sheet to be measured (9) can be continuously measured online.

In the above example, the thickness of the sheet is measured, but if the thickness of the sheet is stable, the thickness of the paint film formed on the sheet can be measured depending on the thickness of the sheet and the thickness of the paint. Changes in the thickness of the coating film can also be measured by measuring the total thickness of the film.

〔Effect of the invention〕

As is clear from the above description, this invention includes two detection heads housing optical systems together, the seventh detection head is fixed for reference value measurement, and the second detection head is mounted on a rotating roller. Since automatic scanning is performed in the axial direction, changes in the gap at each position due to the accuracy of the mechanism that forms the gap, and changes in the gap due to temperature etc. are corrected by calculation, allowing for more accurate thickness measurement. can. Also.

Thickness measurement over the entire width of the sheet can be performed continuously online, making it effective for use in controlling the manufacturing process.

[Brief explanation of the drawing]

7 to 3 show one embodiment of the present invention, FIG. 1 is a front view of the main part, FIG. 2 is a partial front view for explaining the operation, and FIG. 3 is a schematic perspective view. . FIG. 7 is a schematic perspective view of a conventional film thickness measuring device, and FIG. S is a partial front view for explaining the operation. (/h) (/b')・Excellent first and second detection heads, (g)-・Rotating roller, (!;ta)(!;b')・φ light shielding plate, (6a) (6b) @-first and second distance detectors, (
7)...Movement device, (W) φe measured sheet, (//)
(/ko) II, first and second soza light sources, (/, ta)
(/3b”) working - 7th degree second scanning mechanism, (iy) (/
r)(/bN/y)-・Condensing lens f#(/za)(tq
)a1 11th second photoreceiver, (so)(,2/)--first and second counters, (2r'J bit/arithmetic processing unit, (2
3)...Display section. In each figure, the same reference numerals indicate the same or corresponding parts.ゝ4 1a, lb 1st. Second detection head 4, rotating rollers 5a, 5b, light shielding plate

Claims (1)

[Claims] It includes a laser light source, a condensing lens group that focuses laser light from the laser light source, and a scanning mechanism that scans the laser light, the sheet to be measured is supported by a rotating roller, and the sheet to be measured is supported by the rotating roller and the sheet to be measured. A reference light-shielding plate is provided at a predetermined distance on the contact surface with the rotating roller, and a laser beam is scanned from either direction of the rotating roller parallel to the moving direction of the sheet to be measured and passes through the light-shielding plate. photoelectrically converting the laser beam with a photoreceiver, and measuring the time during which the laser beam is received from the obtained output as a count number with a counter,
In the film thickness measuring device that measures at least one of the thickness of the sheet to be measured and the thickness of the coating film on the sheet to be measured, a first and a second optical system housing the optical system together are provided.
The first optical head is fixed for measuring a reference value, and the second detection head scans in the axial direction of the rotating roller to measure the thickness over the entire width of the sheet to be measured. A film thickness measuring device characterized by: