JPH0414671A - magnetic storage device - Google Patents

Abstract

PURPOSE:To attain miniaturization and light weight of the magnetic storage device by sharing a housing of the device partially with a housing of a motor. CONSTITUTION:The housing 30 of the device consists of base housings 30a and 30b, where bearing 32a and 32b for holding a rotor core 31 of a rotor 33 of a spindle motor are provided on an extension part 30c of the housing 30b. A deformation part 30d of the base housing 30a is projected inward for a part to be occupied by a seek motor in this housing. A rotor core 45 for supporting a rotor 30 is held by an extension part 30e formed by extending the deformation part 30d with a bearing 46. By this constitution, since the housing of the device and the housing of constitutive elements are shared with each other, the constitutive elements can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a structure of a magnetic storage device that is lighter and thinner and consumes less power during power outage.

[Prior Art 1 An example of the prior art will be described with reference to FIGS. 10 to 12.

Figure 10 shows a bottom view and a side sectional view of the magnetic storage device (a).
and (b). Figure 11 shows a magnetic storage medium (
(a) and (b) are a bottom view and a side sectional view of a spindle motor that rotates a medium (hereinafter abbreviated as medium) at a predetermined rotational speed.
Indicated by FIG. 12 shows (a) and (b) a bottom view and a side sectional view of a seek motor that seeks a track on a medium.

In FIG. 10, reference numeral 1 denotes a frame, which is composed of a base frame 1a and a cover frame 1b. 3 is a spindle motor and the base frame 1a
Fix it with screw 4. The spindle motor 3 is fixed to the shaft core 5 with a stopper 6 and rotates the medium 2 at a predetermined rotational speed.

A seek motor 7 is fixed to the base frame 1a with screws 8. Reference numeral 11 denotes an arm body, which serves as a rotating shaft 10 and has a magnetic head 13 mounted on the medium 2, and an arm llb and a spring body 11 at the other end.
It consists of a still band 12 supported by b and wrapped around the shaft core 9 of the seek motor.

In the second configuration, the seek motor 7 receives the seek position information of the track of the medium 2 and rotates to place the magnetic head 13 at a predetermined position.
access.

Next, a conventional embodiment of the spindle motor 3 will be explained with reference to FIG. A rotor 15 is fixed to the shaft core 5 with a stopper 17, and has a permanent magnet 16 magnetized with four poles. 1
8a and 18b are bearings.

Reference numeral 19 denotes a frame that supports the rotor 15 and the stator 22, which together with a cover frame (not shown) forms the housing of the completed motor.

The stake 22 has a coil 23 wound around three poles, and the terminals of the coil 23 are connected to the printed circuit board 21. 22 is a position detection means for detecting the rotational position of the rotor 15; a coil 23;
energization timing.

The spindle motor shown in FIG. 11 constitutes a three-phase drive motor with the minimum number of poles. Therefore, the number of coils is three, and the coil height becomes high to obtain a predetermined ampere tan.

Furthermore, since the motor is a complete product, the height of the housing is added, making it both taller and heavier.

Next, a conventional embodiment of Sikumo Turf will be explained with reference to FIG. 25 is a frame that constitutes the motor housing.
It consists of two pieces, a and 26b. 26a and 26b are bearings that hold the shaft core 9. Reference numeral 27 consists of a permanent magnet 28 magnetized in the thrust direction by a rotor, and uneven yokes 27a and 27b sandwiching this permanent magnet 28 and having tooth phases different from each other by 180 degrees. A stator 29 is associated with the teeth of the rotor 27, and four coils 30 are provided at stator poles in which the phases of the teeth 29a differ by 90 degrees. This seek motor configuration is called a hybrid step motor. The Sikumo tough shown in FIG. 12 is excited by a four-phase drive system and rotates in steps.

The seek motor 7 in FIG. 12 also has the minimum number of coils, so the coil height is high. Furthermore, since it is assembled into the device as a complete unit, it becomes large and heavy if the frame of the housing is included. Furthermore, the coil occupancy rate is small and there is a lot of wasted space.

Specifically, the height of the seek motor is at most 20 mm, the mechanical part of the arm body including the thickness of the housing is about 10 mm, and the total height of the device is about 30 mm. The weight is 700 g to 1 kg for a 35-inch medium.

The above is an overview of the magnetic storage device according to the prior art.

[Problem to be Solved by the Invention 1] However, the above-mentioned prior art has a major problem in that the ratio of storage capacity to volume, weight, and cost is poor due to duplication of components and wasteful space arrangement. Particularly when applied to a portable personal computer, there is a problem in that it is difficult to install because it is light, thin, small and compact.

The purpose of the present invention is to solve these problems.The purpose of the present invention is to simplify and share the components, and also to disperse the motor coils to increase the occupancy rate so that the motor is light, thin, short, and compact, and has a wide range of applications. Provides magnetic storage devices.

[Means for Solving the Problems] 1. The present invention provides a spindle motor that rotates a magnetic storage medium at a predetermined speed, a seek motor that seeks through an arm a magnetic head that reads and writes data to the storage medium, and each of the above-mentioned devices. It consists of a housing body that supports the components in a predetermined layout, and the housing body and one or both of the housings of the spindle motor and the seek motor share a part to simplify waste elements and space and create a lightweight and thin magnetic structure. Its feature is that it constitutes a storage device.

2. The present invention further provides that the seek motor is a hybrid step motor, is a four-phase drive type, and the coil height is suppressed by making the number of coils the same as the number of poles of the stake that corresponds to the equivalent number of magnetic poles of the rotor. Another feature is that it eliminates wasted space.

3. The present invention further provides a tachometer for detecting the speed of the spindle motor, two variable adjustment timers that start the pulse train of this tachometer with alternately separated pulses, and
Frequency discriminator means consisting of a logic means which inputs the output signal of a variable length timer is provided in the speed control loop of the spindle motor to read and write at a constant storage density independent of the position of the magnetic storage medium depending on the position of the magnetic head. It is also a feature.

4. The present invention also has the feature that a magnetic storage device can be realized with a single magnetic storage medium of 3.5 inches or less, a housing height of 17 mm or less, or a weight of 300 grams or less.

5. Another feature of the present invention is that power consumption can be reduced by driving the spindle motor and the seek motor at a low voltage of 5 or less secondary batteries.

[Function] According to the above configuration of the present invention, since the device housing and the component housing are shared, the number of components can be reduced.

Regarding motors, the coils are distributed and the height of the coils is reduced, which shortens the line length, reduces resistance, and enables low-voltage driving. Furthermore, the height of the motor can also be reduced.

By these means, magnetic storage devices can be made lighter, thinner, and smaller.

[Embodiment] FIG. 1 is a diagram showing specific components in an embodiment of the present invention. Fig. 1(a) is a side cross-sectional view of a magnetic storage device (hereinafter abbreviated as the device), and Fig. 1(b') is a partial view of an example of the arrangement of the stator poles of a spindle motor and the coils of a tachometer that detects the speed of the motor. FIG. Figure 1 (C)
FIG. 2 is a diagram showing a pole arrangement of a stator of a seek motor. FIGS. 1(b) and 1(C) are scaled down compared to FIG. 1(a).

In Figure 1, 30 is the frame of the device, 30a is the base frame, 3
0b is the lid frame. Extension portion 30c of base frame 30b
Bearings 32a and 32b are provided to hold the rotor core 31 of the rotor 33 of the spindle motor.

The rotor 33 has a rotor yoke 34a that holds the permanent magnet 35.
, a separate rotor yoke 36 and a tachometer magnet 37 for a tachometer that detects the speed of the spindle motor, and an index pulse magnet 38a that outputs one signal per rotation of the rotor 33.
, a stopper 35 for holding the medium 34, and a screw 36.

40 is a stator, and a coil 41 is arranged on a stator pole 41a. The printed circuit board 39 serves as a relay terminal leading to the outside of the spindle motor, and is a terminal of the coil 41, a zigzag tachometer coil corresponding to the number of magnetized magnetic poles of the tachometer magnet 37 shown in FIG. 1(b). Although not shown, three magnetically sensitive elements for detecting the pole position of the permanent magnet 35 and a magnetically sensitive element 38b for detecting an index pulse are provided.

The permanent magnets 35 and the stator 40 are arranged so that their facing positions are slightly shifted in FIG. 1 so as to apply downward pressure to the rotor 33.

Here, various quantities related to the spindle motor will be summarized, assuming that the medium 34 is one sheet.

The outer diameter is 50 mm, and the outer diameter, height, and thickness of the permanent magnet 35 are 3.
They are approximately 3mm, 4mm, and 1mm. Assuming that the spindle motor is driven in three phases and the number of poles of the permanent magnet 35 is 20, the total number of coils in the stator 40 is 15. The number of coils is 95, which corresponds to 1, and the height of the coil is one-fifth of that shown in FIG. 11 if the number of turns is the same. Assuming that the number of turns for one phase is 250 tan and the wire diameter is about 0°15 mm, if the stake is constructed within the above dimensions, the coil height will be within 1 mm, and the resistance per liter will be about 3 Ω.

When the permanent magnet 35 is composed of a rare earth magnet, the magnetic flux density is 0.
4 to 0.6 wb/m2 is easily obtained.

If the supply voltage is 5 V, and the results are omitted, a starting torque Tgψ: 6X I Oo-3N-N-N-m) and a maximum rotational speed nvax 8000 rpm are obtained.

The spindle motor weighs approximately 60 grams, excluding the extension 30c and the medium 34.

Inertia r of the rotor 33 including one 35-inch medium 34
becomes I:2.9X10-'kgm''.

Rotational speed n = no(1-E X P (-t/i:
The start-up time constant can be expressed as ol). “It will be F2.5sec.

Therefore, it takes about 15 to 25 seconds for the control loop to actually reach the predetermined rotation and stabilize.

The weight and inertia of the spindle motor were calculated based on the assumption that components not related to the magnetic path were made of aluminum.

The height of the spindle motor, including the frame 30b, can be designed to be approximately 14 mm in the example shown in FIG.

Next, the seek motor will be explained. In FIG. 1, the portion of the base frame 30a occupied by the seek motor is the deformed portion 30.
d should protrude inward. A rotor core 45 that supports the rotor 30 is held by a bearing 46 at an extension portion 30e extending downward from the deformation portion 30d.

The outer periphery of the rotor 47 is a permanent magnet 4 magnetized in the thrust direction.
Uneven yokes 49a and 49 whose tooth phases differ by 180 degrees across 8
b is placed. If the number of teeth on one side is 150, then it is isometrically magnetized with 300 magnetic poles. The reason why the support portion of the rotor 47 is deformed is to ensure verticality by fixing it to the rotor core 45.

Reference numeral 50 denotes a stator, which has a coil 51 and is fixed together with the lower frame body 53 at the deformed portion 30d with screws 52b.

The lower frame body 53 may be dustproof, thin and light. The number of teeth of the stake 50 is 200 when the number of magnetic poles of the rotor 47 is 300, assuming a four-phase drive. Therefore, wind the coil around this number of teeth (then the total number of coils will be 200, and 1
This is equivalent to 950 coils. The current flows in opposite directions for the 1st and 3rd phases, and the 2nd and 4th phases, so if you change the connections, you'll have two sets of coils. There are four external lead-out terminals.

The rotor 47 is made of aluminum with a thickness of about 0.5 mm in order to avoid a short circuit in the magnetic circuit.

Here, the outer diameter of the rotor 47 is 50 mm, 14! The height of iron 49a and 49b is 1.5 mm, the height of permanent magnet 48 is 1 mm,
The outer side of the stator 50 is 57 mm.

The stator has 200 teeth with a tooth width of 0.39 mm and a pitch of 18 degrees. If you wind 3 tans of 0.12mm wire around one tooth, you will get two sets of coils with a resistance of 45Ω and a resistance of 300 tans.

The characteristic value of the seek motor will be described as a drive voltage of 5■, omitting the middle part.

Maximum starting torque 6XIO-3N-m, maximum pool-out rotation speed 850Orpm, rotor inertia 7, 3 x 1
0-6k gm2. The weight excluding the deformed portion 30d is approximately 55 grams.

This hybrid type seek motor uses one-phase excitation drive.6
In 1-2 phase excitation, one rotation is made in 1200 steps.

The height of the seek motor is approximately 8.5 including the deformed portion 30d.
It becomes mm.

Here, if the total height of the device is 15 mm and the thickness of the frame body 30b is about 0.3 to 0.5 mm, the steel band wrapping portion of the rotor core 45 can be about 5 mm, which is sufficient.

Next, to calculate the weight of the frame 30, the cover frame 30b is for dustproofing, so it is made of a 0.3 to 0.5 mm aluminum plate, leaving only the necessary places at the height of 15 mm, and deforming it. Make it stronger.

The base frame 30 is formed by aluminum die-casting to have a shape that causes no difference in plane deformation and partial shrinkage, and has a thickness of 2 to 3 mm in some parts.

The planar area of the frame 30 is approximately 105 mm x 140 mm in order to accommodate one of the 3.5-inch media, the spin toll motor, and the seek motor.

The average thickness of the base frame body 30a and cover frame body 30b is 2
．． Can be designed to 5mm. The weight of the frame 30 is 10.5c
mX14cmX0.25cmX2.7 (specific gravity) 100
grams.

The weight of the entire device shown in Figure 1 is 15 grams for one sheet of media, and the weight of other parts including the arm not shown in Figure 1 is 5 grams.
The total is about 0 grams, 15 + 50 + 60 + 55 + 10
0=280 grams.

Here, the storage capacity of a 3.5-inch medium will be briefly explained. The outer diameter of the medium is approximately 89 mm, and the recording width is 600 cylinders (number of tracks) with a diameter of 80 mm to 60 mm, assuming a normal recording density of 14,000 BPI (bits per inch) and a track density of 1,700 TPI (tracks per inch). ), recording on both sides of the medium will result in 1200 cylinders.

The formatted capacity is approximately 10MB (megabytes). This capacity is usually sufficient, especially for portable personal computers.

As shown in FIG. 1, both the weight and height are less than half that of the conventional technology.

In addition, since the example of seeking 600 cylinders of the medium 34 is shown in Fig. 1, it is necessary to provide a margin before and after 1, and since it is impossible for the seek motor to rotate once due to the winding relationship of the steel band, the 1-2 phase Adopts 1200 steps of excitation.

Furthermore, although it will be mentioned later, in FIG.
A gap of some degree is provided.

Next, another embodiment of the present invention will be explained with reference to FIG.

FIG. 2(a) shows a side sectional view centered on the motor, FIG. 2(b) shows the shape of the stake pole 67a of the spindle motor and the pattern of the tachometer coil 71, and FIG.
C) is a diagram showing the layout of the stator poles 85a and the state of the coils 86 of the seek motor.

In FIG. 2, the spindle motor is also provided on the opposite side of the base frame 60 from the medium (not shown), and if the structure is the same as in FIG. 1, the height of the apparatus will be increased by the thickness of the base frame 60. On the other hand, since the diameter of the motor can be made large, it can actually be designed to be thin, so it can be made almost the same as in Fig. 1. Furthermore, there is a feature that the assembly is somewhat simpler than that shown in FIG.

The seek motor is shown as an example of outer rotor type, in this case,
Although the inertia increases and the response speed decreases, it becomes easier to coil the stake.

Now, in Figure 2, the configuration of the spindle motor is as follows: rotor 62
consists of a rotor core 61, a rotor receiver 63, a permanent magnet 64, and a tachometer magnet. The holding part consists of bearings 66a and 66b fitted into the extension part 61a of the base frame body 60. Stator 67 has coils 68 . Permanent magnet 64
The total number of coils 68 in the stator 67 is based on the number of poles shown in Fig. 1. If the motor diameter is larger than that shown in Fig. A spindle motor is used. Reference numeral 69 is a printed circuit board on which terminal processing of a coil coil 68, a tachometer coil 71, a magnetic sensing element for detecting the pole of a permanent magnet 64, and an index pulse emitting means (not shown) are mounted.

In FIG. 2(c), unlike FIG. 1(c), the stator poles 85a are arranged in four groups for each phase. In this case, the total number of coils will decrease. However, winding the coil 86 is easy.

The result in FIG. 2 can be the same weight and volume as in FIG. 1. However, since the effective track width of the medium increases, the storage capacity can be increased.

Next, another embodiment of the present invention will be explained with reference to FIG.

FIG. 3 shows a case where two media 34 are used, with a gap of 7 mm between the media due to the relationship with the magnetic head. Therefore, the total height of the device can be approximately 1 5 + 7 = 23 mm. Further, since the spindle motor section 90 can be made larger in the height direction, the outer diameter can be made smaller than that of the first section. The seek motor section 91 may be the same as that shown in FIG. 1 or 2.

The other detailed configurations in FIG. 2 are the same as those in FIG. 1 or 2, and will therefore be omitted.

On the other hand, the effect of the mechanism of the present invention diminishes when the number of media exceeds 5 to 6.

Next, control of the magnetic storage device according to the present invention will be explained with reference to FIG. The spindle motor section 95 is connected to three coils 96.
, a detection means 97 for detecting the rotor magnetic pole position, a coccometer 98, and an index pulse emission means 99. The spindle motor section 95 is connected to the medium 101.

The seek motor section 104 has two sets of coils 105 and a medium 10.
1 is connected to the reading head 103. 100 is an operational amplifier that shapes the signal of the tachometer 98. 102 is a spindle motor control means that controls the rotational speed to a predetermined speed. 106
107 is an R/W control unit that sends write/read signals to the head 103. A system control means 108 controls the entire apparatus while communicating with the outside. A line 110 provides positional information of the head 103 to the spindle motor control means 102 when the linear velocity of the medium 10 is kept constant. line 1
11, the spindle check means 102 notifies the system controller 19108 that the predetermined linear velocity in this case has been reached.

The above is a general description of controlling the mechanism section of the present invention.

A detailed example of the spindle motor control means 102 is described in the fifth section.
This will be explained with reference to the figure and FIG. In FIG. 5, the signal released from the operational amplifier 100 is applied to a T-trigger flip-flop 120 and a differentiator 121. AND the differential pulse of the differentiator 121
to gates 122a and 122b. AND gate 12
When one of 2a and 122b is input to outputs Q and Q of a T trigger flip-flop, the differential pulse (a) shown in Fig. 6 is obtained.
are separated alternately as shown in (b) and (C). Timers 125a and 1 count the variable length clock 123, which is set to the same value by the preset data 123, for this separated pulse.
25b. Furthermore, DFFs (delayed flip-flops) 126a and 126b are reset. When the carry signals of timers 125a and 125b are applied to the clock terminals of DFFs 126a and 126b, when the timer time is T, the waveforms as shown in (d) and (e) in FIG.
26a and 126b emit. The timer time T is a period corresponding to a predetermined speed. When the waveforms (d) and (e) are simultaneously given a negative output to the logic means 127, (f) in FIG. 6 is obtained.
and (g) waveforms are obtained. (f) shows a case where the motor speed is slower than the predetermined speed, and (g) shows a case where the motor speed is faster. The waveform of (f) remains unchanged, and the waveform of (g) is inverted and input to the integrating means 128. The integral value becomes as shown in FIG. 6 (h), and the target voltage is obtained with slight corrections. Motor speed control in FIG. 5 involves inserting a digital frequency discriminator into the control loop.

The output of the integrating means 128 passes through the transistor 129 and is connected to the PNP transistor 132 and the NPN transistor 1.
33, the power is amplified by the emitter follower and supplied to the coil 136.

The other ends of the three coils 136 are connected to transistors 138a and 1.
38b and 138c. transistor 138
a, 138b, 138c are phase switching signals 1 of the detection means 97
39 are sequentially switched to bring the motor to a predetermined speed.

The transistor 134 directly applies the supply voltage +Vp to the coil 136, and is used when the motor is rapidly accelerated. The guides 137a, 137b, and 138c and the transistor 135 are used when the coil 136 is short-circuited and an electromagnetic pre-key is applied to rapidly decelerate the motor. At this time, the transistor 129 is made non-conductive via the inverter 131.

To maintain a constant speed regardless of the position of the head 103, for example, if the innermost cylinder diameter of the medium 101 is 60 mm and the outermost cylinder diameter is 80 mm, the timers 125a and 125b are set to the cylinder speed in 60x20 time units - 80x20 time units. Preset in proportion to the diameter.

As described above, the present invention is characterized in that it configures a frequency discriminator using a variable length timer to rapidly control the spindle motor at a predetermined speed.

In addition, the rotation speed of the spindle motor is 3000 to 6000.
rpm. The tachometer has about 50 to 200 magnetic poles and emits a speed signal of 25 to 100 cycles per rotation of the motor.

The configuration of the tachometer is different from that shown in FIGS. 1 and 2, and may be configured as shown in FIG. 7. FIG. 7(a) shows a printed circuit board 152 equipped with the circuit shown in FIG.
A tachometer magnet 151 is provided on the rotor 150 at the illustrated position. In FIG. 7(b), the rotor 155 is expanded to enlarge the ring of the tachometer magnet 156 and increase the number of magnetic poles.

A printed circuit board 157 similar to the printed circuit board 152 is provided with zigzag coils corresponding to the number of magnetic poles of the tachometer magnet 156.

Next, control of the seek motor will be briefly explained with reference to FIGS. 8 and 9. In FIG. 9, the seek motor control means 160 receives commands from the outside and receives phase switching signals 161a, 161b, 162.
a and 162b are released.

In response to these, two sets of coils 165a and 165b are energized by bipolar drive changeover switches 163a and 163b, which are composed of four P-type and N-type transistors.

The seek motor control means 160 operates the changeover switches 165a and 165b within a range that does not deviate from synchronization depending on the amount of rotation of the motor.
The switching speed is determined and controlled to quickly reach the target position.

Emitter followers 166a and l 66b, D/A (
Providing digital to analog) converters 167a and 167b and digital position signals 168a and 168b is
This is not necessary in the 1-phase excitation drive or l-2 phase excitation drive described in FIGS. 1 and 2. It is used to more accurately reduce the step angle and increase the number of steps per rotation of the motor. For example, when stepping at a step of 1/4 of 1-phase excitation drive, the current I flowing through the coils 165a and 165b,
As 2 and L + 12 = IO, (
I,=1. ．． 1. =O), (I, =%■., I2 =
%Eng. ), (I,=274I., l2=2/4I.)
, (I+ = 44IO, I2 = % WORK.) The step angle is determined as follows.

FIG. 8 shows how current is passed through coils 165a and 165b. (a) shows the equally polarized magnetic pole arrangement of the rotor and the divided positions. (b) is the current waveform of l-phase excitation drive, and the step angle is one-fourth of the one-cycle angle of rotor magnetic pole N-3, and (C) is the current waveform of one-two-phase excitation drive, which is one-eighth. is the step angle.

The embodiments of the present invention have been described above, and the present invention also has a significant feature in terms of power consumption. In the prior art, the supply voltage is 12 volts or more and the constant power consumption of the spindle motor is 5 W or more.

In contrast, in the present invention, the power supply voltage may be around 5 volts, and the constant power consumption is less than IW.

In particular, portable basonal computers require low power consumption. This is because the weight of the power source is also reduced.

For example, whereas ten or more secondary batteries with a nominal voltage of 1.2V were required, the present invention requires only five, and furthermore, the battery life can be increased by more than five times.

[Effects of the Invention] As described above, according to the present invention, the device housing and the motor housing can be partially shared, and the number of magnetic poles and coils per rotation of the motor can be maximized without causing a significant increase in cost. As a result, the contribution of making the 6N-1 device lighter, thinner, smaller, and driven at lower voltage and with lower power consumption is enormous.

[Brief explanation of the drawing]

FIG. 1 shows a specific configuration in an embodiment of the present invention, where FIG. 1(a) is a side sectional view, and FIG. 1(b) is a stator pole and coil arrangement of a spindle motor, and a tachometer. FIG. 1C is a diagram showing the stator poles and coil arrangement of the seek motor. Figure 2 shows another embodiment of the present invention, in which Figure 2 (a) is a side sectional view, Figure 2 (b) is a diagram showing the arrangement of stator poles and cocometer coils, and Figure 2 (C) is a diagram showing the arrangement of stator poles and cocometer coils. FIG. 2 is a diagram showing a different stator pole and coil arrangement from FIG. 1 of the seek motor. FIG. 3 is a diagram showing a case where two storage media are used in still another embodiment of the present invention. FIG. 4 is a block diagram showing a control system for controlling the mechanism of the present invention. FIG. 5 is a timing chart illustrating the present invention. i7 Figures (a) and (b) are diagrams showing other embodiments of the arrangement of magnets for a coccometer in a cylinder motor. FIGS. 8(a) to 8(C) are diagrams showing the magnetic pole arrangement and drive current waveform of the seek motor. FIG. 9 is a block diagram and a circuit example of seek motor control. FIGS. 1A and 1B are top and side cross-sectional views of an embodiment according to the prior art. Figures 11(a)(b) and 12
Figures (a) and (b) are diagrams showing configuration examples of a spindle motor and a seek motor according to the prior art. 2': 540 Fig. 6 70 (Q) (b) D; 510 mouth:...TS 9 )-11 Fig. 11 (Q) (b) Fig. 12

Claims (5)

[Claims] (1) A spindle motor that rotates a magnetic storage medium at a predetermined speed, a seek motor that seeks via an arm a magnetic head that reads and writes data to the magnetic storage medium, and a housing that supports each of the above components in a predetermined layout. 1. A magnetic storage device, characterized in that the housing body and one or both of the housings of the spindle motor and the seek motor share a part. (2) The magnetic memory according to claim 1, wherein the seek motor is a hybrid step motor, is a four-phase drive type, and has the same number of coils as the number of poles of a stator that corresponds to the equivalent number of magnetic poles of the rotor. Device. (3) A tachometer that detects the speed of the spindle motor;
The speed control loop of the spindle motor includes two variable length timers that start with pulses that are alternately separated from the pulse train of the tachometer, and a frequency discrimination means that includes logic means that receives the output signals of these two variable length timers. 3. The magnetic storage device according to claim 1, wherein the magnetic storage device is provided with a magnetic storage device. (4) The magnetic storage medium according to claim 1, claim 2, or claim 3, characterized in that the magnetic storage medium is one sheet of 3.5 inches or less, the housing height is 17 mm or less, or the weight is 300 grams or less. Storage device. (5) The magnetic storage device according to claim 1, 2, 3, or 4, wherein the power source supplied to the spindle motor and the seek motor is five or less secondary batteries.