U.S. patent application number 15/377949 was filed with the patent office on 2018-05-03 for optical lens set.
The applicant listed for this patent is Genius Electronic Optical Co., Ltd.. Invention is credited to Jinhui Gong, Huabin Liao, Hai Lin.
Application Number | 20180120539 15/377949 |
Document ID | / |
Family ID | 58972607 |
Filed Date | 2018-05-03 |
United States Patent
Application |
20180120539 |
Kind Code |
A1 |
Gong; Jinhui ; et
al. |
May 3, 2018 |
OPTICAL LENS SET
Abstract
An optical-lens-set includes a first lens element of positive
refractive power, a second lens element of an image surface with a
concave portion near the optical-axis, no air gap between a third
lens element and a fourth lens element, at least one of an object
surface and an image surface of a fifth lens element being
aspherical, both an object surface and an image surface of a sixth
lens element being aspherical so that the total thickness ALT of
all six lens element, the distance TL from an object surface of the
first lens element to the image surface of the sixth lens element
and total five air gaps AAG satisfy ALT/AAG.ltoreq.4.5 or
TL/AAG.ltoreq.5.5.
Inventors: |
Gong; Jinhui; (Xiamen,
CN) ; Lin; Hai; (Xiamen, CN) ; Liao;
Huabin; (Xiamen, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Genius Electronic Optical Co., Ltd. |
Taichung City |
|
TW |
|
|
Family ID: |
58972607 |
Appl. No.: |
15/377949 |
Filed: |
December 13, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 5/005 20130101;
G02B 9/62 20130101; G02B 13/0045 20130101; G02B 27/0025
20130101 |
International
Class: |
G02B 13/00 20060101
G02B013/00; G02B 5/00 20060101 G02B005/00; G02B 27/00 20060101
G02B027/00; G02B 9/62 20060101 G02B009/62 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 2, 2016 |
CN |
201610948407.6 |
Claims
1. An optical imaging lens set, from an object side toward an image
side in order along an optical axis comprising: a first lens
element, a second lens element, a third lens element, a fourth lens
element, a fifth lens element and a sixth lens element, said first
lens element to said sixth lens element each having an object-side
surface facing toward the object side as well as an image-side
surface facing toward the image side, wherein: said first lens
element has positive refractive power; said second lens element has
an image-side surface with a concave portion in a vicinity of said
optical-axis; no air gap between said third lens element and said
fourth lens element; at least one of said object-side surface and
said image-side surface of said fifth lens element is aspherical;
and both said object-side surface and said image-side surface of
said sixth lens element are aspherical; the optical imaging lens
set exclusively has six lens elements with refractive power, TL is
a distance between said object-side surface of said first lens
element and said image-side surface of said sixth lens element
along said optical axis and AAG is a sum of all five air gaps
between each lens elements from said first lens element to said
sixth lens element along said optical axis to satisfy
TL/AAG.ltoreq.5.5.
2. The optical imaging lens set of claim 1, wherein .upsilon.3 is
an Abbe number of said third lens element and .upsilon.4 is an Abbe
number of said fourth lens element to satisfy
16.ltoreq..upsilon.3-.upsilon.4.ltoreq.50.
3. The optical imaging lens set of claim 1, wherein said first lens
element has a first lens element thickness T.sub.1 along said
optical axis and an air gap G.sub.23 between said second lens
element and said third lens element along said optical axis to
satisfy T.sub.1/G.sub.23.ltoreq.2.4.
4. The optical imaging lens set of claim 1, wherein said first lens
element has a first lens element thickness T.sub.1 along said
optical axis, an air gap G.sub.12 between said first lens element
and said second lens element along said optical axis and an air gap
G.sub.45 between said fourth lens element and said fifth lens
element along said optical axis to satisfy
(T.sub.1+G.sub.12)/G.sub.45.ltoreq.2.15.
5. The optical imaging lens set of claim 1, wherein said first lens
element has a first lens element thickness T.sub.1 along said
optical axis, said second lens element has a second lens element
thickness T.sub.2 along said optical axis, said third lens element
has a third lens element thickness T.sub.3 along said optical axis
and an air gap G.sub.12 between said first lens element and said
second lens element along said optical axis to satisfy
(T.sub.1+G.sub.12+T.sub.2)/T.sub.3.ltoreq.2.75.
6. The optical imaging lens set of claim 1, wherein said second
lens element has a second lens element thickness T.sub.2 along said
optical axis, said fourth lens element has a fourth lens element
thickness T.sub.4 along said optical axis, an air gap G.sub.12
between said first lens element and said second lens element along
said optical axis, an air gap G.sub.34 between said third lens
element and said fourth lens element along said optical axis and an
air gap G.sub.56 between said fifth lens element and said sixth
lens element along said optical axis to satisfy
(T.sub.2+T.sub.4)/(G.sub.12+G.sub.34+G.sub.56).ltoreq.3.8.
7. The optical imaging lens set of claim 1, wherein said first lens
element has a first lens element thickness T.sub.1 along said
optical axis to satisfy AAG/T.sub.1.ltoreq.3.45.
8. The optical imaging lens set of claim 1, wherein said fourth
lens element has a fourth lens element thickness T.sub.4 along said
optical axis to satisfy AAG/T.sub.4.ltoreq.4.8.
9. The optical imaging lens set of claim 1, wherein EFL is an
effective focal length of the optical imaging lens set, said first
lens element has a first lens element thickness T.sub.1 along said
optical axis and said sixth lens element has a sixth lens element
thickness T.sub.5 along said optical axis to satisfy
EFL/(T.sub.1+T.sub.6).ltoreq.4.15.
10. The optical imaging lens set of claim 1, wherein ALT is a total
thickness of all six lens elements along said optical axis and EPD
is an entrance pupil diameter of an aperture stop to satisfy
ALT/EPD.ltoreq.1.75.
11. An optical imaging lens set, from an object side toward an
image side in order along an optical axis comprising: a first lens
element, a second lens element, a third lens element, a fourth lens
element, a fifth lens element and a sixth lens element, said first
lens element to said sixth lens element each having an object-side
surface facing toward the object side as well as an image-side
surface facing toward the image side, wherein: said first lens
element has positive refractive power; said second lens element has
an image-side surface with a concave portion in a vicinity of said
optical-axis; no air gap between said third lens element and said
fourth lens element; at least one of said object-side surface and
said image-side surface of said fifth lens element is aspherical;
and both said object-side surface and said image-side surface of
said sixth lens element are aspherical; the optical imaging lens
set exclusively has six lens elements with refractive power, ALT is
a total thickness of all six lens elements along said optical axis
and AAG is a sum of all five air gaps between each lens elements
from said first lens element to said sixth lens element along said
optical axis to satisfy ALT/AAG.ltoreq.4.5.
12. The optical imaging lens set of claim 11, wherein said first
lens element has a first lens element thickness T.sub.1 along said
optical axis and an air gap G.sub.45 between said fourth lens
element and said fifth lens element along said optical axis to
satisfy T.sub.1/G.sub.45.ltoreq.1.95.
13. The optical imaging lens set of claim 11, wherein said first
lens element has a first lens element thickness T.sub.1 along said
optical axis, an air gap G.sub.12 between said first lens element
and said second lens element along said optical axis and an air gap
G.sub.23 between said second lens element and said third lens
element along said optical axis to satisfy
(T.sub.1+G.sub.12)/G.sub.23.ltoreq.2.65.
14. The optical imaging lens set of claim 11, wherein said first
lens element has a first lens element thickness T.sub.1 along said
optical axis, said second lens element has a second lens element
thickness T.sub.2 along said optical axis, said fifth lens element
has a fifth lens element thickness T.sub.5 along said optical axis
and an air gap G.sub.12 between said first lens element and said
second lens element along said optical axis to satisfy
(T.sub.1+G.sub.12+T.sub.2)/T.sub.5.ltoreq.1.85.
15. The optical imaging lens set of claim 11, wherein said fifth
lens element has a fifth lens element thickness T.sub.5 along said
optical axis, an air gap G.sub.12 between said first lens element
and said second lens element along said optical axis, an air gap
G.sub.34 between said third lens element and said fourth lens
element along said optical axis and an air gap G.sub.56 between
said fifth lens element and said sixth lens element along said
optical axis to satisfy
T.sub.5/(G.sub.12+G.sub.34+G.sub.56).ltoreq.4.
16. The optical imaging lens set of claim 11, wherein said second
lens element has a second lens element thickness T.sub.2 along said
optical axis, an air gap G.sub.12 between said first lens element
and said second lens element along said optical axis, an air gap
G.sub.23 between said second lens element and said third lens
element along said optical axis, an air gap G.sub.34 between said
third lens element and said fourth lens element along said optical
axis and an air gap G.sub.56 between said fifth lens element and
said sixth lens element along said optical axis to satisfy
(T.sub.2+G.sub.23)/(G.sub.12+G.sub.34+G.sub.56).ltoreq.3.3.
17. The optical imaging lens set of claim 11, wherein said second
lens element has a second lens element thickness T.sub.2 along said
optical axis to satisfy AAG/T.sub.2.ltoreq.5.7.
18. The optical imaging lens set of claim 11, wherein said sixth
lens element has a sixth lens element thickness T.sub.5 along said
optical axis to satisfy AAG/T.sub.6.ltoreq.3.6.
19. The optical imaging lens set of claim 11, wherein EFL is an
effective focal length of the optical imaging lens set, said third
lens element has a third lens element thickness T.sub.3 along said
optical axis and said fifth lens element has a fifth lens element
thickness T.sub.5 along said optical axis to satisfy
EFL/(T.sub.3+T.sub.6).ltoreq.5.15.
20. The optical imaging lens set of claim 1, wherein TL is a
distance between said object-side surface of said first lens
element and said image-side surface of said sixth lens element
along said optical axis and EPD is an entrance pupil diameter of an
aperture stop to satisfy TL/EPD.ltoreq.4.5.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from Chinese patent
application No. 201610948407.6, filed on Nov. 2, 2016. The contents
of which are hereby incorporated by reference in their entirety for
all purposes.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention generally relates to an optical
imaging lens set. Specifically speaking, the present invention is
directed to an optical imaging lens set for use in portable
electronic devices such as mobile phones, cameras, tablet personal
computers, or personal digital assistants (PDA) for taking pictures
and for recording videos.
2. Description of the Prior Art
[0003] The specifications of portable electronic devices change all
the time and the key element--optical imaging lens set develops
variously so a good imaging quality is needed as well as a larger
aperture stop and wider view angles. As far as the increase of view
angles and aperture stop are concerned, flare usually happens due
to the total reflection of incoming light passing through the first
three lens elements. In addition, in order to correct the spherical
aberration and the chromatic aberration which are caused by the
first two lens elements, there are various injection molding
problems, such as smaller thickness of the third lens element and
the fourth lens element or heavily crooked periphery curves of the
third lens element and the fourth lens element.
SUMMARY OF THE INVENTION
[0004] In light of the above, the present invention proposes an
optical imaging lens set of six lens elements which is shorter in
total length, technically possible, has reduced air gaps, has low
flare and has good optical performance. The optical imaging lens
set of six lens elements of the present invention from an object
side toward an image side in order along an optical axis has a
first lens element, a second lens element, a third lens element, a
fourth lens element, a fifth lens element and a sixth lens element.
Each lens element respectively has an object-side surface which
faces toward an object side as well as an image-side surface which
faces toward an image side.
[0005] In a first aspect, the first lens element has positive
refractive power. The second lens element has an image-side surface
with a concave portion in a vicinity of the optical-axis. There is
no air gap between the third lens element and the fourth lens
element. At least one of the object-side surface and the image-side
surface of the fifth lens element is aspherical. Both the
object-side surface and the image-side surface of the sixth lens
element are aspherical.
[0006] The optical imaging lens set exclusively has the first lens
element, the second lens element, the third lens element, the
fourth lens element, the fifth lens element and the sixth lens
element with refractive power. TL is a distance between the
object-side surface of the first lens element and the image-side
surface of the sixth lens element along the optical axis and AAG is
a sum of all air gaps disposed between adjacent lens elements from
the first lens element to the sixth lens element along the optical
axis to satisfy TL/AAG.ltoreq.5.5.
[0007] The present invention in a second aspect proposes another
optical imaging lens set of six lens elements which is shorter in
total length, technically possible, has reduced air gaps, has low
flare and has good optical performance. The optical imaging lens
set of six lens elements from an object side toward an image side
in order along an optical axis has a first lens element, a second
lens element, a third lens element, a fourth lens element, a fifth
lens element and a sixth lens element. Each lens element
respectively has an object-side surface facing toward an object
side as well as an image-side surface facing toward an image
side.
[0008] The first lens element has positive refractive power. The
second lens element has an image-side surface with a concave
portion in a vicinity of the optical-axis. There is no air gap
between the third lens element and the fourth lens element. At
least one of the object-side surface and the image-side surface of
the fifth lens element is aspherical. Both the object-side surface
and the image-side surface of the sixth lens element are
aspherical. The optical imaging lens set exclusively has the first
lens element, the second lens element, the third lens element, the
fourth lens element, the fifth lens element and the sixth lens
element with refractive power. ALT is a total thickness of all six
lens elements along the optical axis and AAG is a sum of all four
air gaps which are disposed between adjacent lens elements from the
first lens element to the sixth lens element along the optical axis
to satisfy ALT/AAG.ltoreq.4.5.
[0009] In the optical imaging lens set of six lens elements of the
present invention, .upsilon.3 is an Abbe number of the third lens
element and .upsilon.4 is an Abbe number of the fourth lens element
to satisfy 16.ltoreq..upsilon.3-.upsilon.4.ltoreq.50.
[0010] In the optical imaging lens set of six lens elements of the
present invention, the first lens element has a first lens element
thickness T.sub.1 along the optical axis and an air gap G.sub.23
between the second lens element and the third lens element along
the optical axis to satisfy T.sub.1/G.sub.23.ltoreq.2.4.
[0011] In the optical imaging lens set of six lens elements of the
present invention, an air gap G.sub.12 between the first lens
element and the second lens element along the optical axis and an
air gap G.sub.45 between the fourth lens element and the fifth lens
element along the optical axis to satisfy
(T.sub.1+G.sub.12)/G.sub.45.ltoreq.2.15.
[0012] In the optical imaging lens set of six lens elements of the
present invention, the second lens element has a second lens
element thickness T.sub.2 along the optical axis and the third lens
element has a third lens element thickness T.sub.3 along the
optical axis to satisfy
(T.sub.1+G.sub.12+T.sub.2)/T.sub.3.ltoreq.2.75.
[0013] In the optical imaging lens set of six lens elements of the
present invention, the fourth lens element has a fourth lens
element thickness T.sub.4 along the optical axis, an air gap
G.sub.34 between the third lens element and the fourth lens element
along the optical axis and an air gap G.sub.55 between the fifth
lens element and the sixth lens element along the optical axis to
satisfy
(T.sub.2+T.sub.4)/(G.sub.12+G.sub.34+G.sub.56).ltoreq.3.8.
[0014] The optical imaging lens set of six lens elements of the
present invention satisfies AAG/T.sub.1.ltoreq.3.45.
[0015] The optical imaging lens set of six lens elements of the
present invention satisfies AAG/T.sub.4.ltoreq.4.8.
[0016] In the optical imaging lens set of six lens elements of the
present invention, EFL is an effective focal length of the optical
imaging lens set and the sixth lens element has a sixth lens
element thickness T.sub.5 along the optical axis to satisfy
EFL/(T.sub.1+T.sub.6).ltoreq.4.15.
[0017] In the optical imaging lens set of six lens elements of the
present invention, EPD is an entrance pupil diameter of an aperture
stop to satisfy ALT/EPD.ltoreq.1.75.
[0018] In the optical imaging lens set of six lens elements of the
present invention, the first lens element has a first lens element
thickness T.sub.1 along the optical axis and an air gap G.sub.45
between the fourth lens element and the fifth lens element along
the optical axis to satisfy to satisfy
T.sub.1/G.sub.45.ltoreq.1.95.
[0019] In the optical imaging lens set of six lens elements of the
present invention, an air gap G.sub.12 between the first lens
element and the second lens element along the optical axis and an
air gap G.sub.23 between the second lens element and the third lens
element along the optical axis to satisfy
(T.sub.1+G.sub.12)/G.sub.23.ltoreq.2.65.
[0020] In the optical imaging lens set of six lens elements of the
present invention, the second lens element has a second lens
element thickness T.sub.2 along the optical axis and the fifth lens
element has a fifth lens element thickness T.sub.5 along the
optical axis to satisfy
(T.sub.1+G.sub.12+T.sub.2)/T.sub.5.ltoreq.1.85.
[0021] In the optical imaging lens set of six lens elements of the
present invention, an air gap G.sub.34 between the third lens
element and the fourth lens element along the optical axis and an
air gap G.sub.55 between the fifth lens element and the sixth lens
element along the optical axis to satisfy
T.sub.5/(G.sub.12+G.sub.34+G.sub.56).ltoreq.4.
[0022] The optical imaging lens set of six lens elements of the
present invention satisfies
(T.sub.2+G.sub.23)/(G.sub.12+G.sub.34+G.sub.56).ltoreq.3.3.
[0023] The optical imaging lens set of six lens elements of the
present invention satisfies AAG/T.sub.2.ltoreq.5.7.
[0024] In the optical imaging lens set of six lens elements of the
present invention, the sixth lens element has a sixth lens element
thickness T.sub.6 along the optical axis to satisfy
AAG/T.sub.6.ltoreq.3.6.
[0025] In the optical imaging lens set of six lens elements of the
present invention, EFL is an effective focal length of the optical
imaging lens set and the third lens element has a third lens
element thickness T.sub.3 along the optical axis to satisfy
EFL/(T.sub.3+T.sub.5).ltoreq.5.15.
[0026] In the optical imaging lens set of six lens elements of the
present invention, EPD is an entrance pupil diameter of an aperture
stop to satisfy TL/EPD.ltoreq.4.5.
[0027] These and other objectives of the present invention will no
doubt become obvious to those of ordinary skill in the art after
reading the following detailed description of the preferred
embodiment that is illustrated in the various figures and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIGS. 1-5 illustrates the methods for determining the
surface shapes and for determining one region is a region in a
vicinity of the optical axis or the region in a vicinity of its
circular periphery of one lens element.
[0029] FIG. 6 illustrates a first example of the optical imaging
lens set of the present invention.
[0030] FIG. 7A illustrates the longitudinal spherical aberration on
the image plane of the first example.
[0031] FIG. 7B illustrates the astigmatic aberration on the
sagittal direction of the first example.
[0032] FIG. 7C illustrates the astigmatic aberration on the
tangential direction of the first example.
[0033] FIG. 7D illustrates the distortion aberration of the first
example.
[0034] FIG. 8 illustrates a second example of the optical imaging
lens set of five lens elements of the present invention.
[0035] FIG. 9A illustrates the longitudinal spherical aberration on
the image plane of the second example.
[0036] FIG. 9B illustrates the astigmatic aberration on the
sagittal direction of the second example.
[0037] FIG. 9C illustrates the astigmatic aberration on the
tangential direction of the second example.
[0038] FIG. 9D illustrates the distortion aberration of the second
example.
[0039] FIG. 10 illustrates a third example of the optical imaging
lens set of five lens elements of the present invention.
[0040] FIG. 11A illustrates the longitudinal spherical aberration
on the image plane of the third example.
[0041] FIG. 11B illustrates the astigmatic aberration on the
sagittal direction of the third example.
[0042] FIG. 11C illustrates the astigmatic aberration on the
tangential direction of the third example.
[0043] FIG. 11D illustrates the distortion aberration of the third
example.
[0044] FIG. 12 illustrates a fourth example of the optical imaging
lens set of five lens elements of the present invention.
[0045] FIG. 13A illustrates the longitudinal spherical aberration
on the image plane of the fourth example.
[0046] FIG. 13B illustrates the astigmatic aberration on the
sagittal direction of the fourth example.
[0047] FIG. 13C illustrates the astigmatic aberration on the
tangential direction of the fourth example.
[0048] FIG. 13D illustrates the distortion aberration of the fourth
example.
[0049] FIG. 14 illustrates a fifth example of the optical imaging
lens set of five lens elements of the present invention.
[0050] FIG. 15A illustrates the longitudinal spherical aberration
on the image plane of the fifth example.
[0051] FIG. 15B illustrates the astigmatic aberration on the
sagittal direction of the fifth example.
[0052] FIG. 15C illustrates the astigmatic aberration on the
tangential direction of the fifth example.
[0053] FIG. 15D illustrates the distortion aberration of the fifth
example.
[0054] FIG. 16 illustrates a sixth example of the optical imaging
lens set of five lens elements of the present invention.
[0055] FIG. 17A illustrates the longitudinal spherical aberration
on the image plane of the sixth example.
[0056] FIG. 17B illustrates the astigmatic aberration on the
sagittal direction of the sixth example.
[0057] FIG. 17C illustrates the astigmatic aberration on the
tangential direction of the sixth example.
[0058] FIG. 17D illustrates the distortion aberration of the sixth
example.
[0059] FIG. 18 illustrates a seventh example of the optical imaging
lens set of five lens elements of the present invention.
[0060] FIG. 19A illustrates the longitudinal spherical aberration
on the image plane of the seventh example.
[0061] FIG. 19B illustrates the astigmatic aberration on the
sagittal direction of the seventh example.
[0062] FIG. 19C illustrates the astigmatic aberration on the
tangential direction of the seventh example.
[0063] FIG. 19D illustrates the distortion aberration of the
seventh example.
[0064] FIG. 20 illustrates an eighth example of the optical imaging
lens set of five lens elements of the present invention.
[0065] FIG. 21A illustrates the longitudinal spherical aberration
on the image plane of the eighth example.
[0066] FIG. 21B illustrates the astigmatic aberration on the
sagittal direction of the eighth example.
[0067] FIG. 21C illustrates the astigmatic aberration on the
tangential direction of the eighth example.
[0068] FIG. 21D illustrates the distortion aberration of the eighth
example.
[0069] FIG. 22 illustrates a ninth example of the optical imaging
lens set of five lens elements of the present invention.
[0070] FIG. 23A illustrates the longitudinal spherical aberration
on the image plane of the ninth example.
[0071] FIG. 23B illustrates the astigmatic aberration on the
sagittal direction of the ninth example.
[0072] FIG. 23C illustrates the astigmatic aberration on the
tangential direction of the ninth example.
[0073] FIG. 23D illustrates the distortion aberration of the ninth
example.
[0074] FIG. 24 shows the optical data of the first example of the
optical imaging lens set.
[0075] FIG. 25 shows the aspheric surface data of the first
example.
[0076] FIG. 26 shows the optical data of the second example of the
optical imaging lens set.
[0077] FIG. 27 shows the aspheric surface data of the second
example.
[0078] FIG. 28 shows the optical data of the third example of the
optical imaging lens set.
[0079] FIG. 29 shows the aspheric surface data of the third
example.
[0080] FIG. 30 shows the optical data of the fourth example of the
optical imaging lens set.
[0081] FIG. 31 shows the aspheric surface data of the fourth
example.
[0082] FIG. 32 shows the optical data of the fifth example of the
optical imaging lens set.
[0083] FIG. 33 shows the aspheric surface data of the fifth
example.
[0084] FIG. 34 shows the optical data of the sixth example of the
optical imaging lens set.
[0085] FIG. 35 shows the aspheric surface data of the sixth
example.
[0086] FIG. 36 shows the optical data of the seventh example of the
optical imaging lens set.
[0087] FIG. 37 shows the aspheric surface data of the seventh
example.
[0088] FIG. 38 shows the optical data of the eighth example of the
optical imaging lens set.
[0089] FIG. 39 shows the aspheric surface data of the eighth
example.
[0090] FIG. 40 shows the optical data of the ninth example of the
optical imaging lens set.
[0091] FIG. 41 shows the aspheric surface data of the ninth
example.
[0092] FIG. 42 shows some important ratios in the examples.
DETAILED DESCRIPTION
[0093] Before the detailed description of the present invention,
the first thing to be noticed is that in the present invention,
similar (not necessarily identical) elements are labeled as the
same numeral references. In the entire present specification, "a
certain lens element has negative/positive refractive power" refers
to the part in a vicinity of the optical axis of the lens element
has negative/positive refractive power calculated by Gaussian
optical theory. An object-side/image-side surface refers to the
region which allows imaging light passing through, in the drawing,
imaging light includes Lc (chief ray) and Lm (marginal ray). As
shown in FIG. 1, the optical axis is "I" and the lens element is
symmetrical with respect to the optical axis I. The region A that
near the optical axis and for light to pass through is the region
in a vicinity of the optical axis, and the region C that the
marginal ray passing through is the region in a vicinity of a
certain lens element's circular periphery. In addition, the lens
element may include an extension part E for the lens element to be
installed in an optical imaging lens set (that is the region
outside the region C perpendicular to the optical axis). Ideally
speaking, no light would pass through the extension part, and the
actual structure and shape of the extension part is not limited to
this and may have other variations. For the reason of simplicity,
the extension part is not illustrated in the following examples.
More, precisely, the method for determining the surface shapes or
the region in a vicinity of the optical axis, the region in a
vicinity of its circular periphery and other regions is described
in the following paragraphs:
1. FIG. 1 is a radial cross-sectional view of a lens element.
Before determining boundaries of those aforesaid portions, two
referential points should be defined first, middle point and
conversion point. The middle point of a surface of a lens element
is a point of intersection of that surface and the optical axis.
The conversion point is a point on a surface of a lens element,
where the tangent line of that point is perpendicular to the
optical axis. Additionally, if multiple conversion points appear on
one single surface, then these conversion points are sequentially
named along the radial direction of the surface with numbers
starting from the first conversion point. For instance, the first
conversion point (closest one to the optical axis), the second
conversion point, and the N.sup.th conversion point (farthest one
to the optical axis within the scope of the clear aperture of the
surface). The portion of a surface of the lens element between the
middle point and the first conversion point is defined as the
portion in a vicinity of the optical axis. The portion located
radially outside of the N.sup.th conversion point (but still within
the scope of the clear aperture) is defined as the portion in a
vicinity of a periphery of the lens element. In some embodiments,
there are other portions existing between the portion in a vicinity
of the optical axis and the portion in a vicinity of a periphery of
the lens element; the numbers of portions depend on the numbers of
the conversion point(s). In addition, the radius of the clear
aperture (or a so-called effective radius) of a surface is defined
as the radial distance from the optical axis I to a point of
intersection of the marginal ray Lm and the surface of the lens
element. 2. Referring to FIG. 2, determining the shape of a portion
is convex or concave depends on whether a collimated ray passing
through that portion converges or diverges. That is, while applying
a collimated ray to a portion to be determined in terms of shape,
the collimated ray passing through that portion will be bended and
the ray itself or its extension line will eventually meet the
optical axis. The shape of that portion can be determined by
whether the ray or its extension line meets (intersects) the
optical axis (focal point) at the object-side or image-side. For
instance, if the ray itself intersects the optical axis at the
image side of the lens element after passing through a portion,
i.e. the focal point of this ray is at the image side (see point R
in FIG. 2), the portion will be determined as having a convex
shape. On the contrary, if the ray diverges after passing through a
portion, the extension line of the ray intersects the optical axis
at the object side of the lens element, i.e. the focal point of the
ray is at the object side (see point M in FIG. 2), that portion
will be determined as having a concave shape. Therefore, referring
to FIG. 2, the portion between the middle point and the first
conversion point has a convex shape, the portion located radially
outside of the first conversion point has a concave shape, and the
first conversion point is the point where the portion having a
convex shape changes to the portion having a concave shape, namely
the border of two adjacent portions. Alternatively, there is
another common way for a person with ordinary skill in the art to
tell whether a portion in a vicinity of the optical axis has a
convex or concave shape by referring to the sign of an "R" value,
which is the (paraxial) radius of curvature of a lens surface. The
R value is commonly used in conventional optical design software
such as Zemax and CodeV. The R value usually appears in the lens
data sheet in the software. For an object-side surface, positive R
means that the object-side surface is convex, and negative R means
that the object-side surface is concave. Conversely, for an
image-side surface, positive R means that the image-side surface is
concave, and negative R means that the image-side surface is
convex. The result found by using this method should be consistent
as by using the other way mentioned above, which determines surface
shapes by referring to whether the focal point of a collimated ray
is at the object side or the image side. 3. For none conversion
point cases, the portion in a vicinity of the optical axis is
defined as the portion between 0.about.50% of the effective radius
(radius of the clear aperture) of the surface, whereas the portion
in a vicinity of a periphery of the lens element is defined as the
portion between 50.about.100% of effective radius (radius of the
clear aperture) of the surface.
[0094] Referring to the first example depicted in FIG. 3, only one
conversion point, namely a first conversion point, appears within
the clear aperture of the image-side surface of the lens element.
Portion I is a portion in a vicinity of the optical axis, and
portion II is a portion in a vicinity of a periphery of the lens
element. The portion in a vicinity of the optical axis is
determined as having a concave surface due to the R value at the
image-side surface of the lens element is positive. The shape of
the portion in a vicinity of a periphery of the lens element is
different from that of the radially inner adjacent portion, i.e.
the shape of the portion in a vicinity of a periphery of the lens
element is different from the shape of the portion in a vicinity of
the optical axis; the portion in a vicinity of a periphery of the
lens element has a convex shape.
[0095] Referring to the second example depicted in FIG. 4, a first
conversion point and a second conversion point exist on the
object-side surface (within the clear aperture) of a lens element.
In which portion I is the portion in a vicinity of the optical
axis, and portion III is the portion in a vicinity of a periphery
of the lens element. The portion in a vicinity of the optical axis
has a convex shape because the R value at the object-side surface
of the lens element is positive. The portion in a vicinity of a
periphery of the lens element (portion III) has a convex shape.
What is more, there is another portion having a concave shape
existing between the first and second conversion point (portion
II).
[0096] Referring to a third example depicted in FIG. 5, no
conversion point exists on the object-side surface of the lens
element. In this case, the portion between 0.about.50% of the
effective radius (radius of the clear aperture) is determined as
the portion in a vicinity of the optical axis, and the portion
between 50.about.100% of the effective radius is determined as the
portion in a vicinity of a periphery of the lens element. The
portion in a vicinity of the optical axis of the object-side
surface of the lens element is determined as having a convex shape
due to its positive R value, and the portion in a vicinity of a
periphery of the lens element is determined as having a convex
shape as well.
[0097] As shown in FIG. 6, the optical imaging lens set 1 of six
lens elements of the present invention, sequentially located from
an object side 2 (where an object is located) to an image side 3
along an optical axis 4, has an aperture stop (ape. stop) 80, a
first lens element 10, a second lens element 20, a third lens
element 30, a fourth lens element 40, a fifth lens element 50, a
sixth lens element 60, a filter 70 and an image plane 71. Generally
speaking, the first lens element 10, the second lens element 20,
the third lens element 30, the fourth lens element 40, the fifth
lens element 50 and the sixth lens element 60 may be made of a
transparent plastic material but the present invention is not
limited to this, and each has an appropriate refractive power.
There are exclusively six lens elements, which means the first lens
element 10, the second lens element 20, the third lens element 30,
the fourth lens element 40, the fifth lens element 50 and the sixth
lens element 60, with refractive power in the optical imaging lens
set 1 of the present invention. The optical axis 4 is the optical
axis of the entire optical imaging lens set 1, and the optical axis
of each of the lens elements coincides with the optical axis of the
optical imaging lens set 1.
[0098] Furthermore, the optical imaging lens set 1 includes an
aperture stop (ape. stop) 80 disposed in an appropriate position.
In FIG. 6, the aperture stop 80 is disposed between the object side
2 and the first lens element 10. When light emitted or reflected by
an object (not shown) which is located at the object side 2 enters
the optical imaging lens set 1 of the present invention, it forms a
clear and sharp image on the image plane 71 at the image side 3
after passing through the aperture stop 80, the first lens element
10, the second lens element 20, the third lens element 30, the
fourth lens element 40, the fifth lens element 50, the sixth lens
element 60 and the filter 70. In one embodiments of the present
invention, the optional filter 70 may be a filter of various
suitable functions, for example, the filter 70 may be an infrared
cut filter (IR cut filter), placed between the image-side surface
62 of the sixth lens element 60 and the image plane 71.
[0099] Each lens element in the optical imaging lens set 1 of the
present invention has an object-side surface facing toward the
object side 2 as well as an image-side surface facing toward the
image side 3. For example, the first lens element 10 has an
object-side surface 11 and an image-side surface 12; the second
lens element 20 has an object-side surface 21 and an image-side
surface 22; the third lens element 30 has an object-side surface 31
and an image-side surface 32; the fourth lens element 40 has an
object-side surface 41 and an image-side surface 42; the fifth lens
element 50 has an object-side surface 51 and an image-side surface
52; the sixth lens element 60 has an object-side surface 61 and an
image-side surface 62. In addition, each object-side surface and
image-side surface in the optical imaging lens set 1 of the present
invention has a part (or portion) in a vicinity of its circular
periphery (circular periphery part) away from the optical axis 4 as
well as a part in a vicinity of the optical axis (optical axis
part) close to the optical axis 4.
[0100] Each lens element in the optical imaging lens set 1 of the
present invention further has a central thickness T on the optical
axis 4. For example, the first lens element 10 has a first lens
element thickness T.sub.1, the second lens element 20 has a second
lens element thickness T.sub.2, the third lens element 30 has a
third lens element thickness T.sub.3, the fourth lens element 40
has a fourth lens element thickness T.sub.4, the fifth lens element
50 has a fifth lens element thickness T.sub.5, the sixth lens
element 60 has a sixth lens element thickness T.sub.5. Therefore,
the total thickness of all the lens elements in the optical imaging
lens set 1 along the optical axis 4 is
ALT=T.sub.1+T.sub.2+T.sub.3+T.sub.4+T.sub.5+T.sub.6.
[0101] In addition, between two adjacent lens elements in the
optical imaging lens set 1 of the present invention there may be an
air gap along the optical axis 4. For example, there is an air gap
G.sub.12 disposed between the first lens element 10 and the second
lens element 20, an air gap G.sub.23 disposed between the second
lens element 20 and the third lens element 30, an air gap G.sub.45
disposed between the fourth lens element 40 and the fifth lens
element 50 as well as there is an air gap G.sub.56 disposed between
the fifth lens element 50 and the sixth lens element 60 but there
is no air gap G.sub.34 disposed between the third lens element 30
and the fourth lens element 40 so G.sub.34 is 0. Therefore, the sum
of total four air gaps between adjacent lens elements from the
first lens element 10 to the sixth lens element 60 along the
optical axis 4 is AAG=G.sub.12+G.sub.23+G.sub.45+G.sub.56.
[0102] In addition, the distance from the object-side surface 11 of
the first lens element 10 to the image-side surface 62 of the sixth
lens element 60 along the optical axis 4 is TL. The distance
between the object-side surface 11 of the first lens element 10 to
the image plane 71, namely the total length of the optical imaging
lens set along the optical axis 4 is TTL; the effective focal
length of the optical imaging lens set is EFL; the distance between
the image-side surface 62 of the sixth lens element 60 and the
image plane 71 along the optical axis 4 is BFL. EPD is an entrance
pupil diameter of the aperture stop 80.
[0103] Furthermore, the focal length of the first lens element 10
is f1; the focal length of the second lens element 20 is f2; the
focal length of the third lens element 30 is f3; the focal length
of the fourth lens element 40 is f4; the focal length of the fifth
lens element 50 is f5; the focal length of the sixth lens element
60 is f6; the refractive index of the first lens element 10 is n1;
the refractive index of the second lens element 20 is n2; the
refractive index of the third lens element 30 is n3; the refractive
index of the fourth lens element 40 is n4; the refractive index of
the fifth lens element 50 is n5; the refractive index of the sixth
lens element 60 is n6; the Abbe number of the first lens element 10
is .upsilon.1; the Abbe number of the second lens element 20 is
.upsilon.2; the Abbe number of the third lens element 30 is
.upsilon.3; and the Abbe number of the fourth lens element 40 is
.upsilon.4; the Abbe number of the fifth lens element 50 is
.upsilon.5; and the Abbe number of the sixth lens element 60 is
.upsilon.6.
First Example
[0104] Please refer to FIG. 6 which illustrates the first example
of the optical imaging lens set 1 of the present invention. Please
refer to FIG. 7A for the longitudinal spherical aberration on the
image plane 71 of the first example; please refer to FIG. 7B for
the astigmatic field aberration on the sagittal direction; please
refer to FIG. 7C for the astigmatic field aberration on the
tangential direction, and please refer to FIG. 7D for the
distortion aberration. The Y axis of the spherical aberration in
each example is "field of view" for 1.0. The Y axis of the
astigmatic field and the distortion in each example stands for
"image height", which is 3.528 mm.
[0105] The optical imaging lens set 1 of the first example has six
lens elements 10 to 60 with refractive power. The optical imaging
lens set 1 also has a filter 70, an aperture stop 80, and an image
plane 71. The aperture stop 80 is provided between the object side
2 and the first lens element 10. The filter 70 may be used for
preventing specific wavelength light (such as the infrared light)
reaching the image plane to adversely affect the imaging
quality.
[0106] The first lens element 10 has positive refractive power. The
object-side surface 11 facing toward the object side 2 has a convex
part 13 in the vicinity of the optical axis and a convex part 14 in
a vicinity of its circular periphery. The image-side surface 12
facing toward the image side 3 has a concave part 16 in the
vicinity of the optical axis and a concave part 17 in a vicinity of
its circular periphery. Besides, both the object-side surface 11
and the image-side 12 are aspherical surfaces.
[0107] The second lens element 20 is of a plastic material and has
negative refractive power. The object-side surface 21 facing toward
the object side 2 has a convex part 23 in the vicinity of the
optical axis and a convex part 24 in a vicinity of its circular
periphery. The image-side surface 22 facing toward the image side 3
has a concave part 26 in the vicinity of the optical axis and a
concave part 27 in a vicinity of its circular periphery. Besides,
both the object-side surface 21 and the image-side 22 of the second
lens element 20 are aspherical surfaces.
[0108] The third lens element 30 has negative refractive power. The
object-side surface 31 facing toward the object side 2 has a
concave part 33 in the vicinity of the optical axis and a concave
part 34 in a vicinity of its circular periphery. The image-side
surface 32 facing toward the image side 3 has a convex part 36 in
the vicinity of the optical axis and a convex part 37 in a vicinity
of its circular periphery. The object-side surface 31 of the third
lens element 30 is an aspherical surface.
[0109] The fourth lens element 40 has positive refractive power.
The object-side surface 41 facing toward the object side 2 has a
concave part 43 in the vicinity of the optical axis and a concave
part 44 in a vicinity of its circular periphery. The image-side
surface 42 facing toward the image side 3 has a convex part 46 in
the vicinity of the optical axis and a convex part 47 in a vicinity
of its circular periphery. The image-side 42 of the fourth lens
element 40 is an aspherical surface. The third lens element 30 and
the fourth lens element 40 may be attached together with glue or a
film so there is no air gap between the image-side surface 32 of
the third lens element 30 and the object-side surface 41 of the
fourth lens element 40.
[0110] The fifth lens element 50 has positive refractive power. The
object-side surface 51 facing toward the object side 2 has a
concave part 53 in the vicinity of the optical axis and a concave
part 54 in a vicinity of its circular periphery. The image-side
surface 52 facing toward the image side 3 has a convex part 56 in
the vicinity of the optical axis and a convex part 57 in a vicinity
of its circular periphery. Besides, at least one of the object-side
surface 51 and the image-side 52 of the fifth lens element 50 is an
aspherical surface.
[0111] The sixth lens element 60 has negative refractive power. The
object-side surface 61 facing toward the object side 2 has a convex
part 63 in the vicinity of the optical axis and a concave part 64
in a vicinity of its circular periphery. The image-side surface 62
facing toward the image side 3 has a concave part 66 in the
vicinity of the optical axis and a convex part 67 in a vicinity of
its circular periphery. Both the object-side surface 61 and the
image-side 62 of the sixth lens element 60 are aspherical surfaces.
The filter 70 is disposed between the image-side 62 of the sixth
lens element 60 and the image plane 71.
[0112] In the first lens element 10, the second lens element 20,
the third lens element 30, the fourth lens element 40, the fifth
lens element 50 and the sixth lens element 60 of the optical
imaging lens element 1 of the present invention, there are 12
surfaces, such as the object-side surfaces 11/21/31/41/51/61 and
the image-side surfaces 12/22/32/42/52/62. If a surface is
aspherical, these aspheric coefficients are defined according to
the following formula:
Z ( Y ) = Y 2 R / ( 1 + 1 - ( 1 + K ) Y 2 R 2 ) + i = 1 n a i
.times. Y i ##EQU00001##
In which: R represents the curvature radius of the lens element
surface; Z represents the depth of an aspherical surface (the
perpendicular distance between the point of the aspherical surface
at a distance Y from the optical axis and the tangent plane of the
vertex on the optical axis of the aspherical surface); Y represents
a vertical distance from a point on the aspherical surface to the
optical axis; K is a conic constant; a.sub.i is the aspheric
coefficient of the i.sup.th order.
[0113] The optical data of the first example of the optical imaging
lens set 1 are shown in FIG. 24 while the aspheric surface data are
shown in FIG. 25. In the present examples of the optical imaging
lens set, the f-number of the entire optical lens element system is
Fno, EFL is the effective focal length, HFOV stands for the half
field of view which is half of the field of view of the entire
optical lens element system, and the unit for the curvature radius,
the thickness and the focal length is in millimeters (mm). TTL is
5.3323 mm. Fno is 1.6740. The image height is 3.528 mm. HFOV is
38.5720 degrees.
Second Example
[0114] Please refer to FIG. 8 which illustrates the second example
of the optical imaging lens set 1 of the present invention. It is
noted that from the second example to the following examples, in
order to simplify the figures, only the components different from
what the first example has, and the basic lens elements will be
labeled in figures. Other components that are the same as what the
first example has, such as the object-side surface, the image-side
surface, the part in a vicinity of the optical axis and the part in
a vicinity of its circular periphery will be omitted in the
following examples. Please refer to FIG. 9A for the longitudinal
spherical aberration on the image plane 71 of the second example,
please refer to FIG. 9B for the astigmatic aberration on the
sagittal direction, please refer to FIG. 9C for the astigmatic
aberration on the tangential direction, and please refer to FIG. 9D
for the distortion aberration. The components in the second example
are similar to those in the first example, but the optical data
such as the curvature radius, the refractive power, the lens
thickness, the lens focal length, the aspheric surface or the back
focal length in this example are different from the optical data in
the first example, and in this example, the third lens element 30
has positive refractive power, the object-side surface 31 of the
third lens element 30 facing toward the object side 2 has a convex
part 33' in the vicinity of the optical axis and the object-side
surface 61 of the sixth lens element 60 facing toward the object
side 2 has a concave part 63' in the vicinity of the optical
axis.
[0115] The optical data of the second example of the optical
imaging lens set are shown in FIG. 26 while the aspheric surface
data are shown in FIG. 27. TTL is 5.0778 mm. Fno is 1.6971. The
image height is 3.528 mm. HFOV is 42.2740 degrees. In particular,
1) the TTL of the second example is shorter than that of the first
example of the present invention, 2) the HFOV of the second example
is better than that of the first example of the present
invention.
Third Example
[0116] Please refer to FIG. 10 which illustrates the third example
of the optical imaging lens set 1 of the present invention. Please
refer to FIG. 11A for the longitudinal spherical aberration on the
image plane 71 of the third example; please refer to FIG. 11B for
the astigmatic aberration on the sagittal direction; please refer
to FIG. 11C for the astigmatic aberration on the tangential
direction, and please refer to FIG. 11D for the distortion
aberration. The components in the third example are similar to
those in the first example, but the optical data such as the
curvature radius, the refractive power, the lens thickness, the
lens focal length, the aspheric surface or the back focal length in
this example are different from the optical data in the first
example, and in this example, the object-side surface 31 of the
third lens element 30 facing toward the object side 2 has a convex
part 33' in the vicinity of the optical axis and the object-side
surface 61 of the sixth lens element 60 facing toward the object
side 2 has a convex 64' in a vicinity of its circular
periphery.
[0117] The optical data of the third example of the optical imaging
lens set are shown in FIG. 28 while the aspheric surface data are
shown in FIG. 29. TTL is 5.5551 mm. Fno is 1.8078. The image height
is 3.528 mm. HFOV is 43.1208 degrees. In particular, the HFOV of
the third example is better than that of the first example of the
present invention.
Fourth Example
[0118] Please refer to FIG. 12 which illustrates the fourth example
of the optical imaging lens set 1 of the present invention. Please
refer to FIG. 13A for the longitudinal spherical aberration on the
image plane 71 of the fourth example; please refer to FIG. 13B for
the astigmatic aberration on the sagittal direction; please refer
to FIG. 13C for the astigmatic aberration on the tangential
direction, and please refer to FIG. 13D for the distortion
aberration. The components in the fourth example are similar to
those in the first example, but the optical data such as the
curvature radius, the refractive power, the lens thickness, the
lens focal length, the aspheric surface or the back focal length in
this example are different from the optical data in the first
example, and in this example, the object-side surface 31 of the
third lens element 30 facing toward the object side 2 has a convex
part 33' in the vicinity of the optical axis and a convex part 34'
in a vicinity of its circular periphery, and the object-side
surface 51 of the fifth lens element 50 facing toward the object
side 2 has a convex part 53' in the vicinity of the optical
axis.
[0119] The optical data of the fourth example of the optical
imaging lens set are shown in FIG. 30 while the aspheric surface
data are shown in FIG. 31. TTL is 5.4516 mm. Fno is 1.7041. The
image height is 3.528 mm. HFOV is 41.6654 degrees. In particular,
the HFOV of the fourth example is larger than that of the first
example of the present invention.
Fifth Example
[0120] Please refer to FIG. 14 which illustrates the fifth example
of the optical imaging lens set 1 of the present invention. Please
refer to FIG. 15A for the longitudinal spherical aberration on the
image plane 71 of the fifth example; please refer to FIG. 15B for
the astigmatic aberration on the sagittal direction; please refer
to FIG. 15C for the astigmatic aberration on the tangential
direction, and please refer to FIG. 15D for the distortion
aberration. The components in the fifth example are similar to
those in the first example, but the optical data such as the
curvature radius, the refractive power, the lens thickness, the
lens focal length, the aspheric surface or the back focal length in
this example are different from the optical data in the first
example, and in this example, the object-side surface 31 of the
third lens element 30 facing toward the object side 2 has a convex
part 33' in the vicinity of the optical axis.
[0121] The optical data of the fifth example of the optical imaging
lens set are shown in FIG. 32 while the aspheric surface data are
shown in FIG. 33. TTL is 4.9785 mm. Fno is 1.7114. The image height
is 3.528 mm. HFOV is 41.9604 degrees. In particular, 1) the TTL of
the fifth example is shorter than that of the first example of the
present invention, 2) the HFOV of the fifth example is better than
that of the first example of the present invention, 3) the imaging
quality of the fifth example is better than that of the first
example of the present invention.
Sixth Example
[0122] Please refer to FIG. 16 which illustrates the sixth example
of the optical imaging lens set 1 of the present invention. Please
refer to FIG. 17A for the longitudinal spherical aberration on the
image plane 71 of the sixth example; please refer to FIG. 17B for
the astigmatic aberration on the sagittal direction; please refer
to FIG. 17C for the astigmatic aberration on the tangential
direction, and please refer to FIG. 17D for the distortion
aberration. The components in the sixth example are similar to
those in the first example, but the optical data such as the
curvature radius, the refractive power, the lens thickness, the
lens focal length, the aspheric surface or the back focal length in
this example are different from the optical data in the first
example, and in this example, the object-side surface 31 of the
third lens element 30 facing toward the object side 2 has a convex
part 33' in the vicinity of the optical axis, the object-side
surface 51 of the fifth lens element 50 facing toward the object
side 2 has a convex part 53' in the vicinity of the optical axis
and the object-side surface 61 of the sixth lens element 60 facing
toward the object side 2 has a concave part 63' in the vicinity of
the optical axis.
[0123] The optical data of the sixth example of the optical imaging
lens set are shown in FIG. 34 while the aspheric surface data are
shown in FIG. 35. TTL is 5.5487 mm. Fno is 1.7123. The image height
is 3.528 mm. HFOV is 42.9492 degrees. In particular, the HFOV of
the sixth example is better than that of the first example of the
present invention.
Seventh Example
[0124] Please refer to FIG. 18 which illustrates the seventh
example of the optical imaging lens set 1 of the present invention.
Please refer to FIG. 19A for the longitudinal spherical aberration
on the image plane 71 of the seventh example; please refer to FIG.
19B for the astigmatic aberration on the sagittal direction; please
refer to FIG. 19C for the astigmatic aberration on the tangential
direction, and please refer to FIG. 19D for the distortion
aberration. The components in the seventh example are similar to
those in the first example, but the optical data such as the
curvature radius, the refractive power, the lens thickness, the
lens focal length, the aspheric surface or the back focal length in
this example are different from the optical data in the first
example, and in this example, the object-side surface 31 of the
third lens element 30 facing toward the object side 2 has a convex
part 33 ` in the vicinity of the optical axis and the object-side
surface 51 of the fifth lens element 50 facing toward the object
side 2 has a convex part 53` in the vicinity of the optical
axis.
[0125] The optical data of the seventh example of the optical
imaging lens set are shown in FIG. 36 while the aspheric surface
data are shown in FIG. 37. TTL is 5.3528 mm. Fno is 1.7167. The
image height is 3.528 mm. HFOV is 45.7400 degrees. In particular,
the HFOV of the seventh example is better than that of the first
example of the present invention.
Eighth Example
[0126] Please refer to FIG. 20 which illustrates the eighth example
of the optical imaging lens set 1 of the present invention. Please
refer to FIG. 21A for the longitudinal spherical aberration on the
image plane 71 of the eighth example; please refer to FIG. 21B for
the astigmatic aberration on the sagittal direction; please refer
to FIG. 21C for the astigmatic aberration on the tangential
direction, and please refer to FIG. 21D for the distortion
aberration. The components in the eighth example are similar to
those in the first example, but the optical data such as the
curvature radius, the refractive power, the lens thickness, the
lens focal length, the aspheric surface or the back focal length in
this example are different from the optical data in the first
example, and in this example, the third lens element 30 has
positive refractive power, the fourth lens element 40 has negative
refractive power, the object-side surface 31 of the third lens
element 30 facing toward the object side 2 has a convex part 33' in
the vicinity of the optical axis and the image-side surface 42 of
the fourth lens element 40 facing toward the image side 3 has a
concave part 47' in a vicinity of its circular periphery.
[0127] The optical data of the eighth example of the optical
imaging lens set are shown in FIG. 38 while the aspheric surface
data are shown in FIG. 39. TTL is 5.5135 mm. Fno is 1.6862. The
image height is 3.528 mm. HFOV is 36.7581 degrees.
Ninth Example
[0128] Please refer to FIG. 22 which illustrates the ninth example
of the optical imaging lens set 1 of the present invention. Please
refer to FIG. 23A for the longitudinal spherical aberration on the
image plane 71 of the ninth example; please refer to FIG. 23B for
the astigmatic aberration on the sagittal direction; please refer
to FIG. 23C for the astigmatic aberration on the tangential
direction, and please refer to FIG. 23D for the distortion
aberration. The components in the ninth example are similar to
those in the first example, but the optical data such as the
curvature radius, the refractive power, the lens thickness, the
lens focal length, the aspheric surface or the back focal length in
this example are different from the optical data in the first
example, and in this example, the object-side surface 31 facing
toward the object side 2 has a convex part 33' in the vicinity of
the optical axis and the object-side surface 61 facing toward the
object side 2 has a concave part 63' in the vicinity of the optical
axis.
[0129] The optical data of the ninth example of the optical imaging
lens set are shown in FIG. 40 while the aspheric surface data are
shown in FIG. 41. TTL is 5.6143 mm. Fno is 1.7124. The image height
is 3.528 mm. HFOV is 39.3455 degrees. In particular, 1) the HFOV of
the ninth example is larger than that of the first example of the
present invention.
[0130] Some important ratios in each example are shown in FIG. 42.
The distance between the image-side surface 62 of the sixth lens
element 60 to the filter 70 along the optical axis 4 is G6F; the
thickness of the filter 70 along the optical axis 4 is TF; the
distance between the filter 70 to the image plane 71 along the
optical axis 4 is GFP; the distance between the image-side surface
62 of the sixth lens element 60 and the image plane 71 along the
optical axis 4 is BFL. Therefore, BFL=G6F+TF+GFP.
[0131] In the light of the above examples, the inventors observe at
least the following features of the lens arrangement of the present
invention and the corresponding efficacy:
1. The third lens element and the fourth lens element may be
attached to each other by glue or a film to render no air gap
disposed between the image-side surface 32 of the third lens
element 30 and the object-side surface 41 of the fourth lens
element 40. 2. The positive refractive power of the first lens
element facilitates the concentration of light. 3. The image-side
surface with a concave portion of the second lens element in a
vicinity of the optical-axis facilitates the correction of the
spherical aberration of the first lens element. 4. No air gap
disposed between the third lens element and the fourth lens element
facilitates to greatly lower the problem of flare which is caused
by the total reflection of imaging light which passes through the
first three lens elements. 5. The conditional formulae
16.ltoreq..upsilon.3-.upsilon.4.ltoreq.50 make the third lens
element and the fourth lens element have a smoother shape to solve
the problems of injection molding such as smaller thickness of the
third lens element and the fourth lens element or heavily crooked
periphery curves of the third lens element and the fourth lens
element in order to correct the spherical aberration and the
chromatic aberration which are caused by the first two lens
elements. 6. The fourth lens element has an image-side surface with
a convex part in the vicinity of the optical axis. It facilitates
the correction of the aberration caused by the previous three lens
elements. 7. At least one of the object-side surface and the
image-side surface of the fifth lens element is aspherical. It
facilitates the adjustment of the aberration caused by the previous
four lens elements. 8. Both the object-side surface and the
image-side surface of the sixth lens element are aspherical. They
make the correction of the aberration of high order easier.
[0132] In addition, the inventors further discover that there are
some better ratio ranges for different data according to the above
various important ratios. Better ratio ranges help the designers to
design a better optical performance and an effectively reduce
length of a practically possible optical imaging lens set. For
example:
1. When the optical lens set satisfies the conditional formula
ALT/AAG.ltoreq.4.5 or TL/AAG.ltoreq.5.5, it facilitates the
correction of longitudinal spherical aberration to go with the
third lens element and the fourth lens element. It is preferably
2.5.ltoreq.TL/AAG.ltoreq.5.5 or 1.5.ltoreq.ALT/AAG.ltoreq.4.5. 2.
EFL/(T.sub.1+T.sub.6).ltoreq.4.15 or
EFL/(T.sub.3+T.sub.5).ltoreq.5.15 restricts the relationships
between the focal length and the lens thickness. It goes with
ALT/EPD.ltoreq.1.75 or TL/EPD.ltoreq.4.5 to restrict the
relationships between the lens thickness and the entrance pupil
diameter to lower the Fno without compromising the imaging quality.
It is preferably 1.3.ltoreq.EFL/(T.sub.1+T.sub.6).ltoreq.4.15,
2.0.ltoreq.EFL/(T.sub.3+T.sub.5).ltoreq.5.15,
0.8.ltoreq.ALT/EPD.ltoreq.1.75, 1.2.ltoreq.TL/EPD.ltoreq.4.5. 3.
With respect to T.sub.1/G.sub.23.ltoreq.2.4,
(T.sub.1+G.sub.12)/G.sub.45.ltoreq.2.15,
(T.sub.1+G.sub.12+T.sub.2)/T.sub.3.ltoreq.2.75,
(T.sub.2+T.sub.4)/(G.sub.12+G.sub.34+G.sub.56).ltoreq.3.8,
AAG/T.sub.1.ltoreq.3.45, AAG/T.sub.4.ltoreq.4.8,
ALT/AAG.ltoreq.4.5, T.sub.1/G.sub.45.ltoreq.1.95,
(T.sub.1+G.sub.12)/G.sub.23.ltoreq.2.65,
(T.sub.1+G.sub.12+T.sub.2)/T.sub.5.ltoreq.1.85,
T.sub.5/(G.sub.12+G.sub.34+G.sub.56).ltoreq.4,
(T.sub.2+G.sub.23)/(G.sub.12+G.sub.34+G.sub.56).ltoreq.3.3,
AAG/T.sub.2.ltoreq.5.7, AAG/T.sub.6.ltoreq.3.6, it is preferably
1.2.ltoreq.T.sub.1/G.sub.23.ltoreq.2.4,
0.7.ltoreq.(T.sub.1+G.sub.12)/G.sub.45.ltoreq.2.15,
1.15.ltoreq.(T.sub.1+G.sub.12+T.sub.2)/T.sub.3.ltoreq.2.75,
0.5.ltoreq.(T.sub.2+T.sub.4)/(G.sub.12+G.sub.34+G.sub.56).ltoreq.3.8,
0.7.ltoreq.AAG/T.sub.1.ltoreq.3.45,
1.4.ltoreq.AAG/T.sub.4.ltoreq.4.8, 1.5.ltoreq.ALT/AAG.ltoreq.4.5,
0.65.ltoreq.T.sub.1/G.sub.45.ltoreq.1.95,
1.4.ltoreq.(T.sub.1+G.sub.12)/G.sub.23.ltoreq.2.65,
0.8.ltoreq.(T.sub.1+G.sub.12+T.sub.2)/T.sub.5.ltoreq.1.85,
0.5.ltoreq.T.sub.5/(G.sub.12+G.sub.34+G.sub.56).ltoreq.4,
0.5.ltoreq.(T.sub.2+G.sub.23)/(G.sub.12+G.sub.34+G.sub.56).ltoreq.3.3,
2.2.ltoreq.AAG/T.sub.2.ltoreq.5.7 or
1.5.ltoreq.AAG/T.sub.6.ltoreq.3.6 in order to keep each thickness
of the lens element and each air gap in preferred ranges. A good
ratio helps to control the lens thickness or the air gaps to
maintain a suitable range and keeps a lens element from being too
thick to facilitate the reduction of the overall size or too thin
to assemble the optical imaging lens set.
[0133] In the light of the unpredictability of the optical imaging
lens set, the present invention suggests the above principles to
have a shorter total length of the optical imaging lens set, a
larger aperture available, a wider field angle, better imaging
quality or a better fabrication yield to overcome the drawbacks of
prior art. The above limitations may be properly combined at the
discretion of persons who practice the present invention and they
are not limited as shown above.
[0134] The above-mentioned one or more conditions may be optionally
combined in the embodiments of the present invention. In addition
to the above ratios, the curvatures of each lens element or
multiple lens elements may be fine-tuned to result in more fine
structures to enhance the performance or the resolution. For
example, the object-side surface of the first lens element may
additionally have a convex part in the vicinity of the optical
axis. The above limitations may be properly combined in the
embodiments without causing inconsistency.
[0135] Those skilled in the art will readily observe that numerous
modifications and alterations of the device and method may be made
while retaining the teachings of the invention. Accordingly, the
above disclosure should be construed as limited only by the metes
and bounds of the appended claims.
* * * * *