U.S. patent application number 09/761212 was filed with the patent office on 2001-05-31 for automated media storage library with variable focal length lens.
This patent application is currently assigned to International Business Machines Corp.. Invention is credited to Bingham, Robert LaMar, Dimitri, Kamal Emile, Hasegawa, Masaki, Winarski, Daniel James.
Application Number | 20010002033 09/761212 |
Document ID | / |
Family ID | 23301174 |
Filed Date | 2001-05-31 |
United States Patent
Application |
20010002033 |
Kind Code |
A1 |
Winarski, Daniel James ; et
al. |
May 31, 2001 |
Automated media storage library with variable focal length lens
Abstract
A bar code reader for an automated storage library has a lens
assembly with a pair of polarized liquid crystal lenses. Each lens
has pair of parallel glass plates that are separated by upper and
lower glass substrates. A series of polymer films are symmetrically
spaced apart between the substrates. Both the substrates and the
films are perpendicular to the glass plates. Electrodes are formed
on the films and combine to form a semi-cylindrical stack of film.
Liquid crystal fills the spaces between adjacent pairs of the
films. The films are coated and/or treated by an alignment process
to predispose the liquid crystals to a specific rotational
direction. When a selected voltage is applied between adjacent ones
of the electrodes, the liquid crystals are synchronously rotated to
alter their refractive index to a desired value. Thus, when the
layers of each lens are manipulated in unison, the bar code reader
is able to quickly adjust its focal length to read bar codes at
various distances.
Inventors: |
Winarski, Daniel James;
(Tucson, AZ) ; Hasegawa, Masaki; (Kanagawa-ken,
JP) ; Dimitri, Kamal Emile; (Tucson, AZ) ;
Bingham, Robert LaMar; (Tucson, AZ) |
Correspondence
Address: |
Andrew J. Dillon, Esq.
Bracewell & Patterson, LLP
Lakewood On The Park, Suite 350
7600B N. Capital of Tx., Hwy
Austin
TX
78731
US
|
Assignee: |
International Business Machines
Corp.
Armonk
NY
10504
|
Family ID: |
23301174 |
Appl. No.: |
09/761212 |
Filed: |
January 16, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09761212 |
Jan 16, 2001 |
|
|
|
09333079 |
Jun 14, 1999 |
|
|
|
Current U.S.
Class: |
235/383 |
Current CPC
Class: |
G06K 7/10831 20130101;
G06K 7/10574 20130101; G06K 7/10811 20130101 |
Class at
Publication: |
235/383 |
International
Class: |
G06K 015/00 |
Claims
We claim:
1. An apparatus for identifying components, each having a label
fixedly mounted in relation to the component and having information
associated with the component, comprising: a first element having a
plurality of storage positions that are adapted to support the
components; a second element located adjacent to the first element,
such that the first and second elements are movable relative to one
another; a sensor mounted to the second element and having a light
source and a variable focal length lens assembly that is adapted to
read the labels associated with the components; and a controller
connected to the sensor and at least one of the first and second
elements for moving said one of the first and second elements
relative to the other and adjusting the focal length of said lens
assembly of the sensor to focus on and read the labels so that the
information associated with their respective components may be
processed by the controller:
2. The apparatus of claim 1, further comprising a picking device
fixed mounted adjacent to the first element for moving the
components in response to the controller processing the
information.
3. The apparatus of claim 1 wherein the sensor comprises a
plurality of sensors that are equal in number to the number of
storage positions of the first element, and wherein each of the
sensors is aligned and associated with one of the storage
positions.
4. The apparatus of claim 1 wherein the second element is pivoted
relative to the first element.
5. The apparatus of claim 1 wherein the first element is pivoted
relative to the second element.
6. The apparatus of claim 1 wherein the first element is a
stationary support structure and the second element is an arcuate
door which is both manually and automatically operable relative to
the stationary support structure.
7. The apparatus of claim 1 wherein the storage positions of the
first element are an array of parallel slots for supporting a
plurality of the components in a one-to-one ratio.
8. The apparatus of claim 1 wherein the lens assembly of the sensor
has a focal length range of approximately 10 mm to infinity.
9. The apparatus of claim 1 wherein the sensor is devoid of moving
parts.
10. The apparatus of claim 1 wherein the sensor is a bar code
reader.
11. The apparatus of claim 1 wherein the focal length of the lens
assembly is altered by liquid crystal material.
12. The apparatus of claim 1 wherein the lens assembly of the
sensor comprises a pair of polarized liquid crystal lenses.
13. The apparatus of claim 12 wherein the lenses are separated by a
transparent spacer having a width equal to one-half wavelength of
the light source of the sensor.
14. The apparatus of claim 12 wherein each lens comprises a
plurality of parallel substrates containing liquid crystal
therebetween, each of the substrates having an electrode for
applying a variable voltage to the liquid crystal located between
said electrode and an adjacent electrode for altering the
refractive index of the liquid crystal and, thus, the focal length
of the lens assembly.
15. The apparatus of claim 14 wherein each of the substrates is
coated with an alignment material.
16. The apparatus of claim 15 wherein the alignment material has
been processed to set a desired alignment direction for the liquid
crystal.
17. The apparatus of claim 14 wherein adjacent ones of the
substrates are equally spaced apart by a distance in the range of
30 to 70 microns.
18. The apparatus of claim 14 wherein each of the substrates has a
thickness of approximately 2 microns and a width of approximately
70 microns.
19. The apparatus of claim 14 wherein the electrodes on the
substrates are generally arcuate in shape.
20. An automated media storage library having a base with a media
drive unit and a picking device for interacting with data storage
devices located therein, each of the data storage devices having a
label fixedly mounted in relation thereto and having information
associated with its respective data storage device, the library
comprising: an input/output station mounted to the base and having
a scanner and a magazine with a plurality of storage positions that
are adapted to contain the data storage devices, the scanner and
the magazine being movable relative to one another; the scanner
having a sensor mounted thereto with a light source and a variable
focal length lens assembly that is adapted to read the labels
associated with the data storage devices; a controller adapted to
be connected to the media drive unit, the picking device, and the
input/output station for moving one of the scanner and the magazine
relative to the other and adjusting the focal length of said lens
assembly to focus on and read the labels so that the information
associated with their respective data storage devices may be
processed by the controller; and wherein the picking device moves
selected ones of the data storage devices from said positions of
the magazine to the media drive unit in response thereto.
21. The library of claim 20 wherein the scanner comprises a
plurality of sensors which are equal in number to the number of
positions in the magazine, and wherein each of the sensors is
aligned and associated with one of the positions.
22. The library of claim 20 wherein the scanner is pivoted relative
to the magazine.
23. The library of claim 20 wherein the magazine is pivoted
relative to the scanner.
24. The library of claim 20 wherein the scanner is an arcuate door
which is both manually and automatically operable relative to the
magazine.
25. The library of claim 20 wherein the input/output station is
mounted inside the base and is manually accessible from an exterior
of the base.
26. The library of claim 20 wherein the lens assembly of the sensor
has a focal length range of approximately 10 mm to infinity.
27. The library of claim 20 wherein the scanner is a bar code
reader.
28. The library of claim 20 wherein the focal length of the lens
assembly is altered with liquid crystal material.
29. The library of claim 20 wherein the lens assembly of is the
sensor comprises a pair of polarized liquid crystal lenses.
30. The library of claim 29 wherein the pair of lenses are
separated by a transparent spacer having a width equal to one-half
wavelength of the light source of the sensor.
31. The library of claim 29 wherein each lens comprises a plurality
of parallel substrates containing liquid crystal therebetween, each
of the substrates having an electrode for applying a variable
voltage to the liquid crystal located between said electrode and an
adjacent electrode for altering the refractive index of the liquid
crystal and, thus, the focal length of the lens assembly.
32. The library of claim 31 wherein each of the substrates is
coated with an alignment material.
33. The library of claim 32 wherein the alignment material has been
processed to set a desired alignment direction for the liquid
crystal.
34. The library of claim 31 wherein adjacent ones of the substrates
are equally spaced apart by a distance in the range of 30 to 70
microns.
35. The library of claim 31 wherein each of the substrates has a
thickness of approximately 2 microns and a width of approximately
70 microns.
36. The library of claim 31 wherein the electrodes on the
substrates are generally arcuate in shape.
37. An automated media storage library having a base with a media
drive unit and a picking device for interacting with data storage
devices located therein, each of the data storage devices having a
label fixedly mounted in relation thereto and having information
associated with its respective data storage device, the library
comprising: an input/output station mounted to the base and having
a scanner and a magazine with a plurality of storage positions that
are adapted to contain the data storage devices, the scanner being
pivotable relative to the magazine; the scanner having a plurality
of sensors mounted thereto, each having a light source and a
variable focal length lens assembly that is adapted to read the
labels associated with the data storage devices, the sensors being
equal in number to the number of positions in the magazine, and
wherein each of the sensors is aligned and associated with one of
the positions; a controller adapted to be connected to the media
drive unit, the picking device, and the input/output station for
moving the scanner relative to the magazine and adjusting the focal
lengths of said lens assemblies to focus on and read the labels so
that the information associated with their respective data storage
devices may be processed by the controller; and wherein the picking
device moves selected ones of the data storage devices from said
positions of the magazine to the media drive unit in response
thereto.
38. The library of claim 37 wherein the scanner is an arcuate door
which is both manually and automatically operable relative to the
magazine.
39. The library of claim 37 wherein each of the lens assemblies has
a focal length range of approximately 10 mm to infinity.
40. The library of claim 37 wherein the scanner is a bar code
reader.
41. The library of claim 37 wherein the focal lengths of the lens
assemblies are altered with liquid crystal material.
42. The library of claim 37 wherein each of the lens assemblies
comprises a pair of polarized liquid crystal lenses.
43. The library of claim 42 wherein each pair of lenses is
separated by a transparent spacer having a width equal to one-half
wavelength of the light sources.
44. The library of claim 42 wherein each lens comprises a plurality
of parallel substrates containing liquid crystal therebetween, each
of the substrates having an electrode for applying a variable
voltage to the liquid crystal located between said electrode and an
adjacent electrode for altering the refractive index of the liquid
crystal and, thus, the focal lengths of the lens assemblies.
45. The library of claim 44 wherein each of the substrates is
coated with an alignment material.
46. The library of claim 45 wherein the alignment material has been
processed to set a desired alignment direction for the liquid
crystal.
47. The library of claim 44 wherein adjacent ones of the substrates
are equally spaced apart by a distance in the range of 30 to 70
microns.
48. The library of claim 44 wherein the electrodes on the
substrates are generally arcuate in shape.
49. An automated media storage library having a base with a media
drive unit and a picking device for interacting with data storage
devices located therein, each of the data storage devices having a
label fixedly mounted in relation thereto and having information
associated with its respective data storage device, the library
comprising: an input/output station mounted to the base and having
a door and a magazine with a plurality of storage slots that are
adapted to contain the data storage devices, the door being
pivotable relative to the magazine; the door having a plurality of
sensors mounted thereto, each having a light source and a variable
focal length lens assembly with a pair of liquid crystal lenses
that are adapted to read the labels associated with the data
storage devices, the sensors being equal in number to the number of
slots in the magazine, and wherein each of the sensors is aligned
and associated with one of the slots; each lens comprising a
plurality of parallel substrates containing liquid crystal
therebetween, each of the substrates having an electrode for
applying a variable voltage to the liquid crystal located between
said electrode and an adjacent electrode for altering the
refractive index of the liquid crystal and, thus, the focal lengths
of the lens assemblies; a controller adapted to be connected to the
media drive unit, the picking device, and the input/output station
for moving the door relative to the magazine and adjusting the
focal lengths of the lens assemblies to focus on and read the
labels so that the information associated with their respective
data storage devices may be processed by the controller; and
wherein the picking device moves selected ones of the data storage
devices from said slots of the magazine to the media drive unit in
response thereto.
50. The library of claim 49 wherein the door is both manually and
automatically pivotable relative to the magazine.
51. The library of claim 49 wherein each of the lens assemblies has
a focal length range of approximately 10 mm to infinity.
52. The library of claim 49 wherein each pair of lenses is
separated by a transparent spacer having a width equal to one-half
wavelength of the light sources.
53. The library of claim 49 wherein each of the substrates is
coated with an alignment material that has been processed to set a
desired alignment direction for the liquid crystal.
54. The library of claim 49 wherein adjacent ones of the substrates
are equally spaced apart by a distance in the range of 30 to 70
microns.
55. The library of claim 49 wherein the electrodes on the
substrates are generally arcuate in shape.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] This invention relates in general to automated media storage
libraries and in particular to an automated media storage library
with a variable focal length lens for scanning bar coded labels
associated with data storage media in the library.
[0003] 2. Background Art
[0004] Automated media storage libraries which utilize storage
devices such as data cartridges are well known in the art. A large
number of the cartridges are typically mounted in a rotatable
housing or magazine and individually indexed with bar coded labels.
The labels may be positioned in a variety of locations, including
on the cartridges themselves, adjacent to a mail slot on the
housing, or on a door around each mail slot. A bar code reader
system is located adjacent to the housing for reading the labels so
that the desired cartridge may be selected and accessed. In order
to scan a label associated with a moving cartridge and/or reader
system, the focal length of the reader must be adjustable to
accommodate for cartridges and labels which differ in size and,
thus, distance from the reader. This problem has become even more
acute with libraries which contain multimedia storage devices.
[0005] Therefore, it is a feature of the present invention to
provide an assembly with a high speed, variable focal length lens
for reading bar code labels on media devices located in an
automated media storage library.
SUMMARY OF THE INVENTION
[0006] A bar code reader for an automated storage library has a
lens assembly with a pair of polarized liquid crystal lenses. Each
lens has pair of parallel glass plates that are separated by upper
and lower glass substrates. A series of rectangular polymer films
are symmetrically spaced apart between the two glass substrates.
Both the substrates and the films are perpendicular to the glass
plates. A semi-circular electrode is formed on each side of each
piece of film to form a semi-cylindrical "stack" of film. The
electrodes do not completely cover the film. Liquid crystal fills
the space between each adjacent pair of the films. The films are
coated and/or treated by an alignment process to predispose the
liquid crystals to an alignment and rotation direction.
[0007] When a selected voltage is applied between adjacent ones of
the electrodes, the liquid crystals are synchronously rotated to
alter their refractive index to a desired value. Thus, when the
layers of each lens are manipulated in unison, the bar code reader
is able to quickly adjust its focal length to read bar codes labels
on media devices at various distances. For example, when the
applied voltage is zero, there is no refractive index difference
between the electrode portion and the non-electrode portion of the
liquid crystal. Therefore, the focal length is infinite. Applying a
voltage to the electrodes alters the refractive index of the liquid
crystal and, thus, shortens the focal length of the lens assembly
to the proper distance for reading the labels.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] So that the manner in which the features, advantages and
objects of the invention, as well as others which will become
apparent, are attained and can be understood in more detail, more
particular description of the invention briefly summarized above
may be had by reference to the embodiment thereof which is
illustrated in the appended drawings, which drawings form a part of
this specification. It is to be noted, however, that the drawings
illustrate only a preferred embodiment of the invention and is
therefore not to be considered limiting of its scope as the
invention may admit to other equally effective embodiments.
[0009] FIG. 1 is an isometric view of a lens assembly constructed
in accordance with the invention.
[0010] FIG. 2 is an isometric view of a single liquid crystal (LC)
lens of the lens assembly of FIG. 1.
[0011] FIG. 3 is a schematic, sectional side view of the LC lens of
FIG. 2.
[0012] FIG. 4 is a schematic top view of the LC lens of FIG. 2
taken along the line 4-4 of FIG. 3.
[0013] FIG. 5 is a front view of the LC lens of FIG. 2 showing a
first configuration.
[0014] FIG. 6 is a front view of the LC lens of FIG. 2 showing a
second configuration.
[0015] FIG. 7 is a schematic, enlarged, sectional side view of a
portion of the LC lens of FIG. 2 shown without an applied voltage
and taken along the line 7-7 of FIG. 4.
[0016] FIG. 8 is a sectional side view of the portion of the LC
lens of FIG. 7 shown with an applied voltage.
[0017] FIG. 9 is an isometric view of an automated media storage
library that incorporates the lens assembly of FIG. 1 and is
constructed in accordance with the invention.
[0018] FIG. 10 is an enlarged front isometric view of a cartridge
station of the library of FIG. 9 wherein the door of the station is
open.
[0019] FIG. 11 is a schematic front isometric view of the cartridge
station of FIG. 10 with the door closed.
[0020] FIG. 12 is a schematic, rear isometric view of the cartridge
station of FIG. 11.
[0021] FIG. 13 is a schematic, rear isometric view of an alternate
embodiment of the cartridge station of FIG. 11.
[0022] FIG. 14 is a schematic drawing of a method for making the LC
lens of FIG. 2.
BEST MODE FOR CARRYING OUT THE INVENTION
[0023] Referring to FIG. 1, a sensor or lens assembly 11 for use
with a bar code reader in an automated media storage library 12
(FIG. 9) is shown. Lens assembly 11 comprises a front liquid
crystal (LC) lens 13, a rear LC lens 15, and a transparent spacer
plate 17 therebetween. A laser light source 19 (indicated
schematically by the arrow) is projected into rear lens 15 from
right to left. Light source 19 is independently focused by each
lens 13, 15 into a conical beam 23, 25, respectively, and focused
to a common point 21 to the left of front lens 13. The thickness of
spacer plate 17 is selected to be one half of one wavelength of the
light emitted by light source 19.
[0024] Lenses 13, 15 are identical in construction and are is
illustrated in detail in FIGS. 2-4. For simplicity, only lens 13
will be discussed even though the following description applies
equally to lens 15. Lens 13 consists of a pair of parallel, glass
plates, 31, 33, and a plurality of thin, rectangular, insulative,
polymer films 35 therebetween. In the embodiment shown, plates 31,
33 are 1 mm squares. The inner surfaces of plates 31, 33 are spaced
apart by 70 microns which is also the width of films 35. Each film
35 has a length of 1 mm and a thickness of 2 microns. A pair of
glass substrates 41, 43 are located at the upper and lower ends,
respectively, of lens 13 with films 35 therebetween. Films 35 and
substrates 41, 43 are parallel to one another, and perpendicular to
plates 31, 33. Films 35 and substrates 41, 43 are evenly spaced
apart from one another by 50 microns. Thus, in the embodiment
shown, there are 19 films 35 which define 20 layers between
substrates 41, 43.
[0025] The upper and lower surfaces of each film 35 and the inner
surfaces of substrates 41, 43 have an electrode 45 formed on them.
In the embodiment shown, electrodes 45 are semi-circular in shape
with a radius of 2 mm, but they may be formed in any other shape
that also would produce a positive focal length. As will be
discussed below, the radius of electrodes 45 is determined by the
range of focal lengths required by the application. Although
electrodes 45 have a thickness that is less than 10 nm, they are
shown much thicker for illustration purposes. Electrodes 45 may be
sputtered to the desired shape with a patterned mask, or sputtered
over the entire rectangular surface of films 35 and substrates 41,
43, and then chemically etched with a patterned photo-resist to
obtain the desired shape. Other processes, such as
photolithography, may also be used to obtain the desired pattern
for electrodes 45.
[0026] After electrodes 45 are formed, an alignment material (not
shown) is spin-coated or printed on top of the electrodes and the
remaining surface area of the underlying substrate. The most
popular alignment material for liquid crystal is polyimide.
However, any material for homogenous parallel alignment, such as
polyvinyl alcohol, may be used. The alignment material has a
thickness of 30 nm or less. After the alignment material has coated
the electrodes and their substrates, an alignment process, such as
rubbing, is performed on the alignment material to set the desired
alignment direction for the liquid crystals. Other alignment
processes, such as photoalignment, which establish parallel
homogenous alignment may also be used.
[0027] The alignment effect from the surface of the substrate is
limited to several dozen microns (approximately 30 to 70 microns).
Therefore, films 35 are mounted in spacers (not shown) to maintain
their 50 micron spacing. The spacing between films 35 could be
larger or smaller, as long as the alignment effect is maintained.
The films 35, substrates 41, 43, and plates 31, 33 are then
assembled together to form lens 13 before the liquid crystals 47
are injected into the spaces or cells.
[0028] Note that the total thickness of each film 35, including an
electrode 45 and outer layer of alignment material on each surface
(which are substantially negligible at 20 nm and 60 nm total) is
approximately 2 microns. Since there is only one film 35 for every
50 microns of transmission width, the amount of light transmitted
by lens assembly 11 is diminished by only 4% per lens 13, 15, or 8%
total.
[0029] Referring to FIG. 14, lens 13 is assembled by dispensing
heat curable epoxy resin 37 around the perpendicular glass plates
31, 33, films 35, substrates 41, 43 and spacers to form a seal 38
therebetween. An opening 39 in the lens body assembly 13 is
reserved for injecting the liquid crystals 47. After curing the
epoxy, the liquid crystals 47 are injected through opening 39 into
the cells between films 35 with a vacuum injection technique. The
air in the cells is removed with a pump 40 to create a vacuum and
opening 39 in seal 38 is immersed into the liquid crystals 47 to
fill the cells by capillary action. Opening 39 is sealed after the
lens 13 is filled.
[0030] As shown in FIGS. 5 and 6, liquid crystal 47 fills the
spaces between films 35 and substrates 41, 43. FIGS. 1, 5 and 6
also show the perpendicular orientation of lenses 13, 15 relative
to one another and the lens assembly 11 overall. In the embodiment
shown, the layers of front lens 13 are vertically oriented, and the
layers of rear lens 15 are horizontally oriented to form a
polarized lens assembly
[0031] Each lens 13, 15 can only focus in one direction, hence,
lenses 13, 15 are rotated and fixed at 90 degrees relative to each
other. Spacer plate 17 is required for two-dimensional focusing.
For example, referring to the Cartesian coordinate system 67 in
FIG. 1, lens 13 could control focusing in an Y-plane angle of light
beam 19, while lens 15 controls the Z-plane angle. Thus, the
coaxial direct-ion is the X-direction.
[0032] Referring now to FIGS. 3, 7, and 8, the leads 51, 53 of a
voltage source 55 are connected to electrodes 45 in an alternating
pattern. A focal length controller 57 is provided for controlling
the voltage of voltage source 55. Although both electrodes 45 on
each film 35 have the same the same orientation, the adjacent films
35 (both above and below) have the opposite orientation so that the
liquid crystal 47 lying therebetween is exposed to the voltage
potential. Thus, the liquid crystal 47 in each cell or space
between the films 35 may be manipulated simultaneously and in
unison. The amount of voltage required to manipulate liquid
crystals 47 is minimized as the spacing between films 35 is only 50
microns.
[0033] Note that electrodes 45 do not extend across the entire
width of films 35 and substrates 41, 43. In the embodiment shown,
electrodes 45 only cover about two-thirds of the surface area of
their respective substrates. Thus, a portion of the birefringent
liquid crystal 47 lying between adjacent films 35 (above and below
the left sides of films 35) is not subjected to the voltage
potential in order to vary the focal length of lens assembly 11.
Since, the minimum focal length is 10 mm and the difference between
the ordinary (left side) and extraordinary (right side) refractive
indexes of liquid crystal 47 is about 0.2, the radius of electrodes
45 must be no larger than the product of the focal length and the
index difference (hence, 10 mm.times. 0.2=2 mm radius).
[0034] In FIG. 7, the applied voltage is zero, so liquid crystals
47 are identically aligned and oriented on both sides of films 35
(only two films shown). In FIG. 8, the applied voltage does not
equal zero, so the alignment direction of the liquid crystals 47 on
the right side of films 35 are proportionately reoriented, and the
liquid crystals 47 on the left side of films 35 remain unaffected.
This changes the refractive index of the liquid crystals 47 and,
thus, the focal length of lens assembly 11.
[0035] Note that since lenses 13, 15 are spaced apart from each
other along the X-axis, the voltages applied to them must be
different in order to focus at the same X-axial point 21. The focal
length of lens 15 should be longer than that of lens 13. Since the
difference in the focal lengths is fixed by the configuration, the
relation of the applied voltage to lenses 13, 15 can be calculated.
Controller 57 calculates the applied voltages to lenses 13, 15
according to the information from the bar code reader. For example,
if the focal length of lens 15 is 15.0 mm, and the total thickness
of spacer plate 17 and lens 13 is 5.0 mm, the focal length of lens
13 would be 10 mm. Lenses 13, 15 focus light 19 simultaneously to a
single point 21.
[0036] In operation (FIGS. 9-13), library 12 has a base 61
containing a plurality of drives (not shown) and a door 63 with an
opening 64. Door 63 is pivotally mounted to base 61 and is normally
closed, but shown open in FIG. 9. A mail slot or cartridge
input/output (I/O) station 65 is mounted to door 63 (shown exploded
from door 63 in FIG. 9). Station 65 has a generally cylindrical,
stationary body or magazine 71 with a coaxial door 73 that is
pivotable or rotatable about the Z-axis relative to body 71. Door
73 has a generally cylindrical shape and is shown open in FIG. 10
and closed in FIG. 11. Magazine 71 has a plurality of parallel,
cartridge storage slots 75, each of which may contain one or more
data cartridges 77 (two shown). Cartridges 77 may comprise tape,
magneto-optical disk, digital versatile disk (DVD), high density
floppy disks, or high density removable hard disk cartridges.
Typically, library 12 does not have mixed media in it, but it is
capable of handling such. Cartridges 77 are exported from library
12 in the +X direction, and imported in the -X direction. A robotic
picker 79 (FIG. 9) moves cartridges 77 to and from magazine 71 in
the Y-Z plane.
[0037] When door 73 is open (FIG. 10), a user can manually insert
cartridges 77 into or remove them from slots 75 in magazine 71
through opening 64 in door 63. When door 73 is closed by the user,
robotic picker 79 can access the cartridges 77 placed into slots 75
(cartridge import). Alternately, when door 73 is closed, picker 79
can place more cartridges 77 into magazine 71 for removal from
library 12 (cartridge export). Both of these operations are
necessary since library 12 has a finite amount of cartridge storage
space. Inactive cartridges which still contain valuable data are
exported and shipped to a warehouse, the lowest tier in the data
storage hierarchy. Each inactive cartridge is replaced by a newly
imported cartridge.
[0038] Referring now to FIGS. 11 and 12, a plurality of sensors 11
are mounted to an inner portion 81 of door 73 and, thus, rotatable
therewith. Sensors 11 are vertically arrayed to align with the
slots 75 of magazine 71 in a one-to-one ratio. Door 73 and sensors
11 pivot relative to stationary magazine 71. Power to and
electrical signals from sensors 11 are transmitted on cable 83.
Cable 83 also carries power to a motor 85 that opens and closes
door 73. A master cable (not shown) extends from motor 85 and
sensors 11 to controller 57. Door 73 allows a user to manually
access cartridges 77 in library 12 through opening 64.
[0039] A bar coded label 87 is affixed to a rear side edge of each
cartridge 77. Labels 87 may also be located adjacent to cartridges
77 near slots 75 (not shown). The lines of the bar code are
parallel to the axis of rotation of sensors 11. The orientation of
the bar code lines causes the sensors 11 to sweep along a line
perpendicular thereto. In the preferred embodiment, door 73 is
pivoted and sensors 11 pivot past the rear side edges of stationary
cartridges 77 to scan labels 87. It is the swinging of door 73
which moves sensors 11, with their liquid crystal lenses 13, 15,
across the labels 87 which identifies cartridges 77 in station 65
to controller 57. If the bar code reader cannot read the code on a
label 87, controller 57 changes the focal length of lenses 13, 15
in the respective sensor 11 to focus the code image on the
reader.
[0040] Alternatively, sensors 11 remain stationary and magazine 71
is pivoted about the Z-axis (FIG. 13) by motor 85. Sensors 11 read
the barcodes 87 (not shown) on the backs of cartridges 77 as
magazine 71 sweeps around. This alternate embodiment also utilizes
a siding planar door 89 rather than the cylindrical door 73 of the
preferred embodiment. Door 89 may be configured to move or slide in
either the Y-direction or in the Z-direction to allow a user to
manually access cartridges 77 through opening 64 in library 12.
With both of these embodiments, there is no mechanical motion of
the components of sensor 11. Thus, the focus action is always fast
and responsive.
[0041] The information scanned from the cartridges 77 in magazine
71 is relayed to controller 57 or a central data base for
processing. The robotic picker 79 would then move or handle
individual cartridges 77 based on instructions from controller 57.
However, controller 57 must identify each cartridge 77 before
giving commands to picker 79. Thus, controller 57 can give
instructions to picker 79 as to which cartridges 77 are to be
stored in which slots 75 and which cartridges (if any) are to be
directed into drives for immediate data I/O operations.
[0042] The invention has several advantages. The lens assembly uses
liquid crystal lenses that can change their focal lengths at high
speeds by merely varying an applied voltage in response to the
focal length controller. The lens assembly is completely stationary
and utilizes no moving parts. This design is readily incorporated
into automated storage libraries having various configurations. The
invention is well suited for libraries which contain various types
of storage media or bar code labels or differing sizes.
[0043] While the invention has been shown or described in only some
of its forms, it should be apparent to those skilled in the art
that it is not so limited, but is susceptible to various changes
without departing from the scope of the invention.
* * * * *