JPH03224115A - Rotating drum device - Google Patents

Abstract

PURPOSE:To accurately detect the height of a head without making a device large in size by providing a coil bobbin fixing part with an extension part and providing a means, which detects the height in the movement direction of a coil bobbin, so that this means faces the extension part. CONSTITUTION:A head 5 is held on the same plane as the coil bobbin fixing part of one of two or more springs 41 and 54, and the coil bobbin fixing part of the other spring is provided with an extension part 54a, and a means 53 which detects the height in the movement direction of the coil bobbin is provided to face the extension part 54a. In such a case, the extension part 54a of not the spring 41 of the coil bobbin holding the head but the other spring is detected to detect the height of the coil bobbin and that of the head. Thus, the height of the head is detected to record a signal by the head without spoiling the performance of the head and its driving mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides an apparatus for magnetically recording and reproducing signals for TV or the like using a magnetic tape, which includes a head movable in a direction substantially perpendicular to a recording track. The present invention relates to a rotating drum device that makes it possible to record signals on a magnetic tape by using a head drive device (hereinafter referred to as an auto-tracking device) that can perform special reproduction without noise using this head.

[Prior Art] Fig. 4 is a partial vertical sectional view showing an example of a conventional rotating drum device disclosed in, for example, Japanese Patent Application Laid-open No. 173217/1983.
The figure is a plan view of a part of it.

In Figures 4 and 5, (1) is the rotation axis, (2)
is the lower drum, which is connected to the above rotating shaft (
1) is rotatably supported. (3) is an upper drum, which is rotated by being attached to a pedestal (9) fixed to the upper end of the rotating shaft (1). (4) is a head drive unit that drives and moves the head (5) fixed to the tip in the width direction of the magnetic tape (13). (7) is an upper transformer, which is fixed to the pedestal (9).

(8) is a lower transformer, which is fixed to the lower drum (2).

(10) is a connection part, (11) is a wiring board, (12) is a connection part, and (14) is a contact, which supplies a control current to the head drive part (4). (15) is an electrode, and the contactor (14)
It is provided on a part of the pedestal (9) so as to be in contact with the pedestal (9).

In Fig. 5, (16) is the connection part, and the connection part (12)
and the electrode (15) and the drive unit (4) via the wiring board (11).
) and make an electrical connection. (17) is the head signal line, (50
) is the upper drum (3) to accommodate the head drive unit (4).
), and is formed one size larger than the head drive section (4) in order to adjust the position of the head drive section (4).

The head drive unit (4) is positioned using the position adjustment hole (51).
) and fix the yoke (47) with screws (48). Note that the head (5) is electrically connected to the upper transformer (7) via a connection part (10), a wiring board (11), and a connection part (12).

6, 7, and 8 show details of the head drive unit (4). In each figure, (41) is a non-magnetic plate spring, and the head (41) is attached to the tip of its extension (41a). 5) is installed. (43) is a coil bobbin attached to the inner periphery of the leaf spring (41); (44) is a cylindrical driving coil wound around the coil bobbin (43);
2) supports the coil bobbin (43) and supports the leaf spring (
(45) is a cylindrical permanent magnet, and (46) is a cylindrical permanent magnet with the same magnetic poles facing each other. The arranged cylindrical permanent magnets (46a) are the pair of cylindrical permanent magnets (45).

A ferromagnetic center ball provided between (46), (
47) is a yoke.

This yoke (47) has plate springs (41), (42)
, a cylindrical coil (44), a coil bobbin (43), a pair of cylindrical permanent magnets (45), (48), and a center ball (46a) are stored and held therein, and are designed to be easy to store and assemble. Three yoke parts (47
a), (47b).

(47c).

(48a) is a screw hole for attaching and fixing the yoke (47) to the upper drum (3).
8b) is connected to. (49) is the yoke (47
), through which the head (5) protrudes outward and is placed on the upper drum (3) so as to come into sliding contact with the magnetic tape (13). There is.

In addition, a cylindrical coil (44) and a coil bobbin (43)
) is vertically movably arranged in an annular gap (G) formed between a pair of cylindrical permanent magnets (45), (46) and a center ball (46a) and a yoke (47).

In addition, the leaf springs (41) and (42) are shown in Fig. 9(a).
, As shown in (b), a large number of arc-shaped slit grooves (41s) and (42s) are formed in the disc part, giving it a highly elastic structure. A part of the outer circumference of (41) is sandwiched between the divided parts (47a) and (47b) of the yoke (47), and the entire outer circumference of the other leaf spring (42) is held between the divided parts (47b).
and (47c).

Next, the operation of the above configuration will be explained.

In FIG. 7, the magnet (45) transfers magnetic flux CD) from the center ball (48a) to the yoke (
47) are generated radially toward.

Similarly, the magnet (46) is connected to the divided portion (4) of the yoke (47).
7b) and (47C) form a closed magnetic path in the opposite direction and generate magnetic flux (E), and these magnetic fluxes (D) and (E) both cross the annular gap (G) in the same direction, and this The magnet (45) is attached to the cylindrical coil (44) by
The total magnetic flux of and (46) crosses.

In this state, a current is passed through the coil (44) from the contactor (14) through the electrode (15), the connection parts (12) and (16), and the coil (44) and coil bobbin (43)
) and the head (5) move vertically in parallel in a straight line as one body. This allows the head (5) to move the magnetic tape (
13) is driven and displaced in the width direction.

In the above operation, during playback in which the head (5) reads a signal pre-recorded on the magnetic tape (13), the head (5) is driven and displaced in the direction of increasing the signal depending on the magnitude of the read video signal. Therefore, the trace can be traced without deviating from the original trajectory, and noiseless playback can be performed.

However, using such a head drive unit (4),
When recording signals on the magnetic tape (13), the absolute height of the head (5) with respect to the magnetic tape (13) is unknown, so if the signal is recorded as is, it will not be possible to record according to the standards. .

Therefore, a method as shown in FIG. 10 has been proposed. In Fig. 10, (55) is a reflective photosensor, which is composed of a pair of light-emitting element and light-receiving element, and is supported by the lower drum (2) facing the head (5). The height position of the head (5) is measured before the head (5) comes into sliding contact with the magnetic tape (13), and a current corresponding to the difference between the initial measurement value and the measurement value during recording is applied to the coil (44). ), the height of the head (5) is finely adjusted to maintain a certain height.

In addition, (56) in the figure 's10 is the path of light from the senna (55), (57) is the signal line of the sensor (55), and (58)
) is the sensor stand.

Another known method is to keep the height of the head (5) constant by installing a COD (not shown) that monitors the tip of the head (5) and directly capturing the image. There is.

[Problems to be Solved by the Invention] Since the conventional rotating drum device equipped with an auto-tracking device is configured as described above, when reading a signal on a recorded tape, it is necessary to read the signal on the recorded tape depending on the strength of the signal. Although it is possible to achieve an accurate tracking function by adjusting the amount of drive of the coil, when recording signals on magnetic tape using such an auto-tracking device, the absolute height of the head (5) Since the pattern is unknown, it is not possible to record in a pattern that conforms to the standard.

In addition, in order to read the absolute height of the head, the surface of the head itself may be measured using an image sensor such as a CCD, or the mounting part of the head (5) may be mounted using a reflective type as shown in Figure 10. In the case of measuring using a photo sensor, not only does the entire device become larger, but also the head (5) and the adhesive used to join the head (5) to the spring (41) protrude, Due to the presence of the signal line (17), it is not possible to form a reflective surface with good responsiveness, and as a result, there is a drawback that the intended head height detection device cannot be properly performed.

This invention was made to solve the above-mentioned problems, and it is possible to accurately detect the head height without increasing the size of the device, and to use the auto-tracking device as is to comply with the standard. It is an object of the present invention to provide a rotating drum device that can record signals in a pattern that is consistent with the above.

[Means for Solving the Problems] A rotating drum device according to the present invention holds the head on the same plane as the coil bobbin fixing portion of two or more springs, and also holds the head on the same plane as the coil bobbin fixing portion of the two or more springs. The coil bobbin fixing part is provided with an extension part, and a means for detecting the height in the moving direction of the coil bobbin is provided in opposition to the extension part.

[Function] According to the present invention, the heights of the coil bobbin and the head can be detected by detecting not the spring of the coil bobbin holding the head but the extension of another spring. The height of the head can be detected and signals can be recorded by the head without impairing the performance of the drive mechanism.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described based on the drawings.

FIG. 1 is a partial vertical cross-sectional view of a rotating drum device according to an embodiment of the present invention, and FIG. 2 is an enlarged vertical cross-sectional view of its head drive section (4). ), (4
1), (43) to (50) are the same as the conventional example shown in FIGS. 4 and 7, so the corresponding parts are given the same reference numerals.
Their detailed explanation will be omitted.

In FIGS. 1 and 2, (54a) is a yoke (4
Opening (52) formed in the divided portion (47c) of 7)
The coil bobbin (
It is an extension of a leaf spring (54) that holds the sensor (53), and is opposed to the leaf spring extension (54a).
) is supported and fixed to the lower drum (2) or a drum fixing part (not shown) via a holder (53a).

(53b) is 4 sensor wiring, (2a) is lower drum (2)
This is a holder mounting hole formed in the holder.

Figures 3(a) and 3(b) are views from below of the two leaf springs (54) and (41) that hold the coil bobbin (43). A large number of slit grooves (54s) are also formed in the leaf spring (54) that holds (43).

Next, the operation of the above configuration will be explained.

In the above structure, both the springs (41).

The joint part of (54) with the coil bobbin (43) and the extension parts (41a) and (54a) from there are integrated through the coil bobbin (43), so the head (5) and the spring extension part (54a) The relative position of remains unchanged.

Therefore, first, the sensor (53) and the spring extension part (54a)
By measuring the initial distance between the lower drum (2) and the head (5) at the same time, the head (5) can be adjusted at any time based on the output of the sensor (53).
) can be regulated.

Note that the sensor (53) may be a reflective photosensor as in the conventional example, and in this case, the reflective surface is close to the head (
5), it is possible to perform surface treatment within a range that does not impair the characteristics of the spring, and therefore it becomes easy to improve the detection output.

Moreover, a magnetic sensor can also be used as the sensor (53). In the conventional example, it was impossible to use a magnetic sensor to detect the vicinity of the head, but in this invention, in order to improve the accuracy of the sensor, a magnetic material is provided on the extension of the spring facing the sensor. However, there is no risk of affecting the original performance of the device.

Furthermore, the sensor (53) may be fixed to the rotating upper drum (2) and its detection output may be transmitted through a slip ring or a rotary transformer. In this case, since the spring extension (54a) and the sensor (53) are constantly facing each other, the height of the head (5) can be continuously detected.

[Effects of the Invention] As described above, according to the present invention, the absolute height of the head of an auto-tracking device is detected by the extension of the spring that moves in a one-to-one relationship with the head. Without impairing the performance of the drive device or being restricted by the reflective surface, the height of the head can be detected appropriately, and the head of the auto-tracking device can be used as is to record signals on the magnetic tape. be able to.

Furthermore, mounting the head has the advantage that the entire device can be more easily miniaturized than the case where the sensor is provided on the part side.

[Brief explanation of drawings]

FIG. 1 is a partial vertical sectional view of a rotating drum device equipped with a head driving device according to an embodiment of the present invention, FIG. 2 is an enlarged vertical sectional view of the head driving device, and FIGS. 3(a) and (b) )
is a bottom view of the two springs that hold the coil bobbin, FIG. 4 is a vertical sectional view of a portion of a conventional rotating drum device, FIG. 5 is a bottom view of a portion thereof, and FIG. An enlarged plan view, FIG. 7 is a vertical sectional side view of FIG.'tS6, FIG. 8 is a front view of FIG. 7, and FIG. 9(a). (b) is a bottom view of the two springs holding the coil bobbin;
FIG. 10 is a partial vertical sectional view of a rotating drum device equipped with a conventional head height measuring device. (5)...Head, (13)...Magnetic tape, (4
1), (54)...Spring, (41a), (5
4a)...extension part, (43)...coil bobbin, (
44)...Coil, (45), (46)...Cylindrical permanent magnet, (47)...Yoke, (53)...
sensor. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A permanent magnet, a yoke of magnetic material that is arranged with a gap outside the permanent magnet and forms a magnetic path for the lines of magnetic force from the permanent magnet, and a yoke that is arranged within the gap so as to cross the lines of magnetic force; A coil is supported so as to be movable in a direction perpendicular to the magnetic lines of force, and the coil is moved in the width direction of the tape so that the head trajectory during recording and the head trajectory during playback match according to the movement of the coil by energizing the coil. A circular shape made of two or more non-magnetic materials, with a movable head, a part or almost the entire outer circumference held by a fixed member, and a coil bobbin held on the innermost circumference. Alternatively, in a rotating drum device in which the coil is supported by a substantially circular spring, the head is held on the same plane as the coil bobbin fixing part of the spring, and the head is held on the same plane as the coil bobbin fixing part of the spring, and A rotary drum device comprising: an extension portion provided on the coil bobbin fixing portion; and means for detecting the height of the coil bobbin in a moving direction by opposing the extension portion.