Dynamic magnetic information storage or retrieval – Record medium – In container
Reexamination Certificate
2000-10-26
2003-01-07
Miller, Brian E. (Department: 2652)
Dynamic magnetic information storage or retrieval
Record medium
In container
C369S291100
Reexamination Certificate
active
06504679
ABSTRACT:
TECHNICAL FIELD
The present invention generally relates to a compact optical disc cartridge of a type accommodating therein a rewritable optical disc such as, for example, an erasable optical disc, a magnetooptical disc or a phase-changeable optical disc. More particularly, the present invention relates to a safety device in the optical disc cartridge for preventing information, recorded or otherwise stored on the rewritable disc, from being erased inadvertently.
BACKGROUND ART
Optical disc cartridges are available in a variety of types. Of those optical disc cartridges, the optical disc cartridges utilizing a rewritable optical disc such as, for example, an erasable optical disc, a magnetooptical disc or a phase-changeable optical disc require a safety device installed therein for preventing information recorded or stored on the rewritable optical disc from being erased inadvertently. The safety device generally comprises a movable element that moves selectively between enabled and protected positions. While information can be recorded or overwritten on the optical disc when the movable element is moved to the enabled position, the information recorded, or otherwise stored on the optical disc can be neither recorded nor overwritten in any way whatsoever when the movable element is held at the protected position. To move the movable element in this way, the movable element has a safety lug accessible to the user.
By way of example, the rewritable optical disc cartridges generally comprises a generally square flat casing including top and bottom panels and four side walls. all assembled together to define a disc chamber therein. An optical disc is rotatably housed within the disc chamber. The safety device is operatively accommodated within one of four, generally triangular corner spaces each defined inside and at a corner region of the disc casing. One of the four side walls of the optical disc cartridge that is adjacent the triangular corner space where the safety device is housed has an opening defined therein with the safety lug held in position accessible from outside of the optical disc cartridge so that the user can manipulate the safety lug.
Other than the safety device, the optical disc cartridge has two or more positioning and identifier holes defined in the bottom panel and positioned adjacent two or more corner regions of the disc casing. The positioning holes are cooperable with corresponding positioning pins installed in an optical disc player and are utilized to set the optical disc cartridge in position ready to establish an interactive relation between the optical disc and an optical read/write head once the optical disc cartridge is loaded in the optical disc player. On the other hand, the identifier hole or holes are utilized to allow the optical disc player to recognize the specification of the optical disc cartridge loaded therein. The specification of an optical disc cartridge includes the recording capacity of the optical disc and/or the optical characteristic (e.g., erasable or non-erasable) of the optical disc. It is pointed out that where the optical disc housed in the cartridge is a non-erasable type, the optical disc cartridge may not be provided with the safety device.
The optical disc cartridge also has a sensor hole defined at a location aligned with the movable element of the safety device, which hole is selectively opened or closed by the movable element. By way of example, the sensor hole may left open when the movable element is in the protected position, but be closed when the movable element is in the enabled position. The movable element employed in the prior art safety device is generally in the form of an elongated slide piece linearly slidable along the side wall of the disc casing between the enabled and protected positions.
Considering that the optical disc cartridge is getting. compact and compact and a currently commercially available MD (Mini-Disc) cartridge has a size of about 7.2×6.8 cm with the erasable optical disc being about 6.4 cm, the corner spaces available in the optical disc cartridge are correspondingly getting smaller. The smaller the corner spaces, the smaller the safety device and, thus, the smaller the stroke of movement of the slide piece. If the slide piece is reduced in size, the safety lug must also be reduced in size in order to secure a required stroke of movement for the slide piece. The smaller the safety lug, the more difficult the user feels to manipulate it.
In order to ensure the movable element to be assuredly moved between the enabled and protected positions even though the safety lug is minute, the Japanese Laid-open Patent Publication No. 10-338286, for example, discloses a cartridge storage casing for accommodating a rewritable optical disc cartridge when the latter is not in use, which storage casing is provided with an operating pawl that triggers the slide piece externally through the safety lug while the optical disc cartridge is within the cartridge storage casing. Although the safety system disclosed in this patent publication appears satisfactory, the external operating piece disclosed in the above mentioned publication would no longer work out if the optical disc cartridge is further reduced in size, accompanied by corresponding reduction in size of the movable element inside the. optical disc cartridge. More specifically, if the external operating piece is reduced in size in correspondence with reduction in size of the movable element, difficulty would be encountered in securing a sufficient physical strength in the external operating piece, or the external operating piece would become susceptible to damage when the optical disc cartridge is inadvertently subjected to impacts.
The possibility of the external operating piece being excessively reduced in size may be eliminated if the cartridge storage casing is assembled to a size slightly larger than the optical disc cartridge. However, since demands have arisen for the optical disc cartridge to be manufactured in, a further reduced size while efforts have been made along with it to increase the information recording density of an optical disc, increase in size of the cartridge storage casing is limited.
DISCLOSURE OF INVENTION
Accordingly, the present invention has for its primary object to provide an improved optical disc cartridge wherein the safety device makes use of a switching element, in place of the slidable element such as employed in the prior art optical disc cartridges, to thereby reduce the space occupied inside the optical disc cartridge by the safety device, so that the optical disc cartridge as a whole can be manufactured in a further compact size.
Another object of the present invention is to provide an improved optical disc cartridge of the type referred to above, wherein maximized utilization is made of at least one of the limited corner spaces available in the optical disc cartridge to enable the safety device to be accommodated therein snugly.
A further object of the present invention is to provide an improved optical disc cartridge of the type referred to above, wherein a tubular boss positioned inside the optical disc cartridge so as to surround one of the positioning holes for reinforcing a peripheral lip region around the positioning hole is advantageously utilized for the support of the switching element for movement between the enabled and protected positions.
A still further object of the present invention is to provide an improved optical disc cartridge of the type referred to above, wherein means is provided for-enabling the user to ascertain the position of the switching element from outside of the optical disc cartridge.
A still further object of the present invention is to provide an improved optical disc cartridge of the type referred to above, wherein means is provided to lock the switching element at any one of the enabled and protected positions.
In order to accomplish these and other objects of the present invention, there is provided a disc cartridge accommodating therein an erasable disc-shaped
Birch & Stewart Kolasch & Birch, LLP
Hitachi Maxell Ltd.
Miller Brian E.
LandOfFree
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