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Digital Camera Patent Abstract
A digital camera module (100) includes a barrel (10), a first lens
element (14), a spacer (19) and a second lens element (18). The
barrel defines a hole (102). The first lens element is received
in the hole. The spacer is received in the hole and is pressed against
the first lens element. The second lens element is received in the
hole and is pressed against the spacer. A glue space (20) is formed
between the first lens element and an inner periphery of the barrel
for allowing the first lens element, the spacer and the second lens
element to be fixed to the barrel.
Digital Camera Patent Claims
1. A digital camera module, comprising: a barrel defining a hole;
a first lens element being received in the hole; a spacer being
received in the hole and pressed against the first lens element;
and a second lens element being received in the hole and being pressed
against the spacer; wherein a glue space is formed between the first
lens element and the barrel for allowing the first lens element,
the spacer and the second lens element to be fixed to the barrel.
2. The digital camera module as claimed in claim 1, wherein the
hole is a stepped hole defined by an inner peripheral wall of the
barrel, the peripheral wall forms a step, and the first lens element
presses against the step.
3. The digital camera module as claimed in claim 1, wherein the
second lens element forms two plane surfaces, and the two plane
surfaces and the barrel cooperatively form the glue space.
4. The digital camera module as claimed in claim 1, further comprising
an aperture, the aperture is received in the hole of the barrel,
and presses against the first lens element opposite to the spacer.
5. The digital camera module as claimed in claim 4, further comprising
a filter, the filter is received in the hole of the barrel, and
presses against the aperture.
6. The digital camera module as claimed in claim 5, wherein the
hole is a stepped hole with a peripheral wall, the peripheral wall
forms a step, and the filter presses against the step.
7. A digital camera module, comprising: a barrel defining a hole
with an inner peripheral wall; and at least one optical element
of a lens element and an aperture being received in the barrel;
wherein a glue space is configured between the optical element and
the peripheral wall of the barrel for allowing the optical element
to be fixed to the barrel.
8. The digital camera module as claimed in claim 7, wherein the
at least one optical element includes a lens element received in
the hole, and the lens element forms two plane surfaces, the plane
surfaces and the peripheral wall of the barrel cooperatively form
the glue space.
9. The digital camera module as claimed in claim 7, wherein the
at least one optical element includes a first lens element, a spacer
and a second lens element, the first lens element, the spacer and
the second lens element are received in the hole, one of the first
lens element, the spacer, and the second lens element situated at
one end with the peripheral wall of the barrel forms the glue space.
10. The digital camera module as claimed in claim 9, wherein the
second lens element forms two plane surfaces, the two plane surfaces
and the barrel forms the glue space.
11. The digital camera module as claimed in claim 10, further comprising
an aperture, the aperture is received in the hole of the barrel,
and presses against the first lens element opposite to the spacer.
12. The digital camera module as claimed in claim 11, further comprising
a filter, the filter is received in the hole of the barrel, and
presses against the aperture.
13. A method of assembling a digital camera module, comprising
the steps of: providing a barrel, the barrel defining a hole; placing
a first lens element, a spacer and a second lens element in the
hole with the spacer being located between the first and second
lens elements; forming a space between the first lens element and
an inner periphery of the barrel; and dropping an adhesive means
into the space to fix the second lens element to the barrel.
14. The method as claimed in claim 13, wherein the adhesive means
is an ultraviolet glue, and the ultraviolet glue can be irradiated
with UV light so as to solidify the ultraviolet glue.
15. The method as claimed in claim 13, wherein the second lens
element forms two plane surfaces, the two plane surfaces and the
peripheral wall forms the glue space.
16. The method as claimed in claim 14, wherein the hole is a stepped
hole with a peripheral wall, the peripheral wall forms a step, and
the first lens element presses against the step.
Digital Camera Patent Description
TECHNICAL FIELD
[0001] The present invention relates generally to camera modules,
and more particularly, to a digital camera module for use in a portable
electronic device, such as a mobile phone or a personal digital
assistant (PDA), and also to a method of assembly.
BACKGROUND
[0002] With the development of wireless communication technologies,
increasing numbers of mobile phones and PDAs now include digital
cameras as a special feature.
[0003] Generally, digital cameras are image recording media capable
of photographing a plurality of still images without using film.
Such a digital camera typically uses an image pickup device, which
is a kind of semiconductor device, such as a charge coupled device
(CCD) or complementary metal oxide semiconductor (CMOS). In the
digital camera, an object image formed on the image pickup device
through a lens is converted into an electronic signal by the image
pickup device, and the electrical signal is stored as a digital
signal, for example, either in the camera unit or in a mobile phone
or PDA in which the digital camera is mounted. In such digital cameras,
a high performance digital camera module mounted with an image sensor
is in greatly increasing demand. In particular, a good image quality
for digital camera is desired. The method used for assembling a
digital camera module is one of factors which determine the image
quality. The method needs not only to satisfy large-scale production,
but also needs to maintain a clear and un-polluted image sensor
area.
[0004] A typical digital camera module includes a barrel, a first
lens element, a second lens element, a spacer, an aperture and a
filter. The first lens element, the second lens element, the spacer,
the aperture and the filter are received in the barrel. During assembly,
firstly, the first lens element, the spacer, the second lens element
and the aperture are placed in the barrel from a bottom-to-top in
that order. Then, an ultraviolet glue (UV) is applied at the connection
between the barrel and the aperture. After that, the filter is placed
in the barrel, and pressed against the aperture. Finally, the UV
glue is irradiated with UV light so as to solidify it and the filter
is thus fixed in the barrel and the camera module elements are assembled
together. However, with this method of assembly it is not easy to
control the quantity of the glue used, and in addition, if the force
pressing on the filter is not uniform, the glue might leak so as
to effect the image quality.
[0005] Therefore, a digital camera module and an assembling method
thereof is desired in order to overcome the above-described shortcomings.
SUMMARY
[0006] In one aspect, a digital camera module includes a barrel,
a first lens element, a spacer and a second lens element. The barrel
defines a hole. The first lens element is received in the hole.
The spacer is received in the hole and is pressed against the first
lens element. The second lens element is received in the hole and
is pressed against the spacer. A glue space is formed between the
first lens element and the barrel for allowing the first lens element,
the spacer and the second lens element to be fixed to the barrel.
[0007] In another aspect, a method of assembling a digital camera
module includes the steps of: providing a barrel defining a hole;
placing a first lens element, a spacer and a second lens element
in the hole; forming a space between the first lens element and
an inner periphery of the barrel; and applying an adhesive means
in the space to fix the second lens element to the barrel.
[0008] 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
[0009] 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 drawn to scale, the emphasis
instead being placed upon clearly illustrating the principles of
the digital camera module. Moreover, in the drawings, like reference
numerals designate corresponding parts throughout the several views.
[0010] FIG. 1 is a cut-away view of an embodiment of a digital
camera module;
[0011] FIG. 2 is an isometric view of one embodiment of a second
lens element of the digital camera module;
[0012] FIG. 3 is an isometric view of another embodiment of a second
lens element of a digital camera module; and
[0013] FIG. 4 is an isometric view of another embodiment of a second
lens element of a digital camera module.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0014] Referring now to the drawings, FIG. 1 shows a digital camera
module 100, according to a preferred embodiment. The digital camera
module 100 is adapted for use in a portable electronic device such
as a mobile phone or a personal digital assistant (PDA), but its
compact nature could also prove useful in compact digital camera
units, digital camcorders or in regular film cameras. The digital
camera module 100 includes a barrel 10, a filter 12, an aperture
13, a first lens element 14, a second lens element 18 and a spacer
19.
[0015] The barrel 10 is substantially cylindrical, and defines
a stepped hole 102 in a central area. The stepped hole 102 communicates
with two open ends of the barrel 10. The barrel 10 has an inner
peripheral wall, and a step 104 is formed adjacent to one end of
the barrel 10.
[0016] The filter 12 is made of optical glass. At least one surface
of the filter 12 is coated with an IR-cut coating. The IR-cut coating
can filter out incoming infrared rays so as to improve image quality.
[0017] The aperture 13 is used for controlling the amount of light
entering into the digital camera module 100. The aperture 13 may
be widened or narrowed so as to adjust the quantity of light.
[0018] The first lens element 14 and the second lens element 18
are substantially disk shaped. Such aspheric lens elements are relatively
easy to make. Furthermore, the overall weight of the lens elements
is light and, the lens elements are not easily damaged if they are
subjected to shock, such as being dropped to the ground.
[0019] Referring to FIG. 2, one structure of the second lens element
18 symmetrically forms four plane surfaces 182 at a periphery. Referring
to FIG. 3, another structure of the second lens element 18 symmetrically
forms two opposite plane surfaces 182. Referring to FIG. 4, another
structure of the second lens element 18 symmetrically forms two
opposite plane surfaces 184. Each plane surface 182 only communicates
with one side thereof. The above plane surfaces together with the
peripheral wall of the barrel 10 may form a glue space 20 so as
to allow the second lens element 18 to be fixed in the barrel 10.
[0020] The spacer 19 is made of metal and is used for adjusting
the distance between the first lens element 14 and the second lens
element 18 so as to avoid interference between lens elements.
[0021] A method of assembling the digital camera module includes
the following steps where firstly placing the filter 12 in the stepped
hole 102 of the barrel 10. Then filter 12 is pressed against the
step 104 of the barrel 10. Secondly, the aperture 12, the first
lens element 14, the spacer 19 and the second lens element 18 are
placed in the stepped hole 102 of the barrel 10 in that order. The
plane surfaces 182 or 184 and the peripheral wall of the barrel
10 cooperatively define a glue space 20. Finally, an ultraviolet
glue (UV) is dropped into the glue space 20, and the ultraviolet
glue is irradiated with UV light so as to solidify the ultraviolet
glue. The second lens element 18 is thus fixed in the barrel and
assembly is completed.
[0022] A main advantage of the digital camera module 100 is that
the glue space 20 can reduce overflow, and, as the second lens element
18 has a non-circular shape, not only is the size of the glue space
between the second lens element 18, the spacer and the barrel 10
increased, but also the bonding force between them is strengthened.
Accordingly, the reliability of the digital camera module 100 is
improved.
[0023] In alternative embodiments, the second lens element may
be replaced with other structure such as an ellipse shape, rectangular
or non-circular so as to provide the glue space.
[0024] In another alternative embodiment, the optical element arrangement
of the first lens element, the filter, the aperture, the spacer
and the second lens element may be changed, with only one optical
element being provided with a glue space.
[0025] In other alternative embodiments, the stepped hole 102 may
be omitted, and the optical elements located at two ends of the
barrel can be fixed by adhesive means.
[0026] As described above, the preferred embodiment provides a
digital camera module 100 for devices such as mobile phones, which
has both simplicity and ease of use. It is, however, to be understood
that the digital camera module 100 could potentially be useful in
other applications in which it may be desirable to allow incoming
light to be adjusted so as to attain a clear image.
[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. |