Media labeling system for data storage elements having a common form factor

The media labeling system makes use of human-readable and machine-readable label indicia to automatically identify of the media type contained within each of a plurality of data storage elements that have a substantially uniform external form factor. The machine-readable indicia includes a standard 3-of-9 bar code in addition to a unique bar and space code to provide error detection for damaged or partially obliterated labels, and to help low resolution bar code interpreters to distinguish the media type label from other label indicia present on the data storage element.

CROSS-REFERENCE TO RELATED APPLICATIONS 
This application is related Ser. No. 07/857,166 filed Mar. 25, 1992 now 
U.S. Pat. 5,412,194. 
FIELD OF THE INVENTION 
This invention relates to labeling systems, and in particular to a label 
which contains indicia that facilitates automated identification of the 
media type within each of a plurality of data storage elements having a 
substantially uniform external form factor, in addition to containing an 
error detection code indicia that helps to determine whether a media label 
is damaged and to distinguish the media label's indicia from indicia on 
other labels. 
PROBLEM 
Bar codes, Optical Character Recognition (OCR) characters, and color codes 
are common indicia found on labels used by present day labeling systems. 
Bar codes, OCR characters, and color codes are machine-readable by 
electronic interpreters, and OCR characters and color codes are also 
easily human-readable. These indicia can be printed on labels in order to 
uniquely identify items to which the labels are attached. 
One example of using bar code and OCR labeling technology is to identify 
3480-type magnetic tape cartridges commonly used in the data processing 
industry. The 3480-type magnetic tape cartridges are an industry standard 
for reading and writing data for two reasons: 1) the magnetic tape is a 
reliable and durable media type; and 2) the cartridge housing itself has a 
substantially uniform external form factor capable of housing many 
different media types besides the traditional longitudinal tape, including 
but not limited to disk, solid state memory, helical tape, and other 
magnetic tapes of varying lengths, thicknesses and data recording 
characteristics. For this latter reason, the 3480-type magnetic tape 
cartridge is more generically called a data storage element rather than a 
magnetic tape cartridge. 
In some data processing facilities, each data storage element contains the 
same media type and a human operator manually retrieves and loads a 
particular data storage element into a media drive when requested by a 
data storage system user. In other facilities, many data storage elements 
are stored in automated libraries such as the 4400 Automated Cartridge 
System (ACS) library manufactured by Storage Technology Corporation of 
Louisville, Colo. An ACS uses a centrally located robotic data storage 
element handling mechanism to automatically retrieve and load a user 
requested data storage element from a surrounding cylindrical library 
stack into a media drive. In either facility, a label applied to each data 
storage element identifies an individual data storage element by its 
unique VOLame SERial number (VOLSER). To accommodate both human operators 
and automated libraries, the typical labeling system includes a redundant 
combination of bar code, OCR character, and/or color code indicia on each 
label. In automated libraries, only the bar code is typically read. The 
OCR and color code indicia exist so that a human operator can identify the 
data storage element in the event it is removed from the automated 
library. 
One problem with existing labeling systems is that each label contains only 
a VOLSER to distinguish one data storage element from the next. Such a 
labeling system does not identify the media type contained within a data 
storage element. Therefore, an automated library or human operator must 
either assume that only one media type exists within all data storage 
elements, or maintain a separate data base identifying the media type 
associated with each VOLSER. Further, relying on users to specify a 
particular type media drive in advance of retrieving and loading the data 
storage element in the media drive means that the media type is no longer 
transparent to the user. 
A second problem with existing labeling systems is that because the VOLSER 
does not identify the media type contained within a data storage element, 
and because different media types are often only compatible with 
corresponding media drives, either the media type, the media drive, or 
both can be damaged if a particular media type is inadvertently mounted in 
an incompatible media drive. Damaging either 
A third problem with existing labeling systems is that they lack the 
ability to identify damaged or unreliably altered labels. Therefore, a 
damaged or altered label may be misread by the bar code interpreting 
device thereby resulting in data loss by inadvertently overwriting data 
already on the media or by causing component damage as previously 
discussed. 
Another problem with existing labeling systems is that the lines and spaces 
of standard 3-of-9 bar codes found on existing VOLSER labels can be too 
fine to be reliably read by low resolution bar code interpreters. 
Therefore, merely integrating media type identification into the existing 
VOLSER label's bar code indicia is not a solution compatible with low 
resolution bar code interpreters since the VOLSER label is already at the 
resolution limit without media type identification. Further, implementing 
a binary bar code indicia containing error detection or more elaborate 
error correction codes, creates closely packed bars and spaces that are 
indistinguishable by low resolution bar code interpreters. Finally, there 
is insufficient space to add a VOLSER style media type label to the data 
storage element's already limited edgewise labeling surface area. This is 
because there is only room for a single OCR character and bar code 
equivalent, and no room for the VOLSER style start and stop characters 
that mark the beginning and end of significant label characters. For these 
reasons, automated library system owners with low resolution interpreters 
are forced into purchasing expensive high resolution optical equipment 
upgrades, in addition to the new media type's expense, if they wish to 
benefit from alternative media types in their existing automated 
libraries. 
SOLUTION 
The above described problems are solved and a technical advance achieved in 
the field by the media labeling system of the present invention. A 
preferred embodiment of this labeling system is located on the edgewise 
surface of a data storage element similar to the 3480-type magnetic tape 
cartridge form factor. Although the media labeling system of the present 
invention can be implemented on a substrate with primed indicia on one 
surface and an adhesive on the opposing surface, labeling can also be 
implemented by physically and materially integrating the indicia with the 
data storage element's surface in ways that include but are not limited 
to, molding, color molding, etching, engraving, painting, or stamping. 
The present invention facilitates automated media type identification of 
the media contained within a data storage element. This is accomplished by 
way of a coded media type label containing an error detection bar code and 
a machine-readable 3-of-9 type bar code indicia that is interpretable 
independent of existing VOLSER identifying indicia. The media type label 
also accommodates redundant OCR character indicia and/or color coded 
indicia as commonly found on existing VOLSER labels. The redundant indicia 
is used to uniquely identify any one of a plurality of media types, so 
that an automated library or a human operator can identify a compatible 
media drive, thereby avoiding physical damage to either or both 
components, or inadvertently overwriting data already on the media. In the 
typical automated library with a low resolution bar code interpreter, only 
the bar code indicia is read. 
Each media type label also contains an error detection bar code that when 
read in combination with the 3-of-9 type bar code indicia representing a 
specific media type, creates a unique key indicating whether or not the 
media type label is damaged. This provides a compact error detection 
capability heretofore not found with standard 3-of-9 bar coded labels. 
Finally, the media type label's error detection bar code also serves to 
distinguish the media type label from the VOLSER label without using 
traditional VOLSER style start and stop characters. This results in a 
significant space savings on bar code and error correction code, so that 
the bar codes are readable by low resolution bar code interpreters and 
distinguishable from the VOLSER bar code. 
Therefore, implementing the media labeling system of the present invention 
offers automated library owners a reliable means for automatically 
identifying alternative media types, in addition to a cost effective 
alternative to upgrading expensive robotic bar code interpreter devices.

DETAILED DESCRIPTION 
To overcome deficiencies in present labeling systems, a label identifying 
the media type within the data storage element is attached to each data 
storage element that is stored in either a manual library or automated 
library. The media type label is affixed to the same data storage element 
surface as the VOLSER label and can be either a separate label from the 
VOLSER label or on a separate section of the same label surface containing 
the VOLSER indicia. In the preferred embodiment, a separate media type 
label is attached in a defined area to the data storage element by the 
data storage element manufacturer. The user/customer typically attaches 
the VOLSER label to the data storage element at the time the data storage 
element is placed in service. In either case, the media type label 
conforms to the VOLSER indicia format by including both human-readable and 
machine-readable indicia on each label, although the color coded indicia 
is optional. In addition, the media type label of the present invention 
contains a unique error detection code to determine if the label has been 
damaged or smudged, and to help distinguish the media type label from the 
VOLSER label. 
FIG. 1 illustrates the present invention's media type label 102 as it would 
be found on a data storage element 1 where the data storage element has a 
similar form factor to the 3480-type magnetic tape cartridge. Although the 
VOLSER label 101 is physically separate from the media type label 102 by 
distance z which is substantially 1/8 inch or less, both labels and the 
indicia on each label are considered substantially juxtaposed if the 
distance z is substantially 1/8 inch or less. Both labels 101 and 102 are 
contained in separate recessed label receiving areas 104 and 105, 
respectively, which are formed in the data storage element 1. Each label 
101 and 102 has a print receiving surface 100 which is attached to an 
adhesively backed substrate that affixes each label to a surface of the 
data storage element 1. The media type label 102 and the VOLSER label 101 
can be printed and affixed to data storage element 1 by either the 
manufacturer or the user, however, the media type label 102 is preferably 
affixed by the manufacturer. 
Labels 101 and 102 both contain human-readable and machine-readable indicia 
top T to bottom B of the data storage element 1, and the machine-readable 
indicia is read from the bottom B to top T, the labeling system of the 
present invention is not directionally dependent. However, the error 
detection code is preferably oriented in the same direction that the bar 
code interpreter reads. 
The media type label 102 also has a length L and width W such that the 
width W is substantially 60 percent of the length L. The width of the bar 
code indicia 181 in column 120 of media type label 102 is substantially 21 
percent of length L. 
Finally, to accommodate low resolution bar code interpreters, the nominal 
width of a narrow space or narrow bar in either bar code 180 or 181, is at 
or about 0.029 inches. The nominal width of a corresponding wide bar or 
space is at or about 0.058 inches. 
Human-Readable Indicia 
The first indicia column 110 on labels 101 and 102 is divided into a series 
of vertically aligned, rectangular segments 130-137. Each rectangular 
segment contains one human-readable character 160-167, where each 
character is substantially centrally located in spaces 130-137. When 
column 110 of label 101 is read by a human, the indicia characters 
represent a VOLSER. When column 110 of label 102 is read by a human, the 
single indicia character represents a media type. 
Each rectangular segment 130-137 of column 110 may also contain a 
background color 170-177 that uniquely corresponds to the respective 
characters 160-167. The indicia colors represent the same human-readable 
VOLSER as the characters 160-166. In addition, the color in column 110 of 
label 102 represents the same human-readable media type as the character 
167. Therefore, both the OCR character and color indicia in column 110 
form the same VOLSER and media type identification that is useful to 
humans who must identify a data storage element that has been removed from 
the automated library system. 
Machine-Readable Indicia 
Column 120 of label 101 and 102 represents the same respective VOLSER and 
standard 3-of-9 bar code form. The bar code represents alphanumeric 
characters in the range A-Z and 0-9. 
Unique to the bar code in column 120 of VOLSER label 101 are the start and 
stop characters 140 and 150 respectively which are used to indicate the 
beginning and end of the significant VOLSER characters 160-166. The start 
and stop characters 140 and 150 are by tradition, either a $, *, or the 
character P. Becaase the bar code representation of the VOLSER contains 
additional start and stop characters not also found in human-readable 
column 110, the bar code equivalent of the significant VOLSER characters 
160-166 are not necessarily directly opposite the corresponding 
human-readable indicia in spaces 130-136. 
Column 120 of media label 102 contains a 3-of-9 type bar code indicia 181 
representing a single character A-Z, 0-9, or any special character 
including $, *, or P, because start and stop characters are not used in a 
media label. An error detection code 180, seen also in detail in FIG. 2, 
distinguishes the column 120 bar code indicia of media label 102 from the 
start character 140 of the VOLSER label 101 Error detection code 180 is 
also used to determine if an error exists in the media type bar code 181 
as discussed below. The distinction between a media type bar code 181 and 
a VOLSER bar code is made simultaneously with the error detection process 
as discussed below. 
Error Detection Code 
FIG. 2 illustrates an enlarged error detection code matrix showing the four 
error detection code configurations used in the error detection code 180. 
Specifically, the four configurations are illustrated in columns 210, 220, 
230, and 240, and each configuration includes two bars 158 and 159, and 
two spaces 154 and 155. Therefore, 7 total bars appear on any one media 
type label's machine-readable bar code indicia: 5 bars for the 3-of-9 type 
bar code indicia 181, and 2 bars for the error detection code 180. 
In addition to the error detection code 180 always having two bars and two 
spaces, only one of the bars 158 and 159, and only one of the spaces 154 
and 155, are wide at any one time. Further, the first error detection 
indicia 154 is always a space and the last error code indicia 159 is 
always a bar. This creates the four distinct configurations 210, 220, 230, 
and 240 that are unique to error detection code 180. In the present FIG. 2 
perspective where the error detection code is read from the bottom up, the 
bars and spaces create an incomplete or invalid 3-of-9 bar code sequence. 
Therefore, because the error detection code is an illegal 3-of-9 code, the 
error detection code further distinguishes the media type bar code 181 
from the VOLSER label indicia. 
The error detection code 180 and machine-readable media label indicia 181 
combination, is generated by consulting a lookup table at the time each 
label or set of labels for a particular media type is printed. The lookup 
table matches one of the four error detection code configurations 210, 
220, 230, or 240, with a corresponding one of the 3-of-9 bar code 
representation of the character A-Z, 0-9, or special character assigned to 
the particular media type. For example, the bar code representation of the 
alphabetic, numeric, or special character selected to represent any media 
type A, B, C, D, E . . . is assigned one of a repeating cycle of error 
detection code configurations 210, 220, 230, 240, and 210 of FIG. 2 
respectively. In other words every fourth media type character, A and E in 
the present example, are assigned the same error detection code 
configuration 210. Other error detection code configuration assignment 
schemes can be used as desired. The unique combination of media type bar 
code 181 and error detection code 180 is printed on one side of a media 
label substrate and the substrate is subsequently attached to the data 
storage element by an adhesive. Alternatively, the combination of media 
type bar code 181 and error detection code 180 can be physically and 
materially integrated with the data storage element surface as previously 
discussed herein. 
When a bar code Interpreter reads the bar code indicia 120 of media label 
102, the media type bar code 181 is read as a complete 3-of-9 bar code 
that is independent from the 4 element bar code of error detection code 
180. The bar code interpreter will first consult the lookup table to find 
a match for the media type bar code 181. If the lookup table does not 
contain a match for the media type bar code 181, then the media type bar 
code 181 most certainly contains an error or is otherwise damaged so as to 
prevent accurate reading. In this case, the data storage element bearing 
the media label 102 will not be loaded into any media drive. If the lookup 
table does contain a match for the media type bar code 181, then the 
lookup table is consulted further to determine if the error detection code 
180, read from the media label 102, is the error detection code that is 
expected to accompany the media type bar code 181 in question. For 
instance, the media type bar code representation for A in the above 
example could only be considered a valid media type bar code if it is 
accompanied by the error detection code configuration 210. Therefore, if 
the error detection code 180 accompanying the media type bar code 181 in 
question does not match the lookup table entry, then an error is detected 
in the bar code indicia 120 of media label 102 and the data storage 
element bearing the media label 102 is not loaded into any media drive. 
Alternatively, if the error detection code 180 accompanying the media type 
bar code 181 in question does match the lookup table entry, then the media 
type bar code is considered valid and the data storage element bearing 
media label 102 is loaded into a corresponding media drive. It is 
Important to note that media type bar code 181 and error detection code 
180 are independent bar codes. 
Other Embodiments 
FIG. 3 illustrates an embodiment of the present invention which is 
identical in all respects to the FIG. 1 embodiment except that there is no 
physical distance z separating the media type label 102 from the VOLSER 
label 101. Here, the data storage element 1 contains a single label 
receiving recessed area 304 sized to hold both the individual VOLSER label 
101 and the individual media type label 102. Although the indicia on each 
label are separated by white space borders 306 on each label, the labels 
and the indicia on each label are considered substantially juxtaposed. The 
media type label 102 contains the same error detection code 180 as 
discussed in FIG. 2. 
FIG. 4 illustrates an embodiment of the present invention which is 
identical in all respects to the FIG. 3 embodiment except that the indicia 
on media type label 102 and VOLSER label 101 both reside on a single 
substrate surface 100. Here the data storage element 1 contains a single 
label receiving recessed area 404 within each label are considered 
substantially juxtaposed. The media type indicia 102 contains the same 
error detection code 180 discussed in FIG. 2. 
FIG. 5 illustrates an embodiment of the present invention which is 
identical in all respects to the FIG. 4 embodiment except that there is no 
white space at z, between the indicia on media type label 102 and VOLSER 
label 101, and both reside on the same substrate surface 100. The media 
type indicia 102 contains the same error detection code 180 as discussed 
in FIG. 2. 
FIG. 6 illustrates an embodiment of the present invention where a redundant 
media label 600 is located on a surface 2 of the data storage element 1 
that is not also occupied by the VOLSER label 101 and media type label 102 
which reside on surface 3. Surface 3 of data storage element 1 can contain 
any embodiment previously illustrated herein. Alternatively, the media 
type label 102 need not exist at all on surface 3 of data storage element 
1 since the redundant media label 600 on surface 2 alone could serve to 
identify the media type within the data storage element 1. 
FIG. 7 illustrates an embodiment of the present invention where the media 
type label 102 is molded into surface 3 of data storage element 1. The 
indicia on media type label 102 is identical in function and content to 
the media type label 102 in all previously discussed embodiments. By 
molding the media type label 102 into the surface 3 of data storage 
element 1, the manufacturer eliminates the separate steps necessary when 
printing and affixing adhesive labels to the data storage element 1. To 
achieve color contrast in the bar codes 181 and 180, either the bars or 
spaces can be painted or molded with appropriate colors used in the 
molding process. Any similar coloring process can be used to color the 
human readable indicia 177 of column 110. The VOLSER label 101, however, 
can be made of the traditional printed substrate backed with adhesive to 
affix the label to the data storage element 1. The VOLSER label 101 is 
preferably affixed to the data storage element 1 in recess 104 by the 
user. In addition to physically and materially integrating the media type 
label 102 with data storage element 1 by molding or color molding, other 
types of integrating include, but are not limited to, etching, engraving, 
painting, or stamping. Finally, the molded media type label 102 of the 
present invention can appear alone or in combination with a VOLSER label 
101 as illustrated in any of the alternative embodiments herein. 
While specific embodiments of this invention have been disclosed, it is 
expected that those skilled in the art can and will design alternate 
embodiments of this invention that fall within the scope of the appended 
claims. Further, although the 3480-type form factor may be common in the 
industry and was used herein as an example, the media labeling system of 
the present invention is applicable to similar labeling systems on any 
size or type data storage element form factor.