U.S. patent application number 13/855259 was filed with the patent office on 2013-08-22 for portable computer housing with integral display.
This patent application is currently assigned to Apple Inc.. The applicant listed for this patent is Apple Inc.. Invention is credited to Peteris K. Augenbergs, Brett W. Degner, Adam Garelli, Chris Ligtenberg, Dinesh C. Mathew, Bryan W. Posner, Thomas W. Wilson, Victor H. Yin.
Application Number | 20130215642 13/855259 |
Document ID | / |
Family ID | 43925248 |
Filed Date | 2013-08-22 |
United States Patent
Application |
20130215642 |
Kind Code |
A1 |
Mathew; Dinesh C. ; et
al. |
August 22, 2013 |
Portable Computer Housing with Integral Display
Abstract
An electronic device such as a portable computer may have a
housing with a rectangular recess in which layers of display
structures such as a light guide panel layer and other light guide
structures are directly mounted without intervening chassis
members. Mating alignment features in the housing and display
structures may be used to align the display structures relative to
the housing. A display may be formed from glass layers such as a
color filter glass layer and a thin-film transistor glass layer.
Backlight for the display may be generated by an array of
light-emitting diodes. The light guide panel may direct light from
the light-emitting diodes through the glass layers. A clamp may be
used to hold the light-emitting diodes and light guide structures
in place in the recess. An undercut in the housing may also hold
the light guide structures in place.
Inventors: |
Mathew; Dinesh C.; (Fremont,
CA) ; Wilson; Thomas W.; (Saratoga, CA) ; Yin;
Victor H.; (Cupertino, CA) ; Posner; Bryan W.;
(La Selva Beach, CA) ; Ligtenberg; Chris; (San
Carlos, CA) ; Degner; Brett W.; (Menlo Park, CA)
; Augenbergs; Peteris K.; (San Francisco, CA) ;
Garelli; Adam; (Santa Clara, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Apple Inc.; |
|
|
US |
|
|
Assignee: |
Apple Inc.
Cupertino
CA
|
Family ID: |
43925248 |
Appl. No.: |
13/855259 |
Filed: |
April 2, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12691714 |
Jan 21, 2010 |
8408780 |
|
|
13855259 |
|
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|
61257807 |
Nov 3, 2009 |
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Current U.S.
Class: |
362/606 ;
29/592.1; 362/612; 362/615; 362/624; 362/627 |
Current CPC
Class: |
G02B 6/0011 20130101;
G06F 1/1616 20130101; Y10T 29/49002 20150115; G02B 6/0033 20130101;
G06F 1/1637 20130101; G02B 6/0073 20130101; G02B 6/0031
20130101 |
Class at
Publication: |
362/606 ;
362/615; 362/624; 362/612; 362/627; 29/592.1 |
International
Class: |
F21V 8/00 20060101
F21V008/00 |
Claims
1-28. (canceled)
29. Apparatus, comprising: a computer housing having a
substantially rectangular recess with four edges; and a
substantially rectangular light guide panel disposed in the
rectangular recess, wherein the light guide panel has four edges
that are adjacent to the four edges of the rectangular recess
without any intervening chassis structures.
30. The apparatus defined in claim 29 further comprising a clamp
structure disposed over an edge of the light guide panel.
31. The apparatus defined in claim 30, wherein the clamp structure
comprises a sheet of metal.
32. The apparatus defined in claim 30, wherein the clamp structure
comprises a strip of stainless steel that is screwed into the
computer housing.
33. The apparatus defined in claim 29, wherein the light guide
panel comprises at least one alignment tab and wherein the computer
housing has at least one mating tab-shaped recess into which the
alignment tab protrudes.
34. The apparatus defined in claim 33, further comprising a
reflective coating in the rectangular recess that reflects light
back into the light guide panel.
35. The apparatus defined in claim 34, wherein the reflective
coating comprises white paint in the rectangular recess.
36. The apparatus defined in claim 33, wherein the reflective
coating comprises a layer of metal.
37. The apparatus defined in claim 29, further comprising a white
reflective sheet disposed between the light guide panel and the
recess in the computer housing, wherein the white reflective sheet
has portions that cover at least one of the edges of the light
guide panel.
38. The apparatus defined in claim 29, wherein the computer housing
comprises machined aluminum.
39. The apparatus defined in claim 29, further comprising: an array
of light-emitting diodes that emit light into one of the four edges
of the light guide panel.
40. The apparatus defined in claim 29, further comprising: a
thin-film transistor glass layer; and a color filter glass layer,
wherein the thin-film transistor glass layer and the color filter
glass layer are positioned above the rectangular recess and wherein
light from the light guide panel passes through the thin-film glass
layer and the color filter glass layer.
41. The apparatus defined in claim 29, wherein the light guide
panel comprises at least one alignment tab, wherein the computer
housing has at least one mating tab-shaped recess into which the
alignment tab protrudes, wherein the apparatus further comprises
layers of optical films including a diffuser layer, and wherein the
layers of optical films each include at least one alignment tab
that protrudes into the tab-shaped recess in the computer
housing.
42. The apparatus defined in claim 41, further comprising a plastic
reflective sheet under the light guide panel, wherein the plastic
reflective sheet has bent edges that cover at least two of the
edges of the light guide panel.
43. The apparatus defined in claim 29, further comprising: glass
layers through which light from the light guide panel passes; and a
bezel that covers at least part of the glass layers.
44. The apparatus defined in claim 29, further comprising: an array
of light-emitting diodes that emit light into one of the edges of
the light guide panel; a flex circuit on which the light-emitting
diodes are mounted; and reflective tape that covers at least part
of the flex circuit.
45. The apparatus defined in claim 44, further comprising a sheet
of reflective material under the light guide panel, wherein at
least a portion of the sheet of reflective material covers the flex
circuit.
46. A computer, comprising: a housing having a base unit hingedly
connected to a display housing, wherein the display housing
comprises: a machined rectangular recess having four recess edges
and having alignment notches disposed along at least two of the
four recess edges; and a rectangular light guide panel having at
least four light guide panel edges and having alignment tabs
disposed along at least two of the four light guide panel edges;
wherein the alignment taps protrude into and mate with the
alignment notches in the display housing.
47. The computer defined in claim 46, further comprising a color
filter glass layer through which light from the rectangular light
guide panel passes.
48. The computer defined in claim 47, further comprising a white
reflective sheet with tabs that mate with the alignment
notches.
49. The computer defined in claim 48, further comprising at least
one optical film layer on the light guide panel, wherein the at
least one optical film layer includes a diffuser layer with tabs
that mate with the alignment notches.
50. A method of forming a liquid-crystal display in an electronic
device, comprising: forming a rectangular recess in an electronic
device housing, wherein the electronic device housing has an
exterior surface that serves as an exterior for the electronic
device and has an interior surface in which the rectangular recess
is formed; and placing individual layers of light guide structures
directly into the rectangular recess without mounting the light
guide structures in a chassis.
51. The method defined in claim 50, wherein the rectangular recess
and the light guide structures have respective mating recess
alignment features and light guide structure alignment features and
wherein placing the light guide structures directly into the
rectangular recess comprises placing the light guide structures
into the rectangular recess so that the recess alignment features
mate with the light guide structure alignment features.
52. The method defined in claim 51, wherein the light guide
structures include at least one planar rectangular light guide
panel, the method further comprising: attaching a clamp to the
electronic device housing to hold the light guide structures in
place within the recess.
53. The method defined in claim 52, further comprising: inserting
at least an edge of the light guide structures into an undercut
groove in the metal electronic device housing.
54. The method defined in claim 52, further comprising: holding
light-emitting diodes under the clamp.
Description
[0001] This application claims the benefit of provisional patent
application No. 61/257,807, filed Nov. 3, 2009, which is hereby
incorporated by reference herein in its entirety.
BACKGROUND
[0002] This invention relates to electronic devices and, more
particularly, to display structures for electronic devices such as
portable computers.
[0003] Portable computers typically have upper and lower housing
portions that are connected by a hinge. The lower housing portion
contains components such as printed circuit boards, disk drives, a
keyboard, and a battery. The upper housing portion contains a
display. When the computer is in an open configuration, the upper
housing portion is vertical and the display is visible to the user
of the portable computer. When the computer is closed, the upper
housing lies flat against the lower housing. This protects the
display and keyboard and allows the portable computer to be
transported.
[0004] Portable computer displays typically contain fragile
structures such as layers of glass. Displays can therefore be
challenging to mount properly within the upper housing. If care is
not taken, the display and the surrounding portions of the upper
housing will be bulky and unsightly. At the same time, the
elimination of certain structures in the display may result in
display that is overly fragile. This could lead to damage to the
display during normal use.
[0005] It would therefore be desirable to be able to provide
improved display structures in electronic devices such as portable
computers.
SUMMARY
[0006] An electronic device such as a portable computer may have a
housing. The housing may have upper and lower portions that are
connected by a hinge. Display structures for a display may be
mounted in a portion of the housing such as the upper housing
portion.
[0007] The display structures may include a color filter glass
layer and a thin-film transistor substrate layer. Light-guide
structures may be mounted under the thin-film transistor substrate
layer. The light guide structures may include a reflective sheet of
material such as white polyester (e.g., Mylar.RTM.), a layer of
light guide material (sometimes referred to as a light guide panel
or LGP), and one or more layers of optical film (e.g., diffuser
layers, light collimating layers, etc.). The light guide structures
may be mounted directly in a rectangular recess in the interior of
the housing without using chassis structures. For example, the
light guide structures may be provided with tabs that mate directly
with corresponding features in the housing.
[0008] Undercut structures may be formed in the housing to
accommodate the display structures. For example, the undercut
structures may receive some or all of the light guide
structures.
[0009] An array of light-emitting diodes may provide backlight for
the display structures. The light-emitting diodes may emit light
into an edge of the light guide panel. A reflective sheet on the
rear of the light guide panel may be used to reflect light outwards
through the display structures. The edges of the reflective sheet
may be wrapped around the edges of the light guide panel to reflect
light that would otherwise leak out of the edges of the panel.
Light may also be reflected by coating interior housing surfaces
with a reflective coating.
[0010] Clamp structures may be used to hold the light-emitting
diode array and light-guide panel in place.
[0011] Reflective tape and reflective sheets of material may be
used to help guide light from the light-emitting diode array into
the edge of the light guide panel. Reflective tape may be placed on
the lower surface of a clamp member.
[0012] A cosmetic bezel may be used to cover edges of the display
structures. For example, in display structure configurations in
which a driver integrated circuit might be visible from the
exterior of the device, a bezel may be used to hide the integrated
circuit from view.
[0013] Further features of the invention, its nature and various
advantages will be more apparent from the accompanying drawings and
the following detailed description of the preferred
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of an illustrative portable
computer with display structures in accordance with an embodiment
of the present invention.
[0015] FIG. 2 is a cross-sectional side view of a conventional
liquid crystal display (LCD) module in a portable computer display
housing.
[0016] FIG. 3 is a cross-sectional side view of an edge portion of
a conventional LCD module.
[0017] FIG. 4 is an exploded view of a conventional computer
housing and conventional display structures.
[0018] FIG. 5 is a cross-sectional side view of a conventional
light-emitting-diode array in a conventional display module.
[0019] FIG. 6 is a perspective view of conventional
light-emitting-diodes mounted on a flex circuit.
[0020] FIG. 7 is a cross-sectional side view of conventional
backlight component in a conventional computer housing.
[0021] FIG. 8 is a cross-sectional side view of illustrative
display structures in an electronic device such as a portable
computer in accordance with an embodiment of the present
invention.
[0022] FIG. 9 is an exploded view showing how display components
may be mounted directly in a recess in a computer housing in
accordance with an embodiment of the present invention.
[0023] FIG. 10 is a top view of a computer housing in which a ledge
has been formed to ensure that a light guide panel does not damage
an associated array of light-emitting diodes in accordance with an
embodiment of the present invention.
[0024] FIG. 11 is a cross-sectional side view of illustrative
display structures in an electronic device such as a computer in
which a device housing has been provided with an undercut groove
portion to accommodate an edge of a light guide panel and other
light guide components in accordance with an embodiment of the
present invention.
[0025] FIG. 12 is a perspective view showing how light guide
components may have alignment features such as tabs that mate with
corresponding housing alignment features such as tab-shaped
recesses in accordance with an embodiment of the present
invention.
[0026] FIG. 13 is a perspective view showing how a reflective layer
may be wrapped around the back and edges of a light guide panel to
ensure that light is reflected back into the panel in accordance
with an embodiment of the present invention.
[0027] FIG. 14 is a perspective view of a portion of an electronic
device housing showing how a clamp structure may be used to help
retain an array of light emitting diodes while reflecting and
guiding light that is produced by the light emitting diodes in
accordance with an embodiment of the present invention.
[0028] FIG. 15 is a cross-sectional side view of an illustrative
electronic device showing how a planar clamp structure may be used
to help retain an array of light emitting diodes in accordance with
an embodiment of the present invention.
[0029] FIG. 16 is a cross-sectional side view of a light-emitting
diode array showing how a reflective sheet may be placed over the
edge of the light-emitting diode flex circuit in accordance with an
embodiment of the present invention.
[0030] FIG. 17 is a cross-sectional side view of a light-emitting
diode array showing how reflective tape may be placed over the edge
of the light-emitting diode flex circuit and under the edge of a
reflective sheet in accordance with an embodiment of the present
invention.
[0031] FIG. 18 is a cross-sectional side view of a light-emitting
diode array showing how a reflective coating such as reflective
paint may be used to reflect light in accordance with an embodiment
of the present invention.
[0032] FIG. 19 is a cross-sectional side view of a light-emitting
diode array showing how exposed interior surfaces of a computer
housing may be coated with reflective coating such as reflective
paint in accordance with an embodiment of the present
invention.
[0033] FIG. 20 is a cross-sectional side view of an illustrative
electronic device such as a computer in which a bezel is used in
covering display structures in accordance with an embodiment of the
present invention.
DETAILED DESCRIPTION
[0034] An illustrative electronic device such as a portable
computer in which display structures may be provided is shown in
FIG. 1. As shown in FIG. 1, portable computer 10 may have housing
12. Housing 12, which is sometimes referred to as a case, may be
formed from one or more individual structures. For example, housing
12 may have a main structural support member that is formed from a
solid block of machined aluminum or other suitable metal. One or
more additional structures may be connected to the housing 12.
These structures may include, for example, internal frame members,
external coverings such as sheets of metal, etc. Housing 12 and its
associated components may, in general, be formed from any suitable
materials such as such as plastic, ceramics, metal, glass,
composites, etc. An advantage of forming housing 12 at least partly
from metal is that metal is durable and attractive in appearance.
Metals such as aluminum may be anodized to form an insulating oxide
coating.
[0035] In general, the components of portable computer 10 can be
formed from any suitable materials. As examples, the components of
portable computer 10 may be formed from materials such as metals
(e.g., aluminum, stainless steel, alloys of metals, electroplated
metals, plated and other coated metals, etc.), plastics (e.g.,
polycarbonate (PC) plastics, acrylonitrile butadiene styrene (ABS)
plastics, thermoplastics, PC/ABS plastic blends, etc.), composite
materials (e.g., carbon fibers or other fibers bound by a binder
such as a polymer resin), plastics that have been injection molded
around metal structures, laminated plastic layers, ceramics, metal,
glass, composites, metal-filled epoxy, other suitable materials,
and combinations of these and other materials. Components of
portable computer 10 which are described herein as being formed
from one or more specific materials (e.g., housing 12 which is
sometimes described herein as being formed from machined aluminum
as an example) can be formed from any of the above-mentioned
materials, other suitable materials, or combinations of such
materials.
[0036] Housing 12 may have an upper portion 26 and a lower portion
28. Lower portion 28 may be referred to as the base or main unit of
computer 10 and may contain components such as a hard disk drive,
battery, and main logic board. Upper portion 26, which is sometimes
referred to as a cover, lid, or display housing, may rotate
relative to lower portion 28 about rotational axis 16. Portion 18
of computer 10 may contain a hinge and associated clutch structures
and is sometimes referred to as a clutch barrel.
[0037] Lower housing portion 28 may have a slot such as slot 22
through which optical disks may be loaded into an optical disk
drive. Lower housing portion may also have a touchpad such as
touchpad 24 and may have keys 20. If desired, additional components
may be mounted to upper and lower housing portions 26 and 28. For
example, upper and lower housing portions 26 and 28 may have ports
to which cables can be connected (e.g., universal serial bus ports,
an Ethernet port, a Firewire port, audio jacks, card slots, etc.).
Buttons and other controls may also be mounted to housing 12.
Speaker openings such as speaker openings 30 may be formed in lower
housing portion 28 by creating an array of small openings
(perforations) in the surface of housing 12.
[0038] A display such as display 14 may be mounted within upper
housing portion 26. Display 14 may be, for example, a liquid
crystal display (LCD), organic light emitting diode (OLED) display,
or plasma display (as examples). Display 14 may contain a number of
layers of material. These display structures may include, for
example, layers of optically transparent materials such as plastic
and glass. Layers of plastic and optical adhesive may also be
incorporated into display 14. In a liquid crystal display, layers
of polarizer, light diffusing elements and light guides for
backlight structures, a liquid crystal layer, and a thin-film
transistor array that drives the image pixels in the display may be
incorporated into the display.
[0039] Computer 10 may have input-output components such as touch
pad 24. Touch pad 24 may include a touch sensitive surface that
allows a user of computer 10 to control computer 10 using
touch-based commands (gestures). A portion of touchpad 24 may be
depressed by the user when the user desires to "click" on a
displayed item on screen 14.
[0040] A cross-sectional side view of a conventional liquid crystal
display (LCD) display module mounted in a computer housing is shown
in FIG. 2. As shown in FIG. 2, display module 32 may have display
structures 46 such as an upper polarizer layer, a color filter, a
thin-film transistor glass layer, a lower polarizer, and a layer of
light-guide structures. The light guide structures may include a
reflective bottom sheet, a light guide panel that guides light from
an array of edge-mounted light-emitting diodes over the full
surface area of the display, and layers of optical films such as
diffuser layers. Display module 32 may also have a plastic chassis
member such as plastic chassis member 44 and a metal chassis member
such as metal chassis member 42 into which the layers of glass and
other display module structures may be mounted. Cover glass 36 may
be placed on top of structures 46.
[0041] Metal chassis member 42 may have a tab with a hole through
which screw 40 passes. Screw 40 may be screwed into a threaded hole
in housing 34. In the arrangement of FIG. 2, housing 34 is formed
of aluminum. The presence of the extending tab portion of chassis
42 allows module 32 to be firmly secured in housing 34, but adds
undesirable width to the perimeter of display module 32.
[0042] Elastomeric gasket 38 is used to form a cushioned interface
between cover glass layer 36 and housing 34. This helps to prevent
damage to cover glass layer 36. Cover glass 36 is formed from clear
glass and helps to protect layers 46 of LCD module 32 from damage,
but adds undesirable thickness.
[0043] Another cross-sectional view of a conventional liquid
crystal display module is shown in FIG. 3. As shown in FIG. 3,
display module 32 may have polarizers such as upper polarizer layer
50 and lower polarizer 62. Light guide structure 64 may provide
backlight for module 32. The light from structure 64 passes through
the display pixels of module 32 and exits display module 32 in
direction 31.
[0044] Color filter glass layer 52, liquid crystal layer 54, and
thin-film transistor (TFT) glass layer 58 are interposed between
polarizer layers 50 and 62.
[0045] The polarization of individual pixels of liquid crystal
material in liquid crystal layer 54 interacts with the polarizing
effects of layers 50 and 62 to determine which display pixels block
light and which pixels allow light to pass. Color filter glass
layer 52 contains an array of colored filters that provide display
32 with the ability to represent different colors. The polarization
of liquid crystal material in liquid crystal layer 54 is controlled
electrically by thin-film transistor array 56. Thin-film
transistors in array 56 are formed on the upper surface of
thin-film transistor (TFT) glass layer 58.
[0046] Thin-film transistors 56 are controlled by drivers contained
in driver circuit 60. Color filter layer 52 is horizontally
(laterally) recessed with respect to TFT layer 58 to form a ledge
on which driver circuit 60 is mounted. In a typical display module,
there may be a number of driver chips such as circuit 60 that are
mounted around the periphery of the display. Conductive traces on
the upper surface of TFT layer 58 interconnect driver circuit 60
with thin-film transistors 56.
[0047] In conventional arrangements of the type shown in FIG. 3,
black ink 48 is placed on the underside of cover glass 36 around
the periphery of the display. This creates an opaque region that
blocks inactive peripheral portions of display module 32 from view.
Black ink 48 can also hide mounting structures such as screw 40 of
FIG. 2 from view. Display glass 36 may help provide structural
support to the display housing of the portable computer in which
display module 32 is mounted, but the presence of glass 36 can add
a non-negligible amount of extra thickness and weight to a
display.
[0048] An exploded view of a conventional display and computer
housing is shown in FIG. 4. As shown in FIG. 4, light guide
structures 64 may have tabs 68 that mate with recesses in plastic
chassis 44. Light-emitting diode array 66 is covered with plastic
chassis parts in regions 72. In region 74, part of metal chassis 42
(shown as metal chassis portion 42') is bent up and over the
light-emitting diode array to hold the array in place. Chassis 42
and chassis 44 may be mounted in housing 34.
[0049] A cross-sectional side view of the conventional structures
of FIG. 4 taken along line 76-76 of FIG. 4 is shown in FIG. 5. As
shown in FIG. 5, light guide structures 64 include reflective
polyester sheet 80 (e.g., white polyester), light-guide panel 82,
and optical films 84. Metal chassis portion 42' covers
light-emitting diode array 66. Light-emitting diode array 66
contains light-emitting diodes that provide backlight for the
display. The light-emitting diode chips are mounted on flexible
printed circuit ("flex circuit") 78. The edge of reflective sheet
80 covers the edge of flex circuit 78.
[0050] FIG. 6 shows a perspective view of a conventional
light-emitting diode array containing light-emitting diodes 66 and
flex circuit substrate 78.
[0051] Conventional light guide structures 64 may be provided with
a peripheral strip of double-sided tape, as shown by tape 86 in
FIG. 7.
[0052] FIG. 8 shows a cross-sectional side view of a portion of
upper housing 26 of device 10 (FIG. 1) in which display structures
106 have been mounted. Upper housing 26 may, for example, be formed
from machined aluminum. Elastomeric gasket 104 may be used to
provide a soft interface between potentially fragile glass layers
in structures 106 and housing 26.
[0053] Display structures 106 may produce an image using any
suitable display technology (e.g., light-emitting diodes such as an
array of organic light-emitting diodes, liquid crystal display
pixels, plasma-based pixels, etc.). In general, display structures
106 may be formed from any suitable materials (e.g., plastic,
glass, other optically suitable materials, etc.). An arrangement in
which display structures 106 are based on liquid crystal display
(LCD) technology is sometimes described herein as an example. The
use of LCD structures in display structures 106 is, however, merely
illustrative. Display structures 106 may, in general, be formed
from any suitable type of display structures.
[0054] As shown in FIG. 8, display structures 106 may have an upper
polarizer layer 102 and a lower polarizer layer 96. Light guide
structures 88 may provide backlight for structures 106. Light-guide
structures 88 may include reflective structures such as reflective
sheet 90 (e.g., white polyester), light-guide panel 92, and optical
films 94. Optical films 94 may include a diffuser layer and light
collimating layers (as an example). If desired, light reflection
functions may be provided by housing 26. Housing 26 may be formed
from a reflective material such as metal and/or the interior
surfaces of housing 26 may be coated with a reflective coating such
white paint or ink, silver paint or ink, a reflective material such
as chromium, etc. In arrangements in which housing 26 is highly
reflective, some or all of reflective sheet 90 may be omitted.
[0055] Clearances D2 and D1 help prevent damage to display
structure 106 during use of device 110. In a typical arrangement,
clearance D2 may be about 1.2 to 1.8 mm and clearance D1 may be
about 0.11 mm. End clearance D3 may be about 0.3 mm.
[0056] Light from a light-emitting diode array or other backlight
source is provided to an edge of light guide panel 92. Panel 92 and
the other structures in light guide structures 88 direct this light
upwards in direction 108 through thin film transistor layer 98 and
color filter layer 100.
[0057] Thin-film transistor substrate glass layer 98 may contain
thin-film transistors in array 110. Color filter glass layer 100
may contain an array of optical filters of different colors to
provide display structures 106 with the ability to display color
images. Color filter layer 100 may be formed from glass into which
dye of different colors has been impregnated, from a glass layer
coated with a pattern of colored dye, from a glass or plastic layer
that is covered with a pattern of thin colored filter structures
(e.g., filters formed from polymer or glass containing dye), or any
other suitable color filter structures. Liquid crystal layer 112
may be controlled by the electric fields produced by the thin-film
transistors of array 110.
[0058] As shown in FIG. 8, the layer of cover glass that is present
in conventional display modules need not be present in display
structures 106 and device 10. Rather, color filter layer 100 may
serve as the uppermost glass layer in structures 106 and device 10.
To ensure that structures 106 are sufficiently robust, color filter
layer 100 may be thickened or may be stiffened using support
structures within display structures 106. Color filter layer 100
may be formed of a durable clear layer (e.g., a strong glass or
plastic) that resists damage from contact. Anti-scratch coatings
may also be provided on the surface of color filter layer 100
(e.g., as part of polarizer layer 102 or above polarizer layer
102).
[0059] To hide the peripheral portions of display structures 106
that lie along the outer edges of display housing 26 from view, an
opaque material such as ink layer 114 may be incorporated around
the periphery of display structures 106 to form a border. Opaque
layer 114 may be formed on the underside of color filter layer 100
or on the upper surface of thin-film transistor glass layer 98 (as
examples). The opaque material may have any suitable color (e.g.,
black, grey, silver, white, blue, red, etc.).
[0060] With the arrangement of FIG. 8, color filter layer 100 and
thin-film transistor layer 98 extend outwardly (in the leftward
direction in the orientation of FIG. 8) so as to form an
overhanging portion 116 that is supported by the matching ledge in
housing 26. If desired, only color filter layer 100 may extend in
this way (e.g., so that the overhanging portion of layer 100 rests
on the ledge formed by housing 26). In this type of arrangement,
the thin-film transistor layer may extend only as far as
light-guide structures 88 of FIG. 8. If desired, portions of gasket
104 may be interposed between display structures 106 and housing 26
in region 116, as illustrated by protruding lower lip portion 105
of gasket 104 in the example of FIG. 8. Display driver circuitry
118 may, if desired, be formed in region 116 (e.g., as part of thin
film transistor layer 98 or in a chip mounted on thin film
transistor layer or color filter layer 100).
[0061] To ensure that light guide structures 88 are properly
aligned within housing 26 even in the absence of conventional
structures such as plastic chassis 44 and metal chassis 42 (FIG.
2), housing 26 may be provided with alignment features such as
rectangular recesses 122 of FIG. 9 that mate with corresponding
alignment features on light guide structures 88 such as protruding
tabs 120 of FIG. 9. When housing 26 is formed by a molding process
(e.g., plastic injection molding), alignment features can be molded
into housing 26 as part of the housing fabrication process. When
housing 26 is formed by a machining process (e.g., a process in
which an aluminum block or other block of material is machined
using a computer-controlled machining tool), alignment features can
be machined directly into the aluminum housing. In the example of
FIG. 9, there are four alignment tabs 120 and four corresponding
housing pockets 122. This is merely illustrative. There may be one
tab and one recess, two or more tabs and recesses, etc.
[0062] Light-emitting diode array 122 may be received within recess
124 in housing 26. Rectangular recess 134 in housing 26 may be
sized to receive the rectangular outline of light guide structures
88. The depth of these recesses in housing 26 may be about 0.2 mm
to 5 mm (as an example). The diagonal distance across the
rectangular light guide structures 88 may be, for example, 5 to 20
inches.
[0063] With an arrangement of the type shown in FIG. 9, recesses
122 and tabs 120 may help align light guide in recess 134. For
example, tabs may hold at least one of the edges of light guide
structures 88 at a slight distance (clearance) from housing 26 to
avoid creating pressure that might otherwise buckle light guide
structures 88. Along edge 136 structures 88 may, if desired,
protrude under a lip in housing 26 (i.e., a lip that forms a
capturing groove). This optional lip (groove) may help retain light
guide structures 88 in housing 26 (e.g., by receiving and retaining
the edge of light guide structures 88). Along edge 138 of housing
26, clamp structure 130 may be used to help retain light guide
structures 88 and light-emitting diode array 122 in housing 26.
Clamp structure 130 may be secured to housing 26 using adhesive,
fasteners such as screws 132, or other suitable attachment
mechanisms. Screws 132 may pass through holes 128 in clamp 130 and
may be received in threaded holes 126 in housing 26 (as an
example). Clamp structure 130 may be formed in a single piece (as
shown in FIG. 9) or one or more separate members may be used in
forming clamp structure 130.
[0064] Clamp structure 130 may be formed from metal, plastic,
composites, or other materials. For example, clamp structure 130
may be formed from a material such as stainless steel. Stainless
steel can be formed in thin sheets that are relatively stiff,
allowing the thickness of clamp structure 130 to be minimized.
Housing 26 may be formed from aluminum or one or more other
materials that are molded or machined into a desired shape (e.g.,
to form the alignment tab recesses of FIG. 9 and the rectangular
recess that receives rectangular light guide structures 88).
[0065] To help ensure that light guide structures 88 do not bear
against light-emitting diode array 122 with excessive force, recess
134 may have lips such as lip 140. As shown in more detail in FIG.
10, lip 140 of housing 26 may help prevent edge 142 of light guide
structures 88 from directly contacting light-emitting diode array
122. The nominal clearance D4 between edge 142 and light-emitting
diodes 122 may be, for example, 0 mm to 1 mm.
[0066] As shown in FIG. 11, a portion of housing 26 (e.g., the
portion along edge 134) may be provided with an undercut. In region
148, for example, lip 144 may extend outwards over undercut opening
146 to form a groove. Groove opening 146 may receive the edge of
light guide structures 88, allowing the edge of housing 26 that
surrounds display structure 106 to be narrowed.
[0067] A perspective view of one of recesses 122 (i.e., an
alignment notch) and one of matching tabs 120 on light guide
structures 88 is shown in FIG. 12. A strip of tape 150 with a layer
of adhesive 152 may be placed over tabs 120. The tape may stick to
housing 26 in regions 154 to hold tabs 120 in place in recess 122.
Tape 150 may be removed to permit rework. If desired, recesses 122
may be provided with integral housing lips (i.e., recesses 122 may
be implemented as covered notches rather than as exposed notches).
This may help avoid the need for tape strips 150, but may require
that light guide structures 88 be flexed slightly as part of the
assembly process (i.e., to tuck tabs 120 into the covered notches
and any grooves in the housing).
[0068] Light-emitting diodes 122 (FIG. 9) emit light into the edge
of light-guide panel 92. Light guide panel 92 directs the emitted
light upwards through layers such as layers 98 and 100. To increase
backlight efficiency, light leakage at the edges of light guide
panel 92 should be minimized. With one suitable arrangement, the
side walls of housing recess 134 that surround the edges of light
guide panel 92 and the other light guide structures 88 may be
machined to form a reflective surface or may be coated with white
paint, chromium, or other reflective coatings. With another
suitable arrangement, which is shown in FIG. 13, the edges of
reflective sheet 90 (i.e., edges 156 and 158) may be wrapped
upwards so as to surround the edges of light guide panel 92 and
optical films 94. By reflecting light back into the edges of light
guide panel 92, backlight that would otherwise be wasted is
properly directed through the display.
[0069] In arrangements of the type shown in FIG. 13, reflective
sheet 90 and wrapped reflective sheet edges 156 and 158 are formed
from a unitary piece of material. If desired, separate layers of
reflective material may be used for the main rear reflective sheet
layer and for the reflective edges (as an example).
[0070] A perspective view of an illustrative clamping arrangement
in which reflective tape is used to help ensure satisfactory
backlight performance is shown in FIG. 14. Clamp 130 has bends 162
that allow clamp 130 to pass over housing structures such as wall
166. Screws 132 may pass through holes 128 and into threaded holes
126 in housing 26 to hold clamp 130 in place over light-emitting
diodes 122. A strip of reflective material such as reflective tape
160 may be attached along edge 164 of clamp 130. Tape 160 may help
to reflect light from diodes 122 into the edge of light guide panel
92.
[0071] A cross-sectional side view of an illustrative mounting
arrangement that uses a planar clamp is shown in FIG. 15. As shown
in FIG. 15, driver circuitry 118 may be implemented using separate
integrated circuits (as an example). Planar clamp structure 130 may
be attached to housing 26 using screws such as screw 132.
Reflective tape 160 may be placed above light-emitting diodes 122
to help guide light 172 into the edge of light guide panel 92.
Reflective sheet 90 may be placed below the lower surface of light
guide panel 92 to reflect escaping light back into light guide
panel 92. Additional reflective structures such as reflective tape
170 may provide further light reflection. Light-emitting diodes 122
may be mounted on a substrate such as flex circuit 168. Tape 170
can be placed over the edge of flex circuit 168 as shown in FIG.
15.
[0072] If desired, the edge of reflective sheet 90 may overlap the
edge of flex circuit 168. This type of arrangement is shown in FIG.
16.
[0073] FIG. 17 shows how tape 170 may have one edge that is placed
over flex circuit 168 and one edge that is placed under reflective
sheet 90 (as shown in the example of FIG. 15).
[0074] Light may also be reflected using reflective coatings. For
example, tape 170 may be omitted and flex circuit 168 may be coated
with reflective coating 174, as shown in FIG. 18. Coating 174 may
be formed from reflective coating such as white paint or white ink,
from a shiny substance such as a metallic paint or a metal coating,
or other reflective materials.
[0075] In the illustrative configuration of FIG. 19, housing 26 has
been provided with reflective coating 174. Some of reflective
coating 174 has also been formed over exposed edge 176 of flex
circuit 168. Reflective coating 174 may be formed by physical vapor
deposition (e.g., sputtering), by silk screen printing, pad
printing, spray coating, electrochemical deposition,
electroplating, manual application with a paint brush or foam pad,
ink jet printing, etc.
[0076] If desired, a bezel may be used in covering display
components. This type of arrangement is shown in FIG. 20. As shown
in FIG. 20, bezel 178 may cover edge portions of display structures
106. Bezel 178 may be formed from plastic, glass, metal,
composites, other suitable materials, or combinations of these
materials. Driver circuitry 188 may be provided in the form of
integrated circuits mounted on layer 98 or mounted on layer 100 or
driver circuitry 188 may be provided in the form of circuitry
integrated on layer 98 or on layer 100 (as examples). By using
bezel 178, internal device structures such as circuitry 188 may be
hidden from view from the exterior of device 10. Adhesive such as
adhesive 180 may be used to attach bezel 178 to housing 26.
Adhesive 182 may be used to attach display structures 106 to
housing 26.
[0077] The foregoing is merely illustrative of the principles of
this invention and various modifications can be made by those
skilled in the art without departing from the scope and spirit of
the invention.
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