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Digital Camera Patent Abstract
A digital camera module (100) with a focusing function includes
a holder, an image sensor package (30) and a wedge (60). The holder
has several lens elements (16) received therein. The image sensor
package is movably received in the holder. The wedge is inserted
into the holder and resists the image sensor package so that when
the wedge is pushed, the image sensor is caused to slide axially
relative to the holder.
Digital Camera Patent Claims
1. A digital camera module, comprising: a holder having at least
one lens element received therein; an image sensor package movably
received in the holder; and a wedge, the wedge inserted into the
holder and resisting the image sensor package so that when the wedge
is moved, the image sensor package is caused to slide axially relative
to the holder.
2. The digital camera module as claimed in claim 1, wherein the
holder defines a cutout, the wedge is received in the cutout.
3. The digital camera module as claimed in claim 1, further comprising
a base board, the holder is mounted on the base board, and the wedge
slides on the base board.
4. The digital camera module as claimed in claim 1, wherein the
holder includes a barrel and a sleeve, the barrel receives the at
least one lens element, and the sleeve is fixed on the base board.
5. The digital camera module as claimed in claim 1, further comprising
a driving mechanism for driving the wedge to move, and the driving
mechanism is disposed at one side of the wedge opposite to the holder.
6. The digital camera module as claimed in claim 5, wherein the
driving mechanism includes a gear and a rack, the rack resists the
wedge, and the gear meshes with the rack to drive the wedge to move.
7. The digital camera module as claimed in claim 6, wherein the
driving mechanism further comprises a step motor, and the step motor
drives the gear to rotate.
8. The digital camera module as claimed in claim 3, further comprising
a return spring, one end of the return spring is fixed on the base
board, the opposite end of the return spring is fixed under the
image sensor package, and the return spring draws the image sensor
package toward the base board.
9. The digital camera module as claimed in claim 3, wherein a stopper
is disposed between the return spring and the wedge so as to limit
the displacement range of the wedge.
10. A digital camera module, comprising: a holder; a holder and
an image sensor apparatus, one of the holder and the image sensor
apparatus being fixed relative to a base, the holder and the image
sensor being slidably connected with each other; and a wedge, the
wedge sliding on the base so as to cause one of the holder or the
image sensor apparatus to slide relative to the other.
11. The digital camera module as claimed in claim 10, wherein the
holder is attached to the base.
12. The digital camera module as claimed in claim 11, wherein the
holder includes a barrel, the barrel defines a cutout, and the wedge
is received in the cutout.
13. The digital camera module as claimed in claim 10, further comprising
a driving mechanism for driving the wedge to move, and the driving
mechanism is disposed at one side of the wedge opposite to the holder.
14. The digital camera module as claimed in claim 13, wherein the
driving mechanism includes a gear and a rack, the rack resists the
wedge, and the gear meshes with the rack to drive the wedge to move.
15. The digital camera module as claimed in claim 14, wherein the
driving mechanism further comprises a step motor, the step motor
drives the gear to rotate.
16. The digital camera module as claimed in claim 14, further comprising
a limiting structure, the limiting structure includes a first stopper
and a second stopper, the first stopper is disposed at one side
of the rack opposite to the holder so as to limit the displacement
range of the rack, and the second stopper is disposed at one side
of the wedge opposite to the rack so as to limit the displacement
range of the rack.
17. A digital camera, comprising: a holder; an image sensor apparatus
axially movably received in the holder; and a resisting element
with a slope, the slope resisting the image sensor apparatus; wherein
when the resisting element is horizontally moved, the image sensor
apparatus is axially moved relative to the holder.
18. The digital camera as claimed in claim 17, further comprising
a base board, the holder is mounted on the base board, and the resisting
element slides on the base board.
19. The digital camera as claimed in claim 17, further comprising
a driving mechanism for driving the resisting element to move, and
the driving mechanism is disposed at one side of the resisting element
opposite to the holder.
Digital Camera Patent Description
TECHNICAL FIELD
[0001] The present invention relates generally to a camera module
with a focusing function, and more particularly, to a small-sized
digital camera module with a focusing function and to a portable
electronic device, such as a mobile phone or a personal digital
assistant (PDA), having such a camera module mounted therein.
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.
[0004] Since the digital camera is to be mounted in a small mobile
phone or PDA, a fixed focus lens module is usually used to facilitate
mounting thereof. However, images photographed by a digital camera
module with a fixed focus lens module tend to be of poor quality.
This is partly due to the fixed focus lens, which is incapable of
adjusting distance between the lens and the image pickup device
to make a clearer image when photographing objects at different
distances from the camera.
[0005] A typical focusing structure has a focusing adjusting apparatus
using a thread structure, which includes a lens module and a base.
The base includes an image sensor. When adjusting focus, the lens
module needs to be extensible or compressible relative to the base
so that the distance between the lens module and the image sensor
is changed. Therefore, a space above/over the lens module is required
in order to provide the movement space. Furthermore, the lens module
will rotate relative to the base at work. This structure causes
eccentricity problems so as to effect the image quality.
[0006] Therefore, a digital camera with a focusing function is
desired in order to overcome the above-described shortcomings.
SUMMARY
[0007] In one embodiment thereof, a digital camera module with
a focusing function includes a holder, an image sensor package and
a wedge. The holder has at least one lens element received therein.
The image sensor package is movably received in the holder. The
wedge is inserted into the holder and resists the image sensor package
so that when the wedge is pushed, the image sensor is caused to
slide axially relative to the holder.
[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 DRAWING
[0009] Many aspects of the digital camera module with the focusing
function can be better understood with reference to the following
drawing. The components in the drawing are not necessarily drawn
to scale, the emphasis instead being placed upon clearly illustrating
the principles of the digital camera module with the focusing function.
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 with a focusing function.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0011] Referring now to the drawings, FIG. 1 shows a digital camera
module 100 with a focusing function, 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 the compact nature thereof could prove useful in compact digital
camera units, digital camcorders or regular film cameras as well.
The digital camera module 100 includes a barrel 10, a sleeve 20,
an image sensor package 30, a base board 40, a return spring 50,
a wedge 60, a driving mechanism 70 and a limiting structure 80.
[0012] The barrel 10 includes a flange 12 and a barrel body 14
formed together. The flange 12 is formed at a top end of the barrel
body 14. The flange 12 has a through hole 13 defined in a middle
thereof The barrel body 14 is a hollow cylinder, and the through
hole 13 communicates with the barrel body 14 so that light beams
can be transmitted therethrough. The barrel body defines an outer
thread 15 at an outer periphery wall thereof. Several lens elements
16 are disposed in the barrel body 14, and receive light beams that
enter from the outside.
[0013] The sleeve 20 is a substantially hollow cylinder with two
open ends so that light beams can be transmitted therethrough. One
open end of the sleeve 20 receives the barrel 10, the opposite end
of the sleeve 20 defines a cutout 22 at one sidewall thereof. An
axis of the sleeve 20 aligns with a center of the image sensor package
30 such that the sleeve 20 is capable of routing the input light
beams. The sleeve 20 has an inner periphery wall 24 thereof and
a thread wall 26 connected with each other. A diameter of the inner
periphery wall 24 is larger than a diameter of the thread wall 26.
The outer thread 15 of the barrel body 14 engages with the thread
wall 26 of the sleeve 20 so that the barrel 10 may be received in
the sleeve 20 and mounted relative to the sleeve 20 by means of
thread structure.
[0014] The image sensor package 30 is received in one open end
of the sleeve 20 opposite to the barrel 10, and may slide relative
to the sleeve 20. The image sensor package 30 includes a carrier
32, an image sensor chip 34 and a cover 36. The carrier 32 is a
hollow cylinder with an open end and a closed end, and is formed
by plastic. The image sensor chip 34 is received in the carrier
32, and is adhered to the bottom of the carrier 32 via an adhesive
means. The image sensor chip 34 can be a charge-coupled device (CCD)
or a complementary metal-oxide semiconductor (CMOS). The cover 36
is transparent and is laid over the image sensor chip 34 which receives
light transmitted through the cover 36. The cover 36 is adhered
on the carrier 32 by adhesive means and therefore seals the image
sensor chip 34 in the carrier 32. The image sensor chip 34 may convert
the optical image data of an object into electronic signals. The
image sensor chip 34 is sealed in a package so as to protect the
image sensor chip 34 from contamination or pollution (i.e. from
dust or water vapor).
[0015] The base board 40 is mounted under the sleeve 20 for supporting
the sleeve 20. One end of the return spring 50 is mounted on a bottom
of the image sensor package 30, the opposite end of the return spring
50 is fixed on the base board 40. The return spring 50 is in a stretched
state, and always has a tendency of drawing the image sensor package
30 toward the base board 40. The wedge 60 is disposed on the base
board 40, and is received in the cutout 22 of the sleeve 20. The
wedge 60 includes a slope 62, which resists the image sensor package
30. The wedge 60 may move horizontally, and the image sensor package
30 may move vertically along the axis of the barrel 10 under the
role of the wedge 60.
[0016] The driving mechanism 70 is disposed on the base board 40,
and is located at one side of the wedge 60. The driving mechanism
70 includes a step motor 72, a gear 74 and a rack 76. The rack 76
may slide on the base board 40. The step motor 72 may drive the
gear 74 to rotate relative to the step motor 72. The gear 74 may
further drive the rack 76 to move horizontally. The rack 76 pushes
the wedge 60 to move so that the distance between the image sensor
package 30 and the barrel 10 may be automatically adjusted.
[0017] The limiting structure 80 includes a first stopper 82 and
a second stopper 84. The first stopper 82 is mounted on the base
board 40, and is spaced from the rack 76. The first stopper 82 may
limit the displacement of the rack 7 so as to avoid the rack 76
exceeding the predetermined range. The second stopper 84 is disposed
between the wedge 60 and the return spring 50. The second stopper
84 is substantially a short cylinder, and may limit the movement
range of the wedge 60.
[0018] In assembly, one end of the return spring 50 is mounted
on the base board 40, the other end of the return spring 50 is fixed
on the image sensor package 30. Then, the barrel 10 is inserted
into the sleeve 20 from one end thereof, with the flange 12 located
outside the sleeve 20. One end of the sleeve 20 opposite to the
barrel 10 is fixed on the base board 40 by means of adhesion and/or
welding, and surrounds the image sensor package 30. The image sensor
chip 34 aligns with the axis of the barrel 10. After that, the wedge
60 is inserted into the cutout 22 of the sleeve 20. The rack 76
is situated adjacent to the wedge 60. The gear 74 is located on
the rack 76 and meshes each other. Finally, the gear 74 is also
connected with the step motor 72.
[0019] In use, the digital camera module 100 is fitted within a
portable electronic device, such as a mobile phone, and the image
sensor is electrically connected with a circuit board of the mobile
phone for receiving power. When taking pictures, the light reflected
from an image object (not shown) pass through the lens elements.
The lens elements focus the light, after which the light arrives
at the image sensor chip 34. The image sensor chip 34 transforms
the light signal into 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 prove
not to be clear enough (i.e. out of focus), the user may move the
rack 76 by hand forward or backward. The rack 76 further enables
the wedge 60 to move horizontally. The wedge 60 causes the image
sensor package 30 to slide axially relative to the sleeve 20 up
and down. Accordingly, the distance between the barrel 10 and the
image sensor chip 34 is changed, thereby resulting in the stable
telescopic movement of the barrel 10. The image distance is changed
so that a distant object can be imaged in the image sensor. When
the image becomes clear, the image sensor package 30 stops sliding.
The barrel 10 is kept in the focusing position because of the limitation
influence of the rack 76. Thus, the focusing purpose is achieved
by changing the distance between the image sensor 34 and the barrel
10. If accurate control is needed, the step motor 72 may be activated.
The step motor 72 further drives the gear 74 to rotate so as to
cause the rack 76 to move. In this way, the image sensor package
30 can be precisely controlled to move to the required position.
The return spring 50 helps the image sensor package 30 to move downwards
so as to avoid the image sensor package 30 becoming stuck in the
sleeve 20. The first stopper 82 and the second stopper 84 may limit
the displacement range of the rack 76 and the wedge 60.
[0020] A main advantage of the digital camera module 100 with a
focusing function is that the wedge 60 drives the telescopic movement
of the image sensor package 30. The focusing operation of the digital
camera module 100 is simple. In addition, the digital camera module
100 may be conveniently operated by manual or mechanical means.
[0021] In alternative embodiments, two wedges 60 may be located
at two sides of the sleeve 20 so as to provide the uniform forces
to drive the image sensor package 30 to slide axially. The wedge
may be replaced with a resisting element with a slope so as to change
the distance between the image sensor package and the sleeve.
[0022] In a still further alternative embodiment, the driving mechanism
70 may be an piezoelectric element. The piezoelectric material may
lengthen or shorten under the influence of an electric field. The
wedge 60 may be driven by the piezoelectricity element so as to
change the distance between the image sensor package 30 and the
barrel 10.
[0023] In a still further alternative embodiment, the driving mechanism
70 may be omitted, and the wedge 60 can be directly pushed by hand.
The barrel 10 and the sleeve 20 together may be acted as a holder
to receive the image sensor package. Understandably, the sleeve
20 may be omitted, and the holder only has a barrel with directly
mounted on the base board 40. Alternatively, the barrel 10 may be
omitted, the holder only has a sleeve. The lens elements are disposed
in the sleeve, and the sleeve is mounted on the base board.
[0024] As described above, the preferred embodiment provides a
digital camera module 100 with a focusing function 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.
[0025] 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. |