United States Patent 19
`Horstman et al.
`
`73) Assignee:
`
`54 TAKE-UPREEL ASSEMBLY HAVING RADII
`AT DISCONTINUTESTOMINIMIZE TAPE
`IMPRESSIONS
`75 Inventors: Justus A. W. Horstman, Boulder;
`Michael V. Konshak, Louisville, both
`of Colo.
`Storage Technology Corporation,
`Louisville, Colo.
`21 Appl. No.: 115,751
`22 Filed:
`Sep. 3, 1993
`I51) Int. Cl............................................... G11B 23/04
`52 U.S. Cl. .............................. 242/348.2; 242/332.8;
`242/.532.6
`58 Field of Search ............... 242/332.7, 332.8, 348.2,
`242/.532.5, 532.6, 587, 587.1, 587.2
`References Cited
`U.S. PATENT DOCUMENTS
`4,350,309 9/1982 Richard et al. .................... 242/68.3
`4,399,959 8/1983 Godsoe et al....................... 242/195
`4,452,406 6/1984 Richard ............
`... 242/195
`4,577,811 3/1986 Bray et al.....
`... 242/195
`4,681,278 7/1987 Smith .......
`... 242/195
`4,717,090 1/1988 Smith et al.
`... 242/197
`4,826,101 5/1989 Smith ...........
`... 242/195
`5,261,626 11/1993 Hoge et al. ......................... 242/197
`
`56)
`
`US005431356A
`Patent Number:
`Date of Patent:
`
`11
`45
`
`5,431,356
`Jul. 11, 1995
`
`Primary Examiner-John P. Darling
`Attorney, Agent, or Firm-Sterne, Kessler, Goldstein &
`Fox
`ABSTRACT
`57
`A take-up reel assembly for use with a single-reel tape
`cartridge in a cartridge-based tape transport includes a
`take-up reel and a leader block. The take-up reel in
`cludes an annular hub having an axis of rotation and a
`radial surface adapted to have the tape wound thereon.
`A radial slot in the hub extends from the radial surface
`towards the axis of rotation. The leader block is config
`ured for attachment to a free end of a length of tape in
`the tape cartridge. The leader block has a shape substan
`tially the same as the shape of the radial slot in the hub
`of the take-up reel. The leader block has a first end
`adapted for coupling with a threading post and a second
`end having an end surface with a radius of curvature
`substantially the same as the radius of curvature of the
`radial surface of the hub so that when the leader block
`is pulled into the slot by a loading post, first and second
`leader block edges of the end surface substantially mate
`with first and second hub edges of the radial surface to
`cover the slot. The first and second leader block edges
`and the first and second hub edges are radiused to sub
`stantially eliminate tape damage caused by impression
`Ing.
`
`8 Claims, 4 Drawing Sheets
`
`
`
`FUJIFILM, Exh. 2013, p. 1
`FUJIFILM v. Sony, 2018-00876
`
`

`

`U.S. Patent
`
`July 11, 1995
`
`Sheet 1 of 4
`
`5,431,356
`
`
`
`FUJIFILM, Exh. 2013, p. 2
`FUJIFILM v. Sony, 2018-00876
`
`

`

`U.S. Patent
`
`July 11, 1995
`
`Sheet 2 of 4
`
`5431,356
`
`
`
`TAKE-UP-REEL
`
`04
`
`EADER
`
`SCALE 2.000
`
`FIG. 4
`(PRIOR ART)
`O
`
`
`
`FUJIFILM, Exh. 2013, p. 3
`FUJIFILM v. Sony, 2018-00876
`
`

`

`U.S. Patent
`
`July 11, 1995
`
`Sheet 3 of 4
`
`5,431,356
`
`STRESS
`(BENDING)
`st to
`S(r,t)
`
`FIG. 6
`
`602
`..
`y
`
`.
`2
`
`7.04
`6.5-104
`6-10
`. An4
`5.50
`5'10"
`45.404
`. An4
`40
`3.5-104
`3. 04
`
`
`
`2.5:10
`
`2.04
`1.5.10
`A.104
`5000
`
`600
`
`S(r, t2)
`S(r, ta)
`x is a
`3.
`
`a
`
`sew as a
`
`a
`
`FUJIFILM, Exh. 2013, p. 4
`FUJIFILM v. Sony, 2018-00876
`
`

`

`U.S. Patent
`
`July 11, 1995
`
`Sheet 4 of 4
`
`5,431,356
`
`
`
`FUJIFILM, Exh. 2013, p. 5
`FUJIFILM v. Sony, 2018-00876
`
`

`

`1.
`
`TAKE-UPREEL ASSEMBLY HAVING RADAT
`DISCONTINUTES TO MNMIZE TAPE
`MPRESSIONS
`
`5,431,356
`2
`were affected by tape impressions, then the practice in
`the industry has been to not store data on those first 100
`wraps of the tape.
`Tape impressions are a continuing problem in the
`data storage industry. Not using the portion of the tape
`with impressions results in wasted data storage capabil
`ity and wasted time, as the tape must always be ad
`vanced past the unusable portions. What is needed is a
`means for substantially reducing or eliminating the
`cause of tape impressions so that the maximum amount
`of storage capacity can be obtained from each tape
`cartridge.
`SUMMARY OF THE INVENTION
`The invention is a take-up reel assembly for use with
`a single-reel tape cartridge in a cartridge-based tape
`transport. The assembly includes a take-up reel and a
`leader block which act together to significantly reduce
`tape impressions The take-up reel includes an annular
`hub having an axis of rotation and a radial surface con
`figured to have a tape wound thereon. A radial slot in
`the hub extends from the radial surface towards the axis
`of rotation. The leader block is provided for attachment
`to a free end of a length of tape in a tape cartridge. The
`leader block has a shape substantially the same as the
`shape of the radial slot in the hub of the take-up reel.
`A first end of the leader block is adapted for coupling
`with a threading post of a tape transport. A second end
`of the leader block has an end surface with a radius of
`curvature substantially the same as the radius of curva
`ture of the radial surface of the hub. When the leader
`block is pulled into the slot in the hub by a loading post,
`first and second leader block edges of the end surface of
`the leader block substantially mate with first and second
`hub edges of the radial surface to cover the slot. The
`first and second leader block edges and the first and
`second hub edges are radiused to substantially eliminate
`tape damage caused by impressioning.
`The inventors have discovered that strategically
`placing radiused curves on the edges of the hub slot and
`the corresponding edges of the leader block substan
`tially eliminates impressioning.
`The take-up reel assembly further includes tape
`guides which extend radially outward from the sides of
`the hub to guide a tape as it is wrapped or unwrapped
`on the hub.
`The foregoing and other objects, features and advan
`tages of the invention will be apparent from the follow
`ing, more particular description of a preferred embodi
`ment of the invention, as illustrated in the accompany
`ing drawings.
`BREEF DESCRIPTION OF THE DRAWENGS
`FIG. 1 is a perspective view of a tape cartridge in
`cluding a length of tape and a leader block.
`FIG. 2 is a perspective, exploded view of a take-up
`reel for use with a tape cartridge in a cartridge tape
`transport.
`FIG. 3 is a top view of the hub of the take-up reel of
`FIG. 2 with a leader block present in the slot.
`FIG. 4 is a magnified view of a portion of FIG. 3
`illustrating prior art mating of the leader block and the
`hub at the radial surface of the hub.
`FIG. 5 is a magnified view of a portion of FIG. 3
`illustrating the mating of the leader block and the hub at
`the radial surface of the hub wherein the mating edges
`are radiused according to the invention.
`
`BACKGROUND OF THE INVENTION
`1. Field of the Invention
`This invention relates to the storage of data on single
`reel cartridges containing a length of magnetic record
`ing tape, and more specifically, to a take-up reel for a
`single-reel cartridge transport.
`2. Related Art
`The data processing industry stores large amounts of
`digital data on magnetic tapes. The 3480 tape cartridge
`(developed by IBM Corporation, Armonk, N.Y.
`15
`U.S.A.) is an industry standard for magnetic storage
`media. The 3480 cartridge includes a single reel with a
`length of inch wide magnetic tape wrapped thereon.
`Data is stored on the-tape in a longitudinal format.
`The cartridge housing protects the tape from damage
`20
`while allowing the tape reel to be driven from a drive
`mechanism on the underside of the cartridge housing.
`The tape is withdrawn from an opening formed at one
`corner of the cartridge. A leader block attached to a
`free end of the tape allows the tape to be withdrawn
`25
`from the cartridge for read/write operations.
`Read/write operations are performed by a tape
`“transport.” The standard tape transport accepts the
`tape cartridge into an elevator assembly. A threading
`mechanism grabs the leader block and pulls it free from
`30
`the cartridge. The leader block is then used to thread
`the tape through a series of guide posts, across a longitu
`dinal read/write head, and into a slot in a take-up reel.
`Once threaded, the tape from the cartridge can be
`driven across the read/write heads for data transfer
`operations.
`The leader block and take-up reel are precisely manu
`factured so that when the leader block is inserted into
`the slot in the take-up reel, the slot is closed by the end
`of the leader block so that a relatively smooth surface is
`created on the hub of the take-up reel for winding the
`tape on the hub. Ideally, the leader block covers the
`opening to the slot such that the interface between the
`top of the leader block and the hub of the take-up reel is
`perfectly smooth. Unfortunately, however, such a per
`45
`fectly smooth interface is not practical to manufacture.
`Therefore, small discontinuities between the leader
`block and the hub are always present. Such discontinu
`ities can cause impressions in the first wraps of the tape
`around the hub.
`50
`The impressions may affect as many as the first few
`hundred wraps. The tighter the tape is wrapped, the
`more pronounced will be the impressions. Moreover, as
`more wraps are put on the hub, the pressure from the
`outer wraps accumulates to exacerbate the impressions
`on the inner wraps.
`Tape impressions are highly undesirable. Data bits
`written on the area of an impression may not be consis
`tently retrievable due to the deformation of the tape
`media. This results in data errors. Conventionally, to
`reduce these data errors, the leader block and take-up
`reel hub have been manufactured to close tolerances in
`an attempt to reduce the discontinuity between the end
`of the leader block and the take-up reel hub. Nonethe
`less, tape impressions still occurred. To insure data
`65
`integrity, the conventional practice has been to not
`write data to the portions of the tape having impres
`sions. For example, if the first 100 wraps of the tape
`
`10
`
`55
`
`FUJIFILM, Exh. 2013, p. 6
`FUJIFILM v. Sony, 2018-00876
`
`

`

`15
`
`10
`
`5,431,356
`3
`4.
`FIG. 6 is a graph illustrating the bending stresses on
`block 106. Note also that curved surface 110 of leader
`different thicknesses of tape as the degree of radiusing
`block 106 has covered opening 214 of slot 212 to create
`of an edge is varied.
`s
`a continuous and relatively smooth radial surface 210 of
`FIG. 7 is a magnified view of a portion of FIG. 3
`hub 202. This is more fully illustrated now with refer
`illustrating the mating of the leader block and the hub
`ence to FIGS. 4 and 5. A length of tape 104 is shown
`wherein the end of the leader block is positioned
`wrapped on hub 202.
`slightly above the radial surface of the hub and the
`A portion 304 of FIG. 3 illustrating the intersection
`mating edges are radiused according to the invention.
`of radial surface 210 of hub 202 and end surface 110 of
`leader block 106 is shown in greater detail in FIGS. 4
`DETAILED DESCRIPTION OF THE
`and 5. FIG. 4 illustrates a conventional-type intersec
`PREFERRED EMBODIMENT OF THE
`tion between leader block 106 and hub 202. Note that
`INVENTION
`slot 212 has been precisely machined to match the di
`The preferred embodiment of the invention is dis
`mensions of leader block 106 so that a precise fit is
`cussed in detail below. While specific part numbers and
`formed at the junction between end-surface 110 of
`configurations are discussed, it should be understood
`leader block 106 and radial surface 210 of hub 202.
`that this is done for illustration purposes only. A person
`Radial surface 210 mates with end surface 110 of leader
`skilled in the art will recognize that other components
`block 106 at comer edges 402 and 403. Similarly, end
`and configurations may be used without departing from
`surface 110 of leader block 106 mates with radial sur
`the spirit and scope of the invention.
`face 210 of take-up reel 202 at corner edges 404 and 405.
`Storage Technology Corporation of Louisville, Colo.
`As discussed above, conventional designs have at
`has developed a new tape cartridge for use with a heli
`tempted through precise machining/manufacturing to
`cal transport. The helical cartridge has essentially the
`closely mate corner edge 403 with corner edge 405 and
`same dimensions and basic features as the 3480 car
`corner edge 402 with corner edge 404. This was done in
`tridge. However, the helical cartridge feeds tape from
`an attempt to eliminate the gap between leader block
`the take-up reel when it is turned in a clockwise direc
`25
`106 and hub 202 at radial surface 210. The conventional
`tion. Thus, the tape feeds from a front, left-side corner
`wisdom was that a smaller gap would reduce tape im
`of the cartridge rather than a front, right-side corner as
`pressions. However, manufacturing tolerances, clear
`in the 3480 cartridge.
`ance required for a smooth insertion of leader block 106
`The helical cartridge is detailed in co-pending and
`into slot 212, and other variables have prevented a per
`commonly owned U.S. patent application Ser. No.
`fect mating of these corner edges. The result has been
`07/870,576, filed on Apr. 17, 1992, and titled “Magnetic
`that one corner edge of each intersection has tended to
`Tape Cartridge for Helical Scan Transport,” which is
`protrude out from radial surface 210 of hub 202. Such a
`incorporated herein by reference.
`protrusion of a relatively sharp corner edge has resulted
`The preferred embodiment of the invention is illus
`in tape indentations on the first wraps of tape 104 on hub
`trated with reference to a helical cartridge as shown in
`35
`202. In severe cases, the indentations may affect hun
`FIG. 1. Helical cartridge 100 includes a body 102 and a
`dreds of the inner wraps of tape on the hub. The inven
`length of magnetic recording tape 104. A leader block
`tors have discovered that these indentations may be
`106 is attached to the distal end of tape 104. Leader
`substantially reduced, not by reducing the gap at the
`block 106 is an elongated member having a first end and
`intersection of leader block 106 and hub 202 as conven
`a second end. At the first end, leader block 106 includes
`tional wisdom has taught, but by radiusing the corners,
`a groove 108. Groove 108 is configured to couple to a
`which increases the gap.
`loading post of a tape transport. The second end of
`The take-up reel/leader block assembly of the inven
`leader block 106 includes a curved end surface 110.
`tion is illustrated in FIG. 5. FIG. 5 is similar to FIG. 4
`Tape 104 is coupled to the second end of leader block
`in that both figures show a magnified view of portion
`106.
`45
`304 of FIG. 3. However, FIG. 5 illustrates radiused
`Leader block 106 is used to withdraw tape 104 from
`edges according to the invention. Note gaps 502, which
`body 102 of cartridge 100.
`have been formed at the intersection of end surface 110
`FIG. 2 illustrates a take-up reel (shown in an ex
`ploded view) for use in a tape transport. Take-up reel
`of leader block 106 and radial surface 210 of hub 202.
`Gaps 502 have been formed by “radiusing” corner
`200 is configured to couple with leader block 106 and to
`SO
`edges 402-405. By "radiusing,' it is meant that each
`allow tape 104 to be wound thereon. Take-up reel 200
`corner edge has been formed into a smooth curve. In
`includes a hub 202 and tape guides 204 and 206. Take-up
`the preferred embodiment, the curve is a constant ra
`reel 200 is configured to be rotated about an axis of
`dius curve. Computation of the radius of curvature is
`rotation 208. When rotated about axis 208, take-up reel
`200 will wrap tape 104 on surface 210 of hub 202. Tape
`discussed below.
`55
`As a tape is kept under tension and wrapped on hub
`guides 204 and 206 guide tape 104 as it is wrapped
`202, the forces on the inner wraps increases with each
`around hub 202.
`additional wrap. The inner wraps will be forced into
`A radial slot 212 is provided in both hub 202 and tape
`spaces 502. However, since no sharp edges are present,
`guides 204,206 to allow leader block 106 to enter hub
`the radiused edges 402-405 will not cause indentations.
`202. When leader 106 is fully inserted into slot 212,
`The theoretical basis for the invention is as follows.
`curved end-surface 110 of leader block 106 will fill
`In theory, a tape impression will not occur if the elastic
`end-opening 214 of slot 212 such that radial surface 210
`of hub 202 provides a continuous and relatively smooth
`limit of the tape is not exceeded. The stress on the tape
`surface for the wrapping of tape 104.
`is inversely proportional to the radius to which it must
`FIG. 3 is a top view of take-up reel 200 with tape
`conform. Theoretically, a sharp corner will inflict infi
`65
`nite stress and will always cause an impression. The
`guides 204,206 removed. Leader block 106 is shown
`theoretical stress on the tape may be computed using
`fully positioned within slot 212 of hub 202. Note that a
`the following equation:
`loading post 302 is positioned within notch 108 of leader
`
`FUJIFILM, Exh. 2013, p. 7
`FUJIFILM v. Sony, 2018-00876
`
`

`

`10
`
`5,431,356
`6
`requirement of a removable leader block is not present,
`the radial surface of the take-up reel hub at the position
`of the key/groove interface is often smoother due to a
`more precise key/groove fit. Nonetheless, the cartridge
`take-up reel may find some improvement in tape impres
`sioning through the use of the invention.
`While the invention has been particularly shown and
`described with reference to several preferred embodi
`ments thereof, it will be understood by those skilled in
`the art that various changes in form and details may be
`made therein without departing from the spirit and
`scope of the invention as defined in the appended
`claims.
`What is claimed is:
`1. A take-up reel assembly for use with a single-reel
`tape cartridge in a cartridge-based tape transport, com
`prising:
`an annular hub having an axis of rotation and a radial
`surface adapted to have a tape wound thereon;
`a radial slot in said hub extending from said radial
`surface towards said axis of rotation; and
`a leader block configured for attachment to a free end
`of a length of tape in the tape cartridge, said leader
`block having a shape substantially the same as the
`shape of said radial slot and having a first end
`adapted for coupling with a threading post and a
`second end having an end surface with a radius of
`curvature substantially the same as the radius of
`curvature of said radial surface of said hub so that
`when said leader block is pulled into said slot by a
`loading post, first and second leader block edges of
`said end surface substantially mate with first and
`second hub edges of said radial surface to cover
`said slot, said first and second leader block edges
`and said first and second hub edges being radiused
`to substantially eliminate tape damage caused by
`impressioning,
`wherein each said radiused edge has a radius of cur
`vature not less than a critical radius (r), said critical
`radius (r) being computed from the equation
`
`where:
`S=the tensile or compressive stress on the tape
`E=the modulus of elasticity of the material from
`which the tape is manufactured
`t=the thickness of the tape
`r= the radius of curvature of the bend.
`Using this formula, a radius can be chosen which will
`assure that the stress on the tape is less than its elastic
`limit. For example, given a tape thickness of 0.53 mils, a
`modulus of elasticity of 1.16x106 and a maximum al
`lowable stress of 2.09X10psi (pounds per square inch),
`15
`a critical radius of 0.015 inches can be computed. So
`long as corner edges 402-405 are radiused, each with a
`curve having a minimum radius of 0.015 inches, then
`permanent tape impressions should not result when a
`tape is wrapped on hub 202.
`20
`Experiments by the inventors have shown that add
`ing radii to comer edges 402-405 does not totally elimi
`nate tape impressions. However, the severity of the tape
`impressions is substantially reduced, such that fewer
`wraps of the tape on hub 202 are required before the
`25
`tape can be used to store data without the risk of data
`errors caused by tape impressions. For example, a test
`was conducted which compared the tape impressions
`for sharp edges versus radiused edges. The sharp edges
`caused impressions in the first 200 wraps of the tape on
`30
`hub 202, while the radiused edges caused impressions in
`only the first five wraps of the tape on hub 202.
`It is preferred that a radius well above the critical
`radius be chosen for edges 402-405. This further re
`duces tape impressions. For optimal results, it is also
`35
`preferred that each of edges 402-405 be radiused. This,
`however, is not absolutely required. If leader block 106
`is slightly recessed into hub 202 such that edges 404,405
`do not contact the tape, then these edges need not be
`radiused. Similarly, as shown in FIG. 7, if leader block
`40
`106 is slightly raised with respect to radial surface 210
`of hub 202 such that edges 402,403 do not contact the
`tape, then these edges need not be radiused.
`FIG. 6 is a graph illustrating the theoretical bending
`stress placed on polyester tape of varying thicknesses as
`45
`the radius of curvature of an edge is varied. The vertical
`axis represents bending stress in pounds per square inch
`(psi). The horizontal axis represents the radius of curva
`ture of the edge in inches. Plot 602 represents a tape
`thickness of 1.2 mils. Plot 604 represents a tape thick
`ness of 0.67 mils. Plot 606 represents a tape thickness of 50
`0.53 mils. Plot 608 represents a tape thickness of 0.42
`mils. The maximum stress, indicated by reference num
`ber 600, for the polyester material is specified by the
`manufacturer as 20,900 psi.
`The invention has been described in the environment
`55
`of a take-up reel for a helical cartridge or a 3480 car
`tridge. These cartridges were chosen for illustration
`purposes. It will be apparent to a person skilled in the
`relevant art, however, that the invention has application
`to any take-up reel/leader block assembly. In fact, the
`inventors contemplate that the invention may be used in
`a two-reel tape cassette also.
`In a tape cassette, the distal end of the tape is perma
`nently attached to the take-up reel. Often the attach
`ment is performed by a key piece which is snapped or
`65
`otherwise secured into place in a matching groove in
`the take-up reel. The tape is secured in place between
`the key piece and the take-up reel groove. Because the
`
`60
`
`where s is equal to the maximum allowable com
`pressive stress on the tape, E is equal to the modu
`lus of elasticity of the material from which the tape
`is manufactured, and t is equal to the thickness of
`the tape.
`2. The take-up reel assembly of claim 1, further com
`prising:
`at least one tape guide extending radially outward
`from a first side of said hub substantially perpendic
`ular to said axis of rotation to maintain the tape on
`said hub; and
`at least one tape. guide extending radially outward
`from a second side of said hub substantially perpen
`dicular to said axis of rotation to maintain the tape
`on said hub.
`3. The take-up reel assembly of claim 2, wherein the
`tape cartridge is a helical cartridge containing a length
`of magnetic tape.
`4. A take-up reel for use with a single-reel tape car
`tridge in a cartridge-based tape transport, wherein the
`tape cartridge includes a length of tape stored on a
`supply reel and a leader block attached to the free end
`of the tape, the take-up reel comprising:
`
`FUJIFILM, Exh. 2013, p. 8
`FUJIFILM v. Sony, 2018-00876
`
`

`

`5
`
`O
`
`15
`
`r = 2 s,
`
`5,431,356
`7
`8
`being configured for coupling with a threading
`an annular hub having an axis of rotation and a radial
`surface adapted to have a tape wound thereon; and
`post of the transport, a second end of the body
`a radial slot in said hub extending from said radial
`having an end surface with a radius of curvature
`surface towards said axis of rotation, said radial slot
`substantially the same as a radius of curvature of
`having a shape configured to accept entry of the
`the radial surface of the hub so that when the
`leader block into said hub, said radial slot having
`leader block is fully pulled with into the slot by a
`axially oriented edges at said radial surface, said
`loading post the second end of the leader block is
`edges being radiused to substantially eliminate tape
`positioned slightly above the radial surface and the
`damage caused by impressioning when the tape is
`hub wherein said first and second leader block
`wrapped on said hub,
`edges are radiused to substantially eliminate tape
`wherein each said radiused edge has a radius of cur
`damage caused by impressioning.
`vature not less than a critical radius (r), said critical
`8. A leader block for use with a single-reel tape car
`radius (r) being computed from the equation
`tridge and a cartridge-based tape transport, wherein the
`tape cartridge includes a length of tape stored on a
`supply reel, and wherein the transport includes a take
`up reel for receiving the tape from the cartridge, the
`take-up reel including an annular hub having an axis of
`rotation and a radial surface adapted to have the tape
`wound thereon and a radial slot in the hub extending
`from the radial surface towards the axis of rotation, the
`leader block comprising an elongated body having a
`shape and size corresponding to the radial slot in the
`hub of the take-up reel, a first end of the body being
`configured for coupling with a threading post of the
`transport, a second end of the body having an end sur
`face with a radius of curvature substantially the same as
`a radius of curvature of the radial surface of the hub so
`that when the leader block is pulled into the slot by a
`loading post, first and second leader block edges of said
`end surface substantially mate with first and second hub
`edges of the radial surface to cover the slot, wherein
`said first and second leader block edges are radiused to
`substantially eliminate tape damage caused by impres
`sioning,
`each said radiused edge having a radius of curvature
`not less than a critical radius (r), said critical radius
`(r) being computed from the equation
`
`where s is equal to the maximum allowable com
`pressive stress on the tape, E is equal to the modu
`lus of elasticity of the material from which the tape
`20
`is manufactured, and t is equal to the thickness of
`the tape.
`5. The take-up reel of claim 4, further comprising:
`at least one tape guide extending radially outward
`from a first side of said hub substantially perpendic
`25
`ular to said axis of rotation to maintain the tape on
`said hub; and
`at least one tape guide extending radially outward
`from a second side of said hub substantially perpen
`dicular to said axis of rotation to maintain the tape
`30
`on said hub.
`6. The take-up reel of claim 5, wherein the tape car
`tridge is a helical cartridge containing a length of mag
`netic tape.
`7. A take-up reel assembly for use with a single-reel
`tape cartridge and a cartridge-based tape transport,
`wherein the tape cartridge includes a length of tape
`stored on a supply reel, the take-up reel assembly com
`prising:
`a take-up reel on the transport for receiving the tape
`from the cartridge, with an annular hub having an
`axis of rotation and a radial surface adapted to have
`the tape wound thereon and a radial slot in the hub
`extending from the radial surface towards the axis
`of rotation; and
`45
`a the leader block with an elongated body having a
`shape and size corresponding to the radial slot in
`the hub of the take-up reel, a first end of the body
`
`35
`
`50
`
`55
`
`65
`
`where s is equal to the maximum allowable com
`pressive stress on the tape, E is equal to the modu
`lus of elasticity of the material from which the tape
`is manufactured, and t is equal to the thickness of
`the tape.
`
`3k
`
`k
`
`k
`
`3k
`
`FUJIFILM, Exh. 2013, p. 9
`FUJIFILM v. Sony, 2018-00876
`
`