JPH0413765Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a magnetic head protection mechanism in a magnetic head device in which a magnetic head is electrically connected to a main body circuit board using a flexible board and a connector.

(Prior Art) A magnetic head used in a magnetic recording/reproducing device such as a magnetic disk device has a coil wound around a recording/reproducing core and a coil wound around an erasing core, and these coils are energized. The wiring process is performed as follows. When wiring the magnetic head, for example,
As shown in FIG. 1 of Japanese Patent Application Laid-Open No. 57-167173, a flexible substrate is often used. When wiring to the magnetic head using a flexible board, connectors are provided on the flexible board side and the circuit board side of the recording/reproducing device main body, and by connecting both connectors, the magnetic head and main body can be wired. Electrical connections are being made with circuit boards.

FIG. 2 shows an example of the wiring of a conventional magnetic head device in which a flexible board and a connector are used to connect a magnetic head and a main body circuit board. In FIG. 2, reference numeral 10 is a connector provided at one end of the flexible board connected to the magnetic head, and 20 is a connector provided on the circuit board on the main body side of the recording/reproducing apparatus. The connector 10 on the flexible board side has five connector terminals a, b, c,
d and e, and a connector 20 on the main circuit board side.
has connector terminals 1, 2, 3, 4, and 5 to be respectively coupled to terminals a, b, c, d, and e of the connector 10 on the flexible board side. In FIG. 2, E1 is an erasing coil wound around an erasing core, W1 is a recording/reproducing coil wound around a recording/reproducing core, and W2 is another recording/reproducing coil wound around another recording/reproducing core. , one end of each of these coils E1, W1, W2 is commonly connected at a connection point 12.

Terminal a of the connector 10 is connected to a metal gimbal plate 11 to which a magnetic head is attached, terminal b of the connector 10 is connected to one end of the erasing coil E1, and terminal c of the connector 10 is the connection point of each of the coils. 12, the terminal d of the connector 10 is connected to one end of the recording/reproducing coil W1, and the terminal e of the connector 10 is connected to one end of the recording/reproducing coil W2. Further, terminal 1 of the connector 20 on the main body circuit board side is grounded, and terminal 2 of the connector 20 is connected to the ground via a diode D1, a resistor R1, and a switching transistor Tr1. The terminal 3 is connected to the power supply +Vcc via the switching transistor Tr2, and the terminals 4 and 5 of the connector 20 are connected to the recording/reproducing circuit 2.
1 and 22.

Therefore, if the connectors 10 and 20 are connected in the correct orientation, the gimbal plate 11 is grounded via terminals a and 1, and the power supply +Vcc is connected to transistor Tr2, terminal 3, terminal c,
It is supplied to each coil E1, W1, W2 via the connection point 12, the other end of the erasing coil E1 is grounded via terminal b, terminal 2, and transistor Tr1, and the other end of the recording/reproducing coil W1 is connected to terminal d, terminal The other end of the recording/reproducing coil W2 is connected to the recording/reproducing circuit 21 via terminal e and terminal 5, and the other end of the recording/reproducing coil W2 is connected to the recording/reproducing circuit 22 via terminal e and terminal 5. I'm starting to do it.

(Problems to be solved by the invention) According to the conventional magnetic head device using a flexible board and connector as described above, the connector on the flexible board side and the connector on the main body circuit board side must be oriented in the correct direction. There is no problem when they are connected, but there is a problem in terms of protecting the magnetic head if both connectors are accidentally connected in opposite directions. That is, in FIG. 2, both connectors 1
When connectors 0 and 20 are connected in opposite directions, terminals a and 5, b and 4, c and 3, d and 2, and e and 1 of both connectors 10 and 20 are connected, respectively, and in this state, the recording mode is activated. If it is, then the transistor
When Tr2 is turned on, the power supply +Vcc flows to the ground via terminal 3, terminal c, recording/reproducing coil W2, terminal e, and terminal 1, and coil W2 is directly grounded, so there is no excessive load on coil W2. A current flows and damages the magnetic head including the coil W2.

An object of the present invention is to provide a magnetic head protection mechanism that can prevent damage to the magnetic head even if the connector is accidentally connected in the opposite direction in a magnetic head device using a flexible board and a connector. .

(Means for Solving the Problems) The magnetic head protection mechanism of the present invention is provided in a magnetic head device comprising a flexible board and a connector that connect the magnetic head and the main body circuit board.
The flexible board has multiple circuit patterns for energizing each coil of the magnetic head, two grounding circuit patterns sandwiching these circuit patterns, and connector terminals formed at the ends of each circuit pattern. The main body circuit board includes a connector terminal to which each connector terminal of the flexible board is connected, a ground conductive to the connector terminals on both sides of these connector terminals, an erasing circuit conductive to the intermediate connector terminal, and a recording circuit. a reproduction circuit, at least one of the two grounding circuit patterns of the flexible board is connected to the metal plate, and connector terminals at both ends of the flexible board to which the two grounding circuit patterns are connected, The device is characterized in that it is connected to the ground via the connector terminal of the main body circuit board.

(Function) Even if the connector on the flexible board side and the connector on the main circuit board side are connected in opposite directions by mistake, the two wires provided on the flexible board sandwich multiple circuit patterns for energizing each coil. The grounding circuit pattern is connected to the ground on the main circuit board side through both connectors mentioned above.
The plurality of circuit patterns for energizing each of the coils are not directly grounded.

(Example) FIG. 1 shows an example of the present invention.
Components common to those of the conventional example shown in FIG. 2 are given the same reference numerals.

In FIG. 1, reference numeral 35 indicates a magnetic head, and the magnetic head 35 includes an erasing coil wound around an erasing core and a recording/reproducing coil wound around a recording/reproducing core. magnetic head 35
is attached to a gimbal plate 33 made of a metal plate. The gimbal board 33 is a flexible substrate 3
It holds a connecting part 34 formed at one end of the 0. The flexible board 30 is for electrically connecting the magnetic head 35 to the circuit board of the main body of the recording/reproducing apparatus, and the other end of the flexible board 30 is a connector 31.
has six connector terminals a, b, c, d, e, f. These connector terminals a, b,
The four intermediate connector terminals b, c, d, and e among c, d, e, and f are circuit patterns B and C for energizing the erasing coil and recording/reproducing coil that constitute a part of the magnetic head 35. , D, and E, and the connector terminals b, c, d, and e are connected to the circuit patterns B, C, D, and E and the connecting portion 34.
It is connected to the erasing coil and the two recording/reproducing coils through the circuit so as to constitute a circuit similar to the circuit configuration shown in FIG. On both longitudinal edges of the flexible substrate 30, the circuit patterns B, C,
Grounding circuit patterns A and F are formed with D and E sandwiched between them. Among these grounding circuit patterns A and F, one circuit pattern A is connected to the gimbal plate 33 through the connection part 34, while the other grounding circuit pattern F only extends halfway down the flexible board 30. And it's not connected anywhere. However, the grounding circuit pattern F may also be connected to the gimbal plate 33.

In FIG. 1, reference numeral 40 indicates a connector of a circuit board on the main body side of the recording/reproducing apparatus, and this connector 40 has six connector terminals 1, 2, 3, 4,
It has 5 and 6. The connector 40 is connected to the connector 31 on the flexible board 30 side, and when these two connectors 40 and 31 are connected in the normal direction, both connector terminals 1 and a, 2 and b, and 3 are connected. c, 4 and d, 5 and e, and 6 and f are connected, respectively. Each connector terminal 1, 2, of the connector 40 on the main circuit board side
3, 4, and 5 are connected to have a circuit configuration similar to that shown in FIG. That is, connector terminal 1 is grounded, connector terminal 2 is grounded via diode D1, resistor R1, and transistor Tr1, and connector terminal 3 is grounded via transistor Tr2.
Connected to power supply +Vcc via connector terminal 4
is connected to the recording/reproducing circuit 21, and the connector terminal 5
is connected to the recording/reproducing circuit 22. and,
A sixth connector formed on the connector 40 on the main body circuit board side
The th connector terminal 6 is electrically connected to the first connector terminal 1 and grounded.

In the embodiment shown in FIG. 1, suppose that the connector 31 on the flexible board 30 side and the connector 40 on the main body circuit board side are connected in the normal orientation.
Each coil constituting a part of the magnetic head 35 is properly connected to a circuit on the main body circuit board side, thereby performing a predetermined recording/reproducing operation. Since the circuit patterns B, C, D, and E of the flexible board 30 for energizing each coil of the magnetic head 35 are sandwiched between the two ground circuit patterns A and F, the two ground circuit patterns B, C, D, and E are sandwiched between the two ground circuit patterns A and F. circuit pattern A,
F has a shielding effect on the circuit patterns B, C, D, and E for energizing each coil, and recording and reproducing can be performed with less noise.

Next, the connector 31 on the flexible board 30 side
If the connector 40 on the circuit board side of the main body is connected in the opposite direction by mistake, both connector terminals a and 6, b and 5, c and 4, d and 3, e and 2, and f and 1 will be connected. Ru. Therefore, only the gimbal plate 33 is grounded, and the coils constituting the magnetic head 35 are not directly grounded, so that no excessive current flows through the coils. To explain this more specifically, power supply + Vcc
is supplied to the recording/reproducing coil W1 via the transistor Tr2, the connector terminal 3, and the connector terminal d, and then an electric path leading to the connector terminal c, the connector terminal 4, the recording/reproducing circuit 21, the recording/reproducing coil W2, and the connector terminal. e, connector terminal 2, diode D1, resistor R1, electric path leading to transistor Tr1, erasing coil E1, connector terminal b,
The coils are supplied to the connector terminal 5 and the electric path leading to the recording/reproducing circuit 22, so that each coil is not directly grounded.

In this way, even if the connectors 31 and 40 are connected in the opposite direction by mistake, each coil of the magnetic head will not be directly grounded, so an excessive current will not flow through each coil, and the magnetic head will damage can be prevented.

(Effects of the invention) According to the invention, in a magnetic head device in which a magnetic head and a main body circuit board are connected using a flexible board and a connector, the flexible board has a plurality of wires for energizing each coil. The book's circuit pattern and this circuit pattern are in between.
A book grounding circuit pattern and a connector terminal formed at the end of each circuit pattern are provided, and at least one of these two grounding circuit patterns is connected to a metal plate on which a magnetic head is attached. Since the connector terminals at both ends of the flexible board to which the grounding circuit pattern is connected are connected to the ground via the connector terminals on the main circuit board, it is possible to accidentally connect the connector on the flexible board side to the connector on the main circuit board side. Even if they are connected in the opposite direction, only the two grounding circuit patterns on the flexible board will be directly grounded through both connectors, and the circuit patterns for energizing each coil will be directly grounded. Therefore, excessive current is prevented from flowing through each coil, and damage to the magnetic head can be prevented.

In addition, since the grounding circuit pattern is formed on both sides of the circuit pattern for energizing each coil, the grounding circuit pattern has a shielding effect with respect to the circuit pattern for energizing each coil. There is also an effect that recording and reproduction can be performed with less noise.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is a circuit diagram showing an example of the connection of a conventional magnetic head device using a flexible board and a connector. 30...Flexible board, 31...Connector, 33...Gimbal plate which is a metal plate, 35...
Magnetic head, 40... Connector on main circuit board side, A, F... Grounding circuit pattern, B, C,
D, E...Circuit pattern for energizing the coil, a, b, c, d, e, f...Connector terminal,
1, 2, 3, 4, 5, 6... Connector terminals.

Claims (1)

[Scope of Claim for Utility Model Registration] A magnetic head equipped with a coil wound around an erasing core and a coil wound around a recording/reproducing core is attached to a metal plate, and a flexible substrate with one end held by the metal plate is used. In a magnetic head device in which the magnetic head is electrically connected to a main body circuit board, the flexible board has a plurality of circuit patterns for energizing each of the coils, and is arranged on both sides with the circuit patterns in between. The main body circuit board includes two grounding circuit patterns formed on the flexible board, and connector terminals formed at the ends of each circuit pattern. The flexible substrate is provided with a ground conductive to the connector terminals on both sides, and an erasing circuit and a recording/reproducing circuit conductive to the middle connector terminal, and at least one of the two grounding circuit patterns of the flexible substrate is connected to the metal plate. , connect the connector terminals at both ends of the flexible board to which the two earthing circuit patterns are connected,
A magnetic head protection mechanism connected to earth via the connector terminal of the main circuit board.