JPS6280879A - Feeding drive cam - Google Patents

Abstract

PURPOSE:To improve the manufacturing performance, productivity and accuracy of a cam by fixing a reinforcing plate nearly similar to a cam plate and having a smaller diameter than that of the cam plate to both faces of the thin cam plate with a prescribed shape respectively. CONSTITUTION:It is required to form the cam 53 for the shape with high accuracy to attain highly accurate feed drive. In order to form a cam plate 153 specifying the shape of the cam 53 into a thin plate, the plate is manufactured with high accuracy by discharge processing, laser processing or etching processing. Then the reinforcing plates 154, 155 having a slightly smaller diameter than that of the cam plate 163 and formed nearly similarly clip the cam plate 153 from both the faces. Thus, although the circumferential ridge of the cam plate 153 pressed into contact onto a cam follower 45 is provided with sufficient rigidity to attain a prescribed feeding drive while being pressed into contact with the cam follower 45 regardless of the thin plate. Thus, the productivity and accuracy are improved in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a feeding drive cam, and is suitable for use in feeding a magnetic head of a rotating magnetic sheet device in an electronic still camera system or the like.

Conventional technology> An electronic still camera system that combines an imaging device using a solid-state image sensor or an image pickup tube and a rotating magnetic sheet device as a recording and reproducing device using a magnetic sheet as a recording medium electronically captures the subject. Still images are taken and recorded on a rotating magnetic sheet, and the image information recorded on the magnetic sheet is reproduced by a television, printer, etc. The magnetic sheet used in the rotating magnetic sheet device of such an electronic still camera system is rotatably housed in a casing, and is generally used in the form of a magnetic sheet pack called a video floppy.

This magnetic sheet has a diameter of about 508, about lOOμm
High-density recording is performed on about 50 tracks in the radial direction at intervals of .

Several types of feed drive devices have been considered for positioning the magnetic head in the radial direction of the magnetic sheet, and among them, one uses a cam. This is for high-precision cams whose cam lift changes depending on the rotation angle position.
The magnetic head is positioned via the cam follower by bringing the cam follower installed on the carriage carrying the magnetic head into contact with the cam and rotating the cam with a stepping motor, resulting in lower costs and smaller compaction. It is suitable for use in a rotating mountain seat device for an electronic still camera with 7 stems. , 1 <Problems to be Solved by the Invention> As mentioned above, extremely high precision is required of the cam used to drive the magnetic head. Means that can perform precision machining and L7 include electrical discharge machining, laser machining,
Etching processing and the like are known, but with all of these methods, the processing accuracy decreases as the thickness of the workpiece increases. However, since the plate thickness of the above-mentioned cam cannot be made much thinner than the above-mentioned cam, it is difficult to obtain sufficient machining accuracy in the plate thickness direction even with the above-mentioned precision machining means. Manufacturability and productivity were extremely low in order to obtain the desired accuracy.

The present invention has been made in view of the above-mentioned conventional circumstances, and an object of the present invention is to provide a feed drive cam that is highly manufacturable, highly productive, and highly accurate.

<Means for Solving the Problems> The feed drive cam of the present invention has a thin cam plate with a predetermined shape, and reinforcements each having a diameter smaller than the cam plate and having a substantially similar shape to the cam plate are provided on both sides of the thin cam plate. The plate is fixed with the periphery of the cam plate slightly protruding from the periphery of the reinforcing plate.

Function: The thin cam plate, which can be easily machined with high precision, lacks the strength to function as a cam by itself, but since it is supported by being sandwiched between reinforcing plates very close to its periphery, this The peripheral edge is given sufficient strength for practical use.

<Embodiment> An embodiment in which the present invention is applied to a magnetic head feeding drive device of a rotating magnetic sheet device in an electronic still camera system will be described below.

FIG. 1f is a schematic perspective view of the electronic camera body and magnetic notebook pack according to this embodiment.

As shown in FIG. The information is recorded on the magnetic sheet 13 in the polishing sheet/kunk 11 loaded from there. Also, 15 is a finder, 1
7 (is the finder optical system, 19 is the Stro DS, 21
23 is a battery.

FIG. 12 is a perspective view of the rotating magnetic sheet device 7 shown together with the magnetic sheet/pack 11, and FIG. 13 is an exploded perspective view of four parts thereof. As shown in FIGS. 12 and 13, a spindle motor 27 for rotationally driving the magnetic sheet 13 is fixed approximately at the center of the roller 725. As shown in FIGS. A magnet 31 for attaching the center core 29 of the magnetic sheet 13 is provided on the rotating shaft of the spindle motor 27, and when the center core 29 is pressed against the magnet 31 by the center core pushing member Ill, which will be described later, the magnetic 7- ) 13 is fixed to the rotating shaft of a spindle motor 27.

In addition, on the 7-year 725, a caliper 35 equipped with a magnetic head 33 next to the spindle motor 27 is slidably supported in the radial direction of the magnetic sheet 13 attached to the spindle motor 27. It is biased toward the center of the motor 27. That is, a guide/gift 39 is fixed to one end of the carriage 35, and it is attached to the seven yarns 25 with an oil renu metal bearing 41.
While the other end of the claw 35 is fitted into a guide groove 43 formed in the seven yarns 25, its rotation is prevented. The carriage 35 also has an arm 47 with a cam follower 45 pivoted at its tip.
is movably attached by a pin 49 (b), and the arm 47 is urged by a torsion coil spring 51 and normally comes into contact with the caliper 35 via a stopper (not shown) to integrate the caliper 35. There is. This cam follower 45 has a cam 53 that is pivotally supported by a roller 725.
is pressed against the cam surface by the spring force of the tension spring 37. A cam gear 55 is coaxially fixed to the cam 53, and as shown in FIG.
A pinion 61 fixed to a rotating shaft of a stepping motor 59 is in mesh with the rotating shaft of a stepping motor 59 fixed thereto.

Therefore, when the nutetting motor 59 is driven to rotate, the cam 53 rotates at a reduced speed, and the carino 35 moves in the radial direction of the magnet 7-) 13 via the cam follower 45 depending on the shape of the cam surface.

FIG. 1 is a sectional view showing the structure of the cam 53. As shown in FIG. 1, the cam 53 has a plate thickness of, for example, 20 μm to 5 Qt.
It consists of a pole (light cam gray) 153 that is about 1 m thick and sandwiched between a pair of reinforcing plates 154 and 155 from both sides. ; f Since the reinforcing plates 154 and 155 are installed in a slightly smaller diameter and approximately similar shape to the cam gray) 153, the peripheral edge of the cam plate 153 is slightly smaller than the periphery of the reinforcing plates 154 and 155. (This causes the cam relay to come into contact with the cam follower 45)
Although the peripheral edge of 153 is thin plate-like, the cam follower 4
Sufficient rigidity is provided to achieve a predetermined feed 9 drive by contacting with 5.

The cam 53 must be formed into the shape described below with extremely high precision in order to achieve the specified feed and drive with an extremely high sheath resistance.The cam plate 153 that defines the shape of the cam 53 is formed as described above. Since it is in the form of a thin plate, it is manufactured into a predetermined shape with extremely high precision using well-known means for achieving precision machining, such as electric discharge machining, laser machining, and diagonal machining. Here, since the machinability t of the peripheral edge of the cam plate 153 changes depending on the amount of protrusion from the reinforcing plates 154 and 155, it is necessary to position and fix the cam plate 153 and the reinforcing plates 154 and 355 to each other with high precision. There is something left. Therefore, in the one shown in FIG. 1, the cam plate 153 and the reinforcing plate 1
A dowel pin 157 is inserted into a positioning hole 156 pre-drilled in 54, 154 to position the cam plate 153 and reinforcing plate 154, 155, and a large number of screws 1
58, the cam plate 153 and reinforcing plates 154, 155
and are fixed together. Note that 159 in FIG. 1 is a support shaft fitted to the center of rotation of the cam 53, and this support shaft 159 is pivotally supported by the wheel 725 via a bearing 160.

The cam plate 153 and the reinforcing plates 154 and 155 may be bonded together with an adhesive. In this case, as shown in FIG. It is preferable to increase the area. In addition, in order to obtain greater rigidity, it is sufficient to use a plurality of cam plates 153 stacked one on top of the other. In this case, in order to position the cam plates 153L7E with high accuracy, the cam plates 153 should be stacked one on top of the other as shown in FIG. Opposing recesses 162 may be provided and the space formed between these recesses 162 may be completely filled with adhesive 163, or the recesses 162 may be used as through holes 164 and these through holes 164 may be filled with adhesive L 63. and cured adhesive 163
11 to the circumferential direction of the cam plate 153 t'L?
It would be clever to try to prevent it. In addition, cam plate 1
Of course, the dowel pins 157 may be used to position the cam plates 15 to each other, and in this case, the dowel pins 157
In addition to penetrating the cam plates 165 through 3, as shown in FIG. A knock screw I57 provided on the upper reinforcing plate 154 is provided on the top uneven portion 165. At the same time as fitting, the bottom step (D uneven part 1
65 is provided on the reinforcement f155 of F i, ii f, , -Q
The cam plate 153 may be fitted with the cam plate 153 as shown in FIG.
A spacer 167 having a small diameter and a similar shape to the cam plate 153 may be inserted between each cam plate 153. In this way, the contact range of the cam follower 45 is expanded with a small number of cam plates 153, and the cam 7 follower 45 And the durability of the cam 53 can be improved. In addition, the cam plate 153
When assembling the reinforcing plates 154 and 155, as shown in FIG.
The assembly work will be extremely facilitated if it is fixed to the base.

In this case, the reinforcing plates 154, 155 are provided with recesses 154a, 155a in the center of their inner surfaces.
By sandwiching the cam plate 153 at the peripheral edge of the cam plate 153, the clamping force of the reinforcing plate 155 at the center can be effectively applied to the circumferential edge of the cam plate 153. The reinforcing effect can be improved.

FIG. 8 is a diagram illustrating an example of the shape of the cam 53, that is, the cam plate 153, FIG. 9 is a diagram illustrating another example of the shape of the cam plate 153, and FIG. 1θ is an enlarged back view of the cam portion. First, the cam plate 153 shown in FIG.
The cam lift diagram in Fig. 8 (as shown by the duck), there is a gentle slope area 153a in which the cam lift amount gradually changes in one direction over the range of rotation angles 0 to 250, and a gentle slope area 153a where the cam lift amount is smaller than 153a. Rotation angle range 250-350
It has a steeply inclined region 153b where the same amount of cam lift can be obtained as a gently inclined region 153a, and a rotation angle of 350 to 0.
The range is the connecting portion 153C. As shown in the partial enlarged view of the cam lift diagram (c) K, in the gently inclined region 153a, the cam lift changes approximately linearly according to changes in the rotation angle, and in the steeply inclined region 153b, the cam lift changes at predetermined rotation angle intervals. The amount changes in steps by a predetermined amount. These cam lift amounts correspond to the amount of movement of the carriage 35 via the cam follower 45 and the amount of movement of the magnetic head 33, and their maximum value is 5 points for 50 tracks. Further, in the steeply inclined region 153b, the angle changes stepwise by 100 μm, which corresponds to one track, for every 2 rotation angles of the cam 530.

On the other hand, as shown in FIG. 10, a slit 55a is opened in a part of the cam gear 55, and a photo sensor 63 that detects this slit 55a when the cam follower 45 is at the connecting portion 153 (!) It is fixed to 25.

This cam 53 is used to feed and drive the magnetic head 33, and at the time of reproduction, the gently inclined area 153a of the cam plate 153 is used.
is used, while the steep slope area 153b is used during recording.
is used. In other words, when using it, first
Using the output of the photosensor 63 as shown in (a) in the figure, the cam follower 45 is positioned at the connecting portion 153c located between the gently sloped area 1saa and the steeply sloped area 153b. During reproduction, the cam 7 follower 45 is engaged with the gently sloped area 153a to position the magnetic head 33, while during recording, the cam 53 is driven in the opposite direction to engage the cam follower 45 with the steeply sloped area 153b. Match. In addition, in this embodiment, the steppinder motor 59 has 6 l steps.
The number of teeth of the cam gear 55 and pinion 61 is 120.
and lO, one step of the stepper motor 59 rotates the cam 53 by 30'. Therefore, the gentle slope area 1
The angular range 250 of 53a and the angular range 100 of steep slope region 153b are respectively
corresponds to 500 steps and 200 steps, and 100
A cam lift of 1m will be given by 10 teg, 47 teg each.

Next, in the example shown in FIG.
A q# oblique area 153d where the cam lift a gradually changes in one direction as shown in the cam lift diagram (b) in the figure;
Rotation angle range 300 smaller than the gentle slope area 153d
-360, it has a gentle slope area 153d and a steep slope area 153e where the same amount of cam lift is obtained. In this example, in the steep slope area 153e, the cam lift changes approximately linearly according to the change in rotation angle, and in the gentle slope area 153d.
Now, as shown in the partial enlarged view of the cam lift diagram (cl), the cam lift changes stepwise in a predetermined manner at predetermined rotation angle intervals, that is, in steps of l100a, which corresponds to one track in 12 steps of the stepping motor 59. As shown in the enlarged view (c) above,
] The feed for a track (12 steps) is a pattern in which the cam lift m is set to zero for each step at the starting end and the end, and the 10 step in between is 10 μm/step, achieving a feed of 100 μm in 12 steps. However, this pattern can be modified in various other ways, for example, as shown in (C') in the same figure, the pattern is 7.5 μm.
/ Steg for 4 steps and 2 sets of Uno l turns and 20
It is also possible to combine a pattern of two steps of μm/step to create nine turns with a change in feed rate, thereby achieving highly accurate positioning and shortening the access time between tracks.

The cam 53 having the shape shown in FIG.
The gently sloped area 153d of the cam plate 153 is used, while the steeply sloped area 153e of the cam plate 153 is used when returning to the origin. That is, in its use, the cam follower 45 is engaged with the gently sloped area 153d during recording or reproduction, and recording or reproduction is performed at each step portion (the above-mentioned portion where the cam lift amount is zero), while the cam follower 45 is suddenly engaged when returning to the origin. By engaging the inclined region 1536, a quick return to the origin is performed.

In the rotating magnetic sheet device 7 according to this embodiment, as shown in FIGS. 12 and 13, a loading motor 65 is fixedly installed on a wheel 725 on the opposite side of the stepping motor 59 with the spindle motor 27 in between. This loading motor 65 rotationally drives a control shaft 67 supported by a shaft 725 via a reduction gear unit 69 . Furthermore, first and second encoders 70.71 are provided which rotate in conjunction with the control shaft 67, and photo sensors 73.75 are provided corresponding to their xy=+-/70, 71K, respectively. This makes it possible to detect the rotational position of the control shaft 67.

Left and right side plates 7 on the left and right walls of the Nya 725
7.79 is fixed. As shown in FIG. 15, which is a perspective view of the left and right side plates 77 and 79, the left side plate 77 has a holder guide 77a that guides a left holder 81, which will be described later, in the vertical direction (in a direction parallel to the rotation axis of the spindle motor 27). Support I in the longitudinal force direction (the insertion/extraction force direction of the magnetic sheet link 11) that slidably supports the end of the door opening/closing control pin 91e, which will be described later. 477b is bored, and a guide pin 77c for supporting the left control plate 91, which will be described later, is provided on the outer surface of the hole 477b.
[Setting up. - The right side plate 79 is provided with an L-shaped holder guide groove 79a that guides a right holder 83 (described later) in the vertical and longitudinal directions, and a right control plate 93 (described later) is formed on the outer surface of the right side plate 79.
A guide pin 79b is implanted to support the.

Left and right holders 81 and 83 are attached to the insides of the left and right side plates 77 and 79, respectively.

As shown in FIG. 8, which is a perspective view of the left and right holders 81.83, the left and right holders 81.83 are magnetically attached to the tonneau 11.
The left and right side ends of the left and right side ends fit together to form a U-shaped cross section, and a pair of guide shafts sta implanted on the outer surface of the left holder 81 are attached to the holder guide @ of the left side plate 77.
By slidingly fitting into the left holder 8 and 77 and
1 is supported by the left side plate 77 so as to be vertically movable. On the other hand, the right holder 83 has a guide shaft 83a implanted on its outer surface.
The tiles 79 are slidably fitted into the holder guide grooves 79a of the right side plate 79, respectively.
It is supported so that it can be moved up and down and back and forth along the line a. In addition, the left and right holders 81 and 83 are respectively formed with spring-like pack holding portions 81b and 83b that push out and hold the magnetic cartridge knob 11 when it is inserted. A knock detection switch 85 that detects when the magnetic sheet pack 11 is inserted into the holder 83, an opening/closing mechanism (not shown) that opens and closes the window 87 of the magnetic sheet pack 11, and a knock pushing mechanism 89 are provided. .

Left and right control plates 91 are provided on the outside of the left and right side plates 77 and 79, respectively.
．． 93 is installed. As shown in FIG. 17, which is a perspective view of the left and right control plates 91 and 93, the guide pins 77c of the left side plate 77 described above are attached to the left control plate 91, respectively.
A guide groove 91a into which the guide groove 91a can be freely fitted is formed, and the guide bin 77c is fitted into the guide groove 91a, so that the left control plate 91 is supported by the left side plate 77 so as to be slidable in the front-rear force direction. Also,
A rack 91b is formed at a part of the lower end of the left control board 91, and the rack 91b is connected to the control shaft 67.
The left control plate 9 is engaged with a pinion 95 fixed to the left control plate 9 by operation of the loading motor 65.
1 is designed to be driven in the front-back direction. Further, the left control plate 91 is formed with one guide groove 91 & a can tilt guide circular groove 91c, which is connected to the left holder 81.
One of the guide shafts 81a passes through the holder guide groove 77a of the left side plate 77, and is fitted into the inclined guide #91c via the roller 81C. Holder 81 is holder guide #
It moves up and down along 77a. Furthermore, the left control board 91
has a sloped part 91d for driving the center core push arm 99 (described later) and a sloped part 91e for driving the insertion door control arm 125 (described later) at its upper end, and has a gear arm l35 for opening and closing the door (described later) on its inner surface. #! A control pin 91f for A movement is implanted.

On the other hand, the right control plate 93 has a guide groove 9 in the front and rear direction.
3a, and the guide bins 79b of the right side plate 79 are slidably fitted into the guide grooves 93&, so that the right control plate 93 is supported by the right side plate 79 so as to be slidable in the front and rear direction, and the right control plate 93 is slidably supported by the right side plate 79. Rack 93 formed at the lower end of 93
When the pinion 97 fixed to the control shaft 67 engages with the pinion b, the right control plate 93 is driven in the front and back direction in synchronization with the left control plate 91 by the operation of the loading motor 65. Similarly, the right control plate 93 has an inclined guide groove 93.
c is formed and the right holder 83 guide donyahu) 8
3a is the holder guide groove 79 a f of the right side plate 79
By penetrating and fitting into the inclined guide groove 93e via the roller 83e, the right holder 83 moves back and forth and up and down along the holder guide groove 79a by the back and forth movement of the right hand control plate 3. Further, the right control plate 93 has an inclined portion 93d for driving a regulating plate support arm 99 (described later) and a tilted portion 93e for driving an insertion door control arm 127 (described later) at its upper end.

On the other hand, the upper blade of the loading motor 65 has a center core push arm 99 and a regulating plate support arm l.
O1 are rotatably mounted on support shafts 103 and 105, respectively, and torsion coil springs l (
17.

109 urges the tip toward the spindle motor 2f side. As shown in FIG. 18, which is a perspective view of that part, a center core pushing member 111 made of a spring material is fixed to the tip of the center core pushing arm 99, and
The tip of the center core pushing member Ill is connected to the spindle motor 2.
The center core 29 of the magnetic sheet 13 is pressed against the steering magnet 31 of the spindle motor 27 by the spring force of the spring 107. A pin 113 that engages with the inclined portion 91d of the left control plate 91 is implanted in the side of the center core push arm 99. This pin 113 is attached to the left control plate 91 when the left control plate 91 is located forward (the state shown in FIG. 12).
The center core pushing arm 99 is rotated in a direction to move the center core pushing member 111 away from the spindle motor 27 against the spring force of the spring 107 . On the other hand, as the left control plate 91 moves rearward, the pin 113 descends on its inclined portion 91d, and as a result, the center core pushing member 111 descends to push the center core, and the left control plate 91 moves backward at the most backward position. The pin 113 rides on the stepped portion 91g of the inclined portion 91d, and the center core pushing member ill is slightly separated from the center core 29 of the magnetic 7-toe 13.

- Further, a regulating plate grate 115 is pivotally supported at the tip of the regulating plate support arm 101, and this regulating plate grate l
A regulating plate 117 is fixed to the lower surface of the magnetic sheet 13 so as to sandwich the magnetic sheet 13 and face the magnetic head 33 to regulate the position of the magnetic head 13 with respect to the magnetic head 33.

The above-mentioned right control plate 93 is attached to the side of the regulation plate support arm 101.
A pin 119 that engages with the inclined portion 93d is implanted. When the right control plate 93 is located forward, this pin 119 also comes into contact with the upper end of the right control plate 93 and rotates the regulating plate support arm 1oi so that the mJI plate 117 is separated from the spindle motor 27. As the force and the right control move backward, the pin 119 moves down its slope 93d and moves to the force of the regulating plate (gray) 1152>E spindle motor 27, and the regulating plate 115 is installed on the 7-year 725 side. The regulating plate 11 is brought into contact with the
7 is positioned at a predetermined position.

On the other hand, an insertion port door 123 is attached to the pack insertion port 9 of the rotating magnetic sheet device 7 so that it can be opened and closed at will. As shown in FIG. 19, which is a perspective view of the insertion door portion, the insertion door 123 has a vertical plate 123a and a horizontal plate 12, which are at right angles to each other.
3b, and its left and right ends are pivoted to the left and right insertion door control arms 125 and 127, respectively, and are connected to the arms 125 and 127 by screw coil springs 129 in FIG. It is biased in the direction of the arrow. Left and right insertion door control arms 125°127
are the guide pins 77 of the left and right side plates 77 and 79 mentioned above, respectively.
It is rotatably supported by c and 79b. The left and right insertion door control arms 125.127 are bent to form protrusions 125a and 127a that engage with the inclined portions 91e and 936 of the left and right control plates 91.93, respectively. 127 and left and right side plates 77
．． Tension coil springs 131 and 133 are connected between the
are stretched, and their protrusions 125a and 127a are pressed against the inclined portions 91e and 93e, respectively. Further, a door opening/closing gear arm 135 is rotatably supported on the guide bin 77c of the left side plate 77, and a sector gear 1351L is formed at the tip of the door opening/closing gear arm 135. It meshes with a sector gear 137 provided concentrically with the rotation center. In addition, the gear arm 135 for opening and closing the door is provided with the aforementioned left control plate 9.
A stepped portion 135b is formed with which the first control bin 91f engages. Therefore, when the left and right control plates 91.93 are located forward, the insertion port door 123 closes the pack insertion port 9 with its standing plate 123a, but when the left and right control plates 91.93 move backward, Door control arm 125°12
The protrusions 125a and 127a of 7 rotate by lowering the inclined parts 916°93e of the left and right control plates 91.93, thereby moving the fulcrum of the insertion door 123 upward, and the insertion door 123 is rotated 90 times. The control pin 91f of the left control plate 91 engages with the stepped portion 135b of the door opening/closing gear arm 135, thereby locking the door opening/closing gear arm 135 in a state in which the door opening 9 is closed by moving the horizontal plate 1231.

In the electronic still camera described above, when loading the magnetic sheet/tack 11, the magnetic sheet pack 1
1. Push open the insertion slot door 123 and insert the magnetic sheet pack 11 from the insertion slot 9. When the magnetic sheet/tack 11 reaches the notch holding portion 83b of the right holder 83, the tuck detection switch 85 is activated, thereby starting the loading motor 65 and moving the left and right control plates 91 and 93 backward. . Then, due to the movement of the left and right control plates 91 and 93, the magnetic rack 1 is drawn into the inside together with the right holder 83, and then both the left and right holders 81 and 83 are lowered toward the spindle motor 27, and the magnetic sheet 1
The center core 29 of No. 3 is inserted into the rotating shaft of the spindle motor 27. Thereafter, due to the movement of the left and right control plates 91.93, the center core pushing arm 99 is actuated and the center core is pushed by the center core pushing member 111, and the regulating plate support arm 101 is actuated to move the regulating plate 1.17 to a predetermined position. Then, the slot insertion port 9 is closed by the insertion port door 123, and loading is completed.

Next, when recording and playing, first cam gray) 153
The cam follower 45 is brought into contact with the first stage of the connecting portion 1530 or the gently sloped region 153d to position the magnetic head 33 at the outermost diameter portion, and by rotating the cam 53 from there, the magnetic head 33 is moved to the magnetic 7 - Sequentially positioning is carried out by sending it in the radial direction of the plate 13. Here, in the feeding drive of the magnetic head 33, the gently inclined region 153a or l53d
Since the cam rift (t) per unit rotation of the cam 53 is small, highly accurate positioning of the magnetic head 33 at any position is possible during reproduction. - force, steep slope area 153b or 1
In the 53el, the cam lift amount changes in steps of 100 μm and with a steep slope, so the magnetic head 33
This enables high-speed feeding in increments of 100 μm.

In addition, the unloading of the magnetic 7-tonogukkull is
By operating the isoext button in the operation button group 21,
The loading motor 65 rotates in the opposite direction to that during loading and moves the left and right control plates 91, 93 forward, thereby performing the reverse procedure of loading.

<Effects of the Invention> According to the present invention, since the accuracy of the cam depends on the thin cam plate to which well-known precision machining can be applied, it is possible to obtain an extremely high-precision feed drive cam that is easy to manufacture and has a high yield. I can do it.

If the cam of the present invention is applied to the magnetic head feeding drive of a rotating magnetic sheet device such as an electronic still camera stem, it is possible to provide high-precision products at low cost, and achieve even higher precision feeding. Subtle settings of the cam shape can be easily achieved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of a cam according to an embodiment of the present invention, FIG. 2 is a plan view of the cam plate, and FIGS. 3 to 5 each show a positioning structure between a plurality of cam plates. 6 is a side view showing another embodiment of the cam having a plurality of cam plates, FIG. 7 is a sectional view showing another embodiment of the cam plate insertion structure, and FIG. 8 is a cam FIG. 9 is an explanatory diagram showing another example of the shape of the cam, FIG. 10 is an enlarged back view of the cam part in the rotating magnetic seven-point device, and FIG. 11 is the main body of the electronic camera. A schematic perspective view of the magnetic sheet nosock, @12 A perspective view of the rotating magnetic sheet device shown together with the magnetic sheet nosock, 1st
Figure 3 is an exploded perspective view of the main parts, Figure +4 is a perspective view of the cam gear part, Figure 15 is a perspective view of the left and right side plates, Figure 16 is a perspective view of the left and right holders, and Figure 17 is the left and right sides. FIG. 18 is a perspective view of the control plate, FIG. 18 is a perspective view of the center core push arm and regulating plate support arm portion thereof, and FIG. 19 is a perspective view of the insertion door portion thereof. In the drawing, 53 is a cam, 153 is a cam plate, 154 and 155 are reinforcing plates, and 167 is a spacer. Patent applicant: Fuji Photo Film Co., Ltd. (1 other person) Agent: Patent attorney: Shibu Mitsuishi (1 other person) No. 1
Figure 2 Figure 6 Figure 7 Figure 10 Figure 17

Claims (1)

[Claims] A reinforcing plate having a diameter smaller than that of the cam plate and having a substantially similar shape to that of the cam plate is placed on both sides of a thin cam plate having a predetermined shape, with the periphery of the cam plate slightly protruding from the periphery of the reinforcing plate. Feed drive cam that is fixed with