Dynamic magnetic information storage or retrieval – Head mounting – For moving head into/out of transducing position
Reexamination Certificate
2001-10-10
2004-06-29
Watko, Julie Anne (Department: 2652)
Dynamic magnetic information storage or retrieval
Head mounting
For moving head into/out of transducing position
Reexamination Certificate
active
06757139
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an information recording apparatus including an actuator which has a head arm for holding a recording/reproducing head for a recording medium and which loads and unloads the head arm for the recording medium by swinging. More particularly, the present invention relates to an information recording apparatus including a function for preventing the actuator from being swung accidentally toward the recording medium side when the apparatus is subjected to an external shock in a state that the actuator is located at a shunt position.
2. Description of the Related Art
As a shunt position of an actuator at non-operating, a ramp block is arranged on a periphery of a disc. Holding the actuator on the ramp block prevents a slider from moving accidentally to a data area of the disc. This is done to avoid adsorbing the slider onto the disc surface during stoppage or damaging the data area.
It is required that the actuator is held at a shunt position also when the apparatus is subjected to an external shock at non-operating. In particular, in a magnetic disc apparatus carried on a portable personal computer such as a notebook computer, a high reliability to cope with the shock is required at non-operating.
As measures against a shock, it is considered to provide an inertia lever and a latch lever. When the apparatus is subjected to an external shock, the inertia lever is swung by the inertia, the swung inertia lever is engaged with the latch lever, and the latch lever is caused to move to a swing locus of the actuator, thereby latching the actuator by the latch lever. This holds the actuator at a shunt position in spite of the shock. This function is exhibited in a clockwise direction or in a counterclockwise direction.
On the other hand, the actuator may excessively swing in a load direction or in an unload direction exceeding a limit of its original swing range due to some unusual condition such as an abnormal run of a voice coil motor during the operation of the apparatus. At this time, in order to prevent the actuator from hitting a spindle motor or other areas of the apparatus, crush stops are provided. The crush stops has two ones: one in a load direction side; and another in an unload direction side.
In order to restrain the accidental swing of the actuator due to a shock, using two elements of the inertia lever and the latch lever causes the reliability of operation to become unstable.
The inertia lever has a lager mass than that of the latch lever, so that the inertia lever, when subjected to a shock, swings earlier than the latch lever. The latch lever having a smaller mass swings later.
There is a time difference in the start of swing between both levers as described above, and the actuator is not engaged with the latch lever in a stationary state at the shunt position. This brings about a possibility that the latch operation of the actuator by the latch lever fails. In particular, when the actuator hits the crush stops, thus causing a rebound thereof, there becomes higher a possibility that the latch operation fails.
The fact that the latch mechanism consists of two elements of the inertia lever and the latch lever to cause the each structure to become complex, and that two crush stops are required, as a whole, leads to an increased structural complex and an increased cost.
Although the above-mentioned problems are associated with a magnetic disc apparatus, the problems can be addressed by applying them not only to a case where the recording medium is a magnetic disc, but also widely to general information recording apparatuses.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide an information recording apparatus wherein an actuator can securely be held at a shunt position against an external shock.
Another object of the present invention is provide an information recording apparatus which can prevent the actuator from swinging excessively due to some unusual conditions such as an abnormal run of a voice coil motor.
A further object of the present invention is to provide an information recording apparatus wherein the number of parts is reduced to thereby achieve a slim shape.
Other objects, features and advantages of the present invention will appear in the description thereof which follows.
The actuator has a head arm for holding a recording/reproducing head for a recording medium, and loads and unloads the head arm for the recording medium by swinging. The information recording apparatus includes an inertia arm for restraining the swing of the actuator when the apparatus is subjected to an external shock. Here, the loading means moving of the head (slider) from the shunt position of the actuator to a position opposed to the data area of the recording medium, while the unloading means moving of the head from the position opposed to the data area to the shunt position. The swingable pivotally supported actuator generates a rotational moment when subjected to an external shock, while the inertia arm also generates a rotational moment in the same direction. The present invention restrains the swing of the actuator, when the actuator is located at least in the shunt position, by competing a rotational force generated from the actuator due to the external shock with a rotational force generated from the inertia arm, in spite of the above-mentioned shock.
A shock transmitting portion is provided on the actuator while a shock transmitting portion is also provided on the inertia arm. The transmitting portion on the actuator side and that on the inertia arm side are in a state in which they are dynamically interlocked with each other in a form of engagement or abutment with the actuator located at the shunt position.
The direction of the rotational moment of the actuator is the same as that of the inertia arm. The moving direction of the shock transmitting portion on the actuator side and that on the inertia arm side are opposite to each other. In other words, both the transmitting portions are related dynamically to each other such that both the portions are pushed to each other, or pulled from each other so that an action and a reaction work. However, this is a case where a rotational moment generates simultaneously on both the actuator and the inertia arm due to an external shock. Otherwise, when the actuator is driven to swing itself, the inertia arm generates no rotational moment, and however, the above-mentioned action and reaction do not occur on both the transmitting portions, whereby the actuator becomes possible to swing for loading and unloading with respect to the recording medium. As long as a free swing of the actuator is allowed, the relationship between both the transmitting portions is such that they may lose interlocking each other in a load and unload state, or they may interlock with each other on a condition that no substantial action and reaction occur.
Due to an external shock, a rotational moment is generated on the actuator, and the rotational moment in the same rotational direction is also generated on the inertia arm. The actuator tries to swing using the supporting axis of itself as a center with the rotational moment while the inertia arm also tries to swing using the supporting axis of itself as a center with the rotational moment.
As a result of such a trend of the swing of both the actuator and the inertia arm, the shock transmitting portion on the actuator side and that on the inertia arm side exert a rotational force on each other. The action and reaction causes the rotational forces by the both to be competed with each other.
The competing with each other causes an effect due to an external shock to be reduced. This is a function of absorbing a shock.
Therefore, when an external shock is exerted, substantially at the moment, that is, without delay in response, the function of absorbing a shock works by the above-mentioned competing with each other in rotational force. This makes it possible to prevent the actuator located at the shu
Matsushita Electric - Industrial Co., Ltd.
McDermott & Will & Emery
Watko Julie Anne
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