Electrical computers and digital processing systems: memory – Storage accessing and control – Specific memory composition
Reexamination Certificate
1999-12-10
2003-01-14
Nguyen, Than (Department: 2187)
Electrical computers and digital processing systems: memory
Storage accessing and control
Specific memory composition
C711S004000, C711S111000, C711S147000, C711S148000, C711S202000, C711S206000, C360S055000, C360S069000, C369S024010, C369S030060, C369S027010, C369S030380, C369S047100
Reexamination Certificate
active
06507889
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a recording medium library device which houses a plurality of recording media loadable/unloadable to/from a recording and reproducing apparatus, such as cassette tapes, and is capable of recording/reproducing various information to/from the housed recording medium as necessary. The present invention also relates to methods of setting occupancy, determining and notifying completion of loading a recording medium, and cleaning for such a recording medium library device.
BACKGROUND ART
There has long been a system which houses a plurality of recording media (cassette tapes or disk-shaped recording media, for example) loadable/unloadable to/from a recording and reproducing apparatus and records various information onto the housed recording media and reproduces the recorded information as necessary. Such a system is called a library system, auto-changer, or the like. In the following description, it will be called a library system.
Some library systems have predetermined compositions. Other library systems have compositions which can be adapted to a certain degree to suit the user. An example of the latter library systems has a plurality of consoles. The consoles are combined freely to form library systems of various sizes and arrangements. Examples of the consoles are a drive console and a console for housing recording media. A drive console has a recording and reproducing apparatus which records and reproduces information onto/from a recording medium. A console for housing recording media has a plurality of housing sections, each capable of housing a recording medium. Some consoles for recording and reproduction further comprise a plurality of housing sections, each capable of housing a recording medium. Moreover, the latter library system comprises a carrier apparatus and a control unit. The carrier apparatus carries a recording medium between any one of the housing sections and the recording and reproducing apparatus. The control unit controls the recording and reproducing apparatus and the carrier apparatus.
In the library system, under the control of the control unit, the carrying apparatus is controlled to carry a recording medium between any one of the housing sections and the recording and reproducing apparatus. Various information is recorded on the recording medium carried to the recording and reproducing apparatus, and the recorded information is reproduced.
Such a library system has some problems as described hereinbelow.
The first problem is as follows.
Some library systems are connected to one or more host computers serving as client(s) so that the host computer can use the library systems. In this case, a library system is connected to the host computer by, for example, a transmission line of the standard for jukebox in the SCSI (Small Computer System Interface) standard established by ANSI (American National Standards Institute).
In cases, as for example where one library system is shared by a plurality of host computers, a control unit of the library system may set occupancy of a plurality of recording and reproducing apparatuses, housing sections and the like for each host computer as a client. The occupancy is set through giving continuous address numbers to the recording and reproducing apparatuses and allocating the address numbers to each host computer. By the operation, each host computer can use only the occupied recording and reproducing apparatus and the like. At this time, it is necessary to allocate continuous address numbers to one host computer because of the standard of the transmission line used to connect the host computer to the library system.
Conventionally, the only method of setting occupancy is therefore to allocate physically continuous recording and reproducing apparatuses or the like to one host computer. An arbitrary address number cannot be allocated to one host computer. This results in a problem of the low degree of freedom in setting occupancy. For example, when one of the physically continuous recording and reproducing apparatuses fails, the address numbers are interrupted. This causes a problem that, in the host computer occupying the failed recording and reproducing apparatus, a process of changing the occupancy setting so as to occupy a recording and reproducing apparatus for replacement cannot be performed.
The second problem is as follows.
In a library system having the composition as mentioned above, when a recording medium is carried by the carrying apparatus from the console for housing recording media and loaded to the recording and reproducing apparatus, the recording and reproducing apparatus performs a preparing operation for reading predetermined retrieval information from the loaded recording medium. The retrieval information, which is read by the preparing operation, includes information on, for example, an address on the recording medium of data recorded on the recording medium. By reading the retrieval information in advance, the processing speed with which data on the recording medium is accessed in response to a reproduction request from an upper control computer can be increased. This speed-up contributes to the improvement of the processing efficiency of the library system as a whole.
In this case, after the preparing operation is finished, the recording and reproducing apparatus notifies the upper control computer of completion of carriage of the recording medium. When the upper control computer receives the notification, the upper control computer issues the next recording medium carrying command to the library system.
The preparing operation requires, however, a relatively long time of 30 seconds to one minute. During the period, the upper control computer remains waiting for the notification from the recording and reproducing apparatus of completion of carriage of the recording medium. The carrying apparatus of the library system therefore also remains waiting. This waiting period becomes a useless time, causing a problem of deterioration in the processing efficiency of the library system as a whole.
The third problem is as follows.
In a library system having the above-described composition, a number of recording media are used. In order to maintain always the high recording and reproduction quality, it is necessary to clean the recording and reproducing head of the recording and reproducing apparatus periodically or as necessary. Conventionally, a cleaning medium is housed in part of the console for housing recording media. With manual operation by the user, periodically or as necessary, the cleaning medium is carried from the console for housing recording media to each recording and reproducing apparatus to clean the head.
As described above, cleaning the head of the recording and reproducing apparatus by manual operation is time-consuming. Also, it is not easy to manage timely head cleaning of each recording and reproducing apparatus without missing the timing of head cleaning. As a result, the operating cost of the system is high and it is difficult to properly control the system operation. A possible way to deal with the problem is to perform automatically and periodically the head cleaning process of each recording and reproducing apparatus by using a cleaning medium housed in the console for housing recording media.
When the recording medium used in the library system as described above is in a tape form such as a video cassette tape, the cleaning medium used for cleaning the recording and reproducing apparatus is also in a tape form. That is, a cleaning cassette is used. Some cleaning cassettes cannot be rewound and used repeatedly and are to be disposed when the tape is used up. In order to ensure cleaning by using such a cleaning cassette, it is indispensable that a usable tape area is left in the cleaning cassette.
In cases where head cleaning is performed by manual operation, it is possible to keep track of the amount of the usable tape area of the cleaning cassette accurately by checking the number of times each cleaning cassette is used. If the nu
Tadokoro Keiji
Tsurumaki Nobuhiro
Yokota Masato
Yumine Toru
Frommer William S.
Frommer & Lawrence & Haug LLP
Nguyen Than
Polito Bruno
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