JPH0445773B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention measures the haze value of moving films, sheets, and other film-like materials by using optical fibers for emitting and receiving light at a high scanning speed and efficiently measuring the amount of diffused transmitted light. The present invention relates to an apparatus for measuring haze value of a film-like material by detecting changes.

Conventionally, the haze value of a film-like material is often measured by visual observation with the naked eye or by measuring a cut sample with a conventional haze value meter. However, the former method not only cannot avoid variations due to individual differences, but also cannot quantitatively record visual results, making it difficult to capture changes over time. In addition, the latter method is extremely inefficient because the product is cut and damaged in order to collect samples, and the process must be interrupted, so it is not suitable for continuous processes. Therefore, in order to measure the haze value without stopping the running of the film-like material, a haze value measuring device was devised and put to trial using a tungsten lamp as the light source and a phototube or photoelectric element as the light receiving part. For example, scanning back and forth in the width direction on both the front and back sides of the film-like object inside the film may result in insufficient mechanical strength against inertial force due to the relatively large weight of the light source and light receiving section, or the scanning There were problems such as slowing down the speed and slipping.

On the other hand, in recent years, as the manufacturing technology of membrane-like materials such as films has improved, there has been a demand for high-quality products with high visual transparency.
However, the causes of changes in haze value in film-like materials include, in addition to external dirt adhesion, factors originating from process control, such as changes in internal crystallinity due to changes in manufacturing conditions such as cooling conditions. It has become more important. Therefore, in order to meet the demand for highly transparent and high-quality film products, it is necessary to continuously control the haze value over the entire surface of the film that is moving at high speed during process control. Recently, there has been a desire for a haze value measuring device for film-like materials that has recently become more robust and capable of scanning efficiently and at high speed.

As a result of research aimed at meeting such demands, the present inventors used a large number of optical fibers to fix the position of the light emitting end and the light receiving end relative to the film-like object.
The above purpose is achieved by moving and distributing the light from the light source to each optical fiber at a high speed at a separate location, and by having the light receiving end receive the light from the light emitting end at a wider angle than its emission angle. The present invention was completed by investigating what can be achieved.

That is, the present invention provides a haze value measuring device for a film-like object characterized by comprising the following parts (a), (b), and (c): (a) a light source and a certain distance from one side of the film-like object; They are arranged in a line almost adjacent to each other along the width direction with one end as a light emitting end facing the one side, and the other end as a distributed light receiving end is arranged at a constant pitch according to the arrangement order. One end serving as a light source light receiving end receives the light from the light source, and the other end serving as a light distributing moving end moves while the distributing light receiving end of the light projecting optical fiber moves. (b) a position facing the light emitting end of the light emitting optical fiber on the other surface of the film-like object; has a light-receiving eye made of optical fibers arranged in a row, and there is a relationship between the light-receiving eye and the light-emitting end such that the maximum opening angle at which the light-receiving eye can receive light is larger than the emission angle of the light-emitting end. , a light-receiving section comprising a plurality of light-transmitting paths made of optical fibers that separately transmit light from each light-receiving eye that receives light from the light-emitting end of the light-emitting optical fiber and enters a light-receiving state; c) a light receiving element connected to the light sending end of each light sending path of the light receiving section and an arithmetic circuit that calculates an electric signal corresponding to the amount of light detected by the light receiving element to measure the haze value of the film-like object; The present invention relates to a signal processing unit comprising:

The present invention will be explained in detail below with reference to the drawings showing embodiments of the apparatus of the present invention.

FIG. 1 is a partially perspective schematic explanatory diagram of an embodiment of the device of the present invention, and FIG. 2 is an explanatory diagram showing a state in which a light projection distribution optical fiber is arranged in a manner different from that in FIG. 1. Figures 3 and 3 are (a) front view and (b) side sectional view showing one example of the light emitting end in an enlarged manner, and Figure 4 is an explanatory view showing one aspect of the light receiving part with some parts omitted. FIG. 5 is a schematic explanatory diagram partially perspectively showing another aspect of the light receiving section;
Fig. 6 is a diagram showing the scanning state on the surface of a film-like object during traveling when the light distribution moving end of the light-emitting and distributing optical fiber is rotated; FIG. 8 is an explanatory diagram schematically showing the state in which the light passes through and reaches the receiving eye. FIG. 8 is a diagram showing an example of the distribution state of the received light power in the device of the present invention.
The figure shows an example of how the device of the present invention is used. In the drawing, 1 is a light source, which is a light emitting diode LED,
LD, white light source, etc. can be used. 2
is an optical fiber for light projection, and one end of each of the many optical fibers 2 for light projection is positioned at a certain distance from one side of the film-like material 9, which will be described later as the light-emitting end 2b, that is, on a surface parallel to the film-like material 9. They are arranged substantially adjacent to each other in a line along the width direction toward the one surface. The other end serves as a distributed light receiving end 2a and is arranged, for example, adjacently at a constant pitch in accordance with the arrangement order of the light emitting ends 2b. In the case of FIG. 1, the arrangement of the distributed light receiving ends 2a is a perfect circle, but they may be linear. The material of the optical fibers used in the present invention, including the light emitting optical fiber 2, may be glass-based or plastic-based, and the refractive index distribution may be of a step index type or graded index type. Details of the light emitting end 2b will be explained together with the light receiving eye 4, which will be described later.

Reference numeral 3 denotes a light projection/distribution optical fiber, one end of which is positioned near the light source 1 as a light source light receiving end 3a and receives light from the light source 1, and the other end is normally fixed as a light distribution moving end 3b. While moving intermittently at high speed, it sequentially connects to the distributed light receiving ends 2a that are lined up at a constant pitch, and receives the light sent from the light source light receiving end 3a through the light projection and distribution optical fiber 3. Light is sequentially transmitted to end 2. The movement locus of the light distribution moving end 3b is selected to match the arrangement shape of the distribution light receiving end 2a of the light emitting optical fiber 2. For example, in FIG. 1, the light distributing moving ends 3b of the light emitting and distributing optical fibers 3 are in contact with the distributed light receiving ends 2a of the light emitting optical fibers 2 arranged in a perfect circle, and the rotation axis passing through the light source 1 is The rotation is made to rotate intermittently in the direction of arrow X, for example, and extremely fast rotation is possible by such rotation in one direction. When one optical fiber 3 for light projection and distribution is used as shown in Fig. 1, that one
Due to the rotation, light is transmitted once over the entire row of light emitting ends 2b of the light emitting optical fiber 2, and therefore, one scan of the film-like object 9 is performed as described later. When the speed is high, for example, as shown in FIG. 2, a plurality of light emitting and distributing optical fibers 3 integrated at equal angular intervals are used and rotated, thereby reducing the number of scans per time. You can increase the number of times. Furthermore, if the distributed light receiving ends 2a of the light emitting optical fiber 2 are lined up in a straight line, the light distributing moving end 3b will reciprocate while being in contact with it. Only one optical fiber will be used. As described above, a light projecting unit is constituted by the light source 1, the light projecting optical fiber 2, and the light projecting and distributing optical fiber 3, and thus the light from the light source 1 is transmitted through the light projecting and distributing optical fiber 3 to each light projecting optical fiber 2. The light is rapidly distributed one after another and projected onto the film-like material 9 from the light projecting end 2b.

Reference numeral 4 denotes light-receiving eyes made of optical fibers, and a large number of light-receiving eyes 4 are on the side opposite to the one side of the film-like material 9, and the end surface 4a thereof is the light-emitting end 2b of the light-emitting optical fiber 2.
They are arranged in positions facing each other and receive light emitted from the light emitting end 2b and transmitted through the film-like material 9.
By the way, the emission angle of the light emitting end 2b of the light emitting optical fiber 2 (maximum opening angle of the emitted light) and the light receiving eye 4
The maximum opening angle of light that can be received by (referred to as acceptance angle)
An important point in the present invention is how to establish a relationship with The present inventors have found that the diffuse transmitted light component of the film-like substance 9 is hardly detected between the light emitting end 2b and the end face of the light receiving eye 4, where the light emission angle and the light receiving angle are the same, but the light component of the diffused transmitted light of the light receiving eye 4 is The receiving angle is at least at the light emitting end 2b
They discovered that the above detection is possible only when the emission angle exceeds . and membranous material 9
Depending on the degree of diffusion, the former is 10 to 30 degrees, the latter
Preferably, the angle is in the range of 50 to 70 degrees. In order to satisfy such requirements, it is effective to adopt the following aspect.

(i) Attach a spot made of a material that has good absorption of the light beam to be used to the light emitting end 2b of the light emitting optical fiber 2,
Narrow down the emission angle.

(ii) A convex lens system is provided at the tip of the light emitting end 2b to reduce the light emission angle.

(iii) The emission angle is made small by changing the refractive index distribution of the light emission optical fiber 2. For example, in the case of a step index type optical fiber, if the refractive index of the core is n ₁ and the refractive index of the cladding is n ₂ , the emission angle is expressed as sin ^-1 √ ² ₁ − ² ₂ , so n ² ₁
-n ² ₂ can be made small within a positive range.

(iv) A concave lens system is provided at the tip of the light-receiving eye 4 to increase the light-receiving angle.

(v) The light-receiving angle is increased by changing the refractive index distribution of the optical fiber used in the light-receiving eye 4. For example, in the case of a step index type optical fiber, n ² ₁ −n ² ₂ may be increased, contrary to the above (iii).

By adopting one or more of the above aspects, the above conditions can be easily satisfied by increasing the light emission angle or decreasing the light reception angle. FIG. 3 shows an embodiment of the light emitting end 2b according to the above embodiment (i), in which the tip of the light emitting optical fiber 2 with a diameter of 1 mm is fixed with black polyethylene fixtures 2b' at intervals of 0.2 mm. The fixture 2b' is made to protrude 6 mm longer than the tip of the light emitting optical fiber 2 to increase the light emission angle by 20 mm.
It is narrowed down to a certain degree. When the same optical fiber was used for the light-receiving eye 4 without the protrusion of the fixture 2b', the light-receiving angle was 60 degrees.

Reference numeral 5 denotes a plurality of light transmission paths made of optical fibers, in which each of the plurality of light receiving eyes 4 is in a light receiving state (light is emitted from the light emitting end 2b of the light emitting optical fiber 2 and the film-like object 9
(a state in which the light transmitted through the light receiving element 7 is received) and the received light is transmitted to a light receiving element 7, which will be described separately later. The specific number of plurality may be determined in each case depending on how many light-receiving eyes 4 are included in the range in which the transmitted light of the film-like substance 9 is diffused, but it is preferable to have some margin. preferable. Two representative examples of the configuration of the light transmission path 5 are shown in FIGS. 4 and 5. Fourth
In the figure, optical fibers 5' for the light transmission path similar to the light-receiving eyes 4 arranged almost adjacent to each other are separately connected to each light-receiving eye 4 (in this case, the light-receiving eyes 4 and the optical fibers 5' are each (It may be an optical fiber 5' with the light receiving eye 4 as one end), and a plurality of light receiving eyes 4 are counted sequentially from any light receiving eye 4 according to the order in which they are arranged.
The optical fibers 5' respectively connected to the light-receiving eyes 4 become light transmission paths 5 that individually transmit the light from each light-receiving eye 4 when the plurality of light-receiving eyes 4 enter the light-receiving state. Then, as the plurality of light-receiving eyes 4, which will be in the light-receiving state at the next moment, are shifted one by one, the optical fiber 5' that transmits the received light is also automatically shifted and becomes a new light-transmitting path 5, and thus all Each light receiving eye 4
The provision of the optical fibers 5' connected to the optical fibers 5' means that the optical transmission path 5 is provided. As will be described later, since the ends of the light transmission paths 5 are connected to the light receiving elements 7 separately for each light transmission path 5, the ends of the light transmission paths 5 are bundled as shown in FIG. 4 as follows. That is, for example, when the number of light receiving eyes 4 in the light receiving state and therefore the number of the plurality of light transmission paths 5 corresponding thereto is seven, for example, the light receiving eyes 4
If the numbers assigned sequentially from the end of the sequence are the numbers of the optical fibers 5' connected to it, each group of every seventh number, ie (,,,...), (, ,,...),,
,,...),(,,,...),(,,
,……),(,,……),as well as(,,
,...) in each group (○ in sequence in Figure 4)

Claims (1)

[Scope of Claims] 1. A device for measuring haze value of a film-like material characterized by comprising the following parts (a), (b), and (c): (a) a light source 1 and a film-like material 9; Distributed light receiving ends 2 are arranged at a certain distance from one surface in a line substantially adjacent to each other along the width direction with one end as the light emitting end 2b facing the one surface, and the distributed light receiving ends 2 are arranged in a line substantially adjacent to each other along the width direction.
A large number of light emitting optical fibers 2 are arranged at a constant pitch, and one end as a light source light receiving end 3a receives light from the light source 1, and the other end as a light distribution moving end 3b receives light from the light source 1. (b) a light projecting section comprising a predetermined number of light projecting and distributing optical fibers 3 that sequentially connect to the distributed light receiving ends 2a of the light projecting optical fibers 2 while moving and transmitting light; It has a light-receiving eye 4 made of optical fibers arranged in a position facing the light-emitting end 2b of the light-emitting optical fiber 2 on the other side,
There is a relationship between the light-receiving eye 4 and the light-emitting end 2b, in which the maximum opening angle at which the light-receiving eye 4 can receive light is larger than the light emission angle of the light-emitting end 2b, and the light emitted from the light-emitting optical fiber 2 is A plurality of light transmission paths 5 each made of an optical fiber that individually transmits light from each light receiving eye 4 that has received light 10 from the end 2b and is in a light receiving state.
(c) a light receiving element 7 connected to the light transmitting end 6 of each light transmitting path 5 of the light receiving part, and calculating an electric signal corresponding to the amount of light detected by the light receiving element 7 to a signal processing section including an arithmetic circuit 8 for measuring a haze value of a shaped object 9;