JPH0311018B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic sheet jacket for use in a so-called electronic camera, in which, for example, still image information is magnetically recorded on a magnetic sheet. The present invention relates to a rotary drive stand for rotationally driving a magnetic sheet in the magnetic sheet jacket when the electronic camera is mounted on the electronic camera or the like.

[Conventional technology]

2. Description of the Related Art Magnetic sheet jackets have been proposed in which a magnetic sheet for magnetically recording still images and the like is accommodated in a housing for convenience in handling and storage. This magnetic sheet jacket is used by being loaded into a recording/reproducing device such as a so-called electronic still camera.

In an electronic still camera that uses this magnetic sheet jacket as a recording medium, for example, the magnetic sheet of the magnetic sheet jacket is rotated at a constant speed by a drive shaft inside the camera, and a magnetic head provided on the camera side is brought into sliding contact with the magnetic sheet. The purpose is to magnetically record still image information concentrically on the magnetic sheet.

[Problem to be solved by the invention]

In a device that records still image information etc. by making relative sliding contact between a rotating magnetic sheet and a magnetic head as described above, in order to record still image information with good recording characteristics, It is necessary that the magnetic sheet and the magnetic head come into sliding contact reliably and accurately. Therefore, in a device such as the electronic still camera described above, when a magnetic sheet jacket is loaded, the signal recording surface of the magnetic sheet in the jacket and the reinforcing member provided at the center of rotation of the magnetic sheet are placed on top of each other. It is required that the receiving portion of the drive shaft of the rotary drive base be parallel to each other.

In addition, conventionally, the attachment of the magnetic sheet to the drive shaft was
This is done by magnetically attracting a reinforcing member having a magnetic material attached to the center of the magnetic sheet with a magnet disposed on the rotary drive table side, and when ejecting the magnetic sheet, the reinforcing member is pulled away from the magnet. The magnetic sheet is ejected from inside the device.

Therefore, the magnetic attraction force of the magnet attached to the rotary drive base is such that the magnetic sheet and drive shaft are reliably integrated when the magnetic sheet is rotated, and the magnetic sheet can be easily ejected when the magnetic sheet is ejected. It is desirable that this is set.

If the reinforcing member is directly attracted to the magnet of the rotary drive base, the drive shaft of the reinforcing member can be integrated with a large adsorption force, but the force at the time of separation is also extremely large. If the size of the magnetic sheet increases, there is a risk that the reinforcing member attached to the magnetic sheet may come off when the magnetic sheet is ejected.

In addition, in order to record and reproduce still image information with good recording and reproduction characteristics in electronic still cameras, etc., it is necessary to accurately and securely attach the magnetic sheet to the drive shaft, and to control the rotation of the magnetic sheet accurately. need to be done. Therefore, it is necessary to detect the rotation speed of the magnetic sheet and control it so that it can rotate at a constant speed. In the case of recording and reproducing devices such as electronic still cameras, they are used portable, so in order to achieve miniaturization of the device itself, the mechanism for detecting the rotational speed of the magnetic sheet is also made small. A simple configuration is also required.

Accordingly, the present invention enables accurate and reliable attachment of the magnetic sheet to the drive shaft, and facilitates detachment of the magnetic sheet from the drive shaft. This was proposed for the purpose of providing something that can accurately detect the rotation of a magnetic sheet with a simple configuration.

[Means to accomplish the task]

In order to achieve the above-mentioned objects, the present invention includes: a cradle having a protrusion for receiving a reinforcing member including a magnetic material provided at the center of a magnetic sheet; a central drive shaft; A magnet disposed at a position intermediate to the cradle and lower than the protrusion of the cradle, a rotation detection pin provided on the reinforcing member, and a rotation detection pin disposed at a position facing the magnet with the reinforcing member in between. Equipped with a rotation detector,
The magnetic sheet is attracted by the magnetic force of the magnet, and the rotation of the magnetic sheet is detected.

[Effect]

In the rotary drive stand according to the present invention, when a magnetic sheet is placed on the holder, a predetermined space is maintained between the magnet and the reinforcing member containing the magnetic material by the protrusion of the holder, and the magnetic sheet is attracted and held.

Furthermore, when the magnetic sheet is driven to rotate, a rotation detector detects the magnetic flux from the magnet transmitted through a rotation detection pin provided on the reinforcing member, thereby detecting the rotation of the magnetic sheet.

〔Example〕

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

First, the magnetic sheet jacket applied to the rotary drive base according to the present invention will be explained. This magnetic sheet jacket 1 is constructed as shown in FIGS. 1 to 4, and includes, for example, It is formed in a size that can fit into the palm of the hand, and a disc-shaped magnetic sheet 3 is rotatably housed in a jacket 2 formed by butting and joining two halves, an upper and a lower part, as shown in FIG. It consists of A magnetic head enters and slides into this magnetic sheet 3 through a window 4 opened in a part of the jacket 2, so that, for example, still image information forms a large number of concentric recording tracks. recorded.

A reinforcing member 6 is attached to the rotational center of the magnetic sheet 3 for receiving and holding the rotational drive shaft 5 of the magnetic recording/reproducing device. This reinforcing member 6 is made of synthetic resin and is formed into a disk shape or a plate shape.

A driving shaft insertion insertion hole 7 into which the rotational drive shaft 5 is inserted is formed through the reinforcing member 6 at approximately the center thereof, and as shown in FIG. , contacts the outer circumferential surface 5a of the drive shaft 5, and aligns the rotation center of the magnetic sheet 3 with the drive shaft 5.
Positioning surfaces 8, 8 are formed in a substantially V-shape for alignment with the axis of the. This positioning surface 8, 8
The center of rotation of the magnetic sheet 3 with respect to the rotation drive shaft 5 is determined using the reference . Further, at a position in the insertion hole 7 facing the positioning surfaces 8, 8, there is an elastic portion 9 for elastically pressing the drive shaft 5 against the positioning surfaces 8, 8, as shown in FIG. It is formed. The elastic portion 9 is formed by providing a long hole 10 on the side opposite to the pressing surface 9a that contacts the outer circumferential surface 5a of the drive shaft 5. The center part a of the pressing surface 9a and the magnetic sheet 3
The length of the straight line R' connecting the rotation center X with the rotation center X is set shorter than the length of the radius R of the drive shaft 5. Therefore, when the drive shaft 5 is inserted into the insertion hole 7, the outer circumferential surface 5a of the drive shaft 5 can be elastically pressed against the positioning surfaces 8, 8 by the pressing surface 9a of the elastic portion 9.

Further, an annular magnetic body 11 is integrally attached to the center side of the lower surface 6a of the reinforcing member 6. This magnetic body 11 is connected to a magnet 12 integrally provided around the drive shaft 5 as shown in FIG.
and are arranged in positions facing each other, and are attracted by the magnetic force of this magnet 12. Therefore, when the magnetic sheet 3 is attached to the drive shaft 5, it is integrated and rotationally driven.

Further, at a position facing the insertion hole 7 of the reinforcing member 6, there is a detection pin 13 formed of a magnetic material for detecting the rotational phase of the magnetic sheet 3, and a detection pin 13 having a weight similar to that of the detection pin 13. A balance non-magnetic pin 14 having a diameter is embedded therein. The detection pin 13 is used to detect whether or not the magnetic sheet 3 is rotating at a constant rotation speed using a detection coil 15 provided on the rotation locus of the pin 13. Specifically, each time the magnetic sheet 3 rotates and the detection pin 13 approaches the detection coil 15, the magnetic flux from the magnet 12 transmitted through the detection pin 13 is detected by the detection coil 15. As a result, a detection signal for detecting the rotational phase of the magnetic sheet 3 is output.

Next, on the lower surface 6a of the reinforcing member 6 outside the annular magnetic body 11, at least three locations (in this embodiment, three
Support portions 16, 16, 16 are provided in a protruding manner. The supporting parts 16, 16, 16 serve as mounting reference surfaces that regulate the mounting position so that the axial center of the drive shaft 5 and the signal recording surface 3a of the magnetic sheet 3 are accurately perpendicular to each other. . That is, when the magnetic sheet 3 is mounted on the drive shaft 5, the lower end surfaces 16a, 16a, 16 of each of these supporting parts 16, 16, 16
The signal recording surface 3a of the magnetic sheet 3 is brought into contact with the upper end surface of the protruding part 17a provided protrudingly on the upper end surface side of the cradle 17 that constitutes the rotary drive base integrally attached to the drive shaft 5. A horizontal state is ensured.

On the other hand, as shown in FIG. 8, between the innermost diameter part of the recording portion of the magnetic sheet 3 and the outer circumference of the reinforcing member 6, a large number of radial holes 17', 17'... ing. These radiation holes 17', 17'... are designed to prevent wrinkles from forming on the signal recording surface 3a of the magnetic sheet 3 due to the difference in thermal expansion coefficients between the reinforcing member 6 and the magnetic sheet 3, or to prevent the reinforcing member 6 from being connected to the drive shaft. This prevents the occurrence of wrinkles, unevenness, etc. on the signal recording surface 3a of the magnetic sheet 3 due to deformation that occurs when the magnetic sheet 3 is attached to the reinforcing member 6, deformation of the adhesive layer 18 for bonding the magnetic sheet 3 to the reinforcing member 6, etc. It was established for the purpose of

Furthermore, a display means 19 for displaying the number of annular tracks magnetically recorded on the magnetic sheet 3 is provided in a part of the jacket housing 2. As shown in FIG. 6, this display means 19 includes a disc-shaped dial display member 22 having a keyhole-shaped display hole 21, and a sawtooth-shaped rotating gear 23 provided integrally with this dial display member 22. The stopper member 24 includes an engaging portion 24a that elastically engages with the portion 23a. The dial display member 22 is housed in the jacket casing 2, and is rotatable at the position of an opening 25 formed in the casing 2. Further, the stopper member 24 is attached to the set screw 2 within the jacket housing 2.
6 and 26, and the rotating gear 2
3 rotates intermittently relative to the engaging portion 24a of the stopper member 24.

A scale 27 is provided around the opening 25 of the jacket 2 to display a number corresponding to the number of annular tracks magnetically recorded on the magnetic sheet 3. In this embodiment, a scale 27 from "1" to "50" is provided. A notch 28 formed in the display hole 21 indicates each position of the scale 27.

On the other hand, the jacket 2 has a sheet-like lid 2 for closing the window 4 formed in the jacket 2.
9 are arranged so as to be openable and closable. This lid body 29
This is to prevent dust and the like from entering the jacket 2 through the window portion 4, and in this embodiment, it is formed to have a U-shaped cross section so as to cover the upper and lower sides of the magnetic sheet 3.

Further, a locking pin 29a is fixed to one end of the one side edge of the lid body 29.
One end 30a of a coil spring 30 is locked to 9a. The other end 30b of this coil spring 30 is connected to a pin 3 fixed in the jacket 2.
1 is locked. This coil spring 30
A rotary pulley 33 is rotatably attached to a fixed shaft 32 near the middle of the coil spring 30 in order to improve the expansion and contraction state of the coil spring 30. Therefore, the lid body 29 is always urged rightward in FIG. 6 by the elastic force of the coil spring 30. Therefore, the window portion 4 is always completely closed by the lid body 29. A stopper part 34 is provided integrally with the jacket 2 at a position on the outer periphery of the window part 4 facing the locking pin 29a, so that the cover body 29 can be attached to the stopper in the position shown in FIG. Part 3
4, and movement to the right in the figure is prevented.

At both end portions of one end edge of the lid body 29, a housing 2 is provided.
Guide pieces 36, 36 are bent and guided by a protrusion 35 provided along one end edge. One of the guide pieces 36 , 36 is further formed with a protruding piece 37 , and this protruding piece 37 has a long groove 38 formed in a notch in one end edge of the housing 2 . It is inserted into the interior and is exposed to the outside through its long groove portion 38. The protruding piece 37 is
Jacket 2 inside the magnetic recording device or magnetic reproducing device
When loading the device, it engages with a lid opening protrusion 39 provided on the device side. Therefore, when the jacket housing 2 is forcibly pushed in the right direction in FIG. 6 with the protrusion 37 on the jacket housing 2 side pressed against the lid opening protrusion 39, the window portion 4 will open. The completely closed lid 29 moves along the protrusion 35 against the elastic force of the elastic member 30 to the position indicated by the two-dot chain line in FIG. The lid body 29 is opened so that a portion thereof is exposed.

As shown in FIG. 4, a breakable anti-erase claw 40 is provided on the back surface of the jacket housing 2 to prevent the recorded contents from being erased by mistake.

Next, when the magnetic sheet jacket configured as described above is attached to a magnetic recording/reproducing device,
The details of the rotary drive base according to the present invention that rotates the magnetic sheet inside this jacket will be explained.

This rotary drive stand is constructed as shown in FIG. 7, and has a rotary drive shaft 5 at its center, and a pedestal 17 formed in the shape of a table on the tip side of the drive shaft 5. It is integrally installed and configured. When the drive shaft 5 is inserted into the insertion hole 7 of the magnetic sheet 3, the reinforcing member 6 attached to the center of the magnetic sheet 3 is placed on the pedestal 17.

On the upper surface of the cradle 17 constituting the rotary drive table 1, there are supporting parts 16, 16,
A protrusion 17a supporting the support member 16 is formed in a protruding annular shape. The protruding portion 17a has a flat upper surface facing the supporting portions 16, 16, 16 so as to ensure the horizontal state of the magnetic sheet 3.

Further, as shown in FIG. 7, an annular magnet 12 is disposed between the protrusion 17a and the drive shaft 5 on the inner circumferential side so as to be at a position lower than the height of the protrusion 17a. has been done. This magnet 12 is disposed opposite to the magnetic body 11 attached to the reinforcing member 6 of the magnetic sheet 3, and by magnetically attracting the magnetic body 12, the magnet 12 is attached to the magnetic sheet 3. Platform 17
The integration into is achieved.

However, since the magnet 12 attached to this pedestal 17 is disposed at a lower position than the protrusion 17a, even when the magnetic sheet 3 is placed on this pedestal 17, the reinforcement of the magnetic sheet 3 is A slight gap is created between the member 6 and the magnetic body 11 attached thereto. This gap is for adjusting the magnetic attraction force of the magnet 12 to a favorable state. That is, this gap is achieved by providing a predetermined gap between the magnet 12 attached to the inner periphery of the protrusion 17a of the pedestal 17 and the magnetic body 11 attached to the reinforcing member 6 of the magnetic sheet 3. This is for adjusting the attraction and holding force of the magnetic sheet 3. By setting the magnetic attraction force of the magnet 12 in this manner, the magnetic sheet 3 and the pedestal 17 can be integrated when the magnetic sheet 3 is rotated, and the magnetic sheet 3
When discharging the magnetic sheet 3, the magnetic sheet 3 can be easily discharged.

Therefore, it becomes easy to select the magnet 12 to be attached to the rotary drive stand configured in this way.
Further, since the magnetic attraction force of the magnet 12 is set well, the magnetic sheet 3 and the reinforcing member 6 will not come off when the magnetic sheet 3 is ejected, and the magnetic sheet and the magnetic recording/reproducing device can be protected. Can be done.

In order to attach the magnetic sheet jacket described above to a magnetic recording and reproducing apparatus having a rotary drive base having the above configuration, first, the magnetic sheet jacket 1 is attached to a jacket holder (not shown) provided on the magnetic recording apparatus or the like. ). When the magnetic sheet jacket 1 is loaded into the jacket holder, the lid opening protrusion 39 (see FIG. 6) provided in the jacket holder causes the lid 29 to open against the elastic force of the elastic member 30. pushed out of section 4,
A portion of the signal recording surface 3a of the magnetic sheet 3 faces outward from the window portion 4. Next, when the jacket holder is loaded into a magnetic recording device or the like with the magnetic sheet jacket 1 loaded therein, the magnetic sheet 3 inside the jacket 2 passes through the center hole 41 formed in the center of the jacket 2. The rotation drive shaft 5 is inserted into the insertion hole 7 of the reinforcing member 6 provided at the center of rotation. Then, since the tip of the drive shaft 5 is formed into a conical shape, the drive shaft 5 is smoothly inserted into the insertion hole 7 along the conical surface. When the drive shaft 5 is inserted, the pressing surface 9a of the elastic part 9 elastically presses the outer peripheral surface 5a against the positioning surfaces 8, 8, so that the rotation center X of the magnetic sheet 3 is aligned with the axis of the drive shaft 5. In addition, since the drive shaft 5 is held between the positioning surfaces 8, 8 and the elastic portion 9, the magnetic sheet 3 can be held without wobbling. Further, on the lower surface 6a of the reinforcing member 6, there are provided supporting parts 16, 16, 16 that come into contact with the protruding part 17a of the pedestal 17 and support the entire magnetic sheet 3 at three points. The reinforcing member 6 can be placed on the stand 17 in an accurate positional relationship. Therefore, the magnetic sheet 3 can be mounted in such a manner that the signal recording surface 3a of the magnetic sheet 3 is exactly orthogonal to the axis of the drive shaft 5. Therefore, it is inserted from inside the window 4 of the jacket 2, and the magnetic sheet 3
The contact relationship between the signal recording surface 3a and the magnetic head that is in contact with the signal recording surface 3a can be set accurately, and magnetic recording or reproduction can be performed in a stable state.

Also, at this time, since the magnetic body 11 attached to the reinforcing member 6 of the magnetic sheet 3 is magnetically attracted by the magnet 12 disposed on the pedestal 17 side, the magnetic sheet 3 and the pedestal 17 are securely integrated. will be promoted.

Furthermore, in this embodiment, a synthetic resin that is the same as or close to the thermal expansion coefficient of the base material of the magnetic sheet 3 is used as the material for forming the reinforcing member 6, and signals are recorded under the influence of temperature changes of the reinforcing member 6. Surface 3a
Since wrinkles, etc. are prevented from forming, together with the formation of the radiation holes 17', 17'... or 17a', 17a'..., it is possible to prevent wrinkles, etc. from forming in those areas. Therefore, the contact characteristics between the magnetic head and the magnetic sheet can always be made stable.

Next, when the drive shaft 5 is rotated while the magnetic head provided on the side of the magnetic recording device is in contact with the signal recording surface 3a of the magnetic sheet 3, the signal recording surface 3a of the magnetic sheet 3 is rotated. Since the magnet 12 provided on the pedestal 17 side and the magnetic body 11 provided on the magnetic sheet 3 side are integrally attracted and coupled by magnetic force, the magnetic sheet 3 is precisely connected to the drive shaft 5. Rotate and drive in synchronization.

On the other hand, since a magnet 12 is integrally attached to the drive shaft 5 side, this magnet 1
2 is also rotationally driven in the same direction as the drive shaft 5. At this time, the magnetic flux from the magnet 12 is led out to the detection pin 13 made of a magnetic material and provided on the reinforcing member 66 made of synthetic resin. The rotation of the magnetic sheet 3 is detected by detecting the magnetic flux led out to the detection pin 13 by a detection coil 15 forming a rotation detector disposed at a position facing the magnet 12.
That is, each rotation of the magnetic sheet 3 causes the detection pin 13 from which the magnetic flux from the magnet 12 is derived to move closer to and away from the detection coil 15, so that the detection coil 15 has a predetermined effect due to the action of the magnetic flux. A pulsed position detection signal is generated.
In this way, each time the drive shaft 5 is driven one rotation, a pulse-like signal is periodically obtained in the detection coil 15 corresponding to the rotational speed of the drive shaft 5, so this periodic signal is used as a reference. By controlling the rotation of the drive shaft 5 as follows, the rotation speed of the magnetic sheet 3 can be controlled. In addition, the magnetic material 11
The magnet 12 itself that magnetically attracts the magnetic field also serves as a magnetic flux generating magnet for forming a magnetic field that generates a predetermined signal in the detection coil 15. The rotational position of the seat 3 can be detected.

Further, when the drive shaft 5 rotates at high speed and the magnetic sheet 3 also rotates in the same direction, for example, still image information is recorded so as to form an annular recording track at the innermost or outermost bottom surface position of the signal recording surface 3a. Magnetic recording is performed on that part. Immediately after one rotation of the magnetic sheet 3 is completed, the magnetic head is automatically sent to the position next to the recorded track by the magnetic head feeding mechanism, and the dial display member 22 provided on the jacket housing 2 is displayed on the magnetic recording device, etc. The scale 27 is rotated by a rotating pin (not shown) provided on the side of the scale 27.
indicates the "1" position. Therefore, the current number of recorded tracks can be reliably confirmed with the naked eye using the dial display means 19.

Next, from the innermost or outermost circumference of the magnetic sheet 3,
While rotating the magnetic sheet 3 at high speed, required information is magnetically recorded at the position of the second magnetic track by a magnetic head. In this way, the magnetic head is deflected in the radial direction of the magnetic sheet 3 at a predetermined position on the magnetic sheet 3, and predetermined information is magnetically recorded at the moved position so as to form an annular magnetic track.

Finally, when the magnetic sheet jacket 1 is ejected from the magnetic recording/reproducing apparatus, it is ejected by a reverse operation to the above-described mounting operation of the jacket 1. In this case, the magnetic force of the magnetic sheet 3 is Since it is adjusted by
This does not interfere with the ejection of the magnetic sheet 3.

〔Effect of the invention〕

As is clear from the above explanation, in the rotary drive stand according to the present invention, a gap can be provided between the magnet attached to the cradle and the magnetic body attached to the reinforcing member of the magnetic sheet. This prevents adsorption with the magnetic material on the side.
The separation operation of the magnetic sheet and the reinforcing member when the magnetic sheet is ejected becomes easy, and the magnetic sheet and the magnetic recording/reproducing device can be protected. Further, by adjusting the gap, the attraction and holding force of the magnetic sheet by the magnet can be easily adjusted.

In addition, since the rotation of the magnetic sheet can be detected using the magnetic flux of the magnet that attracts and holds the magnetic sheet, the magnetic sheet rotation detection mechanism can be simplified, making it possible to use a portable electronic still camera. By applying the present invention to devices such as the above, it is possible to further reduce the size and weight of the camera.

[Brief explanation of the drawing]

1 to 6 show magnetic sheet jackets applied to the present invention, in which FIG. 1 is a plan view of the magnetic sheet jacket, FIG. 2 is a back view of the magnetic sheet jacket, and FIG. 3 is a back view of the magnetic sheet jacket. A front view of the magnetic sheet jacket, FIG. 4 is a bottom view of the magnetic sheet jacket,
FIG. 5 is an enlarged sectional view showing a state across the magnetic sheet jacket, and FIG. 6 is an enlarged bottom view showing the inside of the magnetic sheet jacket. FIG. 7 is an enlarged cross-sectional view of the main part showing a state in which a magnetic sheet jacket is attached to the rotary drive base according to the present invention, and FIG. 8 is an enlarged bottom view showing the vicinity of the reinforcing member provided at the center of the magnetic sheet. It is. 1... Magnetic sheet jacket, 2... Jacket housing, 3... Magnetic sheet, 4... Window, 5...
Drive shaft, 6... Reinforcement member, 6a... Lower surface of reinforcing member, 13... Detection pin, 15... Detection coil, 1
6, 16, 16...support part, 17...cradle, 1
7a... Protrusion.

Claims (1)

[Scope of Claims] 1. A pedestal having a protrusion for receiving a reinforcing member containing a magnetic material provided at the center of a magnetic sheet, a central drive shaft, and an intermediate portion between the central drive shaft and the pedestal. a magnet disposed at a position lower than the protrusion of the pedestal; a rotation detection pin disposed on the reinforcing member; and a rotation detector disposed at a position facing the magnet with the reinforcing member interposed therebetween; A rotary drive stand that attracts a magnetic sheet by the magnetic force of the magnet and detects rotation of the magnetic sheet.