Imaging lens system

Abstract

A camera lens system includes: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, arranged sequentially from the object side; and an aperture stop, disposed on the image side of one of the first to sixth lenses, wherein one or more of the second to seventh lenses disposed on the image side of the aperture stop each has a positive refractive power and a negative temperature coefficient of refractive index.

Description

Technical Field

[0001] The following description relates to a camera lens system that can achieve constant optical performance regardless of changes in ambient temperature. Prior Technology

[0002] The small surveillance camera is configured to acquire image information from the monitored area. For example, the small surveillance camera can be mounted on the front and rear bumpers of a vehicle and can provide the acquired images to the driver.

[0003] Because early models of small surveillance cameras were configured to image obstacles near vehicles, they had relatively low resolution, which could vary depending on temperature ranges from -40°C to 80°C. More recently, vehicles have been required to have self-driving functions, necessitating surveillance cameras with high resolution and the ability to maintain constant optical properties under harsh temperature conditions. Summary of the Invention

[0004] This summary is provided to introduce, in a simplified form, a series of concepts further elaborated in the embodiments below. This summary is not intended to identify key or essential features of the claimed object, nor is it intended to help determine the scope of the claimed object.

[0005] A camera lens system that can maintain constant optical properties regardless of ambient temperature.

[0006] In a general configuration, a camera lens system includes: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, arranged sequentially from the object side; and an aperture stop, disposed on the image side of one of the first to sixth lenses, wherein one or more of the second to seventh lenses disposed on the image side of the aperture stop each has a positive refractive power and a negative refractive index temperature coefficient.

[0007] The aperture can be positioned between the third lens and the fourth lens.

[0008] The fourth lens or the sixth lens may have positive refractive power.

[0009] The fourth lens or the sixth lens may have a negative temperature coefficient of refractive index.

[0010] The refractive index temperature coefficient of the fourth lens or the sixth lens may be greater than -10*10-6 / ℃ and less than -0.5*10-6 / ℃.

[0011] The second lens may have a concave object-side surface.

[0012] The sixth lens may have a convex image-side surface.

[0013] The seventh lens may have negative refractive power.

[0014] The seventh lens may have a concave object-side surface.

[0015] In another general example, a camera lens system includes: a first lens group disposed on the object-side surface of an aperture stop; and a second lens group disposed between the aperture stop and the image-side surface. The sum of the refractive index temperature coefficients of the lenses included in the first lens group and the refractive index temperature coefficients of the lenses included in the second lens group, DTnT, is -3.5 [10⁻⁶ / ℃] or greater than -3.5 [10⁻⁶ / ℃] and 3.5 [10⁻⁶ / ℃] or less than 3.5 [10⁻⁶ / ℃].

[0016] The sum of the temperature coefficients of the refractive index of the lenses included in the first lens group, DTnF, may be 5.0 [10-6 / ℃] or greater than 5.0 [10-6 / ℃] and 15 [10-6 / ℃] or less than 15 [10-6 / ℃].

[0017] The sum of the temperature coefficients of the refractive index of the lenses included in the second lens group, DTnR, can be -20 [10-6 / ℃] or greater than -20 [10-6 / ℃] and -8.0 [10-6 / ℃] or less than -8.0 [10-6 / ℃].

[0018] The sum of the temperature coefficients of the refractive index of the lenses included in the first lens group, DTnF, and the sum of the temperature coefficients of the refractive index of the lenses included in the second lens group, DTnR, can satisfy 0.8 ≤ |DTnF / DTnR| ≤ 1.2.

[0019] Among the lenses included in the first lens group, the lens closest to the aperture stop may have a positive refractive power.

[0020] Among the lenses included in the second lens group, the lens closest to the aperture stop may have a positive refractive power.

[0021] In the second lens group, the lens closest to the image-side surface may have a negative refractive power.

[0022] In another general example, a camera lens system includes: an aperture; a first lens group disposed on the object side of the aperture and including two or more lenses, each of the two or more lenses in the first lens group having a positive temperature coefficient of refractive index; and a second lens group disposed between the image side of the aperture and an image sensor, and including two or more lenses, each of the two or more lenses in the second lens group having a negative temperature coefficient of refractive index.

[0023] The first lens group may include three lenses, and the second lens group may include four lenses.

[0024] The lens in the second lens group that is closest to the aperture stop may have a positive temperature coefficient of refractive index.

[0025] At least two of the lenses in the first lens group may each have a negative refractive power, and at least two of the lenses in the second lens group may each have a negative refractive power.

[0026] Other features and characteristics will become apparent from reading the following detailed description, drawings and claims. Simple Explanation of the Diagram

[0027] Figure 1 is a diagram showing a first example of a camera lens system. Figure 2 shows the aberration curve of the camera lens system shown in Figure 1. Figure 3 shows the modulation transfer function (MTF) curve of the camera lens system shown in Figure 1. Figure 4 shows a curve representing the back focal length (BFL) of the camera lens system shown in Figure 1 as a function of temperature. Figure 5 is a diagram showing a second example of a camera lens system. Figure 6 shows the aberration curves of the camera lens system shown in Figure 5. Figure 7 shows the MTF curve of the camera lens system shown in Figure 5. Figure 8 shows a curve representing the change in back focal length (BFL) of the camera lens system shown in Figure 5 as a function of temperature. Figure 9 is a diagram showing a third example of a camera lens system. Figure 10 shows the aberration curves of the camera lens system shown in Figure 9. Figure 11 shows the MTF curve of the camera lens system shown in Figure 9. Figure 12 shows a curve representing the change in back focal length (BFL) of the camera lens system shown in Figure 9 as a function of temperature. Figure 13 is a diagram showing a fourth example of a camera lens system. Figure 14 shows the aberration curves of the camera lens system shown in Figure 13. Figure 15 shows the MTF curve of the camera lens system shown in Figure 13. Figure 16 shows a curve representing the change in back focal length (BFL) of the camera lens system shown in Figure 13 as a function of temperature. Figure 17 is a diagram showing a fifth example of a camera lens system. Figure 18 shows the aberration curves of the camera lens system shown in Figure 17. Figure 19 shows the MTF curve of the camera lens system shown in Figure 17. Figure 20 shows a curve representing the change in back focal length (BFL) of the camera lens system shown in Figure 17 as a function of temperature. Figure 21 is a diagram showing a sixth example of a camera lens system. Figure 22 shows the aberration curves of the camera lens system shown in Figure 21. Figure 23 shows the MTF curve of the camera lens system shown in Figure 21. Figure 24 shows a curve representing the change in back focal length (BFL) of the camera lens system shown in Figure 17 as a function of temperature. Throughout all drawings and in the detailed description, the same reference numerals refer to the same components. The drawings may not be drawn to scale, and for clarity, illustrative purposes and convenience, the relative sizes, proportions, and depictions of the components in the drawings may be exaggerated. Implementation

[0028] The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various modifications, refinements, and equivalents of the methods, apparatus, and / or systems described herein will be apparent to those skilled in the art. The order of operations described herein is merely illustrative and is not intended to limit the reader to it; rather, as will be apparent to those skilled in the art, changes may be made, except for operations that must be performed in a specific order. Furthermore, for clarity and brevity, descriptions of functions and structures well-known to those skilled in the art may be omitted.

[0029] The features described herein may be implemented in various forms and are not to be construed as limited to the examples described herein. Rather, the examples described herein are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0030] Note that in this document, the term "may" (e.g., what an instance or embodiment may include or implement) is used with respect to examples or embodiments to mean that there is at least one instance or embodiment that includes or implements such a feature, but not all instances and embodiments are limited thereto.

[0031] 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, the element may be directly "on," directly "connected to," or directly "coupled to" the other element, or there may be one or more other elements in between. Conversely, when an element is described as being "directly on," "directly connected to," or "directly coupled to" another element, there may be no other elements in between.

[0032] The term "and / or" as used in this document includes any one of the relevant listed items or any combination of any two or more of the relevant listed items.

[0033] Although terms such as "first," "second," and "third" may be used in this document to describe various components, parts, regions, layers, or sections, these components, parts, regions, layers, or sections are not limited by these terms. Specifically, these terms are used only to distinguish individual components, parts, regions, layers, or sections. Therefore, without departing from the teaching of the examples, the first component, part, region, layer, or section mentioned in the examples described herein may also be referred to as the second component, part, region, layer, or section.

[0034] In this document, for ease of explanation, spatially relative terms such as "above," "upper," "below," and "lower" are used to describe the relationship of one element relative to another shown in the figures. These spatially relative terms are intended to encompass not only the orientation depicted in the figures but also different orientations of the device during use or operation. For example, if the device in the figure is rotated, an element described as being "above" or "upper" relative to another element will now be described as being "below" or "lower" relative to that other element. Therefore, the term "above" encompasses both upper and lower orientations depending on the spatial orientation of the device. The device may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative terms used herein will be interpreted accordingly.

[0035] The terminology used herein is for illustrative purposes only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the articles "a" and "the" are intended to include the plural form as well. The terms "comprises," "includes," and "has" specify the presence of the 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.

[0036] Due to manufacturing techniques and / or tolerances, the shapes shown in the drawings may vary. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings, but include shape variations that occur during manufacturing.

[0037] As will be apparent upon understanding the disclosure of this application, the features of the examples described herein can be combined in various ways. Furthermore, as will be apparent upon understanding the disclosure of this application, although the examples described herein have multiple configurations, other configurations may exist.

[0038] In this example, the first lens refers to the lens closest to the object, and the seventh lens refers to the lens closest to the image-side surface (or image sensor). In this example, the radius of curvature, thickness, distance from the object-side surface to the image-side surface of the first lens (TTL), half the diagonal length of the image-side surface (IMG HT), and focal length are expressed in millimeters (mm).

[0039] Lens thickness, inter-lens gap, and TTL refer to the distance between lenses along the optical axis. Furthermore, in the description of lens shape, a configuration where one surface is convex indicates that the paraxial region of said surface is convex, and a configuration where one surface is concave indicates that the paraxial region of said surface is concave. Therefore, even when one surface of the lens is described as convex, the edge of the lens can be concave. Similarly, even when one surface of the lens is described as concave, the edge of the lens can be convex.

[0040] The camera lens system includes seven lenses. For example, the camera lens system may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially from the object-side surface. The first through seventh lenses may be configured with a certain gap between each of the adjacent lenses. For example, the image-side and object-side surfaces of adjacent lenses may not be in contact with each other in the paraxial region. Therefore, even when the image-side surface of a lens on one side is in contact with the object-side surface of a lens on another surface, as shown in the figures, the image-side and object-side surfaces do not contact each other between the two lenses.

[0041] The first lens has refractive power. For example, the first lens has negative refractive power. One surface of the first lens may be convex. For example, the object-side surface of the first lens may be convex.

[0042] The first lens includes a spherical surface. For example, both surfaces of the first lens may be spherical. The first lens may be manufactured using a material with high light transmittance and excellent workability. For example, the first lens may be made of glass or plastic. The first lens has a high refractive index. For example, the refractive index of the first lens may be 1.7 or greater than 1.7. As another example, the refractive index of the first lens may be 1.7 or greater than 1.7 and 1.8 or less than 1.8.

[0043] The second lens has refractive power. For example, the second lens may have negative refractive power. One surface of the second lens may be concave. For example, the object-side surface or image-side surface of the second lens may be concave.

[0044] The second lens may include a spherical surface. For example, both surfaces of the second lens may be spherical. The second lens may be made of a material with high light transmittance and excellent machinability. For example, the second lens may be made of glass or plastic. The second lens may have a refractive index greater than that of the first lens. For example, the refractive index of the second lens may be 1.8 or greater than 1.8. As another example, the refractive index of the second lens may be 1.8 or greater than 1.8 and less than 2.0.

[0045] The third lens may have refractive power. For example, the third lens may have positive refractive power. One surface of the third lens may be convex. For example, the object-side surface of the third lens may be convex.

[0046] The third lens may include a spherical shape. For example, both surfaces of the third lens may be spherical. The third lens may be made of a material with high light transmittance and excellent machinability. For example, the third lens may be made of glass or plastic. The third lens may have a refractive index similar to that of the second lens. For example, the refractive index of the third lens may be 1.8 or greater than 1.8. As another example, the refractive index of the third lens may be 1.8 or greater than 1.8 and less than 2.0.

[0047] The fourth lens may have refractive power. For example, the fourth lens may have positive refractive power. One surface of the fourth lens may be convex. For example, the object-side surface of the fourth lens may be convex.

[0048] The fourth lens may include an aspherical surface. For example, both surfaces of the fourth lens may be aspherical. The fourth lens may be manufactured using a material with high light transmittance and excellent machinability. For example, the fourth lens may be made of glass or plastic. Among the first to seventh lenses, the fourth lens may have the lowest refractive index. As an example, the refractive index of the fourth lens may be less than 1.6. As another example, the refractive index of the fourth lens may be 1.2 or greater than 1.2 and less than 1.6.

[0049] The fifth lens may have refractive power. The fifth lens may have negative refractive power. One surface of the fifth lens may be concave. For example, the object-side surface of the fifth lens may be concave.

[0050] The fifth lens may include a spherical shape. For example, both surfaces of the fifth lens may be spherical. The fifth lens may be manufactured using materials with high light transmittance and excellent machinability. For example, the fifth lens may be made of glass or plastic. The fifth lens may have a refractive index similar to that of the third lens. For example, the refractive index of the fifth lens may be 1.8 or greater than 1.8. As another example, the refractive index of the fifth lens may be 1.8 or greater than 1.8 and less than 2.0.

[0051] The sixth lens may have refractive power. For example, the sixth lens may have positive refractive power. One surface of the sixth lens may be convex. For example, the image-side surface of the sixth lens may be convex.

[0052] The sixth lens may include a spherical surface. For example, both surfaces of the sixth lens may be spherical. The sixth lens may be made of a material with high light transmittance and excellent machinability. For example, the sixth lens may be made of glass or plastic. The sixth lens may have a refractive index similar to that of the fourth lens. For example, the refractive index of the sixth lens may be 1.5 or greater than 1.5 and less than 1.7.

[0053] The seventh lens may have refractive power. For example, the seventh lens may have negative refractive power. At least one surface of the seventh lens may be concave. For example, the object-side surface of the seventh lens may be concave.

[0054] The seventh lens may include an aspherical shape. 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 made of glass or plastic. The seventh lens may have a refractive index similar to that of the first lens. For example, the refractive index of the seventh lens may be 1.7 or greater than 1.7. As another example, the refractive index of the seventh lens may be 1.7 or greater than 1.7 and less than 1.9.

[0055] The fourth and seventh lenses may include the aspherical surfaces described above. The aspherical surfaces of the fourth and seventh lenses can be represented by the following Equation 1. Equation 1:

[0056] 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" and "D" are aspherical constants, and "Z" (or SAG) is the height from a point on the aspherical surface of the lens to the vertex of the aspherical surface, obtained in the direction of the optical axis.

[0057] The camera lens system may include a filter, an image sensor, and an aperture. The camera lens system may further include a cover glass.

[0058] A filter can be positioned between the seventh lens and the image sensor. The filter blocks light of a specific wavelength. For example, the filter blocks light with infrared wavelengths. The image sensor can form an image-side surface. An aperture can be configured to adjust the amount of light incident on the lens. For example, the aperture can be positioned between the third and fourth lenses. A cover glass can be positioned between the filter and the image sensor to prevent contamination and damage to the image sensor caused by foreign objects.

[0059] Each of the first through seventh lenses may have a certain temperature coefficient of refractive index (TDI) (10⁻⁶ / ℃). The TDI of the lenses (DTn) can be distinguished from each other by an aperture stop disposed between the lenses. As an example, most of the lenses disposed on the object-side surface of the aperture stop (first lens group) may have a positive TDI, while most of the lenses disposed between the aperture stop and the image-side surface (second lens group) may have a negative TDI. However, not all lenses included in the second lens group may have a negative TDI. As an example, among the lenses included in the second lens group, the lens disposed closest to the object-side surface may have a positive TDI.

[0060] Lenses with positive refractive power included in the second lens group may have a negative temperature coefficient of refractive index. For example, the fourth or sixth lens included in the second lens group may have positive refractive power and a negative temperature coefficient of refractive index.

[0061] Each lens in a lens group may have a specific refractive power at a specific location. For example, in the first lens group, the lens closest to the aperture stop may have a positive refractive power. As another example, in the second lens group, the lens closest to the aperture stop may have a positive refractive power. As yet another example, in the second lens group, the lens closest to the image-side surface may have a negative refractive power.

[0062] The lenses included in the imaging lens system may satisfy one or more of the following conditional equations regarding the temperature coefficient of refractive index (hereinafter referred to as "DTn"). Conditional equation 1: -3.5 ≤ DTnT ≤ 3.5 [10⁻⁶ / ℃] Conditional equation 2: 5.0 ≤ DTnF ≤ 15 [10⁻⁶ / ℃] Conditional equation 3: -20 ≤ DTnR ≤ -8.0 [10⁻⁶ / ℃] Conditional equation 4: 0.8 ≤ |DTnF / DTnR| ≤ 1.2 [10⁻⁶ / ℃]

[0063] In conditional equations 1-4, "DTnT" is the sum of the DTn values ​​of the lenses included in the imaging lens system, "DTnF" is the sum of the DTn values ​​of the lenses (first lens group) disposed on the object side of the aperture stop, and "DTnR" is the sum of the DTn values ​​of the lenses (second lens group) disposed between the aperture stop and the image side.

[0064] The temperature coefficient of refractive index (DTn) of the lenses included in the second lens group can have a certain range. As an example, the temperature coefficient of refractive index (DTn4) of the fourth lens or the temperature coefficient of refractive index (DTn6) of the sixth lens can be greater than -10*10-6 / ℃ and less than -0.5*10-6 / ℃.

[0065] The lenses included in the imaging lens system may have a certain constant of thermal expansion (CTE) (10⁻⁶ / ℃). For example, the CTE of the first to seventh lenses may be 2.0 [10⁻⁶ / ℃] or greater than 2.0 [10⁻⁶ / ℃] and 20 [10⁻⁶ / ℃] or less than 20 [10⁻⁶ / ℃]. At least one of the lenses included in the imaging lens system may have a different CTE from the other lenses. As an example, the CTE of the sixth lens (CTE6) may be greater than the CTEs of the other lenses (CTE1, CTE2, CTE3, CTE4, CTE5, and CTE7). As another example, the CTE of the seventh lens (CTE7) may be less than the CTE of the sixth lens (CTE6).

[0066] The difference (CTE6-CTE7) between the thermal expansion constant of the sixth lens (CTE6) and the thermal expansion constant of the seventh lens (CTE7) can be 1.0 [10-6 / ℃] or greater than 1.0 [10-6 / ℃] and 5.0 [10-6 / ℃] or less than 5.0 [10-6 / ℃].

[0067] Each of the lenses included in the imaging lens system may have a focal length temperature coefficient (VT) that varies with temperature. The focal length temperature coefficient (VT) of each lens can be obtained by the following equation. VTi = [DTni / (Ndi-1)-CTEi]-1

[0068] In the equation, "VTi" is the focal length temperature coefficient of the i-th lens, "DTni" is the refractive index temperature coefficient of the i-th lens, "Ndi" is the refractive index of the i-th lens, and "CTEi" is the thermal expansion constant of the i-th lens.

[0069] The focal length temperature coefficient obtained from the above equations can satisfy the following conditional equations. Conditional equation 5: VT5 < VT4 Conditional equation 6: |1 / (f5*VT5)| < |1 / (f4*VT4)| Conditional equation 7: 1 / (F4*VT4) + 1 / (F6*VT6) < -2 / (F5*VT5)

[0070] In conditional equation 5-7, "f4" is the focal length of the fourth lens, "f5" is the focal length of the fifth lens, "f6" is the focal length of the sixth lens, "VT4" is the focal length temperature coefficient of the fourth lens, "VT5" is the focal length temperature coefficient of the fifth lens, and "VT6" is the focal length temperature coefficient of the sixth lens.

[0071] Each of the lenses included in the imaging lens system may have a negative focal length temperature coefficient. A negative focal length temperature coefficient can be expressed by the following conditional equation. Conditional equation 8: VTi < 0

[0072] The focal length temperature coefficient of the lens in the camera lens system, which is configured to have an aperture stop sandwiched between it, can satisfy the following conditional equation. Conditional equation 9:100 < VTS1-VTS2 < 400[10-6 / ℃]

[0073] In conditional equation 9, "VTS1" is the focal length temperature coefficient of the lens that is closest to the object side of the aperture stop, and "VTS2" is the focal length temperature coefficient of the lens that is closest to the image side of the aperture stop.

[0074] In the imaging lens system, the focal length temperature coefficient of the lens adjacent to the image side surface can satisfy the following conditional equation. Conditional equation 10: 300 < VTM2 - VTM1 < 900 [10⁻⁶ / ℃]

[0075] In the imaging lens system, the focal length temperature coefficient between lenses adjacent to the image-side surface can be greater than that between lenses adjacent to the object. This configuration can be represented by the following conditional equation. Conditional equation 11: 0 < (VTO1-VTO2) / (VTM1-VTM2) < 1.0

[0076] In conditional equations 10 and 11, "VTO1" is the focal length temperature coefficient of the lens closest to the object, "VTO2" is the focal length temperature coefficient of the lens second closest to the object, "VTM1" is the focal length temperature coefficient of the lens closest to the image side surface, and "VTM2" is the focal length temperature coefficient of the lens second closest to the object side surface.

[0077] The camera lens system can satisfy one of the following conditional equations. Conditional equation 12:30 < V4 - V5 Conditional equation 13: |f⁴| < 2*f Conditional equation 14: |f5| < 2*f

[0078] In conditional equations 12-14, "V4" is the Abbe number of the fourth lens, "V5" is the Abbe number of the fifth lens, and "f" is the focal length of the camera lens system.

[0079] In the following description, a camera lens system will be illustrated with one or more examples.

[0080] The first example of a camera lens system will be illustrated with reference to Figure 1.

[0081] The camera 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, and a seventh lens 170.

[0082] 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 negative refractive power and may have a concave object-side surface and a convex image-side surface. The third lens 130 may have positive refractive power and may have a convex object-side surface and a convex 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 negative refractive power and may have a concave object-side surface and a concave image-side surface. The sixth lens 160 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The seventh lens 170 may have negative refractive power and may have a concave object-side surface and a convex image-side surface.

[0083] The camera lens system 100 may further include a filter 182, a cover glass 184, an image sensor 190, and an aperture ST. The filter 182 and the cover glass 184 may be disposed between the seventh lens 170 and the image sensor 190. The aperture ST may be disposed between the third lens 130 and the fourth lens 140.

[0084] Figures 2 and 3 illustrate the aberration and MTF properties of the camera lens system 100. Figure 4 shows the change in back focal length (ΔBFL: micrometers) of the camera lens system 100 as a function of temperature. As shown in Figure 4, the change in back focal length of the camera lens system is 2.2 micrometers at -40°C or less and 2.6 micrometers at 80°C or greater, but is 1.5 micrometers or less in the range of -20°C to 60°C.

[0085] Tables 1 and 2 list the lens properties and aspherical surface values ​​of the camera lens system 100.

[0086] Table 1 Surface number Remark radius of curvature Thickness / Gap Refractive index Abbe number DTn CTE VT(103) 1 First lens 65.772 2.500 1.7725 49.62 3.60 8.00 -301.8 2 13.56 9.131 3 Second lens -25.204 6.049 1.8348 42.72 3.80 8.00 -284.2 4 -35.65 15.173 5 Third lens 62.362 4.599 1.8042 46.5 3.70 8.00 -292.8 6 -62.362 6.918 7 Aperture infinity 4.000 8 Fourth lens 19.35 6.496 1.4971 81.56 -6.80 8.00 -46.4 9 -34.344 3.768 10 Fifth lens -90.178 2.550 1.8081 22.76 -3.70 8.00 -79.5 11 18.264 4.535 12 Sixth lens 26.083 7.204 1.5928 68.62 -7.00 11.10 -43.7 13 -31.09 8.682 14 Seventh Lens -45.976 3.050 1.7555 45.59 4.90 8.00 -658.8 15 -120 0.500 16 filter infinity 1.100 1.5168 64.17 17 infinity 0.500 18 Cover glass infinity 1.100 1.5168 64.17 19 infinity 3.388 20 Like side surface infinity 0.000

[0087] Table 2 Surface number K A B C D 8 -7.7205E-01 5.2940E-06 3.4185E-08 - - 9 -3.4660E+00 2.7021E-05 -3.4495E-08 - - 15 - -7.9572E-05 -2.2783E-07 -9.8448E-10 1.3392E-11 16 - -7.5011E-05 -3.6238E-07 1.9905E-09 5.4521E-13

[0088] A second example of a camera lens system will be described with reference to Figure 5.

[0089] The camera 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, and a seventh lens 270.

[0090] 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 negative refractive power and may have a concave object-side surface and a convex image-side surface. The third lens 230 may have positive refractive power and may have a convex object-side surface and a convex 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 negative refractive power and may have a concave object-side surface and a concave image-side surface. The sixth lens 260 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The seventh lens 270 may have negative refractive power and may have a concave object-side surface and a convex image-side surface.

[0091] The camera lens system 200 may further include a filter 282, a cover glass 284, an image sensor 290, and an aperture ST. The filter 282 and the cover glass 284 may be disposed between the seventh lens 270 and the image sensor 290. The aperture ST may be disposed between the third lens 230 and the fourth lens 240.

[0092] Figures 6 and 7 illustrate the aberration and MTF properties of the imaging lens system 200. Figure 8 shows the change in back focal length of the imaging lens system 200 with temperature (ΔBFL: micrometers). As shown in Figure 8, the change in back focal length of the imaging lens system is expected to be approximately 2.2 micrometers at -40°C or less and 2.8 micrometers at 80°C or greater. However, utilizing the lens property that the focal length can change with temperature (ΔLENS BACK), the substantial change in back focal length (defocus) of the imaging lens system 200 is reduced to ±0.5 micrometers even in the range of -40°C to 80°C.

[0093] Tables 3 and 4 list the lens properties and aspherical surface values ​​of the camera lens system 200.

[0094] Table 3 Surface number Remark radius of curvature Thickness / Gap Refractive index Abbe number DTn CTE VT(103) 1 First lens 62.561 2.518 1.773 49.62 3.60 8.00 -301.8 2 13.565 9.077 3 Second lens -27.214 5.900 1.835 42.72 3.80 8.00 -284.2 4 -42.497 15.027 5 Third lens 61.159 4.691 1.804 46.50 3.70 8.00 -292.8 6 -61.159 7.788 7 Aperture infinity 4.000 8 Fourth lens 19.140 6.496 1.497 81.56 -6.80 8.00 -46.4 9 -35.374 3.858 10 Fifth lens -96.821 2.550 1.808 22.76 -3.70 8.00 -79.5 11 18.101 4.458 12 Sixth lens 26.191 7.327 1.593 68.62 -7.00 11.10 -43.7 13 -29.622 8.772 14 Seventh Lens -42.943 3.050 1.756 45.59 4.90 8.00 -658.8 15 -120.000 0.500 16 filter infinity 1.100 1.517 64.17 17 infinity 0.500 18 Cover glass infinity 1.100 1.517 64.17 19 infinity 3.388 20 Like side surface infinity 0.000

[0095] Table 4 Surface number K A B C D 8 -7.72E-01 5.01E-06 3.53E-08 - - 9 -3.47E+00 2.80E-05 -3.40E-08 - - 15 - -8.19E-05 -1.97E-07 -7.33E-10 1.23E-11 16 - -8.14E-05 -3.05E-07 1.95E-09 4.71E-13

[0096] The third example of a camera lens system will be described with reference to Figure 9.

[0097] The camera 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, and a seventh lens 370.

[0098] 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 negative refractive power and may have a convex object-side surface and a concave image-side surface. The third lens 330 may have positive refractive power and may have a convex object-side surface and a convex 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 negative refractive power and may have a concave object-side surface and a concave image-side surface. The sixth lens 360 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The seventh lens 370 may have negative refractive power and may have a concave object-side surface and a convex image-side surface.

[0099] The camera lens system 300 may further include a filter 382, ​​a cover glass 384, an image sensor 390, and an aperture ST. The filter 382 and the cover glass 384 may be disposed between the seventh lens 370 and the image sensor 390. The aperture ST may be disposed between the third lens 330 and the fourth lens 340.

[0100] Figures 10 and 11 illustrate the aberration and MTF properties of the imaging lens system 300. Figure 12 shows the change in back focal length of the imaging lens system 300 with temperature (ΔBFL: micrometers). As shown in Figure 12, the change in back focal length of the imaging lens system is expected to be approximately 1.0 micrometers at -40°C or less and 4.6 micrometers at 80°C or greater. However, utilizing the lens property that the focal length can change with temperature (ΔLENS BACK), the actual change in back focal length (defocus) of the imaging lens system 300 is reduced to ±2.0 micrometers even in the range of -40°C to 80°C.

[0101] Tables 5 and 6 list the lens properties and aspherical surface values ​​of the camera lens system 300.

[0102] Table 5 Surface number Remark radius of curvature Thickness / Gap Refractive index Abbe number DTn CTE VT(103) 1 First lens 24.328 2.598 1.773 49.62 3.60 8.00 -301.8 2 15.264 9.725 3 Second lens 500,000 2.500 1.835 42.72 3.80 8.00 -284.2 4 20.273 21.609 5 Third lens 49.060 4.691 1.804 46.50 3.70 8.00 -292.8 6 -85.802 10.081 7 Aperture infinity 6.266 8 Fourth lens 20.279 6.546 1.497 81.56 -6.80 8.00 -46.4 9 -36.788 4.915 10 Fifth lens -302.321 2.500 1.808 22.76 -3.70 8.00 -79.5 11 17.125 1.521 12 Sixth lens 22.180 6.392 1.593 68.62 -7.00 11.10 -43.7 13 -37.145 11.003 14 Seventh Lens -53.514 3.050 1.756 45.59 4.90 8.00 -658.8 15 -120.000 0.500 16 filter infinity 1.100 1.517 64.17 17 infinity 0.500 18 Cover glass infinity 1.100 1.517 64.17 19 infinity 3.390 20 Like side surface infinity 0.000

[0103] Table 6 Surface number K A B C D 8 -7.72E-01 3.51E-06 4.83E-08 - - 9 -3.47E+00 2.82E-05 -1.04E-08 - - 15 - 1.33E-05 -4.56E-07 2.63E-10 -4.37E-12 16 - 1.04E-05 -6.41E-07 1.66E-10 2.85E-12

[0104] The fourth example of a camera lens system will be described with reference to Figure 13.

[0105] The camera 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, and a seventh lens 470.

[0106] 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 negative refractive power and may have a concave object-side surface and a convex image-side surface. The third lens 430 may have positive refractive power and may have a convex object-side surface and a convex 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 negative refractive power and may have a concave object-side surface and a concave image-side surface. The sixth lens 460 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The seventh lens 470 may have negative refractive power and may have a concave object-side surface and a convex image-side surface.

[0107] The camera lens system 400 may further include a filter 482, a cover glass 484, an image sensor 490, and an aperture ST. The filter 482 and the cover glass 484 may be disposed between the seventh lens 470 and the image sensor 490. The aperture ST may be disposed between the third lens 430 and the fourth lens 440.

[0108] Figures 14 and 15 illustrate the aberration and MTF properties of the imaging lens system 400. Figure 16 shows the change in back focal length of the imaging lens system 400 with temperature (ΔBFL: micrometers). As shown in Figure 16, the change in back focal length of the imaging lens system 400 is approximately -6.0 micrometers at -40°C or less and 12 micrometers at 80°C or greater. However, utilizing the lens property that the focal length can change with temperature (ΔLENS BACK), the substantial change in back focal length (defocus) of the imaging lens system 400 is reduced to 3.0 micrometers even in the range of -40°C to 80°C.

[0109] Tables 7 and 8 list the lens properties and aspherical surface values ​​of the camera lens system 400.

[0110] Table 7 Surface number Remark radius of curvature Thickness / Gap Refractive index Abbe number DTn CTE VT(103) 1 First lens 73.796 2.549 1.773 49.62 3.60 8.00 -301.8 2 13.356 9.898 3 Second lens -21.157 6.310 1.835 42.72 3.80 8.00 -284.2 4 -27.375 12.715 5 Third lens 74.491 4.790 1.835 42.72 3.80 8.00 -284.2 6 -74.491 5.794 7 Aperture infinity 4.847 8 Fourth lens 19.719 6.925 1.497 81.56 -6.80 8.00 -46.4 9 -30.988 3.171 10 Fifth lens -121.884 2.500 1.808 22.76 -3.70 8.00 -79.5 11 20.397 1.792 12 Sixth lens 25.066 6.017 1.593 68.62 -7.00 11.10 -43.7 13 -67.459 10.091 14 Seventh Lens -86.229 6.000 1.770 49.35 3.80 7.40 -401.9 15 -120.000 0.500 16 filter infinity 1.100 1.517 64.17 17 infinity 0.500 18 Cover glass infinity 1.100 1.517 64.17 19 infinity 3.388 20 Like side surface infinity 0.000

[0111] Table 8 Surface number K A B C D 8 -7.72E-01 4.69E-06 2.63E-08 - - 9 -3.47E+00 1.96E-05 -2.34E-08 - - 15 - -5.35E-05 -3.29E-07 -9.15E-10 -4.88E-12 16 - -3.68E-05 -3.84E-07 3.62E-10 1.79E-12

[0112] The fifth example of a camera lens system will be described with reference to Figure 17.

[0113] The camera 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, and a seventh lens 570.

[0114] 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 negative refractive power and may have a concave object-side surface and a convex image-side surface. The third lens 530 may have positive refractive power and may have a convex object-side surface and a convex 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 negative refractive power and may have a concave object-side surface and a concave image-side surface. The sixth lens 560 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The seventh lens 570 may have negative refractive power and may have a concave object-side surface and a convex image-side surface.

[0115] The camera lens system 500 may further include a filter 582, a cover glass 584, an image sensor 590, and an aperture ST. The filter 582 and the cover glass 584 may be disposed between the seventh lens 570 and the image sensor 590. The aperture ST may be disposed between the third lens 530 and the fourth lens 540.

[0116] Figures 18 and 19 illustrate the aberration and MTF properties of the imaging lens system 500. Figure 20 shows the change in back focal length of the imaging lens system 500 with temperature (ΔBFL: micrometers). As shown in Figure 20, the change in back focal length of the imaging lens system is expected to be approximately -4.0 micrometers at -20°C or less and 10 micrometers at 80°C or greater. However, utilizing the lens property that the focal length can change with temperature (ΔLENS BACK), the substantial change in back focal length (defocus) of the imaging lens system 500 is reduced to 2.5 micrometers even in the range of -20°C to 80°C.

[0117] Tables 9 and 10 list the lens properties and aspherical surface values ​​of the camera lens system 500.

[0118] Table 9 Surface number Remark radius of curvature Thickness / Gap Refractive index Abbe number DTn CTE VT(103) 1 First lens 73.449 2.590 1.773 49.62 3.60 8.00 -301.8 2 13.367 9.679 1.000 0.00 3 Second lens -21.099 6.296 1.835 42.72 3.80 8.00 -284.2 4 -27.339 12.933 1.000 0.00 5 Third lens 70.821 4.826 1.835 42.72 3.80 8.00 -284.2 6 -70.821 5.420 1.000 0.00 7 Aperture infinity 5.435 1.000 0.00 8 Fourth lens 19.439 6.942 1.497 81.56 -6.80 8.00 -46.4 9 -30.510 2.682 1.000 0.00 10 Fifth lens -94.519 2.500 1.808 22.76 -3.70 8.00 -79.5 11 21.323 2.469 1.000 0.00 12 Sixth lens 25.687 6.178 1.593 68.62 -7.00 11.10 -43.7 13 -62.987 9.450 1.000 0.00 14 Seventh Lens -72.856 6.000 1.770 49.35 3.80 7.40 -401.9 15 -120.000 0.500 1.000 0.00 16 filter infinity 1.100 1.517 64.17 17 infinity 0.500 1.000 0.00 18 Cover glass infinity 1.100 1.517 64.17 19 infinity 3.389 1.000 0.00 20 Like side surface infinity 0.000 1.000 0.00

[0119] Table 10 Surface number K A B C D 8 -7.72E-01 6.35E-06 2.83E-08 - - 9 -3.47E+00 2.19E-05 -3.10E-08 - - 15 - -5.36E-05 -3.43E-07 -1.03E-09 -2.78E-12 16 - -3.30E-05 -4.21E-07 6.41E-10 1.35E-12

[0120] The sixth example of a camera lens system will be described with reference to Figure 21.

[0121] The camera 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, and a seventh lens 670.

[0122] 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 negative refractive power and may have a concave object-side surface and a convex image-side surface. The third lens 630 may have positive refractive power and may have a convex object-side surface and a convex 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 negative refractive power and may have a concave object-side surface and a concave image-side surface. The sixth lens 660 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The seventh lens 670 may have negative refractive power and may have a concave object-side surface and a convex image-side surface.

[0123] The camera lens system 600 may further include a filter 682, a cover glass 684, an image sensor 690, and an aperture ST. The filter 682 and the cover glass 684 may be disposed between the seventh lens 670 and the image sensor 690. The aperture ST may be disposed between the third lens 630 and the fourth lens 640.

[0124] Figures 22 and 23 illustrate the aberration and MTF properties of the imaging lens system 600. Figure 24 shows the change in back focal length of the imaging lens system 600 with temperature (ΔBFL: micrometers). As shown in Figure 24, the change in back focal length of the imaging lens system is expected to be approximately -4.0 micrometers at -20°C or less and 10 micrometers at 80°C or greater. However, utilizing the lens property that the focal length can change with temperature (ΔLENS BACK), the substantial change in back focal length (defocus) of the imaging lens system 600 is reduced to 2.5 micrometers even in the range of -20°C to 80°C.

[0125] Tables 11 and 12 list the lens properties and aspherical surface values ​​of the camera lens system 600.

[0126] Table 11 Surface number Remark radius of curvature Thickness / Gap Refractive index Abbe number DTn CTE VT(103) 1 First lens 69.503 1.500 1.773 49.62 3.60 8.00 -301.8 2 12.132 6.891 1.000 0.00 3 Second lens -19.552 6.214 1.835 43.13 3.80 8.00 -289.7 4 -27.113 3.304 1.000 0.00 5 Third lens 52.797 3.324 1.835 43.13 3.80 8.00 -289.7 6 -55.126 9.687 1.000 0.00 7 Aperture infinity 2.811 1.000 0.00 8 Fourth lens 17.961 5.432 1.553 71.68 -7.40 8.00 -46.9 9 -23.868 1.423 1.000 0.00 10 Fifth lens -101.211 1.500 1.808 22.76 -3.70 8.00 -79.5 11 19.934 6.972 1.000 0.00 12 Sixth lens 20.272 6.096 1.619 63.85 -4.20 8.80 -64.3 13 -34.491 5.846 1.000 0.00 14 Seventh Lens -22.863 3.000 1.810 40.95 5.60 7.40 -888.4 15 -120.000 0.500 1.000 0.00 16 filter infinity 0.500 1.517 64.17 17 infinity 0.500 1.000 0.00 18 Cover glass infinity 0.500 1.517 64.17 19 infinity 4.006 1.000 0.00 20 Like side surface infinity -0.012 1.000 0.00

[0127] Table 12 Surface number K A B C D 8 -7.72E-01 4.99E-08 6.95E-09 - - 9 -3.47E+00 2.45E-05 -5.69E-08 - - 15 - -9.06E-05 -2.41E-07 1.27E-09 8.58E-12 16 - -4.84E-05 -3.36E-07 2.69E-09 -4.94E-12

[0128] The imaging lens system in the example may have the following optical properties. For example, the total length (TTL) of the imaging lens system may be in the range of 60 to 100 mm, the focal length (f) may be in the range of 12.0 to 16.0 mm, the focal length (f1) of the first lens may be in the range of -18 mm or less, the focal length (f2) of the second lens may be in the range of -20 mm or less, the focal length (f3) of the third lens may be in the range of 30 to 50 mm, the focal length (f4) of the fourth lens may be in the range of 17 to 30 mm, the focal length (f5) of the fifth lens may be in the range of -30 to -10 mm, the focal length (f6) of the sixth lens may be in the range of 15 to 40 mm, and the focal length of the seventh lens may be in the range of -20 mm or less.

[0129] Figure 13 lists the optical properties of the camera lens systems according to the first to sixth examples.

[0130] Table 13 Remark First Case Second example Third Case Fourth example Fifth Case Sixth Case f1 -22.583 -22.935 -60.605 -21.505 -21.558 -19.245 f2 -139.896 -109.963 -25.371 -207.282 -204.707 -134.125 f3 39,421 38,686 39,424 45,278 43,086 32,756 f4 25,940 26,014 27,339 25,393 25,042 19,421 f5 -18.599 -18.686 -19.986 -21.454 -21.324 -20.495 f6 25.104 24,653 24,406 31,594 31,599 21,550 f7 -100.433 -90.051 -130.420 -431.523 -255.117 -35.358 TTL 91,243 92.100 99.987 89.987 89.989 70.006 BFL 6.588 6.588 6.590 6.588 6.589 6.006 f 14.257 14.268 14.236 14.189 14.186 14.110

[0131] Table 14 lists the values ​​of the conditional equations for the camera lens systems based on the first to sixth examples.

[0132] Table 14 equation First Case Second example Third Case Fourth example Fifth Case Sixth Case DTnT -1.500 -1.500 -1.500 -2.500 -2.500 1.500 DTnF 11.100 11.100 11.100 11.200 11.200 11.200 DTnR -12.600 -12.600 -12.600 -13.700 -13.700 -9.700 |DTnF / DTnR| 0.8810 0.8810 0.8810 0.8175 0.8175 1.1546 CTE6-CTE7 3.1000 3.1000 3.1000 3.7000 3.7000 1.4000 1 / (f4*Vt4) -0.0008 -0.0008 -0.0008 -0.0008 -0.0009 -0.0011 1 / (f5*Vt5) 0.0007 0.0007 0.0006 0.0006 0.0006 0.0006 1 / (f6*Vt6) -0.0009 -0.0009 -0.0009 -0.0007 -0.0007 -0.0007 VT4-VT3 246.4 246.4 246.4 237.8 237.8 242.8 VT6-VT7 615.1 615.1 615.1 358.2 358.2 824.1 |(VT1-VT2) / (VT6-VT7)| 0.0286 0.0286 0.0286 0.0491 0.0491 0.0147 V4-V5 58.80 58.80 58.80 58.80 58.80 48.92

[0133] Based on the foregoing examples, a camera lens system that can maintain constant optical properties at high or low ambient temperatures can be provided.

[0134] Although this disclosure includes specific examples, it will be apparent to those skilled in the art 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 set forth herein are intended to be illustrative only and not for limiting purposes. The description of features or manner in each example is intended to be applicable to similar features or manner in other examples. Suitable results may be achieved if the described technology is performed in a different order, and / or if components in the described system, architecture, apparatus, or circuit are combined in a different manner and / or replaced or supplemented by other components or their equivalents. Therefore, the scope of this disclosure is not defined by the detailed description but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are intended to be included in this disclosure.

[0135] 100, 200, 300, 400, 500, 600: Camera lens system 110, 210, 310, 410, 510, 610: First lens 120, 220, 320, 420, 520, 620: Second lens 130, 230, 330, 430, 530, 630: Third lens 140, 240, 340, 440, 540, 640: Fourth lens 150, 250, 350, 450, 550, 650: Fifth lens 160, 260, 360, 460, 560, 660: Sixth lens 170, 270, 370, 470, 570, 670: Seventh Lens 182, 282, 382, ​​482, 582, 682: Filters 184, 284, 384, 484, 584, 684: Cover glass 190, 290, 390, 490, 590, 690: Image sensor IMG HT: Half the length of the diagonal ST: Aperture ΔBFL: Change ΔLENS BACK: Lens properties

Claims

1. A camera lens system, comprising: A first lens group, comprising a first lens, a second lens, and a third lens; A second lens group, comprising a fourth lens, a fifth lens, a sixth lens, and a seventh lens; An aperture stop is disposed between the first lens group and the second lens group, wherein the first lens group, the aperture stop, and the second lens group are arranged sequentially from an object side toward an imaging plane. The imaging lens system has a total of seven lenses with refractive power, wherein the seventh lens has negative refractive power. The sum of the temperature coefficients of refractive index (DTnF) of the first to third lenses included in the first lens group is 5.0 [10⁻⁶ / ℃] or greater than 5.0 [10⁻⁶ / ℃] and 15 [10⁻⁶ / ℃] or less than 15 [10⁻⁶ / ℃]. The sum of the temperature coefficients of refractive index (DTnR) of the fourth to seventh lenses included in the second lens group is -20 [10⁻⁶ / ℃] or greater than -20 [10⁻⁶ / ℃] and -8.0 [10⁻⁶ / ℃] or less than -8.0 [10⁻⁶ / ℃].

2. The camera lens system as claimed in claim 1, wherein the first lens has a convex object-side surface.

3. The camera lens system as claimed in claim 1, wherein the second lens has a concave object-side surface.

4. The camera lens system as claimed in claim 1, wherein the third lens has a convex object-side surface.

5. The camera lens system as claimed in claim 1, wherein the fourth lens has a convex object-side surface.

6. The camera lens system as claimed in claim 1, wherein the fifth lens has a concave object-side surface.

7. The camera lens system as claimed in claim 1, wherein the sixth lens has a convex object-side surface.

8. The camera lens system as claimed in claim 1, wherein the seventh lens has a concave object-side surface.

9. The camera lens system as claimed in claim 1, wherein |f4| < 2*f, f is the focal length of the camera lens system, and f4 is the focal length of the fourth lens.

10. The camera lens system as claimed in claim 1, wherein |f5| < 2*f, f is the focal length of the camera lens system, and f5 is the focal length of the fifth lens.

Images