JPS63183666A - Reference track detecting mechanism - Google Patents

Abstract

PURPOSE:To simplify a track detecting mechanism by providing a mechanical limit on a feed screw member for moving a head to the outside periphery further from a reference track provided on the outside periphery of a disk-like recording medium, and detecting a fact that the head exists in the outermost periphery of whether its screw turns or not. CONSTITUTION:A magnetic head 1 is fixed to a head holding member 2, and this member 2 is coupled to a first guide shaft 3 like a round bar, and guided so as to be movable linearly in the radial direction passing through the rotation center of a magnetic disk rotation driving motor 30. Also, a second guide shaft 16 like a round bar is coupled to a groove 15 provided on one end of the member 2, and by the guide shaft 16 coupled to this groove 15, turning of the member 2 for using the guide shaft 3 as the rotation center is controlled. Also, to the tip of a shaft 8 for receiving a driving rotational force from a stepping motor 5, a rotation limiting member 40 for abutting on a rotation limiting member 2c of the member 2 which can move by turning, and limiting the turning of the shaft 8 is attached with a screw 40a, and turning of a projection 41 provided on the member 40 is detected by a photointerrupter 42.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention records information so as to rotate a disc-shaped recording medium to form a plurality of concentric recording tracks at equal intervals, or The present invention relates to a mechanism for detecting a reference position of a head feeding device for moving a recording or reproducing head a certain distance in the radial direction of a rotating disc-shaped recording medium in order to reproduce information on a recording track recorded on a recording medium.

[Prior Art] There are various types of disk-shaped recording media, and a typical example will be described below using a floppy magnetic disk as an example.

For the recording tracks of floppy magnetic disks, the outermost track radius, innermost track radius, and track spacing between tracks are determined by various standards. When recording on a recording track, the track position specified by the standards is determined. For this purpose, a general head feeding device is equipped with a means for detecting that the magnetic head is on a reference track that serves as a reference for absolute position, such as the outermost track, and The head is moved to a reference track, and each time recording is performed, the magnetic head is moved by a predetermined track interval (track pitch) to sequentially record on the magnetic disk so as to form concentric tracks.

Take, for example, the so-called still floppy disk, which was developed and standardized for an electronic still camera system that records still images on a magnetic disk using an electronic camera.
There are 50 recording tracks, and the pitch of the recording tracks is 0. Since the reference track is extremely minute, several reference track detection mechanisms have been devised.

Conventional methods for detecting a reference track in this type of device are as follows: 1. The outermost track of the magnetic disk is used as the reference track, and a restriction member is provided to prevent the magnetic head from moving further outside beyond the outermost track. When positioning the head on the reference track, current pulses for 50 tracks are applied to drive the magnetic head, assuming that the magnetic head is located on the innermost track regardless of the current position of the head. Sent to the stepping motor.If the initial position of the magnetic head was not on the innermost track, the driving force of the stepping motor is transferred to the stepping motor after the magnetic head moves to the outermost track and comes into contact with the limit. A method in which the reference track is obtained by absorbing the motor's magnetic slip and causing the magnetic head to remain on the outermost track.

2. The magnetic head drive device is equipped with a track minute position detection mechanism that provides an output every 10 tracks, and a track coarse position detection mechanism that provides an output when the magnetic head is within 10 tracks from the outermost track. , a method of detecting a reference track by the logical product of the above two detection mechanisms.

There is.

[Problem that the invention seeks to solve]

However, in the first method, the drive mechanism of the magnetic head is limited to the maximum number of tracks that the magnetic disk has (for example, 50 times).
However, there are disadvantages in that it generates noise, reduces the durability of the device, and takes a long time to complete the entire sequence.

Furthermore, the second method has a problem in that the detection mechanism becomes complicated and the manufacturing cost increases.

The present invention aims to solve these drawbacks and to obtain a highly accurate reference track detection mechanism in a short time and at low manufacturing cost.

[Means for solving problems]

The present invention provides a method for recording information by rotating a disc-shaped recording medium to form a plurality of concentric recording tracks at equal intervals, or for reproducing information from recording tracks recorded in such a manner. In a head feeding device for moving a recording or reproducing head at regular intervals in the radial direction of a rotating disc-shaped recording medium, the head moves further to the outer periphery from a reference track provided on the outer periphery of the disc-shaped recording medium. In order to prevent this, a mechanical limit is provided to the feed screw member that moves the head, and a head stop detection means is provided to detect whether or not the head is moving by detecting whether or not the feed screw is rotating. When the head is on the outermost track, even if the motor that drives the feed screw is energized to move the head further to the outer circumference, the feed screw member will not rotate due to mechanical limitations and the head will not move. A head stop detection means detects that the head is located on the outermost track.

〔Example〕

FIG. 1 is a plan view showing an embodiment of the present invention.

First, the configuration will be explained. Reference character l denotes a magnetic head, and the magnetic head 1 is fixed at a predetermined position on a head holding member 2. As shown in FIG. An electric cable 1a for transmitting signals to the magnetic head 1 passes through 'llll2b provided on the head holding member 2 and is connected to a recording/reproducing circuit (not shown). The head holding member 2 is fitted to a round bar-shaped first guide shaft 3 at -@14 and is guided so as to be movable in a radial direction (in the direction of the arrow) passing through the rotation center of the magnetic disk rotation drive motor 30. .

Further, a groove 15 is provided on the other end side of the head holding member 2, and a round bar-shaped second guide shaft 16 is fitted into the groove 15. Intervention first
The rotation of the head holding member 20 about the guide shaft 3 is restricted, and the vertical movement of the magnetic head 1 fixed to the head holding member 2 is restricted, and the direction in which the magnetic head contacts the magnetic disk 4 is controlled. The height is kept almost constant.

5 is a stepping motor for driving the head, and the rotational driving force from the stepping motor 5 is transmitted to the shaft 8 via gears 6 and 7. A male threaded portion 17 provided on the shaft 8 is screwed into a threaded engagement member 18 attached to the head holding member 2 to convert rotational motion of the shaft 8 into linear motion.

The rotation of the shaft 8 causes the head holding member 2 to slide in the direction D shown by the arrow. Further, the shaft 8 is fitted with a ball bearing 22, which is a bearing member, at a fitting portion 8a at one end remote from the screw engagement member.

22b is a ball bearing, and the inner ring 22a is an outer ring.

The outer ring 22a is a bearing holding member 9 fixed to the mounting board 31.
is maintained. A tension spring 21 is provided between the protrusion 2a provided at one end of the head holding member 2 and the pin 20 implanted in the mounting board 31, and the tension spring 21 is provided between the projection 2a provided at one end of the head holding member 2 and the pin 20 implanted in the mounting board 31. The driving gap between the head holding member 2 and the first guide shaft 3, and the fitting gap in the bearing section consisting of the ball bearing 22 in the direction of the blade feed (in the direction of the arrow) are removed or urged to be minimized. are doing.

At the tip of the shaft 8, there is a rotation limiting member 40 that comes into contact with the rotation limiting member contact surface 2C of the head holding member 2 that has moved due to the rotation of the shaft 8, and limits the rotation of the shaft 8.
The rotation limiting member 40 is attached with a screw 40.
a tightens the shaft 8 and rotates together with the shaft 8. Also, the rotation limiting member 4
0 is attached with a protrusion 41, and the presence or absence of this protrusion is detected by a photointerlab 42, which is an optical detection means. This protrusion is detected by a photointerrupter every rotation. At the standard position, it is adjusted so that it blocks the photo ink printer.

Of course, the protrusion may be configured to have a slit so that only that portion transmits light.

The innermost limit switch 50 is mounted on the substrate 31 in order to prevent the control circuit that controls the present head feeding device from going out of control and causing the magnetic head 1 to move inward from a predetermined innermost track. The protrusion 2a of the head holding member 2 that has moved inward from the predetermined innermost track comes into contact with the first electrical contact 50a of the innermost limit switch 50, and the electricity moved by the protrusion 2a A control circuit is configured to stop head feeding when the contact 50a comes into contact with the second electrical contact 50b.

FIG. 2 is an electrical block diagram for controlling the present head feeding device. A stepping motor 5 for moving the magnetic head is connected to the control circuit 60. A signal for lighting the LED 42a of the photointerrupter 42 is sent from the control circuit 60;
When the protrusion 41 blocks the light from the photo ink converter 42, the level changes from low to high. A signal is input to control circuit 60. Furthermore, the first contact 50a of the inner mift switch 50 is connected to the control circuit 60, and the second contact 50b is grounded. Also connected to the control circuit 60 is a recording and reproducing circuit 62 that controls the magnetic sheet rotation drive motor 30 and recording and reproducing signals of the magnetic head 1 .

FIG. 3 is a flowchart showing the flow of the control circuit for detecting the reference track in this embodiment.

4A to 4D show the movement of the device until the reference track is detected, and are an enlarged view of the vicinity of the rotation limiting member 40 shown in FIG. The movement of protrusion 41 is shown. Since the description of each member overlaps with the description of FIG. 1, it will be omitted.

FIG. 4A shows an example of the state of the apparatus before performing reference track detection. In FIG. 4B, the protrusion 41 is the photo ink printer 4.
2, the presence of the protrusion 41 is detected from the control circuit side, and the rotation limiting member 40 is not in contact with the rotation limiting member contact surface 2C. FIG. 4C shows a state in which the magnetic head has moved slightly toward the outer circumference compared to FIG. 4B.

FIG. 4D shows a state in which the magnetic head is on the reference track, and at this time, the protrusion 41 is attached to the photo ink club 42.
The rotation limiting member 40 is in contact with the rotation limiting member contact surface 2C, and the magnetic head does not move further toward the outer circumference.

The sequence for detecting a reference track, which is the gist of the present invention, will be explained using FIGS. 1 to 4 above. Although this sequence may be started at any time regardless of the position of the magnetic head, let us assume, for example, that the reference track detection sequence shown in FIG. 3 is started when the magnetic head is in the state shown in FIG. 4A. Then step 1
01 “ONJ was performed on the photo ink label LED,
The LED 42a of the photo ink club 4'2 is turned on.Next, Step 102 "Move the head one track to the outer periphery of the disk" is performed, and the rotation of the shaft 8 and the rotation attached to the shaft 8 is performed by the rotation of the stepping motor 5. The limiting member 40 and the protrusion 41 rotate by a predetermined angle in the direction of the arrow E (FIG. 4A), and as the shaft 8 rotates, the head holding member 2 and the magnetic head 1 move toward the outer circumferential side of the magnetic disk, that is, the arrow F (FIG. 4A). Move by one track pinch in the direction shown in Figure 4A).

In addition, when the magnetic head is on each predetermined recording track,
The excitation state (phase state a) of each excitation coil of the stepping motor 5 is configured to always be in the same phase state. After the magnetic head is moved, the protrusion 41 is removed in step 103.
A determination is made as to whether or not there is. This is done in order to detect that the relationship between the rotation limiting member 40 and the protrusion 41 is at an angle as shown in FIG. 4B or 4D. The control circuit 60 recognizes the protrusion 41 when the signal becomes high. If the protrusion 41 is not detected in step 103, the sequence proceeds in the direction of the arrow indicated by "NO", and step 102 of "tracking the head toward the outer circumference of the disk" is performed again. This step 1
The protrusion 41 rotates until the protrusion 41 is detected by the photointerrupter 42 through the loop formed by step 02 and step 103, and the magnetic head moves toward the outer circumference. Note that the male screw portion 17 of the shaft 8 is threaded so that the magnetic head 1 moves by n tracks (n is an integer) when the shaft 8 rotates once, so when the magnetic head moves by n tracks, the protrusion 41 is sure to move. If the protrusion 41 is detected in step 103, the sequence proceeds in the direction indicated by the arrow rYESJ, and the device is in the state shown in FIG. 4B. Alternatively, the process proceeds to the state shown in FIG. 4D, that is, the sequence for determining whether the position is on the reference track.

The state shown in FIG. 4B and the state shown in FIG. 4D are distinguished in terms of the sequence as follows. The difference between FIG. 4B and FIG. 4D is whether or not the rotation limiting member 40 is in contact with the rotation limiting member contact surface 2C.

Therefore, if an attempt is made to move the magnetic head toward the outer circumferential side in the state shown in FIG. 4B, it is possible, and the protrusion 41 also rotates, making it impossible for the photo ink clubter 42 to detect the protrusion. However, when the stepping motor is excited to move the magnetic head toward the outer circumference in the state shown in FIG. Since the excitation phase state of each excitation coil of the motor is configured to be always excited in the same phase after the movement of the magnetic head, the state shown in FIG. 4D is maintained, and the protrusion is 41 can be detected.

Using the above differences, step 104 and step 105
The state shown in FIG. 4D is detected by this.

Step 104 ``Move the head one track toward the outer circumference of the disk'' causes the stepping motor 5 to be excited, and the stepping motor 5 and shaft 8 are about to rotate. If the apparatus is in the state shown in FIG. 4B before step 104 is executed, there is no restriction on rotation of the shaft 8, so after step 104 is executed, the apparatus will be in the state shown in FIG. It deviates from 42. Furthermore, if the apparatus is in the state shown in FIG. 4D before step 104 is executed, even after step 104 is executed, the apparatus remains in the state shown in FIG. Then, step 105 ``Protrusion detection or J'' is executed, and if a protrusion is detected, it is determined that the device is in the state shown in FIG. The sequence progresses to Step 106: ``Turn off the power to the LED 42a of the Photo-Ink Rubber 42 by turning the Photo-Ink Rubber LED 0FFJ'', Step 107
The reference track detection sequence ends at .

On the other hand, if no protrusion is detected in step 105, it is determined that the device is in the state shown in FIG.
Return to step 102 according to the arrow "O" and detect the protrusion again.

Through the above sequence, the device is finally placed in the state shown in Figure 4D, and the magnetic head is positioned above the reference head. In this embodiment, the reference track is one track from the outermost track defined by the standard. When recording on a magnetic sheet, first move the magnetic head onto the reference track and then move the magnetic head onto the recording track located on the inner periphery of the magnetic disk. The structure is such that the influence of buff crash caused by the moving a-groove of the magnetic head does not occur during recording.

The method of assembling this embodiment is to move the magnetic head to the reference track, and while the shaft 8 is fixed, rotate the rotation limiting member 40 so that it comes into contact with the rotation limiting member contact surface 2C as shown in FIG. 4D. Installation is done with 4 screws
Fix it to the shaft 8 at 0a.

Since the protrusion 41 is attached to the rotation limiting member 40 by gluing or the like using a tightening jig or the like so as to form a predetermined angle, the protrusion 41 is inevitably attached to the rotation limiting member 40 by fixing the rotation limiting member 40 to the shaft 8 as described above. 41 and photo interrupter 42
The positional relationship between the photointerrupter and the protrusion is as shown in FIG. 4D, and there is no need to particularly adjust the positional relationship between the photointerrupter and the protrusion.

In detecting the reference track in the present invention, the rotation limiting member 40 comes into contact with the rotation limiting member contact surface 2C due to the rotation of the stamping motor 5, and as a result, the rotation limiting member 40 contacts the rotation limiting member contact surface 2C. You will have to hit it twice. However, the control circuit is normally back-amplified by a lithium battery, etc., and the position of the magnetic head is memorized by the control circuit, so it is necessary to detect the reference track only after replacing the lithium battery for the bank amplifier. This occurs only when the control circuit goes out of control and the control circuit is reset. These operations are carried out several times a year, and the durability of rotation limiting members and the like is not a problem.

In the above embodiment, a photointerrupter is used as a means for detecting that movement of the head in one direction has stopped. However, the present invention is not limited to this. Since it increases rapidly if it is limited by the means, we need a method to detect it, or a magnetic element is incorporated into a member that rotates when the head moves, such as a gear for transmitting driving force, and the magnetic force from the magnetic element is detected by a Hall element. Various methods can be adopted, such as a method of detecting whether or not the rotating member rotates.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to detect a reference track with an extremely small number of parts, and there is no need for complicated adjustment work in the assembly process of the device, which has the advantage that the device can be supplied at a low cost. Furthermore, the drive mechanism of the magnetic head only hits the limit twice, and at this level, noise and durability are not a problem.

[Brief explanation of the drawing]

FIG. 1 is an embodiment of the device according to the present invention, FIG. 2 is a block diagram of a control circuit of the device according to the present invention, FIG. 3 is a flowchart for controlling the device, and FIG. 4 is the rotation limiting member of FIG. 1. It is an enlarged view of the vicinity. [Explanation of symbols of main parts] ■−・・・・・−・−・・−１−−−−−−−−−−−
------
・・・・・・・−１−−−−−・−・−−−−−−
Bend holding member 2 C---1---・---1---・
−・〜・・・−・・−−−１−−・−・−・One rotation limiting member contact surface 5−・・・・・・・−・−１〜−１−−−−
−・・−・・・・・・・・・・・・・・・Station, ping motor 40−−−−−−・−・・−・−・・
・・−・−−１−−−−−−−−−・−・・−・
−・・Rotation limiting member 41・−・−・・−・・−
−−１−・−・・−・−・・−・−・・−・−１−−−
−−−Protrusion 42−−−−1−−−−−・・・・・・−
1---------------・------Photoink Lavata Applicant Nippon Kogaku Kogyo Co., Ltd. Agent Patent Attorney Takashi Watanabe)v Figure 2, Figure 4A, Figure 48 C Repair plan

Claims (1)

[Claims] A disc-shaped recording medium is rotated to record information so as to form a plurality of concentric recording tracks at equal intervals, or to reproduce information from recording tracks recorded in this manner. Therefore, in a head moving device that moves the head in the radial direction of the disc-shaped recording medium, a movement limiting means that mechanically limits the movement of the head in one direction; A reference track detection mechanism comprising a head stop detection means for detecting that the movement of the reference track has stopped.