JPH0991638A - Rotary cylinder device and recording or reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary cylinder device capable of measuring inductance of a rotary transformer when the rotary cylinder assembled with a magnetic head and the rotary transformer is fed in. SOLUTION: When the rotary cylinder 4 assembled with the magnetic head 10 and a rotation side rotary transformer 7 on a prescribed position is assembled on a fixed cylinder 5 assembled with a fixed side rotary transformer 6, the inductance of the rotary transformers 6, 7 are measurable, and a gap between the fixed side rotary transformer 6 and the rotation side transformer 7 is set in based on the measured inductance. The rotation side rotary transformer 7 is connected to the magnetic head 10 separably through a relay terminal 11, and a conductive state between the magnetic head 10 and the rotation side rotary transformer 7 is set in from the outside.

Description

Detailed Description of the Invention TECHNICAL FIELD OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording or reproducing apparatus such as a video tape recorder (VTR), and more particularly to a rotary cylinder for recording or reproducing information on a magnetic tape pulled out from a cassette. It relates to the device.

[0002]

2. Description of the Related Art Conventionally, as a rotary cylinder device used for a VTR or the like, a rotary shaft is arranged at the center and the rotary shaft is arranged at the center of the rotary shaft, as disclosed in Japanese Unexamined Patent Publication No. 56-165926. It is known that bearings are provided by two ball bearings, and a motor for driving a cylinder to rotate is directly connected to a rotary shaft. In this apparatus, a rotary cylinder is arranged at the end opposite to the rotary shaft via a ball bearing, and a magnetic head is fixed to the rotary cylinder to drive the rotary drive.

In recent years, in order to downsize the cylinder device,
For example, as disclosed in Japanese Patent Application Laid-Open No. 2-9041, the central shaft is fixed to the fixed cylinder side, the rotary drive motor is arranged on the rotary cylinder side, and the rotary transformer for transmitting signals is arranged on the fixed cylinder side. As a result, a thin and compact cylinder device is provided. Also,
As another example, as disclosed in JP-A-6-231437, there is proposed a cylinder device in which a magnetic head and a rotary transformer are fixed to a rotary cylinder to reduce the number of parts.

Recently, so-called 8 mm VTR and digital V
In TRs and the like, further miniaturization of VTRs and narrowing of track pitches in magnetic tapes are progressing. Therefore, the track written on the magnetic tape is reduced to about 10 μm.
As shown in Japanese Patent Publication No. 9041-90, it is necessary to use a bearing with a shaft to maintain accuracy. In other words, 2 single bearings
In the case of a narrow track pitch of 10 μm as described above, the two bearings have to have a large gap between the center shaft and the single bearing, which makes it possible to reduce the size of the equipment. This is because it cannot be done.

By the way, conventionally, when the shaft alone is attached to the fixed cylinder, it is done by shrink fitting. That is, according to this method, the press-fitting hole is heated and expanded to be expanded,
It is possible to fix the shaft with high accuracy by cooling after inserting the shaft. On the other hand, in the case of bearings with shafts, they are mounted by a normal press-fitting method. Especially in a small cylinder device, in order to secure a press-fitting clearance, the temperature during shrink fitting is set to 1
It is necessary to raise the temperature to 00 ° C. or higher, but the bearing with a shaft may be damaged by such heating. Therefore, the normal press-fitting method is used as described above,
In this case, after press-fitting the bearing with shaft,
A fall of about 2 μm occurs. In order to correct this tilt, it is necessary to rework the tape running lead surface and the like with the central axis as a reference.

During press-fitting in the above-mentioned press-fitting method, the axial press-fitting position is brought out while the gap between the rotary side and the fixed side in the rotary transformer is driven to the set value. There are two methods for this method. The first method is to press-fit the rotary rotary transformer while measuring the inductance L of the fixed rotary transformer. Since the inductance L changes as the rotary rotary transformer approaches the fixed rotary transformer, press fitting is terminated when the inductance L reaches a predetermined value.
According to this method, the clearance of the rotary transformer is set from the electrical characteristics, which is data that is naturally necessary for the assembly configuration of the cylinder device, and it is desirable to set the inductance L in this way.

In the second method, the press-fitting amount is set by measuring the position of the facing surface forming the gap between the rotary side and the fixed side of the rotary transformer from the reference surface during press-fitting. Then, after press-fitting by a predetermined amount, the gap is mechanically set. At this time, the correlation between the amount of mechanical clearance and the electrical characteristics of the rotary transformer is measured in advance, and the amount of mechanical clearance is set from the range where the required electrical characteristics are obtained. With this method, it is difficult to mechanically check the gap after press fitting, and it is necessary to measure the inductance L of the rotary transformer as in the case of the first method described above.

[0008]

As described above, the magnetic head and the rotary rotary transformer are connected and fixed on the rotary cylinder, and the central shaft is press-fit into the magnetic head to set the gap between the rotary rotary transformer and the fixed rotary transformer. . However, since the inductance L _H of the magnetic head differs from the inductance L of the rotary transformer by 10 times or more, since the magnetic head and the rotary transformer are connected in advance, even if a change in the inductance is observed on the fixed side, It is influenced by the inductance L _H.

For this reason, the change in the inductance L on the rotary transformer side cannot be read, and the electrical characteristics cannot be confirmed. In this way, it is not possible to set the clearance of the rotary transformer by using the originally required electrical characteristics of the rotary transformer, and for example, mechanical dimensions are measured to determine the press-fitting amount and then press-fitting is performed. After that, it was difficult to confirm the gap amount and electrical characteristics.

In view of the above situation, the present invention provides a rotary cylinder device capable of measuring the inductance of the rotary transformer even when the magnetic head and the rotary transformer, which are already fixed to the rotary cylinder, are press-fitted. With the goal.

[0011]

In the rotary cylinder device according to the present invention, the rotary cylinder in which the magnetic head and the rotary rotary transformer are assembled in predetermined positions is a fixed cylinder in which the fixed rotary transformer is assembled in predetermined positions. When assembled in, the inductance of the rotary transformer is configured to be measurable, and the gap between the fixed rotary transformer and the rotary rotary transformer can be set based on the measured inductance.

Further, in the rotary cylinder device of the present invention, the magnetic head and the rotary rotary transformer assembled in the rotary cylinder are connected so that mutual conduction can be controlled to be turned on and off, and at least the rotary cylinder. Is assembled to the fixed cylinder, the magnetic head and the rotary rotary transformer become non-conductive.

Further, in the rotary cylinder device of the present invention, the rotary rotary transformer is detachably connected to the magnetic head via a relay terminal or a wiring substrate, and the magnetic head and the rotary rotary transformer are separated from each other. The conduction state can be set from the outside.

In the rotary cylinder device of the present invention, the cutout portion for accessing the relay terminal or the wiring board from the outside to set the conduction state of the magnetic head and the rotary rotary transformer is fixed. It is provided in the proper place on the cylinder.

[0015]

According to the present invention, in particular, the magnetic head and the rotary rotary transformer are preferably detachably connected via the relay terminal or the wiring board, and the conduction state of both is controlled at a desired stage of assembly. enable. Thereby, for example, when the rotary cylinder in which the magnetic head and the rotary rotary transformer are assembled at predetermined positions is assembled to the fixed cylinder, the electrical connection between the magnetic head and the rotary rotary transformer can be temporarily insulated. Therefore, when assembling the rotary cylinder and the fixed cylinder via the central axis, it becomes possible to measure the inductance of the rotary transformer in a state of being separated from the magnetic head, and based on this inductance, the fixed-side rotary transformer and the rotary-side rotary transformer can be measured. A proper gap between them can be set.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of a rotary cylinder device according to the present invention will be described below with reference to FIGS. Here, first, an example of the overall configuration of a recording or reproducing apparatus including the rotary cylinder device of the present invention will be described. 1 and 2
In the recording / reproducing apparatus 100, the cylinder apparatus 1
01 is provided. The cylinder device 101 is arranged at a predetermined position on the main chassis 102, while being slidable with respect to the main chassis 102 (see double arrow in FIG. 1).
A tape reel or the like is arranged on the slide chassis 103 configured as described above. That is, in this example, the main chassis 1
02 and the slide chassis 103 are separate structures, and the tape cassette 200 mounted on the slide chassis 103 (cassette mounting member) is moved back and forth with respect to the cylinder device 101 (the states shown in FIGS. 1 and 2 correspond to each other. ) Is a configuration.

Further, the recording or reproducing apparatus 100 includes a capstan 104, a capstan motor 105, a tape guide member 106 for pulling out a tape on the tape entry side of the cylinder device 101, and a tape for pulling out a tape on the tape exit side of the cylinder device 101. The tape guide member 107 and the like are provided.

As shown in FIG. 1, the tape loading operation of the recording / reproducing apparatus 100 is performed after the tape cassette 200 is mounted on the slide chassis 103 and then the tape guide members 106 and 107 are used to magnetically insert the tape cassette 200 from the opening 200a of the tape cassette 200. At the same time as the tape 201 is pulled out, the slide chassis 103 slides toward the cylinder device 101. Then, as shown in FIG.
The magnetic tape 201 is arranged in the cylinder device 101 by the tape guide members 106 and 107.
Wrapped around the circumference of. Thus, according to this recording / reproducing apparatus 100, recording / reproducing can be performed by causing the magnetic tape 201 to travel along a predetermined tape path.

Now, the detailed structure of the cylinder device 101 used in the recording or reproducing apparatus 100 according to the present invention outlined above will be described. FIG. 3 is a cross-sectional view of a cylinder device 101 according to an embodiment that best illustrates the features of the present invention. In the figure, 1 is a central axis, which is press-fitted and fixed in the center of the fixed cylinder 5. Reference numeral 2 is an outer ring that constitutes a vertically integrated housing that slidably holds the upper and lower balls 3 of the bearing. Reference numeral 4 denotes a rotary cylinder, in which the rotary rotary transformer 7 and the magnetic head 10 are fixed to predetermined positions via a head base 9 by adhesion and screwing. The head base 9 is fixed to the rotary cylinder 4 by screws 12. Reference numeral 5a is a lead portion for guiding the running of the magnetic tape.

Reference numeral 6 is a fixed-side rotary transformer, which is fixed cylinder 5 so as to face the rotary-side rotary transformer 7.
It is glued and fixed to. Reference numeral 8 is a connection terminal connected to a signal processing board (not shown), and 11 is a relay metal terminal for electrically connecting the rotary transformer 7 and the magnetic head 10.

The metal terminal 11 has its own elastic force,
It is elastically pressed against the conduction pattern portion provided on the head base 9. The winding of the rotary transformer 7 is electrically connected to the other end of the metal terminal 11, whereby the magnetic head 10 and the rotary transformer 7 are electrically connected. At the time of recording, a signal from a signal processing board (not shown) is transmitted to the rotary cylinder 4 side by the rotary transformers 6 and 7 via the connection terminal 8, and further supplied to the magnetic head 10 via the relay metal terminal 11. It Also, during reproduction, the magnetic head 10 to the relay metal terminal 11
A signal is sent to the rotary transformers 6 and 7 via, and a signal is sent via the connection terminal 8 during signal processing. In addition,
The height of the magnetic head 10 is adjusted by a bending screw 13.

Further, in the figure, 19 is a motor pedestal, and the drive motor is arranged on the motor pedestal 19 on the rotary cylinder 4 side. Reference numeral 14 denotes a rotor magnet, which is screwed and fixed to the rotary cylinder 4 via a rotor yoke 15. The drive coil 16 is fixed to a predetermined position on the flexible wiring board 20 so as to face the rotor magnet 14 and sandwich the flexible wiring board 20 between the stator yoke 18 and the spacer mold 17. The stator yoke 18 is fixed to the motor pedestal 19 with screws.

Reference numeral 21 denotes a mold thin plate. By inserting this thin plate 21 between the head base 9 and the relay metal terminal 11, the conduction between the magnetic head 10 and the rotary transformer 7 is interrupted. , Can create a non-conducting state. In this way, when the magnetic head 10 and the rotary transformer 7 are not electrically connected, the rotary transformer 6
Also, since the inductance seen from the fixed rotary transformer 6 side changes in response to the change in the gap of the rotary transformer 7, the gap can be set by measuring this inductance L.

Next, FIG. 4 shows a diagram before the press-fitting process of the central shaft 1 on the fixed cylinder 5 side. A hole 5b for press-fitting the central shaft 1 is provided at the center of the fixed cylinder 5, and a lead portion 5a for guiding the tape is provided on the outer tape running surface. The fixed-side rotary transformer 6 is adhesively fixed at a predetermined position, and the ends of the windings are soldered to the connection terminals 8. The connection terminal 8 projects from the inside of the cylinder to the outside at a notch 5c provided on the side of the fixed cylinder 5 opposite to the tape running surface.

FIG. 5 shows the structure of the rotary rotary transformer 7 and the metal terminal 11. The metal contact 11a of the metal terminal 11 has a mold base 11b for each channel.
Is insert molded against. The windings of the rotary transformer 7 adhered and fixed to predetermined positions of the rotary rotary transformer 7 are connected to the metal contact pieces 11a, respectively. The tip of the metal contact piece 11a has a bent portion on the outer peripheral side of the cylinder. Since the tip of the metal contact piece 11a is bent toward the outer peripheral side of the cylinder in this way, the thin plate 21 of the mold for blocking the contact between the connection pattern on the head base 9 and the metal contact piece 11a can be easily inserted and removed. It is composed.

FIG. 6 shows another configuration example of the metal terminal. The basic structure of the metal terminal 22 in this example is similar to that shown in FIG. 5, that is, the metal contact piece 22a is insert-molded into the mold base 22b. The metal contact piece 22 a is extended substantially along the circumferential direction of the rotary transformer 7 and is configured to project from the lateral side in the circumferential direction with respect to the head base 9. As a result, the length of the arm of the metal contact piece 22a can be increased, so that the contact pressure with the head base 9 can be effectively secured within the elastic deformation of the metal contact piece 22a. Also in this case, a bent portion is provided so that the tip of the metal contact piece 22a is bent toward the outer peripheral side of the cylinder, whereby the insulating mold thin plate 21 is provided between the connection pattern on the head base 9 and the metal contact piece 22a. (See FIG. 3) is easy to insert and remove.

Next, a process of assembling the rotary cylinder device 101 according to the first embodiment will be described. The outer ring 2 of the shaft bearing is fixed to the center of the rotary cylinder 4 at a predetermined height position by shrink fitting, press fitting, or bonding. Magnetic head 1
0 is fixed to a predetermined position of the rotary cylinder 4 by a screw 12 via the head base 9. As shown in FIG. 5 or 6, the rotary side rotary transformer 7 has a metal terminal 11
Alternatively, the metal terminal 22 is assembled. Then, the rotary transformer 7 is adhesively fixed to a predetermined position of the rotary cylinder 4.

In this case, a thin insulating plate 21 of the mold is sandwiched between the metal contact piece 11a or 22a of the metal terminal 11 or 22 and the set pattern on the head base 10.
Alternatively, after the rotary transformer 7 is adhesively fixed,
By sandwiching the insulating thin plate 21 of the mold, the connection between the magnetic head 10 and the rotary transformer 7 is released. Next, the rotary cylinder unit with a bearing assembled as described above is installed in the central hole 5b of the fixed cylinder 5 shown in FIG.
Assemble by pressing the central shaft 1 into. During this press-fitting, the gap can be set while measuring the inductance L of the rotary transformer 7 from the connection terminal 8.

Alternatively, the inductance L of the rotary transformer 7 can be measured after mechanically measuring the dimensions, calculating the gap mechanically, determining the press-fitting amount, and press-fitting. According to this method, it is possible to check the electrical characteristics, and it is possible to confirm whether or not the mechanical positioning has been completed.

After the press-fitting is completed and the inductance L of the rotary transformer 7 is checked, as shown in FIG. 4, the insulating cylinder 5 is insulated through the notch 5c provided on the side opposite to the tape running surface of the fixed cylinder 5. The thin plate 21 of the mold can be removed. By removing the thin plate 21 of the mold in this manner, it becomes possible to contact the magnetic head 9 and the rotary transformer 7 via the metal contact piece 11a or 22a, and it is possible to make them conductive.

FIG. 7 shows a second embodiment of the rotary cylinder device according to the present invention. FIG. 7 particularly shows a configuration example of the rotary transformer 7 in this embodiment.
In this example, the metal contact piece 11a or 22a as described above is used.
Unlike the case where the rotary transformer 7 and the magnetic head 10 are brought into contact with each other by the method described above, the magnetic head 10 and the rotary transformer 7 are previously connected via the flexible wiring board 23 and then fixed to the rotary cylinder 4. .

The rotary transformer 7 is fixed to the flexible wiring board 23 with an adhesive or an adhesive, and the winding is soldered to a predetermined land portion. A shaft bearing is fixed to the rotary cylinder 4, and the magnetic head 10 is attached to the head base 9
It is fixed by screws at a predetermined angle and height position via. Next, the connection land portion on the head base 9 is electrically connected to the land portion provided on the end portion of the flexible wiring board 23 on the side opposite to the rotary transformer 7 by soldering. On the pattern of the flexible wiring board 23, the flexible wiring board 2 is provided at the cut-off portion 23a.
Since the pattern 3 is partially cut, the magnetic head 10
And the rotary transformer 7 are not electrically connected.

In this state, the flexible wiring board 23 is bent and adhered and fixed to the rotary cylinder 4. Next, the rotary cylinder 4 is press-fitted into the fixed cylinder 5 shown in FIG. In this case, the connection terminal 8 to the rotary transformer 7
The gap can be set by measuring the change in the inductance L. Further, as another method, the inductance L of the rotary transformer 7 can be measured even when the dimensions are mechanically measured for each and the gap is mechanically calculated to determine the press-fitting amount and press-fit. Therefore, the electrical characteristics can be checked, and the mechanically positioned gap can be confirmed by measuring the inductance L.

After the press-fitting is completed and the inductance L of the rotary transformer 7 is confirmed, the cut-off portion 23a is formed through the cut-out portion 5c provided on the side opposite to the tape running surface of the fixed cylinder 5 shown in FIG. Can be conducted by soldering or the like.

[0035]

As described above, according to the present invention, when the magnetic head and the rotary transformer are fixed to the rotary cylinder, the magnetic head and the rotary transformer can be changed to the connection state or the non-connection state. This allows the connection state to be changed from the surface opposite to the tape running surface of the fixed cylinder even after the cylinder device is assembled, which allows the inductance of the rotary transformer to be measured. It is now possible to check the gap.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of the overall configuration of a recording or reproducing device equipped with a rotary cylinder device of the present invention.

FIG. 2 is a plan view showing an example of the overall configuration of a recording or reproducing apparatus equipped with the rotary drum device of the present invention.

FIG. 3 is a sectional view of the rotary cylinder device according to the first embodiment of the present invention.

FIG. 4 is a perspective view of a fixed cylinder according to the first embodiment of the present invention.

FIG. 5 is a perspective view of a rotary rotary transformer according to the first embodiment of the present invention.

FIG. 6 is a perspective view of a modified example of the rotary rotary transformer according to the first embodiment of the present invention.

FIG. 7 is a perspective view of a rotary cylinder and a rotary rotary transformer according to a second embodiment of the present invention.

[Explanation of symbols]

 1 center axis 2 outer ring 3 bearing balls 4 rotary cylinder 5 fixed cylinder 6 fixed side rotary transformer 7 rotary side rotary transformer 8 connection terminal 9 head base 10 magnetic head 11 metal terminal for relay 13 bending screw 14 rotor magnet 15 rotor yoke 16 drive Coil 17 Spacer mold 18 Stator yoke 19 Motor pedestal 20 Flexible wiring board 21 Thin plate 23 Flexible wiring board

Claims (5)

[Claims] 1. A rotary cylinder provided with a magnetic head at a predetermined position and a fixed cylinder for guiding and running a magnetic tape,
In a rotary cylinder device that is coaxially arranged via a central axis, the rotary cylinder in which the magnetic head and the rotary rotary transformer are assembled in a predetermined position is a fixed cylinder in which a fixed rotary transformer is assembled in a predetermined position. A rotary cylinder characterized in that when assembled, the inductance of the rotary transformer is configured to be measurable, and the gap between the fixed rotary transformer and the rotary rotary transformer can be set based on the measured inductance. apparatus. 2. The magnetic head and the rotary rotary transformer assembled to the rotary cylinder are connected so that mutual conduction can be controlled to be turned on and off, and at least the rotary cylinder is assembled to the fixed cylinder. At this time, the rotary cylinder device according to claim 1, wherein the magnetic head and the rotary rotary transformer are made non-conductive. 3. The rotary rotary transformer is detachably connected to the magnetic head via a relay terminal or a wiring board, and a conduction state of the magnetic head and the rotary rotary transformer can be set from the outside. The rotary cylinder device according to claim 2, wherein the rotary cylinder device is configured. 4. A cutout for accessing the relay terminal or the wiring board from the outside to set a conduction state of the magnetic head and the rotary rotary transformer is provided at an appropriate position of the fixed cylinder. The rotary cylinder device according to claim 3, wherein: 5. A rotary cylinder device according to any one of claims 1 to 4, which has a head for recording or reproducing information on a magnetic tape, and a cassette for accommodating the magnetic tape. A cassette mounting member that supports the cassette so that the cassette can move forward and backward with respect to the rotary cylinder device; and a tape guide member that pulls out the magnetic tape from the cassette and causes the magnetic tape to run along a predetermined tape path, A recording or reproducing apparatus comprising: