JP3670345B2 - Tape width measuring device for magnetic tape - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a tape width measuring apparatus for measuring a width dimension of a magnetic tape obtained by dividing a wide web, a straightness of a tape side edge, and the like with high accuracy.
[0002]
[Prior art]
As this type of conventional apparatus, a video tape dynamic measuring apparatus (Kosaka Laboratory Ltd. ZDR type) is known. In this method, the video tape is run at a constant speed while applying a constant tension, and an enlarged optical image on both sides of the video tape is captured by a CCD line camera. The straightness is measured continuously.
[0003]
[Problems to be solved by the invention]
In the device that measures the tape width while running the magnetic tape as described above, the running state of the magnetic tape varies depending on the mechanical accuracy and vibration of the guide roller that defines the running path of the tape. There is a limit. The tape tension acting on the magnetic tape in the running state does not always match the tape tension when the magnetic tape is loaded into the tape drive and used, and the magnetic tape is stretched during measurement. The degree cannot be measured correctly. Fluctuation in tape tension during running also hinders the advancement of measurement accuracy.
[0004]
Such a conventional measuring apparatus can be applied to existing magnetic tape width measurement without any trouble, but in the case where the signal recording density is further enhanced, the allowable range of straightness of the tape side edge is small. In the case of a magnetic tape having a width of 4 mm or less, a straightness of about 3 to 4 μm is required, so that it cannot be applied. Regarding the periodic fluctuation of the straightness of the side edge of the tape, the conventional apparatus is limited to observing with a period of about 100 mm, and the reliability is low for a smaller period.
[0005]
An object of the present invention is to provide a tape width measuring apparatus capable of measuring the width dimension of a magnetic tape, the straightness of a tape side edge, and the like with high accuracy.
Another object of the present invention is to provide a tape width measuring apparatus capable of capturing periodic dimensional variations of the tape side edge with a smaller periodic dimension.
[0006]
The tape width measuring apparatus according to the present invention includes a pair of holders 2 and 3 that linearly stretch a magnetic tape T on a base 1, and a guide 4 that slidably guides a measuring table 5 along the magnetic tape T; A drive mechanism for reciprocating the measurement table 5 is provided.
One holder 3 is provided with a tension mechanism 7 for setting the tension of the magnetic tape T. The measuring table 5 is provided with a length measuring device 6 for measuring the width dimension of the magnetic tape T. The length measuring device 6 receives a laser beam oscillated by scanning the laser beam in a direction orthogonal to the tape side edge S of the magnetic tape T, and receives the laser beam oscillated from the light emitter 6a. It comprises a light receiver 6b that outputs a signal.
[0007]
The drive mechanism is connected to a screw shaft 19 which is arranged in parallel with the guide 4 and rotatably supported, a female screw block 20 which is fixed to the measuring table 5 and meshes with the screw shaft 19, and one end of the screw shaft 19. Thus, the servomotor 21 is configured to be able to rotate forward and reverse the screw shaft 19.
The tension mechanism 7 includes an arm 27 that is swingably supported by the holder frame 3, a tension roller 28 that is rotatably supported at the tip of the arm 27, and a weight 30 that is detachably attached to the arm 27. The magnetic tape T is stretched horizontally by a pair of holders 2 and 3, the light emitter 6 a is disposed above the upper surface, and the light receiver 6 b is disposed below the lower surface.
[0008]
[Action]
The tape width B is measured because the magnetic tape T is linearly stretched by a pair of holders 2 and 3 and a laser beam is projected onto the stationary magnetic tape T to which a predetermined tension is applied by the tension mechanism 7. In addition, the straightness of the tape side edge S can be measured with sufficiently high accuracy. The measuring table 5 that supports the length measuring device 6 can move with a minute movement pitch. Therefore, the periodic dimensional variation of the tape side edge S can be accurately captured with a sufficiently small periodic dimension. In particular, since the measuring table 5 is moved by a drive mechanism using the servo motor 21 as a driving source, the moving accuracy of the measuring table 5 can be increased. Since the tension mechanism 7 has the weight 30 detachably attached to the arm 27, the tension applied to the magnetic tape T can be changed between large and small by exchanging the weight 30.
[0009]
【The invention's effect】
In the present invention, the magnetic tape T is stretched linearly with a predetermined tension, and the laser-type length measuring device 6 is moved along the magnetic tape T in a stationary state, whereby the tape width B and the tape side edge S are straightened. The degree etc. can be measured. Therefore, a measurement result with sufficiently high accuracy can be obtained as compared with a conventional apparatus that performs the same type of measurement while the tape is running. For example, even in a magnetic tape T having a high signal recording density and a small tape width, measurement errors such as straightness between the tape width B and the tape side edge S can be suppressed to several μm or less. Further, since the measuring table 5 can be moved and moved at a minute pitch, the periodic dimensional fluctuation of the tape side edge S can be grasped with a smaller fluctuation periodic dimension, and the dimensional accuracy variation related to the tape width of the magnetic tape T can be accurately determined. Know exactly.
[0010]
【Example】
1 to 4 show an embodiment of a tape width measuring apparatus according to the present invention. In FIG. 1, the tape width measuring apparatus is horizontally held and fixed by a thick plate-like base 1 made of stone, a pair of left and right holders 2 and 3 arranged on both sides of the front edge of the base 1, and both holders 2 and 3. The guide 4 arranged in parallel with the magnetic tape T as a reference, the measurement table 5 guided and supported by the guide 4 so as to be slidable to the left and right along the magnetic tape T, and the measurement table 5 reciprocating along the guide 4 It comprises a drive mechanism for driving, a length measuring device 6 provided on the measuring table 5, a tension mechanism 7 provided on the right holder 3 as viewed in the figure, and the like.
[0011]
2 and 3, each of the holders 2 and 3 has a holder frame 9 having an L shape in a side view, and a drum 10 for fixing an end portion of the magnetic tape T is disposed on the front upper portion thereof. A pair of left and right guide rollers 11 are rotatably supported adjacent to the drum 10 in the right holder 3, and a tension mechanism 7 is disposed below these rollers 11. Both ends of the magnetic tape T cut to a predetermined length are fixed to the left and right drums 10, the middle part thereof is inverted and guided downward between the pair of guide rollers 11, and the lower end bent part is pushed down by the tension mechanism 7. Thus, a predetermined tension can be applied to the magnetic tape T.
[0012]
The measurement table 5 has a U-shaped slider 12 that is guided and supported by the guide 4. A horizontal base plate 13 extending forward of the base is fixed to the upper surface of the slider 12, and a vertical mounting is provided on the front portion of the base plate 13. The frame 14 is fixed. The slider 12 and the guide 4 are commercially available products that make a pair, and can move and guide the slider 12 with sufficient straightness. A U-shaped tape opening 15 for passing the magnetic tape T is cut out in the middle part of the front edge of the mounting frame 14 (see FIG. 3).
[0013]
The length measuring device 6 is arranged and fixed on one side of the mounting frame 14. The length measuring device 6 is a laser length measuring device in which a light emitter 6a and a light receiver 6b are integrated. The light emitter 6a is disposed above the magnetic tape T, and the light receiver 6b is disposed below. The light emitter 6a scans and oscillates the laser beam in a parallel state in a direction orthogonal to the tape side edge S of the magnetic tape T. The light receiver 6b receives the oscillated laser beam and outputs a position signal of the tape side edge S. Specifically, as shown in FIG. 4, a signal corresponding to the distance X from the virtual reference line P to one tape side edge S is output, and a signal corresponding to the tape width B is output. These signals are taken into the computer 17 via the controller 16 for the length measuring device 6 (see FIG. 2).
[0014]
The drive mechanism includes a screw shaft 19 arranged in parallel to the guide 4 on the back of the guide 4, a female screw block 20 that meshes with the screw shaft 19, and a servo motor 21 that can perform forward / reverse driving to rotate the screw shaft 19. Constitute. Both ends of the screw shaft 19 are rotatably supported by bearings 18. The female screw block 20 is fixed to the back surface of the slider 12 and accommodates a group of balls that engage with the screw shaft 19 therein. By the drive mechanism using the servo motor 21 as a drive source, the feed pitch of the slider 12 can be changed to an arbitrary amount every 0.01 mm within a range of 0.01 to 20.00 mm. The feed stroke of the slider 12 can be changed to an arbitrary amount every 1 mm within a range of 100 to 300 mm. In order to control the operation of the servo motor 21 and the length measuring device 6, a control panel 25 including a programmable controller 22, a pulse oscillator 23, a servo driver 24, an operation switch and the like is provided separately.
[0015]
1 and 2, the tension mechanism 7 has support shafts projecting from the back surfaces of both ends of the horizontally long arm 27, and the tension roller 28 is supported by these support shafts so that it can freely rotate. A fixed shaft 29 is supported to be swingable. Further, a tension adjusting weight 30 is detachably screwed to the front surface of the arm between the shaft 29 and the tension roller 28. When the weight 30 is attached, the left and right gravity balance of the arm 27 is lost, and the arm 27 can be tilted to the upper right so that a predetermined tension can be applied to the magnetic tape T. The tension can be changed.
[0016]
When measuring the width of the magnetic tape T, the magnetic tape T is stretched between the pair of holders 2 and 3 as described above, and the tension mechanism 7 applies the same tension as the tape tension in the actual use state. Next, the measurement table 5 is moved to the start position near the left holder 2 to start measurement. Thereafter, every time the measuring table 5 moves at a predetermined feed pitch, a laser beam is projected from the light emitter 6a in a state where it crosses the magnetic tape T in the width direction, and an output signal from the light receiver 6b is received to the computer 17. Capture measurement results.
[0017]
From all the measured data, the tape width B, the straightness of the tape side edge S, etc. can be known as real values or as graphed variation characteristic curves. The magnetic tape T is stationary at the time of measurement, and the width is measured in a non-contact state using laser light, so that all the fluctuations of the magnetic tape T and the disturbance caused by the running mechanism that could not be avoided in the conventional measuring device can be eliminated. The accuracy of the width measurement can be improved sufficiently and the length measurement accuracy can be improved to about ± 0.5 μm. Since the width can be measured by making the tape tension coincide with the actual tension in the tape drive, it is possible to accurately grasp the influence of elongation on the width dimension and the like of the magnetic tape T. Since the measuring table 5 can be moved at an arbitrary feed pitch every 0.01 mm, periodic fluctuations in the straightness of the tape side edge S can be grasped with a smaller period dimension with high accuracy.
[0018]
In the above embodiment, the magnetic tape T is stretched from side to side with the tape surface being horizontal. For example, the magnetic tape T is stretched up and down or the tape surface is slanted back and forth. Also good.
[Brief description of the drawings]
FIG. 1 is a front view of a tape width measuring apparatus.
FIG. 2 is a plan view of the tape width measuring apparatus.
FIG. 3 is a cross-sectional view taken along line AA in FIG.
FIG. 4 is an explanatory diagram showing a measurement form of a magnetic tape.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base 2/3 Holder 4 Guide 5 Measuring stand 6 Length measuring device 6a Light emitting device 6b Light receiving device 7 Tension mechanism 19 Screw shaft 20 Female screw block 21 Servo motor T Magnetic tape

Claims (4)

A pair of holders 2 and 3 that linearly stretch the magnetic tape T on the base 1, a guide 4 that slidably guides the measurement table 5 along the magnetic tape T, and a drive that reciprocates the measurement table 5. Mechanism is provided,
One holder 3 is provided with a tension mechanism 7 for setting the tension of the magnetic tape T.
The measuring table 5 is provided with a length measuring device 6 for measuring the width of the magnetic tape T in a stationary state .
The length measuring device 6 scans and oscillates laser light in a direction orthogonal to the tape side edge S of the magnetic tape T, and receives the laser light oscillated from the light emitter 6a and receives a position signal of the tape side edge S. The tape width measuring device of the magnetic tape comprised with the light receiver 6b which outputs.   The drive mechanism is connected to a screw shaft 19 that is arranged in parallel with the guide 4 and rotatably supported, a female screw block 20 that is fixed to the measurement table 5 and meshes with the screw shaft 19, and one end of the screw shaft 19. 2. A tape width measuring device for a magnetic tape according to claim 1, wherein the tape shaft is constituted by a servo motor 21 capable of rotating forward and backward to rotate the screw shaft 19.   The tension mechanism 7 includes an arm 27 that is swingably supported by the holder frame 3, a tension roller 28 that is rotatably supported at the tip of the arm 27, and a weight 30 that is detachably attached to the arm 27. The tape width measuring device of the magnetic tape according to claim 1 or 2.   The magnetic tape T is stretched horizontally by a pair of holders 2 and 3, the light emitter 6a is disposed above the upper surface, and the light receiver 6b is disposed below the lower surface. Tape width measuring device for magnetic tape.

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