CN202758089U - Fresnel lens - Google Patents
Fresnel lens Download PDFInfo
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- CN202758089U CN202758089U CN 201220134019 CN201220134019U CN202758089U CN 202758089 U CN202758089 U CN 202758089U CN 201220134019 CN201220134019 CN 201220134019 CN 201220134019 U CN201220134019 U CN 201220134019U CN 202758089 U CN202758089 U CN 202758089U
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Abstract
The utility model discloses a Fresnel lens, comprising a first lens part, a second lens part, a third lens part and a fourth lens part, which are integrated on a lens surface. Each lens part comprises a plurality of windows. According to the Fresnel lens of the utility model, the design of a multi-layer combined lens is adopted, the focal distance is designed by adopting different lens in each layer, and the long-distance detection, the middle-distance detection and the close-distance detection are realized by changing the focal distance. Furthermore, blind areas of a detection area are reduced through mutual complementation of the multi-layer lens. Lights are gathered to the same point by adjusting the position of the optical center of the lens, so that the problem that an object to be detected moves towards the lens direction but can not be detected or can be detected only when moving to the very close distance. According to the Fresnel lens adopting the ultrathin wall design, the problems caused by great energy loss due to thick Fresnel lenses can be reduced.
Description
Technical field
The utility model relates to a kind of optical device, relates in particular to a kind of Fresnel Lenses for Safety defence detector.
Background technology
Fresnel Lenses is exactly the lens that equidistant groove is arranged in a side, by these grooves, can play the effect that the light belt of specifying spectral range is reflected or reflects.
Fresnel Lenses is normally by the injection molded thin slice of the polymeric materials such as polyolefin, and lens surface simultaneously is the light face, the another side imprinting ascending groove concentric circles.Under many circumstances, Fresnel Lenses is equivalent to the convex lens of infrared ray and visible light.The Fresnel Lenses effect mainly contains two: the one, and focussing force; The 2nd, release infrared signal with the form of temperature variation in the heat that the passive infrared line detector (PIR) with Fresnel Lenses changes with being divided into several area pellucidas and dark space in the search coverage, making the motive objects physical efficiency that enters search coverage.Fresnel Lenses utilizes the special optical principle of lens, produces " blind area " and " highly sensitive district " that alternately changes in detector the place ahead, to improve its detection receiving sensitivity.Out-of-date when there being the people to walk before the lens, the infrared ray that human body sends just constantly alternately enters " highly sensitive district " from " blind area ", and the infrared signal that receives is inputted with dynamic impulse form, thus its energy discharge amplitude by force.Therefore, Fresnel Lenses is through being usually used in the devices such as alarm.
There is following problem in existing Fresnel Lenses:
One, detection range is single, and there is the blind area in detection.Present Fresnel Lenses is made of a plurality of eyeglasses with single focal length usually, and can occur sensing range " blind area " between the eyeglass.
Two, proximity detection is bad.When Infrared slants the concentric circles groove of closeup lens, can produce refraction, but its aperture is very large, without focus point, so this type of lens do not possess in-plant detecting function.Be reflected in the concrete application, when object to be detected in face of the athletic meeting of lens direction occur to survey less than or move to very near apart from the time problem that just can detect.
The utility model content
For the problem that prior art exists, the purpose of this utility model provides a kind of Fresnel Lenses that can realize multiple detection range, minimizing blind area and improve the proximity detection effect.
The Fresnel Lenses that the utility model provides comprises first lens section, the second lens section, the 3rd lens section, the 4th lens section, and described four lens sections are integrated on the lens face, and each lens section includes a plurality of forms.Wherein: the focal length of first lens section is less than the focal length of the second lens section; The focal length of the second lens section is less than the focal length of the 3rd lens section; The focal length of the 3rd lens section is less than the focal length of the 4th lens section, the second lens section is adjacent to be arranged on first lens subordinate side, the 3rd lens section is adjacent to be arranged on the second lens section below, the 4th lens section is adjacent to be arranged on the 3rd lens section below, and the focus of described four lens sections is positioned at same point.
Preferably, in the second lens section in the middle part of each form and the first lens section limit between the adjacent form align, in the 3rd lens section in middle part and second lens section of each form the limit between the adjacent form align, in the 4th lens section in middle part and the 3rd lens section of each form the limit between the adjacent form align.
Preferably, the focal length of described first lens section is 26mm, and the distance of detection is 10 meters-18 meters; The focal length of the second lens section is 26.5mm, and the distance of detection is 10 meters-15 meters; The focal length of the 3rd lens section is 27.5mm, and the distance of detection is 6 meters-10 meters; The focal length of the 4th lens section is 29mm, and the distance of detection is 0.5 meter-6 meters.
Preferably, each in first lens section, the second lens section, the 3rd lens section, the 4th lens section includes row's form, each form measure-alike.
Preferably, first lens section comprises 13 forms that are arranged in a row; The second lens section comprises 10 forms that are arranged in a row; The 3rd lens section comprises 7 forms that are arranged in a row; The 4th lens section comprises 5 forms that are arranged in a row.
Preferably, the concentrically ringed center of circle of groove of the 3rd row's form and the 4th row's form is offset to the below of form geometric center.
Preferably, the thickness of described Fresnel Lenses is 0.38 millimeter-0.42 millimeter.
Preferably, the thickness of described Fresnel Lenses is 0.4 millimeter.
Preferably, the concentrically ringed tooth Profile Machining tolerance of groove is less than 0.002 millimeter.
Preferably, described four lens sections are integrated on a column type lens face or the ball-type lens face.
With respect to prior art, Fresnel Lenses of the present utility model adopts the design of multiple layer combination lens, and every layer is adopted different Lens Design focal lengths, by zoom realize at a distance, middle distance, in-plant detection.And, by mutually remedying of multilayer lens, reduced the blind area of search coverage.
In the utility model, by adjusting the photocentre position of lens, realize that light-ray condensing is to same point.Thereby solved object and moved the problem that just can detect very closely the time to the distance lens less than maybe needing of surveying in face of the lens direction.
The utility model adopts the Fresnel Lenses of ultra-thin wall thickness, has reduced because Fresnel Lenses is thick the problem of the large generation of energy loss.
In addition, traditional Fresnel Lenses is because employing electroforming mould copies processing, so mismachining tolerance is large, light often can not be refracted on a bit, thereby cause the large problem of energy loss.And Fresnel Lenses of the present utility model adopts the superhigh precision machine work, has improved the machining precision of lens, has reduced energy loss.
Description of drawings
Fig. 1 is the plane projection schematic diagram of minute surface of the Fresnel Lenses of a kind of preferred implementation of the utility model;
Fig. 2 is the profile of tooth schematic diagram of first row lens shown in Figure 1;
Fig. 3 is second row lens shown in Figure 1, the profile of tooth schematic diagram of the 3rd row's lens;
Fig. 4 is the profile of tooth schematic diagram of the 4th row's lens shown in Figure 1;
Fig. 5 is the index path of single lens of the Fresnel Lenses of a kind of preferred implementation of the utility model;
Fig. 6 is the index path of the Fresnel Lenses of a kind of preferred implementation of the utility model.
Embodiment
In a kind of embodiment of the present utility model, Fresnel Lenses comprises first lens section 10, the second lens section 20, the 3rd lens section 30, the 4th lens section 40, and described four lens sections are integrated on the lens face.Four lens sections are vertically being gone up from top to bottom arrangement, that is: the second lens section is adjacent to be arranged on first lens subordinate side, the 3rd lens section is adjacent to be arranged on the second lens section below, and the 4th lens section is adjacent to be arranged on the 3rd lens section below.And the focus of described four lens sections is positioned at same point.
In present embodiment, adopt four row's Lens Designs, first lens section 10, the second lens section 20, the 3rd lens section 30, the 4th lens section 40 are respectively the first row lens, second row lens, the 3rd row's lens and the 4th row's lens.Every row's lens have respectively different focal lengths, with the different detection range of correspondence.It will be understood by those skilled in the art that each lens section also can be many row's lens.
In the present embodiment, the first row lens are the long-range detection lens, and second row lens, the 3rd row's lens are the middle distance finder lens, and the 4th row's lens are the proximity detection lens.The focal length of first lens section 10 is less than the focal length of the second lens section 20.The focal length of the second lens section 20 is less than the focal length of the 3rd lens section 30.The focal length of the 3rd lens section 30 is less than the focal length of the 4th lens section 40.
In the present embodiment, described four lens sections are integrated on the column type lens face.In other preferred implementations, four lens sections can be integrated on the ball-type lens face.
In a preferred embodiment, the focal length of first lens section is 26mm, and detection range is 10 meters-18 meters; The focal length of the second lens section is 26.5mm, and detection range is 10 meters-15 meters; The focal length of the 3rd lens section is 27.5mm, and detection range is 6 meters-10 meters; The focal length of the 4th lens section is 29mm, and detection range is 0.5 meter-6 meters.
Fig. 1 is the integral layout figure of the Fresnel Lenses of a kind of preferred implementation of the utility model, and in this embodiment, whole Fresnel Lenses adopts 35 forms, and each form is a slice lens.
The first row lens are the long-range detection district among Fig. 1, and larger to the size at edge from the concentrically ringed center of groove, the zone of light penetration is larger.Second row lens, the 3rd row's lens are the middle distance detecting area, and Area comparison is little, light penetration regional smaller, and the scope of detection is relatively little.The 4th row's lens are the proximity detection district.
Fig. 2 is the profile of tooth schematic diagram of first row lens, and these row's lens comprise 13 forms that wait the tooth depth design.Fresnel Lenses to be set as example at a Cylinder Surface: adjacent two forms of first row lens in a circumferential direction interval 7.5 degree are installed, each form has the size of formed objects, to guarantee that each form investigative range equates, also can guarantee that the energy acquisition of each form when cooperating passive infrared detector to use is identical simultaneously.In addition, the form of first row lens is oblong, and this can guarantee can collect more energy effectively when long-range detection, so that Effect on Detecting is surveyed with middle distance, proximity detection is consistent.
Fig. 3 is the flute profile Pareto diagram of Fresnel Lenses middle distance finder lens, and namely second row lens, the 3rd are arranged the schematic diagram of lens, and second row comprises 10 forms; 7 forms are drawn together in the 3rd package.Fig. 4 is Fresnel Lenses proximity detection flute profile Pareto diagram, namely the 4th row lens schematic diagram, the 4th row lens comprises 5 forms.
The tooth depth designs such as above-mentioned first row lens, second row lens, each form in the 3rd row's lens and the 4th row's lens adopt.Form number among each row and the size of each form can be determined according to practical application.
In preferred implementation of the present utility model, the light that reflects for the form that makes different detection ranges converges in same point, the concentrically ringed center of circle of groove of the 3rd row's form and the 4th row's form need to be deviated from the setting of form geometric center.As shown in Figure 1, the concentrically ringed center of circle of groove of the 3rd row's form and the 4th row's form is offset to the below of form geometric center.Concrete amount of bias need to be determined according to the concrete debugging that should be used for.The purpose of doing like this be with middle distance survey, low coverage survey from the time focus drop on the focus of first row form, thereby realize adopting a sensor to realize the detection of different distance with a focus.
Fig. 5 is the index path of the single lens (being form) in the Fresnel Lenses of a kind of preferred implementation of the utility model; As shown in Figure 5, directional light shines on the single lens (for example form) in the Fresnel Lenses, and through the refraction of lens, light converges on the focus f of these lens.
Fig. 6 is the index path of the Fresnel Lenses of a kind of preferred implementation of the utility model.In Fig. 6, show the index path of the Fresnel Lenses that has comprised four lens sections in the utility model.Directional light in remote the detection shines on the first row lens, and behind the in-plant oblique ray irradiation second row lens, the 3rd row's lens, the 4th row's lens, also all converges on the focus f.According to the refraction principle of lens, after light is through groove concentrically ringed " upper semi-circle " part refraction, formation be the angle of depression, the light that namely bends inwards; After light is through groove concentrically ringed " lower half circle " part refraction, formation be the elevation angle, i.e. the light of outward.So shown in Fig. 1,2,3,4,6, in Fresnel Lenses of the present utility model, first and third, four row's forms all are to have utilized groove concentrically ringed " upper semi-circle part ", the second row form has then utilized groove concentrically ringed " center of circle " part.
In the utility model, every row's lens mutual dislocation ground arranges, that is, in the second lens section 20 in the middle part of each form and the first lens section 10 limit between the adjacent form align, in the 3rd lens section 30 in middle part and second lens section 20 of each form the limit between the adjacent form align, in the 4th lens section 40 in middle part and the 3rd lens section 30 of each form the limit between the adjacent form align.Can avoid like this in the investigative range blind area excessive, can also in the situation that mobile object faces detector walks about, detect the movement of objects in the search coverage.Like this, can form reticulate texture, the dead angle of effectively reducing search coverage in whole search coverage.
Preferably, on the Fresnel Lenses flute profile machining tolerance of each form less than 0.002mm.Traditional Fresnel Lenses often can not be refracted on some light, thereby causes the large problem of energy loss because mismachining tolerance is large.The process of Fresnel Lenses comprises: with polymeric material injection mo(u)ldings such as polyolefin; On the parts after the injection moulding, go out corresponding groove concentric circles by machine tooling, thereby form Fresnel Lenses.In the utility model, the operable lathe of Fresnel Lenses injection mo(u)lding is horizontal injection press, the horizontal injection press of the brands such as hero, Mitsubishi of shaking such as Taiwan.And, in order to guarantee above-mentioned machining precision, the utility model utilizes ultrahigh precision degree process equipment to process Fresnel Lenses, and the instrument of processing is ultrahigh precision degree lathe or ultrahigh precision degree milling machine, for example, the equipment such as three-shaft linkage numerically controlled lathe, three-shaft linkage CNC milling machine, machining center.The cutter of lathe or milling machine is the diamond cutter head.
Preferably, by above-mentioned process equipment and processing mode, the thickness of Fresnel Lenses of the present utility model is 0.38 millimeter-0.42 millimeter.More preferably, the thickness of Fresnel Lenses is 0.4 millimeter.Therefore, the utility model has reduced the large problem of energy loss that traditional Fresnel Lenses thickness causes greatly.
Above embodiment is only in order to illustrate the utility model and the described technical scheme of unrestricted the utility model; Therefore, although this instructions has been described in detail the utility model with reference to each above-mentioned embodiment,, those of ordinary skill in the art should be appreciated that still and can make amendment or be equal to replacement the utility model; And all do not break away from technical scheme and the improvement thereof of spirit and scope of the present utility model, and it all should be encompassed in the middle of the claim scope of the present utility model.
Claims (10)
1. a Fresnel Lenses is characterized in that, described Fresnel Lenses comprises first lens section, the second lens section, the 3rd lens section, the 4th lens section, and described four lens sections are integrated on the lens face, and each lens section includes a plurality of forms, wherein:
The focal length of first lens section is less than the focal length of the second lens section; The focal length of the second lens section is less than the focal length of the 3rd lens section; The focal length of the 3rd lens section is less than the focal length of the 4th lens section, the second lens section is adjacent to be arranged on first lens subordinate side, the 3rd lens section is adjacent to be arranged on the second lens section below, the 4th lens section is adjacent to be arranged on the 3rd lens section below, and the focus of described four lens sections is positioned at same point.
2. Fresnel Lenses according to claim 1, it is characterized in that, in the second lens section in the middle part of each form and the first lens section limit between the adjacent form align, in the 3rd lens section in middle part and second lens section of each form the limit between the adjacent form align, in the 4th lens section in middle part and the 3rd lens section of each form the limit between the adjacent form align.
3. Fresnel Lenses according to claim 1 and 2 is characterized in that, the focal length of described first lens section is 26mm, and the distance of detection is 10 meters-18 meters; The focal length of the second lens section is 26.5mm, and the distance of detection is 10 meters-15 meters; The focal length of the 3rd lens section is 27.5mm, and the distance of detection is 6 meters-10 meters; The focal length of the 4th lens section is 29mm, and the distance of detection is 0.5 meter-6 meters.
4. Fresnel Lenses according to claim 1 and 2 is characterized in that, each in first lens section, the second lens section, the 3rd lens section, the 4th lens section includes row's form, each form measure-alike.
5. Fresnel Lenses according to claim 4 is characterized in that, first lens section comprises 13 forms that are arranged in a row; The second lens section comprises 10 forms that are arranged in a row; The 3rd lens section comprises 7 forms that are arranged in a row; The 4th lens section comprises 5 forms that are arranged in a row.
6. Fresnel Lenses according to claim 4 is characterized in that, the concentrically ringed center of circle of groove of the 3rd row's form and the 4th row's form is offset to the below of form geometric center.
7. Fresnel Lenses according to claim 1 is characterized in that, the thickness of described Fresnel Lenses is 0.38 millimeter-0.42 millimeter.
8. Fresnel Lenses according to claim 6 is characterized in that, the thickness of described Fresnel Lenses is 0.4 millimeter.
9. Fresnel Lenses according to claim 6 is characterized in that, the concentrically ringed tooth Profile Machining tolerance of groove is less than 0.002 millimeter.
10. Fresnel Lenses according to claim 1 is characterized in that, described four lens sections are integrated on a column type lens face or the ball-type lens face.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220134019 CN202758089U (en) | 2012-04-01 | 2012-04-01 | Fresnel lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220134019 CN202758089U (en) | 2012-04-01 | 2012-04-01 | Fresnel lens |
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| CN202758089U true CN202758089U (en) | 2013-02-27 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN 201220134019 Withdrawn - After Issue CN202758089U (en) | 2012-04-01 | 2012-04-01 | Fresnel lens |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102608681A (en) * | 2012-04-01 | 2012-07-25 | 浙江大华智网科技有限公司 | Fresnel lens |
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2012
- 2012-04-01 CN CN 201220134019 patent/CN202758089U/en not_active Withdrawn - After Issue
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102608681A (en) * | 2012-04-01 | 2012-07-25 | 浙江大华智网科技有限公司 | Fresnel lens |
| CN102608681B (en) * | 2012-04-01 | 2015-10-07 | 浙江大华技术股份有限公司 | Fresnel Lenses |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| ASS | Succession or assignment of patent right |
Owner name: DAHUA TECHNOLOGY CO., LTD., ZHEJIANG Free format text: FORMER OWNER: ZHEJIANG DAHUA ZWAN TECHNOLOGY CO., LTD. Effective date: 20140718 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20140718 Address after: Hangzhou City, Zhejiang province Binjiang District 310053 shore road 1187 Patentee after: Zhejiang Dahua Technology Co., Ltd. Address before: Hangzhou City, Zhejiang province Binjiang District 310053 shore road 1199 Patentee before: Zhejiang Dahua Zwan Technology Co., Ltd. |
|
| AV01 | Patent right actively abandoned |
Granted publication date: 20130227 Effective date of abandoning: 20151007 |
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| C25 | Abandonment of patent right or utility model to avoid double patenting |