JPH02143961A - Head moving device - Google Patents

Abstract

PURPOSE:To simplify adjusting work without using a complex optical sensor, etc., by setting the reference position of a head by outputting an instruction to drive the head in a direction to press-contact the head with a regulating member for the moving range of the head or more. CONSTITUTION:A fixed position of a regulating member 16 is set to a position at which the regulating member 16 press-contacts a head 4 with a locking protrusion 9c of a cam board 9 at a point where the head 4 obtains the innermost circumferential moving position and locks the further rotation of the head 4, namely, the further moving of the head 4 in a disk inner circumferential direction when a head carriage 3a is moved in the disk inner circumferential direction. Consequently, the head carriage 3 can be moved in the radial direction, the inner circumferential direction, and the outer circumferential direction of a disk D through a cam 9a of the cam board 9, and the head 4 can be positioned to a desired recording track on the disk D by driving a step motor 11 and changing the rotating direction and the rotating quantity of the cam board 9. Thus, the head can be surely positioned at the reference position without using various sensors, sensor control circuits, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a head moving device suitable for use in a recording or reproducing device or the like.

[Conventional technology]

Conventionally, as in electronic still video cameras, a magnetic head accesses multiple concentric tracks formed on a disk-shaped recording medium such as a magnetic disk, and information is recorded or reproduced on the selected track. Devices that do this are known.

The head moving mechanism used in this type of device generally has a head that is movable in the radial direction of the disk, and is moved to any desired track using a step motor or the like. When trying to record captured images onto a disc track, if the track position to be recorded and the actual track position do not match exactly, the recording position will shift and the compatibility with other devices or discs may be affected. gatorena (becomes). Therefore, usually,
The reference position of the head is detected so that the position of the track to be recorded matches the actual track position.

One method is to drive a stepping motor for moving the head regardless of the position of the head, and move the head in one direction (for example, toward the inner circumference) via a cam or screw shaft as a transmission mechanism. The apparatus is configured to detect this by a switch that is turned on when the head is moved to a predetermined reference position. In addition to microswitches, optical detection means such as photointerrupters and photoreflectors are used as this switch.

[Problem to be solved by the invention]

However, with the above-mentioned conventional device, the number of parts required to realize the detection means for detecting the reference position of the head is large, and the mounting position has to be adjusted at many points, making the work cumbersome. . Therefore, the adjustment work also takes a lot of time, reducing productivity and reliability.

[Means for solving problems]

The present invention has been made with the aim of solving the above-mentioned problems, and is characterized by a head that performs recording or reproduction on a plurality of tracks on a recording medium; a driving means for moving the head in a predetermined direction and positioning it on each of the tracks; a regulating means for regulating the moving position of the head within a predetermined range; The head moving device is equipped with a control means for outputting a command to drive the head in a direction beyond the predetermined range, and thereby eliminates the use of various sensors and sensor control circuits for detecting the moving position of the head. can be reliably positioned at the reference position.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the head moving device according to the present invention will be described in detail with reference to the drawings, taking as an example the case where it is applied to a head moving mechanism of an electronic camera.

Figures 1 and 2 are plan views showing details of the head feeding mechanism. Figure 1 is a plan view with the head moved to the innermost position of the disk, and Figure 2 is a plan view with the head moved to the outermost position of the disk. It is a top view of the state moved to the position.

In each figure, 1 is the chassis of the main body of the apparatus, and in the center thereof, a spindle 2 that holds and rotates a disk D housed in a cassette C is arranged by being attached to the rotation shaft of a spindle rotation motor. There is. 3 is a head carriage with magnetic head 4 attached to chassis 1;
It is attached to the upper part of the disk D by a guide shaft 5 so as to be movable in the radial direction of the disk D, that is, in the directions of arrows A and B in the figure, and is normally biased by a spring 6 in the six directions of arrows. A cam follower pin 3a is disposed at one end of the head carriage 3, and is always pressed against a head position control cam 9a, which will be described later, by the elasticity of the spring 6.The head carriage 3 can be moved by changing its engagement position with respect to the cam 9a. Arrow A along guide axis 5.

It moves in direction B. Further, the head carriage 3 has its other end side engaging portion 3b constantly pressed against a guide shaft 7 fixed on the chassis l in parallel with the guide shaft 5 by a spring (not shown), so that the head 4 can be moved against the disk recording surface. The location can be regulated. Therefore, the head carriage 3 is moved to the guide shaft 5.
By rotating the engaging portion 3b in a direction away from the guide shaft 6, the head 4 can be moved away from the disk D, and a head loading/unloading mechanism can be constructed. Also, the head carriage 3
Instead of inserting both the guide shafts 5 and 7, the guide shafts 5 and 7 are inserted rotatably relative to one shaft and are elastically pressed against the other shaft to regulate the position of the head, so there is no play in the head carriage. can be absorbed and accuracy can be increased.

8 moves the Herad carriage 3 along the guide shaft 5;
This is a head carriage drive unit for positioning the head 4 with respect to the recording track on the disk D.

9 is rotatably arranged on the chassis 1 by a shaft 10,
This is a cam disk for position control that moves the head carriage 3 along the guide shaft 5.7. The cam disc 9 is constantly engaged with the cam follower pin 3a of the herad carriage 3, and its shaft 10
A spiral cam 9a whose diameter changes continuously from to the outer circumference, and a gear 9 for transmitting drive to a drive source to be described later.
(b) A locking protrusion 9c for regulating the rotation range of the cam disc 9 is formed integrally with the cam disc 9. Further, the cam 9a is formed so that its diameter from the central axis 10 changes so that the head carriage 3, that is, the head 4, can be moved by a predetermined amount in the radial direction of the disk D.

Here, to explain the format of disk D used in electronic cameras, each track width is 60 μm.)
The guard band width between the racks is 40 μm, and the track numbers 1 to 50 are sequentially numbered from the outer circumference of the disk to the inner circumference of the disk.
50 recording tracks are formed. Therefore, the track pitch is 100 μm.

Reference numeral 11 denotes a step motor serving as a driving source for rotationally driving the cam disc 9 and moving the head carriage 3 using the cam 9a.

The step motor 11 is driven in units of a predetermined step angle, and a gear 12 is press-fitted into its rotating shaft 11a. is transmitted to the gear 9b of the cam disk 9 at a predetermined reduction ratio. As a result, the cam 9a is rotated, and the head carriage 3 can be moved in the radial direction of the disk D according to the direction of rotation, and the head 4 can be moved to a desired track on the disk.

Numeral 16 is a regulating member that engages with the locking protrusion 9C of the cam disc 9 and regulates the rotation limit position of the cam disc 9 in the counterclockwise direction.

This regulating member 16 has one end attached to the shaft 10 so as to be able to rotate independently of the cam disk 9, and is fixed by being attached to the chassis 1 through a long hole 16a formed at the other end with a screw 17. The hole 16a is formed in an arc shape centered on the axis IO, and the rotation restriction position of the cam disk 9 can be adjusted by changing the fixing position of the screw 17 within the long hole.

Moreover, 16a is a protrusion for ensuring engagement with the locking protrusion 9C of the cam disc 9.

As shown in FIG. 1, the fixing position of the regulating member 16 is determined by rotating the cam disc 9 counterclockwise and moving the cam follower pin 3a from its engagement position to the small diameter portion of the cam 9a. When the head 4 is moved toward the inner circumference of the disk, the locking protrusion of the cam disc 9 is engaged when the head 4 reaches the innermost movement position, that is, the 51.5) rack (middle position of the 52nd track in the present invention) position. 9C, and is set at a position where further rotation, that is, movement of the head 4 in the inner circumferential direction is stopped.

With the above configuration, by driving the step motor 11 to change the direction and amount of rotation of the cam disc 9, the head carriage 3 can be moved in the radial direction of the disk D to the inner and outer peripheries via the cam 9a. , the head 4 can be positioned at a desired recording track on the disc.

As mentioned above, FIG. 1 shows a state in which the head 4 has been moved to the innermost position (51.5 rack) of the disk D, and FIG. 2 shows a state in which the cam disk 9 is rotated clockwise. As a result, the cam follower pin 3a is moved to the maximum diameter portion of the cam 9a, and the head carriage 3, that is, the head 4 is moved to the outermost position (first track) of the disk.

The configuration of the head moving mechanism has been described above. Next, the circuit configuration of the main parts of the electronic camera to which the present invention is applied will be described using FIG. 3.

FIG. 3 is a block diagram of the electronic camera according to the present invention, and the parts explained in FIGS. 1 and 2 are omitted. 20 is a disk rotation motor for rotating the disk D, 21 is a motor servo circuit for rotating the motor 20 at a constant speed, and 22 is a magnetic head as shown in FIGS. 1 and 2 above. 4 in the radial direction, that is, the inner circumference of the magnetic disk D;
A head moving mechanism 23 is a drive circuit for controlling the step motor 11 for moving the head in the outer circumferential direction.

Reference numeral 24 denotes a camera section including a photographic lens and an image sensor such as a CCD that converts the image formed by the photographic lens into an electrical signal; 25 a signal for processing, emphasis, FM modulation, etc. on the signal output from the camera section 10; A recording signal processing circuit performs processing and converts the signal into a signal suitable for recording on a disc via the magnetic head 4, and 26 is a recording amplifier for amplifying the signal output from the recording signal processing circuit 25. The magnetic head 4 is configured to supply a recording signal to the magnetic head 4 via the recording/reproducing main changeover switch SW.

Therefore, the image captured by the camera unit 24 is converted into an electrical signal and output, and the image is output to the recording signal processing circuit 2.
After being subjected to predetermined signal processing in step 5, the signals are supplied to the magnetic head 4 via the recording amplifier 26 and recorded concentrically on the disk.

27 is a reproduction amplifier that amplifies the signal reproduced by the magnetic head 4 from the disk D to a predetermined level, and 28 is a reproduction signal outputted from the reproduction amplifier 27 which is subjected to FN-1 demodulation and de-emphasis, contrary to the recording operation. 29 is a monitor display that inputs the reproduced signal and outputs a video image.

30 is an envelope detection circuit that envelope-detects the reproduction signal output from the reproduction amplifier 27, 31 is an A/D converter that converts the signal level output from the envelope detection circuit 30 into a digital signal, and 32 is the entire system of the device. This is a control circuit that controls the The control circuit 32 is
A CPU, a ROM that stores a control program, and a RAM that stores various information during control operations.

It is composed of input/output interfaces with each controlled object, etc., and inputs various information such as playback signal level information output from the A/D converter 31 and the operation status of each operation switch, The circuit 21, the recording/reproduction changeover switch SW, the recording signal processing circuit 11, the reproduction signal processing circuit 28, the driver 23 for driving the head feeding step motor 11, etc., are used to collectively control the entire apparatus.

The control circuit 32 is connected to an operation section 33 equipped with various operation switches, and this operation section includes a mode setting switch for selectively setting the device to a recording mode or a playback mode, and a recording or playback switch. Each time the execution trigger switch is turned on, the magnetic head 4 moves the track on the disk D toward the inner circumference, that is, the track number is thicker, or toward the outer circumference, that is, the track number is smaller. This includes switches, etc.

Therefore, at the time of recording B (photographing), by setting the recording mode using the operation unit 33, the control circuit 32 switches the switch sW to the recording amplifier 26 side, and the recording system is connected. Then, by operating the shirt release switch in the operation unit 33, the image signal captured by the camera unit 24 is converted into a signal suitable for recording on the magnetic disk D via the recording signal processing circuit 25 and the recording amplifier 26. After that, the data is recorded on a track on the disk D which is rotated at a constant speed by the motor 20.

Furthermore, during playback, by setting the playback mode using the operation unit 33, the control circuit 32 switches the switch SW to the playback amplifier 27 side, thereby connecting the playback system. Then, the recording signal on the track reproduced by the magnetic head 4 is transmitted to the reproduction amplifier 27. After being subjected to predetermined signal processing via the reproduction signal processing circuit 28, the signal is output to the monitor 29, and the image information is reproduced.

In addition, before the above-mentioned recording, playback, etc.
Determining whether each track above has been recorded or not, and head 4
Initial operations such as setting a reference position for movement of the disk are performed, for example, at the same time as the disk is loaded.

In this initial operation, the head 4 is moved to the innermost track (further inside the recording range) of the disk D, for example, and then scans all the tracks toward the outer circumference of the disk, and the reproduction RF envelope of each track is detected by the envelope detection circuit. 30 performs envelope detection, supplies the signal to the control circuit 32 via the A/D converter 31, and compares the level with a preset playback RF envelope level of an unrecorded track to determine whether or not the signal is recorded. It is something. The determination results for each track are stored as a track information table in the memory M in the control circuit 32, and various controls are performed based on the information in this table. The details of this initial operation will be described later.

FIG. 4 shows an energization waveform for driving the step motor 11. As shown in FIG.

Figure (a) shows the energization waveform when performing normal head feeding;
FIG. 2B shows an energization waveform when detecting the head reference position prior to head movement accompanying the recording/reproducing operation. Further, the step motor 11 is a four-phase excitation type step motor of A phase to C phase.

In the normal head feeding using the energization waveform shown in FIG. 4(a), first, the step motor is energized for 15 m5ec to the phase in which it is currently located, for example, the C phase, and then to the B phase.

If it is a phase that you want to sequentially energize and step C phase and C phase for 6 msec and then stop at the end, for example, C phase,
Electrify this for 15m5ec. When the step motor 11 is driven by this energization waveform and the cam disc 9 is driven in the direction of moving the head 4 toward the inner circumference of the disk, the head 4 reaches the innermost position and the cam disc 9 stops. Member 16
When the head carriage 3 is locked, it cannot rotate any further, so there is no risk of the head carriage 3 being repeatedly repelled by the regulating member 16 and bouncing back, and causing damage to the mechanism due to the head carriage 3 being forcibly moved to the inner periphery.

The step motor energization waveform at the time of detecting the head reference position shown in FIG. 4B has energization times of 36 m5 ec and 18 m5 ec, respectively, compared to the energization waveform used for normal head feeding shown in FIG. According to this energizing waveform, even if the cam disk 9 comes into contact with the regulating member 16 during head feeding and is locked, this energizing waveform will not drive the step motor as compared to the one shown in FIG. Since the speed is slow, the cam disk 9 does not bounce back and is held stationary in the driving direction. The phase excitation pulse shown in FIG. 4B may be appropriately selected to the extent that bounce does not occur.

On the other hand, the step motor 11 is configured to move the head 4 by one track on the disk D in four steps by the reduction ratio of the rotation transmission mechanism between it and the cam disk 9, and the track pitch is 100 μm. Therefore, the step motor 11 operates to move the head 4 2571 m in l steps.

The head moving device according to the present invention is constructed as described above.Next, the reference position detection operation of the head will be explained using the flowchart of FIG.

In order to accurately move the head to each of a plurality of tracks on the disk, it is necessary to perform a predetermined operation to detect a reference position for moving the head before recording, reproducing, etc. (when loading the disk).

First, when the disk D is loaded onto the spindle 2 by known means (not shown) (Sl), regardless of the position of the head 4 with respect to the disk D, as shown in FIG.
With the energization waveform a), it is moved toward the inner circumference of the disk by 50 tracks (S2). At this time, in many cases, the locking protrusion 9C of the cam disc 9 collides with the regulating member 16 and is locked while the step motor 11 is being driven, and the step motor 11 loses its driving state, and the cam disc 9 , the head carriage 3 is in a state where the head 4 repeats the bouncing operation at the 51.5 track position.

When the energization for transferring the head by 501-rack is completed, the step motor 1 is then energized with the energization waveform shown in FIG. 4(b).
1 is further step fed in the inner circumferential direction until the next C phase is in an excited state (S3) (Here, the C phase is defined as
This is because the head is set in advance to be at the recording position with respect to the opposing track during the C phase). This is to align the head 4 with the C phase, which is the recording position, with respect to the opposing track.

Next, the head 4 is further moved toward the inner circumferential side of the disk using the energization waveform shown in FIG.
Forward 2 steps (S4). These 22 steps correspond to 5.5 tracks since one track is sent in 4 steps. The reason why the cam disc 9 is fed by 5.5 tracks is to ensure that the cam disc 9 is positioned at the 51.5 track, taking into account the amount of rebound caused by collision with the regulating member 16. This position is a state in which the locking protrusion 9c of the cam disk 9 just contacts the regulating member 16, that is, 51.
5) The rack position (head reference position). Also,
At this time, the step motor 11 is energized to the C phase.

By the above operations, the head 4 can be positioned at the head reference position of the rack 51.5).

Then, when the head 4 is driven two steps toward the outer circumference of the disk (S5), the head 4 is located at the 51st track, and the excitation phase of the step motor 11 becomes the C phase (recording position).

Thereafter, the step motor 11 is driven to move the head 4 toward the outer circumference of the disk using the energization waveform shown in FIG. 4(a) (S
6). When the head 4 moves toward the outer circumference of the disk, the switch SW is switched to the playback side, and the envelope detection circuit 30 performs envelope detection of the playback RF signal of each recording track played by the head 4, and its envelope level It is detected whether each track is recorded or unrecorded (empty track) by comparing and determining whether or not the playback level of the unrecorded track is higher than a predetermined level set to the playback level of the unrecorded track (S8). control circuit 32
(S9, 5IO).

While repeating this operation, the head 4 is moved to the first track (Sll). When the head 4 reaches the first track, the next recording, playback, etc. operation becomes possible, but if the first track has already been recorded, it moves to the empty track with the smallest track number. Then, the initial setting operation is completed (S12).

After that, you can move to recording or playback mode,
Based on commands set by the operation unit 33, the control circuit 32 accesses the head using the table in the memory M described above.

In the above-mentioned configuration, when adjusting the position of the regulating member 16 that serves as a stopper for the cam disc 9, play a disc on which a signal has been recorded on the 51°5 track in advance, and move the head to
1.5 track, and in that state contact the locking protrusion 9C of the cam disc 9, and fix it with the screw 17. Therefore, the adjustment time is much shorter than that required for adjusting the ON position of an optical sensor such as a photo interrupter or photo reflector using conventional equipment, which not only simplifies the configuration but also significantly reduces the number of work steps. .

In addition, in the initial setting operation described above, the step motor 1
2 shown in Fig. 4 (a) and (b) as the energizing waveform of 1.
Since it has different types of patterns and is used selectively depending on the control operation to speed up the head movement and increase the precision of the detection operation, the time required to detect the head reference position (51st track) can be significantly reduced. be able to.

Although the above embodiment uses a spiral cam as the head moving mechanism, it is also possible to use a lead screw by providing a locking protrusion on the screw and an adjustable stopper on the head carriage. realizable.

This can also be achieved by bringing the head carriage or the like into contact with a stopper on the chassis.

〔Effect of the invention〕

As described above, according to the head moving device of the present invention, when performing the operation of detecting the reference position of the head, a regulating member (stopper) is provided that abuts and locks a part of the head driving means, Since the reference position of the head is set by outputting a command to drive the head in the direction of contacting the regulating member beyond its movement range, it is no longer necessary to use an optical sensor, etc., which has a complicated configuration and requires troublesome adjustment work. Without the use of the above, the configuration with a small number of parts and the adjustment work can be greatly simplified. Further, even after being incorporated into the device, it is possible to realize a head moving device that can detect the head reference position with high accuracy and speed.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of a head moving device according to the present invention, FIG. 2 is a plan view of this embodiment in a different state from FIG. 1, and FIG. 3 is an electronic still video camera to which the present invention is applied. FIG. 4 is a waveform diagram showing the energization waveform of the step motor for moving the head, and FIG. 5 is a flowchart for explaining the head reference position detection operation.

Claims (1)

[Scope of Claims] A head that performs recording or reproduction on a plurality of tracks on a recording medium; a driving means that moves the head in a predetermined direction with respect to the recording medium and positions it on each of the tracks; A regulating means for regulating the movement position of the head within a predetermined range; and a control means for controlling the driving means and outputting a command to drive the head in the direction of the regulating means beyond the predetermined range. Characteristic head moving device.