U.S. patent application number 16/542370 was filed with the patent office on 2020-09-10 for backlight module.
The applicant listed for this patent is AU Optronics Corporation. Invention is credited to Hsin-Chun HUANG, Yen-Hua LO.
Application Number | 20200284971 16/542370 |
Document ID | / |
Family ID | 1000005047079 |
Filed Date | 2020-09-10 |
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United States Patent
Application |
20200284971 |
Kind Code |
A1 |
LO; Yen-Hua ; et
al. |
September 10, 2020 |
BACKLIGHT MODULE
Abstract
A backlight module includes a light guide plate that has a first
side and a second side, a light emitting element, and a light guide
element. The light emitting element is adjacent to the first side
of the light guide plate. The light guide element is disposed
between the first side and the second side, and forms a first
opening therein. The light guide element includes a first
refractive part and a second refractive part. The first refractive
part has a first refractive index, the second refractive part has a
second refractive index, and the first refractive index and the
second refractive index are different from a refractive index of
the light guide plate. The orthogonal projections of the first
refractive part and the second refractive part on the first side
are non-overlapped with each other.
Inventors: |
LO; Yen-Hua; (HSIN-CHU,
TW) ; HUANG; Hsin-Chun; (HSIN-CHU, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AU Optronics Corporation |
HSIN-CHU |
|
TW |
|
|
Family ID: |
1000005047079 |
Appl. No.: |
16/542370 |
Filed: |
August 16, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 6/0088 20130101;
G02B 6/0078 20130101 |
International
Class: |
F21V 8/00 20060101
F21V008/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 5, 2019 |
TW |
108107311 |
Jul 24, 2019 |
TW |
108126223 |
Claims
1. A backlight module, comprising: a light guide plate having a
first side and a second side opposite the first side; a light
emitting element adjacent to the first side of the light guide
plate; and a light guide element disposed in the light guide plate
and forming a first opening therein, the light guide element
comprising a first refractive part, a second refractive part, a
third refractive part, and a fourth refractive part, wherein the
third refractive part is connected the first refractive part and
the second refractive part, the fourth refractive part is connected
the first refractive part and the second refractive part, the third
refractive part and the fourth refractive part are located on two
opposite sides of the first opening, the third refractive part is
closer to the first side than the fourth refractive part, the first
refractive part has a first refractive index, the second refractive
part has a second refractive index, the first refractive index and
the second refractive index are different from a refractive index
of the light guide plate, and wherein an orthogonal projection of
the first refractive part and an orthogonal of the second
refractive part on the first side are non-overlapped with each
other.
2. The backlight module of claim 1, wherein the first refractive
part and the second refractive part are located on two opposite
sides of the first opening.
3. The backlight module of claim 1, wherein the first refractive
index is equal to the second refractive index and smaller than the
refractive index of the light guide plate.
4. (canceled)
5. The backlight module of claim 1, wherein the third refractive
part has a third refractive index, the fourth refractive part has a
fourth refractive index, wherein the third refractive index is
equal to the fourth refractive index.
6. The backlight module of claim 5, wherein the third refractive
index is equal to the refractive index of the light guide
plate.
7. The backlight module of claim 6, wherein the third refractive
part and the fourth refractive part are integrally formed with the
light guide plate.
8. The backlight module of claim 1, wherein there is a first
interface between the first refractive part and the third
refractive part, and there is a second interface between the second
refractive part and the third refractive part, wherein the first
interface and the second interface are separated from each
other.
9. The backlight module of claim 8, wherein the light guide element
further comprises: a first reflective part disposed in the third
refractive part, directly connected to the first opening, and
located between the first interface and the second interface.
10. The backlight module of claim 9, wherein the first reflective
part has a first reflective surface and a second reflective
surface, the first reflective surface is connected to the first
interface, the second reflective part is connected to the second
interface, and the first reflective surface is connected to the
second reflective surface.
11. The backlight module of claim 10, wherein an angle between the
first reflective surface and the second reflective surface is
between 24 degrees and 166 degrees.
12. The backlight module of claim 9, wherein the light guide
element further comprises: a second reflective part disposed in the
fourth refractive part, and the second reflective part and the
first reflective part are located on two opposite sides of the
first opening.
13. The backlight module of claim 1, wherein the light guide
element further comprises: a reflective ring disposed on an inner
surface of the first opening.
14. The backlight module of claim 1, wherein the first refractive
part has a plurality of refractive layers, and the refractive
layers sequentially arranged in a direction away from the first
opening.
15. The backlight module of claim 14, wherein the refractive layers
comprises: a first refractive layer surrounding a portion of the
first opening; and a second refractive layer surrounding the first
refractive layer.
16. The backlight module of claim 15, wherein a refractive index of
the first refractive layer is smaller than a refractive index of
the second refractive layer.
17. The backlight module of claim 16, wherein the first refractive
part comprises: a third refractive layer surrounding the second
refractive layer, wherein a refractive index of the third
refractive layer is between the refractive index of the first
refractive layer and the refractive index of the second refractive
layer.
18. The backlight module of claim 1, wherein a distance d between
an outer edge of the light guide element and the first opening and
a radius R of the first opening satisfy d.ltoreq.R/10.
19. The backlight module of claim 1, wherein the light guide plate
has a second opening, and the light guide element is detachably
disposed in the second opening.
20. The backlight module of claim 1, wherein a distance between the
light guide element and the second side is smaller than a distance
between the light guide element and the first side.
Description
RELATED APPLICATION
[0001] This application claims priority to Taiwan Application
Serial Number 108107311, filed Mar. 5, 2019, and Taiwan Application
Serial Number 108126223, filed Jul. 24, 2019, all of which are
herein incorporated by reference.
BACKGROUND
Technical Field
[0002] The present disclosure relates to a backlight module.
Description of Related Art
[0003] In conventional handheld electronic devices, a variety of
functional components are buried in the areas of the upper frame
and the lower frame. In some electronic devices nowadays, the
design of the upper frame is called off and the front camera is
disposed in the center of the display area in order to pursue a
higher screen-to-body ratio. However, as a result, an opening need
to be formed in the display module and the backlight module in the
display area, and such a design may cause a problem of nonuniform
brightness near the opening of the display area. Therefore, how to
solve the above problem is one of the important topics in the
field.
SUMMARY
[0004] The present disclosure is related to a backlight module. The
backlight module includes a light guide plate, a light emitting
element, and a light guide element. The light guide plate has a
first side and a second side. The light emitting element is
adjacent to the first side of the light guide plate. The light
guide element is disposed between the first side and the second
side, and forms a first opening therein. The light guide element
includes a first refractive part and a second refractive part. The
first refractive part has a first refractive index, and the second
refractive part has a second refractive index, in which the first
refractive index and the second refractive index are different from
a refractive index of the light guide plate. The orthogonal
projections of the first refractive part and the second refractive
part on the first side are non-overlapped with each other.
[0005] In summary, the backlight module provided in the present
disclosure is able to guide the light emitted by the light emitting
element on the first side to an end of the first opening close to
the second side, thereby avoiding the problem that the light
intensity cannot be uniformly distributed due to the first opening
of the backlight module.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a front view of an electronic device according to
one embodiment of the present disclosure.
[0007] FIG. 2 is a cross-sectional view taken along line 2-2 shown
in FIG. 1.
[0008] FIG. 3 is a front view of a backlight module in the
electronic device according to the embodiment of FIG. 1.
[0009] FIG. 4 is a cross-sectional view taken along line 4-4 in
FIG. 3.
[0010] FIG. 5 is a top view of a light guide element according to
one embodiment of the present disclosure.
[0011] FIG. 6 is a top view of a light guide element according to
another embodiment of the present disclosure.
[0012] FIG. 7 is a top view of a light guide element according to
another embodiment of the present disclosure.
[0013] FIG. 8 is a top view of a light guide element according to
another embodiment of the present disclosure.
[0014] FIG. 9 is a top view of a light guide element according to
another embodiment of the present disclosure.
[0015] FIG. 10 is a top view of a light guide element according to
another embodiment of the present disclosure.
[0016] FIG. 11 is a top view of a light guide element according to
another embodiment of the present disclosure.
DETAILED DESCRIPTION
[0017] For the embodiment below is described in detail with the
accompanying drawings, embodiments are not provided to limit the
scope of the present disclosure. Moreover, the operation of the
described structure is not for limiting the order of
implementation. Any device with equivalent functions that is
produced from a structure formed by a recombination of elements is
all covered by the scope of the present disclosure. Drawings are
for the purpose of illustration only, and not plotted in accordance
with the original size.
[0018] Referring to FIG. 1, which illustrates a front view of an
electronic device 10 according to an embodiment of the present
disclosure. Taking the present embodiment as an example, the
electronic device 10 is a mobile phone having a display function
and a photographing function. As shown in FIG. 1, the first surface
10a of the electronic device 10 has a display area DA and a frame
area PA, in which the display area DA may display color images, and
a first opening O1 is formed in the display area DA.
[0019] As shown in FIG. 1, the electronic device 10 further
includes a camera module 11. The photographying module 11 is
disposed in the first opening O1. In the present embodiment, the
camera module 11 may include a charged coupled device (CCD), and
the lens there of faces toward the first surface 10a, thereby
allowing the electronic device 10 to capture an external image
facing the first surface 10a.
[0020] Next, referring to FIG. 2, which illustrates a
cross-sectional view taken along line 2-2 shown in FIG. 1. As shown
in FIG. 2, the electronic device 10 further includes a cover glass
12, a display module (including a filter layer 13, a liquid crystal
layer 14, and a voltage control layer 15), a backlight module 16,
and a back cover module 17.
[0021] As shown in FIG. 2, the cover glass 12 can be made of glass,
acrylic or other types of transparent materials. The cover glass 12
forms the first surface 10a of the electronic device 10. The cover
glass 12 may protect components inside the electronic device 10
from the damage caused by the external environment.
[0022] As shown in FIG. 2, the display module in the present
embodiment is a liquid crystal display (LCD) module, and the filter
layer 13 includes a color filter therein. For example, in the
present embodiment, the filter layer 13 includes a red filter
layer, a blue filter layer, and a green filter layer. Different
color filter layers allow light of different wavelengths to pass
through. The filter layer with each color defines one sub-pixel,
and multiple sub-pixels define one pixel unit.
[0023] As shown in FIG. 2, the liquid crystal layer 14 and the
voltage control layer 15 are disposed between the filter layer 13
and the backlight module 16. The liquid crystal layer 14 contains
liquid crystal molecules. The voltage control layer 15 includes
sub-pixel electrodes, thin film transistors (TFTs), data lines, and
scan lines. Each of the sub-pixel electrodes corresponds to one
thin film transistor, each thin film transistor corresponds to one
sub-pixel, and each set of data lines and scan lines corresponds to
one thin film transistor. The external controller can individually
control the switching of each thin film transistor through the data
line and the scan line. According to the switching of the thin film
transistor, the sub-pixel electrode applies different degrees of
voltage to the liquid crystal molecules in the liquid crystal layer
14, and changes the tilt angles of the liquid crystal molecules,
thereby controlling the light transmittance in each sub-pixel.
[0024] The backlight module 16 can provide light that is
transmitted toward the first surface 10a. The light sequentially
passes through the voltage control layer 15, the liquid crystal
layer 14, and the filter layer 13 that are located above the
backlight module. As described above, the voltage control layer 15
and the liquid crystal layer 14 can control the light transmittance
in different sub-pixels, and thereafter the light is converted into
color light with different colors while passing through the filter
layer 13. As a result, the electronic device 10 can display color
images by the filter layer 13, the liquid crystal layer 14, the
voltage control layer 15, and the backlight module 16.
[0025] As shown in FIG. 2, the back cover module 17 can include a
variety of different functional components, such as a processor, a
battery, a radio or a playback device, and the like. The present
disclosure is not limited thereto, and thus the above elements are
not explicitly shown in FIG. 2. In the present embodiment, the
camera module 11 is disposed on the back cover module 17 and
protrudes toward the first surface 10a.
[0026] As shown in FIG. 2, the first opening O1 of the electronic
device 10 is located within the filter layer 13, the liquid crystal
layer 14, the voltage control layer 15, and the backlight module
16. The first opening O1 extends through the filter layer 13, the
liquid crystal layer 14, the voltage control layer 15, and the
backlight module 16, so that the camera module 11 is able to be
accommodated in the first opening O1. With the above design, the
camera module 11 of the electronic device 10 can be located within
the display area DA (see FIG. 1), so that the display area DA can
extend and surround the camera module 11 to increase the area of
the display area DA.
[0027] Next, referring to FIG. 3 and FIG. 4. FIG. 3 illustrates a
front view of the backlight module 16 in the electronic device 10
according to the embodiment of FIG. 1. FIG. 4 is a cross-sectional
view taken along line 4-4 shown in FIG. 3. The light guide plate
164 has a first side 16a and a second side 16b opposite the first
side 16a, and the first opening O1 is disposed between the first
side 16a and the second side 16b.
[0028] As shown in FIG. 4, in the present embodiment, the backlight
module 16 includes a light emitting element 161, a light guide
element 162, a reflective film 163, a light guide plate (LGP) 164,
and a diffusion film 165. The light emitting element 161 is close
to the first side 16a of the light guide plate 164. The light guide
element 162 is closer to the second side 16b of the light guide
plate 164 and the first opening O1 is formed therein. In other
words, a distance between the light guide element 162 and the
second side 16b is smaller than a distance between the light guide
element 162 and the first side 16a. The light guide plate 164 is
disposed between the reflective film 163 and the diffusion film
165, in which the diffusion film 165 is closer to the first surface
10a of the electronic device 10 (refer to FIG. 1).
[0029] As shown in FIG. 4, the light emitting element 161 can be a
light emitting diode (LED) or other light emitting elements. The
light emitting element 161 is configured to emit light toward the
second side 16b of the light guide plate 164. The light is guided
by the reflective film 163 and the light guide plate 164 to change
its traveling direction, and finally passes through the diffusion
film 165 and leaves the backlight module 16. Specifically, the
backlight module 16 in the present embodiment is side-light type,
that is, the light emitting element 161 is located on one side of
the display area DA of the electronic device 10 (refer to FIG. 1
simultaneously).
[0030] As shown in FIG. 4, a portion of the light emitted by the
light emitting element 161 reaches the first opening O1. The light
guide element 162 is configured to guide the light to reach an end
of the first opening O1 close to the second side 16b. As a result,
it can be ensured that the light emitted by the light emitting
element 161 can uniformly reach the space near the second side 16b
of the light guide plate 164 without overflowing from the first
opening O1. In the present embodiment, the light guide element 162
is detachably disposed in the backlight module 16. In other words,
as shown in FIG. 4, the backlight module 16 has a second opening
O2, and the light guide element 162 is detachably disposed within
the second opening O2. As shown in FIG. 4, the first opening O1 has
an inner diameter r1, and the second opening O2 has an outer
diameter r2, in which the inner diameter r1 is smaller than the
outer diameter r2. Next, various embodiments of the detachable
light guide element 162 will be described with reference to FIG. 5
to FIG. 11. However, it should be understood that one skilled in
the art can make changes according to actual needs, and thus it is
not limited to those shown in FIG. 5 to FIG. 11.
[0031] Referring to FIG. 5, which illustrates a top view of a light
guide element 50 according to one embodiment of the present
disclosure. In the present embodiment, the light guide element 50
is actually the light guide element 162 in FIG. 3 and FIG. 4.
Therefore, the following description of FIG. 5 may also refer to
FIG. 3 and FIG. 4 simultaneously.
[0032] As shown in FIG. 5, the light guide element 50 is
ring-shaped entirely, and the first opening O1 is formed in the
center thereof. Specifically, the light guide element 50 has an
inner diameter r1 and an outer diameter r2, in which the inner
diameter r1 defines the size of the first opening O1 and the outer
diameter r2 defines the size of the second opening O2 (refer to
FIG. 4 simultaneously). It should be understood that the dimensions
of the elements in FIG. 5 are not shown in actual scale. In some
embodiments, a distance between an outer edge of the light guide
element 50 and the first opening O1 is d, and a radius of the first
opening O1 is R, which satisfy d.ltoreq.R/10 to achieve better
light transmission effect.
[0033] As shown in FIG. 5, the light guide element 50 includes a
first refractive part 51 and a second refractive part 52, in which
the orthogonal projections of the first refractive part 51 and the
second refractive part 52 on the first side 16a of the light guide
plate 164 are non-overlapped with each other. The first refractive
part 51 and the second refractive part 52 may be made of
transparent refractive materials. For example, the first refractive
part 51 and the second refractive part 52 may be made of a resin.
The first refractive part 51 has a first refractive index n1, and
the second refractive part 52 has a second refractive index n2. In
the present embodiment, the first refractive part 51 and the second
refractive part 52 are made of the same material, and thus the
first refractive index n1 is equal to the second refractive index
n2.
[0034] As shown in FIG. 5, the light guide element 50 further
includes a third refractive part 53 and a fourth refractive part
54. The third refractive part 53 and the fourth refractive part 54
are connected to the first refractive part 51 and the second
refractive part 52, and the third refractive part 53 is closer to
the first side 16a than the fourth refractive part 54. The third
refractive part 53 and the fourth refractive part 54 may be made of
transparent refractive materials. In the present embodiment, the
third refractive part 53 has a third refractive index n3, and the
fourth refractive part 54 has a fourth refractive index n4. In the
present embodiment, the third refractive part 53 and the fourth
refractive part 54 may be made of the same material, and thus the
third refractive index n3 is equal to the fourth refractive index
n4. More specifically, the third refractive index n3 and the fourth
refractive index n4 are equal to the refractive index of the light
guide plate 164 in FIG. 4.
[0035] Referring to FIG. 3 and FIG. 5 simultaneously, it should be
understood that the third refractive part 53 is closer to the light
emitting element 161. Therefore, the light L emitted from the light
emitting element 161 firstly passes through the light guide plate
164 and then enters the third refractive part 53. In the present
embodiment, since the refractive indices of the light guide plate
164 and the third refractive part 53 are the same, the light L does
not deflect after passing through the interface 53a between the
light guide plate 164 and the third refractive part 53.
[0036] Thereafter, as shown in FIG. 5, the light L passes through
the interface 51a between the third refractive part 53 and the
first refractive part 51 (or the interface 52a between the third
refractive part 53 and the second refractive part 52). In the
present embodiment, the first refractive index n1 of the first
refractive part 51 is greater than the third refractive index n3 of
the third refractive part 53. Due to the difference between the
above refractive indices, the first refractive part 51 guides the
light L to be deflected.
[0037] Next, as shown in FIG. 5, after leaving the interface 51a
between the first refractive part 51 and the third refractive part
53, the light L is incident on the interface 51b between the first
refractive part 51 and the light guide plate 164. Since the
incident angle of the light L at the interface 51b is smaller than
the total reflection angle of the interface 51b, the light L is
reflected and shifted in the direction toward the first opening
O1.
[0038] Finally, as shown in FIG. 5, the light L shifted in the
direction toward the first opening O1 is incident on the interface
51c between the first refractive part 51 and the fourth refractive
part 54. In the present embodiment, the first refractive index n1
of the first refractive part 51 is greater than the fourth
refractive index n4 of the fourth refractive part 54. Due to the
difference between the above refractive indices, the fourth
refractive part 54 guides the light L away from the first opening
O1.
[0039] As shown in FIG. 5, the light L incident on the light guide
element 50 from the front of the first opening O1 is guided to the
rear of the first opening O1 and is advanced toward the second side
16b, and the emergent direction is close to the incident direction.
In other words, the light guide element 50 enables the light L to
be uniformly distributed to a region close to the second side 16b
of the light guide plate 164 (refer to FIG. 3). As a result, the
brightness uniformity of the display area DA (see FIG. 1) of the
electronic device 10 can be ensured.
[0040] As shown in FIG. 5, the horizontal axis x1 at the
intersection of the interface 51a and the first opening O1 is
parallel to the first side 16a, and there is an angle a1 between
the interface 51a and the horizontal axis x1. Similarly, the
horizontal axis x2 at the intersection of the interface 51c and the
first opening O1 is parallel to the first side 16a and the second
side 16b, and there is an angle a2 between the interface 51c and
the horizontal axis x2. In the present embodiment, the interface
51a is located below the horizontal axis x1 and the interface 51c
is located above the horizontal axis x2. In other words, the
directions of the angle a1 and the angle a2 are contrary, but the
values of them are the same (the difference between them is a
minus).
[0041] Different angle a1 and angle a2 may affect the degree of
deflection of the light L. Specifically, the incident angle
incident on the interface 51b should be smaller than the total
reflection angle of the interface 51b, so that the light L can
reach the fourth refractive part 54. The angle a1 of the interface
51a and the angle a2 of the interface 51c affect the degree of
deflection of the light L. One skilled in the art can adjust the
angle a1 and the angle a2 according to actual needs, so that the
maximum proportion of the light L can be successfully reflected by
the interface 51c to the fourth refractive part 54.
[0042] For example, referring to FIG. 6 herein, which illustrates a
top view of a light guide element 60 according to another
embodiment of the present disclosure. As shown in FIG. 6, the light
guide element 60 is entirely the same as the light guide element
50, and the difference is that the inclination angles of the
interface 61a and the interface 61c of the light guide element 60
are different from that of the interfaces 51a and 51c.
Specifically, in FIG. 6, the interface 61a is parallel to the
horizontal axis x1, and the interface 61c is parallel to the
horizontal axis x2. In other words, in the present embodiment, the
angle a1 and the angle a2 are both zero.
[0043] Alternatively, referring to FIG. 7, which illustrates a top
view of a light guide element 70 according to another embodiment of
the present disclosure. As shown in FIG. 7, the light guide element
70 is entirely the same as the light guide element 50, and the
difference is that the inclination angles of the interface 71a and
the interface 71c of the light guide element 70 are different from
that of the interfaces 51a and 51c. In the present embodiment, the
interface 71a is located above the horizontal axis x1, and the
interface 71c is located below the horizontal axis x2. In other
words, the signs of the angle a1 and the angle a2 in the present
embodiment are opposite to that shown in FIG. 5.
[0044] Next, referring to FIG. 8, which illustrates a top view of a
light guide element 80 according to another embodiment of the
present disclosure. As shown in FIG. 8, the light guide element 80
is entirely the same as the light guide element 50, and the
difference is that the first refractive part 81, the second
refractive part 82, and the fourth refractive part 84 of the light
guide element 80 are combined with each other. In other words, in
the present embodiment, the first refractive part 81, the second
refractive part 82, and the fourth refractive part 84 are made of
the same material, and the three are integrally formed such that
the first refractive part 81, the second refractive part 82, and
the fourth refractive parts 84 are combined into one C-shaped
refractive part. In the present embodiment, the light can be guided
through the interface 81a to the fourth refractive part 84 behind
the first opening O1. In addition, the design in which the rear of
the first opening O1 is changed to the C-shape has an advantage of
being easy to manufacture.
[0045] Next, referring to FIG. 9, which illustrates a top view of a
light guide element 90 according to another embodiment of the
present disclosure. The light guide element 90 is entirely the same
as the light guide element 50, and the difference is that the light
guide element 90 further includes a reflective ring 95.
[0046] As shown in FIG. 9, the reflective ring 95 is located at the
center of the light guide element 90 and surrounds the first
opening O1. The reflective ring 95 may be disposed on an inner
surface of the first opening O1. Specifically, the reflective ring
95 can be a reflective metal ring, or a ring structure made of
other total reflective materials. By disposing the reflective ring
95 around the first opening O1, it is able to prevent a portion of
the light L that is not guided by the first refractive part 91 from
directly entering the first opening O1. As a result, it is ensured
that the camera module 11 (see FIG. 2) located in the first opening
O1 is not disturbed by the light. In addition, the reflective ring
95 may also be disposed in the embodiment of FIG. 7, and the
embodiment of FIG. 7 needs the configuration of the reflective ring
95 more than that of FIG. 5.
[0047] Next, referring to FIG. 10, which illustrates a top view of
a light guide element 100 according to another embodiment of the
present disclosure. As shown in FIG. 10, the light guide element
100 is similar to the light guide element 90, and the difference is
that the light guide element 100 further includes a first
reflective part 106 and a second reflective part 107, and the angle
a1 and the angle a2 are slightly different. In this embodiment, the
reflective ring 105 may not exist, and may be omitted, such that
the first reflective part 106 may be directly connected to the
first opening O1.
[0048] As shown in FIG. 10, the first reflective part 106 and the
second reflective part 107 may be made of metal or various
reflective materials. The first reflective part 106 and the second
reflective part 107 are respectively disposed in the third
refractive part 103 and the fourth refractive part 104, and each of
the first reflective part 106 and the second reflective part 107 is
disposed between the first refractive part 101 and the second
refractive part 102. In the present embodiment, the first
reflective part 106 has a reflective surface 106a and a reflective
surface 106b. The reflective surface 106a is connected to the
interface 101a, and the reflective surface 106b is connected to the
interface 102a. Similarly, the second reflective part 107 has a
reflective surface 107a and a reflective surface 107b. The
reflective surface 107a is connected to the interface 101c, and the
reflective surface 107b is connected to the interface 102c.
[0049] As shown in FIG. 10, by disposing the first reflective part
106 in the third refractive part 103, the emitted light L can be
incident on the interface 101a and the interface 102a through the
guiding of the reflective surface 106a and the reflective surface
106b. The subsequent progression of the light L is similar to that
shown in FIG. 5, and thus the description will not be repeated
herein.
[0050] As shown in FIG. 10, the third refractive part 103 and the
fourth refractive part 104 in the present embodiment are
substantially the same. By disposing the second reflective part 107
in the fourth refractive part 104, it enables the light L emergent
from the interface 101c and the interface 102c can be guided
through the reflective surface 107a and the reflective surface 107b
to leave the light guide element 100 in the uniform direction. In
summary, by designing the first reflective part 106 and the second
reflective part 107 in the light guide element 100, it further
enables more light L to be guided to one side of the first opening
O1 close to the second side 16b, and thus the brightness uniformity
of the display area DA of the electronic device 10 is improved
(refer to both FIG. 1 and FIG. 3).
[0051] As shown in FIG. 10, there is an angle a3 between the
reflective surface 106a and the vertical axis y, and there is also
an angle a3 between the reflective surface 106b and the vertical
axis y with opposite direction. In the present embodiment, the
following mathematical relation (1) between the angle a3, the first
refractive index n.sub.101 of the first refractive part 101 and the
third refractive index n.sub.103 of the third refractive part 103
is satisfied by:
a 3 > .pi. 2 - arcsin ( n 101 n 103 * sin ( .pi. 2 - arcsin ( n
103 n 101 ) ) ) ( 1 ) ##EQU00001##
[0052] For example, in one embodiment, the first refractive index
n.sub.101 of the first refractive part 101 is between 1.51 and
2.10, the third refractive index n.sub.103 of the third refractive
part 103 is 1.5, and the angle a3 is between 12 and 83 degrees. As
shown in FIG. 10, the angle between the reflective surface 106a and
the reflective surface 106b is twice the angle a3, that is, the
angle between the two reflective surfaces is between about 24 and
166 degrees.
[0053] As shown in FIG. 11, the second reflective part 107 and the
first reflective part 106 in the present embodiment are disposed on
two opposite sides of the first opening O1, and they are presented
as symmetrically designed. It should be understood that the degrees
of inclination of the reflective surface 106a, the reflective
surface 106b, the reflective surface 107a, and the reflective
surface 107b can be adjusted according to actual needs, and thus it
is not limited to those shown in FIG. 10.
[0054] Finally, referring to FIG. 11, which illustrates a top view
of a light guide element 110 according to another embodiment of the
present disclosure. As shown in FIG. 11, the light guide element
110 is similar to the light guide element 100, and the difference
is that the first refractive part 111 and the second refractive
part 112 of the light guide element 110 respectively include a
plurality of refractive layers.
[0055] As shown in FIG. 11, the first refractive part 111 includes
a first refractive layer 1111, a second refractive layer 1112, and
a third refractive layer 1113. The first refractive layer 1111, the
second refractive layer 1112, and the third refractive layer 1113
are sequentially arranged in a direction away from the first
opening O1. The first refractive layer 1111 is adjacent to the
reflective ring 115. The second refractive layer 1112 surrounds the
first refractive layer 1111. The third refractive layer 1113
surrounds the second refractive layer 1112. In the present
embodiment, the first refractive layer 1111, the second refractive
layer 1112, and the third refractive layer 1113 may be made of
transparent refractive materials, such that the first refractive
layer 1111 has the refractive index n11, the second refractive
layer 1112 has the refractive index n12, and the third refractive
layer 1113 has the refractive index n13.
[0056] Similarly, the second refractive part 112 includes a first
refractive layer 1121, a second refractive layer 1122, and a third
refractive layer 1123. The first refractive layer 1121 is adjacent
to the reflective ring 115. The second refractive layer 1122
surrounds the first refractive layer 1121. The third refractive
layer 1123 surrounds the second refractive layer 1122. In the
present embodiment, the first refractive layer 1121, the second
refractive layer 1122, and the third refractive layer 1123 may be
made of transparent refractive materials, such that the first
refractive layer 1121 has the refractive index n11, the second
refractive layer 1122 has the refractive index n12, and the third
refractive layer 1123 has the refractive index n13. In other words,
in the present embodiment, the second refractive part 112 and the
first refractive part 111 are mirror-symmetrical to each other.
[0057] In the present embodiment, the refractive index n12 is
greater than the refractive index n13, and the refractive index n13
is greater than the refractive index n11. In other words, the
refractive indices of the first refractive layer 1111, the second
refractive layer 1112, and the third refractive layer 1113 are
different from each other. In the present embodiment, the
refractive index n11, the refractive index n12, and the refractive
index n13 are all greater than the third refractive index n3 of the
third refractive part 113. Therefore, when the light L is incident
on the first refractive part 111, the deflection is occurred at the
interface 111a. The degree of the deflection is various according
to the location where the light L enters.
[0058] Specifically, the greater the difference between the
refractive indices of two adjacent media is, the greater the degree
of deflection is. Therefore, by appropriately adjusting the
refractive indices of the first refractive layer 1111, the second
refractive layer 1112, and the third refractive layer 1113, the
amount of deflection of the light L incident with different angles
can be more accurately adjusted, so that most of the light L can be
transmitted to the fourth refractive part 114.
[0059] Furthermore, as shown in FIG. 11, the refractive indices of
the first refractive layer 1111, the second refractive layer 1112,
and the third refractive layer 1113 are different from each other.
Therefore, in addition to an interface 111b existed between the
third refractive layer 1113 and the external medium, there is an
interface 111c between the third refractive layer 1113 and the
second refractive layer 1112 inside the first refractive part 111
and there is an interface 111d between the second refractive layer
1112 and the first refractive layer 1111. The interface 111b, the
interface 111c, and the interface 111d may have the same or
different total reflection angles from each other. Since there are
a plurality of interfaces in the first refractive part 111, there
is more chance of generating total reflection during the traveling
of the light L in the first refractive part 111 to reach the fourth
refractive part 114 behind the first opening O1.
[0060] In the present embodiment, since the first refractive part
111 has a plurality of interfaces, the light L can be effectively
confined within the first refractive part 111. Since the second
refractive layer 1112 has the greater refractive index n12,
furthermore, most of the light L is confined within the second
refractive layer 1112. As a result, after most of the light L
enters the first refractive part 111 from the interface 111a, it
leaves the first refractive part 111 through the interface 111e
rather than leaving the interface 111b through the interface 111b
or entering the reflective ring 115. Therefore, in some
embodiments, it can remove the reflective ring 115 and still has a
good light guiding effect. In the embodiment in which the
reflective ring 115 is removed, the refractive index n11 of the
first refractive layer 1111, the refractive index n12 of the second
refractive layer 1112, and the refractive index n13 of the third
refractive layer 1113 may be greater than the refractive index
n.sub.air (approximately equal to 1) of the air in the first
opening O1, and thus it is further ensured that the light L is
unable to enter the first opening O1.
[0061] In the present embodiment, the first refractive part 111
includes three refractive layers. However, in some embodiments, the
first refractive part 111 may include two, four, or more refractive
layers. For example, the first refractive part 111 in FIG. 11 may
include only the first refractive layer 1111 and the second
refractive layer 1112 in which the refractive index n11 is smaller
than the refractive index n12, so that it also can prevents the
light L from entering the first opening O1.
[0062] As shown in FIG. 11, the vertical axis y at the connection
of the reflective surface 116a and the reflective surface 116b is
perpendicular to the first side 16a and the second side 16b. There
is an angle a4 between the reflective surface 116a and the vertical
axis y, and there is also an angle a4 between the reflective
surface 116b and the vertical axis y with opposite direction. In
the present embodiment, the following mathematical relationship (2)
between the angle a4, the refractive index n.sub.1112 of the second
refractive layer 1112 and the refractive index n.sub.1113 of the
third refractive layer 1113 is satisfied by:
a 4 > .pi. 2 - arcsin ( n 1112 n 1113 * sin ( .pi. 2 - arcsin (
n 1113 n 1112 ) ) ) ( 2 ) ##EQU00002##
[0063] As shown in FIG. 11, the second reflective part 117 and the
first reflective part 116 in the present embodiment are disposed on
two opposite sides of the first opening O1, and they are presented
as a symmetrical design. It should be understood that the degrees
of inclination of the reflective surface 116a, the reflective
surface 116b, the reflective surface 117a, and the reflective
surface 117b can be adjusted according to actual needs, and thus it
is not limited to those shown in FIG. 11.
[0064] As shown in FIG. 11, in the present embodiment, the first
refractive layer 1111, the second refractive layer 1112, and the
third refractive layer 1113 are all circular arcs, and the three
are concentric with each other. The first refractive layer 1111 has
a thickness t1, the second refractive layer 1112 has a thickness
t2, and the third refractive layer 1113 has a thickness t3.
[0065] Specifically, the thickness t1 refers to the difference
between the radius of curvature of the surface of the first
refractive layer 1111 close to the reflective ring 115 and the
radius of curvature of the surface of the first refractive layer
1111 away from the reflective ring 115. The thickness t2 refers to
the difference between the radius of curvature of the surface of
the second refractive layer 1112 close to the reflective ring 115
and the radius of curvature of the surface of the second refractive
layer 1112 away from the reflective ring 115. The thickness t3
refers to the difference between the radius of curvature of the
surface of the third refractive layer 1113 close to the reflective
ring 115 and the radius of curvature of the surface of the third
refractive layer 1113 away from the reflective ring 115. In the
present embodiment, the sum of the thickness t1, the thickness t2,
and the thickness t3 may be less than 5% of the inner diameter r1
of the first opening O1. It should be understood that the drawings
are not shown in the actual scale for explanation.
[0066] Various embodiments of the light guide element 162 in FIG. 4
have been described above with reference to FIG. 5 to FIG. 11. In
other words, the user can mount the light guide elements 50-110
shown in FIG. 5 to FIG. 11 in the backlight module 16 in FIG. 4.
However, in some embodiments, the light guide element 162 can be
integrally formed with the light guide plate 164.
[0067] The light guide element 50 illustrated in FIG. 5 is taken as
an example herein. The refractive indices of the third refractive
part 53 and the fourth refractive part 54 of the light guide
element 50 are the same as the refractive index of the light guide
plate 164, so that the third refractive part 53, the fourth
refractive part 54, and the light guide plate 164 can be integrally
formed with the same material. In such an embodiment, the first
refractive part 51 and the second refractive part 52 are disposed
on the light guide plate 164. Similarly, the first refractive parts
61-111 and/or the second refractive parts 62-112 of the light guide
elements 60-110 in FIG. 6 to FIG. 11 may be integrally formed with
the same material as the light guide plate 164.
[0068] To sum up, the electronic device provided in the present
disclosure has an opening located in the display area and the
camera module is disposed in the opening, and such design reduces
the area of the frame region required by the electronic device and
increases the display area correspondingly. On the other hand, the
electronic device provided in the present disclosure further
includes a specially designed backlight module for guiding the
light emitted by the light emitting element to be uniformly
distributed in the display area of the camera module relative to
one side of the light emitting element, so that the overall
brightness of the display area is uniform.
[0069] While various embodiments of the present invention have been
described above, it should be understood that they have been
presented by way of example only, and not limitation. Numerous
changes to the disclosed embodiments can be made in accordance with
the disclosure herein without departing from the spirit or scope of
the invention. Thus, the breadth and scope of the present invention
should not be limited by any of the above described embodiments.
Rather, the scope of the invention should be defined in accordance
with the following claims and their equivalents.
* * * * *