JPH01287876A - Method for moving magnetic head - Google Patents

Abstract

PURPOSE:To attain the correct head sending without receiving the influence of a backlash by moving to a new track position again after a magnetic head set to a new track position in order to execute the next recording is moved in one sending direction immediately before the recording start. CONSTITUTION:When a shutter button 39 is half-pushed, a CPU 37 supplies five inversion pulses to a pulse motor 20 in accordance with a sequence program stored in a program ROM 38. Consequently, a magnetic head 28 is moved in a Y direction away from the center of a magnetic sheet 13 and moved to the position to slip off to the outside from a first scheduled track 42. In succession to this, since five normal rotations are supplied to the pulse motor 20, the mag netic head 28 is moved in an X direction and head-sent just onto the first sched uled track 42. Thus, without receiving the influence of the backlash, the correct head sending can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of moving a magnetic head that performs writing/reading at an access position close to the recording surface of a magnetic disk such as a floppy disk.

[Prior Art] A magnetic disk device, for example, a magnetic disk device built into an electronic still camera, uses a magnetic head that moves in the radial direction of a magnetic sheet housed in a still video floppy to create tracks for writing/reading video signals. It has a built-in head movement mechanism to determine the position.

The head feeding mechanism generally has a structure in which a head carriage holding a magnetic head is screwed onto a feed screw, and the feed screw is driven by a pulse motor via a transmission gear. For example, the pulse motor is driven by 10 pulses. When a pulse is supplied, the magnetic head is moved by one track.

By the way, the above-mentioned head feeding requires high accuracy on the order of microns. This is because when writing video signals, if the feeding position accuracy of the magnetic head is poor, the pitch of the recording tracks formed on the magnetic sheet will not be constant, and when rewriting or playing back the video signal, the pitch of the recording tracks will not be constant. This is because it becomes impossible to accurately trace the top with a magnetic head.

In conventional electronic still cameras, the video signal for one still image is written on the magnetic sheet by a single operation of the shutter button, and then the forward feed mechanism is activated to move the magnetic head to the next new position. It is sent to the truck position and is on standby for the next shooting.

[Problem to be solved by the invention]

However, in the above-described head feeding method, if there is an interval before the next photographing, an error often occurs in the feeding position of the magnetic head. This is because play is essential in the meshing parts of the transmission gear, feed screw, etc. used in the head feeding mechanism, and this play tends to cause backlash in the head carriage.

In other words, after one shot, the magnetic head is moved to the next track position, but if you move or vibrate the electronic still camera before taking the next shot, the magnetic head will be moved by the backlash of the gear system. The head is returned to the previous recording position. Therefore, if the next photographing is performed as it is, the pitch interval of the recording tracks will become narrower, causing a reading error during playback.

The present invention was made in order to solve the above-mentioned deficiencies of the prior art, and an object of the present invention is to provide a method for moving a magnetic head that enables accurate head movement without being affected by backlash. do.

[Means to solve the problem]

In order to achieve the above object, the present invention moves the magnetic head, which has been set to a new track position for the next recording, in one direction in the head feeding direction immediately before starting recording, and then moves the magnetic head to the new track position again. It is designed to be moved to a track position.

Of course, the present invention is not limited to recording devices such as electronic still cameras, but can be similarly applied to playback devices that move a magnetic head when reading data.

(Function) According to the above, just before the magnetic head writes/reads data at a new track position, the magnetic head is always moved from one side of the head feeding position, so the magnetic head is affected by backlash. The track position is always moved at a constant pitch interval without any trouble.

Embodiments of the present invention will be described below with reference to the drawings.

(Example) In FIG. 2 showing the recording section of an electronic still camera,
A binder motor 10 is disposed approximately at the center of a substrate 12 of a recording section 11, and rotates a magnetic sheet in a still video floppy set in the recording section 11. X-
The lead screw 14, which has a cylindrical shape with an axis in the Y direction, has a threaded portion 16 formed at its end, and is rotatably disposed with both ends being supported by bearing members 17 and 18. Stopper 1 constituting bearing member 17, 18
9 prevents the lead screw 14 from moving in the longitudinal direction. A worm wheel 14 is fixed to one end of the lead screw 14 and meshes with the worm 22. The worm 22 rotates according to the rotation of the pulse motor 20. The head carriage 23 has an "L" shape consisting of a sliding part 24 and a head mounting part 26, and the sliding part 24 covers the lead screw 14. It is located. The head mounting portion 26 has a mounting piece 27 that protrudes upward.
is provided. The magnetic head 28 can move integrally with the head carriage 23 by being fixed to the mounting piece 27 via the mounting member 29.

The needle 31 is attached to the inner surface of the sliding part 23 and meshes with the valley of the threaded part 16. And pulse motor 2
When ten normal rotation pulses are supplied to the magnetic head 2
8 is moved in the X direction by one track pitch along with the helad carriage 23.

On the other hand, a head crimping device 3 consisting of a latch type solenoid, etc.
2, the head carriage 23 is rotated at a small angle in the direction A-B around the lead screw 14 and then positioned. At the same time, the head 28 also moves in the A-B direction, making it possible to contact and retreat from the magnetic sheet. This head crimping device 32 is activated when the still video floppy is replaced. , the magnetic head 28 is retracted to a position away from the recording surface of the magnetic sheet.

In FIG. 1, which is an explanatory diagram of the electrical system of this electronic still camera, a magnetic head 2 is in contact with a magnetic sheet 13.
8 controls the density of the magnetic flux emitted by a control signal from the recording circuit 34. Spindle motor 10 is rotated according to spindle motor drive device 36 . Head crimping device 32. Pulse motor 20. The a circuit 34 and the spindle motor drive device 36 are controlled by control signals from the CPU 37. The program ROM38 has a CPU
A sequence processing program executed by the computer 37 is stored.

The shutter button 39 can be pressed halfway or fully depending on the pressing force, and a half-press signal or a full-press signal is sent from the release signal generation circuit 41 to the CPU 37 depending on the pressing force.
is supplied to Further, when the quick shooting mode is set, a continuous shooting mode signal is inputted from the continuous shooting mode setting section 45 to the CPU 37.

The operation of this embodiment having such a configuration will be explained below.

First, a floppy disk is inserted into the recording section 11 of an electronic still camera, and when it is set correctly in a predetermined position, the magnetic sheet 13 is rotated by the spindle motor 10 by turning on the power switch, and the head crimping device 32 is activated. Then, the magnetic head 28 is brought into contact with the recording surface of the magnetic sheet 13. Then, the pulse motor 20 rotates by a certain amount,
As shown in FIG. 3, the magnetic head 28 is moved in the X direction parallel to the sheet surface, is positioned in contact with the first track 42, and is in a standby state for photographing.

When the shutter button 39 is pressed halfway, the CPU 37 executes the processing shown in the flowchart of FIG. 4 according to the sequence program stored in the program ROM 3B. That is, in response to the half-press signal of the shutter button 39, five reverse rotation pulses are first supplied to the pulse motor 20. As a result, the magnetic head 28, which was located at the position shown by the solid line in FIG. Ru. Following this, five normal rotation pulses are supplied to the pulse motor 20. As a result, the magnetic head 28 moves in the X direction and is once again sent to the position shown by the solid line, that is, directly above the intended first trunk 42.

In this way, by always shifting the magnetic head 28 from a certain direction every time the shutter button 390 is pressed halfway, backlash caused by the engagement between the worm wheel 21 and the worm 212 or the lead screw 14 and the needle 31 can be avoided. The magnetic head 28 can be positioned at a predetermined standby position without being affected by this.

When the shutter button 39 is fully pressed, the recording circuit 34 is activated, and the video signal for one screen outputted from the COD is magnetically recorded within one track of the magnetic sheet 13, thereby forming the first track 42. After magnetic recording for one screen is completed in this way, ten normal rotation pulses are supplied to the pulse motor 20, and the magnetic head 28 moves to the next track position, that is, as shown in FIG. The second track 42 is separated from the first track 42 by a constant track pitch d.
It is moved to the scheduled writing position on the track 43. If the continuous shooting mode is not set, one shooting sequence is completed in this state.

Also, even when taking the next photo, the shutter button 39
When the button is pressed halfway, the backlash removal process described above is executed. Therefore, even if there is a time interval between the first photographing and the second photographing, and even if the magnetic head 2 is displaced due to backlash, the magnetic head 28 will be positioned exactly at the true position of the second track 43 during recording. Since the track pitch d is fed upward, the track pitch d is always maintained constant. Note that when the snapshot mode is set, recording continues immediately after the magnetic head 28 is sent to the next track position, so backlash removal processing is not necessary.

In the above example, the half-pressing of the shank button 39 is used as the start timing for the hack lash removal process, but this can also be performed, for example, when the shutter button 39 is fully pressed. That is, when the shutter button 39 is fully pressed, the above-described backlash removal process may be executed, and then the recording circuit 34 may be activated to perform magnetic recording.

Note that the present invention can be applied not only to the electronic still camera described above, but also to a recording device using a general magnetic disk as a recording medium, or to a reproducing device or a reading device. The present invention can also be applied to a device in which the magnetic head 28 is moved while being separated from the recording surface of the magnetic sheet 13.

〔Effect of the invention〕

As described above, according to the present invention, immediately before the magnetic head writes/reads data, the magnetic head is once moved to one side in the track feeding direction, and then is sent back to the original position. Therefore, the magnetic head can be track-fed while always maintaining a constant track pitch without being affected by backlash of a head-feeding mechanism using gears or the like.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the circuit configuration of an electronic still camera to which the present invention is applied. FIG. 2 is a schematic diagram of the recording section of the electronic still camera shown in FIG. FIG. 3 is an explanatory diagram of the head moving method of the present invention. FIG. 4 is a flowchart showing the photographing sequence of an electronic still camera using the present invention. 10. Spindle motor 12.. Substrate 14.. Lead screw 16.. Thread portion 20.. Pulse motor 21.. Worm wheel 22.. War 11. 23.. Head carriage 28.. Magnetic head 32.. Head crimping device. 3rd...Program ROM 41...Release signal generation circuit 42...First track 43...Second track.

Claims (1)

[Claims] (1) A method for moving a magnetic head in which, after writing/reading data, the magnetic head is moved to a predetermined track position for performing the next write/read, wherein writing is performed by the magnetic head at the predetermined track position. /
A method for moving a magnetic head, characterized in that immediately before reading, the magnetic head is moved in a fixed track feeding direction, and then the magnetic head is moved again to the predetermined track position.