CN112363303B - Common-caliber visible light and near infrared imaging optical system and application thereof - Google Patents
Common-caliber visible light and near infrared imaging optical system and application thereof Download PDFInfo
- Publication number
- CN112363303B CN112363303B CN202110041845.5A CN202110041845A CN112363303B CN 112363303 B CN112363303 B CN 112363303B CN 202110041845 A CN202110041845 A CN 202110041845A CN 112363303 B CN112363303 B CN 112363303B
- Authority
- CN
- China
- Prior art keywords
- optical system
- imaging optical
- double
- visible light
- lens
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
- G02B13/008—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras designed for infrared light
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
- G02B13/0055—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras employing a special optical element
- G02B13/006—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras employing a special optical element at least one element being a compound optical element, e.g. cemented elements
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
- G02B7/006—Filter holders
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
- G02B7/02—Mountings, adjusting means, or light-tight connections, for optical elements for lenses
- G02B7/025—Mountings, adjusting means, or light-tight connections, for optical elements for lenses using glue
Abstract
The invention provides a common-caliber visible light and near infrared imaging optical system which sequentially comprises a fairing D, a diaphragm S, a double-cemented lens C1, a double-convex positive focal power lens L3, a double-cemented lens C2, a meniscus negative focal power lens L6, a double-convex positive focal power lens L7 and a filter F from an object plane to an image plane along an optical axis; the double cemented lens C1 is composed of a double convex positive power lens L1 and a double concave negative power lens L2; the double cemented lens C2 is composed of a double concave negative power lens L4 and a meniscus negative power lens L5. The invention also provides application of the common-caliber visible light and near infrared imaging optical system in the field of traditional Chinese medicine diagnosis and the field of military optical guidance technology. The invention realizes the common light path design of visible light and near infrared, and can clearly image in both visible light and near infrared spectrum bands; meanwhile, the problems of large volume and low imaging quality of a discrete optical system can be solved, and the method is favorable for wide application and popularization in the traditional Chinese medicine diagnosis and military optical guidance technology.
Description
Technical Field
The invention relates to the technical field of optics, in particular to a common-caliber visible light and near infrared imaging optical system and application thereof.
Background
The existing imaging optical systems have achieved good performance and wide-ranging applications, such as security, monitoring, aerial photography, and measurement. In most of the existing imaging optical systems, discrete optical systems are used.
For example, in the intelligent diagnosis equipment of traditional Chinese medicine, the facial diagnosis instrument or the tongue diagnosis instrument adopts an optical imaging method to obtain facial image information or tongue image characteristic information of a human body, and provides digitalized and objective auxiliary information for the diagnosis of traditional Chinese medicine, so that the intelligent and practical development of modern traditional Chinese medicine diagnosis and treatment equipment is an important way. In a facial diagnosis instrument or a tongue diagnosis instrument, a separate optical system is generally adopted to obtain facial or tongue image characteristic information of a human body with different spectral bands, so that the equipment system is complex, the registration precision between different spectral bands is low, and the effectiveness of mutual verification is not high.
The optical guidance technology in the military field also adopts an imaging optical system to realize the accurate detection and identification of over-the-horizon targets, and provides long-distance target searching with high identification rate for the accurate guidance. Most of the existing optical guidance technologies also adopt a discrete optical system arranged at the front end of the guidance head to serve as imaging guidance. However, the discrete optical systems detect the target in different spectral bands, so that the volume and the weight of the seeker are increased, the requirement on light and small size cannot be met, the visual axis consistency of the different optical systems is difficult to guarantee, and the precision of accurate guidance is reduced. The current optical guidance technology also adopts an infrared composite optical system, but the infrared composite optical system mainly focuses on the dual-spectrum band or the multi-spectrum band of an infrared band, is limited by the performance of an infrared device, has relatively low detection precision, is generally applied to the detection of a long-distance point target, realizes the function of finding the target, and needs to be improved in the aspect of target identification capability.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a common-caliber visible light and near-infrared imaging optical system and application thereof; the imaging optical system realizes the common light path design of visible light and near infrared, and can clearly image in both visible light and near infrared spectral bands; meanwhile, the problems of large volume and low imaging quality of a discrete optical system can be solved, and the method is favorable for wide application and popularization in the traditional Chinese medicine diagnosis and military optical guidance technology.
In order to achieve the purpose, the invention is realized by the following technical scheme: a common-caliber visible light and near infrared imaging optical system is characterized in that: the optical lens sequentially comprises a fairing D, a diaphragm S, a double-cemented lens C1, a double-convex positive power lens L3, a double-cemented lens C2, a meniscus negative power lens L6, a double-convex positive power lens L7 and a filter F from an object plane to an image plane along an optical axis; the double cemented lens C1 consists of a double convex positive power lens L1 and a double concave negative power lens L2; the double cemented lens C2 is composed of a double concave negative power lens L4 and a meniscus negative power lens L5.
The focal power phi C1 of the double cemented lens C1 and the focal power phi of the imaging optical system satisfy the following relationship:
-0.18≤φC1/φ≤-0.08。
the focal power phi L3 of the biconvex positive power lens L3 and the focal power phi of the imaging optical system satisfy the following relation:
2.25≤φL3/φ≤2.85。
the focal power phi C2 of the double cemented lens C2 and the focal power phi of the imaging optical system satisfy the following relationship:
-1.75≤φC2/φ≤-1.25。
the focal power phi L6 of the meniscus negative power lens L6 and the focal power phi of the imaging optical system satisfy the following relationship:
-1.55≤φL6/φ≤-1.15。
the focal power phi L7 of the biconvex positive power lens L7 and the focal power phi of the imaging optical system satisfy the following relationship:
1.2≤φL7/φ≤1.6。
the aperture F # of the imaging optical system is between 1.5 and 3. The diaphragm S of the present invention is located on the front surface of the double convex positive power lens L1.
The optical surface of the optical filter F is coated with an antireflection film layer in a visible spectrum range, an antireflection film layer in a near infrared spectrum range or an antireflection film layer covering the visible light to the near infrared spectrum range.
The application of the common-caliber visible light and near infrared imaging optical system in the field of traditional Chinese medicine diagnosis is characterized in that: the imaging optical system is used as an optical imaging device of a facial diagnosis instrument or a tongue diagnosis instrument to acquire human body facial image information or tongue image characteristic information.
The invention adopts the imaging optical system of common caliber visible light and near infrared as the optical imaging device of the facial diagnosis instrument or the tongue diagnosis instrument, the facial diagnosis instrument or the tongue diagnosis instrument can clearly image in both visible light and near infrared spectrum sections through the imaging optical system, and can acquire multi-spectrum optical images with registration precision reaching pixel level by combining a high-performance detector, thereby improving the accuracy of the facial diagnosis instrument or the tongue diagnosis instrument for acquiring the facial or tongue image characteristic information of a human body by utilizing optical imaging.
The application of the common-caliber visible light and near infrared imaging optical system in the technical field of military optical guidance is characterized in that: the imaging optical system is used as a seeker optical system; the seeker optical system is arranged at the front end of the seeker to realize all-time imaging guidance.
The imaging optical system is used as a seeker optical system, so that the seeker has the characteristics of high resolution, light weight, small size and wide working temperature range while the seeker performs all-day optical imaging, and the guidance performance of the optical seeker is favorably improved. The imaging optical system has the application advantages in the technical field of military optical guidance:
1) the imaging optical system can clearly image in visible light and near infrared spectral bands, the spectral range covers 0.45-1.0 mu m, the best image plane confocal planes of the two spectral bands realize day-time and night all-day imaging, and the fighting efficiency of the seeker is greatly improved.
2) The imaging optical system realizes common-caliber design, the volume and the weight are greatly reduced, the imaging optical system is matched with a high-performance CMOS detector to work, one set of lens can realize two-spectrum imaging, and the visual axis consistency is good.
3) The spatial resolution is high, and the imaging detection requirement of the guide head on a long-distance target is met.
4) The thermal-free effect is good, no virtual coke is generated within the range of minus 40 ℃ to plus 60 ℃, and the imaging quality is excellent.
Compared with the prior art, the invention has the following advantages and beneficial effects: the common-caliber visible light and near infrared imaging optical system realizes common light path design of visible light and near infrared and can clearly image in both visible light and near infrared spectral bands; meanwhile, the problems of large volume and low imaging quality of a discrete optical system can be solved, and the method is favorable for wide application and popularization in the traditional Chinese medicine diagnosis and military optical guidance technology.
Drawings
FIG. 1 is a schematic diagram of a common aperture visible and near infrared imaging optical system of the present invention;
FIG. 2 is a graph of the optical transfer function of the imaging optical system of the present invention in the visible spectrum at 20 deg.C;
FIG. 3 is a graph of the optical transfer function of the imaging optical system of the present invention in the near infrared spectrum at 20 deg.C
FIG. 4 is a graph of the optical transfer function of the full visible and near infrared spectral ranges of the imaging optical system of the present invention;
FIG. 5 is a graph of the optical transfer function of the imaging optical system of the present invention in the visible region at-40 deg.C;
FIG. 6 is a graph of the optical transfer function of the imaging optical system of the present invention in the near infrared spectrum at-40 deg.C;
FIG. 7 is a graph of the optical transfer function of the imaging optical system of the present invention in the visible range at +60 ℃;
FIG. 8 is a graph of the optical transfer function of the imaging optical system of the present invention in the near infrared spectrum at +60 ℃.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
Example one
As shown in fig. 1 to 8, the common-aperture visible light and near-infrared imaging optical system of the present invention sequentially includes a fairing D, a diaphragm S, a double cemented lens C1, a double convex positive power lens L3, a double cemented lens C2, a meniscus negative power lens L6, a double convex positive power lens L7, and a filter F along an optical axis from an object plane to an image plane Ima, wherein the double cemented lens C1 is composed of a double convex positive power lens L1 and a double concave negative power lens L2, and the double cemented lens C2 is composed of a double concave negative power lens L4 and a meniscus negative power lens L5.
Specifically, the power Φ C1 of the doublet C1 and the power Φ of the imaging optical system satisfy the following relationship:
-0.18≤φC1/φ≤-0.08。
the power Φ L3 of the double convex positive power lens L3 and the power Φ of the imaging optical system satisfy the following relationship:
2.25≤φL3/φ≤2.85。
the power phi C2 of the double cemented lens C2 and the power phi of the imaging optical system satisfy the following relationship:
-1.75≤φC2/φ≤-1.25。
the power Φ L6 of the meniscus negative power lens L6 and the power Φ of the imaging optical system satisfy the following relationship:
-1.55≤φL6/φ≤-1.15。
the power Φ L7 of the double-convex positive power lens L7 and the power Φ of the imaging optical system satisfy the following relationship:
1.2≤φL7/φ≤1.6。
the aperture F # of the imaging optical system of the present invention is between 1.5 and 3. The diaphragm S of the present invention is located on the front surface of the double convex positive power lens L1.
In the embodiment of the invention, according to different application requirements, the optical surface of the optical filter F can be coated with an antireflection film layer in a visible spectrum range, an antireflection film layer in a near infrared spectrum range or an antireflection film layer covering from visible light to the near infrared spectrum range.
The optical parameters of the imaging optical system of the present embodiment are specifically shown in the following table.
In the embodiment of the invention, the imaging optical system composed of the lens achieves the following technical indexes:
(1) the working wave band is as follows: visible light is 0.45-0.65 μm, and near infrared is 0.65-1 μm; (2) focal length: 72 mm; (3) a detector: 1024 × 1024, 5.5 μm; (4) relative pore diameter: f #/2.4; (5) pixel resolution: 0.076 mrad.
In the embodiment of the invention, the imaging optical system can be matched with a high-performance CMOS detector to work, and detection imaging of visible light, near infrared or a full spectrum range from visible light to near infrared can be respectively realized by combining the arrangement of a film layer on the optical filter F.
Fig. 2, 3 and 4 respectively show the optical transfer function curve distribution of the optical system of the embodiment of the invention in the visible spectrum, near infrared spectrum and visible and near infrared full spectrum at 20 ℃. Wherein, the average optical transfer function value of the visible spectrum band reaches 0.61@90lp/mm, and the average optical transfer function value of the near infrared spectrum band reaches 0.59@90 lp/mm; the optical transfer function value under the visible light and near infrared full spectrum band reaches 0.58@90lp/mm, and the imaging quality is excellent at normal temperature.
In the embodiment of the invention, the structural member of the imaging optical system is made of an aluminum alloy material, the optical system avoids the use of glass materials such as HFK61 and the like which are beneficial to reducing chromatic aberration but are easy to cause thermal defocusing, and the athermalization design in the range of minus 40 ℃ to plus 60 ℃ is realized by the passive athermalization design of an optical machine and the matching of the thermal parameters of the optical glass and the structural material. FIGS. 5 to 8 respectively show the optical transfer function curve distributions of the visible spectrum band and the near infrared spectrum band at-40 ℃ and the visible spectrum band and the near infrared spectrum band at +60 ℃ in the optical system of the embodiment of the present invention. Wherein the average optical transfer function value of a visible spectrum band at-40 ℃ reaches 0.51@90lp/mm, and the average optical transfer function value of a near infrared spectrum band reaches 0.61@90 lp/mm; the average optical transfer function value of the visible spectrum band at +60 ℃ reaches 0.64@90lp/mm, and the average optical transfer function value of the near infrared spectrum band reaches 0.51@90 lp/mm. Therefore, the imaging optical system has excellent imaging quality at different temperatures, and can adapt to complex temperature environments.
Example two
The common-caliber visible light and near infrared imaging optical system disclosed by the invention is applied to the field of traditional Chinese medicine diagnosis: the imaging optical system is used as an optical imaging device of a facial diagnosis instrument or a tongue diagnosis instrument to acquire human body facial image information or tongue image characteristic information.
The invention adopts the imaging optical system of common caliber visible light and near infrared as the optical imaging device of the facial diagnosis instrument or the tongue diagnosis instrument, the facial diagnosis instrument or the tongue diagnosis instrument can clearly image in both visible light and near infrared spectrum sections through the imaging optical system, and can acquire multi-spectrum optical images with registration precision reaching pixel level by combining a high-performance detector, thereby improving the accuracy of the facial diagnosis instrument or the tongue diagnosis instrument for acquiring the facial or tongue image characteristic information of a human body by utilizing optical imaging.
EXAMPLE III
The application of the common-caliber visible light and near infrared imaging optical system in the technical field of military optical guidance is as follows: the imaging optical system is used as a seeker optical system which is arranged at the front end of the seeker to realize all-day imaging guidance.
The imaging optical system is used as a seeker optical system, so that the seeker has the characteristics of high resolution, light weight, miniaturization and wide working temperature range while the seeker performs optical imaging all day long, the guidance performance of the optical seeker is improved, and the clear imaging and tracking of military hit targets are guaranteed. The imaging optical system can be matched with a high-performance CMOS detector to work, can respectively realize detection imaging of visible light, near infrared or a full spectrum range from visible light to near infrared by combining the arrangement of a film layer on the optical filter F, is used for an optical precision guidance seeker system, and realizes all-day imaging guidance.
The imaging optical system has the application advantages in the technical field of military optical guidance:
1) the imaging optical system can clearly image in visible light and near infrared spectral bands, the spectral range covers 0.45-1.0 mu m, the best image plane confocal planes of the two spectral bands realize day-time and night all-day imaging, and the fighting efficiency of the seeker is greatly improved.
2) The imaging optical system realizes common-caliber design, the volume and the weight are greatly reduced, the imaging optical system is matched with a high-performance CMOS detector to work, one set of lens can realize two-spectrum imaging, and the visual axis consistency is good.
3) The spatial resolution is high, and the imaging detection requirement of the guide head on a long-distance target is met.
4) The thermal-free effect is good, no virtual coke is generated within the range of minus 40 ℃ to plus 60 ℃, and the imaging quality is excellent.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.
Claims (9)
1. A common-caliber visible light and near infrared imaging optical system is characterized in that: the optical lens sequentially comprises a fairing D, a diaphragm S, a double-cemented lens C1, a double-convex positive power lens L3, a double-cemented lens C2, a meniscus negative power lens L6, a double-convex positive power lens L7 and a filter F from an object plane to an image plane along an optical axis; the double cemented lens C1 consists of a double convex positive power lens L1 and a double concave negative power lens L2 in sequence from the object plane to the image plane along the optical axis; the double cemented lens C2 consists of a double concave negative power lens L4 and a meniscus negative power lens L5 in sequence from an object plane to an image plane along an optical axis;
the focal power phi C1 of the double cemented lens C1 and the focal power phi of the imaging optical system satisfy the following relationship:
-0.18≤φC1/φ≤-0.08。
2. the common-aperture visible light and near-infrared imaging optical system according to claim 1, characterized in that: the focal power phi L3 of the biconvex positive power lens L3 and the focal power phi of the imaging optical system satisfy the following relation:
2.25≤φL3/φ≤2.85。
3. the common-aperture visible light and near-infrared imaging optical system according to claim 1, characterized in that: the focal power phi C2 of the double cemented lens C2 and the focal power phi of the imaging optical system satisfy the following relationship:
-1.75≤φC2/φ≤-1.25。
4. the common-aperture visible light and near-infrared imaging optical system according to claim 1, characterized in that: the focal power phi L6 of the meniscus negative power lens L6 and the focal power phi of the imaging optical system satisfy the following relationship:
-1.55≤φL6/φ≤-1.15。
5. the common-aperture visible light and near-infrared imaging optical system according to claim 1, characterized in that: the focal power phi L7 of the biconvex positive power lens L7 and the focal power phi of the imaging optical system satisfy the following relationship:
1.2≤φL7/φ≤1.6。
6. the common-aperture visible light and near-infrared imaging optical system according to claim 1, characterized in that: the aperture F # of the imaging optical system is between 1.5 and 3.
7. The common-aperture visible light and near-infrared imaging optical system according to claim 1, characterized in that: the optical surface of the optical filter F is coated with an antireflection film layer in a visible spectrum range, an antireflection film layer in a near infrared spectrum range or an antireflection film layer covering the visible light to the near infrared spectrum range.
8. Use of the common-aperture visible light and near-infrared imaging optical system according to any one of claims 1 to 7 in the field of diagnosis of traditional Chinese medicine, wherein: the imaging optical system is used as an optical imaging device of a facial diagnosis instrument or a tongue diagnosis instrument to acquire human body facial image information or tongue image characteristic information.
9. The application of the common-caliber visible light and near infrared imaging optical system of any one of claims 1 to 7 in the technical field of military optical guidance is characterized in that: the imaging optical system is used as a seeker optical system; the seeker optical system is arranged at the front end of the seeker to realize all-time imaging guidance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110041845.5A CN112363303B (en) | 2021-01-13 | 2021-01-13 | Common-caliber visible light and near infrared imaging optical system and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110041845.5A CN112363303B (en) | 2021-01-13 | 2021-01-13 | Common-caliber visible light and near infrared imaging optical system and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112363303A CN112363303A (en) | 2021-02-12 |
| CN112363303B true CN112363303B (en) | 2021-03-23 |
Family
ID=74534929
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110041845.5A Active CN112363303B (en) | 2021-01-13 | 2021-01-13 | Common-caliber visible light and near infrared imaging optical system and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112363303B (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20200007219A (en) * | 2018-07-12 | 2020-01-22 | 삼성전기주식회사 | Image Capturing Lens System |
| CN212302039U (en) * | 2020-05-21 | 2021-01-05 | 广东奥普特科技股份有限公司 | High-resolution optical lens |
-
2021
- 2021-01-13 CN CN202110041845.5A patent/CN112363303B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN112363303A (en) | 2021-02-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102495474B (en) | Visible light/long-wave infrared broad band spectrum joint focusing optical imaging system | |
| CN107991763B (en) | High-definition long-focus long-wave infrared lens | |
| CN112305721B (en) | Infrared dual-band telescopic optical system | |
| CN110687668A (en) | Optical passive type athermal long-focus short-wave infrared continuous zoom lens | |
| CN111025529B (en) | Ultra-small F number medium-long wave infrared fixed-focus lens | |
| CN109739025B (en) | Common-path two-waveband optical system, imaging device and optical lens | |
| CN210090814U (en) | Long-focus medium-wave infrared refrigeration double-view-field lens | |
| CN214151214U (en) | Infrared dual-band telescopic optical system, search tracking system and forward-looking infrared system | |
| CN113741009A (en) | Thermal difference eliminating infrared lens with focal length of 25mm and assembling method thereof | |
| CN208506352U (en) | It can be used for the portable camera lens that unmanned plane is shot on a large scale | |
| CN112363303B (en) | Common-caliber visible light and near infrared imaging optical system and application thereof | |
| CN108363190B (en) | Lens system and lens | |
| CN103207443A (en) | Objective lens system for near-infrared flight vehicle attitude and position measurement | |
| CN216133244U (en) | High-zoom-ratio long-wave infrared continuous zoom lens | |
| CN114624896A (en) | Long-focus double-view-field television/short-wave infrared common-path optical system | |
| CN108732720A (en) | A kind of object lens of large relative aperture fish eye lens can be applied to photography | |
| CN114252982A (en) | Thermal difference elimination infrared lens with focal length of 35mm, assembling method thereof and imaging method | |
| CN107092076B (en) | A kind of high pass light quantity compact LONG WAVE INFRARED tight shot | |
| CN113835212B (en) | Ultra-light digital sighting device optical system | |
| CN217443630U (en) | High-resolution camera lens optical system | |
| CN114089511B (en) | Very wide band transmission type telescopic optical system | |
| CN111381352A (en) | Transmission type double-spectrum common-aperture zooming optical system | |
| CN218497244U (en) | Optical lens system | |
| CN116149031B (en) | Wide-angle lens and virtual reality device | |
| CN109683295B (en) | Long-focus short-wave infrared optical lens and electronic equipment applying same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |