JP2001050715A - Dimension measuring device and method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain measured result nearby the true value with high working efficiency by providing a measuring means measuring the dimension of a measured object by non-contact, and in addition forming a loading face loading the measured object into a projecting curved face. SOLUTION: An optical dimension measuring machine 22 and a frame base 23 positioned opposite to it are fitted to the upper and lower parts of a same back plate 21. The optical dimension measuring machine 22 incorporates a light emitting part 22a transmitting laser beam 24 toward a magnetic tape 20. The frame base 23 incorporates an optical dimension measuring machine 30 provided with a light receiving part 30b receiving the laser beam 24, and the light receiving part 30b receives laser beam except the later beam with the magnetic tape 20 within the laser beam 24. The loading face 25 of the frame base 23 is formed for example into a cylindrical face of the radius of curvature of 100 mm, and the magnetic tape 20 is loaded in a natural state as a measured object thereon. Force extending in the width direction by the vector component of dead weight is applied to the loaded magnetic tape 20, a cupping phenomenon disappears, and the tape flatly adheres closely along the loading face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dimension measuring apparatus and a dimension measuring method for measuring a dimension in a width direction of a long body such as a magnetic tape.

[0002]

2. Description of the Related Art Magnetic tapes, which are used today for video and audio, and are widely used as familiar recording media, have a structure in which a magnetic layer is formed on a plastic base film. It is manufactured as follows.

That is, a long base film running at high speed between rolls is coated on one side with a magnetic paint (a powdery magnetic material for recording information, a binder, an organic solvent, an additive for imparting durability, etc.). ), A drying step thereof, a calendering step of flattening the formed magnetic layer, and a slitting step of cutting the base film with the magnetic layer into a narrow width.

Further details will be described with reference to the drawings.

FIG. 7 shows a typical process of manufacturing a magnetic tape. First, the base film 1 is fed out from the hub 2a and tension is applied to the guide rollers 3a, 3b and 3b.
The magnetic paint is applied to one surface of the base film 1 through the gap between the backup roll 4 and the gravure roll 5 through this c.

In the coating step, the gravure roll 5
The rotary machine rotates in a state where a part thereof is immersed in the magnetic paint 7 filled in the paint tank 6, and excess paint can be wiped off by the doctor blade 8.

The base film 1a on which the magnetic layer in the wet state is formed is introduced into the dryer 10 through the guide rollers 9a and 9b, where the magnetic layer is dried by, for example, hot air, and then constituted by a number of rollers 11a. The magnetic layer is passed through a calendar section 11, where the magnetic layer is flattened, and then wound around the hub 2 b.

A wide original film 1b (magnetic tape) can be obtained as described above, but for commercial use, the original film 1b is sent to, for example, a slitting process as described below. It is common to cut to a narrow width suitable for

That is, in FIG.
b is fed out of the hub 2c, passes through a roll 3e, etc., and enters the cutting machine 12, where it is cut into a predetermined width by a rotating shaft 3f with an upper blade, a rotating shaft 3g with a lower blade, and the like, and two magnetic members are cut. The tape is divided into groups of tapes 1c and 1d, and after passing through roll groups 3g, 3h, 3i and 3j, 3k, 3l, the pancakes 1 are wound around the hubs 2d, 2e.
e (the pancake is a wound long magnetic tape before being cut into a predetermined length.
The magnetic tape cut into a predetermined length according to the application is assembled into a case or the like. ).

By the way, magnetic tapes manufactured in such a process are required to have characteristics specified in various standards, one of which is a tape width dimension (dimensional characteristic).

That is, unless the magnetic tape is cut into appropriate widths in accordance with the respective applications, running performance in a VTR (video tape recorder) and compatibility between VTRs may be impaired.

For example, when the width dimension of the magnetic tape is set to a standard value (1/2, 3/4, 1 inch, 8 mm) suitable for the application.
If the size is larger or smaller, the running position of the tape is not determined when the tape is mounted on the VTR, and the scanning position of the magnetic head tends to be unstable.

As a result, the information originally contained in the magnetic tape is not correctly transmitted to the magnetic head, which may adversely affect sound and images.

For these reasons, the measurement of the width of a magnetic tape in the width direction has been conventionally performed as one of the evaluation items.

FIG. 5 shows a typical dimension measuring device (disclosed in JP-A-7-182724, JP-A-8-327330, etc.), and a plastic or metal base 16 having a flat surface 15 is provided. An optical size measuring device 17 is provided, and these are fixed to the back plate 14. The optical dimension measuring device 17 includes a light emitting section 22a as a transmitting section for transmitting laser light toward the magnetic tape 18, a light receiving section 22b as a receiving section for receiving (receiving) laser light reflected from the magnetic tape 18. Built-in. Then, at the time of measurement, the magnetic tape 18 of the object to be measured is placed on the flat surface 15 in a natural state where "wrinkles" and "stress" are not applied.

[0016]

However, it has been known that a phenomenon called cupping occurs in a magnetic tape as an object to be measured depending on the type thereof.
Due to this phenomenon, it is extremely difficult to measure the true tape width.

This will be described with reference to the drawings. Cupping refers to a phenomenon in which both edges 18a and 18b along the longitudinal direction of the magnetic tape 18 rise in the height direction as shown in FIG. Seen from the direction, it refers to a state where it has risen in a concave shape as shown in FIG.

There are various possible causes of this cupping, but the thickness of the base film is close to the thickness of the magnetic layer, the thickness of the magnetic layer is thicker, or the glass transition temperature (Tg) of the adhesive used is high. In such a case, it tends to occur when the thickness of the base film is thin, or when the calendering temperature is high. Of course, it easily occurs when there is no back coat layer, when the back coat layer is extremely thin, or when the glass transition temperature is low.

If the magnetic tape in such a state is measured as it is in the width direction by using the above-described dimension measuring apparatus, only a smaller (narrower) measurement result than the actual one is obtained, and it is extremely difficult to measure the true tape width. It is.

In order to deal with this, conventionally, when using the dimension measuring apparatus shown in FIG. 5, a pressing glass plate (for example, 7 cm × 2 cm × 0.3 mm) 19
Was placed on a magnetic tape 18 and the magnetic tape 18 was pressed flat against the flat surface 15 of the gantry 16 to measure the tape width.

However, the operation is troublesome, and there is a problem that the error of the measured value becomes large due to the light refraction of the glass plate.

The present invention has been made in order to improve the above circumstances, and an object of the present invention is to improve the mounting surface of the gantry so as to reduce the adverse effect of the cupping phenomenon without using a pressing glass plate. It is an object of the present invention to provide a dimension measuring apparatus and a dimension measuring method which are significantly reduced.

[0023]

That is, a dimension measuring apparatus according to the present invention comprises a mounting surface on which an object to be measured is mounted, and measuring means for measuring the dimensions of the object to be measured in a non-contact manner. The surface is formed as a convex curved surface.

Further, according to the dimension measuring method of the present invention, an object to be measured is placed on a mounting surface formed on a convex curved surface, thereby holding the object to be measured in a predetermined shape. Is measured in a non-contact manner.

As described above, when an object to be measured such as a magnetic tape is mounted on the mounting surface formed on the convex curved surface, the force to extend in the width direction is applied to the object to be measured by its own weight. 6B, the object to be measured becomes flat, as if the cupping phenomenon disappeared, as shown in FIG.

The reason why the cupping phenomenon disappears will be described with reference to FIG.

When the magnetic tape 20 which is concavely cupped is placed on the mounting surface 25 formed in a convex curved surface, particularly a cylindrical curved surface, as shown in FIG. 4A, the magnetic tape 20 acts on an arbitrary point P of the tape. vector F ₁ in the direction of gravity is decomposed into the vector F ₂ parallel to a normal direction vector F ₃ and the mounting surface 25. Further, as shown in FIG.
Gravity center P of each unit length of, and occurs 'different vector components F ₂ and F ₂ of the inclination angle because the described above' P, these vectors F ₄ synthesized occurs.

Therefore, as shown in FIG. 4C, a force f is applied to both edges 20a and 20b of the magnetic tape 20 to push the magnetic tape 20 downward. As a result, the magnetic tape 20 becomes flat and the cupping disappears. It is thought that it does.

According to the knowledge of the present inventor, cupping is eliminated based on the weight of the object to be measured in this way, and in this state, when a dimension is measured by an optical dimension measuring machine or the like, a pressing Unlike the case of using a glass plate, the width of an object to be measured can be measured with high working efficiency without error, and the measurement result is equal to or close to a true value.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred dimension measuring apparatus of the present invention is a flexible apparatus for measuring the width dimension of a strip, wherein the strip is placed on the mounting surface having the convex curved surface. And a receiving unit that receives the transmitted measurement wave as reflected light, transmitted light, or direct light accompanied by light shielding by the strip. be able to.

As the measurement wave, visible light, ultraviolet light, infrared light and the like can be used, but laser light and ultrasonic wave are preferable, and laser light is particularly preferable.

In the present invention, the object to be measured for dimension is preferably a flat object, for example, a thin long body such as a magnetic tape. It is better to do in the direction.

In the dimension measuring device of the present invention, the mounting surface on which the magnetic tape or the like is mounted is 200 mm or less, particularly 200 to 5 mm.
It is preferably formed on a cylindrical surface having a radius of curvature R of 0 mm. The reason is that if this R exceeds 200 mm, the effect of eliminating cupping becomes small. Further, when R is less than 50 mm, the stability of the tape on the mounting surface deteriorates, and a measurement error easily occurs.

The receiving unit and the transmitting unit, which are indispensable for the dimension measuring device of the present invention, are combined with each other when a measuring wave is transmitted from the transmitting unit and the reflected wave is received by the receiving unit. Is preferred.

In the present invention, the distances from the mounting surface to the receiving unit and the transmitting unit do not have to be limited to the same,
It is desirable that they be the same. Otherwise, the measurement accuracy is further reduced.

Hereinafter, the present invention will be described more specifically by way of preferred embodiments with reference to the drawings.

FIG. 1 shows an apparatus for measuring the size of a magnetic tape 20 according to an embodiment of the present invention, in which an optical size measuring machine 22 and a mount 23 opposed thereto are vertically mounted on the same back plate 21. Mounted on Optical dimension measuring device 2
The light emitting unit 2 includes a light emitting unit 22a as a transmitting unit that transmits the laser light 24 toward the magnetic tape 20.
Further, the gantry 23 incorporates an optical dimension measuring device 30 having a light receiving section 30b as a receiving section for the laser light 24, and the receiving section of the laser light 24 transmits the laser light 24 by the magnetic tape 20. The remaining laser light excluding the light that has been shielded can be received.

As shown in FIG. 3, the mounting surface 25 of the gantry 23 is formed as a transparent cylindrical surface having a radius of curvature of, for example, 100 mm. Is placed. The mounting surface 25 is made of, for example, glass and is formed on the upper surface of a transparent member provided on the gantry 23.

It is preferable that the distance relationship between the optical size measuring device 22 and the optical size measuring device 30 in the gantry 23 is limited as follows.

That is, the distance d ₁ from the vertex of the mounting surface 25 of the gantry 23 (indicated by a dashed line) to the light emitting part 22a of the transmitting part and the distance d ₂ from the light receiving part 30b of the receiving part are the same. There should be.

In the above configuration, when measuring the width of the magnetic tape 20 in the width direction, the magnetic tape 20 is first placed on the mounting surface 25 of the gantry 23 in a natural state as described above.

Since the mounting surface 25 is formed in the cylindrical surface defined as described above, the magnetic tape 20 is subjected to a force to expand in the width direction due to its own weight vector component, so that the cupping is performed. The phenomenon disappears, and the flat surface closely adheres along the mounting surface 25.

Therefore, by measuring the width of the magnetic tape 20 by receiving the laser beam 24, a measurement result close to the true width can be obtained.

FIG. 2 shows a magnetic tape 20 dimension measuring apparatus according to another embodiment of the present invention.
An optical size measuring device 22 and a mount 23 facing the optical size measuring device 22 are vertically mounted on the same back plate 21, and the optical size measuring device 22 has a transmitting portion for transmitting a laser beam 24 toward the magnetic tape 20. Light emitting section 22a and magnetic tape 2
A light receiving section 22b as a receiving section for receiving the reflected light of the laser light reflected from 0 is built in.

The mounting surface 25 of the gantry 23 is formed as a cylindrical surface having a radius of curvature of, for example, 100 mm, as shown in FIG.
0 is placed.

It is preferable that the distance relationship between the optical dimension measuring device 22 and the gantry 23 is limited as follows.

That is, the distance d ₁ from the vertex of the mounting surface of the gantry 23 (indicated by a dashed line) to the light emitting portion 22a of the transmitting portion.
And the distance d ₂ to reach the light receiving part 30b of the receiving portion may be between the same.

In the above configuration, when measuring the width dimension of the magnetic tape 20, the magnetic tape 20 is first placed on the mounting surface 25 of the gantry 23 in a natural state as described above.

Since the mounting surface 25 is formed in the cylindrical surface defined as described above, the magnetic tape 20 is subjected to a force to expand in the width direction due to its own weight vector component, so that the cupping is performed. The phenomenon disappears, and the flat surface closely adheres along the mounting surface 25.

Therefore, by measuring the width of the magnetic tape 20 by receiving the reflected light of the laser beam 24 from the magnetic tape, a measurement result close to the true width can be obtained.

The present inventor measured the width of the magnetic tape in the width direction based on the present invention using, for example, a dimension measuring device as shown in FIG. 2 (Example). In parallel with this, for the purpose of comparative study, the same measurement was performed using a conventional dimension measuring device having a flat mounting surface (using a glass plate for pressing) (comparative example).

The measurement conditions are as follows, and the measurement results are shown in Table 1. (B) to the distance d ₂ leading to the apex of the convex curved surface of the mounting surface 25 from the transmission portion 22a of the laser beam 24 and 80cm in the embodiment. The distance d ₁ from the receiving part 22 b of the reflected light of the laser light 24 to the vertex of the mounting surface 25 of the convex curved surface is also 80.
cm. (B) In both the examples and the comparative examples, the material of the gantry 23 was aluminum. (C) In both the example and the comparative example, after mounting the magnetic tape 20 on the mounting surface of the gantry, it was visually confirmed that there was no cupping. (D) In each of the examples and the comparative examples, the magnetic tape was moved by hand.
The measurement was made at each point, and the average was taken as the measured value.

[0053]

As is clear from the above table, according to the dimension measuring device of the present invention, the measurement result is not much different from the measurement result obtained by the conventional device, but is closer to the true value because the pressing glass plate is not used. In addition, it is excellent in that the measurement operation can be performed efficiently.

The above embodiment may be variously modified without departing from the gist of the present invention.

For example, a light emitting diode may be used for the transmitting part of the above-mentioned measuring wave and a photodiode may be used for the receiving part in order to more accurately measure the dimension of the object to be measured. In this case, the light receiving surface may be constituted by a photodiode array including a large number of photodiodes, and the upper surface of the array may be convex. In this case, since the mounting surface can be directly formed by the diode array, the incidence efficiency is improved and a measurement error hardly occurs.

The shape of the mounting surface described above is not limited to a cylindrical surface, but may be another curved surface such as a paraboloid, or a combination of a curved surface and a flat surface.

In the first embodiment, the mounting surface is made of a transparent material such as glass, and when the refractive index affects the dimension measurement, an electric circuit for correcting the output of the light receiving section is provided. Good.

Further, the subject of the dimension measurement in the present invention is not limited to a magnetic tape. In other words, not only the object to which the cupping phenomenon is likely to occur, but also the object to which the tendency is likely to be included can be included in the object of dimension measurement.

[0060]

According to the dimension measuring apparatus and the dimension measuring method of the present invention, since the mounting surface on which the object to be measured such as a magnetic tape is mounted is formed in a convex curved surface, the object to be measured is mounted. Sometimes the dimensions can be measured with the cupping phenomenon disappearing based on its own weight, and unlike the previous case of using a pressing glass plate, the true value under high work efficiency without measurement error Can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a dimension measuring device according to an embodiment of the present invention.

FIG. 2 is a perspective view of a dimension measuring device according to another embodiment of the present invention.

FIG. 3 is a schematic diagram showing a radius of curvature of a mounting surface used in the embodiment.

FIG. 4 is a schematic diagram showing a process in which the cupping phenomenon disappears in the embodiment.

FIG. 5 is a perspective view of a conventional dimension measuring device.

6A and 6B show the presence or absence of a cupping phenomenon occurring in a magnetic tape, and FIG. 6A is a perspective view when the phenomenon occurs.
(B) is a perspective view when the same phenomenon does not occur, and (C) is a cross-sectional view of the above (A).

FIG. 7 is a chart showing the steps of manufacturing a magnetic tape (raw film).

FIG. 8 is a chart showing a tape cutting process.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base film, 1a ... Raw film, 1e ... Pancake, 4 ... Backup roll, 5 ... Gravure roll, 6 ... Paint tank, 10 ... Dryer, 11 ... Calendar part, 1
2: Cutting machine, 15: Flat surface, 16, 23: Stand, 17:
Optical dimension measuring machine, 18, 20: magnetic tape, 19: pressing glass plate, 22: dimension measuring machine, 22a: light emitting section of transmitting section, 22b, 30b: light receiving section of receiving section, 24: laser beam, 25 … Cylinder surface

Claims (16)

[Claims] 1. A dimension measuring device comprising: a mounting surface on which an object to be measured is mounted; and measuring means for measuring a dimension of the object to be measured in a non-contact manner, wherein the mounting surface is formed as a convex curved surface. . 2. The dimension measuring device according to claim 1, wherein the object to be measured has a flat shape on the mounting surface. 3. A device for measuring a width dimension of a flexible strip, comprising: a transmitter for transmitting a measurement wave to the strip placed on the mounting surface; The dimension measuring device according to claim 1, further comprising: a receiving unit that receives a measurement wave. 4. The dimension measuring device according to claim 3, wherein the measurement wave is a laser beam or an ultrasonic wave. 5. The dimension measuring device according to claim 1, wherein the object to be measured is a magnetic tape. 6. The dimension measuring device according to claim 1, wherein the placing surface is formed as a cylindrical surface having a radius of curvature of 200 mm or less. 7. The dimension measuring device according to claim 3, wherein the transmitting unit and the receiving unit are combined. 8. The dimension measuring device according to claim 3, wherein a distance from a vertex of the placement surface to the transmitting unit and the receiving unit is the same. 9. An object to be measured is placed on a mounting surface formed on a convex curved surface, whereby the object to be measured is held in a predetermined shape,
A dimension measuring method in which the dimension of the object is measured in a non-contact manner in this state. 10. The dimension measuring method according to claim 9, wherein the object to be measured has a flat shape on the placement surface. 11. A method for measuring a width dimension of a flexible strip, comprising: placing the strip on a mounting surface; transmitting a measurement wave from the transmitting unit to the strip; The dimension measuring method according to claim 9, wherein the dimension is received by a receiving unit. 12. The method according to claim 11, wherein the measuring wave is a laser beam or an ultrasonic wave. 13. The method according to claim 9, wherein the object to be measured is a magnetic tape. 14. The dimension measuring method according to claim 9, wherein the placing surface is formed as a cylindrical surface having a radius of curvature of 200 mm or less. 15. The dimension measuring method according to claim 11, wherein the transmitting unit and the receiving unit are combined. 16. The dimension measuring method according to claim 11, wherein a distance from a vertex of the placement surface to the transmitting section and the receiving section is the same.