JPH0812565B2 - Positioning device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device such as a head of a floppy magnetic disk device among external storage devices used in personal computers and the like.

[Conventional technology]

Hereinafter, a case of a Flotpies magnetic disk device will be described as an example of the positioning device.

There are three types of head positioning methods for the currently practically used Flotpie magnetic disk device: lead screw method, spiral cam method, and steel belt method.
The head movement of these head positioning methods uses a stepping motor, and the angle of the rotating shaft changes according to the number of input pulses, and the amount of change becomes the movement amount of the head carriage. There are three types of methods of transmitting the angle change due to the rotational movement of the rotary shaft to the head carriage and converting it into linear movement of the head carriage, the lead screw, spiral cam, and steel belt. Among them, the head positioning method related to the lead screw will be described below with reference to the drawings.

Fig. 10 shows "5V single power supply with low power consumption, battery-powered
3.5 inch floppy disc device NIKKEI ELECTRON
ICS 1986.5.19 (No.395) ”shows a magnified and schematic view of the lead screw and head carriage part of the drive system of the conventional Flotpie magnetic disk device shown in (1) in the figure. Is a magnetic recording disk, (2)
Is a magnetic head, (3) is a head carriage serving as a moving body, and (4) is a guide rod. Magnetic recording disk (1)
Although details of the structure are omitted in the drawing, information is recorded / reproduced in a state in which the DC motor is rotated at a constant rotation speed and is always in contact with the magnetic head (2). The head carriage (3) is generally made of a plastic molding material, and fixes the magnetic head (2) via a leaf spring (not shown). Further, both sides of the head carriage (3) are supported by a cylindrical guide rod (4) having a very good surface precision so as not to mechanically rattle in the lateral direction, and the guide rod (4) is also supported by the head carriage (4). It is passed through a lubrication pipe (38) with lubricity provided in the through hole of 3), and is designed to have a low friction structure so that the head carriage (3) can move smoothly in both directions of arrow (A). ing.

Next, the feeding mechanism for moving the head carriage will be described. In the figure, (5) is a stepping motor, (6) is a lead screw which is a rotating body, (7) is a lead guide bar which is an engaging portion attached to a head carriage (3) which is a moving body, (8a) , (8b) shows a preload spring, and (9) shows a frame. The stepping motor (5) controls the rotation angle and direction of the lead screw (6) by rotating and stopping the rotation shaft according to the number and direction of input pulses from an external control circuit (not shown). In the present invention, the stepping motor (5) is not directly related and therefore detailed description is omitted. Lead Screen (6)
The groove (39) has been previously dug in the spiral, and this groove (3
9) forms the engaged part. That is, this groove (3
9) and the lead guide bar (7) are pressed by a plate-shaped preload spring (8a) from the back surface of the head carriage (3), and they are engaged with each other with a proper pressure. Further, the preload spring (8b) always holds the head carriage (3) laterally against the guide rod (4) and supports the head carriage (3) so as not to rattle when moving. As described above, these structures are directly or indirectly attached to the frame (9).

FIG. 11 is a view showing an example of an engaging portion between the lead guide bar (7) and the lead screw (6), and FIG. 11 (a) is perpendicular to the axial direction of the lead screw (6). FIG. 11 (b) is a side view of the lead screw (6) as viewed from the side. The lead guide bar (7) engages with the groove (39) of the lead screw (6) so that the engagement does not come off, while the steel ball (37) reduces friction and the preload spring (8a) is applied. Pressing.
Therefore, there is a clearance (x) between the head carriage (3) and the lead screw (6), and the preload spring (8a)
Acts to keep this clearance (x) constant even when the head carriage (3) is moving. In such a structure, when the lead screw (6) rotates, the groove (3
The lead guide bar (7) engaged with 9) moves linearly in the A direction, and the head carriage (3) fixing the lead guide bar (7) also interlocks. In addition,
The other preload spring (8b) shown in FIG. 10 is omitted in this figure.

Generally, the biggest problem at the time of recording / reproducing of a fixed magnetic disk device or a floppy magnetic disk device is the positioning of the head. That is, if data is reproduced from the recorded track in a state where the magnetic head is deviated due to an external factor, crosstalk from the adjacent track and unerased data of the previous history affect the analog signal SN ratio (Signal Noise R
ratio) becomes worse and the ratio of data errors increases. In addition, the same data error may occur when data is recorded with the track deviation. Many of the causes of these track deviations are thermal, and the typical ones are the magnetic recording disk, the difference in the temperature coefficient of the magnetic head and the positioning mechanism of the magnetic head, and the spindle motor for rotating the magnetic recording disk. This is due to the thermal collapse of the rotating shaft of. Also, especially in the Flotpies magnetic disk device, since the substrate of the magnetic recording disk is made of plastic material, in addition to temperature, influence on humidity, temperature,
Due to the influence of humidity, the magnetic head and the recording track are relatively displaced. Generally, this track deviation is called off-track.

As a method of increasing the magnetic recording density, there are improvements in the bit density in the circumferential direction and the track density in the radial direction.
To improve the track density, how to reduce the above off-track is a major issue. The degree of thermal and humidity influence becomes more remarkable as the track density increases.
As a method for reducing this influence, recently, a device incorporating a sector servo system has appeared.

The sector servo method is that the servo information for correcting the off-track is pre-recorded in the front or rear of each sector of the data recording surface, the servo information is reproduced by the magnetic head, and the off-track amount is detected. The magnetic head is moved to the center of the track so that it is always positioned at the correct track position.

FIG. 12 is a diagram showing the arrangement of servo information in the sector servo system. (10) in the figure is the servo sector area, (1
1) is a data sector area, servo information for head positioning is recorded in the servo sector area (10), and the data sector area (11) is an area in which arbitrary information can be recorded and reproduced. Servo sector areas in general (10)
The data sector area (11) is called a sector.

FIG. 13 is a positioning servo system diagram for positioning the head using the information of the servo sector of FIG. In the figure, (12) is a spindle motor for rotating the magnetic recording disk (1), (3) is a head carriage for moving the magnetic head (2), and (14) is a linear voice mechanically connected to the head carriage (3). Coil motor,
A drive mechanism consisting of a rotary voice coil motor or a stepping motor, (15) an amplifier circuit for amplifying the reproduction signal of the magnetic head (2), and (16) an amplifier circuit (1
The position detection circuit for processing the head positioning information from the signal of the servo sector (10) in the analog signal of 5) and producing the signal necessary for applying servo, (17) is the position detection circuit (16) A control circuit that generates signals for position control and speed control from signals, (18) is a control circuit (17)
The current amplifier which produces the electric current which moves the drive mechanism (14) based on the signal of is shown. When a command to move the magnetic head (2) is input from the external controller to the control circuit (17), the distance between the current track position and the target track position is calculated, and the head carriage (3) is targeted according to the predetermined speed profile. Move to the track position. This operation is called seek. At the stage where this seek operation is completed, the information on the servo sector area (10) is reproduced and followed so that it always stays on the target track. This operation is called track following.

The linear voice coil motor or rotary voice coil motor used as the drive mechanism (14) in FIG. 13 is mainly mounted on the fixed magnetic disk device, and the stepping motor is part of the small fixed magnetic disk device and the floppy disk device. It is mounted on a magnetic disk device. As an example of the sector servo system of the Floppy magnetic disk device, a stepping motor of one-phase excitation, two-phase excitation, and one-two-phase excitation is used, and the phase currents flowing in the two coils are changed to make a minute step angle. There is a method to change the track tracking.

As mentioned above, it is important to prevent off-tracking of the magnetic head in order to increase the recording density, but there is US Patent 4630145 as a technology devised to improve the positioning accuracy of the conventional device. .
FIG. 14 is a diagram for explaining this technical content, and is a diagram showing a conventional positioning device having a coarse feed mechanism and a fine feed mechanism. In the figure, (5a) is a coarse feed stepping motor, (5b) is a fine feed stepping motor, and (6
a) and (6b) are lead screws, (56) is a lever arm mechanically connecting the lead screws (6a) and (6b), and (48) is a fulcrum pin that serves as a fulcrum of the lever arm. . Rotor (80) of stepping motor (5a) for coarse feed
The rotating shaft (22) is configured to rotate and move in the axial direction (A) of the lead screw (6a). The lever arm (56) has a fulcrum pin (48).
It can be rotated in the direction (B) around the center.

Next, a method of actually performing the positioning operation will be described. The lead screw (6a) is rotated by the rotation of the coarse feed stepping motor (5a), and the head carriage (3) engaged with the spiral groove (39) provided in the lead screw (6a) is Performs a linear motion in the axial direction (A). This is the same principle as that in a combination of a bolt and a nut, when the bolt (lead screw) rotates, the nut (head carriage) moves in the axial direction of the bolt. In addition, the lead screw (6b) is rotated by the rotation of the stepping motor (5b) for fine feed, and the lever arm (which engages with the spiral groove (39) provided in the lead screw (6b) ( 56) rotates in the B direction around the fulcrum pin (48). Rotation of the lever arm (56) causes the lead screw (6a) and the lever arm (56) to engage with each other (2
0) also moves slightly in the B direction. The lead screw (6a) can be freely rotated with respect to the lever arm (56) in the engaging portion (20), but the lever arm (56) can be moved in the B direction by A of the lead screw (6a). It has a structure that can be converted into movement in the direction. As described above, in the lead screw (6a), since the rotor (80) and the rotary shaft (22) of the coarse feed stepping motor (5a) can move in the A direction, the lever arm (56) moves in the B direction. Is converted to the movement of the lead screw (6a) in the A direction.
The accuracy of the movement in the A direction is determined by the ratio of the length from the fulcrum pin (48) to the engaging portion (20) and the length of the lever arm (56). The movement accuracy of the head carriage (3) in the A direction by the rotation of (5a) can be made finer. Therefore, the coarse feed mechanism moves between tracks, and the dense feed mechanism performs track tracking on the same track, so that the magnetic head can be positioned with high accuracy.

Further, Japanese Patent Application Laid-Open No. 63-52384 discloses, as a head moving device, a technique for moving the lead screw in the axial direction thereof via a fine movement mechanism as in the above-mentioned US patent.

[Problems to be Solved by the Invention]

The conventional positioning device such as a magnetic head is configured as described above, and has the following problems in positioning.

Generally, when a stepping motor is used, a displacement angle is generated by the load torque applied to the rotor, and the displacement angle is doubled when accessed in both positive and negative directions. The increase in load torque is mainly related to the friction generated when moving the head carriage. Therefore, in the method using the stepping motor, it is difficult to secure the accuracy when performing the positioning correction based on the information from the servo sector. Particularly, in the method using the conventional lead screw shown in FIG. 10, the friction between the lead screw (6) and the lead guide bar (7) and the friction between the guide rod (4) and the head carriage (3) are reduced. At the same time, it is necessary to use a stepping motor with a large thrust, which is a technical and cost problem.

Further, even in a system in which two stepping motors are provided and rough feed is performed on one side and fine feed is performed on the other side, the rotor (80) and rotary shaft (22) in the stepping motor are axially oriented. The use of a special stepping motor that can be moved to and from the lever arm (56) and the fulcrum pin (48) make the structure complicated, and engage with the lead screws (6a) and (6b). Due to the fact that the parts must be special, there was the problem of requiring expensive members and special structures.

The present invention has been made in order to solve the above problems, and an object thereof is to realize a positioning device with high accuracy relatively easily by using the structural know-how of the device using the conventional technology. .

[Means for solving the problem]

The positioning device according to the first invention has the following elements.

(A) a head portion having an engaging portion, (b) a motor having a rotating shaft, (c) an engaged portion that engages with the engaging portion of the head portion, and is integrally formed with the rotating shaft of the motor. (D) Linear movement of the head portion at a predetermined conversion ratio of rotational movement of the rotating body through engagement of the engaging portion of the head portion and the engaged portion of the rotating body. And (e) means for switching and selecting the moving accuracy of the head portion by changing the conversion ratio for converting the rotary motion to the linear motion. f) Detection means for detecting the reference position of movement of the head section by monitoring the rotation state of the rotating body.

Further, the positioning device according to the second invention has the following elements.

(A) Head part, (b) First and second motors for moving the head part to a predetermined position, (c) Converting rotational motion of the first motor into linear motion, and transmitting the linear motion to the head part. First conversion means, (d) a gear that reduces the rotation speed of the second motor, (e) the head part is freely moved by the first conversion means when the first conversion means is in operation. And second conversion means for converting the rotational movement of the gear into a linear movement and transmitting the linear movement to the head portion, (f) monitoring the rotational state of the gear to detect the reference position of movement of the head portion. Detection means.

A third aspect of the present invention is a head unit positioning device that moves a head unit that acts on a medium to an arbitrary position on the medium and positions the head unit, wherein a carriage on which the head unit is mounted is engaged with the carriage. A first drive unit that moves the carriage, and a second drive unit that moves the carriage by engaging with the carriage are provided, and at least one of the first drive unit and the second drive unit. One of the features is that detection means for detecting a reference position of movement is provided.

Further, the first driving means has a first lead screw that engages with the carriage, the carriage is moved by rotating the first lead screw, and the second driving means is A second lead screw engaging with the carriage is provided, and the carriage is moved by rotating the second lead screw.

Further, a speed reducing mechanism is provided in either one of the first driving means and the second driving means.

Further, the detection means detects the reference position of movement of the carriage based on the rotation angle of the lead screw.

A seventh aspect of the invention is a head unit positioning device that moves a head unit that acts on a medium to an arbitrary position on the medium and positions the head unit, wherein a carriage equipped with the head unit is engaged with the carriage. A first driving means for moving the carriage; and a second driving means for moving the carriage by engaging the carriage, wherein the first driving means engages with the first carriage. The carriage has a lead screw and moves the carriage by rotating the first lead screw, and the second drive means has a circumferential portion having a spiral groove engaging with the carriage and the spiral. A second lead screw having a flat portion having no groove,
The second lead screw is rotated to engage the spiral groove in the circumferential portion with the carriage to move the carriage, and the flat portion disengages the carriage, and the first driving means is provided. It is characterized in that the carriage can be moved freely by.

[Action]

In the positioning device according to the first aspect of the present invention, the means for switching the movement accuracy of the head portion can independently perform the coarse feed movement and the fine feed movement without interfering with each other. As a result, rough feed can be performed in the initial stage of positioning, and fine feed can be performed in the latter stage of positioning, which enables high-speed and highly accurate positioning. And
Since the coarse feed and the fine feed can be independently performed by the switching means, most of the conventional means for converting the rotational movement into the linear movement can be applied to the head portion positioning means, and the structure is simplified. For example, using two sets of conventional stepping motor and lead screw, the first set performs coarse feed positioning for each track unit in the same way as the conventional floppy magnetic disk device, and another set of stepping motor and lead By performing off-track correction that requires dense feed in the screen and switching between these two, it is possible to always perform accurate tracking.

Further, according to the present invention, accurate positioning is performed by detecting the movement reference position of the head portion by monitoring the rotation state of the rotating body.

In the positioning device according to the second aspect of the present invention, the first conversion means converts the rotational movement of the first motor into a linear movement to position the head portion, and the second conversion means operates the first conversion means. In some cases, the first converting means allows the head section to move freely, so that the first converting section can position the head section without being affected by the second converting section.

Further, the second conversion means converts the rotational movement of the gear that reduces the rotational speed of the second motor into a linear movement.
It is possible to position the head with a positioning accuracy different from that of the converting means of.

Further, according to the present invention, the reference position of movement of the head portion is detected by monitoring the rotation state of the gear, and accurate positioning is performed.

In the positioning device according to the third aspect of the present invention, the first drive means engages with the carriage to move the carriage, and the second drive means also engages with the carriage to move the carriage. By changing the positioning accuracy of to the positioning accuracy of other driving means,
It is possible to move by rough feed and fine feed.

Further, according to the present invention, the reference position of the movement of the head portion is detected to perform accurate positioning.

In the positioning device according to the fourth aspect of the invention, both the first driving means and the second driving means have lead screws, and the carriage is moved by rotating each of the lead screws. Positioning by coarse and fine feed is possible without taking a complicated structure such as moving in the direction.

In the positioning device according to the fifth aspect of the invention, since the speed reducing mechanism is provided in either one of the first drive means and the second drive means, the same motor is used for the first and second drive means. Even if there is, the deceleration mechanism enables positioning by coarse and fine feed.

In the positioning device according to the sixth aspect of the present invention, the detecting means detects the reference position based on the rotation angle of the lead screw, so there is no need to detect the reference position from the linear movement of the head portion.

In the positioning device according to the seventh aspect, the carriage is densely fed by the circumferential portion of the second lead screw, the carriage is disengaged by the flat portion, and the rough feed of the first lead screw is freely performed.

〔Example〕

The first embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a stepping motor (5) serving as a means for rotating or stopping a lead screw as a rotating body is provided on the left and right of the head carriage (3) as a moving body.
There are a) and (5b), (5a) is a stepping motor for coarse feed, and (5b) is a stepping motor for fine feed for precision feed. Here, the structure of the coarse feed mechanism will be described first. The lead screw (6a) is connected to the stepping motor (5a) for coarse feed, and the head carriage (3) is operated by a mechanism similar to that of the device using the conventional lead screw shown in FIG. That is, the lead screw (6a) engages with the spiral feed groove (39) of the lead guide bar (7a) and the coarse feed stepping motor (5a).
Guide rod (4) for feeding the head carriage of the moving guide (19) connected to the preload spring (8a) according to the movement of the
Move in the direction A along. This moving guide (19) has a structure in which the head carriage (3) and the helical spring (21) are tensioned with each other, and as a result, the moving guide (19)
And the head carriage (3) move linearly in conjunction with each other.

Next, the configuration of the close feed mechanism will be described. The drive gear (23) attached to the rotary shaft (22) of the stepping motor (5b) for close-feeding and the reduction gear (24) are mechanically meshed with 1 to N (N is 1 or more), and the reduction gear The lead screw (6b) is located at the center of (24), and the rotation of the stepping motor (5b) for fine feed smoothly rotates the lead screw supported by the bearings (25a) and (25b). . The lead screw (6b) is combined with the lead guide bar (7b) to support the head carriage (3) via preload springs (8a) and (8b).

FIG. 2 is a diagram showing the relationship between the lead guide bar (7b) and the lead screw (6b) of the dense feed mechanism of the present invention. The lead screw (6b) lacks a part of the cross section as shown in the figure, and has a shape in which a part of the lead screw, which has been grooved in a spiral shape in advance in a cylinder, is cut. While the coarse feed mechanism is operating, as shown in (a) of the figure, the missing portion of the lead screw is oriented in the direction of the lead guide bar (7b), and the lead guide bar (7b) is Since it does not contact (6b), the fine feed mechanism does not interfere with the operation of the coarse feed mechanism. The means for switching and selecting the movement accuracy is to move the lead screw (6b) of the precision feed mechanism in the direction of the arrow in Fig. 2 (b) at the stage when the rough feed mechanism reaches the preset track position or shortly before it reaches. When the coarse feed mechanism completely stops the seek, the lead screw bar (7b) is engaged with the lead screw (6b), and then the precision feed operation is started.

The lead screw and the lead screw bar (7b) do not engage with each other in a flat portion where a part of the cross section of the lead screw (6b) is missing. Therefore, when the lead screw (6b) once engages with the lead screw bar (7b) and then rotates again to reach a flat part where a part of the cross section is missing, the lead screw bar (7b) The screw (6b) is disengaged. Precision feed is performed only while the lead screw (6b) and the lead screw bar (7b) are engaged. That is, in the circumferential portion other than the flat portion of the lead screw (6b), engage with the lead screw bar, and the engagement with the circumferential portion allows the lead screw bar to move at least a distance necessary for precision feeding. deep. For example, when the minimum required distance for precision feed is one track, the moving distance of the lead screw bar (7b) by the circumferential portion of the lead screw (6b) is set to one track or more.

FIG. 3 shows a drive gear (23) and a reduction gear (24) of the present invention.
It is a figure showing a combination state of the gears. In the figure, (a) is a diagram showing a meshed state of gears, and (b) is an embodiment diagram in which the photodetecting means is provided in (a). In the figure, (26) is a light transmission slit provided on the reduction gear, and (27) is a photo sensor. The reduction gear (24) rotates in conjunction with the rotation of the drive gear (23), and the light from the light emitting element built in the photo sensor (27) is transmitted through a certain section of the reduction gear (24). Since the light passes through the slit (26) and illuminates the light receiving element, an electrically ON signal is generated during this period. In addition, at the location where there is no light transmission slit (26), the light from the light emitting element of the photo sensor (27) does not reach the light receiving element, so the signal is turned off. Therefore, it serves as a sensor that rotates the reduction gear to a predetermined position and detects it. By applying this to the rotation angle control of the lead screw (6b) in Fig. 2, the fine feed mechanism is prevented from interfering during the operation of the coarse feed mechanism, and the coarse feed operation and the precision feed operation are switched and selected. Positioning can be performed smoothly. That is, in the control of the coarse feed mechanism,
By positioning the lead screw in the state shown in Fig. 2 (a) so that the lead guide bar (7b) does not come into contact with the lead screw (6b), the coarse feed operation can be performed independently and the precise feed operation This is possible from the stage when the operation shifts from (b) to (c) in Fig. 2. The lead guide bar (7b) can move the head carriage (3) back and forth in minute units along the groove of the lead screw (6b). it can. However, it is necessary to operate the head carriage (3) of FIG. 1 after leaving the movement guide (19) to obtain a distance required for tracking the track. That is, when the lead guide bar (7b) is moved in the A ₁ direction, the moving guide (19) is in contact with the lead guide bar (7a) and the lead screw (6a) of the coarse feed mechanism when the A ₁ Since the structure is such that it cannot move in the direction, the stepping motor (5a) for coarse feed is operated after the state shown in FIG. 2 (c) is reached.
Move the lead guide bar (7a) in the A ₁ direction via
After the moving guide (19) is separated from the head carriage (3), the lead guide bar (7b) is moved in the A1 direction.

Alternatively, the coarse feed mechanism should move the head carriage until half a track before the target track, and after the coarse feed mechanism has positioned it until a half track before, the fine feed mechanism unconditionally removes the remaining half track. It may be moved and then track followed.

Next, after the track following operation is completed, it is possible to move to a new track by returning from the state of (c) of FIG. 2 to the state of (a) and operating the coarse feed mechanism. The pitch of the lead screw for coarse feed (6a) advances at the step angle of the stepping motor (5a), so the feed distance is designed to be equivalent to one track, and the lead screw for precision feed (6b) is designed. The pitch of the screw is related to the ratio of the gears of the drive gear (20) and the reduction gear (21) and the feed angle per pulse of the stepping motor, but the head feed pitch per pulse is 1/10 or less of one track. It is preferable to design so that

Next, a second embodiment will be described with reference to FIG. In the first embodiment described above, the moving guide (19) and the head carriage (3) are arranged to be pulled by the spiral spring (21), but as shown in FIG. 4, the spiral spring (21) is pulled. Place the two between the moving guide (19) and the head carriage (3) with a predetermined distance (usually a half-track) sufficient for moving the head carriage in the A ₁ direction by the dense feed mechanism. You may do it. The spiral spring (21) interlocks the head carriage (3) when the movement guide (19) moves. The spiral spring (21) expands and contracts when a force is applied in the A1 direction and the A2 direction,
When no force is applied in the A1 direction or the A2 direction, the movement guide (19) and the head carriage (3) are made to stand still, for example, keeping a distance of a half track. And
The distance between the two when moving shall be strong enough to maintain the same predetermined distance as when stationary. Then, when the dense feed mechanism operates and the head carriage (3) moves in minute units, the winding spring (21) that is produced when moving in any direction (A ₁ , A ₂ direction) can absorb the minute movement. To The helical spring (21) stops the moving guide (19) and the head carriage (3) half a track apart when no force is applied in the A1 or A2 direction. When moves, it cannot withstand the force and expands and contracts. With such a structure, when the head carriage (3) is moved in the A ₁ direction by the dense feed mechanism as shown in the first embodiment, the movement guide (19) is previously moved by the coarse feed mechanism to the A direction. Eliminates the inconvenience of having to move in _one direction. Alternatively, it is not necessary to move to the front of the semi-track by coarse feed and unconditionally advance the semi-track by dense feed. In the first and second embodiments described above, the spiral spring (21) is an example, and as long as it has the elastic function of the spiral spring (21), it may be rubber or an elastic body. Often, the same effect as the present invention is achieved.

FIG. 5 is a diagram showing a third embodiment of the present invention.
In the figure, (6a) and (6b) are lead screws, but the pitch (Pa) of the groove (39) of the lead screw (6a).
Is larger than the pitch (Pb) of the groove (39) of the lead screw (6b). Moreover, the reduction gear (24) does not exist, and the rotation shaft of the stepping motor (5b) and the lead screw (6b) are coaxial. In other respects, it has the same structure as the above-mentioned embodiment. In this embodiment, the accuracy of movement of the head carriage (3) is changed by changing the groove pitches of the lead screws (6a) and (6b). For example, the groove pitch (Pa) is twice as large as the groove pitch (Pb), and the stepping motors (5a), (5
If the feed angle per pulse in b) is the same, the positioning by the fine feed mechanism will be twice as accurate as that by the coarse feed mechanism.

Also, as an improvement example of FIG. 5, groove pitch (Pa) and (P
Steps b) are the same and stepping motors (5a) and (5b)
It is also possible to use those having different feed angles per pulse. Furthermore, by changing the groove pitches (Pa) and (Pb) and using different stepping motors (5a) and (5b) with different feed angles per pulse, the groove pitch and feed angle are synergistically , The positioning accuracy may be switched.

In the above embodiment, the lead screens (6a), (6a)
Although b) engages the lead guide bars (7a) and (7b) to move the head carriage (3), a structure similar to the conventional bolt and nut combination can be used. FIG. 6 is an embodiment diagram in the case of assuming a conventional combination of a bolt and a nut. In the figure, (a) shows a coarse feed configuration and (b) shows a precision feed configuration.

Even in the case of this bolt and nut combination, by changing the groove pitches (Pa) and (Pb),
The positioning accuracy can be selected as in the case of the combination of the lead screen and the lead guide bar. Furthermore, the positioning accuracy can be selected by using the stepping motors (5a) and (5b) with different feed angles per pulse, as in the case of the combination of the lead screw and the lead guide bar. .

Next, FIGS. 7 and 8 are views showing an embodiment using the steel belt system. FIG. 7 (a) is a perspective view of a steel belt, FIG. 7 (b) is a diagram for explaining the operation of the steel belt system, and FIG. 8 is a diagram in which the steel belt system is applied to the present invention. , (30) is a steel belt, (31) is a pulley around which the steel belt is wound,
(5) is a stepping motor having a rotating shaft (22) for rotating a pulley, and (19) is both ends (30) of a steel belt.
A) and (30b) are fixed moving guides, and (4) is a guide rod for sliding the moving guide (19) in the A direction.

Next, the operation will be described. When the stepping motor (5) rotates, the pulley (31) also rotates, and the steel belt (30) wound in pressure contact with the pulley (31) also moves. Both ends (30a) and (30b) of the steel belt (30) are fixed to the movement guide (19), and the stepping motor (5) and the rotary shaft (22) of the pulley (31) are also fixed. Therefore, rotation of the pulley (31) causes the movement guide (1
9) slides the guide rod (4) in the A direction. The steel belt thus converts rotational movement into linear movement. FIG. 8 uses this steel belt system for a coarse feed mechanism, and the dense feed mechanism is the same as that of the embodiment shown in FIG.

Also in the embodiment using the steel belt system, an example in which the moving guide (19) and the head carriage (3) are separated by a predetermined distance as shown in FIG. 4 can be applied. Further, the combination of the bolt and nut shown in FIG. 6 (b) may be used for the close feed mechanism.

Further, in the above embodiment, the case where the steel belt system is used for the rough feed mechanism is shown, but the spiral cam system may be used for the rough feed mechanism.

FIG. 9 is a view showing another embodiment according to the present invention, in which the lead guide bar (7) has an elliptical cross section instead of a circle. (A) And (b) is a sectional view and a side view when the lead guide bar (7) is engaged with the groove (39) of the lead screw (6). Also, in (c) and (d), the lead guide bar (7) rotates 90 degrees and the groove (3
FIG. 9 is a cross-sectional view and a side view when not engaging 9). This is an example of disengaging the lead guide bar (7) and the lead screw (6), but when the lead guide bar (7) rotates 90 degrees, the To prevent the close feed mechanism from preventing this movement,
It is when you want to disengage the tight feed mechanism. Also,
On the contrary, it is when it is desired to disengage the coarse feed mechanism during the operation of the fine feed mechanism so that the coarse feed mechanism cannot prevent this operation. As described above, the method of rotating the lead guide bar (7) by 90 degrees is, for example, when the lead guide bar (7) is connected to the shaft of a new stepping motor (not shown) and the coarse feed and the fine feed are switched. In addition, the lead guide bar (7) may be rotated 90 degrees by this new stepping motor. When the stepping motor (5a) for coarse feed starts its operation, the fine feed mechanism is disengaged at the first rotation and the coarse feed mechanism is engaged, and vice versa. When the stepping motor (5b) starts its operation, the coarse feed mechanism may be disengaged and the fine feed mechanism may be engaged at the first rotation of the stepping motor (5b). In this way, when the movement precision is switched and selected, the coarse feed mechanism and the fine feed mechanism can operate independently without interfering with each other.

In addition, as an example of disengagement, the cross section of the lead guide bar (7) is circular as usual, and a force is applied between the lead guide bar (7) and the preload spring (8a) to separate them. 9 By setting the clearance (x) between the head carriage (3) and lead screw (6) shown in Fig. 9 (b) to zero, the lead screw (6) and lead guide bar (7) are disengaged. Good.

As described above, the case where the positioning device according to the present invention is applied to the magnetic disk device is summarized as follows.

(1) In a magnetic disk device that has a feed mechanism that uses a stepping motor as a drive source and moves a head / carriage via a lead screw to position the head on an arbitrarily selected track, rough feed in track pitch units is applied to one of the head carriages. The coarse feed mechanism consisting of the attached stepping motor and lead screw, steel belt, or spiral cam is used, and precise positioning control in the range of about 1 track is performed by the same stepping as the coarse feed mechanism attached to the head carriage. A magnetic disk device characterized by using a dense feed mechanism composed of a lead screw having a cross section having a semicircle or a circumference of a semicircle or more at the center of a drive gear and a reduction gear attached to a motor and its rotation shaft. .

(2) Rough feed operation is performed by rotating the lead screw of the fine feed mechanism and directing the flat surface toward the lead screw without the lead screw and the lead guide bar contacting each other. The magnetic disk device according to (1) above, wherein the magnetic disk device is capable of performing tracking from a state where the lead guide bar and the lead screw are in contact with each other and performing track following within a range in which the lead guide bar can move along the groove of the lead screw.

(3) When a lead screw is used for the coarse feed mechanism, the lead guide bar that is in contact with the groove of the coarse feed lead screw is mechanically connected to the moving guide that moves on the guide rod for the head carriage feed. The magnetic guide device according to (1) above, wherein the moving guides are connected to each other by a head carriage and a spiral spring.

(4) The magnetic disk according to (1) above, wherein the precision feed can be operated only in a range in which the spiral spring connecting the moving guide and the head carriage is extended with the coarse feed mechanism stopped. apparatus.

(5) When a lead screw is used in the coarse feed mechanism, its groove pitch is determined by the pitch between the tracks of the applicable device, and the groove pitch of the lead screw of the fine feed mechanism and the arc of the cross section of the lead screw are tracks. The magnetic disk device according to (1) above, which is determined by the tracking accuracy and the tracking range.

(6) The magnetic disk device according to the above (1), wherein the reduction ratio between the reduction gear and the drive gear can be arbitrarily set by the feed accuracy per pulse of the stepping motor and the track following speed.

(7) An arc-shaped through hole is formed in the reduction gear, and optical sensors consisting of a light emitting element and a light receiving element are attached to both sides of the through hole to detect the rotational position of the reduction gear and the position of the lead screw of the fine feed mechanism. The magnetic disk device according to (1) above, which is capable of sensing

(8) The magnetic disk device according to (1) above, wherein the lead screw of the coarse feed mechanism or the fine feed mechanism has a structure in which it is held by preload springs in the vertical and horizontal directions.

(9) The coarse feed mechanism is operated by open loop control,
The dense feed mechanism reads track position information from the magnetic recording disk through the magnetic head, performs closed loop control operation, and follows the magnetic head so that it is always located at the center of the track (1). The magnetic disk device described.

The positioning device according to the present invention has been described above by taking the case of a magnetic disk device as an example. The present invention can be summarized as a general moving device positioning device as follows.

(A) Moving body having first and second engaging portions, (B) Positioning means for rough feed having the following elements, (a) Engagement engaged with the first engaging portion of the moving body A first rotating body having a portion, (b) means for rotating the first rotating body in forward and reverse directions, or for making it stationary, (c) first engaging portion of the moving body and the first rotating body Means for converting the rotational movement of the first rotating body into the linear movement of the moving body through the engagement of the engaged portion of (1), and positioning the moving body by the rotational stationary of the first rotating body, (C) (A) a second rotating body having an engaged portion that engages with a second engaging portion of the moving body, and (b) a second rotating body Means for rotating or stationary in the direction of rotation, (c) The rotation of the second rotating body through the engagement of the second engaging portion of the moving body and the engaged portion of the second rotating body. A means for converting a motion into a linear motion of a moving body with a moving accuracy different from that of the first positioning means, and positioning the moving body by the rotation stationary of the second rotating body, (D) Positioning control having the following elements Means, (a) means for selecting one of the first positioning means and the second positioning means, (b) a moving body by means of one of the first positioning means and the second positioning means Means for independently moving the engaging means of the moving body and the engaged portion of the rotating body in the other means.

〔The invention's effect〕

As described above, according to the first aspect of the present invention, the conventional coarse feed mechanism is provided with the fine feed mechanism, and the movement accuracy switching selection means is provided so that the two can operate independently without interfering with each other. This has the effect of providing a highly accurate and relatively inexpensive positioning device.

Further, by detecting the reference position by the detecting means, accurate positioning can be performed.

According to the second aspect of the invention, the first converting means provides the first converting means.
The converting means can freely position the head, and the second converting means can use the gear to position the head portion with accuracy different from that of the first converting means.

Also, according to the present invention, the reference position can be detected by monitoring the rotation state of the gear, and accurate positioning can be performed.

According to the third aspect of the invention, the first drive means and the second drive means engage with the carriage to move the carriage, respectively, so that the first drive means and the second drive means have a simple configuration. With this, it is possible to position the head portion, and there is an effect that a relatively inexpensive positioning device can be obtained.

Further, according to the present invention, accurate positioning can be performed by detecting the reference position of movement. The reference position can be detected by a simple configuration of detecting the rotation angle of the lead screw.

Further, according to the fourth aspect of the invention, the first and second driving means are configured by using a conventional mechanism called a lead screw, so that a relatively inexpensive positioning device can be obtained.

Further, according to the fifth aspect of the invention, since the positioning can be performed by the fine feed by the reduction mechanism, the first drive means and the second drive means can perform the rough feed and the fine feed with substantially the same configuration. There is an effect.

Further, according to the sixth aspect of the present invention, the detection unit detects the reference position of movement of the carriage based on the rotation angle of the lead screw, thereby enabling precise positioning based on the detected reference position. Become.

According to the seventh aspect of the invention, the rough feed mechanism and the fine feed mechanism can operate without interfering with each other due to the simple structure in which a part of the cross section of the lead screw is omitted.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a magnetic disk device according to an embodiment of the present invention, FIG. 2 is a diagram showing a relationship between a lead guide bar and a lead screw of a close feed mechanism of the present invention, and FIG. Showing a combination state of the drive gear and the reduction gear of FIG. 4, FIG. 4 is a view showing a second embodiment of the magnetic disk device according to the present invention, and FIG. 5 is a third embodiment of the magnetic disk device according to the present invention. FIG. 6 is a diagram showing an example, FIG. 6 is a diagram showing an embodiment of the present invention when a conventional combination of bolt and nut is assumed, and FIGS. FIG. 9 is a diagram showing an embodiment of the present invention, FIG. 9 is a diagram showing the relationship between the lead guide bar and the lead screw in another embodiment of the present invention, and FIG. 10 is a schematic diagram of a conventional Flotpie magnetic disk device. Figure 11 shows a conventional lead Fig. 12 shows the relationship between the id bar and the lead screw, Fig. 12 shows the layout of servo information in the sector servo system, and Fig. 13 shows the servo system for positioning the head using the servo sector information. The figure is a diagram showing a conventional magnetic disk device having a coarse feed mechanism and a fine feed mechanism. (1) is a magnetic recording disk, (2) is a magnetic head, (3) is a head carriage, (4) is a guide rod, (5) is a stepping motor, (6) is a lead screw, (7).
Is a lead guide bar, (8) is a preload spring, (9) is a frame, (10) is a servo sector area, (11) is a data sector area, (12) is a spindle motor, (14) is a drive mechanism, and (15) ) Is an amplifier circuit, (16) is a position detection circuit,
(17) is a control circuit, (18) is a current amplifier, (19) is a movement guide, (20) is an engaging part, (21) is a helical spring, and (22).
Is a rotating shaft, (23) is a drive gear, (24) is a reduction gear, and (2
5) bearings, (26) light-transmitting slits, (27) photo sensors, (30) steel belts, (31) pulleys,
(37) indicates a steel ball, (38) indicates a lubricating pipe, and (39) indicates a groove. In the drawings, the same reference numerals indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-61-217968 (JP, A) JP-A-58-144593 (JP, A) JP-A-55-92596 (JP, A) JP-A-63- 209073 (JP, A) JP 63-52384 (JP, A) JP 58-151613 (JP, A) Actually opened 56-163843 (JP, U) Actually opened 49-37684 (JP, U) 57-60211 (JP, U) US Patent 4630145 (US, A)

Claims (7)

[Claims] 1. A head positioner having the following elements: (a) a head part having first and second engaging parts, and holding the first engaging part through an elastic member; ) First and second motors having a rotating shaft, (c) A rotating shaft of the first motor, which has a first engaged portion that engages with the first engaging portion of the head portion. Engagement / non-engagement of the first rotating body integrally formed with the second engaging portion of the head portion can be selected according to the rotation angle, and is integrated with the rotating shaft of the second motor. A configured second rotating body, and (d) the first and second engaging portions of the head portion and the engaged portions of the first and second rotating bodies engage with each other And a means for converting the rotational movement of the second rotating body into a linear movement of the head portion at a predetermined conversion ratio, and positioning the head portion by the rotational stationary of the first and second rotating bodies. The first engaging portion and the engaged portion of the first rotating body are engaged with each other, and
The rough positioning of the head portion is performed without engaging the engaging portion of the second rotating body with the engaging portion of the second rotating body, and the second engaging portion and the second rotating body are engaged, and the first engaging portion and the second rotating body are engaged. No. 1 means for moving the head portion within the elastically deformable range of the elastic body while performing engagement with the engaged portion of the rotating body to perform fine positioning, (e) the rotating state of the rotating body. Detecting means for detecting the reference position of the movement of the head portion by monitoring. 2. A head positioner having the following elements: (a) head part, (b) first and second motors for moving the head part to a predetermined position, (c) the first motor. First conversion means for converting the rotational movement of the above into a linear movement and transmitting it to the head portion, (d) a gear for reducing the rotational speed of the second motor, (e) a linear movement of the rotational movement of the gear. A second converting means including a lead screw and a lead guide bar for converting and transmitting to the head portion, and by disengaging the lead screw and the lead guide bar, when the first converting means operates, Second converting means for freely moving the head portion by the first converting means, (f) Detection means for detecting a reference position of movement of the head portion by monitoring a rotation state of the gear. 3. A head unit positioning apparatus for moving and positioning a head unit acting on a medium to an arbitrary position on the medium, wherein a carriage on which the head unit is mounted, and the carriage engaging with the carriage, The first drive means for coarsely moving and the second drive means for engaging with the carriage to move the carriage densely are provided, and the first drive means is configured to close the carriage by the second driving means. The second drive means is engaged with the carriage via an elastic body that absorbs movement.
In order to allow the coarse movement of the carriage by the first drive means,
A positioning device for a head portion, characterized in that engagement of a carriage is released. 4. The first drive means has a first lead screw that engages with the carriage, and the carriage is moved by rotating the first lead screw, while the second drive means is provided. The driving means is a second means for engaging with the carriage.
The lead screw, and the carriage is moved by rotating the second lead screw within the range of the predetermined rotation angle, and the second lead screw is rotated outside the range of the predetermined rotation angle. The positioning device according to claim 3, wherein the engagement with the carriage is released. 5. The positioning device according to claim 3 or 4, wherein one of the first driving means and the second driving means is provided with a speed reducing mechanism. . 6. A detecting means for detecting a reference position of movement is provided in at least one of the first driving means and the second driving means, and the detecting means comprises:
The positioning device according to claim 4 or 5, wherein the reference position of the movement of the carriage is detected based on the rotation angle of the lead screw. 7. A head positioner for moving and positioning a head part acting on a medium to an arbitrary position on the medium, comprising: a carriage on which the head part is mounted; A first driving means for moving the carriage, and a second driving means for moving the carriage by engaging the carriage, wherein the first driving means engages with the carriage by the first driving means.
And a second driving means for moving the carriage by rotating the first lead screw, and the second driving means includes a circumferential portion having a spiral groove that engages with the carriage, and A carriage having a second lead screw with a flat portion having no spiral groove, and rotating the second lead screw to engage the spiral groove of the circumferential portion with the carriage. And a flat portion that disengages the carriage to allow the carriage to be freely moved by the first driving means.