JP2619538B2 - Method and apparatus for correcting dimensions of magnetic head and method for manufacturing VTR - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an apparatus for correcting the size of a magnetic head (hereinafter, referred to as a VTR head), and particularly relates to a distance between a gap, a height difference and a height of a double azimuth head. Method and apparatus for correcting magnetic head dimensions suitable for correcting dimensions
It relates to a method of manufacturing a VTR.

[Conventional technology]

A conventional VTR head size correction device is disclosed in, for example,
As described in JP-A-8-129310, first, two T
The image of the VTR head taken by the V camera is displayed on the monitor, and then the two magnetic gaps of the VTR head are aligned with the horizontal and vertical cursor lines drawn on the monitor before moving the VTR head and optical system. Then, the distance between the gaps of the VTR head and the height difference are measured based on the movement amount. As a result of the measurement, it is proposed that a non-defective product is put into a standard size and is made a non-defective product without any repair work.

[Problems to be solved by the invention]

In the above prior art, the repair work is performed based on the measured VTR head dimensions based on the intuition and experience of the operator.Therefore, there is a large difference in the dimensions of the corrected VTR head, and There is a problem that a lot of time is spent, and only a skilled person can work.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and to make it possible to easily fix the dimensions of a VTR head after modification even by a non-expert, and to provide a method and apparatus for modifying the dimensions of a magnetic head. Another object of the present invention is to provide a method of manufacturing a VTR.

Means for Solving the Problems In order to achieve the above object, the present invention provides a magnetic head provided with a pair of head chips, in which a predetermined value of a head-to-head distance or a head-to-head step is recorded in advance, The head-to-head distance or the head-to-head level difference of the head is measured, and the difference between the measured value and the previously recorded predetermined value of the head-to-head distance or the head-to-head level difference is calculated. Calculate the value of each of the head-to-head distance or head-to-head step (difference value + deformation amount up to the elastic limit) and the force for plastically deforming the magnetic head by the respective difference value, and calculate the head-to-head distance or head of the magnetic head. A magnetic head, wherein the magnetic head is plastically deformed in accordance with the value of each (difference value + the amount of deformation up to the elastic limit) of the step and the force for plastically deforming the magnetic head by the difference value. Dimensions It is a correction method.

The present invention also provides a VTR head dimension correcting apparatus, wherein inspection means for inspecting an inter-head distance or an inter-head level difference of a magnetic head provided with a pair of head chips; When one is modified, the other is deformed, so the storage means for storing the relationship between the amount of modification of one and the amount of deformation of the other, and according to the inspection result of the inspection means, read the contents of the storage means, And read from the storage means, when correcting any one of the head-to-head distance and the head-to-head step, the other is deformed, so based on the relationship between one correction amount and the other deformation amount, the deformation amount or Calculating means for calculating the correction amount;
Correction means for correcting the distance between the heads of the magnetic head and the dimension of the step between the heads based on a command from the calculation means.

Further, the inspection means measures a magnetic gap of the magnetic head, and inspects a head-to-head distance and a head-to-head level difference based on the measured magnetic gap.

Further, the inspection means, a window forming means for forming a window parallel to the magnetic gap, a secondary differential processing means for performing a second derivative in a direction perpendicular to the magnetic gap in the window formed by the window forming means, Adding means for adding the secondary differential value processed by the secondary differential processing means in a direction parallel to the magnetic gap, so as to measure the magnetic gap.

Also, the present invention provides a method for correcting the distance between the magnetic heads and the step between the heads by taking into account a result measured by a measuring means for measuring at least one of a correcting force and a moving amount for correcting the head-to-head step by the correcting means. Is calculated.

Also, the present invention provides a comparing means for comparing the amount of deformation calculated by the calculating means with the correction result measured by the measuring means, and a calculation based on the contents of the storage means based on the comparison result by the comparing means. And a correcting means for correcting the amount of deformation or the correction force to be applied.

Further, the present invention inspects at least the distance between the heads and the step between the heads of a magnetic head, which is obtained by attaching and fixing a pair of head chips to the tips of the pair of heads with an adhesive, and Since at least one of the steps is deformed when the other is deformed, the relationship between the one corrected amount and the other deformed amount is stored, and the relationship between the one corrected amount and the other deformed amount is calculated according to the inspection result. The distance between the magnetic heads or the dimension of the step between the magnetic heads is corrected, and the corrected magnetic head is incorporated in a VTR body.

Also, when performing the inspection, a window parallel to the magnetic gap is formed, the window is secondarily differentiated in a direction perpendicular to the magnetic gap, and the secondary differential value is added in a direction parallel to the magnetic gap.
The distance between the magnetic heads and the step between the magnetic heads are inspected by detecting the magnetic gap.

Further, after the dimension correction, at least one of a correction force and a moving amount for correcting the head-to-head distance and the head-to-head level difference is measured.

Further, according to the present invention, the displacement of the magnetic head is determined by attaching and fixing a pair of head chips to the tips of the pair of heads with an adhesive, and is obtained and stored in advance based on the inspection result. The actual deformation is calculated from the relationship between the amount of deformation that the magnetic head permanently exceeds beyond the elastic limit and the apparent deformation required to correct the dimensions of the magnetic head, and the calculated amount of deformation is calculated. The dimensions of the magnetic head are corrected based on the above, and the corrected magnetic head is incorporated in the VTR body.

In addition, the displacement of the magnetic head, which is obtained by attaching and fixing a pair of head chips to the tips of the pair of heads with an adhesive, is inspected. The apparent correction force required to correct the dimensions of the magnetic head was calculated based on the relationship between the amount of deformation permanently remaining beyond the limit and the correction force required to correct the magnetic head. The dimensions of the magnetic head are corrected based on the correction force, and the corrected magnetic head is incorporated into the VTR body.

[Action]

In the method and apparatus for correcting the dimensions of the VTR head configured as described above, the head-to-head distance, head-to-head difference,
The right height height and the left height height are inspected, and the head-to-head distance correcting means corrects the head-to-head distance of the VTR head based on the inspection result, and the height correcting means corrects the height difference of the VTR head and the right height height. And the height of the left height is corrected, so that the head chip attached to the head base with an adhesive is not replaced, and the distance between the head distance correcting means and the height correcting means and the correcting force are measured by the measuring means. Therefore, it is possible to efficiently correct the dimensional defect of the VTR head, and to improve the quality and the yield by reducing the dimensional variation.

In addition, the drive unit of the head-to-head distance correction unit is rotated or expanded / contracted based on a command from the inspection unit, and both ends of the correction unit are opened / closed to correct the head-to-head distance while plastically deforming the VTR head. Since the moving amount and the correcting force of the head are measured by the measuring means, the distance between the heads can be automatically corrected, the quality can be improved due to the reduction of the dimensional variation, and the time for the dimensional correction can be shortened.

In addition, the drive unit of the height correction means is rotated based on a command from the inspection means, and the end of the VTR head is plastically deformed upward or downward by the correction part, and the head gap, right height height and left height height are determined. In addition to the correction, the moving distance and the correction force of the correction part are measured by the measuring part, so the height difference, right height height and left height height can be corrected automatically, and the quality due to the reduction of dimensional variation The time for improvement and correction can be shortened.

In addition, since the inspection means gives a command so that the dimensions of the VTR head can remain permanently even after the correction, the dimensions of the VTR head are corrected through the head-to-head distance correction means and the height correction means. Since it is possible to omit the reworking of the dimensions, it is possible to improve the operability and to automate the inspection, so that the time for the inspection can be shortened.

〔Example〕

First, a VTR head to which the present invention is applied and a dimension measurement technology thereof will be described.

As shown in FIG. 3 (a), the VTR tape 4 is simultaneously wound obliquely around the outer peripheral surface of the fixed lower cylinder 2 and the rotating upper cylinder 3, and attached to the upper cylinder 3.
Recording and reproducing operations are performed when the tip of the VTR head 1 crosses the tape 4 in an oblique direction.

FIG. 3 (b) shows an enlarged view of the VTR head, which is composed of a head base 5, a head chip 6, and a groove 58 of the head base. The head base 5 has a tip portion divided into two, and a head chip 6 is adhered to each tip portion. Each of the head chips 6 constitutes a magnetic circuit. The relative positions of the magnetic gaps for this purpose are represented by the coordinate axes x, y, and z in FIG.
With reference to the intersection with the head, the one in the x-axis direction is called a head-to-head distance (hereinafter, gap distance) GL, and the one in the y-axis direction is called a head-to-head gap (height difference) TH. Further, based on the surface on which the head chip 6 is attached to the head mace 5, the absolute height from this surface is defined as the right height R
H, left height LH.

As a result of the inspection, if the VTR head 1 is determined to be defective in dimension, the gap distance GL is too wide or too narrow than the reference distance, or the absolute value of the height difference TH is equal to the reference difference. In this case, the heights RH and LH are too large or smaller than the reference distance.

Therefore, the present invention plastically deforms the head base 5 in the x and y directions with respect to the VTR head 1 deviated from the reference as in the above-described case, so that the gap distance GL height difference TH, the right height height RH, And correcting the left height LH to make the VTR head 1 non-defective.

Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an overall view of a dimension correcting device according to the present invention, which comprises a VTR head 1, a visual mechanism 12, a camera 13, a correcting mechanism control device 14, an overall control device 17, an image processing device 18, and a correcting mechanism control device 19. FIG. 2 is an enlarged view of FIG. 1 excluding a control part. As shown in FIGS. 1 and 2,
On the base 21, the head before correction is transported from the correction mechanism 14 and the two head storage magazines before correction to the correction mechanism 14, and the corrected head is transported from the correction mechanism 14 to the head storage magazine 25 after correction. Mechanism 15 and a visual mechanism 12 for measuring the dimensions of the VTR head 1 are provided.

The VTR head 1 before correction is the head storage magazine 2 before correction.
The reference position 26 of the correction mechanism 14 by one by the transport mechanism 15 from 4
Transported and fixed. Opposite to the correction surface of the VTR head 1, the two chip surfaces are enlarged and photographed by the visual mechanism 12 mainly composed of the microscope 22 and the camera 13 (enlarged visual fields 30-(a), 30-shown in FIG. 4). (B))
The dimensions GL, TH, RH and LH are measured by the image processing device 18 shown in FIG.
The image processed for the dimension measurement by the image processing device 18 is projected on the television monitor 16. The image processing device 18
The dimensions GL, TH, RH, and LH measured by the controller are sent to the overall control device 17, and inside the overall control device 17, the acceptable reference dimensions CGL, CTH, CRH, CLH, and the dimensions Acceptable ranges gl, th, rh, and lh are entered. The measured dimensions, GL, TH, RH, and LH, transmitted to the overall control device 17 are determined to be good if the following equations (1) to (4) are satisfied, and to be defective if they are not satisfied.

Equation 1 ... CG L-gl≤GL≤CG L + gl Equation 2 ... CT H-th≤TH≤CT H + th Equation 3 ... CR H-rh≤RH≤CR H + rh Equation 4 ... CL H-lh≤LH≤CL H + lh Plastic deformation The amount (correction amount) MG L, MT H, MR H, ML H is calculated by the formula 5
It is calculated using Expression 8, and transmitted to the correction mechanism controller 19 together with the correction start command.

Equation 5 ... MG L = GL-CG L Equation 6 ... MTH = TH-CT H Equation 7 ... MR H = RH-CR H Equation 8 ... ML H = LH-CL H In the correction mechanism control device 19, Since the correction algorithm has been entered, this plastic deformation amount MG L, MT
By substituting H, MR H, and ML H, the movement amount (total deformation) of the drive unit (piezo, motor) required for the actual operation of the mechanism
eGL, eLH, and eTH are calculated and transmitted to the drivers 54, 55, 56, and 57. The drivers 54, 55, 56, and 57 control the voltage so that the driving sections operate, move the correction mechanism 14, and plastically deform the head base 5 of the VTR head 1 to correct the dimensions. The corrected VTR head 1 is transported by the transport mechanism 15 to the post-correction head storage magazine 25 again (see FIG. 2).

First, the dimension measurement method will be described with reference to FIGS. In order to recognize the magnetic gap 27 in the head chip 6 in FIG. 4 and calculate the dimensions, as shown in FIG. 2, a microscope 22 and two cameras 13 are arranged opposite the surface of the head chip 6. A visual mechanism 12 is provided. The surface of the head chip 6 is enlarged by a microscope 22 in the visual mechanism 12,
The head chip 6- (a) is photographed by the camera 13- (a), and the head chip 6- (b) is photographed by the camera 13- (b). The two captured images are separately processed by the image processing device 18, and a magnetic gap (shown as a straight line) 27 is recognized. In order to obtain the magnetic gap 27, it is possible to perform image processing on the entire field of view 30 captured by the camera 13. However, in the present invention, as shown in FIG. , Magnetic gap
A window 29 is provided in a portion where 27 is supposed to exist, and only the inside of the window 29 is obtained by image processing.

The magnetic gap 27 is a straight line provided at an inclination angle 35 near the center of the belt-shaped track 28.
Therefore, in order to set the window 29, first, as shown in FIG.
The track 28 of the head chip 6 in 30 is obtained. As a method, the photographed image is binarized to divide the track 28 into white and the background 32 into black. This white part is vertically and horizontally and horizontally (the magnetic gap 27 and the inclination 35 of the track 28).
(Diagonally in the diagonal direction) for each pixel to obtain the distribution of brightness. The distribution 33 in the vertical direction has a shape like a valley where the track 28 is low, and the distribution 34 in the diagonal direction is high when the track 28 is high. It looks like a mountain. A band-like track 28 is obtained using the position data of the valley portion and the mountain portion of this distribution. A window 29 for measuring the magnetic gap 27 is formed near the center of the track.

Next, in order to measure the magnetic gap 27, the inside of the window 29 is secondarily differentiated in the oblique and horizontal directions 37 for each pixel (see FIG. 5). When the second derivative is performed, a portion having a different brightness from the track portion, such as the magnetic gap 27 or dust or scratch 39, is obtained as a large second derivative value. (Graph 36 of the change in the value of the second derivative). The secondary differential value 36 in the oblique horizontal direction 27 obtained for each column is added to the oblique vertical direction 38, which is the same as the inclination 35 of the magnetic gap 27. When added in the oblique vertical direction 38, dust and scratches 39 are randomly scattered, so that 2
The next differential value is a large value, but when added in the oblique and vertical directions 38, the added value 40 does not become so large. However, since the magnetic gap 27 portion also shows the second derivative in the vertical direction in the same manner, when the addition is performed in the oblique vertical direction 38, the added value 40 becomes a large value. When the added value exceeds a certain value, the magnetic gap 27 can be detected by a method of recognizing the point as a magnetic gap without erroneous recognition due to dust, scratches 39 or the like.

Next, a reference point 41 for position measurement is obtained as shown in FIG. The reference point 41 is the magnetic gap 27 determined earlier,
The intersection point of the boundary (edge 31) between the track 28 and the background 32. The edge 31 moves the pattern 42 taught in advance on the image in the vertical direction, and regards a line segment where the pattern 42 matches the actual image as the edge 31. Then, the intersection (reference point 41) of the magnetic gap 27 and the edge 31 is defined as two images 30
The relative distance in the x direction (distance GL between gaps) between the two reference points 41 in the y direction is obtained by multiplying the scales on the previously input image by calculating from (a) and 30- (b), respectively. And the absolute distance (right height RH, left height LH) in the y-direction from the surface of the head chip 6 to which the head chip 6 is attached to the head base 5 to the reference point, respectively.

Next, the correcting mechanism 14 will be described with reference to FIGS.

As shown in FIG. 6, the correcting mechanism 14 includes a gap widening mechanism 50, a narrowing mechanism 51, a right height height correcting mechanism 52, and a left height height correcting mechanism 53.

As shown in FIG. 7, the gap widening mechanism 50 includes a finger 43, a driving unit 45, a cassette 44, a slide shaft 47,
It comprises a slide bearing 46 and a tension spring 48.

 Next, the operation will be described.

Photographed by microscope 22 and camera 13 (see Fig. 6)
Based on the dimension data of the gap distance GL measured by the image processing device 18, the correction start command and the amount of plastic deformation MG L, MR are increased from the overall control device 17 to the correction mechanism control device 19 so as to increase the gap distance GL. When H and ML H are transmitted, the supply of the amplified voltage from the driver 54 to the driving unit 45 is temporarily stopped to contract the driving unit 45, and the finger units 43 move in the opposite closing directions. And base 49 in this state
Move to the head base 5 side, and the groove 58 of the head base 5
Insert

Next, the amount of plastic deformation MG L, MR H,
In order to give the plastic deformation amount MGL to the head base 5 by the correction mechanism control device 19 according to the ML H, the driver adjusts the total deformation amount eGL, the correction force pGL, and the finger 43 to be moved by the specified amount. 54 supplies the amplified voltage to the drive unit 45. When the voltage is supplied, the driving unit 45 spreads in the x direction.
When the drive unit 45 is expanded, the slide bearing 46 in the finger 43 is moved by using the slide shaft 47 as a guide, and the finger 43 is moved in the opposite spreading direction to deform the head base 5 to reduce the gap distance GL. spread.
The correction force at this time is detected by the power sensor 48. Also, the total deformation amount during the work of widening the gap distance GL can be obtained by the visual mechanism 12, and the moving amount of the driving unit 45 and the tip of the finger 43 are obtained by, for example, photoelectric conversion means, and the moving amount is calculated. Can be obtained by converting to the actual deformation amount of the head base 5.

FIG. 8 shows a modified example of the gap widening mechanism 50.
This mechanism includes a spreading pin 108, a driving unit 109, an encoder 110, a coupling 111, a ball screw 112, a ball screw nut 113, a block 114, and a power sensor 115.

The operation of this configuration is performed by the overall control device 17 to the correction mechanism control device 19 when a correction start command and a plastic deformation amount MGL, MR H, ML H are transmitted so as to increase the gap distance GL to the drive unit 109. Power is supplied from the driver 54. As a result, the drive unit 109 rotates, and this rotation is transmitted to the ball screw 112 via the coupling 111. When the ball screw 112 rotates, the ball screw nut 113 and the block 114 attached to the ball screw nut 113,
5. The spreading pin 108 moves straight in the y direction. When expanding the head base, rotate the drive
8 descends and is inserted into the groove 58. After insertion, spread pin 108
When the head is lowered, the lower surface of the head base 5 is fixed by the base 49, so that the head base 5 spreads by a wedge effect.

The correction force at this time is detected by the power sensor 115. Further, the total deformation amount during the work of widening the gap distance GL can also be obtained by the visual mechanism 12.
The amount of rotation of 9 is obtained by the encoder 110 and converted into the amount of movement of the spread pin 108, or the amount of movement of the spread pin 108 is obtained directly by photoelectric conversion means, etc. Can be obtained by converting to the amount of deformation of the head base 5.

As shown in FIG. 9, the gap narrowing mechanism 51 includes a narrowing pin 59, a driving unit 60, an encoder 69, a power sensor 61, and a lever.
63, a rotation center pin 62, a ball screw fixing block 64, a ball screw 65, a ball screw nut 66, a slider 67, and a coupling 68.

 Next, the operation will be described.

When a correction start command and a plastic deformation amount MGL, MR H, ML H are transmitted from the general control device 17 to the correction mechanism control device 19 to reduce the gap distance GL, the drive unit 60 rotates through the driver 55. . When the ball screw 65 connected to the drive unit 60 is rotated by the coupling 68, the ball screw nut 66 and the ball screw fixing block 64- (a) attached to the ball screw nut 66 are attached to the drive unit 60. Approaching-(b). Here, since the ball screw fixing blocks 64 are respectively mounted on the sliders 67, they can be translated. When the ball screw fixing blocks 64 come closer to each other, the lever 63 swings around the rotation center pin 62, and a pair of narrowing pins 59- (a) and 59- (b) in the base 49 accompanying this.
Once move in opposite spreading directions. Then, in this state, the base 49 moves to the head base 5 side, or
Move the head base 5 to the gap narrowing mechanism 51 side,
The narrowing pin 59 narrows the tip of the head base 5.

Next, the amount of plastic deformation MG L, MR H,
According to the ML H, the correction mechanism controller 19 calculates the total deformation amount eGL corrected by the narrowing pin 59 and the correction force pGL to obtain the plastic deformation amount on the head base 5, and specifies the narrowing pin 59. The drive unit 60 is rotated in the opposite direction by the signal of the driver 55 so that the ball screw 65 is moved by the distance, and the ball screw 65 is rotated accordingly. When the ball screw 65 rotates, the ball screw nut 66 and the ball screw fixing block 64- (a) attached to the ball screw nut 66 move away from the ball screw fixing block 64- (b) attached to the drive unit 60. When the ball screw fixing blocks 64 move away from each other, the lower end of the lever 63 is pushed by the ball screw fixing block 64, and the lever 63 swings around the rotation center pin 62, and is narrowed through the force sensor 61 attached to the upper end of the lever 63. The pin 59 presses the tip portion of the head base 5 inward while moving in the opposite contracting directions using the base 49 as a guide, so that the head base 5 is plastically deformed and the gap distance GL is reduced. In this mechanism, both ball screw fixing blocks 64
Since it is mounted on the top, the self-alignment of the narrowing pin 59 is possible, and the pair of narrowing pins 59 applies an equal force to the pair of head tips without moving the head base 5 during the correction. Is possible. The correction force at this time is detected by the power sensor 61. Further, the total deformation amount during the work of narrowing the gap distance GL can also be obtained by the visual mechanism 12, and the amount of rotation of the drive unit 60 is obtained by the encoder 69 and converted into the amount of movement of the narrowing pin 59. Alternatively, the amount of movement of the narrowing pin 59 can be directly obtained by photoelectric conversion means or the like, and the amount of movement can be obtained by converting the amount of movement into the actual amount of deformation of the head base 5.

As shown in FIG. 10, the right height correction mechanism 52 includes a lower correction pin 70, an upper correction pin 71, a rotation center pin 72, a lever 73, a power sensor 74, a driving unit 75, an encoder 76, a ball screw 77, a coupling 78, a ball It is composed of a screw nut 79 and a moving block 80.

 Next, the movement will be described.

When the configuration is in the home position and the head base 5 is mounted and fixed at the correction position, the general control device 17 sends a correction start command for the right height height RH or height difference LH to the correction mechanism control device 19. , Plastic deformation MG L, MR H, M
When the LH is transmitted, the correction mechanism controller 19 calculates the total deformation amount eRH and the correction force pRH corrected by the lower correction pin 70 or the upper correction pin 71 in order to obtain the plastic deformation amount on the head base 5. The driver 56 rotates the drive unit 75 so that the lower correction pin 70 or the upper correction pin 71 moves by a specified amount. When the lower correction pin 70 is operated to lift the right base portion 81 of the head base 5, the rotation of the driving portion 75 is transmitted to the ball screw 77 via the coupling 78. When the ball screw 77 rotates, the ball screw nut 79 moves downward accordingly,
The moving block 80 attached to the ball screw nut 79 also moves downward, and pushes down one end of the lever 73- (a) via the cal sensor 74- (a). Lever 73- (a)
Swings about the rotation center pin 72- (b), and the lever 72
The other end of (a) pushes the lower correction pin 70 upward to plastically deform the head base 5 to correct the right height height RH and the height difference TH.

Conversely, when the upper correction pin 71 is operated to lower the right base portion 81 of the head base 5, the driving portion 75 rotates in the opposite direction to the above, and the ball screw nut 79 and the moving block 80 Move upward, opposite to the above, and
By pushing up one end of the lever 73- (b) via 74- (b), the other end pushes down the upper correction pin 71,
The right base height RH and the height difference TH are corrected by plastically deforming the head base 5.

The correction force at this time is detected by the power sensor 74- (a) when correcting from below and by the power sensor 74- (b) when correcting from above.

The total deformation amount during the work of correcting the right height height RH and the height difference TH can also be obtained by the visual mechanism 12, the rotation amount of the drive unit 75 is obtained by the encoder 76, and this is obtained by the lower correction pin 70 or Converted to the amount of movement of the upper correction pin 71 (a conversion formula is obtained in advance through preliminary experiments), or calculated directly, using a photoelectric converter, etc., to calculate the amount of movement of the lower correction pin 70 or the upper correction pin 71. Then, the amount of movement can be obtained by converting the amount of movement into the actual amount of deformation of the head base 5.

The left height correcting mechanism 53 has exactly the same mechanism and principle as the right height correcting mechanism 52, and is attached to the left base portion 82 side of the head base 5. Details here are omitted.

FIG. 11 shows a modification of the height correction mechanism. This mechanism is composed of a right correction pin 116, a left correction pin 117, a drive unit 118, an encoder 119, a coupling 120, a ball screw 121, a ball screw nut 122, a block 123, a lever 124, a rotation center pin 125, and a sensor 126. I have.

This mechanism differs from the height correction mechanism in that the right height R
H, the left height LH can be reduced, but not increased. However, the right driving height RH can be reduced, the left driving height LH can be reduced, and the height difference TH can be corrected by one driving source.

The operation will be described. When the correction start command and the plastic deformation amounts MGL, MRH, MLH are transmitted from the overall control device 17 to the correction mechanism control device 19, the driver rotates the drive section 118. When correcting the right base portion 81, the rotation of the driving portion 118 is transmitted to the ball screw 121 via the coupling 120.
When the ball screw 121 rotates, the ball screw nut 122 moves in the x direction toward the drive unit 118, and the block 123 attached to the ball screw nut 122 pushes the lower end of the lever 124- (a) via the calipers 126- (a). . The lever 124 (a) swings around the rotation center pin 125- (a),
The upper end of (a) pushes up the right correction pin 116 upward to plastically deform the head base 5 to correct the right height height RH and the height step TH.

Conversely, when correcting the left base portion 82, the driving portion 118 rotates in the opposite direction to the above, and the ball screw nut 122,
The block 123 moves in the direction away from the drive unit opposite to the above, and the lever 124- is moved via the calipers 126- (b).
By pushing the lower end of (b), the upper end is
And the head base 5 is plastically deformed to correct the left height LH and the height step TH.

At this time, the correction force is a force sensor when the right base unit 81 is corrected.
126- (a), and when the left base portion 82 is corrected, the force sensor 126- (b) detects it.

Further, the total deformation amount during the correction work can also be obtained by the visual mechanism 12, the rotation amount of the drive unit 118 is obtained by the encoder 119, and this is converted into the movement amount of the right correction pin 116 or the left correction pin 117. Or right correction pin 116 or left correction pin 1 directly by a photoelectric converter or the like.
For example, the movement amount of the head base 5 can be obtained by converting the movement amount of the head base 5 into the actual movement amount.

 Next, the control unit 19 will be described.

First, the correction control principle of the control part is shown in FIGS.
This will be described with reference to FIG.

The gap distance GL of the VTR head 1, the height difference TH,
The dimensions of the right height height RH and the left height height LH are corrected by plastically deforming the head base 5 to which the two head chips 6 are bonded as described above.

Generally, in a mechanical material, the relationship between stress σ and strain ε has a property close to that of FIG. That is, when the mechanical material is subjected to a stress corresponding to the elastic limit 83 even when distorted by applying a force, the mechanical material has such a property that when the force is removed, the strain returns to the original zero state.

Therefore, when it is desired to deform the mechanical material by the plastic deformation amount 84, it is necessary to apply a force exceeding the elastic limit 83 to the mechanical material to deform it to a total deformation amount of about 85.

Therefore, in the present invention, the amount of deformation during correction is measured,
The position reference method that performs correction in consideration of the relationship between the total deformation amount and the plastic deformation amount required in advance and the relationship between the force and the plastic deformation amount determined in advance by the material of the head base 5 are taken into consideration. The correction is performed using any one of three methods, a force reference method for performing correction and a position / force reference method for performing correction in consideration of correction force information in the position reference method. .

First, the principle of the position reference control will be described with reference to FIGS.

In performing the actual correction, not only the relationship between the total deformation amount (horizontal axis) in the correction direction (eg, plastic deformation in the height direction when correcting the right height) and the plastic deformation amount (vertical axis), but also the correction direction It is necessary to consider the relationship of the amount of plastic deformation that occurs slightly outside (eg, when correcting the right height, plastic deformation between gaps).

In the present invention, the pre-preliminary experiments, and the total deformation amount eR H of the right height shown in FIG. 13, plastic deformation of the right height FR ₁
(ERH) relationship, Fig. 13- (a), total deformation at right height
the relationship between eR H and the amount of plastic deformation FG ₂ (eR H) between the gap,
Figure 13 - (b), the relationship of the plastic deformation amount of the total deformation amount eR H and left height of the right height FL _{2 (eR} H), Fig. 13 - and (c),
FIG. 14 shows the relationship between the total deformation eL H of the left height and the plastic deformation FL ₁ (eL H) of the left height, FIG. 14- (a), the relationship between the total deformation eL H of the left height and the gap. Plastic deformation FG ₃ (e
LH), Fig. 14- (b), total deformation eL of left height
Relationship between H and plastic deformation FR ₂ (eL H) of right height, Fig. 14-
This is shown in (c) and FIG. Total deformation between gaps eGL
Relation plastic deformation FG _{1 (EGH)} the gap between, Fig. 15 - (a), the relationship of the total deformation amount eG L and right height of plastic deformation FR _{3 (EGH)} the gap, Figure 15 - (b), the plastic deformation amount eG L and the left height plastic deformation FL ₃ between the gaps _(eG
H) and FIG. 15- (c) are obtained and stored in the memory 19c shown in FIG. Then, the size of the gap distance GL, the height difference TH, the right height height RH, and the left height LH measured by the image processing device are transmitted to the overall control device 17. A pass / fail decision is made inside the overall control device 17, and for the head determined to be defective, a plastic deformation amount (correction amount) MGL, MRH, MLH is transmitted to the correction mechanism control device 19 together with a correction command. The correction mechanism control device 19 calculates the amount of plastic deformation MG L, MR H, ML
When H is transmitted, the correction mechanism 14 operates to obtain the plastic deformation amounts MG L, MR H, and ML H by reading the contents of the memory 19c and solving the equations 19 through 11 using the above relationship. The total deformation amount eGL, eRH, eLH that must be
In order to obtain the total deformation amounts eGL, eRH, and eLH, the drivers 54, 55, and 5 are sent to the drive units of the correction mechanisms 50, 51, 52, and 53, respectively.
In this method, power is supplied via 6, 57 to correct the dimensions.

Equation 9 ... MR H = FR ₁ (eR H) + FR ₂ (eL H) + FR ₃ (eGL) Equation 10 ... ML H = FL ₁ (eL H) + FL ₂ (eR H) + FL ₃ (eGL) Equation 11 _{... MG L = FG 1 (eG} L) + FG 2 (eR H) + FG 3 (eL H) MR H ... plastic deformation of the right height (correction amount) plastic deformation of ML H ... left height (correction amount) MG L ... plastic deformation between gaps (correction amount) eR H ... total deformation amount when correcting right height eL H ... total deformation amount when correcting left height eGL L ... total deformation amount when correcting between gaps F ... experiment (Figure 13 Figure 14 Figure 15
Next, the principle of force-based control will be described with reference to FIG.

The difference from the position reference control principle of this method is that, in the case of the position reference, the total deformation amount 85 (eRH, eLH, eGL) is obtained when the reference F (the relational expression obtained by experiment) in the above equation is used. The relationship between the amount of plastic deformation 84 was determined by experiment, and the amount of movement of each correction mechanism was calculated from this relational expression. On the other hand, in the case of the force standard, the stress-strain curve unique to the head base as shown in FIG. Is converted into a mathematical expression to determine the relationship between the correction force 94 and the amount of plastic deformation 84, and correction is performed based on this relationship.

Ideally, when a material having no yield point and a small plastic strain as shown in FIG. 16 is used, the amount of strain can be approximated by the following equation.

ε: Strain σ: Stress σe: Yield stress (proof stress) F: Plasticity coefficient E: Longitudinal elasticity coefficient n: Constant By solving Equation 12, the correction forces pGL, pRH, and pLH that are the target of the work are calculated. can do.

However, in reality, since there is a play component in the correction mechanism and a plastic region, a difference or variation between the theory and the actual one becomes large, and a highly accurate dimension correction operation cannot be performed.

Therefore, in the present invention, similarly to the position reference control, the correction force (pR
H, pL H, pGL) (horizontal axis) and the amount of plastic deformation (KR ₁ (pR H),
KR ₂ (pL H), KR ₃ (pGL), KL ₁ (pL H), KL ₂ (pR
_{H), KL 3 (pG L} ), KG 1 (pG L), KG 2 (pR H), KG 3 (p
LH)) (vertical axis) and the relationship (not shown) are experimentally determined, stored in FIG. 19c, and the amount of plastic deformation (correction) transmitted from the overall controller 17 (formula MG L, MR H , ML H) into the following equation to solve for the plastic deformation amount MG L, MR H,
Calculate the correction force pR H, pL H, pGL that the correction mechanism 14 must operate to obtain ML H, and calculate the correction force pR H, pL H,
In order to obtain pGL, power is supplied to the drive units of the correction mechanisms 50, 51, 52, 53 via the drivers 54, 55, 56, 57 to correct the dimensions.

Wherein _{13 ... MR H = KR 1 (} pR H) + KR 2 (pL H) + KR 3 (pG L) Formula _{14 ... ML H = KL 1 (} pL H) + KL 2 (pR H) + KL 3 (pG L) Equation 15 _{... MG L = KG 1 (pG} L), KG 2 (pR H) + KG 3 (pL H) pR H ... modify force at the time of the right height modified pL H ... modify force at the time of the left-height correction pG L ... when the correction between the gap Correcting force K: Relational expression obtained by experiment Next, the principle of position / force reference control will be described with reference to FIG.

This control principle utilizes a unique load-elongation curve 95 (stress-strain curve) of the material of the head base 5. Ideally, the plastic deformation can be performed with exactly the same accuracy using the load-elongation curve 95 regardless of the position-based control principle or the force-based control principle. However, in reality, the deformation exceeds the elastic limit 83 in the case of the deformation having the permanent residual strain. In practical use, the elasticity limit and the proportionality limit are almost the same, and it can be considered that up to the elasticity limit 83, Hooke's law is satisfied.

Equation 16: Hooke's law σ = Eε σ: stress ε: strain E: longitudinal elastic modulus However, in the case of a plastic region exceeding the elastic limit of 83, the above equation is used.
As described in 12, the equation itself becomes complicated, and each coefficient includes an error factor. Further, since the equation itself is an approximate equation, the plastic deformation Mδ varies even when the same total deformation eδ or the same correction force pF is applied.

As an example, when obtaining the plastic deformation Mδ shown in FIG. 17, the head base 5 may be deformed by the total deformation eδ from the load-elongation curve 95 in the case of the position reference. But load has been mentioned above the object - when the elongation curve actually was as dashed 99, plastic deformation amount becomes [delta] _1. In the case of the force reference, the head base 5 may be deformed until the correction force becomes pF. However the load of the object - when elongation curve is as shown by the broken line 99, plastic deformation is likely to become different from the plastic deformation Mδ goal becomes a [delta] _2.

Therefore, according to this principle, the hook constant of Equation 16 is satisfied up to the elastic limit 83, so that a proportional constant (slope α) up to the elastic limit 83 is obtained, and a slope 96 having the same slope α ′ is defined as the boundary of the end of the adjustment work. Used as a line. The inclined line 96 is a boundary for judging that the correcting operation is completed when the total deformation amount and the correcting force during the correcting operation become values on the right side of the inclined line 96 in the drawing.

Taking an actual operation as an example, given a target amount of plastic deformation Mδ, an inclination line 96 is obtained from the amount of plastic deformation Mδ.
Set. Even when the load-elongation curve of the product to be worked is a curve 99 shown by a broken line unlike the ideal curve 95, the correction work is performed with the total deformation amount eδ + Δδ and the correction force pF +
Continue until ΔF is to the right of the slope. This is because when the load-elongation curve of the product is different from the ideal curve 95, the total deformation amount during the correction work is corrected by Δδ and the correction force is corrected by ΔF, so that the load-elongation curve of the product is different from the ideal curve 95. , The same amount of plastic deformation Mδ can always be obtained. Therefore, highly accurate correction work is possible.

Also in this method, in the actual device, the play of the mechanism,
Considering factors such as the shape of the product, Equations 9 to 11, 13
18 (a), (b), (c),
For example, as shown in (d) and FIGS. 19 (a) and (b), it is necessary to consider the influence on the gap between the right heights and the left height. These FIGS. 18 and 19 need to be obtained by conducting experiments using the target product in advance.

The above position / force reference control principle is expressed by the following equation.

Wherein 17 ... mR H = MR H + FR 1 (mL H) + FR 2 (mG L) Formula 18 ... mL H = ML H + FL 1 (mR H) + FL 2 (mG L) Formula 19 ... mG L = MG L + FG 1 (mR H ) + FG ₂ (mL H) MR H: plastic deformation of right height (correction amount) ML H: plastic deformation of left height (correction amount) MG L: plastic deformation amount between gaps (correction amount) mR: plastic deformation amount of right height after correction mL… Plastic deformation amount after correction of left height mG… Plastic deformation amount after correction between gaps eR… Total deformation amount when correcting right height eL… Total deformation amount when correcting left height eG… Correction between gaps Total deformation amount at the time pR: Correction force at the time of right height correction pL ... Correction force at the time of left height correction pG: Correction force at the time of correction between gaps F: Relational expression obtained by experiment (Figs. 18, 19) Figure) Plastic deformation amount MG together with a correction command from the overall control unit 17
When L, MR H, ML H are transmitted to the correction mechanism control device 19, the plastic deformation amounts mG L, mR H,
Determine mL H.

Next, the correction work is started, and the total deformation amount eG L, e during the correction work
RH, eL H and the correction force pGL, pRH, pLH are measured, and
The work is completed by terminating the correction work when the expressions 20 to 22 hold.

Next, the correction processing procedure will be described with reference to the flowchart shown in FIG.

First, the distance GL between the gap, the height difference TH, the right height height RH, and the left height height LH of the VTR head 1 are obtained by the image processing device 18, and the data and the preset reference are set in the overall control device 17. The value is compared with the value to determine 104 whether or not a correction operation is necessary. If corrective action is needed, the type of inter-gap correction is determined 105.
(If it is not necessary to correct the gap, it is determined to be widened and the amount of plastic deformation is set to zero.) Next, the type of height correction is determined 106 (if height correction is not necessary, the right correction is determined and the amount of plastic deformation is set to zero), and the amount of plastic deformation MG is determined.
L, MR H, and ML H are transmitted to the correction mechanism control device 19. In the correction mechanism device 19, the total deformation amount eG L, e
RH, eL H, correction force pGL, pRH, pLH are calculated, and correction work 1
07 is performed, and the correction work 107 is performed while monitoring the deformation amount and the correction force at that time to be appropriate values.

When the correction work 107 is completed by the above procedure, the visual mechanism 12
And the gap distance GL,
Height difference TH, right height height RH and left height height L
The dimensions of H are measured, and the data is transmitted to the overall control device 17. It is determined whether or not the measured dimension falls within a range of a reference value input in advance in the overall control device 17, and in the case of rejection, a first correction result (a target plastic deformation amount, Using the difference in the amount of plastic deformation as a result of the correction and the difference between the target correction force and the amount of plastic deformation as a result of the correction), the variation in the correction caused by the dimensional difference of the object and the play positioning accuracy of the correction mechanism, etc. The correction principle is corrected 108 so as to be removed in the second correction work, and the second correction work is performed in the same manner as described above. As a result, high-precision dimensional work of the VTR head 1 can be performed.

There are three correction work principles: a position reference method, a force reference method, and a position / force reference method. In either method, there is a possibility that a target correction amount cannot be obtained by a relational expression obtained in advance by experiments due to a change in material of the base itself due to a difference in rod, abrasion of a correction jig, and the like. Therefore, in the present invention, by proceeding with the correction work, based on the correction result several times or several tens of times ago, so that the amount of plastic deformation is appropriate, the relational expression used for the correction principle is always corrected. .

Specifically, in the case of the position reference control principle, FIGS.
The relational expression between the total deformation (horizontal axis) and the plastic deformation (vertical axis) shown in Fig. 15 and Fig. 15 is constantly monitored to see if it is in accordance with the theory. The relational expression itself is corrected based on the correction result ten times before to prevent a reduction in correction accuracy due to a change in a target product and a correction jig (mechanism).

Similarly, in the case of the force-based control principle, the relational expression between the correction force and the amount of plastic deformation is corrected.

In the case of the position / force reference control principle, the inclination α ′ of the inclined line 96
By constantly correcting 97 from the actual correction result, the accuracy of correction is reduced.

〔The invention's effect〕

The present invention can inspect a gap distance, a height difference, a right height height, a left height height, and the like without replacing the VTR head, and can perform correction based on the inspection result. Since defects due to defective head dimensions can be efficiently corrected and the work can be automated, not only can the time for inspection and correction be reduced, but also the quality and yield can be improved by reducing the dimensional variation. Can be measured.

In addition, the configuration for correcting the gap distance can be simplified.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an entire dimension correcting device of a VTR head according to an embodiment of the present invention, FIG. 2 is a perspective view showing a mechanism of the correcting device shown in FIG. 1, and FIGS. b) is a perspective view showing a cylinder portion of the VTR to which the present invention is applied, and an enlarged perspective view of the VTR head. FIG. 4 is an enlarged front view showing a dimension measurement point of the VTR head shown in FIG. FIG. 5 is a principle diagram showing the principle of detecting the magnetic gap, FIG. 6 is a block diagram of the present invention, FIG. 7 is an enlarged front view of the gap widening mechanism, and FIG. 8 shows a modification of FIG. FIG. 9 is an enlarged front view of the gap narrowing mechanism, FIG. 10 is an enlarged front view of the height correcting mechanism, FIG. 11 is an enlarged front view showing a modification of FIG. 10, and FIG. 13 (a), 13 (b) and 13 (c) are empirical equations showing the relationship between the total deformation and the plastic deformation when correcting the right height. FIGS. 14 (a), (b), and (c) show empirical formulas showing the relationship between the total deformation and the plastic deformation when correcting the left height, and FIGS. 15 (a) and (b). , (C) is a diagram showing an empirical formula showing a relationship between a total deformation amount and a plastic deformation amount at the time of correction between gaps, FIG. 16 is a stress-strain diagram showing a relationship between a correction force and a permanent strain, and FIG. Is a force-elongation diagram showing the relationship between the correction force and the amount of plastic deformation and the relationship between the total amount of deformation and the amount of plastic deformation, and FIGS. 18 (a), (b),
(C) and (d) are empirical formulas showing the relationship between the amount of plastic deformation of the right height when correcting the right height and the gap, and the relationship between the amount of plastic deformation of the left height and the amount of plastic deformation when the left height is corrected. FIGS. 19 (a) and 19 (b) are diagrams showing empirical formulas showing the relationship between the amount of plastic deformation of the right height and the amount of plastic deformation between the right height and the left height when correcting the gap. FIG. 20 is a diagram showing an empirical formula showing the relationship, and FIG. 20 is a diagram showing a flowchart showing the procedure of the correction processing. DESCRIPTION OF SYMBOLS 1 ... VTR head, 5 ... Head base, 6 ... Head chip, 12 ... Visual mechanism, 14 ... Correction mechanism, 17 ... Overall control device, 18 ... Image processing device, 19 ... Correction mechanism control device, 27: magnetic gap, 83: elastic limit, 84: plastic deformation amount, 85: total deformation amount, 50: gap widening mechanism, 51 ...
… Gap narrowing mechanism, 52… Right height height correction mechanism,
53 …… Left height height correction mechanism

Claims (11)

(57) [Claims] A predetermined value of a head-to-head distance or a head-to-head level difference of a magnetic head provided with a pair of head chips; measuring a head-to-head distance or a head-to-head level difference of the magnetic head; The difference between the previously recorded predetermined value of the distance or the step between the heads and the measured value is calculated, and according to the difference value, the difference between the head distance or the step between the heads of the magnetic head is calculated as (difference value + elastic limit). And the force for plastically deforming the magnetic head by an amount corresponding to each difference value, and calculating the difference between the head distance between the magnetic heads or the step between the heads (difference value + deformation amount up to the elastic limit). The magnetic head is plastically deformed in accordance with the value of the magnetic head and the force for plastically deforming the magnetic head by the respective difference values. An inspection means for inspecting a head distance or a step between heads of a magnetic head provided with a pair of head chips; and modifying one of the head distance and the step between heads, the other is deformed. Therefore, storage means for storing the relationship between one correction amount and the other deformation amount, and the contents of the storage means are read out according to the inspection result of the inspection means, and the contents of the inspection result are read out from the storage means. When correcting any one of the head-to-head distance and the head-to-head step, the other deforms, so based on the relationship between the one correction amount and the other deformation amount, a calculating unit that calculates the deformation amount or the correction amount, Correction means for correcting the distance between the heads of the magnetic head and the dimension of the step between the heads based on a command from the calculation means. 3. The apparatus according to claim 2, wherein said inspection means measures a magnetic gap of said magnetic head, and inspects a head distance and a head step based on the measured magnetic gap. Item 3. The dimension correcting device for a magnetic head according to Item 2. 4. The inspection means comprises: a window forming means for forming a window parallel to the magnetic gap; and a secondary part for performing a second derivative in a window formed by the window forming means in a direction perpendicular to the magnetic gap. Differential processing means, and adding means for adding the secondary differential value processed by the secondary differential processing means in a direction parallel to the magnetic gap, wherein the magnetic gap is measured. 4. The apparatus for correcting the dimensions of a magnetic head according to claim 3, wherein: 5. A deformation amount or a correction force in consideration of a result measured by a measurement unit for measuring at least one of a correction force for correcting the distance between the magnetic heads and a step between the heads by the correction unit, and a movement amount. 3. The magnetic head dimensional correction device according to claim 2, wherein: 6. A comparing means for comparing the amount of deformation calculated by the calculating means with the correction result measured by the measuring means, and calculating based on the contents of the storage means based on the comparison result by the comparing means. 3. The magnetic head size correcting device according to claim 2, further comprising a correction unit configured to correct a deformation amount or a correction force to be applied. 7. A magnetic head formed by attaching and fixing a pair of head chips to an end of the pair of heads with an adhesive, at least a head-to-head distance and a head-to-head level difference are inspected.
When correcting at least one of the head-to-head distance and the head-to-head level difference, the other deforms. Therefore, the relationship between the correction amount of one and the deformation amount of the other is stored. The relationship between the deformation amounts is read, the deformation amount is calculated from the contents of the inspection result, the distance between the magnetic heads or the dimension of the step between the magnetic heads is corrected, and the corrected magnetic head is incorporated in the VTR body. VTR manufacturing method. 8. When performing the inspection, a window parallel to the magnetic gap is formed, and the inside of the window is secondarily differentiated in a direction perpendicular to the magnetic gap, and the secondary differential value is set in a direction parallel to the magnetic gap. 8. The VTR manufacturing method according to claim 7, wherein the distance between the magnetic heads and the step between the magnetic heads are detected by detecting the magnetic gap. 9. The VT according to claim 7, wherein after the dimension correction, at least one of a correction force and a moving amount for correcting a head-to-head distance and a head-to-head level difference is measured.
R manufacturing method. 10. A magnetic head, which is formed by attaching and fixing a pair of head chips to the tips of a pair of heads with an adhesive, is inspected, and is obtained and stored in advance based on the inspection result. The actual deformation is calculated from the relationship between the amount of deformation that the magnetic head permanently exceeds beyond the elastic limit and the apparent deformation required to correct the dimensions of the magnetic head, and the calculated amount of deformation is calculated. A method of manufacturing a VTR, comprising: modifying the dimensions of a magnetic head based on the method; and incorporating the modified magnetic head into a VTR body. 11. A displacement of a magnetic head, which is obtained by attaching and fixing a pair of head chips to the tips of a pair of heads with an adhesive, is inspected, and is obtained and stored in advance based on the inspection result. Calculate the apparent correction force required to correct the dimensions of the magnetic head based on the relationship between the amount of deformation that the magnetic head permanently exceeds beyond the elastic limit and the correction force required to correct the magnetic head. A method of correcting the dimensions of the magnetic head based on the calculated correction force, and incorporating the corrected magnetic head into a VTR body.