JP2550872Y2 - Sheet material online measuring device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-line measuring apparatus for a sheet-like substance, and more particularly, to an on-line measuring apparatus for a sheet-like substance which has improved running characteristics which are problematic in measurement. .

[0002]

2. Description of the Related Art Conventionally, as this kind of technology, an object to be measured (hereinafter, referred to as a "sheet"), which is a sheet-like substance, is positioned between an upper head and a lower head, and the upper head and the lower head are moved over the entire width of the sheet. A technique for measuring the characteristics (for example, the thickness) of a sheet by scanning over a range is known (for example, see Japanese Utility Model Laid-Open No. 2-7508 and Japanese Utility Model Laid-Open No. 2-14004).

[0003]

However, such a conventional technique has a unique characteristic that the device output (hereinafter referred to as "sensor output") fluctuates when the movements of the upper and lower heads are different from each other (this is referred to as a running characteristic). Due to this characteristic, there is a problem that a stable measurement result cannot be obtained when measuring the film thickness of the sheet.

The present invention has been made in view of the above-mentioned problems of the related art, and has as its object the purpose of the present invention is to provide a light amount generated from a relative position shift generated when the upper and lower heads are running on a sheet. An object of the present invention is to provide a sheet-like substance online measuring apparatus which obtains a stable signal without fluctuation.

[0005]

In order to achieve the above object, the present invention provides a method for positioning a sheet material between an upper head and a lower head and scanning the sheet material over the entire width of the sheet material. an apparatus for measuring the properties of the material, prior
The above-mentioned sheet-like material is placed on the upper head (or lower head).
It is arranged so that the longitudinal direction is parallel to the moving direction.
Both ends are shaped so that they have a certain angle from the bottom to the bottom
The formed triangular prism and the lower head (or upper
Where the head is located opposite to the triangular prism
A triangular prism made of a reflecting mirror having a fixed length;
A reflective film is formed on the surface excluding both ends and the bottom of
Light is emitted from one end of the prism and is interposed between the prism and the reflector.
Reflected multiple times and exited from the other end of the triangular prism
A sheet-like substance online measuring device , wherein light is detected by a photodetector.

[0006]

[Function] Light incident from one end of the triangular prism is prism.
Diffracted by the beam and transmitted through the sheet and incident on the reflector at a predetermined angle
I do. The light reflected in a V-shape by the reflecting mirror returns to the sheet again.
Transmitted and incident from the bottom of the prism with the top of the prism
Reach the nearby slope. The light that reaches the slope is reflected by the reflective film
The light travels through the prism toward the other slope.

The light that reaches the other slope of the prism is
Further, the light is reflected by the reflection film and returns to the reflection mirror side. This behavior
Is repeated a plurality of times, and the light exits from the other end of the prism. This
The light emitted by the light enters the photodetector and is converted into an electrical signal.
You. Here, the sheet flow direction is X,
When the angular direction is Y and the vertical direction of the head is Z direction, X
And the deviation in the Z direction causes light near the center of the entrance surface of the prism.
Absorption of incident light is absorbed by making it incident, resulting in deviation
Similarly, the deviation of the emitted light is absorbed in the range of the light receiving surface of the photodetector.
Take it. Also, the deviation in the Y direction is the area range of the slope of the prism.
Absorb in the enclosure. Furthermore, the parallelism of the upper and lower head facing surfaces changes
If the reflected light is within the width of the bottom of the prism,
A quantity decay can be prevented.

[0008]

[0009]

[0010]

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments will be described below with reference to specific drawings.

FIG. 1 is a front view showing a specific embodiment of the present invention. FIG. 2 is a side view of FIG.

In FIGS. 1 and 2, S is a sheet, A is an upper head, and B is a lower head.

1 is a triangular prism as an optical system provided on the upper head side, 2 is a light source, 3 is a lens (collie-mate lens) for converting light from the light source into a light beam, and 4 is a photodetector. In the upper head A, the triangular prism 1 has both ends α and β at a predetermined angle with respect to the sheet surface (for example, provided so as to enter the sheet at a Brewster angle).
The light beam passing through the lens 3 of the light source 2 is cut so as to enter and exit (see FIG. 1). Furthermore, two surfaces hitting the triangular prism side gamma, the δ form so as not to exit by disposing using means such as depositing a reflection enhancing film 1 _a, 1 _b, a light beam in the prism to the outside (FIG. 2 reference).

In the lower head B, reference numeral 6 denotes a reflection film on the back surface of the reflection optical system (reverse reflection mirror) 5, so that the reflection surface is not damaged when removing stains generated during online measurement. It is configured.

In such a configuration, the light beam that has passed through the lens 3 of the light source 2 is applied to one end surface α of the triangular prism 1.
As a light incident surface. The triangular prism 1 emits the incident light toward the sheet S at a certain incident angle θ. The light that has passed through the sheet S is reflected by the back reflection mirror 6 of the lower head B, and then enters the sheet S again.
The light transmitted through the sheet S is reflected on the triangular prism 1 of the upper head.
The light enters the inside from the lower surface. In the case of a triangular prism, the incident light is reflected by the reflection enhancing films 1 _a and 1 _b on the side surfaces γ and δ.
And then re-emitted toward the sheet S to form one measurement optical path.

After a plurality of measurement optical paths formed around such a triangular prism are formed (this process is repeated several times), light emitted from the other end surface β of the triangular prism 1 is light. Detected by the detector 4.

As described above, when a specific wavelength passes through a predetermined optical path, the sheet is absorbed according to the thickness of the sheet, so that the thickness of the sheet can be measured.

In FIG. 1, there is no change in the optical path even if the positions of the triangular prism 1 and the back reflector 6 are shifted in the X direction. Further, as shown in FIG. 2 also pairs to the shift of the Y-direction, there is no variation in the amount of light to be reflected back to the sheet S is reflected by the triangular prism side gamma, reflective amplification films of δ 1 _a, 1 _b. Also,
The variation in the Z-axis direction is hardly affected because the length measuring optical path and the end surface β of the triangular prism 1 can be widened. Further, even if the parallelism between the upper and lower reflecting surfaces changes, the attenuation of the light amount can be prevented if the reflected light is within the width of the bottom side of the prism.

[0020]

According to the present invention, as described above, since the optical system is configured using the triangular prism and the back reflector, the following effects can be obtained.

[0021]

(A) Even if the X-, Y-, and Z-direction deviations and the parallelism of the upper and lower reflecting surfaces change during online measurement, these can be absorbed, so that stable and accurate measurement can be performed in film thickness measurement. Can be. Further, since light is transmitted through the sheet a plurality of times, the optical path length in the sheet is increased, and interference is eliminated.

[0023]

[0024]

[Brief description of the drawings]

FIG. 1 is a front view showing a specific embodiment of the present invention.

FIG. 2 is a side view of FIG.

[Explanation of symbols]

S sheet A upper head B lower head 1 triangular prism 2 light source 3 lens (collie-mate lens) for converting light from light source into light flux 4 photodetector 6 reflective film

Claims (1)

(57) [Scope of request for utility model registration] An apparatus for measuring the characteristics of a sheet-like substance by scanning a sheet-like substance over an entire width thereof while positioning the sheet-like substance between an upper head and a lower head. ) To the sheet-like material
Are arranged so that the longitudinal direction is parallel to the moving direction of
At a certain angle from the top to the bottom at both ends
The formed triangular prism and the lower head (or
The upper head is disposed opposite to the triangular prism.
It consists of a reflecting mirror having a predetermined length, and forms a reflecting film on the surface excluding both ends and the bottom of the triangular prism.
And irradiate light from one end of the triangular prism.
And is reflected a plurality of times between the reflecting mirror and the triangular prism.
A sheet-like substance online measurement apparatus , wherein light emitted from the other end of the mechanism is detected by a photodetector.