|
Digital Camera Patent Abstract
A digital camera module includes a first barrel (10), a second barrel
(20), a beam splitter (30), an IR-cut filter (40) and an image sensor
(50). The first barrel receives a first lens element group (12)
therein. The second barrel receives a second lens element group
(22). The beam splitter is located between the first lens element
group and the second lens element group. The presence of the beam
splitter may effectively facilitate a decrease in the thickness
needed to fit an optical path of a required length (to accommodate
optics necessary for high resolution) within a mobile electronic
device (e.g., phone, PDA), allowing a portion of the optical path
to be positioned in the longer, vertical direction of the device
body. This digital camera facilitates the miniaturization of a portable
electronic device.
Digital Camera Patent Claims
1. A digital camera module having an optical path, the digital camera
module comprising: a first barrel receiving a first lens element
group therein; a second barrel receiving a second lens element group
therein, the second barrel connecting with the first barrel at an
angle; and a reflection apparatus located between the first lens
element group and the second lens element group; and an image sensor
disposed within the optical path after the second lens element group,
the image sensor being fixed relative to the second barrel.
2. The digital camera module as claimed in claim 1, wherein the
reflection apparatus is one of a beam splitter, a mirror, and a
prism.
3. The digital camera module as claimed in claim 2, wherein the
reflection apparatus is a beam splitter.
4. The digital camera module as claimed in claim 1, further comprising
an IR-cut filter, the IR-cut filter being positioned between the
second lens element group and the image sensor.
5. The digital camera module as claimed in claim 1, further comprising
a glass board, the glass board being located, relative to the optical
path, before the first lens element group and covering one end of
the first barrel.
6. The digital camera module as claimed in claim 1, wherein the
second barrel comprises a housing portion, a connection portion
and a bottom board, the connection portion connecting with the first
barrel.
7. The digital camera module as claimed in claim 6, wherein the
reflection apparatus is located in the connection portion.
8. The digital camera module as claimed in claim 6, wherein the
image sensor is positioned on the bottom board.
9. A digital camera having an optical path, the digital camera
comprising: a first barrel receiving a first lens element group
therein, the first lens element group being within the optical path;
a second barrel receiving a second lens element group therein, the
second barrel connecting with the first barrel at an angle, the
second lens element group being within the optical path, the second
lens element group being positioned after the first lens element
group with respect to the optical path; a light redirection apparatus,
the light redirection apparatus located between the first lens element
group and the second lens element group; and an image sensor being
located behind the second lens element group, relative to the optical
path.
10. The digital camera as claimed in claim 9, wherein the light
redirection apparatus is one of a beam splitter, a mirror, and a
prism.
11. The digital camera as claimed in claim 9, wherein the light
redirection apparatus is a beam splitter.
12. The digital camera as claimed in claim 9, further comprising
an IR-cut filter, the IR-cut filter behind the second lens elements
group and before the image sensor, relative to the optical path.
13. A portable electronic device comprising: a body including an
optical opening and a body cavity therein; a digital camera module
being secured at the optical opening and within the body cavity,
the digital camera module having an optical path associated therewith,
the digital camera module comprising: a first barrel receiving a
first lens element group therein, the first barrel being secured
proximate the optical opening of the body, the optical path beginning
at the optical opening; a second barrel receiving a second lens
element group therein, the second barrel connecting with the first
barrel at an angle; a light redirection apparatus located between
the first lens element group and the second lens element group,
the light redirection apparatus being configured for providing a
change in direction within the optical path of the digital camera
module; and an image sensor positioned behind the second lens element
group, relative to the optical path of the digital camera module,
the image sensor being electronically coupled with the display.
14. The portable electronic device as claimed in claim 13, wherein
the body includes a display on a first side thereof and the optical
opening in a second side thereof.
15. The portable electronic device as claimed in claim 13, wherein
the portable electronic device is a mobile phone.
Digital Camera Patent Description
BACKGROND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to digital camera modules
and, particularly, to a thin digital camera module and a mobile/cellular
phone using the thin digital camera module.
[0003] 2. Discussion of the Invention
[0004] In recent years, digital cameras have been rapidly becoming
widespread. Such digital cameras convert an optical image to electronic
signals by using an image sensor such as a charge coupled devices
(CCD) or a complementary metal-oxide semiconductor (CMOS) sensor
instead of silver halide film, convert the data to digital form,
and record or transfer the digitized data. In such digital cameras,
since a CCD and a CMOS sensor each have high number of pixels (about
between two million pixels and three million pixels), a high performance
digital camera module mounted with an image sensor is in greatly
increasing demand. In particular, a compact digital camera is desired.
Further, in recent years, digital cameras have been becoming incorporated
in or externally attached to personal computers, web cams, mobile
computers, mobile telephones, PDAs and the like, which further spurs
the demand for a thin digital camera.
[0005] The conventional digital camera includes a barrel and an
image sensor. Several lens elements are secured in the barrel. The
image sensor is located behind the lens elements. The lens elements
and the image sensor are disposed on the same optical axis. Accordingly,
a thickness of digital camera greatly depends on a thickness of
the module, in the optical axis direction. In order to decrease
the thickness of the digital camera, the axis-direction thickness
has been decreased by means of decreasing the number of lens elements.
However, a good image quality is still desired, even under the condition
of reduction of the number of lens elements to reduce the module
thickness. For a low-resolution digital camera, fewer lens elements
indeed may be employed, thereby reducing the thickness of digital
camera. Nevertheless, in order to achieve the resolution level desired
for high-resolutions digital camera (e.g., about eight mega pixels),
the full complement of lens elements is needed to satisfy some requirements
so as to secure a better image quality. Thus, with the increasing
digital camera's pixel requirements, the axis-direction thickness
of previously-available digital cameras have increased accordingly.
As such, digital cameras with lens elements aligned along a single
axis cannot effectively satisfy the requirement of miniaturization.
[0006] Therefore, a thin digital camera module is desired in order
to overcome the above-described shortcomings.
SUMMARY OF THE INVENTION
[0007] A thin digital camera module is provided, which may be incorporated
in or externally attached to portable electronic devices such as
mobile computers, PDAs, mobile phones, etc.
[0008] The digital camera module is suitable for a digital camera
in a foldable electronic device. A preferred embodiment of the digital
camera module includes a first barrel, a second barrel, and a reflection
apparatus. The first barrel receives a first lens element group
therein. The second barrel receives a second lens element group
therein, and the second barrel connects with the first barrel in
a range of angles. The reflection apparatus is located between the
first lens element group and the second lens element group. The
effective thickness of the digital camera may be decreased. This
thickness decrease is achieved by providing two optical axis directions,
instead of only one, to accommodate all the desired lens elements.
[0009] Other advantages and novel features will become more apparent
from the following detailed description when taken in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Many aspects of the digital camera module can be better
understood with reference to the following drawings. The components
in the drawings are not necessarily to scale, the emphasis instead
being placed upon clearly illustrating the principles of the present
digital camera module and its potential applications. Moreover,
in the drawings, like reference numerals designate corresponding
parts throughout the several views.
[0011] FIG. 1 is a cut-away view of a digital camera according
to one embodiment;
[0012] FIG. 2 is a top plan view of a mobile phone according to
another embodiment; and
[0013] FIG. 3 is a cross-sectional view taken along line III-III
of FIG. 2, showing a digital module used in the mobile phone.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0014] Referring now to the drawings in detail, FIG. 1 shows a
digital camera 100 in accordance with one embodiment. A system of
coordinates is defined in FIG. 1. The system of coordinates includes
an x-axis and a z-axis, perpendicular to each other.
[0015] The digital camera 100 generally includes a first barrel
10, a second barrel 20, a reflection or light-redirection apparatus
(beam splitter 30, as illustrated), an IR-cut filter 40, and an
image sensor 50.
[0016] The first barrel 10 is substantially a hollow cylinder.
A first lens elements group 12 is received in the first barrel 10.
The first lens elements group 12 is made up of several lens elements
(not individually labeled), and the first lens elements group 12
firstly receiving light rays which enter from the outside. The first
barrel 10 is aligned in the z-axis direction. Also disposed in the
first barrel 10 is a glass board 14. The glass board 14 is disposed
before the first lens elements group 12 and covers one end of the
first barrel 10. As such, the glass board 14 protects the first
lens elements group 12 from potentially being scraped or otherwise
abraded and keeps dust from entering the system.
[0017] The second barrel 20 has a second lens elements group 22
mounted therein. The second lens elements group 22 is made up of
several lens elements (not individually labeled). The second barrel
20 includes a housing portion 24, a connection portion 26, and a
bottom board 28. The housing portion 24 is aligned in the x-axis
direction, and the second lens elements group 22 is received in
the housing portion 24. Thereby, an optical axis of the first lens
element group 12 is perpendicular to an optical axis of the second
lens element group 22. The connection portion 26 is disposed at
one end of the housing portion 24, and one end of the connection
portion 26 correspondingly communicates with the housing portion
24. One opposite end of the connection portion 26 connects with
the first barrel 10 by means of screw thread, the opposite end of
the connection portion 26 connecting and communicating with the
first barrel 10. A bottom board 28 is disposed in another opposite
end of the housing portion 24.
[0018] The beam splitter 30 is secured in the second barrel 20
and is located in the connection portion 26 of the second barrel
20. The beam splitter 30 may reflect light rays from the first lens
elements group 12 to the second lens elements group 22. An optical
path 31 of digital camera 100 is illustrated by a set of orthogonal
lines. Essentially, the reflection or light redirection apparatus
(e.g., beam splitter 30) provides for a change in direction within
the optical path 31. The angle of the optical path 31, while illustrated
as orthogonal, can potentially take on any of a range of angles
between 0.degree. and 180.degree. (not inclusive), depending on
the positioning of the reflection or light redirection apparatus
30. An angle of approximately 90.degree. (e.g., .+-.10.degree.)
does offer the advantage of a reduced potential for image distortion.
However, depending on space requirements for camera module 100,
other angles may prove more suitable (for example, if the angle
between barrels 10 and 20 must be chosen differently), with potential
distortion being minimized by methods known in the imaging art.
[0019] The IR-cut filter 40 is situated behind the second lens
element group 22, so as to protect the image sensor 50. At least
one surface of the IR-cut filter 40 is coated with an IR-cut coating.
The IR-cut coating can filtrate infrared rays from the air so as
to improve the image quality.
[0020] The image sensor 50 is usually a charge-coupled device (CCD)
or a complementary metal-oxide semiconductor (CMOS). The image sensor
50 is located behind the IR-cut filter 40 and is fixed on the bottom
board 28 of the second barrel 20. The image sensor 50 may transfer
light signals to electronic signals.
[0021] In operation, the light rays reflected from an image object
(not shown) pass through the first lens elements group 12. The first
lens elements group 12 focuses the light rays, and focused light
passes through the beam splitter 30. The beam splitter 30 will lead
(i.e., redirect) the light rays to the second lens elements 22.
After that, the light rays pass through the IR-cut filter 40, and
the infrared rays are filtered therefrom. At the end, the light
rays arrive at the image sensor 50. The image sensor 50 will transfer
the light signal to an electronic signal, permitting the storage
of the image information in a memory of the digital camera. As such,
the photographic process is finished. If the image should not prove
to be clear enough (i.e., out of focus), the user may adjust the
first barrel 10 by hand, thereby changing the focal distance between
the first barrel 10 and the second barrel 20.
[0022] In another embodiment, the digital camera can advantageously
be used in portable electronic devices such as mobile phones. Referring
to FIG. 2 and FIG. 3, the mobile phone 60 includes a body 61 and
incorporates a digital camera 200. One end of the body 61 disposes
a display 62, while another opposite end of the body 61 has a keypad
63 disposed thereon. A printed circuit board 68 is housed in the
body 61 of the mobile phone 60. An optical opening 66 is defined
in a middle of the body 61 of the mobile phone 60, in the side opposite
to the side carrying the display 62 of the mobile phone 60. The
body 61 has a body cavity 67 therein. A digital camera 200 is secured
at or at least proximate optical opening 66 within the body cavity
67, such that light can enter through optical opening 66 and into
digital camera 200 (specifically first barrel 10). Accordingly,
the optical opening 66 is within the optical path (not labeled in
FIG. 3) of the digital camera 200.
[0023] The digital camera 200 is mostly the same with the digital
camera 100 of the first embodiment. A different point is that the
digital camera 200 deletes the bottom board 28 and makes one end
of the second barrel 20 open, since the digital camera 200 is already
contained within body 61. The image sensor 50 will connect with
the printed circuit board 68 of the mobile phone 60 through lead
lines (in the form of wires, printed circuitry, pin connectors,
etc., depending on the system configuration). The embodiment of
the invention may fully use the x-axis direction space and greatly
decrease the z-axis height, which would help satisfy the requirement
of the camera miniaturization for the portable electronic device.
[0024] In still further alternative embodiments, the first barrel
10 is connected with the second barrel 20 at any of a variety of
angles, between 0.degree. and 180.degree., not inclusive. The first
barrel 10 and the second barrel 20 may be molded together as a whole
during manufacture (molding offers the advantage of simplified manufacture
but eliminates the opportunity of manual focus). Alternatively,
the first barrel 10 may be fixed relative to the second barrel 20
by means of a glue or other adhesive or by a plastic welding procedure.
The connection portion 24 may be separate from the second barrel
20, making both ends of the second barrel 20 open. The end opposite
to the bottom board 28 could connect the connection portion 26 by
means of screw thread, which may allow adjustment of the x-axis
distance (i.e., facilitate focusing).
[0025] In a still further alternative embodiment, the beam splitter
10 may be replaced by another reflection apparatus such as a mirror
or a prism.
[0026] In a still further alternative embodiment, the optical opening
66 for receiving the digital camera module may be defined in other
positions of the mobile phone.
[0027] It is believed that the present embodiments and their advantages
will be understood from the foregoing description, and it will be
apparent that various changes may be made thereto without departing
from the spirit and scope of the invention or sacrificing all of
its material advantages, the examples hereinbefore described merely
being preferred or exemplary embodiments of the invention.
|