Imaging lens system

Abstract

An imaging lens system includes: a first lens having negative refractive power; a second lens having refractive power; a third lens having negative refractive power; a fourth lens having positive refractive power; a fifth lens having positive refractive power; a sixth lens having negative refractive power; a seventh lens having positive refractive power; an eighth lens having refractive power; and a ninth lens having negative refractive power. The first to ninth lenses are arranged sequentially from the object side toward the imaging plane. The imaging lens system has a total of nine lenses with refractive power. One of the first to ninth lenses is a temperature-compensated lens having positive refractive power and an absolute value of a refractive index temperature coefficient of 10 or less. The unit of the refractive index temperature coefficient is 10. ‑6 / ℃, wherein the temperature-compensated lens has a larger refractive index than other lenses, and wherein 8.0 < |DTnR / (DTnC*10)| < 18.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2020-0107243, filed with the Korean Intellectual Property Office on August 25, 2020, the entire disclosure of which is incorporated herein by reference for all purposes. Technical Field

[0003] This disclosure relates to an imaging lens system that can achieve constant optical performance independent of temperature changes in the surrounding environment. Background Technology

[0004] Small surveillance cameras can be configured to capture images or video information in a monitored area. For example, a small surveillance camera can be mounted on the front bumper, rear bumper, etc. of a vehicle to provide the driver with the captured images or videos.

[0005] Early small surveillance cameras were configured to image obstacles near vehicles, resulting in relatively low resolution, which varied significantly with temperature changes ranging from -40°C to +80°C. However, with the increasing demand for autonomous driving capabilities in vehicles, there is a need to develop surveillance cameras that maintain constant optical characteristics and high resolution even under harsh temperature conditions.

[0006] The above information is presented as background information only to aid in understanding this disclosure. No determination or assertion is made as to whether any of the above content can be used as prior art relating to this disclosure. Summary of the Invention

[0007] The summary portion of this invention is intended to provide a brief overview of the chosen inventive concepts, which will be further described in the detailed description portion below. This summary portion is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter.

[0008] In a general sense, the imaging lens system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged sequentially from the object side. One of the first through ninth lenses is a temperature-compensating lens, which has positive refractive power and an absolute value of 10(10). -6 ( / ℃) or lower refractive index temperature coefficient.

[0009] The imaging lens system may also include an aperture stop disposed between the third lens and the fourth lens.

[0010] A temperature compensation lens can be placed on the image side of the aperture stop.

[0011] Temperature-compensated lenses can have a higher refractive index than other lenses.

[0012] Each lens adjacent to the temperature compensation lens can have a temperature less than -80 (10) -6 The temperature coefficient of refractive index (°C).

[0013] A lens adjacent to the object side of a temperature-compensated lens can have negative refractive power.

[0014] The combined focal length f45 of the fourth and fifth lenses can be less than the focal length f of the imaging lens system.

[0015] The seventh lens may have a convex image-side surface.

[0016] The eighth lens may have a convex object-side surface.

[0017] In another general aspect, an imaging lens system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged sequentially from the object side, and an aperture stop disposed between the first lens and the ninth lens, wherein the composite focal length fstp12 of two lenses continuously disposed on the image side of the aperture stop is greater than 0 and less than the focal length f of the imaging lens system.

[0018] The aperture can be positioned between the third lens and the fourth lens.

[0019] The first lens can be a temperature-compensated lens, which has positive refractive power and an absolute value of 10(10). -6 ( / ℃) or lower refractive index temperature coefficient.

[0020] Temperature-compensated lenses can have a refractive index of 1.7 or greater.

[0021] The absolute value of the ratio of the sum of the temperature coefficients of the refractive index of the lens set on the object side of the temperature compensation lens, DTnF, to ten times the temperature coefficient of the refractive index of the temperature compensation lens, DTnC, can be greater than 4.0 and less than 7.0.

[0022] The absolute value of the ratio of the sum of the temperature coefficients of the refractive index DTnR of the lens set on the image side of the temperature compensation lens to ten times the temperature coefficient of the refractive index DTnC of the temperature compensation lens can be greater than 8.0 and less than 18.

[0023] The first lens can have negative refractive power.

[0024] Other features and aspects will become apparent from the following detailed description, the accompanying drawings, and the appended claims. Attached Figure Description

[0025] Figure 1 This is a view showing an imaging lens system according to the first example.

[0026] Figure 2 It is shown Figure 1 A view of the aberration curves of the imaging lens system shown.

[0027] Figure 3 It is shown Figure 1 The diagram shows the modulation transfer function (MTF) curve of the imaging lens system.

[0028] Figure 4 This is the basis for showing the back focal length (BFL). Figure 1 The graph shows the temperature change curve of the imaging lens system.

[0029] Figure 5 This is a view showing an imaging lens system according to the second example.

[0030] Figure 6 It is shown Figure 5 A view of the aberration curves of the imaging lens system shown.

[0031] Figure 7 It is shown Figure 5 The graph shows the MTF curve of the imaging lens system.

[0032] Figure 8 This is the basis for showing BFL. Figure 5 The graph shows the temperature change curve of the imaging lens system.

[0033] Figure 9 This is a view showing an imaging lens system according to the third example.

[0034] Figure 10 It is shown Figure 9 A view of the aberration curves of the imaging lens system shown.

[0035] Figure 11 It is shown Figure 9 The graph shows the MTF curve of the imaging lens system.

[0036] Figure 12 This is the basis for showing BFL. Figure 9 The graph shows the temperature change curve of the imaging lens system.

[0037] Figure 13 This is a view showing the imaging lens system according to the fourth example.

[0038] Figure 14 It is shown Figure 13 A view of the aberration curves of the imaging lens system shown.

[0039] Figure 15 It is shown Figure 13 The graph shows the MTF curve of the imaging lens system.

[0040] Figure 16 This is the basis for showing BFL. Figure 13 The graph shows the temperature change curve of the imaging lens system.

[0041] Figure 17 This is a view showing the imaging lens system according to the fifth example.

[0042] Figure 18 It is shown Figure 17 A view of the aberration curves of the imaging lens system shown.

[0043] Figure 19 It is shown Figure 17 The graph shows the MTF curve of the imaging lens system.

[0044] Figure 20 This is the basis for showing BFL. Figure 17 The graph shows the temperature change curve of the imaging lens system.

[0045] Figure 21 This is a view showing the imaging lens system according to the sixth example.

[0046] Figure 22 It is shown Figure 21 A view of the aberration curves of the imaging lens system shown.

[0047] Figure 23 It is shown Figure 21 The graph shows the MTF curve of the imaging lens system.

[0048] Figure 24 This is the basis for showing BFL. Figure 21 The graph shows the temperature change curve of the imaging lens system.

[0049] Figure 25 This is a view showing the imaging lens system according to the seventh example.

[0050] Figure 26 It is shown Figure 25 A view of the aberration curves of the imaging lens system shown.

[0051] Figure 27 It is shown Figure 25 The graph shows the MTF curve of the imaging lens system.

[0052] Figure 28 This is the basis for showing BFL. Figure 25 The graph shows the temperature change curve of the imaging lens system.

[0053] Figure 29 This is a view showing the imaging lens system according to the eighth example.

[0054] Figure 30 It is shown Figure 29 A view of the aberration curves of the imaging lens system shown.

[0055] Figure 31 It is shown Figure 29 The graph shows the MTF curve of the imaging lens system.

[0056] Figure 32 This is the basis for showing BFL. Figure 29 The graph shows the temperature change curve of the imaging lens system.

[0057] Throughout the accompanying drawings and detailed embodiments, the same reference numerals refer to the same elements. For purposes of clarity, illustration, and convenience, the drawings may not be drawn to scale, and the relative dimensions, scale, and depiction of elements in the drawings may be exaggerated. Detailed Implementation

[0058] In the following text, although examples of this disclosure will be described in detail with reference to the accompanying drawings, it should be noted that the examples are not limited thereto.

[0059] The following detailed embodiments are provided to help the reader gain a full understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will be apparent after understanding this disclosure. For example, the order of operations described herein is merely illustrative, except for operations that must occur in a specific order, and is not limited to the order set forth herein; changes may be made that will become apparent after understanding this disclosure. Furthermore, descriptions of functions and constructions well-known in the art may be omitted for clarity and conciseness.

[0060] The features described herein may be implemented in various forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein, which will be apparent upon understanding this disclosure.

[0061] In this document, it should be noted that the use of the word "may" (e.g., what an example or implementation may include or implement) with respect to examples or implementations means that there exists at least one example or implementation that includes or implements such a feature, but not all examples and implementations are limited thereto.

[0062] Throughout this specification, when an element such as a layer, region, or substrate is described as being "on," "connected to," or "attached to" another element, the element may be directly "on," directly "connected to," or directly "attached to" the other element, or there may be one or more other elements between the element and the other element. Conversely, when an element is described as being "directly on," "directly connected to," or "directly attached to" another element, there are no other elements between the element and the other element. As used herein, a "part" of an element may include the entire element or less than the entire element.

[0063] As used herein, the term “and / or” includes any one of the associated listed items and any combination of any two or more items. “At least one” includes any one of the associated listed items and any combination of any two or more items.

[0064] Although terms such as “first,” “second,” and “third” may be used herein to describe various components, parts, regions, layers, or sections, these components, parts, regions, layers, or sections are not limited by these terms. Rather, these terms are used only to distinguish one component, part, region, layer, or section from another. Therefore, without departing from the teachings of the examples, the first component, first part, first region, first layer, or first section mentioned in the examples described herein may also be referred to as a second component, second part, second region, second layer, or second section.

[0065] Spatial relative terms such as “above,” “above,” “below,” and “below” may be used herein for descriptive convenience to describe the relationship of one element relative to another, as shown in the accompanying drawings. In addition to covering the orientation depicted in the drawings, these spatial relative terms are intended to also cover different orientations of the device in use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “above” another element would be located “below” or “below” that other element. Thus, depending on the spatial orientation of the device, the term “above” covers both “above” and “below” orientations. The device may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0066] The terminology used herein is for the purpose of describing various examples only and is not intended to limit the scope of this disclosure. Unless the context clearly indicates otherwise, the articles “a,” “an,” and “the” are intended to include plural forms as well. The terms “comprising,” “including,” and “having” indicate the presence of stated features, numbers, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, components, elements, and / or combinations thereof.

[0067] The shapes shown in the accompanying drawings may vary due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include shape variations that occur during manufacturing.

[0068] The features of the examples described herein can be combined in various ways, as will be apparent upon understanding this disclosure. Furthermore, while the examples described herein have multiple configurations, other configurations are also possible, as will be apparent upon understanding this disclosure.

[0069] One aspect of this disclosure is to provide an imaging lens system that achieves constant optical properties independent of ambient temperature.

[0070] An imaging lens system includes multiple lenses arranged along the optical axis. The multiple lenses may be spaced apart from each other by a predetermined distance along the optical axis.

[0071] For example, an imaging lens system may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged in ascending numerical order along the optical axis from the object side of the imaging lens system toward the imaging surface of the imaging lens system, wherein the first lens is closest to the object side of the imaging lens system, and the ninth lens is closest to the imaging surface.

[0072] In each lens, the object side or first surface is the surface of the lens closest to the object side of the imaging lens system, and the image side or second surface is the surface of the lens closest to the imaging surface.

[0073] Unless otherwise stated, references to the shape of a lens surface refer to the shape of the paraxial region of the lens surface. The paraxial region of a lens surface is the central portion of the lens surface that surrounds and includes the optical axis of the lens surface, in which light rays incident on the lens surface form a small angle θ with the optical axis, and the following approximations are valid: sinθ≈θ, tanθ≈θ, and cosθ≈1.

[0074] In the example, the first lens refers to the lens closest to the object (or target), and the ninth lens refers to the lens closest to the imaging plane (or image sensor). In the example, the radius of curvature, thickness, TTL (distance from the object-side surface of the first lens (or the foremost lens) to the imaging plane), IMGHT (half the diagonal length of the imaging plane), and focal length are expressed in millimeters (mm). The lens thickness, the gap between lenses, and TTL refer to the distance between lenses along the optical axis. Furthermore, in the description of the lens shape, a configuration where one surface is convex indicates that the optical axis region of that surface is convex, and a configuration where one surface is concave indicates that the optical axis region of that surface is concave. Therefore, even when one surface of a lens is described as convex, the edge of the lens can be concave. Similarly, even when one surface of a lens is described as concave, the edge of the lens can be convex.

[0075] The first lens has refractive power. For example, the first lens may have negative refractive power. One surface of the first lens may be convex. For example, the first lens may have a convex object-side surface. The first lens may have a spherical or aspherical surface. For example, both surfaces of the first lens may be spherical or aspherical. The first lens may be made of a material with high light transmittance and excellent processability. For example, the first lens may be made of a plastic material. The first lens may have a predetermined refractive index. For example, the refractive index of the first lens may be less than 1.6.

[0076] The second lens has refractive power. For example, the second lens may have positive or negative refractive power. One surface of the second lens may be convex. For example, the second lens may have a convex object-side or image-side. The second lens may have an aspherical surface. For example, both surfaces of the second lens may be aspherical. The second lens may be made of a material with high light transmittance and excellent processability. For example, the second lens may be made of a plastic material. The second lens may have a predetermined refractive index. For example, the refractive index of the second lens may be less than 1.6.

[0077] The third lens has refractive power. For example, the third lens may have negative refractive power. One surface of the third lens may be convex. For example, the third lens may have a convex object-side surface. The third lens may have an aspherical surface. For example, both surfaces of the third lens may be aspherical. The third lens may be made of a material with high light transmittance and excellent processability. For example, the third lens may be made of a plastic material. The third lens may have a higher refractive index than the first and second lenses. For example, the refractive index of the third lens may be 1.6 or greater.

[0078] The fourth lens has refractive power. For example, the fourth lens may have positive refractive power. One surface of the fourth lens may be convex. For example, the fourth lens may have a convex object-side surface. The fourth lens may have a spherical or aspherical surface. For example, both surfaces of the fourth lens may be spherical or aspherical. The fourth lens may be manufactured using materials with high light transmittance and excellent machinability. The fourth lens may have a predetermined refractive index. For example, the refractive index of the fourth lens may be 1.5 or greater.

[0079] The fifth lens has refractive power. The fifth lens may have positive refractive power. One surface of the fifth lens may be convex. For example, the fifth lens may have a convex object-side surface or a convex image-side surface. The fifth lens may have a spherical or aspherical surface. For example, both surfaces of the fifth lens may be spherical or aspherical. The fifth lens may be manufactured using materials with high light transmittance and excellent machinability. The fifth lens may have a predetermined refractive index. For example, the refractive index of the fifth lens may be 1.5 or greater.

[0080] The sixth lens has refractive power. For example, the sixth lens may have negative refractive power. One surface of the sixth lens may be concave. For example, the sixth lens may have a concave object-side surface. The sixth lens may have an aspherical surface. For example, both surfaces of the sixth lens may be aspherical. The sixth lens may be manufactured using materials with high light transmittance and excellent machinability. For example, the sixth lens may be manufactured using plastic materials. The refractive index of the sixth lens may be substantially similar to that of the third lens. For example, the refractive index of the sixth lens may be 1.6 or greater.

[0081] The seventh lens has refractive power. For example, the seventh lens may have positive refractive power. One surface of the seventh lens may be convex. For example, the seventh lens may have a convex image-side surface. The seventh lens may have an aspherical surface. For example, both surfaces of the seventh lens may be aspherical. The seventh lens may be manufactured using materials with high light transmittance and excellent machinability. For example, the seventh lens may be manufactured using plastic materials. The refractive index of the seventh lens may be substantially similar to that of the second lens. For example, the refractive index of the seventh lens may be less than 1.6.

[0082] The eighth lens has refractive power. For example, the eighth lens may have positive or negative refractive power. One surface of the eighth lens may be convex. For example, the eighth lens may have a convex object-side surface. The eighth lens may have an aspherical surface. For example, both surfaces of the eighth lens may be aspherical. A recurve point may be formed on at least one surface of the eighth lens. For example, at least one recurve point may be formed on the object-side and image-side surfaces of the eighth lens. The eighth lens may be manufactured using a material with high light transmittance and excellent processability. For example, the eighth lens may be manufactured using a plastic material. The refractive index of the eighth lens may be substantially similar to the refractive index of the seventh lens. For example, the refractive index of the eighth lens may be less than 1.6.

[0083] The ninth lens may have refractive power. For example, the ninth lens may have negative refractive power. One surface of the ninth lens may be concave. For example, the ninth lens may have a concave image-side surface. The ninth lens may have an aspherical surface. For example, both surfaces of the ninth lens may be aspherical. A recurve point may be formed on at least one surface of the ninth lens. For example, at least one recurve point may be formed on both the object-side and image-side surfaces of the ninth lens. The ninth lens may be manufactured using a material with high light transmittance and excellent processability. For example, the ninth lens may be manufactured using a plastic material. The refractive index of the ninth lens may be substantially similar to that of the seventh lens. For example, the refractive index of the ninth lens may be less than 1.6.

[0084] Lenses constituting an imaging lens system may selectively have aspherical surfaces. The aspherical surface of a lens can be represented by the following Equation 1:

[0085] (Equation 1)

[0086]

[0087] In Equation 1, “c” is the reciprocal of the radius of curvature of the corresponding lens, “k” is the conic constant, “r” is the distance from a point on the aspherical surface of the lens to the optical axis, “A, B, C, D, E, F and G” are aspherical constants, and “Z” (or SAG) is the distance from a point on the aspherical surface to the vertex of the aspherical surface in the direction of the optical axis.

[0088] The imaging lens system may also include a filter, an image sensor, and an aperture. Furthermore, the imaging lens system may also include a cover glass.

[0089] A filter may be disposed between the ninth lens and the image sensor. The filter may block light of certain wavelengths. For example, the filter may block light of infrared wavelengths. The image sensor may have an imaging surface disposed at the imaging plane of the imaging lens system. An aperture may be configured to adjust the intensity of light incident on the lens. For example, the aperture may be disposed between the third and fourth lenses. The lens disposed on the image side of the aperture may have a predetermined focal length. For example, the combined focal length fstp12 of two lenses consecutively disposed on the image side of the aperture may be greater than 0 and less than the focal length f of the imaging lens system. A cover glass may be disposed between the filter and the image sensor. For example, the cover glass may be formed to be in close contact with a surface of the image sensor. The cover glass may be configured to cover the image sensor. For example, the cover glass may cover the image sensor to prevent foreign objects from contaminating the imaging surface of the image sensor, or to prevent foreign objects from contacting the image sensor.

[0090] The first through ninth lenses have 10 -6 A predetermined refractive index temperature coefficient (rate of change of refractive index) on the order of / ℃. At least one of the first to ninth lenses may have a positive refractive index temperature coefficient. Furthermore, one of the first to ninth lenses may have a positive refractive index and an absolute value of 10 (10 -6 A temperature coefficient of refractive index of -80°C or lower. The corresponding lens can be used as a temperature compensation lens in an imaging lens system. For example, a temperature compensation lens can reduce changes in back focal length (BFL) in response to changes in ambient temperature. The refractive index of the temperature compensation lens can be greater than that of other lenses. For example, the refractive index of the temperature compensation lens can be 1.7 or greater. The temperature compensation lens can be positioned in a specific location. For example, the temperature compensation lens can be positioned on the image side of the aperture stop. Lenses positioned near the temperature compensation lens can have a very low temperature coefficient of refractive index. For example, the temperature coefficient of refractive index of a lens adjacent to the temperature compensation lens can be less than -80°C. -6 / ℃). A lens positioned on one side of the temperature compensation lens can have a specific refractive power. For example, a lens positioned on the object side of the temperature compensation lens can have negative refractive power.

[0091] An imaging lens system may satisfy one or more of the following conditional expressions.

[0092] F45 <f

[0093] 4.0 < |DTnF / (DTnC*10)| < 7.0

[0094] 8.0 < |DTnR / (DTnC*10)| < 18

[0095] 0.3 <DTnF / DTnR<0.8

[0096] 1.2 <f / IMGHT<1.4

[0097] 0.6 <f / fc<1.3

[0098] In the above equations, f is the focal length of the imaging lens system, f45 is the composite focal length of the fourth and fifth lenses, DTnF is the sum of the refractive index temperature coefficients of the lenses positioned on the object side of the temperature-compensating lens, DTnR is the sum of the refractive index temperature coefficients of the lenses positioned on the image side of the temperature-compensating lens, DTnC is the refractive index temperature coefficient of the temperature-compensating lens, IMGHT is the maximum effective image height of the imaging lens system, which is equal to half the diagonal length of the effective imaging area of ​​the image sensor's imaging surface, and fc is the focal length of the temperature-compensating lens.

[0099] The lenses constituting an imaging lens system can each have 10 -6 A predetermined coefficient of thermal expansion (CTE) on the order of / ℃. For example, the CTE of the first through ninth lenses could be 6.0 (10⁻⁶). -6 / ℃) or higher to less than 80 (10 -6 / ℃).

[0100] The lens constituting an imaging lens system may have a focal length variation rate VT according to temperature. The focal length variation rate VT of the lens can be obtained by the following equation.

[0101] VTi = [DTni / (Ndi-1)-CTEi] -1

[0102] In the above equation, VTi is the rate of change of focal length of the i-th lens, DTni is the rate of change of refractive index (temperature coefficient of refractive index) of the i-th lens, Ndi is the refractive index of the i-th lens, and CTEi is the coefficient of thermal expansion (CTE) of the i-th lens. Compared to other lenses, the rate of change of focal length VT of a temperature-compensated lens can be very small. For example, the rate of change of focal length VT of a temperature-compensated lens can be -400 or less.

[0103] In the following description, several examples of imaging lens systems will be described.

[0104] In the following text, reference will be made to Figure 1 The imaging lens system 100 according to the first example is described.

[0105] The imaging lens system 100 may include a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, a seventh lens 170, an eighth lens 180, and a ninth lens 190.

[0106] The first lens 110 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The second lens 120 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The third lens 130 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fourth lens 140 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The fifth lens 150 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The sixth lens 160 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. The seventh lens 170 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The eighth lens 180 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The ninth lens 190 may have negative refractive power and may have a convex object-side surface and a concave image-side surface.

[0107] The imaging lens system 100 may further include a filter IF, a cover glass CG, an image sensor IP, and an aperture ST. The filter IF and the cover glass CG may be sequentially disposed between the ninth lens 190 and the image sensor IP. The aperture ST may be disposed between the third lens 130 and the fourth lens 140.

[0108] Figure 2 and Figure 3 The aberration characteristics and MTF characteristics of the imaging lens system 100 according to the first example are shown. Figure 4 The back focal length of the imaging lens system 100 is shown as a function of temperature, ΔBFL (μm).

[0109] The lens characteristics and aspherical values ​​of the imaging lens system 100 according to the first example are listed in Tables 1 and 2. In the first example, the temperature-compensated lens is a fourth lens with a refractive index change rate (temperature coefficient of refractive index) (DTn) value of 4.40.

[0110] Table 1

[0111]

[0112]

[0113] Table 2

[0114] Face number K A B C D E F S3 0 6.9600E-04 -1.4500E-05 -7.1900E-08 2.4100E-09 - - S4 0 1.3700E-03 -3.0600E-05 -2.8900E-07 1.2300E-08 - - S5 0 -2.8600E-04 -1.8300E-06 -4.4600E-07 1.3900E-08 - - S6 0 -1.2800E-03 3.2800E-05 -1.2900E-06 2.9800E-08 - - S8 0 -2.5500E-05 2.0500E-06 -3.2000E-07 9.1300E-09 - - S9 0 1.0700E-04 -4.1300E-06 1.0500E-08 1.1500E-09 - - S10 0 -8.7800E-05 -5.4700E-06 1.0200E-07 1.4300E-09 - - S11 0 -7.1400E-04 2.5400E-05 -6.8200E-07 9.0100E-09 - - S12 0 -5.1800E-04 2.5500E-05 -7.9900E-07 7.7400E-09 - - S13 0 -3.8500E-04 1.6400E-05 -3.3300E-07 3.4700E-10 - - S14 0 -2.5600E-04 7.6400E-06 3.4400E-07 -7.1500E-09 -1.7300E-11 - S15 0 -4.4300E-04 2.3700E-05 -3.9500E-07 7.3800E-09 -7.3600E-11 - S16 0 -1.6500E-03 2.2700E-05 -8.4900E-08 -5.3100E-09 6.1200E-11 - S17 0 -1.7600E-03 2.0100E-05 -1.6700E-07 4.6400E-10 -3.9700E-13 - S18 0 -1.9200E-03 4.0900E-05 -4.0300E-07 1.9100E-09 -4.5200E-12 5.9900E-15 S19 0 -1.9500E-03 4.3600E-05 -6.9000E-07 6.8200E-09 -3.7800E-11 8.1300E-14

[0115] In the following text, reference will be made to Figure 5 The imaging lens system 200 according to the second example is described.

[0116] The imaging lens system 200 may include a first lens 210, a second lens 220, a third lens 230, a fourth lens 240, a fifth lens 250, a sixth lens 260, a seventh lens 270, an eighth lens 280, and a ninth lens 290.

[0117] The first lens 210 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The second lens 220 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The third lens 230 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fourth lens 240 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The fifth lens 250 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The sixth lens 260 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. The seventh lens 270 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The eighth lens 280 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The ninth lens 290 may have negative refractive power and may have a convex object-side surface and a concave image-side surface.

[0118] The imaging lens system 200 may further include a filter IF, a cover glass CG, an image sensor IP, and an aperture ST. The filter IF and the cover glass CG may be sequentially disposed between the ninth lens 290 and the image sensor IP. The aperture ST may be disposed between the third lens 230 and the fourth lens 240.

[0119] Figure 6 and Figure 7 The aberration characteristics and MTF characteristics of the imaging lens system 200 according to the second example are shown. Figure 8 The back focal length of the imaging lens system 200 as a function of temperature is shown as ΔBFL (μm).

[0120] The lens characteristics and aspherical values ​​of the imaging lens system 200 according to the second example are listed in Tables 3 and 4. In the second example, the temperature-compensating lens is a fourth lens with a DTn value of 4.40.

[0121] Table 3

[0122]

[0123]

[0124] Table 4

[0125]

[0126]

[0127] In the following text, reference will be made to Figure 9 The imaging lens system 300 is described according to the third example.

[0128] The imaging lens system 300 may include a first lens 310, a second lens 320, a third lens 330, a fourth lens 340, a fifth lens 350, a sixth lens 360, a seventh lens 370, an eighth lens 380, and a ninth lens 390.

[0129] The first lens 310 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The second lens 320 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The third lens 330 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fourth lens 340 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The fifth lens 350 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The sixth lens 360 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. The seventh lens 370 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The eighth lens 380 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The ninth lens 390 may have negative refractive power and may have a concave object-side surface and a concave image-side surface.

[0130] The imaging lens system 300 may further include a filter IF, a cover glass CG, an image sensor IP, and an aperture ST. The filter IF and the cover glass CG may be sequentially disposed between the ninth lens 390 and the image sensor IP. The aperture ST may be disposed between the third lens 330 and the fourth lens 340.

[0131] Figure 10 and Figure 11 The aberration characteristics and MTF characteristics of the imaging lens system 300 according to the third example are shown. Figure 12 The back focal length of the imaging lens system 300 as a function of temperature is shown as ΔBFL (μm).

[0132] The lens characteristics and aspherical values ​​of the imaging lens system 300 according to the third example are listed in Tables 5 and 6. In the third example, the temperature-compensating lens is a fourth lens with a DTn value of 4.40.

[0133] Table 5

[0134]

[0135]

[0136] Table 6

[0137]

[0138]

[0139] In the following text, reference will be made to Figure 13 The imaging lens system 400 is described according to the fourth example.

[0140] The imaging lens system 400 may include a first lens 410, a second lens 420, a third lens 430, a fourth lens 440, a fifth lens 450, a sixth lens 460, a seventh lens 470, an eighth lens 480, and a ninth lens 490.

[0141] The first lens 410 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The second lens 420 may have positive refractive power and may have a concave object-side surface and a convex image-side surface. The third lens 430 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fourth lens 440 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The fifth lens 450 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The sixth lens 460 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. The seventh lens 470 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The eighth lens 480 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The ninth lens 490 may have negative refractive power and may have a convex object-side surface and a concave image-side surface.

[0142] The imaging lens system 400 may further include a filter IF, a cover glass CG, an image sensor IP, and an aperture ST. The filter IF and the cover glass CG may be sequentially disposed between the ninth lens 490 and the image sensor IP. The aperture ST may be disposed between the third lens 430 and the fourth lens 440.

[0143] Figure 14 and Figure 15 The aberration characteristics and MTF characteristics of the imaging lens system 400 according to the fourth example are shown. Figure 16 The back focal length ΔBFL (μm) of the imaging lens system 400 as a function of temperature is shown.

[0144] The lens characteristics and aspherical values ​​of the imaging lens system 400 according to the fourth example are listed in Tables 7 and 8. In the fourth example, the temperature-compensating lens is a fourth lens with a DTn value of 4.50.

[0145] Table 7

[0146]

[0147]

[0148] Table 8

[0149] Face number K A B C D E F S3 0 4.9321E-04 -1.5961E-05 -8.0062E-09 2.1774E-09 - - S4 0 1.0640E-03 -2.1909E-05 -5.9067E-08 4.4272E-09 - - S5 0 -6.3621E-04 2.6559E-05 -5.5006E-07 8.7074E-09 - - S6 0 -1.6198E-03 4.7034E-05 -9.6408E-07 1.7997E-08 - - S8 0 1.0623E-05 -7.4896E-06 2.2917E-07 -1.5116E-09 - - S9 0 6.4693E-05 -6.0843E-06 2.3106E-07 -3.5552E-09 - - S10 0 -1.1175E-04 -3.8051E-06 2.1238E-07 -2.5931E-09 - - S11 0 -1.8786E-04 -2.0288E-05 7.8863E-07 -8.0348E-09 - - S12 0 -5.4213E-05 -1.6359E-05 5.4112E-07 -4.9037E-09 - - S13 0 -3.2284E-04 8.8836E-06 -2.3310E-07 2.2812E-09 - - S14 0 -2.6587E-04 7.8980E-06 -1.2490E-07 2.6830E-09 -4.1934E-11 - S15 0 -5.5898E-04 2.6826E-05 -7.3072E-07 1.4964E-08 -1.2145E-10 - S16 0 -1.3371E-03 4.1179E-06 -2.0940E-07 5.1191E-09 -3.3205E-11 - S17 0 -3.8694E-04 -1.4674E-05 4.0990E-07 -5.1913E-09 2.4471E-11 - S18 0 -1.0968E-03 3.4071E-05 -5.6814E-07 5.7289E-09 -3.6710E-11 1.1829E-13 S19 0 -1.7607E-03 3.7552E-05 -7.6496E-07 1.0336E-08 -7.5071E-11 2.1462E-13

[0150] In the following text, reference will be made to Figure 17 The imaging lens system 500 is described according to the fifth example.

[0151] The imaging lens system 500 may include a first lens 510, a second lens 520, a third lens 530, a fourth lens 540, a fifth lens 550, a sixth lens 560, a seventh lens 570, an eighth lens 580, and a ninth lens 590.

[0152] The first lens 510 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The second lens 520 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The third lens 530 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fourth lens 540 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The fifth lens 550 may have positive refractive power and may have a concave object-side surface and a convex image-side surface. The sixth lens 560 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. The seventh lens 570 may have positive refractive power and may have a concave object-side surface and a convex image-side surface. The eighth lens 580 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The ninth lens 590 may have negative refractive power and may have a convex object-side surface and a concave image-side surface.

[0153] The imaging lens system 500 may further include a filter IF, a cover glass CG, an image sensor IP, and an aperture ST. The filter IF and the cover glass CG may be sequentially disposed between the ninth lens 590 and the image sensor IP. The aperture ST may be disposed between the third lens 530 and the fourth lens 540.

[0154] Figure 18 and Figure 19 The aberration characteristics and MTF characteristics of the imaging lens system 500 according to the fifth example are shown. Figure 20 The back focal length ΔBFL (μm) of the imaging lens system 500 as a function of temperature is shown.

[0155] The lens characteristics and aspherical values ​​of the imaging lens system 500 according to the fifth example are listed in Tables 9 and 10. In the fifth example, the temperature-compensating lens is the fourth lens with a DTn value of 4.50.

[0156] Table 9

[0157]

[0158]

[0159] Table 10

[0160]

[0161]

[0162] In the following text, reference will be made to Figure 21 The imaging lens system 600 is described according to the sixth example.

[0163] The imaging lens system 600 may include a first lens 610, a second lens 620, a third lens 630, a fourth lens 640, a fifth lens 650, a sixth lens 660, a seventh lens 670, an eighth lens 680, and a ninth lens 690.

[0164] The first lens 610 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The second lens 620 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The third lens 630 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fourth lens 640 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The fifth lens 650 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The sixth lens 660 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. The seventh lens 670 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The eighth lens 680 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The ninth lens 690 may have negative refractive power and may have a convex object-side surface and a concave image-side surface.

[0165] The imaging lens system 600 may further include a filter IF, a cover glass CG, an image sensor IP, and an aperture ST. The filter IF and the cover glass CG may be sequentially disposed between the ninth lens 690 and the image sensor IP. The aperture ST may be disposed between the third lens 630 and the fourth lens 640.

[0166] Figure 22 and Figure 23 The aberration characteristics and MTF characteristics of the imaging lens system 600 according to the sixth example are shown. Figure 24 The back focal length ΔBFL (μm) of the imaging lens system 600 as a function of temperature is shown.

[0167] The lens characteristics and aspherical values ​​of the imaging lens system 600 according to the sixth example are listed in Tables 11 and 12. In the sixth example, the temperature-compensating lens is a fourth lens with a DTn value of 4.40.

[0168] Table 11

[0169]

[0170]

[0171] Table 12

[0172] Face number K A B C D E F S1 0 -3.3800E-07 -4.2400E-07 8.2000E-10 8.7700E-12 - - S2 0 9.5800E-06 -5.6700E-07 -1.4400E-08 -4.9300E-11 - - S3 0 6.7100E-04 -1.5300E-05 4.3500E-08 -1.1000E-10 - - S4 0 1.1700E-03 -3.0600E-05 1.6400E-07 5.6300E-10 - - S5 0 -4.0600E-04 1.9700E-06 -5.5900E-08 3.2000E-09 - - S6 0 -1.3000E-03 3.4800E-05 -8.7400E-07 1.8100E-08 - - S8 0 2.4800E-05 -1.7700E-06 6.1600E-09 9.7300E-10 - - S9 0 7.1300E-05 -3.8700E-06 1.6700E-07 -3.5700E-09 - - S10 0 -1.9300E-04 -4.5900E-06 1.6200E-07 -4.0100E-10 - - S11 0 -5.8400E-04 1.4600E-05 -1.5500E-07 1.4400E-09 - - S12 0 -6.4200E-04 2.4600E-05 -4.5400E-07 1.3800E-09 - - S13 0 -5.4800E-04 2.0100E-05 -3.4200E-07 -3.0600E-10 - - S14 0 -1.9700E-04 5.0700E-06 2.7800E-07 -3.7500E-09 -5.08E-11 - S15 0 -5.0700E-04 2.5100E-05 -5.6000E-07 1.1600E-08 -1.05E-10 - S16 0 -1.7700E-03 1.8300E-05 -1.7200E-08 -6.4600E-09 8.10E-11 - S17 0 -1.8500E-03 1.6000E-05 -8.8200E-08 4.1000E-10 -4.58E-12 - S18 0 -2.0200E-03 4.3500E-05 -4.0400E-07 1.4300E-09 8.55E-13 -1.31E-14 S19 0 -2.0500E-03 4.8900E-05 -7.6500E-07 6.9000E-09 -3.28E-11 5.49E-14

[0173] In the following text, reference will be made to Figure 25 The imaging lens system 700 according to the seventh example is described.

[0174] The imaging lens system 700 may include a first lens 710, a second lens 720, a third lens 730, a fourth lens 740, a fifth lens 750, a sixth lens 760, a seventh lens 770, an eighth lens 780, and a ninth lens 790.

[0175] The first lens 710 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The second lens 720 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The third lens 730 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fourth lens 740 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The fifth lens 750 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The sixth lens 760 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. The seventh lens 770 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The eighth lens 780 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The ninth lens 790 may have negative refractive power and may have a convex object-side surface and a concave image-side surface.

[0176] The imaging lens system 700 may further include a filter IF, a cover glass CG, an image sensor IP, and an aperture ST. The filter IF and the cover glass CG may be sequentially disposed between the ninth lens 790 and the image sensor IP. The aperture ST may be disposed between the third lens 730 and the fourth lens 740.

[0177] Figure 26 and Figure 27 The aberration characteristics and MTF characteristics of the imaging lens system 700 according to the seventh example are shown. Figure 28 The back focal length ΔBFL (μm) of the imaging lens system 700 as a function of temperature is shown.

[0178] The lens characteristics and aspherical values ​​of the imaging lens system 700 according to the seventh example are listed in Tables 13 and 14. In the seventh example, the temperature-compensating lens is a fourth lens with a DTn value of 3.0.

[0179] Table 13

[0180]

[0181]

[0182] Table 14

[0183]

[0184]

[0185] In the following text, reference will be made to Figure 29 The imaging lens system 800 is described according to the eighth example.

[0186] The imaging lens system 800 may include a first lens 810, a second lens 820, a third lens 830, a fourth lens 840, a fifth lens 850, a sixth lens 860, a seventh lens 870, an eighth lens 880, and a ninth lens 890.

[0187] The first lens 810 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The second lens 820 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The third lens 830 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fourth lens 840 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The fifth lens 850 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The sixth lens 860 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. The seventh lens 870 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The eighth lens 880 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The ninth lens 890 may have negative refractive power and may have a convex object-side surface and a concave image-side surface.

[0188] The imaging lens system 800 may further include a filter IF, a cover glass CG, an image sensor IP, and an aperture ST. The filter IF and the cover glass CG may be sequentially disposed between the ninth lens 890 and the image sensor IP. The aperture ST may be disposed between the third lens 830 and the fourth lens 840.

[0189] Figure 30 and Figure 31 The aberration characteristics and MTF characteristics of the imaging lens system 800 according to the eighth example are shown. Figure 32 The back focal length ΔBFL (μm) of the imaging lens system 800 as a function of temperature is shown.

[0190] The lens characteristics and aspherical values ​​of the imaging lens system 800 according to the eighth example are listed in Tables 15 and 16. In the eighth example, the temperature-compensating lens is the fifth lens with a DTn value of 4.50.

[0191] Table 15

[0192]

[0193]

[0194] Table 16

[0195]

[0196]

[0197] The imaging lens system according to this disclosure typically has the following optical characteristics. For example, the total lens length (TTL) of the imaging lens system can be determined in the range of 35mm to 45mm, the total focal length f can be determined in the range of 12mm to 16mm, and the focal length f1 of the first lens can be determined in the range of -32mm to -15mm, the focal length f2 of the second lens can be determined in the range of 15mm or greater or -500mm or less, the focal length f3 of the third lens can be determined in the range of -290mm to -35mm, the focal length f4 of the fourth lens can be determined in the range of 8.0mm to 24mm, the focal length f5 of the fifth lens can be determined in the range of 11mm to 110mm, and the focal length f6 of the sixth lens can be determined in the range of -18mm to -11mm. The focal length f7 of the seventh lens can be determined in the range of 15mm to 35mm, the focal length f8 of the eighth lens can be determined in the range of 15mm or greater or -30mm or less, and the focal length f9 of the ninth lens can be determined in the range of -110mm to -10mm.

[0198] The optical characteristics of the imaging lens systems according to the first to eighth examples are listed in Table 17.

[0199] Table 17

[0200]

[0201]

[0202] The conditional expression values ​​for the imaging lens systems according to the first to eighth examples are listed in Table 18.

[0203] Table 18

[0204]

[0205] As described above, this disclosure provides an imaging lens system that can achieve constant optical properties even in high or low temperature environments.

[0206] While specific examples have been shown and described above, it will be apparent upon gaining an understanding of this disclosure that various changes in form and detail may be made to these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein should be interpreted in a descriptive sense only and not for limiting purposes. 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 system, architecture, apparatus, or circuit are combined in different ways and / or replaced or supplemented with other components or their equivalents. Therefore, the scope of this disclosure is not limited by specific embodiments but by the appended claims and their equivalents, and all variations within the scope of the appended claims and their equivalents should be understood to be included in this disclosure.

Claims

1. An imaging lens system, comprising: A first lens having a negative refractive power; A second lens having a refractive power; A third lens having a negative refractive power; A fourth lens having a positive refractive power; A fifth lens having a positive refractive power; A sixth lens having a negative refractive power; A seventh lens having a positive refractive power; An eighth lens having a refractive power; And A ninth lens having a negative refractive power, wherein the first lens to the ninth lens are sequentially arranged from the object side toward the imaging surface, wherein the imaging lens system has a total of 9 lenses having refractive powers, Among them, one of the first to the ninth lenses is a temperature-compensated lens having positive refractive power and an absolute value of a refractive index temperature coefficient of 10 or less, wherein the unit of the refractive index temperature coefficient is 10. -6 / ℃, wherein the temperature compensation lens has a larger refractive index than other lenses, and wherein 8.0 < |DTnR / (DTnC * 10)| < 18, where DTnR is the sum of the refractive index temperature coefficients of the lenses disposed on the image side of the temperature compensation lens, and DTnC is the refractive index temperature coefficient of the temperature compensation lens.

2. The imaging lens system according to claim 1, wherein, Each lens adjacent to the temperature-compensating lens has a refractive index temperature coefficient of less than -80, wherein the unit of the refractive index temperature coefficient is 10. -6 / ℃.

3. The imaging lens system according to claim 1, wherein, When the fourth lens is the temperature compensation lens, the lens adjacent to the object side of the temperature compensation lens has a negative refractive power.

4. The imaging lens system according to claim 1, wherein, f45 < f, where f45 is the combined focal length of the fourth lens and the fifth lens, and f is the focal length of the imaging lens system.

5. The imaging lens system according to claim 1, wherein, The seventh lens has a convex image side surface.

6. The imaging lens system according to claim 1, wherein, The eighth lens has a convex object side surface.

7. The imaging lens system according to claim 1, wherein, When the fifth lens is the temperature compensation lens, the lens adjacent to the object side of the temperature compensation lens has a positive refractive power.

8. An imaging lens system, comprising: A first lens having a negative refractive power; A second lens having a refractive power; A third lens having a negative refractive power; A fourth lens having a positive refractive power; A fifth lens having a positive refractive power; A sixth lens having a negative refractive power; A seventh lens having a positive refractive power; An eighth lens having a refractive power; And A ninth lens having a negative refractive power, wherein the first lens to the ninth lens are sequentially arranged from the object side toward the imaging surface, wherein the imaging lens system has a total of 9 lenses having refractive powers, Among them, one of the first to the ninth lenses is a temperature-compensated lens having positive refractive power and an absolute value of a refractive index temperature coefficient of 10 or less, wherein the unit of the refractive index temperature coefficient is 10. -6 / ℃, wherein the temperature compensation lens has a larger refractive index than other lenses, and wherein 0.3 < DTnF / DTnR < 0.8, where DTnF is the sum of the refractive index temperature coefficients of the lenses disposed on the object side of the temperature compensation lens, and DTnR is the sum of the refractive index temperature coefficients of the lenses disposed on the image side of the temperature compensation lens.

9. The imaging lens system according to claim 8, wherein, The fourth lens or the fifth lens is the temperature compensation lens.

10. The imaging lens system according to claim 8, wherein, The temperature compensation lens has a refractive index of 1.7 or greater.

11. The imaging lens system according to claim 8, wherein, 4.0 < |DTnF / (DTnC * 10)| < 7.0, where DTnC is the refractive index temperature coefficient of the temperature compensation lens.

12. The imaging lens system according to claim 8, wherein, 8.0 < |DTnR / (DTnC * 10)| < 18, where DTnC is the refractive index temperature coefficient of the temperature compensation lens.

Images