CN114563860A - Optical imaging system - Google Patents

Optical imaging system Download PDF

Info

Publication number
CN114563860A
CN114563860A CN202210423465.2A CN202210423465A CN114563860A CN 114563860 A CN114563860 A CN 114563860A CN 202210423465 A CN202210423465 A CN 202210423465A CN 114563860 A CN114563860 A CN 114563860A
Authority
CN
China
Prior art keywords
lens
imaging system
optical imaging
convex
concave
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.)
Granted
Application number
CN202210423465.2A
Other languages
Chinese (zh)
Other versions
CN114563860B (en
Inventor
蔡奎玟
李恩宠
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Samsung Electro Mechanics Co Ltd
Original Assignee
Samsung Electro Mechanics Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from KR1020210039790A external-priority patent/KR102642903B1/en
Application filed by Samsung Electro Mechanics Co Ltd filed Critical Samsung Electro Mechanics Co Ltd
Priority to CN202210423465.2A priority Critical patent/CN114563860B/en
Publication of CN114563860A publication Critical patent/CN114563860A/en
Application granted granted Critical
Publication of CN114563860B publication Critical patent/CN114563860B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • G02B13/0015—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
    • G02B1/041—Lenses
    • 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
    • G02B13/0015—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design
    • G02B13/002—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface
    • G02B13/0045—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface having five or more lenses
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/18—Optical objectives specially designed for the purposes specified below with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B29/00—Combinations of cameras, projectors or photographic printing apparatus with non-photographic non-optical apparatus, e.g. clocks or weapons; Cameras having the shape of other objects
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B30/00—Camera modules comprising integrated lens units and imaging units, specially adapted for being embedded in other devices, e.g. mobile phones or vehicles

Abstract

An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, which are arranged in this order from an object side. The optical imaging system satisfies | Pnu | [10 | ]‑6℃‑1mm‑1]30 ≦ wherein Pnu is ∑ Pnui, wherein i ═ 1, 2,. and 7, Pnui is 1/(vti · fi), vti is [ DTni/(ni-1) -CTEi ≦ CTEi]‑1Where fi is an effective focal length of the ith lens, ni is a refractive index of the ith lens, DTni is a rate of change of the refractive index of the ith lens according to temperature (dni/dT), and CTEi is a coefficient of thermal expansion of the ith lens.

Description

Optical imaging system
Cross Reference to Related Applications
This application claims the benefit of priority of korean patent application No. 10-2021-0039790, filed on 26.3.2021 to the korean intellectual property office, the entire disclosure of which is incorporated herein by reference for all purposes.
Technical Field
The following description relates to an optical imaging system, and more particularly, to an optical imaging system applied to a camera mounted on a vehicle.
Background
As the number of vehicles equipped with image processing functions such as lane keeping or autonomous driving increases, the demand for monitoring cameras and sensing cameras that can support these functions also increases. As the number of required cameras increases, the demand for cameras that can provide higher resolution for precise image processing also increases, and thus the demand for development of high-definition precision lenses suitable for mass production has arisen.
Taking a camera lens mounted on a vehicle as an example, a lens formed of glass is mainly used because resolution should be maintained even in a relatively large temperature range. Glass lenses are relatively expensive and therefore disadvantageous in terms of mass production and economy. The use of the plastic lens is advantageous for mass production, and the cost of the lens can be effectively reduced.
However, compared to glass, since plastic has the following characteristics: the refractive index or volume change is relatively large according to the temperature change, and thus it is difficult to provide an appropriate level of resolution in different environments. For example, plastic has a refractive index change about 100 times higher than that of glass and a thermal expansion coefficient about 10 times higher than that of glass according to temperature change, and thus, the amount of defocus caused by temperature change is large and it is difficult to maintain focus over a relatively wide temperature range.
Disclosure of Invention
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
Examples provide an optical imaging system having high quality resolution even over a relatively wide temperature range. In particular, examples provide an optical imaging system in which BFL variation is significantly low even over a wide temperature range, and thus the focal length can be maintained at a predetermined level.
In one general aspect, an optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, which are arranged in this order from an object side. The optical imaging system satisfies | Pnu | ≦ 30, wherein Pnu is Σ Pnui, wherein i ═ 1, 2,. and 7, Pnui is 1/(vti × fi), vti is [ DTni/(ni-1) -CTEi ≦ 30]-1Where fi is an effective focal length of the ith lens, ni is a refractive index of the ith lens, DTni is a rate of change of the refractive index of the ith lens according to temperature (dni/dT), and CTEi is a coefficient of thermal expansion of the ith lens.
The optical imaging system can satisfy 0.4 ≦ f/f3, where f is an effective focal length of the optical imaging system, and f3 is an effective focal length of the third lens.
The optical imaging system may include an aperture stop disposed between the second lens and the third lens.
The optical imaging system can satisfy | Pnu3/Pnu | < 0.2.
The third lens may be composed of glass, and the second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens may be composed of plastic.
The optical imaging system can satisfy-2.0<∑1/(DTni·fi)[104℃ mm-1]<20.0, wherein i ═ 1, 2,. and 7.
The optical imaging system may satisfy 0.2< DTnF/DTnR <0.6, where DTnF is a sum Σ DTni (i ═ 1, 2) of DTn values of the first lens and the second lens, and DTnR is a sum Σ DTni (i ═ 3, 4,., 7) of DTn values of the third lens to the seventh lens.
The optical imaging system can satisfy-620<DTnT[10-6℃-1]<-450, wherein DTnT isThe sum Σ DTni (i ═ 1, 2,. and 7) of the DTn values of the first to seventh lenses.
The optical imaging system can satisfy-220<DTnF[10-6℃-1]<-100, wherein DTnF is the sum Σ DTni (i ═ 1, 2) of the DTn values of the first and second lenses.
The optical imaging system can satisfy-400<DTnR[10-6℃-1]<300, wherein DTnR is the sum Σ DTni (i ═ 3, 4,. 7) of the DTn values of the third lens to the seventh lens.
The object side surface of the seventh lens may be convex, and the image side surface of the seventh lens may be concave.
The first lens may have a negative refractive power, the third lens may have a positive refractive power, the fourth lens may have a positive refractive power, the fifth lens may have a negative refractive power, and the sixth lens may have a positive refractive power.
Other features and aspects will become apparent from the following detailed description, the appended claims, the drawings, and the following drawings.
Drawings
Fig. 1 is a diagram showing an optical imaging system according to a first example.
Fig. 2 is a graph showing aberrations of the optical imaging system according to the first example.
Fig. 3 is a graph illustrating resolving power according to a field of view of an optical imaging system according to a first example.
Fig. 4 is a graph illustrating a change in BFL according to temperature in the optical imaging system according to the first example.
Fig. 5 is a diagram showing an optical imaging system according to a second example.
Fig. 6 is a graph showing aberrations of the optical imaging system according to the second example.
Fig. 7 is a graph showing resolving power according to a field of view of an optical imaging system according to a second example.
Fig. 8 is a graph illustrating a change in BFL according to temperature in the optical imaging system according to the second example.
Fig. 9 is a diagram illustrating an optical imaging system according to a third example.
Fig. 10 is a graph showing aberrations of the optical imaging system according to the third example.
Fig. 11 is a graph showing resolving power according to a field of view of an optical imaging system according to the third example.
Fig. 12 is a graph illustrating a change in BFL according to temperature in the optical imaging system according to the third example.
Fig. 13 is a diagram illustrating an optical imaging system according to a fourth example.
Fig. 14 is a graph showing aberrations of the optical imaging system according to the fourth example.
Fig. 15 is a graph showing resolving power according to a field of view of an optical imaging system according to the fourth example.
Fig. 16 is a graph illustrating a change in BFL according to temperature in the optical imaging system according to the fourth example.
Fig. 17 is a diagram illustrating an optical imaging system according to a fifth example.
Fig. 18 is a graph showing aberrations of the optical imaging system according to the fifth example.
Fig. 19 is a graph showing resolving power according to a field of view of an optical imaging system according to the fifth example.
Fig. 20 is a graph illustrating a change in BFL according to temperature in the optical imaging system according to the fifth example.
Fig. 21 is a diagram showing an optical imaging system according to a sixth example.
Fig. 22 is a graph showing aberrations of the optical imaging system according to the sixth example.
Fig. 23 is a graph showing resolving power according to a field of view of the optical imaging system according to the sixth example.
Fig. 24 is a graph illustrating a change in BFL according to temperature in the optical imaging system according to the sixth example.
Fig. 25 is a diagram showing an optical imaging system according to a seventh example.
Fig. 26 is a graph showing aberrations of the optical imaging system according to the seventh example.
Fig. 27 is a graph showing resolving power according to a field of view of an optical imaging system according to the seventh example.
Fig. 28 is a graph illustrating a change in BFL according to temperature in the optical imaging system according to the seventh example.
Like reference numerals refer to like elements throughout the drawings and detailed description. The figures may not be drawn to scale and the relative sizes, proportions and depictions of the elements in the figures may be exaggerated for clarity, illustration and convenience.
Detailed Description
The following detailed description is provided to assist the reader in obtaining a thorough understanding of the methods, devices, and/or systems described herein. Various changes, modifications, and equivalents of the methods, devices, and/or systems described herein will, however, be apparent to those of ordinary skill in the art. The order of operations described herein is merely an example, and is not limited to the order set forth herein, except as operations must occur in a particular order, but rather may be changed as would be apparent to one of ordinary skill in the art. Also, descriptions of functions and constructions well known to those of ordinary skill in the art may be omitted for clarity and conciseness.
The features described herein may be embodied in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein have been provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
In this document, it should be noted that use of the phrase "may" in relation to an embodiment or example (e.g., in relation to what an embodiment or example may include or implement) means that there is at least one embodiment or example in which such a feature is included or implemented, and all embodiments and examples are not limited thereto.
Throughout the specification, when an element such as a layer, region or substrate is described as being "on," "connected to" or "coupled to" another element, it can be directly on, "connected to" or "coupled to" the other element or one or more other elements may be present between the element and the other element. In contrast, when an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element, there are no other elements intervening between the element and the other element.
As used herein, the term "and/or" includes any one of the associated listed items as well as any combination of any two or more of the items.
Although terms such as "first," "second," and "third" may be used herein to describe various elements, components, regions, layers or sections, these elements, components, regions, layers or sections should not be limited by these terms. Rather, these terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first member, component, region, layer or section referred to in an example can also be referred to as a second member, component, region, layer or section without departing from the teachings of the examples described herein.
Spatially relative terms such as "above," "upper," "lower," and "lower" may be used herein for descriptive convenience to describe one element's relationship to another element as illustrated in the figures. These spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "upper" relative to other elements would then be oriented "below" or "lower" relative to the other elements. Thus, the term "above" encompasses both an orientation of "above" and "below," depending on the spatial orientation of the device. The device may also be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative terms used herein should be interpreted accordingly.
The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting of the disclosure. The articles "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," and "having" specify the presence of stated features, integers, operations, elements, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, operations, elements, components, and/or groups thereof.
The shapes of the illustrations as a result of manufacturing techniques and/or tolerances may vary. Thus, examples described herein are not limited to the particular shapes shown in the drawings, but include changes in shapes that occur during manufacturing.
The features of the examples described herein may be combined in various ways that will be apparent after an understanding of the disclosure of the present application. Further, while the examples described herein have a variety of configurations, it will be apparent that other configurations are possible after an understanding of the disclosure of the present application.
The figures may not be drawn to scale and the relative sizes, proportions and descriptions of elements in the figures may be exaggerated for clarity, illustration and convenience.
In the following lens configuration diagrams, the thickness, size and shape of the lens are slightly exaggerated for the sake of description, and in particular, the shape of a spherical surface or an aspherical surface suggested in the lens configuration diagrams is presented by way of example, but not limited thereto.
In the present disclosure, the first lens refers to a lens closest to an object, and the last lens refers to a lens closest to an image sensor (or an imaging plane).
Further, in each lens, the first surface refers to a surface (or an object side surface) close to an object, and the second surface refers to a surface (or an image side surface) close to an imaging surface. Further, in the present specification, numerical values of the radius of curvature, thickness, distance, and focal length of the lens are all expressed in mm, and a unit of a field of view (FOV) is expressed in degrees.
Further, in the description of the shape of the respective lenses, unless otherwise specified, the meaning of a convex shape on one surface means that the paraxial region portion of the surface is convex, and the meaning of a concave shape on one surface means that the paraxial region portion of the surface is concave. That a surface is flat means that the paraxial region portion of the surface is flat. The paraxial region refers to a very narrow region near the optical axis.
Therefore, even when it is described that one surface of the lens is convex, the edge portion of the lens may be concave. Similarly, even when one surface of the lens is described as having a concave shape, an edge portion of the lens may be convex. Further, even when one surface of the lens is described as flat, the edge portion of the lens may be convex or concave.
An optical imaging system according to an example includes at least 7 lenses.
For example, an optical imaging system according to an example includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, which are arranged in order from an object side. In an example, the first to seventh lenses are spaced apart from each other by a predetermined distance along the optical axis. In another example, adjacent lenses of the first to seventh lenses may be disposed in a combined state.
The optical imaging system according to an example may further include an image sensor for converting an incident image of the object into an electrical signal. Further, the optical imaging system may further include an infrared cut filter IRCF (hereinafter referred to as "filter") for blocking infrared rays. The filter IRCF is arranged between the last lens and the image sensor.
The optical imaging system may also include an imaging plane IP. The imaging plane IP refers to a plane on which light refracted by the first to seventh lenses is imaged. For example, the imaging plane IP may indicate a surface of the image sensor on which an optical element (e.g., a photodiode) is disposed.
In an example, the optical imaging system may further include an aperture stop AS for adjusting the amount of incident light. The aperture stop AS may be disposed between lenses constituting the optical imaging system. In an example, the aperture stop AS may be disposed on the object side of a lens having the highest refractive index among lenses constituting the optical imaging system. For example, the aperture stop AS may be disposed between the second lens and the third lens.
The lens constituting the optical imaging system according to the example may have an aspherical surface. For example, the object-side surface and the image-side surface of the second lens and the fourth to seventh lenses may have aspherical surfaces. In another example, the object-side surface and the image-side surface of the first lens, the second lens, and the fourth to seventh lenses may have aspherical surfaces. The aspherical surface of the lens is represented by equation 1.
Figure BDA0003607453570000081
In equation 1, c is the curvature (inverse of the radius of curvature) of the lens, K is a conic constant, and Y is the distance from an arbitrary point on the aspherical surface of the lens to the optical axis. Further, the constants a to D refer to aspherical coefficients. Z denotes a distance along the optical axis from an arbitrary point on the aspherical surface of the lens to the vertex of the aspherical surface.
The first lens to the seventh lens of the optical imaging system may have negative refractive power/positive refractive power/negative refractive power in order from the object side. Alternatively, the first lens to the seventh lens of the optical imaging system may have negative refractive power/positive refractive power/negative refractive power/positive refractive power in order from the object side. Alternatively, the first lens to the seventh lens of the optical imaging system may have negative refractive power/positive refractive power/negative refractive power/positive refractive power in order from the object side.
The first lens may have a negative refractive power, an object side surface of the first lens may have a convex shape, and an image side surface of the first lens may have a concave shape.
In an example, the second lens may have a negative refractive power, the object side surface of the second lens may have a concave shape, and the image side surface of the second lens may have a convex shape.
In another example, the second lens may have a positive refractive power, the object-side surface of the second lens may have a convex shape, and the image-side surface of the second lens may have a concave shape.
The third lens may have a positive refractive power, an object side surface of the third lens may have a convex shape, and an image side surface of the third lens may have a convex shape.
The fourth lens may have a positive refractive power, and an image side surface of the fourth lens may have a convex shape.
In an example, the fifth lens may have a negative refractive power, an object side surface of the fifth lens may have a concave shape, and an image side surface of the fifth lens may have a concave shape.
In an example, the sixth lens may have a positive refractive power, an object side surface of the sixth lens may have a convex shape, and an image side surface of the sixth lens may have a convex shape. The sixth lens may have at least one inflection point on at least one of the object-side surface and the image-side surface. For example, the object side surface of the sixth lens may be convex in the paraxial region and concave in a region other than the paraxial region. The image-side surface of the sixth lens may be convex in the paraxial region and concave in a region other than the paraxial region.
In an example, an object side surface of the seventh lens may have a convex shape, and an image side surface of the seventh lens may have a concave shape. The seventh lens may have at least one inflection point on at least one of the object-side surface and the image-side surface. For example, the object side surface of the seventh lens may be convex in the paraxial region and concave in a region other than the paraxial region. The image-side surface of the seventh lens may be concave in the paraxial region and convex in a region other than the paraxial region.
The lens constituting the optical imaging system according to the example may be formed of a plastic or glass material. For example, the first lens and the third lens may be formed of glass, and the other lenses may be formed of plastic. In another example, the third lens may be formed of glass, and the other lenses may be formed of plastic.
Plastic lenses have the advantage of having a relatively high degree of precision when manufactured in large quantities using molds. However, the plastic lens has a disadvantage in that the degree of refractive index change or thermal expansion according to temperature is greater than that of the glass lens according to temperature. For example, the change of the refractive index of the plastic lens according to temperature is 50 to 100 times greater than the change of the refractive index of the glass lens according to temperature, and the linear expansion coefficient is about 10 times higher. Due to these disadvantages, there is a limit in applying the plastic lens to the vehicle camera in that an operating temperature of-40 degrees celsius (° c) to +80 degrees celsius (° c) should be ensured.
According to an example of the present disclosure, in an optical imaging system composed of a plurality of lenses, a glass lens and a plastic lens may be appropriately set in consideration of the influence of the refractive power of each lens on the focal length. Therefore, even in the case where the temperature around the lens changes, the focus of the optical imaging system can be maintained.
The present disclosure provides an optical imaging system in which a variation of a back focal length (hereinafter referred to as "BFL") in a temperature range of-40 (° c) to 80(° c) is within 10 μm. In this case, BFL refers to the distance between the image side surface of the lens closest to the imaging plane and the imaging plane.
In an example, a glass lens may be used in a portion having a larger optical refractive power, and a plastic lens may be provided in the remaining portion. For example, the third lens, which is disposed near the aperture stop AS and has a relatively strong refractive power, may be formed of glass, and the remaining lenses may be formed of plastic. In another example, the first and third lenses, which are externally exposed, may be formed of glass, and the other lenses may be formed of plastic.
The optical imaging system according to the example may be configured by appropriately combining a plastic lens and a glass lens, and thus, the variation amount of BFL in a wide operating temperature range of-40 degrees celsius (° c) to 80 degrees celsius (° c) may be limited to within 10 μm.
In an example, the optical imaging system may include an imaging plane IP (or image sensor) having a diagonal length of about 6 mm. In an example, the optical imaging system can be configured to have a total length of 15mm or less.
In an example, the optical imaging system may be characterized in that a lens that can generate an image with a resolving power of 80lp/mm or more may be used so that the length of the entire optical imaging system is shortened to 15mm or less. Therefore, the optical imaging system can be easily mounted in a mobile device or the like. When a pattern corresponding to a spatial frequency of 80lp/mm is properly imaged on the imaging plane, it can be seen that 1/960 resolution of the diagonal length of the 6mm sensor is ensured. Thus, when the camera system is configured with a total field of view of 120 degrees, an angular resolution of 0.125 degrees may be ensured, thereby ensuring a resolving power capable of distinguishing objects of about 20cm intervals at a distance of 10 m.
The optical imaging system according to the example includes a total of 7 lenses composed of a plastic lens and a glass lens, and can obtain a required sufficient level of resolving power at a wide operating temperature of-40 degrees celsius (° c) to +80 degrees celsius (° c) by suppressing BFL variation.
The optical imaging system may satisfy one or more of the following conditional expressions.
In an example, there is provided a hybrid optical imaging system in which a glass lens and a plastic lens are used together, and which controls a change in BFL according to temperature in such a manner that a refractive power of each lens is optimized so as to satisfy conditional expression (1).
|Pnu|[10-6℃-1mm-1]≤30 (1)
Pnu is an index representing the change of refractive power of the entire optical imaging system according to temperature, and is defined as the sum of Pnu values of lenses constituting the optical imaging system (i.e., Pnu ∑ Pnui, i ═ 1, 2, ·, 7). The Pnu value (i.e., Pnui) of the i-th lens from the object side is defined as 1/(vti × fi). For example, the Pnu value of the entire optical imaging system is calculated as Σ 1/(vti · fi) (i ═ 1, 2, …, 7).
vti is [ DTni/(ni-1) -CTEi]-1(° c), fi is an effective focal length of the i-th lens, ni is a refractive index of the i-th lens, and DTni is a rate of change of the refractive index of the i-th lens according to temperature (dni/dT), and CTEi is a coefficient of thermal expansion of the i-th lens.
In an example, the third lens closest to the aperture stop AS is formed of glass, and the optical imaging system may satisfy conditional expression (2). For example, the effective focal length of the third lens may be 0.4 times or more the effective focal length of the entire optical imaging system.
f/f3≥0.4 (2)
In the above conditional expression, f is an effective focal length of the entire optical imaging system, and f3 may be an effective focal length of the third lens.
In an example, the optical imaging system may satisfy conditional expression (3). In an example, the optical imaging system is configured such that a change in refractive power of the third lens as a function of temperature (Pnu3) is substantially less than a change in refractive power of the entire optical imaging system as a function of temperature (Pnu). Therefore, the variation in BFL in a relatively wide temperature range can be suppressed to 10 μm or less.
|Pnu3/Pnu|<0.2 (3)
In an example, the optical imaging system may additionally satisfy one or more of the following conditional expressions (4) to (8).
-2.0<∑1/(DTni·fi)[104℃mm-1]<20.0(i＝1,2,…,7) (4)
0.2<DTnF/DTnR<0.6 (5)
0.3-620<DTnT[10-6℃-1]<-450 (6)
-220<DTnF[10-6℃-1]<-100 (7)
-400<DTnR[10-6℃-1]<-300 (8)
DTnT is the sum of the DTn values of the first to seventh lenses (i.e., Σ DTni (i ═ 1, 2,.. 7)), DTnF is the sum of the DTn values of the first and second lenses (i.e., Σ DTni (i ═ 1, 2)), DTnR is the sum of the DTn values of the third to seventh lenses (i.e., Σ DTni (i ═ 3, 4,.. 7)), and imht is half the diagonal length of the imaging plane IP.
Hereinafter, examples will be described in detail with reference to the accompanying drawings.
Fig. 1 shows an optical imaging system 100 according to a first example. Fig. 2 is a graph illustrating aberrations of the optical imaging system 100. Fig. 3 is a graph illustrating resolving power according to the field of view of the optical imaging system 100. Fig. 4 is a graph illustrating a change in BFL according to temperature in the optical imaging system 100.
The optical imaging system 100 includes a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, and a seventh lens 170, and may further include an aperture stop AS, an optical filter IRCF, and an imaging plane IP. A separate filter F may be additionally provided on the imaging plane IP. The filter F may be used to protect the imaging plane IP. In the example, the aperture stop AS is located between the second lens 120 and the third lens 130.
In an example, the first lens 110 and the third lens 130 are formed of glass, and the other lenses are formed of plastic.
Table 1 shows the characteristics (radius of curvature, thickness of lens or distance between lenses, refractive index and abbe number) of the respective lenses. Table 1 also shows the refractive index change rate (DTn), Coefficient of Thermal Expansion (CTE), and vt values for each lens as a function of temperature.
[ Table 1]
Figure BDA0003607453570000121
Figure BDA0003607453570000131
The first lens 110 has a negative refractive power, an object side surface of the first lens 110 is convex, and an image side surface of the first lens 110 is concave.
The second lens 120 has a negative refractive power, the object side surface of the second lens 120 is concave, and the image side surface of the second lens 120 is convex.
The third lens 130 has a positive refractive power, an object-side surface of the third lens 130 is convex, and an image-side surface of the third lens 130 is convex.
The fourth lens 140 has a positive refractive power, an object-side surface of the fourth lens 140 is convex, and an image-side surface of the fourth lens 140 is convex.
The fifth lens 150 has a negative refractive power, the object side surface of the fifth lens 150 is concave, and the image side surface of the fifth lens 150 is concave.
The sixth lens 160 has a positive refractive power, the object-side surface of the sixth lens 160 is convex, and the image-side surface of the sixth lens 160 is convex.
The seventh lens 170 has a negative refractive power, an object side surface of the seventh lens 170 is convex, and an image side surface of the seventh lens 170 is concave. The seventh lens 170 may have at least one inflection point on at least one of the object side and the image side. For example, the object side surface of the seventh lens 170 may be convex in the paraxial region and concave in a region other than the paraxial region. The image-side surface of the seventh lens 170 may be concave in the paraxial region and convex in a region other than the paraxial region.
The respective surfaces of the second lens 120 and the fourth to seventh lenses 140 to 170 have aspherical coefficients as shown in table 2.
[ Table 2]
Figure BDA0003607453570000132
Figure BDA0003607453570000141
Referring to fig. 4, in the optical imaging system 100, the variation of BFL is maintained at a level of 9 μm in a temperature range of-40 degrees celsius (° c) to 80 degrees celsius (° c).
Fig. 5 shows an optical imaging system 200 according to a second example. Fig. 6 is a graph illustrating aberrations of the optical imaging system 200. Fig. 7 is a graph illustrating resolving power according to the field of view of the optical imaging system 200. Fig. 8 is a graph illustrating a change in BFL according to temperature in the optical imaging system 200.
The optical imaging system 200 includes a first lens 210, a second lens 220, a third lens 230, a fourth lens 240, a fifth lens 250, a sixth lens 260, and a seventh lens 270, and may further include an aperture stop AS, an optical filter IRCF, and an imaging plane IP. A separate filter F may be additionally provided on the imaging plane IP. The filter F may be used to protect the imaging plane IP. In the example, the aperture stop AS is located between the second lens 220 and the third lens 230.
In an example, the first lens 210 and the third lens 230 are formed of glass, and the other lenses are formed of plastic.
Table 3 shows the characteristics (radius of curvature, thickness of lens or distance between lenses, refractive index and abbe number) of the respective lenses. Table 3 also shows the refractive index change rate (DTn), Coefficient of Thermal Expansion (CTE), and vt values for each lens as a function of temperature.
[ Table 3]
Figure BDA0003607453570000142
Figure BDA0003607453570000151
The first lens 210 has a negative refractive power, the object side surface of the first lens 210 is convex, and the image side surface of the first lens 210 is concave.
The second lens 220 has a positive refractive power, the object side surface of the second lens 220 is concave, and the image side surface of the second lens 220 is convex.
The third lens 230 has a positive refractive power, the object side surface of the third lens 230 is convex, and the image side surface of the third lens 230 is convex.
Fourth lens 240 has positive refractive power, the object-side surface of fourth lens 240 is concave, and the image-side surface of fourth lens 240 is convex.
The fifth lens 250 has a negative refractive power, an object side surface of the fifth lens 250 is concave, and an image side surface of the fifth lens 250 is concave.
Sixth lens 260 has positive refractive power, the object-side surface of sixth lens 260 is convex, and the image-side surface of sixth lens 260 is convex. Sixth lens 260 may have at least one inflection point on at least one of the object side surface and the image side surface. For example, the object side surface of the sixth lens 260 may be convex in the paraxial region and concave in a region other than the paraxial region. The image-side surface of the sixth lens 260 may be convex in the paraxial region and concave in a region other than the paraxial region.
The seventh lens 270 has positive refractive power, the object side surface of the seventh lens 270 is convex, and the image side surface of the seventh lens 270 is concave. The seventh lens 270 may have at least one inflection point on at least one of the object-side surface and the image-side surface. For example, the object side surface of the seventh lens 270 may be convex in the paraxial region and concave in a region other than the paraxial region. The image-side surface of the seventh lens 270 may be concave in the paraxial region and convex in a region other than the paraxial region.
Respective surfaces of the second lens 220 and the fourth to seventh lenses 240 to 270 have aspherical surface coefficients as shown in table 4.
[ Table 4]
Noodle numbering K A B C
3 -1.9178E+00 -6.8773E-03 -4.8305E-05 -1.7677E-05
4 9.2986E-01 -4.3618E-03 1.2975E-04 6.0999E-05
8 -5.4817E+01 -1.1096E-02 1.1958E-03 7.1589E-05
9 2.2549E+01 -1.5180E-02 2.4476E-03 9.4191E-05
10 6.9512E+00 -7.2864E-03 1.2951E-03 0.0
11 -2.5817E+01 -8.0063E-04 2.7939E-04 -1.2485E-04
12 -8.6693E+00 -4.5403E-03 1.0275E-03 -1.7864E-04
13 0.0 -1.2453E-03 4.1014E-04 -4.3439E-05
14 0.0 -1.4026E-02 8.8105E-05 -6.5722E-05
15 0.0 -1.3579E-02 -1.9796E-04 -1.6600E-05
Referring to fig. 8, in the optical imaging system 200, the BFL variation is maintained at a level of 2 μm in a temperature range of-40 degrees celsius (° c) to 80 degrees celsius (° c).
Fig. 9 shows an optical imaging system 300 according to a third example. Fig. 10 is a graph illustrating aberrations of the optical imaging system 300. Fig. 11 is a graph illustrating resolving power according to the field of view of the optical imaging system 300. Fig. 12 is a graph illustrating a change in BFL according to temperature in the optical imaging system 300.
The optical imaging system 300 includes a first lens 310, a second lens 320, a third lens 330, a fourth lens 340, a fifth lens 350, a sixth lens 360, and a seventh lens 370, and may further include an aperture stop AS, an optical filter IRCF, and an imaging plane IP. A separate filter F may be additionally provided on the imaging plane IP. The filter F may be used to protect the imaging plane IP. In the example, the aperture stop AS is located between the second lens 320 and the third lens 330.
In an example, the first lens 310 and the third lens 330 are formed of glass, and the other lenses are formed of plastic.
Table 5 shows the characteristics (radius of curvature, thickness of lens or distance between lenses, refractive index and abbe number) of each lens. Table 5 also shows the refractive index change rate (DTn), Coefficient of Thermal Expansion (CTE), and vt values for each lens as a function of temperature.
[ Table 5]
Figure BDA0003607453570000171
Figure BDA0003607453570000181
The first lens 310 has a negative refractive power, an object side surface of the first lens 310 is convex, and an image side surface of the first lens 310 is concave.
The second lens 320 has a negative refractive power, the object side surface of the second lens 320 is concave, and the image side surface of the second lens 320 is convex.
The third lens 330 has positive refractive power, the object-side surface of the third lens 330 is convex, and the image-side surface of the third lens 330 is convex.
The fourth lens 340 has a positive refractive power, the object-side surface of the fourth lens 340 is convex, and the image-side surface of the fourth lens 340 is convex.
The fifth lens 350 has a negative refractive power, an object side surface of the fifth lens 350 is concave, and an image side surface of the fifth lens 350 is concave.
The sixth lens 360 has a positive refractive power, the object-side surface of the sixth lens 360 is convex, and the image-side surface of the sixth lens 360 is convex.
The seventh lens 370 has a positive refractive power, an object side surface of the seventh lens 370 is convex, and an image side surface of the seventh lens 370 is concave. The seventh lens 370 may have at least one inflection point on the image side surface.
The respective surfaces of the second lens 320 and the fourth to seventh lenses 340 to 370 have aspherical surface coefficients as shown in table 6.
[ Table 6]
Figure BDA0003607453570000182
Figure BDA0003607453570000191
The lens shape having both the concave shape and the convex shape on one surface may be advantageous in making the entire optical imaging system 300 small and correcting the image-side curvature of field, but has a disadvantage of being difficult to manufacture. In the third example, the seventh lens 370 has a relatively simple shape, which may be advantageous in ensuring mass production.
Referring to fig. 12, in the optical imaging system 300, the BFL variation is maintained at a level of 6 μm in a temperature range of-40 degrees celsius (° c) to 80 degrees celsius (° c).
Fig. 13 is a diagram illustrating an optical imaging system 400 according to a fourth example. Fig. 14 is a graph illustrating aberrations of the optical imaging system 400. Fig. 15 is a graph illustrating resolving power according to the field of view of the optical imaging system 400. Fig. 16 is a graph illustrating a change in BFL according to temperature in the optical imaging system 400.
The optical imaging system 400 includes a first lens 410, a second lens 420, a third lens 430, a fourth lens 440, a fifth lens 450, and sixth and seventh lenses 460 and 470, and may further include an aperture stop AS, an optical filter IRCF, and an imaging plane IP. A separate filter F may be additionally provided on the imaging plane IP. The filter F may be used to protect the imaging plane IP. In the example, the aperture stop AS is located between the second lens 420 and the third lens 430.
In an example, the first lens 410 and the third lens 430 are formed of glass, and the other lenses are formed of plastic.
Table 7 shows the characteristics (radius of curvature, thickness of lens or distance between lenses, refractive index and abbe number) of each lens. Table 7 also shows the refractive index change rate (DTn), Coefficient of Thermal Expansion (CTE), and vt values for each lens as a function of temperature.
[ Table 7]
Figure BDA0003607453570000192
Figure BDA0003607453570000201
The first lens 410 has a negative refractive power, an object side surface of the first lens 410 is convex, and an image side surface of the first lens 410 is concave.
The second lens 420 has a positive refractive power, an object side surface of the second lens 420 is convex, and an image side surface of the second lens 420 is concave.
The third lens 430 has a positive refractive power, an object side surface of the third lens 430 is convex, and an image side surface of the third lens 430 is convex.
The fourth lens 440 has a positive refractive power, an object side surface of the fourth lens 440 is concave, and an image side surface of the fourth lens 440 is convex.
The fifth lens 450 has a negative refractive power, the object side surface of the fifth lens 450 is concave, and the image side surface of the fifth lens 450 is concave.
The sixth lens 460 has a positive refractive power, an object-side surface of the sixth lens 460 is convex, and an image-side surface of the sixth lens 460 is convex. The sixth lens 460 may have at least one inflection point on the image side.
The seventh lens 470 has a positive refractive power, the object side surface of the seventh lens 470 is convex, and the image side surface of the seventh lens 470 is concave. The seventh lens 470 may have at least one inflection point on the image side surface.
Respective surfaces of the second lens 420 and the fourth to seventh lenses 440 to 470 have aspherical surface coefficients as shown in table 8.
[ Table 8]
Noodle numbering K A B C
3 -1.9178E+00 1.6847E-03 7.9798E-05 9.3773E-05
4 9.2986E-01 -3.0996E-03 3.1458E-04 2.6065E-04
8 -5.4817E+01 -1.8991E-02 7.7995E-04 1.8995E-04
9 2.2549E+01 -3.5607E-02 5.3216E-03 -4.2579E-04
10 6.9512E+00 2.8062E-03 -1.1297E-03 0.0
11 -2.5817E+01 1.3599E-02 -3.5750E-03 2.8194E-04
12 -8.6693E+00 -1.3414E-02 2.3052E-03 -2.5433E-05
13 0.0 2.5580E-03 -1.3568E-04 1.6813E-04
14 0.0 -1.8436E-02 2.2527E-03 -1.5342E-04
15 0.0 -2.5029E-02 2.5506E-03 -1.5835E-04
In the fourth example, the object side of the second lens 420 has a convex meniscus shape. If the object side of the second lens 420 is concave, there may be a disadvantage that the incident angle of the lower rays of the field of view with large field angles increases, so that the entire optical imaging system 400 becomes sensitive. In a fourth example, the above disadvantages can be compensated for.
Referring to fig. 16, in the optical imaging system 400, the BFL variation is maintained at a level of 5 μm in a temperature range of-40 degrees celsius (° c) to 80 degrees celsius (° c).
Fig. 17 shows an optical imaging system 500 according to a fifth example. Fig. 18 is a graph illustrating aberrations of the optical imaging system 500. Fig. 19 is a graph illustrating resolving power according to the field of view of the optical imaging system 500. Fig. 20 is a graph illustrating a change in BFL according to temperature in the optical imaging system 500.
Optical imaging system 500 includes first lens 510, second lens 520, third lens 530, fourth lens 540, fifth lens 550, sixth lens 560, and seventh lens 570, and may further include aperture stop AS, filter IRCF, and imaging plane IP. A separate filter F may be additionally provided on the imaging plane IP. The filter F may be used to protect the imaging plane IP. In the example, the aperture stop AS is located between the second lens 520 and the third lens 530.
In an example, the third lens 530 is formed of glass, and the other lenses are formed of plastic. In contrast to the other examples discussed above, in the fifth example, the first lens 510 is formed of plastic. In the case where the indoor camera is not externally exposed, the optical imaging system may withstand external impact even when the first lens 510 is formed of plastic. Since the first lens 510 is formed of plastic, the manufacturing cost and weight of the optical imaging system can be reduced.
Table 9 shows the characteristics (radius of curvature, thickness of lens or distance between lenses, refractive index and abbe number) of each lens. Table 9 also shows the refractive index change rate (DTn), Coefficient of Thermal Expansion (CTE), and vt values for each lens as a function of temperature.
[ Table 9]
Figure BDA0003607453570000221
Figure BDA0003607453570000231
The first lens 510 has a negative refractive power, the object-side surface of the first lens 510 is convex, and the image-side surface of the first lens 510 is concave.
Second lens 520 has a negative refractive power, the object side surface of second lens 520 is concave, and the image side surface of second lens 520 is convex.
The third lens 530 has a positive refractive power, an object side surface of the third lens 530 is convex, and an image side surface of the third lens 530 is convex.
The fourth lens 540 has a positive refractive power, the object side surface of the fourth lens 540 is convex, and the image side surface of the fourth lens 540 is convex.
The fifth lens 550 has a negative refractive power, the object-side surface of the fifth lens 550 is concave, and the image-side surface of the fifth lens 550 is concave.
Sixth lens 560 has positive refractive power, the object-side surface of sixth lens 560 is convex, and the image-side surface of sixth lens 560 is convex. The sixth lens 560 may have at least one inflection point on the image side. For example, the image side surface of the sixth lens 560 may be convex in the paraxial region and concave in a region other than the paraxial region.
The seventh lens 570 has a negative refractive power, an object side surface of the seventh lens 570 is convex, and an image side surface of the seventh lens 570 is concave. The seventh lens 570 may have at least one inflection point on at least one of the object side and the image side. For example, the object side surface of the seventh lens 570 may be convex in the paraxial region and concave in a region other than the paraxial region. The image side surface of the seventh lens 570 may be concave in the paraxial region and convex in regions other than the paraxial region.
Respective surfaces of the first lens 510, the second lens 520, and the fourth through seventh lenses 540 through 570 have aspherical surface coefficients as shown in table 10.
[ Table 10]
Noodle numbering K A B C D
1 0.0 -3.0840E-03 1.7243E-04 0.0 0.0
2 0.0 -4.2724E-03 -1.1762E-03 1.8247E-04 -5.5977E-05
3 0.0 -7.9443E-03 3.0115E-05 0.0 0.0
4 0.0 -3.3383E-03 2.8733E-04 0.0 0.0
8 0.0 -2.3219E-03 2.1379E-04 0.0 0.0
9 0.0 -9.6846E-03 1.4454E-03 -9.0746E-05 0.0
10 0.0 -7.1012E-03 2.2366E-03 -1.7958E-04 0.0
11 0.0 -5.6064E-03 3.2073E-04 5.2821E-05 0.0
12 0.0 3.4063E-03 -1.5930E-03 3.1484E-04 -2.2605E-05
13 0.0 1.3986E-02 -1.0799E-03 4.8465E-04 -4.8779E-05
14 0.0 -1.3655E-02 -3.1122E-04 3.5269E-04 -3.3992E-05
15 0.0 -2.3233E-02 1.5920E-03 -5.9528E-05 -2.9653E-06
Referring to fig. 20, in the optical imaging system 500, the BFL variation amount is maintained at a level of 5 μm.
Fig. 21 shows an optical imaging system 600 according to a sixth example. Fig. 22 is a graph illustrating aberrations of the optical imaging system 600. Fig. 23 is a graph illustrating resolving power according to the field of view of the optical imaging system 600. Fig. 24 is a graph illustrating a change in BFL according to temperature in the optical imaging system 600.
Optical imaging system 600 includes first lens 610, second lens 620, third lens 630, fourth lens 640, fifth lens 650, sixth lens 660, and seventh lens 670, and may further include aperture stop AS, filter IRCF, and imaging plane IP. A separate filter F may be additionally provided on the imaging plane IP. The filter F may be used to protect the imaging plane IP. In the example, the aperture stop AS is located between the second lens 620 and the third lens 630.
In an example, the first lens 610 and the third lens 630 are formed of glass, and the other lenses are formed of plastic.
Table 11 shows the characteristics (radius of curvature, thickness of lens or distance between lenses, refractive index and abbe number) of each lens. Table 11 also shows the refractive index change rate (DTn), Coefficient of Thermal Expansion (CTE), and vt values for each lens as a function of temperature.
[ Table 11]
Figure BDA0003607453570000251
The first lens 610 has a negative refractive power, an object side surface of the first lens 610 is convex, and an image side surface of the first lens 610 is concave.
Second lens 620 has a negative refractive power, the object side surface of second lens 620 is concave, and the image side surface of second lens 620 is convex.
The third lens 630 has a positive refractive power, the object-side surface of the third lens 630 is convex, and the image-side surface of the third lens 630 is convex.
The fourth lens 640 has positive refractive power, the object-side surface of the fourth lens 640 is convex, and the image-side surface of the fourth lens 640 is convex.
The fifth lens 650 has a negative refractive power, an object side surface of the fifth lens 650 is concave, and an image side surface of the fifth lens 650 is concave.
The sixth lens 660 has positive refractive power, the object-side surface of the sixth lens 660 is convex, and the image-side surface of the sixth lens 660 is convex. Sixth lens 660 may have at least one inflection point on at least one of the object side and the image side. For example, the object side surface of the sixth lens 660 may be convex in the paraxial region and concave in a region other than the paraxial region. The image side surface of the sixth lens 660 may be convex in the paraxial region and concave in a region other than the paraxial region.
Seventh lens 670 has a negative refractive power, an object side surface of seventh lens 670 is convex, and an image side surface of seventh lens 670 is concave. The seventh lens 670 may have at least one inflection point on at least one of the object side and the image side. For example, the object side surface of the seventh lens 670 may be convex in the paraxial region and concave in a region other than the paraxial region. The image-side surface of the seventh lens 670 may be concave in the paraxial region and convex in a region other than the paraxial region.
Respective surfaces of the second lens 620 to the seventh lens 670 have aspherical coefficients as shown in table 12.
[ Table 12]
Figure BDA0003607453570000261
Figure BDA0003607453570000271
Referring to fig. 24, in the optical imaging system 600, the BFL variation amount is maintained at a level of 3 μm.
Fig. 25 shows an optical imaging system 700 according to a seventh example. Fig. 26 is a graph illustrating aberrations of the optical imaging system 700. Fig. 27 is a graph illustrating resolving power according to the field of view of the optical imaging system 700. Fig. 28 is a graph illustrating a change in BFL according to temperature in the optical imaging system 700.
Optical imaging system 700 includes first lens 710, second lens 720, third lens 730, fourth lens 740, fifth lens 750, sixth lens 760, and seventh lens 770, and may also include aperture stop AS, optical filter IRCF, and imaging plane IP. A separate filter F may be additionally provided on the imaging plane IP. The filter F may be used to protect the imaging plane IP. In the example, the aperture stop AS is located between the second lens 720 and the third lens 730.
In an example, the first lens 710 and the third lens 730 are formed of glass, and the other lenses are formed of plastic.
Table 13 shows the characteristics (radius of curvature, thickness of lens or distance between lenses, refractive index and abbe number) of each lens. Table 13 also shows the refractive index change rate (DTn), Coefficient of Thermal Expansion (CTE), and vt values for each lens as a function of temperature.
[ Table 13]
Figure BDA0003607453570000272
Figure BDA0003607453570000281
The first lens 710 has a negative refractive power, an object side surface of the first lens 710 is convex, and an image side surface of the first lens 710 is concave.
The second lens 720 has a negative refractive power, the object-side surface of the second lens 720 is concave, and the image-side surface of the second lens 720 is convex.
The third lens 730 has a positive refractive power, the object-side surface of the third lens 730 is convex, and the image-side surface of the third lens 730 is convex.
Fourth lens 740 has positive refractive power, the object-side surface of fourth lens 740 is convex, and the image-side surface of fourth lens 740 is convex.
The fifth lens 750 has a negative refractive power, an object side surface of the fifth lens 750 is concave, and an image side surface of the fifth lens 750 is concave.
Sixth lens 760 has positive refractive power, the object-side surface of sixth lens 760 is convex, and the image-side surface of sixth lens 760 is convex. Sixth lens 760 may have at least one inflection point on at least one of the object side and the image side. For example, the object side surface of sixth lens 760 may be convex in the paraxial region and concave in a region other than the paraxial region. The image-side surface of sixth lens 760 may be convex in the paraxial region and concave in a region other than the paraxial region.
The seventh lens 770 has a negative refractive power, the object side surface of the seventh lens 770 is convex, and the image side surface of the seventh lens 770 is concave. The seventh lens 770 may have at least one inflection point on at least one of the object side and the image side. For example, the object side surface of the seventh lens 770 may be convex in the paraxial region and concave in a region other than the paraxial region. The image side surface of the seventh lens 770 may be concave in the paraxial region and convex in a region other than the paraxial region.
Respective surfaces of the first lens 710, the second lens 720, and the fourth lens 740 to the seventh lens 770 have aspherical surface coefficients as shown in table 14.
[ Table 14]
Noodle numbering K A B C D
1 0.0 -2.3483E-03 1.8531E-05 0.0 0.0
2 0.0 -2.7242E-03 -4.6246E-04 0.0 0.0
3 0.0 1.5923E-03 1.3811E-03 0.0 0.0
4 0.0 2.3964E-03 5.2067E-04 0.0 0.0
8 0.0 2.0679E-03 1.5744E-04 5.2633E-05 -2.5139E-05
9 0.0 -5.5756E-03 -4.8888E-04 3.6114E-04 -3.8940E-05
10 0.0 -1.2112E-02 3.1724E-04 6.9229E-04 -6.3864E-05
11 0.0 -1.3503E-02 3.0251E-03 -5.5277E-04 6.6208E-05
12 0.0 -1.0109E-03 5.0109E-04 -1.7585E-04 1.4231E-05
13 0.0 7.7453E-03 1.0580E-03 5.5385E-05 -4.7434E-06
14 0.0 -3.1178E-02 8.1158E-04 -4.3599E-05 1.5809E-05
15 0.0 -4.0082E-02 1.8155E-03 -7.9485E-05 -2.3984E-06
Referring to fig. 28, in the optical imaging system 700, the amount of BFL variation is maintained at a level of 7 μm.
Table 15 shows values of conditional expressions of the optical imaging systems according to the respective examples.
[ Table 15]
Figure BDA0003607453570000291
Figure BDA0003607453570000301
As described above, the optical imaging system according to various examples can provide a relatively high quality resolution even in a wide temperature range. Furthermore, the optical imaging system may be configured such that the BFL variation is significantly small even over a wide temperature range, and thus, the focal length may be maintained at a certain level.
While the present disclosure includes specific examples, it will be apparent to those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be construed in a descriptive sense only and not for purposes of limitation. The description of features or aspects in each example should be considered applicable to similar features or aspects in other examples. Suitable results may also be obtained if the described techniques are performed in a different order and/or if components in the described systems, architectures, devices, or circuits are combined and/or replaced or supplemented in a different manner and/or with other components or their equivalents. Therefore, the scope of the present disclosure is defined not by the specific embodiments but by the claims and their equivalents, and all modifications within the scope of the claims and their equivalents should be understood as being included in the present disclosure.

Claims (12)

1. An optical imaging system comprising:
a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged in this order from an object side, and an image sensor for converting an incident image of an object into an electric signal,
wherein, Pnu | [10 | ]-6℃-1mm-1]30 ≦ wherein Pnu is Σ Pnui, wherein i ═ 1, 2,. and 7, Pnui is 1/(vti · fi), vti is [ DTni/(ni-1) -CTEi ≦ c]-1Fi is an effective focal length of the ith lens, ni is a refractive index of the ith lens, DTni is a rate of change of the refractive index of the ith lens according to temperature (dni/dT), and CTEi is a thermal expansion coefficient of the ith lens.
2. The optical imaging system of claim 1, wherein
0.4 ≦ f/f3, where f is an effective focal length of the optical imaging system, and f3 is an effective focal length of the third lens.
3. The optical imaging system of claim 2, further comprising an aperture stop disposed between the second lens and the third lens.
4. The optical imaging system of claim 1, wherein | Pnu3/Pnu | < 0.2.
5. The optical imaging system of claim 1, wherein the third lens is composed of glass, and the second, fourth, fifth, sixth, and seventh lenses are composed of plastic.
6. The optical imaging system of claim 1, wherein-2.0<∑1/(DTni·fi)[104℃mm-1]<20.0, wherein i ═ 1, 2,. and 7.
7. The optical imaging system of claim 1, wherein 0.2< DTnF/DTnR <0.6, wherein DTnF is a sum Σ DTni (i ═ 1, 2) of the DTn values of the first lens and the second lens, and DTnR is a sum Σ DTni (i ═ 3, 4,..., 7) of the DTn values of the third lens to the seventh lens.
8. The optical imaging system of claim 1, wherein-620<DTnT[10-6℃-1]<-450, wherein DTnT is the sum Σ DTni (i ═ 1, 2,.., 7) of the DTn values of the first to seventh lenses.
9. The optical imaging system of claim 1, wherein-220<DTnF[10-6℃-1]<-100 ofIn (d), DTnF is a sum Σ DTni (i ═ 1, 2) of the DTn values of the first lens and the second lens.
10. The optical imaging system of claim 1, wherein-400<DTnR[10-6℃-1]<-300, wherein DTnR is a sum Σ DTni (i ═ 3, 4,.., 7) of DTn values of the third lens to the seventh lens.
11. The optical imaging system of claim 1, wherein an object side surface of the seventh lens is convex and an image side surface of the seventh lens is concave.
12. The optical imaging system of claim 1, wherein the first lens has a negative optical power, the third lens has a positive optical power, the fourth lens has a positive optical power, the fifth lens has a negative optical power, and the sixth lens has a positive optical power.
CN202210423465.2A 2021-03-26 2021-10-19 optical imaging system Active CN114563860B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210423465.2A CN114563860B (en) 2021-03-26 2021-10-19 optical imaging system

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR1020210039790A KR102642903B1 (en) 2021-03-26 2021-03-26 Optical Imaging System
KR10-2021-0039790 2021-03-26
CN202111213945.8A CN115128765B (en) 2021-03-26 2021-10-19 Optical imaging system
CN202210423465.2A CN114563860B (en) 2021-03-26 2021-10-19 optical imaging system

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
CN202111213945.8A Division CN115128765B (en) 2021-03-26 2021-10-19 Optical imaging system

Publications (2)

Publication Number Publication Date
CN114563860A true CN114563860A (en) 2022-05-31
CN114563860B CN114563860B (en) 2023-09-01

Family

ID=81731949

Family Applications (2)

Application Number Title Priority Date Filing Date
CN202311024479.8A Pending CN116794807A (en) 2021-03-26 2021-10-19 Optical imaging system
CN202210423465.2A Active CN114563860B (en) 2021-03-26 2021-10-19 optical imaging system

Family Applications Before (1)

Application Number Title Priority Date Filing Date
CN202311024479.8A Pending CN116794807A (en) 2021-03-26 2021-10-19 Optical imaging system

Country Status (1)

Country Link
CN (2) CN116794807A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117434695A (en) * 2023-12-20 2024-01-23 协益电子（苏州）有限公司 Front-view optical lens, imaging device and driving tool with same

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018109667A (en) * 2016-12-28 2018-07-12 株式会社タムロン Optical system and imaging apparatus
CN109541780A (en) * 2018-11-16 2019-03-29 江西联创电子有限公司 Optical lens and imaging device
CN110456475A (en) * 2018-05-08 2019-11-15 宁波舜宇车载光学技术有限公司 Optical lens
CN211627919U (en) * 2020-02-21 2020-10-02 天津欧菲光电有限公司 Optical system, camera module, electronic device and automobile
CN111830679A (en) * 2020-07-22 2020-10-27 天津欧菲光电有限公司 Optical imaging system, image capturing module, terminal and automobile
CN216052401U (en) * 2021-03-26 2022-03-15 三星电机株式会社 Optical imaging system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018109667A (en) * 2016-12-28 2018-07-12 株式会社タムロン Optical system and imaging apparatus
CN110456475A (en) * 2018-05-08 2019-11-15 宁波舜宇车载光学技术有限公司 Optical lens
CN109541780A (en) * 2018-11-16 2019-03-29 江西联创电子有限公司 Optical lens and imaging device
CN211627919U (en) * 2020-02-21 2020-10-02 天津欧菲光电有限公司 Optical system, camera module, electronic device and automobile
CN111830679A (en) * 2020-07-22 2020-10-27 天津欧菲光电有限公司 Optical imaging system, image capturing module, terminal and automobile
CN216052401U (en) * 2021-03-26 2022-03-15 三星电机株式会社 Optical imaging system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117434695A (en) * 2023-12-20 2024-01-23 协益电子（苏州）有限公司 Front-view optical lens, imaging device and driving tool with same
CN117434695B (en) * 2023-12-20 2024-03-08 协益电子（苏州）有限公司 Front-view optical lens, imaging device and driving tool with same

Also Published As

Publication number Publication date
CN114563860B (en) 2023-09-01
CN116794807A (en) 2023-09-22

Similar Documents

Publication Publication Date Title
CN110927925B (en) Optical imaging system
CN110716291B (en) Optical imaging system
CN112558270B (en) Imaging lens system
CN214751071U (en) Imaging lens system
CN110471162B (en) Image capturing lens system
CN215769181U (en) Optical imaging system, camera module and mobile terminal device
CN115616739A (en) Optical imaging system
CN110967809B (en) Optical imaging system and camera module
CN216052401U (en) Optical imaging system
CN112526713B (en) Optical imaging system
CN114563860B (en) optical imaging system
CN210376847U (en) Image capturing lens system
CN214895985U (en) Optical imaging system
CN117970607A (en) Imaging lens system
CN117369088A (en) Optical imaging system
CN117148550A (en) Optical imaging system

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