CN212645896U - Spectrum collecting lens with large aperture - Google Patents
Spectrum collecting lens with large aperture Download PDFInfo
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- CN212645896U CN212645896U CN202021389831.XU CN202021389831U CN212645896U CN 212645896 U CN212645896 U CN 212645896U CN 202021389831 U CN202021389831 U CN 202021389831U CN 212645896 U CN212645896 U CN 212645896U
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Abstract
The utility model discloses a spectrum collecting lens of big light ring, this camera lens includes first lens group from the thing side to picture side in proper order, fixed diaphragm and second lens group, first lens group, positive focal power and position can be removed along the optical axis direction has, the second lens group, positive focal power and position can be removed along the optical axis direction has, first lens group includes first negative lens group and first positive lens group, first negative lens group includes two at least negative lenses, first positive lens group includes the positive and negative cemented lens of positive focal power, can realize the nearly focus distance of short focal length and big angle of vision, improve the sensitivity that the spectrum was gathered.
Description
Technical Field
The utility model relates to a lens technical field, in particular to spectrum collecting lens of big light ring.
Background
Spectrometer product functional requirements are more and more tending to develop into substantial increases in spectral detection sensitivity. In order to meet the improvement of the spectral detection sensitivity, on one hand, the structural quality of a lens is improved, on the other hand, the sensitivity of a signal acquisition sensor CMOS/CCD of a spectrometer is improved, and the light transmission amount (FNO) of the signal acquisition lens of the spectrometer is directly improved, the target surface size of the existing signal acquisition sensor CMOS/CCD of the spectrometer is mostly 1/2 or 2/3 inches, the FNO of an aperture is 1.4 to 2.0, and the detection sensitivity to weak spectral signals is poor.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a spectrum collecting lens of big light ring, its first negative lens group realizes the nearly focus distance of short focal length and big angle of vision through being equipped with two negative lens cooperation burden positive cemented lens, improves the sensitivity of spectrum collection, has solved the relatively poor problem of sensitivity of spectrum collecting lens.
To achieve the purpose, the utility model adopts the following technical proposal:
a spectrum collecting lens with a large aperture comprises a first lens group, a fixed diaphragm and a second lens group from an object side to an image side in sequence;
the first lens group has positive focal power and can move along the direction of an optical axis;
the second lens group has positive focal power and can move along the direction of the optical axis;
the first lens group comprises a first negative lens group and a first positive lens group, the first negative lens group comprises at least two negative lenses, and the first positive lens group comprises a positive and negative cemented lens with positive focal power;
the first lens group and the second lens group satisfy the following formula:
1＜f1/f2＜2；－1＜f11/f1＜－0.5；
wherein f1 represents the focal length of the first lens group, f2 represents the focal length of the second lens group, and f11 represents the focal length of the first negative lens group.
Therefore, the first lens group can move to realize a focusing function, the second lens group can move to realize zooming, the structural combination of the first negative lens group and the first positive lens group of the first lens group can realize short focal length close focusing distance and large field angle, the sensitivity of spectrum collection is improved, and the focal length of the first lens group and the focal length of the second lens group satisfy the relation of 1 & lt f1/f2 & lt 2, so that the lens meets the rear working distance of the optical system, and the focal length of the first negative lens group and the total focal length of the first lens group satisfy the relation of-1 & lt f11/f1 & lt-0.5, so that the optical system can bear the field angle.
In some embodiments, the second lens group comprises at least one negative optic, and a positive and negative cemented lens comprising a positive optical power and a negative and positive cemented lens of a negative optical power.
Therefore, the negative lens is the eighth lens, the coma aberration and astigmatism of the front lens group and the rear lens group can be effectively balanced, the matching tolerance sensitivity of the front lens group and the rear lens group is greatly reduced, the positive cemented lens and the negative cemented lens are composed of the ninth lens and the tenth lens, the negative and positive cemented lens is composed of the eleventh lens and the twelfth lens, and the chromatic aberration and the distortion can be corrected through the combination of the two cemented lenses.
In some embodiments, the first negative lens group further comprises a negative positive cemented lens of negative optical power.
Therefore, the first lens group is provided with the two cemented lenses, light beams are converged and then diffused continuously, and the light path trend is in a gourd shape, so that the astigmatism and the field curvature of the first lens group are small, and the tolerance sensitivity of the front lens group and the rear lens group can be reduced.
In some embodiments, the back working distance of the lens is BFL, the focal length of the lens is f, and the following equation is satisfied: BFL/f is more than 0.5 and less than 1.
Therefore, the lens forms a reverse long-distance light path structure, and ensures enough rear working distance.
In some embodiments, the refractive index of the sixth lens of the first lens group is between 1.85 and 1.95.
Therefore, the higher refractive index can reduce the thickness of the lens, and is more beneficial to compactness and light weight.
In some embodiments, the refractive index of the tenth lens of the second lens group is between 1.70 and 1.80.
Therefore, the higher refractive index can reduce the thickness of the lens, and is more beneficial to compactness and light weight.
In some embodiments, the first lens group includes at least three lenses having a refractive index greater than 1.8.
Therefore, when the light with large angle enters the system diaphragm, the deflection angle is reduced. And meanwhile, the total length of a light path can be effectively shortened, the number of lenses can be reduced, and a compact optical structure is realized, preferably, the refractive indexes of the fifth lens, the sixth lens and the seventh lens in the scheme are all larger than 1.8, and the refractive indexes of the rest lenses can be also set to be larger than 1.8.
In some embodiments, the total length from the first mirror to the last mirror of the lens is between 90 and 100 mm, and the maximum aperture of the lens is between 32 and 36 mm.
Therefore, the maximum aperture of the lens is the aperture of the first lens group, and the total space of the lens is compact and light.
In some embodiments, the lens can be applied to a spectrometer and can be used with a large aperture flux F0.95 and a large target surface 1 inch sensor.
Therefore, the lens can meet the high-sensitivity detection of weak spectral signals, and the sensitivity of the spectrometer is improved.
The utility model has the advantages that: the first negative lens group is provided with two negative lenses matched with the negative and positive cemented lens, so that the short focal length close focusing distance and the large field angle are realized, the sensitivity of spectrum acquisition is improved, and the positive and negative cemented lens matched with the first positive lens group is favorable for correcting chromatic aberration and distortion;
the eighth lens of the second lens group can effectively balance coma and astigmatism of the front and rear lens groups, so that the matching tolerance sensitivity of the front and rear lens groups is greatly reduced, and the eighth lens is further provided with two cemented lenses, thereby being beneficial to correcting chromatic aberration and distortion.
The lens is provided with a plurality of lenses with large refractive indexes, and can effectively turn the incident light of a wide angle, so that when the light of a large angle enters a system diaphragm, the deflection angle is reduced, the total length of a light path can be effectively shortened and the number of the lenses can be reduced, the structure is compact, the short-focus near focusing distance can be realized, the low-distortion full-field high definition can be considered, the large-aperture small size can be realized, and the detection sensitivity to weak spectrum signals can be improved.
Drawings
Fig. 1 is a structural diagram of a large-aperture spectrum collecting lens according to the present invention;
fig. 2 is an axial coloring differential view of a large-aperture spectrum collecting lens according to the present invention;
fig. 3 is a schematic vertical axis chromatic aberration diagram of a large-aperture spectrum capturing lens according to the present invention;
fig. 4 is a schematic view of curvature of field of a large-aperture spectrum capturing lens according to the present invention;
fig. 5 is a schematic diagram of light aberration of a large-aperture spectrum collecting lens according to the present invention;
fig. 6 is a schematic diagram of a diffuse spot of a large-aperture spectrum collecting lens according to the present invention;
fig. 7 is a schematic MTF diagram of a large-aperture spectrum-capturing lens according to the present invention;
fig. 8 is a schematic view of MTF and field of view of a large-aperture spectrum-capturing lens according to the present invention;
wherein: g1-first lens group; g2-second lens group; g11 — first negative lens set; g12 — first positive lens group; l1-first lens; l2-second lens; l3-third lens; l4-fourth lens; l5-fifth lens; l6-sixth lens; l7-seventh lens; l8-eighth lens; l9-ninth lens; l10-tenth lens; l11-eleventh lens; l12-twelfth lens; l13-thirteen lenses; l14-fourteenth lens.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
Referring to fig. 1, a large-aperture spectrum taking lens includes, in order from an object side to an image side, a first lens group G1, a fixed stop STO, and a second lens group G2;
the first lens group G1 has positive power and is movable in position in the optical axis direction;
the second lens group G2 has positive power and is movable in position in the optical axis direction;
the first lens group G1 includes a first negative lens group G11 and a first positive lens group G12, the first negative lens group G11 includes at least two negative lenses, and the first positive lens group G12 includes a positive and negative cemented lens of positive power;
the first lens group G1 and the second lens group G2 satisfy the following formula:
1＜f1/f2＜2；－1＜f11/f1＜－0.5；
where f1 represents the focal length value of the first lens group G1, f2 represents the focal length value of the second lens group G2, and f11 represents the focal length value of the first negative lens group G11.
Further, the second lens group G2 includes at least one negative lens, and includes a positive and negative cemented lens of positive power and a negative and positive cemented lens of negative power.
Further, the first negative lens group G11 further includes a negative positive cemented lens of negative power.
Further, the back working distance of the lens is BFL, the focal length of the lens is f, and the following equation is satisfied: BFL/f is more than 0.5 and less than 1. The lens forms a reverse long-distance light path structure, and ensures enough rear working distance.
In detail, the refractive index of the sixth lens L6 of the first lens group G1 is between 1.85 and 1.95.
In addition, the refractive index of the tenth lens L10 of the second lens group G2 is between 1.70 and 1.80.
Further, the first lens group G1 includes at least three lenses with refractive index greater than 1.8.
Further, the total length from the first mirror surface to the last mirror surface of the lens is between 90 and 100 mm, and the maximum aperture of the lens is between 32 and 36 mm.
Further, the lens can be applied to a spectrometer and can be used with a large aperture light flux F0.95 and a large target surface 1 inch sensor.
The working principle is as follows:
the lens comprises a first lens group G1 and a second lens group G2, wherein the first lens group G1 can move for focusing, and the second lens group G2 can move for changing magnification.
The first lens group G1 comprises a first negative lens group G11 and a first positive lens group G12, the first negative lens group G11 sequentially comprises a first lens L1 with negative focal power, a second lens L2 with negative focal power and a negative and positive cemented lens from the object side to the image side, wherein the cemented lens is formed by cementing a third lens L3 with negative focal power and a fourth lens L4 with positive focal power, and the first negative lens group G11 can realize short focal distance and large field angle through two negative lenses and a negative cemented lens structure, can better collect a spectrum, and can improve the sensitivity of spectrum collection through the combined structure of the lenses.
The first lens group G1 may be provided with a plurality of negative lenses, and the short focal length close-focus distance and the angle of view can be further improved.
The first positive lens group G12 sequentially comprises a fifth lens L5 with positive focal power and a positive and negative cemented lens with positive focal power from the object side to the image side, wherein the cemented lens is formed by cementing a sixth lens L6 with positive focal power and a seventh lens L7 with negative focal power, light beams are converged and then diffused in the first lens group G1 continuously, the light path is in a gourd shape, so that astigmatism and curvature of field of the first lens group G1 are small, tolerance sensitivity of the front and rear lens groups can be reduced, and the matched structure of the cemented lens of the first negative lens group G11 and the cemented lens of the first positive lens group G12 can correct chromatic aberration and distortion and improve imaging resolution.
The second lens group G2 includes, in order from the object side to the image side, an eighth lens L8 with negative power, a positive-negative cemented lens with positive power, a negative-positive cemented lens with negative power, a thirteenth lens L13 with positive power, and a fourteenth lens L14 with positive power, in which the ninth lens L9 with positive power and the tenth lens L10 with negative power are cemented into a positive-negative cemented lens, and the eleventh lens L11 with negative power and the twelfth lens L12 with positive power are cemented into a negative-positive cemented lens.
The first lens L1 is a negative lens, and can effectively balance coma and astigmatism of the front and rear lens groups, so that the sensitivity of the front and rear lens groups to the matching tolerance is greatly reduced. The first lens group G1 may be provided with a plurality of negative lenses.
The two cemented lenses are arranged approximately oppositely, and the structural combination can correct chromatic aberration and distortion.
The lens can be assembled in optical instruments such as a spectrometer and the like, and can be matched with a large-aperture luminous flux F0.95 and a large-target-surface 1-inch sensor for use, so that the high-sensitivity detection of weak spectral signals is further improved.
Referring now to Table one, numerical data for some embodiments, such as radius of curvature, thickness, refractive index, Abbe number, etc. of the lens are shown, where S1-S25 represent the mirror surface of the lens from the object side to the image side, and the numerical data are typically in "mm" units.
Table one:
fig. 2 is an on-axis chromatic aberration diagram of an embodiment of the disclosure, fig. 3 is a vertical axis chromatic aberration diagram of an embodiment of the disclosure, fig. 4 is a field curvature distortion diagram of an embodiment of the disclosure, fig. 5 is a light aberration diagram of an embodiment of the disclosure, fig. 6 is a dispersed speckle diagram of an embodiment of the disclosure, fig. 7 is an MTF diagram of an embodiment of the disclosure, and fig. 8 is an MTF and field view diagram of an embodiment of the disclosure.
What has been disclosed above are only some embodiments of the invention. For those skilled in the art, without departing from the inventive concept, several modifications and improvements can be made, which are within the scope of the invention.
Claims (9)
1. The large-aperture spectrum collecting lens is characterized by comprising a first lens group (G1), a fixed diaphragm and a second lens group (G2) in sequence from an object side to an image side;
the first lens group (G1) has positive power and is movable in position in the optical axis direction;
the second lens group (G2) has positive power and is movable in position in the optical axis direction;
the first lens group (G1) comprises a first negative lens group (G11) and a first positive lens group (G12), the first negative lens group (G11) comprises at least two negative lenses, and the first positive lens group (G12) comprises a positive and negative cemented lens of positive optical power;
the first lens group (G1) and the second lens group (G2) satisfy the following formula:
1＜f1/f2＜2；－1＜f11/f1＜－0.5；
wherein f1 represents a focal length value of the first lens group (G1), f2 represents a focal length value of the second lens group (G2), and f11 represents a focal length value of the first negative lens group (G11).
2. The large aperture spectrum taking lens as claimed in claim 1, wherein the second lens group (G2) comprises at least one negative lens, and comprises a positive and negative cemented lens of positive power and a negative and positive cemented lens of negative power.
3. The large aperture spectrum taking lens as claimed in claim 1, wherein the first negative lens group (G11) further comprises a negative positive cemented lens of negative power.
4. The large aperture spectrum collecting lens of claim 1, wherein the back working distance of the lens is BFL, the focal length of the lens is f, and the following equation is satisfied: BFL/f is more than 0.5 and less than 1.
5. The large aperture spectrum taking lens as claimed in claim 1, wherein the refractive index of the sixth lens (L6) of the first lens group (G1) is between 1.85 and 1.95.
6. The large aperture spectrum taking lens as claimed in claim 1, wherein the refractive index of the tenth lens (L10) of the second lens group (G2) is between 1.70 and 1.80.
7. The large aperture spectrum taking lens as claimed in claim 1, wherein the first lens group (G1) comprises at least three lenses with refractive index greater than 1.8.
8. The large aperture spectrum collecting lens of claim 1, wherein the total length from the first mirror to the last mirror of the lens is between 90 and 100 mm, and the maximum aperture of the lens is between 32 and 36 mm.
9. The large aperture spectrum capture lens of claim 1, wherein the lens is capable of being used in a spectrometer and is capable of being used with a large aperture optical flux F0.95 and a large target surface 1 inch sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021389831.XU CN212645896U (en) | 2020-07-15 | 2020-07-15 | Spectrum collecting lens with large aperture |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021389831.XU CN212645896U (en) | 2020-07-15 | 2020-07-15 | Spectrum collecting lens with large aperture |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN212645896U true CN212645896U (en) | 2021-03-02 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202021389831.XU Active CN212645896U (en) | 2020-07-15 | 2020-07-15 | Spectrum collecting lens with large aperture |
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| CN (1) | CN212645896U (en) |
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2020
- 2020-07-15 CN CN202021389831.XU patent/CN212645896U/en active Active
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